LSST: From Science Drivers to Reference Design and Anticipated Data Products

Not yet classified.

LSST's effective étendue will exceed 300 m2 deg2, more than ten times larger than any existing facility.

“The effective étendue for LSST will be greater than 300 m 2 deg 2 , which is more than an order of magnitude larger than that of any existing facility.”

• AssumptionRests on an assumption: The LSST system will achieve the specified design parameters (mirror, field of view, camera, filters) in operation.

Not yet classified.

Simulations indicate that imaging about 20,000 deg2 to a 5σ point-source depth of r~27.5 provides enough signal to measure shapes for roughly 2 billion galaxies for WL.

“Detailed simulations of WL techniques show that imaging over ∼ 20,000 deg 2 to a 5 σ pointsource depth of r AB ∼ 27.5 gives adequate signal to measure shapes for of order 2 billion galaxies for WL.”

• AssumptionRests on an assumption: The detailed WL simulations accurately represent future LSST performance.

Not yet classified.

The constants Cm depend on the overall throughput of the instrument and are computed using current best throughput estimates for optical elements and sensors.

“The constants Cm depend on the overall throughput of the instrument and are computed using our current best throughput estimates for optical elements and sensors.”

Not yet classified.

Systematic and random astrometric errors become similar at about r = 22, and there are about 100 stars per LSST sensor (0.05 deg2) to this depth even at the Galactic poles.

“Systematic and random errors become similar at about r = 22, and there are about 100 stars per LSST sensor ( 0.05 deg 2 ) to this depth ( and fainter than the LSST saturation limit at r ∼ 16 ) even at the Galactic poles.”

• AssumptionThe authors state this as an assumption: Systematic astrometric errors of 10 mas are assumed to be uncorrelated between different observations of a given object.

Not yet classified.

If these fields were selected at Galactic latitudes of |b| ~ 30°, they would include about 10 million stars with r < 21 observed with S/N above 100 in each visit.

“If these fi elds were selected at Galactic latitudes of b 30 ~ ∣ ∣ ° , they would include about 10 million stars with r &lt; 21 observed with S / N above 100 in each visit.”

Not yet classified.

Each 15 s exposure in a sequence would have an equivalent 5σ depth of r ~ 24, and each filter subsequence when co-added would be 2 mag deeper than main survey visits (r ~ 26.5).

“Each 15 s exposure in a sequence would have an equivalent 5 σ depth of r ∼ 24, and each fi lter subsequence when co-added would be 2 mag deeper than the main survey visits ( r ∼ 26.5 ) .”

Not yet classified.

The effect of finite readout noise is only substantial in the u band, as demonstrated by Cm(τ=2) values in Table 2.

“Again, this effect is only substantial in the u band, as demonstrated by the values of C 2 m t D = ( ) listed in Table 2.”

Not yet classified.

Blue stars fainter than r ~ 23 will have about 50% larger proper-motion and parallax errors than given in Table 3, due to decreased numbers of z- and y-band detections.

“Blue stars ( e.g., F / G stars ) fainter than r ∼ 23 will have about 50% larger proper-motion and parallax errors than given in the table, due to decreased numbers of z - and y -band detections.”

• AssumptionThe authors state this as an assumption: Systematic astrometric errors of 10 mas are assumed to be uncorrelated between different observations of a given object.

Not yet classified.

The anticipated total number of visits for a 10 yr LSST survey is about 2.45 million (~4.9 million 15 s exposures summing over six filters).

“The anticipated total number of visits for a 10 yr LSST survey is about 2.45 million ( ∼ 4.9 million 15 s long exposures, summing over the six fi lters ) .”

Not yet classified.

Considering this extended LSST in the context of existing/ongoing surveys would result in a system-wide cumulative completeness of 86% for PHAs (77% for NEOs), approaching the 90% required by the congressional mandate.

“Considering this ' extended ' LSST in the context of existing / ongoing surveys would result in a system-wide cumulative completeness of 86% for PHAs ( 77% for NEOs ) , approaching the 90% required by the congressional mandate ( see bottom panels of Figure 20 ) .”

• AssumptionThe authors state this as an assumption: All potentially hazardous asteroids are assumed to be C-type asteroids.

Not yet classified.

By improving MOPS and increasing the MOPS linking window from 15 to 30 days, completeness can be boosted by about 3%.

“By improving MOPS and increasing the MOPS linking window from 15 to 30 days, we can boost completeness by about 3%.”

• AssumptionThe authors state this as an assumption: All potentially hazardous asteroids are assumed to be C-type asteroids.

Not yet classified.

In all six bands, the implied single-visit depths m5 lie between the minimum and design specification values from the SRD listed in Table 1.

“In all six bands they imply single-visit depths m 5 ( also listed in Table 2 ) that lie between the minimum and design speci fi cation values from the SRD listed in Table 1.”

Not yet classified.

Taking weather into account, selected fields would each have on average about 40 hr long sequences of 200 exposures each.

“Taking weather into account, the selected fi elds would each have on average about 40 hr long sequences of 200 exposures each.”

May combine two claims.

The impact on red stars is smaller, but extremely red objects such as L and T dwarfs will have larger errors, depending on their SEDs.

“The impact on red stars is smaller, due to a relatively small number of observations in the u and g bands, but extremely red objects, such as L and T dwarfs, will de fi nitely have larger errors, depending on details of their SEDs.”

• AssumptionThe authors state this as an assumption: Systematic astrometric errors of 10 mas are assumed to be uncorrelated between different observations of a given object.

Not yet classified.

Realistic MOPS simulations show >99% linking efficiency across all classes of solar system objects and at least 93% efficiency for NEOs.

“Realistic MOPS simulations show &gt; 99% linking ef fi ciency across all classes of solar system objects ( Denneau et al. 2013 ) , and at least 93% ef fi ciency for NEOs ( Vere š &amp; Chesley 2017a, 2017b ) .”

• cites Denneau et al. 2013 sourceNot checked yet

  Not checked in the free run.

• cites Vereš & Chesley 2017a, 2017bNot checked yet

  Not checked in the free run.

Not yet classified.

After the first 3 yr of the survey, proper-motion errors will be about five times as large, and parallax errors about twice as large, as the values in Table 3; errors scale as t^-3/2 and t^-1/2, respectively.

“After the fi rst 3 yr of the survey, the proper-motion errors will be about fi ve times as large, and parallax errors will be about twice as large, as the values given in Table 3; the errors scale as t -3 / 2 and t -1 / 2 , respectively.”

• AssumptionThe authors state this as an assumption: Systematic astrometric errors of 10 mas are assumed to be uncorrelated between different observations of a given object.

Not yet classified.

When all 40 sequences and main survey visits are co-added, they would extend the depth to r ~ 28.

“When all 40 sequences and the main survey visits are co-added, they would extend the depth to r ∼ 28.”

Not yet classified.

These completeness figures are likely uncertain at the level of ±5%, due to uncertainties in orbital distribution, size distribution, shape distributions, surface properties, and weather variations.

“These fi gures are likely to be uncertain at the level of ± 5%, due to uncertainties in the orbital distribution of the true population, the size distribution, uncertain distributions of shape ( and thus light-curve variations ) , and surface properties ( thus colors and albedo ) , plus variations in survey cadence due to weather, etc.”

• AssumptionThe authors state this as an assumption: All potentially hazardous asteroids are assumed to be C-type asteroids.

Not yet classified.

A mini-survey using 1 hr per night on a single pointing could obtain about 50 consecutive 15 s exposures in each of four filters in an hour.

“Accounting for readout time and fi lter changes, it could obtain about 50 consecutive 15 s exposures in each of four fi lters in an hour.”

Not yet classified.

This cadence spends 6% of total observing time on NEO-optimized observations north of δ = +5°, and MOPS links objects with windows of 15 days.

“This cadence spends 6% of the total observing time on NEO-optimized observations north of δ = + 5 ° , and MOPS links objects with windows of 15 days.”

• AssumptionThe authors state this as an assumption: All potentially hazardous asteroids are assumed to be C-type asteroids.

Not yet classified.

For the nominal exposure time of 30 s and θ = 0.7, the loss of limiting magnitude is 0.04 mag for v = 0.25° day-1 (typical main asteroid belt) and 0.46 mag for v = 1.0° day-1 (typical PHAs passing near Earth).

“For the nominal exposure time of 30 s and θ = 0 7, the loss of limiting magnitude is 0.04 mag for v = 0 ° . 25 day -1 , typical for objects in the main asteroid belt, and 0.46 mag for v = 1 ° . 0 day -1 , typical of PHAs passing near Earth.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

The overwhelming majority of the almost 8000 refereed papers based on SDSS data to date were written by scientists outside the project.

“The overwhelming majority of the almost 8000 refereed papers based on SDSS data to date have been written by scientists from outside the project”

Probably not a substantial claim: may not pass S3 (load-bearing).

By 2017, 34 institutions from 23 countries had signed Memoranda of Agreement to contribute substantially to LSST operating costs in return for participation in the science collaborations and access to data.

“As of 2017, 34 institutions from 23 countries have signed Memoranda of Agreement to contribute signi fi cantly to the LSST operating costs, in exchange for participation in the science collaborations and data access.”

May combine two claims.

The LSST science collaborations have helped develop the science case and continue to advise on optimizing science.

“The LSST science collaborations in particular have helped develop the LSST science case and continue to provide advice on how to optimize their science”

Probably not a substantial claim: may not pass S3 (load-bearing).

There are over 800 participants in the LSST science collaborations.

“there are over 800 participants in these collaborations.”

Not yet classified.

The LSST project is in construction and is projected to start regular survey operations in 2022.

“The project is in the construction phase and will begin regular survey operations by 2022.”

• Also stated in: § 1. Introduction · p. 3

  “the 10 yr sky survey is projected to begin in 2022.”

• AssumptionRests on an assumption: The LSST construction will be completed and the survey will operate for the planned 10 years.

Not yet classified.

The LSST project's design is organized around four primary science goals: dark energy and dark matter, solar system inventory, transient optical sky, and Milky Way mapping.

“The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the solar system, exploring the transient optical sky, and mapping the Milky Way.”

• cites Science Working Group of the LSST & Strauss 2004Not checked yet

  Not checked in the free run.

Not yet classified.

LSST will be a large, wide-field, ground-based telescope located on Cerro Pachón in northern Chile, designed to repeatedly image a large portion of the sky.

“LSST will be a large, wide- fi eld ground-based system designed to obtain repeated images covering the sky visible from Cerro Pachón in northern Chile.”

• Also stated in: § 1. Introduction · p. 3

  “Located on Cerro Pachón in northern Chile, the LSST will be a large, widefi eld, ground-based telescope designed to obtain multiband images over a substantial fraction of the sky every few nights.”

Not yet classified.

The LSST telescope will have an 8.4 m primary mirror (6.5 m effective), a 9.6 deg2 field of view, a 3.2-gigapixel camera, and six filters ugrizy spanning 320-1050 nm.

“The telescope will have an 8.4 m ( 6.5 m effective ) primary mirror, a 9.6 deg 2 fi eld of view, a 3.2-gigapixel camera, and six fi lters ( ugrizy ) covering the wavelength range 320 -1050 nm.”

• AssumptionRests on an assumption: The LSST system will achieve the specified design parameters (mirror, field of view, camera, filters) in operation.

Not yet classified.

Testing competing dark energy models or modified gravity requires percent-level measurements of cosmic expansion and dark matter structure growth versus redshift.

“Distinguishing competing models for the physical nature of dark energy, or alternative explanations involving modi fi cations of the general theory of relativity, will require percent-level measurements of both the cosmic expansion and the growth of dark matter structure as a function of redshift.”

Not yet classified.

The main survey will produce a co-added map reaching r ~ 27.5.

“and will yield a co-added map to r ∼ 27.5.”

• AssumptionRests on an assumption: The LSST system will achieve the specified design parameters (mirror, field of view, camera, filters) in operation.

Not yet classified.

Photometric repeatability should achieve 5 mmag precision at the bright end, with zero-point stability across the sky of 10 mmag and band-to-band calibration errors not larger than 5 mmag.

“Photometric repeatability should achieve 5 mmag precision at the bright end, with zero-point stability across the sky of 10 mmag and band-to-band calibration errors not larger than 5 mmag.”

Not yet classified.

Type Ia supernovae provided the first strong evidence that cosmic expansion is accelerating.

“SNe Ia provided the fi rst robust evidence that the expansion of the universe is accelerating”

• cites Riess et al. 1998 sourceNot checked yet

  Not checked in the free run.

• cites Perlmutter et al. 1999 sourceNot checked yet

  Not checked in the free run.

Not yet classified.

Even a single supernova provides redshift-distance information, unlike other cosmological probes.

“Unlike other cosmological probes, even a single object gives information on the relationship between redshift and distance.”

Not yet classified.

A large sample of supernovae across the sky enables a search for directional dependence of dark energy properties, which would signal new physics.

“Thus, a large number of SNe across the sky allows one to search for any dependence of dark energy properties on direction, which would be an indicator of new physics.”

Not yet classified.

The paper shows how LSST science drivers determined the system design parameters.

“We illustrate how the LSST science drivers led to these choices of system parameters”

• Also stated in: § 1. Introduction · p. 4

  “The purpose of this paper is to provide an overall summary of the main LSST science drivers and how they led to the current system design parameters”

Not yet classified.

Weak lensing maps mass distribution versus redshift and traces cosmic expansion and structure growth.

“WL techniques can be used to map the distribution of mass as a function of redshift and thereby trace the history of both the expansion of the universe and the growth of structure”

• cites Hu & Tegmark 1999Not checked yet

  Not checked in the free run.

• cites Kilbinger 2015 sourceNot checked yet

  Not checked in the free run.

• cites Mandelbaum 2018 sourceNot checked yet

  Not checked in the free run.

Not yet classified.

Current cosmological models need both dark matter and dark energy to fit observational constraints.

“Current models of cosmology require the existence of both dark matter and dark energy to match observational constraints”

• cites Riess et al. 2007 sourceNot checked yet

  Not checked in the free run.

• cites Komatsu et al. 2009 sourceNot checked yet

  Not checked in the free run.

• cites Percival et al. 2010 sourceNot checked yet

  Not checked in the free run.

Not yet classified.

SN anisotropy results can be compared with anisotropy measures from combined WL and LSS.

“The results from this method can be compared with similar measures of anisotropy from the combination of WL and LSS ( Zhan et al. 2009 ) .”

• cites Zhan et al. 2009 sourceNot checked yet

  Not checked in the free run.

Not yet classified.

Given the expected SN flux distribution at dark-energy-relevant redshifts, single-visit depth should be at least r~24.

“Given the expected SN fl ux distribution at the redshifts where dark energy is important, the single-visit depth should be at least r ∼ 24.”

• AssumptionRests on an assumption: The expected supernova flux distribution at dark-energy-relevant redshifts is known.

Not yet classified.

Image quality should maintain the limit set by the atmosphere, with median free-air seeing of 0.65 in the r band at the chosen site, and should not be degraded appreciably by the hardware.

“Image quality should maintain the limit set by the atmosphere ( the median free-air seeing is 0 65 in the r band at the chosen site; see Figure 1 ) and not be degraded appreciably by the hardware.”

Not yet classified.

The Pan-STARRS project, which has similar science goals to LSST, envisions a distributed aperture design where total system étendue is the sum of étendue values for an array of small 1.8 m telescopes.

“We note that the Pan-STARRS project ( Kaiser et al. 2002, 2010 ) , with similar science goals to LSST, envisions a distributed aperture design, where the total system étendue is a sum of étendue values for an array of small 1.8 m telescopes.”

• cites Kaiser et al. 2002 sourceNot checked yet

  Not checked in the free run.

• cites Kaiser et al. 2010 sourceNot checked yet

  Not checked in the free run.

Not yet classified.

Turning precision into accuracy requires modeling and marginalizing over systematic effects.

“The challenge is to turn this available precision into accuracy, by careful modeling and marginalization over a variety of systematic effects”

• cites Krause & Eifler 2017Not checked yet

  Not checked in the free run.

Not yet classified.

The Milky Way and its environment provide a unique data set for understanding the detailed processes that shape galaxy formation and for testing the small-scale predictions of the standard cosmological model.

“The Milky Way and its environment provide a unique data set for understanding the detailed processes that shape galaxy formation and for testing the smallscale predictions of our standard cosmological model.”

Not yet classified.

Recent surveys have shown the power of measuring variability of celestial sources for studying gravitational lensing, supernovae, gamma-ray bursts, gravitational wave counterparts, active galactic nuclei, variable stars, exoplanets, and other forefront astrophysics.

“Recent surveys have shown the power of measuring variability of celestial sources for studying gravitational lensing, searching for SNe, determining the physical properties of gamma-ray burst sources, discovering gravitational wave counterparts, probing the structure of active galactic nuclei ( AGNs ) , studying variable star populations, discovering exoplanets, and many other subjects at the fore”

• cites SciBook, Chap. 8Not checked yet

  Not checked in the free run.

• cites Law et al. 2009 sourceNot checked yet

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• cites Djorgovski et al. 2012Not checked yet

  Not checked in the free run.

Not yet classified.

This depth and surface brightness limit maximize the number of galaxies with measured shapes in ground-based seeing and allow detection beyond redshift two.

“This depth, as well as the corresponding deep surface brightness limit, optimizes the number of galaxies with measured shapes in ground-based seeing and allows their detection in signi fi cant numbers to beyond a redshift of two.”

Not yet classified.

Exploiting SN science fully requires light curves sampled in multiple bands every few days over several months.

“To fully exploit the SN science potential, light curves sampled in multiple bands every few days over the course of a few months are required.”

Not yet classified.

Cross-correlating the 3D mass distribution traced by neutral hydrogen or galaxies with LSST tomographic shear will complement other dark energy constraints and test gravity.

“The cross-correlation of the three-dimensional mass distribution -as probed by neutral hydrogen in CHIME ( Newburgh et al. 2014 ) , HIRAX ( Newburgh et al. 2016 ) , or SKA, or galaxies in DESI and PFS -with the gravitational growth probed by tomographic shear in LSST will be a complementary way to constrain dark energy properties beyond simply characterizing its equation of state and to test the”

Not yet classified.

K-corrections require calibration of relative photometric zero-point offsets between filters and system response functions, especially near band edges, to about 1%.

“Carrying out these K -corrections requires that the calibration of the relative offsets in photometric zero-points between fi lters and the system response functions, especially near the edges of bandpasses, be accurate to about 1% ( Wood-Vasey et al. 2007 )”

• cites Wood-Vasey et al. 2007 sourceNot checked yet

  Not checked in the free run.

Not yet classified.

Large survey volumes are essential for probing dynamical dark energy models with subhorizon clustering or anisotropic stresses.

“Large survey volumes are key to probing dynamical dark energy models ( with subhorizon dark energy clustering or anisotropic stresses ) .”

Not yet classified.

The most robust cosmological constraints come from combining multiple probes.

“Therefore, the most robust cosmological constraints are the result of using interlocking combinations of probes.”

Not yet classified.

Controlling shear systematic errors requires achieving the desired depth with many short exposures.

“In order to control systematic errors in shear measurement, the desired depth must be achieved with many short exposures”

Not yet classified.

Deeper data (r>26) over small areas can extend SN discovery to mean redshift 0.7, compared with ~0.5 for the main survey, with some beyond z~1.

“Deeper data ( r &gt; 26 ) for small areas of the sky can extend the discovery of SNe to a mean redshift of 0.7 ( from ∼ 0.5 for the main survey ) , with some objects beyond z ∼ 1 ( Garnavich et al. 2004; Pinto et al. 2004; SciBook, Chap. 11 ) .”

• cites Garnavich et al. 2004Not checked yet

  Not checked in the free run.

• cites Pinto et al. 2004Not checked yet

  Not checked in the free run.

• cites SciBook, Chap. 11Not checked yet

  Not checked in the free run.

Not yet classified.

Rather than co-adding all images, individual exposures with their own PSF and noise should be analyzed simultaneously to measure galaxy shapes optimally.

“rather than simply co-adding all images in a given region of sky, the individual exposures, each with their own PSF and noise characteristics, should be analyzed simultaneously to optimally measure the shapes of galaxies”

• cites Tyson et al. 2008Not checked yet

  Not checked in the free run.

• cites Jee & Tyson 2011Not checked yet

  Not checked in the free run.

Not yet classified.

The single-visit depth should reach r ~ 24.5.

“The single-visit depth should reach r ∼ 24.5.”

• Also stated in: § 2.1.2. Taking an Inventory of the Solar System · p. 6

  “The images should reach a depth of at least 24.5 ( 5 σ for point sources ) in the r band to reach high completeness down to the 140 m mandate for NEOs.”

• Also stated in: § 2.2.1. The Aperture Size · p. 9

  “the depth of a single visit, r ∼ 24.5”

Not yet classified.

Weak lensing, large-scale structure, and supernova probes each place unique and independent constraints on LSST system design.

“Three of the primary dark energy probes, WL, LSS, and SN, provide unique and independent constraints on the LSST system design ( SciBook, Chaps. 11 -15 ) .”

• cites SciBook, Chaps. 11-15Not checked yet

  Not checked in the free run.

Not yet classified.

The main survey will cover an 18,000 deg2 area about 800 times summed over all six bands over the anticipated 10 years.

“that will uniformly observe a 18,000 deg 2 region about 800 times ( summed over all six bands ) during the anticipated 10 yr of operations”

• AssumptionRests on an assumption: The LSST construction will be completed and the survey will operate for the planned 10 years.
• AssumptionRests on an assumption: The observing time allocation and survey cadence described will be implemented as planned.

Not yet classified.

Analyzing these data will require sophisticated data processing techniques.

“Analyzing these data will require sophisticated data processing techniques.”

Not yet classified.

A major challenge in extragalactic cosmology today concerns the formation of structure on subgalactic scales, where baryon physics becomes important and the nature of dark matter may manifest in observable ways.

“A major challenge in extragalactic cosmology today concerns the formation of structure on subgalactic scales, where baryon physics becomes important, and the nature of dark matter may manifest itself in observable ways ( e.g., Weinberg et al. 2015 ) .”

• cites Weinberg et al. 2015 sourceNot checked yet

  Not checked in the free run.

Not yet classified.

This sampling is needed to search for systematic differences among SN populations and to derive photometric redshifts from the SNe themselves.

“This is essential to search for systematic differences in SN populations ( e.g., due to differing progenitor channels ) , which may masquerade as cosmological effects, as well as to determine photometric redshifts from the SNe themselves.”

Not yet classified.

The WL program imposes the strongest constraints on LSST image quality.

“The strongest constraints on the LSST image quality arise from this science program.”

Not yet classified.

At least five photometric bands are needed to measure proper K-corrected light curves over a range of redshifts.

“Observations in at least fi ve photometric bands will allow proper K -corrected light curves to be measured over a range of redshift.”

Not yet classified.

Cosmic shear measurements versus redshift determine angular distances versus cosmic time and give independent dark energy constraints.

“Measurements of cosmic shear as a function of redshift allow determination of angular distances versus cosmic time, providing multiple independent constraints on the nature of dark energy.”

Not yet classified.

Roughly 90% of LSST observing time will be used for a deep-wide-fast main survey.

“About 90% of the observing time will be devoted to a deep-wide-fast survey mode”

• Also stated in: § 2. From Science Drivers to Reference Design · p. 4

  “About 90% of the observing time will be devoted to a deep-wide-fast ( main ) survey mode.”

• AssumptionRests on an assumption: The observing time allocation and survey cadence described will be implemented as planned.

Not yet classified.

Good image quality is needed to separate supernovae photometrically from host galaxies.

“Good image quality is required to separate SN photometrically from their host galaxies.”

Not yet classified.

Weak lensing investigations require deep wide-area multicolor imaging with tight shear systematics in at least two bands and excellent photometry in at least five bands for photometric redshifts.

“These investigations require deep wide-area multicolor imaging with stringent requirements on shear systematics in at least two bands, and excellent photometry in at least fi ve bands to measure photometric redshifts”

Not yet classified.

The remaining 10% of observing time will go to special projects such as Very Deep and Very Fast time-domain surveys, with details still under discussion.

“The remaining 10% of the observing time will be allocated to special projects such as Very Deep and Very Fast time domain surveys, whose details are currently under discussion.”

• AssumptionRests on an assumption: The observing time allocation and survey cadence described will be implemented as planned.

Not yet classified.

The most powerful cosmological probes include weak lensing, galaxy clustering and BAO, cluster mass function and clustering, lensed quasar and SN time delays, and Type Ia SN photometry, all as functions of redshift.

“The most powerful probes include weak gravitational lens cosmic shear ( weak lensing ( WL )) , galaxy clustering and baryon acoustic oscillations ( large-scale structure, LSS ) , the mass function and clustering of clusters of galaxies, time delays in lensed quasar and supernova ( SN ) systems, and photometry of Type Ia SNe -all as functions of redshift.”

Not yet classified.

The LSST filter complement (ugrizy) is modeled after the SDSS system because of its demonstrated success in photometric redshifts of galaxies, separation of stellar populations, and photometric selection of quasars.

“The LSST fi lter complement ( ugrizy ; see Figure 4 ) is modeled after the SDSS system ( Fukugita et al. 1996 ) because of its demonstrated success in a wide variety of applications, including photometric redshifts of galaxies ( Budavári et al. 2003 ) , separation of stellar populations ( Lenz et al. 1998; Helmi et al. 2003 ) , and photometric selection of quasars ( Richards et al. 2002; Ross et”

• cites Fukugita et al. 1996 sourceNot checked yet

  Not checked in the free run.

• cites Budavári et al. 2003 sourceNot checked yet

  Not checked in the free run.

• cites Lenz et al. 1998 sourceNot checked yet

  Not checked in the free run.

Not yet classified.

In times of good seeing and low air mass, preference is given to r- and i-band observations.

“In times of good seeing and at low air mass, preference is given to r - and i -band observations.”

Not yet classified.

The single-visit exposure time should be less than about a minute and longer than approximately 20 seconds.

“The single-visit exposure time should be less than about a minute to prevent trailing of fast-moving objects and to aid control of various systematic effects induced by the atmosphere. It should be longer than ∼ 20 s to avoid signi fi cant ef fi ciency losses due to fi nite readout, slew time, and read noise.”

Not yet classified.

The total number of visits of any given area of sky, when accounting for all filters, should be of the order of 1000.

“The total number of visits of any given area of sky, when accounting for all fi lters, should be of the order of 1000, as mandated by WL science, the search for NEOs, and proper-motion and trigonometric parallax measurements.”

Not yet classified.

The distribution of visits per filter should enable accurate photometric redshifts, separation of stellar populations, and sufficient depth to detect faint extremely red sources such as brown dwarfs and high-redshift quasars.

“The distribution of visits per filter should enable accurate photometric redshifts, separation of stellar populations, and suf fi cient depth to enable detection of faint extremely red sources ( e.g., brown dwarfs and high-redshift quasars ) .”

Not yet classified.

The remaining 10% of observing time will be used for improved coverage of parameter space such as very deep observations, short revisit times, and special regions.

“The remaining 10% of the observing time will be used to obtain improved coverage of parameter space such as very deep ( r ∼ 26 ) observations, observations with very short revisit times ( ∼ 1 minute ) , and observations of ' special ' regions such as the ecliptic plane, Galactic plane, and the Large and Small Magellanic Clouds.”

Not yet classified.

Surveying efficiency considerations place a lower limit on the visit exposure time of greater than 20 seconds.

“To maintain ef fi ciency losses below ∼ 30% ( i.e., at least below the limit set by the weather patterns ) , and to minimize the read noise impact, t vis &gt; 20 s is required.”

Not yet classified.

The reference design has a primary mirror effective diameter of approximately 6.5 m, corresponding to a geometrical diameter of approximately 8 m, adopted as 8.4 m.

“A primary mirror effective diameter of ∼ 6.5 m. With the adopted optical design, described below, this effective diameter corresponds to a geometrical diameter of ∼ 8 m. Motivated by characteristics of the existing equipment at the Steward Mirror Laboratory, which fabricated the primary mirror, the adopted geometrical diameter is set to 8.4 m.”

Not yet classified.

Additional coverage of a crescent within 10 degrees of the northern ecliptic plane would sample the full azimuthal distribution of KBOs, crucial for understanding dynamical families.

“Additional coverage of a crescent within 10 degrees of the northern ecliptic plane would sample the full azimuthal distribution of KBOs, crucial for understanding the different dynamical families in which they fall.”

Not yet classified.

The ranking criteria ensure visits to each field are widely distributed in position angle and camera rotation to minimize systematic effects in galaxy shape determination.

“The ranking criteria also ensure that the visits to each fi eld are widely distributed in position angle on the sky and rotation angle of the camera in order to minimize systematic effects in galaxy shape determination.”

Not yet classified.

The LSST system will explicitly measure the atmospheric transmission spectrum associated with each image it acquires.

“In addition, the LSST system will explicitly measure the atmospheric transmission spectrum associated with each image acquired.”

Not yet classified.

Photometric and astrometric accuracy will be limited not by instrumentation or software, but rather by atmospheric effects.

“Extensive precursor data including the SDSS data set and our own data obtained using telescopes close to the LSST site of Cerro Pachón ( e.g., the SOAR and Gemini South telescopes ) , as well as telescopes of similar aperture ( e.g., Subaru ) , indicate that the photometric and astrometric accuracy will be limited not by our instrumentation or software, but rather by atmospheric effects.”

Not yet classified.

In order to measure the tangential velocity of stars at a distance of 10 kpc, where the halo dominates over the disk, to within 10 km/s, the proper-motion accuracy should be 0.2 mas/yr or better.

“In order to measure the tangential velocity of stars at a distance of 10 kpc, where the halo dominates over the disk, to within 10 km s -1 ( comparable to the accuracy of large-scale radial velocity surveys ) , the proper-motion accuracy should be 0.2 mas yr -1 or better.”

Not yet classified.

The sky area for the main survey is maximized to its practical limit of 18,000 square degrees, determined by the requirement to avoid air masses less than 1.5.

“For this reason, the sky area for the main survey is maximized to its practical limit, 18,000 deg 2 , determined by the requirement to avoid air masses less than 1.5, which would substantially deteriorate the image quality and the survey depth ( see Equation ( 6 )) .”

Not yet classified.

LSST's photometric calibration approach is to measure the instrumental sensitivity as a function of wavelength at 1 nm resolution using monochromatic light injected into the telescope pupil.

“The overall photometric calibration philosophy ( Stubbs &amp; Tonry 2006 ) is to measure explicitly, at 1 nm resolution, the instrumental sensitivity as a function of wavelength using light from a monochromatic source injected into the telescope pupil.”

• cites Stubbs & Tonry 2006Not checked yet

  Not checked in the free run.

Not yet classified.

The LSST Data Management system will automatically reduce the data collected by LSST into scientifically useful catalogs and images.

“The data collected by the LSST system will be automatically reduced to scienti fi cally useful catalogs and images by the LSST Data Management ( DM; Juri ć et al. 2017a ) system.”

• cites Jurić et al. 2017aNot checked yet

  Not checked in the free run.

Not yet classified.

Data processing, data products, and data access should result in products that approach the statistical uncertainties in the raw data, and processing latency for variable sources should be less than a minute.

“Data processing, data products, and data access should result in data products that approach the statistical uncertainties in the raw data, i.e., the processing must be close to optimal. To enable fast and ef fi cient response to transient sources, the processing latency for variable sources should be less than a minute, with a robust and accurate preliminary characterization of all reported vari”

Not yet classified.

The chosen filter complement corresponds to a design 'sweet spot'.

“The chosen fi lter complement corresponds to a design ' sweet spot. '”

Not yet classified.

The reference design has a visit exposure time of 30 seconds, using two 15-second exposures, yielding an efficiency of 77%.

“A visit exposure time of 30 s ( using two 15 s exposures to ef fi ciently reject cosmic rays; the possibility of a single exposure per visit, to improve observing ef fi ciency, will be investigated during the commissioning phase ) , yielding ò = 77%.”

Not yet classified.

The universal cadence will be extended to the northern ecliptic crescent using r and i filters only, with relaxed air mass and seeing limits.

“Thus, we plan to extend the universal cadence to this region using the r and i fi lters only, along with more relaxed limits on air mass and seeing.”

Not yet classified.

The universal cadence yields the main deep-wide-fast survey and meets the core science goals.

“We present here a speci fi c realization, the so-called ' universal cadence, ' which yields the main deep-wide-fast survey and meets our core science goals.”

Not yet classified.

Such an instrument would probe the approximately 100 m size range at main belt distances and discover rare distant trans-Neptunian objects such as Sedna and 2012 VP113.

“Such an instrument would probe the ∼ 100 m size range at main belt distances and discover rare distant TNOs such as Sedna ( Brown et al. 2004 ) and 2012 VP113 ( Trujillo &amp; Sheppard 2014 ) .”

• cites Brown et al. 2004 sourceNot checked yet

  Not checked in the free run.

• cites Trujillo & Sheppard 2014 sourceNot checked yet

  Not checked in the free run.

Not yet classified.

A system with a smaller étendue would require separate specialized surveys to address the science goals, resulting in a loss of surveying efficiency.

“A system with a smaller étendue would require separate specialized surveys to address the science goals, which results in a loss of surveying ef fi ciency.”

Not yet classified.

Each field will be observed twice as often as possible, with visits separated by 15-60 minutes.

“As often as possible, each fi eld will be observed twice, with visits separated by 15 -60 minutes.”

Not yet classified.

Placing the red edge of the u band blueward of the Balmer break allows optimal separation of stars and quasars, and the telluric water absorption feature at 9500 Angstroms effectively defines the blue edge of the y band.

“Placing the red edge of the u band blueward of the Balmer break allows optimal separation of stars and quasars, and the telluric water absorption feature at 9500 Å effectively de fi nes the blue edge of the y band.”

Not yet classified.

Mapping the Galaxy requires large-area coverage, excellent image quality to maximize photometric and astrometric accuracy, photometric precision of at least 1%, and systematic astrometric errors not exceeding about 10 mas per observation.

“Mapping the Galaxy requires large-area coverage; excellent image quality to maximize photometric and astrometric accuracy, especially in crowded fi elds; photometric precision of at least 1% to separate main-sequence and giant stars ( e.g., Helmi et al. 2003 ) , as well as to identify variable stars such as RR Lyrae ( Sesar et al. 2010; Sharma et al. 2011 ) ; and systematic astrometric errors not”

• cites Helmi et al. 2003 sourceNot checked yet

  Not checked in the free run.

• cites Sesar et al. 2010 sourceNot checked yet

  Not checked in the free run.

• cites Sharma et al. 2011 sourceNot checked yet

  Not checked in the free run.

Not yet classified.

The adopted survey lifetime of 10 years is a compromise between a shorter time, which would require an excessively large and expensive mirror, and a smaller telescope, which would require more time to complete the survey with increased operations cost.

“The adopted survey lifetime of 10 yr is a compromise between a shorter time, which leads to an excessively large and expensive mirror ( 15 m for a 3 yr survey and 12 m for a 5 yr survey ) and not as effective proper-motion measurements, and a smaller telescope, which would require more time to complete the survey, with the associated increase in operations cost.”

Not yet classified.

This strategy will provide motion vectors to link detections of moving objects and fine-time sampling for short-period variability.

“This strategy will provide motion vectors to link detections of moving objects in the solar system and fi ne-time sampling for measuring short-period variability.”

Not yet classified.

The extension of the SDSS system to longer wavelengths, with the y band at approximately 1 micron, is driven by the increased effective redshift range achievable with LSST, the desire to study substellar objects, high-redshift quasars, and regions of the Galaxy obscured by interstellar dust, and the scientific opportunity enabled by modern CCDs with high near-infrared quantum efficiency.

“The extension of the SDSS system to longer wavelengths ( the y band at ∼ 1 μ m ) is driven by the increased effective redshift range achievable with the LSST, due to deeper imaging; the desire to study substellar objects, high-redshift quasars, and regions of the Galaxy that are obscured by interstellar dust; and the scienti fi c opportunity enabled by modern CCDs with high quantum ef fi ciency in”

Not yet classified.

About 90% of the observing time will be devoted to a deep-wide-fast survey mode, with the remaining 10% allocated to special programs that will also address multiple science goals.

“The vast majority ( about 90% ) of the observing time will be devoted to a deepwide-fast survey mode of the sort we have just described, with the remaining 10% allocated to special programs that will also address multiple science goals.”

Not yet classified.

Any one of the four main science drivers could be removed, and the remaining three would still yield very similar requirements for most system parameters.

“Indeed, any one of the four main science drivers could be removed, and the remaining three would still yield very similar requirements for most system parameters.”

Not yet classified.

The co-added survey depth should reach r ~ 27.5, with sufficient signal-to-noise ratio in other bands to address both extragalactic and Galactic science drivers.

“The co-added survey depth should reach r ∼ 27.5, with suf fi cient signal-to-noise ratio ( S / N ) in other bands to address both extragalactic and Galactic science drivers.”

Not yet classified.

Astrometric calibration will be based on Gaia mission results, which will provide numerous high-accuracy astrometric standards in every LSST field.

“Astrometric calibration will be based on the results from the Gaia mission ( Lindegren et al. 2018 ) , which will provide numerous high-accuracy astrometric standards in every LSST fi eld.”

• cites Lindegren et al. 2018 sourceNot checked yet

  Not checked in the free run.

Not yet classified.

None of the individual science programs are severely overdesigned; despite their scientific diversity, the programs are highly compatible in terms of desired data characteristics.

“Remarkably, even with these joint requirements, none of the individual science programs are severely overdesigned, i.e., despite their signi fi cant scienti fi c diversity, these programs are highly compatible in terms of desired data characteristics.”

Classified as probably not a substantial claim.

The filter complement should include at least six filters in the wavelength range 320-1050 nm, with roughly rectangular filters and no large gaps in coverage.

“The filter complement should include at least six fi lters in the wavelength range limited by atmospheric absorption and silicon detection ef fi ciency ( 320 -1050 nm ) , with roughly rectangular fi lters and no large gaps in the coverage, in order to enable robust and accurate photometric redshifts and stellar typing.”

Not yet classified.

The images must be well sampled to enable accurate astrometry, with absolute accuracy of at least 0.1 arcseconds, in order to measure orbital parameters of trans-Neptunian objects with enough precision to constrain theoretical models and enable prediction of occultations.

“The images must be well sampled to enable accurate astrometry, with absolute accuracy of at least 0 1 in order to measure orbital parameters of TNOs with enough precision to constrain theoretical models and enable prediction of occultations.”

Not yet classified.

There is a minimum étendue of approximately 300 square degrees square meters that enables the disparate science goals to be addressed with a single data set.

“In summary, given the science requirements as stated here, there is a minimum étendue of ∼ 300 deg 2 m 2 , which enables our seemingly disparate science goals to be addressed with a single data set.”

Not yet classified.

Individual exposures should be shorter than about 30 seconds to minimize the effects of trailing for the majority of moving objects.

“Individual exposures should be shorter than about 30 s to minimize the effects of trailing for the majority of moving objects.”

Not yet classified.

A dedicated 1.2 m auxiliary calibration telescope will obtain spectra of standard stars in LSST fields to calibrate atmospheric throughput as a function of wavelength.

“A dedicated 1.2 m auxiliary calibration telescope will obtain spectra of standard stars in LSST fi elds, calibrating the atmospheric throughput as a function of wavelength ( Stubbs et al. 2007; see Figures 5 and 6 ) .”

• cites Stubbs et al. 2007 sourceNot checked yet

  Not checked in the free run.

Not yet classified.

The three requirements place a firm upper limit on the optimal visit exposure time of less than 40 seconds.

“These three requirements place a fi rm upper limit on the optimal visit exposure time of t vis &lt; 40 s.”

• AssumptionThe authors state this as an assumption: Two visits per night are assumed.
• AssumptionThe authors state this as an assumption: Uniform cadence is assumed for the mean revisit time.

Not yet classified.

Precise determination of the point-spread function across each image, accurate photometric and astrometric calibration, and continuous monitoring of system performance and observing conditions are needed to reach the full potential of the LSST mission.

“Precise determination of the PSF across each image, accurate photometric and astrometric calibration, and continuous monitoring of system performance and observing conditions will be needed to reach the full potential of the LSST mission.”

Not yet classified.

The congressional mandate can be fulfilled with a 10 m class telescope equipped with a multi-gigapixel camera and a sophisticated and robust data processing system.

“The congressional mandate can be ful fi lled with a 10 m class telescope equipped with a multi-gigapixel camera and a sophisticated and robust data processing system ( Ivezi ć et al. 2007b ) .”

• cites Ivezić et al. 2007bNot checked yet

  Not checked in the free run.

Not yet classified.

The main deep-wide-fast survey will use about 90% of the observing time.

“The main deep-wide-fast survey will use about 90% of the observing time.”

Not yet classified.

Replacing the ugrizy system with a filter complement that includes only five filters is not satisfactory.

“We have investigated the possibility of replacing the ugrizy system with a fi lter complement that includes only fi ve fi lters. For example, each fi lter width could be increased by 20% over the same wavelength range ( neither a shorter wavelength range nor gaps in the wavelength coverage are desirable options ) , but this option is not satisfactory.”

Not yet classified.

The LSST observing strategy is designed to maximize scientific throughput by minimizing slew and other downtime and by choosing filter bands according to realtime weather conditions.

“The LSST observing strategy is designed to maximize the scienti fi c throughput by minimizing slew and other downtime and by making appropriate choices of the fi lter bands given the realtime weather conditions.”

Not yet classified.

The reference design has a revisit time of 3 days on average for 10,000 square degrees of sky, with two visits per night.

“A revisit time of 3 days on average for 10,000 deg 2 of sky, with two visits per night.”

Probably not a substantial claim: may not pass S4 (based).

The observing strategy for the main survey will be optimized for homogeneity of depth and number of visits.

“The observing strategy for the main survey will be optimized for the homogeneity of depth and number of visits.”

Probably not a substantial claim: may not pass S4 (based).

The photometric calibration should be better than 1%-2% to measure asteroids' colors and thus determine their types.

“The photometric calibration should be better than 1% -2% to measure asteroids ' colors and thus determine their types.”

Not yet classified.

The chosen primary mirror diameter is the minimum diameter that simultaneously satisfies the depth constraints of r ~ 24.5 for a single visit and r ~ 27.5 for co-added depth, and the cadence constraints of a revisit time of 3-4 days with 30 seconds per visit.

“To summarize, the chosen primary mirror diameter is the minimum diameter that simultaneously satis fi es the depth ( r ∼ 24.5 for single visit and r ∼ 27.5 for co-added depth ) and cadence ( revisit time of 3 -4 days, with 30 s per visit ) constraints described above.”

Not yet classified.

The universal cadence provides most of LSST's power for detecting NEOs and KBOs and incorporates the southern half of the ecliptic within 18,000 square degrees, with a declination cut of about +2°.

“The universal cadence provides most of LSST ' s power for detecting NEOs and Kuiper Belt objects ( KBOs ) and naturally incorporates the southern half of the ecliptic within its 18,000 square degrees, with a decl. cut of about δ = + 2 ° .”

Not yet classified.

The planned LSST calibration process separates the establishment of a stable and uniform internal relative calibration from the assignment of absolute optical flux to celestial objects.

“The planned calibration process decouples the establishment of a stable and uniform internal relative calibration from the task of assigning absolute optical fl ux to celestial objects.”

Not yet classified.

The required co-added survey depth provides a direct constraint on the minimum effective primary mirror diameter of 6.4 m.

“The required co-added survey depth provides a direct constraint, independent of the details of survey execution such as the exposure time per visit, on the minimum effective primary mirror diameter of 6.4 m, as illustrated in Figure 2.”

• AssumptionThe authors state this as an assumption: 22% of the total observing time, corrected for weather and other losses, is allocated for the r band.
• AssumptionThe authors state this as an assumption: The ratio of the surveyed sky area to the field-of-view area is 2000.

Not yet classified.

A larger field of view would lead to unacceptable deterioration of the image quality.

“A larger fi eld of view would lead to unacceptable deterioration of the image quality.”

Not yet classified.

The revisit time distribution should enable determination of orbits of solar system objects and sample supernova light curves every few days, while accommodating constraints set by proper-motion and trigonometric parallax measurements.

“The revisit time distribution should enable determination of orbits of solar system objects and sample SN light curves every few days, while accommodating constraints set by proper-motion and trigonometric parallax measurements.”

Not yet classified.

Redesigning the riz bands as two wider bands is undesirable because the r and i bands are primary for weak lensing studies and star/galaxy separation, and atmospheric dispersion would worsen the point-spread function for a wider bandpass.

“As a last option, the riz bands could be redesigned as two wider bands. However, this option is also undesirable because the r and i bands are the primary bands for WL studies and for star / galaxy separation, and atmospheric dispersion would worsen the PSF for a wider bandpass ( e.g., at air mass of 1.3, the typical dispersion in the u , g , and r bands is 0 55, 0 46, and 0 19, respectively; if”

Not yet classified.

These mini-surveys aim to extend the parameter space accessible to the main survey by going deeper or employing different time/filter sampling.

“These surveys aim to extend the parameter space accessible to the main survey by going deeper or by employing different time / fi lter sampling.”

Not yet classified.

This error behavior is a strong independent argument for a survey lifetime of at least 10 yr.

“This error behavior is a strong independent argument for a survey lifetime of at least 10 yr ( see Section 2 ) .”

• AssumptionThe authors state this as an assumption: Systematic astrometric errors of 10 mas are assumed to be uncorrelated between different observations of a given object.

Not yet classified.

The SN sample would be extended to redshifts of z ~ 1.2, with more densely sampled light curves than from the universal cadence.

“For example, the SN sample would be extended to redshifts of z ∼ 1.2, with more densely sampled light curves than obtained from the universal cadence.”

Not yet classified.

Prompt products will support discovery and follow-up of solar system objects.

“In addition to transient science, the prompt products will support discovery and follow-up of objects in the solar system.”

Not yet classified.

Based on SDSS experience (Sesar et al. 2007), the random photometric error for point sources as a function of magnitude is well described by Equation (5).

“Based on SDSS experience ( Sesar et al. 2007 ) , the random photometric error for point sources, as a function of magnitude, is well described 98 by”

• cites Sesar et al. 2007 sourceNot checked yet

  Not checked in the free run.

Not yet classified.

The calibration system and procedures are designed to maintain σsys < 0.005 mag.

“The calibration system and procedures are designed to maintain σ sys &lt; 0.005 mag.”

Not yet classified.

Roughly 10% of the time will be allocated to other strategies that significantly enhance the scientific return.

“Although the uniform treatment of the sky provided by the universal cadence proposal can satisfy the majority of LSST scienti fi c goals, roughly 10% of the time will be allocated to other strategies that signi fi cantly enhance the scienti fi c return.”

Not yet classified.

Another meaning of Cm∞ is the loss of depth at the nominal tvis due to finite readout noise.

“Another meaning of Cm D ¥ is the loss of depth at the nominal value of t vis due to fi nite readout noise.”

Not yet classified.

The baseline universal cadence represents a proof of concept that it is possible to design an observing strategy that addresses a wide variety of science goals in a nearly optimal way.

“Rather, it represents a proof of concept that it is indeed possible to design a observing strategy that addresses a wide variety of science goals in a nearly optimal way.”

May combine two claims.

Alerts to such events will be published within 60 s of observation; several million alerts per night are expected.

“The alerts to such events will be published within 60 s of observation; we expect several million alerts per night ( Ridgway et al. 2014 ) .”

• cites Ridgway et al. 2014 sourceNot checked yet

  Not checked in the free run.

Not yet classified.

When this assumption is not correct (e.g., in the u band), the coefficients Cm do slightly depend on tvis.

“When this assumption is not correct ( e.g., in the u band ) , the coef fi cients Cm do slightly depend on t vis .”

Not yet classified.

Three examples of mini-surveys are the northern ecliptic spur, the southern celestial cap, and the Galactic plane survey.

“We have already discussed three examples of such mini-surveys: the northern ecliptic spur to improve completeness of the asteroid and KBO population, the southern celestial cap to extend the survey footprint to the South Pole ( thus providing coverage of the Magellanic Clouds ) , and the Galactic plane survey to include low Galactic latitude fi elds.”

Not yet classified.

Due to very red V-u colors and the relatively bright limiting magnitude in the y band, the smallest objects are preferentially detected in the griz bands.

“Due to very red V - u colors and the relatively bright limiting magnitude in the y band, the smallest objects are preferentially detected in the griz bands.”

Not yet classified.

When subsequences from a given night were co-added, they would provide dense time sampling to a faint limit of r ~ 26.5 and enable deep searches for SNe, TNOs, and other faint transient, moving, and variable sources.

“When subsequences from a given night were co-added, they would provide dense time sampling to a faint limit of r ∼ 26.5 and would enable deep searches for SNe, TNOs, and other faint transient, moving, and variable sources.”

Not yet classified.

There are close to 1000 galaxies per sensor with r < 22, which will provide exquisite control of systematic astrometric errors and enable absolute proper-motion measurements.

“Furthermore, there are close to 1000 galaxies per sensor with r &lt; 22, which will provide exquisite control of systematic astrometric errors as a function of magnitude, color, and other parameters and thus enable absolute proper-motion measurements.”

• AssumptionThe authors state this as an assumption: Systematic astrometric errors of 10 mas are assumed to be uncorrelated between different observations of a given object.

Not yet classified.

After accounting for differences in input assumptions and models, each of the independent works (Jones et al. 2018; Vereš & Chesley 2017a, 2017b; Grav et al. 2016) calculates a completeness value that is consistent within a few percent.

“After accounting for differences in their input assumptions and models, each of these independent works calculates a completeness value that is consistent within a few percent.”

• cites Jones et al. 2018 sourceNot checked yet

  Not checked in the free run.

• cites Vereš & Chesley 2017a, 2017bNot checked yet

  Not checked in the free run.

• cites Grav et al. 2016 sourceNot checked yet

  Not checked in the free run.

Not yet classified.

This decoupling is only correct in the limit that instrumental noise (dominated by readout noise) is negligible compared to background noise.

“However, this decoupling between the system sensitivity expressed via Cm and observing conditions is only correct in the limit that the instrumental noise ( dominated by the readout noise ) is negligible compared to the background noise.”

Not yet classified.

The differences in performance between LSST and SDSS follow directly from these relations.

“The differences in performance between LSST and, for example, SDSS follow directly from these relations.”

Not yet classified.

These four fields are only the first chosen for deep-drilling observations.

“These four fi elds are only the fi rst chosen for deep-drilling observations.”

Not yet classified.

Prompt products will include alerts to objects that were newly discovered or have changed brightness or position at a statistically significant level.

“They will include alerts to objects that were newly discovered or have changed brightness or position at a statistically signi fi cant level.”

Not yet classified.

The Galactic plane proposal provides 30 observations in each of six filters, distributed roughly logarithmically in time.

“Within this region, the Galactic plane proposal provides 30 observations in each of the six fi lters, distributed roughly logarithmically in time ( it may not be necessary to use the u and g fi lters for this heavily extincted region ) .”

Not yet classified.

Prompt products will be generated continuously every observing night by detecting and characterizing sources in images differenced against deep templates.

“These will be generated continuously every observing night, by detecting and characterizing sources in images differenced against deep templates.”

Not yet classified.

The structure of Equation (6) illustrates decoupling between system sensitivity absorbed into Cm and observing conditions specified by msky, θ, tvis, km, and X.

“The structure of Equation ( 6 ) nicely illustrates decoupling between the system sensitivity that is fully absorbed into Cm and observing conditions speci fi ed by m sky , θ , t vis , km , and X .”

Not yet classified.

The universal cadence excludes observations at low Galactic latitudes, where high stellar density leads to a confusion limit at brighter magnitudes.

“Finally, the universal cadence proposal excludes observations at low Galactic latitudes, where the high stellar density leads to a confusion limit at much brighter magnitudes than those attained in the rest of the survey.”

Not yet classified.

Data collected by LSST will be automatically processed to data products (catalogs, alerts, reduced images) by the LSST Data Management system.

“Data collected by the LSST telescope and camera will be automatically processed to data products -catalogs, alerts, and reduced images -by the LSST Data Management system ( Section 2.6.3 ) .”

Not yet classified.

LSST will smoothly extend Gaia's error versus magnitude curve about 4 mag fainter.

“Hence, LSST will smoothly extend Gaia ' s error versus magnitude curve about 4 mag fainter ( for illustration, see Figure 21 in Ivezi ć et al. 2012 ) .”

• cites Ivezić et al. 2012 sourceNot checked yet

  Not checked in the free run.

• AssumptionThe authors state this as an assumption: Systematic astrometric errors of 10 mas are assumed to be uncorrelated between different observations of a given object.

Not yet classified.

The values of Cm listed in Table 2 assume instrumental noise of 9 e- per pixel and per readout.

“The values of Cm listed in Table 2 assume instrumental noise of 9 e -per pixel and per readout ( whose effect on m 5 is signi fi cant only in the u band ) .”

Not yet classified.

Such sequences would serve as excellent tests of photometric calibration procedures.

“Such sequences would also serve as excellent tests of our photometric calibration procedures.”

Not yet classified.

Even SDSS delivers uncorrelated systematic errors at the level of 20-30 mas; the expected image quality for LSST will be twice as good as for SDSS.

“Even a drift-scanning survey such as SDSS delivers uncorrelated systematic errors ( dominated by seeing effects ) at the level of 20 -30 mas ( measured from repeated scans; Pier et al. 2003 ) ; the expected image quality for LSST will be twice as good as for SDSS.”

• cites Pier et al. 2003 sourceNot checked yet

  Not checked in the free run.

• AssumptionThe authors state this as an assumption: Systematic astrometric errors of 10 mas are assumed to be uncorrelated between different observations of a given object.

Not yet classified.

Prompt products are designed to support discovery, characterization, and rapid follow-up of time-dependent phenomena.

“Prompt products, 101 designed to support the discovery, characterization, and rapid follow-up of time-dependent phenomena ( ' transient science ' ) .”

Not yet classified.

The individual sequences would be sensitive to 1% variability on subminute timescales, allowing discovery of planetary eclipses and interstellar scintillation effects.

“The individual sequences would be sensitive to 1% variability on subminute timescales, allowing discovery of planetary eclipses and of interstellar scintillation effects, expected when the light of a background star propagates through a turbulent gas medium ( Moniez 2003; Habibi et al. 2011 ) .”

• cites Moniez 2003 sourceNot checked yet

  Not checked in the free run.

• cites Habibi et al. 2011 sourceNot checked yet

  Not checked in the free run.

Not yet classified.

The MOPS software system and its algorithms are significantly more advanced than anything previously fielded for this purpose to date.

“The MOPS software system and its algorithms are signi fi cantly more advanced than anything previously fi elded for this purpose to date.”

Not yet classified.

In both examples (NEO completeness and astrometric errors), the conclusions crucially depend on the assumed accuracy of the photometry and astrometry.

“In both examples, the conclusions crucially depend on the assumed accuracy of the photometry and astrometry, as we now describe.”

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

For a given albedo and spherical asteroids, H depends only on the asteroid diameter.

“For a given albedo and spherical asteroids, H depends only on the asteroid diameter.”

Not yet classified.

LSST has selected four distant extragalactic survey fields (Elias S1, XMM-LSS, Extended Chandra Deep Field-South, and COSMOS) to be observed as Deep Drilling Fields with deeper coverage and more frequent temporal sampling than the standard LSST observing pattern.

“The LSST has already selected four distant extragalactic survey fi elds 97 that the project guarantees to observe as Deep Drilling Fields with deeper coverage and more frequent temporal sampling than provided by the standard LSST observing pattern.”

Not yet classified.

Objects with motions sufficient to cause trailing in a single exposure will be identified and flagged as such when alerts are broadcast.

“Objects with motions suf fi cient to cause trailing in a single exposure will be identi fi ed and fl agged as such when the alerts are broadcast.”

Not yet classified.

These products are designed to enable a large majority of LSST science cases without working directly with raw pixels.

“These products are designed to enable a large majority of LSST science cases, without the need to work directly with the raw pixels.”

Not yet classified.

SDSS-POSS proper-motion measurements have an accuracy of ~5 mas yr-1 per coordinate at r = 20, and Gaia DR2 has delivered a median uncertainty in parallax of 0.7 mas and in proper motion of 1.2 mas yr-1 at its faint end (r ~ 20).

“For comparison with Table 3, the SDSS-POSS propermotion measurements have an accuracy of ∼ 5 mas yr -1 per coordinate at r = 20 ( Munn et al. 2004 ) , and Gaia DR 2 has delivered a median uncertainty in parallax of 0.7 mas and in proper motion of 1.2 mas yr -1 at its faint end, approximately corresponding to r = 20 ( Gaia Collaboration et al. 2018; Lindegren et al. 2018 ) .”

• cites Munn et al. 2004 sourceNot checked yet

  Not checked in the free run.

• cites Gaia Collaboration et al. 2018 sourceNot checked yet

  Not checked in the free run.

• cites Lindegren et al. 2018 sourceNot checked yet

  Not checked in the free run.

• AssumptionThe authors state this as an assumption: Systematic astrometric errors of 10 mas are assumed to be uncorrelated between different observations of a given object.

Not yet classified.

In the JupyterLab aspect, computation and analysis will occur at the LSST Data Access Center, giving a user experience nearly identical to local Jupyter notebooks.

“The user experience will be nearly identical to working with Jupyter notebooks locally, except that computation and analysis will occur with resources provided at the LSST Data Access Center.”

Not yet classified.

The JupyterLab aspect will provide a Jupyter Notebook-like interface for next-to-the-data remote analysis, with a large suite of astronomical software including the LSST software stack.

“The JupyterLab aspect, which will provide a Jupyter 106 Notebook-like interface and is geared toward enabling next-to-the-data remote analysis. A large suite of commonly used astronomical software, including the LSST software stack ( Section 2.6.4 ) , will be made available through this interface.”

Not yet classified.

LSST will produce roughly 30 trillion photometric measurements of celestial sources.

“Each sky position within the main survey area will be observed close to 1000 times, with timescales spanning seven orders of magnitude ( from 30 s to 10 yr ) , and produce roughly 30 trillion photometric measures of celestial sources.”

Not yet classified.

Each sky position in the main survey area will be observed close to 1000 times, with timescales spanning seven orders of magnitude from 30 s to 10 yr.

“Each sky position within the main survey area will be observed close to 1000 times, with timescales spanning seven orders of magnitude ( from 30 s to 10 yr ) , and produce roughly 30 trillion photometric measures of celestial sources.”

Not yet classified.

The main LSST product will be a multicolor ugrizy image of about half the sky to r~27.5.

“The main product of the LSST system will be a multicolor ugrizy image of about half the sky to unprecedented depth ( r ∼ 27.5 ) .”

Not yet classified.

LSST data releases will contain reduced and raw single-epoch images, deep co-adds, catalogs of detected objects, catalogs of sources, and catalogs of forced sources.

“These will include the ( reduced and raw ) singleepoch images, deep co-adds of the observed sky, catalogs of objects detected in LSST data, catalogs of sources ( the detections and measurements of objects on individual visits ) , and catalogs of ' forced sources ' ( measurements of fl ux on individual visits at locations where objects were detected by LSST or other surveys ) .”

Not yet classified.

The LSST Science Platform is LSST's vision for a large-scale astronomical data archive that enables effective research with data sets of LSST size and complexity.

“The LSST Science Platform ( Juri ć et al. 2017 ) represents LSST ' s vision for a large-scale astronomical data archive that can enable effective research with data sets of LSST size and complexity.”

• cites Juri ć et al. 2017Not checked yet

  Not checked in the free run.

May combine two claims.

At i<25.3 (S/N>20 for point sources), LSST galaxy photometry will be high enough for photometric redshifts with rms σ/(1+z) of 2% over 0.3<z<3.0, with only 10% of the sample having errors larger than 6%.

“At i &lt; 25.3 ( S / N &gt; 20 for point sources ) , the photometry of galaxies will be of high enough quality to provide photometric redshifts with an rms accuracy ( σ / ( 1 + z )) of 2% over the range 0.3 &lt; z &lt; 3.0 ( only 10% of the sample will have redshift errors larger than 6% ) .”

• AssumptionRests on an assumption: Known templates for galaxy spectral energy distributions are available for photometric redshift estimation.

Not yet classified.

In LSST DR processing, co-adds will be used for object detection, while object properties will be measured by simultaneously fitting PSF-convolved models to all single-epoch observations.

“That is, while the co-adds will be used to perform object detection , the measurement of their properties will be performed by simultaneously fi tting ( PSF-convolved ) models to all single-epoch observations.”

Not yet classified.

User-generated LSST data products can be created or used at the LSST Data Facility through the LSST Science Platform.

“We will make it possible for the end users to create ( or use ) such user-generated 105 products at the LSST Data Facility, using the services offered within the LSST Science Platform ( Section 3.3.1 ) .”

Not yet classified.

Mini-survey data products will be generated with the same processing system and released on the same timescale as the rest of the survey; specialized processing will be the community's responsibility.

“The data products for these programs will be generated using the same processing system and will be released on the same timescale as the rest of the survey; any specialized processing that these require will be the responsibility of the community.”

Probably not a substantial claim: may not pass S3 (load-bearing).

An extended source model, a constrained linear combination of two Sérsic profiles, and a point-source model with proper motion will generally be fitted to each detected object.

“An extended source model -a constrained linear combination of two Sérsic pro fi les -and a pointsource model with proper motion -will generally be fi tted to each detected object.”

Not yet classified.

Based on current plans and technology projections, the reserved Science Platform resources equate to about 2400 cores, 4 PB of file storage, and 3 PB of database storage at the start of LSST operations in 2022.

“Based on the current plans and technology projections, these equate to approximately 2400 cores, 4 PB of fi le storage, and 3 PB of database storage at the beginning of LSST operations ( in 2022 ) .”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

LSST data releases will also include fully reprocessed prompt products, plus metadata and software needed to reproduce any part of LSST DR processing.

“LSST DRs will also include fully reprocessed prompt products, as well as all metadata and software necessary for the end user to reproduce any aspect of LSST DR processing.”

Not yet classified.

Euclid's planned 6-year survey should reach a similar galaxy density over 15,000 square degrees, providing a complementary weak lensing survey of comparable constraining power but limited by different systematics.

“The Euclid mission ' s planned 6 yr survey should reach a similar galaxy density over 15,000 square degrees of sky ( Laureijs et al. 2011 ) ; its space-based resolution and broadband optical and NIR fi lters should provide a complementary WL survey of comparable constraining power but limited by different systematics.”

• cites Laureijs et al. 2011Not checked yet

  Not checked in the free run.

May combine two claims.

The galaxy-shear correlation function probes growth of dark matter large-scale structure and is a diagnostic of the underlying cosmology.

“The galaxy -shear correlation function probes the growth of dark matter large-scale structure and is a diagnostic of the underlying cosmology.”

Not yet classified.

Combining cosmological probes allows systematics to be calibrated and degeneracies to be broken because individual probes constrain degenerate parameter combinations and are affected by different systematics.

“Any given probe constrains degenerate combinations of cosmological parameters, and each probe is affected by different systematics; thus, the combination of probes allows systematics to be calibrated and for degeneracies to be broken.”

Not yet classified.

Photometric redshift calibration can be further improved by cross-correlating the photometric sample with redshift surveys of galaxies and quasars in the same fields.

“It will be possible to further improve photometric redshift calibration by crosscorrelating the photometric sample with redshift surveys of galaxies and quasars in the same fi elds ( Newman 2008; Matthews &amp; Newman 2010; Ménard et al. 2013; Davis et al. 2017 ) .”

• cites Newman 2008 sourceNot checked yet

  Not checked in the free run.

• cites Matthews & Newman 2010Not checked yet

  Not checked in the free run.

• cites Ménard et al. 2013Not checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S4 (based).

Objects that are not trailed will be identified and linked based on their motion from observation to observation over a few days.

“Those that are not trailed will be identi fi ed and linked based on their motion from observation to observation, over a period of a few days.”

Not yet classified.

The LSST Science Platform will be a set of web applications and services through which users access LSST data products and, if desired, conduct remote analyses or create user-generated products.

“The LSST Science Platform will be a set of web applications ( portals ) and services through which the users will access the LSST data products and, if desired, conduct remote analyses or create user-generated products.”

Not yet classified.

LSST design and optimization exploit its ability to scan a large sky area to a faint flux limit in a short time.

“The design and optimization of the LSST system leverage its unique capability to scan a large sky area to a faint fl ux limit in a short amount of time.”

Not yet classified.

The Web API aspect will expose LSST DAC services to other software tools and services using commonly accepted formats and protocols.

“The Web API aspect will expose the LSST DAC services to other software tools and services using commonly accepted formats and protocols.”

May combine two claims.

At a slightly brighter cut, there will be around 30 galaxies per arcmin^2 with shapes measured well enough for weak lensing, with the realized number depending on deblending and shape measurement algorithms.

“At a slightly brighter cut, there will be around 30 galaxies arcmin -2 with shapes measured well enough for WL measurements ( Chang et al. 2013, 2015 ) , with the number realized in practice being dependent on the performance of the deblending and shape measurement algorithms.”

• cites Chang et al. 2013, 2015Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Probably not a substantial claim: may not pass S3 (load-bearing).

The web Portal is designed to provide essential data access and visualization through a simple website, enabling querying and browsing similar to IRSA, MAST, or the SDSS archive.

“The web Portal, designed to provide the essential data access and visualization services through a simple-to-use website. It will enable querying and browsing of the available data sets in ways the users are accustomed to at archives such as IRSA, MAST, or the SDSS archive.”

Not yet classified.

Approximately 10% of LSST observing time will be devoted to mini-surveys that do not follow the baseline cadence.

“As described in Section 3.1.2, approximately 10% of the observing time will be devoted to mini-surveys that do not follow the LSST baseline cadence.”

Not yet classified.

The Web API will enable remote access and analysis of LSST data using applications such as TOPCAT or libraries such as Astropy, and will allow federation with other astronomical archives.

“This interface will open the possibility for remote access and analysis of the LSST data set using applications that the users are already comfortable with such as TOPCAT ( Taylor 2005 ) , or libraries such as Astropy ( Astropy Collaboration et al. 2013; Jenness et al. 2016 ) . Furthermore, the offered APIs will allow for federation with other astronomical archives, bringing added value to the LS”

• cites Taylor 2005Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

• cites Astropy Collaboration et al. 2013; Jenness et al. 2016Not matched

  Couldn’t be matched to a paper in Crossref, so it can’t be checked.

Not yet classified.

By measuring growth of large-scale structure and luminosity and angular distances as functions of redshift via weak lensing, large-scale structure, supernovae, and cluster counting, LSST data can reveal whether recent cosmic acceleration is due to dark energy or modified gravity.

“By simultaneously measuring the growth of large-scale structure and luminosity and angular distances as functions of redshift ( via WL, LSS, SN, and cluster counting ) , LSST data can reveal whether the recent cosmic acceleration is due to dark energy or modi fi ed gravity”

• cites Lue et al. 2004 sourceNot checked yet

  Not checked in the free run.

• cites Ishak et al. 2006 sourceNot checked yet

  Not checked in the free run.

• cites Knox et al. 2006 sourceNot checked yet

  Not checked in the free run.

Not yet classified.

LSST's dark energy and dark matter probing uses multiple cross-checking probes that reach unprecedented precision.

“A unique aspect of LSST as a probe of dark energy and dark matter is the use of multiple cross-checking probes that reach unprecedented precision ( see Figure 23 ) .”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

SDSS provides ugriz images of about a quarter of the sky to r~22.5 with twice as large seeing.

“For a comparison, one of the best analogous contemporary data sets is that of SDSS, which provides ugriz images of about a quarter of the sky to r ∼ 22.5, with twice as large seeing ( see Figures 21 and 22 ) .”

Not yet classified.

BAOs in galaxy angular correlation functions are a strong cosmological probe on their own.

“In addition, the presence of BAOs in the galaxy angular correlation functions is a strong cosmological probe on its own.”

Not yet classified.

These measurements consist of two-point auto- and cross-correlations of shear and positions for billions of galaxies across about 10 redshift bins.

“These measurements consist of the two-point auto- and cross-correlations of shear and positions for billions of galaxies across ∼ 10 redshift bins.”

Not yet classified.

The likelihood surface characterization will be done by sampling, with up to about 200 independent likelihood samples retained per object.

“The characterization will be accomplished by sampling, with up to ∼ 200 ( independent ) likelihood samples retained for each object.”

Probably not a substantial claim: may not pass S3 (load-bearing).

For storage cost reasons, these likelihood samples may be retained only for the bands most important for weak lensing studies.

“For storage cost reasons, these samples may be retained only for those bands of greatest interest for WL studies.”

Probably not a substantial claim: may not pass S3 (load-bearing). May combine two claims.

The WFIRST baseline survey is expected to cover about 2000 square degrees and reach a galaxy density of 45 arcmin^-2.

“The WFIRST baseline survey is expected to cover some 2000 square degrees but reach a galaxy density of 45 arcmin -2 ( Spergel et al. 2015 ) .”

• cites Spergel et al. 2015Not checked yet

  Not checked in the free run.

Not yet classified.

This photometric redshift accuracy is a requirement on the accuracy of the photometry given known SED templates.

“This number represents a requirement on the accuracy of the photometry at delivering photometric redshifts given known templates for the SEDs.”

• AssumptionRests on an assumption: Known templates for galaxy spectral energy distributions are available for photometric redshift estimation.

Probably not a substantial claim: may not pass S4 (based). May combine two claims.

The galaxy-galaxy correlation function is vital to constrain galaxy bias affecting galaxy-shear and is therefore essential in joint LSS and WL analysis.

“The galaxy -galaxy correlation function is vital to constrain the galaxy bias impacting the galaxy -shear correlation and is therefore an essential component in the joint analysis of LSS and WL.”

Not yet classified.

Their orbits as derived by MOPS will be published within 24 hr of identification.

“Their orbits as derived by MOPS will be published within 24 hr of identi fi cation.”

May combine two claims.

Requiring more training data than currently exists to define the template set degrades the expected σ/(1+z) to about 0.05, which is still within the expected range for a Stage IV dark energy experiment.

“The degradation in photometric redshift quality associated with requiring more training data than currently exists to de fi ne the template set increases the expected σ / ( 1 + z ) to ∼ 0.05 ( e.g., Newman et al. 2015; Graham et al. 2018 ) , which is still well within the expected range for a Stage IV dark energy experiment.”

• cites Newman et al. 2015 sourceNot checked yet

  Not checked in the free run.

• cites Graham et al. 2018 sourceNot checked yet

  Not checked in the free run.

Probably not a substantial claim: may not pass S3 (load-bearing), S4 (based).

The efficiency of linking (and thus completeness of the orbit catalog) will depend on the final observing cadence and the performance of the linking algorithm.

“The ef fi ciency of linking ( and thus the completeness of the resulting orbit catalog ) will depend on the fi nal observing cadence chosen for LSST, as well as the performance of the linking algorithm ( Section 3.2.2 ) .”

May combine two claims.

LSST data release products are intended to support science limited by systematics and flux, and they will be issued annually.

“2. DR products 102 are designed to enable systematics- and fl ux-limited science and will be made available in annual DRs.”

Not yet classified.

About 10% of the total LSST Data Facility compute and storage budget is reserved for the LSST Science Platform and shared by all LSST DAC users.

“Approximately 10% of the total budget for the LSST Data Facility compute and storage capacity has been reserved for the LSST Science Platform needs, and to be shared by all LSST DAC users.”

Not yet classified.

LSST DR processing will rely largely on multi-epoch model fitting (MultiFit) for near-optimal characterization of object properties.

“A noteworthy aspect of LSST DR processing is that it will largely rely on multi-epoch model fi tting, or MultiFit , to perform near-optimal characterization of object properties.”

Not yet classified.

Weak lensing and large-scale structure are highly complementary, and their auto- and cross-correlations will constrain late-time accelerated expansion while providing internal cross-checks for systematic uncertainties.

“WL and LSS are highly complementary probes, and the combination of their autoand cross-correlations will constrain the properties of the late-time accelerated expansion while providing internal cross-checks for marginalizing over systematic uncertainties ( e.g., Mandelbaum 2018 ) .”

• cites Mandelbaum 2018 sourceNot checked yet

  Not checked in the free run.

Not yet classified.

Combining galaxy-shear with galaxy-velocity correlation from planned spectroscopic surveys could test general relativity and its variants at high redshift.

“The combination with the galaxy -velocity correlation function estimated from currently planned spectroscopic surveys could test general relativity and its variants at high redshift ( Reyes et al. 2010 ) .”

• cites Reyes et al. 2010 sourceNot checked yet

  Not checked in the free run.

Not yet classified.

The platform implements the 'bringing computation to the data' paradigm, reducing barriers to entry and shortening the path to science for the LSST community.

“This is an implementation of the ' bringing computation to the data ' paradigm: rather than imposing the burden of downloading, storing, and processing ( potentially large ) subsets of LSST data at their home institutions, we make it possible for the users to bring their codes and perform analyses at the LSST DAC. This reduces the barrier to entry and shortens the path to science for the LSST sci”

May combine two claims.

The median redshift for this weak lensing sample will be z~1.2, with the third quartile at z~2.

“The median redshift for this sample will be z ∼ 1.2, with the third quartile at z ∼ 2.”