The Palomar Transient Factory: System Overview, Performance, and First Results

“The Bayesian framework for event clustering is given in Bloom et al. (2008).”

“The former identified eight SNe in this group (SN2000ds, SN2001co, SN2003H, SN2003dg, SN2003dr, SN2005cz, SN2005E and SN2007ke) and the latter identified three additional objects in this class from the Palomar Transient Factory survey (Law et al. 2009; Rau et al. 2009, henceforth PTF).”

“This SN was discovered as part of the Palomar Transient Factory (PTF14; Rau et al. 2009; Law et al. 2009), a five year project surveying the optically transient sky.”

“Data from the Palomar Transient Factory (Law et al. 2009) was automatically processed and images of candidate supernovae uploaded on a nightly basis; this triggered an email to volunteers who, upon responding, were shown the new image, a reference image and the difference between the two.”

“Recent wide field surveys, such as the Palomar Transient Factory (PTF) (Law et al. 2009; Rau et al. 2009) and Pan-STARRS1 (PS1) (Kaiser et al. 2010) have uncovered that the schema for classifying the highly luminous and energetic endpoints of massive stars known as supernovae (SNe) may be more…”

“The Palomar Transient Factory is a fully automated, wide-field survey aimed at a systematic exploration of explosions and variable phenomena in optical wavelengths.”

“Silverman et al. (2013) reported on the discovery of additional SNe Ia-CSM in archival and Palomar Transient Factory (PTF; Law et al. 2009) data, raising the total number to 16 objects.”

“The Palomar Transient Factory15 (PTF; Law et al. 2009; Rau et al. 2009) is a synoptic survey designed to explore the transient sky and to study stellar variability.”

“Supernova (SN) 2011fe was discovered soon after explosion in the nearby galaxy M101 (NGC 5457) by the Palomar Transient Factory (Rau et al. 2009; Law et al. 2009) on 2011 August 24.167 UT (all calendar dates herein are UT) and rapidly classified as a supernova of Type Ia (SN Ia; Nugent et al.…”

“(iv) The Palomar Observatory 1.2m Oschin telescope in California with the PTF camera, with a 7.8 deg2 field of view (Law et al. 2009) and a cadence of ∼40 minutes.”

“We study the host galaxies of both nearby (z < 0.2) core-collapse SNe discovered by “galaxy-untargeted” transient searches (e.g., the Palomar Transient Factory (PTF); Rau et al. 2009; Law et al. 2009), which do not target specific potential hosts or z < 1.2 LGRBs detected by γ -ray satellites.”

“…binaries, flaring stars, pulsing white dwarfs and transiting planets, and will be well placed for follow-up observations of short-duration transients discovered by the intermediate Palomar Transient Factory (iPTF, Law et al. 2009; Rau et al. 2009), and the upcoming Zwicky Transient Facility (ZTF)2.”

“The Intermediate Palomar Transient Factory project is a scientific collaboration among the California Institute of Technology; Los Alamos National Laboratory; the University of Wisconsin, Milwaukee; the Oskar Klein Center; the Weizmann Institute of Science; the TANGO Program of the University System of Taiwan; and the…”

“• The Palomar Transient Factory (PTF;Law et al. 2009 and Rau et al. 2009) is an on- going wide-area, two-band (SDSS-g′ and Mould-R filters), deep (R ∼ 20.6, g′ ∼ 21.3) survey aimed at systematic exploration of the optical transient sky.”

“…active large area transient surveys include the Catalina Realtime Transient Survey (CRTS, Drake et al. 2009), the Palomar Transient Factory (PTF, Law et al. 2009), the Mobile Astronomical System of the Telescope Robots (MASTER, Lipunov et al. 2010) and the All Sky Automated Survey (ASAS,…”

“Since 2013, as the successor of PTF (Law et al. 2009), iPTF have been performing several fast-cadence experiments to systematically search for and characterize young SNe and fast-evolving transients.”

“However, rapid optical followup observations from the Palomar Transient Factory (Law et al. 2009) pointed to a compact progenitor star, as evidenced by its short-lived (∆t ≈ 1 day) coolingenvelope emission (Arcavi et al. 2011).”

“Two years after the SN Refsdal event was the first discovery of a strongly lensed Type Ia SN by Goobar et al. (2017) in the intermediate Palomar Transient Factory (Law et al. 2009), namely the iPTF16geu system.”

“We obtained g- and r-band photometry from the following sources: Pan-STARRS1 (PS1; Kaiser et al. 2010), Palomar Transient Factory (PTF; Law et al. 2009), Zwicky Transient Facility (ZTF; Bellm et al. 2019) Data Release 3 and SDSS (York et al. 2000).”

“…dedicated SNe follow-up programs and telescopes (e.g., Filippenko et al. 2001; Bloom et al. 2006; Hamuy et al. 2006; Quimby 2006; Drake et al. 2009; Law et al. 2009; Rau et al. 2009), SNe IIn are now being studied more frequently in both the optical and near-IR (e.g., Pastorello et al. 2002;…”

“Wide-field photometric surveys, such as the Palomar Transient Factory (PTF; Law et al. 2009), Pan-STARRS (Jewitt 2003), and the Large Synoptic Survey Telescope (LSST; Becker et al. 2007) are becoming a larger part of astronomical science and would initially seem to be potential sources of flicker…”

“However, SNe are more likely to be found early with the current generation of automated surveys (e.g. Law et al. 2009; Shappee et al. 2012) which also observe sources over an extended period with a well-defined cadence.”

“Silverman et al. (2013) studied SNIIn detected by the Palomar Transient Factory (PTF; Rau et al. 2009; Law et al. 2009) and found that ∼10 per cent of explosions classified as SNIIn were more likely to be thermonuclear supernovae, interacting with a dense CSM.”

“SN 2010jp (PTFaaxi) SN 2010jp was discovered on 2010 Nov. 11.3 by Maza et al. (2010), and was found independently on 2010 Nov. 16 as PTF10aaxi in the course of the Palomar Transient Factory (PTF; Law et al. 2009; Rau et al. 2009), as we describe below.”

“(e.g. Bildsten et al. 2007; Metzger et al. 2009; Shen et al. 2010; Moriya et al. 2010) The Palomar Transient Factory2 (PTF; see Rahmer et al. 2008; Law et al. 2009; Rau et al. 2009) was designed to undertake a systematic exploration of the transient sky in the optical bands.”

“…Transient Survey (CRTS; Drake et al. 2009), the CHilean Automatic Supernova sEarch (CHASE; Pignata et al. 2009), the Palomar Transient Factory (PTF; Law et al. 2009), the Gaia transient survey (Hodgkin et al. 2013), the La Silla-QUEST (LSQ) Low Redshift Supernova Survey (Baltay et al. 2013), the…”

“The PTF11 (Law et al. 2009; Rau et al. 2009) is a synoptic survey designed to explore the transient sky.”

“Archival data from different surveys, namely LSQ, the Intermediate Palomar Transient Factory (iPTF4; Law et al. 2009; Rau et al. 2009, where the transient was designated as iPTF13ajw) and the Catalina Real-Time Transient Survey (CRTS5; Drake et al. 2009; Djorgovski et al. 2012) revealed an outburst…”

“The Palomar Transient Factory (PTF; Law et al. 2009) is developing the necessary instrumentation, algorithms, and observational discipline to detect optical counterparts to GBM GRBs.”

“Within our distance limit, systematic surveys such as the Catalina Real Time Transient Survey (Drake et al. 2009), the Palomar Transient Survey (Law et al. 2009), the Lick Observatory SN Search (Leaman et al. 2011), PanSTARRS-1 (Kaiser et al. 2010) and ASAS-SN (Shappee et al. 2014) ensure that most SNe are detected (a…”

“In a typical night, up to ∼ 2, 000 deg2 are observed to a depth of R ∼ 20.6 (Law et al. 2009; Rau et al. 2009).”

“PTF 10nvg, in the North America Nebula region of recent star formation, was identified by the Palomar Transient Factory (PTF; Law et al. 2009; Rau et al. 2009) on 2010 July 8, as an optical transient based on automatic discovery and classification codes (Bloom et al. 2011).”

“…of 15 SNe discovered by the Palomar Transient Factory and/or intermediate Palomar Transient Factory (PTF/iPTF, hereafter we use PTF for simplicity; Law et al. 2009; Rau et al. 2009), optimized to search for off-axis GRBs, namely, a sample of BLIcs selected blindly in random galaxies (mostly…”

“We also performed forced photometry on archival PTF/iPTF difference images spanning 2009 May 07 to 2016 Jun 13 (Law et al. 2009; Rau et al. 2009).”

“To that end, we present here the discovery by the Intermediate Palomar Transient Factory (iPTF; Law et al. 2009) of iPTF14yb, a luminous (Mr ≈ −27.8 mag), rapidly fading optical transient at redshift z = 1.9733.”

“17 Survey observations were conducted with the CFH12K camera (Rahmer et al. 2008) on the Palomar Observatory 48-inch telescope (P48; Law et al. 2009).”

“…SN catalogues exist, including the Dark Energy Survey (Flaugher 2005), Catalina Real-Time Survey (Drake et al. 2009), the Palomar Transient Factory (Law et al. 2009), SuperNova Legacy Survey (Bazin et al. 2009), Pan-STARRS (Kaiser et al. 2002), La Silla Quest (Hadjiyska et al. 2012), the Gaia…”

“During our nightly monitoring of M31 in the intermediate Palomar Transient Factory (iPTF; hereafter called simply PTF; Law et al. 2009), we discovered a transient at the location of a known nova in M31 (Tang et al. 2013), and confirmed it to be a RN with a recurrence time of 1yr with four optical…”

“SN 2011fe was discovered less than one day after the explosion by the Palomar Transient Factory (Law et al. 2009) in a sparse region of the outer disk of the well-studied, face-on spiral M101.”

“In the future, we expect projects like the Large Synoptic Survey Telescope (LSST; Ivezic et al. 2008), Palomar Transient Factory (PTF; Law et al. 2009; Rau et al. 2009), and Panoramic Survey Telescope and Rapid Response System (Pan-STARRS; Tonry et al. 2012) to uncover thousands of new eclipsing…”

“In Figure 8 we show the LINEAR, CRTS, PTF, P60 r¢, and LCOGT r¢ photometry from 2003–2014.”

“The transient iPTF13z was first detected in an image taken in the Mould R band (Law et al. 2009) on 2013 February 1.48 UT1 with the 1.2 m Samuel Oschin telescope (P48; Rahmer et al. 2008) on Palomar Mountain (California, USA).”

“…in the Southern Hemisphere (Hadjiyska et al. 2012), the Catalina Sky Survey (Drake et al. 2009), the Palomar Transient Factory (PTF, Law et al. 2009), All-Sky Automated Survey (ASAS, Pojmanski 2002), the Lincoln Near-Earth Asteroid Research survey (LINEAR, Palaversa et al. 2013)…”

“The bright, broad-lined SNIc SN2010ah was discovered by the Palomar Transient Factory (PTF, Law et al. 2009; Rau et al. 2009) on 23 Feb 2010 in a galaxy at a redshift z = 0 .”

“Largearea rolling surveys, such as the Palomar Transient Factory (PTF; Rau et al. 2009; Law et al. 2009), the Catalina Real-Time Transient Survey (CRTS Drake et al. 2009), PanSTARRS (Kaiser et al. 2010), the La Silla Quest Variability Survey (Baltay et al. 2013), the All-Sky Automated Survey for…”

“…et al. 2012) has gathered, published, and analysed their SN Ia spectral data, larger transient searches such as the Palomar Transient Factory (PTF; Rau et al. 2009; Law et al. 2009) and Pan-STARRS (Kaiser et al. 2002) will be able to add significantly to the number of late-time SN Ia spectra.”

“Coaddition is playing, and will play, a major role in ongoing and future surveys (e.g., SDSS, York et al. 2000; PanSTARRS, Kaiser et al. 2002; PTF, Law et al. 2009, DES, The Dark Energy Survey Collaboration 2005; LSST, Ivezic et al. 2008).”

“n lines at a redshift of z =0:2657, and hence an absolute magnitude of M = 22:5 0:08mag at the time of discovery (Methods). A search of archival images from the intermediate Palomar Transient Factory [11] revealed a rising light curve going back to at least 2015 December 02 UT, with maximum brightness on 2016 January…”

“…Sky Survey (SDSS, Alam et al. 2015), the All-Sky Automated Survey for SuperNovae (ASAS-SN; Shappee et al. 2014), the Palomar Transient Factory (PTF; Law et al. 2009; Rau et al. 2009), the intermediate PTF (iPTF), the Asteroid Terrestrialimpact Last Alert System (Tonry et al. 2018), and the Zwicky…”

“…al. 2012; Aartsen et al. 2015c), namely the Robotic Optical Transient Search Experiment (ROTSE; Akerlof et al. 2003), the Palomar Transient Factory (Law et al. 2009; Rau et al. 2009), and the Swift satellite (Gehrels et al. 2004), as well as the Subaru Hyper-Suprime-Cam with a field of view (FOV)…”

“5◦ (angular resolution), from any direction) alerts are sent to the Robotic Optical Transient Search Experiment (ROTSE) [31]1 and the Palomar Transient Factory (PTF) [32] for optical observations, and to Swift [33, 34] for X-ray follow-up, depending on the multiplet’s significance.”

“For example, surveys like Pan-STARRS (Chambers et al. 2016) and the Palomar Transient Factory (Law et al. 2009) generated a large number of transient candidates which have to be cross-matched with multiple catalogs in order to be vetted, classified and followed up.”

“Employing the wide-field imaging and rapid transient identification capabilities of the Intermediate Palomar Transient Factory (iPTF; Law et al. 2009; Rau et al. 2009), Singer et al. (2013b) discovered the optical afterglow of GRB 130702A.”

“Time domain astronomy is undergoing a revolution, with new dedicated facilities such as ASAS (Pojmanski 1997), Pan-STARRS (Kaiser et al. 2002), and the Palomar Transient Factory (Law et al. 2009) recently coming on line, and LSST Claver et al. (2004) on the near horizon.”

“We also make use of five ground-based optical spectra, taken with Gemini-N with GMOS and the William Herschel Telescope 1 Discoverers of PTF10ygu in ‘Galaxy Zoo Supernovae’: Peter Woolliams, tracey, Graham Dungworth, lpspieler, John P Langridge, Elisabeth Baeten, Tomas Raudys, adam elbourne, Robert Gagliano.”

“The Palomar Transient Factory (PTF; Law et al. 2009; Rau et al. 2009) is a wide-field untargeted sky survey which explores the transient optical sky.”

“The advent of a new generation of large field–of– view astronomical optical CCD cameras already operational (e.g. iPTF, Law et al. 2009; SkyMapper, Keller et al. 2007; Pan–STARRS, Hodapp et al. 2004; OmegaCam, Kuijken et al. 2002; DECam, Flaugher et al. 2015; Hyper Suprime–Cam, Furusawa et al.…”

“We demonstrate this on a set of variables from CRTS-S a Southern set corresponding to the main training set used here [10], and corresponding PTF data [11].”

“…et al. 2017), NMW (Sokolovsky, Korotkiy & Lebedev 2014), NSVS (Woźniak et al. 2004), Pan-STARRS (Kaiser et al. 2010, Chambers et al. 2016), PTF (Law et al. 2009), SuperWASP (Butters et al. 2010), TrES (Alonso et al. 2007), VVV (Minniti et al. 2010) with even 19 https://www.aavso.org/vsx/ c©…”

“Here, we present the intermediate Palomar Transient Factory (iPTF) follow-up effort. iPTF uses the Samuel Oschin 48-inch telescope on Palomar mountain equipped with the CFH12K camera with a field-of-view of 7.1 deg2 (Law et al. 2009).”

“Then there are multi-epoch, wide-area surveys such as the LINEAR (Sesar et al. 2011) and PTF (Law et al. 2009), which are currently finding thousands of RR Lyrae stars within 30 kpc from the Sun (Sesar 2011).”

“SDSSJ1721+2733 Porb = 38.1 min HJD(t0) = 2456078.0 −10 0 10 20 30 40 50 60 70 16 17 18 19 20 CRTSJ0450–0931 Porb = 47.3 min HJD(t0) = 2456253.9 −10 0 10 20 30 40 50 60 70 15 16 17 18 19 20 PTF1J1523+1845 HJD(t0) = 2455384.8 −10 0 10 20 30 40 50 60 70 18 19 20 21 22 23 SDSSJ1240–0159 Porb = 37.4 min HJD(t0) = 2453469.8…”

“In this paper, we present the discovery and analysis of the SN Ia, PTF10ops, which was discovered by the Palomar TransientFactory (PTF, Rau et al. 2009; Law et al. 2009).”

“PSRJ1048+2339 has a 20th magnitude optical counterpart detected by SDSS, CRTS, PTF, and Pan-STARRS, whose intensity modulation matches the pulsar orbital period.”

“…Infrared Imaging Telescope (Bloom et al. 2006), Caltech Core Collapse Program(Gal-Yam et al. 2007), Palomar Transient Factory (Rau et al. 2009; Law et al. 2009), and the efforts of the Center for Astrophysics Supernova (SN) Group, nearby CCSNe are now being more frequently monitored in both…”

“New large-scale surveys are already obtaining SN Ia data, and they are observing to higher redshifts and gathering larger amounts of data than what is in the BSNIP sample (e.g., Rau et al. 2009; Law et al. 2009; Kaiser et al. 2002).”

“With next-generation surveys such as the Palomar Transient Factory (Law et al. 2009), SNIa measurements are becoming more complete.”

“Today, a new generation of highenergy, optical, and radio sky surveys are being conducted with a focus on sensitivity to time-domain phenomena like supernovae and GRBs (Gehrels et al. 2004; Law et al. 2009; Mooley et al. 2016).”

“For example, the Palomar Transient Factory (PTF; Law et al. 2009), the PanSTARRS1 Medium Deep Survey (PS1 MDS; Chambers et al. 2016), the Catalina Real-time Transient Survey (Drake et al. 2009), the All-Sky Automated Survey for SuperNovae (ASASSN; Shappee 2014), the Dark Energy Survey (DES; The…”

“Because of the successful operation of the optical followup program with ROTSE, the program was extended in August 2010 to the Palomar transient factory (PTF) (Law et al. 2009; Rau et al. 2009), which will provide deeper images and a fast processing pipeline including a spectroscopic follow-up of interesting SN candid…”

“Current and future surveys such as the Nearby Supernova Factory (Aldering et al. 2002), Palomar Transient Factory (Law et al. 2009), SkyMapper (Keller et al. 2007) and Pan-STARRS (Kaiser 2004) will largely address this problem.”

“SN 2011fe was discovered by the Palomar Transient Factory (Rau et al. 2009; Law et al. 2009) within hours of its explosion on 23.7 Aug. 2011 (dates are UT throughout this paper) and spectroscopically classified as a normal SN Ia (Nugent et al. 2011).”

“The PTF infrastructure is described in Law et al. (2009); we focus here on the components associated with the P48, which we used to conduct our monitoring campaign.”

“However, the addition of literature data and inspection of images provided by the Palomar Transient Factory (PTF Law et al. 2009) reveals that the faint R magnitudes are probably part of the “normal” variability of the source, which seems to be characterised by irregular, short-term variability…”

“The above properties are broadly consistent with some of the rapid blue transients detected by Pan-STARRS and PTF.”

“We used the Lucky Imaging plus adaptive optics pipeline described in Law et al. (2009b) to perform the image alignment, along with frame selection at the 10% level to boost the imaging resolution.”

“The PTF (Law et al. 2009; Rau et al. 2009) was a rolling, wide-field transient survey, operating from 2009 to 2012, using the CFH12k camera (Rahmer et al. 2008) mounted on the Samuel Oschin 48-inch telescope at the Palomar Observatory (P48).”

“Deep synoptic optical surveys including the Palomar Transient Factory (PTF; Rau et al. 2009; Law et al. 2009) and Pan-STARRS (Kaiser et al. 2010) have revealed a wealth of new transient and variable phenomena across a wide range of characteristic luminosities and time scales (Kasliwal 2011).”

“We have not incorporated such a sample in our forecast, but one could argue that existing facilities (e.g. PTF Law et al. 2009; Skymapper Keller et al. 2007) could deliver it soon.”

“Interestingly, a SN IIn was recently discovered in a search with the Palomar Transient Factory (PTF) (Law et al. 2009) following an IceCube neutrino doublet trigger alert.”

“After imposing the photometric color cut, we cross-matched the resulting sample with the archival Palomar Transient Factory (PTF; Law et al. 2009) photometric database.”

“The NSC expands the search carried out by projects such as the Palomar Transient Factory (Law et al. 2009), ZTF, CSS, and PS1, and the ones that will soon be possible with the Rubin Observatory’s LSST.”