Synthetic properties of starburst galaxies

“Leitherer & Heckman (1995) have published an extensive grid of models that is optimized for applications to starburst galaxies.”

“An estimate of the ionizing energy is obtained from the reddening-corrected Hα flux, using the formula of Leitherer & Heckman (1995).”

“The prescription for the switch between extended and plane-parallel atmospheres is the same as in Leitherer & Heckman (1995).”

“Leitherer and Heckman (1995) varied other parameters in their population models including metallicity, IMF slope and cutoff, and other star formation histories (i.e. instantaneous bursts).”

“…the Rayleigh-Jeans part of the massive stars spectrum, the intrinsic UV spectral slope8 β26,o is relatively constant over a fairly large range of ages, with values −2.7& β26,o & −2.2 for constant star formation over 106 yr.age.109 yr (see Leitherer & Heckman 1995, and the Table in Appendix B).”

“Dopita et al. (2005) present another modeling technique which reproduces SEDs from the ultraviolet through the farinfrared, and out through the radio by combining stellar synthesis output from STARBURST99 (Leitherer and Heckman, 1995), nebular line emission modeling, a dynamic evolution model of Hii regions and a simp…”

“…at 1 ryd from massive stars may push the hydrogen reionization epoch to higher redshifts, the ratio between the number of He II and H I Lyman continuum photons emitted from star-forming galaxies is only about two percent (Leitherer & Heckman 1995), five times smaller than in typical QSO spectra.”

“However, a comparison between the Leitherer & Heckman (1995) models and the BC96 models results in almost identical tracks up to approximately log t \ 6.9.”

“(7) In this expression, we have used the momentum Ñux supplied by stellar winds and supernovae (Leitherer & Heckman 1995) in a starburst having a bolometric luminosity equal to the median value for the outÑow sample (2] 1011 and have adopted the estimates in ° 3 aboveL _ ) for N and Starbursts with…”

“For example, Meurer et al. (1999) obtained a relationship between FIR/FUV and the attenuation at FUV (AFUV) using the stellar population synthesis models of Leitherer & Heckman (1995) and then they derived an AFUV–β relation using this FIR/FUV–based AFUV for starburst galaxies.”

“Leitherer & Heckman (1995) have computed the power injected into the ISM by stellar winds and supernovae for stellar populations with various IMFs and star formation histories.”

“The ranking of EW(Hβ) with age (Copetti, Pastoriza & Dottori, 1986; Leitherer & Heckman 1995) goes in the sense that EW(Hβ) in emission reaches values of several hundred Å for an H ii region photoionized by a zero-age coeval stellar population and decreases as the cluster evolves and the stellar…”

“…Tinsley 1978; Bruzual 1983; Arimoto & Yoshii 1987; Guiderdoni & Rocca-Volmerange 1987; Buzzoni 1989; Bressan, Chiosi & Fagotto 1994; Worthey 1994; Leitherer & Heckman 1995; Fioc & RoccaVolmerange 1997; Bruzual & Charlot 2003; Maraston 2005; Conroy & Gunn 2010; Vazdekis et al. 2010; Maraston &…”

“Only O and B stars, and the most massive A stars (spectral type A1, A0) contribute significantly at these blue wavelengths (e.g., Leitherer & Heckman 1995; Calzetti et al. 1994).”

“The code is an improved version of that previously published by Leitherer & Heckman (1995).”

“…(1998) scaling relation between LIR(8−1000) and SFR take both the contribution of “infrared circus” cold-dust emission and “warm” dust around young star forming regions into account and is generated using stellar synthesis models (Leitherer & Heckman 1995) for continuous bursts aged 10-100 Myr.”

“…parameters depending on evolutionary stage and environment) are crucial for the chemical and dynamical evolution of galaxies through their input of energy, momentum, and nuclear processed material into the interstellar medium (e.g., Leitherer & Heckman 1995; Silich & Tenorio-Tagle 2001; Oey 2003).”

“For a stellar initial mass function (IMF) with power law index α = −2.35 from 1.0 M⊙ to 100 M⊙, the Hα luminosity implies a SFR of 0.16 M⊙ yr −1(Leitherer & Heckman 1995; Kennicutt 1998).”

“…New York, NY 10003 4 European Southern Observatory, Alonso de Cordova 3107, Vitacura, Santiago, Chile models demonstrate how the characteristics of the galaxy evolve with the age of the dominant star-forming episode (e.g., Rieke et al. (1993); Leitherer & Heckman (1995); Engelbracht et al. (1998)).”

“Indeed (repeating the arguments we presented in Greene et al. 2012), for every solar mass of stars formed the stellar winds and supernovae can yield at most 7 × 1041 erg s−1 worth of kinetic energy of the outflow (Leitherer & Heckman 1995; Veilleux et al. 2005).”

“…and supernovae depend on the rate of star formation and the Initial Mass Function of the stars, which may have a lower upper mass cutoff in starbursts compared with normal galaxies (Leitherer and Heckman, 1995), or may be dominated by massive stars if the metallicity is low (Bromm and Loeb, 2003).”

“The relation between LFIR and SFR deduced by Leitherer & Heckman (1995) is9 SFR=0.045(LFIR/10 42) M⊙ yr−1 (see also Kennicutt 1998).”

“Model spectral energy distributions (e.g. Leitherer & Heckman 1995) show that β changes relatively little with age and metallicity; for a Salpeter IMF from M = 100 to 0.1 M⊙ the Bruzual & Charlot (1996) continuous star formation models have β increasing from ∼ −2.5 to ∼ −2 over the period 107 to…”

“Nebular Continuum Evolutionary synthesis modeling suggests that nebular continuum emission can impact broadband photometry (Leitherer & Heckman 1995; Mollá et al. 2009; Raiter et al. 2010).”

“For stars with strong winds, we switch to the Schmutz et al. (1992) extended model atmospheres using the prescription of Leitherer & Heckman (1995).”

“The DCO star formation rates imply momentum fluxes of this order (Leitherer & Heckman 1995), while the HST images yield typical DCO radii of 100 pc (O9).”

“…Properties and Evolution of Star Formation in ULIRGs In the framework of starburst models with a Salpeter IMF and upper mass cutoffs of 50 to 100 M (Krabbe et al 1994, Leitherer & Heckman 1995), the ULIRG data are fit with burst ages/durations of t∼ 1t ∼ 5 to 100× 106 years (Genzel et al 1998).”

“…formation rate is proportional to LIR according to (Kennicutt 1998) SFR ¼ LIR 5:8 109 L : ð13Þ This equation is based on the stellar synthesis models of Leitherer & Heckman (1995) and assumes the following: a continuous burst of star formation of length 10–100 Myr (the mean bolometric luminosity…”

“The energy injection rate over this period is approximately constant (see, e.g., Leitherer & Heckman 1995).”

“…et al. 1998; Madau et al. 1999) states that only the hard spectra of AGNs could produce enough photons with eV to reionize He ii, based in part onhn ≥ 54.4 the result for low-metallicity stellar spectra toQ /Q ≤ 0.022 0 which Wolf-Rayet stars contribute only minimally (Leitherer & Heckman 1995).”

“Adopting the models of Leitherer & Heckman (1995) for continuous bursts of age 10–100 Myr and using the same IMF as in the H calculation yields SFR(M yr 1) ¼ 4:5 ; 10 37L(FIR) W (Kennicutt 1998).”

“…these same massive stars are extraordinarily efficient at ionizing the gas around them – resulting in substantial nebular emission and leaving the galaxy with a net β no bluer (and likely redder) than the young ( 1 Myr) bursts shown in Figures 3-4 (see also discussion in Leitherer & Heckman 1995).”

“…1993b; Charbonnel et al. 1993; Meynet et al. 1994), and is similar to other models developed by various investigators (e.g. Tinsley 1972; Huchra 1977; Bruzual 1983; Guiderdoni & Rocca-Volmerange 1987; Mas-Hesse & Kunth 1991; Bruzual & Charlot 1993; Leitherer & Heckman 1995; Leitherer et al. 1999).”

“It also relies on the synthetic model grid of Leitherer & Heckman (1995), which has been superseded by the newer models incorporated in the Calzetti et al. (2007) calibration.”

“For a pure instantaneous starburst, the V−K index might change in the first 100 Myr by 1 to 3 mag, depending on the metallicity (Leitherer & Heckman 1995).”

“…limb-brightened Ha and X-ray emission, is EI w ZV (1 [ gX vray [ gHa)cm~3, where is(tPHa/2kmHvw2 )2D (1È13) ] 1057t2v3~4 v3the wind velocity in units of 3000 km s~1 for stan-(v3D 1dard mass and energy injection rates ; e.g., see Leitherer & Heckman 1995) and assuming t\ 1 to yield a lower limit.”

“…our stellar atmosphere grid, in combination with evolutionary models, to carry out " population synthesis " computations (Bruzual & Charlot 1993; Leitherer & Heckman 1995; Sternberg 1998; Leitherer et al. 1999) of the time-dependent spectral energy distributions (SEDs), and time-dependent Lyc…”

“…Haarsma et al. 2000), IR (eg., Hunter et al. 1986; Lehnert & Heckman 1996; Meurer et al. 1997; Kennicutt 1998), optical (eg., Gallagher et al. 1989; Leitherer & Heckman 1995; Kennicutt 1998; Madau, Pozzetti, & Dickinson 1998; Rosa-Gonzàlez, Terlevich, & Terlevich 2002), or UV (eg., Buat,…”

“Based on the simulations of Leitherer & Heckman (1995) and assuming an escape fraction of zero for Lymancontinuum photons into the intergalactic medium, the Hα luminosity L(Hα) can be expressed in terms of the production rate of Lyman-continuum photons N(H0), as L(Hα)[ergs s −1 ] = 1.36×…”

“In the absence of dust, the ultraviolet luminosity of a galaxy is proportional to the mean SFR on a timescale t ∼ 108 yr (Donas & Deharveng 1984; Leitherer & Heckman 1995).”

“Also see Leitherer & Heckman 1995 and Mollá et al. 2009.)”

“This is comparable to the relation derived from the models of Leitherer & Heckman (1995) and Kennicutt (1998).”

“…a lower limit (due to the uncertain inclination); the molecular mass estimate is clearly uncertain given the extreme excitation conditions; and lastly, the derived young stellar mass depends sensitively on the starburst IMF and the duration of the starbursts (cf. SYB and Leitherer & Heckman 1995).”

“The total bolometric luminosity and ionizing luminosity of M82 (McLeod et al. 1993 and references therein) can be used together with the starburst models of Leitherer & Heckman (1995) to predict the rate at which the starburst injects mechanical energy and momentum.”

“These provide evolution of the stellar tracks for various scenarios, while also helping to investigate possible effects related to extinction or to abundances (Worthey 1994; Leitherer and Heckman 1995; Charlot 1996a; Charlot et al, 1996).”

“The average age of the young stellar component is 40 Myr: a steady state in the production of the UV continuum is not reached (Leitherer & Heckman, 1995).”

“…emission line diagrams have been improved and refined in their interpretation by many theorists using photoionisation codes (e.g., Stasińska 1990; Leitherer & Heckman 1995; Leitherer et al. 1999; Kewley et al. 2001, 2006; Groves et al. 2004a,b) and by observational work (e.g., Veilleux &…”

“We want to derive the UV β slope as accurately as possible because this quantity is known to be related to the dust attenuation, while also dependent on the age of the stellar population and the star formation history (Leitherer & Heckman 1995; Meurer et al. 1999).”

“The starburst model of Leitherer & Heckman (1995) yields L bol D L FIR D 1.5 ] 1010(SFR/1 M_ yr~1) L _ ;as a cross-check, the empirical relation for radio emission (Condon 1992) is L R \ 1.4] 1028(l/GHz)~a(SFR/M _yr~1) ergs s~1 Hz~1, where a D 0.8.”

“Nebular continuum emission is significantly redder than the star light from a very young, low-metallicity stellar population (e.g. Leitherer & Heckman 1995), and so, given other information (e.g. Labbé et al. 2013; Stark et al. 2013) or assumptions, β can in principle be used to estimate (or…”

“Leitherer & Heckman (1995) showed that for both instantaneous bursts and constant star formation synthetic stellar populations, changes of the order of ∆β = ±0.2 around a typical value of β ∼ −2.3 are introduced by variations in age (1 Myr to 1 Gyr) and metallicity (0.1 Z⊙ to 2 Z⊙).”

“If the star formation rate is approximately constant, O star births and deaths will reach equilibrium in D107 yr, after which time the number of O stars will remain constant (Leitherer & Heckman 1995).”

“A high estimate for the SNR for this SFR is 10−12 SN pc−2 yr−1 (e.g. Leitherer & Heckman 1995).”

“For an instantaneous burst, the ratio EW+(Hβ) EW+(Hα) varies between 0.14 and 0.26 (Mayya (1995), Leitherer & Heckman (1995)).”

“…were enough to model the few datapoints acquired (e.g., models based on the evolutionary population synthesis technique: Spinrad & Taylor 1969, Bruzual A. 1983, Guiderdoni & Rocca-Volmerange 1987, Worthey 1994, Bruzual A. & Charlot 1993, Leitherer & Heckman 1995, Maraston 1998, Vazdekis 1999).”

“We use the calculation of the mechanical energy injection rate from a constant rate of star formation by Leitherer & Heckman (1995) and Veilleux et al. (2005).”

“…some caution has been suggested when using this method on stellar populations dominated by young to intermediate aged stars, as red supergiants can become a significant source of enhanced K-band luminosity, and thereby lead to an overestimate of the stellar mass, e.g. Leitherer & Heckman (1995).”

“This is comparable to the relation derived from the models of Leitherer & Heckman (1995).”

“For a relatively young galaxy forming stars at a stable rate, the SFR is proportional to the UV luminosity (Leitherer & Heckman 1995), while the degree of redden- overzier@mpa-garching.mpg.de 1 Max-Planck-Institut for Astrophysics, D-85748 Garching,Germany.”

“A high estimate for the SNR for this SFR is 10−12 SN pc−2 yr−1 (e.g. Leitherer & Heckman 1995).”