An empirical calibration of star formation rate estimators

By D. Rosa-González, E. Terlevich, R. T. Inaoe, Puebla, M. IoA, Cambridge, UK.. 2001

144 citations recorded by the source corpus.

ABSTRA C T The observational determination of the behaviour of the star formation rate (SFR) with lookback time or redshift has two main weaknesses: (i) the large uncertainty of the dust/extinction corrections, and (ii) that systematic errors may be introduced by the fact that the SFR is estimated using different methods at different redshifts. Most frequently, the luminosity of the Ha emission line, that of the forbidden line [O II] l3727 and that of the far-ultraviolet continuum are used with low-, intermediate- and high-redshift galaxies, respectively. To assess the possible systematic differences among the different SFR estimators and the role of dust, we have compared SFR estimates using Ha ,[ OII] l3727 A ˚ , ultraviolet (UV) and far-infrared (FIR) luminosities [SFR(Ha), SFR(O II), SFR(UV) and SFR(FIR), respectively] of a sample comprising the 31 nearby star-forming galaxies that have high-quality photometric data in the UV, optical and FIR. We review the different ‘standard’ methods for the estimation of the SFR and find that while the standard method provides good agreement between SFR(Ha) and SFR(FIR), both SFR(O II) and SFR(UV) are systematically higher than SFR(FIR), irrespective of the extinction law. We show that the excess in the SFR(O II) and SFR(UV) is mainly due to an overestimation of the extinction resulting from the effect of underlying stellar Balmer absorptions in the measured emission line fluxes. Taking this effect into consideration in the determination of the extinction brings the SFR(O II) and SFR(UV) in line with the SFR(FIR), and simultaneously reduces the internal scatter of the SFR estimations. Based on these results, we have derived ‘unbiased’ SFR expressions for the SFR(UV), SFR(O II) and SFR(Ha). We have used these estimators to recompute the SFR history of the Universe using the results of published surveys. The main results are that the use of the unbiased SFR estimators brings into agreement the results of all surveys. Particularly important is the agreement achieved for the SFR derived from the FIR/millimetre and optical/UV surveys. The ‘unbiased’ star formation history of the Universe shows a steep rise in the SFR from za 0t oza 1 with SFR/O1a zU 4:5 , followed by a decline for z . 2 where SFR/O1a zU 21:5 . Galaxy formation models tend to have a much flatter slope from za 0t o za 1.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/9836decf6a1fb381c33f471ee926ad34e0d4114b

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Citations in the corpus

UV Star Formation Rates in the Local Universe (2007, background): “Rosa-González et al. (2002) showed that even the relatively reliable determination of Hα attenuation can be affected by the systematics when not correcting for the underlying stellar absorption in Balmer emission lines.”
Galaxies as simple dynamical systems: observational data disfavor dark matter and stochastic star formation (2014, background): “The SFR is obtained from observations but depends on assuming whether the galaxy-wide IMF is an invariant stochastically sampled probability density distribution function, or whether it is a computable systematically varying IGIMF (Sec.”
Star Formation Rate Indicators in the Sloan Digital Sky Survey (2003, background): “Stellar absorption in the Balmer emission lines, if not accounted for, can cause a significant overestimation in the implied obscuration from measurements of the Balmer decrement (Rosa-González et al. 2002).”
Optical Star Formation Rate Indicators (2005, unknown): “Therefore, unlike the Balmer recombination lines, [O ii] is not directly proportional to the SFR and must be calibrated either empirically (Kennicutt1992b;Rosa-González et al. 2002;Kewley et al. 2004) or theoretically (Barbaro& Poggianti 1997; Charlot & Longhetti 2001).”
On the Origin of [O II] Emission in Red-Sequence and Poststarburst Galaxies (2005, methodology): “…[O ii] k3727 luminosity is commonly used (Dressler & Gunn 1983; Zabludoff et al. 1996; Hammer et al. 1997; Hogg et al. 1998; Dressler et al. 1999; Poggianti et al. 1999; Balogh et al. 1999; Rosa-González et al. 2002; Tran et al. 2003; Hippelein et al. 2003; Yang et al. 2004; Tran et al. 2004).”
Characterization of Scuba-2 450 μm and 850 μm selected galaxies in the COSMOS field (2013, background): “These Scuba-2 sources are known to be unusual in that the are directly detected in the infrared, so the discrepancy between star formation rate measurements is not unexpected or new (Rosa-González et al. 2002; Dye et al. 2008; Yun et al. 2012).”
The Hα Galaxy Survey ⋆ I. The galaxy sample, Hα narrow-band observations and star formation parameters for 334 galaxies (2003, background): “…for [N] line contamination and extinction internal to the galaxies under study, since these dominate the uncertainties in the derived star formation rates (see also the detailed examination of this question by Charlot et al. 2002, and work by Buat et al. 2002 and Rosa-González et al. 2002).”