Strategies for obtaining robust SED fitting parameters for galaxies at z~1 and z~2 in the absence of IR data

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Main Authors: Osborne, Chandler, Salim, Samir
Format: Preprint
Published: 2024
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author Osborne, Chandler
Salim, Samir
author_facet Osborne, Chandler
Salim, Samir
contents Robust estimation of star formation rates (SFRs) at higher redshifts (z>1) using UV-optical-NIR photometry is contingent on the ability of spectral energy distribution (SED) fitting to simultaneously constrain the dust attenuation, stellar metallicity, and star formation history (SFH). IR-derived dust luminosities can help break the degeneracy between these parameters, but IR data is often not available. Here, we explore strategies for SED fitting at z>1 in the absence of IR data using a sample of log M*>10.2 star-forming galaxies from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) for which 24mu data are available. We adopt the total IR luminosity (L_TIR) obtained from 24mu as the 'ground truth' that allows us to assess how well it can be recovered (as L_dust) from UV-optical-NIR SED fitting. We test a variety of dust attenuation models, stellar population synthesis models, metallicity assumptions, and SFHs separately to identify which assumptions maximize the agreement (correlation and linearity) between L_TIR and L_dust. We find that a flexible dust attenuation law performs best. For stellar populations, we find that BC03 models are favored over those of BPASS. Fixing the stellar metallicity at solar value is preferred to other fixed values or leaving it as a free parameter. For SFHs, we find that minimizing the variability in the recent (<100 Myr) SFH improves the agreement with L_TIR. Finally, we provide a catalog of galaxy parameters (including M* and SFR) for CANDELS galaxies with log M*>8 and 0.7<z<1.3 obtained using the models we found to be the most robust.
format Preprint
id arxiv_https___arxiv_org_abs_2401_06865
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Strategies for obtaining robust SED fitting parameters for galaxies at z~1 and z~2 in the absence of IR data
Osborne, Chandler
Salim, Samir
Astrophysics of Galaxies
Robust estimation of star formation rates (SFRs) at higher redshifts (z>1) using UV-optical-NIR photometry is contingent on the ability of spectral energy distribution (SED) fitting to simultaneously constrain the dust attenuation, stellar metallicity, and star formation history (SFH). IR-derived dust luminosities can help break the degeneracy between these parameters, but IR data is often not available. Here, we explore strategies for SED fitting at z>1 in the absence of IR data using a sample of log M*>10.2 star-forming galaxies from the Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) for which 24mu data are available. We adopt the total IR luminosity (L_TIR) obtained from 24mu as the 'ground truth' that allows us to assess how well it can be recovered (as L_dust) from UV-optical-NIR SED fitting. We test a variety of dust attenuation models, stellar population synthesis models, metallicity assumptions, and SFHs separately to identify which assumptions maximize the agreement (correlation and linearity) between L_TIR and L_dust. We find that a flexible dust attenuation law performs best. For stellar populations, we find that BC03 models are favored over those of BPASS. Fixing the stellar metallicity at solar value is preferred to other fixed values or leaving it as a free parameter. For SFHs, we find that minimizing the variability in the recent (<100 Myr) SFH improves the agreement with L_TIR. Finally, we provide a catalog of galaxy parameters (including M* and SFR) for CANDELS galaxies with log M*>8 and 0.7<z<1.3 obtained using the models we found to be the most robust.
title Strategies for obtaining robust SED fitting parameters for galaxies at z~1 and z~2 in the absence of IR data
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2401.06865