A Catalog of Emission-line Galaxies from the Faint Infrared Grism Survey: Studying Environmental Influence on Star Formation

Abstract

We present a catalog of 208 0.3 < z < 2.1 Emission Line Galaxies (ELG) selected from 1D slitless spectroscopy obtained using Hubble's WFC3 G102 grism, as part of the Faint Infrared Grism Survey (FIGS). We identify ELG candidates by searching for significant peaks in all continuum-subtracted G102 spectra, and, where possible, confirm candidates by identifying consistent emission lines in other available spectra or with published spectroscopic redshifts. We provide derived emission line fluxes and errors, redshifts, and equivalent widths (EW) for Hα λ6563, [Oiii]λλ4959, 5007, and [Oii]λλ3727 emission lines, for emission line galaxies down to AB(F105W) > 28 and > 10 −17 erg cm −2 s −1 line flux. We use the resulting line catalog to investigate a possible relationship between line emission and a galaxy's environment. We use 7thnearest-neighbor distances to investigate the typical surroundings of ELGs compared to non-ELGs, and we find that [Oiii] emitters are preferentially found at intermediate galaxy densities near galaxy groups. We characterize these ELGs in terms of the galaxy specific star formation rate (SSFR) versus stellar mass, and find no significant influence 2 Pharo et al.of environment on that relation. We calculate star formation rates (SFR), and find no dependence of SFR on local galaxy surface density for 0.3 < z < 0.8 Hα emitters and for 0.8 < z < 1.3 [Oiii] emitters. We find similar rates of close-pair interaction between ELGs and non-ELGs. For galaxy surface densities Σ ≤ 30 Mpc −2 , we find no consistent effect of environment on star formation.

The VLA-COSMOS 3 GHz Large Project: Evolution of Specific Star Formation Rates out to z ∼ 5

“…Results tend to agree that higher density environments increase the fraction of quiescent (red) galaxies and we do see this in the COSMOS field (see top right panel of Figure 28; Peng et al 2010;McGee et al 2011;Scoville et al 2013;Darvish et al 2014Darvish et al , 2016. Whether or not the normalization of the MS (defined for starforming galaxies) depends on galaxy environment is still under debate, but many studies identify no variations of MS with environments such as clusters and voids, e.g., Tyler et al (2013), Koyama et al (2014), Ricciardelli et al (2014), Tyler et al (2014), Grossi et al (2018), Paulino-Afonso et al (2019), Pharo et al (2020 (although see Duivenvoorden et al 2016 who found a difference at 1.5 < z < 2 in COSMOS). However, at low redshift (z < 0.3), studies have reported a clear dependence of the MS on galaxy environment (e.g., von der Linden et al 2010, Haines et al 2013, Gu et al 2018, Paccagnella et al 2016).…”

The VLA-COSMOS 3 GHz Large Project: Evolution of specific star formation rates out to $z\sim5$

“…Results tend to agree that higher density environments increase the fraction of quiescent (red) galaxies and we do see this in the COSMOS field (see top right panel of Figure 28; Peng et al 2010;McGee et al 2011;Scoville et al 2013;Darvish et al 2014Darvish et al , 2016. Whether or not the normalization of the MS (defined for starforming galaxies) depends on galaxy environment is still under debate, but many studies identify no variations of MS with environments such as clusters and voids, e.g., Tyler et al (2013), Koyama et al (2014), Ricciardelli et al (2014), Tyler et al (2014), Grossi et al (2018), Paulino-Afonso et al ( 2019), Pharo et al (2020) (although see Duivenvoorden et al 2016 who found a difference at 1.5 < z < 2 in COSMOS). However, at low redshift (z < 0.3), studies have reported a clear dependence of the MS on galaxy environment (e.g., von der Linden et al 2010, Haines et al 2013, Gu et al 2018, Paccagnella et al 2016).…”

The Dwarf Galaxy Population at z ∼ 0.7: A Catalog of Emission Lines and Redshifts from Deep Keck Observations

“…The standard deviation of continuum-subtracted fluxes in this surrounding region is combined with the intrinsic flux error of the pixel (largely influenced by the skyline model) to get a flux error estimate, resulting in a continuum-subtracted residual spectrum and an error spectrum. This method of continuum-subtracted peak detection has demonstrated success in detecting emission lines from faint and low-mass sources in other deep surveys (e.g., Yang et al 2017;Pharo et al 2019Pharo et al , 2020. See Figure 2 for some example spectra showing the continuum subtraction.…”

“…For example, Guo et al (2016b) measured star formation burstiness with Keck/DEIMOS spectroscopy at 0.5 < z < 1 for 164 galaxies with ( )  < <  M M 8.5 log 10.5, but only 17 galaxies in the sample had ( )  <  M M log 9. Grism spectroscopy can be a means to achieve the necessary depth; Pharo et al (2020) measured emission lines for ∼50 low-mass galaxies at 0.3 < z < 2 with Hubble Space Telescope (HST) WFC3-G102 near-IR grism spectroscopy with a 40-orbit depth (FIGS;…”