Title:	Probing Star Formation in Galaxies at z ≈ 1 via a Giant Metrewave Radio Telescope Stacking Analysis
Authors:	Apurba, Bera Nissim, Kanekar Benjamin, Weiner J Sethi, S.K. Dwarakanath, K.S.
Keywords:	galaxies: high-redshift galaxies: star formation radio continuum galaxies
Issue Date:	20-Sep-2018
Publisher:	IOP Sciences for The American Astronomical Society
Citation:	Astrophysical Journal, 2018, Vol. 865, p39
Abstract:	We report deep Giant Metrewave Radio Telescope (GMRT) 610 MHz continuum imaging of four subfields of the DEEP2 Galaxy Redshift Survey. We stacked the radio emission in the GMRT images from a near-complete (absolute blue magnitude M B ≤ −21) sample of 3698 blue star-forming galaxies with redshifts 0.7 lesssim z lesssim 1.45 to detect (at ≈17σ significance) the median rest-frame 1.4 GHz radio continuum emission of the sample galaxies. The stacked emission is unresolved, with a rest-frame 1.4 GHz luminosity of L 1.4GHz = (4.13 ± 0.24) × 1022 W Hz−1. We used the local relation between total star formation rate (SFR) and 1.4 GHz luminosity to infer a median total SFR of (24.4 ± 1.4) M ⊙ yr−1 for blue star-forming galaxies with M B ≤ −21 at 0.7 lesssim z lesssim 1.45. We detect the main-sequence relation between SFR and stellar mass, M sstarf, obtaining SFR = (13.4 ± 1.8) × [(M sstarf/1010 M ⊙)]0.73±0.09 M ⊙ yr−1; the power-law index shows no change over z ≈ 0.7–1.45. We find that the nebular line emission suffers less extinction than the stellar continuum, contrary to the situation in the local universe; the ratio of nebular extinction to stellar extinction increases with decreasing redshift. We obtain an upper limit of 0.87 Gyr to the atomic gas depletion time of a subsample of DEEP2 galaxies at z ≈ 1.3; neutral atomic gas thus appears to be a transient phase in high-z star-forming galaxies
Description:	Open Access
URI:	http://hdl.handle.net/2289/7011
ISSN:	0004-637X 1538-4357-(Online)
Alternative Location:	https://doi.org/10.3847/1538-4357/aad698
Copyright:	2018. The American Astronomical Society
Appears in Collections:	Research Papers (A&A)

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