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Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Extinction and Nebular Line Properties of a Herschel-selected Lensed Dusty Starburst at z = 1.027
AU - Timmons, Nicholas
AU - Cooray, Asantha
AU - Nayyeri, Hooshang
AU - Casey, Caitlin
AU - Calanog, Jae
AU - Ma, Brian
AU - Messias, Hugo
AU - Baes, Maarten
AU - Bussmann, R. Shane
AU - Dunne, Loretta
AU - Dye, Simon
AU - Eales, Steve
AU - Fu, Hai
AU - Ivison, R. J.
AU - Maddox, Steve
AU - Michałowski, Michał J.
AU - Oteo, I.
AU - Riechers, Dominik A.
AU - Valiante, Elisabetta
AU - Wardlow, Julie
PY - 2015/6/1
Y1 - 2015/6/1
N2 - We present Hubble Space Telescope Wide Field Camera 3 (WFC3) imaging and grism spectroscopy observations of the Herschel-selected gravitationally lensed starburst galaxy HATLASJ1429-0028. The lensing system consists of an edge-on foreground disk galaxy at z = 0.218 with a nearly complete Einstein ring of the infrared luminous galaxy at z = 1.027. The WFC3 spectroscopy with G102 and G141 grisms, covering the wavelength range of 0.8-1.7 μm, resulted in detections of Hα + [Nii], Hβ, [Sii], and [Oiii] for the background galaxy from which we measure line fluxes and ratios. The Balmer line ratio Hα/Hβ of 7.5 ± 4.4, when corrected for [Nii], results in an extinction for the starburst galaxy of E(B-V)=0.8+/- 0.5. The Hα-based star formation rate (SFR), when corrected for extinction, is 60 ± 50 {{M}⊙ } yr-1, lower than the instantaneous SFR of 390 ± 90 {{M}⊙ } yr-1 from the total IR luminosity. We also compare the nebular line ratios of HATLASJ1429-0028 with other star-forming and sub-millimeter bright galaxies. The nebular line ratios are consistent with an intrinsic ultra-luminous infrared galaxy with no evidence for excitation by an active galactic nucleus (AGN). We estimate the metallicity, 12 + log(O/H), of HATLASJ1429-0028 to be 8.49 ± 0.16. Such a low value is below the average relation for stellar mass versus metallicity of galaxies at z˜ 1 for a galaxy with a stellar mass of ˜ 2× {{10}11} {{M}⊙ }. The combination of high stellar mass, the lack of AGN indicators, low metallicity, and the high SFR of HATLASJ1429-0028 suggest that this galaxy is currently undergoing a rapid formation.
AB - We present Hubble Space Telescope Wide Field Camera 3 (WFC3) imaging and grism spectroscopy observations of the Herschel-selected gravitationally lensed starburst galaxy HATLASJ1429-0028. The lensing system consists of an edge-on foreground disk galaxy at z = 0.218 with a nearly complete Einstein ring of the infrared luminous galaxy at z = 1.027. The WFC3 spectroscopy with G102 and G141 grisms, covering the wavelength range of 0.8-1.7 μm, resulted in detections of Hα + [Nii], Hβ, [Sii], and [Oiii] for the background galaxy from which we measure line fluxes and ratios. The Balmer line ratio Hα/Hβ of 7.5 ± 4.4, when corrected for [Nii], results in an extinction for the starburst galaxy of E(B-V)=0.8+/- 0.5. The Hα-based star formation rate (SFR), when corrected for extinction, is 60 ± 50 {{M}⊙ } yr-1, lower than the instantaneous SFR of 390 ± 90 {{M}⊙ } yr-1 from the total IR luminosity. We also compare the nebular line ratios of HATLASJ1429-0028 with other star-forming and sub-millimeter bright galaxies. The nebular line ratios are consistent with an intrinsic ultra-luminous infrared galaxy with no evidence for excitation by an active galactic nucleus (AGN). We estimate the metallicity, 12 + log(O/H), of HATLASJ1429-0028 to be 8.49 ± 0.16. Such a low value is below the average relation for stellar mass versus metallicity of galaxies at z˜ 1 for a galaxy with a stellar mass of ˜ 2× {{10}11} {{M}⊙ }. The combination of high stellar mass, the lack of AGN indicators, low metallicity, and the high SFR of HATLASJ1429-0028 suggest that this galaxy is currently undergoing a rapid formation.
KW - cosmology: observations
KW - galaxies: evolution
KW - infrared: galaxies
KW - submillimeter: galaxies
U2 - 10.1088/0004-637X/805/2/140
DO - 10.1088/0004-637X/805/2/140
M3 - Journal article
VL - 805
SP - 140
JO - The Astrophysical Journal
JF - The Astrophysical Journal
SN - 0004-637X
IS - 2
ER -