Marques-Chaves_2018_ApJ_854_151.pdf (4.1 MB)
The strong gravitationally lensed Herschel galaxy HLock01: optical spectroscopy reveals a close galaxy merger with evidence of inflowing gas
Version 2 2023-06-12, 08:49
Version 1 2023-06-09, 11:49
journal contribution
posted on 2023-06-12, 08:49 authored by Rui Marques-Chaves, Ismael Perez-Fournon, Raphael Gavazzi, Paloma Martinez-Navajas, Dominik Riechers, Dimitra Rigopoulou, Seb OliverSeb Oliver, Alain Omont, Douglass Scott, Yiping Shu, Julie WardlowThe submillimeter galaxy (SMG) HERMES J105751.1+573027 (hereafter HLock01) at z = 2.9574±0.0001 is one of the brightest gravitationally lensed sources discovered in the Herschel Multi-tiered Extragalactic Survey. Apart from the high flux densities in the far-infrared, it is also extremely bright in the rest-frame ultraviolet (UV), with a total apparent magnitude mUV ˜19.7 mag. We report here deep spectroscopic observations with the Gran Telescopio Canarias of the optically bright lensed images of HLock01. Our results suggest that HLock01 is a merger system composed of the Herschel-selected SMG and an optically bright Lyman break-like galaxy (LBG), separated by only 3.3 kpc in projection. While the SMG appears very massive (M* ˜ 5×10^11 M?), with a highly extinguished stellar component (AV ' 4.3), the LBG is a young, lower-mass (M* ˜ 1×10^10 M?), but still luminous (10×L * UV) satellite galaxy. Detailed analysis of the high signal-to-noise (S/N) rest-frame UV spectrum of the LBG shows complex kinematics of the gas, exhibiting both blueshifted and redshifted absorption components. While the blueshifted component is associated with strong galactic outflows from the massive stars in the LBG, as is common in most star-forming galaxies, the redshifted component may be associated with gas inflow seen along a favorable sightline to the LBG. We also find evidence of an extended gas reservoir around HLock01 at an impact parameter of 110 kpc, through the detection of C II ??1334 absorption in the red wing of a bright Lya emitter at z˜ 3.327. The data presented here highlight the power of gravitational lensing in high S/N studies to probe deeply into the physics of high-z star forming galaxies.
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Publication status
- Published
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- Published version
Journal
Astrophysical JournalISSN
0004-637XPublisher
IOP PublishingExternal DOI
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151Volume
854Page range
1-20Department affiliated with
- Physics and Astronomy Publications
Research groups affiliated with
- Astronomy Centre Publications
Full text available
- Yes
Peer reviewed?
- Yes
Legacy Posted Date
2018-01-29First Open Access (FOA) Date
2018-01-29First Compliant Deposit (FCD) Date
2018-01-29Usage metrics
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