TY - JOUR
T1 - Revealing the Nature of a Ly α Halo in a Strongly Lensed Interacting System at z = 2.92
AU - Solimano, Manuel
AU - González-López, Jorge
AU - Aravena, Manuel
AU - Johnston, Evelyn J.
AU - Moya-Sierralta, Cristóbal
AU - Barrientos, Luis F.
AU - Bayliss, Matthew B.
AU - Gladders, Michael
AU - Infante, Leopoldo
AU - Ledoux, Cédric
AU - López, Sebastián
AU - Poudel, Suraj
AU - Rigby, Jane R.
AU - Sharon, Keren
AU - Tejos, Nicolás
N1 - Funding Information:
We thank the anonymous referee for helpful suggestions that have contributed to improving the quality of this manuscript. We also warmly thank Lucia Guaita for her insightful comments and discussion. This work was partly funded by Becas-ANID scholarship #21221511. N.T. and S.L. acknowledge support from FONDECYT grant 1191232. M.A. acknowledges support from FONDECYT grant 1211951, CONICYT + PCI + INSTITUTO MAX PLANCK DE ASTRONOMIA MPG190030, CONICYT+PCI+REDES 190194, and ANID BASAL project FB210003. E.J.J. acknowledges support from FONDECYT Iniciación en Investigación 2020 Project 11200263. This paper is based on observations made with the ESO Telescopes at the La Silla Paranal Observatory under program ID 101.A-0364. This research is also based on observations made with the NASA/ESA HST obtained from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with programs GO-12368 and GO-15378. Support for analysis of the data from HST Program GO-15378 was provided through a grant from the STScI under NASA contract NAS5-26555.
Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.
PY - 2022/8/1
Y1 - 2022/8/1
N2 - Spatially extended halos of H i Lyα emission are now ubiquitously found around high-redshift star-forming galaxies. But our understanding of the nature and powering mechanisms of these halos is still hampered by the complex radiative transfer effects of the Lyα line and limited angular resolution. In this paper, we present resolved Multi Unit Spectroscopic Explorer (MUSE) observations of SGAS J122651.3+215220, a strongly lensed pair of L∗ galaxies at z = 2.92 embedded in a Lyα halo of L Lyα = (6.2 ± 1.3) × 1042 erg s-1. Globally, the system shows a line profile that is markedly asymmetric and redshifted, but its width and peak shift vary significantly across the halo. By fitting the spatially binned Lyα spectra with a collection of radiative transfer galactic wind models, we infer a mean outflow expansion velocity of ≈211 km s-1, with higher values preferentially found on both sides of the system's major axis. The velocity of the outflow is validated with the blueshift of low-ionization metal absorption lines in the spectra of the central galaxies. We also identify a faint (M 1500 ≈ -16.7) companion detected in both Lyα and the continuum, whose properties are in agreement with a predicted population of satellite galaxies that contribute to the extended Lyα emission. Finally, we briefly discuss the impact of the interaction between the central galaxies on the properties of the halo and the possibility of in situ fluorescent Lyα production.
AB - Spatially extended halos of H i Lyα emission are now ubiquitously found around high-redshift star-forming galaxies. But our understanding of the nature and powering mechanisms of these halos is still hampered by the complex radiative transfer effects of the Lyα line and limited angular resolution. In this paper, we present resolved Multi Unit Spectroscopic Explorer (MUSE) observations of SGAS J122651.3+215220, a strongly lensed pair of L∗ galaxies at z = 2.92 embedded in a Lyα halo of L Lyα = (6.2 ± 1.3) × 1042 erg s-1. Globally, the system shows a line profile that is markedly asymmetric and redshifted, but its width and peak shift vary significantly across the halo. By fitting the spatially binned Lyα spectra with a collection of radiative transfer galactic wind models, we infer a mean outflow expansion velocity of ≈211 km s-1, with higher values preferentially found on both sides of the system's major axis. The velocity of the outflow is validated with the blueshift of low-ionization metal absorption lines in the spectra of the central galaxies. We also identify a faint (M 1500 ≈ -16.7) companion detected in both Lyα and the continuum, whose properties are in agreement with a predicted population of satellite galaxies that contribute to the extended Lyα emission. Finally, we briefly discuss the impact of the interaction between the central galaxies on the properties of the halo and the possibility of in situ fluorescent Lyα production.
UR - http://www.scopus.com/inward/record.url?scp=85136004877&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/ac7c1a
DO - 10.3847/1538-4357/ac7c1a
M3 - Article
AN - SCOPUS:85136004877
VL - 935
JO - Astrophysical Journal
JF - Astrophysical Journal
SN - 0004-637X
IS - 1
M1 - 17
ER -