TY - JOUR
T1 - Discovery of a Damped Ly α Absorber Originating in a Spectacular Interacting Dwarf Galaxy Pair at z = 0.026
AU - Boettcher, Erin
AU - Gupta, Neeraj
AU - Chen, Hsiao Wen
AU - Chen, Mandy C.
AU - Józsa, Gyula I.G.
AU - Rudie, Gwen C.
AU - Cantalupo, Sebastiano
AU - Johnson, Sean D.
AU - Balashev, S. A.
AU - Combes, Françoise
AU - Cooksey, Kathy L.
AU - Faucher-Giguère, Claude André
AU - Krogager, Jens Kristian
AU - Lopez, Sebastian
AU - Momjian, Emmanuel
AU - Noterdaeme, Pasquier
AU - Petitjean, Patrick
AU - Rafelski, Marc
AU - Srianand, Raghunathan
AU - Walth, Gregory L.
AU - Zahedy, Fakhri S.
N1 - Funding Information:
This work is based on observations made with ESO telescopes at the Paranal Observatory under program ID 0104.A-0147(A), observations made with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, and spectroscopic data gathered under the HST-GO-15163.01A program using the NASA/ESA Hubble Space Telescope, operated by the Space Telescope Science Institute and the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. The MeerKAT telescope is operated by the South African Radio Astronomy Observatory, which is a facility of the National Research Foundation, an agency of the Department of Science and Innovation. The MeerKAT data were processed using the MALS computing facility at IUCAA ( https://mals.iucaa.in/releases ).
Funding Information:
This project used public archival data from the Dark Energy Survey (DES). Funding for the DES Projects has been provided by the U.S. Department of Energy, the U.S. National Science Foundation, the Ministry of Science and Education of Spain, the Science and Technology Facilities Council of the United Kingdom, the Higher Education Funding Council for England, the National Center for Supercomputing Applications at the University of Illinois at Urbana-Champaign, the Kavli Institute of Cosmological Physics at the University of Chicago, the Center for Cosmology and Astro-Particle Physics at the Ohio State University, the Mitchell Institute for Fundamental Physics and Astronomy at Texas A&M University, Financiadora de Estudos e Projetos, Fundação Carlos Chagas Filho de Amparo à Pesquisa do Estado do Rio de Janeiro, Conselho Nacional de Desenvolvimento Científico e Tecnológico and the Ministério da Ciência, Tecnologia e Inovação, the Deutsche Forschungsgemeinschaft, and the Collaborating Institutions in the Dark Energy Survey.
Funding Information:
E.B. and H.W.C. acknowledge partial support from grants HST-GO-15163.001A and NSF AST-1715692. S.C. gratefully acknowledges support from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program grant agreement No. 864361. K.L.C. acknowledges partial support from NSF AST-1615296. C.A.F.G. was supported by NSF through grants AST-1715216 and AST-2108230 and CAREER award AST-1652522; NASA through grant 17-ATP17-0067; STScI through grant HST-AR-16124.001-A; and the Research Corporation for Science Advancement through a Cottrell Scholar Award. J.K.K. acknowledges support by the Swiss National Science Foundation under grant 185692. S.L. was funded by FONDECYT grant No. 1191232. F.S.Z. is grateful for the support of a Carnegie Fellowship from the Observatories of the Carnegie Institution for Science. This material is based upon work supported by NASA under award No. 80GSFC21M0002.
Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.
PY - 2022/2/1
Y1 - 2022/2/1
N2 - We present the discovery of neutral gas detected in both damped Lyα absorption (DLA) and H i 21 cm emission outside of the stellar body of a galaxy, the first such detection in the literature. A joint analysis between the Cosmic Ultraviolet Baryon Survey and the MeerKAT Absorption Line Survey reveals an H i bridge connecting two interacting dwarf galaxies (log (M star/M ⊙) = 8.5 ± 0.2) that host a z = 0.026 DLA with log[N(H i)/cm-2] = 20.60 ± 0.05 toward the QSO J2339-5523 (z QSO = 1.35). At impact parameters of d = 6 and 33 kpc, the dwarf galaxies have no companions more luminous than ≈0.05L ∗ within at least "v = ±300 km s-1 and d ≈ 350 kpc. The H i 21 cm emission is spatially coincident with the DLA at the 2σ-3σ level per spectral channel over several adjacent beams. However, H i 21 cm absorption is not detected against the radio-bright QSO; if the background UV and radio sources are spatially aligned, the gas is either warm or clumpy (with a spin temperature to covering factor ratio T s /f c > 1880 K). Observations with VLT-MUSE demonstrate that the α-element abundance of the ionized interstellar medium (ISM) is consistent with the DLA (≈10% solar), suggesting that the neutral gas envelope is perturbed ISM gas. This study showcases the impact of dwarf-dwarf interactions on the physical and chemical state of neutral gas outside of star-forming regions. In the SKA era, joint UV and H i 21 cm analyses will be critical for connecting the cosmic neutral gas content to galaxy environments.
AB - We present the discovery of neutral gas detected in both damped Lyα absorption (DLA) and H i 21 cm emission outside of the stellar body of a galaxy, the first such detection in the literature. A joint analysis between the Cosmic Ultraviolet Baryon Survey and the MeerKAT Absorption Line Survey reveals an H i bridge connecting two interacting dwarf galaxies (log (M star/M ⊙) = 8.5 ± 0.2) that host a z = 0.026 DLA with log[N(H i)/cm-2] = 20.60 ± 0.05 toward the QSO J2339-5523 (z QSO = 1.35). At impact parameters of d = 6 and 33 kpc, the dwarf galaxies have no companions more luminous than ≈0.05L ∗ within at least "v = ±300 km s-1 and d ≈ 350 kpc. The H i 21 cm emission is spatially coincident with the DLA at the 2σ-3σ level per spectral channel over several adjacent beams. However, H i 21 cm absorption is not detected against the radio-bright QSO; if the background UV and radio sources are spatially aligned, the gas is either warm or clumpy (with a spin temperature to covering factor ratio T s /f c > 1880 K). Observations with VLT-MUSE demonstrate that the α-element abundance of the ionized interstellar medium (ISM) is consistent with the DLA (≈10% solar), suggesting that the neutral gas envelope is perturbed ISM gas. This study showcases the impact of dwarf-dwarf interactions on the physical and chemical state of neutral gas outside of star-forming regions. In the SKA era, joint UV and H i 21 cm analyses will be critical for connecting the cosmic neutral gas content to galaxy environments.
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U2 - 10.3847/2041-8213/ac5250
DO - 10.3847/2041-8213/ac5250
M3 - Article
AN - SCOPUS:85125992281
SN - 2041-8205
VL - 926
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 2
M1 - L33
ER -