LADUMA: Discovery of a luminous OH megamaser at $z > 0.5$
LADUMA: Discovery of a luminous OH megamaser at $z > 0.5$
In the local Universe, OH megamasers (OHMs) are detected almost exclusively in infrared-luminous galaxies, with a prevalence that increases with IR luminosity, suggesting that they trace gas-rich galaxy mergers. Given the proximity of the rest frequencies of OH and the hyperfine transition of neutral atomic hydrogen (HI), radio surveys to probe the cosmic evolution of HI in galaxies also offer exciting prospects for exploiting OHMs to probe the cosmic history of gas-rich mergers. Using observations for the Looking At the Distant Universe with the MeerKAT Array (LADUMA) deep HI survey, we report the first untargeted detection of an OHM at $z > 0.5$, LADUMA J033046.20$-$275518.1 (nicknamed "Nkalakatha"). The host system, WISEA J033046.26$-$275518.3, is an infrared-luminous radio galaxy whose optical redshift $z \approx 0.52$ confirms the MeerKAT emission line detection as OH at a redshift $z_{\rm OH} = 0.5225 \pm 0.0001$ rather than HI at lower redshift. The detected spectral line has 18.4$\sigma$ peak significance, a width of $459 \pm 59\,{\rm km\,s^{-1}}$, and an integrated luminosity of $(6.31 \pm 0.18\,{\rm [statistical]}\,\pm 0.31\,{\rm [systematic]}) \times 10^3\,L_\odot$, placing it among the most luminous OHMs known. The galaxy's far-infrared luminosity $L_{\rm FIR} = (1.576 \pm 0.013) \times 10^{12}\,L_\odot$ marks it as an ultra-luminous infrared galaxy; its ratio of OH and infrared luminosities is similar to those for lower-redshift OHMs. A comparison between optical and OH redshifts offers a slight indication of an OH outflow. This detection represents the first step towards a systematic exploitation of OHMs as a tracer of galaxy growth at high redshifts.
Bradley Frank、Andrew J. Baker、Marc Verheijen、Se-Heon Oh、John P. Hughes、Hans-Rainer Kl?ckner、Rosalind Skelton、Amir Kazemi-Moridani、Kelley M. Hess、Masayuki Tanaka、Gerhardt R. Meurer、Wim van Driel、Barbara Catinella、Mathew Smith、Danail Obreschkow、D. J. Pisano、Hengxing Pan、Steven M. Crawford、Tom Oosterloo、Martin Meyer、Catherine Cress、Sheila Kannappan、Romeel Dav¨|、Marie Korsaga、Erwin de Blok、Ren¨|e C. Kraan-Korteweg、Ed Elson、Julia Healy、Anja C. Schr?der、Fabian Walter、Sphesihle Makhathini、Jeremy Darling、Benne W. Holwerda、Du?an Kere?、Michelle Lochner、Matt Jarvis、Munira Hoosain、Swara Ravindranath、Patricia Henning、Philip Lah、Nandrianina Randriamiarinarivo、Marcin Glowacki、Eric Gawiser、Natasha Maddox、Jacinta Delhaize、Ian Heywood、Rebecca Bowler、Laurent Chemin、Neal Katz、Hayley Roberts、Tariq Blecher、Joshua Oppor、John F. Wu、Roger Deane、Zackary L. Hutchens、Kenneth Duncan、Peter Hatfield、Nathan Adams、Sean February、Sarah-Louise Blyth、Raghunathan Srianand、Jordan D. Collier、Lister Staveley-Smith、Mattia Vaccari、Matthew Bershady、Rachel S. Somerville、Oleg Smirnov、Martin A. Zwaan
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Bradley Frank,Andrew J. Baker,Marc Verheijen,Se-Heon Oh,John P. Hughes,Hans-Rainer Kl?ckner,Rosalind Skelton,Amir Kazemi-Moridani,Kelley M. Hess,Masayuki Tanaka,Gerhardt R. Meurer,Wim van Driel,Barbara Catinella,Mathew Smith,Danail Obreschkow,D. J. Pisano,Hengxing Pan,Steven M. Crawford,Tom Oosterloo,Martin Meyer,Catherine Cress,Sheila Kannappan,Romeel Dav¨|,Marie Korsaga,Erwin de Blok,Ren¨|e C. Kraan-Korteweg,Ed Elson,Julia Healy,Anja C. Schr?der,Fabian Walter,Sphesihle Makhathini,Jeremy Darling,Benne W. Holwerda,Du?an Kere?,Michelle Lochner,Matt Jarvis,Munira Hoosain,Swara Ravindranath,Patricia Henning,Philip Lah,Nandrianina Randriamiarinarivo,Marcin Glowacki,Eric Gawiser,Natasha Maddox,Jacinta Delhaize,Ian Heywood,Rebecca Bowler,Laurent Chemin,Neal Katz,Hayley Roberts,Tariq Blecher,Joshua Oppor,John F. Wu,Roger Deane,Zackary L. Hutchens,Kenneth Duncan,Peter Hatfield,Nathan Adams,Sean February,Sarah-Louise Blyth,Raghunathan Srianand,Jordan D. Collier,Lister Staveley-Smith,Mattia Vaccari,Matthew Bershady,Rachel S. Somerville,Oleg Smirnov,Martin A. Zwaan.LADUMA: Discovery of a luminous OH megamaser at $z > 0.5$[EB/OL].(2022-04-05)[2025-05-17].https://arxiv.org/abs/2204.02523.点此复制
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