Looking at the Distant Universe with the MeerKAT Array: Discovery of a Luminous OH Megamaser at z > 0.5

Glowacki, Marcin; Collier, Jordan D.; Kazemi-Moridani, Amir; Frank, Bradley; Roberts, Hayley; Darling, Jeremy; Kloeckner, Hans-Rainer; Adams, Nathan; Baker, Andrew J.; Bershady, Matthew; Blecher, Tariq; Blyth, Sarah-Louise; Bowler, Rebecca; Catinella, Barbara; Chemin, Laurent; Crawford, Steven M.; Cress, Catherine; Dave, Romeel; Deane, Roger; de Blok, Erwin; Delhaize, Jacinta; Duncan, Kenneth; Elson, Ed; February, Sean; Gawiser, Eric; Hatfield, Peter; Healy, Julia; Henning, Patricia; Hess, Kelley M.; Heywood, Ian; Holwerda, Benne W.; Hoosain, Munira; Hughes, John P.; Hutchens, Zackary L.; Jarvis, Matt; Kannappan, Sheila; Katz, Neal; Keres, Dusan; Korsaga, Marie; Kraan-Korteweg, Renee C.; Lah, Philip; Lochner, Michelle; Maddox, Natasha; Makhathini, Sphesihle; Meurer, Gerhardt R.; Meyer, Martin; Obreschkow, Danail; Oh, Se-Heon; Oosterloo, Tom; Oppor, Joshua; Pan, Hengxing; Pisano, D. J.; Randriamiarinarivo, Nandrianina; Ravindranath, Swara; Schroeder, Anja C.; Skelton, Rosalind; Smirnov, Oleg; Smith, Mathew; Somerville, Rachel S.; Srianand, Raghunathan; Staveley-Smith, Lister; Tanaka, Masayuki; Vaccari, Mattia; Driel, Wim van; Verheijen, Marc; Walter, Fabian; Wu, John F. und Zwaan, Martin A. (2022): Looking at the Distant Universe with the MeerKAT Array: Discovery of a Luminous OH Megamaser at z > 0.5. In: Astrophysical Journal Letters, Bd. 931, Nr. 1, L7

Abstract

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 (H i), radio surveys to probe the cosmic evolution of H i 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 H i 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 approximate to 0.52 confirms the MeerKAT emission-line detection as OH at a redshift z (OH) = 0.5225 +/- 0.0001 rather than H i at lower redshift. The detected spectral line has 18.4 sigma peak significance, a width of 459 +/- 59 km s(-1), and an integrated luminosity of (6.31 +/- 0.18 [statistical] +/- 0.31 [systematic]) x 10(3) L (circle dot), placing it among the most luminous OHMs known. The galaxy's far-infrared luminosity L (FIR) = (1.576 +/- 0.013) x 10(12) L (circle dot) marks it as an ultraluminous 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 toward a systematic exploitation of OHMs as a tracer of galaxy growth at high redshifts.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 2041-8205
• Sprache: Englisch