TY - JOUR
T1 - Looking at the Distant Universe with the MeerKAT Array
T2 - Discovery of a Luminous OH Megamaser at z > 0.5
AU - SKA South Africa/MeerKAT
AU - Glowacki, Marcin
AU - Collier, Jordan D.
AU - Kazemi-Moridani, Amir
AU - Frank, Bradley
AU - Roberts, Hayley
AU - Darling, Jeremy
AU - Klöckner, Hans Rainer
AU - Adams, Nathan
AU - Baker, Andrew J.
AU - Bershady, Matthew
AU - Blecher, Tariq
AU - Blyth, Sarah Louise
AU - Bowler, Rebecca
AU - Catinella, Barbara
AU - Chemin, Laurent
AU - Crawford, Steven M.
AU - Cress, Catherine
AU - Davé, Romeel
AU - Deane, Roger
AU - De Blok, Erwin
AU - Delhaize, Jacinta
AU - Duncan, Kenneth
AU - Elson, Ed
AU - February, Sean
AU - Gawiser, Eric
AU - Hatfield, Peter
AU - Healy, Julia
AU - Henning, Patricia
AU - Hess, Kelley M.
AU - Heywood, Ian
AU - Holwerda, Benne W.
AU - Hoosain, Munira
AU - Hughes, John P.
AU - Hutchens, Zackary L.
AU - Jarvis, Matt
AU - Kannappan, Sheila
AU - Katz, Neal
AU - Kereš, Dušan
AU - Korsaga, Marie
AU - Kraan-Korteweg, Renée C.
AU - Lah, Philip
AU - Lochner, Michelle
AU - Maddox, Natasha
AU - Makhathini, Sphesihle
AU - Meurer, Gerhardt R.
AU - Meyer, Martin
AU - Obreschkow, Danail
AU - Oh, Se Heon
AU - Oosterloo, Tom
AU - Oppor, Joshua
N1 - Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.
PY - 2022/5/1
Y1 - 2022/5/1
N2 - 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 ≈ 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 18.4σ peak significance, a width of 459 ± 59 km s-1, and an integrated luminosity of (6.31 ± 0.18 [statistical] ± 0.31 [systematic]) × 103 L ⊙, placing it among the most luminous OHMs known. The galaxy's far-infrared luminosity L FIR = (1.576 ±0.013) × 1012 L ⊙ 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.
AB - 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 ≈ 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 18.4σ peak significance, a width of 459 ± 59 km s-1, and an integrated luminosity of (6.31 ± 0.18 [statistical] ± 0.31 [systematic]) × 103 L ⊙, placing it among the most luminous OHMs known. The galaxy's far-infrared luminosity L FIR = (1.576 ±0.013) × 1012 L ⊙ 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.
UR - http://www.scopus.com/inward/record.url?scp=85131684558&partnerID=8YFLogxK
U2 - 10.3847/2041-8213/ac63b0
DO - 10.3847/2041-8213/ac63b0
M3 - Article
AN - SCOPUS:85131684558
SN - 2041-8205
VL - 931
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 1
M1 - L7
ER -