GBT22B-020

Confirming the nature of a 380GHz H2O maser disk in a lensed quasar at z=3.91

Abstract

Water megamasers are a powerful tool for measuring black-hole masses of AGNs and for determining angular distances of the host galaxies, thus constraining critical cosmological parameters. We have recently detected the 380 GHz (rest-frame) H2O line in a redshift 3.91 quasar, being the first extragalactic detection of this line. The flux of the 380 GHz H2O maser line is at least three times stronger than the 22 and 183 GHz H2O maser lines, suggesting that the 380 GHz line is a promising or even better extragalactic maser tracer. Interestingly, we have identified 2-sigma satellite emission lines lying up to more than 2000 km/s from the 380 GHz H2O line, indicating that the maser may originate from the accretion disk around the AGN. Therefore, we here propose deeper observations to confirm the detection of the satellite high-velocity lines and to better study the properties of the 380 GHz maser emission. This project will serve as an essential first step for a future survey of the 380 GHz H2O maser in a large sample of high-redshift galaxies, further enabling subsequent constraints of the cosmological parameters in the early days of dark energy and studies of the supermassive black holes at high redshifts.

Investigators

Name	Institution
Cheng-Yu Kuo	Virginia, University of; National Sun Yat-sen University
Violette Impellizzeri	National Radio Astronomy Observatory; Leiden, University of; Joint ALMA Observatory
Jim Braatz	National Radio Astronomy Observatory
Chentao Yang *	Chalmers University of Technology
Alexandre Beelen	Orsay University
Pierre Cox	Paris, Institut d'Astrophysique de
Liz Humphreys	Center for Astrophysics | Harvard & Smithsonian; European Southern Observatory
Chris Henkel	Max-Planck-Institut für Radioastronomie
Alain Omont	Paris, Institut d'Astrophysique de
Dominic Pesce	Virginia, University of; Smithsonian Astrophysical Observatory
Hugo Messias	Joint ALMA Observatory
Sergio Martin	Center for Astrophysics | Harvard & Smithsonian; Institut de Radio Astronomique Millimétrique; Instituto de RadioAstronomia Milimetrica ; European Southern Observatory
Roberto Neri	Institut de Radio Astronomique Millimétrique
Cong Ma	Cape Town, University of; South African Radio Astronomy Observatory
Rob Ivison	Edinburgh, University of; European Southern Observatory
Eduardo Gonzalez-Alfonso	Alcalá, Universidad de
Raphael Gavazzi	Paris, Institut d'Astrophysique de

* indicates the PI