TY - JOUR
T1 - A search forH2O masers in 100 active dwarf galaxies
AU - Rosenthal, M. J.
AU - Zaw, I.
N1 - Funding Information:
We thank the anonymous referee for their helpful comments. We also thank Joseph Gelfand and Lincoln J. Greenhill for helpful discussions. This work was made possible by the use of the Robert C. Byrd Green Bank Telescope at the Green Bank Observatory. The Green Bank Observatory is a facility of theNational Science Foundation operated under cooperative agreement by Associated Universities, Inc. This work makes use of data products from the SDSS. Funding for SDSS-III has been provided by the Alfred P. Sloan Foundation, the Participating Institutions, the National Science Foundation, and the U.S. Department of Energy Office of Science. The SDSS-III web site is http://www.sdss3.org/. SDSS-III is managed by the Astrophysical Research Consortium for the Participating Institutions of the SDSS-III Collaboration including the University of Arizona, the Brazilian Participation Group, Brookhaven National Laboratory, Carnegie Mellon University, University of Florida, the French Participation Group, the German Participation Group, Harvard University, the Instituto de Astrofisica de Canarias, the Michigan State/Notre Dame/JINA Participation Group, Johns Hopkins University, Lawrence Berkeley National Laboratory, Max Planck Institute for Astrophysics, Max Planck Institute for Extraterrestrial Physics, New Mexico State University, New York University, Ohio State University, Pennsylvania State University, University of Portsmouth, Princeton University, the Spanish Participation Group, University of Tokyo, University of Utah, Vanderbilt University, University of Virginia, University of Washington, and Yale University. This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This research made use of ASTROPY, a community-developed core PYTHON package for astronomy (Astropy Collaboration 2013), IPYTHON (Pérez & Granger 2007), MATPLOTLIB (Hunter 2007), NUMPY (van der Walt, Colbert & Varoquaux 2011), and TOPCAT (Taylor 2005).
Funding Information:
This work was made possible by the use of the Robert C. Byrd Green Bank Telescope at the Green Bank Observatory. The Green Bank Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.
Publisher Copyright:
© 2020 The Author(s).
PY - 2020/11/1
Y1 - 2020/11/1
N2 - We present the results of the first dedicated survey for 22 GHz H2O maser emission in dwarf galaxies outside of the Local Group, with the aim of discovering disc masers. Studies of disc masers yield accurate and precise measurements of black hole (BH)mass, and such measurements in dwarf galaxies would be key to understanding the low-mass end of BH-galaxy coevolution. We used the Green Bank Telescope to survey 100 nearby (z ≤ 0.055) dwarf galaxies (M* ≤ 109.5 M⊙) with optical emission line ratios indicative of accretion on to amassive black hole.We detected no new masers down to a limit of ~12 mJy (5s).We compared the properties of our sample with those of ~1850 known detections and non-detections in massive galaxies. We find, in agreement with previous studies, that masers are preferentially hosted by Seyferts and highly obscured, [O III]-bright active galactic nuclei (AGNs). Our sample has fewer Seyferts, is less obscured, and is [O III]-faint. Though the overall maser detection rate is ~3 per cent in massive galaxies, the predicted rate for our sample, weighted by its optical properties, is ~0.6-1.7 per cent, corresponding to a probability of making no detections of ~20-50 per cent. We also found a slight increase in the detection rate with increased stellar mass in previously surveyed galaxies. However, further observations are required to discern whether there is an intrinsic difference between the maser fraction in active dwarf galaxies and in their massive counterparts for the same AGN properties.
AB - We present the results of the first dedicated survey for 22 GHz H2O maser emission in dwarf galaxies outside of the Local Group, with the aim of discovering disc masers. Studies of disc masers yield accurate and precise measurements of black hole (BH)mass, and such measurements in dwarf galaxies would be key to understanding the low-mass end of BH-galaxy coevolution. We used the Green Bank Telescope to survey 100 nearby (z ≤ 0.055) dwarf galaxies (M* ≤ 109.5 M⊙) with optical emission line ratios indicative of accretion on to amassive black hole.We detected no new masers down to a limit of ~12 mJy (5s).We compared the properties of our sample with those of ~1850 known detections and non-detections in massive galaxies. We find, in agreement with previous studies, that masers are preferentially hosted by Seyferts and highly obscured, [O III]-bright active galactic nuclei (AGNs). Our sample has fewer Seyferts, is less obscured, and is [O III]-faint. Though the overall maser detection rate is ~3 per cent in massive galaxies, the predicted rate for our sample, weighted by its optical properties, is ~0.6-1.7 per cent, corresponding to a probability of making no detections of ~20-50 per cent. We also found a slight increase in the detection rate with increased stellar mass in previously surveyed galaxies. However, further observations are required to discern whether there is an intrinsic difference between the maser fraction in active dwarf galaxies and in their massive counterparts for the same AGN properties.
KW - Galaxies: active
KW - Galaxies: dwarf
KW - Masers
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U2 - 10.1093/mnras/staa2730
DO - 10.1093/mnras/staa2730
M3 - Article
AN - SCOPUS:85098596283
SN - 0035-8711
VL - 499
SP - 1233
EP - 1249
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 1
ER -