@article{06f008dc1d274d71bfcbec2cb81d558f,
title = "Stability of the Broad-line Region Geometry and Dynamics in Arp 151 over Seven Years",
abstract = "The Seyfert 1 galaxy Arp 151 was monitored as part of three reverberation mapping campaigns spanning 2008-2015. We present modeling of these velocity-resolved reverberation mapping data sets using a geometric and dynamical model for the broad-line region (BLR). By modeling each of the three data sets independently, we infer the evolution of the BLR structure in Arp 151 over a total of 7 yr and constrain the systematic uncertainties in nonvarying parameters such as the black hole mass. We find that the BLR geometry of a thick disk viewed close to face-on is stable over this time, although the size of the BLR grows by a factor of ∼2. The dynamics of the BLR are dominated by inflow, and the inferred black hole mass is consistent for the three data sets, despite the increase in BLR size. Combining the inference for the three data sets yields a black hole mass and statistical uncertainty of log10(/) = with a standard deviation in individual measurements of 0.13 dex.",
keywords = "galaxies: active, galaxies: individual (Arp 151), galaxies: nuclei, methods: statistical",
author = "A. Pancoast and Barth, {A. J.} and K. Horne and T. Treu and Brewer, {B. J.} and Bennert, {V. N.} and G. Canalizo and Gates, {E. L.} and W. Li and Malkan, {M. A.} and D. Sand and T. Schmidt and S. Valenti and Woo, {J. H.} and Clubb, {K. I.} and Cooper, {M. C.} and Crawford, {S. M.} and H{\"o}nig, {S. F.} and Joner, {M. D.} and Kandrashoff, {M. T.} and M. Lazarova and Nierenberg, {A. M.} and E. Romero-Colmenero and D. Son and E. Tollerud and Walsh, {J. L.} and H. Winkler",
note = "Funding Information: We thank the Lick Observatory staff for their exceptional support during our LAMP 2008 and 2011 observing campaigns. AP is supported by NASA through Einstein Postdoctoral Fellowship grant number PF5-160141 awarded by the Chandra X-ray Center, which is operated by the Smithsonian Astrophysical Observatory for NASA under contract NAS8-03060. Research by A.J.B. has been supported by NSF grant AST-1412693. V.N.B. acknowledges assistance from National Science Foundation (NSF) Research at Undergraduate Institutions (RUI) grant AST-1312296. Note that findings and conclusions do not necessarily represent views of the NSF. K.H. acknowledges support from STFC grant ST/M001296/1. S.F.H. acknowledges support from the EU/ Horizon 2020 programme via ERC Starting Grant 677117 and the UK STFC via grant ST/N000870/1. Research by D.J.S. is supported by NSF grant AST-1412504 and AST-1517649. T.T. gratefully acknowledges support from the Packard Foundations through a Packard Research Fellowship and by NSF through grant AST-1412315. J.H.W. acknowledges support by the National Research Foundation of Korea (NRF) grant funded by the Korean government (No. 2017R1A5A1070354). Publisher Copyright: {\textcopyright} 2018. The American Astronomical Society. All rights reserved..",
year = "2018",
month = apr,
day = "1",
doi = "10.3847/1538-4357/aab3c6",
language = "English (US)",
volume = "856",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "2",
}