Zobrazeno 1 - 10
of 61
pro vyhledávání: '"James A Braatz"'
Autor:
Dominic W. Pesce, James A. Braatz, Christian Henkel, Elizabeth M. L. Humphreys, C. M. Violette Impellizzeri, Cheng-Yu Kuo
Publikováno v:
The Astrophysical Journal, Vol 948, Iss 2, p 134 (2023)
We present the results of an Atacama Large Millimeter/submillimeter Array survey to identify 183 GHz H _2 O maser emission from active galactic nuclei (AGNs) already known to host 22 GHz megamaser systems. Out of 20 sources observed, we detect signif
Externí odkaz:
https://doaj.org/article/7af0f84cc0ae4eabbf99c3d8c9b1e7f2
Autor:
Elisabetta Ladu, Andrea Tarchi, Gabriele Surcis, Paola Castangia, James A Braatz, Francesca Panessa, Dominic Pesce
Publikováno v:
Proceedings of 15th European VLBI Network Mini-Symposium and Users' Meeting — PoS(EVN2022).
Autor:
Brian R. Kent, Dominic W. Pesce, James A. Braatz, Davor Krajnović, Anil C. Seth, Jenny E. Greene, James J. Condon
We present the results from an observing campaign to confirm the peculiar motion of the supermassive black hole (SMBH) in J0437+2456 first reported in Pesce et al. (2018). Deep observations with the Arecibo Observatory have yielded a detection of neu
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b4e271a4ab41613d56229543bce1f492
Autor:
Mark J. Reid, James A. Braatz, J. J. Condon, Violette Impellizzeri, Feng Gao, K. Y. Lo, Eugenia Litzinger, Dominic W. Pesce, Christian Henkel
Publikováno v:
Proceedings of the International Astronomical Union. 13:125-128
Many accretion disks surrounding supermassive black holes in nearby AGN are observed to host 22 GHz water maser activity. We have analyzed single-dish 22 GHz spectra taken with the GBT to identify 32 such “Keplerian disk systems,” which we used t
Autor:
Anca Constantin, James A. Braatz, Dominic W. Pesce, Fred K. Y. Lo, Eugenia Litzinger, Jenny E. Greene, Lei Hao, W. Zhao, Christian Henkel, C. M. Violette Impellizzeri, Feng Gao, Mark J. Reid, C. Y. Kuo, James J. Condon
Publikováno v:
Proceedings of the International Astronomical Union. 13:86-91
The Megamaser Cosmology Project (MCP) measures the Hubble Constant by determining geometric distances to circumnuclear 22 GHz H2O megamasers in galaxies at low redshift (z < 0.05) but well into the Hubble flow. In combination with the recent, exquisi
Autor:
W. Zhao, Jenny E. Greene, Feng Gao, James A. Braatz, K. Y. Lo, Mark J. Reid, Christian Henkel, Cheng-Yu Kuo, I. Zaw, James J. Condon, Caterina M. V. Impellizzeri
Publikováno v:
Proceedings of the International Astronomical Union. 10:56-60
We made dynamical black hole mass measurements from nineteen Seyfert 2 galaxies which host sub-parsec H2O maser disks using the H2O megamaser technique. The nearly perfect Keplerian rotation curves in many of these maser systems guarantee the high ac
Autor:
C. M. V. Impellizzeri, W. Zhao, Jenny E. Greene, James J. Condon, Jan Wagner, F. Gao, K. Y. Lo, Mark J. Reid, C. Y. Kuo, James A. Braatz, Dominic W. Pesce, Christian Henkel
As part of the Megamaser Cosmology Project (MCP), we present VLBI maps of nuclear water masers toward five galaxies. The masers originate in sub-parsec circumnuclear disks. For three of the galaxies, we fit Keplerian rotation curves to estimate their
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::ef5e4f431a1b46034a01e1a5fe6357d0
http://arxiv.org/abs/1610.06802
http://arxiv.org/abs/1610.06802
Autor:
Christian Henkel, Cheng-Yu Kuo, K. Y. Lo, James J. Condon, W. Zhao, James A. Braatz, Feng Gao, Mark J. Reid, Violette Impellizzeri, Jenny E. Greene
Publikováno v:
Proceedings of the International Astronomical Union. 8:255-261
To constrain models of dark energy, a precise measurement of the Hubble constant, H0, provides a powerful complement to observations of the cosmic microwave background. Recent, precise measurements of H0 have been based on the ‘extragalactic distan
Autor:
Christian Henkel, Victor V. Flambaum, Rui-Qing Mao, James A. Braatz, Jürgen Ott, N. Jethava, Michael T. Murphy, Karl M. Menten, Sebastien Muller
Publikováno v:
Astronomy & Astrophysics. 500:725-734
Based on measurements with the Effelsberg 100-m telescope, a multi-line study of molecular species is presented toward the gravitational lens system PKS1830-211. Obtaining average radial velocities and performing Large Velocity Gradient radiative tra
Publikováno v:
The Astrophysical Journal. 695:287-291
The Megamaser Cosmology Project (MCP) seeks to measure the Hubble Constant (Ho) in order to improve the extragalactic distance scale and constrain the nature of dark energy. We are searching for sources of water maser emission from AGN with sub-pc ac