Related papers: A Possible Detection of M31* with Chandra
We confirm our earlier tentative detection of M31* in X-rays and measure its light-curve and spectrum. Observations in 2004-2005 find M31* rather quiescent in the X-ray and radio. However, X-ray observations in 2006-2007 and radio…
We report on the first observation of the nuclear region of M31 with the Chandra X-ray Observatory. The nuclear source seen with the Einstein and ROSAT HRIs is resolved into five point sources. One of these sources is within 1'' of the M31…
We identified a new X-ray transient CXOM31 004252.457+411631.17 (T13) in M31 during a 2013 June Chandra observation. This system is particularly exciting because it is located within 100" of M31*; it is thought that this region of the bulge…
The hypothesized supermassive black hole in the nucleus of M31 (which we shall hereafter call M31*) has many features in common with Sgr A* at the Galactic Center, yet they differ in several significant and important ways. Though M31* is…
The recent Chandra X-ray observations of the nucleus of M31, combined with earlier VLA radio and HST UV spectral measurements, provide the strictest constraints on the nature of accretion onto the supermassive black hole (called M31*…
As part of the Chandra GTO program we are monitoring and surveying M31 using the HRC and ACIS cameras. These observations have resolved the nuclear X-ray source into five separate sources, one of which is very soft and may (or may not!) be…
Gas undergoing Bondi accretion onto a supermassive black hole (SMBH) becomes hotter toward smaller radii. We searched for this signature with a Chandra observation of the hot gas in NGC 3115, which optical observations show has a very…
The Andromeda galaxy (M31) hosts a central super-massive black hole (SMBH), known as M31$^\ast$, which is remarkable for its mass ($\sim$$10^8{\rm~M_\odot}$) and extreme radiative quiescence. Over the past decade, the Chandra X-ray…
As one of the nearest and most dormant supermassive black holes (SMBHs), M31* provides a rare but promising opportunity for studying the physics of black hole accretion and feedback at the quiescent state. Previous Karl G. Jansky Very Large…
We present results from a 47 ks observation of the Andromeda galaxy, M31, using the High-Resolution Camera of the Chandra X-Ray Observatory. We detect 142 point sources spanning three orders of magnitude in luminosity, from $L_X = 2\times…
We report the detection of diffuse hot gas in M31, using archival Chandra observations which allow us to map out a 30' by 30' field (covering a galactocentric radius up to 4.5 kpc) and to detect sources in the galaxy down to a 0.5-8 keV…
We append an additional fifteen years (2009-2024) to the Chandra X-ray light curve of M31*, the supermassive black hole at the center of M31, the Andromeda galaxy. Extending and expanding on the work in Li et al. 2011, we show that M31* has…
We have previously identified 10 M31 black hole candidates (BHCs) in M31, from their X-ray properties alone. They exhibit "hard state" emission spectra that are seen at luminosities < ~10% Eddington in X-ray binaries (XBs) containing a…
We present a multiwavelength investigation of the circumnuclear environment of M31. Based on Chandra/ACIS data, we tightly constrain the X-ray luminosity of M31*, the central supermassive black hole of the galaxy, to be L (0.3-7 keV)<=…
We have been regularly observing the bulge and inner disk of M31 for nearly 1 year, using both the HRC-I and ACIS-I instruments on the Chandra X-Ray Observatory. We present results from our program that are of interest to the study of the…
Chandra X-ray observations of the giant elliptical galaxy M87 resolve the thermal state of the hot interstellar medium into the accretion (Bondi) radius of its central 3 10^9 Msun black hole. We measure the X-ray gas temperature and density…
Using ROSAT, we have made the first deep X-ray observations of NGC 7331, discovering a nuclear X-ray source coincident with the previously determined radio and optical nuclear centers. Positions, luminosities, and fluxes of X-ray sources in…
Chandra X-ray observations of the nearby brightest cluster galaxy M87 resolve the hot gas structure across the Bondi accretion radius of the central supermassive black hole, a measurement possible in only a handful of systems but…
The nearby galaxy M33 hosts the most luminous steady X-ray source in the Local Group. The high spatial resolution of Chandra allows us to confirm that this ultra-luminous X-ray source is within the nucleus and rule out at the 4.6 sigma…
We report NOEMA and ALMA observations of the nucleus of Andromeda (M31), putting strong constraints on the presence of gas in the form of cold or warm phase, as proposed by Chang et al. M31 hosts the largest supermassive black hole (SMBH)…