Detection of the “Active” Nucleus of M32

M32 hosts a 2.5 × 106 M☉ central black hole, but signs of nuclear activity in this galaxy have long eluded detection. We report the first conclusive detection of the nucleus of M32 in X-rays, based on high-resolution, sensitive observations made with Chandra. The 2-10 keV luminosity is merely 9.4 × 1035 ergs s-1, ~3 × 10-9 times the Eddington luminosity of the black hole. Weak diffuse emission, consistent with thermal gas at a temperature of 0.37 keV, is seen in an annular region ~100 pc from the center. We also present a deep, moderately high-resolution (0.″9) radio continuum observation obtained with the Very Large Array, which places a tight upper bound on the nuclear radio power at 8.4 GHz. We combine these new measurements with upper limits at other wavelengths to discuss implications for the nature of accretion onto the central black hole.

[1]  L. Ho,et al.  A Search for “Dwarf” Seyfert Nuclei. VI. Properties of Emission-Line Nuclei in Nearby Galaxies , 2002, astro-ph/0210048.

[2]  S. Virani,et al.  Chandra Spectra of the Soft X-Ray Diffuse Background , 2002, astro-ph/0209441.

[3]  Y. Terashima,et al.  SUBMITTED TO The Astrophysical Journal Preprint typeset using L ATEX style emulateapj v. 21/08/00 CHANDRA SNAPSHOT OBSERVATIONS OF LOW-LUMINOSITY AGNS WITH A COMPACT RADIO SOURCE , 2002 .

[4]  L. Ho,et al.  Detailed Structural Decomposition of Galaxy Images , 2002, astro-ph/0204182.

[5]  L. Ho,et al.  X-Ray Properties of LINERs and Low-Luminosity Seyfert Galaxies Observed with ASCA. I. Observations and Results , 2002, astro-ph/0203005.

[6]  M. Sauvage,et al.  Mid-Infrared Observation of Mass Loss in Elliptical Galaxies , 2002, astro-ph/0201338.

[7]  M. Cappellari,et al.  A SAURON study of M32: measuring the intrinsic flattening and the central black hole mass , 2002 .

[8]  M. C. Weisskopf,et al.  An Overview of the Performance and Scientific Results from the Chandra X‐Ray Observatory , 2001, astro-ph/0110308.

[9]  L. Ho,et al.  TO APPEAR IN The Astrophysical Journal (Letters). Preprint typeset using L ATEX style emulateapj v. 14/09/00 THE ORIGIN OF RADIO EMISSION IN LOW-LUMINOSITY ACTIVE GALACTIC NUCLEI: JETS, ACCRETION FLOWS, OR BOTH? , 2001 .

[10]  Caltech,et al.  Rapid X-ray flaring from the direction of the supermassive black hole at the Galactic Centre , 2001, Nature.

[11]  G. Welch,et al.  The Interstellar Medium of M32 , 2001 .

[12]  Prague,et al.  Continuous stellar mass-loss in N -body models of galaxies , 2001, astro-ph/0107160.

[13]  Fulvio Melia,et al.  Electron Acceleration around the Supermassive Black Hole at the Galactic Center , 2001, astro-ph/0106162.

[14]  J. P. Laboratory,et al.  High-Resolution Mid-Infrared Images of the Nucleus of M81 , 2001, astro-ph/0103459.

[15]  L. Ho,et al.  Radio Continuum Survey of an Optically Selected Sample of Nearby Seyfert Galaxies , 2001, astro-ph/0102506.

[16]  F. Melia,et al.  Accretion Processes in the Nucleus of M31 , 2001, astro-ph/0101330.

[17]  Gerard A. Luppino,et al.  The SBF Survey of Galaxy Distances. IV. SBF Magnitudes, Colors, and Distances , 2000, astro-ph/0011223.

[18]  R. Bender,et al.  The Nuclear Dynamics of M32. I. Data and Stellar Kinematics , 2000, astro-ph/0005530.

[19]  B. Peterson,et al.  Probing the physics of active galactic nuclei by multiwavelength monitoring : proceedings of the meeting held at NASA's Goddard Space Flight Center, Greenbelt, Maryland, USA 20-22 June 2000 , 2001 .

[20]  L. Ho,et al.  Double-peaked Broad Emission Lines in NGC 4450 and Other LINERs , 2000, astro-ph/0004401.

[21]  K. Makishima,et al.  Metal Abundances in the Hot Interstellar Medium in Early-Type Galaxies Observed with ASCA , 2000, astro-ph/0003140.

[22]  E. Meurs,et al.  The case for a low-level active nucleus in M32 , 1999 .

[23]  R. Bender,et al.  The Double Nucleus and Central Black Hole of M31 , 1999 .

[24]  Roger D. Blandford,et al.  On the fate of gas accreting at a low rate on to a black hole , 1998, astro-ph/9809083.

[25]  J. E. Pringle,et al.  Theory of black hole accretion disks , 1999 .

[26]  Luis C. Ho,et al.  The Spectral Energy Distributions of Low-Luminosity Active Galactic Nuclei , 1998, astro-ph/9905012.

[27]  G. F. Mitchell,et al.  The Missing Interstellar Medium of NGC 147 and M32 , 1998 .

[28]  E. Becklin,et al.  High Proper-Motion Stars in the Vicinity of Sagittarius A*: Evidence for a Supermassive Black Hole at the Center of Our Galaxy , 1998, astro-ph/9807210.

[29]  M. Skrutskie,et al.  Characteristics of the 2MASS Prototype Survey , 1998 .

[30]  J. Holtzman,et al.  Far-Ultraviolet and Visible Imaging of the Nucleus of M32 , 1998, astro-ph/9804014.

[31]  ON THE NATURE OF THE X-RAY EMISSION FROM M32 , 1998, astro-ph/9802043.

[32]  P. T. de Zeeuw,et al.  Improved Evidence for a Black Hole in M32 from HST/FOS Spectra. II. Axisymmetric Dynamical Models , 1997, astro-ph/9705081.

[33]  L. Ho,et al.  A Search for “Dwarf'' Seyfert Nuclei. III. Spectroscopic Parameters and Properties of the Host Galaxies , 1997, astro-ph/9704107.

[34]  Reinhard Genzel,et al.  Stellar proper motions in the central 0.1 PC of the galaxy , 1997 .

[35]  Raymond E. White,et al.  X-Ray Emission from M32: X-Ray Binaries or a μAGN? , 1996, astro-ph/9603100.

[36]  Takashi Ichikawa,et al.  GALAXY COLORS IN VARIOUS PHOTOMETRIC BAND SYSTEMS , 1995 .

[37]  P. D. Zeeuw,et al.  Axisymmetric galaxy models with central black holes, with an application to M32 , 1994, astro-ph/9412067.

[38]  Duane A. Liedahl,et al.  New Calculations of Fe L-Shell X-Ray Spectra in High-Temperature Plasmas , 1995 .

[39]  K. Makishima,et al.  Discovery and implications of very low metal abundances in NGC 1404 and NGC 4374 , 1994 .

[40]  H. Rix,et al.  Velocity profiles of galaxies with claimed black holes – II. f (E, Lz) models for M32 , 1994 .

[41]  P. Padovani,et al.  Stellar Mass Loss in Elliptical Galaxies and the Fueling of Active Galactic Nuclei , 1993 .

[42]  P. Crane,et al.  Detection of an unresolved nuclear radio source in M31 , 1992 .

[43]  D. Frail,et al.  A Transient Radio Source near the Center of the Milky Way Galaxy , 1992, Science.

[44]  Carl Heiles,et al.  The bell laboratories H I survey , 1992 .

[45]  A. Dressler,et al.  Constraints on the mass distribution near the centers of M31 and M32 , 1990 .

[46]  T. Davidge.  Two Micron Spectroscopy of the Nucleus of M32 , 1989 .

[47]  D. Osterbrock,et al.  Astrophysics of Gaseous Nebulae and Active Galactic Nuclei , 1989 .

[48]  Alan Dressler,et al.  Stellar dynamics in the nuclei of M31 and M32 - evidence for massive black holes , 1988 .

[49]  J. Tonry.  A central black hole in M32 , 1987 .

[50]  J. Tonry.  Evidence for a central mass concentration in M32 , 1984 .

[51]  R. Ramaty,et al.  Tenth Texas Symposium on Relativistic Astrophysics , 1981 .

[52]  S. Faber,et al.  H I in Early-Type Galaxies. II. Mass Loss and Galactic Winds , 1976 .

[53]  D. Osterbrock,et al.  Astrophysics of Gaseous Nebulae , 1976 .

[54]  H. Bondi,et al.  On spherically symmetrical accretion , 1952 .