The M31 nucleus in the mid-infrared
Abstract
The central region of the Andromeda Galaxy (M31) is a complicated place, containing a massive but quiescent black hole, a multi-component nucleus, young stars, cold gas, and ionized gas among other ingredients. While this region has been extensively studied at radio, visible, and X-ray wavelengths, it has received relatively little attention in the mid-infrared. Mid-infrared observations constrain the dust properties of the nucleus and surrounding region. As part of a larger project to study the properties of PAH emission in M31, we obtained Spitzer low-resolution (R~100) spectroscopy of a 30x50 arcsec (114 x 190 pc) region containing the nucleus. We detected 10 micron silicate emission from a marginally resolved source at the center of the galaxy, consistent with emission from an unobscured but weak active nucleus. We also detected the 11.3 micron polycyclic aromatic hydrocarbon (PAH) emission feature, but not other PAH features, from a region about 15 arcsec north of the nucleus. We discuss these spectral features in comparison with those of other nearby low-luminosity AGN and the properties of the M31 supermassive black hole.
- Publication:
-
American Astronomical Society Meeting Abstracts #225
- Pub Date:
- January 2015
- Bibcode:
- 2015AAS...22542905B