Direct evidence from Spitzer for a low-luminosity AGN at the center of the elliptical galaxy NGC 315

Creators: Gu, Q.-S.; Huang, J.-S.; Wilson, G.; Fazio, G. G.

Abstract

We present Spitzer Space Telescope InfraRed Array Camera (IRAC) and Multiband Imaging Photometer (MIPS) observations of the elliptical galaxy NGC 315. After removal of the host galaxy's stellar emission, we detected for the first time an infrared-red nucleus in NGC 315. We measured the spectral energy distribution (SED) for this active nucleus with a wavelength range from radio to X-ray, and obtained a bolometric luminosity of Lbol ≈ 1.9 x 10^43 ergs s^(-1), corresponding to an extremely low Eddington ratio L/L_(Edd) of 4.97 x 10^(-4). Our results confirm that the physical nature of the nucleus of NGC 315 is a low-luminosity AGN, consistent with recent optical and Chandra X-ray observations.

Additional Information

© 2007. The American Astronomical Society. Received 2007 September 15; accepted 2007 October 31; published 2007 November 16. The authors are very grateful to the anonymous referee for her/his constructive report which improved the Letter very much. We also thank Jorge Melnick, Matthew Ashby, and Luis Ho for thoughtful discussion, and Feng Yuan for providing us the SED of Sgr A*. This work has been supported by Program for New Century Excellent Talents in University (NCET) of China. Q. G. U. would like to acknowledge the financial support from the China Scholarship Council (CSC), the National Natural Science Foundation of China under grants 10221001 and 10633040, and the National Basic Research Program (973 program 2007CB815405). This research has made use of NASA's Astrophysics Data System Bibliographic Services and the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under NASA contract 1407.

Attached Files

Published - GUQapjl08.pdf

Files

GUQapjl08.pdf

Files (134.7 kB)

Name	Size	Download all
GUQapjl08.pdf md5:661eca313d2ae547b45f315333d5e761	134.7 kB	Preview Download

Additional details

	All versions	This version
Views	0	0
Downloads	0	0
Data volume	0 Bytes	0 Bytes