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Direct Evidence from Spitzer for a low-luminosity AGN at the center of the Elliptical Galaxy NGC 315

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 نشر من قبل Qiusheng Gu
 تاريخ النشر 2007
  مجال البحث فيزياء
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 تأليف Qiusheng Gu




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We present the {it Spitzer} Space Telescope InfraRed Array Camera (IRAC) and Multiband Imaging Photometer (MIPS) observations of the elliptical galaxy NGC 315. After removal of the host galaxys 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 wavelength range covering from radio to X-ray, and obtained the bolometric luminosity of $rm L_{bol} approx 1.9 times 10^{43} ergs s^{-1}$, corresponding to an extremely low Eddington ratio (L/L$_{rm Edd}$) of 4.97 $times$ 10$^{-4}$. Our results confirm that the physical nature of the nucleus of NGC 315 is a low-luminosity AGN, consistent with the recent optical and {it Chandra} X-ray observations.



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