We report the results of a broadband (0.1-100 keV) X-ray observation of the nearby elliptical galaxy NGC 1052, performed with the BeppoSAX observatory. We confirm the presence of a bright (2-10 keV luminosity similar to4 x 10(42) erg s(-1)) and strongly absorbed (N-H similar to 2 x 10(23) cm(-2)) X-ray source. The flatness of the X-ray spectrum (photon index, Gamma, similar or equal to1.4), the estimated low accretion rate ((m) over dot equivalent to (M) over dot/(M) over dot(Edd) similar to 10(-4)) and the radio-to-X-ray spectral energy distribution suggest that this observation may represent the first direct measurement above 10 keV of an accretion-dominated flow in an elliptical galaxy.
Guainazzi M, Oosterbroek T, Antonelli LA, & Matt G (2000). On the hypothesis of an advection-dominated flow in the core of NGC 1052: new constraints from a BeppoSAX observation. ASTRONOMY & ASTROPHYSICS, 364(2), L80-L84.
On the hypothesis of an advection-dominated flow in the core of NGC 1052: new constraints from a BeppoSAX observation
MATT, Giorgio
2000
Abstract
We report the results of a broadband (0.1-100 keV) X-ray observation of the nearby elliptical galaxy NGC 1052, performed with the BeppoSAX observatory. We confirm the presence of a bright (2-10 keV luminosity similar to4 x 10(42) erg s(-1)) and strongly absorbed (N-H similar to 2 x 10(23) cm(-2)) X-ray source. The flatness of the X-ray spectrum (photon index, Gamma, similar or equal to1.4), the estimated low accretion rate ((m) over dot equivalent to (M) over dot/(M) over dot(Edd) similar to 10(-4)) and the radio-to-X-ray spectral energy distribution suggest that this observation may represent the first direct measurement above 10 keV of an accretion-dominated flow in an elliptical galaxy.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
