We report on the first observation of the Seyfert 1 galaxy NGC 4593 in the 0.1-200 keV band, performed with the BeppoSAX observatory. Its spectral components are for the first time simultaneously! measured: a power-law with photon spectral index Gamma similar or equal to 1.9; the Compton-reflection of the primary power-law; a moderately broad (sigma > 60 eV) K-alpha fluorescent line from neutral iron; and an absorption edge, whose threshold energy is consistent with K-shell photoionization from OVII. The amount of reflection and the iron line properties are consistent with both being produced in a plane-parallel, X-ray illuminated relativistic accretion disc surrounding the nuclear black hole, seen at an inclination of similar or equal to 30 degrees. Any cutoff of the intrinsic continuum is constrained to lap above 150 keV. The claim for a strongly variable soft excess is dismissed by our data and by a reanalysis of archival ASCA and ROSAT data.
Guainazzi, M., Perola, G.c., Matt, G., Nicastro, F., Bassani, L., Fiore, F., et al. (1999). The complex 0.1-200 keV spectrum of the Seyfert 1 Galaxy NGC 4593. ASTRONOMY & ASTROPHYSICS, 346(2), 407-414.
The complex 0.1-200 keV spectrum of the Seyfert 1 Galaxy NGC 4593
MATT, Giorgio;
1999-01-01
Abstract
We report on the first observation of the Seyfert 1 galaxy NGC 4593 in the 0.1-200 keV band, performed with the BeppoSAX observatory. Its spectral components are for the first time simultaneously! measured: a power-law with photon spectral index Gamma similar or equal to 1.9; the Compton-reflection of the primary power-law; a moderately broad (sigma > 60 eV) K-alpha fluorescent line from neutral iron; and an absorption edge, whose threshold energy is consistent with K-shell photoionization from OVII. The amount of reflection and the iron line properties are consistent with both being produced in a plane-parallel, X-ray illuminated relativistic accretion disc surrounding the nuclear black hole, seen at an inclination of similar or equal to 30 degrees. Any cutoff of the intrinsic continuum is constrained to lap above 150 keV. The claim for a strongly variable soft excess is dismissed by our data and by a reanalysis of archival ASCA and ROSAT data.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
