1999/03/30 by M. Guainazzi, G. C. Perola, Guainazzi, M. +14
Decision Sciences · Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics (astro-ph) #FOS: Physical sciences #Scientific Measurement and Uncertainty Evaluation #astro-ph
paper · pdf · doi:10.48550/arxiv.astro-ph/9903449
9 Latex pages, 10 figures, Accepted for publication in Astronomy & Astrophysics
arxiv created 1999/03/30 · openalex publication_date 1999/03/30 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We report on the first observation of the Seyfert 1 galaxy NGC4593 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 ~1.9; the Compton-reflection of the primary power-law; a moderately broad (>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 30 degrees. Any cutoff of the intrinsic continuum is constrained to lay 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.