Title: X-ray spectral variability of the Seyfert 1 galaxy NGC 4051
Abstract: view Abstract Citations (25) References (16) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS X-Ray Spectral Variability of the Seyfert I Galaxy NGC 4051 Kunieda, Hideyo ; Hayakawa, Satio ; Tawara, Yuzuru ; Koyama, Katsuji ; Tsuruta, Sachiko ; Leighly, Karen Abstract The Seyfert I galaxy NGC 4051 was observed with the Japanese X-ray astronomy satellite Ginga in 1988 May. Fast variability of a factor of 2-3 within 1000 s is confirmed in the soft X-ray band (2.3-6.4 keV), and that of smaller amplitude within a few thousand seconds in the hard X-ray band (8.7-20.9 keV). A single power-law model cannot explain all the observed energy spectra. A blob (N_blob_ = 10^24.5^ cm^-2^) model with intrinsically almost constant photon index of {GAMMA} = 1.9-2.0 is successfully applied to all the spectra. Intensity and spectral changes are well described by changes of intrinsic luminosity and the blob number v in the line of sight. The observed variability time scale of ~2000 s implies an upper limit of the central mass of 2 x 10^7^ M_sun_. Publication: The Astrophysical Journal Pub Date: January 1992 DOI: 10.1086/170890 Bibcode: 1992ApJ...384..482K Keywords: Galactic Radiation; Seyfert Galaxies; X Ray Astronomy; X Ray Spectra; Astronomical Models; Energy Spectra; Light Curve; Temporal Distribution; Astrophysics; GALAXIES: INDIVIDUAL NGC NUMBER: NGC 4051; GALAXIES: SEYFERT; X-RAYS: GALAXIES full text sources ADS | data products SIMBAD (1) NED (1)