Open AccessThe highly variable X‐ray spectrum of the luminous Seyfert 1 galaxy 1H 0419−577
Author(s) -
Page K. L.,
Pounds K. A.,
Reeves J. N.,
O'Brien P. T.
Publication year - 2002
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2002.05184.x
Subject(s) - physics , astrophysics , rosat , black body radiation , galaxy , spectral line , astronomy , power law , corona (planetary geology) , flux (metallurgy) , photon , optics , statistics , materials science , mathematics , radiation , astrobiology , venus , metallurgy
An XMM‐Newton observation of the luminous Seyfert 1 galaxy 1H 0419−577 is presented. We find that the spectrum is well fitted by a power law of canonical slope (Γ∼1.9) and three blackbody components (to model the strong soft excess). The XMM‐Newton data are compared and contrasted with observations by ROSAT in 1992 and by ASCA and BeppoSAX in 1996. We find that the overall X‐ray spectrum has changed substantially over the period, and suggest that the changes are driven by the soft X‐ray component. When bright, as in our XMM‐Newton observation, it appears that the enhanced soft flux cools the Comptonizing corona, causing the 2–10 keV power law to assume a ‘typical’ slope, in contrast to the unusually hard (‘photon‐starved’) spectra observed by ASCA and BeppoSAX 4 years earlier.