2005/10/27 by L. C. Gallo · 2 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2005.09780.x
published as Mon.Not.Roy.Astron.Soc.365:960-968,2006 · 9 pages, 8 figures. Accepted for publication in MNRAS. Correction made to reported aox value. No changes in conclusions
arxiv created 2005/10/27 · openalex publication_date 2005/12/07 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
We present two XMM-Newton observations of the luminous (Lx > 1046erg s−1), radio-quiet quasar PG 1407+265, separated by 11 months. The data indicate two distinct states: a highly variable, bright state (first epoch); and a quiescent, low-flux one (second epoch). During the low-flux state the spectrum is consistent with a single, unabsorbed power law. However, during the brighter state a highly variable, steep component is statistically required. Contemporaneous ultraviolet data from the Optical Monitor allow an estimate of the optical-to-X-ray spectral index (αox), which appears typical of radio-quiet quasars during the low-flux state, but extremely flat during the high-flux state. The XMM-Newton data can be described as originating from a combination of jet and accretion disc processes, in which the (relativistic) X-ray jet only works intermittently. The scenario could help to describe some of the complexities seen in the broad-band spectral energy distribution of PG 1407+265, such as weak high-ionization emission lines, strong Fe ii, unbeamed continuum and the weak radio emission relative to the optical.