2016/07/09 by Pramod Pawar, G. C. Dewangan, Pawar, Pramod +7
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysical Phenomena and Observations #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #High Energy Astrophysical Phenomena (astro-ph.HE)
paper · pdf · doi:10.48550/arxiv.1607.02635
openalex publication_date 2016/07/09 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We performed time resolved spectroscopy of 1H0707-495 and IRAS 13224-3809\nusing long XMM-Newton observations. These are strongly variable narrow line\nSeyfert 1 galaxies and show broad features around 1 keV that has been\ninterpreted as relativistically broad Fe L\α lines. Such features are not\nclearly observed in other AGN despite sometimes having high iron abundance\nrequired by the best fitted blurred reflection models. Given the importance of\nthese lines, we explore the possibility if rapid variability of spectral\nparameters may introduce broad bumps/dips artificially in the time averaged\nspectrum, which may then be mistaken as broadened lines. We tested this\nhypothesis by performing time resolved spectroscopy using long (> 100 ks)\nXMM-Newton observations and by dividing it into segments with typical exposure\nof few ks. We extracted spectra from each such segment and modelled using a two\ncomponent phenomenological model consisting of a power law to represent hard\ncomponent and a black body to represent the soft emission. As expected both the\nsources showed variations in the spectral parameters. Using these variation\ntrends, we simulated model spectra for each segment and then co-added to get a\ncombined simulated spectrum. In the simulated spectra, we found no broad\nfeatures below 1 keV and in particular no deviation near 0.9 keV as seen in the\nreal average spectra. This implies that the broad Fe L? line that is seen in\nthe spectra of these sources is not an artifact of the variation of spectral\ncomponents and hence providing evidence that the line is indeed genuine.\n