X-ray development of the classical nova V2672 Ophiuchi with Suzaku

Abstract

We report on the Suzaku detection of a rapid flare-like X-ray flux amplification early in the development of the classical nova V2672 Ophiuchi. Two target-of-opportunity ∼25ks X-ray observations were made 12 and 22d after the outburst. The flux amplification was found in the latter half of day 12. Time-sliced spectra are characterized by a growing supersoft excess with edge-like structures and a relatively stable optically-thin thermal component with Kα emission lines from highly ionized Si. The observed spectral evolution is consistent with a model that has a time development of circumstellar absorption, for which we obtained a decline rate of ∼10%-40% on a time scale of 0.2d on day 12. Such a rapid drop of absorption and short-term flux variability on day 12 suggests inhomogeneous ejecta with dense blobs/holes in the line-of-sight. Then on day 22 the fluxes of both supersoft and thin-thermal plasma components became significantly fainter. Based on the serendipitous results we discuss the nature of this source in the context of both short-and long-term X-ray behavior. © 2014 The Author.