XMM-NEWTON DETECTION OF A TRANSIENT X-RAY SOURCE IN THE VICINITY OF V838 MONOCEROTIS
- Department of Physics and Center for Computational Relativity and Gravitation, Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester, NY 14623 (United States)
- Chester F. Carlson Center for Imaging Science, Rochester Institute of Technology, 85 Lomb Memorial Drive, Rochester, NY 14623 (United States)
- Space Telescope Science Institute, 3700 San Martin Dr., Baltimore, MD 21218 (United States)
- Department of Physics, Technion, Haifa 32000 (Israel)
- Department of Astrophysics, Nicolaus Copernicus Astronomical Center, Rabianska 8, 87-100 Torun (Poland)
- School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287-1404 (United States)
We report the XMM-Newton/EPIC detection in 2008 March of a luminous (L{sub X} {approx} 10{sup 32-33} erg s{sup -1}), variable X-ray source in the vicinity (within {approx}6'') of the enigmatic star V838 Mon, which underwent a spectacular outburst in early 2002. Spectral modeling of the XMM-Newton X-ray source indicates the presence of two plasma components with characteristic temperatures of T{sub X} {approx} 2 x 10{sup 6} K and {approx}1.5 x 10{sup 7} K, attenuated by an absorbing column (N{sub H} {approx} 4 x 10{sup 21} cm{sup -2}) that is consistent with the visual extinction measured toward V838 Mon (A{sub V} {approx} 2). No such luminous source was detected in the immediate vicinity of V838 Mon in Chandra/ACIS-S observations obtained about one year after outburst or, most recently, in 2010 January. The two XMM -Newton source spectral components appear to be marginally spatially resolved, with the spatial centroid of the hard component lying closer to (within {approx}2'' of) the position of V838 Mon than the broadband source or the soft source component; however, if there are two sources at or near V838 Mon, the Chandra nondetections would imply that both of them are variable. An alternative is that there is a single variable source, and that the apparent spatial separation may actually be due to photon-counting statistics or is perhaps instrumental in origin. We consider constraints placed by the X-ray detection and nondetections on a stellar merger model for the 2002 V838 Mon outburst, in which the spun-up merger product drives a powerful magnetic dynamo. Alternatively, the transient behavior of the X-ray source could indicate that the X-rays arose as a consequence of an interaction between V838 Mon's ejecta and its early-type (B3 V) companion.
- OSTI ID:
- 21455179
- Journal Information:
- Astrophysical Journal, Vol. 717, Issue 2; Other Information: DOI: 10.1088/0004-637X/717/2/795; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
The continued optical to mid-infrared evolution of V838 Monocerotis
Discovery of the candidate off-nuclear ultrasoft hyper-luminous X-ray source 3XMM J141711.1+522541