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XMM-Newton Observations of the 2003 X-Ray Minimum of Eta CarinaeThe XMM-Newton X-ray observatory took part in the multi-wavelength observing campaign of the massive, evolved star Eta Carinae in 2003 during its recent X-ray minimum in June 2003. This paper reports on the first results of these observations, which were performed (1) before the minimum (five times in January, 2003), (2) near the X-ray maximum just before the minimum (two times in June) and (3) during the minimum (four times in July-August). Hard X-ray emission from the point source of Eta Carinae was detected even during the minimum. The observed flux above 3 keV was approx. 3x10(exp -12) ergs cm(exp -2)/s, which is about one percent of the flux before the minimum. Light curves from the individual observations show no time variability on the scale of a few kilo-seconds. Changes in the spectral shape occurred, but these changes were smaller than expected if the minimum is produced solely by an increase of hydrogen column density. Fits of the hard X-Ray source by an absorbed 1T model show a constant plasma temperature at around 5 keV and an increase of column density from 5x10(exp 22) cm(exp -2) to 2x10(exp 23) cm(exp -2). The spectra below 6 keV significantly deviate from the models that fit the higher energy emission. The X-ray minimum seems to be dominated by an apparent decrease of the emission measure, suggesting that the brightest part of the X-ray emitting region is completely obscured during the minimum in the form of an eclipse. Partial covering plasma emission models might be considered for the spectral variation. The spectra also showed strong iron K line emission from both hot and cold gases, and weak line emission from Ni, Ca, Ar, S and Si.
Document ID
20040171536
Acquisition Source
Goddard Space Flight Center
Document Type
Conference Paper
Authors
Hamaguchi, K.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Corcoran, M. F.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
White, N. E.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Damineli, A.
(IAGUSP Brazil)
Davidson, K.
(Minnesota Univ. MN, United States)
Gull, T. R.
(NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 22, 2013
Publication Date
January 1, 2004
Subject Category
Astronomy
Meeting Information
Meeting: American Astronomical Society Meeting
Location: Atlanta, GA
Country: United States
Start Date: January 4, 2004
End Date: January 8, 2004
Distribution Limits
Public
Copyright
Other

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