Astronomy and Astrophysics – Astrophysics
Scientific paper
2006-06-12
Astrophys.J.649:979-991,2006
Astronomy and Astrophysics
Astrophysics
Accepted in ApJ
Scientific paper
10.1086/506602
We present a combined analysis of the X-ray emission of the Capella corona obtained with \textit{XMM-Newton} RGS, \textit{Chandra} HETGS, and LETGS. An improved atomic line database and a new differential emission measure (DEM) deconvolution method are developed for this purpose. Our new atomic database is based on the Astrophysical Plasma Emission Database and incorporates improved calculations of ionization equilibrium and line emissivities for L-shell ions of abundant elements using the Flexible Atomic Code. The new DEM deconvolution method uses a Markov Chain Monte-Carlo (MCMC) technique which differs from existing MCMC or $\chi^2$-fitting based methods. We analyze the advantages and disadvantages of each individual instrument in determining the DEM and elemental abundances. We conclude that results from either RGS or HETGS data alone are not robust enough due to their failure to constrain DEM in some temperature region or the lack of significant continuum emission in the wavelength band of the spectrometers, and that the combination of HETGS and RGS gives more stringent constraints on the DEM and abundance determinations. Using the LETGS data, we show that the recently discovered inconsistencies between the EUV and X-ray lines of Fe XVIII and XIX also exist in more highly charged iron ions, up to Fe XXIII, and that enhanced interstellar absorption due to partially ionized plasma along the Capella line of sight may explain some, but not all, of these discrepancies.
Gu Min Feng
Gupta Rachana
Kahn Steve M.
Peterson James R.
Sako Masao
No associations
LandOfFree
Capella Corona Revisited: A Combined View from \textit{XMM-Newton} RGS, \textit{Chandra} HETGS, and LETGS does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Capella Corona Revisited: A Combined View from \textit{XMM-Newton} RGS, \textit{Chandra} HETGS, and LETGS, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Capella Corona Revisited: A Combined View from \textit{XMM-Newton} RGS, \textit{Chandra} HETGS, and LETGS will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-45263