An X-ray Spectroscopic Study of the Hot Interstellar Medium Toward the Galactic Bulge
arXiv:1108.4236 · doi:10.1093/pasj/63.sp3.S889
Abstract
We present a detailed spectroscopic study of the hot gas toward the Galactic bulge along the 4U 1820-303 sight line by a combination analysis of emission and absorption spectra. In addition to the absorption lines of OVII Kalpha, OVII Kbeta, OVIII Kalpha and NeIX Kalpha by Chandra LTGS as shown by previous works, Suzaku detected clearly the emission lines of OVII, OVIII, NeIX and NeX from the vicinity. We used simplified plasma models with constant temperature and density. Evaluation of the background and foreground emission was performed carefully, including stellar X-ray contribution based on the recent X-ray observational results and stellar distribution simulator. If we assume that one plasma component exists in front of 4U1820-303 and the other one at the back, the obtained temperatures are T= 1.7 +/- 0.2 MK for the front-side plasma and T=3.9(+0.4-0.3) MK for the backside. This scheme is consistent with a hot and thick ISM disk as suggested by the extragalactic source observations and an X-ray bulge around the Galactic center.
14 pages, 15 figures, accepted to be published in PASJ (Replace figure files to fix latex problem)
References in corpus (3)
Cited by in corpus (9)
- The Structure of the Milky Way's Hot Gas Halo
- The Rotation of the Hot Gas Around the Milky Way
- Where Do Galaxies End?
- Discovery of a very hot phase of the Milky Way CGM with non-solar abundance ratios
- A Search for a keV Signature of Radiatively Decaying Dark Matter with Suzaku XIS Observations of the X-ray Diffuse Background
- GARROTXA Cosmological Simulations of Milky Way-sized Galaxies: General Properties, Hot Gas Distribution, and Missing Baryons
- Cosmic ray transport and anisotropies
- Suzaku and XMM-Newton Observations of the North Polar Spur: Charge Exchange or ISM Absorption?
- The hot interstellar medium towards 4U 1820-30: a Bayesian analysis