ar X iv : a st ro - p h / 02 03 07 0 v 1 6 M ar 2 00 2 1 CHANDRA DEEP X - RAY OBSERVATION ON THE GALACTIC PLANE
نویسنده
چکیده
Using the Chandra ACIS-I instruments, we have carried out the deepest X-ray observation on a typical Galactic plane region at l ≈ 28.5, where no discrete X-ray sources have been known previously. We have detected, as well as strong diffuse emission, 275 new point X-ray sources (4 σ confidence) within two partially overlapping fields (∼250 arcmin in total) down to ∼ 3×10 erg s cm (2 – 10 keV) or ∼ 7 × 10 erg s cm (0.5 – 2 keV). We have studied spectral distribution of these point sources, and found that very soft sources detected only below ∼ 3 keV are more numerous than hard sources detected only above ∼ 3 keV. Only small number of sources are detected both in the soft and hard bands. Surface density of the hard sources is almost consistent with that at high Galactic regions, thus most of the hard sources are considered to be Active Galactic Nuclei seen through the milky way. On the other hand, some of the bright hard X-ray sources which show extremely flat spectra and iron line or edge features are considered to be Galactic, presumably quiescent dwarf novae. The soft sources show thermal spectra and small interstellar hydrogen column densities, and some of them exhibit X-ray flares. Therefore, most of the soft sources are probably X-ray active nearby late type stars.
منابع مشابه
ar X iv : a st ro - p h / 04 03 64 6 v 1 28 M ar 2 00 4 X - ray Survey Results on Active Galaxy Physics and Evolution
The cosmic X-ray background (XRB) is largely due to accretion onto supermassive black holes integrated over cosmic time. Thus, extragalactic X-ray surveys offer the potential to contribute substantially to our understanding of the physics of Active Galactic Nuclei (AGN) as well as the evolution of the AGN population. Such surveys have dramatically advanced over the past four years, largely due ...
متن کاملar X iv : a st ro - p h / 03 08 07 9 v 1 5 A ug 2 00 3 THE 2 MS CHANDRA DEEP FIELD - NORTH
The 2 Ms Chandra Deep Field-North survey provides the deepest view of the Universe in the 0.5–8.0 keV X-ray band. In this brief review we investigate the diversity of X-ray selected sources and focus on the constraints placed on AGNs (including binary AGNs) in high-redshift submm galaxies.
متن کاملar X iv : a st ro - p h / 06 03 13 0 v 1 6 M ar 2 00 6 The INTEGRAL Galactic Bulge monitoring program
The Galactic Bulge region is a rich host of variable high-energy point sources. These sources include bright and relatively faint X-ray transients, X-ray bursters, persistent neutron star and black-hole candidate binaries, X-ray pulsars, etc.. We have a program to monitor the Galactic Bulge region regularly and frequently with the γ-ray observatory INTEGRAL. As a service to the scientific commu...
متن کاملar X iv : a st ro - p h / 04 03 67 6 v 1 3 0 M ar 2 00 4 1 STUDY OF UNIDENTIFIED EGRET SOURCES WITH INTEGRAL : FIRST RESULTS AND FUTURE PROSPECTS
The primary objective of the study of unidentified EGRET sources with INTEGRAL is to locate with a few arcminute accuracy the hard X-ray / soft γ-ray counterparts within the EGRET error circle or to determine upper limits on their emission in the INTEGRAL energy range. The INTEGRAL Galactic Plane Scan (GPS) and Galactic Centre Deep Exposure (GCDE) data have been analysed and cross–correlated wi...
متن کامل