Old Isolated Accreting Neutron Stars: The Diffuse X–ray Emission From The Galactic Center
نویسندگان
چکیده
The contribution of weakly–magnetized (B ∼ 10 G) neutron stars accreting the interstellar medium to the diffuse X–ray emission observed in the Galactic Center is investigated. It is shown that, under rather conservative assumptions about the neutron stars and gas distributions, the accretion luminosity can account for a sizable fraction, possibly most, of the detected X–ray flux in the 2.5–7 keV band. In particular, model results are compared with Granat data and show a general agreement in both the flux energy and radial distributions. Subject headings: Accretion, accretion disks — Galaxy: center — stars: neutron — X–rays: general — X–rays: stars
منابع مشابه
On the Nature of the X-ray Emission from the Galactic Center Region
The origin of the X-ray emission from the central region of the Galaxy has remained a mystery, despite extensive study over the past two decades. A fundamental question is the relative contribution of the point-source and diffuse components of this emission, which is critical to understanding the high-energy phenomena and processes unique to this Galactic nuclear environment. Here, we report on...
متن کاملOld Isolated Accreting Neutron Stars: Contribution to the Soft X–ray Background in the 0.5–2 Kev Band
The issue of the observability of Old Isolated Neutron Stars (ONSs) accreting from the interstellar gas, is reconsidered using the spectra presented in Zampieri et al. (1995). In particular, we focus our attention on the overall soft X–ray emission of ONSs, which may provide a substantial contribution to the X–ray background in the 0.5–2 keV band. It is found that if accretion is channeled into...
متن کاملA DEEP Chandra CATALOG OF X-RAY POINT SOURCES TOWARD THE GALACTIC CENTER
We present a catalog of 2357 point sources detected during 590 ks of Chandra observations of the 17-by-17 arcminute field around Sgr A. This field encompasses a physical area of 40 by 40 pc at a distance of 8 kpc. The completeness limit of the sample at the Galactic center is 10 erg s (2.0–8.0 keV), while the detection limit is an order of magnitude lower. The 281 sources detected below 1.5 keV...
متن کاملChandra Observation of Diffuse Gas and LMXBs in the Elliptical Galaxy NGC 4649 ( M 60 )
We present a Chandra X-ray observation of the X-ray bright E2 elliptical galaxy NGC 4649. In addition to bright diffuse emission, we resolve 165 discrete sources, most of which are presumably low-mass X-ray binaries (LMXBs). As found in previous studies, the luminosity function of the resolved sources is well-fit by a broken power-law. In NGC 4697 and NGC 1553, the break luminosity was comparab...
متن کاملOn the Chandra X-ray Sources in the Galactic Center
Recent deep Chandra surveys of the Galactic center region have revealed the existence of a faint, hard X-ray source population. While the nature of this population is unknown, it is likely that several types of stellar objects contribute. For sources involving binary systems, accreting white dwarfs and accreting neutron stars with main sequence companions have been proposed. Among the accreting...
متن کامل