1 Xmm-newton Results on the Ultracompact Low Mass X–ray Binary 4u 1850-087 in the Globular Cluster Ngc 6712
نویسندگان
چکیده
We report on preliminary results from our XMM-Newton observation of the Low Mass X-ray Binary 4U 1850-087, located in the galactic globular cluster NGC 6712. It is an ultracompact binary system, with an orbital period of 20.6 min. In previous low-resolution X-ray observations 4U 1850-087 displayed a soft excess residual around 0.7 keV, possibly indicative of the presence of a high Ne/O ratio, as already found in other three ultracompact LMXBs containing a neutron star (4U 0614+091, 4U 0918-549, and 4U 1543-624). We discuss here our preliminary analysis of high resolution X-ray spectra of 4U 1850-087, and timing results.
منابع مشابه
The ultra-compact binary 4U 1850−087 observed with INTEGRAL: hard X–ray emission from an X–ray burster
Context. The X–ray burster 4U 1850−087, located in the Galactic globular cluster NGC 6712, is an ultracompact binary (orbital period ∼21 minutes), likely harbouring a degenerate companion. Aims. The source has been observed at soft γ-rays several times with the INTEGRAL satellite, during the monitoring of the Galactic plane, with an unprecedented exposure time. We analysed all available INTEGRA...
متن کاملLow - energy absorption towards the ultra - compact X – ray binary 4 U 1850 − 087 located in the globular cluster NGC 6712
We report the results of two XMM–Newton observations of the ultra-compact low-mass X–ray binary 4U 1850−087 located in the galactic globular cluster NGC6712. A broad emission feature at 0.7 keV was detected in an earlier ASCA observation and explained as the result of an unusual Ne/O abundance ratio in the absorbing material local to the source. We find no evidence for this feature and derive N...
متن کاملXMM - Newton observations of the low – mass X – ray binary XB 1832 – 330 in the galactic globular cluster NGC 6652
Context. We report on two XMM-Newton observations performed in 2006 of the luminous low–mass X–ray binary XB 1832–330 which is located in the galactic globular cluster NGC 6652 and is probably an ultracompact binary (orbital period, P orb , of <1 hour). Aims. The aim of these observations is to investigate the low-energy absorption towards XB 1832–330 and in particular to search for Ne-rich mat...
متن کاملXMM - Newton X - ray and optical observations of the globular clusters M 55 and NGC 3201
We have observed two low concentration Galactic globular clusters with the X-ray observatory XMM-Newton. We detect 47 faint X-ray sources in the direction of M 55 and 62 in the field of view of NGC 3201. Using the statistical Log N-Log S relationship of extragalactic sources derived from XMM-Newton Lockman Hole observations, to estimate the background source population, we estimate that very fe...
متن کاملUltracompact X-Ray Binaries in Globular Clusters: Variability of the Optical Counterpart of X1832-330 in NGC 6652.
Evidence is emerging that the luminous X-ray sources in the cores of globular clusters may often consist of, or perhaps even as a class be dominated by, ultracompact (P less, similar1 hr) binary stars. To the two such systems already known, in NGC 6624 and NGC 6712, we now add evidence for two more. We detect large-amplitude variability in the candidate optical counterpart for the X-ray source ...
متن کامل