Discovery of an obscured globular cluster associated with GX 354+0 /=4U/MXB 1728-34/

Abstract

view Abstract Citations (53) References (16) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Discovery of an obscured globular cluster associated with GX 354+0 (=4U/MXB 1728-34). Grindlay, J. E. ; Hertz, P. Abstract A diffuse infrared source identified as the most heavily obscured globular cluster yet found, was observed using the NASA 3m infrared telescope facility and Einstein positions for the X-ray source GX 354+0 (=4U/MXB 1728-34). Color excesses were measured to 1.4 + or - 0.3 for E(J-H) and 0.63 + or - 0.07 for E(H-K), and the visual extinction was determined at 10.6 + or - 1.3. The magnitude of several giant branch stars imply the cluster to be at a distance of 10.0 + or - 3.9 kpc, if metal rich, or 5.2 + or - 1.4 kpc, if metal poor. A single burst from MXB 1728-34 was observed with a blackbody temperature and cluster distance that indicated the luminosity to be not less than 10 times the Eddington limit for a neutron star model. This identification brings to 11 the number of compact X-ray sources in globular clusters, and reinforces the connection between GX sources, bursters, and globular clusters. Publication: The Astrophysical Journal Pub Date: July 1981 DOI: 10.1086/183580 Bibcode: 1981ApJ...247L..17G Keywords: Globular Clusters; Heao 2; Infrared Astronomy; Signal To Noise Ratios; Stellar Spectrophotometry; X Ray Sources; Flare Stars; Interstellar Extinction; Metallic Stars; Star Distribution; Stellar Luminosity; Astronomy full text sources ADS | data products SIMBAD (2)