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A Hydrogen Atmosphere Spectral Model Applied to the Neutron Star X7 in the Globular Cluster 47 Tucanae
Current X-ray missions are providing high-quality X-ray spectra from neutron stars (NSs) in quiescent low-mass X-ray binaries (qLMXBs). This has motivated us to calculate new hydrogen atmosphereExpand
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Bayesian Estimation of Hardness Ratios: Modeling and Computations
A commonly used measure to summarize the nature of a photon spectrum is the so-called hardness ratio, which compares the numbers of counts observed in different passbands. The hardness ratio isExpand
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High-Resolution X-ray Imaging of a Globular Cluster Core: Compact Binaries in 47Tuc
We have obtained high-resolution (≲1") deep x-ray images of the globular cluster 47Tucanae (NGC 104) with the Chandra X-ray Observatory to study the population of compact binaries in the high stellarExpand
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We have detected 300 X-ray sources within the half-mass radius (279) of the globular cluster 47 Tucanae in a deep (281 ks) Chandra exposure. We perform photometry and simple spectral fitting for ourExpand
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Formation and evolution of compact binaries in globular clusters – II. Binaries with neutron stars
In this paper, the second of a series, we study the stellar dynamical and evolutionary processes leading to the formation of compact binaries containing neutron stars (NSs) in dense globularExpand
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Analysis of the Quiescent Low-Mass X-Ray Binary Population in Galactic Globular Clusters
Quiescent low-mass X-ray binaries (qLMXBs) containing neutron stars have been identified in several globular clusters using Chandra or XMM X-ray observations, via their distinctive soft thermalExpand
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Discovery of Powerful Gamma-Ray Flares from the Crab Nebula
Gamma-ray observations of the Crab Nebula by two different space telescopes challenge particle acceleration theory. The well-known Crab Nebula is at the center of the SN1054 supernova remnant. ItExpand
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Flaring Activity of Sagittarius A* at 43 and 22 GHz: Evidence for Expanding Hot Plasma
We have carried out Very Large Array (VLA) continuum observations to study the variability of Sgr A* at 43 GHz (λ = 7 mm) and 22 GHz (λ = 13 mm). A low level of flare activity has been detected withExpand
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Faint X-Ray Sources in the Globular Cluster Terzan 5
We report our analysis of a Chandra X-ray observation of the rich globular cluster Terzan 5, in which we detect 50 sources to a limiting 1.0-6 keV X-ray luminosity of 3 × 1031 ergs s-1 within theExpand
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Further Constraints on Thermal Quiescent X-Ray Emission from SAX J1808.4-3658
We observed SAX J1808.4-3658 (1808), the first accreting millisecond pulsar, in deep quiescence with XMM-Newton and (near simultaneously) Gemini-South. The X-ray spectrum of 1808 is similar to thatExpand
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