Edward F. Brown

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We develop and calibrate a realistic model flame for hydrodynamical simulations of deflagrations in white dwarf (Type Ia) supernovae. Our flame model builds on the advection-diffusion-reaction model of Khokhlov and includes electron screening and Coulomb corrections to the equation of state in a self-consistent way. We calibrate this model flame—its(More)
Neutron stars and black holes often reside in binaries where the accretion rate onto the compact object varies by orders of magnitude. These ““ X-ray transients ÏÏ are observed both in outburst (when the high accretion rate makes them X-ray bright) and quiescence (when the accretion rate is very low, or potentially zero). In a previous paper, we showed that(More)
We present an analytic calculation of the thermonuclear depletion of lithium in contracting, fully convective, pre-main sequence stars of mass M ∼< 0.5M⊙. Previous numerical work relies on still-uncertain physics (atmospheric opacities and convection, in particular) to calculate the effective temperature as a unique function of stellar mass. We assume that(More)
Using the Chandra/ACIS-I detector, we have identified an X-ray source (CXOU 132619.7-472910.8) in the globular cluster NGC 5139 with a thermal spectrum identical to that observed from transiently accreting neutron stars in quiescence. The absence of intensity variability on timescales as short as 4 seconds (< 25% rms variability) and as long as 5 years(More)
The quasi-persistent neutron star X-ray transient and eclipsing binary EXO 0748−676 recently started the transition to quiescence following an accretion outburst that lasted more than 24 years. We report on two Chandra and 12 Swift observations performed within five months after the end of the outburst. The Chandra spectrum is composed of a soft, thermal(More)
In late 2008, the quasi-persistent neutron star X-ray transient and eclipsing binary EXO 0748−676 started a transition from outburst to quiescence, after it actively accreted for more than 24 yr. In a previous work, we discussed Chandra and Swift observations obtained during the first 5 months of this transition. Here, we report on further X-ray(More)
Chronic care facility stay has been shown to be an independent risk factor for venous thromboembolism. Review of the literature, however, reveals a paucity of data addressing the issue of venous thromboembolism in nursing home residents. The purpose of this study was to determine the incidence of venous thromboembolic events among nursing home residents. A(More)
OBJECTIVE To characterize changing patterns of antidepressant use in nursing facilities across the urban-rural continuum during the mid-1990s. DESIGN Retrospective analysis of antidepressant drug codes and demographic/clinical data from the Minimum Data Set (MDS) 1994 to 1997. SETTING Kansas nursing facilities. PARTICIPANTS Facility residents aged 65(More)
The monitoring of quiescent emission from neutron star transients with accretion outbursts long enough to significantly heat the neutron star crust has opened a new vista onto the physics of dense matter. In this paper we construct models of the thermal relaxation of the neutron star crust following the end of a protracted accretion outburst. We confirm the(More)