Supernova Light Curves Powered by Young Magnetars (2009)
We show that energy deposited into an expanding supernova remnant by a highly magnetic (B ~ 5 x 10^14 G) neutron star spinning at an initial period of P ~ 2-20 ms can substantially brighten the light...
Exploring the Optical Transient Sky with the Palomar Transient Factory (2009)
Rau, Arne, Kulkarni, Shrinivas R., Law, Nicholas M., Bloom, Joshua S., Ciardi, David, Djorgovski, George S., ...
The Palomar Transient Factory (PTF) is a wide-field experiment designed to investigate the optical transient and variable sky on time scales from minutes to years. PTF uses the CFH12k mosaic camera,...
Helium White Dwarfs in Cataclysmic Variables (2009)
Shen, Ken J., Idan, Irit, Bildsten, Lars
Binary evolution predicts a population of helium core (M < 0.5 Msol) white dwarfs (WDs) that are slowly accreting hydrogen-rich material from low mass main sequence or brown dwarf donors with orbital...
Globular Clusters as Testbeds for Type Ia Supernovae (2009)
Pfahl, Eric, Scannapieco, Evan, Bildsten, Lars
Fundamental mysteries remain regarding the physics of Type Ia supernovae (SNIa) and their stellar progenitors. We argue here that important clues to these questions may emerge by the identification...
Unstable Helium Shell Burning on Accreting White Dwarfs (2009)
AM Canum Venaticorum (AM CVn) binaries consist of a degenerate helium donor and a helium, C/O, or O/Ne WD accretor, with accretion rates of Mdot = 1e-13 - 1e-5 Msol/yr. For accretion rates < 1e-6...
Pulsations of the low-mass ZZ Ceti star HS 1824+6000 (2008)
Steinfadt, Justin D. R., Bildsten, Lars, Ofek, Eran O., Kulkarni, Shri R.
Measuring g-mode pulsations of isolated white dwarfs can reveal their interior properties to high precision. With a spectroscopic mass of ≈0.51 M⊙ (log g = 7.82), the DAV white dwarf HS 1824+6000...
Pulsations of the Low Mass ZZ Ceti Star HS 1824+6000 (2008)
Steinfadt, Justin D. R., Bildsten, Lars, Ofek, Eran O., Kulkarni, Shri R.
Measuring g-mode pulsations of isolated white dwarfs can reveal their interior properties to high precision. With a spectroscopic mass of ~0.51 M_{\odot} (log g = 7.82), the DAV white dwarf HS...
Guillot, Sebastien, Rutledge, Robert E., Bildsten, Lars, Brown, Edward F., Pavlov, George G., Zavlin, Vyacheslav E.
We report the search for low-mass X-ray binaries in quiescence (qLMXBs) in the globular cluster NGC 6304 using XMM observations. We present the spectral analysis leading to the identification of...
The Effect of Composition on Nova Ignitions (2008)
The accretion of hydrogen-rich matter onto C/O and O/Ne white dwarfs in binary systems leads to unstable thermonuclear ignition of the accreted envelope, triggering a convective thermonuclear runaway...
Classical Nucleation Theory of the One-Component Plasma (2008)
Cooper, Randall L., Bildsten, Lars
We investigate the crystallization rate of a one-component plasma (OCP) in the context of classical nucleation theory. From our derivation of the free energy of an arbitrary distribution of solid...
Detecting gravitational wave emission from the known accreting neutron stars (2008)
Watts, Anna, Krishnan, Badri, Bildsten, Lars, Schutz, Bernard
Detection of gravitational waves from accreting neutron stars (NSs) in our galaxy, due to ellipticity or internal oscillation, would be a breakthrough in our understanding of compact objects and...
Discovery of the Partially Eclipsing White Dwarf Binary SDSS J143547.87+373338.5 (2008)
Steinfadt, Justin D. R., Bildsten, Lars, Howell, Steve B.
We have discovered a partially eclipsing white dwarf, low-mass M dwarf binary (3 hour 54.41 second orbital period), SDSS J143547.87+373338.5, from May 2007 observations at the WIYN telescope. Here we...
Detecting gravitational wave emission from the known accreting neutron stars (2008)
Watts, Anna L., Krishnan, Badri, Bildsten, Lars, Schutz, Bernard F.
Detection of gravitational waves from accreting neutron stars (NSs) in our galaxy, due to ellipticity or internal oscillation, would be a breakthrough in our understanding of compact objects and...
Detecting gravitational wave emission from the known accreting neutron stars (2008)
Watts, Anna L., Krishnan, Badri, Bildsten, Lars, Schutz, Bernard F.
Pegasi Geoffrey Paul, Eric Marcy, Lars Bildsten, James R. Graham, Andrea M. Ghez, ...
Doppler measurements of 51 Pegasi have been made from 1995 October through 1996 August, with a precision of5ms~1. We nd a period of 4.231 days, a velocity amplitude of 56 ^1ms~1, and a velocity curve...
Dong Lai, Lars Bildsten, Victoria M. Kaspi
The spin-induced quadrupole moment of a rapidly rotating star changes the orbital dynamics in a binary system, giving rise to advance (or regression) of periastron and precession of the orbital...
Lars Bildsten, Deepto Chakrabarty, John Chiu, Mark H. Finger, Danny T. Koh, Mark Stollberg, ...
We summarize 5 years of continuous monitoring of accretion-powered pulsars with the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory. Our 20È70 keV observations...
Robert W. Nelson, Lars Bildsten, Deepto Chakrabarty, Mark H. Finger, Danny T. Koh, Thomas A. Prince, ...
Dramatic torque reversals between spin-up and spin-down have been observed in half of the persistent X-ray pulsars monitored by the BATSE all-sky monitor on the Compton Gamma Ray Observatory....
Deepto Chakrabarty, Lars Bildsten, Mark H. Finger, Robert W. Nelson, Thomas A. Prince, Brian A. Vaughan, ...
To appear in The Astrophysical Journal Letters Over five years of daily hard X-ray (?20 keV) monitoring of the 2 min accretion-powered pulsar GX 1+4 with the Compton Gamma Ray Observatory /BATSE...
Danny T. Koh, Lars Bildsten, Deepto Chakrabarty, Robert W. Nelson, Thomas A. Prince, Brian A. Vaughan, ...
The accreting pulsar GX 301--2 (P = 680 s) has been observed continuously by the large area detectors of the Burst and Transient Source Experiment (BATSE) instrument on the Compton Gamma Ray...
Deepto Chakrabarty, Towsian Koh, Lars Bildsten, Thomas A. Prince, Mark H. Finger, Robert B. Wilson, ...
We have detected an 18.7 s accreting X-ray pulsar in the Cygnus region, using the BATSE large-area detectors on the Compton Gamma Ray Observatory. GRO J1948+32 has been localized to within 10 deg 2...
OBSERVATIONS OF ACCRETING PULSARS (2007)
Thomas A. Prince, Lars Bildsten, Deepto Chakrabarty, Robert B. Wilson, Mark H. Finger
We discuss recent observations of accreting binary pulsars with the allsky BATSE instrument on the Compton Gamma Ray Observatory. BATSE has detected and studied nearly half of the known accreting...
Deepto Chakrabarty, Lars Bildsten, John M. Grunsfeld, Danny T. Koh, Thomas A. Prince, Brian A. Vaughan, ...
Over five years of hard X-ray (20--60 keV) monitoring of the 7.66 s accretionpowered pulsar 4U 1626--67 with the Compton/BATSE large-area detectors have revealed that the neutron star is now steadily...
Mark H. Finger, Lars Bildsten, Deepto Chakrabarty, Thomas A. Prince, D. Matthew Scott, Colleen A. Wilson, ...
We present observations of a series of 10 outbursts of pulsed hard X-ray Ñux from the transient 10.6 mHz accreting pulsar GS 1843[02, using the Burst and Transient Source Experiment on the Compton...
Danny T. Koh, Lars Bildsten, Deepto Chakrabarty, Robert W. Nelson, Thomas A. Prince, ...
The accreting pulsar GX 301[2 (P\680 s) has been observed continuously by the large-area detectors of the Burst and Transient Source Experiment (BATSE) instrument on the Compton Gamma Ray Observatory...
OBSERVATIONS OF ACCRETING PULSARS (2007)
Lars Bildsten, Deepto Chakrabarty, John Chiu, Mark H. Finger, Danny T. Koh, Robert W. Nelson, ...
We summarize ve years of continuous monitoring of accretion-powered pulsars with the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory. Our 20{70 keV observations...
bildsten @ re.berkeley.edu (2007)
Colleen A. Wilson, Mark H. Finger, B. Alan Harmon, D. Matthew Scott, Robert B. Wilson, Lars Bildsten, ...
GS 0834{430, a 12.3 second accretion-powered pulsar, has been observed in seven outbursts with the BATSE large area detectors on the Compton Gamma Ray Observatory. The rst 5 outbursts observed by...
The Turbulent Story of X-ray Bursts: Effects of Shear Mixing on Accreting Neutron Stars (2007)
Piro, Anthony L., Bildsten, Lars
During accretion, a neutron star (NS) is spun up as angular momentum is transported through its liquid surface layers. We study the resulting differentially rotating profile, focusing on the impact...
Neutronization During Type Ia Supernova Simmering (2007)
Piro, Anthony L., Bildsten, Lars
Prior to the incineration of a white dwarf (WD) that makes a Type Ia supernova (SN Ia), the star "simmers" for ~1000 years in a convecting, carbon burning region. We have found that weak interactions...
Carbon Detonation and Shock-Triggered Helium Burning in Neutron Star Superbursts (2007)
Weinberg, Nevin N., Bildsten, Lars
The strong degeneracy of the 12C ignition layer on an accreting neutron star results in a hydrodynamic thermonuclear runaway, in which the nuclear heating time becomes shorter than the local...
Turbulent Mixing in the Surface Layers of Accreting Neutron Stars (2007)
Piro, Anthony L., Bildsten, Lars
During accretion a neutron star (NS) is spun up as angular momentum is transported through its surface layers. We study the resulting differentially rotating profile, focusing on the impact this has...
Faint Thermonuclear Supernovae from AM Canum Venaticorum Binaries (2007)
Bildsten, Lars, Shen, Ken J., Weinberg, Nevin N., Nelemans, Gijs
Helium that accretes onto a Carbon/Oxygen white dwarf in the double white dwarf AM Canum Venaticorum (AM CVn) binaries undergoes unstable thermonuclear flashes when the orbital period is in the...
Thermally Stable Nuclear Burning on Accreting White Dwarfs (2007)
One of the challenges to increasing the mass of a white dwarf through accretion is the tendency for the accumulating hydrogen to ignite unstably and potentially trigger mass loss. It has been known...
Hydrodynamic Thermonuclear Runaways in Superbursts (2006)
Weinberg, Nevin N., Bildsten, Lars, Brown, Edward F.
We calculate the thermal and dynamical evolution of the surface layers of an accreting neutron star during the rise of a superburst. For the first few hours following unstable 12C ignition, the...
The Advanced Compton Telescope Mission (2006)
Boggs, Steven E., Kurfess, James, Ryan, James, Aprile, Elena, Gehrels, Neil, Kippen, Marc, ...
The Advanced Compton Telescope (ACT), the next major step in gamma-ray astronomy, will probe the fires where chemical elements are formed by enabling high-resolution spectroscopy of nuclear emission...
Pulsational Instabilities in Accreting White Dwarfs (2006)
Arras, Phil, Townsley, Dean M., Bildsten, Lars
(Abridged) The Cataclysmic Variable (CV) population harbors a diverse range of donor stars and accreting white dwarfs (WDs). A range of WD masses is expected, from low mass Helium core WDs, to...
Thermal Structure and Radius Evolution of Irradiated Gas Giant Planets (2006)
We consider the thermal structure and radii of strongly irradiated gas giant planets over a range in mass and irradiating flux. The cooling rate of the planet is sensitive to the surface boundary...
Engineering Microorganisms for Energy Production (2006)
Brenner, Michael P., Bildsten, Lars, Dyson, Freeman, Fortson, Norval, Garwin, Richard, Grober, Robert, ...
JASON was asked by the Office of Biological and Environmental Research of the Department of Energy to assess the possibilities for using microorganisms to produce fuels as a metabolic product, in...
Exposing the Nuclear Burning Ashes of Radius Expansion Type I X-ray Bursts (2005)
Weinberg, Nevin N., Bildsten, Lars, Schatz, Hendrik
We solve for the evolution of the vertical extent of the convective region of a neutron star atmosphere during a Type I X-ray burst. The convective region is well-mixed with ashes of nuclear burning...
X-ray binaries in Sculptor (2005)
Maccarone, Thomas J., Kundu, Arunav, Zepf, Stephen E., Piro, Anthony L., Bildsten, Lars
We report the results of a deep Chandra survey of the Sculptor dwarf spheroidal galaxy. We find five X-ray sources with L_X of at least 6*10^33 ergs/sec with optical counterparts establishing them as...
The Energy Dependence of Neutron Star Surface Modes and X-ray Burst Oscillations (2005)
Piro, Anthony L., Bildsten, Lars
We calculate the photon energy dependence of the pulsed amplitude of neutron star (NS) surface modes. Simple approximations demonstrate that it depends most strongly on the bursting NS surface...
The Thermal State of the Accreting White Dwarf in AM Canum Venaticorum Binaries (2005)
Bildsten, Lars, Townsley, Dean M., Deloye, Christopher J., Nelemans, Gijs
We calculate the heating and cooling of the accreting white dwarf (WD) in the ultracompact AM Canum Venaticorum (AM CVn) binaries and show that the WD can contribute significantly to their optical...
The discovery of X-ray binaries in the Sculptor Dwarf Spheroidal Galaxy (2005)
Maccarone, Thomas J., Kundu, Arunav, Zepf, Stephen E., Piro, Anthony L., Bildsten, Lars
We report the results of a deep Chandra survey of the Sculptor dwarf spheroidal galaxy. We find five X-ray sources with $L_X$ of at least $6\times10^{33}$ ergs/sec with optical counterparts...
The Type Ia Supernova Rate (2005)
Scannapieco, Evan, Bildsten, Lars
We explore the idea that the Type Ia supernovae (SNe Ia) rate consists of two components: a prompt piece that is proportional to the star formation rate (SFR) and an extended piece that is...
White Dwarf Heating and Subsequent Cooling in Dwarf Nova Outbursts (2005)
Piro, Anthony L., Arras, Phil, Bildsten, Lars
We follow the time dependent thermal evolution of a white dwarf (WD) undergoing sudden accretion in a dwarf nova outburst, using both simulations and analytic estimates. The post-outburst lightcurve...
Classical Novae as a Probe of the Cataclysmic Variable Population (2005)
Townsley, Dean M., Bildsten, Lars
Classical Novae (CNe) are the brightest manifestation of mass transfer onto a white dwarf in a cataclysmic variable (CV). As such, they are probes of the mass transfer rate, Mdot, and WD mass, Mwd,...
Surface Modes on Bursting Neutron Stars and X-ray Burst Oscillations (2005)
Piro, Anthony L., Bildsten, Lars
Accreting neutron stars (NSs) often show coherent modulations during type I X-ray bursts, called burst oscillations. We consider whether a nonradial mode can serve as an explanation for burst...
Arbitrarily Degenerate Helium White Dwarfs as Donors in AM CVn Binaries (2005)
Deloye, Christopher J., Bildsten, Lars, Nelemans, Gijs
We apply the Deloye & Bildsten (2003) isentropic models for donors in ultracompact low-mass X-ray binaries to the AM CVn population of ultracompact, interacting binaries. The mass-radius relations of...
Christopher Stubbs, Michael Brenner, Lars Bildsten, Paul Dimotakis, Stanley Flatté, Jeremy Goodman, ...
OMB No. 0704-0188 Public reporting burden for this collection of information estimated to average 1 hour per response, including the time for review instructions, searching existing data sources,...
A Spreading Layer Origin for Dwarf Nova Oscillations (2004)
Piro, Anthony L., Bildsten, Lars
Dwarf nova outbursts often show coherent ($Q\sim10^4-10^6$) sinusoidal oscillations with the largest pulsed fraction in the extreme ultraviolet. Called dwarf nova oscillations (DNOs), they have...
Seismology of Accreting White Dwarfs (2004)
Arras, Phil, Townsley, Dean, Bildsten, Lars
Pulsation modes have recently been observed in a handful of white dwarf (WD) primaries of cataclysmic variables, allowing an interesting new probe into the structure of accreting WD's. We briefly...
Neutron Star Crustal Interface Waves (2004)
Piro, Anthony L., Bildsten, Lars
The eigenfrequencies of nonradial oscillations are a powerful probe of a star's interior structure. This is especially true when there exist discontinuities such as at the neutron star (NS)...
Lai, Dong, Bildsten, Lars, Kaspi, Victoria M.
The spin-induced quadrupole moment of a rapidly rotating star changes the orbital dynamics in a binary system, giving rise to advance (or regression) of periastron and precession of the orbital...
The Spreading Layer and Dwarf Nova Oscillations (2004)
Piro, Anthony L., Bildsten, Lars
We describe recent theoretical work on the final stage of accretion when material passes from an accretion disk onto a white dwarf surface. Our calculations focus on understanding the latitudinal...
Seismology of the Accreting White Dwarf in GW Lib (2004)
Townsley, Dean M., Arras, Phil, Bildsten, Lars
We present a first analysis of the g-mode oscillation spectrum for the white dwarf (WD) primary of GW Lib, a faint cataclysmic variable (CV). Stable periodicities have been observed from this WD for...
Ultracompact Binaries as Bright X-Ray Sources in Elliptical Galaxies (2004)
Bildsten, Lars, Deloye, Christopher J.
Chandra observations of distant elliptical galaxies have revealed large numbers of Low Mass X-ray Binaries (LMXBs) accreting at rates in excess of 10^{-8} solar masses per year. The majority of these...
Spreading of Accreted Material on White Dwarfs (2004)
Piro, Anthony L., Bildsten, Lars
When a white dwarf (WD) is weakly magnetized and its accretion disk is thin, accreted material first reaches the WD's surface at its equator. This matter slows its orbit as it comes into co-rotation...
Physical interpretation of dwarf nova primary effective Temperaturas (2004)
Bildsten , Lars, Townsley , Dean M.
Hemos llevado a cabo un estudio teórico del impacto de las envolventes acumulativas sobre el estado térmico de la enana blanca subyacente (WD). Esto nos permitió encontrar las temperaturas de...
Unstable Nonradial Oscillations on Helium Burning Neutron Stars (2003)
Piro, Anthony L., Bildsten, Lars
Material accreted onto a neutron star can stably burn in steady state only when the accretion rate is high (typically super-Eddington) or if a large flux from the neutron star crust permeates the...
Measuring White Dwarf Accretion Rates via their Effective Temperatures (2003)
Townsley, Dean M., Bildsten, Lars
Our previous theoretical study of the impact of an accreting envelope on the thermal state of an underlying white dwarf (WD) has yielded equilibrium core temperatures, classical nova ignition masses...
White Dwarf Donors in Ultracompact Binaries: The Stellar Structure of Finite Entropy Objects (2003)
Deloye, Christopher J., Bildsten, Lars
We discuss the mass-radius (M-R) relations for low-mass (M
Townsley, Dean M., Bildsten, Lars
White dwarfs experience a thermal renaissance when they receive mass from a stellar companion in a binary. For accretion rates < 10^-8 Msun/yr, the freshly accumulated hydrogen/helium envelope...
New Views of Thermonuclear Bursts (2003)
Strohmayer, Tod, Bildsten, Lars
Since the advent of powerful new X-ray observatories, NASA's Rossi X-ray Timing Explorer (RXTE), the Italian - Dutch BeppoSAX mission, XMM-Newton and Chandra, a number of entirely new phenomena...
Arresting Accretion Torques with Gravitational Radiation (2002)
Recent theoretical work has made it plausible for neutron stars (NSs) to lose angular momentum via gravitational radiation on long timescales (around Myrs) while actively accreting. The gravitational...
Sinking of Ne-22 in Liquid White Dwarf Interiors (2002)
Deloye, Christopher J., Bildsten, Lars
We assess the impact of the trace element Ne-22 on the cooling and seismology of a liquid C/O white dwarf (WD). Due to this element's neutron excess, it sinks towards the interior as the liquid WD...
White Dwarf Colors in Low Accretion Rate Binaries (2002)
Townsley, Dean M., Bildsten, Lars
Our recent theoretical work (Townsley and Bildsten 2002) on the thermal state of white dwarfs (WDs) in low mass transfer rate binaries allows us to predict the broadband colors of the binary from...
Internal Conditions of Accreting White Dwarfs (2002)
Bildsten, Lars, Townsley, Dean M.
We explain the physics of compressional heating of the deep interior of an accreting white dwarf (WD) at accretion rates low enough so that the accumulated hydrogen burns unstably and initiates a...
Hot White Dwarf Donors in Ultracompact X-Ray Binaries (2002)
The discovery of two accreting millisecond X-ray pulsars in binaries with 43 minute orbital periods allows for a new probe of the donor's structure. For XTE J1751-305, only a hot white dwarf (WD) can...
Deloye, Christopher J., Bildsten, Lars
We assess the impact of the trace element ^{22}Ne on the cooling and seismology of a liquid C/O white dwarf (WD). Due to this elements' neutron excess, it sinks towards the interior as the liquid WD...
Transient X-ray Binaries in Elliptical Galaxies (2002)
Piro, Anthony L., Bildsten, Lars
Chandra observations of elliptical galaxies have revealed large numbers of Low Mass X-ray Binaries (LMXBs) accreting at rates above 10^-9 solar masses per year. One scenario which generates this...
Variable Thermal Emission from Aql X-1 in Quiescence (2002)
Rutledge, Robert E., Bildsten, Lars, Brown, Edward F., Pavlov, George G., Zavlin, Vyacheslav E.
We obtained four Chandra/ACIS-S observations beginning two weeks after the end of the November 2000 outburst of the neutron star (NS) transient Aql X-1. Over the five month span in quiescence, the...
Variability in the Thermal Emission from Accreting Neutron Star Transients (2002)
Brown, Edward F., Bildsten, Lars, Chang, Philip
The composition of the outer 100 m of a neutron star sets the heat flux that flows outwards from the core. For an accreting neutron star in an X-ray transient, the thermal quiescent flux depends...
Four New Delta Scuti Pulsators from a Variability Survey of 131 Stars (2002)
Sokoloski, J. L., Bildsten, Lars, Chornock, R., Filippenko, Alexei V.
In a photometric variability survey of 131 stars with B < 14 mag, we have found four new Delta Scuti stars. We were sensitive to oscillation amplitudes as low as a few mmag. The detection rate of...
Crustal emission and the quiescent spectrum of the neutron star in KS 1731-260 (2002)
Rutledge, Robert E., Bildsten, Lars, Brown, Edward F., Pavlov, George G., Zavlin, Vyacheslav E., Ushomirsky, Greg
The type I X-ray-bursting low-mass X-ray binary KS 1731-260 was recently detected for the first time in quiescence by Wijnands et al. following a tau(ob) approximate to 13 yr outburst, which ended in...
Variable thermal emission from aquila X-1 in quiescence (2002)
Rutledge, Robert E., Bildsten, Lars, Brown, Edward F., Pavlov, George G., Zavlin, Vyacheslav E.
We obtained four Chandra/ACIS-S observations beginning 2 weeks after the end of the 2000 November outburst of the neutron star (NS) transient Aql X-1. Over the 5 month span in quiescence, the X-ray...
Compressional Heating of Accreting White Dwarfs in CV's (2001)
Townsley, Dean M., Bildsten, Lars
In recent years several Dwarf Novae (DN) systems have been observed in quiescence, when the accretion rate is low and the WD photosphere can be directly detected. The WDs are observed to cool after...
Faint Cataclysmic Variables in Quiescence: Globular Cluster and Field Surveys (2001)
Townsley, Dean M., Bildsten, Lars
Current evolutionary models imply that most Cataclysmic Variables (CVs) have P_orb
Crustal Emission and the Quiescent Spectrum of the Neutron Star in KS 1731-260 (2001)
Rutledge, Robert E., Bildsten, Lars, Brown, Edward F., Pavlov, George G., Zavlin, Vyacheslav E., Ushomirsky, Greg
(Abridged). The type-I X-ray bursting low mass X-ray binary KS 1731-260 was recently detected for the first time in quiescence by Wijnands et al., following an approximately 13 yr outburst which...
Hydrostatic Expansion and Spin Changes During Type I X-Ray Bursts (2001)
Cumming, Andrew, Morsink, Sharon M., Bildsten, Lars, Friedman, John L., Holz, Daniel E.
We present calculations of the spin-down of a neutron star atmosphere due to hydrostatic expansion during a Type I X-ray burst. We show that (i) Cumming and Bildsten overestimated the spin-down of...
Carbon Flashes in the Heavy Element Ocean on Accreting Neutron Stars (2001)
Cumming, Andrew, Bildsten, Lars
We show that burning of a small mass fraction of carbon in a neutron star ocean is thermally unstable at low accumulated masses when the ocean contains heavy ashes from the hydrogen burning rapid...
Identification of A Transient Neutron Star in Quiescence in the Globular Cluster NGC 5139 (2001)
Rutledge, Robert E., Bildsten, Lars, Brown, Edward F., Pavlov, George G., Zavlin, Vyacheslav E.
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...
Quiescent Thermal Emission from the Neutron Star in Aql X-1 (2001)
Rutledge, Robert E., Bildsten, Lars, Brown, Edward F., Pavlov, George G., Zavlin, Vyacheslav E.
We report on the quiescent spectrum measured with Chandra/ACIS-S of the transient, type-I X-ray bursting neutron star Aql X-1, immediately following an accretion outburst. The neutron star radius,...
A Brown Dwarf Companion for the Accreting Millisecond Pulsar SAX J1808.4-3658 (2001)
Bildsten, Lars, Chakrabarty, Deepto
BeppoSAX has revealed a population of faint neutron star X-ray transients in the Galactic bulge. King conjectured that these neutron stars are accreting from brown dwarfs (BD) with a time-averaged...
A Search for Rapid Photometric Variability in Symbiotic Binaries (2001)
Sokoloski, J. L., Bildsten, Lars, Ho, Wynn C. G.
We report on our survey for rapid (time scale of minutes) photometric variability in symbiotic binaries. These binaries are becoming an increasingly important place to study accretion onto white...
Dissipation for Euler's Disk and a Desktop Demonstration of Coalescing Neutron Stars (2001)
I show that the recent calculation of Moffatt's regarding the viscous dissipation of a spinning coin overlooked the importance of the finite width of the viscous boundary layer. My new estimates are...
Magnetic Screening in Accreting Neutron Stars (2001)
Cumming, Andrew, Zweibel, Ellen G., Bildsten, Lars
We investigate whether the magnetic field of an accreting neutron star may be diamagnetically screened by the accreted matter. We assume the freshly accumulated material is unmagnetized, and...
Gravitational Settling of 22Ne in Liquid White Dwarf Interiors (2001)
Bildsten, Lars, Hall, David M.
The nuclear reactions that occur in the stellar progenitors of white dwarfs (WDs) lead to an internal composition of 12C, 16O, and a ``contaminant'' nucleus, 22Ne. The 22Ne is produced by helium...
The Quiescent X-Ray Spectrum of the Neutron Star in Cen X-4 Observed with Chandra/ACIS-S (2000)
Rutledge, Robert E., Bildsten, Lars, Brown, Edward F., Pavlov, George G., Zavlin, Vyacheslav E.
We report on spectral and intensity variability analysis from a Chandra/ACIS-S observation of the transient, type-I X-ray bursting low-mass X-ray binary Cen X-4. The quiescent X-ray spectrum during...
Chandra Detection of an X-ray Flare from the Brown Dwarf LP 944-20 (2000)
Rutledge, Robert E., Basri, Gibor, Martin, Eduardo, Bildsten, Lars
We have detected a bright X-ray flare from the nearby brown dwarf LP 944-20 with the Chandra/ACIS-S. This is an old (500 Myr), rapidly rotating, lithium-bearing M9 object, with a bolometric...
Rotational Evolution During Type I X-Ray Bursts (2000)
Cumming, Andrew, Bildsten, Lars
The rotation rates of six weakly-magnetic neutron stars accreting in low-mass X-ray binaries have most likely been measured by Type I X-ray burst observations with RXTE. The nearly coherent...
Nearly Coherent Oscillations in Type I X-Ray Bursts from KS 1731-260 (2000)
Muno, Michael P., Fox, Derek W., Morgan, Edward H., Bildsten, Lars
We present an analysis of the nine type I X-ray bursts that were observed from KS 1731-260 with RXTE. We find that the bursts divide naturally into two populations: ``fast bursts'' occur on the...
Gravitational Waves from Low-Mass X-ray Binaries: a Status Report (2000)
Ushomirsky, Greg, Bildsten, Lars, Cutler, Curt
We summarize the observations of the spin periods of rapidly accreting neutron stars. If gravitational radiation is responsible for balancing the accretion torque at the observed spin frequencies of...
Theory and Observations of Type I X-Ray Bursts from Neutron Stars (2000)
I review our understanding of the thermonuclear instabilities on accreting neutron stars that produce Type I X-Ray bursts. I emphasize those observational and theoretical aspects that should interest...
Deformations of Accreting Neutron Star Crusts and Gravitational Wave Emission (2000)
Ushomirsky, Greg, Cutler, Curt, Bildsten, Lars
Motivated by the narrow range of spin frequencies of nearly 20 accreting neutron stars, Bildsten (1998) conjectured that their spin-up had been halted by the emission of gravitational waves. He also...
Coronal X-Ray Emission from the Stellar Companions to Transiently Accreting Black Holes (1999)
Bildsten, Lars, Rutledge, Robert E.
Observations of soft X-ray transients (SXTs) in quiescence have found that the binaries harboring black holes are fainter than those that contain a neutron star. Narayan and collaborators postulated...
Viscous Boundary Layer Damping of R-Modes in Neutron Stars (1999)
Bildsten, Lars, Ushomirsky, Greg
Recent work has raised the exciting possibility that r-modes (Rossby waves) in rotating neutron star cores might be strong gravitational wave sources. We estimate the effect of a solid crust on their...
Rutledge, Robert E., Bildsten, Lars, Brown, Edward F., Pavlov, George G., Zavlin, Vyatcheslav E.
We fit hydrogen atmosphere models to the X-ray data for four neutron stars (three from a previous paper, plus 4U 2129+47) and six black hole candidates (A0620-00, GS 2000+25, GS 1124-68, GS 2023+33,...
The rp Process Ashes from Stable Nuclear Burning on an Accreting Neutron Star (1999)
Schatz, Hendrik, Bildsten, Lars, Cumming, Andrew, Wiescher, Michael
We calculate the nucleosynthesis during stable nuclear burning on an accreting neutron star. This is appropriate for weakly magnetic neutron stars accreting at near-Eddington rates in low mass X-ray...
The Outbursts and Orbit of the Accreting Pulsar GS 1843-02 = 2S 1845-024 (1998)
Finger, Mark H., Bildsten, Lars, Chakrabarty, Deepto, Prince, Thomas A., Scott, D. Matthew, Wilson, Colleen A., ...
We present observations of a series of 10 outbursts of pulsed hard X-ray flux from the transient 10.6 mHz accreting pulsar GS 1843-02, using the Burst and Transient Source Experiment on the Compton...
Discovery of a Magnetic White Dwarf in the Symbiotic Binary Z Andromedae (1998)
Sokoloski, J. L., Bildsten, Lars
We report the first result from our survey of rapid variability in symbiotic binaries: the discovery of a persistent oscillation at P=1682.6 +- 0.6 s in the optical emission from the prototype...
Portable Energy for the Dismounted Soldier (1998)
Lewis, Nathan S., Abarbanel, Henry, Bildsten, Lars, Dimotakis, Paul, Dyson, Freeman
In response to the study charge, the JASONs focused primarily on fuel cells for portable electrical energy production. Fuel cell technologies that were evaluated included high temperature fuel cells...
Stubbs, Christopher, Brenner, Michael, Bildsten, Lars, Dimotakis, Paul, Flatte, Stanley, Goodman, Jeremy, ...
JASON was asked to assist the U.S. Army's National Ground Intelligence (NGIC) in finding ways to enhance the effectiveness of infrasound monitoring. In addition, we were also tasked with determining...
Hammer, David, Bildsten, Lars, Abarbanel, Henry, Cornwall, John, Eardley, Douglas, Happer, Will, ...
JASON was asked by the National Nuclear Security Administration (NNSA) to assess the plan and prospects for achieving inertial confinement fusion (ICF) ignition at the National Ignition Facility...
Crustal Heating and Quiescent Emission from Transiently Accreting Neutron Stars (1998)
Brown, Edward F., Bildsten, Lars, Rutledge, Robert E.
Nuclear reactions occurring deep in the crust of a transiently accreting neutron star efficiently maintain the core at a temperature >5e7 K. When accretion halts, the envelope relaxes to a thermal...
Bildsten, Lars, Cumming, Andrew
We investigate hydrogen electron capture in the oceans of neutron stars accreting at rates appropriate for most Low-Mass X-Ray Binaries. These stars burn the accreted hydrogen and helium unstably in...
Gravitational Radiation and Rotation of Accreting Neutron Stars (1998)
Recent discoveries by the Rossi X-Ray Timing Explorer indicate that most of the rapidly accreting and weakly magnetic neutron stars in the Galaxy are rotating at spin frequencies greater than 250 Hz....
Rapid Rotation and Nonradial Pulsations: Kappa-Mechanism Excitation of G-Modes in B Stars (1998)
Ushomirsky, Greg, Bildsten, Lars
Several classes of stars (most notably O and B main-sequence stars, as well as accreting white dwarfs and neutron stars) rotate quite rapidly, at spin frequencies greater than the typical g-mode...
The Angular Momentum of Accreting Neutron Stars (1998)
I review the rotation measurements of accreting neutron stars. Many of the highly magnetic accreting X-ray pulsars have been continuously observed with the Burst and Transient Source Experiment...
Bildsten, Lars, Cumming, Andrew, Ushomirsky, Greg, Cutler, Curt
Observations of quasi-periodic oscillations (QPOs) in the luminosity from many accreting neutron stars (NS) have led us to investigate a source of periodicity prevalent in other stars: non-radial...
Light Element Depletion in Contracting Brown Dwarfs and Pre--Main-Sequence Stars (1997)
Ushomirsky, Greg, Matzner, Christopher D., Brown, Edward F., Bildsten, Lars, Hilliard, Vadim G., Schroeder, Peter C.
We present an analytic calculation of the thermonuclear depletion of the light elements lithium, beryllium, and boron in fully convective, low-mass stars. Under the presumption that the...
Brown, Edward F., Bildsten, Lars
We investigate the atmosphere, ocean, and crust of neutron stars accreting at rates sufficiently high (typically in excess of the local Eddington limit) to stabilize the burning of accreted hydrogen...
Thermonuclear Burning on Rapidly Accreting Neutron Stars (1997)
Neutron stars in mass-transferring binaries are accreting the hydrogen and helium rich matter from the surfaces of their companions. This article simply explains the physics associated with how that...
On the Dramatic Spin-up/Spin-down Torque Reversals in Accreting Pulsars (1997)
Nelson, Robert W., Bildsten, Lars, Chakrabarty, Deepto, Finger, Mark H., Koh, Danny T., Prince, Thomas A., ...
Dramatic torque reversals between spin up and spin down have been observed in half of the persistent X-ray pulsars monitored by the BATSE all-sky monitor on CGRO. Theoretical models developed to...
Observations of Accreting Pulsars (1997)
Bildsten, Lars, Chakrabarty, Deepto, Chiu, John, Finger, Mark H., Koh, Danny T., Nelson, Robert W., ...
We summarize five years of continuous monitoring of accretion-powered pulsars with the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory. Our 20-70 keV observations...
On the Correlation of Torque and Luminosity in GX 1+4 (1997)
Chakrabarty, Deepto, Bildsten, Lars, Finger, Mark H., Grunsfeld, John M., Koh, Danny T., Nelson, Robert W., ...
Over five years of daily hard X-ray (>20 keV) monitoring of the 2-min accretion-powered pulsar GX 1+4 with the Compton Gamma Ray Observatory/BATSE large-area detectors has found nearly continuous...
Lithium Depletion in Fully Convective Pre-Main Sequence Stars (1996)
Bildsten, Lars, Brown, Edward F., Matzner, Christopher D., Ushomirsky, Greg
We present an analytic calculation of the thermonuclear depletion of lithium in contracting, fully convective, pre-main sequence stars of mass M < 0.5 M_sun. Previous numerical work relies on...
Thermonuclear Burning on the Accreting X-Ray Pulsar GRO J1744-28 (1996)
Bildsten, Lars, Brown, Edward F.
We investigate the thermal stability of nuclear burning on the accreting X-ray pulsar GRO J1744-28. The neutron star's dipolar magnetic field is 50 years. We also discuss the nature of the binary and...
Lai, Dong, Bildsten, Lars, Kaspi, Vicky
The spin-induced quadrupole moment of a rapidly rotating star changes the orbital dynamics in a binary system, giving rise to advance (or regression) of periastron and precession of the orbital...
Cutler, Curt, Apostolatos, Theocharis A., Bildsten, Lars, Finn, Lee Samuel, Flanagan, Eanna E., Kennefick, Daniel, ...
Gravitational-wave interferometers are expected to monitor the last three minutes of inspiral and final coalescence of neutron star and black hole binaries at distances approaching cosmological,...
Cutler, Curt, Apostolatos, Theocharis A., Bildsten, Lars, Finn, Lee Samuel, Flanagan, Eanna E., Kennefick, Daniel, ...
Gravitational-wave interferometers are expected to monitor the last three minutes of inspiral and final coalescence of neutron star and black hole binaries at distances approaching cosmological,...
Thesis (Ph. D.)--Cornell University, August, 1991.