Explanipedia

A Systematic Search for Periodicities inRXTEASM Data Open

L. Wen, Alan M. Levine, R. H. D. Corbet, H. Bradt · 2006

We present the results of a systematic search in 8.5 years of Rossi X-ray Timing Explorer All-Sky Monitor data for evidence of periodicities. The search was conducted by application of the Lomb-Scargle periodogram to the light curves of ea…

Observations of Gamma-Ray Bursts with the Rossi X-Ray Timing Explorer Open

H. Bradt, Alan M. Levine, Francis E. Marshall, Ronald A. Remillard, D. A. Smith , et al. · 2006

HIGHLIGHTS OF RXTE STUDIES OF COMPACT OBJECTS AFTER ~5 YEARS Open

H. Bradt, R. E. Rothschild, J. H. Swank · 2002

Observations with the Rossi X-ray Timing Explorer (RXTE) have led to\nfundamental progress in the study of compact objects, in particular neutron\nstars and black holes. In this paper we present briefly some highlights from ~5\nyears of RX…

HE 0435-1223: A wide separation quadruple QSO and gravitational lens Open

L. Wisotzki, Paul L. Schechter, H. Bradt, J. Heinmüller, D. Reimers · 2002

\n We report the discovery of a new gravitationally lensed QSO, \nat a redshift $z = 1.689$,\nwith four QSO components in a cross-shaped arrangement around a bright galaxy.\nThe maximum separation between images is $2\\farcs 6$, enabling a…

X‐Ray Light Curves of Gamma‐Ray Bursts Detected with the All‐Sky Monitor onRXTE Open

D. A. Smith, Alan M. Levine, H. Bradt, K. Hurley, M. Feroci , et al. · 2002

We present X-ray light curves (1.5-12 keV) for fifteen gamma-ray bursts (GRBs) detected by the All-Sky Monitor on the Rossi X-ray Timing Explorer. We compare these soft X-ray light curves with count rate histories obtained by the high-ener…

An All-sky Advanced X-ray Monitor (AXM) Mission Open

H. Bradt, Ronald A. Remillard · 2001

A concept for an all-sky monitor mission substantially more powerful than the RXTE ASM is presented in brief. It makes use of 31 Gas Electron Multiplier (GEM) proportional counters to provide continuous monitoring of the entire x-ray sky, …

The Correlated Intensity and Spectral Evolution of Cygnus X-1 During State Transitions Open

L. Wen, Wei Cui, H. Bradt · 2001

Using data from the All-Sky Monitor (ASM) aboard the Rossi X-Ray Timing Explorer (RXTE), we found that the 1.5-12 keV X-ray count rate of Cygnus X-1 is, on timescales from 90 s to at least 10 days, strongly correlated with the spectral har…

Gas electron multiplier (GEM) detectors for an advanced x-ray monitor Open

Ronald A. Remillard, Alan M. Levine, E. Boughan, H. Bradt, E. Morgan , et al. · 2000

We describe a concept for a NASA SMEX Mission in which Gas Electron Multiplier (GEM) detectors, developed at CERN, are adapted for use in X-ray astronomy. These detectors can be used to obtain moderately large detector area and two-dimensi…

X-ray intensity-hardness correlation in Cyg X-1 Open

L. Wen, Wei Cui, H. Bradt · 2000

Using data from the All-Sky Monitor aboard the Rossi X-ray Timing Explorer (RXTE), we found that the 1.5-12 keV X-ray count rate of Cyg X-1 is, on time scales from 90 seconds to at least 10 days, strongly correlated with the spectral hardn…

Observation of X-ray Lines from a Gamma-Ray Burst (GRB991216): Evidence of Moving Ejecta from the Progenitor Open

L. Piro, G. P. Garmire, Michael Garcia, G. Stratta, E. Costa , et al. · 2000

We report on the discovery of two emission features observed in the x-ray spectrum of the afterglow of the gamma-ray burst (GRB) of 16 December 1999 by the Chandra X-ray Observatory. These features are identified with the Ly α line and the…

X1908+075: An X‐Ray Binary with a 4.4 Day Period Open

L. Wen, Ronald A. Remillard, H. Bradt · 2000

X 1908+075 is an optically unidentified and highly absorbed X-ray source that appears in early surveys such as Uhuru, OSO-7, Ariel V, HEAO-1, and the EXOSAT Galactic Plane Survey. These surveys measured a source intensity in the range of 2…

Transient X--Ray Sources Observed with the Rxte All-Sky Monitor after 3.5 Years Open

H. Bradt, A. Levine, Ronald A. Remillard, D. A. Smith · 2000

We present light curves of a sample of "transient" sources observed with the All-Sky Monitor (ASM) of the Rossi X-ray Timing Explorer (RXTE). The light curves extend over 3.5 years. They are presented in three groups: six neutron-star syst…

Localizations of 13 Gamma‐Ray Bursts by the All‐Sky Monitor on theRossi X‐Ray Timing Explorer Open

D. A. Smith, Alan M. Levine, H. Bradt, Ronald A. Remillard, J. G. Jernigan , et al. · 1999

The All-Sky Monitor (ASM) on the Rossi X-ray Timing Explorer (RXTE) has been used to localize 13 confirmed X-ray counterparts to gamma-ray bursts (GRBs) detected over 3 yr of operation. We quantify the errors in ASM localizations of brief …

Orbital Modulation of X‐Rays from Cygnus X‐1 in its Hard and Soft States Open

L. Wen, Wei Cui, Alan M. Levine, H. Bradt · 1999

We have analyzed over 2 yr of RXTE/All-Sky Monitor data for Cygnus X-1. We have detected the 5.6 day orbital period in Lomb-Scargle periodograms of both light curves and hardness ratios when Cyg X-1 was in the hard state. This detection wa…

Localizations of Thirteen Gamma-ray Bursts by the All-Sky Monitor on RXTE Open

D. A. Smith, A. M. Levine, H. Bradt, Ronald A. Remillard, J. G. Jernigan , et al. · 1999

The All-Sky Monitor (ASM) on the Rossi X-ray Timing Explorer (RXTE) has been used to localize thirteen confirmed X-ray counterparts to Gamma-Ray Bursts (GRBs) detected over three years of operation. We quantify the errors in ASM localizati…

[ITAL]Rossi X-Ray Timing Explorer[/ITAL] All-Sky Monitor Localization of SGR 1627−41 Open

D. A. Smith, H. Bradt, Alan M. Levine · 1999

The fourth unambiguously identified soft gamma repeater (SGR), SGR 1627-41, was discovered with the BATSE instrument on 1998 June 15. Interplanetary Network (IPN) measurements and BATSE data constrained the location of this new SGR to a 6°…

X-ray Orbital Modulation of Cygnus X-1 Open

L. Wen, Wei Cui, Alan M. Levine, H. Bradt · 1999

We have analyzed over 2 years of RXTE/ASM data for Cygnus X-1. We have detected the 5.6-day orbital period in Lomb-Scargle periodograms of both light curves and hardness ratios when Cyg X-1 was in the hard state. This detection was made wi…

RXTE All-Sky Monitor Localization of SGR 1627-41 Open

D. A. Smith, H. Bradt, Alan M. Levine · 1999

The fourth unambiguously identified Soft Gamma Repeater (SGR), SGR1627-41, was discovered with the BATSE instrument on 1998 June 15 (Kouveliotou et al. 1998). Interplanetary Network (IPN) measurements and BATSE data constrained the locatio…

Highlights from RXTE after 2.5 Years: Neutron-star Spins at KiloHertz Frequencies, Microquasars and More Open

H. Bradt · 1999

The Rossi X-ray Timing Explorer (RXTE) satellite was launched on 30 December 1995. It has made substantial contributions pertaining to compact objects and their environs. Broad-band spectral and short-time-scale temporal studies are explor…

Highlights from RXTE after 2.5 Years: Neutron-star Spins at KiloHertz\n Frequencies, Microquasars and More Open

H. Bradt · 1999

The Rossi X-ray Timing Explorer (RXTE) satellite was launched on 30 December\n1995. It has made substantial contributions pertaining to compact objects and\ntheir environs. Broad-band spectral and short-time-scale temporal studies are\nexp…

Observations of circinus X-1 with RXTE Open

H. Bradt, R. Shirey, Alan M. Levine · 1999

[ITAL]Rossi X-Ray Timing Explorer[/ITAL] Discovery of Coherent Millisecond Pulsations during an X-Ray Burst from KS 1731−260 Open

D. A. Smith, E. Morgan, H. Bradt · 1997

A highly coherent 523.92+-0.05 Hz periodic X-ray signal has been observed during a type I X-ray burst from the low-mass X-ray binary system KS 1731-260 with the PCA on RXTE. The spectral evolution of the burst indicates photospheric-radius…

Some Early Results from the Rossi X-ray Timing Explorer (RXTE) Open

H. Bradt · 1997

The Rossi X-ray Timing Explorer (RXTE) was successfully launched on 1995 December 30 and has been operational since that time. Its three instruments are probing regions close to compact objects, degenerate dwarfs, neutron stars, stellar bl…

First Results from the All-Sky Monitor on the [ITAL]Rossi X-Ray Timing Explorer[/ITAL] Open

Alan M. Levine, H. Bradt, Wei Cui, J. G. Jernigan, E. Morgan , et al. · 1996

The All-Sky Monitor on the Rossi X-ray Timing Explorer has been monitoring the sky in the 1.5 - 12 keV band since late February. The instrument consists of three coded-aperture cameras which can be rotated to view different regions by a mo…

X-Ray Timing and Spectral Evolution of Circinus X-1 versus Orbital Phase with the [ITAL]Rossi X-Ray Timing Explorer[/ITAL] Open

R. Shirey, H. Bradt, Alan M. Levine, E. Morgan · 1996

We have carried out a study of Cir X-1 through (1) detailed sampling over a single 16.5 day intensity cycle with the Rossi X-Ray Timing Explorer (RXTE) proportional counter array and (2) complementary monitoring over six such cycles with t…

The Weak Blue Bump of H2106-099 and Active Galactic Nuclei Dereddening Open

B. Grossan, R. A. Remillard, H. Bradt, Roger Brissenden, T. Ohashi , et al. · 1996

We present multi-frequency spectra of the Seyfert 1 galaxy H2106-099, from radio to hard X-rays, spanning over a decade of observations. The hard X-ray (2-20 keV) spectrum measured with Ginga had a Log slope of -0.80 +/- 0.02 on 1988 May 1…

The X-Ray Timing Explorer Open

H. Bradt, Alan M. Levine, E. Morgan, Ronald A. Remillard, J. H. Swank , et al. · 1990

The capabilities of the X-ray Timing Explorer (XTE) are described with particular attention paid to current scientific problems it will address from galactic neutron star systems to active galactic nuclei. It features a low-background cont…

Candidates for a gamma-ray burster optical counterpart Open

Patrick Seitzer, Bradley E. Schaefer, H. Bradt · 1983

view Abstract Citations (48) References (14) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Candidates for a gamma-ray burster optical counterpart. Schaefer, B. E. ; Seitzer, P. ; Bradt, H. V. Abstract The…

Location of the recurrent /LMC/ X-ray transient A0538-66 with the HEAO 1 scanning modulation collimator Open

Mark Johnston, H. Bradt, R. Doxsey, R. E. Griffiths, D. A. Schwartz , et al. · 1979

view Abstract Citations (34) References (25) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Location of the recurrent (LMC?) X-ray transient A0538-66 with the HEAO 1 scanning modulation collimator. Johnsto…

The X-ray, optical, and radio behavior of Scorpius X-1 - The 1971 coordinated observations Open

H. Bradt, G. K. G. Moore, L. L. E. Braes, G. K. Miley, W. Forman , et al. · 1975

view Abstract Citations (41) References (21) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The X-ray, optical, and radio behavior of Scorpius X-1: the 1971 coordinated observations. Bradt, H. V. ; Braes, …

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