相关论文: An Unusual X-ray Burst from the Globular Cluster M…
We argue that the bursting, transient X-ray source GRO J1744-28 is a binary consisting of a very low-mass ($M \approx 0.2 M_\sun$), highly evolved giant star that is transferring mass by Roche lobe overflow onto a high-mass ($M \approx 1.8…
We have identified an X-ray transient (hereafter M15 X-3) in the globular cluster M15 from an archival Chandra grating observation. M15 X-3 appears at an X-ray luminosity of 6*10^{33} ergs/s with a spectrum consistent with an absorbed power…
The Rapid Burster (MXB 1730-335) is a unique object, showing both type I and type II X-ray bursts. A type I burst of the Rapid Burster was observed with Swift/XRT on 2009 March 5, showing photospheric radius expansion for the first time in…
Accompanied by an X-ray burst, the fast radio burst (FRB) FRB 200428 was recently confirmed as originating from the Galactic magnetar soft gamma repeater (SGR) SGR J1935+2154. Just before and after FRB 200428 was detected, the…
Low Mass X-Ray Binaries (LMXBs) are systems in which a compact object accretes from a binary companion star via an accretion disk. The X-ray properties of LMXBs show strong variability over timescales ranging from milliseconds to decades,…
Variable X-ray and gamma-ray emission is characteristic of the most extreme physical processes in the Universe, and studying the sources of these energetic photons has been a major driver in astronomy for the past 50 years. Here we present…
The bursting pulsar GRO J1744-28 is a Galactic low-mass X-ray binary that distinguishes itself by displaying type-II X-ray bursts: brief, bright flashes of X-ray emission that likely arise from spasmodic accretion. Combined with its…
A lightning surge generator generates a high voltage surge with 1.2 microsec. rise time. The generator fed a spark gap of two pointed electrodes at 0.7 to 1.2 m distances. Gap breakdown occurred between 0.1 and 3 microsec. after the maximum…
[Abridged] Type-I X-ray bursts are thermonuclear flashes that take place on the surface of accreting neutron stars. The wait time between consecutive bursts is set by the time required to accumulate the fuel needed to trigger a new burst;…
Two new bright X-ray sources in globular clusters, and many less luminous ones in globular clusters and in old open clusters, have been discovered with ROSAT. Accurate positions obtained with ROSAT help identification with optical objects,…
Ultraluminous X-ray sources (ULX) are off-nuclear point sources in nearby galaxies whose X-ray luminosity exceeds the theoretical maximum for spherical infall (the Eddington limit) onto stellar-mass black holes. Their luminosity ranges from…
The globular cluster M15 has recently been found to host a possible central black hole with a mass of ~2000 solar masses. A deep, high-resolution Chandra image failed to detect the "nucleus" of the cluster in X-rays. The upper limit on the…
The neutron star X-ray binary, EXO 0748--676, was observed regularly by the Rossi X-ray Timing Explorer (RXTE) and XMM-Newton during its first detected outburst (1985 - 2008). These observations captured hundreds of asymmetric,…
We have detected a transient X-ray source in the M31 bulge through a continuing monitoring campaign with the Chandra ACIS-I camera. The source was detected at R.A.=00:42:33.428 +/- 0.11'', Dec.=+41:17:03.37 +/- 0.11'' in only a single…
We report the discovery of a bright X-ray transient object, XMMU J174554.4-285456, observed in outburst with XMM-Newton on October 3, 2002,and located at 6.3' from SgrA*, the supermassive black hole at the Galactic center.This object…
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*10^{31} ergs/s within the half-mass radius of the cluster. Thirty-three…
We report the discovery of two new types of variability in the neutron star low-mass X-ray binary MXB 1730-335 (the 'Rapid Burster'). In one observation in 1999, it exhibits a large-amplitude quasi-periodic oscillation with a period of…
Despite considerable evidence verifying that millisecond pulsars are spun up through sustained accretion in low-mass X-ray binaries (LMXBs), it has proven surprisingly difficult to actually detect millisecond X-ray pulsars in LMXBs. There…
On September 21, 2006, an intense (~10^39 erg/s) and short (20 ms) burst was detected by Swift BAT at a position consistent with that of the candidate Anomalous X-ray Pulsar, CXOU J164710.2-455216, discovered by Chandra in 2005. Swift…
Short duration (<2 s) Gamma-ray bursts (GRBs) have been a mystery since their discovery. Until May 2005 very little was known about short GRBs, but this situation has changed rapidly in the last few months since the Swift and HETE-2…