相关论文: Discovery of a Second Transient Low-Mass X-ray Bin…
For the second time in 27 years a bright transient X-ray source has been detected coincident with the globular cluster NGC 6440. It was found to be active in August, 1998, with the Wide Field Camera and the narrow field instruments on the…
We report the discovery of the second accreting millisecond X-ray pulsar (AMXP) in the globular cluster NGC 6440. Pulsations with a frequency of 205.89 Hz were detected with the Rossi X-Ray Timing Explorer on August 30th, October 1st and…
We report the discovery of millisecond oscillations in an X-ray burst from the X-ray transient SAX J1748.9-2021 in the globular cluster NGC 6440. Oscillations at a frequency of 409.7 +/- 0.3 Hz were present in one of nine X-ray bursts…
The globular cluster NGC 6440 is known to harbor a bright neutron-star X-ray transient. We observed the globular cluster with Chandra on two occasions when the bright transient was in its quiescent state in July 2000 and June 2003 (both…
After 3 years of quiescence, the globular cluster NGC 6440 exhibited a bright transient X-ray source turning on in August 2001, as noted with the RXTE All-Sky Monitor. We carried out a short target of opportunity observation with the…
As part of our campaign to determine the nature of the various source populations of the low-luminosity globular cluster X-ray sources, we have obtained a Chandra X-ray Observatory ACIS-S3 image of the globular cluster NGC 6440. We detect…
We report on the serendipitous discovery of a 442-Hz pulsar during a Rossi X-ray Timing Explorer (RXTE) observation of the globular cluster NGC 6440. The oscillation is detected following a burst-like event which was decaying at the…
The BeppoSAX Wide Field Cameras detected a transient in NGC6440 on 1998 Aug 22. ROSAT did not detect this source on 1998 Sep 8, indicating that the X-ray flux had decreased by a factor 400 at least, and/or that the X-ray spectrum had become…
We report on the discovery of a transient X-ray pulsars, located in the Small Magellanic Cloud, with a pulse period of 292 s. A series of Chandra pointings fortuitously recorded in 2010 April-May the occurrence of a two-weeks-long outburst,…
We report on intermittent X-ray pulsations with a frequency of 442.36 Hz from the neutron-star X-ray binary SAX J1748.9--2021 in the globular cluster NGC 6440. The pulsations were seen during both 2001 and 2005 outbursts of the source, but…
We report the discovery of a flaring X-ray source in the globular cluster NGC 6540, obtained during the EXTraS project devoted to a systematic search for variability in archival data of the XMM-Newton satellite. The source had a quiescent…
Our 5 ks Chandra ACIS-S observation of the globular cluster NGC 6652 detected 7 X-ray sources, 3 of which are previously unidentified. This cluster hosts a well-known bright low-mass X-ray binary, source A (or XB 1832-330). Source B shows…
Quiescent low-mass X-ray binaries (qLMXBs) containing neutron stars have been identified in several globular clusters using Chandra or XMM X-ray observations, using their soft thermal spectra. We report a complete census of the qLMXB…
We report Chandra and XMM-Newton observations of the transient neutron star low-mass X-ray binary GRS 1741.9-2853. Chandra detected the source in outburst on 2000 October 26 at an X-ray luminosity of ~10^{36} erg/s (2--8 keV; 8 kpc), and in…
Monitor of All sky X-ray Image (MAXI) discovered a new outburst of an X-ray transient source named MAXI J1421-613. Because of the detection of three X-ray bursts from the source, it was identified as a neutron star low-mass X-ray binary.…
We used a combination of deep optical and Halpha images of the Galactic globular cluster NGC 6440, acquired with the Hubble Space Telescope, to identify the optical counterpart to the accreting millisecond X-ray pulsar SAX…
This paper presents the analysis of candidate quiescent low mass xray binarie (qLMXBs) observed during a short Chandra/ACIS observation of the globular cluster (GC) NGC 6304. Two out of the three candidate qLMXBs of this cluster, XMMU…
Many X-ray binaries are transiently accreting. Having statistics on their recurrence times is helpful to address questions related to binary evolution and populations, as well as the physics of binary systems. We compile a catalog of known…
CONTEXT - Transient low-mass X-ray binaries (LMXBs) often show outbursts lasting typically a few-weeks and characterized by a high X-ray luminosity ($L_{x} \approx 10^{36}-10^{38}$ erg/sec), while for most of the time they are found in…
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…