相关论文: A NICER look at the Aql X-1 hard state
X-ray observations of neutron star (NS) low mass X-ray binaries (LMXBs) are useful to probe physical processes close to the NS and to constrain source parameters. Aql X-1 is a transient NS LMXB which frequently undergoes outbursts provides…
We have analyzed five X-ray outbursts of the neutron-star soft X-ray transient Aql X-1 and investigated the timing properties of the source in correlation with its spectral states as defined by different positions in the color-color and…
Aql X-1 is a soft X-ray transient source and emits type I X-ray bursts. A spectral state transition was observed with RXTE during its outburst decay in February and March 1997. Its 10-30 keV and 5-10 keV count rate ratio increased suddenly…
We report the broadband timing and spectral properties of the neutron star low-mass X-ray binary Aql X-1 during the 2024 outburst with NICER, NuSTAR, and Swift observatories. We detected six thermonuclear X-ray bursts during the NICER and…
Accretion disks around neutron stars regularly undergo sudden strong irradiation by Type I X-ray bursts powered by unstable thermonuclear burning on the stellar surface. We investigate the impact on the disk during one of the first X-ray…
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 X-ray spectra are consistent with thermal…
We report on quasi-simultaneous observations from radio to X-ray frequencies of the neutron star X-ray binary Aql X-1 over accretion state transitions during its 2016 outburst. All the observations show radio to millimetre spectra…
We have analyzed {\it Rossi X-ray Timing Explorer} (RXTE) data of the neutron star transient Aquila X-1 obtained during its outbursts in May/June 1999 and September/October 2000. We find that in the early rise of these outbursts, a hard…
Aql X-1 is a prolific transient neutron star low-mass X-ray binary that exhibits an accretion outburst approximately once every year. Whether the thermal X-rays detected in intervening quiescent episodes are the result of cooling of the…
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, assuming a pure hydrogen atmosphere and…
We present the results of a broadband spectral study of the transient Low Mass X-ray Binary Aql X-1 observed by Suzaku and Rossi X-ray Timing Explorer satellites. The source was observed during its 2007 outburst in the High/Soft (Banana)…
We report on X-ray (NICER/NuSTAR/MAXI/Swift) and radio (MeerKAT) timing and spectroscopic analysis from a three-month monitoring campaign in 2022 of a high-intensity outburst of the dipping neutron star low-mass X-ray binary 1A 1744-361.…
The Swift satellite monitored the quiescence of the low-mass X-ray binary transient Aql X-1 on a weekly basis during the March-November 2012 interval. A total of 42 observations were carried out in the soft X-ray (0.3-10 keV) band with the…
Aql X-1 is one of the best-studied neutron star low-mass X-ray binaries. It was previously targeted using quasi-simultaneous radio and X-ray observations during at least 7 different accretion outbursts. Such observations allow us to probe…
Superbursts are long duration, rare, and extremely energetic thermonuclear explosions of neutron star low-mass X-ray binaries (NS LMXBs), which are proposed to be due to unstable carbon ignition. We report the superburst properties and…
We report the discovery of an episode of coherent millisecond X-ray pulsation in the neutron star low-mass X-ray binary Aql X-1. The episode lasts for slightly more than 150 seconds, during which the pulse frequency is consistent with being…
We present optical spectroscopy and optical and infrared photometry of the neutron star soft X-ray transient Aql X--1 during its X-ray outburst of August 1997. By modelling the X-ray, optical, and IR light curves, we find a 3 day delay…
Aql X-1 is the most prolific low mass X-ray binary transient hosting a neutron star. In this paper we focus on the return to quiescence following the 2010 outburst of the source. This decay was monitored thanks to 11 pointed observations…
Aql X-1 was observed in a Low Intensity State (LIS), a state that is usually characterized by high optical but low X-ray flux. Our daily monitoring of the source using the 1.3m telescope in Cerro Tololo Inter-America Observatory operated by…
We present the results of detailed analysis of X-ray data in 3-20 keV range from a ~70 day outburst of the neutron star transient Aquila X-1 during September-November 2000. Optical monitoring with the YALO 1m telescope was used to trigger…