Related papers: A long-period, violently-variable X-ray source in …
A long (155 hours) ASCA observation was performed of two ultra luminous compact X-ray sources, Source 1 and Source 2, in the spiral galaxy IC 342. While Source 1 that was in a hard spectral state varied little, Source 2 that was in its soft…
We report the results of a search for a point X-ray source (stellar remnant) in the southwest protrusion of the supernova remnant G 315.4-2.30 (MSH 14-63, RCW 86) using the archival data of the Chandra X-ray Observatory. The search was…
Less than half of the SNRs within 5 kpc have identified central sources, and only three are identified as the remnants of Type Ia SNe. Here, we report a systematic effort to search for compact central sources in the remaining 23 SNRs of…
We report on a pair of X-ray Multi-Mirror Mission (XMM-Newton) observations of the Supergiant X-ray binary 4U 1909+07, which were performed on 2021 October 3 and 2021 October 8, respectively. We measure the neutron star rotation period in…
Supernova Remnant RX J1713.7-3946 emits synchrotron X-rays and very high energy $\gamma$-rays. Recently, thermal X-ray line emission is detected from ejecta plasma. CO and HI observations indicate that a highly inhomogeneous medium…
We report the first detection of flux variability in the most luminous X-ray source in the southern ring of the Cartwheel galaxy. XMM--Newton data show that the luminosity has varied over a timescale of six months from L[0.5-10] keV \~1.3…
We present spectroscopy and photometry of the LMC supersoft binary system RX~J0513.9-6951. We derive a refined spectroscopic period of P$=0.761\pm0.004$~d, which is consistent with the value obtained from long term photometric monitoring…
The most luminous X-ray source in the Local Group is associated with the nucleus of M33. This source, M33 X-8, appears modulated by ~20% over a ~106 day period, making it unlikely that the combined emission from unresolved sources could…
Using the Chandra X-ray Observatory we have discovered a diffuse, center-filled region of hard X-ray emission within the young, oxygen-rich supernova remnant (SNR) G292.0+1.8. Near the peak of this diffuse emission lies a point-like source…
The deepest XMM-Newton mosaic map of the central 1.5 deg of the Galaxy is presented, including a total of about 1.5 Ms of EPIC-pn cleaned exposures in the central 15" and about 200 ks outside. This compendium presents broad-band X-ray…
Aims: We present a detailed X-ray study of the recently discovered supernova remnant (SNR) G53.41+0.03 that follows up and further expands on the previous, limited analysis of archival data covering a small portion of the SNR. Methods: With…
The detection and characterization of periodic X-ray signals are crucial for identifying new compact objects and studying the mechanisms powering their emission. We report on the timing and spectral variability of CXOU J204734.8+300105, a…
On May 5 2022, a type Ic supernova (SN) explosion SN~2022jli was discovered. This SN showed additional optical emissions, which were found to exhibit 12.4-day periodic undulations and concordant periodic velocity shifts. These key features…
Core-collapse supernova remnants are the nebular leftover of defunct massive stars which have died during a supernova explosion, mostly while undergoing the red supergiant phase of their evolution. The morphology and emission properties of…
Supernova remnants have long been suggested as a class of potential counterparts to unidentified gamma-ray sources. The mechanisms by which such gamma-rays can arise may include emission from a pulsar associated with a remnant, or a variety…
Magnetars are the most luminous compact objects in the stellar mass range observed in the Milky Way, with giant flares of hard X-ray power ~10^45 erg/sec being detected from three soft gamma repeaters in the Galactic neighborhood.…
XMM-Newton archival observations of the Be/X-ray binary candidate RX J0103.6-7201 revealed pulsations with a period of ~1323 s. This makes RX J0103.6-7201 the X-ray pulsar with the longest period known in the Small Magellanic Cloud (SMC).…
We report on the discovery of X-ray emission from SN 1970G in M101, 35 years after its outburst, using deep X-ray imaging with the Chandra X-ray observatory. The Chandra ACIS spectrum shows that the emission is soft (<2 keV) and…
The transition from supernovae (SNe) to supernova remnants (SNRs) remains poorly understood, given the age gap between well-studied examples of the two. In order to bridge this gap, we analysed archival Chandra data for some of the oldest…
The X-ray source RX J0002+6246 was discovered close to the supernova remnant CTB1 in a ROSAT observation performed in 1992. The source phenomenology (soft spectrum, apparent lack of counterparts, possible pulsations at 242 ms, hints for…