Related papers: Is GRO J1744-28 a Strange Star?
We present a Chandra/ACIS-I observation of GRO J1744-28. We detected a source at a position of R.A = 17h 44m 33.09s and Dec. = -28degr 44' 27.0'' (J2000.0; with a 1sigma error of ~0.8 arcseconds), consistent with both ROSAT and…
The Bursting Pulsar, GRO J1744-28, has been observed with the Rossi X-ray Timing Explorer (RXTE) regularly since the launch of the satellite in December 1995. This accretion driven pulsar has undergone two outbursts which have been…
One of the most important questions in the study of compact objects is the nature of pulsars, including whether they are composed of $\beta$-stable nuclear matter or strange quark matter. Observations of the newly discovered millisecond…
Two giant flares were observed on 5 March 1979 and 27 August 1998 from the soft gamma-ray repeaters SGR 0526-66 and SGR 1900+14, respectively. The striking similarity between these remarkable bursts strongly implies a common nature. We show…
Fast radio bursts are bright, millisecond-scale radio flashes of yet unknown physical origin. Recently, their extragalactic nature has been demonstrated and an increasing number of the sources have been found to repeat. Young, highly…
Anomalous X-ray Pulsars (AXPs) are a class of rare X-ray pulsars whose energy source has been perplexing for some 20 years. Unlike other, better understood X-ray pulsars, AXPs cannot be powered by rotation or by accretion from a binary…
The repetitive X-ray bursts from the accretion-powered pulsar GRO J1744-28 show similarities to the type II X-ray bursts from the Rapid Burster. Several authors (notably Lewin et al.) have suggested that the bursts from GRO J1744-28 are…
We report the ASCA results of the bursting X-ray pulsar \gro, which was observed in February 1996 and March 1997. The source flux in the 2--10 keV band was $2.0\times10^{-8}$ erg/sec/cm$^2$ in 1996 and $5.0\times10^{-9}$ erg/sec/cm$^2$ in…
NGC 4449 is an irregular galaxy with a moderately high star formation activity. The massive stars in NGC 4449 have given rise to many bright HII regions, superbubbles, supergiant shells, and "chimney-like" radial filaments. ROSAT X-ray…
We report on our discovery and follow-up observations of the X-ray source SAX J1747.0-2853 detected in outburst on 1998, March 10 with the BeppoSAX Wide Field Cameras in the energy range 2-28 keV. The source is located about half degree off…
Strange quark matter with the density of ~ 5\times 10^{14} g cm^{-3} might exist up to the surface of a strange star. This differs qualitatively from the case of a neutron star and opens observational possibilities to distinguish strange…
It is proposed that GLEAM-X~J162759.5-523504.3, the newly discovered radio transient with an unusually long spin-period (P$_s$ = 1091.1690s), can be identified to be a Radio Magnetar which has a dipolar surface magnetic field of $2.5 \times…
We report on a 10 ks simultaneous Chandra/HETG-NuSTAR observation of the Bursting Pulsar, GRO J1744-28, during its third detected outburst since discovery and after nearly 18 years of quiescence. The source is detected up to 60 keV with an…
When a neutron star is compressed to huge densities, it may be converted to a strange star. In property of the event/year rate of a neutron star - strange star binary system, we show that the operational phase of advanced gravitational wave…
We report a deep optical imaging observation by the Subaru telescope for a very soft X-ray source RX J1836.2+5925, which has been suspected to be an isolated neutron star associated with the brightest as-yet unidentified EGRET source…
The detection of a short hard X-ray burst and an associated bright soft X-ray source by the Swift satellite in 2020 October heralded a new magnetar in outburst, SGR J1830-0645. Pulsations at a period of ~10.4 s were detected in prompt…
We consider a model in which the soft gamma-ray repeaters (SGRs) result from young, magnetized strange stars with superconducting cores. As such a strange star spins down, the quantized vortex lines move outward and drag the magnetic field…
The internal-plateau X-ray emission of gamma-ray bursts (GRBs) indicates that a newly born magnetar could be the central object of some GRBs. The observed luminosity and duration of the plateaus suggest that, for such a magnetar, a rapid…
When accreting X-ray pulsars (XRPs) undergo bright X-ray outbursts, their luminosity-dependent spectral and timing features can be analysed in detail. The XRP GRO J1750-27 recently underwent one of such episodes, during which it was…
Soft-gamma-ray repeaters (SGRs) are galactic X-ray stars that emit numerous short-duration (about 0.1 s) bursts of hard X-rays during sporadic active periods. They are thought to be magnetars: strongly magnetized neutron stars with…