We revisit the flare on 1992 January 13, which is now universally termed the “Masuda flare”. Our work is motivated by the remarkable improvement of Yohkoh hard X-ray imaging, which was only achieved after the intensive investigations on this famous event. With the calibrated Hard X-ray Telescope (HXT) data, we find that the hard X-ray coronal source is indeed a loop-top source, located slightly...

Aims. In an attempt to catch new X-ray transients while they are still bright, the data taken by XMM-Newton as it slews between targets is being processed and cross-correlated with other X-ray observations as soon as the slew data appears in the XMM-Newton archive. Methods. A bright source, XMMSL1 J070542.7-381442, was detected on 9 Oct 2007 at a position where no previous X-ray source had been...

The Fermi Gamma-ray Space Telescope has revolutionized our knowledge of the gamma-ray pulsar population, leading to the discovery of almost 100 gamma-ray pulsars and dozens of gamma-ray millisecond pulsars (MSPs). Although the outer-gap model predicts different sites of emission for the radio and gamma-ray pulsars, until now all of the known gamma-ray MSPs have been visible in the radio. Here w...

The XDD beamline (http://ssls.nus.edu.sg/facility/beamlines/xdd/xdd.htm) at SSLS delivers a tunable monochromatized photon source with high resolution in a wide energy range (2.3-10 keV). This hard x-ray light source is ideal for diffractometry, fluorescence detection and absorption spectroscopy, especially the study of XAFS (x-ray absorption fine structure) and XANES ( X-ray Absorption Near Ed...

Globular clusters, the most ancient stellar groups in our Galaxy, are known to contain bright X-ray sources, faint X-ray sources and millisecond pulsars. The bright X-ray sources are neutron stars accreting matter from a companion. The millisecond pulsars are believed to be descendents of these sources. At the present time, the origin of the faint sources is unclear. Here we report X-ray satell...

This work reports on the detection of γ-ray emission coincident with the supernova remnant (SNR) G5.7–0.1 using data collected by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. The SNR is believed to be interacting with molecular clouds, based on 1720MHz hydroxyl (OH) maser emission observations in its direction. This interaction is expected to provide targets for the pr...

Context. In the standard solar flare scenario, a large number of particles are accelerated in the corona. Nonthermal electrons emit both X-rays and radio waves. Thus, correlated signatures of the acceleration process are predicted at both wavelengths, coinciding either close to the footpoints of a magnetic loop or near the coronal X-ray source. Aims. We attempt to study the spatial connection b...

Aims. A group of new γ−ray pulsars has recently been detected by FERMI Large Area Telescope (LAT) in a blind search. In this paper, we report the results from searching for the multi-wavelength counterparts of these pulsars. Methods. To search for their counterparts, we have cross-correlated the FERMI LAT Bright γ-ray Source List with the XMM-Newton serendipitous source catalogue (SSC), data ar...

We report on Chandra imaging observations of the Galactic Unidentified γ-ray source GEV J1809-2327, comparing the X-ray images with new VLA 1.46 GHz and 4.86 GHz maps. The X-ray images reveal a point source connected to a non-thermal X-ray/radio nebula, supporting a pulsar/wind model for the γ-ray emitter. We also detect numerous X-ray sources from the young stellar association in the adjacent ...