The Arches cluster is a young, densely packed massive star cluster in our Galaxy that shows a high level of star formation activity. The nature of the extended non-thermal X-ray emission around the cluster remains unclear. The observed bright Fe Kα line emission at 6.4 keV from material that is neutral or in a low ionization state can be produced either by X-ray photoionization or by cosmic-ray...

We have observed the X-ray transient XTEJ0421+56 in quiescence with XMM-Newton. The observed spectrum is highly unusual being dominated by an emission feature at ∼6.5 keV. The spectrum can be fit using a partially covered power-law and Gaussian line model, in which the emission is almost completely covered (covering fraction of 0.98 −0.06) by neutral material and is strongly absorbed with an NH...

We report the discovery of non-thermal pulsed X-ray/soft γ-ray emission up to ∼ 150 keV from the anomalous X-ray pulsar AXP 1E 1841-045 located near the centre of supernova remnant Kes 73 using RXTE PCA and HEXTE data. The morphology of the double-peaked pulse profile changes rapidly with energy from 2 keV up to ∼ 8 keV, above which the pulse shape remains more or less stable. The pulsed spectr...

We present a modified stratified jet model to interpret the observed spectral energy distributions of knots in 3C 273 jet. Based on the hypothesis of the single index of the particle energy spectrum at injection and identical emission processes among all the knots, the observed difference of spectral shape among different 3C273 knots can be understood as a manifestation of deviation of the equi...

We have discovered a Narrow-Line Seyfert 1 (NLS1) galaxy and identified it with an ultrasoft X-ray source (RX 215319-1514) detected with ROSAT . We present its X-ray and optical spectral characteristics. Its redshift is found to be 0.0778±0.0002. Its optical spectrum shows fairly strong Fe II emission lines, and its X-ray spectrum has an extremely steep power-law index of Γ ≥4, making it an ext...

We briefly reviewed some recent progress on the studies of supernova remnants (SNRs), including the radio SNRs (the structure, polarization, spectrum etc.), observational characteristics of X-ray emission, pulsar wind nebulae (PWNe), association properties between SNR and PSR, interaction of SNR and interstellar medium (ISM), cosmos ray and the SNRs in external galaxies, etc.. Correspondingly t...

X-ray emission from the eastern radio lobe of the FRII Radio Galaxy Pictor A was serendipitously discovered by a short observation of XMM-Newton in 2001. The X-ray spectrum, accumulated on a region covering about half of the entire radio lobe, was well described by both a thermal model and a power law, making non-univocal the physical interpretation. A new XMM-Newton observation performed in 20...

Prominent Fe Kα line emission is detected in the XMM-Newton spectrum of the ultraluminous infrared galaxy Arp220. The centroid of the line is found at an energy of 6.7 keV and the equivalent width of the line is EW ∼ 1.9 keV (at 3.5σ significance). A few other spectral features are found at various degrees of significance in the lower energy range on a hard 2.5–10 keV continuum (Γ ∼ 1). The lar...

We present a systematic fit of a model of resonant cyclotron scattering (RCS) to the X and soft γ-ray data of four magnetars, including anomalous X-ray pulsars, and soft gamma repeaters. In this scenario, non-thermal magnetar spectra in the soft X-rays result from resonant cyclotron scattering of the thermal surface emission by hot magnetospheric plasma. We find that this model can successfully...

Monitoring of the narrow line Seyfert 1 galaxy Markarian 335 (Mrk 335) with the Swift satellite discovered an X-ray flare beginning 2014 August 29. At the peak, the 0.5-5 keV count rate had increased from that in the low flux state by a factor of 10. A target of opportunity observation was triggered with NuSTAR, catching the decline of the flare on 2014 September 20. We present a joint analysis...