V. Hambaryan

The XMM-Newton serendipitous survey: V - The Second XMM-Newton serendipitous source catalogue

Aims. Pointed observations with XMM-Newton provide the basis for creating catalogues of X-ray sources detected serendipitously in each field. This paper describes the creation and characteristics of the 2XMM catalogue. Methods. The 2XMM catalogue has been compiled from a new processing of the XMM-Newton EPIC camera data. The main features of the processing pipeline are described in detail. Results. The catalogue, the largest ever made at X-ray wavelengths, contains 246 897 detections drawn from 3491 public XMM-Newton observations over a 7-year interval, which relate to 191 870 unique sources. The catalogue fields cover a sky area of more than 500 deg(2). The non-overlapping sky area is similar to 360 deg(2) (similar to 1% of the sky) as many regions of the sky are observed more than once by XMM-Newton. The catalogue probes a large sky area at the flux limit where the bulk of the objects that contribute to the X-ray background lie and provides a major resource for generating large, well-defined X-ray selected source samples, studying the X-ray source population and identifying rare object types. The main characteristics of the catalogue are presented, including its photometric and astrometric properties

Phase-resolved spectroscopic study of the isolated neutron star RBS 1223 (1RXS J130848.6+212708)

Aims. We constrain the mass-to-radius ratio of isolated neutron stars by performing a spin-phase resolved X-ray spectroscopic analysis. Methods. We combined the data from all observations of RBS 1223 (1RXS J130848.6+212708) conducted by XMM-Newton EPIC pn with the same instrumental setup in 2003−2007 to form spin-phase resolved spectra. We implemented a number of complex models of neutron stars with strongly magnetized (Bpole ∼ 10 13 −10 14 G) surfaces, various temperature and magnetic-field distributions around their magnetic poles, and a partially ionized hydrogen-thin atmosphere above into the X-ray spectral fitting package XSPEC for simultaneous fitting of phase-resolved spectra. A Markov-chain Monte Carlo (MCMC) approach is also applied to verify the results of fitting and estimating of parameters in multi-parameter models. Results. The spectra of different rotational phase intervals and light curves of different energy bands with high signal-to-noise ratio show a high complexity. The spectra can be parameterized with a Gaussian absorption-line superimposed on a blackbody spectrum, while the pulsed fraction of light curves with double-humped shape strongly depend upon the energy band (13−42%), which indicates that radiation emerges from at least two emitting areas. Conclusions. A model with a condensed iron surface and partially ionized hydrogen-thin atmosphere above allows us to fit simultaneously the observed general spectral shape and the broad absorption feature observed at 0.3 keV in different spin phases of RBS 1223. We constrain some physical properties of the X-ray emitting areas, i.e. the temperatures (Tp1 ∼ 105 eV, Tp2 ∼ 99 eV), magnetic field strengths (Bp1 ≈ Bp2 ∼ 8.6 × 10 13 G) at the poles, and their distribution parameters (a1 ∼ 0.61, a2 ∼ 0.29, indicating an absence of strong toroidal magnetic field component). In addition, we are able to place some constraints on the geometry of the emerging X-ray emission and the gravitational redshift (z = 0.16 +0.03 −0.01 ) of RBS 1223.

A new strongly X-ray flaring M 9 dwarf in the solar neighborhood

We report on the discovery of a very low mass (VLM) star in the solar neighborhood, originally identified as an optical counterpart of a flaring X-ray source detected in the ROSAT  All-Sky survey. Optical spectroscopy and infrared photometry consistently reveal a spectral type of

Bayesian timing analysis of giant flare of SGR 180620 by RXTE PCA

\rm M\,9\, \pm\, 0.5

XMM-Newton RGS spectrum of RX J0720.4-3125: an absorption feature at 0.57 keV

and a distance of ≈

Orbital motion of the young brown dwarf companion TWA 5 B

11\,\pm\,2

Observational constraints of the compactness of isolated neutron stars

pc. The optical counterpart of 1RXS J115928.5-524717 shows a large proper motion of

Superflares on the slowly rotating solar-type stars KIC10524994 and KIC07133671?

1.08\,\pm\,0.06\arcsec

THE VELA PULSAR WITH AN ACTIVE FALLBACK DISK

/year. 1RXS J115928.5-524717 is the fourth object among the VLM stars displaying a huge X-ray flare, reaching the unprecedent value of

A solar super-flare as cause for the 14C variation in AD 774/5?

L_X/L_{\rm bol}\simeq 0.1