相关论文: Isolated neutron stars: Magnetic fields, distances…
RX J1856.5-3754 is the X-ray brightest among the nearby isolated neutron stars. Its X-ray spectrum is thermal, and is reproduced remarkably well by a black-body, but its interpretation has remained puzzling. One reason is that the source…
RX J0720.4-3125 is an unidentified bright soft X-ray source which shows pulsations at a 8.39 s period and has a thermal spectrum. We present deep B and R band images of its X-ray localization. We find one possible counterpart in the X-ray…
We study several effects that influence the strength of the proton cyclotron and atomic features in the thermal spectra of magnetic neutron stars. We show that it is possible for vacuum polarization to strongly suppress the spectral lines…
We present a unified explanation for the observed properties of the isolated neutron star RX J0720.4-3125 by obtaining, for the first time, a self-consistent model that accounts simultaneously for the observed X-ray spectrum and optical…
Isolated neutron stars are higly magnetized, fast rotating end points of stellar evolution. They are now becoming directly observable through X-ray astronomy, owing to their high surface temperatures. In particular, features in their X-ray…
Although the true origin of the broad absorption lines in X-ray spectra of thermal isolated neutron stars is not clear yet, our current knowledge about the "magnificent seven" strongly suggests that they are highly magnetized ($10^{13} -…
The nearby isolated neutron stars are a group of seven relatively slowly rotating neutron stars that show thermal X-ray spectra, most with broad absorption features. They are interesting both because they may allow one to determine…
We present the discovery of a strongly phase-variable absorption feature in the X-ray spectrum of the nearby, thermally-emitting, isolated neutron star RX J0720.4-3125. The absorption line was detected performing detailed phase-resolved…
A model with a condensed iron surface and partially ionized hydrogen-thin atmosphere 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 the…
The XMM-Newton spectra of the isolated neutron star RX J0720.4-3125 obtained over 4.5 years can be described by sinusoidal variations in the inferred blackbody temperature, the size of the emitting area and the depth of the absorption line…
RX J0720.4-3125 is an isolated neutron star that, uniquely in its class, has shown changes in its thermal X-ray spectrum. We use new spectra taken with Chandra's Low Energy Transmission Grating Spectrometer, as well as archival…
I describe recent high-resolution X-ray spectroscopy of surface emission from nearby, thermally emitting neutron stars. I focus on RX J0720.4-3125, RX J1308.6+2127, and RX J1605.3+3249, all of which have similar temperature, but differ in…
In the past, the isolated, radio-quiet neutron star RX J0720.4-3125 showed variations in the spectral parameters (apparent radius, temperature of the emitting area and equivalent width of the absorption feature) seen in the X-ray spectra,…
We present a combined analysis of XMM-Newton, Chandra and Rosat observations of the isolated neutron star RXJ0720.4-3125, spanning a total period of \sim 7 years. We develop a maximum likelihood periodogramme for our analysis based on the…
Presently seven nearby radio-quiet isolated neutron stars discovered in ROSAT data and characterized by thermal X-ray spectra are known. They exhibit very similar properties and despite intensive searches their number remained constant…
We report significant hard X-ray excesses in the energy range 2-8 keV for two nearby isolated neutron stars RX J1856.6-3754 and RX J0420.0-5022. These neutron stars have previously been observed in soft X-rays to have nearly thermal spectra…
We report on the results of a deep XMM-Newton observation of RBS 1774, the most recent dim isolated neutron star candidate found in the ROSAT archive data. Spectral and timing analysis of the high-quality PN and MOS data confirm the…
Pulsars are rapidly spinning neutron stars, that radiate at the expense of their strong magnetic field and their high surface temperature. Five decades of multi-wavelength observations showed a large variety of physical parameters, such as…
Thermal surface radiation has been detected with X-ray instruments for several neutron stars with high spectral, spatial and timing resolution. These observations allow for direct study of fundamental properties of the source, but require…
We present a phase-connected timing solution for the nearby isolated neutron star RX J1308.6+2127 (RBS 1223). From dedicated Chandra observations as well as archival Chandra and XMM-Newton data spanning a period of five years, we…