相关论文: X-ray line emission in Hercules X-1
We analyze the high-resolution X-ray spectrum of Hercules X-1, an intermediate-mass X-ray binary, which was observed with the XMM-Newton Reflection Grating Spectrometer. We measure the elemental abundance ratios by use of spectral models,…
The UV emission lines of Hercules X-1, resolved with the HST GHRS and STIS, can be divided into broad (FWHM 750 km/s) and narrow (FWHM 150 km/s) components. The broad lines can be unambiguously identified with emission from an accretion…
We present a unified picture of outflowing gas from the X-ray binary system Hercules X-1/HZ Herculis. We suggest that the outflowing gas (a wind) causes UV emission seen in mid-eclipse, narrow UV absorption lines, and broad UV P Cygni…
We present a first emission line analysis of a high resolution X-ray spectrum of the stellar wind of theta 1 Ori C obtained with the High Energy Transmission grating Spectrometer onboard the Chandra X-ray Observatory. The spectra are…
We identify an accretion disk atmosphere and corona from the high resolution X-ray spectrum of Hercules X-1, and we determine its detailed physical properties. More than two dozen recombination emission lines (from Fe XXVI at 1.78 A to N VI…
Hercules X-1 is a nearly edge-on accreting X-ray pulsar with a warped accretion disk, precessing with a period of about 35 days. The disk precession allows for unique and changing sightlines towards the X-ray source. To investigate the…
We present the results of high resolution spectroscopy of the prototype polar AM Herculis observed with Chandra High Energy Transmission Grating. The X-ray spectrum contains hydrogen-like and helium-like lines of Fe, S, Si, Mg, Ne and O…
The study of X-ray pulsar accretion columns helps us characterize accretion physics in this extreme regime of strong gravity and strong magnetic fields. Previous observations of the X-ray pulsar Hercules X-1 revealed a highly broadened Fe K…
We have obtained a far-ultraviolet spectrum of the X-ray binary Hercules X-1/HZ Herculis using the Hopkins Ultraviolet Telescope aboard the Astro-1 space shuttle mission in 1990 December. This is the first spectrum of Her X-1 that extends…
We present the soft X-ray spectrum of the LINER galaxy M81 derived from a long observation with the XMM RGS. The spectrum is dominated by continuum emission from the active nucleus, but also contains emission lines from Fe L, and H-like and…
Hercules X-1 is one of the best studied highly magnetised neutron star X-ray binaries with a wealth of archival data. We present the discovery of an ionised wind in its X-ray spectrum when the source is in the high state. The wind detection…
We report on a Chandra line spectrum observation of the O supergiant, Zeta Orionis (O9.7 Ib). A 73.4 ks HETGS observation shows a wide range of ionization stages and line strengths over the wavelength range of 5 to 26 A. The observed…
We present the first grating-resolution X-ray spectra of the Seyfert 1 galaxy NGC 3783, obtained with the High Energy Transmission Grating Spectrometer on the Chandra X-ray Observatory. These spectra reveal many narrow absorption lines from…
(Abridged) A large fraction of the gas in galactic haloes has temperatures between 10^4.5 and 10^7 K. At these temperatures, cooling is dominated by metal-line emission if the metallicity Z>~0.1 Zsun. We explore the detectability of several…
We present the HERA CO-Line Extragalactic Survey (HERACLES), an atlas of CO emission from 18 nearby galaxies that are also part of The HI Nearby Galaxy Survey (THINGS) and the Spitzer Infrared Nearby Galaxies Survey (SINGS). We used the…
We present evidence for X-ray line emitting and absorbing gas in the nucleus of the Broad-Line Radio Galaxy (BLRG), 3C 445. A 200ks Chandra LETG observation of 3C 445 reveals the presence of several highly ionized emission lines in the soft…
Hercules X-1 is a nearly edge-on X-ray binary with a warped, precessing accretion disk, which manifests through a 35-day cycle of alternating High and Low flux states. This disk precession introduces a changing line of sight towards the…
We obtained optical spectra of the counterpart of the ultraluminous X-ray source NGC 5408 X-1 using the FORS spectrograph on the VLT. The spectra show strong high excitation emission lines, He{\sc ii} $\lambda$4686 and [Ne{\sc V}]…
We mapped quiescent 807 GHz CO(7-6) emission from Orion along a strip in RA extending from 0.7 pc west to 1.2 pc east of Ori theta 1C. The lines arise in warm gas with T > 40 K. The line brightness temperature is > 160 K in the di- rection…
We analyse RXTE/PCA X-ray spectra of the binary X-ray pulsar Her X-1/HZ Her during short high state and one binary orbit in the preceding low state, just before short high turn-on. The spectrum is well described by two continuum components…