Search Publications
XMM-Newton spectral properties of the narrow-line Seyfert 1 galaxy IRAS 13224 - 3809
Brandt, W. N.; Vaughan, S.; Boller, Th. +5 more
We report on the first XMM-Newton observation of the highly X-ray variable, radio-quiet, narrow-line Seyfert 1 galaxy IRAS 13224 - 3809 obtained during the guaranteed time programme with a 64-ks exposure. The most remarkable spectral feature is a sharp drop, by a factor of ~5, in the spectrum at 8 keV. This is a similar, but stronger, feature to t…
Complex optical-X-ray correlations in the narrow-line Seyfert 1 galaxy NGC 4051
Netzer, H.; Uttley, P.; Shemmer, O. +1 more
This paper presents the results of a dense and intensive X-ray and optical monitoring of the narrow-line Seyfert 1 galaxy NGC 4051 carried out in 2000. Results of the optical analysis are consistent with previous measurements. The amplitude of optical emission-line variability is a factor of 2 larger than that of the underlying optical continuum, …
The properties of the absorbing and line-emitting material in IGR J16318 - 4848
Guainazzi, Matteo; Matt, Giorgio
We have performed a detailed analysis of the XMM-Newton observation of IGR J16318-4848, to study the properties of the matter responsible for the obscuration and for the emission of Fe and Ni lines. Even if the line-of-sight material has a column density of about 2 × 1024 cm-2, from the Fe Kα line EW and Compton Shoulder we a…
An absorption event in the X-ray light curve of NGC 3227
Uttley, P.; McHardy, I. M.; Lamer, G.
We have monitored the Seyfert galaxy NGC 3227 with the Rossi X-ray Timing Explorer (RXTE) since 1999 January. During late 2000 and early 2001 we observed an unusual hardening of the 2-10 keV X-ray spectrum which lasted several months. The spectral hardening was not accompanied by any correlated variation in flux above 8 keV. We therefore interpret…
The DA+dMe eclipsing binary EC13471-1258: its cup runneth over ... just
Koester, D.; Stobie, R. S.; O'Donoghue, D. +5 more
The optical spectrum and light curve of EC13471-1258 show that it is an eclipsing binary with an orbital period of 3h 37m comprising a DA white dwarf and a dMe dwarf. Total eclipses of the white dwarf are observed lasting 14 min, with the partial phases lasting 54 s. On one occasion, two pre-eclipse dips were seen. Timings of…
Ram pressure stripping and the formation of cold fronts
Churazov, E.; Forman, W.; Heinz, S. +2 more
Chandra and XMM-Newton observations of many clusters reveal sharp discontinuities in the surface brightness, which, unlike shocks, have lower gas temperature on the X-ray brighter side of the discontinuity. For this reason, these features are called `cold fronts'. It is believed that some cold fronts are formed when a subcluster merges with anothe…
A deep Chandra observation of the cluster environment of the z= 1.786 radio galaxy 3C 294
Fabian, A. C.; Ettori, S.; Sanders, J. S. +1 more
We report the results from a 200-ks Chandra observation of the z= 1.786 radio galaxy 3C 294 and its cluster environment, increasing by ten-fold our earlier observation. The diffuse emission, extending about 100 kpc around the nucleus, has a roughly hourglass shape in the north-south (N-S) direction with surprisingly sharp edges to the N and S. The…
Star cluster formation and disruption time-scales - II. Evolution of the star cluster system in the fossil starburst of M82
de Grijs, Richard; Bastian, Nate; Lamers, Henny J. G. L. M.
We obtain new age and mass estimates for the star clusters in the fossil starburst region B of M82, based on improved fitting methods. Our new age estimates confirm the peak in the age histogram attributed to the last tidal encounter with M81; we find a peak formation epoch at slightly older ages than previously published, log(tpeak yr<…
First-look XMM-Newton EPIC observations of the prototypical starburst galaxy M82
Stevens, Ian R.; Bravo-Guerrero, Jimena; Read, Andrew M.
We present initial XMM-Newton EPIC observations of the prototypical starburst galaxy M82. The superwind is seen to extend continuously from the starburst region to the X-ray emission associated with the Hα`cap'. We also find evidence for a ridge feature, probably associated with the superwind interacting with an HI streamer. Narrow-band images, ce…
Fe K emission and absorption features in XMM-Newton spectra of Markarian 766: evidence for reprocessing in flare ejecta
O'Brien, P. T.; Reeves, J. N.; Page, K. L. +2 more
We report on the analysis of a long XMM-Newton European Photon Imaging Camera (EPIC) observation in 2001 May of the narrow-line Seyfert 1 galaxy Markarian 766 (Mrk 766). The 3-11 keV spectrum exhibits a moderately steep power-law continuum, with a broad emission line at ~6.7 keV, probably blended with a narrow line at ~6.4 keV, and a broad absorpt…