Search Publications
The nature, evolution, clustering and X-ray properties of extremely red galaxies in the Chandra Deep Field South/Great Observatories Origins Deep Survey field
Almaini, Omar; Dunlop, James; Roche, Nathan D.
We identify a very deep sample of 198 extremely red objects (EROs) in the Chandra Deep Field South, selected on the basis of I775-Ks > 3.92, to a limit Ks~= 22 using the public European Southern Observatory (ESO)/Great Observatories Origins Deep Survey (GOODS) survey.
The ERO number counts flatten from a sl…Iron and nickel line properties in the X-ray-reflecting region of the Circinus galaxy
Bianchi, Stefano; Matt, Giorgio; Molendi, Silvano
We discuss the iron and nickel properties in the nuclear X-ray-reflecting region of the Circinus galaxy, studied with XMM-Newton. The main results are as follows. (i) From the depth of the Fe Kα edge, a value of AFe= 1.7 in number with respect to the cosmic value (as for Anders & Grevesse) is measured, if the (not directly visible) …
F stars, metallicity and the ages of red galaxies at z > 1
Dunlop, J. S.; Nolan, L. A.; Jimenez, R. +1 more
We explore whether the rest-frame near-ultraviolet spectral region, observable in high-redshift galaxies via optical spectroscopy, contains sufficient information to allow the degeneracy between age and metallicity to be lifted. We do this by first testing the ability of evolutionary synthesis models to reclaim the correct metallicity when fitted …
XMM-Newton observations of the hot-gas atmospheres of 3C 66B and 3C 449
Hardcastle, M. J.; Croston, J. H.; Birkinshaw, M. +1 more
We present new XMM-Newton observations of the hot-gas environments of two low-power twin-jet radio galaxies, 3C 66B and 3C 449, showing direct evidence for the interactions between X-ray-emitting gas and radio plasma that are thought to determine the large-scale radio structure of these sources. The temperatures that we measure for the two environ…
Mission: impossible (escape from the Lyman limit)
Fernández-Soto, A.; Chen, H. -W.; Lanzetta, K. M.
We investigate the intrinsic opacity of high-redshift galaxies to outgoing ionizing photons using high-quality photometry of a sample of 27 spectroscopically identified galaxies of redshift 1.9 < z < 3.5 in the Hubble Deep Field. Our measurement is based on maximum-likelihood fitting of model galaxy spectral energy distributions - including …
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…