294 citations · 639 across the 7 of their papers we have counts for
5 papers · 1 filter
Iron Kalpha emission from the low-luminosity Active Galaxies M81 and NGC 4579
G. C. Dewangan, R. E. Griffiths, T. Di Matteo +1
We report on XMM-Newton spectroscopy of the low-luminosity active galaxies (LLAGN) M81 and NGC4579 both of which have known black hole masses and well-sampled spectral energy distr…
XMM-Newton view of the prototype narrow-line Seyfert 1 galaxy I Zw 1
G. C. Dewangan, R. E. Griffiths
We present results based on an XMM-Newton observation of the prototype narrow-line Seyfert 1 galaxy I Zw 1 performed in June 2002. The 0.6-12 keV spectrum is well described by a st…
The Consequences of the Cosmic Star-Formation Rate: X-ray Number Counts
A. Ptak, R. Griffiths, N. White +1
We discuss the observable consequences for the detection of galaxies in the X-ray bandpass resulting from a peak in the cosmic star-formation rate at a redshift > 1. Following Whit…
Deep HST Observations of Star Clusters in NGC 1275
Matthew N. Carlson, Jon A. Holtzman, Alan M. Watson +3
We present an analysis of compact star clusters in deep HST/WFPC2 images of NGC 1275. B and R band photometry of roughly 3000 clusters shows a bimodality in the B-R colors, suggest…
A deep ROSAT survey - IV. The evolution of X-ray-selected QSOs
B. J. Boyle, T. Shanks, I. Georgantopoulos +2
We report on a new estimate of the QSO X-ray luminosity function and its evolution with redshift based on a sample of 107 QSOs detected at faint X-ray fluxes, $S{\rm(0.5-2\,keV)}>4…