77 citations · 162 across the 11 of their papers we have counts for
6 papers · 1 filter
A Mass Measurement for the Missing Baryons in the Warm-Hot Intergalactic Medium via the X-ray Forest
F. Nicastro, S. Mathur, M. Elvis +7
Recent Cosmological measurements indicate that baryons comprise about four percent of the total mass-energy density of the Universe, which is in accord with the predictions arising…
Fe XXV and Fe XXVI lines from low velocity, photoionised gas in the X-ray spectra of AGN
Stefano Bianchi, Giorgio Matt, Fabrizio Nicastro +2
We have calculated the equivalent widths of the absorption lines produced by Fe XXV and Fe XXVI in a Compton-thin, low-velocity photoionised material illuminated by the nuclear con…
Opacity Variations in the Ionized Absorption in NGC 3783: A Compact Absorber
Y. Krongold, F. Nicastro, N. S. Brickhouse +2
We show that the Fe (VII-XII) M-shell unresolved transition array (UTA) in the NGC 3783 900 ks Chandra HETGS observation clearly changes in opacity in a timescale of 31 days respon…
The Ionized Nuclear Environment in NGC 985 as seen by Chandra and BeppoSAX
Y. Krongold, F. Nicastro, M. Elvis +3
(Abridged) We investigate the ionized environment of the Seyfert 1 galaxy NGC 985 with a new Chandra-HETGS observation and an archival BeppoSAX observation. Two absorption componen…
An Unveiling Event in the Type 2 AGN NGC4388: A Challenge for a Parsec Scale Absorber
Martin Elvis, G. Risaliti, F. Nicastro +3
We present two Rossi Xray Timing Explorer (RXTE) PCA observations of the type~2 Seyfert galaxy NGC 4388 caught in an unusual low X-ray absorption state. The observations were trigg…
Super-solar N/C in the NLS1 Galaxy Markarian 1044
Dale L. Fields, Smita Mathur, Richard W. Pogge +2
Narrow-Line Seyfert 1s (NLS1s) are known to have extreme values of a number of properties compared to Active Galactic Nuclei (AGN) as a class. In particular, previous emission-line…