337 citations · 652 across the 23 of their papers we have counts for
4 papers · 2 filters
On the nature of the z=0 X-ray absorbers: I. Clues from an external group
Smita Mathur, Gregory R. Sivakoff, Rik J. Williams +1
Absorption lines of OVII at redshift zero are observed in high quality Chandra spectra of extragalactic sightlines. The location of the absorber producing these lines, whether from…
Lost Baryons at Low Redshift
Smita Mathur, Fabrizio Nicastro, Rik J. Williams
We review our attempts to discover lost baryons at low redshift with ``X-ray forest'' of absorption lines from the warm-hot intergalactic medium. We discuss the best evidence to da…
Variable X-ray Absorption toward Gravitationally-Lensed Blazar PKS1830-211
Xinyu Dai, Smita Mathur, George Chartas +2
We present X-ray spectral analysis of five Chandra and XMM-Newton observations of the gravitationally-lensed blazar PKS1830-211 from 2000 to 2004. We show that the X-ray absorption…
Time-Evolving Photoionization: the Thin and Compact X-Ray Wind of NGC 4051
Fabrizio Nicastro, Yair Krongold, Martin Elvis +3
We discuss the power of time-evolving photoionization as a diagnostic tool to measure the electron density of photoionized gas. We apply this technique to a XMM-Newton observation…