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astro-ph2002
AGNs among ROSAT Blank Field Sources
I. Cagnoni, M. Elvis, D. -W. Kim +3
We selected a sample of sources with high X-ray over optical flux ratio from the ROSAT PSPC archives. Out of the 16 sources in our sample, one is a (possibly extreme) BL Lac and tw…
astro-ph2002
XMM-Newton detection of warm/hot integalactic medium at z~0.01
Ilaria Cagnoni
We report a ~3 sigma detection of a 21.82 A absorption feature in the direction of the BL Lac MRK 421 which is interpreted as OVII K(alpha) at z~0.01. This corresponds to the redsh…