We have identified several dust-obscured quasars in the Spitzer First LookSurvey region using a selection based on mid-infrared color. Our selectionallows us to directly compare the number density of obscured quasars with thoseof unobscured quasars from the Sloan survey in the same region of sky, enablingan accurate comparison of the number densities of unobscured, type-1, andobscured, type-2, quasars at a given luminosity for the first time. We requestXMM observations in order to estimate the obscuring column of gas towards thenuclei of these objects, and hence establish what fraction of these objects areCompton thick. The results will be important both for understanding the quasar-2population, and for estimating the fraction of quasars missed in X-ray surveys.
Instrument
EMOS1, EMOS2, EPN, OM, RGS1, RGS2
Temporal Coverage
2006-03-21T20:54:27Z/2006-05-09T00:48:53Z
Version
17.56_20190403_1200
Mission Description
The European Space Agencys (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESAs second cornerstone of the Horizon 2000 Science Programme. It carries 3 high throughput X-ray telescopes with an unprecedented effective area, and an optical monitor, the first flown on a X-ray observatory. The large collecting area and ability to make long uninterrupted exposures provide highly sensitive observations. Since Earths atmosphere blocks out all X-rays, only a telescope in space can detect and study celestial X-ray sources. The XMM-Newton mission is helping scientists to solve a number of cosmic mysteries, ranging from the enigmatic black holes to the origins of the Universe itself. Observing time on XMM-Newton is being made available to the scientific community, applying for observational periods on a competitive basis.
European Space Agency, Dr Mark Lacy, 2007, 'The X-ray properties of quasar-2s selected from Spitzer.s First Look Survey', 17.56_20190403_1200, European Space Agency, https://doi.org/10.5270/esa-jrj6uml
