|Title||Lineless Quasars at High Redshift: Extremely High Accretion Rate Sources|
|Author||Dr Ohad Shemmer|
|Description||We propose to obtain XMM-Newton spectroscopic imaging observations of a remarkable group of five quasars that lack detectable ultraviolet emission lines at z=2.9-4.0 with a total exposure time of 195 ks. Obtaining virgul1000 photons per source, we will measure the hard-X-ray photon index and intrinsic absorption, and search for an iron line and Compton reflection. Steep hard-X-ray spectral slopes will indicate that high accretion rates may be responsible for the emission-line suppression with implications for the physics of the broad-line region. The XMM-Newton data may provide an important linkage between our sources and an apparently related group of radio-quiet, weak-lined active galactic nuclei at low redshift.|
|Publication||No observations found associated with the current proposal|
|Instrument||EMOS1, EMOS2, EPN, OM, RGS1, RGS2|
|Mission Description||The European Space Agency's (ESA) X-ray Multi-Mirror Mission (XMM-Newton) was launched by an Ariane 504 on December 10th 1999. XMM-Newton is ESA's 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 Earth's 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.
|Publisher And Registrant||European Space Agency|
|Credit Guidelines||European Space Agency, 2009-08-02T00:00:00Z, 055175, 17.56_20190403_1200. https://doi.org/10.5270/esa-2zumjge|