|Title||Do X-rays Make Disk Emission Lines in Quiescent Dwarf Novae?|
|Author||Dr Knox Long|
|Description||If the standard disk instability model for outbursts in dwarf novae (DNe) is correct, the disk in quiescence should be cold and optically thick. But quiescent DNe show UV and optical emission lines. Why? Is the disk optically thin in the continuum? Does viscous dissipation near the disk photosphere produce a corona? Or, is a corona created by X-ray illumination of the disk from a hot boundary layer? Here we propose to test the X-ray illumination hypothesis with simultaneous, highly time-resolved observations of SS Cyg in quiescence with XMM-Newton and HST-STIS. The X-ray flux in SS Cyg varies on short timescales. If X-ray illumination is responsible for the emission lines, they should vary in response to the X-ray flux. If not, one of the other mechanisms must be responsible.|
|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, 2019-12-19T23:00:00Z, 082023, 19.17_20220121_1250. https://doi.org/10.5270/esa-hwe1ky1|