CV science with eROSITA surveys
* Questions and objectives
The nature and composition of low-luminosity compact objects, their contribution to the GRXE, and the progenitors of SNIa? The space density of Low-Lum compact objects, constraints on close binary evolution from the eROSITA CV population? The role of the magnetic field in close binary evolution? The duty cycle of LLCOs?
* Expectation
About 2000 - 5000 CVs will be detected in the eROSITA surveys, dependent on the assumed space density, the shape of the luminosity function and the assumed sensitivity. It will be the largest and least-biased sample for evolutionary and galactic studies. The main challenge will be to identify and characterize the objects on the basis of the X-ray detection, their proper motion, their opt/IR colors and their optical spectrum.
* Preparation
Source lists with known X-ray and optical parameters to search for known sources in the eROSITA surveys. Chracterize the known source populations in terms of X-ray and optical colors and spectra. Deliver spectral templates to the follow-up team(?).
* Relation/synergies with other WGs
Relation to TDA, use of the Bamberg simulator to predict eROSITA light curves of known sources with the aim, to understand the power and limitations of the eRO-surveys in pre-selection of CV candidates. The
* Follow-up
The CV follow-up shall be integral part of the AGN survey to be conducted with 4MOST and similar facilities (AS3/BOSS) to achieve a complete identification of point-like eROSITA X-rays sources with a limiting flux of 1e-14 cgs in 0.5-2.0 keV