| 其他摘要 | Accreting white dwarfs (WDs) are a kind of binary systems consisting of WDs and typically main sequence (MS), Hertzsprung gap (HG) or red giant (RG) stars. They can evolve into many important objects, such as cataclysmic variables, supersoft X-ray sources, double WDs, type Ia supernovae and binary millisecond pulsars. They can also evolve into AM Canum Venaticorum (AM CVn) stars whose gravitational wave signal can be detected by space borne gravitational wave detectors, such as LISA, TianQin and Taiji. They are also important for the studies of binary evolution, binary population synthesis, accretion physics. Until now, only a small fraction of stable nuclear burning white dwarfs (SNBWDs) can be detected, and no rapidly accreting white dwarfs (RAWDs) have been found so far. So it would be very necessary to search more accreting WDs from observations.The aim of the paper is to investigate the possibility of searching accreting WDs (i.e., SNBWDs and RAWDs) with the Chinese Space Station Telescope (CSST) and provide a possible criteria to distinguish accreting WDs from other stars. We get the parameter (eg. Logg, logTeff) ranges of accreting WDs from the optically thick wind model. For any given logg and logTeff, we can get a spectrum from a grid of spectra of accreting WDs computed with the non-local thermodynamic equilibrium (NLTE) model. Then we calculate the magnitudes of accreting WDs at different bands with the transmissions of CSST's filters. The upper limit of the companions' masses will be the critical masses at which the binaries still undergo stable mass transfer and the lower limits are determined by the critical mass ratios of binaries at which the mass transfer rates are higher than the minimum stable burning rates. For any given mass of a companion star, we can get its effective temperature and radius from the Modules for Experiments in Stellar Astrophysics (MESA) isochrones and evolutionary tracks (MIST). Then we calculate the magnitudes of companions and binaries. With these information, we investigate the difference between accreting WD binaries and stars with other types.We find that the properties of accreting WDs are very different from isolated WDs and we can distinguish accreting WDs with very high or low effective temperatures from others with (NUV-y, u-y), (NUV-r, u-g), (NUV-i, u-g), (NUV-z,u-g) and (NUV-y,u-g) color-color diagrams. Therefore, we would expect that some accreting WDs can be found by the CSST. Once the CSST starts operate, we can search for accreting WDs with these criteria and study the properties of accreting WDs and relevant objects. |
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