Cataclysmic Variables from Sloan Digital Sky Survey - V. The search for period bouncers continues
Date
2023/09/01
Journal Title
Journal ISSN
Volume Title
Publisher
OXFORD UNIV PRESS
Abstract
SDSS-V is carrying out a dedicated survey for white dwarfs, single, and in binaries, and we report the analysis of the spectroscopy of 118 cataclysmic variables (CVs) and CV candidates obtained during the final plug plate observations of SDSS. We identify eight new CVs, spectroscopically confirm 53 and refute 11 published CV candidates, and we report 21 new or improved orbital periods. The orbital period distribution of the SDSS-V CVs does not clearly exhibit a period gap. In common with previous studies, the distribution shows that spectroscopically identified CVs have a larger proportion of short-period systems compared to samples identified from photometric variability. Remarkably, despite a systematic search, we find very few period bouncers. We estimate the space density of period bouncers to be similar or equal to 0.2 x10(-6) pc(-3) , i.e. they represent only a few percent of the total CV population. This suggests that during their final phase of evolution, CVs either destroy the donor, e.g. via a merger, or that they become detached and cease mass transfer.
Description
Keywords
SPECTROSCOPIC TARGET SELECTION, ORBITAL PERIODS, WHITE-DWARF, X-RAY, DATA RELEASE, XMM-NEWTON, SUBDWARF STARS, SPACE DENSITY, BINARY-STAR, SDSS VIII.