English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We present a spectroscopic component analysis of 18 candidate young, wide,non-magnetic, double-degenerate binaries identified from a search of the SloanDigital Sky Survey Data Release 7 (DR7). All but two pairings are likely to bephysical systems. We show SDSS J084952.47+471247.7 + SDSS J084952.87+471249.4to be a wide DA+DB binary, only the second identified to date. Combining ourmeasurements for the components of 16 new binaries with results for threesimilar, previously known systems within the DR7, we have constructed a massdistribution for the largest sample to date (38) of white dwarfs in young,wide, non-magnetic, double-degenerate pairings. This is broadly similar in formto that of the isolated field population with a substantial peak around M~0.6Msun. We identify an excess of ultra-massive white dwarfs and attribute this tothe primordial separation distribution of their progenitor systems peaking atrelatively larger values and the greater expansion of their binary orbitsduring the final stages of stellar evolution. We exploit this mass distributionto probe the origins of unusual types of degenerates, confirming a mildpreference for the progenitor systems of high-field-magnetic white dwarfs, atleast within these binaries, to be associated with early-type stars.Additionally, we consider the 19 systems in the context of the stellar initialmass-final mass relation. None appear to be strongly discordant with currentunderstanding of this relationship.

Component masses of young, wide, non-magnetic white dwarf binaries in the SDSS DR7