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 Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Swift J1357.2-0933 is a transient low-mass X-ray binary hosting astellar-mass black hole. The source exhibits optical dips and very broademission lines during both outburst and quiescence, which are thought to be theresult of a high orbital inclination. We present phase-resolved spectroscopyobtained with the 10.4m Gran Telescopio Canarias (GTC). The spectra focus onthe $\rm{H}\beta$ spectral region during X-ray quiescence. The emission line isexceptionally broad (full width at half maximum, FWHM > 4000 \AA), in agreementwith previous studies focused on $\rm{H}\alpha$. A two-Gaussian fit to theprominent double-peaked profile reveals a periodic variability in the centroidposition of the line. We also produced a diagnostic diagram aimed atconstraining additional orbital parameters. Together, they allow us toindependently confirm the orbital period of the system using a new datasetobtained five years after the previous outburst. However, our estimates forboth the systemic velocity and the radial velocity semi-amplitude of the blackhole reveal larger values than those found in previous studies. We argue thatthis could be explained by the precession of the disc and the presence of ahotspot. We found evidence of a narrow inner core in the double-peaked H$\beta$emission profile. We studied its evolution across the orbit, finding that it islikely to result from the occultation of inner material by the outer rim bulge,further supporting the high orbital inclination hypothesis.

H$\beta$ spectroscopy of the high-inclination black hole transient Swift J1357.2-0933 during quiescence