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 results obtained from a series of 5~\AA\ resolution spectra of theX-ray Nova GRO~J0422+32 obtained in 1993~October, when the system wasapproximately 2 magnitudes above quiescence, with ${\rm R \sim 19}$. The datawere obtained in an effort to measure the orbital radial velocity curve of thesecondary, but detection of the narrow photospheric absorption lines needed todo this proved elusive. Instead we found wide absorption bands reminiscent ofM~star photospheric features. The parameters determined by fitting accretiondisk line profiles (Smak profiles) to the H$\alpha$ line are similar to thosefound in several strong black-hole candidates. Measurements of the velocity ofthe H$\alpha$ line are consistent with an orbital period of 5.1~hours and avelocity semi-amplitude of the primary of $34 \pm 6$~\kms. These measurements,when combined with measurements of the velocity semi-amplitude of the secondarymade by others, indicate that the mass ratio $q \sim 0.09$. If the secondaryfollows the empirical mass-radius relation found for CVs, the low $q$ implies aprimary mass of $M_x \sim 5.6$\mo, and a rather low (face-on) inclination. TheH$\alpha$ EW is found to be modulated on the orbital period with a phasing thatimplies a partial eclipse of the disk by the secondary, but simultaneous R~bandphotometry shows no evidence for such an eclipse.Comment: Accepted for ApJ, plain latex, 5 figures available as self-extracting  uuendoced, compressed, tarfiles (from uufiles

Observations of the X-Ray Nova GRO J0422+32. II. Optical Spectra Approaching Quiescence