Abstract
view Abstract Citations (80) References (41) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Li Abundances in Late-Type Companions to Neutron Stars and Black Hole Candidates Martin, Eduardo L. ; Rebolo, Rafael ; Casares, Jorge ; Charles, Philip A. Abstract Following our recent report of a strong Li lambda 6708 resonance line in the secondary of the black hole candidate V404 Cyg, we present here its detection in the quiescent spectrum of the neutron star binary Cen X-4. We obtain, via a spectral synthesis Local Thermodynamic Equilibrium (LTE) analysis, a surface lithium abundance in the K-type secondary of log N(Li) = 3.3 +/- 0.4. Taking into account non-LTE effects reduces the abundance by 0.2 dex. Using the same analysis, lithium abundances are also derived for the secondaries of the black hole binaries A0620-00, where a lithium detection has very recently been reported, and V404 Cyg. High lithium abundances appear to be a common feature of late-type secondaries in neutron star and black hole binaries, a result totally unexpected mainly because of post-main-sequence dilution and the mass transfer history of these stars. Convective mixing may cause additional depletion if lithium is taken to layers where it is burnt. In order to counteract the depletion it seems necessary to invoke a process of lithium production. Several mechanisms are plausible: for instance, lithium synthesis in a supernova explosion of the compact primary's progenitor, or an on-going process such as alpha-alpha reactions during the repeated strong outbursts that characterize transient X-ray binaries. The spallative mechanism can be tested by future high-resolution gamma-ray and optical spectroscopic observations. Implications on the Li enrichment of the Galactic interstellar medium are briefly discussed. Publication: The Astrophysical Journal Pub Date: November 1994 DOI: 10.1086/174857 Bibcode: 1994ApJ...435..791M Keywords: Black Holes (Astronomy); Lithium; Neutron Stars; Stellar Luminosity; Stellar Spectra; Astronomical Spectroscopy; X Ray Binaries; Astrophysics; BLACK HOLE PHYSICS; STARS: ABUNDANCES; STARS: INDIVIDUAL CONSTELLATION NAME: CENTAURUS X-4; STARS: NEUTRON full text sources ADS | data products SIMBAD (3)
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
