Bibcode
González Hernández, Jonay I.; Rebolo, Rafael; Israelian, Garik
Bibliographical reference
Black Holes from Stars to Galaxies -- Across the Range of Masses. Edited by V. Karas and G. Matt. Proceedings of IAU Symposium #238, held 21-25 August, 2006 in Prague, Czech Republic. Cambridge, UK: Cambridge University Press, 2007., pp.43-48
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4
2007
Citations
1
Refereed citations
1
Description
The high-velocity black hole in the low mass X-ray binary XTE J1118+480
could be the remnant of an massive star formed in the early stages of
the evolution of the Galaxy (Mirabel et al. 2001). Alternatively, it
could have been ejected from the Galactic plane as a result of a `kick'
received during a supernova explosion (Gualandris et al. 2005). The
chemical composition of the secondary star may provide unique clues on
the origin of this black hole. Here, we present a medium-resolution
optical spectra of the companion and determine the atmospheric
abundances of Fe, Ca, Mg, Ni and Al. We find supersolar abundances for
all these elements, rejecting the black hole was originated from the
direct collapse of an ancient massive halo star. The compact object
probably formed in a supernova event whose nucleosynthetic products
polluted the secondary star. The observed element abundances and their
ratios have been compared with a variety of supernova models for
different metallicities and progenitor masses. Although we cannot
definitely discard a supernova origin in the Galactic halo, the
abundance pattern of the secondary star clearly suggest that black hole
formed in the supernova explosion of a metal-rich massive progenitor and
was violently `kicked out' from its birth place in the Galactic disc.