HIP 60350: A supernova ejected hyper-runaway star?

Irrgang A, Przybilla N, Heber U, Nieva MF, Schuh S (2010)

Publication Type: Conference contribution

Publication year: 2010

Journal

PoS - Proceedings of Science SISSA

Conference Proceedings Title: Proceedings of Science

Abstract

Halo runaway stars, i.e., young, massive, high-velocity stars in the halo of our Galaxy, are widely supposed to be the result of an ejection event from the Galactic disk. The three most likely ejection scenarios are tidal disruptions of binary systems by the supermassive black hole at the Galactic center, dynamical interactions in star clusters, e.g., binary-binary encounters, or a supernova explosion disrupting a binary system. Here, we present a detailed spectroscopic and kinematic analysis of the runaway B star HIP 60350 to discuss the three competing mechanisms. Using spectrum synthesis techniques that allow for deviations from local thermal equilibrium, we derived chemical elemental abundances from high resolution spectra. The analysis of HIP 60350 revealed an outstanding high Galactic rest-frame velocity of 530±35kms-1 slightly exceeding the local Galactic escape velocity and thus qualifying the star as a hyper-runaway candidate, i.e., an unbound runaway star. The kinematically predicted birthplace within the disk is located ∼ 6kpc away from the Galactic center excluding this region as the star's spatial origin and in this way the involvement of the central supermassive black hole. Instead, the obtained chemical abundance pattern shows hints of α-element enhancement being characteristic of supernova debris. HIP 60350 might be the surviving secondary of a massive, close binary system disrupted by the primary's supernova explosion. © Copyright owned by the author(s).

Authors with CRIS profile

Andreas Irrgang Dr.Karl-Remeis-Sternwarte Bamberg, Astronomisches Institut Norbert Przybilla Dr.Karl-Remeis-Sternwarte Bamberg, Astronomisches Institut Ulrich Heber Naturwissenschaftliche Fakultät

Involved external institutions

Georg-August-Universität Göttingen DE Germany (DE) Max-Planck-Institut für Astrophysik / Max Planck Institute for Astrophysics DE Germany (DE)

How to cite

APA:

Irrgang, A., Przybilla, N., Heber, U., Nieva, M.F., & Schuh, S. (2010). HIP 60350: A supernova ejected hyper-runaway star? In Proceedings of Science.

MLA:

Irrgang, Andreas, et al. "HIP 60350: A supernova ejected hyper-runaway star?" Proceedings of the 11th Symposium on Nuclei in the Cosmos, NIC 2010 2010.

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