An r-process Enhanced Star in the Dwarf Galaxy Tucana III Academic Article uri icon

abstract

  • Abstract Chemically peculiar stars in dwarf galaxies provide a window for exploring the birth environment of stars with varying chemical enrichment. We present a chemical abundance analysis of the brightest star in the newly discovered ultra-faint dwarf galaxy candidate Tucana III. Because it is particularly bright for a star in an ultra-faint Milky Way (MW) satellite, we are able to measure the abundance of 28 elements, including 13 neutron-capture species. This star, DESJ235532.66593114.9 (DES J235532), shows a mild enhancement in neutron-capture elements associated with the r-process and can be classified as an r-I star. DESJ235532 is the first r-I star to be discovered in an ultra-faint satellite, and TucIII is the second extremely low-luminosity system found to contain r-process enriched material, after ReticulumII. Comparison of the abundance pattern of DESJ235532 with r-I and r-II stars found in other dwarf galaxies and in the MW halo suggests a common astrophysical origin for the neutron-capture elements seen in all r-process enhanced stars. We explore both internal and external scenarios for the r-process enrichment of TucIII and show that with abundance patterns for additional stars, it should be possible to distinguish between them.

published proceedings

  • ASTROPHYSICAL JOURNAL

altmetric score

  • 15.58

author list (cited authors)

  • Hansen, T. T., Simon, J. D., Marshall, J. L., Li, T. S., Carollo, D., DePoy, D. L., ... Walker, A. R.

citation count

  • 101

complete list of authors

  • Hansen, TT||Simon, JD||Marshall, JL||Li, TS||Carollo, D||DePoy, DL||Nagasawa, DQ||Bernstein, RA||Drlica-Wagner, A||Abdalla, FB||Allam, S||Annis, J||Bechtol, K||Benoit-Levy, A||Brooks, D||Buckley-Geer, E||Carnero Rosell, A||Kind, M Carrasco||Carretero, J||Cunha, CE||da Costa, LN||Desai, S||Eifler, TF||Fausti Neto, A||Flaugher, B||Frieman, J||Garcia-Bellido, J||Gaztanaga, E||Gerdes, DW||Gruen, D||Gruendl, RA||Gschwend, J||Gutierrez, G||James, DJ||Krause, E||Kuehn, K||Kuropatkin, N||Lahav, O||Miquel, R||Plazas, AA||Romer, AK||Sanchez, E||Santiago, B||Scarpine, V||Smith, RC||Soares-Santos, M||Sobreira, F||Suchyta, E||Swanson, MEC||Tarle, G||Walker, AR

publication date

  • March 2017