Chemical Analysis of the Brightest Star of the Cetus II Ultrafaint Dwarf Galaxy Candidate Academic Article uri icon

abstract

  • Abstract We present a detailed chemical abundance analysis of the brightest star in the ultrafaint dwarf (UFD) galaxy candidate Cetus II from high-resolution Magellan/MIKE spectra. For this star, DES J011740.53-173053, abundances or upper limits of 18 elements from carbon to europium are derived. Its chemical abundances generally follow those of other UFD galaxy stars, with a slight enhancement of the -elements (Mg, Si, and Ca) and low neutron-capture element (Sr, Ba, and Eu) abundances supporting the classification of Cetus II as a likely UFD. The star exhibits lower Sc, Ti, and V abundances than Milky Way (MW) halo stars with similar metallicity. This signature is consistent with yields from a supernova originating from a star with a mass of 11.2 M . In addition, the star has a potassium abundance of [K/Fe] = 0.81, which is somewhat higher than the K abundances of MW halo stars with similar metallicity, a signature that is also present in a number of UFD galaxies. A comparison including globular clusters and stellar stream stars suggests that high K is a specific characteristic of some UFD galaxy stars and can thus be used to help classify objects as UFD galaxies.

published proceedings

  • ASTROPHYSICAL JOURNAL

author list (cited authors)

  • Webber, K. B., Hansen, T. T., Marshall, J. L., Simon, J. D., Pace, A. B., Mutlu-Pakdil, B., ... Yanny, B.

complete list of authors

  • Webber, KB||Hansen, TT||Marshall, JL||Simon, JD||Pace, AB||Mutlu-Pakdil, B||Drlica-Wagner, A||Martinez-Vazquez, CE||Aguena, M||Allam, SS||Alves, O||Bertin, E||Brooks, D||Carnero Rosell, A||Carretero, J||da Costa, LN||De Vicente, J||Doel, P||Ferrero, I||Friedel, D||Frieman, J||Garcia-Bellido, J||Giannini, G||Gruen, D||Gruendl, RA||Hinton, SR||Hollowood, DL||Honscheid, K||Kuehn, K||Mena-Fernandez, J||Menanteau, F||Miquel, R||Ogando, RLC||Pereira, MES||Pieres, A||Plazas Malagon, AA||Sanchez, E||Santiago, B||Smith, J Allyn||Smith, M||Suchyta, E||Tarle, G||To, C||Weaverdyck, N||Yanny, B

publication date

  • December 2023