Identifying RR Lyrae Variable Stars in Six Years of the Dark Energy Survey Academic Article uri icon

abstract

  • Abstract We present a search for RR Lyrae stars using the full six-year data set from the Dark Energy Survey covering ∼5000 deg2 of the southern sky. Using a multistage multivariate classification and light-curve template-fitting scheme, we identify RR Lyrae candidates with a median of 35 observations per candidate. We detect 6971 RR Lyrae candidates out to ∼335 kpc, and we estimate that our sample is >70% complete at ∼150 kpc. We find excellent agreement with other wide-area RR Lyrae catalogs and RR Lyrae studies targeting the Magellanic Clouds and other Milky Way satellite galaxies. We fit the smooth stellar halo density profile using a broken-power-law model with fixed halo flattening (q = 0.7), and we find strong evidence for a break at R 0 = 32.1 0.9 + 1.1 kpc with an inner slope of n 1 = 2.54 0.09 + 0.09 and an outer slope of n 2 = 5.42 0.14 + 0.13 . We use our catalog to perform a search for Milky Way satellite galaxies with large sizes and low luminosities. Using a set of simulated satellite galaxies, we find that our RR Lyrae-based search is more sensitive than those using resolved stellar populations in the regime of large (r h ≳ 500 pc), low-surface-brightness dwarf galaxies. A blind search for large, diffuse satellites yields three candidate substructures. The first can be confidently associated with the dwarf galaxy Eridanus II. The second has a distance and proper motion similar to the ultrafaint dwarf galaxy Tucana II but is separated by ∼5 deg. The third is close in projection to the globular cluster NGC 1851 but is ∼10 kpc more distant and appears to differ in proper motion

published proceedings

  • The Astrophysical Journal

altmetric score

  • 57.51

author list (cited authors)

  • Stringer, K. M., Drlica-Wagner, A., Macri, L., Martínez-Vázquez, C. E., Vivas, A. K., Ferguson, P., ... Zhang, Y.

citation count

  • 6

complete list of authors

  • Stringer, KM||Drlica-Wagner, A||Macri, L||Martínez-Vázquez, CE||Vivas, AK||Ferguson, P||Pace, AB||Walker, AR||Neilsen, E||Tavangar, K||Wester, W||Abbott, TMC||Aguena, M||Allam, S||Bacon, D||Bechtol, K||Bertin, E||Brooks, D||Burke, DL||Carnero Rosell, A||Carrasco Kind, M||Carretero, J||Costanzi, M||Crocce, M||Costa, LN da||Pereira, MES||De Vicente, J||Desai, S||Diehl, HT||Doel, P||Ferrero, I||García-Bellido, J||Gaztanaga, E||Gerdes, DW||Gruen, D||Gruendl, RA||Gschwend, J||Gutierrez, G||Hinton, SR||Hollowood, DL||Honscheid, K||Hoyle, B||James, DJ||Kuehn, K||Kuropatkin, N||Li, TS||Maia, MAG||Marshall, JL||Menanteau, F||Miquel, R||Morgan, R||Ogando, RLC||Palmese, A||Paz-Chinchón, F||Plazas, AA||Roodman, A||Sanchez, E||Schubnell, M||Serrano, S||Sevilla-Noarbe, I||Smith, M||Soares-Santos, M||Suchyta, E||Tarle, G||Thomas, D||To, C||Varga, TN||Wilkinson, RD||Zhang, Y

publication date

  • April 2021