The quest RR Lyrae survey: Confirmation of the clump at 50 kiloparsecs and other overdensities in the outer halo

Vivas, AK; Zinn, R; Andrews, P; Bailyn, C; Baltay, C; Coppi, P; Ellman, N; Girard, T; Rabinowitz, D; Schaefer, B; Shin, J; Snyder, J; Sofia, S; van Altena, W; Abad, C; et. al.

Abstract

We have measured the periods and light curves of 148 RR Lyrae variables from V = 13.5 to 19.7 from the first 100 deg(2) of the Quasar Equatorial Survey Team RR Lyrae survey. Approximately 55% of these stars belong to the dump of stars detected earlier by the Sloan Digital Sky Survey. According to our measurements, this feature has similar to 10 times the background density of halo stars, spans at least 37.degrees5 by 3.degrees5 in alpha and delta (greater than or equal to 30 by greater than or equal to3 kpc), lies similar to 50 kpc from the Sun, and has a depth along the line of sight of similar to5 kpc (1 sigma). These properties are consistent with the recent models that suggest that it is a tidal stream from the Sagittarius dwarf spheroidal galaxy. The mean period of the type ab variables, 0.58 days, is also consistent. In addition, we have found two smaller overdensities in the halo, one of which may be related to the globular cluster Pal 5.

Más información

Título según WOS: ID WOS:000169690900008 Not found in local WOS DB
Título de la Revista: ASTROPHYSICAL JOURNAL
Volumen: 554
Número: 1
Editorial: IOP PUBLISHING LTD
Fecha de publicación: 2001
Página de inicio: L33
Página final: L36
DOI:

10.1086/320915

Notas: ISI