Sub-structures in the Halo of the Milky Way
نویسندگان
چکیده
The latest results of the QUEST survey for RR Lyrae stars are described. This survey, which is designed to find and characterize sub-structures in the halo of our Galaxy, has covered about 700 square degrees of the sky and has detected 693 RR Lyrae stars, most of which are new discoveries. The spatial distribution of the RR Lyrae stars reveals several interesting groups in the halo. Some of them appear to be related to previous detections of the destruction of dwarf spheroidal galaxies (the Sagittarius tidal streams, the Virgo stellar stream, the Monoceros ring) or globular clusters (Palomar 5), while others still have an unknown origin.
منابع مشابه
Tidal Imprints Of A Dark Sub-Halo On The Outskirts Of The Milky Way
We present a new analysis of the observed perturbations of the HI disk of the Milky Way to infer the existence of a dark sub-halo that tidally interacted with the Milky Way disk. We examine tidal interactions between perturbing dark sub-halos and the gas disk of the Milky Way using high resolution Smoothed Particle Hydrodynamics (SPH) simulations. We compare our results to the observed HI map o...
متن کاملThe metallicity distribution of the halo and the satellites of the Milky way in the hierarchical merging paradigm
Aims. To account for the observed differential metallicity distribution (DMD) of the Milky Way halo, a semi-analytical model is presented in the framework of the hierarchical merging paradigm for structure formation. Methods. It is assumed that the Milky Way halo is composed of a number of sub-haloes with properties either as observed in the dwarf satellite galaxies of the Local group (shape of...
متن کاملThe dichotomy of the halo of the Milky Way
We summarize evidence that the halo of the Milky Way comprises two different, and broadly overlapping, stellar components. The two structures exhibit different chemical compositions, spatial distributions, and kinematics. These results were obtained through an analysis of more than 20,000 calibration stars from the Sloan Digital Sky Survey (SDSS). The duality of the stellar halo directly impact...
متن کاملThe Observed and Predicted Spatial Distribution of Milky Way Satellite Galaxies
We review evidence that the census of Milky Way satellites similar to those known may be incomplete at low latitude due to obscuration and in the outer halo due to a decreasing sensitivity to dwarf satellites with distance. We evaluate the possible impact that incompleteness has on comparisons with substructure models by estimating corrections to the known number of dwarfs using empirical and t...
متن کاملA Probabilistic Approach to Finding Geometric Objects in Spatial Datasets of the Milky Way
Data from the Sloan Digital Sky Survey has given evidence of structures within the Milky Way halo from other nearby galaxies. Both the halo and these structures are approximated by densities based on geometric objects. A model of the data is formed by a mixture of geometric densities. By using an EM-style algorithm, we optimize the parameters of our model in order to separate out these structur...
متن کامل