منابع مشابه
Star Streams in the Milky Way Halo
The last 10-20 years has seen a profound shift in views of how the Galaxy’s halo formed. The idea of a monolithic early collapse of a single system (Eggen, Lynden-Bell and Sandage 1962) has been challenged by observations at high redshift and by cosmological models of structure formation. These findings imply that we should see clear evidence of hierarchical formation processes in nearby galaxi...
متن کاملThe Shape of the Milky Way Halo
The latest Sloan Digital Sky Survey data tracing the tidal stream from the Sagittarius dwarf spheroidal (dSph) reveals a bifurcation in the distribution of debris. The branching is caused by the projection of the old trailing and young leading tidal arms of the Sagittarius dSph. The angular difference between the branches is a measure of the precession of the orbital plane and hence the aspheri...
متن کاملSub-structures in the Halo of the Milky Way
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 the...
متن کاملChemical Inhomogeneities in the Milky Way Stellar Halo
We have compiled a sample of 699 stars from the recent literature with detailed chemical abundance information (spanning −4.2 . [Fe/H] . +0.3), and we compute their space velocities and Galactic orbital parameters. We identify members of the inner and outer stellar halo populations in our sample based only on their kinematic properties and then compare the abundance ratios of these populations ...
متن کاملAre There Machos in the Milky Way Halo?
Microlensing searches aim to detect compact halo dark matter via its gravitational lensing effect on stars within the Large Magellanic Cloud. The most recent results have led to the claim that a significant fraction of the galactic halo dark matter may be in the form of compact, solar-mass objects. We analyze this hypothesis by considering the goodness-of-fit of the best-fit halo dark matter so...
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ژورنال
عنوان ژورنال: The Astrophysical Journal
سال: 2018
ISSN: 2041-8213
DOI: 10.3847/2041-8213/aab613