Substructure in the Galactic Halo
نویسندگان
چکیده
منابع مشابه
Revealing Substructure in the Galactic Halo - The SEKBO RR Lyrae Survey
We present a search for RR Lyrae variable stars from archival observations of the Southern Edgeworth-Kuiper Belt Object survey. The survey covers 1675 square degrees along the ecliptic to a mean depth of V=19.5, i.e. a heliocentric distance of ∼ 50kpc for RR Lyrae stars. The survey reveals 2016 RR Lyrae candidates. Follow-up photometric monitoring of a subset of these candidates shows ∼24% cont...
متن کاملEffects of Early Cosmic Reionization on the Substructure Problem in Galactic Halo
Recent observations on the cosmic microwave background by Wilkinson Microwave Anisotropy Probe (WMAP) strongly suggest that the reionization of the universe took place quite early (z ∼ 17). On the other hand, it has been pointed out that the cold dark matter cosmology suffers from the substructure problem that subgalactic halos are overproduced than the observed dwarf galaxies in the Local Grou...
متن کاملGalactic substructure and dark-matter annihilation in the Milky Way halo
We study the effects of substructure on the rate of dark-matter annihilation in the Galactic halo. We use an analytic model for substructure that can extend numerical simulation results to scales too small to be resolved by the simulations. We first calibrate the analytic model to numerical simulations, and then determine the annihilation boost factor, for standard weakly interacting massive pa...
متن کاملThe Gamma-Ray-Flux Probability Distribution Function from Galactic Halo Substructure
One of the targets of the recently launched Fermi Gamma-ray Space Telescope is a diffuse gamma-ray background from dark-matter annihilation or decay in the Galactic halo. N-body simulations and theoretical arguments suggest that the dark matter in the Galactic halo may be clumped into substructure, rather than smoothly distributed. Here we propose the gamma-ray-flux probability distribution fun...
متن کاملHi in the galactic halo
We find solid evidence for diffuse Hi gas at substantial z heights in our Galaxy, with a velocity dispersion of σ = 60 km s −1 and a vertical projected column density of N Hi = 1.4 · 10 19 cm −2. This pervasive component of the emission spectrum could be identified in the Leiden/Dwingeloo 21-cm Survey (LDS) after increasing the accuracy further by correcting the observations for reflections fro...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Publications of the Astronomical Society of Australia
سال: 2004
ISSN: 1323-3580,1448-6083
DOI: 10.1071/as04031