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Related papers: The Local Halo Density

200 papers

The dark matter in Galactic halos, or some fraction of it, may be in the form of dark clusters which consist of small mass objects. Carr & Lacey (1987) have derived the permissible properties of such systems, and proposed the existence of…

Astrophysics · Physics 2009-10-22 Eyal Maoz

We present distribution functions and spatial correlations of the shapes of dark matter halos derived from Hubble Volume simulations of a LambdaCDM universe. We measure both position and velocity shapes within spheres encompassing mean…

Astrophysics · Physics 2008-11-26 S. F. Kasun , A. E. Evrard

We study the population statistics of the surviving subhaloes of LCDM dark matter haloes using a set of very high resolution N-body simulations. These include both simulations of representative regions of the Universe and ultra-high…

Cosmology and Nongalactic Astrophysics · Physics 2011-01-26 L. Gao , C. S. Frenk , M. Boylan-Kolchin , A. Jenkins , V. Springel , S. D. M. White

[Abridged] We estimate the contribution of Massive Compact Halo Objects (Machos) and their stellar progenitors to the mass density of the Universe. If the Machos that have been detected reside in the Halo of our Galaxy, then a simple…

Astrophysics · Physics 2016-08-30 Brian D. Fields , Katherine Freese , David S. Graff

The recent detection of microlensing of stars of LMC by compact objects in the halo of our galaxy suggests that our galaxy is surrounded by a non-luminous halo made of compact objects with mass of about $(0.03-0.5) \msun$. The rate of…

Astrophysics · Physics 2007-05-23 T. Padmanabhan , K. Subramanian

A grand rotation curve of the Milky Way Galaxy is constructed, which covers a wide range of radius from the Galactic Center to ~1 Mpc, and is deconvolved into bulge, disk and halo components by least-squares fitting. We determined the scale…

Astrophysics of Galaxies · Physics 2015-05-30 Yoshiaki Sofue

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 roughly one fifth of the galactic halo dark…

Astrophysics · Physics 2009-11-07 Anne M Green , Karsten Jedamzik

The radial number density and flattening of the Milky Way's stellar halo is measured with $\mathrm{5351}$ metal-poor ([Fe/H]$<-1$) K giants from LAMOST DR3, using a nonparametric method which is model independent and largely avoids the…

Recently the French EROS collaboration and the American-Australian MACHO collaboration have reported the observation of altogether three possible microlensing events by monitoring over several years the brightness of millions of stars in…

Astrophysics · Physics 2009-10-22 Philippe Jetzer , Eduard Masso

If the massive compact halo object (MACHO) fraction of the Galactic dark halo is f ~ 20% as suggested by some microlensing experiments, then about 1.2% of lensing events toward the Galactic bulge are due to MACHOs. For the 40% of these that…

Astrophysics · Physics 2009-11-10 Andrew Gould

In this paper we present strong evidence for a core in the density distribution of the dark halo around a (dwarf) galaxy. DDO 47 has a rotation curve that increases linearly from the first data point, at 300 pc, up to to the last one, at 5…

Astrophysics · Physics 2009-11-07 P. Salucci , F. Walter , A. Borriello

We test the proposal by El-Zant et al that the dark matter density of halos could be reduced through dynamical friction acting on heavy baryonic clumps in the early stages of galaxy formation. Using N-body simulations, we confirm that the…

Astrophysics · Physics 2009-11-13 J. R. Jardel , J. A. Sellwood

In cold dark matter models, a galaxy's dark matter halo is more spatially extended than its stars. However, even though the five well-constrained gravitational lenses with time delay measurements must have similar dark matter distributions,…

Astrophysics · Physics 2007-05-23 C. S. Kochanek

We use the recently completed one billion particle Via Lactea II LambdaCDM simulation to investigate local properties like density, mean velocity, velocity dispersion, anisotropy, orientation and shape of the velocity dispersion ellipsoid,…

We present the results of a study of the average mass profile around galaxies using weak gravitational lensing. We use 45.5 deg^2 of R_C band imaging data from the Red-Sequence Cluster Survey (RCS) and define a sample of 1.2\times 10^5…

Astrophysics · Physics 2007-05-23 Henk Hoekstra , Howard K. C. Yee , Michael D. Gladders

To reveal the galactic dark matter in the form of MACHOs ("Massive Astrophysical Compact Halo Objects"), the POINT-AGAPE collaboration is carrying out a search for gravitational microlensing towards M31. A clear microlensing signal is…

Astrophysics · Physics 2007-05-23 S. Paulin-Henriksson , S. Calchi Novati

The French collaboration EROS and the American-Australian collaboration MACHO have reported the observation of altogether $\sim$ 10 microlensing events by monitoring during several years the brightness of millions of stars in the Large…

Astrophysics · Physics 2011-04-15 Philippe Jetzer

If the density distribution \rho (r) of MACHOs is spherically symmetric with respect to the Galactic center, it is shown that the minimal total mass M_{min}^{{ MACHO}} of the MACHOs is 1.7\times 10^{10}\sol \tau_{-6.7}^{{ LMC}} where…

Astrophysics · Physics 2009-10-28 T. Nakamura , Y. Kan-ya , R. Nishi

We use N-body simulations to investigate the structure of dark halos in the standard Cold Dark Matter cosmogony. Halos are excised from simulations of cosmologically representative regions and are resimulated individually at high…

Astrophysics · Physics 2008-11-26 Julio F. Navarro , Carlos S. Frenk , Simon D. M. White

The MACHO project is searching for dark matter in the form of massive compact halo objects (Machos), by monitoring the brightness of millions of stars in the Magellanic Clouds to search for gravitational microlensing events. Analysis of our…

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