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Related papers: Can the Dark Matter be $10^6$ Solar Mass Objects?

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We have searched for long duration microlensing events originating from intermediate mass Black Holes (BH) in the halo of the Milky Way, using archival data from EROS-2 and MACHO photometric surveys towards the Large Magellanic Cloud. We…

If the dark halo of our galaxy is made of compact objects as massive as M = 10^6 solar masses, their detection by means of ordinary microlensing searches would take a very long time as the characteristic time scale of such a lensing event,…

Astrophysics · Physics 2007-05-23 Bohdan Paczynski

In the local Universe, star formation is typically inefficient both globally and when considered as the fraction of gas converted into stars per local free-fall time. An important exception to this inefficiency is regions of high…

Astrophysics of Galaxies · Physics 2025-04-07 Michael Boylan-Kolchin

We present robust constraints from the Sloan Digital Sky Survey (SDSS) on the shape and distribution of the dark matter halo within the Milky Way (MW). Using the number density distribution and kinematics of SDSS halo stars, we probe the…

Two forms are suggested for the energy-momentum source term associated with an aggregate of dark matter (with the properties described in Paper I). Both have large pressure-like components which dominate the density terms. Using one form a…

General Relativity and Quantum Cosmology · Physics 2020-01-20 H. L. Helfer

We compute the properties of dark matter halos with mass $10^{6.5}-10^9\msun$ at redshift $z=6-11$ in the standard cold dark matter cosmological model, utilizing a very high resolution N-body simulation. We find that dark matter halos in…

Astrophysics · Physics 2007-05-23 Renyue Cen , Feng Dong , Paul Bode , Jeremiah P. Ostriker

Five years of EROS data towards the Small Magellanic Cloud have been searched for gravitational microlensing events, using a new, more accurate method to assess the impact of stellar blending on the efficiency. Four long-duration candidates…

Astrophysics · Physics 2012-08-27 EROS Collaboration

We argue that primordial dark matter halos could be generated during radiation domination by long range attractive forces stronger than gravity. In this paper we derive the conditions under which these structures could dominate the dark…

Cosmology and Nongalactic Astrophysics · Physics 2019-10-17 Stefano Savastano , Luca Amendola , Javier Rubio , Christof Wetterich

It was proposed that the massive compact halo objects (MCHOs) would be produced during an earlier epoch of cosmology if the density perturbations are between $3 \times 10^{-4}$ and 0.3. Then these objects can accrete dark matter particles…

Cosmology and Nongalactic Astrophysics · Physics 2011-09-13 Yupeng Yang , Xiaoyuan Huang , Xuelei Chen , Hongshi Zong

Star counts made with the Hubble Space Telescope (HST) probe four populations that are important for dark matter: disk, halo, bulge, and intergalactic. The disk mass function falls for masses M<0.6 Msun in sharp contrast to the rising…

Astrophysics · Physics 2016-08-30 Andrew Gould

We study the impact of the interaction between DM and the cosmic neutrino background on the evolution of galactic dark matter halos. The energy transfer from the neutrinos to the dark matter can heat the center of the galaxy and make it…

High Energy Physics - Phenomenology · Physics 2023-07-12 Wonsub Cho , Ki-Young Choi , Hee Jung Kim

Optically thin cooling gas at most temperatures above 30K will make condensations by pressure pushing material into cool dense regions. This works without gravity. Cooling condensations will flatten and become planar/similarity solutions.…

Astrophysics · Physics 2009-11-06 D. Lynden-Bell , C. A. Tout

The nature of the Massive Compact Halo objects seen in microlensing experiments and interpreted as dark matter in the Halo of our Galaxy remains a mystery. Arguments are presented that these events are probably not ordinary stellar or…

Astrophysics · Physics 2009-09-25 Katherine Freese , Brian Fields , David Graff

Advances in high angular resolution astronomy make it conceivable that black hole dark matter could be detected via angular deviation effects. Assuming the dark matter in the galaxy is made of solar mass black holes, there is a non-trivial…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-08 Leo Stodolsky

The EROS and MACHO collaborations have each published upper limits on the amount of planetary mass dark matter in the Galactic Halo obtained from gravitational microlensing searches. In this paper the two limits are combined to give a much…

Astrophysics · Physics 2012-08-27 EROS Collaboration , MACHO Collaboration

Context. Gas within a galaxy is forced to establish pressure balance against gravitational forces. The shape of an unperturbed gaseous disk can be used to constrain dark matter models. Aims. We derive the 3-D HI volume density distribution…

Astrophysics · Physics 2009-11-13 P. M. W. Kalberla , L. Dedes , J. Kerp , U. Haud

Fuzzy dark matter (FDM) granulations would drive orbital transport of stars in galactic disks, and in particular would produce roughly equal amounts of radial heating and radial migration. However, observations suggest that heating has been…

Astrophysics of Galaxies · Physics 2024-12-19 Chris Hamilton

We studied the formation and evolution of low-mass stars within halos with high concentration of dark matter (DM) particles, using a highly sophisticated expression to calculate the rate at which DM particles are captured inside the star.…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-22 Jordi Casanellas , Ilidio Lopes

The nature of dark matter (DM) remains unknown despite very precise knowledge of its abundance in the universe. An alternative to new elementary particles postulates DM as made of macroscopic compact halo objects (MACHO) such as black holes…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-10 Miguel Zumalacarregui , Uros Seljak

Techniques for inferring the radial and geometric form of dark matter halos and the results they have produced to date are reviewed. Dark halos appear to extend to at least ~50 kpc with total enclosed masses that rise linearly with radius…

Astrophysics · Physics 2007-05-23 Penny D. Sackett