DIFFUSE BARYONIC DARK MATTER IN THE GALACTIC HALO

Baryonic Dark Matter (BDM) candidates are segregated into two main mass ranges: (i) sub-solar mass dwarf stars (MACHOS) and (ii) ∼ 104–106M⊙ Very Massive Objects (VMOs). The lower mass range has been the target of the various micro-lensing programs but the first, tentative conclusions (see Stubbs et al. these proceedings) seem to suggest that MACHOs are unlikely to provide the bulk of the dark matter in the galactic halo. Meanwhile the upper mass range (104–106M⊙) remains largely unexplored. However, Wambsganss & Paczynski 1992 (hereafter WP92), have shown that this mass range is perfectly tuned to a straightforward and direct test: gravitational milli-lensing of macro-lensed images (Fig 1).

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Baryonic dark matter

Nuclear Physics B - Proceedings Supplements ◽

10.1016/s0920-5632(02)80090-1 ◽

2002 ◽

Vol 110 (2) ◽

pp. 16-25 ◽

Cited By ~ 2

Author(s):

R Rebolo

Keyword(s):

Dark Matter ◽

Baryonic Dark Matter

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Detecting Cold Dark Matter Candidates

Symposium - International Astronomical Union ◽

10.1017/s0074180900150703 ◽

1987 ◽

Vol 117 ◽

pp. 490-490

Author(s):

A. K. Drukier ◽

K. Freese ◽

D. N. Spergel

Keyword(s):

Dark Matter ◽

Cold Dark Matter ◽

Galactic Halo ◽

Dark Matter Particle ◽

Low Energy ◽

The Sun ◽

Background Rate ◽

System Noise ◽

Weakly Interacting ◽

Massive Neutrinos

We consider the use of superheated superconducting colloids as detectors of weakly interacting galactic halo candidate particles (e.g. photinos, massive neutrinos, and scalar neutrinos). These low temperature detectors are sensitive to the deposition of a few hundreds of eV's. The recoil of a dark matter particle off of a superheated superconducting grain in the detector causes the grain to make a transition to the normal state. Their low energy threshold makes this class of detectors ideal for detecting massive weakly interacting halo particles.We discuss realistic models for the detector and for the galactic halo. We show that the expected count rate (≈103 count/day for scalar and massive neutrinos) exceeds the expected background by several orders of magnitude. For photinos, we expect ≈1 count/day, more than 100 times the predicted background rate. We find that if the detector temperature is maintained at 50 mK and the system noise is reduced below 5 × 10−4 flux quanta, particles with mass as low as 2 GeV can be detected. We show that the earth's motion around the Sun can produce a significant annual modulation in the signal.

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Gravitational microlensing and dark matter in the galactic halo

Conference on 3K cosmology ◽

10.1063/1.59348 ◽

1999 ◽

Author(s):

Philippe Jetzer

Keyword(s):

Dark Matter ◽

Galactic Halo ◽

Gravitational Microlensing

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Formation of massive globular clusters with dark matter and its implication on dark matter annihilation

Monthly Notices of the Royal Astronomical Society Letters ◽

10.1093/mnrasl/slaa089 ◽

2020 ◽

Vol 496 (1) ◽

pp. L70-L74

Author(s):

Henriette Wirth ◽

Kenji Bekki ◽

Kohei Hayashi

Keyword(s):

Dark Matter ◽

Observational Studies ◽

Globular Clusters ◽

Galactic Halo ◽

Dwarf Galaxies ◽

Large Range ◽

Dark Matter Annihilation ◽

Central Regions ◽

Γ Ray ◽

The Masses

ABSTRACT Recent observational studies of γ-ray emission from massive globular clusters (GCs) have revealed possible evidence of dark matter (DM) annihilation within GCs. It is, however, still controversial whether the emission comes from DM or from millisecond pulsars. We here present the new results of numerical simulations, which demonstrate that GCs with DM can originate from nucleated dwarfs orbiting the ancient Milky Way. The simulated stripped nuclei (i.e. GCs) have the central DM densities ranging from 0.1 to several M⊙ pc−3, depending on the orbits and the masses of the host dwarf galaxies. However, GCs born outside the central regions of their hosts can have no/little DM after their hosts are destroyed and the GCs become the Galactic halo GCs. These results suggest that only GCs originating from stellar nuclei of dwarfs can possibly have DM. We further calculate the expected γ-ray emission from these simulated GCs and compare them to observations of ω Cen. Given the large range of DM densities in the simulated GCs, we suggest that the recent possible detection of DM annihilation from GCs should be more carefully interpreted.

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