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Related papers: Recent developments in the search for baryonic dar…

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We propose that the massive compact halo objects (MACHOs) observed in the recent microlensing experiments with an apparent best fit mass of about $0.5 M_{\odot}$ are objects made out of ``mirror'' baryonic matter rather than familiar…

Astrophysics · Physics 2009-10-31 Rabindra N. Mohapatra , Vigdor L. Teplitz

The nature of the dark matter in the Universe is one of the outstanding questions in astrophysics. In this talk, I address possible stellar baryonic contributions to the 50-90% of our Galaxy that is made of unknown dark matter. First I show…

Astrophysics · Physics 2007-05-23 Katherine Freese , Brian Fields , David Graff

The MACHO project has been monitoring about ten million stars in the Large Magellanic Cloud in the search for gravitational microlensing events caused by massive compact halo objects (Machos) in the halo of the Milky Way. In our standard…

As is well known, most of the baryons are observationally unaccounted. Moreover, certain recent developments suggest that dark baryons are mostly locked up in galactic halos - which are anyway dominated by nonbaryonic dark matter - and a…

Astrophysics · Physics 2007-05-23 Marco Roncadelli

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

We examine the possibility that galactic halos are collisionless ensembles of scalar field ``massive compact halo objects'' (MACHOs). Using mass constraints from MACHO microlensing and from theoretical arguments on halos made up of massive…

Astrophysics · Physics 2022-11-08 Xavier Hernández , Tonatiuh Matos , Roberto A Sussman , Yosef Verbin

There is now abundant evidence for the presence of large quantities of unseen matter surrounding normal galaxies, including our own$^{1,2}$. The nature of this `dark matter' is unknown, except that it cannot be made of normal stars, dust,…

We present the basics of microlensing and give an overview of the results obtained so far. We also describe a scenario in which dark clusters of MACHOs (Massive Astrophysical Compact Halo Objects) and cold molecular clouds (mainly of $H_2$)…

Astrophysics · Physics 2009-10-31 Ph. Jetzer

The dark matter problem is almost a century old. Since the 1930s evidence has been growing that our cosmos is dominated by a new form of non-baryonic matter, that holds galaxies and clusters together and influences cosmic structures up to…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-25 Laura Baudis

The distributions of dark matter and baryons in the Universe are known to be very different: the dark matter resides in extended halos, while a significant fraction of the baryons have radiated away much of their initial energy and fallen…

High Energy Physics - Phenomenology · Physics 2018-02-14 Matthew R. Buckley , Anthony DiFranzo

There is abundant evidence that the mass of the Universe is dominated by dark matter of unknown form. The MACHO project is one of several teams searching for the dark matter around our Galaxy in the form of Massive Compact Halo Objects…

Astrophysics · Physics 2008-11-26 Will Sutherland

We provide a status report on our search for dark matter in our Galaxy in the form of massive compact halo objects (MACHOs), using gravitational microlensing of background stars. This search uses a very large CCD camera on the dedicated…

It has been revealed using microlensing that a considerable part, possibly more than half, of the dark matter in the halo of our Galaxy consists of objects with a mass spectrum ranging from 0.05 to 0.8 of the solar mass. What is the nature…

Astrophysics · Physics 2007-05-23 A. V. Gurevich , K. P. Zybin , V. A. Sirota

A comet-like, but magnitudes smaller, extremely low albedo interstellar meteoroid population of fragile aggregates with solar type composition, measured in space and terrestrially, is most probably the universal dark matter. Although…

Astrophysics · Physics 2007-05-23 Robert K. Soberman , Maurice Dubin

MACHOs (Massive Astrophysical Compact Halo Objects) - as discovered by microlensing experiments towards the LMC - provide a natural explanation for the galactic halo dark matter. A realistic possibility is that MACHOs are brown dwarfs of…

Astrophysics · Physics 2007-05-23 F. De Paolis , G. Ingrosso , Ph. Jetzer , M. Roncadelli

Dark matter in galaxies, its abundance, and its distribution remain a subject of long-standing discussion, especially in view of the fact that neither dark matter particles nor dark matter bodies have yet been found. Experts' opinions range…

Astrophysics of Galaxies · Physics 2017-10-31 A. V. Zasov , A. S. Saburova , A. V. Khoperskov , S. A. Khoperskov

There is good evidence that most of the baryons in the Universe are dark and some evidence that most of the matter in the Universe is nonbaryonic with cold dark matter (cdm) being a promising possibility. We discuss expectations for the…

Astrophysics · Physics 2009-10-22 Evalyn Gates , Michael S. Turner

Observations by the MACHO collaboration indicate that a significant fraction of the galactic halo dark matter may be in form of compact objects with masses $M\sim 0.5M_{\odot}$. Identification of these objects as red or white dwarfs is…

Astrophysics · Physics 2009-10-30 Karsten Jedamzik

Most of the mass density in the Universe---and in the halo of our own galaxy---exists in the form of dark matter. Overall, the contribution of luminous matter (in stars) to the mass density of the Universe is less than 1\%; primordial…

Astrophysics · Physics 2009-09-25 Michael S. Turner

I discuss two hypotheses that might explain LMC microlensing: the Halo stellar remnant lensing hypothesis and the unvirialized LMC lensing hypothesis. I show that white dwarfs cannot contribute substantially to the cosmic baryon budget;…

Astrophysics · Physics 2007-05-23 David S. Graff