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Related papers: Probing the width of the MACHO mass function

200 papers

Microlensing surveys of stars in the Large Magellanic Cloud constrain the fraction of the Milky Way halo in Primordial Black Holes (PBHs) with mass $10^{-9} \lesssim M/M_{\odot} \lesssim 10^{4}$. Various studies have reached different…

Astrophysics of Galaxies · Physics 2025-03-12 Anne M. Green

Observations of the Galactic bulge revealed an excess of short-timescale gravitational microlensing events that are generally attributed to a large population of free-floating or wide-orbit exoplanets. However, in recent years, some authors…

Black hole-like objects with mass greater than $10 M_{\odot}$, as discovered by gravitational antennas, can produce long time-scale (several years) gravitational microlensing effects. Considered separately, previous microlensing surveys…

Astrophysics of Galaxies · Physics 2022-06-13 Tristan Blaineau , Marc Moniez

The EROS-2 project was designed to test the hypothesis that massive compact halo objects (the so-called ``machos'') could be a major component of the dark matter halo of the Milky Way galaxy. To this end, EROS-2 monitored over 6.7 years…

Recent results of microlensing surveys, show that 10-20% of the dark halo mass of the Milky Way consists of compact objects. The masses of these compact objects range from 0.1 to 1 solar mass. New theoretical cooling models for white…

Astrophysics · Physics 2007-05-23 Jelte de Jong , Konrad Kuijken , Mark Neeser

The failure to find evidence for elementary particles that could serve as the constituents of dark matter brings to mind suggestions that dark matter might consist of massive compact objects (MACHOs). In particular, it has recently been…

General Relativity and Quantum Cosmology · Physics 2016-12-07 G. Chapline , P. H. Frampton

If massive compact halo objects (\ms) are detected in ongoing searches, then \tsmctlmc, the ratio of the optical depth toward the Small and Large Magellanic Clouds, will be a robust indicator of the flattening of the Galactic dark matter…

Astrophysics · Physics 2009-10-22 Penny D. Sackett , Andrew Gould

The detection of microlensing has opened the way for the development of new methods in galactic astronomy. This series of papers investigates what microlensing can teach us about the structure and shape of the dark halo. In this paper we…

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 (or Machos), using gravitational microlensing of background stars. This search uses a very large format CCD camera on the…

We investigate the implications of a bulk rotational component of the halo velocity distribution for MACHO mass estimates. We find that for a rotating halo to yield a MACHO mass estimate significantly below that of the standard spherical…

Astrophysics · Physics 2020-11-25 G. Gyuk , E. Gates

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

I present a new analysis of the MACHO Project 5.7 year Large Magellanic Cloud (LMC) microlensing data set that incorporates the effects of contamination of the microlensing event sample by variable stars. Photometric monitoring of MACHO LMC…

Astrophysics · Physics 2009-11-10 David P. Bennett

We study the prospects for the current microlensing searches, which have recently discovered several candidates, to yield useful information about the flattening of the Galaxy dark matter halo. Models of HI warps and N-body simulations of…

Astrophysics · Physics 2009-10-22 Joshua A. Frieman , Román Scoccimarro

There has recently been interest in multi-Solar mass Primordial Black Holes (PBHs) as a dark matter (DM) candidate. There are various microlensing, dynamical and accretion constraints on the abundance of PBHs in this mass range. Taken at…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-06 Anne M Green

We discuss the implications of the more than 50 microlensing events seen by the EROS, MACHO, and OGLE collaborations for the composition of the halo of our galaxy. The event rates indicate that the halo mass fraction in MACHO's is less than…

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

Studying the trajectories of objects like stars, globular clusters or satellite galaxies in the Milky Way allows to trace the dark matter halo but requires reliable models of its gravitational potential. Realistic, yet simple and fully…

Astrophysics of Galaxies · Physics 2016-08-23 Andreas Irrgang , Benjamin Wilcox , Evan Tucker , Lucas Schiefelbein

The nature and the location of the lenses discovered in the microlensing surveys done so far towards the LMC remain unclear. Motivated by these questions we compute the optical depth and particularly the number of expected events for…

Astrophysics · Physics 2009-11-07 Ph. Jetzer , L. Mancini , G. Scarpetta

We present final results from the first phase of the EROS search for gravitational microlensing of stars in the Magellanic Clouds by unseen deflectors (machos: MAssive Compact Halo Objects). The search is sensitive to events with time…

We present an analysis of the longest timescale microlensing events discovered by the MACHO Collaboration during a 7 year survey of the Galactic bulge. We find 6 events that exhibit very strong microlensing parallax signals due, in part, to…