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Related papers: Rotating Halos and the Microlensing MACHO Mass Est…

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It is widely believed that dark matter halos are flattened, that is closer to oblate than prolate. The evidence cited is based largely on observations of galaxies which do not look anything like our own and on numerical simulations which…

Astrophysics · Physics 2009-10-28 Gilbert P. Holder , Lawrence M. Widrow

We combine new results from the search for microlensing towards the Large Magellanic Cloud (LMC) by EROS2 (Experience de Recherche d'Objets Sombres) with limits previously reported by EROS1 and EROS2 towards both Magellanic Clouds. The…

Astrophysics · Physics 2007-05-23 T. Lasserre , EROS Collaboration

Paczy\'nski (1986) suggested that ``dark" objects in the halo of our Galaxy could enhance the luminosity of foreground stars, acting as gravitational microlenses. Such events has been recently reported by different collaborations. We assume…

Astrophysics · Physics 2007-05-23 Sergio Campana

We present a new empirical relation between galaxy dark matter halo mass (${\rm M_{halo}}$) and the velocity along the flat portion of the rotation curve (${\rm V_{flat}}$), derived from 120 late-type galaxies from the SPARC database. The…

Astrophysics of Galaxies · Physics 2018-11-07 Harley Katz , Harry Desmond , Stacy McGaugh , Federico Lelli

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

Models of our galaxy based on dynamical observations predict a spheroid component much heavier than accounted for by direct measurements of star counts and high velocity stars. If, as first suggested by Caldwell and Ostriker, this…

Astrophysics · Physics 2010-11-30 G. F. Giudice , S. Mollerach , E. Roulet

We use simulated merger trees of galaxy-cluster halos to study the effect of the halo concentration distribution on strong lensing and X-ray emission. Its log-normal shape typically found in simulations favors outliers with high…

Astrophysics · Physics 2009-11-13 C. Fedeli , M. Bartelmann , M. Meneghetti , L. Moscardini

In order to determine an upper bound for the mass of the massive compact halo objets (MACHOs) we use the halo binaries contained in a recent catalog (Allen \& Monroy-Rodr\'{\i}guez 2013). To dynamically model their interactions with massive…

Astrophysics of Galaxies · Physics 2015-06-22 Miguel A. Monroy-Rodríguez , Christine Allen

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

The core mass of galaxy clusters is an important probe of structure formation. Here, we evaluate the use of a Single-Halo model (SHM) as an efficient method to estimate the strong lensing cluster core mass, testing it with ray-traced images…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-26 J. D. Remolina González , K. Sharon , N. Li , G. Mahler , L. E. Bleem , M. Gladders , A. Niemiec

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

After a decade of gravitational microlensing experiments, a dozen of microlensing candidates in the direction of the stars of the Large Magellanic Cloud (LMC) have been detected by the EROS and MACHO groups. Recently it was shown that the…

Astrophysics · Physics 2009-11-10 Sohrab Rahvar

It has been shown by Paczy\'nski that gravitational microlensing is potentially a useful method for detecting the dark constituents of the halo of our galaxy, if their mass lies in the approximate domain $10^{-6} < M/M_{\odot} < 10^{-1}$.…

Astrophysics · Physics 2008-02-03 Philippe Jetzer

Stellar mass has been shown to correlate with halo mass, with non-negligible scatter. The stellar mass-size and luminosity-size relationships of galaxies also show significant scatter in galaxy size at fixed stellar mass. It is possible…

Astrophysics of Galaxies · Physics 2017-10-11 Paul J. L. Charlton , Michael J. Hudson , Michael L. Balogh , Sumeet Khatri

We carry out a systematic investigation of the total mass density profile of massive (Mstar>2e11 Msun) early-type galaxies and its dependence on galactic properties and host halo mass with the aid of a variety of lensing/dynamical data and…

Recent observations of microlensing events in the Large Magellanic Cloud by the MACHO and EROS collaborations suggest that an important fraction of the galactic halo is in the form of Massive Halo Objects (MHO) with mass $\sim 0.1…

Astrophysics · Physics 2009-10-22 F. De Paolis , G. Ingrosso , Ph. Jetzer , M. Roncadelli

I review proposals for explaining the current gravitational microlensing results from the EROS and MACHO surveys towards the Magellanic Clouds. Solutions involving massive compact halo objects (MACHOs), both baryonic and non-baryonic, as…

Astrophysics · Physics 2007-05-23 Eamonn Kerins

We investigated, through numerical models, the flaring variability that may arise from the rotation of maser clouds of approximately spheroidal geometry, ranging from strongly oblate to strongly prolate examples. Inversion solutions were…

Solar and Stellar Astrophysics · Physics 2019-05-08 M. D. Gray , J. Baggott , J. Westlake , S. Etoka

We discuss the different definitions of the mass of a halo in common use and how one may convert between them. Using N-body simulations we show that mass estimates based on spherical averages are much more tightly correlated with each other…

Astrophysics · Physics 2009-08-18 Martin White

After a decade of gravitational microlensing experiments, 13 to 17 events by MACHO (depending on quality) and two events by EROS have been detected. All of those have been observed in the direction of Large Magellanic Cloud. We use Evans…

Astrophysics · Physics 2009-11-07 Sohrab Rahvar