English
Related papers

Related papers: Old White Dwarfs as a Microlensing Population

200 papers

I review recent results from gravitational microlensing surveys of the Large Magellanic Cloud. The combined microlensing optical depth of the MACHO and EROS-1 surveys is tau_LMC = 2.1{+1.3/-0.8}* 10^{-7} which is substantially larger than…

Astrophysics · Physics 2009-10-30 David Bennett

We present an analysis of the large set of microlensing events detected so far toward the Galactic center with the purpose of investigating whether some of the dark lenses are located in Galactic globular clusters. We find that in four…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-12 Philippe Jetzer

Although a decade of microlensing searches towards the Large Magellanic Cloud (LMC) has detected 13-25 possible microlensing events, the nature and the location of the lenses, being either halo machos or LMC stars, remains a subject of…

Astrophysics · Physics 2009-11-07 HongSheng Zhao , Rodrigo Ibata , Geraint Lewis , Mike Irwin

Foundations of standard theory of microlensing are described, namely we consider microlensing stars in Galactic bulge, the Magellanic Clouds or other nearby galaxies. We suppose that gravitational microlenses lie between an Earth observer…

Astrophysics · Physics 2017-08-23 Alexander F. Zakharov

The empirical model of Lu et al. 2014 is updated with recent data and used to study galaxy star formation and assembly histories. At $z > 2$, the predicted galaxy stellar mass functions are steep, and a significant amount of star formation…

Astrophysics of Galaxies · Physics 2015-06-22 Zhankui Lu , H. J. Mo , Yu Lu , Neal Katz , Martin D. Weinberg , Frank C. van den Bosch , Xiaohu Yang

In this note we perform an analysis of the large set of microlensing events detected so far toward the Galactic center with the purpose of investigating whether some of the dark lenses are located in Galactic globular clusters. We find that…

Astrophysics · Physics 2010-01-15 Fabiana De Luca , Philippe Jetzer

We report the results of a systematic photometric survey of the peripheral regions of a sample of fourteen globular clusters in the outer halo of the Milky Way at distances d_GC>25 kpc from the Galactic centre. The survey is aimed at…

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…

Galactic double white dwarfs were postulated as a source of confusion limited noise for LISA, the future space-based gravitational wave observatory. Until very recently, the Galactic population consisted of a relatively well studied disk…

We collected F606W- and F814W-band time-series data of the Sagittarius low-reddening window in the Galactic bulge with the Advanced Camera far Surveys mounted on the Hubble Space Telescope. We sampled the region approximately every two…

Solar and Stellar Astrophysics · Physics 2013-08-09 A. Calamida , K. Sahu , J. Anderson , S. Casertano , T. Brown , S. Cassisi , J. Sokol , H. Bond , H. Ferguson , M. Livio , M. Salaris , J. Valenti

The MACHO Project monitors millions of stars in the Large Magellanic Cloud, the Small Magellanic Cloud and the bulge of the Milky Way searching for the gravitational microlensing signature of baryonic dark matter. This Project has yielded…

White dwarfs are the most common endpoints of stellar evolution. They are often found in close binary systems in which the white dwarf is accreting matter from a companion star, either via an accretion disc or channelled along the white…

Solar and Stellar Astrophysics · Physics 2023-03-20 Natalie A. Webb

The motivation for this paper is to review the limits set on the MACHO content of the Galactic halo by microlensing experiments in the direction of the Large Magellanic Cloud. This has been prompted by recent measurements of the Galactic…

Astrophysics of Galaxies · Physics 2015-03-09 M. R. S. Hawkins

We present an update of results from the search for microlensing towards the Large Magellanic Cloud (LMC) by EROS (Experience de Recherche d'Objets Sombres). We have now monitored 25 million stars over three years. Because of the small…

Astrophysics · Physics 2019-08-14 A. Milsztajn , T. Lasserre

There are lines of evidence suggesting that some of the observed microlensing events in the direction of the Large Magellanic Cloud (LMC) are caused by ordinary star lenses as opposed to dark Machos in the Galactic halo. Efficient lensing…

Astrophysics · Physics 2009-10-31 HongSheng Zhao , David Graff , Puragra Guhathakurta

I report on some recent results in the framework of a complex project aimed to characterize the photometric properties of stellar populations in Galactic Globular Clusters.

Astrophysics · Physics 2007-05-23 F. R. Ferraro

We report the discovery of a significant old population in the dwarf spheroidal (dSph) galaxy Leo I as a result of a wide-area search with the ESO New Technology Telescope. Studies of the stellar content of Local Group dwarf galaxies have…

Astrophysics · Physics 2009-10-31 Enrico V. Held , Ivo Saviane , Yazan Momany , Giovanni Carraro

Studies of the resolved stellar populations in nearby systems are crucial to understand galaxy evolution. Here, we summarize how the interpretation of the colour-magnitude diagrams of field stars in late-type dwarfs inside and outside the…

Astrophysics · Physics 2007-05-23 M. Tosi

Increasing evidences suggest that the Galactic halo is lumpy on kpc scales due to the accretion of at least a dozen small galaxies (LMC/SMC, Sgr, Fornax etc.). Faint stars in such lumpy structures can significant microlense a background…

Astrophysics · Physics 2009-10-30 HongSheng Zhao

The surroundings of globular clusters in the outer halo are one of the best places to look for the remnants of ancient dwarf satellites. The classical Searle & Zinn (1978) scenario of the formation of the Milky Way, in which the halo…