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Related papers: Pixel lensing towards M31 in principle and in prac…

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We present the first results from an extended survey of the Andromeda galaxy (M31) using 41.1 h of observations by Spitzer-IRAC at 3.6 and 4.5$\,\mu$m. This survey extends previous observations to the outer disc and halo, covering total…

We apply the pixel method of analysis (sometimes called ``pixel lensing'') to a small subset of the EROS-1 microlensing observations of the bar of the Large Magellanic Cloud (LMC). The pixel method is designed to find microlensing events of…

Astrophysics · Physics 2007-05-23 A. -L. Melchior et al

Traditional approaches to measuring the stellar mass function (MF) are fundamentally limited because objects are detected based on their luminosity, not their mass. These methods are thereby restricted to luminous and relatively nearby…

Astrophysics · Physics 2009-10-28 Andrew Gould

We present a quantitative measurement of the amount of clustering present in the inner $\sim30$ kpc of the stellar halo of the Andromeda galaxy (M31). For this we analyse the angular positions and radial velocities of the carefully selected…

Astrophysics of Galaxies · Physics 2016-12-07 P. R. Kafle , S. Sharma , A. S. G. Robotham , G. F. Lewis , S. P. Driver

I demonstrate that one can detect pixel gravitational microlensing events at the rate $\sim 180\ {\rm events}\ {\rm yr}^{-1}$ and that some fraction of events ($\sim 15$) will be good enough to measure time scales at the $20\%$ level if the…

Astrophysics · Physics 2009-10-28 Cheongho Han

The Andromeda (M31) galaxy subtends nearly 100 sq. deg. on the sky, with severe contamination from the Milky Way halo stars whose surface density displays a steep gradient across the entire M31 field-of-view. Planetary Nebulae (PNe) are a…

We report the discovery of a short-duration microlensing candidate in the Northern field of the POINT-AGAPE pixel lensing survey towards M31. The full-width at half-maximum timescale is very short (tfwhm = 1.8 days) and the source star has…

Astrophysics · Physics 2007-05-23 Stephane Paulin-Henriksson

The existence of a population of wandering Intermediate Mass Black Holes (IMBHs) is a generic prediction of scenarios that seek to explain the formation of Supermassive Black Holes in terms of growth from massive seeds. The growth of IMBHs…

Astrophysics · Physics 2008-11-26 Mattia Fornasa , Marco Taoso , Gianfranco Bertone

It has been shown by Paczy\'nski that gravitational microlensing is a useful method to detect brown dwarfs in the dark halo of our galaxy. At present several experiments are carried out to monitor several million stars in the Large…

Astrophysics · Physics 2008-02-03 Philippe Jetzer

Several exoplanets have been detected towards the Galactic bulge with the microlensing technique. We show that exoplanets in M31 may also be detected with the pixel-lensing method, if telescopes making high cadence observations of an…

Solar and Stellar Astrophysics · Physics 2015-05-18 G. Ingrosso , S. Calchi-Novati , F. De Paolis , Ph. Jetzer , A. A. Nucita , A. F. Zakharov

We show that exoplanets in the M31 galaxy may be detected with the pixel-lensing method by using telescopes making high cadence observations of an ongoing microlensing event. Although the mean mass for detectable exoplanets is about $2…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-14 G. Ingrosso , F. De Paolis , S. Calchi Novati , Ph. Jetzer , A. A. Nucita , A. F. Zakharov

We present a 900 sec, wide-field U image of the inner region of the Andromeda galaxy obtained during the commissioning of the blue channel of the Large Binocular Camera mounted on the prime focus of the Large Binocular Telescope. Relative…

We describe the results and outline the methods used in a search for microlensing events affecting stars in the outer bulge and inner disk of M31, due both to masses in M31 and the Galaxy. These observations, from 1994 and 1995 on the…

Astrophysics · Physics 2007-05-23 Arlin P. S. Crotts

Primordial black holes (PBHs) have long been suggested as a viable candidate for the elusive dark matter (DM). The abundance of such PBHs has been constrained using a number of astrophysical observations, except for a hitherto unexplored…

We present a new technique for monitoring microlensing activity even in highly crowded fields, and use this technique to place limits on low-mass MACHOs in the haloes of M31 and the Galaxy. Unlike present Galactic microlensing surveys, we…

Astrophysics · Physics 2009-09-28 Austin B. Tomaney , Arlin P. S. Crotts

Mid-infrared observations of the Andromeda galaxy, M31, obtained with the Infrared Array Camera on board the Spitzer Space Telescope, are presented. The image mosaics cover areas of approximate 3.7deg x 1.6deg and include the satellite…

A status report of the microlensing search by the pixel method in the direction of M31, on the 2 meter telescope at Pic du Midi is given. Pixels are stable to a level better than 0.5%. Pixel variations as small as 0.02 magnitude can clearly…

Pixel lensing is the gravitational microlensing of light from unresolved stars contributing to the luminosity flux collected by a single pixel. A star must be sufficiently magnified, that is, the lens impact parameter must be less than a…

Astrophysics · Physics 2009-11-10 F. De Paolis , G. Ingrosso , A. A. Nucita , A. F. Zakharov

The only way to detect planets around stars at distances of several kpc is by (photometric or astrometric) microlensing observations. In this paper, we show that the capability of photometric microlensing extends to the detection of signals…

Astrophysics · Physics 2007-05-23 G. Covone , R. de Ritis , M. Dominik , A. A. Marino