相关论文: AGAPE : Gravitational microlensing effect to look …
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 half-maximum timescale is very short, just 1.8 days. Almost certainly, the source…
We have carried out a survey of the Andromeda galaxy for unresolved microlensing (pixel lensing). We present a subset of four short timescale, high signal-to-noise microlensing candidates found by imposing severe selection criteria: the…
The POINT-AGAPE collaboration is carrying out a search for gravitational microlensing toward M31 to reveal galactic dark matter in the form of MACHOs (Massive Astrophysical Compact Halo Objects) in the halos of the Milky Way and M31. A…
POINT-AGAPE is an Anglo-French collaboration which is employing the Isaac Newton Telescope (INT) to conduct a pixel-lensing survey towards M31. In this paper we investigate what we can learn from pixel-lensing observables about the MACHO…
M31 is a very tempting target for a microlensing search of compact objects in galactic haloes. It is the nearest large galaxy, it probably has its own dark halo, and its tilted position with respect to the line of sight provides an…
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…
AGAPE is an observational search of massive compact halo objects (MACHOs) in the direction of M31 by means of a novel method: the gravitational microlensing of unresolved stars. The search consists in examining CCD pixel light curves for…
I report on recent results from the POINT-AGAPE pixel-lensing experiment, which is engaged in a search towards the Andromeda galaxy (M31) for gravitational microlensing signatures from massive compact halo objects (Machos). An analysis of…
AgapeZ1 is the brightest and the shortest duration microlensing candidate event found in the Agape data. It occured only 42" from the center of M31. Our photometry shows that the half intensity duration of the event6 is 4.8 days and at…
We present the first results of the analysis of data collected during the 1998-99 observational campaign at the 1.3 meter McGraw-Hill Telescope, towards the Andromeda galaxy (M31), aimed to the detection of gravitational microlensing…
The Andromeda galaxy (M31) provides a new line of sight for Galactic MACHO studies and also a signature, near-far asymmetry, which may establish the existence of MACHOs in the M31 halo. We outline the principles behind the so-called…
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…
We report our first microlensing candidate NMS-E1 towards M31 from the data accumulated during the four years of Nainital Microlensing Survey. Cousin R and I band observations of ~13'x13' field in the direction of M31 have been carried out…
Recent results of the SLOTT-AGAPE and POINT-AGAPE collaborations on a search for microlensing events in direction of the Andromeda galaxy, by using the pixel method, are reported. The detection of 4 microlensing events, some likely to be…
Gravitational microlensing is a powerful tool for probing the physical properties of quasar accretion disks and properties of the lens galaxy such as its dark matter fraction and mean stellar mass. Unfortunately the number of lensed quasars…
We investigate gravitational microlensing signals produced by a spatially extended object transiting in front of a finite-sized source star. The most interesting features arise for lens and source sizes comparable to the Einstein radius of…
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…
We present analysis of MACHO Alert 95-30, a dramatic gravitational microlensing event towards the Galactic bulge whose peak magnification departs significantly from the standard point-source microlensing model. Alert 95-30 was observed in…
We re-analyze the M31 microlensing event WeCAPP-GL1/Point-AGAPE-S3 taking into account that stars are not point-like but extended. We show that the finite size of stars can dramatically change the self-lensing eventrate and (less…
We present the first M31 candidate microlensing events from the Microlensing Exploration of the Galaxy and Andromeda (MEGA) survey. MEGA uses several telescopes to detect microlensing towards the nearby Andromeda galaxy, M31, in order to…