Related papers: A Spectroscopic Method to Measure Macho Proper Mot…
(Abridged) A close scrutiny of the microlensing results towards the Magellanic clouds reveals that the stars within the Magellanic clouds are major contributors as lenses, and the contribution of MACHOs to dark matter is 0 to 5%. The…
Astrometric observations of microlensing events were originally proposed to determine the lens proper motion with which the physical parameters of lenses can be better constrained. In this proceeding, we demonstrate that besides this…
We detect the weak gravitational lensing distortion of 450,000 background galaxies (20<R<23) by 790 foreground galaxies (R<18) selected from the Las Campanas Redshift Survey (LCRS). This is the first detection of weak lensing by field…
In this paper, we investigate the applicability of the astrometric method to the determination of the lens parameters for gravitational microlensing events toward both the LMC and the Galactic bulge. For this analysis, we investigate the…
We present the first space-based microlens parallax measurement of an isolated star. From the striking differences in the lightcurve as seen from Earth and from Spitzer (~1 AU to the West), we infer a projected velocity v_helio,projected ~…
Microlensing surveys search for the transient brightening of a background star that is the signature of gravitational lensing by a foreground compact object. This technique is an elegant way to search for astrophysical candidates that might…
Because Spitzer is an Earth-trailing orbit, losing about 0.1 AU/yr, it is excellently located to perform microlens parallax observations toward the Magellanic Clouds (LMC/SMC) and the Galactic bulge. These yield the so-called ``projected…
We use 14-year baseline images obtained with the Wide Field Planetary Camera 2 on board the Hubble Space telescope to derive a proper motion for one of the Milky Way's most distant dwarf spheroidal companions, Leo II, relative to an…
There are two observations of galaxies that can offer some insight into the nature of the dark matter (DM), namely the rotation curves and the gravitational lensing. While the first one can be studied using the Newtonian limit, the second…
A significant fraction of non-baryonic or baryonic dark matter in galactic halos may consist of MASsive Compact Objects (MASCOs) with mass M=10^{1-4}M_{sun}. Possible candidates for such compact objects include primordial black holes or…
The infall of the Large Magellanic Cloud (LMC) into the Milky Way (MW) has displaced the MW's centre of mass, manifesting as an observed reflex motion in the velocities of outer halo stars. We use a Simulation Based Inference framework to…
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…
We detail how microlensing internal to M31 could be used to test whether a large fraction of the matter in spiral galaxy haloes is composed of dark objects with masses comparable to those of stars, and in the process show how the…
Current and upcoming wide-field surveys for weak gravitational lensing and the Sunyaev-Zel'dovich effect will generate mass-selected catalogues of dark matter halos with internal or followup photometric redshift information. The angular…
If a microlensing event is caused by a star, the event can exhibit change in color due to the light from the lens. In the previous and current lensing surveys, the color shift could not be used to constrain the lens population because the…
Large samples of Field Horizontal Branch (FHB) stars make excellent tracers of the Galactic halo; by studying their kinematics, one can infer important physical properties of our Galaxy. Here we present the results of a medium-resolution…
The standard light curve of a microlensing event provides only two constraints on the six unknown parameters of the lens. We show that narrow-band photometry during a microlensing event of a giant star can in addition determine the angular…
Kallivayalil et al. have used the \textit{Hubble Space Telescope} to measure proper motions of the LMC and SMC using images in 21 and five fields, respectively, all centered on known QSOs. These results are more precise than previous…
Many distant objects can only be detected, or become more scientifically valuable, if they have been highly magnified by strong gravitational lensing. We use EAGLE and BAHAMAS, two recent cosmological hydrodynamical simulations, to predict…
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…