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We present an analysis of the results of the OGLE-III microlensing campaign towards the Large Magellanic Cloud (LMC). We evaluate for all the possible lens populations along the line of sight the expected microlensing quantities, number of…

Astrophysics of Galaxies · Physics 2011-09-27 S. Calchi Novati , L. Mancini

We present Hubble Space Telescope (HST) WFPC2 photometry of 13 microlensed source stars from the 5.7 year Large Magellanic Cloud (LMC) survey conducted by the MACHO Project. The microlensing source stars are identified by deriving accurate…

The nature and the location of the lenses discovered in the microlensing surveys done so far towards the LMC remain unclear. Motivated by these questions we computed the optical depth for the different intervening populations and the number…

Astrophysics · Physics 2007-05-23 Philippe Jetzer

Microlensing events are now regularly being detected by monitoring the flux of a large number of potential sources and measuring the combined magnification of the images. This phenomenon could also be detected directly from the…

Astrophysics · Physics 2009-10-28 Jordi Miralda-Escude

We present a measurement of the systemic proper motion of the Small Magellanic Cloud (SMC) made using the Advanced Camera for Surveys (ACS) on the \textit{Hubble Space Telescope} (\textit{HST}). We tracked the SMC's motion relative to 4…

Astrophysics · Physics 2008-11-26 Nitya Kallivayalil , Roeland P. van der Marel , Charles Alcock

We present measurements of positions and relative proper motions in the 30 Doradus region of the Large Magellanic Cloud (LMC). We detail the construction of a single-epoch astrometric reference frame, based on specially-designed…

Solar and Stellar Astrophysics · Physics 2015-09-16 I. Platais , R. P. van der Marel , D. J. Lennon , J. Anderson , A. Bellini , E. Sabbi , H. Sana , L. R. Bedin

We present proper motion measurements for more than $0.55$ million main-sequence stars, by comparing astrometric positions of matched stars between the multi-band imaging datasets from the Hyper Suprime-Cam (HSC) Survey and the SDSS Stripe…

Traditional evidence for large amount of dark matter is based on dynamical consideration for systems with $ t_{dyn} \gg t_{obs} $. Recent observational and theoretical developments in gravitational lensing offer a much more robust…

Astrophysics · Physics 2009-10-22 Bohdan Paczyński

We present a method for measuring the Sun's motion using the proper motions of Galactic halo star streams. The method relies on the fact that the motion of the stars perpendicular to a stream from a low-mass progenitor is close to zero when…

Astrophysics of Galaxies · Physics 2017-08-16 Khyati Malhan , Rodrigo A. Ibata

Gravitational microlensing is a robust tool to detect and directly measure the abundance and mass of any kind of compact objects, either in our galaxy or in the extragalatic domain. On basis to generic, broadly applicable arguments, it is…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-27 E. Mediavilla , J. Jiménez-Vicente

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

The mass function of 51 Massive Compact Objects (MACHOs) detected toward the Galactic bulge is statistically estimated from Einstein ring crossing times $t_{\rm e}$. For a Gaussian mass function, the best fitting parameters are $\langle…

Astrophysics · Physics 2009-10-28 Cheongho Han , Andrew Gould

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

We measure the kinematic signature arising from the Milky Way (MW) disc moving with respect to the outer stellar halo, which is observed as a dipole signal in the kinematics of stellar halo tracers. We quantify how the reflex motion varies…

Astrophysics of Galaxies · Physics 2024-02-21 Rashid Yaaqib , Michael S. Petersen , Jorge Peñarrubia

The distance to the Large Magellanic Cloud (LMC) can be directly determined by measuring three of its properties, its radial-velocity field, its mean proper motion, and the position angle \phi_ph of its photometric line of nodes.…

Astrophysics · Physics 2009-10-31 Andrew Gould

The dependence of microlensing time scale frequency distributions and optical depth toward the galactic center on galactic model parameters is explored in detail for a distribution of stars consisting of the Zhao (1996) bar and nucleus and…

Astrophysics · Physics 2009-10-30 S. J. Peale

Studies of weak gravitational lensing by large-scale structures require the measurement of the distortions introduced to the shapes of distant galaxies at the few percent level by anisotropic light deflection along the line of sight. To…

Astrophysics · Physics 2009-11-07 Andrew W. Blain

The observed microlensing events towards the LMC do not have yet a coherent explanation. If they are due to Galactic Halo objects, the nature of these objects is puzzling --- half the halo in dark 0.5 Msol objects. On the other hand,…

Astrophysics · Physics 2007-05-23 E. Aubourg , N. Palanque-Delabrouille , P. Salati , M. Spiro , R. Taillet

We show that the Einstein ring radius and transverse speed of a lens projected on the source plane, $\hat{r}_{\rm e}$ and $\hat{v}$, can be determined from the light curve of a binary-source event, followed by the spectroscopic…

Astrophysics · Physics 2009-10-28 Cheongho Han , Andrew Gould

The rotation of the disk of the Large Magellanic Cloud (LMC) is derived from the radial velocities of 422 carbon stars. New aspects of this analysis include the propagation of uncertainties in the LMC proper motion with a Monte Carlo, and a…

Astrophysics · Physics 2014-10-13 David R. Alves , Cailin A. Nelson