590 citations · 8.8k across the 153 of their papers we have counts for
13 papers · 1 filter
K Band Microlensing of the Inner Galaxy
Andrew Gould
Microlensing searches toward the inner galaxy have several major advantages. First, the event rate is strongly dominated by bulge-bulge lensing even…
Statistics Of Microlensing Optical Depth
Cheongho Han, Andrew Gould
We show that the statistical error, , in estimating the optical depth, , due to microlensing is substantially higher than the naive Poisson estimate: ,…
A New Macho Search Strategy
Andrew Gould
I propose a radical revision in the search strategy for Massive Compact Objects (Machos) toward the Galactic bulge: monitor the entire square deg of the bulge and tune t…
Self-Lensing By Binaries
Andrew Gould
Lensing of one member of a binary by its companion is studied for several classes of binaries. For binaries in which at least one member is an ordinary (non-compact) star, the opti…
The Mass Spectrum Of Machos From Parallax Measurements
Cheongho Han, Andrew Gould
We demonstrate that by making satellite-based parallax measurements of Macho events, it is possible to distinguish disk from bulge Machos and to determine individual masses of disk…
Macho Parallaxes From A Single Satellite
Andrew Gould
Massive Compact Objects (Machos) are currently being discovered at substantially higher rates than would be expected from standard models of known stellar populations. To determine…
Self-Lensing By A Stellar Disk
Andrew Gould
I derive a general expression for the optical depth for gravitational lensing of stars in a disk by Massive Compact Objects (Machos) in the same disk. For the more restricted c…
The Supernova Ring Revisited II: Distance to the LMC
Andrew Gould
I derive an upper limit to the distance to SN 1987A of $\dsn<46.77\pm 0.76\,\kpc$, or a distance modulus $μ_\sn<18.350\pm 0.035$. If SN 1987A lies in the plane of the Large Magella…
Analytic Error Estimates
Andrew Gould
I present an analytic method for estimating the errors in fitting a distribution. A well-known theorem from statistics gives the minimum variance bound (MVB) for the uncertainty in…
M Dwarfs, Microlensing, and the Mass Budget of the Galaxy
John N. Bahcall, Chris Flynn, Andrew Gould +1
We show that faint red stars do not contribute significantly to the mass budget of the Galaxy or to microlensing statistics. Our results are obtained by analyzing two long exposure…
Microlensing by Stars in the Disk of M31
Andrew Gould
The optical depth to microlensing toward M31 due to known stars in the disk of M31 itself is where is the disk scale length and is the dista…
Weak Lensing By Nearby Structures
Andrew Gould, Jens Villumsen
Weak gravitational lensing due to nearby structures, such as the Coma cluster, and the Local Supercluster can be expected to polarize images of distant galaxies by ${\cal O}(0.2%Ω)…
A Spectroscopic Method to Measure Macho Proper Motions
Dan Maoz, Andrew Gould
A Massive Compact Halo Object (Macho) that lenses a background star will magnify different parts of the rotating stellar disk by varying amounts. The differential magnification wil…