590 citations · 8.8k across the 153 of their papers we have counts for
14 papers · 1 filter
A survey for large image-separation lensed quasars
Dan Maoz, Hans-Walter Rix, Avishay Gal-Yam +1
The statistics of gravitationally lensed quasars with multiple images in the 0.1''-7'' range have been measured in various surveys. Little is known, however, about lensed-quasar st…
Signatures of Accretion Disks in Quasar Microlensing
Andrew Gould, Jordi Miralda-Escude
We propose that relative variability on short time-scales of the multiple images of a lensed quasar, after removal of the time delay, may be caused by hot spots or other moving str…
Star Counts From HST: Implications for Dark Matter
Andrew Gould
Star counts made with the Hubble Space Telescope (HST) probe four populations that are important for dark matter: disk, halo, bulge, and intergalactic. The disk mass function falls…
M Dwarfs From Hubble Space Telescope Star Counts III: The Groth Strip
Andrew Gould, John N. Bahcall, Chris Flynn
We analyze the disk M dwarfs found in 31 new fields observed with the Wide Field Camera (WFC2) on the Hubble Space Telescope (HST) together with the sample previously analyzed from…
Measuring the Rotation Speed of Giant Stars From Gravitational Microlensing
Andrew Gould
During some gravitational lensing events, the lens transits the face of the star. This causes a shift in the apparent radial velocity of the star which is proportional to its rotat…
Planet Parameters in Microlensing Events
B. Scott Gaudi, Andrew Gould
A planetary microlensing event occurs when a planet perturbs one of the two images created in a point-mass microlensing event, causing a deviation from the standard Paczyński curve…
Detection Rates for Close Binaries Via Microlensing
B. Scott Gaudi, Andrew Gould
Microlensing is one of the most promising methods of reconstructing the stellar mass function down to masses even below the hydrogen-burning limit. The fundamental limit to this te…
Femtolens Imaging of a Quasar Central Engine Using a Dwarf Star Telescope
Andrew Gould, B. Scott Gaudi
We show that it is possible to image the structure of a distant quasar on scales of AU by constructing a telescope which uses a nearby dwarf star as its ``primary lens''…
Hubble Deep Field Constraint on Baryonic Dark Matter
Chris Flynn, Andrew Gould, John N. Bahcall
We use a new technique to search for faint red stars in the Hubble Deep Field (HDF) imaged by the Wide Field Camera (WFC2) on the {\it Hubble Space Telescope}. We construct a dense…
Microlensing and the Stellar Mass Function
Andrew Gould
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 a…
Einstein Radii from Binary Lensing Events
Cheongho Han, Andrew Gould
We show that the Einstein ring radius and transverse speed of a lens projected on the source plane, and , can be determined from the light curve of a bin…
Luminosity Function of the Perigalactocentric Region
Vijay K. Narayanan, Andrew Gould, D. L. DePoy
We present H and K photometry of 42,000 stars in an area of 250 arcmin centered on the Galactic center. We use the photometry to construct a dereddened K band luminosity func…
Galactic versus Extragalactic Pixel Lensing Events toward M31
Cheongho Han, Andrew Gould
A new type of gravitational microlensing experiment toward a field where stars are not resolved is being developed observationally and theoretically: pixel lensing. When the experi…
Satellite Parallaxes of Lensing Events Towards the Galactic Bulge
B. Scott Gaudi, Andrew Gould
In order to understand the nature of the lenses that generate microlensing events, one would like to measure their mass, distance, and velocity. Unfortunately, current microlensing…