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- Publications
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The MACHO Project: Microlensing Results from 5.7 Years of Large Magellanic Cloud Observations
- T. M. C. C. Alcock, R. Allsman, +22 authors D. Welch
- Physics
- 15 January 2000
We report on our search for microlensing toward the Large Magellanic Cloud (LMC). Analysis of 5.7 yr of photometry on 11.9 million stars in the LMC reveals 13-17 microlensing events. A detailed… Expand
Dark halos formed via dissipationless collapse. I: Shapes and alignment of angular momentum
- Michael S. Warren, P. Quinn, J. Salmon, W. H. Zurek
- Physics
- 1 November 1992
We use N-body simulations on highly parallel supercomputers to study the structure of Galactic dark matter halos. The systems form by gravitational collapse from scale-free and more general Gaussian… Expand
The MACHO Project Large Magellanic Cloud Microlensing Results from the First Two Years and the Nature of the Galactic Dark Halo
- C. Alcock, R. Allsman, +16 authors D. Welch
- Physics
- 26 June 1996
The MACHO Project is a search for dark matter in the form of massive compact halo objects (MACHOs). Photometric monitoring of millions of stars in the Large Magellanic Cloud (LMC), Small Magellanic… Expand
The Macho Project: 45 Candidate Microlensing Events from the First Year Galactic Bulge Data
- C. Alcock, R. Allsman, +15 authors W. Sutherland
- Physics
- 21 December 1995
We report the detection of 45 candidate microlensing events in fields toward the Galactic bulge. These come from the analysis of 24 fields containing 12.6 million stars observed for 190 days in 1993.… Expand
The MACHO Project: Microlensing Optical Depth Toward the Galactic Bulge from Difference Image Analysis
- C. Alcock, R. Allsman, +21 authors D. Welch
- Physics
- 28 February 2000
We present the microlensing optical depth toward the Galactic bulge based on the detection of 99 events found in our Difference Image Analysis (DIA) survey. This analysis encompasses 3 yr of data,… Expand
The MACHO Project Large Magellanic Cloud Variable Star Inventory. XI. Frequency Analysis of the Fundamental-Mode RR Lyrae Stars
We have frequency-analyzed 6391 variables classified earlier as fundamental-mode RR Lyrae (RR0) stars in the MACHO database on the Large Magellanic Cloud (LMC). The overwhelming majority (i.e., 96%)… Expand
Possible gravitational microlensing of a star in the Large Magellanic Cloud
- C. Alcock, C. Akerlof, +15 authors W. Sutherland
- Physics
- Nature
- 29 September 1993
THERE is now abundant evidence for the presence of large quantities of unseen matter surrounding normal galaxies, including our own1,2. The nature of this ’dark matter‘ is unknown, except that it… Expand
THE MACHO PROJECT LARGE MAGELLANIC CLOUD VARIABLE-STAR INVENTORY. IX. FREQUENCY ANALYSIS OF THE FIRST-OVERTONE RR LYRAE STARS AND THE INDICATION FOR NONRADIAL PULSATIONS
- C. Alcock, R. Allsman, +26 authors D. Welch
- Physics
- 17 May 2000
More than 1300 variables classified provisionally as first-overtone RR Lyrae pulsators in the MACHO variable-star database of the Large Magellanic Cloud (LMC) have been subjected to standard… Expand
Globular clusters with tidal tails: deep two-color star counts
- C. Grillmair, K. Freeman, M. Irwin, P. Quinn
- Physics
- 7 February 1995
We examine the outer structure of 12 Galactic globular clusters using star-count analyses. Deep, two-color, photographic photometry is used to select and count stars with colors and magnitudes… Expand
First detection of a gravitational microlensing candidate toward the Small Magellanic Cloud
- T. M. C. C. Alcock, R. Allsman, +19 authors D.L.Welch
- Physics
- 20 August 1997
We report the first discovery of a gravitational microlensing candidate toward a new population of source stars, the Small Magellanic Cloud (SMC). The candidate event's light curve shows no variation… Expand