352 citations · 2.9k across the 43 of their papers we have counts for
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Galactic Bulge Microlensing Events from the MACHO Collaboration
C. L. Thomas, K. Griest, P. Popowski +21
We present a catalog of 450 high signal-to-noise microlensing events observed by the MACHO collaboration between 1993 and 1999. The events are distributed throughout our fields and…
Microlensing Optical Depth towards the Galactic Bulge Using Clump Giants from the MACHO Survey
P. Popowski, K. Griest, C. L. Thomas +20
Using 7 years of MACHO survey data, we present a new determination of the optical depth to microlensing towards the Galactic bulge. We select the sample of 62 microlensing events (…
The MACHO Project Large Magellanic Cloud Variable Star Inventory. XIII. Fourier Parameters for the First Overtone RR Lyrae Variables and the LMC Distance
C. Alcock, D. R. Alves, T. S. Axelrod +21
Fourier coefficents have been derived for the and light curves of 785 overtone RR Lyrae variables in 16 MACHO fields near the bar of the LMC. The and coef…
Ho Measurement from VLT Deep I-band Surface Brightness Fluctuations in NGC 564 and NGC 7619
S. Mei, M. Scodeggio, D. R. Silva +1
We have measured the Hubble constant Ho in NGC 564 at cz ~ 5800 km/s and in NGC 7619 at cz ~ 3700 km/s with deep I-band Surface Brightness Fluctuation distance measurements at the…
Variability-Selected Quasars in MACHO Project Magellanic Cloud Fields
M. Geha, C. Alcock, R. A. Allsman +22
We present 47 spectroscopically-confirmed quasars discovered behind the Magellanic Clouds identified via photometric variability in the MACHO database. Thirty-eight quasars lie beh…
The MACHO Project LMC Variable Star Inventory: XII. Three Cepheid Variables in Eclipsing Binaries
C. Alcock, R. A. Allsman, D. R. Alves +22
We present a method for solving the lightcurve of an eclipsing binary system which contains a Cepheid variable as one of its components as well as the solutions for three eclipsing…
Gravitational Microlensing Events Due to Stellar Mass Black Holes
D. P. Bennett, A. C. Becker, J. L. Quinn +28
We present an analysis of the longest timescale microlensing events discovered by the MACHO Collaboration during a 7 year survey of the Galactic bulge. We find 6 events that exhibi…
K-band versus I-band Surface Brightness Fluctuations as distance indicators
S. Mei, P. J. Quinn, D. Silva
We evaluate the method of optical and infrared Surface Brightness Fluctuations (SBF) as a distance indicator and its application on 8-m class telescopes, such as the Very Large Tel…
The MACHO Project LMC Variable Star Inventory: X. The R Coronae Borealis Stars
C. Alcock, R. A. Allsman, D. R. Alves +26
We report the discovery of eight new R Coronae Borealis (RCB) stars in the Large Magellanic Cloud (LMC) using the MACHO project photometry database. The discovery of these new star…
Mass-Losing Semiregular Variable Stars in Baade's Windows
C. Alard, J. Blommaert, C. Cesarsky +38
By cross-correlating the results of two recent large-scale surveys, the general properties of a well defined sample of semi-regular variable stars have been determined. ISOGAL mid-…
MACHO 96-LMC-2: Lensing of a Binary Source in the LMC and Constraints on the Lensing Object
C. Alcock, R. A. Allsman, D. R. Alves +21
We present photometry and analysis of the microlensing alert MACHO 96-LMC-2. The ~3% photometry provided by the Global Microlensing Alert Network follow--up effort reveals a period…
MACHO Project Limits on Black Hole Dark Matter in the 1-30 Solar Mass Range
The Macho collaboration, C. Alcock, R. A. Allsman +22
We report on a search for long duration microlensing events towards the Large Magellanic Cloud. We find none, and therefore put limits on the contribution of high mass objects to t…
The MACHO Project LMC Variable Star Inventory. IX. Frequency Analysis of the First Overtone RR Lyrae Stars and the Indication for Nonradial Pulsations
C. Alcock, R. Allsman, D. R. Alves +26
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 t…
The MACHO Project: Microlensing Detection Efficiency
The MACHO collaboration, C. Alcock, R. A. Allsman +22
The MACHO project is a search for dark matter in the form of massive compact halo objects (MACHOs). The project has photometrically monitored tens of millions of stars in the Large…
The MACHO project: Microlensing Optical Depth towards the Galactic Bulge from Difference Image Analysis
C. Alcock, R. A. Allsman, D. R. Alves +21
We present the microlensing optical depth towards the Galactic bulge based on the detection of 99 events found in our Difference Image Analysis (DIA) survey. This analysis encompas…
The MACHO Project 9 Million Star Color-Magnitude Diagram of the Large Magellanic Cloud
C. Alcock, R. A. Allsman, D. R. Alves +23
We present a 9 million star color-magnitude diagram (9M CMD) of the LMC bar. The 9M CMD reveals a complex superposition of different age and metallicity stellar populations, with i…
Calibration of the MACHO Photometry Database
C. Alcock, R. A. Allsman, D. R. Alves +18
The MACHO Project is a microlensing survey that monitors the brightnesses of 60 million stars in the Large Magellanic Cloud (LMC), Small Magellanic Cloud, and Galactic bulge. Our d…
Difference Image Analysis of Galactic Microlensing II. Microlensing Events
C. Alcock, R. A. Allsman, D. Alves +18
The MACHO collaboration has been carrying out Difference Image Analysis (DIA) since 1996 with the aim of increasing the sensitivity to the detection of gravitational microlensing.…
Cepheid Variables in the LMC and SMC
The MACHO Collaboration, D. L. Welch, C. Alcock +20
In this paper, we will review major new results regarding classical Cepheids, in the Large Magellanic Cloud (LMC) and Small Magellanic Cloud (SMC). Specifically, we discuss recent…
The MACHO Project Large Magellanic Cloud Variable Star Inventory. VIII. The Recent Star Formation History of the LMC from the Cepheid Period Distribution
C. Alcock, R. A. Allsman, D. R. Alves +20
We present an analysis of the period distribution of Cepheids in the Large Magellanic Cloud, based on data obtained by the MACHO microlensing experiment and on a previo…
The MACHO Project LMC Variable Star Inventory: Classical Cepheids, AGB Variables, and the 9 Million Star Color-Magnitude Diagram
D. R. Alves, A. Basu, K. H. Cook +18
This paper has been withdrawn
Discovery and Characterization of a Caustic Crossing Microlensing Event in the SMC
C. Alcock, R. A. Allsman, D. Alves +21
We present photometric observations and analysis of the second microlensing event detected towards the Small Magellanic Cloud (SMC), MACHO Alert 98-SMC-1. This event was detected e…
The MACHO Project LMC Variable Star Inventory: Classical Cepheids and AGB Variables
D. Alves, C. Alcock, K. Cook +18
This paper has been withdrawn by the author.
EROS and MACHO Combined Limits on Planetary Mass Dark Matter in the Galactic Halo
EROS Collaboration, MACHO Collaboration
The EROS and MACHO collaborations have each published upper limits on the amount of planetary mass dark matter in the Galactic Halo obtained from gravitational microlensing searche…