Parametrization and Classification of 20 Billion LSST Objects: Lessons from SDSS (2008)
Ivezic, Z., Axelrod, T., Becker, A. C.
The Large Synoptic Survey Telescope (LSST) will be a large, wide-field ground-based system designed to obtain, starting in 2015, multiple images of the sky that is visible from Cerro Pachon in...
Rest, A., Welch, D. L., Suntzeff, N. B., Oaster, L., Lanning, H., Olsen, K., ...
We report the discovery of an extensive system of scattered light echo arclets associated with the recent supernovae in the local neighbourhood of the Milky Way: Tycho (SN 1572) and Cassiopeia A....
Exploring the Outer Solar System with the ESSENCE Supernova Survey (2008)
Becker, A. C., Arraki, K., Kaib, N. A., Wood-Vasey, W. M., Aguilera, C., Blackman, J. W., ...
We report the discovery and orbit determination of 14 trans-Neptunian objects (TNOs) from the ESSENCE Supernova Survey difference imaging dataset. Two additional objects discovered in a similar...
Time Dilation in Type Ia Supernova Spectra at High Redshift (2008)
Blondin, S., Davis, T. M., Krisciunas, K., Schmidt, B. P., Sollerman, J., Wood-Vasey, W. M., ...
We present multiepoch spectra of 13 high-redshift Type Ia supernovae (SNe Ia) drawn from the literature, the ESSENCE and SNLS projects, and our own separate dedicated program on the ESO Very Large...
Two More Candidate AM Canum Venaticorum (AM CVn) Binaries from the Sloan Digital Sky Survey (2008)
Anderson, S. F., Becker, A. C., Haggard, D., Prieto, J. L., Knapp, G. R., Sako, M., ...
AM CVn systems are a select group of ultracompact binaries with the shortest orbital periods of any known binary subclass; mass-transfer is likely from a low-mass (partially-)degenerate secondary...
Spectral Identification of an Ancient Supernova using Light Echoes in the LMC (2008)
Rest, A., Matheson, T., Blondin, S., Bergmann, M., Welch, D. L., Suntzeff, N. B., ...
We report the successful identification of the type of the supernova responsible for the supernova remnant SNR 0509-675 in the Large Magellanic Cloud (LMC) using Gemini spectra of surrounding light...
2MASS J01542930+0053266 : A New Eclipsing M-dwarf Binary System (2008)
Becker, A. C., Agol, E., Silvestri, N. M., Bochanski, J. J., Laws, C., West, A. A., ...
We report on 2MASS J01542930+0053266, a faint eclipsing system composed of two M dwarfs. The variability of this system was originally discovered during a pilot study of the 2MASS Calibration Point...
Constraining Cosmic Evolution of Type Ia Supernovae (2007)
Foley, Ryan J., Filippenko, A. V., Aguilera, C., Becker, A. C., Blondin, S., Challis, P., ...
We present the first large-scale effort of creating composite spectra of high-redshift type Ia supernovae (SNe Ia) and comparing them to low-redshift counterparts. Through the ESSENCE project, we...
Davis, T. M., Mortsell, E., Sollerman, J., Becker, A. C., Blondin, S., Challis, P., ...
The first cosmological results from the ESSENCE supernova survey (Wood-Vasey et al. 2007) are extended to a wider range of cosmological models including dynamical dark energy and non-standard...
Wood-Vasey, W. M., Miknaitis, G., Stubbs, C. W., Jha, S., Riess, A. G., Garnavich, P. M., ...
We present constraints on the dark energy equation-of-state parameter, w=P/(rho c^2), using 60 Type Ia supernovae (SNe Ia) from the ESSENCE supernova survey. We derive a set of constraints on the...
The ESSENCE Supernova Survey: Survey Optimization, Observations, and Supernova Photometry (2007)
Miknaitis, G., Pignata, G., Rest, A., Wood-Vasey, W. M., Blondin, S., Challis, P., ...
We describe the implementation and optimization of the ESSENCE supernova survey, which we have undertaken to measure the equation of state parameter of the dark energy. We present a method for...
Light echoes of supernovae in the large magellanic cloud (2006)
R. C. Smith, N. B. Suntzeff, K. Olsen, P. Challis, A. C. Becker, A. Miceli, ...
Light echoes of supernovae in the large magellanic cloud
Evidence for a Supernova Associated with the X-ray Flash 020903 (2006)
Bersier, D., Fruchter, A. S., Gorosabel, J., Levan, A., Burud, I., ...
We present ground-based and Hubble Space Telescope optical observations of the X-ray flash (XRF) 020903, covering 300 days. The afterglow showed a very rapid rise in the first day, followed by a...
Removing the microlensing blending-parallax degeneracy using source variability (2006)
Assef, R. J., Gould, A., Afonso, C., Albert, J. N., Andersen, J., Ansari, R., ...
Microlensing event MACHO 97-SMC-1 is one of the rare microlensing events for which the source is a variable star, simply because most variable stars are systematically eliminated from microlensing...
Light echoes of supernovae in the large magellanic cloud (2006)
Becker, A. C., Challis, P., Clocchiatti, A., Garg, A., Miceli, A., Miknaitis, G. A., ...
Using Line Profiles to Test the Fraternity of Type Ia Supernovae at High and Low Redshifts (2005)
Blondin, S., Dessart, L., Leibundgut, B., Branch, D., Hoeflich, P., Tonry, J. L., ...
Using archival data of low-redshift (z < 0.01) Type Ia supernovae (SN Ia) and recent observations of high-redshift (0.16 < z 1.7] SN Ia, which are also subluminous. In addition, we give the first...
Rest, A., Stubbs, C., Becker, A. C., Miknaitis, G. A., Miceli, A., Covarrubias, R., ...
Characterizing the nature and spatial distribution of the lensing objects that produce the previously measured microlensing optical depth toward the Large Magellanic Cloud (LMC) remains an open...
Hubble Space Telescope Observations of Nine High-Redshift ESSENCE Supernovae (2005)
Krisciunas, Kevin, Garnavich, Peter M., Challis, Peter, Prieto, Jose Luis, Riess, A. G., Barris, B., ...
We present broad-band light curves of nine supernovae ranging in redshift from 0.5 to 0.8. The supernovae were discovered as part of the ESSENCE project, and the light curves are a combination of...
Microlensing optical depth toward the galactic bulge using clump giants from the MACHO survey (2005)
Popowski, P., Griest, K., Thomas, C. L., Cook, K. H., Bennett, D. P., Becker, A. C., ...
Galactic bulge microlensing events from the MACHO Collaboration (2005)
Thomas, C. L., Griest, K., Popowski, P., Cook, K. H., Drake, A. J., Minniti, D., ...
Spectroscopy of High-Redshift Supernovae from the ESSENCE Project: The First Two Years (2004)
Matheson, T., Blondin, S., Foley, R. J., Chornock, R., Filippenko, A. V., Leibundgut, B., ...
We present the results of spectroscopic observations of targets discovered during the first two years of the ESSENCE project. The goal of ESSENCE is to use a sample of ~200 Type Ia supernovae (SNe...
Popowski, P., Griest, K., Thomas, C. L., Cook, K. H., Bennett, D. P., Becker, A. C., ...
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 (60 unique) on clump...
Galactic Bulge Microlensing Events from the MACHO Collaboration (2004)
Thomas, C. L., Griest, K., Popowski, P., Cook, K. H., Drake, A. J., Minniti, D., ...
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, as expected, they...
The SuperMACHO Microlensing Survey (2004)
Becker, A. C., Rest, A., Stubbs, C., Miknaitis, G. A., Miceli, A., Covarrubias, R., ...
We present the first results from our next-generation microlensing survey, the SuperMACHO project. We are using the CTIO 4m Blanco telescope and the MOSAIC imager to carry out a search for...
The Deep Lens Survey Transient Search I : Short Timescale and Astrometric Variability (2004)
Becker, A. C., Wittman, D. M., Boeshaar, P. C., Clocchiatti, A., Dell'Antonio, I. P., Frail, D. A., ...
We report on the methodology and first results from the Deep Lens Survey transient search. We utilize image subtraction on survey data to yield all sources of optical variability down to 24th...
Alcock, C., Alves, D. R., Axelrod, T. S., Becker, A. C., Bennett, D. P., Clement, C. M., ...
Fourier coefficents have been derived for the $V$ and $R$ light curves of 785 overtone RR Lyrae variables in 16 MACHO fields near the bar of the LMC. The $\phi_{31}$ and $R_{21}$ coefficients have...
Recent Microlensing Results from the MACHO Project (2003)
Popowski, P., Nelson, C. A., Bennett, D. P., Drake, A. J., Vandehei, T., Griest, K., ...
We describe a few recent microlensing results from the MACHO Collaboration. The aim of the MACHO Project was the identification and quantitative description of dark and luminous matter in the Milky...
Variability-selected quasars in MACHO project Magellanic Cloud fields (2003)
Geha, M., Alcock, C., Allsman, R. A., Alves, D. R., Axelrod, T. S., Becker, A. C., ...
We present 47 spectroscopically confirmed quasars discovered behind the Magellanic Clouds identified via photometric variability in the MACHO database. Thirty-eight quasars lie behind the Large...
Wittman, D., Tyson, J. A., Dell'Antonio, I. P., Becker, A. C., Margoniner, V. E., Cohen, J., ...
The Deep Lens Survey (DLS) is a deep BVRz' imaging survey of seven 2x2 degree fields, with all data to be made public. The primary scientific driver is weak gravitational lensing, but the survey is...
Weak Lensing Discovery and Tomography of a Cluster at z=0.68 (2002)
Wittman, D., Margoniner, V. E., Tyson, J. A., Cohen, J. G., Dell'Antonio, I. P., Becker, A. C.
We report the weak lensing discovery, spectroscopic confirmation, and weak lensing tomography of a massive cluster of galaxies at $z=0.68$, demonstrating that shear selection of clusters works at...
Variability-Selected Quasars in MACHO Project Magellanic Cloud Fields (2002)
Geha, M., Alcock, C., Allsman, R. A., Alves, D. R., Axelrod, T. S., Becker, A. C., ...
We present 47 spectroscopically-confirmed quasars discovered behind the Magellanic Clouds identified via photometric variability in the MACHO database. Thirty-eight quasars lie behind the Large...
Bennett, D. P., Becker, A. C., Calitz, J. J., Johnson, B. R., Laws, C., Quinn, J. L., ...
We present an re-analysis of the longest timescale gravitational microlensing event discovered to date: MACHO-99-BLG-22/OGLE-1999-BUL-32, which was discovered by both the MACHO and OGLE microlensing...
Optical Photometry of the Type Ia SN 1999ee and the Type Ib/c SN 1999ex in IC 5179 (2002)
Stritzinger, M., Hamuy, M., Suntzeff, N. B., Smith, R. C., Phillips, M. M., Maza, J., ...
We present UBVRIz lightcurves of the Type Ia SN 1999ee and the Type Ib/c SN 1999ex, both located in the galaxy IC 5179. SN 1999ee has an extremely well sampled lightcurve spanning from 10 days before...
MACHO Project Analysis of the Galactic Bulge Microlensing Events with Clump Giants as Sources (2002)
Popowski, P., Vandehei, T., Griest, K., Alcock, C., Allsman, R. A., Alves, D. R., ...
We present preliminary results of the analysis of 5 years of MACHO data on the Galactic bulge microlensing events with clump giants as sources. This class of events allows one to obtain robust...
Alcock, C., Allsman, R. A., Alves, D. R., Becker, A. C., Bennett, D. P., Cook, K. H., ...
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 Cepheids in the...
Gravitational microlensing events due to stellar-mass black holes (2002)
Bennett, D. P., Becker, A. C., Quinn, J. L., Tomaney, A. B., Alcock, C., Allsman, R. A., ...
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 six events that exhibit very strong...
Alcock, C., Allsman, R. A., Alves, D. R., Becker, A. C., Bennett, D. P., Cook, K. H., ...
We present a method for solving the light curve of an eclipsing binary system that contains a Cepheid variable as one of its components as well as the solutions for three eclipsing Cepheids in the...
Gravitational Microlensing Events Due to Stellar Mass Black Holes (2001)
Bennett, D. P., Becker, A. C., Quinn, J. L., Tomaney, A. B., Alcock, C., Allsman, R. A., ...
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 exhibit very strong...
MACHO 96-LMC-2: Lensing of a Binary Source in the LMC and Constraints on the Lensing Object (2000)
Alcock, C., Allsman, R. A., Alves, D. R., Axelrod, T. S., Becker, A. C., Bennett, D. P., ...
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 periodic modulation in...
MACHO Project Limits on Black Hole Dark Matter in the 1-30 Solar Mass Range (2000)
Allsman, R. A., Alves, D. R., Axelrod, T. S., Becker, A. C., Bennett, D. P., ...
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 the Galactic dark...
A 421 d Activity Cycle in the BeX Recurrent Transient A0538-66 from MACHO monitoring (2000)
Alcock, C., Allsman, R. A., Alves, D. R., Axelrod, T. S., Becker, A. C., Bennett, D. P., ...
We present a ~ 5-yr optical light curve of the recurrent Be/X-ray transient A0538-66 obtained as a by-product of the MACHO Project. These data reveal both a long-term modulation at P = 420.8 +/- 0.8...
Alcock, C., Allsman, R. A., Alves, D. R., Axelrod, T. S., Becker, A. C., Bennett, D. P., ...
We attempt to determine whether the MACHO microlensing source stars are drawn from the average population of the LMC or from a population behind the LMC by examining the HST color-magnitude diagram...
Galactic Bulge Microlensing Events with Clump Giants as Sources (2000)
Popowski, P., Alcock, C., Allsman, R. A., Alves, D. R., Axelrod, T. S., Becker, A. C., ...
We present preliminary results of the analysis of 5 years of MACHO data on the Galactic bulge microlensing events with clump giants as sources. In particular, we discuss: 1) the selection of `giant'...
The MACHO Project: Microlensing Detection Efficiency (2000)
Allsman, R. A., Alves, D. R., Axelrod, T. S., Becker, A. C., Bennett, D. P., ...
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 Magellanic Cloud...
Searching for periodicities in the MACHO light curve of LMC X-2 (2000)
Alcock, C., Allsman, R. A., Alves, D. R., Axelrod, T. S., Becker, A. C., Bennett, D. P., ...
Using the exceptional long-term monitoring capabilities of the MACHO project, we present here the optical history of LMC X-2 for a continuous 6-yr period. These data were used to investigate the...
Alcock, C., Allsman, R. A., Alves, D. R., Axelrod, T. S., Becker, A. C., Bennett, D. P., ...
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 encompasses three years of...
The MACHO Project 9 Million Star Color-Magnitude Diagram of the Large Magellanic Cloud (2000)
Alcock, C., Allsman, R. A., Alves, D. R., Axelrod, T. S., Basu, A., Becker, A. C., ...
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 important stellar...
The MACHO Project: Microlensing Results from 5.7 Years of LMC Observations (2000)
Allsman, R. A., Alves, D. R., Axelrod, T. S., Becker, A. C., Bennett, D. P., ...
We report on our search for microlensing towards the Large Magellanic Cloud (LMC). Analysis of 5.7 years of photometry on 11.9 million stars in the LMC reveals 13 - 17 microlensing events. This is...
Searching for periodicities in the MACHO light curve of LMC X-2 (2000)
Alcock, C., Allsman, R.A., Alves, D.R., Axelrod, T.S., Becker, A.C., Bennet, D.P., ...
Calibration of the MACHO Photometry Database (1999)
Alcock, C., Allsman, R. A., Alves, D. R., Axelrod, T. S., Becker, A. C., Bennett, D. P., ...
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 database presently...
Gravitational Microlensing Evidence for a Planet Orbiting a Binary Star System (1999)
Bennett, D. P., Rhie, S. H., Becker, A. C., Butler, N., Dann, J., Kaspi, S., ...
The study of extra-solar planetary systems has emerged as a new discipline of observational astronomy in the past few years with the discovery of a number of extra-solar planets. The properties of...
On Planetary Companions to the MACHO-98-BLG-35 Microlens Star (1999)
Rhie, S. H., Bennett, D. P., Becker, A. C., Peterson, B. A., Fragile, P. C., Johnson, B. R., ...
We present observations of microlensing event MACHO-98-BLG-35 which reached a peak magnification factor of almost 80. These observations by the Microlensing Planet Search (MPS) and the MOA...
EROS and MACHO Combined Limits on Planetary Mass Dark Matter in the Galactic Halo (1999)
Alcock, C., Allsman, R.A., Alves, D., Ansari, R., Aubourg, E., Axelrod, T.S., ...
Difference Image Analysis of Galactic Microlensing II. Microlensing Events (1999)
Alcock, C., Allsman, R. A., Alves, D., Axelrod, T. S., Becker, A. C., Bennett, D. P., ...
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. This is a...
Difference Image Analysis of Galactic Microlensing I. Data Analysis (1999)
Alcock, C., Allsman, R. A., Alves, D., Axelrod, T. S., Becker, A. C., Bennett, D. P., ...
This is a preliminary report on the application of Difference Image Analysis (DIA) to galactic bulge images. The aim of this analysis is to increase the sensitivity to the detection of gravitational...
Cepheid Variables in the LMC and SMC (1999)
Alcock, C., Allsman, R. A., Alves, D. R., Axelrod, T. S., Becker, A. C., ...
In this paper, we will review major