Lane, Richard R., Kiss, László L., Lewis, Geraint F., Ibata, Rodrigo A., Siebert, Arnaud, Bedding, Timothy R., ...
Globular clusters are an important test bed for Newtonian gravity in the weak-acceleration regime, which is vital to our understanding of the nature of the gravitational interaction. Recent claims...
The remnants of galaxy formation from a panoramic survey of the region around M31 (2009)
McConnachie, Alan W., Irwin, Michael J., Ibata, Rodrigo A., Dubinski, John, Widrow, Lawrence M., Martin, Nicolas F., ...
In hierarchical cosmological models, galaxies grow in mass through the continual accretion of smaller ones. The tidal disruption of these systems is expected to result in loosely bound stars...
Martin, Nicolas F., McConnachie, Alan W., Irwin, Mike, Widrow, Lawrence M., Ferguson, Annette M. N., Ibata, Rodrigo A., ...
We present the discovery of two new dwarf galaxies, Andromeda XXI and Andromeda XXII, located in the surroundings of the Andromeda and Triangulum galaxies (M31 and M33). These discoveries stem from...
Testing Newtonian Gravity with AAOmega: Mass-to-Light Profiles of Four Globular Clusters (2009)
Lane, Richard R., Kiss, László L., Lewis, Geraint F., Ibata, Rodrigo A., Siebert, Arnaud, Bedding, Timothy R., ...
Testing Newtonian gravity in the weak-acceleration regime is vital to our understanding of the nature of the gravitational interaction. It has recently been claimed that the velocity dispersion...
Conn, Blair C., Lane, Richard R., Lewis, Geraint F., Irwin, Mike J., Ibata, Rodrigo A., Martin, Nicolas F., ...
This paper concludes a systematic search for evidence of the Monoceros Ring and Canis Major dwarf galaxy around the Galactic Plane. Presented here are the results for the Galactic longitude range of...
A trio of new local group galaxies with extreme properties (2008)
McConnachie, Alan W., Huxor, Avon, Martin, Nicolas F., Irwin, Mike J., Chapman, Scott C., Fahlman, Gregory, ...
We report on the discovery of three new dwarf galaxies in the Local Group. These galaxies are found in new CFHT/MegaPrime g,i imaging of the southwestern quadrant of M31, extending our extant survey...
Kinematic and chemical constraints on the formation of M31's inner and outer halo (2008)
Koch, Andreas, Rich, R. Michael, Reitzel, David B., Martin, Nicolas F., Ibata, Rodrigo A., Chapman, Scott C., ...
The halo of M31 shows a wealth of substructures, some of which are consistent with assembly from satellite accretion. Here we report on kinematic and abundance results from Keck DEIMOS spectroscopy...
Galactic halo stellar structures in the Triangulum-Andromeda region (2007)
Martin, Nicolas F., Ibata, Rodrigo A., Irwin, Mike
This letter reports on the Galactic stellar structures that appear in the foreground of our Canada-France-Hawaii-Telecopse/MegaCam survey of the halo of the Andromeda galaxy. We recover the main...
Conn, Blair C., Lane, Richard R., Lewis, Geraint F., Gil-Merino, Rodrigo, Irwin, Mike J., Ibata, Rodrigo A., ...
We present the results of an AAT wide-field camera survey of the stars in the Monoceros Ring and purported Canis Major overdensity in the Galactic longitudes of {\it l} = (193 - 276)$^\circ$. Current...
Galactic halo stellar structures in the Triangulum-Andromeda region (2007)
Martin, Nicolas F., Ibata, Rodrigo A., Irwin, Mike
This Letter reports on the Galactic stellar structures that appear in the foreground of our Canada-France-Hawaii-Telecopse/MegaCam survey of the halo of the Andromeda galaxy. We recover the main...
A panoramic view of the Southern quadrant of the Andromeda galaxy outer halo (2007)
Martin, Nicolas F., Ibata, Rodrigo A., Irwin, Mike J.
Not Available
Probing the Nature of the G1 Clump Stellar Overdensity in the Outskirts of M31 (2006)
Faria, Daniel, Johnson, Rachel A., Ferguson, Annette M. N., Irwin, Mike J., Ibata, Rodrigo A., Johnston, Kathryn V., ...
We present deep HST/ACS observations of the G1 clump, a distinct stellar overdensity lying at ~30 kpc along the south-western major axis of M31 close to the G1 globular cluster (Ferguson et al....
The stellar halo and outer disk of M33 (2006)
McConnachie, Alan W., Chapman, Scott C., Ibata, Rodrigo A., Ferguson, Annette M. N., Irwin, Mike J., Lewis, Geraint F., ...
We present first results from a Keck/DEIMOS spectroscopic survey of red giant branch (RGB) stars in M33. The radial velocity distributions of the stars in our fields are well described by three...
Gravitational microlensing of quasar Broad Line Regions: the influence of fractal structures (2006)
Lewis, Geraint F., Ibata, Rodrigo A.
Recent models for the emission clouds within the Broad Line Region of quasars suggest that they are due to transient overdensities within an overall turbulent medium. If this were the case, the broad...
Conn, Blair C., Martin, Nicolas F., Lewis, Geraint F., Ibata, Rodrigo A., Bellazzini, Michele, Irwin, Mike J.
An AAT/2dF Spectrograph Survey of low Galactic latitudes targeting the putative Canis Major dwarf galaxy, and the (possibly) associated tidal debris of stars known as the Monoceros Ring, covering...
The Stellar Halo Metallicity - Luminosity Relationship for Spiral Galaxies (2005)
Renda, Agostino, Gibson, Brad K., Mouhcine, Mustapha, Ibata, Rodrigo A., Kawata, Daisuke, Flynn, Chris, ...
The stellar halos of spiral galaxies bear important chemo-dynamical signatures of galaxy formation. We present here the analysis of 89 semi-cosmological spiral galaxy simulations, spanning ~ 4...
The INT/WFC survey of the Monoceros Ring: Accretion origin or Galactic Anomaly? (2005)
Conn, Blair C., Lewis, Geraint F., Irwin, Mike J., Ibata, Rodrigo A., Ferguson, Annette M. N., Tanvir, Nial, ...
We present the results of a wide-field camera survey of the stars in the Monoceros Ring, thought to be an additional structure in the Milky Way of unknown origin. Lying roughly in the plane of the...
Internal Alignment of the Halos of Disk Galaxies in Cosmological Hydrodynamic Simulations (2005)
Bailin, Jeremy, Kawata, Daisuke, Gibson, Brad K., Steinmetz, Matthias, Navarro, Julio F., Brook, Chris B., ...
Seven cosmological hydrodynamic simulations of disk galaxy formation are analyzed to determine the alignment of the disk within the dark matter halo and the internal structure of the halo. We find...
The stellar populations of the M31 halo substructure (2005)
Ferguson, Annette M. N., Johnson, Rachel A., Faria, Daniel C., Irwin, Mike J., Ibata, Rodrigo A., Johnston, Kathryn V., ...
The stellar halo metallicity-luminosity relationship for spiral galaxies (2005)
Renda, Agostino, Gibson, Brad K., Mouhcine, Mustapha, Ibata, Rodrigo A., Kawata, Daisuke, Flynn, Chris, ...
The stellar haloes of spiral galaxies bear important chemodynamical signatures of galaxy formation. We present here the analysis of 89 semi-cosmological spiral galaxy simulations, spanning ~4 mag in...
Internal alignment of the halos of disk galaxies in cosmological hydrodynamic simulations (2005)
Bailin, Jeremy, Kawata, Daisuke, Gibson, Brad K., Steinmetz, Matthias, Navarro, Julio F., Brook, Chris B., ...
Seven cosmological hydrodynamic simulations of disk galaxy formation are analyzed to determine the alignment of the disk within the dark matter halo and the internal structure of the halo. We find...
Internal alignment of the halos of disk galaxies in cosmological hydrodynamic simulations (2005)
Bailin, Jeremy, Kawata, Daisuke, Gibson, Brad K., Steinmetz, Matthias, Navarro, Julio F., Brook, Chris B., ...
Seven cosmological hydrodynamic simulations of disk galaxy formation are analyzed to determine the alignment of the disk within the dark matter halo and the internal structure of the halo. We find...
The stellar halo metallicity-luminosity relationship for spiral galaxies (2005)
Renda, Agostino, Gibson, Brad K., Mouhcine, Mustapha, Ibata, Rodrigo A., Kawata, Daisuke, Flynn, Chris, ...
The stellar haloes of spiral galaxies bear important chemodynamical signatures of galaxy formation. We present here the analysis of 89 semi-cosmological spiral galaxy simulations, spanning ~4 mag in...
Internal alignment of the halos of disk galaxies in cosmological hydrodynamic simulations (2005)
Bailin, Jeremy, Kawata, Daisuke, Gibson, Brad K., Steinmetz, Matthias, Navarro, Julio F., Brook, Chris B., ...
Seven cosmological hydrodynamic simulations of disk galaxy formation are analyzed to determine the alignment of the disk within the dark matter halo and the internal structure of the halo. We find...
The stellar halo metallicity-luminosity relationship for spiral galaxies (2005)
Renda, Agostino, Gibson, Brad K., Mouhcine, Mustapha, Ibata, Rodrigo A., Kawata, Daisuke, Flynn, Chris, ...
The stellar haloes of spiral galaxies bear important chemodynamical signatures of galaxy formation. We present here the analysis of 89 semi-cosmological spiral galaxy simulations, spanning ~4 mag in...
Internal alignment of the halos of disk galaxies in cosmological hydrodynamic simulations (2005)
Bailin, Jeremy, Kawata, Daisuke, Gibson, Brad K., Steinmetz, Matthias, Navarro, Julio F., Brook, Chris B., ...
Seven cosmological hydrodynamic simulations of disk galaxy formation are analyzed to determine the alignment of the disk within the dark matter halo and the internal structure of the halo. We find...
The stellar halo metallicity-luminosity relationship for spiral galaxies (2005)
Renda, Agostino, Gibson, Brad K., Mouhcine, Mustapha, Ibata, Rodrigo A., Kawata, Daisuke, Flynn, Chris, ...
The stellar haloes of spiral galaxies bear important chemodynamical signatures of galaxy formation. We present here the analysis of 89 semi-cosmological spiral galaxy simulations, spanning ~4 mag in...
The stellar halo metallicity-luminosity relationship for spiral galaxies (2005)
Renda, Agostino, Gibson, Brad K., Mouhcine, Mustapha, Ibata, Rodrigo A., Kawata, Daisuke, Flynn, Chris, ...
The stellar haloes of spiral galaxies bear important chemodynamical signatures of galaxy formation. We present here the analysis of 89 semi-cosmological spiral galaxy simulations, spanning ~4 mag in...
Internal alignment of the halos of disk galaxies in cosmological hydrodynamic simulations (2005)
Bailin, Jeremy, Kawata, Daisuke, Gibson, Brad K., Steinmetz, Matthias, Navarro, Julio F., Brook, Chris B., ...
Seven cosmological hydrodynamic simulations of disk galaxy formation are analyzed to determine the alignment of the disk within the dark matter halo and the internal structure of the halo. We find...
The stellar halo metallicity-luminosity relationship for spiral galaxies (2005)
Renda, Agostino, Gibson, Brad K., Mouhcine, Mustapha, Ibata, Rodrigo A., Kawata, Daisuke, Flynn, Chris, ...
The stellar haloes of spiral galaxies bear important chemodynamical signatures of galaxy formation. We present here the analysis of 89 semi-cosmological spiral galaxy simulations, spanning ~4 mag in...
The Canis Major Dwarf Galaxy (2004)
Lewis, Geraint F., Ibata, Rodrigo A., Irwin, Michael J., Martin, Nicolas F., Bellazzini, Michele, Conn, Blair
Recent observational evidence suggests that the Sagittarius dwarf galaxy represents the only major ongoing accretion event in the Galactic halo, accounting for the majority of stellar debris...
Searching for variability in the globular cluster messier 4 (2004)
Brewer, James, Fahlman, Greg G., Ferdman, Robert D., Gibson, Bradley Kenneth, Hansen, Brad M. S., Huber, Mark E., ...
Time-series data taken with the Hubble Space Telescope of a field six core radii (~5') from the center of the globular cluster Messier 4, and covering a period of about 10 weeks in early 2001, have...
Hubble Space Telescope observations of the white dwarf cooling sequence of M4 (2004)
Hansen, Brad M., Richer, Harvey B., Fahlman, Greg G., Stetson, Peter B., Brewer, James, Currie, Thayne, ...
We investigate in detail the white dwarf cooling sequence of the globular cluster Messier 4. In particular, we study the influence of various systematic uncertainties, both observational and...
Kalirai, Jasonjot J., Richer, Harvey B., Hansen, Brad M., Stetson, Peter B., Shara, Michael M., Saviane, Ivo, ...
Not available.
Richer, Harvey B., Brewer, James, Fahlman, Greg G., Kalirai, Jasonjot J., Stetson, Peter B., Hansen, Brad M., ...
We respond to the recent paper by De Marchi et al. on the white dwarf cooling age of M4. The authors question the data analysis and interpretation that led to our conclusions in Hansen et al. in...
Hubble Space Telescope observations of the main sequence of M4 (2004)
Richer, Harvey B., Fahlman, Greg T., Brewer, James, Davis, Stuart, Kalirai, Jasonjot J., Stetson, Peter B., ...
We present new results from a photometric study of the main-sequence stars in M4 (NGC 6121=C1620-264), the closest globular cluster to the Sun. Multifield, multiepoch observations at approximately 1,...
Anisotropy in the Distribution of Satellite Galaxy Orbits (2004)
Knebe, Alexander, Gill, Stuart P., Gibson, Brad. K., Lewis, Geraint F., Ibata, Rodrigo A., Dopita, Michael A., ...
Nearby clusters such as Virgo and Coma possess galaxy distributions that tend to be aligned with the principal axis of the cluster itself. This has also been confirmed by a recent statistical...
Searching for variability in the globular cluster messier 4 (2004)
Ferdman, Robert D., Richer, Harvey B., Brewer, James, Fahlman, Greg G., Gibson, Brad K., Hansen, Brad M., ...
Time-series data taken with the Hubble Space Telescope of a field six core radii (~5') from the center of the globular cluster Messier 4, and covering a period of about 10 weeks in early 2001, have...
Hubble Space Telescope observations of the main sequence of M4 (2004)
Richer, Harvey B., Fahlman, Greg G., Brewer, James, Davis, Stuart, Kalirai, Jasonjot S., Stetson, Peter B., ...
We present new results from a photometric study of the main-sequence stars in M4 (NGC 6121=C1620-264), the closest globular cluster to the Sun. Multifield, multiepoch observations at approximately 1,...
Hubble Space Telescope observations of the white dwarf cooling sequence of M4 (2004)
Hansen, Brad M., Richer, Harvey B., Fahlman, Greg G., Stetson, Peter B., Brewer, James, Currie, Thayne, ...
We investigate in detail the white dwarf cooling sequence of the globular cluster Messier 4. In particular, we study the influence of various systematic uncertainties, both observational and...
Kalirai, Jasonjot S., Richer, Harvey B., Hansen, Brad M., Stetson, Peter B., Shara, Michael M., Saviane, Ivo, ...
Not available.
Richer, Harvey B., Brewer, James, Fahlman, Greg G., Kalirai, Jasonjot S., Stetson, Peter B., Hansen, Brad M., ...
We respond to the recent paper by De Marchi et al. on the white dwarf cooling age of M4. The authors question the data analysis and interpretation that led to our conclusions in Hansen et al. in...
Anisotropy in the Distribution of Satellite Galaxy Orbits (2004)
Knebe, Alexander, Gill, Stuart P., Gibson, Brad K., Lewis, Geraint F., Ibata, Rodrigo A., Dopita, Michael A.
Nearby clusters such as Virgo and Coma possess galaxy distributions that tend to be aligned with the principal axis of the cluster itself. This has also been confirmed by a recent statistical...
Searching for variability in the globular cluster messier 4 (2004)
Ferdman, Robert D., Richer, Harvey B., Brewer, James, Fahlman, Greg G., Gibson, Brad K., Hansen, Brad M., ...
Time-series data taken with the Hubble Space Telescope of a field six core radii (~5') from the center of the globular cluster Messier 4, and covering a period of about 10 weeks in early 2001, have...
Hubble Space Telescope observations of the main sequence of M4 (2004)
Richer, Harvey B., Fahlman, Greg T., Brewer, James, Davis, Stuart, Kalirai, Jasonjot J., Stetson, Peter B., ...
We present new results from a photometric study of the main-sequence stars in M4 (NGC 6121=C1620-264), the closest globular cluster to the Sun. Multifield, multiepoch observations at approximately 1,...
Hubble Space Telescope observations of the white dwarf cooling sequence of M4 (2004)
Hansen, Brad M., Richer, Harvey B., Fahlman, Greg G., Stetson, Peter B., Brewer, James, Currie, Thayne, ...
We investigate in detail the white dwarf cooling sequence of the globular cluster Messier 4. In particular, we study the influence of various systematic uncertainties, both observational and...
Kalirai, Jasonjot J., Richer, Harvey B., Hansen, Brad M., Stetson, Peter B., Shara, Michael M., Saviane, Ivo, ...
Not available.
Richer, Harvey B., Brewer, James, Fahlman, Greg G., Kalirai, Jasonjot J., Stetson, Peter B., Hansen, Brad M., ...
We respond to the recent paper by De Marchi et al. on the white dwarf cooling age of M4. The authors question the data analysis and interpretation that led to our conclusions in Hansen et al. in...
Anisotropy in the Distribution of Satellite Galaxy Orbits (2004)
Knebe, Alexander, Gill, Stuart P., Gibson, Brad. K., Lewis, Geraint F., Ibata, Rodrigo A., Dopita, Michael A.
Nearby clusters such as Virgo and Coma possess galaxy distributions that tend to be aligned with the principal axis of the cluster itself. This has also been confirmed by a recent statistical...
Searching for variability in the globular cluster messier 4 (2004)
Ferdman, Robert D., Richer, Harvey B., Brewer, James, Fahlman, Greg G., Gibson, Brad K., Hansen, Brad M., ...
Time-series data taken with the Hubble Space Telescope of a field six core radii (~5') from the center of the globular cluster Messier 4, and covering a period of about 10 weeks in early 2001, have...
Hubble Space Telescope observations of the white dwarf cooling sequence of M4 (2004)
Hansen, Brad M., Richer, Harvey B., Fahlman, Greg G., Stetson, Peter B., Brewer, James, Currie, Thayne, ...
We investigate in detail the white dwarf cooling sequence of the globular cluster Messier 4. In particular, we study the influence of various systematic uncertainties, both observational and...
Kalirai, Jasonjot J., Richer, Harvey B., Hansen, Brad M., Stetson, Peter B., Shara, Michael M., Saviane, Ivo, ...
Not available.
Anisotropy in the Distribution of Satellite Galaxy Orbits (2004)
Knebe, Alexander, Gill, Stuart P., Gibson, Brad. K., Lewis, Geraint F., Ibata, Rodrigo A., Dopita, Michael A.
Nearby clusters such as Virgo and Coma possess galaxy distributions that tend to be aligned with the principal axis of the cluster itself. This has also been confirmed by a recent statistical...
Richer, Harvey B., Brewer, James, Fahlman, Greg G., Kalirai, Jasonjot J., Stetson, Peter B., Hansen, Brad M., ...
We respond to the recent paper by De Marchi et al. on the white dwarf cooling age of M4. The authors question the data analysis and interpretation that led to our conclusions in Hansen et al. in...
Hubble Space Telescope observations of the main sequence of M4 (2004)
Richer, Harvey B., Fahlman, Greg T., Brewer, James, Davis, Stuart, Kalirai, Jasonjot J., Stetson, Peter B., ...
We present new results from a photometric study of the main-sequence stars in M4 (NGC 6121=C1620-264), the closest globular cluster to the Sun. Multifield, multiepoch observations at approximately 1,...
Anisotropy in the Distribution of Satellite Galaxy Orbits (2004)
Knebe, Alexander, Gill, Stuart P., Gibson, Brad K., Lewis, Geraint F., Ibata, Rodrigo A., Dopita, Michael A.
Nearby clusters such as Virgo and Coma possess galaxy distributions that tend to be aligned with the principal axis of the cluster itself. This has also been confirmed by a recent statistical...
Searching for variability in the globular cluster messier 4 (2004)
Ferdman, Robert D., Richer, Harvey B., Brewer, James, Fahlman, Greg G., Gibson, Brad K., Hansen, Brad M., ...
Time-series data taken with the Hubble Space Telescope of a field six core radii (~5') from the center of the globular cluster Messier 4, and covering a period of about 10 weeks in early 2001, have...
Hubble Space Telescope observations of the white dwarf cooling sequence of M4 (2004)
Hansen, Brad M., Richer, Harvey B., Fahlman, Greg G., Stetson, Peter B., Brewer, James, Currie, Thayne, ...
We investigate in detail the white dwarf cooling sequence of the globular cluster Messier 4. In particular, we study the influence of various systematic uncertainties, both observational and...
Kalirai, Jasonjot S., Richer, Harvey B., Hansen, Brad M., Stetson, Peter B., Shara, Michael M., Saviane, Ivo, ...
Not available.
Richer, Harvey B., Brewer, James, Fahlman, Greg G., Kalirai, Jasonjot S., Stetson, Peter B., Hansen, Brad M., ...
We respond to the recent paper by De Marchi et al. on the white dwarf cooling age of M4. The authors question the data analysis and interpretation that led to our conclusions in Hansen et al. in...
Hubble Space Telescope observations of the main sequence of M4 (2004)
Richer, Harvey B., Fahlman, Greg G., Brewer, James, Davis, Stuart, Kalirai, Jasonjot S., Stetson, Peter B., ...
We present new results from a photometric study of the main-sequence stars in M4 (NGC 6121=C1620-264), the closest globular cluster to the Sun. Multifield, multiepoch observations at approximately 1,...
Anisotropy in the Distribution of Satellite Galaxy Orbits (2003)
Knebe, Alexander, Gill, Stuart P. D., Gibson, Brad K., Lewis, Geraint F., Ibata, Rodrigo A., Dopita, Michael A.
Nearby clusters such as Virgo and Coma possess galaxy distributions which tend to be aligned with the principal axis of the cluster itself. This has also been confirmed by a recent statistical...
Gravitational microlensing of quasar broad line regions at large optical depths (2003)
Lewis, Geraint F., Ibata, Rodrigo A.
Recent estimates of the scale of structures at the heart of quasars suggest that the region responsible for the broad line emission are smaller than previously thought. With this revision of scale,...
Searching for Variability in the Globular Cluster Messier 4 (2003)
Ferdman, Robert D., Richer, Harvey B., Brewer, James, Fahlman, Greg G., Gibson, Brad K., Hansen, Brad M. S., ...
Time-series data taken with the Hubble Space Telescope of a field six core radii (~5') from the center of the globular cluster Messier 4, and covering a period of about 10 weeks in early 2001, have...
Microlensing induced absorption line variability (2002)
Lewis, Geraint F., Ibata, Rodrigo A.
Gravitational microlensing has proven to be a powerful probe of both the structure at the heart of quasars and the mass function of compact objects in foreground lenses. This paper examines the...
Gill, Stuart P. D., Knebe, Alexander, Gibson, Brad K., Flynn, Chris, Ibata, Rodrigo A., Lewis, Geraint F.
An adaptive multi grid approach to simulating the formation of structure from collisionless dark matter is described. MLAPM (Multi-Level Adaptive Particle Mesh) is one of the most efficient serial...
An investigation of gravitational lens determinations of H_o in quintessence cosmologies (2002)
Lewis, Geraint F., Ibata, Rodrigo A.
There is growing evidence that the majority of the energy density of the universe is not baryonic or dark matter, rather it resides in an exotic component with negative pressure. The nature of this...
Lewis, Geraint F., Ibata, Rodrigo A., Ellison, Sara L., Aracil, Bastien, Petitjean, Patrick, Pettini, Max, ...
While gravitationally lensed quasars are expected to display an odd number of images, invariably systems are observed with an even number of quasars. For this, lensing galaxies must have very small...
AAT/WFI observations of the Extragalactic H I Cloud HIPASS J1712-64 (2002)
Lewis, Geraint F., Irwin, Michael J., Ibata, Rodrigo A., Gibson, Brad K.
AAT/WFI optical images of a candidate extragalactic HI cloud, HIPASS J1712-64, are presented. The g and r-band CCD mosaic camera frames were processed using a new data pipeline recently installed at...
AAT/WFI observations of the extragalactic HI cloud HIPASS JI712-64 (2002)
Gibson, Bradley K., Ibata, Rodrigo A., Irwin, Michael J., Lewis, Geraint F.
AAT/WFI optical images of a candidate extragalactic HI cloud, HIPASS J1712–64, are presented. The g and r band CCD mosaic camera frames were processed using a new data pipeline recently installed...
The white dwarf cooling sequence of the globular cluster Messier 4 (2002)
Hansen, Brad M., Brewer, James, Fahlman, Greg G., Gibson, Bradley K., Ibata, Rodrigo A., Limongi, Marco, ...
We present the white dwarf sequence of the globular cluster M4, based on a 123 orbit Hubble Space Telescope exposure, with a limiting magnitude of V~30 and I~28. The white dwarf luminosity function...
The lower main sequence and mass function of the globular cluster Messier 4 (2002)
Richer, Harvey B., Brewer, James, Fahlman, Gregory G., Gibson, Brad K., Hansen, Brad M., Ibata, Rodrigo A., ...
The deepest optical image ever in a globular star cluster, a Hubble Space Telescope (HST) 123 orbit exposure in a single field of Messier 4, was obtained in 2 filters (F606W, F814W) over a 10 week...
The white dwarf cooling sequence of the globular cluster Messier 4 (2002)
Hansen, Brad M., Brewer, James, Fahlman, Greg G., Gibson, Bradley K., Ibata, Rodrigo A., Limongi, Marco, ...
We present the white dwarf sequence of the globular cluster M4, based on a 123 orbit Hubble Space Telescope exposure, with a limiting magnitude of V~30 and I~28. The white dwarf luminosity function...
The lower main sequence and mass function of the globular cluster Messier 4 (2002)
Richer, Harvey B., Brewer, James, Fahlman, Gregory G., Gibson, Brad K., Hansen, Brad M., Ibata, Rodrigo A., ...
The deepest optical image ever in a globular star cluster, a Hubble Space Telescope (HST) 123 orbit exposure in a single field of Messier 4, was obtained in 2 filters (F606W, F814W) over a 10 week...
AAT/WFI observations of the extragalactic HI cloud HIPASS JI712-64 (2002)
Gibson, Bradley K., Ibata, Rodrigo A., Irwin, Michael J., Lewis, Geraint F.
AAT/WFI optical images of a candidate extragalactic HI cloud, HIPASS J1712–64, are presented. The g and r band CCD mosaic camera frames were processed using a new data pipeline recently installed...
The white dwarf cooling sequence of the globular cluster Messier 4 (2002)
Hansen, Brad M., Brewer, James, Fahlman, Greg G., Gibson, Bradley K., Ibata, Rodrigo A., Limongi, Marco, ...
We present the white dwarf sequence of the globular cluster M4, based on a 123 orbit Hubble Space Telescope exposure, with a limiting magnitude of V~30 and I~28. The white dwarf luminosity function...
The lower main sequence and mass function of the globular cluster Messier 4 (2002)
Richer, Harvey B., Brewer, James, Fahlman, Gregory G., Gibson, Brad K., Hansen, Brad M., Ibata, Rodrigo A., ...
The deepest optical image ever in a globular star cluster, a Hubble Space Telescope (HST) 123 orbit exposure in a single field of Messier 4, was obtained in 2 filters (F606W, F814W) over a 10 week...
AAT/WFI observations of the extragalactic HI cloud HIPASS JI712-64 (2002)
Gibson, Bradley K., Ibata, Rodrigo A., Irwin, Michael J., Lewis, Geraint F.
AAT/WFI optical images of a candidate extragalactic HI cloud, HIPASS J1712–64, are presented. The g and r band CCD mosaic camera frames were processed using a new data pipeline recently installed...
AAT/WFI observations of the extragalactic HI cloud HIPASS JI712-64 (2002)
Gibson, Bradley K., Ibata, Rodrigo A., Irwin, Michael J., Lewis, Geraint F.
AAT/WFI optical images of a candidate extragalactic HI cloud, HIPASS J1712–64, are presented. The g and r band CCD mosaic camera frames were processed using a new data pipeline recently installed...
The white dwarf cooling sequence of the globular cluster Messier 4 (2002)
Hansen, Brad M., Brewer, James, Fahlman, Greg G., Gibson, Bradley K., Ibata, Rodrigo A., Limongi, Marco, ...
We present the white dwarf sequence of the globular cluster M4, based on a 123 orbit Hubble Space Telescope exposure, with a limiting magnitude of V~30 and I~28. The white dwarf luminosity function...
The lower main sequence and mass function of the globular cluster Messier 4 (2002)
Richer, Harvey B., Brewer, James, Fahlman, Gregory G., Gibson, Brad K., Hansen, Brad M., Ibata, Rodrigo A., ...
The deepest optical image ever in a globular star cluster, a Hubble Space Telescope (HST) 123 orbit exposure in a single field of Messier 4, was obtained in 2 filters (F606W, F814W) over a 10 week...
The white dwarf cooling sequence of the globular cluster Messier 4 (2002)
Hansen, Brad M., Brewer, James, Fahlman, Greg G., Gibson, Bradley K., Ibata, Rodrigo A., Limongi, Marco, ...
We present the white dwarf sequence of the globular cluster M4, based on a 123 orbit Hubble Space Telescope exposure, with a limiting magnitude of V~30 and I~28. The white dwarf luminosity function...
The lower main sequence and mass function of the globular cluster Messier 4 (2002)
Richer, Harvey B., Brewer, James, Fahlman, Gregory G., Gibson, Brad K., Hansen, Brad M., Ibata, Rodrigo A., ...
The deepest optical image ever in a globular star cluster, a Hubble Space Telescope (HST) 123 orbit exposure in a single field of Messier 4, was obtained in 2 filters (F606W, F814W) over a 10 week...
AAT/WFI observations of the extragalactic HI cloud HIPASS JI712-64 (2002)
Gibson, Bradley K., Ibata, Rodrigo A., Irwin, Michael J., Lewis, Geraint F.
AAT/WFI optical images of a candidate extragalactic HI cloud, HIPASS J1712–64, are presented. The g and r band CCD mosaic camera frames were processed using a new data pipeline recently installed...
Was SN1997ff at z~1.7 magnified by gravitational lensing? (2001)
Lewis, Geraint F., Ibata, Rodrigo A.
The quest for the cosmological parameters has come to fruition with the identification of a number of supernovae at a redshift of $z\sim1$. Analyses of the brightness of these standard candles reveal...
Searching for MACHOs in Galaxy Clusters (2000)
Lewis, Geraint F., Ibata, Rodrigo A., Wyithe, J. Stuart B.
If cluster dark matter is in the form of compact objects it will introduce fluctuations into the light curves of distant sources. Current searches for MACHOs in clusters of galaxies focus on...
Probing the Atmospheres of Planets Orbiting Microlensed Stars via Polarization Variability (2000)
Lewis, Geraint F., Ibata, Rodrigo A.
We present a new method to identify and probe planetary companions of stars in the Galactic Bulge and Magellanic Clouds using gravitational microlensing. While spectroscopic studies of these planets...
The Search for Cosmological Black Holes: A Surface Brightness Variability Test (2000)
Lewis, Geraint F., Ibata, Rodrigo A.
Recently it has been suggested that the majority of dark matter in the universe resides in the form of Jupiter mass black holes distributed cosmologically. This population makes itself apparent by...
Photometric Monitoring of the Gravitationally Lensed Ultraluminous BAL Quasar APM08279+5255 (1999)
Lewis, Geraint F., Robb, Russell M., Ibata, Rodrigo A.
We report on one year of photometric monitoring of the ultraluminous BAL quasar APM 08279+5255. The temporal sampling reveals that this gravitationally lensed system has brightened by ~0.2 mag in 100...
Faint, moving objects in the Hubble Deep Field: components of the dark halo? (1999)
Ibata, Rodrigo A., Richer, Harvey B., Gilliland, Ronald L., Scott, Douglas
The deepest optical image of the sky, the Hubble Deep Field (HDF), obtained with the Hubble Space Telescope (HST) in December 1995, has been compared to a similar image taken in December 1997. Two...
Ibata, Rodrigo A., Lewis, Geraint F., Irwin, Michael J., Lehar, Joseph, Totten, Edward J.
We present a suite of observations of the recently identified ultraluminous BAL quasar APM 08279+5255, taken both in the infra-red with the NICMOS high resolution camera on board the Hubble Space...
Submillimeter Observations of the Ultraluminous BAL Quasar APM 08279+5255 (1998)
Lewis, Geraint F., Chapman, Scott C., Ibata, Rodrigo A., Irwin, Michael J., Totten, Edward J.
With an inferred bolometric luminosity of $5\times10^{15}{\rm \lsun}$, the recently identified z=3.87, broad absorption line quasar APM 08279+5255 is apparently the most luminous object currently...
APM 08279+5255: an ultraluminous BAL quasar at a redshift z=3.87 (1998)
Irwin, Michael J., Ibata, Rodrigo A., Lewis, Geraint F., Totten, Edward J.
We report on the discovery of a highly luminous, broad absorption line quasar at a redshift of $z=3.87$ which is positionally coincident, within one arcsecond, with the IRAS FSC source F08279+5255. A...
HST Photometry of the Globular Cluster M4 (1998)
Ibata, Rodrigo A., Richer, Harvey B., Fahlman, Gregory G., Bolte, Michael, Bond, Howard E., Hesser, James E., ...
This paper presents a detailed description of the acquisition and processing of a large body of imaging data for three fields in the globular cluster M4 taken with the Wide Field and Planetary Camera...
Quasar Image Shifts due to Gravitational Microlensing (1998)
Lewis, Geraint F., Ibata, Rodrigo A.
Gravitational microlensing of quasars by stars in external galaxies can introduce fluctuations in the centroid of the ``point-like'' macro--images. The induced shifts are extremely small, on...
White Dwarfs in Globular Clusters: HST Observations of M4 (1997)
Richer, Harvey B., Fahlman, Gregory G., Ibata, Rodrigo A., Pryor, Carlton, Bell, Roger A., Bolte, Michael, ...
Using WFPC2 on the Hubble Space Telescope, we have isolated a sample of 258 white dwarfs (WDs) in the Galactic globular cluster M4. Fields at three radial distances from the cluster center were...
Hubble Space Telescope Observations of White Dwarfs in the Globular Cluster M4 (1995)
Richer, Harvey B., Fahlman, Gregory G., Ibata, Rodrigo A., Stetson, Peter B., Bell, Roger A., Bolte, Michael, ...
With the Wide Field Planetary Camera 2 (WFPC2) on the Hubble Space Telescope, we have discovered in M4 (NGC 6121, C 1620-264) the first extensive sequence of cooling white dwarfs seen in a globular...