Rachel Somerville

Space Telescope Science Institute The Hubble Ultra Deep Field (2008)

Steven Beckwith, Rachel Somerville, Massimo Stiavelli

Near the beginning of Cycle 12, we will use 412 orbits of director’s discretionary time to observe a single field with the Advanced Camera for Surveys (ACS). The result will be the deepest field...

The Rise and Fall of Galaxy Activity in Dark Matter Haloes (2008)

Pasquali, Anna, Mo, H. J., Yang, Xiaohu, Somerville, Rachel

We use a SDSS galaxy group catalogue to study the dependence of galaxy activity on stellar mass, halo mass, and group hierarchy (centrals vs. satellites). We split our galaxy sample in star-forming...

Objective Classication of Galaxy Spectra using the Information Bottleneck Method (2007)

Noam Slonim, Rachel Somerville, Naftali Tishby, Ofer Lahav

A new method for classication of galaxy spectra is presented, based on a recently introduced information theoretical principle, the information bottleneck. For any desired number of classes, galaxies...

The dependence of Star Formation on Galaxy Stellar Mass (2007)

Zheng, Xian Zhong, Bell, Eric F., Papovich, Casey, Wolf, Christian, Meisenheimer, Klaus, Rix, Hans-Walter, ...

We combine Spitzer 24micron observations with data from the COMBO-17 survey for ~15,000 0.2

The dependence of star formation on galaxy stellar mass (2007)

Zheng, Xian Zhong, Bell, Eric F., Papovich, Casey, Wolf, Christian, Meisenheimer, Klaus, Rix, Hans-Walter, ...

We combine Spitzer 24 mum observations with data from the COMBO-17 survey for ~15,000 0.2

A weak lensing estimate from GEMS of the virial to stellar mass ratio in massive galaxies to z~0.8 (2006)

Heymans, Catherine, Bell, Eric F., Rix, Hans-Walter, Barden, Marco, Borch, Andrea, Caldwell, John A. R., ...

We present constraints on the evolution of the virial to stellar mass ratio of galaxies with high stellar masses in the redshift range 0.2

A weak lensing estimate from GEMS of the virial to stellar mass ratio in massive galaxies to z ~ 0.8 (2006)

Heymans, Catherine, Bell, Eric F., Rix, Hans-Walter, Barden, Marco, Borch, Andrea, Caldwell, John A. R., ...

We present constraints on the evolution of the virial to stellar mass ratio of galaxies with high stellar masses in the redshift range 0.2 < z < 0.8, by comparing weak lensing measurements of virial...

Hubble Space Telescope Imaging of the Ultracompact Blue Dwarf Galaxy HS 0822+3542: An Assembling Galaxy in a Local Void? (2005)

Corbin, Michael R., Vacca, William D., Hibbard, John E., Somerville, Rachel, Windhorst, Rogier A.

We present deep U, narrow-V, and I-band images of the ultracompact blue dwarf galaxy HS 0822+3542, obtained with the Advanced Camera for Surveys / High Resolution Channel of the Hubble Space...

Cosmological weak lensing with the HST GEMS survey (2005)

Heymans, Catherine, Brown, Michael L., Barden, Marco, Caldwell, John A. R., Jahnke, Knud, Peng, Chien Y., ...

We present our cosmic shear analysis of GEMS, one of the largest wide-field surveys ever undertaken by the Hubble Space Telescope. Imaged with the Advanced Camera for Surveys (ACS), GEMS spans 795...

Weak Lensing Results from GEMS (2005)

Heymans, Catherine, Brown, Michael L., Barden, Marco, Caldwell, John A. R., Jahnke, Knud, Rix, Hans-Walter, ...

We present our cosmic shear analysis of the Galaxy Evolution from Morphology and SEDs (GEMS) survey. Imaged with the Advanced Camera for Surveys (ACS) on HST, GEMS provides high resolution imaging...

The Multimission Archive at the Space Telescope Science Institute in the context of VO activities (2004)

Kamp, Inga, Thompson, Randall, Conti, Alberto, Fraquelli, Dorothy, Kimball, Tim, Levay, Karen, ...

In the past year, the Multimission Archive at the Space Telescope Science Institute (MAST) has taken major steps in making MAST's holdings available using VO-defined protocols and standards, and in...

Cosmological weak lensing with the HST GEMS survey (2004)

Heymans, Catherine, Brown, Michael L., Barden, Marco, Caldwell, John A. R., Jahnke, Knud, Peng, Chien Y., ...

We present our cosmic shear analysis of GEMS, one of the largest wide-field surveys ever undertaken by the Hubble Space Telescope. Imaged with the Advanced Camera for Surveys (ACS), GEMS spans 795...

Generating Hot Gas in Simulations of Disk-Galaxy Major Mergers (2004)

Cox, T. J., Primack, Joel, Jonsson, Patrik, Somerville, Rachel

We report on the merger-induced generation of a shock-heated gas wind and formation of a remnant gas halo in simulations of colliding disk galaxies. The simulations use cosmologically motivated...

The z ~ 4 Lyman Break Galaxies: Colors and Theoretical Predictions (2003)

Idzi, Rafal, Somerville, Rachel, Papovich, Casey, Ferguson, Henry C., Giavalisco, Mauro, Kretchmer, Claudia, ...

We investigate several fundamental properties of z ~ 4 Lyman-break galaxies by comparing observations with the predictions of a semi-analytic model based on the Cold Dark Matter theory of...

GEMS Imaging of Red Sequence Galaxies at z~0.7: Dusty or Old? (2003)

Bell, Eric F., McIntosh, Daniel H., Barden, Marco, Wolf, Christian, Caldwell, John A. R., Rix, Hans-Walter, ...

We have used the 30'x30' Hubble Space Telescope image mosaic from the Galaxy Evolution from Morphology and SEDs (GEMS) project in conjunction with the COMBO-17 deep photometric redshift survey to...

Galaxy spectral parameterisation in the 2dF Galaxy Redshift Survey as a diagnostic of star formation history (2002)

Madgwick, Darren, Somerville, Rachel, Lahav, Ofer, Ellis, Richard

We investigate the physical significance of a new spectral parameter, eta. This parameter was defined using a Principal Component Analysis of the 2dF Galaxy Redshift Survey, to retain astrophysical...

Near-Infrared Integral Field Spectroscopy of Damped Lyman-alpha Systems (2000)

Bunker, Andrew, Ferguson, Annette, Johnson, Rachel, McMahon, Richard, Parry, Ian, Pettini, Max, ...

We assess the feasibility of detecting star formation in damped Lyman-alpha systems (DLAs) at z>1 through near-infrared spectroscopy using the forthcoming integral field units on 8m-class telescopes....

Objective Classification of Galaxy Spectra using the Information Bottleneck Method (2000)

Noam Slonim, Rachel Somerville, Naftali Tishby, Ofer Lahav

A new method for classication of galaxy spectra is presented, based on a recently introduced information theoretical principle, the information bottleneck. For any desired number of classes, galaxies...