I investigate whether useful constraints on the evolution of the relationship between galaxy mass and black hole (BH) mass can be obtained from recent measurements of galaxy stellar mass functions...
Robaina, Aday R., Bell, Eric F., Skelton, Rosalind E., McIntosh, Daniel H., Somerville, Rachel S., Zheng, Xianzhong, ...
Both observations and simulations show that major tidal interactions or mergers between gas-rich galaxies can lead to intense bursts of starformation. Yet, the average enhancement in star formation...
Can Gas prevent the Destruction of Thin Stellar Discs by Minor Mergers? (2009)
Moster, Benjamin P., Maccio', Andrea V., Somerville, Rachel S., Johansson, Peter H., Naab, Thorsten
We study the effect of dissipational gas physics on the vertical heating and thickening of disc galaxies during minor mergers. We produce a suite of minor merger simulations for Milky Way-like...
The effect of dry mergers on the color-magnitude relation of early-type galaxies (2009)
Skelton, Rosalind E., Bell, Eric F., Somerville, Rachel S.
We investigate the effect of dry merging on the color-magnitude relation (CMR) of galaxies and find that the amount of merging predicted by a hierarchical model results in a red sequence that...
Arrigoni, Matías, Trager, Scott C., Somerville, Rachel S., Gibson, Brad K.
We study the metallicities and abundance ratios of early-type galaxies in cosmological semi-analytic models (SAMs) within the hierarchical galaxy formation paradigm. To achieve this we implemented a...
GeV Gamma-Ray Attenuation and the High-Redshift UV Background (2009)
Gilmore, Rudy C., Madau, Piero, Primack, Joel R., Somerville, Rachel S., Haardt, Francesco
We present new calculations of the evolving UV background out to the epoch of cosmological reionization and make predictions for the amount of GeV gamma-ray attenuation by electron-positron pair...
Constraints on the relationship between stellar mass and halo mass at low and high redshift (2009)
Moster, Benjamin P., Somerville, Rachel S., Maulbetsch, Christian, Maccio', Andrea V., Naab, Thorsten, ...
We use a statistical approach to determine the relationship between the stellar masses of galaxies and the masses of the dark matter halos in which they reside. We obtain a parameterized...
On the origin and properties of Ultrafaint Milky Way Satellites in a LCDM Universe (2009)
Maccio', Andrea V., Kang, Xi, Fontanot, Fabio, Somerville, Rachel S., Koposov, Sergey E., Monaco, Pierluigi
We study the origin and properties of satellite galaxies within Milky Way size haloes as predicted in LCDM model, making use of hydrodynamic and N-body simulations as well as of three different...
Jogee, Shardha, Miller, Sarah H., Penner, Kyle, Skelton, Rosalind E., Conselice, Christopher J., Somerville, Rachel S., ...
We perform a comprehensive estimate of the frequency of galaxy mergers and their impact on star formation over z~0.24--0.80 (lookback time T_b~3--7 Gyr) using 3698 (M*>=1e9 Msun) galaxies with GEMS...
The Effect of Dry Mergers on the Color-Magnitude Relation (2009)
Skelton, Rosalind E., Bell, Eric F., Somerville, Rachel S.
We investigate the effect of gas-poor (so-called "dry") mergers on the color-magnitude relation (CMR) of early-type galaxies through a simple toy model and compare with low-z observations from the...
Hopkins, Philip F., Somerville, Rachel S., Cox, Thomas J., Hernquist, Lars, Jogee, Shardha, Keres, Dusan, ...
Transformation of disks into spheroids via mergers is a well-accepted element of galaxy formation models. However, recent simulations have shown that bulge formation is suppressed in increasingly...
Fontanot, Fabio, De Lucia, Gabriella, Monaco, Pierluigi, Somerville, Rachel S., Santini, Paola
[abridged] It has been widely claimed that several lines of observational evidence point towards a "downsizing" (DS) of the process of galaxy formation over cosmic time. This behavior is sometimes...
Lee, Seong-Kook, Idzi, Rafal, Ferguson, Henry C., Somerville, Rachel S., Wiklind, Tommy, Giavalisco, Mauro
We investigate the biases and uncertainties in estimates of physical parameters of high-redshift Lyman break galaxies (LBGs), such as stellar mass, mean stellar population age, and star formation...
Diffuse Extragalactic Background Radiation (2008)
Primack, Joel R., Gilmore, Rudy C., Somerville, Rachel S.
Attenuation of high--energy gamma rays by pair--production with UV, optical and IR background photons provides a link between the history of galaxy formation and high--energy astrophysics. We present...
Modeling Gamma-Ray Attenuation in High-Redshift GeV Spectra (2008)
Gilmore, Rudy C., Madau, Piero, Primack, Joel R., Somerville, Rachel S.
We present two models for the cosmological UV background light, and calculate the opacity of GeV gamma--rays out to redshift 9. The contributors to the background include 2 possible quasar...
Fontanot, Fabio, Somerville, Rachel S., Silva, Laura, Monaco, Pierluigi, Skibba, Ramin
The treatment of dust attenuation is crucial in order to compare the predictions of galaxy formation models with multiwavelength observations. Most past studies have either used simple analytic...
The Correlation of Star Formation Quenching with Internal Galaxy Properties and Environment (2008)
Kimm, Taysun, Somerville, Rachel S., Yi, Sukyoung K., Salim, Samir, Fontanot, Fabio, ...
We investigate the correlation of star formation quenching with internal galaxy properties and large scale environment (halo mass) in empirical data and theoretical models. We make use of the...
Somerville, Rachel S., Hopkins, Philip F., Cox, Thomas J., Robertson, Brant E., Hernquist, Lars
We present a new semi-analytic model that self-consistently traces the growth of supermassive black holes (BH) and their host galaxies within the context of the LCDM cosmological framework. In our...
The Co-evolution of Galaxies, Black Holes, and AGN in a Hierarchical Universe (2008)
The observational link between Supermassive Black Holes (SMBH) and galaxies at low redshift seems to be very tight, and statistically the global evolution of star formation activity and BH accretion...
The effect of galaxy mass ratio on merger-driven starbursts (2008)
Cox, T. J., Jonsson, Patrik, Somerville, Rachel S., Primack, Joel R., Dekel, Avishai
We employ numerical simulations of galaxy mergers to explore the effect of galaxy mass ratio on merger-driven starbursts. Our numerical simulations include radiative cooling of gas, star formation,...
Somerville, Rachel S., Hopkins, Philip F., Cox, Thomas J., Robertson, Brant E., Hernquist, Lars
We present a new semi-analytic model that self-consistently traces the growth of supermassive black holes (BH) and their host galaxies within the context of the Lambda cold dark matter (LambdaCDM)...
An explanation for the observed weak size evolution of disk galaxies (2008)
Somerville, Rachel S., Barden, Marco, Rix, Hans-Walter, Bell, Eric F., Beckwith, Steven V. W., Borch, Andrea, ...
Surveys of distant galaxies with the Hubble Space Telescope and from the ground have shown that there is only mild evolution in the relationship between radial size and stellar mass for galactic...
GEMS survey data and catalog (2008)
Caldwell, John A. R., McIntosh, Daniel H., Rix, Hans-Walter, Barden, Marco, Beckwith, Steven V. W., Bell, Eric F., ...
We describe the data reduction and object cataloging for the GEMS survey, a large-area (800 arcmin2) two-band (F606W and F850LP) imaging survey with the Advanced Camera for Surveys on the Hubble...
Expected z>5 QSO number counts in large area deep near-infrared surveys (2007)
Fontanot, Fabio, Somerville, Rachel S., Jester, Sebastian
The QSO luminosity function at z>5 provides strong constraints on models of joint evolution of QSO and their hosts. However, these observations are challenging because the low space densities of...
The effect of galaxy mass ratio on merger--driven starbursts (2007)
Cox, T. J., Jonsson, Patrik, Somerville, Rachel S., Primack, Joel R., Dekel, Avishai
We employ numerical simulations of galaxy mergers to explore the effect of galaxy mass ratio on merger--driven starbursts. Our numerical simulations include radiative cooling of gas, star formation,...
Clustering of Lyman alpha emitters at z ~ 4.5 (2007)
Kovač, Katarina, Somerville, Rachel S., Rhoads, James E., Malhotra, Sangeeta, Wang, JunXian
We present the clustering properties of 151 Lyman alpha emitting galaxies at z ~ 4.5 selected from the Large Area Lyman Alpha (LALA) survey. Our catalog covers an area of 36' x 36' observed with five...
GEMS: Galaxy fitting catalogues and testing parametric galaxy fitting codes (2007)
Ler, Boris Häu\ss, McIntosh, Daniel H., Barden, Marco, Bell, Eric F., Rix, Hans-Walter, Borch, Andrea, ...
In the context of measuring structure and morphology of intermediate redshift galaxies with recent HST/ACS surveys, we tune, test, and compare two widely used fitting codes (GALFIT and GIM2D) for...
Clustering of Lya emitters at z ~ 4.5 (2007)
Kovac, Katarina, Somerville, Rachel S., Rhoads, James E., Malhotra, Sangeeta, Wang, JunXian
We present the clustering properties of 151 Lyman alpha emitting galaxies at z ~ 4.5 selected from the Large Area Lyman Alpha (LALA) survey. Our catalog covers an area of 36' x 36' observed with five...
GEMS: galaxy fitting catalogs and testing parametric galaxy fitting codes: GALFIT and GIM2D (2007)
Häußler, Boris, McIntosh, Daniel H., Barden, Marco, Bell, Eric F., Rix, Hans-Walter, Borch, Andrea, ...
In the context of measuring the structures of intermediate-redshift galaxies with HST ACS surveys, we tune, test, and compare two widely used fitting codes (GALFIT and GIM2D) for fitting...
GEMS: the destiny of blue spheroidal galaxies (2007)
Häußler, Boris, Bell, Eric F., Barden, Marco, McIntosh, Daniel H., Rix, Hans-Walter, Borch, Andrea, ...
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An Explanation for the Observed Weak Size Evolution of Disk Galaxies (2006)
Somerville, Rachel S., Barden, Marco, Rix, Hans-Walter, Bell, Eric F., Beckwith, Steven V. W., Borch, Andrea, ...
Surveys of distant galaxies with the Hubble Space Telescope and from the ground have shown that there is only mild evolution in the relationship between radial size and stellar mass for galactic...
The Hubble Ultra Deep Field (2006)
Beckwith, Steven V. W., Stiavelli, Massimo, Koekemoer, Anton M., Caldwell, John A. R., Ferguson, Henry C., Hook, Richard, ...
This paper presents the Hubble Ultra Deep Field (HUDF), a one million second exposure of an 11 square minute-of-arc region in the southern sky with the Hubble Space Telescope. The exposure time was...
Corbin, Michael R., Vacca, William D., Fernandes, Roberto Cid, Hibbard, John E., Somerville, Rachel S., Windhorst, Rogier A.
We present deep Hubble Space Telescope Advanced Camera for Surveys / High Resolution Channel U, narrow-V, and I images of nine "ultracompact" blue dwarf galaxies (UCBDs) selected from the Sloan...
Hopkins, Philip F., Somerville, Rachel S., Hernquist, Lars, Cox, Thomas J., Robertson, Brant, Li, Yuexing
Using a model for self-regulated growth of black holes (BHs) in mergers involving gas-rich galaxies, we study the relationship between quasars and the population of merging galaxies and predict the...
The merger rate of massive galaxies (2006)
Bell, Eric F., Phleps, Stefanie, Somerville, Rachel S., Wolf, Christian, Borch, Andrea, Meisenheimer, Klaus
We calculate the projected two point correlation function for samples of luminous and massive galaxies in the COMBO-17 photometric redshift survey, focusing particularly on the amplitude of the...
The merger rate of massive galaxies (2006)
Bell, Eric F., Phleps, Stefanie, Somerville, Rachel S., Wolf, Christian, Borch, Andrea, Meisenheimer, Klaus
The large-scale and small-scale clustering of Lyman Break Galaxies at 3.5 (2006)
Lee, Kyoung-Soo, Giavalisco, Mauro, Gnedin, Oleg Y., Somerville, Rachel S., Ferguson, Henry C., Dickinson, Mark, ...
We report on the angular correlation function of Lyman break galaxies (LBGs) at z~4 and 5 from deep samples obtained from the Great Observatories Deep Origins Survey (GOODS). As for LBGs at z~3, the...
Simulations of dust in interacting galaxies. I. Dust attenuation (2006)
Jonsson, Patrik, Cox, T. J., Primack, Joel R., Somerville, Rachel S.
A new Monte Carlo radiative transfer code, SUNRISE, is used in conjunction with hydrodynamic simulations of major galaxy mergers to calculate the effects of dust in such systems. Dust has a profound...
Hopkins, Philip F., Somerville, Rachel S., Hernquist, Lars, Cox, Thomas J., Robertson, Brant, Li, Yuexing
Using a model for the self-regulated growth of supermassive BHs in mergers involving gas-rich galaxies, we study the relationship between quasars and the population of merging galaxies and predict...
Feedback in simulations of disc-galaxy major mergers (2006)
Cox, T. J., Jonsson, Patrik, Primack, Joel R., Somerville, Rachel S.
Using hydrodynamic simulations of disc-galaxy major mergers, we investigate the star formation history and remnant properties when various parametrizations of a simple stellar feedback model are...
Corbin, Michael R., Vacca, William D., Cid Fernandes, Roberto, Hibbard, John E., Somerville, Rachel S., Windhorst, Rogier A.
We present deep Hubble Space Telescope (HST) Advanced Camera for Surveys/High Resolution Channel U-, narrow-V-, and I-band images of nine ``ultracompact'' blue dwarf galaxies (UCBDs) selected from...
The merger rate of massive galaxies (2006)
Bell, Eric F., Phleps, Stefanie, Somerville, Rachel S., Wolf, Christian, Borch, Andrea, Meisenheimer, Klaus
We calculate the projected two-point correlation function for samples of luminous and massive galaxies in the COMBO-17 photometric redshift survey, focusing particularly on the amplitude of the...
Dry mergers in GEMS: The dynamical evolution of massive early-type galaxies (2006)
Bell, Eric F., Naab, Thorsten, McIntosh, Daniel H., Somerville, Rachel S., Caldwell, John A. R., Barden, Marco, ...
We have used the 28'×28' Hubble Space Telescope image mosaic from the GEMS (Galaxy Evolution from Morphology and SEDs) survey in conjunction with the COMBO-17 photometric redshift survey to...
The Hubble Ultra Deep Field (2006)
Beckwith, Steven V. W., Stiavelli, Massimo, Koekemoer, Anton M., Caldwell, John A. R., Ferguson, Henry C., Hook, Richard, ...
This paper presents the Hubble Ultra Deep Field (HUDF), a 1 million s exposure of an 11 arcmin2 region in the southern sky with the Advanced Camera for Surveys on the Hubble Space Telescope using...
Lee, Kyoung-Soo, Giavalisco, Mauro, Gnedin, Oleg Y., Somerville, Rachel S., Ferguson, Henry C., Dickinson, Mark, ...
We report on the angular correlation function of Lyman-break galaxies (LBGs) at z~4 and 5 from deep samples obtained from the Great Observatories Deep Origins Survey (GOODS). Similar to LBGs at z~3,...
Dry Mergers in GEMS: The Dynamical Evolution of Massive Early-Type Galaxies (2005)
Bell, Eric F., Naab, Thorsten, McIntosh, Daniel H., Somerville, Rachel S., Caldwell, John A. R., Barden, Marco, ...
We have used the 28'x 28' HST image mosaic from the GEMS (Galaxy Evolution from Morphology and SEDs) survey in conjunction with the COMBO-17 photometric redshift survey to constrain the incidence of...
Dahlen, Tomas, Mobasher, Bahram, Somerville, Rachel S., Moustakas, Leonidas A., Dickinson, Mark, Ferguson, Henry C., ...
Using Hubble Space Telescope and ground-based U through K- band photometry from the Great Observatories Origins Deep Survey (GOODS), we measure the evolution of the luminosity function and luminosity...
Feedback in simulations of disc-galaxy major mergers (2005)
Cox, T. J., Jonsson, Patrik, Primack, Joel R., Somerville, Rachel S.
Using hydrodynamic simulations of disc-galaxy major mergers, we investigate the star formation history and remnant properties when various parametrizations of a simple stellar feedback model are...
Simulations of Dust in Interacting Galaxies I: Dust Attenuation (2005)
Jonsson, Patrik, Cox, T. J., Primack, Joel R., Somerville, Rachel S.
A new Monte-Carlo radiative-transfer code, Sunrise, is used in conjunction with hydrodynamic simulations of major galaxy mergers to calculate the effects of dust in such systems. The simulations are...
GEMS: The Size Evolution of Disk Galaxies (2005)
Barden, Marco, Rix, Hans-Walter, Somerville, Rachel S., Bell, Eric F., Haeussler, Boris, Peng, Chien Y., ...
We combine HST imaging from the GEMS survey with photometric redshifts from COMBO-17 to explore the evolution of disk-dominated galaxies since z
Observational Gamma-ray Cosmology (2005)
Primack, Joel R., Bullock, James S., Somerville, Rachel S.
We discuss how measurements of the absorption of gamma-rays from GeV to TeV energies via pair production on the extragalactic background light (EBL) can probe important issues in galaxy formation....
McIntosh, Daniel H., Bell, Eric F., Rix, Hans-Walter, Wolf, Christian, Heymans, Catherine, Peng, Chien Y., ...
We combine imaging from the Hubble Space Telescope Advanced Camera for Surveys, as part of the GEMS (Galaxy Evolution from Morphologies and SEDs) survey, with redshifts and rest-frame quantities from...
GEMS: The surface brightness and surface mass density evolution of disk galaxies (2005)
Barden, Marco, Rix, Hans-Walter, Somerville, Rachel S., Bell, Eric F., Häußler, Boris, Peng, Chien Y., ...
We combine HST imaging from the GEMS (Galaxy Evolution from Morphologies and SEDs) survey with photometric redshifts from COMBO-17 to explore the evolution of disk-dominated galaxies since z
McIntosh, Daniel H., Bell, Eric F., Rix, Hans-Walter, Wolf, Christian, Heymans, Catherine, Peng, Chien Y., ...
We combine HST/ACS imaging from the GEMS survey with redshifts and rest-frame quantities from COMBO-17 to study the evolution of morphologically early-type galaxies with red colors since z=1. We use...
Modeling the Multi-wavelength Universe: the assembly of massive galaxies (2004)
Pan-chromatic galaxy surveys are providing tightening constraints on the global mass assembly history, and high-resolution imaging of large fields is telling us when and where stars were formed. How...
GEMS: Galaxy Evolution from Morphologies and SEDs (2004)
Rix, Hans-Walter, Barden, Marco, Beckwith, Steven V. W., Bell, Eric F., Caldwell, John A. R., Haeussler, Boris, ...
GEMS, Galaxy Evolution from Morphologies and SEDs, is a large-area (800 arcmin2) two-color (F606W and F850LP) imaging survey with the Advanced Camera for Surveys on HST. Centered on the Chandra Deep...
GEMS: Galaxy evolution from morphologies and SEDs (2004)
Rix, Hans-Walter, Barden, Marco, Beckwith, Steven V. W., Bell, Eric F., Borch, Andrea, Caldwell, John A. R., ...
GEMS (Galaxy Evolution from Morphologies and SEDs) is a large-area (800 arcmin2) two-color (F606W and F850LP) imaging survey with the Advanced Camera for Surveys on the Hubble Space Telescope....
GEMS imaging of red-sequence galaxies at z~0.7: Dusty or old? (2004)
Bell, Eric F., McIntosh, Daniel H., Barden, Marco, Wolf, Christian, Caldwell, John A. R., Rix, Hans-Walter, ...
We have used the 30'times;30' Hubble Space Telescope image mosaic from the Galaxy Evolution from Morphology and Spectral energy distributions (GEMS) project in conjunction with the COMBO-17 deep...
Colors of AGN host galaxies at 0.5 (2004)
Sánchez, S. F., Jahnke, K., Wisotzki, L., McIntosh, D. H., Bell, E., Barden, M., ...
Ultraviolet light from young stars in GEMS quasar host galaxies at 1.8 (2004)
Jahnke, K., Sánchez, S. F., Wisotzki, L., Barden, M., Beckwith, S., Bell, E., ...
Jogee, Shardha, Barazza, Fabio D., Rix, Hans-Walter, Shlosman, Isaac, Barden, Marco, Wolf, Christian, ...
One-third of present-day spirals host optically visible strong bars that drive their dynamical evolution. However, the fundamental question of how bars evolve over cosmological times has yet to be...
Evolution in the Colors of Lyman-Break Galaxies from Z~4 to Z~3 (2003)
Papovich, Casey, Dickinson, Mark, Ferguson, Henry C., Giavalisco, Mauro, Lotz, Jennifer, Madau, Piero, ...
The integrated colors of distant galaxies provide a means for interpreting the properties of their stellar content. Here, we use rest-frame UV-to-optical colors to constrain the spectral-energy...
Moustakas, Leonidas A., Casertano, Stefano, Conselice, Chris, Dickinson, Mark E., Eisenhardt, Peter, Ferguson, Henry C., ...
Using U'- through Ks-band imaging data in the GOODS-South field, we construct a large, complete sample of 275 ``extremely red objects'' (EROs; K_s3.35; AB), all with deep HST/ACS imaging in B_435,...
The Size Evolution of High Redshift Galaxies (2003)
Ferguson, Henry C., Dickinson, Mark, Giavalisco, Mauro, Kretchmer, Claudia, Ravindranath, Swara, Idzi, Rafal, ...
Hubble Space Telescope images of high-redshift galaxies selected via color and photometric redshifts are used to examine the size and axial-ratio distribution of galaxies as a function of redshift at...
Somerville, Rachel S., Moustakas, Leonidas A., Mobasher, Bahram, Gardner, Jonathan P., Cimatti, Andrea, Conselice, Christopher, ...
The redshift distribution of near-IR selected galaxies is often used to attempt to discriminate between the classical view of galaxy formation, in which present-day luminous galaxies were assembled...
Cosmic Variance in the Great Observatories Origins Deep Survey (2003)
Somerville, Rachel S., Lee, Kyoungsoo, Ferguson, Henry C., Gardner, Jonathan P., Moustakas, Leonidas A., Giavalisco, Mauro
Cosmic variance is the uncertainty in observational estimates of the volume density of extragalactic objects such as galaxies or quasars arising from the underlying large-scale density fluctuations....
The Epoch of Reionization in Models with Reduced Small Scale Power (2003)
Somerville, Rachel S., Bullock, James S., Livio, Mario
Reducing the power on small scales relative to the `standard' LCDM model alleviates a number of possible discrepancies with observations, and is favored by the recent analysis of WMAP plus galaxy and...
Star Formation at the Twilight of the Dark Ages: Which Stars Reionized the Universe? (2003)
Somerville, Rachel S., Livio, Mario
We calculate the global star formation rate density (SFRD) from z ~ 30-3 using a semi-analytic model incorporating the hierarchical assembly of dark matter halos, gas cooling via atomic hydrogen,...
GEMS: The evolution of disc sizes over the last 10 Gyrs (2003)
Barden, Marco, Haeussler, Boris, Rix, Hans-Walter, Bell, Eric, Borch, Andrea, Meisenheimer, Klaus, ...
Maller, Ariyeh H., Prochaska, Jason X., Somerville, Rachel S., Primack, Joel R.
We investigate a model for the high-ionization state gas associated with observed damped Lyman-alpha systems, based on a semi-analytic model of galaxy formation set within the paradigm of...
Evaluating the disk formation paradigm in the LCDM framework: constraints from the Milky Way (2002)
We investigate the properties of a galaxy similar to the Milky Way within the context of standard disk formation theory in a LCDM universe. Using the standard assumption that baryons conserve...
Studying Galaxy Formation with Hubble's Successor (2002)
In this paper, I discuss the capabilities and limitations of an 8-10 meter ultraviolet/optical telescope in space, the proposed successor to the Hubble Space Telescope, in the context of galaxy...
Estimating photometric redshifts with artificial neural networks (2002)
Firth, Andrew E., Lahav, Ofer, Somerville, Rachel S.
A new approach to estimating photometric redshifts - using Artificial Neural Networks (ANNs) - is investigated. Unlike the standard template-fitting photometric redshift technique, a large...
The Masses of Lyman Break Galaxies (2001)
Primack, Joel R., Wechsler, Risa H., Somerville, Rachel S.
Data on galaxies at high redshift, identified by the Lyman-break photometric technique, can teach us about how galaxies form and evolve. The stellar masses and other properties of such Lyman break...
Moustakas, Leonidas A., Somerville, Rachel S.
Wide field near-infrared (IR) surveys have revealed a population of galaxies with very red optical$-$IR colors, which have been termed ``Extremely Red Objects'' (EROs). Modeling suggests that such...
LCDM-based models for the Milky Way and M31 I: Dynamical Models (2001)
Klypin, Anatoly, Zhao, HongSheng, Somerville, Rachel S.
We apply standard disk formation theory with adiabatic contraction within cuspy halo models predicted by the standard LCDM cosmology. The resulting models score remarkably well when confronted with...
Squelched Galaxies and Dark Halos (2001)
Tully, R. Brent, Somerville, Rachel S., Trentham, Neil, Verheijen, Marc A. W.
There is accumulating evidence that the faint end of the galaxy luminosity function might be very different in different locations. The luminosity function might be rising in rich clusters and flat...
Can Photoionization Squelching Resolve the Sub-structure Crisis? (2001)
Cold Dark Matter theory predicts that the Local Group should contain many more dwarf-sized objects than the observed number of dwarf galaxies --- the so-called sub-structure problem. We investigate...
Galaxy Halo Occupation at High Redshift (2001)
Bullock, James S., Wechsler, Risa H., Somerville, Rachel S.
We discuss how current and future data on the clustering and number density of z~3 Lyman-break galaxies (LBGs) can be used to constrain their relationship to dark matter haloes. We explore a...
Modeling Angular-Momentum History in Dark-Matter Halos (2001)
Maller, Ariyeh H., Dekel, Avishai, Somerville, Rachel S.
We model the acquisition of spin by dark-matter halos in semi-analytic merger trees. We explore two different algorithms; one in which halo spin is acquired from the orbital angular momentum of...
Probing Galaxy Formation with High Energy Gamma-Rays (2000)
Primack, Joel R., Somerville, Rachel S., Bullock, James S., Devriendt, Julien E. G.
We discuss how measurements of the absorption of $\gamma$-rays from GeV to TeV energies via pair production on the extragalactic background light (EBL) can probe important issues in galaxy formation....
Galaxy Formation at z~3: Constraints from Spatial Clustering (2000)
Wechsler, Risa H., Somerville, Rachel S., Bullock, James S., Kolatt, Tsafrir S., Primack, Joel R., Blumenthal, George R., ...
We use N-body simulations combined with semi-analytic models to compute the clustering properties of modeled galaxies at z~3, and confront these predictions with the clustering properties of the...
Disks at High Redshift: Interactions, Mergers, and Starbursts (2000)
Do disk galaxies exist at redshifts much greater than unity, and how might they look different from local disks? How does the morphological mix of galaxies change with redshift? What can we learn...
Strong Evolution in the Luminosity-Velocity Relation at z>1? (2000)
Bullock, James S., Dekel, Avishai, Primack, Joel R., Somerville, Rachel S.
We present a method for constraining the evolution of the galaxy luminosity-velocity (LV) relation in hierarchical scenarios of structure formation. The comoving number density of dark-matter halos...
Maller, Ariyeh H., Prochaska, Jason X., Somerville, Rachel S., Primack, Joel R.
We investigate the properties of damped Lyman-alpha systems (DLAS) in semi-analytic models, focusing on whether the models can reproduce the kinematic properties of low-ionization metal lines...
Optical Counterparts to Damped Lyman Alpha Systems (2000)
Maller, Ariyeh H., Prochaska, Jason X., Somerville, Rachel S., Primack, Joel R.
Previously we have shown (Maller et al, 1998) that the kinematics of Damped Lyman Alpha Systems (DLAS) as measured by Prochaska and Wolfe (1998) can be reproduced in a multiple disk model (MDM) if...
Maller, Ariyeh H., Somerville, Rachel S., Prochaska, Jason X., Primack, Joel R.
Previously we have shown that it is possible to account for the kinematic properties of damped Lyman alpha systems (DLAS) in the context of semi-analytic models. In these models, hierarchical...
Clustering of high-redshift galaxies: relating LBGs to dark matter halos (1999)
Wechsler, Risa H., Bullock, James S., Somerville, Rachel S., Kolatt, Tsafrir, Primack, Joel R., Blumenthal, George R., ...
We investigate the clustering properties of high-redshift galaxies within three competing scenarios for assigning luminous galaxies to dark matter halos from N-body simulations: a one galaxy per...
Profiles of dark haloes: evolution, scatter, and environment (1999)
Bullock, James S., Kolatt, Tsafrir S., Sigad, Yair, Somerville, Rachel S., Kravtsov, Andrey V., Klypin, Anatoly A., ...
We study dark-matter halo density profiles in a high-resolution N-body simulation of an LCDM cosmology. Our statistical sample contains ~5000 haloes in the range 10^{11}-10^{14} M_sun. The profiles...
Young galaxies: what turns them on? (1999)
Kolatt, Tsafrir S., Bullock, James S., Somerville, Rachel S., Sigad, Yair, Jonsson, Patrik, Kravtsov, Andrey V., ...
Lyman break galaxies (LBGs) at $z \sim 3$ exhibit number densities and clustering similar to local $L_*$ galaxies; however, their star formation rates (SFRs) are much higher. We explore the scenario...
Probing Galaxy Formation with TeV Gamma Ray Absorption (1998)
Primack, Joel R., Bullock, James S., Somerville, Rachel S., MacMinn, Donn
We present here the extragalactic background light (EBL) predicted by semi-analytic models of galaxy formation, and show how measurements of the absorption of gamma rays of $\sim$ TeV energies via...
Cosmological Implications of Lyman-Break Galaxy Clustering (1998)
Wechsler, Risa H., Gross, Michael A. K., Primack, Joel R., Blumenthal, George R., Dekel, Avishai, Somerville, Rachel S.
We review our analysis of the clustering properties of ``Lyman-break'' galaxies (LBGs) at redshift z~3, previously discussed in Wechsler et al (1998). We examine the likelihood of spikes found by...
Making Damped Lyman Alpha Systems in Semi-Analytic Models (1998)
Maller, Ariyeh H., Somerville, Rachel S., Prochaska, Jason X., Primack, Joel R.
The velocity profiles of weak metal absorption lines can be used to observationally probe the kinematic state of gas in damped Lyman-alpha systems. Prochaska and Wolfe have argued that the flat...
The Star Formation History in a Hierarchical Universe (1998)
Somerville, Rachel S., Primack, Joel R.
Observations now probe the star formation history of the Universe back to a redshift of $z\sim5$. We investigate whether the predictions of semi-analytic models of galaxy formation based on...
Evaluating Semi-Analytic Halo Merging Histories (1998)
Somerville, Rachel S., Lemson, Gerard, Kolatt, Tsafrir S., Dekel, Avishai
We evaluate the accuracy of semi-analytic merger-trees by comparing them with the merging histories of dark-matter halos in N-body simulations, focusing on the joint distribution of the number of...
The nature of Lyman-break galaxies (1998)
Primack, Joel R., Somerville, Rachel S., Faber, S. M, Wechsler, Risa H.
Using semi-analytic models of galaxy formation, we investigate the properties of $z\sim3$ galaxies and compare them with the observed population of Lyman-break galaxies (LBGs). In addition to the...
The Nature of High-Redshift Galaxies (1998)
Somerville, Rachel S., Primack, Joel R., Faber, S. M.
This paper has been withdrawn because the models on which it was based have undergone significant changes and improvements. A new paper with the same title, based on the improved models, is accepted...
Semi-Analytic Modelling of Galaxy Formation: The Local Universe (1998)
Somerville, Rachel S., Primack, Joel R.
Using semi-analytic models of galaxy formation, we investigate galaxy properties such as the Tully-Fisher relation, the B and K-band luminosity functions, cold gas contents, sizes, metallicities, and...
CDM-Variant Cosmological Models - I: Simulations and Preliminary Comparisons (1997)
Gross, Michael A. K., Somerville, Rachel S., Primack, Joel R., Holtzman, Jon, Klypin, Anatoly
We present two matched sets of five simulations each, covering five presently favored simple modifications to the standard cold dark matter (CDM) scenario. One simulation suite, with a linear box...
How to Plant a Merger Tree (1997)
Somerville, Rachel S., Kolatt, Tsafrir S.
We investigate several approaches for constructing Monte Carlo realizations of the merging history of virialized dark matter halos (``merger trees'') using the extended Press-Schechter formalism. We...
Clusters in Various Cosmological Models: Abundance and Evolution (1997)
Gross, Michael A. K., Somerville, Rachel S., Primack, Joel R., Borgani, Stefano, Girardi, Marisa
The combination of measurements of the local abundance of rich clusters of galaxies and its evolution to higher redshift offers the possibility of a direct measurement of $\Omega_0$ with little...
Favored Variants of Cold Dark Matter Cosmologies (1996)
Somerville, Rachel S., Primack, Joel R.
We discuss variants of Cold Dark Matter (CDM) dominated cosmological models that give good agreement with a range of observations. We consider models with hot dark matter, tilt, $\Omega < 1$, or a...
The Small Scale Velocity Dispersion of Galaxies: A Comparison of Cosmological Simulations (1996)
Somerville, Rachel S., Primack, Joel R., Nolthenius, Richard
The velocity dispersion of galaxies on small scales ($r\sim1h^{-1}$ Mpc), $\sigma_{12}(r)$, can be estimated from the anisotropy of the galaxy-galaxy correlation function in redshift space. We apply...
A Reanalysis of Small Scale Velocity Dispersion in the CfA1 Survey (1996)
Somerville, Rachel S., Davis, Marc, Primack, Joel R.
The velocity dispersion of galaxies on scales of $r\sim1h^{-1}$ Mpc, $\sigma_{12}(r)$, may be estimated from the anisotropy of the galaxy-galaxy correlation function in redshift space. We present a...