Thomas J. Cox

A Physical Model for z~2 Dust Obscured Galaxies (2009)

Narayanan, Desika, Dey, Arjun, Hayward, Christopher, Cox, Thomas J., Bussmann, R. Shane, Brodwin, Mark, ...

We present a physical model for the origin of z~2 Dust-Obscured Galaxies (DOGs), a class of high-redshift ULIRGs selected at 24 micron which are particularly optically faint (F24/FR>1000). By...

Discriminating Between the Physical Processes that Drive Spheroid Size Evolution (2009)

Hopkins, Philip F., Bundy, Kevin, Hernquist, Lars, Wuyts, Stijn, Cox, Thomas J.

Massive galaxies at high-z have smaller effective radii than those today, but similar central densities. Their size growth therefore relates primarily to the evolving abundance of low-density...

Resonant stripping as the origin of dwarf spheroidal galaxies (2009)

D'Onghia, Elena, Besla, Gurtina, Cox, Thomas J., Hernquist, Lars

Dwarf spheroidal galaxies are the most dark matter dominated systems in the nearby Universe and their origin is one of the outstanding puzzles of how galaxies form. Dwarf spheroidals are poor in gas...

Color Distributions, Number and Mass Densities of Massive Galaxies at 1.5 < z < 3: Comparing Observations with Merger Simulations (2009)

Wuyts, Stijn, Franx, Marijn, Cox, Thomas J., Schreiber, Natascha M. Forster, Hayward, Christopher C., Hernquist, Lars, ...

We present a comparison between the observed color distribution, number and mass density of massive galaxies at 1.5 < z < 3 and a model by Hopkins et al. that relates the quasar and galaxy population...

The Star-Forming Molecular Gas in High Redshift Submillimeter Galaxies (2009)

Narayanan, Desika, Cox, Thomas J., Hayward, Christopher, Younger, Joshua D., Hernquist, Lars

We present a model for the CO molecular line emission from high redshift Submillimeter Galaxies (SMGs). By combining hydrodynamic simulations of gas rich galaxy mergers with the polychromatic...

The Formation of High Redshift Submillimeter Galaxies (2009)

Narayanan, Desika, Hayward, Christopher C., Cox, Thomas J., Hernquist, Lars, Jonsson, Patrik, Younger, Joshua D., ...

We describe a model for the formation of \zsim 2 Submillimeter Galaxies (SMGs) which simultaneously accounts for both average and bright SMGs while providing a reasonable match to their mean observed...

The imprint of dissipation on the shapes of merger remnant LOSVDs (2009)

Hoffman, Loren K., Cox, Thomas J., Dutta, Suvendra N., Hernquist, Lars E.

The properties of elliptical galaxies are broadly consistent with simulated remnants of gas-rich mergers between spirals, motivating more detailed studies of the imprint of this formation mechanism...

Recovering Stellar Population Properties and Redshifts from Broad-Band Photometry of Simulated Galaxies: Lessons for SED Modeling (2009)

Wuyts, Stijn, Franx, Marijn, Cox, Thomas J., Hernquist, Lars, Hopkins, Philip F., Robertson, Brant E., ...

We present a detailed analysis of our ability to determine stellar masses, ages, reddening and extinction values, and star formation rates of high-redshift galaxies by modeling broad-band SEDs with...

The Effects of Gas on Morphological Transformation in Mergers: Implications for Bulge and Disk Demographics (2009)

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...

A Semi-Analytic Model for the Co-evolution of Galaxies, Black Holes, and Active Galactic Nuclei (2008)

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...

Dissipation and Extra Light in Galactic Nuclei: IV. Evolution in the Scaling Relations of Spheroids (2008)

Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Keres, Dusan, Wuyts, Stijn

We develop a model for the origins and redshift evolution of spheroid scaling relations. We consider spheroid sizes, velocity dispersions, masses, profile shapes (Sersic indices), and black hole (BH)...

Dissipation and the Fundamental Plane: Observational Tests (2008)

Hopkins, Philip F., Cox, Thomas J., Hernquist, Lars

We develop observational tests of the idea that dissipation in gas-rich mergers produces the fundamental plane (FP) and related correlations obeyed by ellipticals. The FP 'tilt' implies lower-mass...

The Radical Consequences of Realistic Satellite Orbits for the Heating and Implied Merger Histories of Galactic Disks (2008)

Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Younger, Joshua D., Besla, Gurtina

Previous models of galactic disk heating in interactions invoke restrictive assumptions not necessarily valid in modern LCDM contexts: that satellites and orbits are rigid and circular, with slow...

Dissipation and Extra Light in Galactic Nuclei: III. 'Core' Ellipticals and 'Missing' Light (2008)

Hopkins, Philip F., Lauer, Tod R., Cox, Thomas J., Hernquist, Lars, Kormendy, John

We investigate how 'extra' central light in the surface brightness profiles of cusp ellipticals relates to the profiles of ellipticals with cores. Cusp elliptical envelopes are formed by violent...

How Do Disks Survive Mergers? (2008)

Hopkins, Philip F., Cox, Thomas J., Younger, Joshua D., Hernquist, Lars

We develop a physical model for how galactic disks survive and/or are destroyed in interactions. Based on dynamical arguments, we show gas primarily loses angular momentum to internal torques in a...

The Star Formation Rate - Dense Gas Relation in the Nuclei of Nearby Galaxies (2008)

Narayanan, Desika, Cox, Thomas J., Hernquist, Lars

We investigate the relationship between the star formation rate (SFR) and dense molecular gas mass in the nuclei of galaxies. To do this, we utilize the observed 850 micron luminosity as a proxy for...

Dissipation and Extra Light in Galactic Nuclei: II. 'Cusp' Ellipticals (2008)

Hopkins, Philip F., Cox, Thomas J., Dutta, Suvendra N., Hernquist, Lars, Kormendy, John, Lauer, Tod R.

We study the origin and properties of 'extra' or 'excess' central light in the surface brightness profiles of cusp or power-law ellipticals. Dissipational mergers give rise to two-component profiles:...

Dissipation and Extra Light in Galactic Nuclei: I. Gas-Rich Merger Remnants (2008)

Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Dutta, Suvendra N., Rothberg, Barry

We study the origin and properties of 'extra' or 'excess' central light in the surface brightness profiles of gas-rich merger remnants. Combining a large set of hydrodynamical simulations with data...

A semi-analytic model for the co-evolution of galaxies, black holes and active galactic nuclei (2008)

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)...

Preprint typeset using LATEX style emulateapj v. 9/08/03 MODELING THE DUST PROPERTIES OF Z ∼ 6 QUASARS WITH ART 2 — ALL-WAVELENGTH RADIATIVE TRANSFER WITH ADAPTIVE REFINEMENT TREE (2008)

Yuexing Li, Philip F. Hopkins, Lars Hernquist, Douglas P. Finkbeiner, Thomas J. Cox, Volker Springel, ...

The detection of large quantities of dust in z ∼ 6 quasars by infrared and radio surveys presents puzzles for the formation and evolution of dust in these early systems. Previously (Li et al....

Molecular Star Formation Rate Indicators in Galaxies (2007)

Narayanan, Desika, Cox, Thomas J., Shirley, Yancy, Dave, Romeel, Hernquist, Lars, Walker, Christopher K.

We derive a physical model for the observed relations between star formation rate (SFR) and molecular line (CO and HCN) emission in galaxies, and show how these observed relations are reflective of...

Rest-Frame Ultraviolet to Near Infrared Observations of an Interacting Lyman Break Galaxy at z = 4.42 (2007)

Younger, Joshua D., Huang, Jia-Sheng, Fazio, Giovanni G., Cox, Thomas J., Lai, Kamson, Hopkins, Philip F., ...

We present the rest-frame ultraviolet through near infrared spectral energy distribution for an interacting Lyman break galaxy at a redshift z=4.42, the highest redshift merging system known with...

An Observed Fundamental Plane Relation for Supermassive Black Holes (2007)

Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Robertson, Brant, Krause, Elisabeth

We study observed correlations between supermassive black hole (BHs) and the properties of their host galaxies, and show that the observations define a BH 'fundamental plane' (BHFP), of the form M_BH...

The Nature of CO Emission From z~6 Quasars (2007)

Narayanan, Desika, Li, Yuexing, Cox, Thomas J., Hernquist, Lars, Hopkins, Philip, Chakrabarti, Sukanya, ...

We investigate the nature of CO emission from z~6 quasars by combining non-LTE radiative transfer calculations with merger-driven models of z~6 quasar formation that arise naturally in LCDM...

Modeling the Dust Properties of z ~ 6 Quasars with ART^2 -- All-wavelength Radiative Transfer with Adaptive Refinement Tree (2007)

Li, Yuexing, Hopkins, Philip F., Hernquist, Lars, Finkbeiner, Douglas P., Cox, Thomas J., Springel, Volker, ...

The detection of large quantities of dust in z ~ 6 quasars by infrared and radio surveys presents puzzles for the formation and evolution of dust in these early systems. Previously (Li et al. 2007),...

A Cosmological Framework for the Co-Evolution of Quasars, Supermassive Black Holes, and Elliptical Galaxies: I. Galaxy Mergers & Quasar Activity (2007)

Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Keres, Dusan

(Abridged) We develop a model for the cosmological role of mergers in the evolution of starbursts, quasars, and spheroidal galaxies. Combining halo mass functions (MFs) with empirical halo occupation...

A Cosmological Framework for the Co-Evolution of Quasars, Supermassive Black Holes, and Elliptical Galaxies: II. Formation of Red Ellipticals (2007)

Hopkins, Philip F., Cox, Thomas J., Keres, Dusan, Hernquist, Lars

(Abridged) We develop and test a model for the cosmological role of mergers in the formation and quenching of red, early-type galaxies. Making the ansatz that star formation is quenched after a...

Photometric Properties of the Most Massive High-Redshift Galaxies (2007)

Robertson, Brant, Li, Yuexing, Cox, Thomas J., Hernquist, Lars, Hopkins, Philip F.

We calculate the observable properties of the most massive high-redshift galaxies in the hierarchical formation scenario where stellar spheroid and supermassive black hole growth are fueled by...

A Theoretical Interpretation of the Black Hole Fundamental Plane (2007)

Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Robertson, Brant, Krause, Elisabeth

We examine the origin and evolution of correlations between properties of supermassive black holes (BHs) and their host galaxies using simulations of major galaxy mergers, including the effects of...

The Co-Formation of Spheroids and Quasars Traced in their Clustering (2006)

Hopkins, Philip F., Lidz, Adam, Hernquist, Lars, Coil, Alison L., Myers, Adam D., Cox, Thomas J., ...

We compare observed clustering of quasars and galaxies as a function of redshift, mass, luminosity, & color/morphology, to constrain models of quasar fueling and spheroid-BH co-evolution. High...

Formation of z ~ 6 quasars from hierarchical galaxy mergers (2006)

Li, Yuexing, Hernquist, Lars, Robertson, Brant, Cox, Thomas J., Hopkins, Philip F., Springel, Volker, ...

The discovery of luminous quasars at redshift z ~ 6 indicates the presence of supermassive black holes (SMBHs) of mass ~10^9 Msun when the Universe was less than one billion years old. This finding...

An Upper Limit to the Degree of Evolution Between Supermassive Black Holes and their Host Galaxies (2006)

Hopkins, Philip F., Robertson, Brant, Krause, Elisabeth, Hernquist, Lars, Cox, Thomas J.

We describe a model-independent integral constraint which defines an upper limit to the allowed degree of evolution in the ratio of black hole (BH) mass to host galaxy luminosity or mass, as a...

Shapes of Stellar Systems and Dark Halos from Simulations of Galaxy Major Mergers (2006)

Novak, Gregory S., Cox, Thomas J., Primack, Joel R., Jonsson, Patrik, Dekel, Avishai

Using a sample of 89 snapshots from 58 hydrodynamic binary galaxy major merger simulations, we find that stellar remnants are mostly oblate while dark matter halos are mostly prolate or triaxial. The...

Molecular Outflows in Galaxy Merger Simulations with Embedded AGN (2006)

Narayanan, Desika, Cox, Thomas J., Robertson, Brant, Dave, Romeel, Di Matteo, Tiziana, Hernquist, Lars, ...

We study the effects of feedback from active galactic nuclei (AGN) on emission from molecular gas in galaxy mergers by combining hydrodynamic simulations which include black holes with a...

Simulated Molecular Gas Emission in Galaxy Mergers with Embedded AGN (2006)

Narayanan, Desika, Cox, Thomas J., Robertson, Brant, Dave, Romeel, Di Matteo, Tiziana, Hernquist, Lars, ...

We investigate the effect of embedded active galactic nuclei (AGN) in galaxy mergers on the CO molecular line emission by combining non-local thermodynamic equilibrium (LTE) radiative transfer...

The Relation Between Quasar and Merging Galaxy Luminosity Functions and the Merger-Induced Star Formation Rate of the Universe (2006)

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...

Lost and found dark matter in elliptical galaxies (2006)

Stoehr, Felix, Mamon, Gary A., Dekel, Avishai, Cox, Thomas J.

The kinematical properties of elliptical galaxies formed during the mergers of equal mass, stars+gas+dark matter spiral galaxies are compared to the observed low velocity dispersions found for...

The relation between quasar and merging galaxy luminosity functions and the merger-driven star formation history of the Universe (2006)

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...

The Evolution in the Faint-End Slope of the Quasar Luminosity Function (2005)

Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Robertson, Brant, Springel, Volker

(Abridged) Based on numerical simulations of galaxy mergers that incorporate black hole (BH) growth, we predict the faint end slope of the quasar luminosity function (QLF) and its evolution with...

Determining the Properties and Evolution of Red Galaxies from the Quasar Luminosity Function (2005)

Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Robertson, Brant, Springel, Volker

(Abridged) We study the link between quasars and the red galaxy population using a model for the self-regulated growth of supermassive black holes in mergers involving gas-rich galaxies. Using a...

The Luminosity Dependence of Quasar Clustering (2005)

Lidz, Adam, Hopkins, Philip F., Cox, Thomas J., Hernquist, Lars, Robertson, Brant

We investigate the luminosity dependence of quasar clustering, inspired by numerical simulations of galaxy mergers that incorporate black hole growth. These simulations have motivated a new...

A Unified, Merger-Driven Model for the Origin of Starbursts, Quasars, the Cosmic X-Ray Background, Supermassive Black Holes and Galaxy Spheroids (2005)

Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Robertson, Brant, Springel, Volker

We present an evolutionary model for starbursts, quasars, and spheroidal galaxies in which mergers between gas-rich galaxies drive nuclear inflows of gas, producing intense starbursts and feeding the...

The Evolution of the M-sigma Relation (2005)

Robertson, Brant, Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Hopkins, Philip F., Martini, Paul, ...

(Abridged) We examine the evolution of the black hole mass - stellar velocity dispersion (M-sigma) relation over cosmic time using simulations of galaxy mergers that include feedback from...

Luminosity-Dependent Quasar Lifetimes: A New Interpretation of the Quasar Luminosity Function (2005)

Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Robertson, Brant, Springel, Volker

We propose a new interpretation of the quasar luminosity function (LF), derived from physically motivated models of quasar lifetimes and light curves. In our picture, quasars evolve rapidly and their...

Luminosity-Dependent Quasar Lifetimes: Reconciling the Optical and X-ray Quasar Luminosity Functions (2005)

Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Robertson, Brant, Springel, Volker

We consider implications of our new model of quasar lifetimes and light curves for the quasar luminosity function (LF) at different frequencies and redshifts. In our picture, quasars evolve rapidly...

Black Holes in Galaxy Mergers: Evolution of Quasars (2005)

Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Martini, Paul, Robertson, Brant, ...

Based on numerical simulations of gas-rich galaxy mergers, we discuss a model in which quasar activity is tied to the self-regulated growth of supermassive black holes in galaxies. Nuclear inflow of...

A Merger-Driven Scenario for Cosmological Disk Galaxy Formation (2005)

Robertson, Brant, Bullock, James S., Cox, Thomas J., Di Matteo, Tiziana, Hernquist, Lars, Springel, Volker, ...

(Abridged) The violent hierarchical nature of the LCDM cosmology poses serious difficulties for the formation of disk galaxies. To help resolve these issues, we describe a new, merger-driven scenario...

A Physical Model for the Origin of Quasar Lifetimes (2005)

Hopkins, Philip F., Hernquist, Lars, Martini, Paul, Cox, Thomas J., Robertson, Brant, Di Matteo, Tiziana, ...

We propose a model of quasar lifetimes in which observational quasar lifetimes and an intrinsic lifetime of rapid accretion are strongly distinguished by the physics of obscuration by surrounding gas...

Simulations of Strong Gravitational Lensing with Substructure (2004)

Amara, Adam, Metcalf, R. Benton, Cox, Thomas J., Ostriker, Jeremiah P.

Galactic sized gravitational lenses are simulated by combining a cosmological N-body simulation and models for the baryonic component of the galaxy. The lens caustics, critical curves, image...

Star formation and feedback in simulations of interacting galaxies / (2004)

Cox, Thomas J.

Thesis (Ph.D.)--University of California, Santa Cruz, 2004.

Star formation and feedback in simulations of interacting galaxies / (2004)

Cox, Thomas J.

Thesis (Ph.D.)--University of California, Santa Cruz, 2004.