Hopkins, Philip F., Younger, Joshua D., Hayward, Christopher C., Narayanan, Desika, Hernquist, Lars
We use a novel method to predict the contribution of normal star-forming galaxies, merger-induced bursts, and obscured AGN, to IR luminosity functions (LFs) and global SFR densities. We use empirical...
Hopkins, Philip F., Hernquist, Lars
The centers of bulges are formed dissipationally via gas inflows over short timescales: the 'starburst' mode of star formation (SF). Recent work has shown that detailed observations can be used to...
When Should We Treat Galaxies as Isolated? (2009)
Hopkins, Philip F., Keres, Dusan, Ma, Chung-Pei, Quataert, Eliot
Traditionally, secular evolution is defined as evolution of systems where the internal growth of structure and instabilities dominates the growth via external drivers (e.g. accretion/mergers). Most...
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...
A Maximum Stellar Surface Density in Dense Stellar Systems (2009)
Hopkins, Philip F., Murray, Norman, Quataert, Eliot, Thompson, Todd A.
We compile observations of the surface mass density profiles of dense stellar systems, including globular clusters in the Milky Way and nearby galaxies, massive star clusters in nearby starbursts,...
Metallicity Gradients at Large Galactocentric Radii Using the Near-infrared Calcium Triplet (2009)
Foster, Caroline, Proctor, Robert N., Forbes, Duncan A., Spolaor, Max, Hopkins, Philip F., Brodie, Jean P.
We describe a new spectroscopic technique for measuring radial metallicity gradients out to large galactocentric radii. We use the DEIMOS multi-object spectrograph on the Keck telescope and the...
Mergers and Bulge Formation in Lambda-CDM: Which Mergers Matter? (2009)
Hopkins, Philip F., Bundy, Kevin, Croton, Darren, Hernquist, Lars, Keres, Dusan, Khochfar, Sadegh, ...
We use a suite of semi-empirical models to predict galaxy merger rates and contributions to bulge growth as functions of merger mass, redshift, and mass ratio. The models use empirical halo...
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...
Quasar Feedback: More Bang for Your Buck (2009)
Hopkins, Philip F., Elvis, Martin
We propose a two-stage model for the effects of feedback from a bright quasar on the cold gas in a galaxy. It is difficult for feedback from near the accretion disk to directly impact dense molecular...
The Small Scatter in BH-Host Correlations & The Case for Self-Regulated BH Growth (2009)
Hopkins, Philip F., Murray, Norman, Thompson, Todd
Supermassive black holes (BHs) obey tight scaling relations between their mass and their host galaxy properties such as total stellar mass, velocity dispersion, and potential well depth. This has led...
Compact High-Redshift Galaxies Are the Cores of the Most Massive Present-Day Spheroids (2009)
Hopkins, Philip F., Bundy, Kevin, Murray, Norman, Quataert, Eliot, Lauer, Tod, Ma, Chung-Pei
Observations suggest that effective radii of high-z massive spheroids are as much as a factor ~6 smaller than low-z galaxies of comparable mass. Given the apparent absence of low-z counterparts, this...
When Is Secular Evolution Important? (2009)
Hopkins, Philip F., Keres, Dusan, Ma, Chung-Pei, Quataert, Eliot
This abstract has been withdrawn.
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...
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...
Are Most Low-Luminosity AGN Really Obscured? (2009)
Hopkins, Philip F., Hickox, Ryan, Quataert, Eliot, Hernquist, Lars
At low Eddington ratio (mdot), two effects make it harder to detect AGN given some selection criteria. First, they may transition to a radiatively inefficient state, changing SED shape and...
A Characteristic Division Between the Fueling of Quasars and Seyferts: Five Simple Tests (2008)
Hopkins, Philip F., Hernquist, Lars
Given the existence of the M_BH-sigma relation, models of self-regulated black hole (BH) growth require both a fuel supply and growth of the host bulge to deepen the potential, or else the system...
Hopkins, Philip F., Hernquist, Lars
We use the observed distribution of Eddington ratios as a function of supermassive black hole (BH) mass to constrain models of AGN lifetimes and lightcurves. Given the observed AGN luminosity...
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...
HeII Reionization and its Effect on the IGM (2008)
McQuinn, Matthew, Lidz, Adam, Zaldarriaga, Matias, Hernquist, Lars, Hopkins, Philip F., Dutta, Suvendra, ...
Observations of the intergalactic medium (IGM) suggest that quasars reionize HeII in the IGM at z ~ 3. We have run a set of 190 and 430 comoving Mpc simulations of HeII being reionized by quasars to...
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...
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...
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:...
The Self-Regulated Growth of Supermassive Black Holes (2008)
Younger, Joshua D., Hopkins, Philip F., Cox, T. J., Hernquist, Lars
We present a series of simulations of the self--regulated growth of supermassive black holes (SMBHs) in galaxies via three different fueling mechanisms: major mergers, minor mergers, and disk...
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...
Li, Yuexing, Hopkins, Philip F., Hernquist, Lars, Finkbeiner, Douglas P., Cox, Thomas J., Springel, Volker, ...
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)...
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....
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...
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),...
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...
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...
Is the dependence of spectral index on luminosity real in optically selected AGN samples? (2007)
Tang, Sumin, Zhang, Shuang Nan, Hopkins, Philip F.
We critically examine the dependence of spectral index on luminosity in optically selected AGN samples. An analysis of optically selected high-redshift quasars showed an anti-correlation of...
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...
Formation of z~6 quasars from hierarchical galaxy mergers (2007)
Li, Yuexing, Hernquist, Lars, Robertson, Brant, Cox, Thomas J., Hopkins, Philip F., Springel, Volker, ...
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...
An Evolutionary Model For Submillimeter Galaxies (2006)
Chakrabarti, Sukanya, Fenner, Yeshe, Hernquist, Lars, Cox, T. J., Hopkins, Philip F.
[abridged]We calculate multi-wavelength spectral energy distributions (SEDs) (spanning optical to millimeter wavelengths) from simulations of major galaxy mergers with black hole feedback which...
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...
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...
Kinematic Structure of Merger Remnants (2006)
Cox, T. J., Dutta, Suvendra N., Di Matteo, Tiziana, Hernquist, Lars, Hopkins, Philip F., Robertson, Brant, ...
We use numerical simulations to study the kinematic structure of remnants formed from mergers of equal-mass disk galaxies. In particular, we show that remnants of dissipational mergers, which include...
An Observational Determination of the Bolometric Quasar Luminosity Function (2006)
Hopkins, Philip F., Richards, Gordon T., Hernquist, Lars
We combine a large set of quasar luminosity function (QLF) measurements from the rest-frame optical, soft and hard X-ray, and near- and mid-infrared bands to determine the bolometric QLF in the...
Chakrabarti, Sukanya, Cox, T. J., Hernquist, Lars, Hopkins, Philip F., Robertson, Brant, Di Matteo, Tiziana
We calculate infrared spectral energy distributions (SEDs) from simulations of major galaxy mergers and study the effect of AGN and starburst driven feedback on the evolution of the SED as a function...
Fueling Low-Level AGN Activity Through the Stochastic Accretion of Cold Gas (2006)
Hopkins, Philip F., Hernquist, Lars
Using a simple description of feedback from black hole (BH) growth, we develop an analytic model for the fueling of Seyferts (low-luminosity AGN) and their relation to their host galaxies, Eddington...
The Shape, Multiplicity, and Evolution of Superclusters in LambdaCDM Cosmology (2006)
Wray, James J., Bahcall, Neta A., Bode, Paul, Boettiger, Carl, Hopkins, Philip F.
We determine the shape, multiplicity, size, and radial structure of superclusters in the LambdaCDM concordance cosmology from z = 0 to z = 2. Superclusters are defined as clusters of clusters in our...
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...
Hopkins, Philip F., Bundy, Kevin, Hernquist, Lars, Ellis, Richard S.
We compile a number of observations to estimate the time-averaged rate of formation or buildup of red sequence galaxies, as a function of mass and redshift. Comparing this with the mass functions of...
The evolution in the faint-end slope of the quasar luminosity function (2006)
Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Robertson, Brant, Di Matteo, Tiziana, Springel, Volker
Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Robertson, Brant, Springel, Volker
Determining the properties and evolution of red galaxies from the quasar luminosity function (2006)
Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Robertson, Brant, Springel, Volker
The evolution of the MBH-σ relation (2006)
Robertson, Brant, Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Hopkins, Philip F., Martini, Paul, ...
The fundamental scaling relations of elliptical galaxies (2006)
Robertson, Brant, Cox, Thomas J., Hernquist, Lars, Franx, Marijn, Hopkins, Philip F., Martini, Paul, ...
X-Ray emission from hot gas in galaxy mergers (2006)
Cox, T. J., Di Matteo, Tiziana, Hernquist, Lars, Hopkins, Philip F., Robertson, Brant, Springel, Volker
The kinematic structure of merger remnants (2006)
Cox, T. J., Dutta, Suvendra N., Di Matteo, Tiziana, Hernquist, Lars, Hopkins, Philip F., Robertson, Brant, ...
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...
How Much Mass do Supermassive Black Holes Eat in their Old Age? (2005)
Hopkins, Philip F., Narayan, Ramesh, Hernquist, Lars
We consider the distribution of local supermassive black hole Eddington ratios and accretion rates, accounting for the dependence of radiative efficiency and bolometric corrections on the accretion...
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...
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...
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...
X-ray Emission from Hot Gas in Galaxy Mergers (2005)
Cox, T. J., Di Matteo, Tiziana, Hernquist, Lars, Hopkins, Philip F., Robertson, Brant, Springel, Volker
We examine X-ray emission produced from hot gas during collisions and mergers of disk galaxies. To study this process, we employ simulations that incorporate cosmologically motivated disk-galaxy...
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...
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, ...
Black holes in galaxy mergers: evolution of quasars (2005)
Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Martini, Paul, Robertson, Brant, ...
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
Hopkins, Philip F., Hernquist, Lars, Cox, Thomas J., Di Matteo, Tiziana, Robertson, Brant, Springel, Volker
Cluster Alignments and Ellipticities in LCDM Cosmology (2004)
Hopkins, Philip F., Bahcall, Neta, Bode, Paul
The ellipticities and alignments of clusters of galaxies, and their evolution with redshift, are examined in the context of a Lambda-dominated cold dark matter cosmology. We use a large-scale,...
Dust Reddening in SDSS Quasars (2004)
Hopkins, Philip F., Strauss, Michael A., Hall, Patrick B., Richards, Gordon T., Cooper, Ariana S., Schneider, Donald P., ...
We explore the form of extragalactic reddening toward quasars using a sample of 9566 quasars with redshifts 0 0.2, where the extinction is relative to quasars with modal colors. Reddening is...