MIT Kavli Institute Directory

Paul Torrey

Hubble Postdoctoral Fellow Postdoctoral Scholar

Paul received his B.S. in Applied and Engineering Physics from Cornell University in 2008.  Paul then completed his Ph.D. work at Harvard University in 2014 under the supervision of Lars Hernquist studying galaxy formation and evolution.  In 2014, he joined MIT as a joint postdoctoral fellow between MIT and Caltech working with Mark Vogelsberger and Phil Hopkins on AGN/Quasar feedback."

Research interests: 

As part of his Ph.D thesis, Paul studied galaxy formation using numerical simulations by running and analyzing some of the first cosmological simulations using the new simulation code AREPO.  Paul's first AREPO related project was to understand the impact of the novel "moving mesh" hydro solver included in AREPO on the properties of galactic gas disks that formed in cosmological simulations. After that, Paul explored a number of galaxy relations (stellar mass function, star formation main sequence, mass-metallicity relation, etc.) as a function of redshift in our AREPO simulations with stellar and AGN feedback included.

During grad school Paul worked on understanding the heavy element distribution in galaxies, and understanding what that tells us about galaxy evolution. Heavy elements serve as tracers of gas flows, and are known to be being rapidly redistributed in merging/interacting galaxies. Paul worked with Lisa Kewley on the metallicity evolution of interacting galaxies by applying idealized galaxy merger simulations to build theoretical expectations for the nuclear metallicity and metallicity gradient evolution. Tha worked was continued in collaboration with Sara Ellison and Dave Patton by comparing the same idealized merger models against observations of enhanced star formation rates, depressed nuclear metallicities, and gas fraction evolution as seen through the Sloan Digital Sky Survey.

Representative publications: 

“The Metallicity Evolution of Interacting Galaxies”
Torrey, Cox, Kewley, & Hernquist, ApJ., 746, 102, 2012

“Moving Mesh Cosmology: The properties of gas disks”
Torrey, Vogelsberger, Sijacki, Springel, & Hernquist, , MNRAS., 427, 2224, 2012

“A physical model for cosmological simulations of galaxy formation: multi-epoch model validation”
Torrey, Vogelsberger, Genel, Sijacki, Springel, & Hernquist, MNRAS., 438, 1985, 2014

"Synthetic Galaxy Images and Spectra from the Illustris Simulation"
Torrey, Snyder, Vogelsberger, Hayward, Genel, et al., arXiv 1411.3717 (MNRAS, accepted)

“An analysis of the evolving comoving number density of galaxies in hydrodynamical simulations” , Torrey, Wellons, Machado, Griffen, Nelson, Rodriguez-Gomez, McKinnon, Pillepich, Ma, Vogelsberger, Springel, & Hernquist, MNRAS, 454, 2770, 2015

“An instability of feedback regulated star formation in galactic nuclei”, Torrey, Hopkins, Faucher-Giguere, Vogelsberger, Quataert, Keres, & Murray (MNRAS, under review)

“Galaxy evolution in comoving number density space ”, Torrey, Wellons, Ma, Hopkins, & Vogelsberger (MNRAS, under review)

For a complete list of publications, please see,%20Paul&db_key=PRE

Honors and awards: 

Hubble Fellowship, awarded 2016

— XSEDE Computing Grant (894k CPU hours; dollar equivalent value of $30,994.58)
— Unfunded CoI on NSF RUI Grant (Award: $260,000)