Date

Speaker

Title

Aug 27

No talk scheduled.

Sept 3

Steve Finkelstein

University of Texas at Austin

Organizational Meeting.

Sept 10

Rebecca Larson

University of Texas at Austin

"Using Herschel Far-Infrared Photometry to Constrain Star Formation Rates in CLASH Cluster Galaxies"

Sept 17

Sabrina Cales

Yale University

(host: Shardha Jogee) Title: TBA.

Sept 24

Xingxing Huang

Johns Hopkins University

"Extreme Strong Emission Line Galaxies at z ~ 1-2 and the Implications for High Redshift Galaxies" (host: Steve Finkelstein.)

abstract

Oct 1

Keely Finkelstein

University of Texas at Austin

"Probing the Physical Properties of High-Redshift Lyman-Alpha Emitters with Spitzer"

abstract

Oct 8

Speaker: TBD

Affiliation: TBD

No talk scheduled.

Oct 15

Greg Zeimann

University of Texas at Austin

"Why Dust Attenuation at High Redshift in Truly a NUISANCE Parameter."

abstract

Oct 22

Jimmy

UT Austin: Physics Dept.

"The Fundamental Metallicity Relation with Dwarf Irregular Galaxies"

abstract

Oct 29

(1) Matt Stevans
(2) Akim Yildirim

(1)University of Texas at Austin
(2)University of Heidelberg, Germany

(1) "The Hobby Eberly Telescope Dark Energy Experiment (HETDEX) and Galaxy Evolution"

(2) "Compact Elliptical Galaxies in the Local Universe"

Nov 5

Bev Wills

University of Texas at Austin

"Magnetic Field Alignment in Relativistic Jets of Active Galactic Nuclei"

Nov 12

John Kormendy

University of Texas at Austin

"Fritz Zwicky: Personal Recollections"

Nov 19

Andrew Leung

University of Texas at Austin

"Bayesian Redshift Classification of Emission-line Galaxies in HETDEX"

Nov 26

Thanksgiving Day Holiday. UT Closed. No talk scheduled.

Dec 3

Nancy Kawinwanichakij

Texas A&M University

"What do Satellite Galaxies tell us about their Dark Matter Halos and Galaxy Quenching?"

We study the statistical distribution of satellites around star-forming and quiescent central galaxies at 1 < z < 3 using imaging from the FourStar Galaxy Evolution Survey (ZFOURGE) and the Cosmic Assembly Near-IR Deep Extragalactic Legacy Survey (CANDELS). Massive quiescent centrals, log(M/M_sol ) > 10.78, have about two times the number of satellites compared to star-forming centrals even after accounting for differences in the centrals' stellar-mass distributions. Compared to the Guo et al. semi-analytic model, we find that the difference in satellites counts corresponds to the same difference in halo mass, with quiescent centrals having halo masses approximately two times larger than star-forming centrals at fixed stellar mass. We use a simple toy model that relates halo mass and quenching, and we find that while halo quenching may be an important mechanism, it is unlikely to be the only factor driving quenching. To get additional clues, we measure the evolution of the quiescent fraction and quenching efficiency of satellites around star-forming and quiescent central galaxies by combining imaging from three deep near-infrared-selected surveys (ZFOURGE/CANDELS, UDS, and UltraVISTA). We find that satellite galaxies are more quenched compared to mass-matched samples of field galaxies. We also observe "galactic conformity": satellites around quiescent centrals are more likely to be quenched compared to the satellites around star-forming centrals. In our sample, this conformity signal is significant at > 3sigma for 0.6 < z < 1.6. We test if galactic conformity is due to a difference in the typical halo mass of star-forming and quiescent centrals. We find that the difference in halo mass can explain most of the conformity signal in our data. However, there still remains evidence for conformity, particularly at 0.6 < z < 0.9. This suggests that satellite quenching is connected to the star-formation properties of the central, beyond the mass of the halo.

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