Next Talk: June 11

Speaker:     Timothy Davis  ESO
The cold ISM in massive early-type galaxies: origin, morphology, kinematics, and black-holes


Recently, massive early-type galaxies have shed their 'red-and-dead' moniker, thanks to the discovery that many host residual star formation. As part of the ATLAS-3D project, we have conducted a complete, volume-limited survey of the molecular gas in 260 local early-type galaxies with the IRAM-30m telescope and the CARMA interferometer, in an attempt to understand the fuel powering this star formation. We find that around 22% of early-type galaxies in the local volume host molecular gas reservoirs, with central discs, polar structures and rings being common. This detection rate is independent of galaxy luminosity and environment, but does depend on the galaxy kinematics. In this talk I will describe these observations, and what they can tell us about the regeneration of red-sequence galaxies. I will show how kinematic misalignment measurements, gas-to-dust ratios and derivations of the gas phase metallicity, combined with simulations and models, can be used to put constraints on the origin of the cold ISM in these systems. It seems that in the field mergers and/or cold gas accretion dominate the gas supply, while in clusters internal secular processes become more important. Finally I will show that molecular gas is an excellent kinematic tracer, better than most others at tracing the underlying potential of galaxies. This provides a powerful tool for both studying the large scale mass and light distribution in galaxies (e.g. with the CO Tully Fisher relation), and probing dark objects lurking at the hearts of galaxies. I will show using high-resolution interferometric observations that one can resolve molecular gas kinematics within the sphere of influence of local supermassive black-holes, and present the first ever black-hole mass measured in this manner.

Full Schedule: Spring 2014

Date Speaker Title
January 15 Bob Armstrong
  Univ. of Pennsylvania
A Vision of Precision: Weak Lensing with the Dark Energy Survey and Beyond
January 22 Vinu Vikram
  Univ. of Pennsylvania
Astrophysical Tests of Gravity: Constraints from the Nearby Universe
January 29 Unscheduled
February 5 Emanuele Castorina
On the Universality of the Halo Mass Function & Halo Bias in Neutrino Cosmologies
February 12 Andrea Kulier
  Princeton U.
Tracing Mass and Light in the Universe: Where is the Dark Matter?
February 19 Pau Amaro-Seoane
  Albert Einstein Institute
Stellar Dynamics and Galactic Nuclei: Testing Mass Segregation with Red Giants and the Connection with GR
February 26 Rualdo Soto-Chavez
  Princeton U.
Chorus Waves in The Earth's Magnetophere
March 5 Annalisa Pillepich
  Harvard, CfA
Buillding Late Type Spiral Galaxies by In-Situ and Ex-Situ Star Formation
March 12 Tim Morton
  Princeton U.
Extracting Exoplanet Demographics from the Kepler Survey
March 19 Emily Rauscher
  Princeton U.
Peering into the 3D Atmosphers of Exoplanets
March 26 Cancelled
April 2 Kedron Silsbee
  Princeton U.
Rocky planet formation in binary systems
April 9 Assaf Horesh
Exploring the Dynamic Radio Sky
April 16 Cristobal Petrovich
  Princeton U.
Kozai-Lidov migration and the formation of Hot and Warm Jupiters
April 23 Jeffrey Ambroziak
  Jeff's Basement
Anaglyphic Mapping of Planetary Surfaces Using the Ambroziak Infinite Perspective Projection (AIPP)
April 30 Guinevere Kauffmann
  Max-Planck-Institut fur Astrophysik, Garching
Atomic and Molecular Gas Properties of Nearby Galaxies
May 7 Kazumi Kashiyama
  Penn State
Cosmological(?) Fast Radio Bursts
May 21 Svitlana Zhukovska
  MPA, Heidelberg
Variations of Interstellar Grain Properties As A Function of Environment
May 28 Linda Watson
  Harvard, CfA
Star Formation in Nearby Late-type Galaxies