From CASS
Seminars
The CASS Astrophysics Seminar features world-class astrophysicists from around the world speaking on current topics of research. Presentations are aimed at the graduate and post-graduate level, but are open to the general public. CASS seminars take place on Wednesdays from 4:00 - 5:00 p.m. in 280 SERF, unless otherwise noted. The organizers are Prof. Adam Burgasser and Dr. Alexei Kritsuk.
Upcoming Seminars
Winter 2012
| Special Astro Seminar: Friday 12-1pm in SERF 280
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| 2/17/2012
| Enectali Figueroa-Feliciano
Assistant Professor of Physics
MIT
| "From Millikelvin to Megakelvin: Using cold detectors to study the hot X-ray universe"
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| Abstract
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| Supernovae are the violent (and bright) deaths of massive stars and white dwarfs. These energetic events can briefly outshine their host galaxy, and are central players in galactic structure formation and the creation and dispersal of the heavy elements. Supernova Remnants (SNRs) are the remains left behind after each stellar demise, and carry the imprints of the explosion and of the interactions between the ejected stellar material and its surroundings. These interactions produce shocks which often heat the material into million-degree plasmas emitting at X-ray energies. Through high-resolution, precision X-ray spectroscopy of this extended, diffuse plasma, we can obtain precise measurements of the kinematics, temperatures, and abundances in SNRs, and thereby probe the complex physics of these astronomical objects in novel ways. We have developed a new sounding rocket experiment called Micro-X that uses a 128-pixel transition-edge sensor microcalorimeter array coupled to a grazing-incidence X-ray optic to obtain imaging spectra at a resolution between 2-4 eV in the 0.2 to 3 KeV band. The first flight is scheduled for later this year, and will be the first space implementation of this technology. In this talk I will describe the science and technology behind Micro-X, its first planned mission to study the Puppis A SNR, and briefly touch on other applications of transition-edge sensors for dark matter detection and neutrino physics.
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| Special Astro Seminar: Tuesday 12-1pm in SERF 280
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| 2/21/2012
| Ruth Murray-Clay
Research Scientist
Harvard/CfA
| TBD
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| 2/22/2012
| Simon Glover
Postdoctoral Research Fellow
Institut fur Theoretische Astrophysik
| "Molecule formation in the turbulent ISM: Insights from numerical models"
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| Abstract
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| Within the past few years, it has become possible to perform high-resolution three-dimensional simulations of molecular cloud formation and evolution that trace the thermal and chemical history of the gas in addition to its dynamical history. In this talk, I will discuss some of the insights that these simulations provide into the behaviour of real molecular clouds. In particular, I will discuss what we can learn about the physical processes responsible for determining the so-called "X-factor", the conversion factor relating the CO luminosity of a Galactic giant molecular cloud (GMC) to its H2 mass. I will also present some results from recent work exploring the role that molecular cooling plays in determining the star formation rate within GMCs.
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| 2/29/2012
| Jessica Lu
NSF Postdoctoral Fellow
U. Hawaii
| "Star formation in extreme environments"
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| 3/7/2012
| Vardha Bennert
Asst. Professor
CalPoly San Luis Obispo
| "The Black-Hole Mass Scaling Relations of Active Galaxies: From the Local Universe out to a Lookback Time of 10 Gyrs"
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| Abstract
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| Supermassive Black Holes (BHs) seem to be ubiquitous in the center of spheroids - elliptical galaxies and bulges of spirals. The tight empirical relations between the mass of the BH and the properties of the host-galaxy spheroid (stellar velocity dispersion sigma, luminosity L, and stellar mass M) discovered in the local Universe indicate a close connection between the growth of BHs and the formation and evolution of galaxies. To understand the origin of these scaling relations, I will present results from a unique three-fold approach. (i) From a sample of ~100 Active Galactic Nuclei (AGNs) in the local Universe, we build a robust baseline of the BH mass scaling relations (MBH-sigma, MBH-L, MBH-M), combining spatially-resolved Keck spectroscopy with SDSS imaging. (ii) We study the evolution of the MBH-sigma and MBH-L relations out to a look-back time of 4-6 Gyrs using Keck spectra and HST images. Our results indicate that black hole growth precedes bulge assembly. (iii) We extend this study out to the pivotal cosmic time between the peak of AGN activity and the establishment of the present-day Hubble sequence, a look-back time of 8-10 Gyrs. We measure spheroid stellar masses using deep multi-color HST images and determine the MBH-M relation. Combining results from (i-iii) allows us to test the hypothesis that evolution is driven by disks being transformed into bulges.
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| 3/14/2012
| Dave Tsang
Sherman Fairchild Fellow
Caltech
| "Resonant Shattering of Neutron Star Crusts"
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| Special Astro Seminar: Friday 12-1pm in SERF 280
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| 3/16/2012
| Katrien Kolenberg
Postdoctoral Researcher
Harvard CfA
| TBD
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| 3/21/2012
| Andrey Kravtsov
Assoc. Professor of Physics
U. Chicago
| TBD
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