Calendar
2010
September-December
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Wed, Nov 24 |
TCC / Cosmos Seminar The Atacama Cosmology Telescope: The Present and the Future [abstract] |
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Mon, Nov 22 |
TCC / Astro Theory Seminar Self-regulated Evolution of Galaxies and Supermassive Black Holes [abstract] |
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Thurs, Nov 18 |
TCC / Exgal Seminar Exploring the Dark Universe with Gravitational Lensing [abstract] |
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Thu, Nov 11 |
Special TCC Seminar A Weak Lensing Study of the Coma Cluster, and a Higher-Order Moment Approach to Weak Lensing [abstract] |
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Mon, Nov 8 |
TCC / Astro Theory Seminar Measuring the Universe: Recent Developments in Baryon Acoustic Oscillations [abstract] |
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Mon, Oct 18 |
TCC / Astro Theory Seminar Looking for WIMPs with the Cryogenic Dark Matter Search (CDMS) [abstract] |
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Wed, Oct 6 |
TCC / Stellar Seminar The Square Kilometre Array [abstract] |
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Tue, Oct 5 |
TCC / Colloquium Equivalence Principle and Cosmic Acceleration [abstract] |
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Mon, Oct 4 |
TCC / Astro Theory Seminar Dynamics of Bubble Collisions: A New Mechanism for Creating Bubbles in the Early Universe [abstract] |
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Wed, Sep 8 |
TCC / Cosmos Seminar Optimizing a ground-based CMB polarization experiment [abstract] |
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Wed, Sep 1 |
TCC / Cosmos Seminar Cosmic Rays and the Quest for New Physics [abstract] |
March-August
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Fri, Mar 12 |
TCC / Special Seminar The Formation of the First Stars: Simulations on a Moving Mesh [abstract] Thomas Greif, Max Planck Institut for Astrophysics, Garching, Germany |
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Mon, Mar 1 |
TCC / Special Supernova Seminar Diversities of the Type Ia Supernova Light Curves from the Ejecta Velocity: Evidence for Systematics in SN Ia distances [abstract] We present a differential analysis of the type SNe Ia supernova (SN Ia)
light curves, in terms of the classifications by the ejecta velocity of
SiII as proposed by Wang et al. (2009). We found that a single light-curve
parameter such as the decline rate dm_{15} or stretch factor s is not
enough to account for the diversities of the light curves (especially in
B) observed between the subsample with higher v_{eject} (or "HV" group)
and the one with the normal values (or "Normal" group). The light curves
of the HV SNe Ia are found to rise faster in the early phase of the explosion,
with respect to the Normal ones with similar dm_{15}. In particular, the
tail portion of the B-band light curves (at times 30 days < t < 90 days
after maximum light) is relatively brighter and evolves in a slower fashion,
while the variation is small in V. As a result, their B- V colors become
bluer at a pace faster than that predicted by the Lira-Phillips relation
during the nebular phase. One more interesting feature is that the flux
excess measured at t = 60 days from the B-band tail is found to correlate
with the ejecta velocity, a larger v_{eject} corresponding to a brighter tail.
Such a velocity-dependent variation in the tail emission is perhaps
related to environmnts surrounding the progenitors, or to the initial
conditions of the exploding white dwarf. The systematic effect of this
finding on the supernova distance determinations from the light curves
differences are discussed. Xiaofeng Wang, Texas A&M University |
January-February
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Mon, Feb 22 |
TCC / Theoretical Astrophysics Seminar The 7-year WMAP Observations: Cosmological Interpretation [abstract] |
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Sat, Feb 6 |
Eighteenth Annual Great Lecture in Astronomy Walk Softly When Exploring the Dark Side of the Universe: Black Holes, Dark Matter and Dark Energy [abstract] |
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Mon, Feb 1 |
TCC / Theoretical Astrophysics Seminar Cosmic Voids as a Cosmological Probe [abstract] |