Description
poster session + beer/refreshment
Dr
Thierry Foglizzo
(CEA-Saclay, France)
10/08/2011, 17:30
Massive stars end their life with the gravitational collapse of their core and the
formation of a neutron star. Their explosion as a supernova depends on the revival of a
spherical accretion shock, located in the inner 200km and stalled during a few hundred
milliseconds. Numerical simulations suggest that an asymmetric explosion is induced by
a hydrodynamical instability named SASI....
Mr
itay Rabinak
(Weizmann institute of science)
10/08/2011, 17:35
We derive a simple approximate model describing the early, up to a few days,
UV/optical supernova emission, which is produced by the expansion of the
outer hundredth solar mass of the shock-heated envelope, following the shock
breakout and preceding the optical emission driven by radioactive decay. Our
model includes an approximate description of the time dependence of the
opacity...
Dr
Rhaana Starling
(University of Leicester)
10/08/2011, 17:40
A growing number of long Gamma-Ray Bursts are indisputably associated with
core-collapse supernovae, discovered through optical spectroscopy and/or photometry
of the GRB afterglow. Three such bursts show evidence of a thermal component in the
early X-ray afterglow emission, claimed by some to be a signature of supernova shock
breakout. This component could equally be attributed to central...
Mr
Ondrej Pejcha
(Department of Astronomy, Ohio State University)
10/08/2011, 17:45
The mechanism of core-collapse supernovae is unknown. Despite considerable effort,
most simulations of supernovae are not successful, and it has proven difficult to
revive the stalled accretion shock, particularly for more massive stellar
progenitors. Although it is known that the stalled accretion shock turns into
explosion when the neutrino luminosity from the collapsed core exceeds a...
Patrick Slane
(Harvard-Smithsonian Center for Astrophysics)
10/08/2011, 17:50
As a pulsar wind nebula evolves inside its host supernova remnant, its gamma-ray
emission becomes increasingly brighter due to the buildup of energetic particles
injected by its pulsar. When the SNR reverse shock collides with the PWN, the
resulting increase in the magnetic field results in rapid synchrotron losses,
modifying the particle spectrum of the nebula. Gamma-ray observations of...
Dr
Dovi Poznanski
(UC Berkeley & LBL)
10/08/2011, 17:55
Dust extinction is generally the least tractable systematic uncertainty in astronomy,
and particularly in supernova science. Often in the past, studies have used the
equivalent width of Na I D absorption measured from low-resolution spectra as proxies
for extinction, based on tentative correlations that were drawn from limited data sets.
We have recently shown, based on 443...
Dr
George Sonneborn
(NASA Goddard Space Flight Center)
10/08/2011, 18:00
The nature and quantity of dust produced in supernovae (SNe) is still poorly
understood. Recent IR observations of freshly-formed dust in supernova remnants
(SNRs) have yielded significantly lower dust masses than predicted by theoretical
models and observations high-redshift galaxies. The Crab Nebula's pulsar wind is
thought to be sweeping up freshly-formed SN dust along with the SN...
Dr
Ross Church
(Lund University)
10/08/2011, 18:05
The presence of a binary companion can have a significant effect on a supernova
explosion. Mass transfer affects the evolution of the stars; a massive star
may transfer so much mass that it fails to explode as a supernova, whilst
conversely an accreting lower-mass star may gain enough material to cause it to
explode. Massive stellar cores in close binaries can be spun up by...
Ms
Io Kleiser
(University of California at Berkeley)
10/08/2011, 18:10
The vast majority of Type II supernovae (SNe) are produced by red supergiants
(RSGs), but SN 1987A revealed that blue supergiants (BSGs) can produce members
of this class as well, albeit with some peculiar properties. This best studied event
revolutionized our understanding of SNe, and linking it to the bulk of Type II events
is essential. We present here optical photometry and...
Mr
Takashi Moriya
(IPMU, University of Tokyo)
10/08/2011, 18:15
We investigate the effect of non-steady dense mass loss on the shock breakout in
dense wind. We found that the effect of the dense wind from non-steady mass loss can
account for two types of interaction-powered luminous supernovae: 06gy-like LSNe
which show the narrow emission lines from wind and 08es-like LSNe which do not
show them.
Dr
Salvatore Orlando
(INAF - Osservatorio Astronomico di Palermo)
10/08/2011, 18:20
During the evolution of SNRs, Rayleigh-Taylor (RT) instability develop at the contact
discontinuity between the ejecta and the shocked interstellar medium (ISM). The
nonlinear instability evolves, giving rise to a turbulent structure with
preferentially radial components, the so-called RT fingers. Current multi-dimensional
models of SNRs describe the development of these structures....
Francesco Taddia
(Stockholm University, department of Astronomy)
10/08/2011, 18:25
Supernova 1987A revealed that a blue supergiant (BSG) can end its life as a
core-collapse supernova (SN). Such objects show peculiar properties distinguishing
them from ordinary Type IIP SNe, whose progenitors are believed to be red
supergiants. A similarity among 1987A-like events include a long rise to maximum
and peak luminosities which are fainter than Type IIP SNe and mainly powered...
Dr
Omer Bromberg
(Racah Institute of Physics, The hebrew University, Jerusalem, Israel)
10/08/2011, 18:30
According the Collapsar model long GRBs (LGRBs) arise during the collapse of
a massive star and involve the emergence of a relativistic jet through the envelope
of the exploding star.
This model naturally explains the links between LGRBs and SNe, such as the
the association of half a dozen LGRBs with broad-line Ic SNe.
However, a closer look at this association reveals that four out of...
Dr
Patrick BLOTTIAU
(CEA, DAM, DIF, Arpajon, France and Laboratoire Univers et Thรฉories, Observatoire de Paris, Meudon, France)
10/08/2011, 18:35
A complete description of the core-collapse supernova mechanism requires an
appropriate treatment of both the hydrodynamics and the microphysics.
Indeed, despite the crucial role played by hydrodynamics (e.g. hydrodynamical
instabilities, rotation, convection or General Relativistic effects), to produce type
II supernovae explosions, the influence of nuclear physics inputs on the outcome...
Dr
Tabetha Hole
(East Tennessee State U.)
10/08/2011, 18:40
Constraining the structure and asymmetries within supernova (SN) ejecta is of great
importance to understanding the explosion mechanism and for constructing better
models of SN feedback mechanisms. SN forbidden line profiles at later times, when
the ejecta is optically thin in the continuum, provide a potential diagnostic of
densities and the distribution of individual ionic species...
Dr
Bernhard Mueller
(MPA Garching)
10/08/2011, 18:45
The collapse of an iron core to a neutron star and the subsequent
supernova explosion are among the greatest challenges in
computational astrophysics due to the complex interplay of
multi-dimensional hydrodynamics, neutrino transport, and
strong-field gravity. Due to the compactness of the newly-born
proto-neutron star and the occurrence of high velocities (up to
~0.3c), general...
Dr
Rino Bandiera
(INAF - Osservatorio Astrofisico di Arcetri)
10/08/2011, 18:55
Bamba et al. (2010) used deep X-ray observations, with Chandra and Suzaku, to
estimate the sizes of faint and old Pulsar Wind Nebulae (PWNe). They found a steady
increase in size with the nebular age, up to ages of about 10^5 yr. Their conclusion
was that these PWNe keep expanding up to large ages, in apparent contradiction
with the idea that a reverse shock from the associated...
Dr
Yudai Suwa
(Kyoto University)
10/08/2011, 19:00
Core-collapse supernovae are violent explosion of massive stars at their end of life. The standard model of the supernova
explosion is so-called ``delayed explosion scenario'', in which the neutrino heating plays an important role. In order to
investigate whether this model works properly, we must solve raditation hydodynamic equations incorporating the neutrino
radiative transfer with...
Dr
Leloudas Giorgos
(Dark cosmology Centre)
10/08/2011, 19:05
Stripped-envelope core-collapse SNe are supposed to result
from the explosions of
stars that have lost their outer hydrogen layers but the
exact nature of their
progenitor and (possible) companion stars remains unknown.
By comparing their
locations to those of WR stars we show that they are indeed
compatible. Furthermore,
SN Ib locations are more closely related to those of WN
stars,...
Dr
Tea Temim
(NASA Goddard Space Flight Center / ORAU)
10/08/2011, 19:10
We present deep Chandra observations and Spitzer Space Telescope infrared (IR)
spectroscopy of the shell in the composite supernova remnant (SNR) Kes 75. The
remnant is composed of a central pulsar wind nebula (PWN) and a bright partial shell
in the South that is visible at radio, IR, and X-ray wavelengths. The X-ray emission
from the shell is dominated by a two-component thermal model...
Dr
Gaston Folatelli
(IPMU, University of Tokyo)
10/08/2011, 19:15
We present a detailed study of the Type Ib/c SN 2010as based on
optical and near-infrared imaging and spectroscopy, plus radio
observations. The data span from about two weeks before to
about 150 days after maximum light. SN colors and spectra indicate
this object suffered considerable reddening by dust. Intermediate resolution
X-Shooter spectra cover the time of
maximum light and show...
Dr
Shin-ichiro Fujimoto
(Kumamoto National College of Technology)
10/08/2011, 19:20
We examine explosive nucleosynthesis during neutrino-driven, aspherical supernova
(SN) explosion
aided by standing accretion shock instability, based on two-dimensional hydrodynamic
simulations
of the explosion of 15-40$M_\odot$ stars with zero metallicity.
The magnitude and asymmetry of the explosion energy are estimated with the simulations,
for a given set of neutrino luminosities...
Dr
Jennifer Hoffman
(University of Denver)
10/08/2011, 19:25
Supernovae of all types are known to be polarized, and many display complex line
polarization effects that evolve over time as the supernova evolves. Such behavior
reveals details of the clumpy nature of the ejecta, as well as illuminating the
characteristics of the circumstellar material lost by the star in its pre-supernova
evolution. With the aid of diagnostic tools developed through...
Ms
Eveline Helder
(Pennsylvania State University)
10/08/2011, 19:35
The evidence for supernova remnants as the main sources for Galactic cosmic rays has
accumulated over the past decades. However, the physics of the acceleration mechanism
is still unclear. In particular, there is a lack of empirical data to test current
shock acceleration models.
RCW 86 is an excellent source to test these models, as the shock velocities of the
remnant vary by an order...
Mr
Jason Dittmann
(Harvard University)
10/08/2011, 19:40
We present time series radio data of the type Ic supernova SN 2004C taken with the
VLA from January 2004 through April 2009 at 4.9 GHz, 8.5 GHz, 15 GHz, and 22
GHz. We also present 3 epochs of Chandra data taken 110, 170, and 1150 days after
the initial explosion. We model our radio data for each epoch with a synchrotron self
absorbed spectrum, and apply the dynamical model of...
Ms
Sarah Wellons
(Harvard University)
10/08/2011, 19:45
We present extensive radio observations of the nearby Type Ibc
supernovae (SNe Ibc) 2004cc, 2004dk, and 2004gq spanning $\Delta
t\approx 8-1800$ days after explosion. Using a dynamical model
developed for synchrotron emission from a slightly decelerated
blastwave, we estimate the velocity and energy of the fastest ejecta
and the density profile of the circumstellar medium. The...
Ms
Kate Alexander
(Harvard-Smithsonian Center for Astrophysics)
10/08/2011, 19:50
We present radio observations of the type Ic supernova 1994I, reanalyzed as part of a
search for radio transients in M51 conducted using archival data from the Very Large
Array. The data includes a detailed 4.9 GHz light curve of SN 1994I and three
spectra of this object from epochs on April 10, May 4, and August 8, 1994, each
spanning frequencies of 1.5-22.5 GHz. We find that the...
