Seminars
Our seminars take place in the lecture room of the building at
Praha–Sporilov.
Next seminar:
28.01.2013 14:00
Bartosz Dabrowski
Astronomical Institute, Academy of Sciences, Ondrejov
News from ALMA
Abstract
Bartosz Dabrowski
News from ALMA
The Atacama Large Millimeter/submillimeter Array (ALMA) is a major new facility for world astronomy. When completed in 2013, ALMA will consist of a giant array of 12-m antennas, with baselines up to 16 km, and an additional compact array of 7-m and 12-m antennas to greatly enhance ALMA's ability to image extended targets. Construction of ALMA started in 2003. The ALMA project is an international collaboration between Europe, East Asia and North America in cooperation with the Republic of Chile.
ALMA Early Science Cycle 1 observations will start in January 2013 and span 10 months. It is anticipated that approximately 800 hours of array time will be available for Cycle 1 projects.
I will present the Czech ALMA Node activity during the previous year.
Previous seminar:
03.01.2013 14:00
Ondrej Pejcha
Ohio State University
The explosion mechanism of core-collapse supernovae and its observational signatures
Abstract
Ondrej Pejcha
The explosion mechanism of core-collapse supernovae and its observational signatures
Abstract: Many massive stars explode as core-collapse supernovae. Supernova simulations show that the shock wave accompanying formation of the proto-neutron star evolves into a quasi-static accretion shock and it proves difficult to revive its outward propagation. The stalled accretion shock turns into explosion when the neutrino luminosity from the collapsed core exceeds a critical value L_crit (the "neutrino mechanism"). I will show the connection between the steady-state isothermal accretion flows with bounding shocks and the neutrino mechanism: there is a maximum, critical sound speed above which it is impossible to maintain accretion with a standoff shock. I will derive the "antesonic" condition, which characterizes the transition to explosion over a broad range in accretion rate, PNS properties and microphysics. Additionally, I will characterize the effects of accretion luminosity and collective neutrino oscillations on L_crit. The physics of the explosion mechanism and the progenitor structure are imprinted in the observed distribution of neutron star masses. I will use Bayesian analysis to model the double neutron star mass distribution to infer the properties of the progenitor binary population, fallback during the explosion, and constrain the mass coordinate where the explosion develops.
The Physics of the Neutrino Mechanism of Core-collapse Supernovae
http://adsabs.harvard.edu/abs/2012ApJ...746..106P
Effect of collective neutrino oscillations on the neutrino mechanism
of core-collapse supernovae
http://adsabs.harvard.edu/abs/2012MNRAS.425.1083P
The observed neutron star mass distribution as a probe of the
supernova explosion mechanism
http://adsabs.harvard.edu/abs/2012MNRAS.424.1570P
The progenitor dependence of the neutrino mechanism of core-collapse supernovae
Pejcha & Thompson, in preparation
If you would like to give a seminar in our group, please contact Vladimir Karas or Jaroslav Hamersky.
Archive
2013,
2012,
2011,
2010,
2009,
2008,
2007,
2006,
2005,
2004
