A popular astronomy lecture about Mars, including observations of the planet with small telescope. For more details see:
www.weizmann.ac.il/young
David Spergel from Princeton, one of the leading cosmologists in the world, will give the annual Bahcall Astrophysics Lecture at Tel Aviv University on Sunday Jan. 6, 2008, 16:00. Those interested in attending please contact Avishay and we can maybe work out some joint transportation.
A popular astronomy lecture about Comets, including observations of the comet Tuttle/P8 with small telescopes. For more details see:
www.weizmann.ac.il/young
A popular astronomy trip to observe the wonders of the winter night sky. For more details see:
www.weizmann.ac.il/young
A popular astronomy lecture about Saturn, including observations of the planet with small telescopes. For more details see:
www.weizmann.ac.il/young
A popular astronomy trip to observe the wonders of the spring sky with small telescopes. For more details see:
www.weizmann.ac.il/young
A popular astronomy lecture about the spring galaxies, including observations with small telescopes. For more details see:
www.weizmann.ac.il/young
A popular astronomy lecture about the sun, including observations with small telescopes. For more details see:
www.weizmann.ac.il/young
A popular astronomy trip to observe the wonders of the summer sky. For more details see:
www.weizmann.ac.il/young
A popular astronomy lecture about the moon, including observations of a partial lunar eclipse. For more details see:
www.weizmann.ac.il/young
Members of the astrophysics community are strongly encouraged to participate and present their work in the upcoming PANIC08, the 18th Int'l Conference on Particles and Nuclei, which will take place in Eilat, Israel (9-14/11/08).
The conference includes sessions on nuclear and particle astrophysics and cosmology, on neutrino physics, as well as many other topics of general interest at the interface between astrophysics / cosmology and nuclear / particle physics. There is also a special student program. Some financial assistance is available for students and postdocs.
The deadline for abstract submission has been extended to 15/7/08 (a week from now!)
For more information, see the conference website
For more details, see the homepage of the Israel Society for Astrobiology.
Condensed Matter Seminar - Weizmann Institute
Date : Wednesday, February 4, 2009 at 13:15
Place: Weissman Auditorium, Physics Bldg
Speaker: A. Fridman
Title: Fully Developed Turbulence in Accretion Discs
Abstract:
Efficiency of accretion discs is 6%-30% Mc2 (compare with 0.3% for nuclear reaction in the stellar cores). So accretion discs are the most effective engine in the Universe! Accretion discs are not rare monsters, but one from the prevalent kind of population in our Galaxy. The reason of this clear: accretion discs are observed in binaries which are about 80% of all stars in the Galaxy. More massive star in the binary turns into a compact object: white dwarf, neutron star or black hole in dependence on its mass. Using 3D numerical simulations we show the existence
of a spiral-vortex structure in an accretion disc in close binary stars. It is a density wave containing a one-armed spiral and an anticyclone vortex, caused by an over-reflection instability. Analytical consideration shows that this instability causes in turn a fully developed turbulence, the turbulent viscosity coefficient of which was estimated. Using the observed variations of the uneclipsed part of the light curves of cataclysmic binary stars we could estimate also the exponent of power turbulent spectrum. In our case, it is different from the Kolmogorov one, because Kolmogorov's hypothesis
Dear Colleagues,
The next Jerusalem Winter School will be held between Dec. 27, 2009 and
Jan. 5, 2010 on the topic: "Frontiers in High-Energy Astrophysics". The
registration form for the school is now available at the school
website
We would be grateful if you could bring the topic of the school to the
attention of excellent students and postdocs at your institution. Our
host organization, the Institute for Advanced Studies at the Hebrew
University of Jerusalem, can provide some financial aid for students and
post-docs if needed.
With best wishes,
Avi Loeb and Re'em Sari
Directors, Jerusalem Winter School
The 24th Annual Meeting of ILASOL (The Israel Society for Astrobiology and the Study of the Origin of Life) will take place on December 5, 2010 in the Botnar Auditorium, Belfer Building, Weizmann Institute of Science.
Everyone:
- Check that your details are correct (phone, room number, web page) in the Members page. To correct errors, update your internal services record.
- List your visitors in the Visitors page.
Faculty:
- Update your Research and Courses pages.
- Inform Tal of any planned meetings, so they can be
posted in the Lectures & Events page.
See Tal for questions, comments, requests for help.
We need to keep our website up-to-date and useful!
Everyone:
- Check that your details in the Members page (phone, fax, room number, link to personal webpage) are correct. To fix errors, update your personal record in the Internal services webpage.
Faculty:
- Update new / graduating students in the Members page.
- List your expected guests in the Visitors page.
- Update your Research and Courses pages.
- Inform Tal of any planned conferences, so they can be announced in the Lectures & Events page.
Please contact Tal with questions, comments, or requests for help.
Dear Colleagues:
In the tradition of co-operation between our two institutions, we are happy to announce a one-day meeting on AGN; the meeting will take place at the Technion, on Tuesday, February 15. We hope to revive a tradition of recurrent meetings on the subject between the two astrophysics groups. Our purposes are to share and discuss new observations and theories on active galactic nuclei and related subjects, and to advance inter-institutional collaboration. Students and faculty
are encouraged to present their works!
Please confirm your participation by sending a “yes” to email astro@physics.technion.ac.il, if you have not done so already (there are no registration fees). If you wish to give a talk, please also send the title.
Sexten Center for Astrophysics, July 18 to July 22, 2011.
The web page of the workshop is:
http://www.sexten-cfa.eu/it/conferenze/2011/details/11-chemical_evo
Ilya Gurwich will discuss the paper by Narayan and McClintock, "Observational Evidence for a Correlation Between Jet Power and Black Hole Spin" (MNRAS, 419, 1, L69).
Monday, Feb. 11th @ 11:15 in De Shalit
Andrey Katz will tell us about partially dissipative dark matter:
Based on observational tests and constraints on halo structure, dark matter is generally thought to be cold and essentially collisionless. We consider a much less constrained and potentially desirable scenario that we call Partially Interacting Dark Matter (PIDM) that contains self-interacting dark matter, but where it is not the dominant dark matter component. Even if PIDM contains only a fraction of the net dark matter density, the subdominant component's interactions can lead to interesting and potentially observable consequences. Our primary focus will be the special case of Partially Dissipative Dark Matter (PDDM), in which self-interactions allow the dark matter to lose enough energy to lead to rich dynamics similar to those in the baryon sector. We explore a simple model of PDDM, deriving the parts of parameter space in which PDDM cools efficiently and forms a disk within galaxies, and evaluating some of the possible observational signatures of such a disk. The most prominent signatures of such a scenario could be an enhanced indirect detection signature. Even though subdominant, the enhanced density at the center of the galaxy and possibly throughout the plane of the galaxy (depending on precise alignment) can lead to effectively large boost factors. We consider this to be the first step toward exploring a very rich array of new possibilities for dark matter dynamics. Partially interacting dark matter could also have significant effects on small-scale structure and could have other observational consequences that we mention.