TUESDAY, MAY 8

12:30 pm: Institute for Theory and Computation (ITC) Seminar. "Galaxy and Cluster Physics with SZ Surveys: The Atacama Cosmology Telescope," Dr. Raul Jimenez, University of Pennsylvania. Pratt Conference Room.

Abstract: The Atacama Cosmology telescope is the highest ground-based telescope in the world. It is scanning the sky at 3 frequencies to detect hot gas via the SZ effect and the primordial CMB signal. Besides the impact the survey will have in cosmology, it will also open a new window to study the properties of hot gas in galaxies, groups and clusters of galaxies. In this talk I will review the status of the project and will give a description of the theorical work that can be done with such a survey.

WEDNESDAY, MAY 9

12:30 pm: High Energy Astrophysics Division Lunch Talk. "Three Things We Can Learn from Gamma-Ray Burst Afterglow Spectral Energy Distributions," Dr. Rhaana Starling, University of Leicester. Pratt Conference Room.

Abstract: Gamma-ray Bursts (GRBs) are highly energetic phenomena occurring throughout cosmological history. A large fraction of them likely form in the core collapse of a massive star, and we find GRBs located in star-forming regions of faint, blue galaxies out to z=6.3. Spectral energy distributions (SEDs) of the GRB afterglow emission provides a means of probing the host galaxies and the GRB physics. I will describe three recent studies I have made using the SEDs of a sample of BeppoSAX GRBs, to measure the host galaxy extinction, the density structure of the circumburst media and further understand the physics of the blastwave.

4:30 pm: Joint ITAMP/Harvard University Physics Department Atomic Physics Colloquium Collisional and Collisionless Expansion of Ultracold Neutral Plasmas," Tom Killian, Rice University. Preceded by refreshments at 4:00 pm. Jefferson 356, Harvard University.

THURSDAY, MAY 10

11:00 am: Science Education Seminar and Open Discussion. Weekly sessions focus on current department programs, literature reviews, and recent trends in science education and assessment. Some sessions feature outside speakers or guests. All members of the CfA community are welcome. Please contact Bruce Ward at bward@cfa, if you wish to attend any session. Phillips Auditorium.

11:00 am: Institute for Theory and Computation (ITC) Seminar. "SGRs in Nearby Galaxies: Rate, Luminosity Function and Fraction Among Short GRBs," Eran Ofek, California Institute of Technology. Pratt Conference Room.

Abstract:It was suggested that some of the short-duration Gamma-Ray Bursts (GRB) are giant flares of Soft Gamma-ray Repeaters (SGR) in nearby galaxies. To test this hypothesis, I have constructed a sample of short GRBs, detected by the Inter-Planetary Network (IPN). For each burst, I have checked whether its IPN 3-sigma error region coincides with the apparent disk of galaxies found within 20 Mpc. I used this to constraint the: fraction of SGRs among short GRBs; the rate of SGR giant flares; and the shape of the SGR flares luminosity function.

12:30 pm: Optical and Infrared Astronomy Division Lunch Talk. "Precision Cosmology and the Structure of Nearby Galaxies," Dr. Kristine Spekkens, Rutgers University. Pratt Conference Room.

Abstract: Recent cosmological measurements combined with simulations of the growth of cosmic structure now explain an impressive array of astrophysical phenomena on large scales and at high redshift. By contrast, there has been little progress toward under standing galactic structure and evolution in the "era of precision cosmology". In this talk, I will focus on key differences between the observed properties of spiral galaxies and predictions from the standard galaxy formation framework, and I'll present some promising new avenues for tackling these problems through de tailed kinematical studies of nearby systems.

4:00 pm: Colloquium. "Fundamentals of Supernova Cosmology," Prof. Robert Kirshner, CfA. Preceded by tea at 3:30 pm. Phillips Auditorium.

Abstract: Supernova observations form the foundation of evidence for an accelerating universe. Diligent work on supernova spectroscopy and supernova photometry in the nearby Universe allows for tests of the assumptions that make supernovae so powerful at high redshift. The current state of the CfA program at low-z, the ESSENCE program at intermediate redshift, and the Higher-Z program with the HST at redshifts near 1 will be discussed, and the best inferences for the properties of dark energy presented. A flat universe with a cosmological constant for the dark energy is consistent with all the current constraints. Alternate hypotheses for DGP gravity and for the Chapylgin gas, inspired by brane physics, are not supported by the current data. Plans for Pan-STARRS, the DESTINY probe as the Joint Dark Energy Mission and the Giant Magellan Telescope as a tool for supernova cosmology will be sketched.

SAO HUMAN RESOURCES NOTES

Leave Donations Requested

Due to a medical emergency, Donna Coletti of the Library has been approved as a leave donor recipient in the Leave Transfer Program. Any SAO Trust Fund employee who wishes to donate annual leave to Donna should complete a Leave Donor Form and send it to MS17.

Under the Leave Transfer Program, Trust Fund employees may only donate annual leave to other Trust Fund employees and Federal employees may donate annual leave only to other Federal employees. If you should have any questions or are not able to access the form, please contact Anne LeBlanc, ext. 5-7371.

Job Vacancies

An online listing of all current SAO job openings is available. For more information, please call Human Resources, ext. 5-7371, or view your nearest bulletin board.

A list of scientists currently visiting the CfA is available here.