MAY 21 - 25, 2007

MONDAY, MAY 21

12:30 pm Institute for Theory and Computation (ITC) Special Seminar. "Probing the Universe at z>5.7 With Lya Emitting Galaxies," Dr. Mark Dijkstra, University of Melbourne. Pratt Conference Room.

Abstract:: The number of known galaxies at z>5.7 has increased dramatically over the past few years. The observed Ly-a lines from these high-z galaxies are on average more prominent than at z~3. This is surprising given the fact that the intergalactic medium is becoming increasingly opaque to Lya-photons with redshift. I will show that a simple model in which galaxies at z~6 go through a brief phase of very massive star formation may simultaneously explain several observations including luminosity functions and Lya equivalent width distributions. Furthermore, this model may resolve some apparently contradicting sets of observations. Last, I will discuss how Ly-a emitting galaxies can be used to probe the ionization state of the IGM. Time permitting, I will discuss my upcoming wedding and may show a picture of my cat Max.

TUESDAY, MAY 22

12:30 pm Institute for Theory and Computation (ITC) Seminar. Reconstruction of Peculiar Velocity Field from Redshift Catalogues," Roya Colin Mohayaee, Institut d'Astrophysique de Paris. Pratt Conference Room.

Abstract:: We present an orbit-retracing method which can be used to reconstruct the peculiar velocity field from the redshift catalogues. When tested against N-body simulations, it works well above a few Mpc scale. Comparison between the reconstructed density field and the catalogue of distances for Nearby Universe (radius of 30 Mpc), can provide an independent measure of the density parameter. We outline how the method can be used to recover the linear power spectrum.

WEDNESDAY, MAY 23

12:30 pm: High Energy Astrophysics Division Lunch Talk. "The Star Formation Properties of Galaxies in Clusters," Dr. Somak Raychaudhury. CfA. Pratt Conference Room.

Abstract:: It has long been known that galaxies in the cores of clusters generally have very little ongoing star formation, and that the star formation rate of a galaxy is correlated with the density of galaxies in its immediate environment. On the other hand, there have been several recent sightings of galaxies with unusually high star formation on the outskirts of clusters. This talk will summarize observational evidence of how the star formation properties of galaxies change as they fall into a cluster, and the insight this gives into the physical processes that are involved.

THURSDAY, MAY 24

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. "Probing Cosmic Inflation: WMAP and Beyond," Joanna Dunkley, Princeton University. Classroom A.

Abstract: Current measurements from WMAP and other cosmological probes are consistent with a simple inflationary model. Such models predict a background of gravitational waves which may soon be observable in the polarized component of the Cosmic Microwave Background. However, WMAP has observed significant levels of polarized radiation from our galaxy, due to both synchrotron radiation and thermal dust emission. A better understanding of this radiation will be vital if we are to correctly remove it and confidently detect an inflationary signal. As well as discussing the observational case for inflation, I will review the physical origins of the polarized galactic emission, present simple models for the galactic magnetic field and the galactic polarized emission, and discuss current and future directions for improving upon our models.

4:00 pm: Colloquium. "Cosmology and Galactic Astronomy from the South Pole," Dr. Antony Stark, CfA. Preceded by tea at 3:30 pm. Phillips Auditorium.

Abstract: The Antarctic Submillimeter Telescope and Remote Observatory (AST/RO) operated from 1995-2005, observing submillimeter-wave spectral lines with arcminute resolution from dense molecular gas in the Milky Way. As the first telescope to operate continuously through the winter on the Antarctic Plateau, it demonstrated feasibility and the superb conditions of the site. AST/RO's legacy includes observations of SST-field star-forming cores and a comprehensive map of the galactic center region. The dense gas surrounding the galactic center is unstable, leading to quasi-periodic starbursts and activation of the central Black Hole. The South Pole Telescope (SPT) is a 10-meter diameter submillimeter-wave telescope, that became operational at the South Pole on February 16, 2007. The SPT is designed to feed thousands of detectors with low background noise. The initial SPT project is a 4000 square degree swath of the southern sky at frequencies of 90, 150, and 220 GHz. This will lead to the discovery of many thousands of clusters of galaxies, detected through their Sunyaev-Zel'dovic effect background decrements. The detection efficiency is essentially independent of redshift: about 30% of these clusters will be at redshifts z > 1. The evolution and size of clusters is a sensitive constraint on Dark Energy.

JOINT ITAMP/CUA WORKSHOP

On May 24-26, 2007, the Institute for Theoretical Atomic, Molecular and Optical Physics (ITAMP) and the Center for Ultracold Atoms (CUA) will hold the workshop Hybrid Approaches to Scalable Quantum Information Systems. The aim of this workshop is to discuss theoretical ideas and experimental methods to interface different quantum systems in order to build larger-scale quantum information processing devices. Talks from the workshop will be webcast live. More information can be found here.

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.