MAY 21 - 25, 2012

TUESDAY, MAY 22

11:00 am: Radio and Geoastronomy Division Lunch Talk. "Studying High-Redshift Star Formation and Accretion in the Lockman Hole North," Robert Lindner, Rutgers University. Room M-340, 160 Concord Avenue.

Abstract: I'll present results from our deep 1.2mm imaging survey of the central 20' x 20' of the Lockman Hole North (LHN) field made using the Max Planck Millimeter Bolometer (MAMBO) array on the IRAM 30m telescope. We detected 41 submillimeter galaxies (SMGs) with S/N > 4.0 which show a significant angular clustering signal on ~arcminute scales. The LHN's substantial multi-wavelength coverage allowed us to make both radio-counterpart identifications and redshift determinations (either spectroscopic or photometric) for 93% of detections, making the LHN SMGs a powerful sample for studies of high-redshift (=2.6) galaxy formation and evolution. I'll also talk about my recent X-ray stacking analysis in the same field, where we detect strong (equivalent width > 1 keV) Fe K-alpha emission in the sample's average rest-frame X-ray spectrum.

WEDNESDAY, MAY 23

12:30 pm: High Energy Astrophysics Division Lunch Talk. "Lensing and X-ray: Masses and Concentrations of Galaxy Clusters," Dr. Elena Rasia, University of Michigan, Ann Arbor. Pratt Conference Room.

Abstract: I will briefly review our recent works on lensing and X-ray estimates of 1) mass and 2) concentration. Our first project is based on 20 simulated massive clusters from which we created Chandra X-ray and Subaru SuprimeCam images using our tools: X-MAS and Skylens. The 'observational' mass derived from these synthetic catalogs is compared with the input value of the simulations. Weak lensing masses resulted underestimated by 5-10% due to presence of substructure and triaxiality. The X-ray masses are more underestimated (25-35%) because of lack of hydrostatic equilibrium and temperature inhomogeneity. I will comment on the significance of these results relating to previous work and observations. The second project investigates the concentration-mass relation and its dependence on the radial range used for the fitting and on the baryonic physics of the Intra Cluster medium (ICM). ~50 objects simulated with four different ICM physics are considered. The results are compared with recent observational efforts.

THURSDAY, MAY 24

4:00 pm: Colloquium. "Evidence for Neutron Superfluidity in Neutron Star Cores," Dr. Craig Heinke, University of Alberta. Preceded by tea at 3:30 pm. Phillips Auditorium.

Abstract: The behavior of matter at the high densities of neutron stars is not well understood. X-ray observations of hot young neutron stars are one method of probing the physics of neutron stars. I will discuss X-ray observations of some young neutron stars, focusing on the youngest known neutron star, in Cassiopeia A. Our team proposed that its unusual X-ray properties are naturally explained by a carbon atmosphere, and discovered that its surface is measurably cooling with time. The observed rate of cooling, and its current temperature, require a rapid, short-lived transition in the neutron star's interior. Our proposed explanation is that the neutrons in the core are undergoing a transition to a superfluid state, radiating away their heat via neutrinos as the neutrons pair up.

SAO HUMAN RESOURCES NOTES

Trust Fund Leave Donations Needed

Christina Debarros of the Travel Department and Patricia Riddle of Central Engineering have been approved as leave recipients under the Leave Transfer Program. Any Trust Fund employee wishing to donate annual leave to Christina or Patricia during their medical emergencies may do so by completing a leave donor form. Please send your completed donor form (do not include your SSN) to Linda McDonald at MS 17. Leave Transfer Program details can be accessed at http://www.cfa.harvard.edu/hr/handbook/leaves.html.

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.

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