Weekly Calendar of Events

NOVEMBER 24 - 28, 2014


10:30 am: Atomic and Molecular Physics Division Seminar. "Molecular Astronomy: Using Infrared Laboratory Spectroscopy to Understand Molecular Environments," Dr. Robert Hargreaves, Department of Chemistry, Old Dominion University. Pratt Conference Room.

Abstract: The spectroscopy of a variety of cool astronomical objects is dominated by the understanding of their molecular spectra, particularly in the infrared. This seminar will cover two aspects of molecular astronomy with an emphasis on laboratory spectroscopy. The first will concentrate on the calculation of carbon chain abundances in circumstellar shells. The second will elaborate on our laboratory method, which produces temperature relevant line lists of key molecules that are important for the atmospheric spectra of brown dwarfs and exoplanets.

Noon: Solar, Stellar, and Planetary Sciences Division Seminar. "Multiplexed Fiber Spectroscopy at Magellan: Searching for Exoplanets in Star Clusters," Jeb Bailey, University of Michigan. Pratt Conference Room.

Abstract: The Michigan/Magellan Fiber System is a new multi-object spectrograph for the Magellan Clay telescope. In its first year of operation, users have studied topics ranging from high-redshift galaxies to Galactic structure as well as nearby star formation. My own efforts have focused on using M2FS to search two nearby open clusters for hot gas giants as a prelude to a survey designed to constrain exoplanet formation and migration theories. Our ongoing efforts are focused on attaining ~20 m/s radial velocity (RV) precision with M2FS while also measuring Teff and other stellar parameters for up to 256 targets simultaneously. After presenting an overview of the diverse capabilities of M2FS and my role in its development, I will describe how M2FS can be used for precision RV work. I will then report the current status of our survey and present plans for an expanded survey to develop a significant sample of hot gas giants with well characterized ages and formation environments.


1:00 pm: Institute for Theory and Computation (ITC) Seminar. "Historical Heat Responsible for Enceladus's Plume," Jing Luan, California Institute of Technology, and "How Common Are Snowline Region Planets? First Results from Second Generation Microlensing," Yossi Shvartzvald, Tel Aviv University. Pratt Conference Room.


12:30 pm: High Energy Astrophysics Division Lunch Talk. "The Most Distant Quasars with Pan-STARRS1," Dr. Eduardo Banados, Max Planck Institute for Astrophysics. Pratt Conference Room.

Abstract: High-redshift quasars provide unique information about the evolution of supermassive black holes and the intergalactic medium at early cosmic time. Numerous studies have established a sample of ~60 quasars at 5.5 < z < 7.1. These studies demonstrated the existence of massive black holes less than a Gyr after the Big Bang, and indicated that the end of cosmic reionization occurred at z~6. These findings suggest that fundamental changes are happening in the intergalactic medium at 6 < z < 7. The discovery and characterization of a statistically significant sample of quasars in this redshift range is crucial to further study this important era in the history of the universe. I will present how in less than 2 years we doubled the number of known 5.7 < z < 6.0 quasars using the Pan-STARRS1 survey. The sample shows a variety of properties, including a number of weak-line quasars and radio-loud quasars, revealing some previously unknown properties and proving that the population of the first quasars is more diverse than originally thought. I will show the preliminary results of our search for z > 6.5 quasars that will allow us to put constraints on the number density of massive black holes when the universe was less than 1/15 its current age. I will also discuss the implications of our search for high-redshift radio-loud quasars for the evolution of the radio-loud fraction of quasars across cosmic time.

The Calendar is prepared by the Web Services Group. Entries may be submitted via email to weekly_cal@cfa.


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