Astrophysics Science Division Colloquium Series
Schedule: Fall 2016

Astrophysics Science Division Colloquium Series
Schedule: Fall 2016

Recent schedules:

2016, Fall 2016, Spring  
2015, Fall 2015, Spring  
2014, Fall 2014, Spring  
2013, Fall 2013, Spring 2013, Summer
2012, Fall 2012, Spring  
2011, Fall 2011, Spring  
2010, Fall 2010, Spring  

ASD Colloquia are Tuesdays at 3:45 pm (Meet the Speaker at 3:30 pm)
in Bldg 34, Room W150 unless otherwise noted.


Aug 30 Tom Brown (STScI) - "The Quenching of the Ultra-faint Dwarf Galaxies in the Reionization Era"


Sep 6 No Colloquium
Sep 13 Special Location: B34, W120A+B
Rodolfo Montez (SAO) - "X-ray observations of planetary nebulae" (tentative)
Sep 20 TBD
Sep 27 TBD


Oct 4 Maria Petropoulou (Purdue) - "Neutrino emission from blazars and predictions for IceCube"
Oct 11 Matthew Baring (Rice) - "Blazar and accretion science" (tentative)
Oct 18 Jonathan Arenberg (Northrop-Grumman) - "Lessons from Chandra" (tentative)
Oct 25 TBD


Nov 1 Dominik Riechers (Cornell) - "Cold gas in high-z galaxies with ALMA" (tentative)
Nov 8 TBD
Nov 15 TBD
Nov 22 TBD
Nov 29 TBD


Dec 6 David Spergel (Princeton) - "WFIRST" (tentative)
Dec 13 TBD
Dec 20 TBD
Dec 27 TBD

The Quenching of the Ultra-faint Dwarf Galaxies in the Reionization Era

Tom Brown


Tuesday, Aug 30, 2016


I will present results from a Hubble Space Telescope survey of the ultra-faint dwarf galaxies. These Milky Way satellites, discovered in the Sloan Digital Sky Survey, appear to be an extension of the classical dwarf spheroidals to low luminosities, offering a new front in the efforts to understand the missing satellite problem. Because they are the least luminous, most dark matter dominated, and least chemically evolved galaxies known, the ultra-faint dwarfs are the best candidate fossils from the early universe. The primary goal of the survey is to measure the star-formation histories of these galaxies and discern any synchronization due to the reionization of the universe.

Neutrino emission from blazars and predictions for IceCube

Maria Petropoulou


Tuesday, Oct 4, 2016


The recent IceCube discovery of 0.1-2 PeV neutrinos of astrophysical origin initiates a new era for high-energy astrophysics. There are various astrophysical candidate sources, including active galactic nuclei (AGN) and starburst galaxies. Yet, a firm association of the detected neutrinos with one (or more) of them is still lacking. This talk investigates the neutrino emission from BL Lacs, a sub-class of radio-loud AGN. We present the results from leptohadronic modeling of six individual BL Lacs, including the closest to Earth, Mrk 421, that were recently selected as probable counterparts of the IceCube neutrinos. We then present the cumulative neutrino emission from BL Lacs, which was calculated by incorporating our results from the modeling of individual sources to Monte Carlo simulations for the blazar evolution. Since blazars are intrinsically variable sources across the electromagnetic spectrum, we finally investigate the potential for neutrino detection from the closest to Earth blazar, i.e. Mrk 421, during periods of flaring activity.

Maxim Markevitch
NASA Logo, National Aeronautics and Space Administration