2017 - 2018 Astro Seminar Schedule

DateEvent TypeSpeakerTitle
09/08/2017Astro SeminarMarcel SchmittfullFundamental physics from the nonlinear Universe [ + Description ]
09/15/2017Astro SeminarNicholas BattagliaLarge-Scale Structure Information Encoded in CMB Photons [ + Description ]
09/22/2017Astro SeminarVivian PoulinCosmological signatures of exotic electromagnetic energy injection [ + Description ]
09/29/2017Astro SeminarTjitske StarkenburgThe diverse history of counterrotating galaxies [ + Description ]
10/06/2017Astro SeminarMansi KasliwalThe Dynamic Infrared Sky [ + Description ]
10/20/2017Astro SeminarJulie ComerfordAGN Fueling and Feedback in Galaxies [ + Description ]
10/27/2017Astro SeminarRenee HlozekNew cosmology with small-scale CMB data: ultra light dark matter, isocurvature and cosmic voids [ + Description ]
11/03/2017Astro SeminarJames PeeblesA Tale of Two Theories: Missing Mass in 1980 and Galaxy Formation Today [ + Description ]
11/10/2017Astro SeminarMatias ZaldarriagaThe spin of the black holes detected by LIGO [ + Description ]
11/17/2017Astro SeminarSarah PearsonThe Milky Way’s Galactic bar can punch holes in stellar streams [ -- Description ]

Description: As clusters of stars orbit our own Milky Way, a gravitational tidal interaction unfolds and the clusters tear apart into distinct morphological and kinematic structures. From our detailed understanding of gravity, the distribution and motion of these stellar structures enable us to work backwards in time and thereby study our Milky Way's past and evolution. Palomar 5 (Pal 5) is an old globular cluster orbiting our Galaxy, while disrupting into thin leading and trailing stellar arms. In this talk, I will show that a previous encounter between the Pal 5 stellar stream and the Milky Way’s Galactic bar has punched a hole in the stream which can explain why the leading arm of Pal 5 appears to be a lot shorter than the trailing arm. The discovery that the bar can punch holes in stellar streams has important implications for near-field cosmology as the Milky Way should be filled with dark matter subhalos of various sizes according to the cold dark matter paradigm. One proposed method to detect subhalos is to search for them through disturbances in the structure of stellar streams, as dark subhalos should create gaps if they pass through or close by stellar streams. My work implies that caution should be applied before interpreting stream gaps as evidence for dark matter subhalos. Additionally, I will demonstrate how the Galactic bar’s interaction with the Palomar 5 stream provides an intriguing methodology for studying our Milky Way’s Galactic bar in more detail. (11:00 AM, 726 Broadway, 940, CCPP Seminar)
12/01/2017Astro SeminarVera GluscevicDark matter: Searches in the lab and the sky [ + Description ]
01/17/2018Astro Seminar [ + Description ]
01/17/2018Astro SeminarOlivier DelignyTowards locating the ultra-high energy cosmic ray accelerators [ + Description ]
01/23/2018Astro SeminarMarilena LoverdeNeutrinos, Quintessence and Structure Formation in the Universe [ + Description ]
01/30/2018Astro SeminarJennifer BarnesWelcome to the multi-messenger era: a report on the first binary neutron star merger detection [ + Description ]
02/06/2018Astro SeminarPhil ArmitageTidal disruption at home and abroad [ + Description ]
02/13/2018Astro SeminarRyan FoleyDiscovery of the First Electromagnetic Counterpart to a Gravitational Wave Source [ + Description ]
02/20/2018Astro SeminarViviana AcquavivaUnderstanding the Universe through distant galaxies [ + Description ]
02/27/2018Astro SeminarChiara MingarelliInsights into Supermassive Black Hole Mergers, Stalling and Demographics with Pulsar Timing Arrays [ + Description ]
03/06/2018Astro SeminarChang FengMeasuring the Universe at microwave, infrared and gamma-ray wavelengths [ + Description ]
03/13/2018Astro SeminarNo Astro Seminar (spring break) [ + Description ]
03/20/2018Astro SeminarLina NecibEmpirical Determination of the Dark Matter Velocity Distribution [ + Description ]
03/27/2018Astro SeminarJackie FahertyTBA (low-mass stars) [ + Description ]
04/03/2018Astro SeminarChris HaywardTBA (galaxy formation) [ + Description ]
04/10/2018Astro SeminarTBA [ + Description ]
04/10/2018Big Apple ColloquiumJulianne DalcantonTba [ + Description ]
04/17/2018Astro SeminarIlsedore CleevesTBA (proto-planetary disks) [ + Description ]
04/24/2018Astro SeminarTBA [ + Description ]
05/01/2018Astro SeminarBen FarrTBA (LIGO, neutron stars) [ + Description ]
05/08/2018Astro SeminarTBA [ + Description ]
05/15/2018Astro SeminarTBA [ + Description ]