Wine and Cheese Fall 2016: Difference between revisions
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=September 26th= | =September 26th= | ||
== | == David Jones == | ||
''' | '''TBA''' <br> | ||
Abstract to be added | Abstract to be added | ||
== Clément Bonnerot == | |||
'''Stream evolution in tidal disruption events'' | |||
Tidal disruption events occur when a star gets scattered on a trajectory that takes it so close to a supermassive black hole that it is torn apart by strong tidal forces. Such events represent unique probes of otherwise quiescent black holes, which constitute the majority of black holes in the local universe. However, this great potential is hampered by the lack of a clear picture of how exactly these events take place. One particular uncertainty concerns the circularization process during which the stellar debris dissipate their large orbital energy to form an accretion disc around the black hole. Hydrodynamical simulations point towards shocks driven by debris self-intersections as an efficient dissipation mechanism. In my talk, I will present a recently developed semi-analytical model that treats the circularization process, accounting for the impact of both shocks and magnetic stresses. This model proves that the net effect of magnetic stresses is to strengthen shocks, thus accelerating circularization. It also allows to predict the form of the lightcurve associated to shock luminosity and demonstrates that the thermal energy excess imparted by shocks is most likely to cause the rapid formation of a thick structure. To conclude the talk, I will present latest advances on ongoing projects and mention future research directions. | |||
=October 3rd= | =October 3rd= |
Revision as of 15:52, 12 September 2016
This page records the schedule, titles and abstracts of the JHU/STScI CAS Astrophysics Wine & Cheese Series in Fall 2016.
Wine and Cheese sessions with one talk will have a 50 minute talk with 10 minutes for questions. Sessions with two speakers will have two 25 minute talks, each with 5 minutes for questions.
Back to W&C Schedule
September 12th
Exoplanet Workshop at STScI
September 19th
Massimo Robberto
GMOX and SAMOS
NSF has recently funded a JHU-led collaboration to build SAMOS, a novel multi-slit spectograph for the 4.1m SOAR telescope in Chile. SAMOS exploits the ground-layer AO system to take hundreds of faint spectra in parallel at R~2000 over a 3’x’3’ field of view. At the same time, Gemini has contracted us with the study of an expanded version of SAMOS, GMOX, to be installed at the Multi-Conjugate extreme-AO system of Gemini South. GMOX covers the full U to K bandpass at R~5000 and can synthetize slits as small as a single HST/WFC3-vis pixel (40mas), reaching unpredentented levels of sensitivity in the near-IR from the ground. I will present the main characteristics of the instruments, their current status, and an outline of the type of science programs that can be carried out in the substantial amount of GTO time.
Bram Ochsendorf
The Location, Clustering, and Propagation of Massive Star Formation in Giant Molecular Clouds
Massive stars are key players in the evolution of galaxies, yet their formation pathway remains unclear. In this talk, I will present results from a project utilizing data from several galaxy-wide surveys to build an unbiased dataset of ∼700 massive young stellar objects (MYSOs), ∼200 giant molecular clouds (GMCs), and ∼100 young (< 10 Myr) optical stellar clusters (SCs) in the Large Magellanic Cloud. We have employed this data to quantitatively study the location and clustering of massive star formation and its relation to the internal structure of GMCs. The main results are as follows: (1) Massive stars do not typically form at the highest column densities nor centers of their parent GMCs. (2) Massive star formation clusters over multiple generations and on size scales much smaller than the size of the parent GMC. (3) The rate of massive star formation is significantly boosted in clouds near SCs. Yet, comparison of molecular clouds associated with SCs with those that are not reveals no significant difference in their global properties. These results reveal a connection between different generations of massive stars on timescales up to 10 Myr. I will compare our findings with Galactic studies and discuss this in terms of GMC collapse, triggered star formation, and a potential dichotomy between low- and high-mass star formation.
September 26th
David Jones
TBA
Abstract to be added
Clément Bonnerot
'Stream evolution in tidal disruption events Tidal disruption events occur when a star gets scattered on a trajectory that takes it so close to a supermassive black hole that it is torn apart by strong tidal forces. Such events represent unique probes of otherwise quiescent black holes, which constitute the majority of black holes in the local universe. However, this great potential is hampered by the lack of a clear picture of how exactly these events take place. One particular uncertainty concerns the circularization process during which the stellar debris dissipate their large orbital energy to form an accretion disc around the black hole. Hydrodynamical simulations point towards shocks driven by debris self-intersections as an efficient dissipation mechanism. In my talk, I will present a recently developed semi-analytical model that treats the circularization process, accounting for the impact of both shocks and magnetic stresses. This model proves that the net effect of magnetic stresses is to strengthen shocks, thus accelerating circularization. It also allows to predict the form of the lightcurve associated to shock luminosity and demonstrates that the thermal energy excess imparted by shocks is most likely to cause the rapid formation of a thick structure. To conclude the talk, I will present latest advances on ongoing projects and mention future research directions.
October 3rd
David Hogg
Chemical tagging of stars with a data-driven model
Abstract to be added
October 10th
Cole Miller
TBD
Abstract to be added
October 17th
JHU-GSFC Interaction Day
October 24th
Speaker Name
Title
Abstract to be added
October 31st
Special Halloween Speakers
Title
Attendance in costume is optional
November 7th
Anthony Pullen
Revealing Intensity Fluctuations with LSS Tracers
Abstract to be added
November 14th
High Contrast Imaging Workshop at STScI
November 21st
Thanksgiving Break
November 28th
Aki Roberge
Star-Grazing Exocomets Around Nearby Young Stars and Big Bang to Biosignatures: The LUVOIR Decadal Mission Concept
A double-barreled talk!
December 5th
Speaker Name
Title
Abstract to be added
December 12th
Subaru Meeting