Astro Tuesday Series
Astro Tuesday Series:
  1. Informal blackboard "ChalkTalk" presentations at noon-1PM in the Hubble Lounge (ERC 501). There are nominally two 30-minute long presentations every week. Some food will be provided. To sign up, please email Daniel Fabrycky or Fausto Cattaneo or Damiano Caprioli.
  2. Forma 1-hr long lunch-time seminars are scheduled occasionally, and these will be held in the ERC 576.

Past Astro Tuesday Series
DateEventTalk
October 15, 2019ChalkTalkCharles Steinhardt, Thermal Regulation and the Star-Forming Main Sequence
Evgeni Grishin, Capturing planetesimals in gaseous disks
September 3, 2019Tuesday SeminarRuediger Pakmor, Magnetic fields and cosmic rays in disk galaxies
June 11, 2019Tuesday SeminarDavid Nataf, Clues to Globular Cluster Formation, and Contributions to the Field Population
May 28, 2019Tuesday SeminarDimitri Veras, Transformative advances in post-main-sequence planetary system science
May 21, 2019Tuesday SeminarKyle Parfrey, Black-Hole Energy Extraction via General-Relativistic Kinetic Plasma Simulations
May 14, 2019Tuesday SeminarRobert Kennicutt, Astro2020 Decadal Survey Update and Discussion
April 30, 2019ChalkTalkCharles Mudd, Exploring the Boundaries of Space Law and Policy: An Attorney's Perspective
Dara Norman, Facing and Tackling the Resource Challenges that Accompany Time Domain Science
April 23, 2019Tuesday SeminarNoemie Globus, The origin of the ultra-high energy cosmic-ray dipole
April 16, 2019ChalkTalkRichard Kessler, Photometric classification challenge
Fausto Cattaneo, The origin of the Earth's magnetic field: a tale of two Taylors
March 19, 2019ChalkTalkThomas Crawford, The basics of CMB data analysis
Edward J. Kibblewhite, Photography and large scale surveys
January 22, 2019ChalkTalkRichard G. Kron, Nancy Roman's contributions to studies of stellar populations in the solar neighborhood
January 8, 2019ChalkTalkSam McDermott, Wavelets: An Ambitious Introduction
Gordan Krnjaic, Distorted neutrino oscillations from ultra-light dark matter

ChalkTalk
January 8, 2019 | ERC 501 | 12:00 PM | ChalkTalk

ChalkTalk
January 22, 2019 | ERC 501 | 12:00 PM | ChalkTalk
  • Richard G. Kron
    Nancy Roman's contributions to studies of stellar populations in the solar neighborhood

ChalkTalk
March 19, 2019 | ERC 501 | 12:00 PM | ChalkTalk

ChalkTalk
April 16, 2019 | ERC 501 | 12:00 PM | ChalkTalk

The origin of the ultra-high energy cosmic-ray dipole
April 23, 2019 | ERC 576 | 12:00 PM | Host: Damiano Caprioli | Tuesday Seminar
Noemie Globus, NYU-CCA

Although their astrophysical sources remain a mystery, new measurements brought by experiments such as the Pierre Auger Observatory and Telescope Array, have radically improved our knowledge of the ultra-high energy cosmic-rays (UHECRs). I will review the current observational status (spectrum, composition, and arrival directions) and present new results on the interpretation of the first 5 sigma anisotropy in the UHECR sky: a "dipole" for UHECRs with energies above 8 EeV, reported in 2017 by the Pierre Auger Observatory.

ChalkTalk
April 30, 2019 | ERC 501 | 12:00 PM | ChalkTalk
  • Charles Mudd, University of Chicago
    Exploring the Boundaries of Space Law and Policy: An Attorney's Perspective
  • Dara Norman, NOAO
    Facing and Tackling the Resource Challenges that Accompany Time Domain Science

Astro2020 Decadal Survey Update and Discussion
May 14, 2019 | ERC Hubble Lounge | 12:00 PM | Host: Hsiao-Wen Chen | Tuesday Seminar
Robert Kennicutt, University of Arizona and Texas A&M University

Black-Hole Energy Extraction via General-Relativistic Kinetic Plasma Simulations
May 21, 2019 | ERC 576 | 12:00 PM | Host: Damiano Caprioli | Tuesday Seminar
Kyle Parfrey, NASA Goddard

Black holes of all masses drive powerful relativistic jets, using magnetic fields dragged in by their accretion flows. The jets' plasma should be so diffuse as to be effectively collisionless, and self-consistently supplied by pair creation near the horizon. I will present the first general-relativistic kinetic plasma simulations of collisionless black-hole magnetospheres, showing the launching of electromagnetic jets by the Blandford-Znajek mechanism. The simulations reveal a population of particles with negative effective energy, which can contribute significantly to black-hole rotational-energy extraction. The kinetic approach will be useful for studying the accretion flows of the primary Event Horizon Telescope targets, M87 and Sgr A*, where the plasma is likewise of low density and collisionless, and for probing black holes' nonthermal X-ray and gamma-ray emission from first principles.

Transformative advances in post-main-sequence planetary system science
May 28, 2019 | ERC 576 | 12:00 PM | Host: Damiano Caprioli | Tuesday Seminar
Dimitri Veras, University of Warwick

Connecting planetary systems at different stages of stellar evolution helps us understand their formation, evolution, and fate, and provides us with exclusive and crucial insights about their dynamics and chemistry. Post-main-sequence white dwarf and giant branch stars host planetary systems which include a variety of observed objects and phenomena, such as planetary debris discs, disintegrating and embedded asteroids, exo-comets, and photospheric metal pollution. Here, I provide a review of both our current knowledge of these systems and models which have been used to explain them. I also highlight the transformative advances expected in upcoming years with the current and next generation of ground-based and space-based initiatives. Looming orders-of-magnitude increases in available data must be accompanied by novel theories and simulations in order to understand the results from this interdisciplinary and expanding research field.

Clues to Globular Cluster Formation, and Contributions to the Field Population
June 11, 2019 | ERC 576 | 12:00 PM | Host: Damiano Caprioli | Tuesday Seminar
David Nataf, Johns Hopkins University

Globular clusters are now well-established to host "Second-generation" stars, which show anomalous abundances in some or all of He, C, N, O, Na, Al, Mg, etc. The simplest explanations for these phenomena typically require the globular clusters to have been ~20x more massive at birth, and to have been enriched by processes which are not consistent with the theoretical predictions of massive star chemical synthesis models. The library of observations is now a vast one, yet there has been comparatively little progress in understanding how globular clusters could have formed and evolved. In this talk I discuss two new insights into the matter. I first report on a meta-analysis of globular cluster abundances that combined APOGEE and literature data for 42 globular clusters, new trends with globular cluster mass are identified. I then discuss the chemical properties of former globular cluster stars that are now part of the field population, and what can be learned. I demonstrate that globular clusters were the predominant sites of star formation in the first epoch of star formation.

Magnetic fields and cosmic rays in disk galaxies
September 3, 2019 | ERC 576 | 12:00 PM | Host: Christine Simpson | Tuesday Seminar
Ruediger Pakmor, MPA-Garching

Only very recently cosmological zoom simulations of galaxies have started to be able to include the evolution of magnetic fields and the treatment of relativistic cosmic ray particles. I will present recent results from the Auriga simulations of high resolution cosmological zoom simulations of Milky Way-like galaxies and show how the magnetic field in these galaxies is amplified and ordered during cosmic evolution. Moreover, I will discuss how the inclusion of cosmic rays in the cosmological simulations changes the properties of disk galaxies and their circumgalactic medium.

ChalkTalk
October 15, 2019 | ERC 501 | 12:00 PM | ChalkTalk
  • Charles Steinhardt, Neils Bohr Institute/DAWN
    Thermal Regulation and the Star-Forming Main Sequence
  • Evgeni Grishin, Technion
    Capturing planetesimals in gaseous disks