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 Dan Fabrycky or Hsiao-Wen Chen.
  2. Formal 1-hr long lunch-time seminars are scheduled occasionally, and these will be held in the ERC 576.

Current & Future Astro Tuesday Series
DateEventTalk
March 28, 2017ChalkTalkPetros Tzeferacos, Penny-sized dynamos: how laser-driven plasma experiments can shed light on the origin of cosmic magnetic fields
Albert Stebbins, Intensity Interferometry in the Era of Giant Telescopes
April 4, 2017ChalkTalkYuanyuan Zhang, Studying Diffused Intra-Cluster Light through Stacking the Images of ~300 Galaxy Clusters
Priscilla Frisch, The heliosphere as paradigm for astrospheres: IBEX uncovers the hidden secrets of energetic neutral atoms
April 11, 2017Tuesday SeminarFarhad Yusef-Zadeh, TBA

Past Astro Tuesday Series
DateEventTalk
March 7, 2017ChalkTalkMarcelle Soares-Santos, Knowing where to look: strategies for gravitational wave triggered kilonova searches with DECam
Adam Miller, Scaling the Zooniverse: Stellar Classification in the LSST Era
February 28, 2017Tuesday SeminarRaffaella Margutti, Astronomical Transients that defy all classification schemes
February 21, 2017ChalkTalkMichael D. Gladders, Gender bias in proposal review process
Heidi Wu, Cosmic far-infrared background and cosmic star-formation history
February 14, 2017Tuesday SeminarB-G Andersson, Status of, and science with, the Stratospheric Observatory For Infrared Astronomy (SOFIA)
February 7, 2017ChalkTalkAnja Feldmeier-Krause, Measuring the Initial Mass Function
Ting Li, How to measure the brightness of a star?
January 31, 2017Tuesday SeminarErika Hamden, Observing the faint universe in emission
January 24, 2017ChalkTalkChihway Chang, (Almost) everything you need to know about weak lensing systematics
Stephan S. Meyer, Implicit Bias
January 17, 2017ChalkTalkScott Feister, Laser laboratory astrophysics: Diffusion and acceleration of charged particles in turbulent magnetized plasma
Daniel Fabrycky, Origin and Death of Contact Binaries
January 10, 2017Tuesday SeminarSasha Philippov, How do pulsars shine?

How do pulsars shine?
January 10, 2017 | ERC 576 | 12:00 PM
Sasha Philippov, Princeton

The modeling of pulsar radio and gamma-ray emission suggests that in order to interpret the observations one needs to understand the field geometry and the plasma state in the emission region. In recent years, significant progress has been achieved in understanding the magnetospheric structure in the limit of abundant plasma supply. However, the very presence of dense plasma everywhere in the magnetosphere is not obvious. Even the region where the observed emission is produced is subject to debate. To address this from first principles, we constructed global kinetic simulations of pulsar magnetospheres using relativistic Particle-in-Cell codes, which capture the physics of plasma production and particle acceleration. In this talk I will describe how plasma is produced in magnetospheres of pulsars. I will present modeling of high-energy lightcurves, calculated self-consistently from particle motion in the pulsar magnetosphere. I will also show evidence that observed radio emission is powered by non-stationary discharge at the polar cap.

ChalkTalk
January 17, 2017 | ERC 501 | 12:00 PM
  • Scott Feister
    Laser laboratory astrophysics: Diffusion and acceleration of charged particles in turbulent magnetized plasma
  • Daniel Fabrycky
    Origin and Death of Contact Binaries

ChalkTalk
January 24, 2017 | ERC 501 | 12:00 PM

Observing the faint universe in emission
January 31, 2017 | ERC 576 | 12:00 PM
Erika Hamden, Caltech

In the last several years, groundbreaking instruments have detected significant Lyman-alpha emission from the circumgalactic media (CGM) of z>2 galaxies, providing an initial corroboration to results from years of absorption line studies. Taken together, these indicate the presence of vast reservoirs of gas that we are only just beginning to observe and understand. To probe when star formation declines throughout the universe, we need to conduct similar observations at lower redshifts, moving into the UV. The Faint Intergalactic medium Redshifted Emission Balloon (FIREBall-2) is a balloon-born UV multi-object spectrograph designed to detect Lyman-alpha emission from the circumgalactic medium (CGM) around z~0.7 galaxies. In this talk, I will discuss the science drivers for this mission and its current status as we prepare for a Fall 2017 flight. In addition to groundbreaking science, FIREBall-2 will flight test several new technologies in a balloon setting, including photon counting, high efficiency UV detectors. I will discuss these technologies in the context of their impact on future space missions.

ChalkTalk
February 7, 2017 | ERC 501 | 12:00 PM

Status of, and science with, the Stratospheric Observatory For Infrared Astronomy (SOFIA)
February 14, 2017 | ERC 576 | 12:00 PM | Host: Erik Shirokoff
B-G Andersson, SOFIA Science Center

The SOFIA project flies a significantly modified Boeing 747SP, carrying a 2.7m telescope into the stratosphere 3-4 times a week, to perform astronomical observations primarily in the mid- to far-infrared. The observatory is just starting Cycle 5 of its general user observations, employing all the first and second generation instruments, and covering all areas of astronomy from Solar System studies to extra-galactic astronomy. The Cycle 6 Call for Proposals will be released at the end of April, offering about 500h of observing time to the astronomical community. I will review the status of the project and provide some science highlights from the first few observing cycles.

ChalkTalk
February 21, 2017 | ERC 501 | 12:00 PM
  • Michael D. Gladders
    Gender bias in proposal review process
  • Heidi Wu, Caltech
    Cosmic far-infrared background and cosmic star-formation history

Astronomical Transients that defy all classification schemes
February 28, 2017 | ERC 576 | 12:00 PM
Raffaella Margutti, Northwestern

Observations are drawing a complex picture of the latest stages of massive stars evolution and their explosions. In this seminar I concentrate on two among the least understood aspects of stellar evolution, adopting an observational perspective: How do massive stars loose a significant fraction of their mass in the years preceding the explosion? What powers the most luminous stellar explosions in our Universe? I address these questions by taking advantage from panchromatic observations of two remarkable transients: (i) the "normal" envelope-stripped SN2014C, which experienced a dramatic metamorphosis and evolved from Type I into Type II supernova over a timescale of a few months, thus violating the supernova classification scheme that hat has existed for decades. (ii) I will then describe the recent results from our efforts to constrain the energy source of Super-Luminous SNe, with a case study of the "bactrian" transient ASASSN-15lh, which might be the first element of an entirely new class of transients.

ChalkTalk
March 7, 2017 | ERC 501 | 12:00 PM
  • Marcelle Soares-Santos, Fermilab
    Knowing where to look: strategies for gravitational wave triggered kilonova searches with DECam
  • Adam Miller, Northwestern
    Scaling the Zooniverse: Stellar Classification in the LSST Era

ChalkTalk
March 28, 2017 | ERC 501 | 12:00 PM
  • Petros Tzeferacos
    Penny-sized dynamos: how laser-driven plasma experiments can shed light on the origin of cosmic magnetic fields
  • Albert Stebbins, Fermilab
    Intensity Interferometry in the Era of Giant Telescopes

ChalkTalk
April 4, 2017 | ERC 501 | 12:00 PM
  • Yuanyuan Zhang, Fermilab
    Studying Diffused Intra-Cluster Light through Stacking the Images of ~300 Galaxy Clusters
  • Priscilla Frisch
    The heliosphere as paradigm for astrospheres: IBEX uncovers the hidden secrets of energetic neutral atoms

TBA
April 11, 2017 | ERC 501 | 12:00 PM | Host: Anja Feldmeier-Krause
Farhad Yusef-Zadeh, Northwestern