Wednesday colloquia

The API colloquia are weekly meetings where people give a 45 minute overview of their work. Afterwards there is time for discussion. At the end of each month the colloquia are jointly held with GRAPPA.

The contact person for the regular API colloquia is Selma de Mink.
The contact person for the joint GRAPPA/API colloquia is Jacco Vink.


Past colloquia

Observing the Strong-Field Region near Black Holes using X-ray Reflection Spectroscopy

Javier Garcia — California Institute of Technology, and Remeis Observatory, Bamberg Germany

In region close to a black hole, the extreme conditions created by the strong gravitational field produces copious emission of radiation, most of it at very high energies. The interaction of this radiation with the material surrounding a black hole results in observables that carry physical information on the system. X-ray spectral and timing techniques have been used for decades to
access these phenomena.

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Wednesday 10 May 2017, 11:00. Location: C4.174

An X-ray View of the Dusty Universe

Lia Corrales — University of Wisconsin, Madison (USA)

A significant fraction of the heavy elements produced by stars spend some time in the interstellar medium as dust grains. These heavy metal transporters influence gas cooling during star formation, eventually becoming the seeds for planet formation.

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Wednesday 3 May 2017, 11:00. Location: C4.174

GRAPPA Seminar - Simulations of Black Holes the Astrophysical Laboratories

Alexander Tchekhovskoy — UC Berkeley

Black holes are responsible for a wide range of astrophysical phenomena. They devour stars, emit gravitational waves, eject relativistic jets, affect star formation and galaxy evolution, and enrich the Universe with heavy elements.

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Wednesday 19 April 2017, 11:00. Location: C4.174

Forming planetesimals and planets in protoplanetary discs

Anders Johansen — Lund Observatory, Sweden

Planets form in protoplanetary discs around young stars as dust and ice particles collide to form larger and larger bodies. I will present a coherent theory framework for the formation of planetary systems.

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Wednesday 12 April 2017, 11:00. Location: C4.174

The physics of Pulsar Wind Nebulae in the light of 3D MHD simulations

Elena Amato — Arcetri Astrophysical Observatory, Italy

Pulsar Wind Nebulae are highly intriguing astrophysical objects in many respects. They are the brightest and closest class of relativistic sources, and hence the ultimate laboratory for the physics of relativistic plasmas: several processes observed (or inferred to occur) in other classes of relativistic sources can here be studied with unique detail.

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Wednesday 29 March 2017, 11:00. Location: C4.174

Looking for giant rings around a directly imaged exoplanet in 2017 - the bRing Project

Matthew Kenworthy — Leiden University

In 2007, the 20 million year old pre-main sequence star J1407 underwent a complex series of eclipses lasting two months, showing temporal structure down to a timescale of 20 minutes. We interpret this as a giant ring system surrounding an unseen secondary companion, J1407b, that is being sculpted by forming exomoons.

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Wednesday 22 March 2017, 11:00. Location: C4.174

Effective Astronomy Public Engagement and Communication

Stephen Pompea — NOAO

Public engagement and science communication is a key mission of the US National Optical Astronomy Observatory, in Tucson, Arizona and La Serena, Chile. They are experimenting to create broad reaching programs that can improve science education and communicate the excitement of astronomy to the public.

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Wednesday 15 March 2017, 11:00. Location: C4.174

From Rorschach to Reality: gaining insight into the local interstellar medium through radio-polarimetry of Galactic synchrotron radiation

Marijke Haverkorn — Nijmegen

Diffuse, polarized radio synchtrotron emission from the Milky Way encodes information about its magnetic field, cosmic ray distribution and thermal electron density. With the advent of the technique of Rotation Measure Synthesis, we can now do Faraday Tomography.

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Wednesday 8 March 2017, 11:00. Location: C4.174

Problem of progenitors of type Ia supernovae

Marat Gilfanov — API -- MPA Garching

Despite the great importance of type Ia supernovae for measuring cosmic distances, there is yet no definitive model for their origin. The key element of the single degenerate scenario - an accreting nuclear burning white dwarf, becomes a powerful source of soft X-ray and UV radiation prior to the supernova explosion.

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Wednesday 1 March 2017, 11:00. Location: C4.174

Measuring gravitational-wave memory with LIGO and Pulsar Timing Arrays

Yuri Levin — Monash University, Australia

Mergers of black holes cause permanent deformation of space, due to the Christodoulou effect. While this gravitational-wave memory signal is weak, I will argue it will be measurable once advanced LIGO reaches its design sensitivity.

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Wednesday 22 February 2017, 11:00. Location: C4.174