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Seminars

Upcoming Seminars

High-Resolution Studies of the Inner Circumstellar Disks of Herbig Ae/Be Stars

  Speaker  Robin Mentel
University College Dublin
Time Thursday 13th February, 10:30am
Location  

PhD Defense.

Abstract:  Herbig Ae/Be stars constitute a fascinating bridge between low-mass and high-mass star formation. This talk present findings of the inner disk around these stars in order to characterise their environment using high-resolution optical and near-infrared spectroscopy. In a first project, the inner disk of the Herbig Ae star HD 141569 is studied with HI lines, showing that the disk is very compact, constrained within few stellar radii, and reaching very close to the star. This infers significant constraints on the nature of the disk winds around the star, and it's mass accretion mode. In a second project, the forbidden emission around a large sample of Herbig Ae/Be stars is studied. The results show a significant discrepancy to the emission from young low-mass stars, and shed light on the disk dispersal mechanisms around young intermediade-mass stars.

Finding Relativistic Stellar Explosions as Fast Optical Transients

  Speaker  Anna Ho
Cornell University 
Time Tuesday 14th January, 14pm
Location   B106 - Beech Hill
For the last half-century, relativistic outflows accompanying the final collapse of massive stars have predominantly been detected via high-energy emission, as long-duration gamma-ray bursts (GRBs). Yet, it has long been hypothesized that GRBs are the tip of the iceberg of relativistic stellar explosions. I will present results from a search for relativistic stellar explosions using optical time-domain surveys. The emerging zoo includes afterglows at cosmological distances with no detected GRB, supernovae with luminous X-ray and radio emission, and mysterious "fast blue optical transients" with minute-timescale optical flares at supernova-like luminosities. An understanding of the origin of these events and their relation to GRBs will be enabled by upcoming time-domain surveys in other bands, including X-ray, UV, and submillimeter.

Spatial and spectral characterization of micrometer scale soft x-ray emitting laser-produced plasmas

  Speaker  Kevin Mongey
University College Dublin
Time Tuesday 12th November, 9am
Location  

PhD Defence.

Abstract: n/a.

Archive of previous seminars: click here

UCD School of Physics

University College Dublin, Belfield, Dublin 4, Ireland.
T: +353 1 716 7777