Seminars
Upcoming Seminars
The what, where, and who of Galactic PeVatrons as probed by high-energy observations and future CTAO prospects
| Speaker | Dr. Fabio Acero CEA Saclay (France) |
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| Time | Tuesday 21st October, 1pm | |
| Location | B000-Beech Hill |
In the last decade, significant progress has been made on the question of the nature and energetics of particles accelerated in SNRs and PWNe by combining the gamma-ray observations provided by the Fermi-LAT at GeV and Cherenkov telescopes at TeV. However, in order to explain the Galactic cosmic-ray spectrum, Galactic accelerators should be able to generate particles up to PeV (10^15 eV) energies, and this evidence has been so far lacking. Water Cherenkov detectors, in particular LHAASO, have provided a transformational view on the gamma-ray sky at 100 TeV, giving new insights on the nature of Galactic PeVatrons. This seminar will discuss the different ways our community is defining PeVatron sources, where we expect to find them, and how our focus has gradually shifted from SNRs to PWNe as plausible PeV accelerators. An overview of the recent GeV and multi-TeV measurements motivating this shift will be presented, followed by a discussion of the advancements that will be made with the next generation Cherenkov Telescope Array Observatory (CTAO) in particular on particle acceleration in supernovae.
The BOAT that rocked: the afterglow of GRB 221009A
| Speaker | Dr. Lauren Rhodes McGill University (Canada) |
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| Time | Thursday 1st May, 2pm | |
| Location | B106-Beech Hill |
GRB 221009A has been dubbed the BOAT or brightest of all time for its record-breaking gamma-ray brightness. At radio frequencies, it is also the brightest radio counterpart detected to date. In this talk, I will present a summary of the observations conducted by my collaborators and I (Bright & Rhodes et al 2023, Fulton et al 2023, Rhodes et al 2024), resulting in comprehensive multi-wavelength coverage including the most detailed radio study of any GRB to date. Our radio campaign spanned over three orders of magnitude in frequency space starting a few hours post burst and continuing to this day. I will discuss the importance of such coverage for theoretical modelling and our understanding of jet geometry. Finally, I will present a brief overview of our plans to continue monitoring this fascinating object.
Ionic Liquids: Applications in Protein Kinetics, Dynamics and Aggregation
| Speaker | Prof. Harekrushna Sahoo National Institute of Technology (Roukela, IND) |
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| Time | Friday 7th March, 10am | |
| Location | Conway Lecture Theatre |
High-Resolution Studies of the Inner Circumstellar Disks of Herbig Ae/Be Stars
| Speaker | Robin Mentel University College Dublin |
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| Time | Thursday 13th February, 10:30am | |
| Location | BH C102 Boardroom |
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 |
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| Time | Tuesday 14th January, 14pm | |
| Location | B106 - Beech Hill |