Dr. Asaf Pe’er
University College Cork (Ireland), Bar-Ilan Universtiy (Israel)
GRBs, Cosmic rays and shock waves
Abstract:
The acceleration site of ultra-high energy cosmic rays is still an open question despite extended research.
Over 20 years ago it was proposed that GRBs are good candidates. However, data of GRB prompt emission spectra at the different bands can be used to put strong constraints on the physical conditions of the outflow. I will show that the physical conditions during the GRB prompt emission do not enable the acceleration of particles to ultra-high energies, both within the frames of the synchrotron and the photospheric emission models. I will show that this is the case also for low luminosity (ll) GRBs, such as GRB060218.
(If time permits) I will discuss some recent results on diffusive shock acceleration (DSA) theory. I will describe a new model for particle acceleration in arbitrarily turbulent magnetic field, which bridges the gap between the very weak and strong turbulence regimes. I will discuss the validity and limitations of the “Bohm”-type diffusion model.
Location: 31 Fitzwilliam Place
Upcoming seminars:
https://www.dias.ie/2018/10/23/astronomy-and-astrophysics-seminar-schedule-2019/(opens in a new tab)
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Posted: 20th March 2019 by Rebeca Garcia
2019-03-27, 15:00: Dr. Asaf Pe’er (University College Cork (Ireland), and Bar-Ilan University (Israel))
Dr. Asaf Pe’er
University College Cork (Ireland), Bar-Ilan Universtiy (Israel)
GRBs, Cosmic rays and shock waves
Abstract:
The acceleration site of ultra-high energy cosmic rays is still an open question despite extended research.
Over 20 years ago it was proposed that GRBs are good candidates. However, data of GRB prompt emission spectra at the different bands can be used to put strong constraints on the physical conditions of the outflow. I will show that the physical conditions during the GRB prompt emission do not enable the acceleration of particles to ultra-high energies, both within the frames of the synchrotron and the photospheric emission models. I will show that this is the case also for low luminosity (ll) GRBs, such as GRB060218.
(If time permits) I will discuss some recent results on diffusive shock acceleration (DSA) theory. I will describe a new model for particle acceleration in arbitrarily turbulent magnetic field, which bridges the gap between the very weak and strong turbulence regimes. I will discuss the validity and limitations of the “Bohm”-type diffusion model.
Location: 31 Fitzwilliam Place
Upcoming seminars:
https://www.dias.ie/2018/10/23/astronomy-and-astrophysics-seminar-schedule-2019/(opens in a new tab)
Category: Seminars
You're invited to join us for the @StpDias Statutory Public Lecture 2019 on 23 May 2019, 6pm by Prof. Don Zagier in @tcddublin. Prof. Zaigier will deliver an exciting look at 'Numbers, Knots, & Quantum Theory'. Info and tickets at: bit.ly/2JLsAUj #DIASdiscovers
As part of IQF 2019 on 22 May, Prof. Marika Taylor will explain what #BlackHoles might teach us about #QuantumComputing and conversely, what quantum theory implies about the fundamental properties of black holes. Register at bit.ly/2WuKgHo #DIASdiscovers
The annual Irish Quantum Foundations meeting will take place this year in @tcddublin on 23 & 24 May, bringing together Irish and international theoretical physicists who work fundamental theory and quantum foundations. More info and registration at maths.tcd.ie/~tristan/IQF20….
At last week's final #WhatIsLife lecture, Director of @StpDias Professor Werner Nahm contemplated the impact of Ada Yonath's work for the question 'what is life?' and tying into the impact and legacy of #Schrödinger. #DIASdiscovers
Martin Möllhoff, Director of Irish National Seismic Network spoke to @OceanFmIreland about yesterday's earthquake in Donegal. You can lsiten back at: oceanfm.ie/2019/04/30/ano… #DIASdiscovers
On Thursday, Werner Nahm had us 'thinking outside the box' at the fourth and final @DIAS_Dublin 'What is Life?' lecture series. The series commemorated the 75th anniversary of Erwin #Schrödinger's ground breaking series being published as a book. #DIASdiscovers
Another Earthquake recorded in Donegal by the Irish National Seismic Network. Magnitude 2.1. You can read more about it at tinyurl.com/y4bewx3h. #DIASdiscovers twitter.com/dias_geophysic…
If you haven't booked your place at today's lunchtime lecture from the @StpDias, exploring the legacy of Schrödinger’s 'What is Life?' lectures and book, do so now at: bit.ly/2KZStSH It's te final one lecture of the series. #DIASdiscovers
Don't miss the 4th and final lecture in our #WhatisLife series with Prof Werner Nahm, Director of @StpDias, looking at ‘Beyond the ‘What is Life?’ lectures and book’. This lecture, at 1pm tomorrow, will explore the legacy of Professor Erwin Schrödinger. bit.ly/2KZStSH
#DidYouKnow the recent earthquake in Donegal was not the county's first? In fact, they're well used to a tremor or 2.7 in the North West. Read about the county's ground shaking history in The @IrishTimes at: bit.ly/2UTkAHw #DIASdiscovers
#OTD John T. Lewis was born in 1932. Lewis served as Director of @StpDias and was described by @IrishTimes as a 'theoretical physicist who revolutionized telecommunication.' You can read his obituary in the @LondonMathSoc newsletter at: bit.ly/2XeTrvn #DIASdiscovers
The @IrishResearch Advanced Laureate Awards are crucial for frontier basic research #LoveIrishResearch #DIASdiscovers twitter.com/IrishResearch/…