THE SPINS-UK SEMINAR SERIES
We announce the launch of the new SPINS-UK seminar series, a monthly series of online talks about neutron star science. We hope that this will be a great tool to bring together the national neutron star community and to learn more about each other's activities, bringing to light new collaborations and discussions!
The seminars are held on Wednesdays, from 1-2pm UK time every 4 weeks. The inaugural talk took place on Wednesday 10th February.
Access to the seminar series is via the following Zoom link: https://zoom.us/j/95275667236
We are now inviting nominations and self-nominations for future speakers for this series. If you would like to propose a speaker to present a talk to the SPINS-UK community, please contact Lucy Oswald at lucy.oswald@physics.ox.ac.uk.
The seminars are held on Wednesdays, from 1-2pm UK time every 4 weeks. The inaugural talk took place on Wednesday 10th February.
Access to the seminar series is via the following Zoom link: https://zoom.us/j/95275667236
We are now inviting nominations and self-nominations for future speakers for this series. If you would like to propose a speaker to present a talk to the SPINS-UK community, please contact Lucy Oswald at lucy.oswald@physics.ox.ac.uk.
UPCOMING TALKS
Dr Andrei Igoshev
Date: Wednesday 10th March 2021
Time: 1pm UK time
Speaker: Dr Andrei Igoshev, Postdoctoral Fellow at the University of Leeds
Link: https://zoom.us/j/95275667236
Time: 1pm UK time
Speaker: Dr Andrei Igoshev, Postdoctoral Fellow at the University of Leeds
Link: https://zoom.us/j/95275667236
Sleeping beasts: magnetic fields shape observational manifestations of neutron stars
Neutron stars (NSs) are seen as radio pulsars, magnetars and central compact objects. Magnetars and central compact objects are bright, young NSs seen close to the centra of supernova remnants. Magnetars are extremely magnetised neutron stars which shows a variety of observational phenomena associated to their magnetic fields, such as burst and giant flashes. Both magnetars and central compact objects are much hotter than it is excepted even for very young neutron stars. We perform first three-dimensional simulations of the magneto-thermal evolution using a spectral MHD code. Our results show that presence of strong toroidal magnetic field in magnetars is necessary to explain their quiescent thermal emission, in particular a formation of a single hot spot. Using our thermal maps we are able to explain light curves of 10 out of 19 magnetars in quiescence.
In the case of the central compact objects, we test the configuration of magnetic field formed as a result of stochastic dynamo. Such a magnetic field consists of multiple randomly orientated loops of magnetic field. The global dipolar field slowly formed as a result of the Hall and Ohmic evolution. In our simulations we see 5-7% pulsed fraction, formation of a few compact hot regions and difference of two times in temperature between hot and cold regions typical for observations of the central compact objects.
Neutron stars (NSs) are seen as radio pulsars, magnetars and central compact objects. Magnetars and central compact objects are bright, young NSs seen close to the centra of supernova remnants. Magnetars are extremely magnetised neutron stars which shows a variety of observational phenomena associated to their magnetic fields, such as burst and giant flashes. Both magnetars and central compact objects are much hotter than it is excepted even for very young neutron stars. We perform first three-dimensional simulations of the magneto-thermal evolution using a spectral MHD code. Our results show that presence of strong toroidal magnetic field in magnetars is necessary to explain their quiescent thermal emission, in particular a formation of a single hot spot. Using our thermal maps we are able to explain light curves of 10 out of 19 magnetars in quiescence.
In the case of the central compact objects, we test the configuration of magnetic field formed as a result of stochastic dynamo. Such a magnetic field consists of multiple randomly orientated loops of magnetic field. The global dipolar field slowly formed as a result of the Hall and Ohmic evolution. In our simulations we see 5-7% pulsed fraction, formation of a few compact hot regions and difference of two times in temperature between hot and cold regions typical for observations of the central compact objects.
Dr Manisha Caleb
Date: Wednesday 7th April 2021
Time: 1pm UK time
Speaker: Dr Manisha Caleb, Postdoctoral Researcher at the University of Manchester
Link: https://zoom.us/j/95275667236
Time: 1pm UK time
Speaker: Dr Manisha Caleb, Postdoctoral Researcher at the University of Manchester
Link: https://zoom.us/j/95275667236
Fast radio bursts and their possible links to neutron stars
Fast radio bursts (FRBs) have a story which has been told and retold many times over the past few years as they have sparked excitement and controversy since the pioneering discovery in 2007. The FRB class encompasses a number of microsecond-millisecond duration pulses occurring at Galactic to cosmological distances with energies spanning over 5 orders of magnitude. While most FRBs have been observed as singular events, a small fraction of them have been observed to repeat over various timescales leading to an apparent dichotomy in the population. Though ~50 progenitor model theories have been proposed with the majority involving neutron stars, no consensus has emerged for their origin(s). However, with the discovery of an FRB-like pulse from the Galactic magnetar SGR J1935+2154, magnetar engine models appear to be the current leading favourite. In this talk, I will present an overview of the field of FRBs and the recent results from the MeerTRAP project at the MeerKAT radio telescope.
Fast radio bursts (FRBs) have a story which has been told and retold many times over the past few years as they have sparked excitement and controversy since the pioneering discovery in 2007. The FRB class encompasses a number of microsecond-millisecond duration pulses occurring at Galactic to cosmological distances with energies spanning over 5 orders of magnitude. While most FRBs have been observed as singular events, a small fraction of them have been observed to repeat over various timescales leading to an apparent dichotomy in the population. Though ~50 progenitor model theories have been proposed with the majority involving neutron stars, no consensus has emerged for their origin(s). However, with the discovery of an FRB-like pulse from the Galactic magnetar SGR J1935+2154, magnetar engine models appear to be the current leading favourite. In this talk, I will present an overview of the field of FRBs and the recent results from the MeerTRAP project at the MeerKAT radio telescope.
Dr Diego Altamirano
Date: TBC
Time: 1pm UK time
Speaker: Dr Diego Altamirano, Principal Research Fellow at the Astronomy Group, School of Physics and Astronomy, University of Southampton
Link: https://zoom.us/j/95275667236
Time: 1pm UK time
Speaker: Dr Diego Altamirano, Principal Research Fellow at the Astronomy Group, School of Physics and Astronomy, University of Southampton
Link: https://zoom.us/j/95275667236
Dr Danai Antonopoulou
Date: TBC
Time: 1pm UK time
Speaker: Dr Danai Antonopoulou, Stephen Hawking Fellow at the University of Manchester
Link: https://zoom.us/j/95275667236
Time: 1pm UK time
Speaker: Dr Danai Antonopoulou, Stephen Hawking Fellow at the University of Manchester
Link: https://zoom.us/j/95275667236
PREVIOUS TALKS
Inaugural talk - Dr Sam Lander
Date: Wednesday 10th February 2021
Time: 1pm UK time
Speaker: Dr Sam Lander, Lecturer in Physics at UEA
Link: https://zoom.us/j/95275667236
Time: 1pm UK time
Speaker: Dr Sam Lander, Lecturer in Physics at UEA
Link: https://zoom.us/j/95275667236
The early life of a neutron star's magnetic field
Neutron stars host the strongest magnetic fields in the Universe, but we still do not have a clear picture of what makes them so strong, nor why the field strengths of young neutron stars vary over roughly four orders of magnitude. This talk will provide an overview of ideas about how dynamo processes might generate highly intense magnetic fields, discussing potential problems with different candidate mechanisms and asking whether any other physics could drive field amplification. After dynamo action has ceased, we present models for the kind of steady state to which the young star’s magnetic field might relax. We conclude by showing how the birth physics of neutron stars could be constrained through measurements of their magnetic inclination angles.
Neutron stars host the strongest magnetic fields in the Universe, but we still do not have a clear picture of what makes them so strong, nor why the field strengths of young neutron stars vary over roughly four orders of magnitude. This talk will provide an overview of ideas about how dynamo processes might generate highly intense magnetic fields, discussing potential problems with different candidate mechanisms and asking whether any other physics could drive field amplification. After dynamo action has ceased, we present models for the kind of steady state to which the young star’s magnetic field might relax. We conclude by showing how the birth physics of neutron stars could be constrained through measurements of their magnetic inclination angles.
