Astrophysics and Cosmology Research at the JBCA 2020-2023

Lead Research Organisation: University of Manchester
Department Name: Physics and Astronomy

Abstract

This grant supports the research of the Jodrell Bank Centre for Astrophysics at the University of Manchester. Our research is a divided into 3 groups. There are too many specific proposals to describe in detail, do below we have given a brief layman's explanation of the work being carried out by the three groups.

Cosmology: This is the study of the Universe as a whole. The main aim is to understand the processes by which the large scale feature of the Universe formed and to constrain the various different kinds of matter that existed within it. These include dark matter and dark energy which are thought to constitute more than 95% of the total. We do this by comparison to observations of weak and strong gravitational lensing which is the distortion of light predicted to be caused by massive objects in Einstein' Theory of General Relativity, the cosmic microwave background which is the faint emission of radiation created at the time when protons and electrons come together to form hydrogen and the emission given off by neutral hydrogen atoms in galaxies. The research we propose here involves both theory and observation as well as the development of the technology necessary to make the observations possible.

Sun, Stars and Galaxies: The researchers in this group study a wide range of astrophysical processes that are reasonable for the formation and evolution of the objects in the name of the group. Specific key areas that the group is interested in are the formation of stars much larger than the Sun and the subsequent evolution, the properties of the so-called interstellar medium (ISM) which comprises molecules not bound to stars and the magnetic fields that permeate space.

Pulsars and Time Domain Astrophysics: The focus of this group is astrophysical signatures that are changing with time- things which come on and off, often with some kind of regularity. These include Pulsars which are a non-standard star type, known as a neutron star, which is a dead star supported by the quantum pressure of neutrons. The radio emission from these objects pulses on an off with extraordinary regularity allowing them to acts cosmic clocks. The constantly measuring these clocks as the neutron stars spin and move through space, often impacted on by a companion star, allows the most precise constraints on the nature of gravity outside the solar system. Other phenomena studied by this group include Nova explosions, other variable stars, and variability induced by the lensing effects of one star passing in front of another, called microlensing.

Planned Impact

The range of research we undertake and the world-class facilities within and in close association with JBCA (the Jodrell Bank Discovery Centre, e-MERLIN, the Lovell Telescope, the ALMA ARC and the SKA HQ) will provide key pathways to increasing our already strong impact on UK and global industry, the next generation of scientists and engineers, and the general public. The University's investment in the Jodrell Bank site combined with significant external funding (e.g. from Heritage Lottery Fund) will enable us to expand its use as an iconic venue for public and industrial engagement. The programme described here formed a key part of the School's submission for REF2014, helping it to be ranked highest in the REF for physics impact with 83% at 4* and 17% at 3*. Our outreach \& public engagement programme is extremely strong and continues to grow, particularly through its work with the University's award-winning Jodrell Bank Discovery Centre and the BBC. With the recent decision on SKA HQ location and our strong research work in this area, there is also growing impact in both outreach and industrial engagement in this area.

Our "Pathways to Impact" statement in the case for support outlines things that we have done in recent times under the headings of "Outreach and Public Engagement" and "Industrial and economic impact". We list some highlights below.

- Jodcast: Podcast run by students with 7000 regular listeners.
- 215000 Twitter and 18000 Facebook followers
- Stargazing live, Pulsar Hunters, Science Programmes presented by Danielle George
- JB Discovery centre with 190000 visitors per year
- Award winning Bluedot Festivals
- Industry contracts for SKA work including CISCO, AASL, NPL, AEON, Critical Software, MMI, GEANT
- Newton programme for Radio Astronomy in Africa.

Publications

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Title IPTA DR2 - GWB analysis MCMC output 
Description IPTA DR2 common red noise, MCMC output These files are the primary output from a Markov chain Monte Carlo (MCMC) sampling process. They are samples from the posterior probability distribution for a particular model described in the companion paper. Each zipped tarball contains four files. The "chain" file has several tab-separated columns, each of which corresponds to a model parameter, except the last four which are metadata. The parameter names (including metadata) are listed in the companion "params" file. The frequencies used in the common red noise models are listed in the "crn_frequencies" file. Additional information is provided in a README file. Each row of the chain file is one sample from the model posterior. The first samples at the beginning of the MCMC are the "burn-in" phase, before the chain has converged to the posterior. We recommend discarding the first ~25% of samples before using them to make inferences. 
Type Of Material Database/Collection of data 
Year Produced 2022 
Provided To Others? Yes  
URL https://zenodo.org/record/5787556