Hertfordshire Astronomy 2021-24

Lead Research Organisation: University of Hertfordshire
Department Name: School of Physics, Astronomy and Maths

Abstract

The Centre for Astrophysics Research carries out observational programmes spanning the wavelength range from X-ray to radio -- supporting this by computer modelling and simulation. Our research ranges from observations of the most distant and extreme galaxies in the universe through to novel statistical analyses of observations seeking to detect planets outside our Solar System. In between these extremes, we seek to understand the properties of brown dwarfs and young stars, we carry out radio surveys of the Milky Way and of nearby galaxies, and we are pioneering wide-area surveys both of the northern radio sky and of the redshifts of the vast number of galaxies that the radio surveys will discover. Our research makes use of observations from all of the main European and international astronomical observatories, including ground-based observatories at optical, radio and submillimetre wavelengths, and space observatories at wavelengths ranging from the far infrared to X-rays. Computer simulations gives us a better understanding of the physical processes detected in our observations, and we need to apply advanced data-mining techniques to work with the very large datasets we are generating.

Planned Impact

We identify three classes of beneficiaries from this research:

1) academic beneficiaries

2) the general public and particularly teachers and pupils in schools locally, nationally and internationally through our outreach and public engagement programme.

3) industry, directly through collaborations / technology transfer, indirectly through our training of undergraduate and graduate students.

For academic beneficiaries see the relevant section of the proposal.

Our outreach and public engagement programme is very strongly driven by the cutting-edge research funded by the STFC grant. Elements of this include (i) public open evenings at the Bayfordbury observatory, which generally have a research-based theme; this reaches local people, particularly families, which is important as parents, along with teachers, are most influential in the career choice of young people. (ii) Observatory group visits from a very wide range of groups, again often including young people. (iii) International outreach through international development programmes in locations such as Thailand and sub-Saharan Africa. In addition, we access the wider public through national and international print media, websites, popular books, TV and radio appearances and so on.

We have close links with various commercial organizations, such as Airbus Defence and Space a few miles away in Stevenage, with whom we have in the past collaborated on project proposals, and GES Ltd, the commercial organization developing the Goonhilly Earth Station for various purposes including public engagement and radio astronomy use. These contacts necessarily rely on the cutting-edge science and technical skills supported by STFC.

Publications

10 25 50
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Alegre L (2022) A machine-learning classifier for LOFAR radio galaxy cross-matching techniques in Monthly Notices of the Royal Astronomical Society

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Barkus B (2022) The application of ridgelines in extended radio source cross-identification in Monthly Notices of the Royal Astronomical Society

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Davis F (2022) Radio AGN in nearby dwarf galaxies: the important role of AGN in dwarf galaxy evolution in Monthly Notices of the Royal Astronomical Society

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Delhaize J (2021) MIGHTEE: are giant radio galaxies more common than we thought? in Monthly Notices of the Royal Astronomical Society

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Di Stefano R (2023) SCATTER: A New Common Envelope Formalism in The Astrophysical Journal

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Gloudemans A (2021) Low frequency radio properties of the z > 5 quasar population in Astronomy & Astrophysics

 
Title LOFAR Two-metre Sky Survey Deep Fields DR1 
Description VizieR online Data Catalogue associated with article published in journal Astronomy & Astrophysics with title 'The LOFAR Two Metre Sky Survey: Deep Fields Data Release 1. III. Host-galaxy identifications and value added catalogues.' (bibcode: 2021A&A...648A...3K) 
Type Of Material Database/Collection of data 
Year Produced 2021 
Provided To Others? Yes  
Impact The data release for the LoTSS deep fields. Huge impact in terms of publications both by the team and the wider community. 
URL https://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/648/A3
 
Title The LOFAR Two-metre Sky Survey -- V. Second data release 
Description In this data release from the LOFAR Two-metre Sky Survey (LoTSS) we present 120-168MHz images covering 27% of the northern sky. Our coverage is split into two regions centred at approximately 12h45m +44$^\circ$30' and 1h00m +28$^\circ$00' and spanning 4178 and 1457 square degrees respectively. The images were derived from 3,451hrs (7.6PB) of LOFAR High Band Antenna data which were corrected for the direction-independent instrumental properties as well as direction-dependent ionospheric distortions during extensive, but fully automated, data processing. A catalogue of 4,396,228 radio sources is derived from our total intensity (Stokes I) maps, where the majority of these have never been detected at radio wavelengths before. At 6" resolution, our full bandwidth Stokes I continuum maps with a central frequency of 144MHz have: a median rms sensitivity of 83$µ$Jy/beam; a flux density scale accuracy of approximately 10%; an astrometric accuracy of 0.2"; and we estimate the point-source completeness to be 90% at a peak brightness of 0.8mJy/beam. By creating three 16MHz bandwidth images across the band we are able to measure the in-band spectral index of many sources, albeit with an error on the derived spectral index of +/-0.2 which is a consequence of our flux-density scale accuracy and small fractional bandwidth. Our circular polarisation (Stokes V) 20" resolution 120-168MHz continuum images have a median rms sensitivity of 95$µ$Jy/beam, and we estimate a Stokes I to Stokes V leakage of 0.056%. Our linear polarisation (Stokes Q and Stokes U) image cubes consist of 480 x 97.6 kHz wide planes and have a median rms sensitivity per plane of 10.8mJy/beam at 4' and 2.2mJy/beam at 20"; we estimate the Stokes I to Stokes Q/U leakage to be approximately 0.2%. Here we characterise and publicly release our Stokes I, Q, U and V images in addition to the calibrated uv-data. 
Type Of Material Database/Collection of data 
Year Produced 2022 
Provided To Others? Yes  
Impact Huge number of current and future publications both by the LoTSS consortium and by the general science community. 
URL https://arxiv.org/abs/2202.11733
 
Description LOFAR Surveys KSP 
Organisation Leiden University
Department Leiden Observatory
Country Netherlands 
Sector Academic/University 
PI Contribution Data analysis, radio astronomy expertise
Collaborator Contribution Observations, survey planning
Impact A number of publications on individual objects; survey publications, many led from Hertfordshire, are forthcoming.
Start Year 2014
 
Description LOFAR Surveys KSP 
Organisation Royal Observatory Edinburgh
Country United Kingdom 
Sector Academic/University 
PI Contribution Data analysis, radio astronomy expertise
Collaborator Contribution Observations, survey planning
Impact A number of publications on individual objects; survey publications, many led from Hertfordshire, are forthcoming.
Start Year 2014
 
Description LOFAR Surveys KSP 
Organisation University of Oxford
Department Department of Physics
Country United Kingdom 
Sector Academic/University 
PI Contribution Data analysis, radio astronomy expertise
Collaborator Contribution Observations, survey planning
Impact A number of publications on individual objects; survey publications, many led from Hertfordshire, are forthcoming.
Start Year 2014
 
Description The WEAVE collaboration 
Organisation University of Groningen
Department Kapteyn Astronomical Institute
Country Netherlands 
Sector Academic/University 
PI Contribution I lead the WEAVE-LOFAR Science team, which is the highest priority extragalactic survey that will be conducted with WEAVE. I was recently recognised as a Builder of the WEAVE facility, which has guaranteed publication rights, in recognition of my fundamental contribution to the WEAVE science case and infrastructure.
Collaborator Contribution My partners across the WEAVE consortium have built the instrument, and are in the process of installing it on the William Herschel Telescope.
Impact 2016sf2a.conf..271S
Start Year 2015
 
Description The WEAVE collaboration 
Organisation University of Oxford
Department Astrophysics
Country United Kingdom 
Sector Academic/University 
PI Contribution I lead the WEAVE-LOFAR Science team, which is the highest priority extragalactic survey that will be conducted with WEAVE. I was recently recognised as a Builder of the WEAVE facility, which has guaranteed publication rights, in recognition of my fundamental contribution to the WEAVE science case and infrastructure.
Collaborator Contribution My partners across the WEAVE consortium have built the instrument, and are in the process of installing it on the William Herschel Telescope.
Impact 2016sf2a.conf..271S
Start Year 2015