New Space and Tech

Bursts From Space: MeerKAT – The First Citizen Science Project Dedicated To Commensal Radio Transients

By Keith Cowing
Status Report
astro-ph.HE
May 7, 2023
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Bursts From Space: MeerKAT – The First Citizen Science Project Dedicated To Commensal Radio Transients
The mean optical and radio flux densities of our sample of radio variables, atop an underlying distribution of astrophysical classes (Stewart et al. 2018). Black crosses denote counterparts within the MeerLICHT database whilst grey triangles are upper limits. Diagonal lines denote a constant ratio between radio and optical flux density, whilst the 𝐴𝑅 marker indicates the horizontal displacement caused by 5 magnitudes of optical extinction. The majority of our radio sources are likely extragalactic as they overlap in parameter space with quasars and GRBs. — astro-ph.IM

The newest generation of radio telescopes are able to survey large areas with high sensitivity and cadence, producing data volumes that require new methods to better understand the transient sky.

Here we describe the results from the first citizen science project dedicated to commensal radio transients, using data from the MeerKAT telescope with weekly cadence. Bursts from Space: MeerKAT was launched late in 2021 and received ~89000 classifications from over 1000 volunteers in 3 months. Our volunteers discovered 142 new variable sources which, along with the known transients in our fields, allowed us to estimate that at least 2.1 per cent of radio sources are varying at 1.28 GHz at the sampled cadence and sensitivity, in line with previous work.

We provide the full catalogue of these sources, the largest of candidate radio variables to date. Transient sources found with archival counterparts include a pulsar (B1845-01) and an OH maser star (OH 30.1-0.7), in addition to the recovery of known stellar flares and X-ray binary jets in our observations. Data from the MeerLICHT optical telescope, along with estimates of long time-scale variability induced by scintillation, imply that the majority of the new variables are active galactic nuclei. This tells us that citizen scientists can discover phenomena varying on time-scales from weeks to several years.

The success both in terms of volunteer engagement and scientific merit warrants the continued development of the project, whilst we use the classifications from volunteers to develop machine learning techniques for finding transients.

Alex Andersson, Chris Lintott, Rob Fender, Joe Bright, Francesco Carotenuto, Laura Driessen, Mathilde Espinasse, Kelebogile Gaseahalwe, Ian Heywood, Alexander J. van der Horst, Sara Motta, Lauren Rhodes, Evangelia Tremou, David R. A. Williams, Patrick Woudt, Xian Zhang, Steven Bloemen, Paul Groot, Paul Vreeswijk, Stefano Giarratana, Payaswini Saikia, Jonas Andersson, Lizzeth Ruiz Arroyo, Loïc Baert, Matthew Baumann, Wilfried Domainko, Thorsten Eschweiler, Tim Forsythe, Sauro Gaudenzi, Rachel Ann Grenier, Davide Iannone, Karla Lahoz, Kyle J. Melville, Marianne De Sousa Nascimento, Leticia Navarro, Sai Parthasarathi, Piilonen, Najma Rahman, Jeffrey Smith, B. Stewart, Newton Temoke, Chloe Tworek, Isabelle Whittle

Comments: Accepted to MNRAS, 14 pages + an appendix containing our main data table
Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Astrophysics of Galaxies (astro-ph.GA); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Cite as: arXiv:2304.14157 [astro-ph.HE] (or arXiv:2304.14157v1 [astro-ph.HE] for this version)
Submission history
From: Alex Andersson
[v1] Thu, 27 Apr 2023 12:53:38 UTC (3,453 KB)
https://arxiv.org/abs/2304.14157

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