The far-infrared-radio correlation in MS0451-03

We present a multiwavelength analysis of star-forming galaxies in the massive cluster MS0451.6-0305 at z ˜ 0.54 to shed new light on the evolution of the far-infrared-radio relationship in distant rich clusters. We have derived total infrared luminosities for a spectroscopically confirmed sample of cluster and field galaxies through an empirical relation based on Spitzer Multiband Imaging Photometer for Spitzer 24 μm photometry. The radio flux densities were measured from deep Very Large Array 1.4 GHz radio continuum observations. We find the ratio of far-infrared to radio luminosity for galaxies in an intermediate-redshift cluster to be qFIR = 1.80 ± 0.15 with a dispersion of 0.53. Due to the large intrinsic dispersion, we do not find any observable change in this value with either redshift or environment. However, a higher percentage of galaxies in this cluster show an excess in their radio fluxes when compared to low-redshift clusters (27^{+23}_{-13} per cent to 11 per cent), suggestive of a cluster enhancement of radio-excess sources at this earlier epoch. In addition, the far-infrared-radio relationship for blue galaxies, where qFIR = 2.01 ± 0.14 with a dispersion of 0.35, is consistent with the predicted value from the field relationship, although these results are based on a sample from a single cluster

MIGHTEE : total intensity radio continuum imaging and the COSMOS/XMM-LSS Early Science fields

Please read abstract in the article.The UK Science and Technology Facilities Council; the South African Radio Astronomy Observatory; the Leverhulme Trust through an Early Career Research Fellowship; the South African Research Chairs Initiative of the Department of Science and Technology; the National Research Foundation; the Science and Technology Foundation (FCT, Portugal); the UK STFC ; the South African Research Chairs Initiative of the Department of Science and Innovation; the Bundesministerium für Bildung und Forschung (BMBF); the Italian Ministry of Foreign Affairs and International Cooperation; the South African Department of Science and Technology’s National Research Foundation (DST-NRF).https://academic.oup.com/mnrashj2022Physic

MIGHTEE: multi-wavelength counterparts in the COSMOS field

In this paper we combine the Early Science radio continuum data from the MeerKAT International GHz Tiered Extragalactic Exploration (MIGHTEE) Survey, with optical and near-infrared data and release the cross-matched catalogues. The radio data used in this work covers 0.86 deg2 of the COSMOS field, reaches a thermal noise of 1.7 μJy/beam and contains 6102 radio components. We visually inspect and cross-match the radio sample with optical and near-infrared data from the Hyper Suprime-Cam (HSC) and UltraVISTA surveys. This allows the properties of active galactic nuclei and star-forming populations of galaxies to be probed out to z≈5. Additionally, we use the likelihood ratio method to automatically cross-match the radio and optical catalogues and compare this to the visually cross-matched catalogue. We find that 94 per cent of our radio source catalogue can be matched with this method, with a reliability of 95 per cent. We proceed to show that visual classification will still remain an essential process for the cross-matching of complex and extended radio sources. In the near future, the MIGHTEE survey will be expanded in area to cover a total of ∼20~deg2; thus the combination of automated and visual identification will be critical. We compare redshift distribution of SFG and AGN to the SKADS and T-RECS simulations and find more AGN than predicted at z∼1

MIGHTEE : are giant radio galaxies more common than we thought?

Please read abstract in the article.DATA AVAILABILITY: The data underlying this article were accessed from the South African Radio Astronomy Observatory (SARAO; www.ska.ac.za).The National Research Foundation (NRF), SARAO. MP, SMR, the UK Science and Technology Facilities Council, the Oxford Hintze Centre for Astrophysical Surveys that is funded through generous support from the Hintze Family Charitable Foundation, the Rhodes University Centre for Radio Astronomy Techniques and Technologies (RATT), the European Union’s Horizon 2020 research and innovation program under a Marie Skłodowska-Curie grant, the Inter-University Institute for Data Intensive Astronomy (IDIA), the South African Research Chairs Initiative of the NRF, the Glasstone Foundation, the Italian Ministry of Foreign Affairs and International Cooperation, the Science and Technology Foundation (FCT, Portugal), the Science and Technology Facilities Council (STFC), the South African Astronomical Observatory, the Bundesministerium für Bildung und Forschung (BMBF), the Inter-University Institute for Data Intensive Astronomy (IDIA) and the ERC-Stg DRANOEL.https://academic.oup.com/mnrashj2022Physic