The superMIGHTEE project: MeerKAT and GMRT Together to Unveil the Deep Radio Sky

Abstract

An international team of researchers has come together to undertake an ultra-broadband exploration of the deep radio sky. The superMIGHTEE project combines data from the MIGHTEE project, using the precursor Square Kilometre Array (SKA) MeerKAT telescope in South Africa, with observations from the upgraded Giant Metrewave Radio Telescope (uGMRT) in India to produce deep images at several $\mu$Jy sensitivity over a frequency range of 200 MHz--2.5 GHz, with an angular resolution of a few arcseconds. This paper describes the initial superMIGHTEE uGMRT data release, comprising total intensity continuum images covering a total of 9.9 deg${}^2$ at 650 MHz and 6.9 deg${}^2$ at 400 MHz in the XMM-LSS, COSMOS, and E-CDFS deep fields. The associated radio source catalogs include 27,101 sources at 650 MHz and 10,946 sources at 400 MHz. The redshift distribution of the sources extends to $z\sim 4$ with a median value of $z=1$. An overview of the broadband spectra of the sources, in combination with the MeerKAT MIGHTEE 1280 MHz data, reveals a clear change in spectral properties at the transition from an active galactic nuclei-dominated population to a population dominated by star-forming galaxies at flux densities of a few mJy. At higher frequencies, the star-forming galaxy population exhibits an optically thin synchrotron spectral index indicative of energy injection from supernovae. At lower frequencies, the spectra flatten significantly with decreasing flux density, and the fraction of sources with peaked spectra increases. This is the first superMIGHTEE uGMRT data release. Subsequent releases will include spectropolarimetric and spectral line image cubes, as well as images at lower frequencies. The goal of the superMIGHTEE ultra-wideband dataset is to enhance our understanding of the evolution of active galactic nuclei and star-forming galaxies over cosmic time, (abridged).

arXiv comment17 pages, 10 Figures, 5 Tables, accepted for publication in the Astrophysics Journal (2025, vol. 991, p. 9). The images and associated catalog data are available on the public data repository at the IDIA science gateway at, url: gateway.idia.ac.za with DOI url: http://dx.doi.org/10.71621/n9hd-sj09

References in corpus (34)

• CASA, the Common Astronomy Software Applications for Radio Astronomy
• The GMRT 150 MHz All-sky Radio Survey: First Alternative Data Release TGSS ADR1
• UltraVISTA: a new ultra-deep near-infrared survey in COSMOS
• First Data Release of the Hyper Suprime-Cam Subaru Strategic Program
• The LOFAR Two-metre Sky Survey -- V. Second data release
• The VLA-COSMOS 3 GHz Large Project: Continuum data and source catalog release
• An Accurate Flux Density Scale from 50 MHz to 50 GHz
• The Australia Telescope 20 GHz Survey: The Source Catalogue
• The VISTA Deep Extragalactic Observations (VIDEO) Survey
• GLEAM: The GaLactic and Extragalactic All-sky MWA survey
• The Rapid ASKAP Continuum Survey I: Design and First Results
• The VIMOS Public Extragalactic Survey (VIPERS): First Data Release of 57 204 spectroscopic measurements
• A lack of evolution in the very bright-end of the galaxy luminosity function from z = 8-10
• The VLA-COSMOS 3~GHz Large Project: AGN and host-galaxy properties out to z$\lesssim$6
• Extragalactic Peaked-Spectrum Radio Sources at Low Frequencies
• High velocity outflows from young star-forming galaxies in the UKIDSS Ultra-Deep Survey
• The sub-mJy radio sky in the Extended Chandra Deep Field South: source population
• Deep multi-frequency radio imaging in the Lockman Hole using the GMRT and VLA: I. The nature of the sub-mJy radio population
• Radio synchrotron spectra of star-forming galaxies
• Photometric redshifts for the next generation of deep radio continuum surveys - II. Gaussian processes and hybrid estimates
• Integrated Radio Continuum Spectra of Galaxies
• MIGHTEE: the nature of the radio-loud AGN population
• Degree of Polarization and Source Counts of Faint Radio Sources from Stacking Polarized Intensity
• HI in Abell 3128
• Multiwavelength characterization of faint Ultra Steep Spectrum radio sources : A search for high-redshift radio galaxies
• Deep GMRT 610 MHz Observations of the ELAIS N1 Field : Catalogue and Source Counts
• VLA imaging of the XMM-LSS / VIDEO deep field at 1-2 GHz
• Remnant Radio Galaxies Discovered in a Multi-frequency Survey
• A Wide-area GMRT 610~MHz survey of ELAIS N1 field
• Hybrid photometric redshifts for sources in the COSMOS and XMM-LSS fields
• Radio spectral properties of star-forming galaxies between 150-5000MHz in the ELAIS-N1 field
• Search and characterization of remnant radio galaxies in the XMM$-$LSS deep field
• Spectral age distribution for radio-loud active galaxies in the XMM-LSS field
• MIGHTEE: exploring the relationship between spectral index, redshift and radio luminosity

Cited by in corpus (1)

• Something Bright at the Edge of Everything: A Uniquely JWST-Dark Radio Source in COSMOS