MeerKAT Open Time Project

MeerLIRGs

MeerKAT Luminous Infrared Galaxies survey

A 1.28 GHz MeerKAT radio continuum survey of all 298 Southern Luminous Infrared Galaxies from the IRAS Revised Bright Galaxy Sample — the deepest, most complete radio census of the local dusty universe ever conducted from the southern hemisphere.

1.28 GHz Continuum Infrared Galaxies Star Formation AGN vs. Starburst IR–Radio Correlation Galaxy Mergers
298
Southern LIRGs (RBGS)
~340
Square Degrees
20 μJy
rms Sensitivity / beam
7.5″
Angular Resolution
1.28 GHz
L-band Frequency

Why Luminous Infrared Galaxies?

Luminous Infrared Galaxies (LIRGs; LTIR ≥ 1011 L) and their ultra-luminous cousins (ULIRGs) rank among the most intensely star-forming systems in the universe. Though rare locally, U/LIRGs account for more than half of the cosmic infrared background and dominate the total star formation rate at z ≳ 1. Their extreme luminosities — often triggered by galaxy–galaxy mergers — make them ideal laboratories for studying the interplay between star formation, AGN fuelling, and dust obscuration that shaped the universe we see today. Radio observations uniquely pierce through the dust that blinds optical and UV telescopes.

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Radio Continuum Census

The first complete 1.28 GHz MeerKAT continuum census of all Southern LIRGs drawn from the IRAS Revised Bright Galaxy Sample, combining new MeerKAT observations with archival VLA data for complete sky coverage.

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IR–Radio Correlation

Measuring the total-infrared to radio correlation (qTIR) across the full RBGS sample, exploring how merger status, AGN activity, and interaction stage affect this fundamental calibrator of star formation rate.

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AGN vs. Starburst Disentanglement

Using radio morphology, spectral classifications, and WISE mid-infrared colour diagnostics to separate AGN-dominated and starburst-dominated systems — resolving the ambiguity that dust obscuration creates at optical wavelengths.

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Background Source Science

The wide MeerKAT primary beam captures hundreds of background radio sources per field. A dedicated commensal programme cross-matches these with multi-wavelength catalogues to study AGN populations and giant radio galaxies.

Merger-Triggered Emission

Comparing the infrared–radio properties of isolated versus interacting and merging LIRGs to quantify the role of galaxy–galaxy interactions in driving starburst activity and in fuelling supermassive black holes.

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Legacy Data Products

Producing public radio continuum mosaics, source catalogues, and cross-matched multi-wavelength tables — community resources designed to underpin future SKA and Rubin/LSST science in the local universe.


Survey Design

MeerLIRGs was observed under two MeerKAT Open Time programmes targeting the complete southern sky sample of LIRGs. Data reduction, continuum imaging, and mosaic production are performed using standard MeerKAT pipelines, with final products hosted at IDIA/ilifu for team access.

Primary Sample
298 LIRGs (RBGS)
Secondary Sample
43 galaxies (IRAS 12MGS)
Frequency
1.28 GHz (L-band)
Resolution
7.5 arcsec
RMS Sensitivity
~20 μJy / beam
Sky Coverage
~340 deg²
MeerKAT OT PIDs
SCI-20210212-TJ-01
SCI-20220822-LM-01
Data Processing
IDIA / ilifu
Ancillary Data
VLA, WISE, Herschel, IRAS

Principal Investigators & Collaborators

MeerLIRGs is led from the University of Cape Town and IDIA in collaboration with SARAO, international partners, and a growing group of students and postdocs.

Dr. Lucia Marchetti
UCT · INAF-IRA Bologna
PI — Multi-wavelength extragalactic surveys, infrared galaxy populations, radio continuum science.
Prof. Tom Jarrett
UCT
Co-PI — Infrared survey astronomy, WISE galaxy characterisation, large-scale structure.
Prof. James Condon
NRAO
Co-I — Radio continuum surveys, IRAS galaxy samples, radio source populations.
Dr. Bill Cotton
NRAO · SARAO
Co-I — Radio interferometry, VLA and MeerKAT data calibration and imaging.
Dr. Amy Matthews
Carnegie Observatories
Co-I — Radio continuum properties of LIRGs, multi-frequency analysis.
Dr. Tony Mauch
SARAO
Co-I — MeerKAT operations, radio survey science, source catalogue production.
Prof. Mattia Vaccari
UCT · IDIA
Co-I — Panchromatic data fusion, photometric redshifts, astroinformatics and ilifu cloud infrastructure.
Malebo Moloko
UCT
PhD Student — Infrared–radio correlation, AGN/starburst classification, RBGS analysis.

Key Papers

A MeerKAT 1.28 GHz Atlas of Southern Sources in the IRAS Revised Bright Galaxy Sample
Condon, Cotton, Jarrett, Marchetti, Matthews, Mauch, Moloko (2021)
The Astrophysical Journal Supplement Series, Volume 257, Issue 2, id.35, 23 pp. · 2021ApJS..257...35C
Probing the Infrared–Radio Correlation of the Full IRAS Revised Bright Galaxy Sample with MeerKAT and the VLA
Moloko, Marchetti, Jarrett, Condon, Cotton, Matthews, Mauch, Vaccari (2025)
Monthly Notices of the Royal Astronomical Society, 543, 2463 · 2025MNRAS.543.2463M
Investigating the Background Radio Sources in the MeerLIRGs Fields
Supervised by Marchetti & Vaccari (UCT) · Student project by Kenzo Sandernbergh 2026/2027
In preparation · MeerKAT commensal science programme