EMU/GAMA: A new approach to characterising radio luminosity functions
Abstract This study characterises the radio luminosity functions (RLFs) for star forming galaxies (SFGs) and active galactic nuclei (AGN) using statistical redshift estimation in the absence of comprehensive spectroscopic data. Sensitive radio surveys over large areas detect many sources with faint optical and infrared counterparts, for which redshifts and spectra are unavailable. This challenges our attempt to understand the population of radio sources. Statistical tools are often used to model parameters (such as redshift) as an alternative to observational data. Using the data from GAMA G23 and EMU early science observations, we explore simple statistical techniques to estimate the redshifts in order to measure the RLFs of the G23 radio sources as a whole and for SFGs and AGN separately. Redshifts and AGN/SFG classifications are assigned statistically for those radio sources without spectroscopic data. The calculated RLFs are compared with existing studies, and the results suggest that the RLFs match remarkably well for low redshift galaxies with an optical counterpart. We use a more realistic high redshift distribution to model the redshifts of (most likely) high redshift radio sources and find that the LFs from our approach match well with measured LFs. We also look at strategies to compare the RLFs of radio sources without an optical counterpart to existing studies.
Authors
- J. Afonso (ORCID: https://orcid.org/0000-0002-9149-2973)
- Joshua Marvil (ORCID: https://orcid.org/0000-0003-1111-8066)
- Andrew Hopkins (ORCID: https://orcid.org/0000-0002-6097-2747)
- Stergios Amarantidis (ORCID: https://orcid.org/0000-0001-7948-5714)
- M. J. I. Brown (ORCID: https://orcid.org/0000-0002-1207-9137)
- Maciej Bilicki (ORCID: https://orcid.org/0000-0002-3910-5809)
- Ummee Tania Ahmed (ORCID: https://orcid.org/0000-0002-0309-1599)
- Tayyaba Zafar (ORCID: https://orcid.org/0000-0003-3935-7018)
- S. Phillipps (ORCID: https://orcid.org/0000-0001-5991-3486)
- Michael J. Cowley (ORCID: https://orcid.org/0000-0002-4653-8637)
- Stanislav S. Shabala (ORCID: https://orcid.org/0000-0001-5064-0493)
- D. A. Leahy (ORCID: https://orcid.org/0000-0002-4814-958X)
- E. M. Sadler (ORCID: https://orcid.org/0000-0002-1136-2555)
- S. M. Croom (ORCID: https://orcid.org/0000-0003-2880-9197)
- Yjan Gordon (ORCID: https://orcid.org/0000-0003-1432-253X)
- Rodrigo Carvajal (ORCID: https://orcid.org/0000-0002-0545-1113)
- Jahang Prathap (ORCID: https://orcid.org/0009-0004-0251-2672)
- Tamal Mukherjee (ORCID: https://orcid.org/0009-0004-7639-869X)
- Jayde Willingham
Institutions
- Commonwealth Scientific and Industrial Research Organisation (AU)
- The University of Sydney (AU)
- University of Tasmania (AU)
- University of Wisconsin–Madison (US)
- University of Lisbon (PT)
- Queensland University of Technology (AU)
- University of Calgary (CA)
- University of Southern Queensland (AU)
- National Radio Astronomy Observatory (US)
- Australian Regenerative Medicine Institute (AU)
- Australian Astronomical Observatory (AU)
- University of Bristol (GB)
- Institut de Radioastronomie Millimétrique (FR)
- Astronomy and Space (AU)
- Monash University (AU)
- Macquarie University (AU)
- Polish Academy of Sciences (PL)
Publication Details
- Journal
- Publications of the Astronomical Society of Australia
- Published
- 2025-01-01
- DOI
- https://doi.org/10.1017/pasa.2025.10044
- Primary Topic
- Infrared Target Detection Methodologies
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Science and Industry Endowment Fund
- Australian Government
- Commonwealth Scientific and Industrial Research Organisation
- Government of Western Australia