J 2024

Radio properties of green pea galaxies

BORKAR, A., Romana GROSSOVÁ, J. SVOBODA, E. MORAVEC, K. KOUROUMPATZAKIS et. al.

Basic information

Original name

Radio properties of green pea galaxies

Authors

BORKAR, A., Romana GROSSOVÁ (703 Slovakia, belonging to the institution), J. SVOBODA, E. MORAVEC, K. KOUROUMPATZAKIS, P. G. BOORMAN, B. ADAMCOVA, B. MINGO and M. EHLE

Edition

Astronomy and Astrophysics, EDP Sciences, 2024, 0004-6361

Other information

Language

English

Type of outcome

Článek v odborném periodiku

Field of Study

10308 Astronomy

Country of publisher

France

Confidentiality degree

není předmětem státního či obchodního tajemství

References:

Impact factor

Impact factor: 6.500 in 2022

Organization unit

Faculty of Science

DOI

UT WoS

001263273200008

Keywords in English

galaxies: dwarf; galaxies: starburst; galaxies: star formation; radio continuum: galaxies

Tags

Tags

International impact, Reviewed
Změněno: 7/8/2024 10:19, Mgr. Marie Šípková, DiS.

Abstract

V originále

Aims. Green peas (GPs) are young, compact, star-forming dwarf galaxies, and local (z ∼ 0.3) analogues of the early galaxies (z ≥ 6) considered to be mainly responsible for the reionisation of the Universe. Recent X-ray observations of GPs led to the detection of high excess emission, which cannot be accounted for by star formation alone and implies the presence of an active galactic nucleus (AGN). We employ radio observations to study the radio properties of GPs, build their radio spectral energy distributions, and verify the presence of AGNs. Methods. We performed new radio observations of three GPs with the Karl G. Jansky Very Large Array (JVLA) in the L, C, and X bands (1.4, 6 and 10 GHz resp.), and analysed them alongside data from archival observations and large radio surveys. We also analysed the archival radio data for a larger sample of GPs and blueberry (BBs) galaxies, which are lower-mass and lower-redshift analogues of the GPs. To understand the significance of the radio observations, we assess the detectability of these sources, and compare the detected radio luminosities with expectations from theoretical and empirical relations. Results. Two of the three targeted GPs are strongly detected (> 10σ) in the JVLA observations and their fluxes are consistent with star formation, while the third source is undetected. Although archival radio surveys have the sensitivity to detect a large fraction (∼75%) of the sources from the larger archival sample of GPs and BBs, we only detect a small number (< 40%) of them and their radio luminosity is significantly lower than the expectation from empirical relations. Conclusions. Our results show that the majority of the dwarf galaxies in our sample are highly underluminous. The radio luminosity–star formation rate (SFR) relation deviates from the empirical relations, especially towards the lower end of galaxy mass and SFR, suggesting that the relations established for larger galaxies may not hold towards the low-mass end.