Comprehending the radio–infrared (IR) relations of the faint extragalactic radio sources is important for using radio emission as a tracer of star formation in high redshift (z) star-forming galaxies (SFGs). Using deep uGMRT observations of the ELAIS-N1 field in the 0.3–0.5 GHz range, we study the statistical properties of the radio–IR relations and the variation of the ‘q-parameter’ up to z = 2 after broadly classifying the faint sources as SFGs and AGN. We find the dust temperature (Tdust) to increase with z. This gives rise to $$q_{\rm 24\,\mu m}$$, measured at $$24\, \mu$$m, to increase with z as the peak of IR emission shifts towards shorter wavelengths, resulting in the largest scatter among different measures of q-parameters. $$q_{\rm 70\,\mu m}$$ measured at $$70\, \mu$$m, and qTIR using total-IR (TIR) emission are largely unaffected by Tdust. We observe strong, non-linear correlations between the radio luminosities at 0.4 and 1.4 GHz with $$70\, \mu$$m luminosity and TIR luminosity(LTIR). To assess the possible role of the radio-continuum spectrum in making the relations non-linear, for the first time we study them at high z using integrated radio luminosity (LRC) in the range 0.1–2 GHz. In SFGs, the LRC–LTIR relation remains non-linear with a slope of 1.07 ± 0.02, has a factor of 2 lower scatter compared to monochromatic radio luminosities, and $$q^{\rm RC}_{\rm TIR}$$ decreases with z as $$q^{\rm RC}_{\rm TIR}= (2.27 \pm 0.03)\, (1+z)^{-0.12 \pm 0.03}$$. A redshift variation of q is a natural consequence of non-linearity. We suggest that a redshift evolution of magnetic field strengths and/or cosmic ray acceleration efficiency in high-z SFGs could give rise to non-linear radio–IR relations.
Sinha, Akriti, et al. "Deep uGMRT observations of the ELAIS-North 1 field: statistical properties of radio–infrared relations up to <i>z</i> ∼ 2." Monthly Notices of the Royal Astronomical Society, vol. 514, no. 3, Jun. 2022. https://doi.org/10.1093/mnras/stac1504
Sinha, Akriti, Basu, Aritra, Datta, Abhirup, & Chakraborty, Arnab (2022). Deep uGMRT observations of the ELAIS-North 1 field: statistical properties of radio–infrared relations up to <i>z</i> ∼ 2. Monthly Notices of the Royal Astronomical Society, 514(3). https://doi.org/10.1093/mnras/stac1504
Sinha, Akriti, Basu, Aritra, Datta, Abhirup, et al., "Deep uGMRT observations of the ELAIS-North 1 field: statistical properties of radio–infrared relations up to <i>z</i> ∼ 2," Monthly Notices of the Royal Astronomical Society 514, no. 3 (2022), https://doi.org/10.1093/mnras/stac1504
@article{osti_1874508,
author = {Sinha, Akriti and Basu, Aritra and Datta, Abhirup and Chakraborty, Arnab},
title = {Deep uGMRT observations of the ELAIS-North 1 field: statistical properties of radio–infrared relations up to <i>z</i> ∼ 2},
annote = {ABSTRACT Comprehending the radio–infrared (IR) relations of the faint extragalactic radio sources is important for using radio emission as a tracer of star formation in high redshift (z) star-forming galaxies (SFGs). Using deep uGMRT observations of the ELAIS-N1 field in the 0.3–0.5 GHz range, we study the statistical properties of the radio–IR relations and the variation of the ‘q-parameter’ up to z = 2 after broadly classifying the faint sources as SFGs and AGN. We find the dust temperature (Tdust) to increase with z. This gives rise to $q_{\rm 24\,\mu m}$, measured at $24\, \mu$m, to increase with z as the peak of IR emission shifts towards shorter wavelengths, resulting in the largest scatter among different measures of q-parameters. $q_{\rm 70\,\mu m}$ measured at $70\, \mu$m, and qTIR using total-IR (TIR) emission are largely unaffected by Tdust. We observe strong, non-linear correlations between the radio luminosities at 0.4 and 1.4 GHz with $70\, \mu$m luminosity and TIR luminosity(LTIR). To assess the possible role of the radio-continuum spectrum in making the relations non-linear, for the first time we study them at high z using integrated radio luminosity (LRC) in the range 0.1–2 GHz. In SFGs, the LRC–LTIR relation remains non-linear with a slope of 1.07 ± 0.02, has a factor of 2 lower scatter compared to monochromatic radio luminosities, and $q^{\rm RC}_{\rm TIR}$ decreases with z as $q^{\rm RC}_{\rm TIR}= (2.27 \pm 0.03)\, (1+z)^{-0.12 \pm 0.03}$. A redshift variation of q is a natural consequence of non-linearity. We suggest that a redshift evolution of magnetic field strengths and/or cosmic ray acceleration efficiency in high-z SFGs could give rise to non-linear radio–IR relations.},
doi = {10.1093/mnras/stac1504},
url = {https://www.osti.gov/biblio/1874508},
journal = {Monthly Notices of the Royal Astronomical Society},
issn = {ISSN 0035-8711},
number = {3},
volume = {514},
place = {United Kingdom},
publisher = {Oxford University Press},
year = {2022},
month = {06}}
US Department of Energy (USDOE), Washington, DC (United States). Office of Science, Sloan Digital Sky Survey (SDSS)
Sponsoring Organization:
Alfred P. Sloan Foundation; National Science Foundation (NSF); USDOE; USDOE Office of Science (SC)
Contributing Organization:
Brookhaven National Laboratory (BNL); Lawrence Berkeley National Laboratory (LBNL)
OSTI ID:
1874508
Alternate ID(s):
OSTI ID: 1982615
Journal Information:
Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Journal Issue: 3 Vol. 514; ISSN 0035-8711