Characterizing the radio continuum emission from intense starburst galaxies

© 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.The intrinsic thermal (free-free) and non-thermal (synchrotron) emission components that comprise the radio continuum of galaxies represent unique, dust-free measures of star formation rates (SFR). Su...

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Main Authors: Galvin, T., Seymour, Nick, Filipovic, M., Tothill, N., Marvil, J., Drouart, G., Symeonidis, M., Huynh, M.
Format: Journal Article
Published: Oxford University Press 2016
Online Access:http://hdl.handle.net/20.500.11937/19525
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author Galvin, T.
Seymour, Nick
Filipovic, M.
Tothill, N.
Marvil, J.
Drouart, G.
Symeonidis, M.
Huynh, M.
author_facet Galvin, T.
Seymour, Nick
Filipovic, M.
Tothill, N.
Marvil, J.
Drouart, G.
Symeonidis, M.
Huynh, M.
author_sort Galvin, T.
building Curtin Institutional Repository
collection Online Access
description © 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.The intrinsic thermal (free-free) and non-thermal (synchrotron) emission components that comprise the radio continuum of galaxies represent unique, dust-free measures of star formation rates (SFR). Such high SFR galaxies will dominate the deepest current and future radio surveys. We disentangle the thermal and non-thermal emission components of the radio continuum of six ultraluminous infrared galaxies (LFIR > 1012.5 L?) at redshifts of 0.2 = z = 0.5 and 22 IR selected galaxies. Radio data over a wide frequency range (0.8 < ? <10 GHz) are fitted with a star-forming galaxy model comprising of thermal and non-thermal components. The luminosities of both radio continuum components are strongly correlated to the 60 µm luminosity across many orders of magnitude (consistent with the far-IR to radio correlation). We demonstrate that the spectral index of the radio continuum spectral energy distribution is a useful proxy for the thermal fraction. We also find that there is an increase in mean and scatter of the thermal fraction with FIR to radio luminosity ratio which could be influenced by different time-scales of the thermal and non-thermal emission mechanisms.
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spelling curtin-20.500.11937-195252017-09-13T13:45:15Z Characterizing the radio continuum emission from intense starburst galaxies Galvin, T. Seymour, Nick Filipovic, M. Tothill, N. Marvil, J. Drouart, G. Symeonidis, M. Huynh, M. © 2016 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society.The intrinsic thermal (free-free) and non-thermal (synchrotron) emission components that comprise the radio continuum of galaxies represent unique, dust-free measures of star formation rates (SFR). Such high SFR galaxies will dominate the deepest current and future radio surveys. We disentangle the thermal and non-thermal emission components of the radio continuum of six ultraluminous infrared galaxies (LFIR > 1012.5 L?) at redshifts of 0.2 = z = 0.5 and 22 IR selected galaxies. Radio data over a wide frequency range (0.8 < ? <10 GHz) are fitted with a star-forming galaxy model comprising of thermal and non-thermal components. The luminosities of both radio continuum components are strongly correlated to the 60 µm luminosity across many orders of magnitude (consistent with the far-IR to radio correlation). We demonstrate that the spectral index of the radio continuum spectral energy distribution is a useful proxy for the thermal fraction. We also find that there is an increase in mean and scatter of the thermal fraction with FIR to radio luminosity ratio which could be influenced by different time-scales of the thermal and non-thermal emission mechanisms. 2016 Journal Article http://hdl.handle.net/20.500.11937/19525 10.1093/mnras/stw1288 Oxford University Press fulltext
spellingShingle Galvin, T.
Seymour, Nick
Filipovic, M.
Tothill, N.
Marvil, J.
Drouart, G.
Symeonidis, M.
Huynh, M.
Characterizing the radio continuum emission from intense starburst galaxies
title Characterizing the radio continuum emission from intense starburst galaxies
title_full Characterizing the radio continuum emission from intense starburst galaxies
title_fullStr Characterizing the radio continuum emission from intense starburst galaxies
title_full_unstemmed Characterizing the radio continuum emission from intense starburst galaxies
title_short Characterizing the radio continuum emission from intense starburst galaxies
title_sort characterizing the radio continuum emission from intense starburst galaxies
url http://hdl.handle.net/20.500.11937/19525