A multifrequency radio continuum study of the Magellanic Clouds - I. Overall structure and star formation rates

B. Q. For; L. Staveley-Smith; N. Hurley-Walker; T. Franzen; A. D. Kapińska; M. D. Filipović; J. D. Collier; C. Wu; K. Grieve; J. R. Callingham; M. E. Bell; G. Bernardi; J. D. Bowman; F. Briggs; R. J. Cappallo; A. A. Deshpande; K. S. Dwarakanath; B. M. Gaensler; L. J. Greenhill; P. Hancock; B. J. Hazelton; L. Hindson; M. Johnston-Hollitt; D. L. Kaplan; E. Lenc; C. J. Lonsdale; B. McKinley; S. R. McWhirter; D. A. Mitchell; M. F. Morales; E. Morgan; J. Morgan; D. Oberoi; A. Offringa; S. M. Ord; T. Prabu; P. Procopio; N. Udaya Shankar; K. S. Srivani; R. Subrahmanyan; S. J. Tingay; R. B. Wayth; R. L. Webster; A. Williams; C. L. Williams; Q. Zheng

doi:10.1093/MNRAS/STY1960

A multifrequency radio continuum study of the Magellanic Clouds - I. Overall structure and star formation rates

B. Q. For^*, L. Staveley-Smith, N. Hurley-Walker, T. Franzen, A. D. Kapińska, M. D. Filipović, J. D. Collier, C. Wu, K. Grieve, J. R. Callingham, M. E. Bell, G. Bernardi, J. D. Bowman, F. Briggs, R. J. Cappallo, A. A. Deshpande, K. S. Dwarakanath, B. M. Gaensler, L. J. Greenhill, P. HancockB. J. Hazelton, L. Hindson, M. Johnston-Hollitt, D. L. Kaplan, E. Lenc, C. J. Lonsdale, B. McKinley, S. R. McWhirter, D. A. Mitchell, M. F. Morales, E. Morgan, J. Morgan, D. Oberoi, A. Offringa, S. M. Ord, T. Prabu, P. Procopio, N. Udaya Shankar, K. S. Srivani, R. Subrahmanyan, S. J. Tingay, R. B. Wayth, R. L. Webster, A. Williams, C. L. Williams, Q. Zheng

^*Corresponding author for this work

Research output: Contribution to journal › Article › peer-review

23 Citations (Scopus)

Abstract

We present the first low-frequency Murchison Widefield Array (MWA) radio continuum maps of the Magellanic Clouds (MCs), usingmosaics from the GaLactic Extragalactic All-SkyMWA (GLEAM) survey. In this paper, we discuss the overall radio continuum morphology between 76 and 227 MHz and compare them with neutral hydrogen maps, 1.4 GHz continuum maps and optical images. Variation of diffuse emission is noticeable across the Large Magellanic Cloud (LMC) but absent across the bar of the Small Magellanic Cloud (SMC). We also measure the integrated flux densities and derive the spectral indices for the MCs. A double power-law model with fixed α₁ = -0.1 fit between 19.7 MHz and 8.55 GHz yields α₀ = -0.66 ± 0.08 for the LMC. A power-law model yields α_8.55GHz^85.5MHz = -0.82 ± 0.03 for the SMC. The radio spectral index maps reveal distinctive flat and steep spectral indices for the HII regions and supernova remnants, respectively. We find strong correlation between HII regions and Ha emission. Using a new 150 MHz-H_α relation as a star formation rate indicator, we estimate global star formation rates of 0.068-0.161 M_⊙ yr^-1 and 0.021-0.050 M_⊙ yr^-1 for the LMC and SMC, respectively. Images in 20 frequency bands, and wideband averages are made available via the GLEAM virtual observatory server.

Original language	English
Pages (from-to)	2743-2756
Number of pages	14
Journal	Monthly Notices of the Royal Astronomical Society
Volume	480
Issue number	2
DOIs	https://doi.org/10.1093/MNRAS/STY1960
Publication status	Published - Oct 2018

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For, B. Q., Staveley-Smith, L., Hurley-Walker, N., Franzen, T., Kapińska, A. D., Filipović, M. D., Collier, J. D., Wu, C., Grieve, K., Callingham, J. R., Bell, M. E., Bernardi, G., Bowman, J. D., Briggs, F., Cappallo, R. J., Deshpande, A. A., Dwarakanath, K. S., Gaensler, B. M., Greenhill, L. J., ... Zheng, Q. (2018). A multifrequency radio continuum study of the Magellanic Clouds - I. Overall structure and star formation rates. Monthly Notices of the Royal Astronomical Society, 480(2), 2743-2756. https://doi.org/10.1093/MNRAS/STY1960

@article{af954ffe4caa4736bcda2dcd6a0d2890,

title = "A multifrequency radio continuum study of the Magellanic Clouds - I. Overall structure and star formation rates",

abstract = "We present the first low-frequency Murchison Widefield Array (MWA) radio continuum maps of the Magellanic Clouds (MCs), usingmosaics from the GaLactic Extragalactic All-SkyMWA (GLEAM) survey. In this paper, we discuss the overall radio continuum morphology between 76 and 227 MHz and compare them with neutral hydrogen maps, 1.4 GHz continuum maps and optical images. Variation of diffuse emission is noticeable across the Large Magellanic Cloud (LMC) but absent across the bar of the Small Magellanic Cloud (SMC). We also measure the integrated flux densities and derive the spectral indices for the MCs. A double power-law model with fixed α1 = -0.1 fit between 19.7 MHz and 8.55 GHz yields α0 = -0.66 ± 0.08 for the LMC. A power-law model yields α8.55GHz85.5MHz = -0.82 ± 0.03 for the SMC. The radio spectral index maps reveal distinctive flat and steep spectral indices for the HII regions and supernova remnants, respectively. We find strong correlation between HII regions and Ha emission. Using a new 150 MHz-Hα relation as a star formation rate indicator, we estimate global star formation rates of 0.068-0.161 M⊙ yr-1 and 0.021-0.050 M⊙ yr-1 for the LMC and SMC, respectively. Images in 20 frequency bands, and wideband averages are made available via the GLEAM virtual observatory server.",

keywords = "Magellanic Clouds, Radiation mechanisms: non-thermal, Radiation mechanisms: thermal, Radio continuum: galaxies",

author = "For, {B. Q.} and L. Staveley-Smith and N. Hurley-Walker and T. Franzen and Kapi{\'n}ska, {A. D.} and Filipovi{\'c}, {M. D.} and Collier, {J. D.} and C. Wu and K. Grieve and Callingham, {J. R.} and Bell, {M. E.} and G. Bernardi and Bowman, {J. D.} and F. Briggs and Cappallo, {R. J.} and Deshpande, {A. A.} and Dwarakanath, {K. S.} and Gaensler, {B. M.} and Greenhill, {L. J.} and P. Hancock and Hazelton, {B. J.} and L. Hindson and M. Johnston-Hollitt and Kaplan, {D. L.} and E. Lenc and Lonsdale, {C. J.} and B. McKinley and McWhirter, {S. R.} and Mitchell, {D. A.} and Morales, {M. F.} and E. Morgan and J. Morgan and D. Oberoi and A. Offringa and Ord, {S. M.} and T. Prabu and P. Procopio and {Udaya Shankar}, N. and Srivani, {K. S.} and R. Subrahmanyan and Tingay, {S. J.} and Wayth, {R. B.} and Webster, {R. L.} and A. Williams and Williams, {C. L.} and Q. Zheng",

note = "Publisher Copyright: {\textcopyright} 2018 The Author(s).",

year = "2018",

month = oct,

doi = "10.1093/MNRAS/STY1960",

language = "English",

volume = "480",

pages = "2743--2756",

journal = "Monthly Notices of the Royal Astronomical Society",

issn = "0035-8711",

publisher = "Oxford University Press",

number = "2",

}

For, BQ, Staveley-Smith, L, Hurley-Walker, N, Franzen, T, Kapińska, AD, Filipović, MD, Collier, JD, Wu, C, Grieve, K, Callingham, JR, Bell, ME, Bernardi, G, Bowman, JD, Briggs, F, Cappallo, RJ, Deshpande, AA, Dwarakanath, KS, Gaensler, BM, Greenhill, LJ, Hancock, P, Hazelton, BJ, Hindson, L, Johnston-Hollitt, M, Kaplan, DL, Lenc, E, Lonsdale, CJ, McKinley, B, McWhirter, SR, Mitchell, DA, Morales, MF, Morgan, E, Morgan, J, Oberoi, D, Offringa, A, Ord, SM, Prabu, T, Procopio, P, Udaya Shankar, N, Srivani, KS, Subrahmanyan, R, Tingay, SJ, Wayth, RB, Webster, RL, Williams, A, Williams, CL & Zheng, Q 2018, 'A multifrequency radio continuum study of the Magellanic Clouds - I. Overall structure and star formation rates', Monthly Notices of the Royal Astronomical Society, vol. 480, no. 2, pp. 2743-2756. https://doi.org/10.1093/MNRAS/STY1960

TY - JOUR

T1 - A multifrequency radio continuum study of the Magellanic Clouds - I. Overall structure and star formation rates

AU - For, B. Q.

AU - Staveley-Smith, L.

AU - Hurley-Walker, N.

AU - Franzen, T.

AU - Kapińska, A. D.

AU - Filipović, M. D.

AU - Collier, J. D.

AU - Wu, C.

AU - Grieve, K.

AU - Callingham, J. R.

AU - Bell, M. E.

AU - Bernardi, G.

AU - Bowman, J. D.

AU - Briggs, F.

AU - Cappallo, R. J.

AU - Deshpande, A. A.

AU - Dwarakanath, K. S.

AU - Gaensler, B. M.

AU - Greenhill, L. J.

AU - Hancock, P.

AU - Hazelton, B. J.

AU - Hindson, L.

AU - Johnston-Hollitt, M.

AU - Kaplan, D. L.

AU - Lenc, E.

AU - Lonsdale, C. J.

AU - McKinley, B.

AU - McWhirter, S. R.

AU - Mitchell, D. A.

AU - Morales, M. F.

AU - Morgan, E.

AU - Morgan, J.

AU - Oberoi, D.

AU - Offringa, A.

AU - Ord, S. M.

AU - Prabu, T.

AU - Procopio, P.

AU - Udaya Shankar, N.

AU - Srivani, K. S.

AU - Subrahmanyan, R.

AU - Tingay, S. J.

AU - Wayth, R. B.

AU - Webster, R. L.

AU - Williams, A.

AU - Williams, C. L.

AU - Zheng, Q.

PY - 2018/10

Y1 - 2018/10

N2 - We present the first low-frequency Murchison Widefield Array (MWA) radio continuum maps of the Magellanic Clouds (MCs), usingmosaics from the GaLactic Extragalactic All-SkyMWA (GLEAM) survey. In this paper, we discuss the overall radio continuum morphology between 76 and 227 MHz and compare them with neutral hydrogen maps, 1.4 GHz continuum maps and optical images. Variation of diffuse emission is noticeable across the Large Magellanic Cloud (LMC) but absent across the bar of the Small Magellanic Cloud (SMC). We also measure the integrated flux densities and derive the spectral indices for the MCs. A double power-law model with fixed α1 = -0.1 fit between 19.7 MHz and 8.55 GHz yields α0 = -0.66 ± 0.08 for the LMC. A power-law model yields α8.55GHz85.5MHz = -0.82 ± 0.03 for the SMC. The radio spectral index maps reveal distinctive flat and steep spectral indices for the HII regions and supernova remnants, respectively. We find strong correlation between HII regions and Ha emission. Using a new 150 MHz-Hα relation as a star formation rate indicator, we estimate global star formation rates of 0.068-0.161 M⊙ yr-1 and 0.021-0.050 M⊙ yr-1 for the LMC and SMC, respectively. Images in 20 frequency bands, and wideband averages are made available via the GLEAM virtual observatory server.

AB - We present the first low-frequency Murchison Widefield Array (MWA) radio continuum maps of the Magellanic Clouds (MCs), usingmosaics from the GaLactic Extragalactic All-SkyMWA (GLEAM) survey. In this paper, we discuss the overall radio continuum morphology between 76 and 227 MHz and compare them with neutral hydrogen maps, 1.4 GHz continuum maps and optical images. Variation of diffuse emission is noticeable across the Large Magellanic Cloud (LMC) but absent across the bar of the Small Magellanic Cloud (SMC). We also measure the integrated flux densities and derive the spectral indices for the MCs. A double power-law model with fixed α1 = -0.1 fit between 19.7 MHz and 8.55 GHz yields α0 = -0.66 ± 0.08 for the LMC. A power-law model yields α8.55GHz85.5MHz = -0.82 ± 0.03 for the SMC. The radio spectral index maps reveal distinctive flat and steep spectral indices for the HII regions and supernova remnants, respectively. We find strong correlation between HII regions and Ha emission. Using a new 150 MHz-Hα relation as a star formation rate indicator, we estimate global star formation rates of 0.068-0.161 M⊙ yr-1 and 0.021-0.050 M⊙ yr-1 for the LMC and SMC, respectively. Images in 20 frequency bands, and wideband averages are made available via the GLEAM virtual observatory server.

KW - Magellanic Clouds

KW - Radiation mechanisms: non-thermal

KW - Radiation mechanisms: thermal

KW - Radio continuum: galaxies

UR - http://www.scopus.com/inward/record.url?scp=85055159832&partnerID=8YFLogxK

U2 - 10.1093/MNRAS/STY1960

DO - 10.1093/MNRAS/STY1960

M3 - Article

SN - 0035-8711

VL - 480

SP - 2743

EP - 2756

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

IS - 2

ER -

A multifrequency radio continuum study of the Magellanic Clouds - I. Overall structure and star formation rates

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