The C-Band All-Sky Survey (C-BASS): Constraining diffuse Galactic radio emission in the North Celestial Pole region

Clive Dickinson; Adam Barr; H C Chiang; C Copley; R. D. P. Grumitt; Stuart Harper; Heiko M. Heilgendorff; Luke R. P. Jew; J L Jonas; Michael Jones; John Leahy; J. Leech; E M Leitch; S J C Muchovej; T. J. Pearson; Michael Peel; A C S Readhead; J. Sievers; M. A. Stevenson; Angela C. Taylor

doi:10.1093/mnras/stz522

The C-Band All-Sky Survey (C-BASS): Constraining diffuse Galactic radio emission in the North Celestial Pole region

Clive Dickinson, Adam Barr, H C Chiang, C Copley, R. D. P. Grumitt, Stuart Harper, Heiko M. Heilgendorff, Luke R. P. Jew, J L Jonas, Michael Jones, John Leahy, J. Leech, E M Leitch, S J C Muchovej, T. J. Pearson, Michael Peel, A C S Readhead, J. Sievers, M. A. Stevenson, Angela C. Taylor

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Abstract

The C-Band All-Sky Survey (C-BASS) is a high-sensitivity all-sky radio survey at an angular resolution of 45 arcmin and a frequency of 4.7 GHz. We present a total intensity map of the North Celestial Pole (NCP) region of sky, above declination > +80, which is limited by source confusion at a level of ≈ 0:6mK rms.We apply the template-tting (cross-correlation) technique to WMAP and Planck data, using the C-BASS map as the synchrotron template, to investigate the contribution of diffuse foreground emission at frequencies 20{40 GHz. We quantify the anomalous microwave emission (AME) that is correlated with far-infrared dust emission. The AME amplitude does not change signicantly (< 10 %) when using the higher frequency C-BASS 4.7 GHz template instead of the traditional Haslam 408MHz map as a tracer of synchrotron radiation. We measure template coecients of 9:930:35 and 9:520:34K per unit 353 when using the Haslam and C-BASS synchrotron templates, respectively. The AME contributes 552 K rms at 22.8 GHz and accounts for 60% of the total foreground emission. Our results show that a harder (atter spectrum) component of synchrotron emission is not dominant at frequencies & 5 GHz; the best-tting synchrotron temperature spectral index is = 􀀀2:91 0:04 from 4.7 to 22.8 GHz and = 􀀀2:85 0:14 from 22:8 to 44.1 GHz. Free-free emission is weak, contributing 7 K rms ( 7%) at 22.8 GHz. The best explanation for the AME is still electric dipole emission from small spinning dust grains.

Original language	English
Journal	Monthly Notices of the Royal Astronomical Society
Early online date	22 Feb 2019
DOIs	https://doi.org/10.1093/mnras/stz522
Publication status	Published - 2019

Keywords

surveys { radiation mechanism
non-thermal { radiation mechanism
thermal { diuse radiation { radio continuum
ISM

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10.1093/mnras/stz522

CBASSNcpPaperAccepted author manuscript, 4.53 MB

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Dickinson, C., Barr, A., Chiang, H. C., Copley, C., Grumitt, R. D. P., Harper, S., Heilgendorff, H. M., Jew, L. R. P., Jonas, J. L., Jones, M., Leahy, J., Leech, J., Leitch, E. M., Muchovej, S. J. C., Pearson, T. J., Peel, M., Readhead, A. C. S., Sievers, J., Stevenson, M. A., & Taylor, A. C. (2019). The C-Band All-Sky Survey (C-BASS): Constraining diffuse Galactic radio emission in the North Celestial Pole region. Monthly Notices of the Royal Astronomical Society. https://doi.org/10.1093/mnras/stz522

@article{bf8e7102b4ef4c63ac10fca23d0085a6,

title = "The C-Band All-Sky Survey (C-BASS): Constraining diffuse Galactic radio emission in the North Celestial Pole region",

abstract = "The C-Band All-Sky Survey (C-BASS) is a high-sensitivity all-sky radio survey at an angular resolution of 45 arcmin and a frequency of 4.7 GHz. We present a total intensity map of the North Celestial Pole (NCP) region of sky, above declination > +80, which is limited by source confusion at a level of ≈ 0:6mK rms.We apply the template-tting (cross-correlation) technique to WMAP and Planck data, using the C-BASS map as the synchrotron template, to investigate the contribution of diffuse foreground emission at frequencies 20{40 GHz. We quantify the anomalous microwave emission (AME) that is correlated with far-infrared dust emission. The AME amplitude does not change signicantly (< 10 %) when using the higher frequency C-BASS 4.7 GHz template instead of the traditional Haslam 408MHz map as a tracer of synchrotron radiation. We measure template coecients of 9:930:35 and 9:520:34K per unit 353 when using the Haslam and C-BASS synchrotron templates, respectively. The AME contributes 552 K rms at 22.8 GHz and accounts for 60% of the total foreground emission. Our results show that a harder (atter spectrum) component of synchrotron emission is not dominant at frequencies & 5 GHz; the best-tting synchrotron temperature spectral index is = 􀀀2:91 0:04 from 4.7 to 22.8 GHz and = 􀀀2:85 0:14 from 22:8 to 44.1 GHz. Free-free emission is weak, contributing 7 K rms ( 7%) at 22.8 GHz. The best explanation for the AME is still electric dipole emission from small spinning dust grains.",

keywords = "surveys { radiation mechanism, non-thermal { radiation mechanism, thermal { diuse radiation { radio continuum, ISM",

author = "Clive Dickinson and Adam Barr and Chiang, {H C} and C Copley and Grumitt, {R. D. P.} and Stuart Harper and Heilgendorff, {Heiko M.} and Jew, {Luke R. P.} and Jonas, {J L} and Michael Jones and John Leahy and J. Leech and Leitch, {E M} and Muchovej, {S J C} and Pearson, {T. J.} and Michael Peel and Readhead, {A C S} and J. Sievers and Stevenson, {M. A.} and Taylor, {Angela C.}",

year = "2019",

doi = "10.1093/mnras/stz522",

language = "English",

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

issn = "1365-2966",

publisher = "Oxford University Press",

}

Dickinson, C, Barr, A, Chiang, HC, Copley, C, Grumitt, RDP, Harper, S, Heilgendorff, HM, Jew, LRP, Jonas, JL, Jones, M, Leahy, J, Leech, J, Leitch, EM, Muchovej, SJC, Pearson, TJ, Peel, M, Readhead, ACS, Sievers, J, Stevenson, MA & Taylor, AC 2019, 'The C-Band All-Sky Survey (C-BASS): Constraining diffuse Galactic radio emission in the North Celestial Pole region', Monthly Notices of the Royal Astronomical Society. https://doi.org/10.1093/mnras/stz522

TY - JOUR

T1 - The C-Band All-Sky Survey (C-BASS): Constraining diffuse Galactic radio emission in the North Celestial Pole region

AU - Dickinson, Clive

AU - Barr, Adam

AU - Chiang, H C

AU - Copley, C

AU - Grumitt, R. D. P.

AU - Harper, Stuart

AU - Heilgendorff, Heiko M.

AU - Jew, Luke R. P.

AU - Jonas, J L

AU - Jones, Michael

AU - Leahy, John

AU - Leech, J.

AU - Leitch, E M

AU - Muchovej, S J C

AU - Pearson, T. J.

AU - Peel, Michael

AU - Readhead, A C S

AU - Sievers, J.

AU - Stevenson, M. A.

AU - Taylor, Angela C.

PY - 2019

Y1 - 2019

N2 - The C-Band All-Sky Survey (C-BASS) is a high-sensitivity all-sky radio survey at an angular resolution of 45 arcmin and a frequency of 4.7 GHz. We present a total intensity map of the North Celestial Pole (NCP) region of sky, above declination > +80, which is limited by source confusion at a level of ≈ 0:6mK rms.We apply the template-tting (cross-correlation) technique to WMAP and Planck data, using the C-BASS map as the synchrotron template, to investigate the contribution of diffuse foreground emission at frequencies 20{40 GHz. We quantify the anomalous microwave emission (AME) that is correlated with far-infrared dust emission. The AME amplitude does not change signicantly (< 10 %) when using the higher frequency C-BASS 4.7 GHz template instead of the traditional Haslam 408MHz map as a tracer of synchrotron radiation. We measure template coecients of 9:930:35 and 9:520:34K per unit 353 when using the Haslam and C-BASS synchrotron templates, respectively. The AME contributes 552 K rms at 22.8 GHz and accounts for 60% of the total foreground emission. Our results show that a harder (atter spectrum) component of synchrotron emission is not dominant at frequencies & 5 GHz; the best-tting synchrotron temperature spectral index is = 􀀀2:91 0:04 from 4.7 to 22.8 GHz and = 􀀀2:85 0:14 from 22:8 to 44.1 GHz. Free-free emission is weak, contributing 7 K rms ( 7%) at 22.8 GHz. The best explanation for the AME is still electric dipole emission from small spinning dust grains.

AB - The C-Band All-Sky Survey (C-BASS) is a high-sensitivity all-sky radio survey at an angular resolution of 45 arcmin and a frequency of 4.7 GHz. We present a total intensity map of the North Celestial Pole (NCP) region of sky, above declination > +80, which is limited by source confusion at a level of ≈ 0:6mK rms.We apply the template-tting (cross-correlation) technique to WMAP and Planck data, using the C-BASS map as the synchrotron template, to investigate the contribution of diffuse foreground emission at frequencies 20{40 GHz. We quantify the anomalous microwave emission (AME) that is correlated with far-infrared dust emission. The AME amplitude does not change signicantly (< 10 %) when using the higher frequency C-BASS 4.7 GHz template instead of the traditional Haslam 408MHz map as a tracer of synchrotron radiation. We measure template coecients of 9:930:35 and 9:520:34K per unit 353 when using the Haslam and C-BASS synchrotron templates, respectively. The AME contributes 552 K rms at 22.8 GHz and accounts for 60% of the total foreground emission. Our results show that a harder (atter spectrum) component of synchrotron emission is not dominant at frequencies & 5 GHz; the best-tting synchrotron temperature spectral index is = 􀀀2:91 0:04 from 4.7 to 22.8 GHz and = 􀀀2:85 0:14 from 22:8 to 44.1 GHz. Free-free emission is weak, contributing 7 K rms ( 7%) at 22.8 GHz. The best explanation for the AME is still electric dipole emission from small spinning dust grains.

KW - surveys { radiation mechanism

KW - non-thermal { radiation mechanism

KW - thermal { diuse radiation { radio continuum

KW - ISM

U2 - 10.1093/mnras/stz522

DO - 10.1093/mnras/stz522

M3 - Article

SN - 1365-2966

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

ER -

The C-Band All-Sky Survey (C-BASS): Constraining diffuse Galactic radio emission in the North Celestial Pole region

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