University of Hertfordshire

From the same journal

From the same journal

By the same authors

Documents

  • 905324

    Accepted author manuscript, 1.96 MB, PDF document

  • A. Bracco
  • A. Cooray
  • M. Veneziani
  • A. Amblard
  • P. Serra
  • J. Wardlow
  • G. White
  • R. Auld
  • M. Baes
  • F. Bertoldi
  • S. Buttiglione
  • A. Cava
  • D. Clements
  • A. Dariush
  • G. de Zotti
  • L. Dunne
  • S. Dye
  • S. Eales
  • J. Fritz
  • H. Gomez
  • R. Hopwood
  • E. Ibar
  • R.J. Ivison
  • M.J. Jarvis
  • G. Lagache
  • M.G. Lee
  • L. Leeuw
  • S. Maddox
  • M. Michalowski
  • C. Pearson
  • M. Pohlen
  • E. Rigby
  • G. Rodighiero
  • P. Temi
  • M. Vaccari
  • P. van der Werf
View graph of relations
Original languageEnglish
Pages (from-to)1151-1161
JournalMonthly Notices of the Royal Astronomical Society
Volume412
Issue2
DOIs
Publication statusPublished - 2011

Abstract

We study the spectral energy distribution (SED) and the power spectrum of Galactic cirrus emission observed in the 14 deg2 Science Demonstration Phase field of the Herschel-ATLAS using Herschel and IRAS data from 100 to 500 mu m. We compare the Spectral and Photometric Imaging Receiver (SPIRE) 250, 350 and 500 mu m maps with IRAS 100-mu m emission, binned in 6-arcmin pixels. We assume a modified blackbody SED with dust emissivity parameter beta (F proportional to lambda-beta) and a single dust temperature T-d, and find that the dust temperature and emissivity index varies over the science demonstration field as <file name="mnr_17971_mu1.gif" type="gif"/> and 1 < beta < 4. The latter values are somewhat higher than the range of beta often quoted in the literature (1 < beta < 2). We estimate the mean values of these parameters to be T-d = 19.0 +/- 2.4 K and beta = 1.4 +/- 0.4. In regions of bright cirrus emission, we find that the dust has similar temperatures with <file name="mnr_17971_mu2.gif" type="gif"/>, and similar values of beta, ranging from 1.4 +/- 0.5 to 1.9 +/- 0.5. We show that T-d and beta associated with diffuse cirrus emission are anti-correlated and can be described by the relationship: beta(T-d) = NT alpha(d) with [N = 116 +/- 38, alpha = -1.4 +/- 0.1]. The strong correlation found in this analysis is not just limited to high-density clumps of cirrus emission as seen in previous studies, but is also seen in diffuse cirrus in low-density regions. To provide an independent measure of T-d and beta, we obtain the angular power spectrum of the cirrus emission in the IRAS and SPIRE maps, which is consistent with a power spectrum of the form P(k) = P-0(k/k(0))gamma, where gamma = 2.6 +/- 0.2 for scales of 50-200 arcmin in the SPIRE maps. The cirrus rms fluctuation amplitude at angular scales of 100 arcmin is consistent with a modified blackbody SED with <file name="mnr_17971_mu3.gif" type="gif"/> and beta = ! 1.3 +/- 0.2, in agreement with the values obtained above.

Notes

The definitive version can be found at : http://onlinelibrary.wiley.com/ Copyright Wiley-Blackwell

ID: 307815