2010/01/31 by T. Culverhouse, P. Ade, P. A. R. Ade +38
Mathematics · Physics and Astronomy · #Astrophysics #Astrophysics and Star Formation Studies #Galactic plane #Galaxies: Formation, Evolution, Phenomena #Galaxy #Geometry #Mathematics #Physics #Plane (geometry) #Scientific Research and Discoveries #astro-ph.GA
paper · pdf · doi:10.1088/0004-637x/722/2/1057
published as The Astrophysical Journal, Vol. 722, Issue 2, pp. 1057-1077 (2010) · 19 pages, 21 figures, accepted for publication in ApJ; new revision includes tests of spectral line contribution. The maps analyzed in this paper are available for public download at http://find.spa.umn.edu/quad/quad_galactic/
openalex publication_date 2010/09/27 · arxiv created 2010/12/18 · arxiv updated 2015/05/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present a survey of ∼800 deg 2 of the galactic plane observed with the QUaD telescope. The primary products of the survey are maps of Stokes I , Q , and U parameters at 100 and 150 GHz, with spatial resolution of 5' and 3 5, respectively. Two regions are covered, spanning approximately 245°–295° and 315°–5° in the galactic longitude l and −4° < b < +4° in the galactic latitude b . At 0 02 square pixel size, the median sensitivity is 74 and 107 kJy sr −1 at 100 GHz and 150 GHz respectively in I , and 98 and 120 kJy sr −1 for Q and U . In total intensity, we find an average spectral index of α = 2.35 ± 0.01(stat) ± 0.02(sys) for | b | ⩽ 1°, indicative of emission components other than thermal dust. A comparison to published dust, synchrotron, and free–free models implies an excess of emission in the 100 GHz QUaD band, while better agreement is found at 150 GHz. A smaller excess is observed when comparing QUaD 100 GHz data to the WMAP five-year W band; in this case, the excess is likely due to the wider bandwidth of QUaD. Combining the QUaD and WMAP data, a two-component spectral fit to the inner galactic plane (| b | ⩽ 1°) yields mean spectral indices of α s = −0.32 ± 0.03 and α d = 2.84 ± 0.03; the former is interpreted as a combination of the spectral indices of synchrotron, free–free, and dust, while the second is largely attributed to the thermal dust continuum. In the same galactic latitude range, the polarization data show a high degree of alignment perpendicular to the expected galactic magnetic field direction, and exhibit mean polarization fraction 1.38 ± 0.08(stat) ± 0.1(sys)% at 100 GHz and 1.70 ± 0.06(stat) ± 0.1(sys)% at 150 GHz. We find agreement in polarization fraction between QUaD 100 GHz and the WMAP W band, the latter giving 1.1% ± 0.4%.