Modeling Thermal Dust Emission with Two Components: Application to the Planck High Frequency Instrument Maps
Abstract
We apply the Finkbeiner et al. two-component thermal dust emission model to the Planck High Frequency Instrument maps. This parameterization of the far-infrared dust spectrum as the sum of two modified blackbodies (MBBs) serves as an important alternative to the commonly adopted single-MBB dust emission model. Analyzing the joint Planck/DIRBE dust spectrum, we show that two-component models provide a better fit to the 100-3000 GHz emission than do single-MBB models, though by a lesser margin than found by Finkbeiner et al. based on FIRAS and DIRBE. We also derive full-sky 6.'1 resolution maps of dust optical depth and temperature by fitting the two-component model to Planck 217-857 GHz along with DIRBE/IRAS 100 μm data. Because our two-component model matches the dust spectrum near its peak, accounts for the spectrum's flattening at millimeter wavelengths, and specifies dust temperature at 6.'1 FWHM, our model provides reliable, high-resolution thermal dust emission foreground predictions from 100 to 3000 GHz. We find that, in diffuse sky regions, our two-component 100-217 GHz predictions are on average accurate to within 2.2%, while extrapolating the Planck Collaboration et al. single-MBB model systematically underpredicts emission by 18.8% at 100 GHz, 12.6% at 143 GHz, and 7.9% at 217 GHz. We calibrate our two-component optical depth to reddening, and compare with reddening estimates based on stellar spectra. We find the dominant systematic problems in our temperature/reddening maps to be zodiacal light on large angular scales and the cosmic infrared background anisotropy on small angular scales.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 2015
- DOI:
- 10.1088/0004-637X/798/2/88
- arXiv:
- arXiv:1410.7523
- Bibcode:
- 2015ApJ...798...88M
- Keywords:
-
- dust;
- extinction;
- infrared: ISM;
- submillimeter: ISM;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- accepted for publication in ApJ, for associated data release please visit http://faun.rc.fas.harvard.edu/ameisner/planckdust