BLAST05: Power Spectra of Bright Galactic Cirrus at Submillimeter Wavelengths

TL;DR

This paper presents multi-wavelength power spectra of Galactic dust emission at submillimeter wavelengths, revealing the structure and cirrus noise characteristics relevant for future astronomical observations.

Contribution

It provides the first detailed analysis of the wavelength dependence of Galactic cirrus power spectra using BLAST data, including dust temperature estimates.

Findings

Power spectra show self-similar structure over broad scales.

Dust temperatures are estimated as 19.9 K in Cygnus X and 16.9 K in Aquila.

Results inform cirrus noise estimates for future submillimeter surveys.

Abstract

We report multi-wavelength power spectra of diffuse Galactic dust emission from BLAST observations at 250, 350, and 500 microns in Galactic Plane fields in Cygnus X and Aquila. These submillimeter power spectra statistically quantify the self-similar structure observable over a broad range of scales and can be used to assess the cirrus noise which limits the detection of faint point sources. The advent of submillimeter surveys with the Herschel Space Observatory makes the wavelength dependence a matter of interest. We show that the observed relative amplitudes of the power spectra can be related through a spectral energy distribution (SED). Fitting a simple modified black body to this SED, we find the dust temperature in Cygnus X to be 19.9 +/- 1.3 K and in the Aquila region 16.9 +/- 0.7 K. Our empirical estimates provide important new insight into the substantial cirrus noise that will be encountered in forthcoming observations.