Galactic cirrus

 

The NGVS and MATLAS surveys have the sensitivity to detect the low surface brightness light scattered by the dust and gas clouds located in our Milky Way. Their structure and sometimes color is unfortunately very similar to that of stellar streams. Cirrus emission is usually observed at far-UV, far-infrared and radio wavelengths. Multi-wavelength observations  thus may help to identify contaminated regions, which should be masked for further analysis.

Galactic cirrus in a nutshell


  1. • Shape: filamentary, usually occupying a large fraction of the image

  2. • Surface brightness: fainter than 27 mag.arcsec-2

  3. • Number: usually not isolated

  4. • Color: no specific color; from green to red on composite images.


Examples of fields (from NGVS) contaminated by Galactic cirrus. Combined u,g,i surface brightness maps, with (bottom) FIR contours superimposed.