3d dust mapping with ps1

Gregory Green (Harvard/CfA)



goal

  • 2D dust maps already exist
  • Determine dust density throughout Galaxy in 3D
  • Give reddening at any point on sky, at any distance

Method

Divide detected stars into ~6'x6' pixels. 

Assume each pixel has a different line-of-sight dust column. 

Method

Infer distance, reddening & stellar type for each star

Method

Probability density in distance & reddening for each star in pixel

Method

Find distance-reddening curves consistent with all stars

Method

Obtain many possible disance-reddening profiles in one pixel

Better Stellar Inferences

Line-of-sight dust informs stellar reddenings & distances.

Detection Density


  • Require 4-band detection, including 2 bands in PS1
  • Aperture - PSF magnitude cut in two PS1 bands
  • 800 million stars

Total Detections


PS1 vs 2MASS


Bands Per Star


Processing


Results


Visualize dust from different positions in Galaxy & directions.

Local Dust


Zooming Out


Voxel Shape


High angular resolution, low radial resolution.

Touring the Galaxy

 

3π Footprint


Future Avenues

  • More NIR data (WISE, UKIDSS GPS, GLIMPSE)
  • Assume spatial correlation between lines of sight
  • Incorporate proper motions, parallaxes
  • Gaia, LSST should allow much improved 3D dust maps