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