DustExtinction.jl

Tools for interstellar dust extinction in astronomy

Install

From package manager ( ] key)

add DustExtinction

Usage

Color laws:

julia> using DustExtinction

julia> ccm89(4000., 3.1)
1.4645557029425842

julia> ccm89([4000., 5000.], 3.1)
2-element Array{Float64,1}:
 1.46456
 1.12225

Dust maps:

julia> ENV["SFD98_DIR"] = "/home/user/data/dust"

# download maps (once)
julia> download_sfd98()

julia> dustmap = SFD98Map()
SFD98Map("/home/user/data/dust")

julia> ebv_galactic(dustmap, 0.1, 0.1)
0.793093095733043

julia> ebv_galactic(dustmap, [0.1, 0.2], [0.1, 0.2])
2-element Array{Float64,1}:
 0.793093
 0.539507

Reference/API

• ccm89(wave, r_v)

  [Cardelli, Clayton and Mathis (1989)] (http://adsabs.harvard.edu/abs/1989ApJ...345..245C) extinction function. Given wavelength(s) in Angstroms, returns A(wave)/A_V: extinction in magnitudes relative to value at 5494.5 Angstroms.

  The implementation of this function and od94 is intended to be as given by the original papers. An error is raised for values outside the range from 10 to 0.3 inverse microns (1000 to 33333.3 angstroms).

• od94(wave, r_v)

  O'Donnell (1994) extinction model in the optical (between 3030 angstroms and 9090 angstroms), otherwise identical to Cardelli, Clayton and Mathis (1989).

• download_sfd98([destdir])

  Download the Schlegel, Finkbeiner and Davis (1998) galactic dust map to the local directory destdir, if specified. The default destination directory is the $SFD98_DIR environment variable.

• SFD98Map([mapdir])

  Type to represent the SFD (1998) map. If mapdir not given, default is the $SFD98_DIR variable.

• ebv_galactic(dustmap, l, b)

  Retrieve E(B-V) value from an SFD98Map at given galactic longitude and latitude. Return value is linearly interpolated between pixel positions in the map.