# Available Dust Maps¶

## Two-Dimensional Dust Maps¶

### SFD¶

A two-dimensional map of dust reddening across the entire sky. The “SFD” dust map is based on far-infrared emission of dust. The authors model the temperature and optical depth of the dust, and then calibrate a relationship between the dust’s far-infrared optical depth and optical reddening. This calibration was updated by Schlafly & Finkbeiner (2011).

In order to convert SFD values of E(B-V) to extinction, one should use the conversions provided in Table 6 of Schlafly & Finkbeiner (2011).

### Lenz, Hensley & Doré (2017)¶

A two-dimensional map of dust reddening, covering 40% of the sky with a 16.1’ resolution. This map is derived from emission from low-velocity (l.o.s. velocity < 90 km/s) HI, which is found to correlate much more strongly with E(B-V) than emission from high-velocity HI. The underlying data comes from the HI4PI Survey. This map reports E(B-V) in magnitudes.

### Planck Collaboration (2013)¶

Two-dimensional maps of dust reddening across the entire sky. The Planck Collaboration (2013) fits a modified blackbody dust emission model to the Planck and IRAS far-infrared maps, and provides three different conversions to dust reddening.

The three maps provided by Planck Collaboration (2013) are based on:

1. τ353: dust optical depth at 353 GHz.
3. A recommended extragalactic reddening estimate, based on thermal dust radiance, but with point sources removed.

### Planck Collaboration (2016; “GNILC”)¶

Two-dimensional maps of dust reddening across the entire sky, using the generalized needlet internal linear combination (GNILC) method to separate out Galactic dust emission from CIB anisotropies.

This map contains both reddening estimates and estimated uncertainties.

### Peek & Graves (2010)¶

A correction to the SFD’98 dust map, based on color excess measurements of “standard crayons” – spectroscopically selected passively evolving galaxies. The maps have an angular resolution of 4.5°, and have a 1σ uncertainty of 1.5 mmag in E(B-V). Subtract this map from SFD’98 to obtain the corrected E(B-V) reddening.

### Burstein & Heiles¶

Primarily of historical interest, the Burstein & Heiles (1982) dust reddening maps are derived from HI column density and galaxy counts.

## Three-Dimensional Dust Maps¶

### Bayestar¶

A three-dimensional map of Milky Way dust reddening, covering the three quarters of the sky north of a declination of -30°. The map is probabilistic. containing samples of the reddening along each line of sight. The “Bayestar” dust map is inferred from stellar photometry of 800 million stars observed by Pan-STARRS 1, and 2MASS photometry for a quarter of the stars. The latest version of Bayestar also makes use of Gaia DR2 parallaxes.

There are three versions of Bayestar, called Bayestar19, Bayestar17 and Bayestar15 here. By default, dustmaps will use the latest version, Bayestar19, although the earlier versions of the map can be selected by providing the keyword argument version='bayestar2017' or version='bayestar2015' in routines such as dustmaps.bayestar.fetch, dustmaps.bayestar.BayestarQuery and dustmaps.bayestar.BayestarWebQuery. If you want to make sure that your code will always use the same version of the map, even as new versions of Bayestar are released, then set the version keyword explicitly.

The units of reddening used by each map are slightly different:

1. Bayestar19 reports reddening in an arbitrary unit that can be converted to extinction in different bands using the coefficients given in Table 1 of Green, Schlafly, Finkbeiner et al. (2019).
2. Bayestar17 reports reddening in an arbitrary unit that can be converted to extinction in different bands using the coefficients given in Table 1 of Green, Schlafly, Finkbeiner et al. (2018).
3. Bayestar15 reports reddening in the same units as those used by SFD. Therefore, in order to convert Bayestar15 reddenings to extinction in different bands, one should use the conversions provided in Table 6 of Schlafly & Finkbeiner (2011).

### Chen et al. (2014)¶

A three-dimensional map of dust extinction in the Galactic anticenter. The map covers about 6000 deg2, from 140° < ℓ < 240° and -60° < b < 40°, and is based on stellar photometry from the Xuyi Schmidt Telescope Photometric Survey of the Galactic Anticentre (XSTPS-GAC), 6MASS and WISE. The map has an angular resolution of 3 to 9 arcminutes, and reports r-band extinction, along with Gaussian error estimates.

### IPHAS¶

A three-dimensional map of Milky Way dust extinction, covering a 10°-thick strip of the Galactic plane, between 30° < ℓ < 120°. The map is probabilistic, containing samples of the cumulative extinction along each line of sight. The map is based on IPHAS imaging of stars. The map returns A0, the monochromatic extinction.

### Leike & Enßlin (2019)¶

A three-dimensional map of Milky Way dust extinction, incorporating a Gaussian process prior on the dust extinction density. The map is based on the Gaia DR2 catalog parallaxes and G-band extinctions, and spans a (600 pc)³ box centered on the Sun.

### Leike, Glatzle & Enßlin (2020)¶

A three-dimensional map of Milky Way dust extinction, incorporating a Gaussian process prior on the dust extinction density, similar to Leike & Enßlin (2019). The map is based on data from Gaia, 2MASS, Pan-STARRS 1 and ALLWISE, and is calculated on a Cartesian grid spanning a (740 pc)×(740 pc)×(540 pc) box (in Galactic x, y and z, respectively) centered on the Sun.

### Marshall et al. (2006)¶

A three-dimensional map of Milky Way dust extinction, covering a 20°-thick strip of the Galactic plane, between -100° < ℓ < 100°. The map is contains 2MASS Ks-band extinctions with a Gaussian uncertainty estimates. The map is based on a comparison of 2MASS colors of stars with expectations from the Besançon model of the Galaxy.