Foregrounds: Diffuse Emissions Overview

Data from surveys of diffuse Galactic emission may be obtained from the product table below. Additional pages related to diffuse emission are also available:

  • An Overview of diffuse astrophysical foreground components typically observed at microwave frequencies.
  • Derived maps of emission from individual physical emission mechanisms (e.g., synchrotron, free-free, dust, lines)
  • Software which may be used to model diffuse emission
  • Images of some of the survey and derived products.

Click on Product, Frequency or Release Date to sort by that column.

Product Frequency Release
DRAO 10 MHZ map 0.010 GHz 2020 Dominion Radio Astrophysical Observatory 10 MHz radio continuum map.
DRAO 22 MHz Map 0.022 GHz 2019 Dominion Radio Astrophysical Observatory 22 MHz radio continuum map.
LWA1 Radio Maps 0.035 GHz to 0.08 GHz 2017 Long Wavelength Array first station maps at nine frequencies from 35 to 80 MHz.
OVRO-LWA Radio Maps 0.036 GHz to 0.073 GHz 2020 Owens Valley Radio Observatory Long Wavelength Array sky maps at eight frequencies from 36.528 to 73.152 MHz.
Maipu and MU Radar 45 MHz Map 0.045 GHz 2019 45 MHz radio continuum all-sky map of Guzman et al. (2011).
Parkes 85 MHz Continuum Map 0.085 GHz 2020 85 MHz radio continuum map covering declination -25° to +25° (Landecker and Wielebinski 1970).
All-sky 150 MHz map 0.150 GHz 2019 150 MHz radio continuum all-sky map of Landecker and Wielebinski (1970).
EDA2 159 MHz Map 0.159 GHz 2022 Engineering Development Array 2 159 MHz radio continuum map (Kriele et al. 2022).
Haslam 408 MHz 0.408 GHz 2003, 2014 408 MHz radio continuum all-sky map of Haslam et al., and 2014 reprocessed data.
Dwingeloo 820 MHz Map 0.82 GHz 2019 Northern sky 820 MHz radio continuum map (Berkhuijsen 1972).
Dickey & Lockman HI Column Density 1.4 GHz 2003 Composite all-sky N(HI) map derived from the Leiden/Dwingeloo survey and supplemented at southern declinations using the compilation of Dickey & Lockman.
LAB HI Survey 1.4 GHz 2005 HEALPIX resampling of Leiden/Argentine/Bonn (LAB) Survey of Galactic HI (from Kalberla et al., 2005).
Effelsberg-Bonn HI Column Density 1.4 GHz 2016 Northern sky N(HI) map from the Effelsberg-Bonn HI survey (Winkel et al. 2016).
HI4PI HI Column Density 1.4 GHz 2016 All-sky N(HI) map for gas with |vLSR|< 600 km s-1, constructed from the Effelsberg-Bonn HI Survey and the Galactic All-Sky Survey.
HI4PI High Velocity HI 1.4 GHz 2018 All-sky maps of the column density and velocity of high velocity HI (Westmeier 2018).
HI4PI Low and Intermediate Velocity HI 1.4 GHz 2017 All-sky N(HI) map for gas with |vLSR|< 90 km s-1 (Lenz et al 2017).
CHIPASS 1.4 GHz (continuum) 2014 CHIPASS 1.4 GHz Continuum Map
Parkes RRL Survey
Jodrell Bank
1.4 GHz (RRL) 2015 HIPASS Galactic Plane Radio Recombination Line Survey (Alves et al 2015).
Stockert and Villa-Elisa 1.4 GHz Continuum Map 1.4 GHz Continuum 1982, 1986, 2001 This is an all-sky 1420 MHz (21cm) continuum map formed from surveys of the northern sky with the 25-m Stockert telescope and the southern sky with the 30-m Villa-Elisa telescope.
Velocity-Integrated W(CO)(Dame, Hartmann, Thaddeus 2001) 115 GHz 2001 Composite CO brightness temperature map of the Galaxy.
Rhodes/HartRAO 2326 MHz Continuum Map 2.3 GHz 2019 2326 MHz radio continuum map covering 67% of the sky (Jonas et al.1998, Platania et al. 2003).
S-PASS 2.3 GHz Continuum Stokes I,Q,U 2019 Southern sky 2.3 GHz polarization survey made with the Parkes radio telescope (Carretti et al. 2019).
WISE 12 micron dust map IR (12 um) 2020 All-sky map of diffuse Galactic 12 micron dust emission (Meisner and Finkbeiner 2014).
IRAS/ISSA Plates IR (12, 25, 60, 100 um) 2005 IRAS diffuse emission data projected info HEALPix format.
IRIS IR (12, 25, 60, 100 um) 2005 Infrared maps from Improved Reprocessing of the IRAS Survey.
AKARI IR (65, 90, 140, 160 um) 2015 AKARI far infrared all-sky maps.
Composite all sky H-alpha (Finkbeiner) optical 2003 Composite all-sky H-alpha map derived from 3 surveys.
WHAM H-alpha map optical 2020 Wisconsin H-Alpha Mapper all-sky velocity-integrated map.

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