Foreground: Velocity Integrated 115 GHz CO Map

Dame & Thaddeus 2022 Velocity Integrated CO Map

Data published by Dame & Thaddeus (2022) significantly extends the Galactic plane CO survey of Dame, Hartmann & Thaddeus (2001) with complementary coverage of the entire northern sky (δ > -17°). The coverage extension was carried out with the same telescope as was used for the plane survey, the CfA 1.2 m, and perfectly meshes with its irregular boundaries in latitude. The merged survey is released by the authors in the form of CO line spectral data cubes.

To create the LAMBDA map, the moment-masked data cube for the combined survey was integrated over +/- 36 km/sec, the full range over which significant emission is detected (see Figure 8 of Dame & Thaddeus 2022; the combined survey does not include the high-velocity observations available from the Dame, Hartmann & Thaddeus 2001 data). The velocity integrated brightness temperature map was then interpolated from the original rectilinear projection onto pixel centers appropriate for HEALPix Nside=256. The LAMBDA map is in units of K-km/sec, and a mask is provided indicating those portions of the sky that are unobserved.

More details can be found in:

"A CO Survey of the Entire Northern Sky", Dame & Thaddeus, 2022, ApJS 262, 5

"The Milky Way in Molecular Clouds: A New Complete CO Survey", Dame, Hartmann and Thaddeus, 2001, ApJ 547, 792

Harvard-Smithsonian Center for Astrophysics Millimeter Wave Group