The LWA1 Low Frequency Sky Survey

This page provides access to the data presented in Dowell et al.(2017, MNRAS, 469, 4537) as well as the Low Frequency Sky Model.

Updated 2018 April 23: The maps and the LFSM have been updated with improved astrometry. We have also made a small modification to the LFSM to remove an inflection in the spectrum below ~50 MHz.

HEALpix Files

FITS files storing HEALpix RING data with 256 sides (pixel size of approximately 0.23°) and equatorial coordinates. More about the HEALpix pixeliztion scheme can be found on this page. These files can be opened by some FITS viewers, such as SAOImage DS9, as well as the healpy Python module.

Each file is approximately 3.1 MB in size:

FITS Images

Standard FITS images in a Mollweide projection with an approximate pixel size of 0.3° and equatorial coordinates. These files can be opened with various FITS viewers, like SAOImage DS9.

Each file is approximately 4.5 MB in size:

Low Frequency Sky Model

Our model of the low frequency radio sky (10 to 408 MHz) based on a principle component analysis of data at 10, 22, 40, 45, 50, 60, 70, 80, 408, 819, 1419, 23000, 33000, 41000, 61000, and 94000 MHz. The 40, 50, 60, 70, and 80 MHz data come from our survey while the data for the other 11 frequencies are from:

The data for the 10, 22, 819, and 1419 MHz surveys can be accessed through the MPIfR Survey Sampler. The 408 MHz map can be found on LAMBDA. The data for the 45 MHz survey can be access through the CDS. The WMAP data at 23, 33, 41, 61, and 94 GHz can be found on the original GSM page.

The model can be downloaded from here as a 13 MB compressed tar file. The model is at a resolution of 5.1° and outputs HEALpix RING format text files with 64 sides. This gives the output models an approximate pixel size of 0.9°. Note: Most of the data going into the model is from the northern hemisphere so there may be additional uncertainities in the southern sky.