This VLA project started in 2012 with a pilot study targeting the 4 square degree around Galactic longitudes of 30 degrees covering the famous W43 complex. Since this pilot study was very successful, in 2013 we conducted the first half of the survey with another 100 hours of VLA time. The observations of the second half of the survey were conducted 2014/2015.

The covered frequencies in 30 spectral windows are:
The HI line at 1.4GHz
Four OH lines at 1.612, 1.665, 1.667 and 1.720GHz
19 H alpha radio recombination lines
The continuum emission between 1 and 2 GHz in full polarization

Calibration and imaging status:
The raw data from the observatory for the full survey comprise about 4.5 TByte. For the calibration we adapted the VLA pipeline for our needs, and, for example, RFI in the continuum bands is well identified and flagged. The calibration and imaging of the first half of the data is finished and published in Beuther et al. (2016). The full data release of the whole survey can be found in Wang et al. (2020). All data can be accessed from the “Data and Publications” page.

THOR 1.4GHz continuum image of the whole survey (Wang et al. 2018). The THOR C-array data are combined with the VGPS D-array and single-dish Effelsberg data from Stil et al. (2006). Yellow and black circles mark HII regions based on the WISE survey (Anderson et al. 2014), red circles mark SNR from Green et al. (2014), and magenta circles show new SNR candidates from Anderson et al. (2017).