The GLOSTAR Survey 01/01/2025

Earth and Space Sciences

The Global View of Star Formation in the Milky Way (GLOSTAR) survey is a blind survey of the Galactic Plane in the 4 – 8 GHz range of frequencies using the Karl G. Jansky Very Large Array, carried out by an international collaboration including IIST. The data are taken with the telescope being in both D and B configurations in order to get good resolution along with sensitivity at large angular scales. When combined with data from the 100-m Effelsberg telescope, the survey will be sensitive to radio emission from angular scales of 1.5" to the largest radio structures in the Milky Way at a sensitivity of 40 μJy/beam. While the full survey will cover a wide area of the Galactic plane from Galactic longitudes of -2° to +85° and Galactic latitudes between -1° and +1°, the first results focus on D-array data at a resolution of 18" on a 16 square degree region. A total of 1575 discrete radio sources and 27 large scale structures including W43 and W44 have been identified. Based on the spectral index, 231 continuum sources have been identified as H II regions, 37 as ionization fronts, and 46 as planetary nebulae, with the remaining sources being consistent with background radio galaxies. These first GLOSTAR results have increased the number of H II regions in this part of the Milky Way by a factor of four.

Caption: The 4 - 8 GHz continuum image and noise map of the 16 square degree region presented as the first result from the GLOSTAR survey. The yellow boxes highlight the complexes detected in this region.