VLA 90cm Image of Inner Galactic Plane



This figure shows a Very Large Array 90cm image of 40 square degrees of the inner Galactic plane. This image covers about 200 times the area of the full moon and has a resolution of 42 seconds of arc (about the angular size of Jupiter viewed from Earth). The most prominent sources are the ionized HII regions that form around massive stars and supernova remnants which are leftover from the death throes of massive stars. From a variety of diagnostics including the number of massive stars in our Galaxy, there should be many more supernova remnants than are currently known. The purpose of this project was to overcome the observational selection effects such as poor sensitivity and resolution that have long been assumed to be responsible for the dearth of observed supernova remnants. From this very high fidelity image we have been able to discover 35 previously unknown remnants, a 300% increase for this region of the plane and an overall 15% increase in the total known in the Galaxy. It has only recently become possible to create such high fidelity images at low radio frequencies (where supernova remnants are brightest) due to significant software improvements and increased computing power.
This image was created from fourteen separate VLA pointings and is comprised of D, C, and B configuration data. An image of each pointing was created using wide-field and multiscale cleaning algorithms in AIPS and mosaicked together in the image plane using FLATN. The resolution of the final image is 42 arcsecond and it is sensitive to structures up to 50 arcminute in size.


Legacy Astronomical Images


NRAO/AUI/NSF does not hold full copyright for this image. Contact the archivist for details.


Legacy Astronomical Image

Object Name

Galactic Plane

Photo Credit

Image courtesy of C. Brogan (NRAO) et al.


Crystal Brogan (NRAO), Yosi Gelfand (CfA), Bryan Gaensler (CfA), Namir Kassim (NRL), Joe Lazio (NRL)


Very Large Array (VLA)

Observation Date


Type of Observation





90 cm


330 MHz

Center of Image

RA 18:13:53.000, Dec: -17:39:43.000 (J2000)

Field of View

16.000000 x 2.500000 degrees


Contact the archivist for a high resolution tif of this image.


Galactic Sources Series


Supernova Remnants Unit


Legacy Astronomical Images, “VLA 90cm Image of Inner Galactic Plane,” NRAO Archives, accessed December 3, 2021, https://www.nrao.edu/archives/items/show/33519.