HI Disk of NGC 2403

NGC 2403 is a well-known spiral galaxy in the northern sky. Galaxies such as NGC 2403 contain, apart from billions of stars that are visible in the right image, a large disk of hydrogen gas. This gas emits radio waves that can be detected with radio telescopes. The image on the left shows, on the same scale as the optical image, the hydrogen disk of NGC 2403 as observed with the VLA C array. Seen on the sky, the size of this gas disk is about the same as that of the full moon. The images shows that the gas disk extends well beyond the optical galaxy. The gas disk shows the spiral structure of the disk, as well as large holes created by large supernova explosions.

Right: optical image of NGC 2403 based on images taken from the Digitized Sky Survey. The image on the left shows the total HI image of the gas disk of the spiral galaxy NGC 2403. The radio image is based on deep observations with the VLA C array (total integration time 48 hr) and covers an area of about 40 arcmin x 40 arcmin.

Legacy Astronomical Images

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

Legacy Astronomical Image

NGC 2403

Tom Oosterloo, Astron, The Netherlands

Fraternali, Oosterloo, Sancisi

Very Large Array (VLA)

spectral line

RA 7:36:51.000, Dec: 65:0:0.000 (J2000)

0.666667 x 0.666667 degrees

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Galaxies Series

Spiral Unit