UGC 813 and UGC 816

This composite image shows visible light (green), neutral Hydrogen gas (blue), and 1.4 GHz radio continuum (red) emission. The bright galaxies UGC 813 (center) and UGC 816 (left) appear white because they emit at all three wavelengths. They were normal disk galaxies that collided face-on at a speed of about 500 km/sec around 50 million years ago. Their disks have already passed through each other and are now separating. The galaxies are connected by a bridge containing magnetic fields and relativistic electrons which were stripped from their disks and still produce radio continuum emission (red). This "cosmic crash test" tells us about the collision itself and about normal galaxies via their response to such a collision.

Legacy Astronomical Images

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

Legacy Astronomical Image

UGC813

J. J. Condon, G. Helou, T. H. Jarrett

Very Large Array (VLA)

2001-07-27

spectral line

21 cm

HI

RA 1:16:16.540, Dec: 46:44:24.200 (J2000)

0.066700 x 0.100000 degrees

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Galaxies Series

Peculiar Unit