Extensive Gas Tail in the Peculiar Galaxy Arp 299

A composite image of the optical light (green and yellow) and cold atomic hydrogen gas (blue) in the peculiar galaxy Arp 299, also known as NGC 3690/IC 694. Arp 299 is the result of two <A HREF="/Galaxy/Spiral"> spiral galaxies which are in the process of colliding and merging into a single object. The atomic hydrogen observations (shown in blue in the image), taken with the Very Large Array, reveal a tremendous HI tail extending 55,000 light years (180 kiloparsecs) from the main bodies of the merging galaxies. Curiously, the gas tail is displaced from the optical tail (green in the figure), an unexpected and presently unexplained phenomena.

VLA C+D array observations with a resolution of 20". Optical image is a B-band image obtained with the University of Hawai'i's 88" telescope. A discussion of possible explanations for the optical/gaseous offsets can be found in Hibbard, Vacca & Yun 2000 (AJ, 119, 1130).

Legacy Astronomical Images

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Legacy Astronomical Image

Arp 299

J. Hibbard, M. Yun

Very Large Array (VLA)

U. Hawaii 89

1995-04-18

spectral line

21 cm

1420.4 GHz

HI

RA 11:25:50.000, Dec: 58:53:28.000 (B1950)

0.145000 x 0.208333 degrees

Galaxies Series

Peculiar Unit