Anne’s Picture of the Day: Interacting Galaxies IC 883

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February 18, 2013

IC 883, the remnant of two interacting galaxies

Image Credit: NASA, ESA, the Hubble Heritage (STScI/AURA)-ESA/Hubble Collaboration, and A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University)

IC 883 (also known as Arp 193) is the bright remnant of two interacting galaxies located some 300 million light-years away toward the constellation of Canes Venatici (the Hunting Dogs).

The name “Arp 193″ derives from being included in Arp’s Atlas of Peculiar Galaxies, a catalog of 338 peculiar galaxies, drawn up by Halton Arp in the years from 1962 through 1967 and published by the California Institute of Technology.

This luminous infrared galaxy (it is very bright in the infrared light) displays a very disturbed, complex central region with two tidal tails of approximately the same length emerging at nearly right angles, creating a reversed “V”: one diagonally to the bottom right of the image and the other, very faint one, to the top right.

The twin tidal tails suggest that IC 883 is the remnant of the merger of two gas-rich disk galaxies. The collision appears to have triggered a burst of star formation, indicated by a number of bright star clusters in the central region, and is therefore also known as a starburst galaxy.

In 2010 the supernova 2010cu could be seen in IC 883 over a period of 28 months, and at the beginning of 2011 a possible supernova (PSN J13203538+3408222) was witnessed on near-infrared images, approximately 3 months after its maximum brightness, what most likely was a core-collapse supernova.

A supernova is a phenomenon in which a star explodes in the final phase of its life. There are two types: Type I and Type II.

The Type I does not show hydrogen in the spectra. Among these, Type Ia are explosions of white dwarf stars. Type Ib supernovae are caused by the core collapse of massive stars. These stars have shed (or been stripped of) their outer envelope of hydrogen. This type is usually referred to as stripped core-collapse supernova.

The other group, Type II, are explosions of massive stars (initially more than 8 times the mass of the Sun). The Type II supernovae do show hydrogen in their spectra.

This image was taken on January 10, 2002 with the Wide Field Channel of the Advanced Camera for Surveys on the Hubble Space Telescope.

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