Theinfrared space telescope WISENASA has grasped a new vision oftwo companion galaxiesshowing obvious morphological differences: one is acalm spiral beautyand another is about onefiery and smoky galaxy in which new stars are formed.
The strange couple, made up ofMessier 81YMessier 82, became much more closely known during an encounter that took place hundreds of millions of years ago. As they swept past each other, gravitational interactions triggered new bursts of star formation. In the case ofMessier 82, also known asthe Cigar Galaxy, the encounter likely triggered a tremendous wave of new star births at its core. Intense radiation from massive newborn stars blows large amounts of gas and dust from the galaxy.
They are both spiral galaxies, butMessier 82it is seen from an edge point of view, and thus appears in visible light as a thin bar, hence its nickname. When viewed in infrared light, it is the brightest galaxy in the sky. It is referred to by astronomers as a “starburst” galaxy because it is producing a large number of new stars. “What is absolutely unique about the WISE image of this duo is thatwe can see the two galaxies in the same shotin which we clearly appreciate their differences, “said UCLA principal investigator Ned Wright at WISE. Because the Cigar Galaxy is a burst of star formation, it is much brighter in the infrared than its less active companion.
The WISE mission completed its primary goal of imaging the Universe in infrared light in October, until its coolant ran out. During that time, it took images of hundreds of millions of objects, the first batch of which will be released to the scientific community in April.WISE continues its exploration of the skies without coolantwith two of its four infrared channels, specifically the two shorter wavelength channels, since it is not affected by warmer temperatures.
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