IC 1623

Webb Explores a Pair of Merging Galaxies (potm2210a).jpeg
(c) ESA/Webb, NASA & CSA, L. Armus & A. Evans Acknowledgement: R. Colombari, CC BY 4.0
This image from the NASA/ESA/CSA James Webb Space Telescope depicts IC 1623, an entwined pair of interacting galaxies which lies around 270 million light-years from Earth in the constellation Cetus. The two galaxies in IC 1623 are plunging headlong into one another in a process known as a galaxy merger. Their collision has ignited a frenzied spate of star formation known as a starburst, creating new stars at a rate more than twenty times that of the Milky Way galaxy.This interacting galaxy system is particularly bright at infrared wavelengths, making it a perfect proving ground for Webb’s ability to study luminous galaxies. A team of astronomers captured IC 1623 across the infrared portions of the electromagnetic spectrum using a trio of Webb’s cutting-edge scientific instruments: MIRI, NIRSpec, and NIRCam. In so doing, they provided an abundance of data that will allow the astronomical community at large to fully explore how Webb’s unprecedented capabilities will help to unravel the complex interactions in galactic ecosystems. These observations are also accompanied by data from other observatories, including the NASA/ESA Hubble Space Telescope, and will help set the stage for future observations of galactic systems with Webb.The merger of these two galaxies has long been of interest to astronomers, and has previously been imaged by Hubble and by other space telescopes. The ongoing, extreme starburst causes intense infrared emission, and the merging galaxies may well be in the process of forming a supermassive black hole. A thick band of dust has blocked these valuable insights from the view of telescopes like Hubble. However, Webb’s infrared sensitivity and its impressive resolution at those wavelengths allows it to see past the dust and has resulted in the spectacular image above, a combination of MIRI and NIRCam imagery.The luminous core of the galaxy merger turns out to be both very bright and highly compact, so much so that Webb’s diffraction spikes appear atop the galaxy in this image. The 8-pronged, snowflake-like diffraction spikes are created by the interaction of starlight with the physical structure of the telescope. The spiky quality of Webb’s observations is particularly noticeable in images containing bright stars, such as Webb’s first deep field image.

MIRI was contributed by ESA and NASA, with the instrument designed and built by a consortium of nationally funded European Institutes (The MIRI European Consortium) in partnership with JPL and the University of Arizona.NIRSpec was built for the European Space Agency (ESA) by a consortium of European companies led by Airbus Defence and Space (ADS) with NASA’s Goddard Space Flight Center providing its detector and micro-shutter subsystems.Results based on this observation of IC 1623 have been published in the Astrophysical Journal.[Image description: The two galaxies swirl into a single chaotic object in the centre. Long, blue spiral arms stretch vertically, faint at the edges. Hot gas spreads horizontally over that, mainly bright red with many small gold spots of star formation. The core of the merging galaxies is very bright and radiates eight large, golden diffraction spikes. The background is black, with many tiny galaxies in orange and blue.]

Hubble Interacting Galaxy IC 1623 (2008-04-24).jpg

IC 1623 is an interacting galaxy system that is very bright when observed in the infrared. One of the two galaxies, the infrared-bright, but optically obscured galaxy VV 114E, has a substantial amount of warm and dense gas. Warm and dense gas is also found in the overlap region connecting the two nuclei. Observations further support the notion that IC 1623 is approaching the final stage of its merger, when a violent central inflow of gas will trigger intense starburst activity that could boost the infrared luminosity above the ultra-luminous threshold. The system will likely evolve into a compact starburst system similar to Arp 220. IC 1623 is located about 300 million light-years away from Earth.

This image is part of a large collection of 59 images of merging galaxies taken by the Hubble Space Telescope and released on the occasion of its 18th anniversary on 24th April 2008.

About the object
Object name	IC 1623, IC 1623A/B, Arp 236, VV 114
Object description	Interacting Galaxies
Position (J2000)	01 07 47.39 -17 30 23.7
Constellation	Cetus
Distance	250 million light-years (100 million parsecs)
About the data
Data description	The Hubble image was created using HST data from proposal 10592: A. Evans (University of Virginia, Charlottesville/NRAO/Stony Brook University)
Instrument	ACS/WFC
Exposure date(s)	July 11, 2002
Exposure time	33 minutes
Filters	F435W (B) and F814W (I)