About This Image
Release DateApril 19, 2022 10:00AM (EDT)
Read the Release2022-012
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NASA is celebrating the Hubble Space Telescope's 32nd birthday with a stunning look at an unusual close-knit collection of five galaxies, called The Hickson Compact Group 40. This menagerie includes three spiral-shaped galaxies, an elliptical galaxy, and a lenticular (lens-like) galaxy. Somehow, these different galaxies crossed paths in their evolution to create an exceptionally crowded and eclectic galaxy sampler. Caught in a leisurely gravitational dance, the whole group is so crowded that it could fit within a region of space that is less than twice the diameter of our Milky Way's stellar disk.
Though such cozy galaxy groupings can be found in the heart of huge galaxy clusters, these galaxies are notably isolated in their own small patch of the universe, in the direction of the constellation Hydra. One possible explanation is that there's a lot of dark matter (an unknown and invisible form of matter) associated with these galaxies. If they come close together, then the dark matter can form a big cloud within which the galaxies are orbiting. As the galaxies plow through the dark matter, they feel a resistive force due to its gravitational effects. This slows their motion and makes the galaxies lose energy, so they fall together. Therefore, this snapshot catches the galaxies at a very special moment in their lifetimes. In about 1 billion years they will eventually collide and merge to form a giant elliptical galaxy.
Astronomers have studied this compact galaxy group not only in visible light, but also in radio, infrared, and X-ray wavelengths. Almost all of them have a compact radio source in their cores, which could be evidence for the presence of supermassive black holes. X-ray observations show that the galaxies have been gravitationally interacting due to the presence of a lot of hot gas among the galaxies. Infrared observations reveal clues to the rate of new star formation.
Though over 100 such compact galaxy groups have been cataloged in sky surveys going back several decades, Hickson Compact Group 40 is one of the most densely packed. Observations suggest that such tight groups may have been more abundant in the early universe and provided fuel for powering black holes, known as quasars, whose light from superheated infalling material blazed across space. Studying the details of galaxies in nearby groups like this help astronomers sort out when and where galaxies assembled themselves, and what they are assembled from.
Hubble was deployed into orbit around Earth by NASA astronauts aboard the space shuttle Discovery, on April 25, 1990. The telescope has taken 1.5 million observations of approximately 50,000 celestial targets to date. This treasure trove of knowledge about the universe is stored for public access in the Mikulski Archive for Space Telescopes, at the Space Telescope Science Institute in Baltimore, Maryland.
Hubble's unique capabilities in observing visible and ultraviolet light are a critical scientific complement to the infrared-light observations of the recently launched Webb Space Telescope, which will begin science observations this summer.
NASA, ESA, STScI
IMAGE PROCESSING: Alyssa Pagan (STScI)
|About The Object|
|Object Name||HCG 40, Arp 321, VV 116|
|Object Description||Compact Galaxy Group|
|Distance||About 300 million light-years.|
|Dimensions||Image is 2.5 arcminutes across (about 220,000 light-years).|
|About The Data|
|Data Description||The Hubble image was created from HST data from proposal: 16848 (C. Britt).|
|Exposure Dates||25 November - 26 November 2021|
|Filters||F475W, F606W, F814W, F665N|
|About The Image|
|Color Info||These images are a composite of separate exposures acquired by the WFC3/UVIS instrument on the Hubble Space Telescope. Several filters were used to sample narrow wavelength ranges. The color results from assigning different hues (colors) to each monochromatic (grayscale) image associated with an individual filter. In this case, the assigned colors are: Blue: F475W Green: F606W Red: F814W Red: F665N|
|About The Object|
|Object Name||A name or catalog number that astronomers use to identify an astronomical object.|
|Object Description||The type of astronomical object.|
|R.A. Position||Right ascension – analogous to longitude – is one component of an object's position.|
|Dec. Position||Declination – analogous to latitude – is one component of an object's position.|
|Constellation||One of 88 recognized regions of the celestial sphere in which the object appears.|
|Distance||The physical distance from Earth to the astronomical object. Distances within our solar system are usually measured in Astronomical Units (AU). Distances between stars are usually measured in light-years. Interstellar distances can also be measured in parsecs.|
|Dimensions||The physical size of the object or the apparent angle it subtends on the sky.|
|About The Data|
|Instrument||The science instrument used to produce the data.|
|Exposure Dates||The date(s) that the telescope made its observations and the total exposure time.|
|Filters||The camera filters that were used in the science observations.|
|About The Image|
|Image Credit||The primary individuals and institutions responsible for the content.|
|Publication Date||The date and time the release content became public.|
|Color Info||A brief description of the methods used to convert telescope data into the color image being presented.|
|Orientation||The rotation of the image on the sky with respect to the north pole of the celestial sphere.|