NASA’s Hubble Telescope Spots Distant Galaxies That May Need Guarding
In a newly released image, NASA's Hubble Space Telescope has displayed many distant galaxies that were previously unseen or faintly seen.
One is the galaxy cluster Abell 370 with a huge assortment of galaxies in different shapes guarding it and bound by mutual gravity in the immense cluster.
Located at 4 billion light-years away and belonging to Cetus constellation, Abell 370 is a huge galaxy cluster imaged in the Frontier Fields project.
The image of Abell 370 was captured with visible and near-infrared light. It is densely packed with a vast array of large and bright galaxies in yellowish color containing billions of stars.
In the image, mysterious arcs of blue light are apparent which indicate the presence of remote galaxies behind the cluster. They are too far and faint that Hubble cannot view them directly. However, Abell 370 is offering an opportunity to view them as well, thanks to its lensing property which magnifies faint images.
Cosmic Coincidence Of Abell 370
Gravitational lensing happens when galaxy cluster Abell 370 warps the light beaming other spiral galaxies behind. This cosmic coincidence of the cluster is an advantage for Hubble in exploiting other galaxies.
For Hubble, the Abell 370 has emerged as a good target for its use as a stepping stone in tracing other remote galaxies using the latter's lensing property for peering through the magnified images galaxies lurking behind.
The gravitational field of the Abell 370 at the foreground bends the light that will be heading toward Earth from the far-flung galaxies. The powerful gravity is the sum of the individual gravity pull exercised by stars and other dark matter present in the galactic cluster.
History Of Abell 370 Cluster
Abell 370 was one of the hundreds of galaxy clusters compiled by George Abell in 1958. His early catalog contained 3,000 galaxy clusters from the Northern Hemisphere and it was updated in 1989 by adding more clusters from the Southern Hemisphere.
Abell 370 is the most distant galaxy cluster in the Abell catalog. The gravitational lensing of the cluster is also evident in the phenomenon of arcs coming up in the farthest background in the cluster images.
A feature called "the Dragon" appearing as a smeared trail behind a spiral galaxy to the lower left middle is another illustration of gravitational lensing.
Elliptical Vs Spiral Galaxies
Unlike the Milky Way that is populated by tens of galaxies clusters, Abell 370 is the hub of hundreds of galaxies that reside in the dense centers.
Massive galaxy clusters are distinguished by the manner in which huge and oldest galaxies are housed at the center, showing up as yellow-red spots.
Also, elliptical galaxies are devoid of dust and gas unlike spiral galaxies in the Milky Way containing younger stars and more volumes of dust and gas rendering visually rich features.
Benefit Of Lensing Effect
Thanks to lensing effect of cluster galaxies, Hubble will discover hundreds of distant galaxies. Astronomers are upbeat that Abell 370's gravitational lensing effects will help in tracking remote galaxies that were part of the early universe.
The collaboration between NASA's Great Observatories and other telescopes harnessed the power of massive galaxy clusters. The earliest stages of galaxy development are brought to the forefront with galaxies that were 10 to 100 times fainter than any previously observed.