A tale of galactic collisions: When  we look into the distant cosmos, the great majority of the objects we  see are galaxies: immense gatherings of stars, planets, gas, dust, and  dark matter, showing up in all kind of shapes. This Hubble picture  registers several, but the galaxy catalogued as 2MASX J05210136-2521450  stands out at a glance due to its interesting shape. This  object is an ultraluminous infrared galaxy which emits a tremendous  amount of light at infrared wavelengths. Scientists connect this to intense star formation activity, triggered by a collision between two  interacting galaxies. The  merging process has left its signs: 2MASX J05210136-2521450 presents a  single, bright nucleus and a spectacular outer structure that consists  of a one-sided extension of the inner arms, with a tidal tail heading in  the opposite direction, formed from material ripped out from the  merging galaxies by gravitational forces. The image is a combination of exposures taken by Hubble’s Advanced Camera for Surveys, using near-infrared and visible light. A version of this image was submitted to the Hubble’s Hidden Treasures image processing competition by contestant Luca Limatola.

Name: 2MASX J05210136-2521450
Type: Early Universe : Galaxy : Activity : Ultraluminous
Category: Galaxies
Constellation: Lepus
Distance: z=0.04 (redshift)
Release date: 6 May 2013, 10:00
Credit: ESA/Hubble & NASAAcknowledgement: Luca Limatola

A spacetime magnifying glass: This Hubble image shows the galaxy cluster Abell S1077. Galaxy clusters are large groupings of galaxies, each of them including millions of stars. They are the largest existing structures in the Universe to be held together by their gravity. The amount of matter condensed in such groupings is so high that their gravity is enough to warp the fabric of spacetime, distorting the path that light takes when it travels through the cluster. In some cases, this phenomenon produces an effect somewhat like a magnifying lens, allowing us to see objects that are aligned behind the cluster and which would otherwise be undetectable from Earth. In this image, you see stretched stripes that look like scratches on a lens but are, in fact, galaxies whose light is heavily distorted by the gravitational field of the cluster. Astronomers use tools like the NASA/ESA Hubble Space Telescope and the effects of gravitational lensing to peer far back in time and space to see the furthest objects located in the early Universe. One of the record holders is MACS0647-JD, a galaxy seen by Hubble and the Spitzer Space Telescope with the help of a gravitational lens much like this one in the galaxy cluster MACS J0647.7+7015. Its light has taken 13.3 billion years to reach us. This image is based in part on data spotted by Nick Rose in the Hubble’s Hidden Treasures image processing competition.

Name: Abell S1077
Type: Early Universe : Star : Grouping : Cluster
Category: Cosmology
Constellation: Piscis Austrinus
Distance: z=0.312 (redshift)
Release date: 13 May 2013, 10:00
Credit: ESA/Hubble & NASA. Acknowledgement: N. Rose

A swirl of star formation: This  beautiful, glittering swirl is named, rather unpoetically,  J125013.50+073441.5. A glowing haze of material seems to engulf the  galaxy, stretching out into space in different directions and forming a  fuzzy streak in this image. It is a starburst galaxy — a name given to  galaxies that show unusually high rates of star formation. The regions  where new stars are being born are highlighted by sparkling bright blue  regions along the galactic arms. Studying  starburst galaxies can tell us a lot about galactic evolution and star  formation. These galaxies start off with huge amounts of gas, which is  used to form new stars. This period of furious star formation is only a  phase; once all the gas is used up, this starbirth slows down. Other  famous starbursts captured by Hubble include the Antennae Galaxies and Messier 82, the latter of which is forming new stars ten times faster than our galaxy, the Milky Way. The data for this image were collected as part of a study named LARS (Lyman Alpha Reference Sample) [1], which is investigating the interaction between radiation and  matter in relatively nearby starburst galaxies. J125013.50+073441.5 is  included as one of its fourteen targets.  This study has characterised how a certain type of emission known as  Lyman-alpha emission interacts with nearby gas, affecting how it travels  out into space. The data for this image were collected using Hubble’s Wide Field Camera 3. [1] Hayes, Östlin et al., The Lyman Alpha Reference Sample: extended Lyman alpha halos produced at low dust content, The Astrophysical Journal, 2013.

Name: J125013.50+073441.5
Type: Local Universe : Galaxy : Activity : Starburst
Category: Galaxies
Constellation: Virgo
Distance: z=0.038 (redshift)
Release date: 20 May 2013, 10:00
Credit: ESA/Hubble & NASA, M. Hayes

The messy result of a galactic collision: This  new image from the NASA/ESA Hubble Space Telescope captures an  ongoing cosmic collision between two galaxies — a spiral galaxy is in  the process of colliding with a lenticular galaxy. The collision looks  almost as if it is popping out of the screen in 3D, with parts of the  spiral arms clearly embracing the lenticular galaxy’s bulge. The  image also reveals further evidence of the collision. There is a bright  stream of stars coming out from the merging galaxies, extending out  towards the right  of the image. The bright spot in the middle of the plume, known as ESO  576-69, is what makes this image unique. This spot is believed to be the  nucleus of the former spiral galaxy, which was ejected from the system  during the collision and is now being shredded by tidal forces to  produce the visible stellar stream. A version of this image was entered into the Hubble’s Hidden Treasures image processing competition by contestant Luca Limatola.

Name: ESO 576-69
Type: Local Universe : Galaxy : Type : InteractingLocal Universe : Galaxy : Activity : AGN
Category: Galaxies
Constellation: Virgo
Distance: 300 million light years
Release date: 27 May 2013, 10:00
Credit: ESA/Hubble & NASAAcknowledgement: Luca Limatola