NASA's Hubble Space Telescope has captured the largest near-infrared image ever. This will enable astronomers to map the star-forming regions of the universe and learn about the origin of the earliest, most distant galaxies. The image was recently released by an international team of scientists.


The high-resolution survey, called 3D-DASH, will allow researchers to find rare objects and targets for follow-up observations with the recently launched James Webb Space Telescope (JWST) during its decades-long mission. 


The study will be published in The Astrophysical Journal. A preprint of the paper is available on arXiv. 


In a statement released by University of Toronto, Lamiya Mowla, the lead author on the paper, said that since the launch of the Hubble Space Telescope more than 30 years ago, it has led a renaissance in the study of how galaxies have changed in the last 10 billion years of the universe. She added that the 3D-DASH program extended Hubble's legacy in wide-area imaging so researchers can begin to unravel the mysteries of the galaxies beyond our own. 


How Does 3D-DASH Help Astronomers?


The 3D-DASH program provides researchers with a complete near-infrared survey of the entire COSMOS field, one of the richest data fields for extragalactic studies beyond the Milky Way, for the first time. Near-infrared is the longest and the reddest wavelength observed with Hubble, and means that astronomers are better able to see the earliest galaxies that are farthest away. This wavelength is just beyond what is visible to the human eye.


Also, astronomers will have to search a vast area of the sky to find rare objects in the universe, the statement said. Until now, such a large image was only available from the ground and suffered from poor resolution, limiting what could be observed. The 3D-DASH program will now help to identify unique phenomena like the universe's most massive galaxies, highly active black holes, and galaxies on the brink of colliding and merging into one. 


Mowla said she is curious about monster galaxies, which are the most massive ones in the universe formed by the mergers of other galaxies. Some of the questions in her mind include how the massive galaxies grow, and what drove the changes in their form. 


Mowla added that it was difficult to study these extremely rare events using existing images, which is what motivated the design of this large survey.


Technique Called DASH Captures Images In A Way Similar To Taking Panoramic Pictures With Smartphone


The researchers employed a new technique with Hubble to image such an expansive patch of the sky. The technique, known as Drift and SHift (DASH), creates an image that is eight times larger than Hubble's standard field of view by capturing multiple shots that are then stitched together into one master mosaic. This is similar to taking a panoramic picture with a smartphone. 


DASH captures images faster than the typical technique. It snaps eight pictures per Hubble's orbit instead of one picture, and achieves in 250 hours what would previously have taken 2,000 hours. 


Ivelina Momcheva, the principal investigator of the study, said 3D-DASH adds a new layer of unique observations in the COSMOS field and is also a stepping stone to the space surveys of the next decade. 


The researcher added that 3D-DASH gives scientists a sneak peek of future scientific discoveries and allows them to develop new techniques to analyse these large datasets.


Will JWST Break Hubble's Record?


According to the University of Toronto, 3D-DASH covers a total area almost six times the size of the Moon in the sky as seen from Earth. Hubble's successor, the JWST, is unlikely to break this record because it is instead built for sensitive, close-up images to capture fine detail of a small area. The image captured by Hubble is the largest near-infrared image of the sky available to astronomers until the next generation of telescopes are launched in the next decade, such as the Nancy Grace Roman Space Telescope and Euclid. 


Astronomers and amateur stargazers can explore the skies using an interactive, online version of the 3D-DASH image.