Hubble captures largest near-infrared image to find universe’s rarest galaxies

An international team of scientists today released the largest near-infrared image ever taken by NASA’s Hubble Space Telescope, allowing astronomers to map star-forming regions of the universe and learn how galaxies the oldest and most distant have appeared. Named 3D-DASH, this high-resolution survey 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.

A prepublication of the article to appear in The Astrophysical Journal is available on arXiv.

“Since its launch more than 30 years ago, the Hubble Space Telescope has led a renaissance in the study of how galaxies have changed over the past 10 billion years of the universe,” Lamiya said. Mowla, Dunlap Fellow at the Faculty of Arts and Science’s Dunlap Institute for Astronomy & Astrophysics at the University of Toronto and lead author of the study. “The 3D-DASH program extends Hubble’s legacy in large-scale imaging so we can begin to unlock the mysteries of galaxies beyond our own.”

For the first time, 3D-DASH provides researchers with a comprehensive near-infrared survey of the entire COSMOS field, one of the richest data fields for extragalactic studies beyond the Milky Way. As the longest and reddest wavelength observed with Hubble – second only to what is visible to the human eye – near infrared means astronomers are best able to see the earliest, most distant galaxies.

Astronomers must also scour a wide area of ​​the sky to find rare objects in the universe. Until now, an image this large was only available from the ground and suffered from poor resolution, which limited what could be observed. 3D-DASH will help identify unique phenomena such as the most massive galaxies in the universe, highly active black holes, and galaxies about to collide and merge into one.

“I am curious about monster galaxies, which are the most massive in the universe formed by the merger of other galaxies. How did their structures develop and what caused the changes in their shape ?” says Mowla, who started working on the project in 2015 when he was a graduate student at Yale University. “It was difficult to study these extremely rare events using existing images, which is what motivated the design of this large survey.”

To image such a vast patch of sky, the researchers used a new technique with Hubble known as Drift And SHift (DASH). DASH creates an image eight times larger than Hubble’s standard field of view by capturing multiple shots which are then stitched together into a master mosaic, similar to taking a panoramic photo on a smartphone.

DASH also takes images faster than the typical technique, taking eight images per Hubble orbit instead of one image, achieving in 250 hours what previously would have taken 2,000 hours.

“3D-DASH adds a new layer of unique observations in the COSMOS realm and also provides a stepping stone to space surveys of the next decade,” says Ivelina Momcheva, Data Science Manager at the Max Planck Institute for Astronomy. and principal investigator of the study. “It gives us insight into future scientific discoveries and allows us to develop new techniques to analyze these large datasets.”

3D-DASH covers a total area nearly six times the size of the moon in the sky as seen from Earth. This record is likely to remain unbroken by Hubble’s successor, JWST, which is designed more for sensitive close-up images to capture fine detail in a small area. It is the largest near-infrared image of the sky available to astronomers until the launch of the next generation of telescopes in the next decade, such as the Nancy Grace Roman Space Telescope and Euclid.

Until then, professional astronomers and amateur astronomers can explore the sky using an interactive online version of the 3D-DASH image created by Gabriel Brammer, a professor at the Cosmic Dawn Center at the Niels Bohr Institute of the University of Copenhagen.

The Hubble Space Telescope is an international cooperation project between NASA and the European Space Agency (ESA). NASA’s Goddard Space Flight Center operates the telescope in Greenbelt, Maryland. The Space Telescope Science Institute (STScI) in Baltimore, Maryland conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.

The full image is available from the Mikulski Archive for Space Telescopes.