Astronomers don't fully understand how massive galaxies like ours grow and evolve in the universe. The first galaxies formed around 670 million years after the Big bang. Mergers play a role in the growth of the universe. Astronomers know that black holes play a role in the growth of the universe, but they don't know how.
Calculating some of this out should be helped by a new Hubble survey.
3D-DASH is a survey of the sky that maps star forming regions. It is the largest of it's type. The goal is to find rare objects that the space telescope can see.
There is a paper titled "3D-DASH: The Widest Near-Infrared Hubble Space Telescope Survey". It will be published in The Astrophysical Journal and can be found at the pre- press site arxiv.org. Lamiya Mowla is a Dunlap Fellow at the University of Toronto.
The Hubble Space Telescope has led a renaissance in the study of how the universe has changed over time. The 3D-DASH program extends Hubble's legacy so we can begin to understand the mysteries of the universe beyond our own.
3D-DASH is an improvement over the previous effort. Multiple space- and ground-based telescopes were used to cover a 2 square degree field. Roughly 75% of the age of the Universe is covered by it.
3D-DASH surveys its entire contents in near-IR. Astronomers are able to see the most distant, earliest galaxies because of that.
It's important that the survey size is large. In order for surveys to be productive, they have to identify unique phenomena in the Universe, such as the oldest and most massive galaxies. Black holes are very active. Huge images are needed to find those.
Ground-based surveys weren't as robust as previous ones Astronomers were limited what they could learn from them. 3D-DASH doesn't have the same limitations.
I am curious about giant galaxies, which are the most massive in the universe. Mowla was a graduate student at Yale University when he began work on the project. The design of this large survey was motivated by the fact that it was hard to study these rare events using existing images.
The new technique that Mowla and her colleagues are using is called DASH. DASH is a way to take a panoramic image with a phone. Multiple images are captured and then merged into a single image. DASH was able to take images in 250 hours, which is more time-saving than 2000 hours.
Instead of one, it captures eight Hubble images instead of one. The Hubble is drifting and shifting, and only the first of the eight images is pointed. The result is worth it even though the data reduction procedure is more demanding.
Ivelina Momcheva is the head of data science at the Max Planck Institute for Astronomy and is the principal investigator of the study. It gives us a glimpse of future scientific discoveries and allows us to develop new techniques to analyze these large datasets.
3D-DASH gives a list of targets for the James Webb Space Telescope. Two of the JWST's science objectives are the Early Universe and Galaxies over Time. Astronomers will be able to compare the earliest galaxies to today's grand spirals and ellipticals thanks to Webb's unprecedented sensitivity. 3D-DASH has a list of targets.
There's an online version of the mosaic.
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