May 2, 2024

Dark Energy Experiment Reveals Galaxy Gold Mine in First Large Survey

The HETDEX partnership involves a big team consisting of astronomers, engineers, service technicians, and college students from 6 scholastic institutions in the United States and Germany.
The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) revealed their very first publicly launched brochure mapping over 200,000 huge things, which consist of distant stars and galaxies rupturing with star development. HETDEX tiles the sky, gathering spectroscopic information that is used to determine area of a star or galaxy and its range from Earth. For the first time, the scientists have actually cataloged astronomical objects– mapping over 51,863 Lyman-alpha-emitting galaxies at high redshift; 123,891 star forming galaxies at lower redshift; 5,274 non-emission line galaxies at low redshift; and 4,976 active galactic nuclei (AGN)– brilliant spots that signify the presence of black holes.
The paper describing the brochure was published on February 7, 2023, in The Astrophysical Journal.
” Weve simply taken off in regards to the variety of redshifts cataloged for the very first time,” said research study co-author Erin Mentuch Cooper, a research researcher at The University of Texas at Austin (UT Austin). Cooper is the information manager for the HETDEX job.
” There is a gold mine of astronomy expedition in the HETDEX catalog. Thats what I love about it,” stated research study co-author Karl Gebhardt, the Herman and Joan Suit Professor in Astronomy, College of Natural Sciences, UT Austin. Gebhardt is project scientist and primary private investigator of HETDEX.
TACCs Maverick2 (top), Stampede2 (left), Corral (right) supercomputers. Credit: TACC
A stars redshift tells astronomers how quick a star is moving away from the Earth because its frequency, similar to its color, gets lower as it moves away, much like the horn of a train as it passes by.
The faster a star moves away, the farther away it is. That relationship between speed and range, called Hubbles Law, can determine a galaxys location and enables astronomers to develop a 3D map of over 200,000 stars and galaxies with HETDEX.
” This is just a little portion of what we will find, but its an excellent start. Ultimately, HETDEX aims to map one million red-shifted galaxies,” Cooper said.
HETDEX is special from previous large sky studies because its a non-targeted survey, blanketing the sky and collecting spectra from the 35,000 fiber optic cables of the Visible Integral Field Replicable Unit Spectrograph (VIRUS).
Infection takes starlight from remote galaxies and divides the light into its element colors like a prism does. HETDEX tiles the sky, collecting 35,000 spectra in a moon-sized swath of sky and moving from area to spot. It collects about 500-600 hours of observations each year for its survey data.
” We have the biggest spectroscopic instrument on the planet, and were doing one of the longest studies in terms of time,” Gebhardt stated. “To examine this data, we require the fastest computer we can get our hands on, and thats where TACC comes in. TACC does all the information storage and all the information analysis for this giant study.”
The information from the telescope goes straight to the TACC Corral data storage system by means of high speed lines at 100 Gigabits/second.
” TACC has striven with us to streamline our system, and its just working remarkably. We can process years of information in a number of days, perhaps a week of time on TACC systems. And we do it numerous times since we keep changing and enhancing our techniques,” Gebhardt added.
HETDEX used the Maverick and Stampede2 supercomputers of the Texas Advanced Computing Center, a leading scholastic supercomputing center at UT Austin. Stampede2 is funded by the National Science Foundation as a shared resource for thousands of researchers throughout the US. They helped procedure and examine about 60 terabytes of image data on TACCs Corral system.
Whats more, Cooper and associates have dealt with TACC to produce JupyterHub public access to the information.
” Anyone with any academic credentials can get a TACC account and go on through a web browser to access our information. The future is going to offer a tradition capacity of the science from HETDEX.
One interesting emphasize from the brochure is the recognition of an active stellar nuclei (AGN) with strong Lyman-alpha light emission. Gebhadt co-authored a study led by UT Austin astronomy post-doctoral researcher Chenxu Liu, published in November 2022 in The Astrophysical Journal. It presents appealing evidence of a black hole without a surrounding host galaxy.
” This is what I call naked great voids,” Gebhardt said. “Nothing verified yet, but we presume these could be out there. Only a study like HETDEX will be able to find these.”
The science produced from HETDEX adds to the larger image of understanding the expansion of the whole universe, unexpectedly growing much faster than expected based upon precise observations from the Hubble Space Telescope in 2019 of supernovae that act like a cosmic yardstick.
The Holy Grail for HETDEX is an accurate step of deep space expansion rate 10 billion years ago that will reveal the physical design for dark energy.
Astronomers are at chances over how to describe the step of the current expansion rate. Comprehending it could require a modification in the theory of gravity, or a change in the basic Big Bang theory. It may be the handiwork of an undiscovered particle.
An accurate value of the expansion rate early in the Universe can be compared to the growth rate today. This contrast can identify if deep space will continue to broaden permanently, or will sooner or later collapse on itself numerous billions of years from now.
” The whole point of the HETDEX job is to determine the expansion of the universe,” Gebhardt said.
” This new brochure adds valuable data in finally addressing the million galaxy concern, which is something the HETDEX Collaboration is working extremely hard on in the coming year. Theres a larger picture here, and thats what we give back to the neighborhood, not just to the researchers around the world however the general neighborhood. We would not be able to do this work without the supercomputing resources and professionals at TACC, through permitting us the computing power to run numerous analyses of the information and continue to enhance the procedure.”
To discover out how you can help identify galaxies for HETDEX, checked out the Dark Energy Explorers task.
Referral: “HETDEX Public Source Catalog 1: 220 K Sources Including Over 50 K Lyα Emitters from an Untargeted Wide-area Spectroscopic Survey” by Erin Mentuch Cooper, Karl Gebhardt, Dustin Davis, Daniel J. Farrow, Chenxu Liu, Gregory Zeimann, Robin Ciardullo, John J. Feldmeier, Niv Drory, Donghui Jeong, Barbara Benda, William P. Bowman, Michael Boylan-Kolchin, Óscar A. Chávez Ortiz, Maya H. Debski, Mona Dentler, Maximilian Fabricius, Rameen Farooq, Steven L. Finkelstein, Eric Gawiser, Caryl Gronwall, Gary J. Hill, Ulrich Hopp, Lindsay R. House, Steven Janowiecki, Hasti Khoraminezhad, Wolfram Kollatschny, Eiichiro Komatsu, Martin Landriau, Maja Lujan Niemeyer, Hanshin Lee, Phillip MacQueen, Ken Mawatari, Brianna McKay, Masami Ouchi, Jennifer Poppe, Shun Saito, Donald P. Schneider, Jan Snigula, Benjamin P. Thomas, Sarah Tuttle, Tanya Urrutia, Laurel Weiss, Lutz Wisotzki, Yechi Zhang and The HETDEX collaboration, 7 February 2023, The Astrophysical Journal.DOI: 10.3847/ 1538-4357/ aca962.

Illustration showing the Hobby-Eberly Telescope and VIRUS spectrograph pairs installed on either side of the telescope. Credit: McDonald Observatory/HETDEX Collaboration
Texas Advanced Computing Center (TACC) systems support catalog release of over 200,000 new star and galaxy areas.
Astronomers have actually hardly scratched the surface of mapping the nearly limitless stars and galaxies of the heavens. Utilizing supercomputers and the assistance of thousands of person scientists around the world, scientists with The University of Texas at Austin have actually now revealed the locations of more than 200,000 new astronomical objects. Their goal is to map even more and utilize that understanding to anticipate the supreme fate of the universe.
The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) has actually scanned the dark skies of the Davis Mountains in West Texas considering that 2017 with a keen eye toward catching spectroscopic data on Lyman-alpha frequency light from neutral hydrogen emission in galaxies over 10 billion light years away. These galaxies give off a signature wavelength of light from hydrogen that indicates to astronomers the intense creation of new stars.

The Hobby-Eberly Telescope Dark Energy Experiment (HETDEX) announced their very first openly launched brochure mapping over 200,000 huge items, which consist of distant stars and galaxies rupturing with star formation. HETDEX tiles the sky, collecting spectroscopic information that is utilized to identify place of a star or galaxy and its distance from Earth.” There is a gold mine of astronomy exploration in the HETDEX brochure. HETDEX used the Maverick and Stampede2 supercomputers of the Texas Advanced Computing Center, a leading academic supercomputing center at UT Austin.” This brand-new catalog adds valuable data in lastly answering the million galaxy question, which is something the HETDEX Collaboration is working extremely hard on in the coming year.

By University of Texas at Austin, Texas Advanced Computing
February 17, 2023