From UCSC: “Earliest galaxies in the universe spin like the Milky Way”

UC Santa Cruz

UC Santa Cruz

January 10, 2018
Tim Stephens

Artist’s impression of spinning galaxies. Credit: Amanda Smith, University of Cambridge

A visualization of a simulated young galaxy taken from a recent simulation that shows an early galaxy, thought to be like those studied with ALMA, in the throes of its formation and growth. Video credit: R. Crain (Liverpool John Moores University) and J. Geach (University of Hertfordshire)

Astronomers looking back to a time soon after the big bang have discovered swirling gas in some of the earliest galaxies to have formed in the universe. These newborn galaxies, observed as they appeared nearly 13 billion years ago, spin like a whirlpool, similar to our own Milky Way galaxy.

Garth Illingworth, professor emeritus of astronomy and astrophysics at UC Santa Cruz and a member of the international team that made the discovery, explained that light from distant objects takes time to reach Earth, so observing objects that are billions of light years away enables astronomers to look back in time and directly observe the formation of the earliest galaxies.

Using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, the team led by Renske Smit at the Kavli Institute of Cosmology, University of Cambridge, identified star-forming galaxies at a very early stage in cosmic history that spin in a way thought not to occur until much later times.

ESO/NRAO/NAOJ ALMA Array in Chile in the Atacama at Chajnantor plateau, at 5,000 metres

This image from a recent simulation of galaxy formation shows swirling gas in an early galaxy thought to be like the two observed with ALMA in the new study. (Image credit: A. Pallottini, University of Pisa)

Researchers studied two galaxies shown here in a Hubble image and as detected by ALMA (inset panels). The color gradients in the ALMA images show the motion of the gas, indicative of rotation. Because of their distance, the galaxies are seen as they were nearly 13 billion years ago, 800 million years after the big bang. Image credit: Hubble (NASA/ESA), ALMA (ESO/NAOJ/NRAO), P. Oesch (University of Geneva) and R. Smit (University of Cambridge)

NASA/ESA Hubble Telescope

The results are reported in the journal Nature and will be presented January 10 at the 231st meeting of the American Astronomical Society in Washington, D.C.

“ALMA opens up a new window in the spectrum that allows us to measure motions in these early galaxies in a way that has been impossible to date, even with telescopes as powerful as Hubble. This provides new insights into the dramatic activity in these young galaxies as the gas is being transformed into stars,” Illingworth said.

Smit and her colleagues used ALMA to observe two small newborn galaxies as they existed just 800 million years after the big bang, which was 13.7 billion years ago. By analyzing the spectral ‘fingerprint’ of the far-infrared light collected by ALMA, the researchers were able to establish the distance to the galaxies and, for the first time, see the internal motion of the gas that fuelled their growth.

“This is a remarkable discovery given that the team used ALMA to look back through 94 percent of all time to capture the faint signals from these two galaxies,” Illingworth said.

“Until ALMA, we’ve never been able to see the formation of galaxies in such detail, and we’ve never been able to measure the movement of gas in galaxies so early in the universe’s history,” said coauthor Stefano Carniani at Cambridge’s Cavendish Laboratory and Kavli Institute of Cosmology.

The researchers found that the gas in these newborn galaxies swirled and rotated in a whirlpool motion, similar to our own spiral galaxy and other mature galaxies much later in the universe’s history. Despite their relatively small size—about five times smaller than the Milky Way—these galaxies were forming stars at a higher rate than other young galaxies. But the researchers were surprised to discover that the galaxies were not as chaotic as expected.

“In the early Universe, gravity caused gas to flow rapidly into the galaxies, stirring them up and forming lots of new stars. Violent supernova explosions from these stars also makes the gas even more turbulent,” said Smit, who is a Rubicon Fellow at Cambridge sponsored by the Netherlands Organization for Scientific Research. “We expected that young galaxies would be dynamically ‘messy’ due to the havoc caused by exploding young stars, but these mini-galaxies show the ability to retain order and appear well regulated. They are already rapidly growing to become one of the ‘adult’ galaxies like we live in today,” she said.

The results from this project pave the way for larger studies of newly-forming galaxies during the first billion years of cosmic time with ALMA’s uniquely powerful capabilities and with the upcoming James Webb Space Telescope. The research was funded in part by the European Research Council and the UK Science and Technology Facilities Council (STFC).

See the full article here .

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UCO Lick Shane Telescope
UCO Lick Shane Telescope interior
Shane Telescope at UCO Lick Observatory, UCSC

Lick Automated Planet Finder telescope, Mount Hamilton, CA, USA

Lick Automated Planet Finder telescope, Mount Hamilton, CA, USA

UC Santa Cruz campus
The University of California, Santa Cruz, opened in 1965 and grew, one college at a time, to its current (2008-09) enrollment of more than 16,000 students. Undergraduates pursue more than 60 majors supervised by divisional deans of humanities, physical & biological sciences, social sciences, and arts. Graduate students work toward graduate certificates, master’s degrees, or doctoral degrees in more than 30 academic fields under the supervision of the divisional and graduate deans. The dean of the Jack Baskin School of Engineering oversees the campus’s undergraduate and graduate engineering programs.

UCSC is the home base for the Lick Observatory.

Lick Observatory's Great Lick 91-centimeter (36-inch) telescope housed in the South (large) Dome of main building
Lick Observatory’s Great Lick 91-centimeter (36-inch) telescope housed in the South (large) Dome of main building

Search for extraterrestrial intelligence expands at Lick Observatory
New instrument scans the sky for pulses of infrared light
March 23, 2015
By Hilary Lebow
The NIROSETI instrument saw first light on the Nickel 1-meter Telescope at Lick Observatory on March 15, 2015. (Photo by Laurie Hatch) UCSC Lick Nickel telescope

Astronomers are expanding the search for extraterrestrial intelligence into a new realm with detectors tuned to infrared light at UC’s Lick Observatory. A new instrument, called NIROSETI, will soon scour the sky for messages from other worlds.

“Infrared light would be an excellent means of interstellar communication,” said Shelley Wright, an assistant professor of physics at UC San Diego who led the development of the new instrument while at the University of Toronto’s Dunlap Institute for Astronomy & Astrophysics.

Wright worked on an earlier SETI project at Lick Observatory as a UC Santa Cruz undergraduate, when she built an optical instrument designed by UC Berkeley researchers. The infrared project takes advantage of new technology not available for that first optical search.

Infrared light would be a good way for extraterrestrials to get our attention here on Earth, since pulses from a powerful infrared laser could outshine a star, if only for a billionth of a second. Interstellar gas and dust is almost transparent to near infrared, so these signals can be seen from great distances. It also takes less energy to send information using infrared signals than with visible light.

UCSC alumna Shelley Wright, now an assistant professor of physics at UC San Diego, discusses the dichroic filter of the NIROSETI instrument. (Photo by Laurie Hatch)

Frank Drake, professor emeritus of astronomy and astrophysics at UC Santa Cruz and director emeritus of the SETI Institute, said there are several additional advantages to a search in the infrared realm.

“The signals are so strong that we only need a small telescope to receive them. Smaller telescopes can offer more observational time, and that is good because we need to search many stars for a chance of success,” said Drake.

The only downside is that extraterrestrials would need to be transmitting their signals in our direction, Drake said, though he sees this as a positive side to that limitation. “If we get a signal from someone who’s aiming for us, it could mean there’s altruism in the universe. I like that idea. If they want to be friendly, that’s who we will find.”

Scientists have searched the skies for radio signals for more than 50 years and expanded their search into the optical realm more than a decade ago. The idea of searching in the infrared is not a new one, but instruments capable of capturing pulses of infrared light only recently became available.

“We had to wait,” Wright said. “I spent eight years waiting and watching as new technology emerged.”

Now that technology has caught up, the search will extend to stars thousands of light years away, rather than just hundreds. NIROSETI, or Near-Infrared Optical Search for Extraterrestrial Intelligence, could also uncover new information about the physical universe.

“This is the first time Earthlings have looked at the universe at infrared wavelengths with nanosecond time scales,” said Dan Werthimer, UC Berkeley SETI Project Director. “The instrument could discover new astrophysical phenomena, or perhaps answer the question of whether we are alone.”

NIROSETI will also gather more information than previous optical detectors by recording levels of light over time so that patterns can be analyzed for potential signs of other civilizations.

“Searching for intelligent life in the universe is both thrilling and somewhat unorthodox,” said Claire Max, director of UC Observatories and professor of astronomy and astrophysics at UC Santa Cruz. “Lick Observatory has already been the site of several previous SETI searches, so this is a very exciting addition to the current research taking place.”

NIROSETI will be fully operational by early summer and will scan the skies several times a week on the Nickel 1-meter telescope at Lick Observatory, located on Mt. Hamilton east of San Jose.

The NIROSETI team also includes Geoffrey Marcy and Andrew Siemion from UC Berkeley; Patrick Dorval, a Dunlap undergraduate, and Elliot Meyer, a Dunlap graduate student; and Richard Treffers of Starman Systems. Funding for the project comes from the generous support of Bill and Susan Bloomfield.

Please help promote STEM in your local schools.


Stem Education Coalition