Sunday, July 22 , 2018, 5:51 am | Fair 66º

 
 
 
 
Sports: A Noozhawk Partnership with The Lab and American Riviera Bank
The LabAmerican Riviera Bank

Scientists Turn Into Space Archaeologists During Galaxy Studies

How a team of scientists, led by UCSB researchers, found and measured an infant galaxy 6 billion light years away from Earth, and why.

An international team of scientists, led by two UCSB researchers, have identified a tiny galaxy, estimated to be 100 times lighter in mass than our own Milky Way. The scientists believe that if this galaxy is just one of a larger population of similar galaxies in the area, then what they found could be a young galaxy cluster in the making.

But if it weren’t for a much larger galaxy positioned in front of this much more distant one, the team may not have been able to see it. Using data collected by NASA’s Hubble Space Telescope and the W.M. Keck Observatory in Hawaii, the scientists, led by postdoctoral fellow Phil Marshall and Tommaso Treu, assistant professor of physics, were able to see the galaxy in the form of an Einstein ring, or a ring of light around a galaxy.{mosimage}

The galaxy in the foreground, said Marshall, acts as a gravitational lens, magnifying, focusing and bending the light of the smaller galaxy in the background, which is more than 6 billion light years away, or roughly about halfway across the observable universe.

“We already knew it was there,” said Marshall, referring to research done by Treu and his colleagues in the Sloan Lens ACS Survey, which studies Einstein ring gravitational lenses. What they had to do, said Marshall, was trace it back through the lens, account for the optical lensing, and try to reconstruct the galaxy without the gravitational lens in front of it. 

What they came up with, by measuring its brightest stars, was a galaxy approximately one-tenth the mass of the smallest distant galaxies typically observed.

Using the optic and near infrared images from the Hubble and the Keck telescopes, the researchers also inferred that many of the stars in this distant galaxy have only recently formed.

“If the galaxy is representative of a larger population, it could be one of the building blocks of today’s spiral galaxies, or perhaps a progenitor of modern dwarf galaxies,” said Treu, who is the second author of the paper, which will be published in the Dec. 20 issue of the Astrophysical Journal.

What this infant galaxy will become, however, will be a mystery. The images the scientists are seeing now reflects how the galaxy looked 6 billion light years ago. It has taken the light from that galaxy that long to reach us, and it would take billions more years to see its evolution.

“If we could freeze the cosmic expansion, stop the clock and walk 6 billion light years to this galaxy, it wouldn’t look small and blue. It would probably look small and red. And it would have the right size to be a dwarf elliptical galaxy, or possibly the bulge of a small spiral galaxy,” Marshall said. 

The researchers are interested in seeing galaxies at different times in the universe’s history, by looking at galaxies of various sizes and at various distances from the Earth.

 “What we’re really doing is a bit like archaeology . . . we can try to put together stories of how an object in the distant past might turn into an object that we see today.” 

Support Noozhawk Today

You are an important ally in our mission to deliver clear, objective, high-quality professional news reporting for Santa Barbara, Goleta and the rest of Santa Barbara County. Join the Hawks Club today to help keep Noozhawk soaring.

We offer four membership levels: $5 a month, $10 a month, $25 a month or $1 a week. Payments can be made through Stripe below, or click here for information on recurring credit-card payments and a mailing address for checks.

Thank you for your vital support.

Become a Noozhawk Supporter

First name
Last name
Enter your email
Select your membership level
×

Payment Information

You are purchasing:

Payment Method

Pay by Credit Card:

Mastercard, Visa, American Express, Discover
One click only, please!

Pay with Apple Pay or Google Pay:

Noozhawk partners with Stripe to provide secure invoicing and payments processing.

  • Ask
  • Vote
  • Investigate
  • Answer

Noozhawk Asks: What’s Your Question?

Welcome to Noozhawk Asks, a new feature in which you ask the questions, you help decide what Noozhawk investigates, and you work with us to find the answers.

Here’s how it works: You share your questions with us in the nearby box. In some cases, we may work with you to find the answers. In others, we may ask you to vote on your top choices to help us narrow the scope. And we’ll be regularly asking you for your feedback on a specific issue or topic.

We also expect to work together with the reader who asked the winning questions to find the answer together. Noozhawk’s objective is to come at questions from a place of curiosity and openness, and we believe a transparent collaboration is the key to achieve it.

The results of our investigation will be published here in this Noozhawk Asks section. Once or twice a month, we plan to do a review of what was asked and answered.

Thanks for asking!

Click Here to Get Started >

Reader Comments

Noozhawk is no longer accepting reader comments on our articles. Click here for the announcement. Readers are instead invited to submit letters to the editor by emailing them to [email protected]. Please provide your full name and community, as well as contact information for verification purposes only.

Daily Noozhawk

Subscribe to Noozhawk's A.M. Report, our free e-Bulletin sent out every day at 4:15 a.m. with Noozhawk's top stories, hand-picked by the editors.

Sign Up Now >