Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hubble Finds Extremely Distant Galaxy through Cosmic Magnifying Glass

20.10.2014

Peering through a giant cosmic magnifying glass, NASA's Hubble Space Telescope has spotted one of the farthest, faintest, and smallest galaxies ever seen. The diminutive object is estimated to be over 13 billion light-years away.

This new detection is considered one of the most reliable distance measurements of a galaxy that existed in the early universe, said the Hubble researchers. They used two independent methods to estimate its distance.


NASA, ESA, A. Zitrin (Caltech), and J. Lotz, M. Mountain, A. Koekemoer, and the HFF Team (STScI)

The heart of the mammoth galaxy cluster Abell 2744, also known as Pandora's Cluster, is shown in this Hubble Space Telescope image. The cluster is so massive that its powerful gravity bends the light from galaxies far behind it, making background objects appear larger and brighter in a phenomenon called gravitational lensing. These powerful lenses allow astronomers to find many dim, distant structures that otherwise might be too faint to see. The small white boxes, labeled "a," "b," and "c," mark multiple images from the same background galaxy, one of the farthest, faintest, and smallest galaxies ever seen. The diminutive object is estimated to be over 13 billion light-years away. Enlarged views of the multiple images are shown in the insets at right. The arrows point to the tiny galaxy far behind the cluster. Each magnified image makes the galaxy appear as much as 10 times larger and brighter than it would look without the intervening lens. To determine the background galaxy's distance, the researchers studied the galaxy's color and measured the positions between the three images. This new detection is considered one of the most reliable distance measurements of a galaxy that existed in the early universe. The galaxy appears as a tiny blob that is only a small fraction of the size of our Milky Way galaxy. But it offers a peek back into a time when the universe was only about 500 million years old, roughly 3 percent of its current age of 13.7 billion years. An analysis of the distant galaxy shows that it measures merely 850 light-years across, 500 times smaller than the Milky Way, and is estimated to have a mass of only 40 million suns. The galaxy's star formation rate is about one star every three years (one-third the star formation rate in the Milky Way). The galaxy was detected as part of the Frontier Fields program, an ambitious three-year effort, begun in 2013, that teams Hubble with NASA's other Great Observatories -- the Spitzer Space Telescope and the Chandra X-ray Observatory -- to probe the early universe by studying large galaxy clusters. Abell 2744 resides about 3.5 billion light-years away. The image was made by combining near-infrared observations from Hubble's Wide Field Camera 3 and visible-light exposures from the Advanced Camera for Surveys. The observations were taken in 2009, 2013, and 2014.

The galaxy appears as a tiny blob that is only a small fraction of the size of our Milky Way galaxy. But it offers a peek back into a time when the universe was only about 500 million years old, roughly 3 percent of its current age of 13.7 billion years. Astronomers have uncovered about 10 other galaxy candidates at this early era. But this newly found galaxy is significantly smaller and fainter than most of those other remote objects detected to date.

"This object is a unique example of what is suspected to be an abundant, underlying population of extremely small and faint galaxies at about 500 million years after the big bang," explained study leader Adi Zitrin of the California Institute of Technology in Pasadena. "The discovery is telling us that galaxies as faint as this one exist, and we should continue looking for them and even fainter objects so that we can understand how galaxies and the universe have evolved over time."

The galaxy was detected as part of the Frontier Fields program, an ambitious three-year effort, begun in 2013, that teams Hubble with NASA's other Great Observatories -- the Spitzer Space Telescope and the Chandra X-ray Observatory -- to probe the early universe by studying large galaxy clusters. These clusters are so massive that their gravity deflects light passing through them, magnifying, brightening, and distorting background objects in a phenomenon called gravitational lensing. These powerful lenses allow astronomers to find many dim, distant structures that otherwise might be too faint to see.

In this new discovery, the lensing power of the mammoth galaxy cluster Abell 2744, nicknamed Pandora's Cluster, produced three magnified images of the same galaxy. Each magnified image makes the galaxy appear as much as 10 times larger and brighter than it would look without the intervening lens.

An analysis of the distant galaxy shows that it measures merely 850 light-years across, 500 times smaller than the Milky Way, and is estimated to have a mass of only 40 million suns. The galaxy's star formation rate is about one star every three years (one-third the star formation rate in the Milky Way). Although this may seem low, Zitrin said that given its small size and low mass, the tiny galaxy is in fact rapidly evolving and efficiently forming stars.

"Galaxies such as this one are probably small clumps of matter that are starting to form stars and shine light, but they don't have a defined structure yet," Zitrin said. "Therefore, it's possible that we only see one bright clump magnified due to the lensing, and this is one possibility as to why it is smaller than typical field galaxies of that time." Zitrin's team spotted the galaxy's gravitationally multiplied images using near-infrared and visible-light photos of the galaxy cluster taken by Hubble's Wide Field Camera 3 and Advanced Camera for Surveys. But at first they didn't know how far away it was from Earth.

Normally, astronomers use spectroscopy to determine an object's distance. The farther away a galaxy, the more its light has been stretched by the universe's expansion. Astronomers can precisely measure this effect through spectroscopy, which characterizes an object's light.

But the gravitationally lensed galaxy and other objects found at this early epoch are too far away and too dim for astronomers to use spectroscopy. Astronomers instead analyze an object's color to estimate its distance. The universe's expansion reddens an object's color in predictable ways, which scientists can measure.

Members of Zitrin's team not only performed the color-analysis technique, but they also took advantage of the multiple images produced by the gravitational lens to independently confirm their distance estimate. The astronomers measured the angular separation between the three magnified images of the galaxy in the Hubble photos. The greater the angular separation due to lensing, the farther away the object is from Earth. To test this concept, the astronomers compared the three magnified images with the locations of several other multiply imaged objects lensed by Abell 2744 that are not as far behind the cluster. The angular distance between the magnified images of the closer galaxies was smaller.

"These measurements imply that, given the large angular separation between the three images of our background galaxy, the object must lie very far away," Zitrin explained. "It also matches the distance estimate we calculated, based on the color-analysis technique. So we are about 95 percent confident that this object is at a remote distance, at redshift 10 (a measure of the stretching of space since the big bang). The lensing takes away any doubt that this might be a heavily reddened, nearby object masquerading as a far more distant object."

Astronomers have long debated whether such early galaxies could have provided enough radiation to warm the hydrogen that cooled soon after the big bang. This process, called "reionization," is thought to have occurred 200 million to 1 billion years after the birth of the universe. Reionization made the universe transparent to light, allowing astronomers to look far back into time without running into a "fog" of cold hydrogen.

"We tend to assume that galaxies ionized the universe with their ultraviolet light," Zitrin said. "But we do not see enough galaxies or light that could do that. So we need to look at fainter and fainter galaxies, and the Frontier Fields and galaxy cluster lensing can help us achieve this goal."

The team's results appeared in the Sept. 5 online edition of The Astrophysical Journal Letters.

For images and more information about Hubble, visit:

http://hubblesite.org/news/2014/39

http://www.nasa.gov/hubble

http://www.spacetelescope.org/news/heic1423

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

Contact Information

Donna Weaver
Sr. Science Writer
dweaver@stsci.edu
Phone: 410-338-4493

Donna Weaver | newswise

Further reports about: Astronomers Cosmic Extremely Galaxies Hubble Magnifying STScI Space Telescope Telescope

More articles from Physics and Astronomy:

nachricht Graphene and quantum dots put in motion a CMOS-integrated camera that can see the invisible
30.05.2017 | ICFO-The Institute of Photonic Sciences

nachricht New Method of Characterizing Graphene
30.05.2017 | Universität Basel

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: New Method of Characterizing Graphene

Scientists have developed a new method of characterizing graphene’s properties without applying disruptive electrical contacts, allowing them to investigate both the resistance and quantum capacitance of graphene and other two-dimensional materials. Researchers from the Swiss Nanoscience Institute and the University of Basel’s Department of Physics reported their findings in the journal Physical Review Applied.

Graphene consists of a single layer of carbon atoms. It is transparent, harder than diamond and stronger than steel, yet flexible, and a significantly better...

Im Focus: Strathclyde-led research develops world's highest gain high-power laser amplifier

The world's highest gain high power laser amplifier - by many orders of magnitude - has been developed in research led at the University of Strathclyde.

The researchers demonstrated the feasibility of using plasma to amplify short laser pulses of picojoule-level energy up to 100 millijoules, which is a 'gain'...

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

3D printer inks from the woods

30.05.2017 | Life Sciences

How circadian clocks communicate with each other

30.05.2017 | Life Sciences

Graphene and quantum dots put in motion a CMOS-integrated camera that can see the invisible

30.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>