“We certainly were surprised to find such a bright young galaxy 13 billion years in the past”, said astronomer Garth Illingworth of the University of California, Santa Cruz, USA and a member of the research team. “This is the most detailed look to date at an object so far back in time.”
According to the authors, the measurements are “highly reliable”. “This object is the strongest candidate for the most distant galaxy so far”, states team member Piero Rosati from ESO, Germany.
“The Hubble images yield insight into the galaxy’s structure that we cannot get with any other telescope,” added astronomer Rychard Bouwens of the University of California, Santa Cruz, one of the co-discoverers of this galaxy.
The new images should offer insights into the formative years of galaxy birth and evolution and yield information on the types of objects that may have contributed to ending the dark ages. During its lifetime the Hubble telescope has peered ever farther back in time, viewing galaxies at successively younger stages of evolution. These snapshots have helped astronomers create a scrapbook of galaxies from infancy to adulthood. The new Hubble and Spitzer images of A1689-zD1 show a time when galaxies were in their infancy.
Current theory holds that the dark ages began about 400,000 years after the Big Bang, as matter in the expanding Universe cooled and formed clouds of cold hydrogen. These cold clouds pervaded the Universe like a thick fog. At some point during this era, stars and galaxies started to form. Their collective light heated and cleared the fog of cold hydrogen, and ended the dark ages about a billion years after the Big Bang.
“This galaxy presumably is one of the many galaxies that helped end the dark ages”, said astronomer Larry Bradley of Johns Hopkins University in Baltimore, USA, and leader of the study. “Astronomers are fairly certain that high-energy objects such as quasars did not provide enough energy to end the dark ages of the Universe. But many young star-forming galaxies may have produced enough energy to end it.”
The galaxy is so far away it did not appear in visible light images taken with Hubble’s Advanced Camera for Surveys, because its light is stretched to infrared wavelengths by the Universe’s expansion. It took Hubble’s NICMOS, Spitzer and a trick of nature called gravitational lensing to see the faraway galaxy.
The astronomers used a relatively nearby massive cluster of galaxies known as Abell 1689, roughly 2.2 billion light-years away, to magnify the light from the more distant galaxy directly behind it. This natural telescope is a gravitational lens. Abell 1689 is one of the most spectacular gravitational telescopes known and its gravitational properties are very well known.
Though the diffuse light of the faraway object is nearly impossible to see, gravitational lensing has increased its brightness by nearly 10 times, making it bright enough for Hubble and Spitzer to detect. A telltale sign of the lensing is the smearing of the images of galaxies behind Abell 1689 into arcs by the gravitational warping of space by the intervening galaxy cluster. Piero Rosati says: “This galaxy lies near the region where the galaxy cluster produces the highest magnification – which was essential to bring this galaxy within reach of Hubble and Spitzer.”
Spitzer’s images show that the galaxy’s mass is typical of galaxies in the early Universe. Its mass is equivalent to several billions of stars like our Sun, or just a tiny fraction of the mass of the Milky Way.
“This observation confirms previous Hubble studies that star birth happens in very tiny regions compared with the size of the final galaxy”, Illingworth said.
The faraway galaxy also is an ideal target for Hubble’s successor, the James Webb Space Telescope (JWST), scheduled to launch in 2013. Even with the increased magnification from the gravitational lens, Hubble’s sharp “eye” can only see knots of the brightest, heftiest stars in the galaxy. The telescope cannot pinpoint fainter, lower-mass stars, individual stars, or the material surrounding the star-birth region. To see those things, astronomers will need the infrared capabilities of JWST currently being developed by NASA, ESA and CSA in a major international collaboration. The planned infrared observatory will have a mirror about seven times the area of Hubble’s primary mirror and will collect more light from faint galaxies. JWST also will be able to view even more remote galaxies whose light has been stretched deep into infrared wavelengths that are out of the reach of NICMOS.
“This galaxy will certainly be one of the first objects that will be observed by JWST”, said team member Holland Ford of Johns Hopkins University. “This galaxy is so bright that JWST will see its detailed structure. This object is a pathfinder for JWST for deciphering what is happening in young galaxies.”
The astronomers noted that the faraway galaxy also would be an ideal target for the ESO/NRAO/NAOJ Atacama Large Millimeter Array (ALMA), which, when completed in 2012, will be the most powerful radio telescope in the world. “ALMA and JWST working together would be an ideal combination to really understand this galaxy”, Illingworth said, noting that: “JWST’s images and ALMA’s measurement of the gas motions will provide revolutionary insights into the very youngest galaxies.”
The astronomers will conduct follow-up observations with infrared spectroscopy to confirm the galaxy’s distance using ESO’s VLT and the Keck telescope atop Mauna Kea in Hawaii.
Lars Christensen | alfa
Computer model predicts how fracturing metallic glass releases energy at the atomic level
20.07.2018 | American Institute of Physics
What happens when we heat the atomic lattice of a magnet all of a sudden?
18.07.2018 | Forschungsverbund Berlin
A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.
The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...
For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.
To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...
For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.
Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...
Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.
A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...
Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.
"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....
13.07.2018 | Event News
12.07.2018 | Event News
03.07.2018 | Event News
20.07.2018 | Power and Electrical Engineering
20.07.2018 | Information Technology
20.07.2018 | Materials Sciences