Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Hubble and Spitzer space telescopes find "Lego-block" galaxies in early Universe

07.09.2007
The conventional model for galaxy evolution predicts that small galaxies in the early Universe evolved into the massive galaxies of today by coalescing.

Nine Lego-like “building block” galaxies initially detected by Hubble likely contributed to the construction of the Universe as we know it. “These are among the lowest mass galaxies ever directly observed in the early Universe” says Nor Pirzkal of the European Space Agency/STScI.


In this image of the Hubble Ultra Deep Field, several objects are identified as the faintest, most compact galaxies ever observed in the distant Universe. They are so far away that we see them as they looked less than one billion years after the Big Bang. Blazing with the brilliance of millions of stars, each of the newly discovered galaxies is a hundred to a thousand times smaller than our Milky Way Galaxy. The bottom row of pictures shows several of these clumps (distance expressed in redshift value). Three of the galaxies appear to be slightly disrupted. Rather than being shaped like rounded blobs, they appear stretched into tadpole-like shapes. This is a sign that they may be interacting and merging with neighboring galaxies to form larger structures. The detection required joint observations between Hubble and NASA's Spitzer Space Telescope. Blue light seen by Hubble shows the presence of young stars. The absence of red light from Spitzer observations conclusively shows that these are truly young galaxies without an earlier generation of stars.

Pirzkal was surprised to find that the galaxies’ estimated masses were so small. Hubble’s cousin observatory, NASA’s Spitzer Space Telescope was called upon to make precise determinations of their masses. The Spitzer observations confirmed that these galaxies are some of the smallest building blocks of the Universe.

These young galaxies offer important new insights into the Universe’s formative years, just one billion years after the Big Bang. Hubble detected sapphire blue stars residing within the nine pristine galaxies. The youthful stars are just a few million years old and are in the process of turning Big Bang elements (hydrogen and helium) into heavier elements. The stars have probably not yet begun to pollute the surrounding space with elemental products forged within their cores.

“While blue light seen by Hubble shows the presence of young stars, it is the absence of infrared light in the sensitive Spitzer images that was conclusive in showing that these are truly young galaxies without an earlier generation of stars,” says Sangeeta Malhotra of Arizona State University in Tempe, USA, one of the investigators.

The galaxies were first identified by James Rhoads of Arizona State University, USA, and Chun Xu of the Shanghai Institute of Technical Physics in Shanghai, China. Three of the galaxies appear to be slightly disrupted – rather than being shaped like rounded blobs, they appear stretched into tadpole-like shapes. This is a sign that they may be interacting and merging with neighbouring galaxies to form larger, cohesive structures.

The galaxies were observed in the Hubble Ultra Deep Field (HUDF) with Hubble’s Advanced Camera for Surveys and the Near Infrared Camera and Multi-Object Spectrometer as well as Spitzer’s Infrared Array Camera and the European Southern Observatory’s Infrared Spectrometer and Array Camera. Seeing and analysing such small galaxies at such a great distance is at the very limit of the capabilities of the most powerful telescopes.

Images taken through different colour filters with the ACS were supplemented with exposures taken through a so-called grism which spreads the different colours emitted by the galaxies into short “trails”. The analysis of these trails allows the detection of emission from glowing hydrogen gas, giving both the distance and an estimate of the rate of star formation.

These “grism spectra” - taken with Hubble and analysed with software developed at the Space Telescope-European Coordinating Facility in Munich, Germany - can be obtained for objects that are significantly fainter than can be studied spectroscopically with any other current telescope.

Lars Christensen | alfa
Further information:
http://www.spacetelescope.org/news/html/heic0714.html

More articles from Physics and Astronomy:

nachricht Neutron star merger directly observed for the first time
17.10.2017 | University of Maryland

nachricht Breaking: the first light from two neutron stars merging
17.10.2017 | American Association for the Advancement of Science

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: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Researchers release the brakes on the immune system

18.10.2017 | Health and Medicine

Separating methane and CO2 will become more efficient

18.10.2017 | Life Sciences

Ocean atmosphere rife with microbes

17.10.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>