Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Pinpointing the most fertile galaxies in the universe

17.04.2013
Using the compound telescope ALMA, a team of researchers has pinpointed the positions of more than 100 of the most fertile star-forming galaxies.

The precise position measurements clear up a mystery about the observed productivity of these objects. They also show that previous studies of these objects have often suffered from mis-identifications, and how precise measurements like these new results avoid this kind of error.


A team of astronomers including MPIA researchers has used ALMA (the Atacama Large Millimeter/submillimeter Array) to pinpoint the locations of over 100 of the most fertile star-forming galaxies in the early Universe. This image shows close-ups of a selection of these galaxies. The ALMA observations, at submillimetre wavelengths, are shown in orange/red and are overlaid on an infrared view of the region as seen by the IRAC camera on the Spitzer Space Telescope. Previous observations had not been sharp enough to unambiguously identify these galaxies in images at other wavelengths.
Credit: ALMA (ESO/NAOJ/NRAO), APEX (MPIfR/ESO/OSO), J. Hodge (MPIA) et al., A. Weiss et al., NASA Spitzer Science Center

Submillimeter galaxies, discovered in the late 1990s, produce so many new stars as to be responsible for a significant fraction of the total energy output of all galaxies over the course of all of cosmic history. A side effect of having many (and many massive) stars is the production of lots of dust. And indeed, in the most extreme cases, these fertile galaxies are so deeply shrouded in dust they are effectively hidden from sight for astronomers observing in visible light. That is why, in order for a full census of these objects, and to reliably gauge their star formation activity, astronomers need to resort to submillimeter observations. Additional information can come from observations using infrared radiation or radio waves.

Previous submillimeter surveys of these distant objects suffered from a lack of detail. But now, a team led by Ian Smail (Durham University, UK) has completed a large, yet highly detailed survey of more than 100 such objects using the international compound telescope ALMA (Atacama Large Millimeter/Submillimeter Array), located in Chile, at a resolution more than a factor 10 better than previous surveys. The observations, targeting a region known as the Extended Chandra Deep Field South in the Southern constellation Fornax, made use of 15 of ALMA's antennas, which were combined to act as a single, large telescope.

The new survey's high-resolution images for a large number of galaxies have helped to solve one apparent mystery concerning submillimeter galaxies. Alexander Karim (Argelander Institute for Astronomy, Bonn and Durham University, UK) explains: "We previously thought the brightest of these galaxies were forming stars more than a thousand times more vigorously than our own galaxy, the Milky Way, putting them at risk of blowing themselves apart. But instead of single, hyperactive galaxies, the ALMA images revealed multiple, smaller galaxies, each forming stars at a more reasonable rate." Karim, formerly a PhD student at the Max Planck Institute for Astronomy, is a member of the survey team and lead author of the paper reporting this key result of the survey.

The newly published survey also promises to put future studies of submillimeter galaxies onto a solid footing. Jacqueline Hodge of the Max Planck Institute for Astronomy, lead author of the survey paper, explains: "Astronomers use many different kinds of light to examine celestial objects. But this only works if you know precise positions – only then can you say 'Yes, this blob here in my infrared image represents the same object as that blob there in my submillimeter image'. Our survey shows that previous attempts to identify the infrared and radio counterparts of submillimeter galaxies were considerably error-prone, leading to incorrect identifications in about a third of all cases. With our precise submillimeter position measurements, such errors can be avoided."

The work by Smail, Hodge, Karim and their colleagues has prepared the stage for the next logical step: Examinations at even higher resolution, deploying the full power of the completed ALMA array with all of its 66 antennas, could help elucidate the nature of submillimeter galaxies. The most plausible scenario is that submillimeter galaxies are created when large galaxies collide, their mutual gravitational pull triggering an intense phase of star formation. High-resolution images could show aspects of those galaxies' shapes, and possibly traces of the collision process itself.

Contact information

Jacqueline Hodge (lead author, survey paper)
Max Planck Institute for Astronomy
Heidelberg, Germany
Phone: (+49|0) 6221 – 528 467
Email: hodge@mpia.de

Fabian Walter (co-author)
Max Planck Institute for Astronomy
Heidelberg, Germany
Phone: (+49|0) 6221 – 528 225
Email: walter@mpia.de

Markus Pössel (public information officer)
Max Planck Institute for Astronomy
Heidelberg, Germany
Phone: (+49|0) 6221 – 528 261
Email: pr@mpia.de

Dr. Markus Pössel | Max-Planck-Institut
Further information:
http://www.mpia.de

More articles from Physics and Astronomy:

nachricht A 100-year-old physics problem has been solved at EPFL
23.06.2017 | Ecole Polytechnique Fédérale de Lausanne

nachricht Quantum thermometer or optical refrigerator?
23.06.2017 | National Institute of Standards and Technology (NIST)

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: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>