Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Detecting dusty clouds and stars in our galaxy in a new way

08.01.2013
Radio wave technique uncovers shadows of clouds and stars in Milky Way's center

The center of our Milky Way galaxy is a wondrous place full of huge star clusters, dust clouds, magnetic filaments and a supermassive black hole. But it can be a confusing place, too, posing challenges to astronomers trying to image these exotic features and learn more about where they are located in the galaxy.

Northwestern University's Farhad Zadeh has discovered a new tool for detecting dusty clouds and stars: simply take a picture using radio waves. He is the first to identify what he calls radio dark clouds and stars. Stars in the early and late phases of their evolution are shrouded by huge dusty envelopes in the form of dust and gas outflows.

"When you see these dark stars or clouds in radio wavelength images, it tells you something very interesting," Zadeh said. "We immediately know there is a cold gas cloud or dusty star mixing with a hot radiative medium and that an interaction is taking place. Knowing details of these clouds is important because the clouds can produce stars and also provide material for the growth of black holes."

Zadeh is a professor of physics and astronomy in the Weinberg College of Arts and Sciences and a member of Northwestern's Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA).

Unlike in the optical, X-ray and infrared wavelengths, it is unusual to see a dark feature with radio waves. Radio is a long wavelength and therefore doesn't get absorbed easily and typically passes through whatever is in its way.

Initially Zadeh thought maybe the dark features he saw on the radio images he was studying were nothing, but then he connected the features to five known dense molecular and dusty clouds located in the center of our galaxy, some near Sagittarius A* (Sgr A*), the black hole.

"This technique provides very good sensitivity of faint dusty features, and it can produce images with even higher resolution than many other telescopes," Zadeh said. "It is an initial observation that tells you something is there that needs to be studied more closely."

In addition, astronomers can measure the size of dusty stars using this new technique.

Zadeh will present his results at 11:30 a.m. PST (Pacific Standard Time) Tuesday, Jan. 8, at the 221st meeting of the American Astronomical Society in Long Beach, Calif. He also will participate in a press conference on the galactic center at 12:45 p.m. PST the same day.

The interaction of a cold dust cloud with a hot radiation field results in a loss in the continuum emission and appears as a dark feature in the radio wavelength image, Zadeh said. The dark features that trace the embedded molecular clouds provide astronomers with the size of the cloud in three dimensions.

Although not part of the work he is presenting, Zadeh said a good example of a dusty cloud that could be imaged with his technique is G2, the tiny cloud that is fast approaching Sgr A*, our galaxy's black hole.

The cloud now is too close to the black hole for Zadeh to take an image, but he is looking at earlier data to see if he can locate G2 as a radio dark cloud.

"If the cloud was farther away from the black hole than it is now, we could detect it," Zadeh said.

For his study, Zadeh used Green Bank Telescope maps and Very Large Array images from the National Radio Astronomy Observatory. The National Science Foundation (grant AST-0807400) supported the research.

The title of Zadeh's paper, which was published Nov. 1 by the Astrophysical Journal Letters, is "Imprints of Molecular Clouds in Radio Continuum Images."

Megan Fellman | EurekAlert!
Further information:
http://www.northwestern.edu

More articles from Physics and Astronomy:

nachricht Nanotechnology for energy materials: Electrodes like leaf veins
27.09.2016 | Helmholtz-Zentrum Berlin für Materialien und Energie GmbH

nachricht First quantum photonic circuit with electrically driven light source
27.09.2016 | Westfälische Wilhelms-Universität Münster

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 welding process joins dissimilar sheets better

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of light metals.
Scientists at the University of Stuttgart have now developed two new process variants that will considerably expand the areas of application for friction stir welding.
Technologie-Lizenz-Büro (TLB) GmbH supports the University of Stuttgart in patenting and marketing its innovations.

Friction stir welding is a still-young and thus often unfamiliar pressure welding process for joining flat components and semi-finished components made of...

Im Focus: First quantum photonic circuit with electrically driven light source

Optical quantum computers can revolutionize computer technology. A team of researchers led by scientists from Münster University and KIT now succeeded in putting a quantum optical experimental set-up onto a chip. In doing so, they have met one of the requirements for making it possible to use photonic circuits for optical quantum computers.

Optical quantum computers are what people are pinning their hopes on for tomorrow’s computer technology – whether for tap-proof data encryption, ultrafast...

Im Focus: OLED microdisplays in data glasses for improved human-machine interaction

The Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP has been developing various applications for OLED microdisplays based on organic semiconductors. By integrating the capabilities of an image sensor directly into the microdisplay, eye movements can be recorded by the smart glasses and utilized for guidance and control functions, as one example. The new design will be debuted at Augmented World Expo Europe (AWE) in Berlin at Booth B25, October 18th – 19th.

“Augmented-reality” and “wearables” have become terms we encounter almost daily. Both can make daily life a little simpler and provide valuable assistance for...

Im Focus: Artificial Intelligence Helps in the Discovery of New Materials

With the help of artificial intelligence, chemists from the University of Basel in Switzerland have computed the characteristics of about two million crystals made up of four chemical elements. The researchers were able to identify 90 previously unknown thermodynamically stable crystals that can be regarded as new materials. They report on their findings in the scientific journal Physical Review Letters.

Elpasolite is a glassy, transparent, shiny and soft mineral with a cubic crystal structure. First discovered in El Paso County (Colorado, USA), it can also be...

Im Focus: Complex hardmetal tools out of the 3D printer

For the first time, Fraunhofer IKTS shows additively manufactured hardmetal tools at WorldPM 2016 in Hamburg. Mechanical, chemical as well as a high heat resistance and extreme hardness are required from tools that are used in mechanical and automotive engineering or in plastics and building materials industry. Researchers at the Fraunhofer Institute for Ceramic Technologies and Systems IKTS in Dresden managed the production of complex hardmetal tools via 3D printing in a quality that are in no way inferior to conventionally produced high-performance tools.

Fraunhofer IKTS counts decades of proven expertise in the development of hardmetals. To date, reliable cutting, drilling, pressing and stamping tools made of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

European Health Forum Gastein 2016 kicks off today

28.09.2016 | Event News

Laser use for neurosurgery and biofabrication - LaserForum 2016 focuses on medical technology

27.09.2016 | Event News

Experts from industry and academia discuss the future mobile telecommunications standard 5G

23.09.2016 | Event News

 
Latest News

New imaging technique in Alzheimer’s disease - opens up possibilities for new drug development

28.09.2016 | Medical Engineering

Innovate coating extends the life of materials for industrial use

28.09.2016 | Materials Sciences

Blockchain Set to Transform the Financial Services Market

28.09.2016 | Business and Finance

VideoLinks
B2B-VideoLinks
More VideoLinks >>>