Scientists study 'galaxy zoo' using Google Maps and thousands of volunteers

ScienceDaily (Nov. 3, 2011) — The reddest galaxies with the largest central bulb show the largest bars -- gigantic central columns of stars and dark matter -- according to a scientific study that used Google Maps to observe the sky. A group of volunteers of more than 200,000 participants of the galaxy classification project Galaxy Zoo contributed to this research.

More than two thirds of spiral galaxies, including our own Milky Way, display a central bar that can extend for thousands of light years. These colossal elongated structures are made up of collections of stars and dark matter which are held together by gravity.

Now a team of researchers from Europe and the USA have measured the bar length of some 5000 galaxies with the help of amateur astronomers. The most precise results (those obtained for 3150 galaxies) have been published in the Monthly Notices of the Royal Astronomical Society.

The study comes under the Galaxy Zoo project, a citizen science initiative in which more than 200,000 volunteers assisted in classifying a million galaxies through images provided by the Sloan Digital Sky Survey astronomical catalogue. As for the bars, 150 amateur astronomers have recorded their observations on a webpage specifically created for this purpose. The page is currently still active despite being closed to any further data entry.

Ben Hoyle, researcher at the Institute of Cosmos Sciences (University of Barcelona, Spain) and coordinator of the study, stresses that "this webpage combines Galaxy Zoo classifications with Google Maps technology." More precisely, the team has used the Google Maps Sky interface which allows to see the sky, especially the galaxies, as seen from Earth's surface.

The redness of bars

"In this way we have compiled some 16,000 measurements of the bars of 5000 galaxies, which is a sample a hundred times greater than previous ones. We have also come to many different conclusions, such as the fact that redder galaxies, which are stopping star formation, have longer bars," says Hoyle.

In the electromagnetic spectrum, the colour red comes from older, cooler stars whereas the colour blue is linked to hotter and younger stars. The study also reveals that the bars tend to be redder than the rest of the galaxy, which indicates that they have an older stellar population.

Other conclusions indicate that those galaxies with a larger bulb (a central agglomeration of stars) have longer bars. In addition, barred galaxies are more likely to display spiral arms than unbarred galaxies.

The images provide examples of barred galaxies with spiral arms. In the first row, the arms are connected to the ring around the bar. In the second row, the arms are connected at the end of the bar and the third row shows a mixture of the two. Image: Ben Hoyle et al./Galaxy Zoo.

Recommend this story on Facebook, Twitter,
and Google +1:

Other bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by Plataforma SINC, via AlphaGalileo.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Journal Reference:

Ben Hoyle, Karen. L. Masters, Robert C. Nichol, Edward M. Edmondson, Arfon M. Smith, Chris Lintott, Ryan Scranton, Steven Bamford, Kevin Schawinski, Daniel Thomas. Galaxy Zoo: bar lengths in local disc galaxies. Monthly Notices of the Royal Astronomical Society, 2011; 415 (4): 3627 DOI: 10.1111/j.1365-2966.2011.18979.x

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Nearby planet-forming disk holds water for thousands of oceans

ScienceDaily (Oct. 20, 2011) — For the first time, astronomers have detected around a burgeoning solar system a sprawling cloud of water vapor that's cold enough to form comets, which could eventually deliver oceans to dry planets.

Water is an essential ingredient for life. Scientists have found thousands of Earth-oceans' worth of it within the planet-forming disk surrounding the star TW Hydrae. TW Hydrae is 176 light years away in the constellation Hydra and is the closest solar-system-to-be.

University of Michigan astronomy professor Ted Bergin is a co-author of a paper on the findings published in the Oct. 21 edition of Science.

The researchers used the Heterodyne Instrument for the Far-Infrared (HIFI) on the orbiting Hershel Space Observatory to detect the chemical signature of water.

"This tells us that the key materials that life needs are present in a system before planets are born," said Bergin, a HIFI co-investigator. "We expected this to be the case, but now we know it is because have directly detected it. We can see it."

Scientists had previously found warm water vapor in planet-forming disks close to the central star. But until now, evidence for vast quantities of water extending into the cooler, far reaches of disks where comets and giant planets take shape had not emerged. The more water available in disks for icy comets to form, the greater the chances that large amounts will eventually reach new planets through impacts.

"The detection of water sticking to dust grains throughout the planet-forming disk would be similar to events in our own solar system's evolution, where over millions of years, these dust grains would then coalesce to form comets. These would be a prime delivery mechanism for water on planetary bodies," said principal investigator Michiel Hogerheijde of Leiden University in the Netherlands.

Other recent findings from HIFI support the theory that comets delivered a significant portion of Earth's oceans. Researchers found that the ice on a comet called Hartley 2 has the same chemical composition as our oceans.

HIFI is helping astronomers gain a better understanding of how water comes to terrestrial planets -- Earth and beyond. If TW Hydrae and its icy disk are representative of many other young star systems, as researchers think they are, then the process for creating planets around numerous stars with abundant water throughout the universe appears to be in place, NASA officials say.

Recommend this story on Facebook, Twitter,
and Google +1:

Other bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by University of Michigan.

Note: ScienceDaily reserves the right to edit materials for content and length. For further information, please contact the source cited above.

Journal Reference:

M. R. Hogerheijde, E. A. Bergin, C. Brinch, L. I. Cleeves, J. K. J. Fogel, G. A. Blake, C. Dominik, D. C. Lis, G. Melnick, D. Neufeld, O. Panic, J. C. Pearson, L. Kristensen, U. A. Yildiz, E. F. van Dishoeck. Detection of the Water Reservoir in a Forming Planetary System. Science, 2011; 334 (6054): 338 DOI: 10.1126/science.1208931

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here

Nearby planet-forming disk holds water for thousands of oceans

ScienceDaily (Oct. 20, 2011) — For the first time, astronomers have detected around a burgeoning solar system a sprawling cloud of water vapor that's cold enough to form comets, which could eventually deliver oceans to dry planets.

Water is an essential ingredient for life. Scientists have found thousands of Earth-oceans' worth of it within the planet-forming disk surrounding the star TW Hydrae. TW Hydrae is 176 light years away in the constellation Hydra and is the closest solar-system-to-be.

University of Michigan astronomy professor Ted Bergin is a co-author of a paper on the findings published in the Oct. 21 edition of Science.

The researchers used the Heterodyne Instrument for the Far-Infrared (HIFI) on the orbiting Hershel Space Observatory to detect the chemical signature of water.

"This tells us that the key materials that life needs are present in a system before planets are born," said Bergin, a HIFI co-investigator. "We expected this to be the case, but now we know it is because have directly detected it. We can see it."

Scientists had previously found warm water vapor in planet-forming disks close to the central star. But until now, evidence for vast quantities of water extending into the cooler, far reaches of disks where comets and giant planets take shape had not emerged. The more water available in disks for icy comets to form, the greater the chances that large amounts will eventually reach new planets through impacts.

"The detection of water sticking to dust grains throughout the planet-forming disk would be similar to events in our own solar system's evolution, where over millions of years, these dust grains would then coalesce to form comets. These would be a prime delivery mechanism for water on planetary bodies," said principal investigator Michiel Hogerheijde of Leiden University in the Netherlands.

Other recent findings from HIFI support the theory that comets delivered a significant portion of Earth's oceans. Researchers found that the ice on a comet called Hartley 2 has the same chemical composition as our oceans.

HIFI is helping astronomers gain a better understanding of how water comes to terrestrial planets -- Earth and beyond. If TW Hydrae and its icy disk are representative of many other young star systems, as researchers think they are, then the process for creating planets around numerous stars with abundant water throughout the universe appears to be in place, NASA officials say.

Recommend this story on Facebook, Twitter,
and Google +1:

Other bookmarking and sharing tools:

Story Source:

The above story is reprinted from materials provided by University of Michigan.

Note: ScienceDaily reserves the right to edit materials for content and length. For further information, please contact the source cited above.

Journal Reference:

M. R. Hogerheijde, E. A. Bergin, C. Brinch, L. I. Cleeves, J. K. J. Fogel, G. A. Blake, C. Dominik, D. C. Lis, G. Melnick, D. Neufeld, O. Panic, J. C. Pearson, L. Kristensen, U. A. Yildiz, E. F. van Dishoeck. Detection of the Water Reservoir in a Forming Planetary System. Science, 2011; 334 (6054): 338 DOI: 10.1126/science.1208931

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

View the original article here