Their results suggest that such magnetic fields play a key role in channeling matter to form denser clouds, and thus in setting the stage for the birth of new stars. The work will be published in the November 24 edition of the journal Nature (online version: November 16).
Image of the Triangulum Galaxy M33, which presents astronomers with a bird’s eye view of its disk. The pink blobs are regions containing newly formed stars.
Credit & Copyright: Thomas V. Davis (http://tvdavisastropics.com)
Stars and their planets are born when giant clouds of interstellar gas and dust collapse. You've probably seen the resulting stellar nurseries in beautiful astronomical images: Colorful nebulae, lit by the bright young stars they have brought forth.
Astronomers know quite a bit about these so-called molecular clouds: They consist mainly of hydrogen molecules – unusual in a cosmos where conditions are rarely right for hydrogen atoms to bond together into molecules. And if one traces the distribution of clouds in a spiral galaxy like our own Milky Way galaxy, one finds that they are lined up along the spiral arms.
But how do those clouds come into being? What makes matter congregate in regions a hundred or even a thousand times more dense than the surrounding interstellar gas?
One candidate mechanism involves the galaxy's magnetic fields. Everyone who has seen a magnet act on iron filings in the classic classroom experiment knows that magnetic fields can be used to impose order. Some researchers have argued that something similar goes on in the case of molecular clouds: that galaxies' magnetic fields guide and direct the condensation of interstellar matter to form denser clouds and facilitate their further collapse.
Some astronomer see this as the key mechanism enabling star formation. Others contend that the cloud matter's gravitational attraction and turbulent motion of gas within the cloud are so strong as to cancel any influence of an outside magnetic field.
If we were to restrict attention to our own galaxy, it would be difficult to find out who is right. We would need to see our galaxy's disk from above to make the appropriate measurements; in reality, our Solar System sits within the galactic disk. That is why Hua-bai Li and Thomas Henning from the Max Planck Institute for Astronomy chose a different target: the Triangulum galaxy, 3 million light-years from Earth and also known as M 33, which is oriented in just the right way (cf. image).
Using a telescope known as the Submillimeter Array (SMA), which is located at Mauna Kea Observatory on Mauna Kea Island, Hawai'i, Li and Henning measured specific properties of radiation received from different regions of the galaxy which are correlated with the orientation of these region's magnetic fields. They found that the magnetic fields associated with the galaxy's six most massive giant molecular clouds were orderly, and well aligned with the galaxy's spiral arms.
If turbulence played a more important role in these clouds than the ordering influence of the galaxy's magnetic field, the magnetic field associated with the cloud would be random and disordered.
Thus, Li and Henning's observations are a strong indication that magnetic fields indeed play an important role when it comes to the formation of dense molecular clouds – and to setting the stage for the birth of stars and planetary systems like our own.
Contact informationHua-bai Li (first author)
The research is supported by the Max Planck Institute for Astronomy and the Harvard-Smithsonian Center for Astrophysics. The Submillimeter Array is a joint project between the Smithsonian Astrophysical Observatory and the Academia Sinica Institute of Astronomy and Astrophysics and is funded by the Smithsonian Institution and the Academia Sinica.
Dr. Markus Pössel | Max-Planck-Institut
Extremely energetic particles coupled with the violent death of a star for the first time
21.11.2019 | University of Copenhagen
First detection of gamma-ray burst afterglow in very-high-energy gamma light
21.11.2019 | Max-Planck-Institut für Kernphysik
Conventional light microscopes cannot distinguish structures when they are separated by a distance smaller than, roughly, the wavelength of light. Superresolution microscopy, developed since the 1980s, lifts this limitation, using fluorescent moieties. Scientists at the Max Planck Institute for Polymer Research have now discovered that graphene nano-molecules can be used to improve this microscopy technique. These graphene nano-molecules offer a number of substantial advantages over the materials previously used, making superresolution microscopy even more versatile.
Microscopy is an important investigation method, in physics, biology, medicine, and many other sciences. However, it has one disadvantage: its resolution is...
Nanooptical traps are a promising building block for quantum technologies. Austrian and German scientists have now removed an important obstacle to their practical use. They were able to show that a special form of mechanical vibration heats trapped particles in a very short time and knocks them out of the trap.
By controlling individual atoms, quantum properties can be investigated and made usable for technological applications. For about ten years, physicists have...
An international team of scientists, including three researchers from New Jersey Institute of Technology (NJIT), has shed new light on one of the central mysteries of solar physics: how energy from the Sun is transferred to the star's upper atmosphere, heating it to 1 million degrees Fahrenheit and higher in some regions, temperatures that are vastly hotter than the Sun's surface.
With new images from NJIT's Big Bear Solar Observatory (BBSO), the researchers have revealed in groundbreaking, granular detail what appears to be a likely...
The Fraunhofer Institute for Manufacturing Technology and Advanced Materials IFAM in Dresden has succeeded in using Selective Electron Beam Melting (SEBM) to...
15.11.2019 | Event News
15.11.2019 | Event News
05.11.2019 | Event News
21.11.2019 | Life Sciences
21.11.2019 | Physics and Astronomy
21.11.2019 | Physics and Astronomy