Researchers study size, distribution and densities of intergalactic hydrogen clouds

Galaxies are sometimes surrounded by a halo of hydrogen fuel. Over time a galaxy can lose this halo, which streams off into the intergalactic medium. Because of this, there might be clouds of hydrogen among the many clusters of galaxies within the universe, with one million stars price of mass. Understanding the evolution of those hydrogen clouds will help astronomers perceive how galaxies evolve. These clouds are invisible to optical telescopes, however they are often detected by radio astronomers due to hydrogen’s 21-centimeter emission line.

To review these clouds, Robert Minchin, Scientist at NRAO has taken observations of seven hydrogen clouds within the Virgo Supercluster captured by the Arecibo Galaxy Surroundings Survey, and mixed them with observations from the Very Massive Array (VLA). Arecibo’s sensitivity was capable of seize the dimensions and distribution of those clouds, whereas the VLA can observe the place the clouds are dense, and the place they’re extra diffuse. This allowed Robert to see the place hydrogen is streaming away from a galaxy, and the way the hydrogen is affected by the intergalactic medium.

In a single case, Robert discovered a big hydrogen cloud not close to any galaxy. The truth that the cloud remains to be intact would appear to point {that a} galaxy forged off its hydrogen halo slightly rapidly, slightly than slowly over time. The precise mechanism of this course of remains to be unclear.

Robert offered this work on the 241st Meeting of the American Astronomical Society.