304 North Cardinal St.
Dorchester Center, MA 02124
Even to the naked eye, the Milky Way is a stunning thing. That makes a high-resolution look at the galaxy’s hydrogen clouds even more dramatic.
Scientists from Australia and Germany have produced a new, detailed survey of the Milky Way, dubbed HI4PI. It shows the presence of hydrogen gas in the galaxy, Naomi McClure-Griffiths, a professor at the Australian National University (ANU) told Mashable, as well as its neighbours, the Andromeda Galaxy and the Magellanic Clouds.
The map is a full sky survey of the Milky Way, in the same way the Earth is sometimes laid out as a 2D map.
"You can see the plane of the Milky Way, that’s what we see as the band in the sky," McClure-Griffiths said. "What we’re pulling out is all of the hydrogen gas associated with the Milky Way and the nearby galaxies."
The purple and orange colours in the map tell us how much gas is present.
"Each frame tells us how fast that gas is moving with respect to us [on Earth]," she added. "When the colours are brightest, that’s where there’s a lot of gas. When you can see the whole screen filled with bright colours, that’s the [gas] that’s closest to us."
According to McClure-Griffiths, the map took a "terrifyingly long time" to create. Researchers began collecting data in 2006. It then took five years to combine two data sets from Australia’s CSIRO Parkes dish and the Max-Planck telescope in Germany.
Advances in camera technology also made such a detailed survey possible. Both telescopes used to have what she called "essentially a one-pixel camera," but new multi-pixel cameras made the process far speedier.
"That meant that instead of it taking 26 years to do the Australian survey, it took two years," she said.
HI4PI could be used as a starting point to map the Milky Way in ever new levels of detail. McClure-Griffiths compared it to a "finding chart" that early explorers used as they set out to carefully trace the coasts of countries like Australia for the first time.
Publishing their findings in the Astronomy and Astrophysics journal, the team hopes the map will also help us understand how the Milky Way’s structures are formed.
That includes how galaxies such as the Milky Way get fresh gas to continue forming stars. "They’re kind of like people — they need to be fed all the time," she explained.
"By having this level of detail, we can look at where the gas may be coming into the Milky Way — we’re sort of searching out the food sources."
from Mashable! http://ift.tt/2e87Gis