The NASA-designed Goddard-IRAM Superconducting 2-Millimeter Observer (GISMO), a bolometer camera installed on the 30-m IRAM radio telescope, has produced a stunning image of the inner part of our Milky Way Galaxy.
This composite image, which combines infrared (blue), radio (red) and microwave (green) observations from the GISMO instrument, reveals emission from cold dust, areas of vigorous star formation, and filaments formed at the edges of a bubble blown by some powerful event at the Milky Way Galaxy’s center. Image credit: NASA’s Goddard Space Flight Center.
“The Galactic center is an enigmatic region with extreme conditions where velocities are higher and objects frequently collide with each other,” said GISMO team leader Dr. Johannes Staguhn, an astronomer at Johns Hopkins University and NASA’S Goddard Space Flight Center.
“GISMO gives us the opportunity to observe microwaves with a wavelength of 2 mm at a large scale, combined with an angular resolution that perfectly matches the size of galactic center features we are interested in. Such detailed, large-scale observations have never been done before.”
GISMO detected the most prominent radio filament — known as the Radio Arc — in the Galactic center, making this the shortest wavelength where these curious structures have been observed.
The filaments delineate the edges of a large bubble produced by some energetic events at the Galactic center, located within the bright region known as Sagittarius A about 27,000 light-years away from Earth. Additional red arcs in the image reveal other filaments.
An annotated version of the GISMO image of the Milky Way’s central region. Image credit: NASA’s Goddard Space Flight Center.
“We’re very intrigued by the beauty of this image. It’s exotic,” Dr. Staguhn said.
“When you look at it, you feel like you’re looking at some really special forces of nature in the Universe.”
“It was a real surprise to see the Radio Arc in the GISMO data,” said Dr. Richard Arendt, an astronomer at the University of Maryland, Baltimore County and NASA’s Goddard Space Flight Center.
“Its emission comes from high-speed electrons spiraling in a magnetic field, a process called synchrotron emission.”
“Another feature GISMO sees, called the Sickle, is associated with star formation and may be the source of these high-speed electrons.”
The new GISMO image is described in two papers in the Astrophysical Journal.
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Richard G. Arendt et al. 2019. 2 mm GISMO Observations of the Galactic Center. I. Dust Emission. ApJ 885, 71; doi: 10.3847/1538-4357/ab451c
Johannes Staguhn et al. 2019. 2 mm GISMO Observations of the Galactic Center. II. A Nonthermal Filament in the Radio Arc and Compact Sources. ApJ 885, 72; doi: 10.3847/1538-4357/ab451b
This article is based on text provided by the National Aeronautics and Space Administration.
