Astronomers reveal new image of candy cane-shaped feature in the center of our galaxy

December 19, 2019

A team of astronomers has produced a new image of an arc-shaped object in the center of our Milky Way galaxy. The feature, which resembles a candy cane, is a magnetic structure that covers an enormous region of some 160 light-years. A light-year is the distance light travels in one year -- almost 6 trillion miles.

Mark Morris, a UCLA professor of physics and astronomy and a member of the research team, discovered the structure, also called the radio arc, with a former student, Farhad Yusef-Zadeh, back in 1983, but they did not have such a complete and colorful image of it then.

The new image shows the inner part of our galaxy, which houses the largest, densest collection of giant molecular clouds in the Milky Way. These vast, cool clouds contain enough dense gas and dust to form tens of millions of stars like the sun, Morris said.

In the image, blue and greenish-blue features reveal cold dust in molecular clouds where star formation is still in its infancy. Yellow features reveal the presence of ionized gas and show where hundreds of massive stars have recently formed. Red and orange regions show areas where high-energy electrons emit radiation by a process called "synchrotron emission," such as in the radio arc and Sagittarius A, the bright source at the galaxy's center that hosts its supermassive black hole.

Many of the universe's secrets are being revealed through the parts of the electromagnetic spectrum of light that are not visible to the human eye. The electromagnetic spectrum encompasses the complete range of light -- seen and unseen -- from gamma rays, X-rays and ultraviolet light on one end to infrared and radio waves on the other. In the middle is the small visible spectrum that includes the colors humans can detect with the unaided eye. Gamma rays have wavelengths billions of times smaller than those of visible light, while radio waves have wavelengths billions of times longer than those of visible light. Astronomers use the entire electromagnetic spectrum. In the study that led to the new image, the research team observed radio waves with a wavelength of 2 millimeters.

"The candy cane is a magnetic feature in which we can literally see the magnetic field lines illuminated by the radio emission," Morris said. "The new result revealed by this image is that one of the filaments is inferred to contain extremely high-energy electrons, the origin of which remains an interesting and unsettled issue."

The candy cane arc is part of a set of radio-emitting filaments extending 160 light-years. It is more than 100 light-years away from the central supermassive black hole. However, in another study recently, Morris and colleagues saw similar magnetic radio filaments that they believe are connected to the supermassive black hole, which may lead to important new ways to study black holes, he said.

To produce the new image, the astronomers used a NASA 2-millimeter camera instrument called GISMO, along with a 30-meter radio telescope located at Pico Veleta, Spain. They also took archival observations from the European Space Agency's Herschel satellite to model the infrared glow of cold dust. They added infrared data from the SCUBA-2 instrument at the James Clerk Maxwell Telescope near the summit of Maunakea, Hawaii, and radio observations from the National Science Foundation's Very Large Array, located near Socorro, New Mexico.

The team's research describing the composite image was published last month in Astrophysical Journal.

Morris' research interests include the center of the Milky Way, star formation, massive stellar clusters, and red giant stars, which are dying stars in the last stages of stellar evolution.
-end-


University of California - Los Angeles

Related Star Formation Articles from Brightsurf:

Low-metallicity globular star cluster challenges formation models
On the outskirts of the nearby Andromeda Galaxy, researchers have unexpectedly discovered a globular cluster (GC) - a massive congregation of relic stars - with a very low abundance of chemical elements heavier than hydrogen and helium (known as its metallicity), according to a new study.

Astronomers turn up the heavy metal to shed light on star formation
Astronomers from The University of Western Australia's node of the International Centre for Radio Astronomy Research (ICRAR) have developed a new way to study star formation in galaxies from the dawn of time to today.

New observations of black hole devouring a star reveal rapid disk formation
When a star passes too close to a supermassive black hole, tidal forces tear it apart, producing a bright flare of radiation as material from the star falls into the black hole.

How galaxies die: New insights into the quenching of star formation
Astronomers studying galaxy evolution have long struggled to understand what causes star formation to shut down in massive galaxies.

The cosmic commute towards star and planet formation
Interconnected gas flows reveal how star-forming gas is assembled in galaxies.

Star formation project maps nearby interstellar clouds
Astronomers have captured new, detailed maps of three nearby interstellar gas clouds containing regions of ongoing high-mass star formation.

Scientists discover pulsating remains of a star in an eclipsing double star system
Scientists from the University of Sheffield have discovered a pulsating ancient star in a double star system, which will allow them to access important information on the history of how stars like our Sun evolve and eventually die.

Distant milky way-like galaxies reveal star formation history of the universe
Thousands of galaxies are visible in this radio image of an area in the Southern Sky, made with the MeerKAT telescope.

Cascades of gas around young star indicate early stages of planet formation
What does a gestating baby planet look like? New research in Nature by a team including Carnegie's Jaehan Bae investigated the effects of three planets in the process of forming around a young star, revealing the source of their atmospheres.

Massive exoplanet orbiting tiny star challenges planet formation theory
Astronomers have discovered a giant Jupiter-like exoplanet in an unlikely location -- orbiting a small red dwarf star.

Read More: Star Formation News and Star Formation Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.