Imaging a galaxy's molecular outflow

March 9, 2018, Harvard-Smithsonian Center for Astrophysics
A Hubble image of the merging galaxies NGC 6240. Like other luminous mergers, this one hosts a rapid flow of molecular gas. Astronomers have now imaged the carbon monoxide gas in the central regions and found it forms jet-like outflows driven by activity around the black holes. Credit: NASA/HST

A merger between galaxies can trigger can intense radiation from bursts star formation and from the accretion of gas onto the two supermassive black holes at their centers. Astronomers have observed a strong statistical correlation between the masses of these black holes and other properties of the galaxies like their velocity structure or luminosity, and have concluded that there must be a connection.

Feedback of some kind seems most likely to explain these correlations, and astronomers have been working to identify its source and nature. One prominent suggestion for feedback is an outflow of molecular gas; once turned on, it would deplete the galaxy of the raw material needed for making new stars and from further enhancing the black hole's mass. Evidence for molecular outflows has been reported in far infrared lines of molecules, but these spectral results lack the convincing spatial information needed to associate the activity with the nuclei themselves.

CfA Junko Ueda is a member of a team of fifteen astronomers who used the ALMA submillimeter telescope facility, with its superb spatial imaging capabilities, to study the outflow in the luminous galaxy NGC6240, known to be a luminous merger in its late stages. Its double nuclei, separated by a modest two thousand light-years, has already been seen at wavelengths from the X-ray to the radio. The astronomers used one of the spectral lines from the abundant molecule carbon monoxide to probe the inner region of the galaxy. The line also revealed the presence of gas motions of up to two thousand kilometers per second, consistent with a powerful wind driving a massive flow of material out of the galaxy.

The new images were able to identify for the first time several regions of outflow activity located only a few thousand light-years from the and aligned as though they were driven by processes associated with the nuclear black holes. Moreover, these regions are spatially coincident with other indicators of general activity like shocked gas and X-rays. The new results are one of the first demonstrations that the widely seen molecular outflow activity does originate from black hole feedback mechanisms.

Explore further: Co-evolution black hole mystery deepened by a new ALMA observation

More information: T Saito et al. Imaging the molecular outflows of the prototypical ULIRG NGC 6240 with ALMA, Monthly Notices of the Royal Astronomical Society: Letters (2017). DOI: 10.1093/mnrasl/slx207

Related Stories

Outflowing gas in ultraluminous galaxies

January 9, 2017

Galaxies evolve over billions of years in part through the activity of star formation and their supermassive nuclear black holes, and also by mergers with other galaxies. Some features of galaxies, in particular the strong ...

The structure of an active galactic nucleus

January 24, 2018

The nuclei of most galaxies host supermassive black holes containing millions to billions of solar-masses of material. The immediate environments of these black holes typically include a tori of dust and gas and, as material ...

the geometry of nuclear black hole accretion disks

January 3, 2018

Supermassive black holes with millions or even billions of solar-masses of material are found at the nuclei of most galaxies, including our Milky Way. A torus of dust and gas orbits around the black hole (at least according ...

Recommended for you

Magnetized inflow accreting to center of Milky Way galaxy

August 17, 2018

Are magnetic fields an important guiding force for gas accreting to a supermassive black hole (SMBH) like the one that our Milky Way galaxy hosts? The role of magnetic fields in gas accretion is little understood, and trying ...

First science with ALMA's highest-frequency capabilities

August 17, 2018

The ALMA telescope in Chile has transformed how we see the universe, showing us otherwise invisible parts of the cosmos. This array of incredibly precise antennas studies a comparatively high-frequency sliver of radio light: ...

Another way for stellar-mass black holes to grow larger

August 17, 2018

A trio of researchers with The University of Hong Kong, Academia Sinica Institute of Astronomy and Astrophysics in Taiwan and Northwestern University in the U.S., has come up with an alternative theory to explain how some ...

Six things about Opportunity's recovery efforts

August 17, 2018

NASA's Opportunity rover has been silent since June 10, when a planet-encircling dust storm cut off solar power for the nearly-15-year-old rover. Now that scientists think the global dust storm is "decaying"—meaning more ...

Sprawling galaxy cluster found hiding in plain sight

August 16, 2018

MIT scientists have uncovered a sprawling new galaxy cluster hiding in plain sight. The cluster, which sits a mere 2.4 billion light years from Earth, is made up of hundreds of individual galaxies and surrounds an extremely ...

Hubble paints picture of the evolving universe

August 16, 2018

Astronomers using the ultraviolet vision of NASA's Hubble Space Telescope have captured one of the largest panoramic views of the fire and fury of star birth in the distant universe. The field features approximately 15,000 ...

3 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

Tuxford
1 / 5 (4) Mar 09, 2018
The new images were able to identify for the first time several regions of outflow activity located only a few thousand light-years from the black holes and aligned as though they were driven by processes associated with the nuclear black holes. Moreover, these regions are spatially coincident with other indicators of general activity like shocked gas and X-rays. The new results are one of the first demonstrations that the widely seen molecular outflow activity does originate from black hole feedback mechanisms.

This comment was spot on until...the last two words. Merger maniacs grasped for 'feedback' since they cannot permit themselves to consider that the outflows originate largely from within the supposed black hole itself. This consideration would simply be career ending. It would be a leap off the bridge for those long-vested in the bridge.
cantdrive85
1 / 5 (2) Mar 10, 2018
Once again, there is no need to conjure up mythical mathematical gravity monsters to explain what is actually a plasm process. Those jets are of course electric currents driven by the central plasmoid of the galaxy.
rrwillsj
2.3 / 5 (3) Mar 10, 2018
Okay, lets take a vote. Who has more crazy imagination? Tux or Cant...

Man, I admire that... in books clearly marked fiction.

Cause if you believe any of that crap? Come to my Spooky Good-Golly website!I

We are having a special sale. Today! Only! On hardly used Orgone Boxes.

And, have I got a deal for you on slightly dented spirit brass horns.

And, just in. A new batch of aether-detecting Odyllic meters. Guaranteed!

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.