Astronomers using the NASA/ESA/CSA James Webb Space Telescope have discovered 36 new star-forming regions in a circumnuclear starburst ring in the barred spiral galaxy NGC 7469.
NGC 7469 is located approximately 206 million light-years away from Earth in the constellation of Pegasus.
Together with its smaller spiral companion, IC 5283, it forms the galaxy pair Arp 298.
Also known as LEDA 70348 or Mrk 1514, NGC 7469 has a diameter of 90,000 light-years.
Discovered on November 12, 1784 by the English astronomer John Herschel, it is also classified as Seyfert galaxy.
It hosts to an active supermassive black hole and a circumnuclear starburst ring with a radius of 500 parsecs (1,631 light-years).
“NGC 7469 provides the unique opportunity to study the starburst-active galactic nucleus connection since it hosts an active galactic nucleus surrounded by a starburst ring,” said Hiroshima University astronomer Thomas Bohn and his colleagues.
“However, due to the compact nature of this system, it was difficult to achieve both the resolution and sensitivity needed to study the circumnuclear environment in the mid-infrared on sub-kiloparsec scales.”
“With Webb, we can now explore the dustiest regions of the starburst ring on these scales.”
In their study, the astronomers analyzed the new images of NGC 7469’s starburst ring obtained with Webb’s Near-Infrared Camera (NIRCam) and the Mid-InfraRed Instrument (MIRI).
They identified a total of 65 star-forming regions, 36 of which were not detected in previous observations.
They also found that 19 of these regions are very dusty and host very young — less than 5 million years old — stellar populations.
“These results illustrate the effectiveness of Webb in identifying and characterizing previously hidden star formation in the densest star-forming environments around active galactic nuclei,” the researchers said.
Their paper will be published in the Astrophysical Journal Letters.
Thomas Bohn et al. 2022. GOALS-JWST: NIRCam and MIRI Imaging of the Circumnuclear Starburst Ring in NGC 7469. ApJL, in press; arXiv: 2209.04466
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