Astronomers using the NASA/ESA/CSA James Webb Space Telescope have captured amazing new photos of NGC 4449, which is found in the constellation of Canes Venatici.
This Webb/MIRI/NIRCam image shows the central area of the irregular galaxy NGC 4449. Image credit: NASA / ESA / CSA / Webb / A. Adamo, Stockholm University / FEAST JWST Team.
NGC 4449 is located some 12.5 million light-years away in the constellation of Canes Venatici.
Otherwise known as Caldwell 21, LEDA 40973 or UGC 7592, this galaxy is approximately 20,000 light-years across.
NGC 4449 was discovered by the German-born British astronomer William Herschel on April 27, 1788.
It is part of the M94 galaxy group, which lies close to the Local Group that hosts our Milky Way.
“NGC 4449 has been forming stars for several billion years, but it is currently experiencing a period of star formation at a much higher rate than in the past,” the Webb astronomers said.
“Such unusually explosive and intense star formation activity is called a starburst and for that reason NGC 4449 is known as a starburst galaxy.”
“In fact, at the current rate of star formation, the gas supply that feeds the production of stars would only last for another billion years or so.”
“Starbursts usually occur in the central regions of galaxies, but NGC 4449 displays more widespread star formation activity, and the very youngest stars are observed both in the nucleus and in streams surrounding the galaxy.”
“It’s likely that the current widespread starburst was triggered by interaction or merging with a smaller companion.”
“Indeed, we think NGC 4449’s star formation has been influenced by interactions with several of its neighbors.”
“NGC 4449 resembles primordial star-forming galaxies which grew by merging with and accreting smaller stellar systems,” they added.
“Since NGC 4449 is close enough to be observed in great detail, it is the ideal laboratory for us to study what may have occurred during galaxy formation and evolution in the early Universe.”
This Webb/NIRCam image shows the irregular galaxy NGC 4449. Image credit: NASA / ESA / CSA / Webb / A. Adamo, Stockholm University / FEAST JWST Team.
NGC 4449 was observed as part of the Feedback in Emerging extrAgalactic Star clusTers (FEAST) survey.
The images combine infrared data from Webb’s MIRI (Mid-InfraRed Instrument) and NIRCam (Near-InfraRed Camera) instruments.
“Observations in the infrared reveal the galaxy’s creeping tendrils of gas, dust and stars,” the astronomers said.
“The bright blue spots reveal countless individual stars, while the bright yellow regions that weave throughout the galaxy indicate concentrations of active stellar nurseries, where new stars are forming.”
“The orange-red areas indicate the distribution of a type of carbon-based compounds known as polycyclic aromatic hydrocarbons (or PAHs) — the MIRI F770W filter is particularly suited to imaging these important molecules.”
“The bright red spots correspond to regions rich in hydrogen that have been ionized by the radiation from the newly formed stars.”
“The diffuse gradient of blue light around the central region shows the distribution of older stars.”
“The compact light-blue regions within the red ionized gas, mostly concentrated in the galaxy’s outer region, show the distribution of young star clusters.”
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