JWST Captures Unprecedented Detail of Colliding Dwarf Galaxies, Offeringโข Clues to Early Universe Formation
WASHINGTON – New โimages from the James Webb Space Telescope (JWST) reveal a spectacular view of two dwarfโ galaxies, NGC 4490 and NGC 4485, currently undergoing aโ cosmicโฃ collision approximately โค24 million light-years โคfromโ Earth. The observations are providing astronomers with valuable insights into the formation and evolution of galaxies in the early universe.
Dwarf galaxies, characterized by thier low mass, high gasโ content,โ and minimalโข metal composition, are considered analogous to โthe first galaxies. The interaction between NGC 4490 and NGC 4485 โคis markedโข by a prominent gas bridge, a flow of young stars, and ongoing gravitational reshaping of both galaxies.
The European Space Agency โค(ESA) released the JWST images, showcasing NGC 4490 dominating the left sideโ of the frame with dust and young stars, while โNGC 4485 shines on the top right. A โขluminous bridge of gas โฃand dust connects the two, speckled with bluish clusters of new stars โขcontrasting with the reddish glow of warm interstellar dust.ESA notes that this interaction is โtriggering โคaโ surge in star formation.
“Aside from the Milky Way’s two dwarfโ companions, theโ Large and Small โMagellanic Clouds, this is the closest known system of โinteracting dwarf galaxies, where astronomers can directly observe gas bridges and their stellar populations,” ESA officials stated.
While previously studied โขwith the Hubble Telescope, JWST’s infrared capabilities โhave revealed previously unseen โdetails, including the fine structure of gas flowing between the โขgalaxies and individual stars within them. Researchers are now โable to map the locations of starsโ ofโข different ages, tracing the timeline of the galactic interaction.
Analysisโค suggests NGC 4490 and NGC 4485 passed very closely approximately 200 million years ago.During this encounter, NGC 4490 drew gas from NGC 4485, โคformingโ the visibleโ gas bridge โขand initiating a wave of โขstarโ formation, some of which occurred as recentlyโ as 30 million years ago.
“By capturing the history of the cosmic โขdance of NGC โข4490 and NGC 4485, Webb reveals new details about how dwarf โคgalaxies interact, giving us a picture of how small galaxies โgrow and evolve,” ESA added.