Large amounts of stars are being born at the center of NGC 4383, a peculiar galaxy located 74 million light-years away in the constellation of Coma Berenices. The most massive ones lose mass over their lifetimes through powerful winds, and end up in violent supernova explosions. These stellar winds and supernovae drag away some of NGC 4383’s gas reservoir: the bright red filaments show hydrogen gas ejected out to at least 20,000 light-years from the galaxy. Since this gas is carried away from the galactic core instead of remaining to form the next generation of stars, this process regulates the rate at which stars can form in the galaxy.
Watts et al. mapped out the chemical composition and motion of NGC 4383’s outflow in great detail, providing insights into the mechanisms that created the dramatic outpour seen in this image from ESO’s Very Large Telescope. Image credit: ESO / Watts et al.
Gas outflows are crucial to regulate how fast and for how long galaxies can keep forming stars.
The gas ejected by these explosions pollutes the space between stars within a galaxy, and even between galaxies, and can float in the intergalactic medium forever.
“The outflow was the result of powerful stellar explosions in the central regions of the galaxy that could eject enormous amounts of hydrogen and heavier elements,” said Dr. Adam Watts, an astronomer with the University of Western Australia node at the International Centre for Radio Astronomy Research (ICRAR).
“The mass of gas ejected is equivalent to more than 50 million Suns.”
“Very little is known about the physics of outflows and their properties because outflows are very hard to detect.”
“The ejected gas is quite rich in heavy elements giving us a unique view of the complex process of mixing between hydrogen and metals in the outflowing gas.”
“In this particular case, we detected oxygen, nitrogen, sulfur and many other chemical elements.”
The astronomers used the MUSE (Multi Unit Spectroscopic Explorer) instrument on ESO’s Very Large Telescope (VLT) in northern Chile to create the high-resolution map of NGC 4383.
The data were collected as part of the VLT/MUSE large program MAUVE (MUSE and ALMA Unveiling the Virgo Environment).
“We designed MAUVE to investigate how physical processes such as gas outflows help stop star formation in galaxies,” said Professor Barbara Catinella, also from the University of Western Australia node at the International Centre for Radio Astronomy Research (ICRAR).
“NGC 4383 was our first target, as we suspected something very interesting was happening, but the data exceeded all our expectations.”
“We hope that in the future, MAUVE observations reveal the importance of gas outflows in the local Universe with exquisite detail.”
The team’s paper was published in the Monthly Notices of the Royal Astronomical Society.
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Adam B. Watts et al. 2024. MAUVE: a 6 kpc bipolar outflow launched from NGC 4383, one of the most H i-rich galaxies in the Virgo cluster. MNRAS 530 (2): 1968-1983; doi: 10.1093/mnras/stae898