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Indian Express
a day ago
- Science
- Indian Express
Surprising discovery by Pune IUCAA astronomers: A small galaxy that blows large bubbles
Two astronomers from the Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune, in collaboration with an astronomer from the University of Tokyo, have captured a spectacular galactic wind phenomenon around a very tiny galaxy called J1044+0353. 'This tiny galaxy (diameter 7.100 light-years) is vigorously forming stars. It is at a distance of 170 million light-years from us. The surprising finding is that it is surrounded by seven giant bubbles,' said IUCAA astronomers Dr Edmund Christian Herenz (Vaidya-Raychaudhuri Fellow) and Soumil Maulick on Thursday. The diameter of those bubbles, 23.000 light-years, is almost as large as the distance from Earth to the black hole in the centre of the Milky Way, they said in a statement. 'While a few of these bubbles look like they have popped, others are still remarkably intact,' they added. According to them, stars that are 25 to 100 times more massive than the Sun do not live very long. After three to five million years, their cores collapse and giant nuclear explosions, dubbed supernovae, blast vast amounts of material into the surrounding space. 'In our Milky Way, such supernovae occur, on average, thrice a century. Given our home Galaxy's large mass and size, these explosions only have a modest effect on the overall interstellar gas distribution,' the scientists explained. However, similar supernovae rates may have dramatic consequences for galaxies that are 10,000 times less massive than the Milky Way. This is because their gravitational pull cannot hold back the high-velocity gas released from all the explosions in such systems. Thus, gas is being blown out in a so-called galactic wind. Making direct images of this wind material is challenging, even with the largest telescopes, since the wind material is very diffuse. According to the astronomers, large-scale wind-driven bubbles around small galaxies have been known for two decades, but the newly discovered bubbles are twice to thrice as large as anything seen before. Classical models of large-scale bubble formation due to the combined effect from supernovae fail to reproduce the properties of the observed structure around J1044+0353. 'Understanding wind phenomena around starburst galaxies is key for grasping galaxy formation and evolution in the early universe, where galaxies such as J1044+0353 are the norm. Yet, to comprehend how these winds really work, we need to collect more such images of diffuse gas around tiny galaxies. Currently, we even do not know whether the structure around J1044+0353 is truly special or whether many more tiny galaxies may blow similar super-sized bubbles,' Maulick added.
Hindustan Times
2 days ago
- Science
- Hindustan Times
Pune astronomers make vital space discovery: Galactic wind around tiny galaxy
In what could be an important step towards the study of space and exploration of its depths, two astronomers from the Inter-University Centre for Astronomy and Astrophysics (IUCAA) in Pune and a collaborator from the University of Tokyo in Japan have captured an image that shows a rare and powerful phenomenon called 'galactic wind' around a tiny but extremely active galaxy. They chanced upon it during the course of their research and captured it for posterity. Galaxy J1044+0355, just 7,100 light-years wide, is surrounded by a 20,000 light-year filamentary gas structure, revealed using the Yepun telescope. The loops, shown in yellow to red, are likely shaped by over 50,000 supernovae in the past 20 million years. (SOURCED) Sharing about this discovery with Hindustan Times on Thursday, the astronomers from IUCAA, Dr Edmund Christian Herenz (Vaidya-Raychaudhuri Fellow) and Soumil Maulick, said that this galaxy, named J1044+0354, is only about 7,100 light-years wide, which is very small as the Milky Way is over 100,000 light-years wide. This tiny galaxy lies at a distance of 170 million light years from Earth and is forming new stars at a very fast rate. But, what surprised the astronomers most was that this galaxy is surrounded by seven huge gas bubbles. According to them, some of the bubbles appear to have burst, but others are still whole and clearly visible, and each one is about 23,000 light-years wide, which is nearly equivalent to the distance from Earth to the supermassive black hole at the centre of the Milky Way. Soumil Maulick said that these giant bubbles are believed to have been caused by explosions of massive stars. He explained: 'Stars that are 25 to 100 times heavier than the Sun do not live long - only about 3 to 5 million years. When they die, they explode in powerful events called supernovae, throwing out huge amounts of gas and energy. In large galaxies like the Milky Way, such explosions happen about three times every century, but the galaxy's strong gravity keeps most of the gas from escaping farther into space.' He further said that in small galaxies like J1044+0354, the gravity is much weaker. 'So, when many such supernovae occur, the gas escapes easily, creating what scientists call a 'galactic wind'. This wind is made of hot, fast-moving gas blowing out from the galaxy. Observing this wind directly is difficult because the gas is very thin and faint, even when using the biggest telescopes,' he explained. According to the two astronomers, large gas bubbles created by such galactic winds have been known for about 20 years. But the bubbles seen around J1044+0354 are two to three times larger than any bubble seen before. 'In fact, existing scientific models that explain how these bubbles form from supernova explosions cannot fully explain what has been observed around this galaxy,' Maulick added. Dr Edmund Christian Herenz said that studying galactic winds in star-forming galaxies like J1044+0354 is very important as these kinds of galaxies were common in the early universe. So, understanding them helps scientists learn how galaxies formed and evolved over time. 'However, to fully understand these winds, astronomers need to find and study more examples of small galaxies with similar bubbles. Right now, they do not know if J1044+0354 is a rare case or if many other small galaxies might also be blowing out such enormous bubbles,' he added.
