Post by Andrei Tchentchik on May 3, 2020 16:58:37 GMT 2
(.#454).- The beginnings of an upcoming merger already visible in the Milky Way. 2020.
The beginnings of an upcoming merger already visible in the Milky Way.
By: Brice Louvet, science editor
January 18, 2020, 12:31 p.m.
The location of this cluster of young stars, on the outskirts of the Milky Way.
Credits: D. NIDEVER; NASA.
The Milky Way will merge with the Large and Small Magellanic Cloud in about two billion years. But the process is probably already underway.
In the Milky Way the youngest stars move in the “city center”, while the oldest move back “in the suburbs”. Recently, astronomers analyzing data from the Gaia telescope, however, recorded the presence of a small cluster of visibly very young stars - barely 120 million years old - on the outskirts of the Galaxy.
Spectral analyzes of these objects also revealed that they had an extragalactic composition. In other words, they did not form in the Milky Way. But where are they from?
These young stars (a thousand objects) are currently evolving near the Magellanic Current, a gas bridge located in the wake of the Magellanic clouds, which extends towards the Milky Way. According to Adrian Price-Whelan, of the Flatiron Institute of Computational Astrophysics, these stars were formed from the gas of this current mixing with that surrounding our Galaxy. Over time the stars would have gotten closer to finally integrate the Milky Way.
A closer merger than previously thought
Until now, it has always been difficult to measure the distance of the magellanic flow from our Galaxy. Thanks to these new stars, researchers now estimate that it is about 90,000 light years away, about half the distance previously estimated.
So it may be a small group of stars, but it has big implications for our Galaxy.
Indeed, "if the Magellanic current is closer, it is therefore likely that it will be integrated into the Milky Way sooner than previously thought, analyzes David Nidever, of the State University of Montana (United States) States) and co-author of the study. Eventually, this gas will turn into new stars on the Milky Way disc. ”
The Small Magellanic Cloud (below) and the Large Magellanic Cloud (above),
Credits: Wikipedia
The Galaxy takes more than it makes
This study also agrees with recent work suggesting that our Galaxy seems to absorb more gas today than it releases.
Researchers using the Cosmic Origins Spectrograph (COS), installed on the Hubble telescope, have recently carried out an audit of the incoming and outgoing gases in the Milky Way. After analysis of 187 clouds of gas and dust, it then emerged that our Galaxy had an excess of gas.
The Milky Way therefore seems to “steal” matter elsewhere. According to the researchers, this gas could come from the intergalactic medium (mainly hydrogen). But it is also possible that the Milky Way is already using its great pulling power to absorb gas reserves in smaller neighboring galaxies, such as the two Magellanic clouds.
F I N .
The beginnings of an upcoming merger already visible in the Milky Way.
By: Brice Louvet, science editor
January 18, 2020, 12:31 p.m.
The location of this cluster of young stars, on the outskirts of the Milky Way.
Credits: D. NIDEVER; NASA.
The Milky Way will merge with the Large and Small Magellanic Cloud in about two billion years. But the process is probably already underway.
In the Milky Way the youngest stars move in the “city center”, while the oldest move back “in the suburbs”. Recently, astronomers analyzing data from the Gaia telescope, however, recorded the presence of a small cluster of visibly very young stars - barely 120 million years old - on the outskirts of the Galaxy.
Spectral analyzes of these objects also revealed that they had an extragalactic composition. In other words, they did not form in the Milky Way. But where are they from?
These young stars (a thousand objects) are currently evolving near the Magellanic Current, a gas bridge located in the wake of the Magellanic clouds, which extends towards the Milky Way. According to Adrian Price-Whelan, of the Flatiron Institute of Computational Astrophysics, these stars were formed from the gas of this current mixing with that surrounding our Galaxy. Over time the stars would have gotten closer to finally integrate the Milky Way.
A closer merger than previously thought
Until now, it has always been difficult to measure the distance of the magellanic flow from our Galaxy. Thanks to these new stars, researchers now estimate that it is about 90,000 light years away, about half the distance previously estimated.
So it may be a small group of stars, but it has big implications for our Galaxy.
Indeed, "if the Magellanic current is closer, it is therefore likely that it will be integrated into the Milky Way sooner than previously thought, analyzes David Nidever, of the State University of Montana (United States) States) and co-author of the study. Eventually, this gas will turn into new stars on the Milky Way disc. ”
The Small Magellanic Cloud (below) and the Large Magellanic Cloud (above),
Credits: Wikipedia
The Galaxy takes more than it makes
This study also agrees with recent work suggesting that our Galaxy seems to absorb more gas today than it releases.
Researchers using the Cosmic Origins Spectrograph (COS), installed on the Hubble telescope, have recently carried out an audit of the incoming and outgoing gases in the Milky Way. After analysis of 187 clouds of gas and dust, it then emerged that our Galaxy had an excess of gas.
The Milky Way therefore seems to “steal” matter elsewhere. According to the researchers, this gas could come from the intergalactic medium (mainly hydrogen). But it is also possible that the Milky Way is already using its great pulling power to absorb gas reserves in smaller neighboring galaxies, such as the two Magellanic clouds.
F I N .
