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what messier object are we talking about in today's video so in today's video we're talking about messier 95. this is a beautiful bad spiral galaxy quite low surface brightness it's one of the faintest objects in the messier catalogue but actually you've already done a video on messier 95 already really oh yeah but in that video it was eight years ago and you said it wasn't an official video and that you would come back to it maybe next year and like i think about four years ago megan said she would come back to this video as well and now it's eight years down the line you can have it's yours so the video that you did on m95 was actually um based on a supernova explosion that had gone on in the outskirts of the galaxy we know that it
was a supernova type 2 so a very classical example of a supernova that was once a star that had reached the end of its life and just exploded so this galaxy it's 33 million light years away in the constellation of leo it lives in a group of galaxies called the m96 group this group of galaxies also consists of m96 and m105 as well as 21 other galaxies at least and there's also this object called the leo ring which is essentially a ring-like structure of h1 regions immense hydrogen and helium gas there so that's like kind of the building blocks for star formation so maggie these h regions these huge areas of gas are they in galaxies or are they between galaxies so usually in galaxies you do have
hydrogen regions but this particular structure it kind of engulfs around m105 and kind of reaches the end of m96 as well so it's a huge massive like collection of little dots of h1 regions going back to m95 it's got this very prominent bar in the center but if you look at it in the uv you can't see that bar at all what we see in the uv of this galaxy is you've got a bright nucleus where there's tons and tons of star formation happening and then like a ring around it so you've blasted out some of this kind of material in the center where there's not much star formation going on contrary on the optical you do see this bar and all the stars around it as well so if we look more into detail we can see
like these clusters of star formation in the spiral arms like bright blue regions and these are like open clusters eventually they'll become like globular clusters even and also around the nucleus we see this bright ring of blue that is where huge violent star formation is happening it's so violent that it's actually blasting bubbles of material out of the way and these huge outflows so this ring is interesting to astronomers because they want to know how stable this ring structure is how did it form but it's not that rare like some spiral galaxies do have these rings of star formation around their nucleus but what is really interesting about this galaxy is the dust lanes so the dust lanes are
the dark brownie kind of regions and what you see by the nucleus is that you've got the primary branch of the dust lane and that's kind of what you expect to see but you also see this kind of secondary dust lanes that curve around making this shell like feature this is unusual this is not something that you expect to see and so i was looking at this paper that was studying what kind of star formation is happening in this galaxy and they made simulations to try and reproduce this structure and they couldn't do it they weren't able to create this dislike and so these simulations that they use they only contain gravity so they're only really modeling for the potential of the galaxy it doesn't contain any uh stellar feedback or any
type of feedback in general that just means that with these simulations we can rule out that any uh asymmetries in the gravitational potential of the galaxy is causing these dust lane features to swing back it could still be caused by um stellar feedback what does stellar feedback mean so stellar feedback is kind of like a measure of um all the effects caused by stars that could go on to make this feedback loop so if you have like strong stellar winds that would like push material out into the interstellar medium and then that could go on back to create more stars so it's kind of a feedback loop so basically what you're saying is they're trying to find out whether this weird tendril could be caused by the stars that are
there as we see them essentially yes so the stars themselves are redistributing the gas and the metals and the energy to create more and more stars so what is it then oh now i'm intrigued what's causing this do you want to hear my guess yeah because this is what you guys always say when you find something weird in a galaxy a collision in the past that is one of like their theories actually so if you look at the carbon monoxide distribution in this galaxy you can see that the outflows from the nucleus is like crashing colliding into this shell of carbon monoxide so there is like this expanding shell of material coming out but what's causing those outflows and what's causing like these kind of collisions and that's
still something that they don't really know it could be several things one could be supernova explosions we know that there was a supernova explosion in 2012 and you talked about that already it could be like stellar wind so the stars themselves because we know there's huge amounts of star formation happening there it could be the photon pressure because of the stars themselves that could be cause pushing it out what we know that it isn't though is agn so typically at the center of most galaxies we know there's a supermassive black hole and if that supermassive black hole is active it's called an agm it's feeding and then it has these jets of materials like pushing things out this galaxy doesn't have that so we can
rule that out that's what they've come up with and they decided that it's probably a mix of the first three that i talked about but it's really important to kind of understand these things because then you can figure out like what the kind of stellar feedback contributions are to include in astronomical simulations and to understand this ring-like feature of star formation that we have there how it formed and how stable it is and how it will evolve this galaxy sounds like a violent place it seems like that at the very center less so at the edges but at the center there's just bursting out of outflows and bubbles it's a violent star-forming region if this is a freak occurrence right if this is like a weird thing
that's happened in this galaxy and you don't often see them why is it really important to understand if it's not like you know the standard procedure can't just be dismissed as oh well something crazy happened that one time but that's not normal in galaxies i think it's really important to understand like these like kind of anomalies because then you can rule out some of the theories that you have because you could say okay this is how star formation works this is how dust lanes work and then you've got something that stands out it doesn't fit into your particular model so you have to refine your models based on the anomalies that we see right so sometimes the anomalies teach you way more than the normal way space works yeah
cool one second i've got a question but before i ask you the question i'm going to move my chihuahua out of the room because she's snoring so loudly sorry she's on the way out she's too loud okay come on you're going you can come back in later
