Explanation: Gorgeous spiral galaxy M33 seems to have more than its fair share of glowing hydrogen gas. A prominent member of the local group of galaxies, M33 is also known as the Triangulum Galaxy and lies a mere 3 million light-years away. The galaxy's inner 30,000 light-years or so are shown in this magnificent 25 panel telescopic mosaic. Based on image data from space and ground-based telescopes, the portrait of M33 shows off the galaxy's reddish ionized hydrogen clouds or HII regions. Sprawling along loose spiral arms that wind toward the core, M33's giant HII regions are some of the largest known stellar nurseries, sites of the formation of short-lived but very massive stars. Intense ultraviolet radiation from the luminous, massive stars ionizes the surrounding hydrogen gas and ultimately produces the characteristic red glow. To enhance this image, broadband data was used to produce a color view of the galaxy and combined with narrowband data recorded through a hydrogen-alpha filter. That filter transmits the light of the strongest visible hydrogen emission line.
Re: APOD: The Hydrogen Clouds of M33 (2019 Oct 03)
Posted: Fri Oct 04, 2019 2:41 am
by Boomer12k
Oooooo.... pretty....and NEW STARS!!!!
Great image.
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Re: APOD: The Hydrogen Clouds of M33 (2019 Oct 03)
Posted: Fri Oct 04, 2019 3:43 am
by TheOtherBruce
I think we can safely call this a starburst galaxy? Those are some really huge HII regions; there must be massive numbers of spectacular nebulae in them.
Hmm... I followed the link to the 2016 picture, and I'm surprised there are so few (and much smaller) visible HII regions. I think I've matched up NGC604 in both pictures, but most of the others are just tiny pink specks. Is the new picture so much more detailed just because it's from the Subaru telescope?
Re: APOD: The Hydrogen Clouds of M33 (2019 Oct 03)
Explanation: Gorgeous spiral galaxy M33 seems to have more than its fair share of glowing hydrogen gas. A prominent member of the local group of galaxies, M33 is also known as the Triangulum Galaxy and lies a mere 3 million light-years away. The galaxy's inner 30,000 light-years or so are shown in this magnificent 25 panel telescopic mosaic. Based on image data from space and ground-based telescopes, the portrait of M33 shows off the galaxy's reddish ionized hydrogen clouds or HII regions. Sprawling along loose spiral arms that wind toward the core, M33's giant HII regions are some of the largest known stellar nurseries, sites of the formation of short-lived but very massive stars.
Re: APOD: The Hydrogen Clouds of M33 (2019 Oct 03)
Posted: Mon Oct 14, 2019 6:13 pm
by Ann
starsurfer wrote: āThu Oct 03, 2019 1:28 pm
Rob Gendler is really good at combining data from multiple sources perfectly.
Also I want to move to M33!
Ann
Re: APOD: The Hydrogen Clouds of M33 (2019 Oct 03)
Posted: Mon Oct 14, 2019 7:19 pm
by TheOtherBruce
Something that just occurred to me, from that comment about the HII regions churning out lots of massive stars. They burn fast and pop as supernovae fast, so are we seeing a lot more SN eruptions and remnants than average in those regions?
Re: APOD: The Hydrogen Clouds of M33 (2019 Oct 03)
Posted: Mon Oct 14, 2019 11:32 pm
by neufer
TheOtherBruce wrote: āMon Oct 14, 2019 7:19 pm
Something that just occurred to me, from that comment about the HII regions churning out lots of massive stars. They burn fast and pop as supernovae fast, so are we seeing a lot more SN eruptions and remnants than average in those regions?
HII regions & SN remnants can only be examined relatively locally.
I doubt that the number of local SN eruptions is high enough to perform significant statistics.