Starship Asterisk*

VictorBorun wrote: ↑Sat Jul 23, 2022 10:34 pm

Chris Peterson wrote: ↑Sat Jul 23, 2022 8:37 pm

VictorBorun wrote: ↑Sat Jul 23, 2022 8:27 pm But there are acid-red dots with no feed from other filters than «21 μm» wide filter

You determined that by looking at all four of those channels in grayscale?

Here a few of red dots so purely red that they disappear if we remove red from RGB
(to please the eye I added a red channel = halfsum of green and blue)
And they have no counterpart in Hubble's pic
M74 w2 arrows at red dots.jpg
M74 w2 arrows.jpg
M74 h2 arrows.jpg

Chris Peterson wrote: ↑Sat Jul 23, 2022 8:37 pm

VictorBorun wrote: ↑Sat Jul 23, 2022 8:27 pm But there are acid-red dots with no feed from other filters than «21 μm» wide filter

You determined that by looking at all four of those channels in grayscale?

VictorBorun wrote: ↑Sat Jul 23, 2022 8:27 pm

Chris Peterson wrote: ↑Sat Jul 23, 2022 7:32 pm

VictorBorun wrote: ↑Sat Jul 23, 2022 6:51 pm I wonder what the bright red dots are (21 μm).
They can't be brown dwarfs, that would be too faint to loom from another galaxy 30 million ly away.
Are they giant proto-stars in thick dust cloud of 20 μm particles, blocking all the shorter wavelengths?
A passing phase that lasts for, say, 10-100 years so we have never seen the like in Milky Way or Magellanic Cloud?

The bright red dots can't be isolated to the light from the 21 μm broad filter. Red is also made up of light from the 10 μm broad filter, the 3.6 μm medium filter (use: brown dwarfs, planets, continuum), and the 2 μm broad filter. So those red dots are a complex mix. To have a better idea what they represent, you'd need to examine the four separate channels that contribute to them.

But there are acid-red dots with no feed from other filters than «21 μm» wide filter

Chris Peterson wrote: ↑Sat Jul 23, 2022 7:32 pm

VictorBorun wrote: ↑Sat Jul 23, 2022 6:51 pm I wonder what the bright red dots are (21 μm).
They can't be brown dwarfs, that would be too faint to loom from another galaxy 30 million ly away.
Are they giant proto-stars in thick dust cloud of 20 μm particles, blocking all the shorter wavelengths?
A passing phase that lasts for, say, 10-100 years so we have never seen the like in Milky Way or Magellanic Cloud?

The bright red dots can't be isolated to the light from the 21 μm broad filter. Red is also made up of light from the 10 μm broad filter, the 3.6 μm medium filter (use: brown dwarfs, planets, continuum), and the 2 μm broad filter. So those red dots are a complex mix. To have a better idea what they represent, you'd need to examine the four separate channels that contribute to them.

VictorBorun wrote: ↑Sat Jul 23, 2022 6:51 pm I wonder what the bright red dots are (21 μm).
They can't be brown dwarfs, that would be too faint to loom from another galaxy 30 million ly away.
Are they giant proto-stars in thick dust cloud of 20 μm particles, blocking all the shorter wavelengths?
A passing phase that lasts for, say, 10-100 years so we have never seen the like in Milky Way or Magellanic Cloud?

Ann wrote: ↑Sat Jul 23, 2022 3:07 pm Thanks, Victor, very nice!
Ann

VictorBorun wrote: ↑Sat Jul 23, 2022 1:58 pm

Ann wrote: ↑Fri Jul 22, 2022 4:53 am M74 is regarded as the perfect spiral galaxy. Not only that, but it is regarded as the quintessential spiral galaxy without a bar.
Ann

to switch between Hubble and Robert Eder's Webb, I fitted and cropped
M74 h.jpg Blue 0.435 μm, Green 0.555 μm, Red 0.656 μm narrow (H-alpha) + 0.814 μm
M74 w.jpg Blue: 3 μm + 7.7 μm, Cyan 3.35 μm, Green: 11.3 μm, Yellow 2 μm, Orange 10 μm, Red 3.6 μm + 21 μm

Click to view full size image 1 or image 2

Ann wrote: ↑Fri Jul 22, 2022 4:53 am M74 is regarded as the perfect spiral galaxy. Not only that, but it is regarded as the quintessential spiral galaxy without a bar.
Ann

daddyo wrote: ↑Fri Jul 22, 2022 8:20 pm

AVAO wrote: ↑Fri Jul 22, 2022 5:34 am
Is there an explanation for the formation of this mesh-like structure, which becomes visible in the IR?

Maybe since you now get to see to the inner cores of dense material, your looking at the condensed bars that are driving the formation of all visible material in the galaxy?

AVAO wrote: ↑Fri Jul 22, 2022 5:34 am
Is there an explanation for the formation of this mesh-like structure, which becomes visible in the IR?

bystander wrote: ↑Fri Jul 22, 2022 5:25 am M74 Like You’ve Never Seen it Before
Universe Today | 2022 Jul 21

The JWST recently imaged NGC628, also knows an M74. Well-known astronomy image processor Judy Schmidt reworked the image to show more detail. Image Credit: NASA/ESA/CSA/STSCI/Judy Schmidt CC BY 2.0

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The JWST is grabbing headlines and eyeballs as its mission gains momentum. The telescope recently imaged M74 (NGC 628) with its Mid-Infrared Instrument (MIRI). Judy Schmidt, a well-known amateur astronomy image processor, has worked on the image to bring out more detail.

M74 is a large spiral galaxy that holds somewhere in the neighbourhood of 100 billion stars. It’s about 32 million light-years away from us and is a great example of a Grand Design Spiral Galaxy. The JWST imaged the galaxy as part of the PHANGS Survey. PHANGS (Physics at High Angular resolution in Nearby GalaxieS) studies nearby galaxies in high resolution and is intended to “… understand the interplay of the small-scale physics of gas and star formation with galactic structure and galaxy evolution,” according to the PHANGS website.

The survey uses several telescopes to study galaxies, but now that the JWST is operating, it’s making a huge contribution to the effort. ...

The JWST recently imaged NGC628, also knows an M74. Well-known astronomy image processor Judy Schmidt reworked the image to show more detail. Image Credit: NASA/ESA/CSA/STSCI/Judy Schmidt CC BY 2.0

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The JWST is grabbing headlines and eyeballs as its mission gains momentum. The telescope recently imaged M74 (NGC 628) with its Mid-Infrared Instrument (MIRI). Judy Schmidt, a well-known amateur astronomy image processor, has worked on the image to bring out more detail.

M74 is a large spiral galaxy that holds somewhere in the neighbourhood of 100 billion stars. It’s about 32 million light-years away from us and is a great example of a Grand Design Spiral Galaxy. The JWST imaged the galaxy as part of the PHANGS Survey. PHANGS (Physics at High Angular resolution in Nearby GalaxieS) studies nearby galaxies in high resolution and is intended to “… understand the interplay of the small-scale physics of gas and star formation with galactic structure and galaxy evolution,” according to the PHANGS website.

The survey uses several telescopes to study galaxies, but now that the JWST is operating, it’s making a huge contribution to the effort. ...