by Ann » Sat Mar 27, 2021 7:35 am
It's always nice to see a new picture of the Antennae Galaxies, and Bernard Miller's image is a very fine example of what amateurs can achieve.
What I like best about Miller's image is how it underscores the difference between the gas-rich galaxy NGC 4038 (at top in his image) and NGC 4039. Note how yellow NGC 4039 is. There is not a lot of star formation going on in that galaxy at all, whereas, by contrast, NGC 4038 is "exploding" with star formation.
I remember reading that most of the star formation in the Antennae Galaxies is actually taking place in the huge dark dust cloud between the two galaxies. So I went looking for an infrared image of the Antennae, which should reveal more of the star formation going on there, and I was a bit disappointed. The infrared Gemini GeMS/GSAORI IR image does not reveal a whole lot more star formation than what is more or less obvious in the Hubble image. Admittedly a few more sources can be seen.
The picture at left was made with the help of great professional telescopes, which is why more details can be seen in it than in Bernard Miller's image.
In the image at left, note the tail emanating from NGC 4038. The tail extends to the left and down. Note that at the end of it, star clusters have formed, which may later turn into dwarf galaxies.
In the image at right, I would guess that the dark blue stuff seen in the tail is (neutral) hydrogen gas, although I'm not sure. Note that we don't see any gas escaping from NGC 4039, the gas-poor galaxy.
Imagine if NGC 4038 and 4039 both had been gas-rich. What starbursting cosmic
train wreck it would have been.
Ann
[float=left][img3="The Antennae galaxies. Photo: Bernard Miller."]https://apod.nasa.gov/apod/image/2103/C60-61_PS2_CROP_FULL1024.jpg[/img3][/float] [float=right][img3="A comparison between a Hubble visible view of the Antennae Galaxies and an infrared image of them by Gemini GeMS/GSAORI IR. Note that these two images are 'upside down' compared with Bernard Miller's image."]https://www.researchgate.net/profile/Fabrice-Vidal-2/publication/259624849/figure/fig3/AS:297168998027271@1447862018713/The-Antennae-galaxy-as-seen-by-the-Hubble-Space-Telescope-left-composite-visible-image.png[/img3][/float]
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It's always nice to see a new picture of the Antennae Galaxies, and Bernard Miller's image is a very fine example of what amateurs can achieve.
What I like best about Miller's image is how it underscores the difference between the gas-rich galaxy NGC 4038 (at top in his image) and NGC 4039. Note how yellow NGC 4039 is. There is not a lot of star formation going on in that galaxy at all, whereas, by contrast, NGC 4038 is "exploding" with star formation.
I remember reading that most of the star formation in the Antennae Galaxies is actually taking place in the huge dark dust cloud between the two galaxies. So I went looking for an infrared image of the Antennae, which should reveal more of the star formation going on there, and I was a bit disappointed. The infrared Gemini GeMS/GSAORI IR image does not reveal a whole lot more star formation than what is more or less obvious in the Hubble image. Admittedly a few more sources can be seen.
[float=left][img3="The Antennae Galaxies. Image Data: Subaru, NAOJ, NASA/ESA/Hubble, R.W. Olsen - Processing: Federico Pelliccia and Rolf Wahl Olsen"]https://apod.nasa.gov/apod/image/1502/AntennaePellicciaOlsen_mark1024.jpg[/img3][/float][float=right][img3="The Southern tail of the Antennae contains several star-forming clumps in a larger HI condensation. Figure courtesy of Pierre-Alain Duc."]https://www.researchgate.net/publication/38107413/figure/fig3/AS:325363780603935@1454584178792/The-Southern-tail-of-the-Antennae-contains-several-star-forming-clumps-in-a-larger-HI.png[/img3][/float]
The picture at left was made with the help of great professional telescopes, which is why more details can be seen in it than in Bernard Miller's image.
In the image at left, note the tail emanating from NGC 4038. The tail extends to the left and down. Note that at the end of it, star clusters have formed, which may later turn into dwarf galaxies.
In the image at right, I would guess that the dark blue stuff seen in the tail is (neutral) hydrogen gas, although I'm not sure. Note that we don't see any gas escaping from NGC 4039, the gas-poor galaxy.
Imagine if NGC 4038 and 4039 both had been gas-rich. What starbursting cosmic [url=https://replicationindex.files.wordpress.com/2017/02/train-wreck-1.jpg?w=640]train wreck[/url] it would have been.
Ann