APOD: The Tadpole Galaxy from Hubble (2021 Jun 21)

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APOD: The Tadpole Galaxy from Hubble (2021 Jun 21)

Post by APOD Robot » Mon Jun 21, 2021 4:05 am

Image The Tadpole Galaxy from Hubble

Explanation: Why does this galaxy have such a long tail? In this stunning vista, based on image data from the Hubble Legacy Archive, distant galaxies form a dramatic backdrop for disrupted spiral galaxy Arp 188, the Tadpole Galaxy. The cosmic tadpole is a mere 420 million light-years distant toward the northern constellation of the Dragon (Draco). Its eye-catching tail is about 280 thousand light-years long and features massive, bright blue star clusters. One story goes that a more compact intruder galaxy crossed in front of Arp 188 - from right to left in this view - and was slung around behind the Tadpole by their gravitational attraction. During the close encounter, tidal forces drew out the spiral galaxy's stars, gas, and dust forming the spectacular tail. The intruder galaxy itself, estimated to lie about 300 thousand light-years behind the Tadpole, can be seen through foreground spiral arms at the upper right. Following its terrestrial namesake, the Tadpole Galaxy will likely lose its tail as it grows older, the tail's star clusters forming smaller satellites of the large spiral galaxy.

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Re: APOD: The Tadpole Galaxy from Hubble (2021 Jun 21)

Post by Ann » Mon Jun 21, 2021 5:56 am

The most amazing thing about the Tadpole galaxy is the stunning wealth of background galaxies. But you need a deep enough image to see them well. Today's APOD only gives us a resolution of 790 KB. I therefore recommend the Wikipedia entry about the Tadpole galaxy, whose picture provides a resolution of 4.43 MB.

Oh, by the way, did you know that "the Tadpole Galaxy" is not "a tadpole galaxy"?
SpaceRef wrote:

This new image from the NASA/ESA Hubble Space Telescope shows a cosmic tadpole, with its bright head and elongated tail, wriggling through the inky black pool of space.

Tadpole galaxies are rare and difficult to find in the local Universe...

The stars in tadpole galaxies are generally very old -- living fossils from the early Universe and from the time when these galaxies formed. LEDA 36252 is in general no exception to that.

However, studying LEDA 36252 has led also to some unexpected results: its head contains a mass of surprisingly young stars with a total mass equivalent to some 10 000 Suns. These stars are grouped into large clusters and appear to consist mainly of hydrogen and helium with hardly any other elements. Astronomers think that this new burst of star formation was triggered when the galaxy accreted primordial gas -- gas which was only very slightly enriched by other elements created by stellar fusion processes in the past -- from its surroundings...

Notes:

[1] There is a specific galaxy named the Tadpole Galaxy, which has been imaged by Hubble in the past. This galaxy was named for its stretched-out appearance, but it is a spiral, not a tadpole, galaxy.
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Re: APOD: The Tadpole Galaxy from Hubble (2021 Jun 21)

Post by VictorBorun » Mon Jun 21, 2021 10:35 am

Where do we think we make the intruder galaxy?
The English Wiki says about 300 thousand light-years behind the Tadpole
The Russian Wiki says на расстоянии около 1 кпк от Головастика и видна сквозь него
which means about 1 kpc behind the Tadpole and can be seen through it.
I think 1 kpc puts the intruder inside the Tadpole ?

I wonder if the intruder's place in the pic is this: And I wonder if the Tadpole has a second 280 thousand ly long tail going towards us, that starts as a dust lane backlighted by the core, then spirals out in the pic ↗ to ↑ to ← to ↙ (running behind the core), then straighten and goes long way toward us and slightly ↘ in the pic like this:

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Re: APOD: The Tadpole Galaxy from Hubble (2021 Jun 21)

Post by orin stepanek » Mon Jun 21, 2021 11:42 am

tadpole_HubbleBiju_960.jpg

Tadpole is a good name; but also reminds me of a Yo-yo on a=string! :mrgreen:
5bad12683c000032000b0e42.jpeg

Kitty has his eye on something; maybe a mouse!!! :wink:
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Re: APOD: The Tadpole Galaxy from Hubble (2021 Jun 21)

Post by VictorBorun » Mon Jun 21, 2021 12:07 pm

orin stepanek wrote:
Mon Jun 21, 2021 11:42 am
Kitty has his eye on something
the background intruder spotted:

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Re: APOD: The Tadpole Galaxy from Hubble (2021 Jun 21)

Post by Chris Peterson » Mon Jun 21, 2021 2:14 pm

Ann wrote:
Mon Jun 21, 2021 5:56 am
The most amazing thing about the Tadpole galaxy is the stunning wealth of background galaxies. But you need a deep enough image to see them well. Today's APOD only gives us a resolution of 790 KB. I therefore recommend the Wikipedia entry about the Tadpole galaxy, whose picture provides a resolution of 4.43 MB.
The two images have exactly the same resolution, which is the native resolution of the HST camera used. The Wikipedia image is processed differently, and is less compressed, giving it more dynamic range, and therefore making some details more apparent.
Chris

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Re: APOD: The Tadpole Galaxy from Hubble (2021 Jun 21)

Post by NCTom » Mon Jun 21, 2021 2:22 pm

What is the source of the intense red of many of the objects and the main dust ring in the Tadpole?

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Re: APOD: The Tadpole Galaxy from Hubble (2021 Jun 21)

Post by Chris Peterson » Mon Jun 21, 2021 2:32 pm

NCTom wrote:
Mon Jun 21, 2021 2:22 pm
What is the source of the intense red of many of the objects and the main dust ring in the Tadpole?
Dust reddens the white light from the stars behind it, just like we see red sunsets. Many distant galaxies are reddened by cosmological redshift. The image Ann referenced from Wikipedia offers a much more realistic sense of color, to the extent that is possible with the filters used to collect this data. The intensity of the red seen in today's APOD is the product of processing choices more than anything.
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Re: APOD: The Tadpole Galaxy from Hubble (2021 Jun 21)

Post by neufer » Mon Jun 21, 2021 3:03 pm

Ann wrote:
Mon Jun 21, 2021 5:56 am

Oh, by the way, did you know that:
"the Tadpole Galaxy" is not "a tadpole galaxy"?
SpaceRef wrote:

This new image from the NASA/ESA Hubble Space Telescope shows a cosmic tadpole, with its bright head and elongated tail, wriggling through the inky black pool of space. Tadpole galaxies are rare and difficult to find in the local Universe... The stars in tadpole galaxies are generally very old -- living fossils from the early Universe and from the time when these galaxies formed. LEDA 36252 is in general no exception to that.

However, studying LEDA 36252 has led also to some unexpected results: its head contains a mass of surprisingly young stars with a total mass equivalent to some 10 000 Suns. These stars are grouped into large clusters and appear to consist mainly of hydrogen and helium with hardly any other elements. Astronomers think that this new burst of star formation was triggered when the galaxy accreted primordial gas -- gas which was only very slightly enriched by other elements created by stellar fusion processes in the past -- from its surroundings...

Notes: [1] There is a specific galaxy named the Tadpole Galaxy, which has been imaged by Hubble in the past. This galaxy was named for its stretched-out appearance, but it is a spiral, not a tadpole, galaxy.
https://en.wikipedia.org/wiki/Tunicate#Life_cycle wrote: <<A tunicate is a marine invertebrate animal whose name derives from their unique outer covering or "tunic" formed from proteins and carbohydrates that acts as an exoskeleton. A tunicate is part of the Chordata, a phylum which includes all animals with dorsal nerve cords and notochords (including vertebrates). They are marine filter feeders with a water-filled, sac-like body structure and two tubular openings, known as siphons, through which they draw in and expel water. During their respiration and feeding, they take in water through the incurrent (or inhalant) siphon and expel the filtered water through the excurrent (or exhalant) siphon. Most adult tunicates are sessile, immobile and permanently attached to rocks or other hard surfaces on the ocean floor. Various species of the subphylum tunicata are commonly known as ascidians, sea squirts, tunicates, sea pork, sea livers, or sea tulips. The earliest probable species of tunicate appears in the fossil record in the early Cambrian period. Despite their simple appearance and very different adult form, their close relationship to the vertebrates is evidenced by the fact that during their mobile larval stage, they possess a notochord or stiffening rod and resemble a tadpole.

Ascidians are almost all hermaphrodites and each has a single ovary and testis, either near the gut or on the body wall. Some larval forms appear very much like primitive chordates with a notochord (stiffening rod) and superficially resemble small tadpoles. These swim by undulations of the tail and may have a simple eye, an ocellus, and a balancing organ, a statocyst. When sufficiently developed, the larva of the sessile species finds a suitable rock and cements itself in place. The larval form is not capable of feeding, though it may have a rudimentary digestive system, and is only a dispersal mechanism. Many physical changes occur to the tunicate's body during metamorphosis, one of the most significant being the reduction of the cerebral ganglion, which controls movement and is the equivalent of the vertebrate brain. From this comes the common saying that the sea squirt "eats its own brain".>>
https://paulbraterman.wordpress.com/2015/06/24/why-the-sea-squirt-eats-its-brains-out-sort-of/ wrote:
Why the Sea Squirt Eats its Brains Out (Sort of)
Posted by [former tenured Professor] Paul Braterman, Jun 24, 2015
<<Good to eat, in traditional Mediterranean and oriental cuisines. Good food for farmed fish, not that they (the fish, I mean) really have much choice in the matter. Good as a source of possible biofuels. And now good for almost £1,000,000 of research funding. Your sister, the sea squirt, actual species Ciona intestinalis, coming shortly to a fjord near you.

The sea squirt is the ultimate in middle-aged complacency. It starts off looking a little bit like a tadpole, with a brain, a tail with a nerve cord and a stiffening rod, an eye, and a balance organ. The reason it looks like a tadpole at this stage is because it is like a tadpole. The notochord is related to the backbone in vertebrates, a spinal cord runs parallel to it along the flexible tail, and at the head end of the spinal cord there primitive brain coordinates sensory inputs.

But when it matures, it sticks its head on a rock, and changes into its adult form, which is not much more than a mouth (branchial siphon), a stomach, and an exit tube (atrial siphon). The sea squirt eats, or to more exact reabsorbs, notochord, tail, sense organs and nervous system, since these are no longer needed, while it feeds by wafting water into its mouth cavity, and filtering out suspended particles. Hence the meme (whose evolution deserves a blog post to itself) that speaks of the sea squirt eating its brains out, comparing the process to a Professor gaining tenure (disclosure: I am myself a former tenured Professor).
>>
Art Neuendorffer