<p>The warped galaxy is in the background. The elliptical galaxy is in the foreground and is part of a massive cluster that is gravitationally lensing the background galaxies.</p>
<p>The distances of the two galaxies can be estimated from their redshift (the redshift is unaffected by the gravitational lensing) and Hubble's law (with assumptions about the relevant cosmological parameters). Assuming the foreground galaxy is part of &quot;SMACS 0723&quot;, then it is at a distance of about 4.6 billion light years. A spectroscopc measurement of the redshift of the warped galaxy would give its distance. I don't know whether that has been done for that galaxy, but it is not a really difficult measurement to obtain.</p>
<p>The image is that of distant galaxies being <a href="https://en.wikipedia.org/wiki/Gravitational_lens" rel="nofollow noreferrer">gravitationally lensed</a> by a foreground (though still very distant) cluster of galaxies. The paths of the light from the distant galaxies are bent by the spacetime curvature caused by the mass in the foreground cluster.</p>
<p>The distorted images are those of the background galaxies. The distortions in their shapes tells you something about the distribution of mass in the foreground lensing object. In this case, the distortions are mostly tangential to a central point, which reveals (perhaps unsurprisingly) that the mass in the foreground object has a distribution that is roughly spherically symmetric and concentrated towards a central point, which is marked by a large, dominant, central elliptical galaxy in the image. Careful analysis of the shape and brightness of the distroted galaxies can reveal the relative distribution of &quot;normal&quot;, luminous matter and dark matter in the foreground cluster.</p>

CC BY-SA 4.0
2022-07-13T22:13:47.880Z
2022-07-14T12:39:29.413Z
2022-07-14T12:39:29.413Z
ProfRob
<p>I find this warping very interesting (it's Webb's), how is it possible? Is warped spiral galaxy behind or in front of spherical one? Have we any data on their distances? Can we obtain or compute their distances from Earth somehow?</p>
<p><a href="https://i.sstatic.net/qYlKP.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/qYlKP.png" alt="enter image description here" /></a></p>

CC BY-SA 4.0
2022-07-13T14:36:53.817Z
Duplicate of https://physics.stackexchange.com/questions/717952/questions-about-first-jwst-image
leftaroundabout
CC BY-SA 4.0
2022-07-13T20:50:28.377Z
@leftaroundabout In Stack Exchange "duplicate" as a very specific meaning and it does not relate to questions posted on other sites. Neither does cross-posting in this case. Calling it a duplicate may attract unnecessary negativity (down voting, closing) that otherwise might happen. Why not just say "answered in Physics SE" or similar, and avoid using a term reserved for something different than this case?
uhoh
CC BY-SA 4.0
2022-07-13T21:13:45.110Z
@leftaroundabout I've explained further in meta: [Should we avoid calling questions that have answers in other SE sites as "duplicate", which already has a specific and different meaning in SE?](https://astronomy.meta.stackexchange.com/q/867/7982)
uhoh
CC BY-SA 4.0
2022-07-15T05:34:56.690Z
I think this is a reasonable question for our site, regardless of the Physics.SE question. However, it asks too many questions, and the OP therefore needs to [edit] it to focus on a specific issue. The first 2 questions are both about the *nature* of the object, so I'd recommend deleting the last 2 questions about the *distances*. It's worth noting that editing the question in this way would not invalidate any answers that happen to provide additional information about those distances. :-)
Chappo Hasn't Forgotten
<galaxy><james-webb-space-telescope>
How to explain this galaxy warping in Webb's newest photo?
sheerun
# How to explain this galaxy warping in Webb's newest photo?

(Asked by: username_0 on 2022-07-13)

I find this warping very interesting (it's Webb's), how is it possible? Is warped spiral galaxy behind or in front of spherical one? Have we any data on their distances? Can we obtain or compute their distances from Earth somehow?

[![enter image description here](https://i.sstatic.net/qYlKP.png)](https://i.sstatic.net/qYlKP.png)

**Tags:** galaxy, james-webb-space-telescope
> **Comments:**
> **username_1**: Duplicate of https://physics.stackexchange.com/questions/717952/questions-about-first-jwst-image  
> **username_2**: @leftaroundabout In Stack Exchange "duplicate" as a very specific meaning and it does not relate to questions posted on other sites. Neither does cross-posting in this case. Calling it a duplicate may attract unnecessary negativity (down voting, closing) that otherwise might happen. Why not just say "answered in Physics SE" or similar, and avoid using a term reserved for something different than this case?  
> **username_2**: @leftaroundabout I've explained further in meta: [Should we avoid calling questions that have answers in other SE sites as "duplicate", which already has a specific and different meaning in SE?](https://astronomy.meta.stackexchange.com/q/867/7982)  
> **username_3**: I think this is a reasonable question for our site, regardless of the Physics.SE question. However, it asks too many questions, and the OP therefore needs to [edit] it to focus on a specific issue. The first 2 questions are both about the *nature* of the object, so I'd recommend deleting the last 2 questions about the *distances*. It's worth noting that editing the question in this way would not invalidate any answers that happen to provide additional information about those distances. :-)  

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## 1 answers

### Answer by username_4 on 2022-07-13. Score: 4

The warped galaxy is in the background. The elliptical galaxy is in the foreground and is part of a massive cluster that is gravitationally lensing the background galaxies.

The distances of the two galaxies can be estimated from their redshift (the redshift is unaffected by the gravitational lensing) and Hubble's law (with assumptions about the relevant cosmological parameters). Assuming the foreground galaxy is part of "SMACS 0723", then it is at a distance of about 4.6 billion light years. A spectroscopc measurement of the redshift of the warped galaxy would give its distance. I don't know whether that has been done for that galaxy, but it is not a really difficult measurement to obtain.

The image is that of distant galaxies being [gravitationally lensed](https://en.wikipedia.org/wiki/Gravitational_lens) by a foreground (though still very distant) cluster of galaxies. The paths of the light from the distant galaxies are bent by the spacetime curvature caused by the mass in the foreground cluster.

The distorted images are those of the background galaxies. The distortions in their shapes tells you something about the distribution of mass in the foreground lensing object. In this case, the distortions are mostly tangential to a central point, which reveals (perhaps unsurprisingly) that the mass in the foreground object has a distribution that is roughly spherically symmetric and concentrated towards a central point, which is marked by a large, dominant, central elliptical galaxy in the image. Careful analysis of the shape and brightness of the distroted galaxies can reveal the relative distribution of "normal", luminous matter and dark matter in the foreground cluster.


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