<p>Diffraction is a negligible contributor to the point spread functions of x-ray and gamma ray telescopes. The artifacts that look a bit like diffraction spikes in the <a href="https://swift.gsfc.nasa.gov/results/publist/Moretti_SPIE_5165_232_2004.pdf" rel="nofollow noreferrer">Swift XRT PSF</a> are the result of slight distortions of the thin mirror shells due to stress at the support points.</p>

CC BY-SA 4.0
2024-10-14T08:47:06.387Z
What about UVOT?
Peter Erwin
CC BY-SA 4.0
2024-10-20T17:39:55.567Z
@John Doty, do you have anything for the UVOT?
Astrovis
CC BY-SA 4.0
2024-10-12T18:20:42.757Z
2024-10-12T18:20:42.757Z
John Doty
<p>How many diffraction lines does the swift and fermi telescopes have? An example of what I am looking for is an image showing these clear diffraction lines, like this one from JWST:
<a href="https://i.sstatic.net/ykBt9B70.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/ykBt9B70.png" alt="JWST Deepfield" /></a></p>
<p>How many diffraction lines do the Swift and Fermi telescopes have, and are there any clear images showing these lines?
Edit: For Swift and Fermi ideally it'd be all the instruments onboard, if applicable.</p>

CC BY-SA 4.0
2024-10-11T11:47:05.693Z
Which specific telescopes on the spacecraft are you asking about? (E.g., Swift has two imaging telescopes: XRT and UVOT.)
Peter Erwin
CC BY-SA 4.0
2024-10-11T15:11:38.297Z
Oh good catch, ideally it would be all of the instruments if possible. I'll edit my question
Astrovis
<observational-astronomy><telescope><space-telescope><electromagnetic-spectrum>
How many diffraction lines do the images of Swift and Fermi have?
Astrovis
# How many diffraction lines do the images of Swift and Fermi have?

(Asked by: username_0 on 2024-10-10)

How many diffraction lines does the swift and fermi telescopes have? An example of what I am looking for is an image showing these clear diffraction lines, like this one from JWST:
[![JWST Deepfield](https://i.sstatic.net/ykBt9B70.png)](https://i.sstatic.net/ykBt9B70.png)

How many diffraction lines do the Swift and Fermi telescopes have, and are there any clear images showing these lines?
Edit: For Swift and Fermi ideally it'd be all the instruments onboard, if applicable.

**Tags:** observational-astronomy, telescope, space-telescope, electromagnetic-spectrum
> **Comments:**
> **username_1**: Which specific telescopes on the spacecraft are you asking about? (E.g., Swift has two imaging telescopes: XRT and UVOT.)  
> **username_0**: Oh good catch, ideally it would be all of the instruments if possible. I'll edit my question  

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## 1 answers

### Answer by username_2 on 2024-10-12. Score: 2

Diffraction is a negligible contributor to the point spread functions of x-ray and gamma ray telescopes. The artifacts that look a bit like diffraction spikes in the [Swift XRT PSF](https://swift.gsfc.nasa.gov/results/publist/Moretti_SPIE_5165_232_2004.pdf) are the result of slight distortions of the thin mirror shells due to stress at the support points.

> **Comments:**
> **username_1**: What about UVOT?  
> **username_0**: @John Doty, do you have anything for the UVOT?  

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