<p>There is no distinction.</p>
<p>No matter which wavelength regime you consider, &quot;image&quot; is an adequate and frequently used description. Also for radio, microwaves, sub-mm, IR, UV, and X-rays.</p>
<p>The reason that we also use the word &quot;map&quot; is that very often we're interested not only in the &quot;full&quot; picture, but in analyzing differences across the image, e.g. looking a the morphology of a galaxy, the distribution of stars, or the extinction at various locations in a nebula. The image can be considered a <em>map</em> of the object, just like a land map is a chart of the differences in a landscape.</p>

CC BY-SA 4.0
2024-03-07T11:31:45.863Z
2024-03-07T11:31:45.863Z
pela
<p>Or is it just historical convention? I know that within research circles, it is common to also use the term &quot;radio image&quot;. I am mainly wondering whether the term originally comes from wanting to differentiate between an &quot;actual&quot; image and something that is more of a representation.</p>
<p>I know that if we want to be really precise, even optical images are representations, but still I feel there is a big difference between those and imaging wavelengths that we cannot see at all.</p>

CC BY-SA 4.0
2024-03-07T11:33:32.287Z
There is no convention that they should be called maps. Do a google search on "radio images astronomy" and see what comes up.
ProfRob
CC BY-SA 4.0
2024-03-07T11:56:31.407Z
Perhaps because "a map is not the territory"? For example, see the famous Magritte painting of a pipe that declares, in French, that "this is not a pipe." Some astronomers are quite compelled by the map-territory relation.
David Hammen
CC BY-SA 4.0
2024-03-07T12:03:35.547Z
@DavidHammen very interesting analogy! I think in Physics/Astronomy in general, the distinction between the description/depiction of something and "reality" (whatever that might be) is really interesting.
Loika
<telescope><radio-astronomy><radio-telescope><radio><wavelength>
Why do we call radio images "maps"? Is it because it is not optical, so therefore not an "image", strictly speaking?
Loika
# Why do we call radio images "maps"? Is it because it is not optical, so therefore not an "image", strictly speaking?

(Asked by: username_0 on 2024-03-07)

Or is it just historical convention? I know that within research circles, it is common to also use the term "radio image". I am mainly wondering whether the term originally comes from wanting to differentiate between an "actual" image and something that is more of a representation.

I know that if we want to be really precise, even optical images are representations, but still I feel there is a big difference between those and imaging wavelengths that we cannot see at all.

**Tags:** telescope, radio-astronomy, radio-telescope, radio, wavelength

> **Comments:**
> **username_1**: There is no convention that they should be called maps. Do a google search on "radio images astronomy" and see what comes up.  
> **username_2**: Perhaps because "a map is not the territory"? For example, see the famous Magritte painting of a pipe that declares, in French, that "this is not a pipe." Some astronomers are quite compelled by the map-territory relation.  
> **username_0**: @username_2 very interesting analogy! I think in Physics/Astronomy in general, the distinction between the description/depiction of something and "reality" (whatever that might be) is really interesting.  

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## 1 answers

### Answer by username_3 on 2024-03-07. Score: 4 | Accepted answer

There is no distinction.

No matter which wavelength regime you consider, "image" is an adequate and frequently used description. Also for radio, microwaves, sub-mm, IR, UV, and X-rays.

The reason that we also use the word "map" is that very often we're interested not only in the "full" picture, but in analyzing differences across the image, e.g. looking a the morphology of a galaxy, the distribution of stars, or the extinction at various locations in a nebula. The image can be considered a *map* of the object, just like a land map is a chart of the differences in a landscape.


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