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I wonder if this says more about our sensor technologies than how the galaxy actually looks (the visible, infrared and microwave images look far richer than the

by hliyan 11y ago

I wonder if this says more about our sensor technologies than how the galaxy actually looks (the visible, infrared and microwave images look far richer than the others).

TeMPOraL 11y ago
They're false-color so if anything, this says more about our Photoshop choices.
- hliyan 11y ago
  I actually meant the level of detail rather than the range of colors.
- jacobolus 11y ago
  It would be awesome to see a separate grayscale (or at least same-color-gradient) image at every wavelength they’ve recorded, with color scaling based on radiant flux and consistent across images. (Could be log-scaled or whatever if some of the images would otherwise be too dim.) Even better would be to show a large chart of all those images at once, so they could be compared on a large display without needing to scrub a slider back and forth. With these false color images, it’s impossible to know without careful investigation what the colors in each image represent or how they’re mixed together, and it’s impossible to make useful comparisons.
  - privong 11y ago
    > Even better would be to show a large chart of all those images at once, so they could be compared on a large display without needing to scrub a slider back and forth. See the "Multiwavelength Milky Way" poster from NASA: http://mwmw.gsfc.nasa.gov/mmw_product.html#poster http://mwmw.gsfc.nasa.gov/mmw_product.html#poster They're still false-color and only show the plane of the galaxy, but you can at least see them all simultaneously.
  - fsargent 11y ago
    Yeah! My thoughts exactly - and if they did representative scaling into the visual light spectrum based on the range you decided. Anyone got an API for this?
privong 11y ago
> I wonder if this says more about our sensor technologies than how the galaxy actually looks (the visible, infrared and microwave images look far richer than the others). There are definite effects from technology. The radio and far-infrared observations are at much lower angular resolution than the optical and near-infrared, for example. So there's less spatial detail in those. Also, some surveys have been carried out in more than one filter/color (e.g., optical, near-infrared) and so the optical image shows some information about the color of objects in the optical. In contrast, the radio image appears to be a single frequency, and so doesn't contain that information for the radio sources. However, there is a lot of information there about the galaxy. The distribution of sources, for example – you can see the well-defined disk of the galaxy in all bands. The dust lanes corresponding to gas clouds are apparent in the optical as the dark patches. You can also see that there are some sources which emit brightly in X-rays, but are not seen in the other images. So that tells you about the types of objects in the galaxy. So, despite the fact that the technology affects the images, I would not say that the map says less about the galaxy than about the technology.

by hliyan 11y ago

I wonder if this says more about our sensor technologies than how the galaxy actually looks (the visible, infrared and microwave images look far richer than the others).

TeMPOraL 11y ago

They're false-color so if anything, this says more about our Photoshop choices.

hliyan 11y ago
I actually meant the level of detail rather than the range of colors.
jacobolus 11y ago
It would be awesome to see a separate grayscale (or at least same-color-gradient) image at every wavelength they’ve recorded, with color scaling based on radiant flux and consistent across images. (Could be log-scaled or whatever if some of the images would otherwise be too dim.) Even better would be to show a large chart of all those images at once, so they could be compared on a large display without needing to scrub a slider back and forth. With these false color images, it’s impossible to know without careful investigation what the colors in each image represent or how they’re mixed together, and it’s impossible to make useful comparisons.
- privong 11y ago
  > Even better would be to show a large chart of all those images at once, so they could be compared on a large display without needing to scrub a slider back and forth. See the "Multiwavelength Milky Way" poster from NASA: http://mwmw.gsfc.nasa.gov/mmw_product.html#poster http://mwmw.gsfc.nasa.gov/mmw_product.html#poster They're still false-color and only show the plane of the galaxy, but you can at least see them all simultaneously.
- fsargent 11y ago
  Yeah! My thoughts exactly - and if they did representative scaling into the visual light spectrum based on the range you decided. Anyone got an API for this?

privong 11y ago

> I wonder if this says more about our sensor technologies than how the galaxy actually looks (the visible, infrared and microwave images look far richer than the others). There are definite effects from technology. The radio and far-infrared observations are at much lower angular resolution than the optical and near-infrared, for example. So there's less spatial detail in those. Also, some surveys have been carried out in more than one filter/color (e.g., optical, near-infrared) and so the optical image shows some information about the color of objects in the optical. In contrast, the radio image appears to be a single frequency, and so doesn't contain that information for the radio sources. However, there is a lot of information there about the galaxy. The distribution of sources, for example – you can see the well-defined disk of the galaxy in all bands. The dust lanes corresponding to gas clouds are apparent in the optical as the dark patches. You can also see that there are some sources which emit brightly in X-rays, but are not seen in the other images. So that tells you about the types of objects in the galaxy. So, despite the fact that the technology affects the images, I would not say that the map says less about the galaxy than about the technology.