# What is frequency range?

Using the NED, you can search via frequency range corresponding to the selected pass band filter. I'm a beginner here and don't really understand. Here's the quote:

NOTES: Objects with observations in the frequency range corresponding to the selected passband filter will be returned. For example, selection of Spitzer MIPS 24 µm will also return objects with photometry from IRAS 25 µm because these filters overlap. This feature permits the location of objects with photometry in the selected region of the spectrum, while cutting across multiple surveys, detectors and filters that have been cross-correlated by NED. A future upgrade will include an option to restrict the search to only the selected passband filter.

There are then a list of 'passbands', all the way up to gamma. What is this actually mean? The amount of radiation given off by a celestial body?

I'm looking at the categories I'm more familiar with:

Redshift
Major Diameter (arcmin)
Minor Diameter (arcmin)
Magnitude and Filter
Classifications

And I'm not sure where this radiation fits in. Is it

Spectral Energy Distribution (SED)


? Could someone explain the following terms to me if this is the case:

• Observed Passband
• Uncertainty Units
• Freq (Hz)
• Mode Aperture/Qualifiers
• Reference Code No.

Wnad what about published and homogenised variables? Are homogenised variables the avarage of all observations?

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