Comparing Radio and X-Ray Galaxies: Redshift vs. Emission Mechanism

[shirin]

Are all the radio galaxies in the (approximarely) same distance from us? And is the reciveing frequency from all of them in radio band?
I am wondering whether the difference between a radio and x-ray galaxy is their redshift or their emission mechanism ?

 

[mfb]

Are all the radio galaxies in the (approximarely) same distance from us?

No, but the difference between "nearby" and "extremely far away" is just a factor of 10 in redshift. The difference between radio and xrays is something like a factor of 100000000000. Also, the observations get corrected for redshift for obvious reasons.

 

[shirin]

When we say a galaxy is a radio-galaxy, does it mean that its reciving frequency is in radio band?
Is it correct that all of observibg synchrotron activities are in radio band? Or we can observe this activity in other bands too?

 

[davenn]

When we say a galaxy is a radio-galaxy, does it mean that its receiving frequency is in radio band?

no, the opposite ... its an intense emitter of RF, visible and X-rays
Centaurus A radio galaxy is a classic object

here's a set of images showing the galaxy at different wavelengths

Dave

 

[shirin]

no, the opposite ... its an intense emitter of RF, visible and X-rays
Centaurus A radio galaxy is a classic object

here's a set of images showing the galaxy at different wavelengths

View attachment 89998Dave

So I don't understand what categorizes a galaxy as a "radio galaxy". If it has radiation in other bands too and it is not its received frequency to us, then what does distinguish it as a "radio" galaxy?

 

[Drakkith]

So I don't understand what categorizes a galaxy as a "radio galaxy". If it has radiation in other bands too and it is not its received frequency to us, then what does distinguish it as a "radio" galaxy?

Radio galaxies emit large amounts of radiation in the RF band of the EM spectrum. Much more than the usual galaxy does. I think davenn misunderstood what you mean by 'receiving frequency'.

 

[davenn]

I think davenn misunderstood what you mean by 'receiving frequency'.

hahaha uh huh
for the first part of my answer yes I did mis-read ... put it down to being exhausted