Recent content by mrjaffa

Thanks very much for this. The whole question was worth 15 marks and I just couldn't see what I'd wrote picking up that many, but I'll be happy with about 10 I guess. I had read somewhere about synchrotron radiation, but after going back through the chapter I can't see anything about that, and...

I've spent far too long on this question now. Thanks again for your time :-) `This is what I ended up with...i) Seyfert galaxies are extremely luminous with an excess of radiation. Optically, this radiation is seen to be variable, implying that the light is coming from a very small region in...

The main differences I'm getting, is that optical astronomers would have missed things like the jests and lobes in radio galaxies. And I think Quasars were first thought to be stars in our own galaxy until it as realized they were in another very distant galaxy, but I'm not sure if this...

It doesn't matter how many times I read the chapter on Active galaxies in the book, it doesn't seem to be sinking in.

Thanks for your reply. I've been told that we just the value in the book of 10-4 for R(t).

Homework Statement Describe what optical astronomers would consider the properties of an active galaxy and also describe what radio astronomers would describe as the properties of an active galaxy and explain how two sets of astronomers came up with these differing conclusions. Homework...

Homework Statement The energy density of the universe for radiation, matter and cosmological constant have changed over the years and there was a time (t), when it was equal for matter and radiation. Assuming the universe is 13.7 billion years old, estimate R(t) / R(0) where R(0) is the...

Hi Marcus. OU is indeed just the Open University which is online online learning. Thanks for your reply. I'm still not understanding this. In the textbook, there is a graph showing the energy densities for radiation and matter on the y-axis and then on the x-axis is the scale factor R(t) /...

Hi everyone. Loving the forum, don't know how I haven't stmble upon it already. I'm studying Astronomy at the OU and finding a lot of the maths tough. Especially finding the chapters on Cosmology very difficult. I've seen another post regarding Scale Factor, so hope it's ok posting this too...