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Huge galaxy Centaurus A

Posted: Wed Jul 08, 2009 2:42 pm
by The Code
I was very interested to read this..

http://www.universetoday.com/2009/07/07 ... lue-whale/

At 14 million LY away, this truly is a monster ..

Mark

Re: Huge galaxy Centaurus A

Posted: Wed Jul 08, 2009 3:38 pm
by bystander
http://www.scienceimage.csiro.au/mediar ... 9-111.html

APOD: 2008 January 10 - Active Galaxy Centaurus A
http://asterisk.apod.com/vie ... =9&t=13062

Centaurus A exposed
Astronomy.com - 2008 January 10
Provided by Chandra X-Ray Center
  • Jet power and black hole assortment revealed in a new Chandra image.
Black hole outflows from Centaurus A detected
Astronomy.com - 2009 January 28
Provided by ESO, Garching, Germany
  • Jets and lobes emanating a from central black hole have been imaged at sub-millimeter wavelengths for the first time.

Re: Huge galaxy Centaurus A

Posted: Wed Jul 08, 2009 5:17 pm
by Loco
Looks more like an upside down Jellyfish to me. And what the heck is this 'emanating from a Black Hole' business when Black Holes are still theoretical entities.

Re: Huge galaxy Centaurus A

Posted: Thu Jul 09, 2009 12:02 am
by harry
G'day from the land of ozzzzzz

This is a nice image

http://www.nasa.gov/multimedia/imagegal ... _1276.html

http://chandra.harvard.edu/photo/2003/c ... _hand.html

http://chandra.harvard.edu/press/02_rel ... 80702.html
X-ray Arcs Tell The Tale Of Giant Eruption August 7, 2002


There are a few more on APOD

Re: Huge galaxy Centaurus A

Posted: Thu Jul 09, 2009 11:27 am
by The Code
Thanks for the links Bystander,Harry

Looking at these images , makes me inclined to say, That the plasma jet is not in the same place over time. It looks as if over millions of years it shifts back and forth, Would this be due to the rotation of the black hole? I have my own views and thoughts but would like to here others. Also If the outer part of a black hole is super dense plasma would this be the form matter/energy takes after the event horizon? or are there other reasons? Would be nice to see a photo of a black hole cut in half, like there are photos of the sun, so we can see the inner workings.. When i looked at the photo of the galaxy i also saw dark patches.. What has caused this, And what are they? Looks to be a very violent place, Centaurus A Maybe a merger has taken place on a colossal scale...

Thanks

Mark

Re: Huge galaxy Centaurus A

Posted: Thu Jul 09, 2009 1:01 pm
by bystander
Astronomers beleive that Cen A is the result of a merger between a spiral and elliptical galaxy (both huge). The dust lanes aroung the middle are the left overs from the spiral (ellipticals don't usually have dust lanes). See: APOD: 2006 March 4 - The Galaxy Within Centaurus A.

What's interesting to me is that the galaxy pictures from ESO, NASA, et al, only seem to span about the middle third (half??) (a little below center) of the CSIRO picture. The dark band across the middle of the CSIRO picture is the dust band, I assume, and the white streak extending up and to the left is the visible jet.

Re: Huge galaxy Centaurus A

Posted: Thu Jul 09, 2009 1:12 pm
by The Code
Maybe radio waves give a unjust magnification.. An abundance of hydrogen ??

Re: Huge galaxy Centaurus A

Posted: Thu Jul 09, 2009 2:14 pm
by Chris Peterson
mark swain wrote:Looking at these images , makes me inclined to say, That the plasma jet is not in the same place over time. It looks as if over millions of years it shifts back and forth, Would this be due to the rotation of the black hole?
I'm not sure what you're seeing that gives you this sense of direction change with time. I suppose that a rotating black hole could show precession. However, the material being ejected is quite tenuous and subject to distortion from lots of sources, so trying to figure out the original direction it was emitted in seems nearly impossible when looking far from the source.
Would be nice to see a photo of a black hole cut in half, like there are photos of the sun, so we can see the inner workings
Well, yes, that would be nice. Unfortunately, our current physics can't describe the interior of a black hole (it may not even have an interior!), which is why you've never seen a diagram like that.

Re: Huge galaxy Centaurus A

Posted: Thu Jul 09, 2009 2:36 pm
by The Code
Chris Peterson wrote: mark swain wrote:Looking at these images , makes me inclined to say, That the plasma jet is not in the same place over time. It looks as if over millions of years it shifts back and forth, Would this be due to the rotation of the black hole?


I'm not sure what you're seeing that gives you this sense of direction change with time. I suppose that a rotating black hole could show precession. However, the material being ejected is quite tenuous and subject to distortion from lots of sources, so trying to figure out the original direction it was emitted in seems nearly impossible when looking far from the source.
There is a pattern at the end of the jet, which forms an arch .. I see part in the foreground and the back ground ,, from bystanders link photo. if we could rotate the black hole in rewind you would see the end of the jet create that arch... Now i know that the length of that jet is millions of light years, so i may be seeing an optical allusion. but i can not answer the reason for the arch in any other way. interesting all the same..

Re: Huge galaxy Centaurus A

Posted: Thu Jul 09, 2009 3:18 pm
by Chris Peterson
mark swain wrote:There is a pattern at the end of the jet, which forms an arch .. I see part in the foreground and the back ground ,, from bystanders link photo. if we could rotate the black hole in rewind you would see the end of the jet create that arch... Now i know that the length of that jet is millions of light years, so i may be seeing an optical allusion. but i can not answer the reason for the arch in any other way. interesting all the same..
The jets are nowhere near millions of light years long. The longest one in Centaurus A is only visible for about 13,000 light years. As the ejected material gets further from the center, it interacts with surrounding gas (there is probably a lot as a result of the galactic collision which is in progress) and is driven all over the place. That's why I think it is difficult or impossible to really determine much from the apparent structure seen at the outside.

This is a relativistic jet, with an outflow speed of about 0.5 c. So the entire jet as we see it represents no more than a few tens of thousands of years of production.

Re: Huge galaxy Centaurus A

Posted: Thu Jul 09, 2009 3:26 pm
by The Code
Chris Peterson wrote:The jets are nowhere near millions of light years long.



Sorry Chris but i got the info from my first link at the top of the page. Quote : The galaxy's black hole generates jets of radio-emitting particles that billow millions of light years out into space. and was probably misled by this quote

mark

Re: Huge galaxy Centaurus A

Posted: Thu Jul 09, 2009 3:48 pm
by Chris Peterson
mark swain wrote:
Chris Peterson wrote:The jets are nowhere near millions of light years long.
Sorry Chris but i got the info from my first link ant the top of the page. Quote : The galaxy's black hole generates jets of radio-emitting particles that billow millions of light years out into space.
The particles produced by the jets are moving far greater than the galaxy's escape velocity, so they have been traveling outwards as long as the jets existed. So certainly, jet material will be found millions of light years away. This is what is seen in the radio wavelength data from your original post. Is that the one with the "arch" structure you mention? I've been discussing the x-ray images posted elsewhere in this discussion. They show the energetic part of the jet- where it is still undergoing acceleration (via poorly understood mechanisms) which maintain the relativistic velocity. That region only extends 10 or 20 thousand light years. Once the material is far enough from the galaxy, it is essentially dispersive in behavior. I'm not sure you would call this distant material a "jet"; it would be more accurate to say it is material from the jet. Regardless of what you call it, however, trying to link the structure of dimly glowing gas millions of light years from the galaxy to the orientation of the original source is about as likely as relating structure in the top of a steam cloud to the orientation of your teapot's spout.

Re: Huge galaxy Centaurus A

Posted: Thu Jul 09, 2009 4:54 pm
by The Code
Sorry Chris but i got the info from my first link at the top of the page. Quote : The galaxy's black hole generates jets of radio-emitting particles that billow millions of light years out into space. and was probably misled by this quote

Re: Huge galaxy Centaurus A

Posted: Thu Jul 09, 2009 6:18 pm
by The Code
Chris Peterson wrote:about as likely as relating structure in the top of a steam cloud to the orientation of your teapot's spout.
There lies another debate ,,,, But i fear not on this forum... Maybe another time <g>

Re: Huge galaxy Centaurus A

Posted: Thu Jul 09, 2009 7:52 pm
by Loco
mark swain wrote:
Chris Peterson wrote:about as likely as relating structure in the top of a steam cloud to the orientation of your teapot's spout.
How can you NOT think the orientation of the teapot's spot will affect the top of the teapot's steam cloud?

Re: Huge galaxy Centaurus A

Posted: Thu Jul 09, 2009 8:54 pm
by Chris Peterson
Loco wrote:How can you NOT think the orientation of the teapot's spot will affect the top of the teapot's steam cloud?
Did I say that the orientation of the teapot's spout wouldn't affect the steam cloud? No, I said that you couldn't use the structure at the top of the steam cloud to understand the orientation of the spout. Very different things.

Re: Huge galaxy Centaurus A

Posted: Fri Jul 10, 2009 5:12 pm
by The Code
I will adhere to the rules, chris,,, only things i do not understand interest me... thanks for pointing out how i was breaking the rules....chris

bye.

Re: Huge galaxy Centaurus A

Posted: Fri Jul 10, 2009 11:03 pm
by aristarchusinexile
Chris Peterson wrote:
Loco wrote:How can you NOT think the orientation of the teapot's spot will affect the top of the teapot's steam cloud?
Did I say that the orientation of the teapot's spout wouldn't affect the steam cloud? No, I said that you couldn't use the structure at the top of the steam cloud to understand the orientation of the spout. Very different things.
I don't think that's what you said, Chris, in fact I just reread, and it's not. Sorry.

Re: Huge galaxy Centaurus A

Posted: Sat Jul 11, 2009 1:45 am
by harry
G'day bystander

You said
Astronomers beleive that Cen A is the result of a merger between a spiral and elliptical galaxy (both huge). The dust lanes aroung the middle are the left overs from the spiral (ellipticals don't usually have dust lanes). See: APOD: 2006 March 4 - The Galaxy Within Centaurus A.
You may be right or may be there is a phase in the evolution of galaxy form from spiral to elliptical.