Author Topic: Quasi-Stellar radio sources. Find a Quasar? Post it here!  (Read 300511 times)

mitch.wheat

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Re: Quasi-Stellar radio sources. Find a Quasar? Post it here!
« Reply #30 on: August 15, 2007, 02:35:20 pm »
I'm claiming the current record!  z=2.665 !!

http://www.galaxyzooforum.org/index.php?topic=4207.0

doomrevival

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Re: Quasi-Stellar radio sources. Find a Quasar? Post it here!
« Reply #31 on: August 15, 2007, 02:36:35 pm »
yep, that's impressive. well deserved record at that... one that may not be beat for a long long time.
The question is not how far.  The question is... do you possess the constitution, the depth of faith, to go as far is as needed...

It has to start someplace, it has to start sometime.  What better place than here, what better time than now?

serpens

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mitch.wheat

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Re: Quasi-Stellar radio sources. Find a Quasar? Post it here!
« Reply #33 on: August 15, 2007, 02:48:45 pm »
yeah!  But zconf in that one is around .7 ....!!

doomrevival

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Re: Quasi-Stellar radio sources. Find a Quasar? Post it here!
« Reply #34 on: August 15, 2007, 02:49:58 pm »
so the question is... do we believe that's the record?  maybe we should put an *asterisk* around it, in case it's tainted by a low zconf
The question is not how far.  The question is... do you possess the constitution, the depth of faith, to go as far is as needed...

It has to start someplace, it has to start sometime.  What better place than here, what better time than now?

lboynton

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Re: Quasi-Stellar radio sources. Find a Quasar? Post it here!
« Reply #35 on: August 15, 2007, 03:30:22 pm »
Based do what I've read here, then this beastie would probably be a starburst as well?  (And thanks for the link to that article, Serpens). 

z = .306, zconf = .966 (remind me what this is again?), spectral spikes in Oxygen rather than Hydrogen.  What do you think?

http://cas.sdss.org/astro/en/tools/explore/obj.asp?id=587731680652296564


doomrevival

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Re: Quasi-Stellar radio sources. Find a Quasar? Post it here!
« Reply #36 on: August 15, 2007, 03:36:58 pm »
zconf is the confidence level that the computer has in the z number. i haven't read up much on the emission spectra, so i'm no help there yet... sorry
The question is not how far.  The question is... do you possess the constitution, the depth of faith, to go as far is as needed...

It has to start someplace, it has to start sometime.  What better place than here, what better time than now?

lboynton

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Re: Quasi-Stellar radio sources. Find a Quasar? Post it here!
« Reply #37 on: August 15, 2007, 03:55:25 pm »
zconf is the confidence level that the computer has in the z number. i haven't read up much on the emission spectra, so i'm no help there yet... sorry

Thanks for that! 

The article I mentioned, well, I've lost the link - I think it was posted in another thread.  BUT all is not lost as I printed out a copy.  The URL on the bottom of the pages is http://astrostatistics.psu.edu/datasets/galspec.html
It's not a long article, but gives some spectra examples for critters with healthy z numbers that aren't quasars (the term them "starburst galaxies).  I'm still struggling with the article, but the spectra charts are neat!   :D

doomrevival

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Re: Quasi-Stellar radio sources. Find a Quasar? Post it here!
« Reply #38 on: August 15, 2007, 04:02:13 pm »
great! we all appreciate it.
The question is not how far.  The question is... do you possess the constitution, the depth of faith, to go as far is as needed...

It has to start someplace, it has to start sometime.  What better place than here, what better time than now?

serpens

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Re: Quasi-Stellar radio sources. Find a Quasar? Post it here!
« Reply #39 on: August 15, 2007, 05:21:13 pm »
Based do what I've read here, then this beastie would probably be a starburst as well?  (And thanks for the link to that article, Serpens). 

z = .306, zconf = .966 (remind me what this is again?), spectral spikes in Oxygen rather than Hydrogen.  What do you think?

http://cas.sdss.org/astro/en/tools/explore/obj.asp?id=587731680652296564


That's not easy to say. It does resemble a quasar's spectrum (as here: http://www.sdss.org/gallery/gal_zqso.html). It is classified on NED as a candidate type II AGN (Active Galactic Nucleus), which, as I understand, are quasars. So, it's probably a quasar.

lboynton

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Re: Quasi-Stellar radio sources. Find a Quasar? Post it here!
« Reply #40 on: August 15, 2007, 05:49:18 pm »
That's not easy to say. It does resemble a quasar's spectrum (as here: http://www.sdss.org/gallery/gal_zqso.html). It is classified on NED as a candidate type II AGN (Active Galactic Nucleus), which, as I understand, are quasars. So, it's probably a quasar.

Hmm.  Well, as the Astrostat article mentions, "SBG's (starburst galaxies) and weaker AGN's can be eaily confused."  I find this fascinating, though.  How do I go about looking up an object's classification on NED?  I certainly wouldn't use the info in classifying for The Zoo, just to satisfy my own (now raging out-of-control) curiosity.   ;D

doomrevival

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Re: Quasi-Stellar radio sources. Find a Quasar? Post it here!
« Reply #41 on: August 15, 2007, 05:51:54 pm »
interestingly enough, there is good research being done out there which couples AGN's with starbursts in the same galaxy!  you wouldn't think that two opposite effects, creation and destruction could be so inherently linked...
The question is not how far.  The question is... do you possess the constitution, the depth of faith, to go as far is as needed...

It has to start someplace, it has to start sometime.  What better place than here, what better time than now?

serpens

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Re: Quasi-Stellar radio sources. Find a Quasar? Post it here!
« Reply #42 on: August 15, 2007, 05:54:44 pm »
That's not easy to say. It does resemble a quasar's spectrum (as here: http://www.sdss.org/gallery/gal_zqso.html). It is classified on NED as a candidate type II AGN (Active Galactic Nucleus), which, as I understand, are quasars. So, it's probably a quasar.

Hmm.  Well, as the Astrostat article mentions, "SBG's (starburst galaxies) and weaker AGN's can be eaily confused."  I find this fascinating, though.  How do I go about looking up an object's classification on NED?  I certainly wouldn't use the info in classifying for The Zoo, just to satisfy my own (now raging out-of-control) curiosity.   ;D
Click the NED search and scroll down to Basic data, you'll find the classification there. It there's just blank space, you can check the notes, references or catalog data from external archives at the bottom.

speedymarie

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doomrevival

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Re: Quasi-Stellar radio sources. Find a Quasar? Post it here!
« Reply #44 on: August 15, 2007, 05:56:22 pm »
and it has a very high zconf. amazing
The question is not how far.  The question is... do you possess the constitution, the depth of faith, to go as far is as needed...

It has to start someplace, it has to start sometime.  What better place than here, what better time than now?