Radio Galaxy Zoo Talk

Possible giant/ host (?)

  • antikodon by antikodon

    ARG0000nwn FIRSTJ105720.4+484259 deg 0.2 possible host SDSS J105709.25+484040.9 photo z ~0.266

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    ARG00011r7 FIRSTJ121600.8+420131 deg 0.2 possible host: SDSS J121609.60+415928.3 photo z~ 0.411

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    ARG0002hlk FIRSTJ132743.3+174937 @WizardHowl supposed SDSS J132743.50+174837.3 deg 0.2

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    ARG00028ra FIRSTJ075705.8+215429 deg 0.2 possible host: -

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    ARG0003ils FIRSTJ002030.5+043822 deg 0.2 possible host: SDSS J002027.90+043700.0 no z

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    ARG0001cd8 FIRSTJ110110.2+363320 possible host : SDSS J110109.45+363429.9 z~0.628
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    ARG0002zhw FIRSTJ112024.3+110239 deg 0.2 @Dolorous Edd supposed SDSS J112021.37+110434.7 z=0.495

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    ARG0002n6u FIRSTJ134140.7+152357 deg 0.2 possible host: -

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    ARG0001xqg FIRSTJ140120.6+262920 deg 0.2 possible host: -

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    ARG00016ar FIRSTJ155430.1+394342 0.2 deg possible host: -

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    ARG00038ql FIRSTJ115127.2+080002 doublelobe or triple deg 0.1 possible host: -

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    Posted

  • antikodon by antikodon

    ARG0000l5e FIRSTJ083702.8+500654 pair overedge doublelobe 0.2deg

    I C:08 36 46.87 +50 06 11.9

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    II C: 08 37 35.88 +50 09 23.3

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    Posted

  • antikodon by antikodon

    ARG0002pwi FIRSTJ230319.8+142105 0.3 deg possible host: -

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    Posted

  • Dolorous_Edd by Dolorous_Edd

    Likely a useless job by now as science team may had looked at all candidates mentioned here

    But I intend to go through all of them, add something useful if possible

    Posted

  • JeanTate by JeanTate in response to Dolorous Edd's comment.

    OT! Reading - again - the Interesting things from NVSS survey thread (which you started), just after reading this thread, I was struck by the fact that so many of the giants reported have candidate hosts at redshifts of at least 0.1 (and many far greater). Suppose, just suppose, the number of giants, per cubic Gpc, is more-or-less constant ... how many giants would we expect to see, in RGZ (or NVSS or VLSSr, or ...), with hosts in the ranges 0<z<0.1, 0.1<z<0.2, 0.2<z<0.3? How many have we found, so far?

    My guess is that giants with hosts with z < ~0.1 are hard, even very hard to find, in RGZ (etc), because they would appear so big, and because there would be so many other sources (to create confusion). There may also be a 'surface density' problem: for a given (source) flux density, giants at higher redshifts may be easier to detect than ones at smaller redshifts (at least in certain key ranges of parameters). True, in a Euclidean (flat) universe, surface density is independant of distance, but radio surveys can be blind to 'diffuse' emission if it's spread over a large enough area (on the sky), even if the surface density is the same.

    And wildly speculating, would we have already detected our own galaxy's doublelobes, if they were ~1 Mpc giants? If they were faded relics? Ditto M31 (Andromeda galaxy)?

    Thoughts?

    Posted

  • ivywong by ivywong scientist, admin

    @DolorousEdd: I strongly disagree with your statement that what you're doing is useless. Some of the science team may eventually look at all the sources but it helps greatly to have verification so that we're not just relying on 1 or 2 pairs of eyes. With many pairs of eyes, we will eventually obtain a sample with greater fidelity. 😃

    @JeanTate: Although much smaller than a Giant Radio Galaxy, we can see the extended radio lobes spanning ~250 kpc from the nearby radio galaxy, Centaurus A (ref: http://www.csiro.au/news/newsletters/SIROSCOPE/2009/July09/htm/space.htm). While it is true that interferometers have a hard time seeing such large diffused structures, typical all sky surveys are done using big single dish telescopes such as Parkes/ Arecibo/ Greenbank which would pick up on the extent of all large diffused structures in the very nearby Universe. Check out this all-sky 1.4 GHz radio continuum image from the Parkes Radio Telescope: http://www.atnf.csiro.au/people/mcalabre/CHIPASS/index.html ... One can clearly see the CenA radio structure popping up above the Galactic plane. Now the increase in giants at higher redshifts is because the volumes that are being probed at higher redshifts are much greater than what is around locally so we will also see many more massive galaxies which are typical hosts of radio galaxies.

    Posted

  • akapinska by akapinska scientist

    I must agree with @ivywong

    As scientists we often would repeat the same analysis a couple of times just done by different people or different method to make sure it's all consistent and we have not make any mistakes - after all we are all humans and very prone to silly mistakes!

    So, nothing what you @DolorousEdd and others are doing here is useless!
    Really, many thanks for helping!!

    😄

    Posted

  • JeanTate by JeanTate in response to ivywong's comment.

    Thanks ivywong! 😃

    That is an awesome image! 😮

    Rather than derail this excellent thread any further, I started a new one, over in the Cafe, If the Milky Way galaxy (SgrA*) were the host of a giant ... Everyone is welcome to join in the discusson ...

    Posted

  • ivywong by ivywong scientist, admin

    You are very welcome, as always 😃

    Posted