Finding the Giants (NVSS)
by DocR scientist
A handful of very exciting sources are so large that they don't fit into one of our RGZ images. What you will see in RGZ is a tiny piece of the source, and will have trouble making sense of it. Here are three examples of such sources that have already been found (which means there might be a LOT more than we expected). Below, I give three links to images to see what these sources look like (and two of the discussion links) . The box, in each case, show what is visible in RGZ, so you can see that it would be impossible to figure out what is going on.
http://umn.edu/~larry/ARG0002gt4.jpg (NVSS on left, FIRST in middle, WISE on right)
For super-zooers, if you want to investigate these yourself,
a) find the coordinates of the source on the object discussion page, below the image (e.g., RA 123.45 DEC 67.8 )
b) go to http://skyview.gsfc.nasa.gov/cgi-bin/query.pl
c) in the box near the top, Coordinates, type in the RA and Dec, from above, e.g., 123.45 67.8
d) in the selection boxes below, select whatever surveys you want, e.g., FIRST (which will give you a bigger version than in RGZ) and then, separately, NVSS (a lower resolution radio survey). NVSS will give you a much larger field.
e) on the page with the Skyview images, you can download jpegs, or FITS images if you know how to use them.
Come back to this discussion with questions. If you find new giants, label them as #giant . At some point, we may be able to create an upload facility for you to post images that you find outside of the Zoo. Happy Giant Hunting!
For these, why not create 'zoomed out' sets of images (radio, IR, contours), and add them back to the 'to be classified' database (or maybe as part of a RGZ2)? You could also treat any over-edge candidates the same way ...
by DocR scientist
You're right, we need some way to handle these. But there are so many compact sources for which the zoomed out would be unnecessary duplication, that we need to think this through strategically. Thanks for the suggestion.
There are two ways that occur to me of finding large and overedge sources (especially triples) that might be missed by the current RGZ approach (which is dependent upon people going outside RGZ as described above to get images themselves). An automated approach might use an algorithm something like this:
- catalog all radio sources with no IR counterpart
- for each radio source from 1) , find all other sources from 1) within the limit of how big you expect your objects to be (the wider the separation the larger the sources you can find but the more false positives from chance alignment you will find).
- For each pair of sources from 2), check for a source in between them, with a tolerance based on the FWHM of the larger source.
This will miss bent triples and triples with a lobe coincident with an IR source but will give a (hopefully) small enough number of objects for individual examination. False positives it will pick up would include chance alignments of doublelobes with other sources and chances alignments of multiple ifrs sources.
A non-automated approach would be to use larger images in RGZ but with the ability to zoom in, like the dashboard in the Zooniverse project Space Warps. This would allow users to pick up the larger sources more easily. There would still be overedge cases, however, and as the surface area of the edges of the images would be greater, there would probably be even more. Perhaps add an 'overedge' button, if the user suspects the origin of the radio source to be outside the field of view?
To work well, the project should not make things too complicated for the user - or the project scientists. Ultimately, we may have to accept that many things can only be found in numbers from a thorough analysis of the RGZ results and not all flagged up by users at the time they process the images. The Discuss feature enables us to bring the attention of some interesting and unusual objects to the project scientists' attention but if there are hundreds of large sources and each one, along with the false positives, gets a thread associated with it then it will be very time consuming to manage this discussion.
Hope this was helpful!
by DocR scientist
Thanks for all the thoughts. Since we're finding more of these than expected, (and the issue is important scientfically, something combining automated and not- , along the lines you suggest, may be the most useful. I'd like to see what @HAndernach says, since he has had students looking for these objects. I tried this also with an undergraduate, but our scheme was so cumbersome that it really couldn't be extended to the whole catalog. However, we did find that you can also use the flux (brightness) comparison between the two spots to help discriminate between random pairs and true large doubles. Thanks again.
List of possible candidates ( not complete ), some of them recognized as possible giants by science team
ARG0003lgd - FIRSTJ115317.4+033643 - commented by DocR ( ~940kpc )
ARG0002qt6 - FIRSTJ091948.3+135943 - discussed by mini.mintaka, but nothing about size or source
ARG0002vl7 - FIRSTJ114707.2+121243 - J114702.12+121230.7 - 1237661949714170457 overedge triple, not a spectacular size, but faint possible source can make up for this
ARG0000ao4 - FIRSTJ141610.6+555927 - looks like overedge triple
ARG000224u - FIRSTJ072056.0+243638 - maybe
ARG0001vl6 - FIRSTJ131057.9+272822 - overedge triple
ARG0002esd - FIRSTJ121234.2+190603 - J121239.93+190554.1- looks interesting
ARG0002m9p - FIRSTJ124501.4+154633 - Could be a large triple, commented by DocR
ARG0000fa1 - FIRSTJ123528.8+531500 - could be a large triple, although separation is enormous, commented by DocR
ARG0002oi0 - FIRSTJ143039.0+145201 - identified as a giant by HAndernach
ARG0002paf - FIRSTJ225625.0+143457 - SDSS J225621.97+143351.3 - 1237656496180691580 looks like a large triple, size to be determined
ARG00014ui - FIRSTJ115542.8+402731 - looks like a large triple, size to be determined
ARG0003gn4 - FIRSTJ231250.4+051646 - discussed by science team, no size
ARG0000zsf - FIRSTJ074441.7+425830 -J074447.34+425839.3 - 1237651274029203803 projected size 960 kpc , source HAndernach
ARG0003lhy - FIRSTJ082317.2+033542 - J082312.91+033301.3 Possible giant wat commented by DocR
ARG0001fgm - FIRSTJ132727.5+350637 - Debateble case , maybe large triple, maybe not, commented by DocR
ARG0001z1c - FIRSTJ124601.9+255354 - identified as possible giant by HAndernach
ARG00025me - FIRSTJ082031.3+231149 - Nice strong triple, commented by HAndernach ( 750kpc )
ARG0002q9v - FIRSTJ084639.0+141251 - overedge triple
ARG0002a70 - FIRSTJ131231.3+211543 - Strong jet
ARG00006do - FIRSTJ142613.0+585359 - Likely narrow angle tail ( 1.3 Mpc ) - commented by DocR
ARG0002bny - FIRSTJ113215.5+203532 - J113220.53+203551 commented by HAndernach ( 780 kpc )
by DocR scientist
Wow! Great list, thanks!
I would add to the list
ARG00005o3 FIRSTJ075319.7+592658 VII Zw 188 - 520 kpc commented by HAndernach
ARG0002yl2 FIRSTJ113337.2+111828 triple
ARG0002esd FIRSTJ121234.2+190603 looks interesting 850 kpc commented by HAndernach
Is already on the list
ARG0002uxz - FIRSTJ002927.1+122326 - Double, commented by HAndernach - 700 kpc
ARG0002xex - FIRSTJ004213.0+113945 - Commented by HAndernach - 750 kpc
ARG00011ga - FIRSTJ125801.8+421033 - looks diffused on the FIRST image, looks clear on the NVSS image
ARG0002rft - FIRSTJ110236.4+134433 - J110252.76+134516.2 - 1237664131020095850 Probaly false positive, but I will mention it anyway
by DocR scientist
Fantastic, thanks! And - everyone - don't worry if you can't find the optical ID. We're going to have to examine each of these carefully by hand. If there's a radio core (making it a triple) the job is usually pretty straightfoward. However, if there's no radio core, then there will be lots of possible IR/optical candidates and it may not be possible to pick the right one. In this case, new deep radio observations may be needed to find the cores.
ARG0001qq0 - FIRSTJ094321.6+294526 - Nice strong overedge triple
ARG00026vf - FIRSTJ145352.0+224258 - J145346.62+224314.1 - 1237665549966901536 Overedge triple
ARG0002ysl - FIRSTJ000310.0+111503
ARG0002k91 - FIRSTJ110155.7+164015
ARG00032am - FIRSTJ101618.6+101209
ARG0001cic - FIRSTJ092539.3+362845 - commented by HAndernach ( 4C+36.14 rediscovery )
ARG0002qvz - FIRSTJ091951.1+135742 - commented by HAndernach ( 720 kpc )
ARG0002zpl FIRSTJ082014.8+105912 quadruple or so it seem
I've been going through my favourites looking for candidates not included above (although some produced comments) and have a list to add. For six of these candidates (overedge cases excluded) the IR source is absent or ambiguous, which is partly because I have tended to flag a lot of sources without an IR counterpart as favourites. As these might be more distant, I have included them even though their lobe separations are not quite as wide as those already flagged as large/giant in discussions.
ARG0003avn FIRSTJ152221.2+071454 ifrs doublelobe
ARG0002gt4 FIRSTJ103649.9+181045 overedge doublelobe (featured discussion, 1Mpc+)
ARG0001g8b FIRSTJ113506.3+344444 possible overedge doublelobe
ARG0002twn FIRSTJ230657.6+124327 overedge doublelobe, hint of radio core
ARG0000esw FIRSTJ111010.9+533155 overedge triple (780kpc estimated by DocR)
ARG0002zqq FIRSTJ003024.6+105846 overedge triple
ARG0000pa2 FIRSTJ082317.3+480239 overedge triple
ARG0002xd1 FIRSTJ152250.2+114036 very strong doublelobe
ARG0002tt1 FIRSTJ120118.5+124526 irregular doublelobe
ARG0002xmv FIRSTJ020026.8+113543 triple with wide lobes
ARG000286a FIRSTJ100105.9+221058 ifrs doublelobe
ARG0002owd FIRSTJ214541.6+144337 strong hourglass with possible relics
ARG0000wba FIRSTJ085742.3+443511 ifrs doublelobe, faint hint of radio core
ARG0002ph6 FIRSTJ124529.6+142954 triple with very strong lobes but faint core
ARG00015rj FIRSTJ113623.6+395902 doublelobe (middle and upper-left), IR source ambiguous or absent
ARG00025fm FIRSTJ153011.6+231618 triple with wide lobes
ARG00000j5 FIRSTJ092809.5+635419 ifrs doublelobe
ARG00029kj FIRSTJ085353.5+213234 ifrs triple
ARG0002crp FIRSTJ133316.2+200312 ifrs doublelobe
ARG0002y10 FIRSTJ161949.3+112819 doublelobe, ambiguous IR source
ARG0002zh2 FIRSTJ131742.7+110306 doublelobe, one lobe connected to the radio core, IR source very faint
ARG0002oi0 FIRSTJ143039.0+145201 commented by HAndernach - 1.45 Mpc
ARG0000nex FIRSTJ070139.2+485730 commented by DocR - Giant (close to 5 Million light years long)
@antikodon FIRSTJ143039.0+145201 is already on the list on the first page , FIRSTJ070139.2+485730 ( DocR example, without link so OK )
To all: do seacrh by object number or by FIRST survey id ... we are putting them to reduce duplicates
ARG00000q5 - FIRSTJ122021.2+634309
ARG0003h2t - FIRSTJ091401.7+050750 - J091401.76+050750.6 - 1237658423544447024 - !!!!!!Known radio galaxy!!!
ARG0000swg - FIRSTJ104856.1+461314 - overedge triple
ARG0001vqk - FIRSTJ123430.5+272425
ARG0000vj9 - FIRSTJ145219.6+445632 - J145223.31+445535.7 - 1237662498925970181
ARG0001xxo - FIRSTJ085852.9+262336 - J085850.22+262321.3 - 1237664879409823991
ARG0002y0f - FIRSTJ092052.8+112828 - Maybe a false positive, but source on the left looks like a triple on the NVSS image
ARG0002zt6 - FIRSTJ003035.4+105757 - J003030.56+105814.7 - 1237678907859533984 identified as large radio galaxy by enno.middelberg
ARG00039fd - FIRSTJ090028.6+074610 - J090018.16+074535.5 - 1237660669809197335 Weird object, maybe giant: commented by enno.middelberg
ARG0002pgk - FIRSTJ165657.7+143023 - J165655.59+142928.3 - 1237665232137486800 Likely faint overedge double
ARG000146r - FIRSTJ101601.8+404701 - J101558.24+404647.2 - 1237661872930422948 large overedge triple
ARG0002r0m - FIRSTJ133112.1+135417 - Large triple
ARG00019s4 - FIRSTJ134234.6+375533 - J134254.51+375818.8 - 1237664294760611939
ARG0002krj - FIRSTJ145608.5+162643 - J145605.67+162654.8 - 1237668272981278921
ARG0002pdg - FIRSTJ225619.1+143255 - J225621.97+143351.3 - 1237656496180691580 commented by akapinska
ARG0001l71 - FIRSTJ102832.9+322259 - J102832.31+322153.2 - 1237665129070658210 commented by akapinska
adding another bright large angle source, sorry no FIRST ID (I do not see the numbers all the time):
ARG0002wlz - suspect another lobe overedge, some strong radio emission in opposing directions from the core
EDIT ADDITIONAL: My other good candidates from today (sorry no FIRST ID):
ARG0002zg0 very strong central emission with two connected lobes there are possible relics further afield
ARG0002x8i overedge triple, part of second lobe visible, core faint but generates a contour
ARG0001qhl core and large detailed lobe visible with large IR source, suspect another lobe overedge
ARG0001aki - FIRSTJ160416.7+373222 - J160420.10+373116.9 - 1237662303518262466 - Known giant
ARG0002yfu - FIRSTJ231717.0+112059 - J231712.70+112012.0 - 1237678918589415640
ARG0003g40 - FIRSTJ231903.4+052649 - I think, there is a second ( weak ) lobe can be seen on the NVSS image
ARG0002x8f - FIRSTJ154707.5+114249 - J154710.20+114329.0 - 1237668270839562953
ARG0003o9v - FIRSTJ211326.5+023135 - J211326.67+023123.3 - 1237678598072238389 - large NAT?
ARG0003o5g - FIRSTJ023835.7+023426 - J023832.67+023349.1 - 1237678619582660656
ARG000058q - FIRSTJ090845.5+594708 - J090839.13+594512.8 - 1237651274038444136
ARG0002xtd - FIRSTJ082335.7+113207 -
ARG0000si0 - FIRSTJ135250.7+462426 - J135253.12+462520.7 - 1237661149771727507
ARG0003027 - FIRSTJ085536.8+105317 - J085540.90+105332.3 - 1237671123760120481
ARG0002rg2 - FIRSTJ122519.3+134425 - J122521.68+134333.7 - 1237661951328911981
ARG0002zlb - FIRSTJ213044.4+110058 - J213043.78+110312.5 - 1237652943159297381
To all: For the sake of reducing duplicates, I propose the following format: Object id - First survey Id - Id of suspected host ( if possible )
by akapinska scientist
ARG0002585 - FIRSTJ075448.2+232132 (giant if host @ z>0.1)
ARG0002xjz - FIRST020025.49+113707.6
ARG0002qrf - FIRSTJ144429.32+140047.5
Three more candidates. Apologies for the lack of FIRST IDs. I've noticed that the RGZ IDs are based on peaks in radio intensity so that multiple RGZ IDs can refer to the same source (e.g. ARG0002xtk is centred on a different part of the same radio lobe as ARG0002xtd and the same for ARG0002x8f and ARG0002x8i). This makes it important to check similar RGZ IDs already given if, like me, you do not always see the FIRST IDs when clicking Discuss.
ARG0002xzn - triple with faint radio core, IR source absent or barely a smudge on the background. The plumes might be angled close to our line of sight, or asymmetric
ARG0002owz - overedge doublelobe possibly with some relic emission present
ARG000221u - overedge triple
ARG0002oqi double-lobe , very large. i'm retty sure that the other lobe has already been tagged
by DocR scientist
@firejuggler - help me out here - i can't figure out why you're calling this double-lobe. It has two tails, which fade off into emission in the upper left which is visible in NVSS but not in FIRST. So it's a #headtail or a #wat seen kind of sideways. Are you referring to the two tails when you say double-lobe, or did you spot something else we should look at more closely? thanks!
Sorry, my mistake. shouldn't have called it doublelobe .I did call it doublelobe because well there isn't one third in the middle.
I didn't tag it doublelobe in the object part.
I'm a noob, and will always be a noob on this.
by DocR scientist
Worry not,@firejuggler, I'll gladly pay the price of a few dead ends for all the fantastic things you guys are finding. There is great scurrying about in the science team now because there are so many new science issues coming up that we hadn't anticipated, which is great!
long jet, maybe long enough to qualify FIRST show two lobe
ARG0000eu0 - FIRSTJ111009.9+533015 - J111011.01+533058.7 - commented by HAndernach ( 700 kpc )
ARG0001drn - FIRSTJ103044.4+355335 - J103044.03+355451.1 - 1237662224057958821
ARG00030uz - FIRSTJ121812.6+103842 - J121810.51+103956.0 - triple
ARG0001064 - FIRSTJ112353.8+424822 -J112351.34+424953.6 - 1237662196132675968
ARG00028gz - FIRSTJ170912.5+220157 - maybe a faint triple
ARG0001w2s - FIRSTJ095413.6+271416 - J095419.19+271559.9 - 1237667112799306517
ARG0002kdj - FIRSTJ110201.3+163656 - J110151.89+164038.6 - well-studied X-shaped source in Abell 1145, 400 kpc in size commented by HAndernach
ARG0002xat - FIRSTJ093014.7+114143 - none - possible giant commented by HAndernach
ARG0002p3w - FIRSTJ225507.8+143848 - J225513.21+143911.4 - 1237656496180560229 commented by HAndernach 570 kpc, unusual lobe morphology
ARG0002zfr - FIRSTJ095421.0+110336 - J095420.99+110336.7 - 1237661068173902733
ARG0000684 - FIRSTJ141622.1+590116 - J141621.74+590032.3 - commented by HAndernach 760kpc
ARG00032el - FIRSTJ140813.8+101013 - J140813.84+101013.3 - 1237662239088705915
ARG0002g0o - FIRSTJ131516.3+183110 - J131511.26+183116.3 - 1237668270823244258
ARG0001rcw - FIRSTJ135519.7+292543 - J135517.61+292333.9
ARG00021lp - FIRSTJ105827.2+244931 - J105838.66+244535.1 - commented by DocR and HAndernach ( 1.8 Mpc )
ARG0000pfu - FIRSTJ120459.3+475813 - commented by DocR ( FR I possible 1.8 Mpc )
ARG0002wze - FIRSTJ002617.4+114711 - J002613.63+114343.6 - 1237678918596821032 - Known? large? triple
ARG0002p8v - FIRSTJ222234.7+143541- J222251.40+144113.5 - 1237680091111817292 - Commented by DocR 1 - 1.3 Mpc
ARG0002qu0 - FIRSTJ083816.3+135859 - J083813.13+135810.6 - Commented by HAndernach 1.2 Mpc
ARG0001cco - FIRSTJ165508.7+363343 - J165508.77+363333.3 - commented by DocR and HHAndernach possible WAT remnant 3-5 Mpc
ARG0001goh - FIRSTJ164748.6+343153 - J164749.15+343253.0 - Commented by HAndernach ~700kpc, redshift = ~2.9 mind you
ARG0002z38 - FIRSTJ120139.8+111000 -J120144.97+110847.9 - commented by HAndernach 1.33 Mpc
ARG000001z - FIRSTJ133410.7+642821 - J133402.69+642939.9 - commented by HAndernach 1.13 Mpc
ARG0000jrp - FIRSTJ105154.2+505150
ARG0001fgd - FIRSTJ132743.9+350643
ARG0003gn8 FIRSTJ093524.8+051642 ~09 35 26.82+05 17 30.0 commented by HAndernach 1.04 Mpc
ARG000007d FIRSTJ072910.4+641325 - 072904.21+641452.2 commented by HAndernach ~1.7 Mpc
ARG0001wdx FIRSTJ141510.1+270624 -14 15 22.41+27 03 18.2 commented by HAndernach 5.7 Mpc
ARG0001nqh FIRSTJ101122.0+311008 ~10 11 12.11+31 11 04.5 commented by HAndernach 1.6 Mpc
ARG0001vek FIRSTJ112912.8+273323 -11291213+2733136 commented by HAndernach over 2 Mpc
ARG0003joh FIRSTJ103224.0+041442 -J103226.34+041429.1 commented by HAndernach 1.07 Mpc
ARG00036sp FIRSTJ120608.3+084016 - 120610.88+083850.6 commented by HAndernach 1.27 Mpc
ARG0002yja FIRSTJ113334.8+111920 -113337.30+111828.0 commented by HAndernach 1.0-1.6 Mpc, asym radio morphology
ARG000202k FIRSTJ162346.1+252431 -16 23 42.45+25 21 46.6 commented by HAndernach 1.44 Mpc
ARG0000zk3 FIRSTJ125637.7+430404 - 12 56 37.74+43 02 28.9 commented by HAndernach 1.18 Mpc
ARG0001ugl FIRSTJ160911.9+275720-SDSS J160909.90+275824.0 commented by HAndernach 1.1 Mpc
ARG0003mqm FIRSTJ205155.6+030738-SDSS J205152.64+030921.0 commented by HAndernach 1.2 Mpc; restarted
ARG0003p6t FIRSTJ015741.4+021011-SDSS J015752.52+020954.0 commented by HAndernach 1.36 Mpc; Xshaped
ARG0001n8o FIRSTJ113826.3+312411-SDSS J113831.01+312327.6 commented by HAndernach 1.05 Mpc
ARG0001nh8 FIRSTJ153431.0+311725 ~15 34 31.92+31 18 36.8 ph_z .716 commented by HAndernach 940 kpc
ARG0001ca8 FIRSTJ072755.9+363540 - 07 28 04.62+36 37 03.1 commented by HAndernach could be called a WAT 770 kpc
ARG0002czs FIRSTJ095641.8+195708 - 2MASX J09563507+1959540 commented by HAndernach 1.0 Mpc
ARG0002cxp FIRSTJ104252.9+195856 - 104251.51+195724.5
ARG0001rng FIRSTJ135121.2+291752 - 135121.24+291752.4
ARG0001grq FIRSTJ075347.3+342929 ~07 53 41.32+34 30 32.0 sp_Z =~.560/~4,5'
ARG000301l FIRSTJ085545.5+105347 ~08 55 40.90+10 53 32.3
ARG0001sx5 FIRSTJ120750.3+284047 ~ 12 07 48.49+28 39 58.7
ARG000128s FIRSTJ092910.4+414646 ~ 09 29 10.38+41 46 44.5
ARG0002bn9 FIRSTJ145637.0+203607 -14 56 40.06+20 34 33.6
ARG00013w4 FIRSTJ085231.2+405520 ~08 52 30.67 +40 56 49.0
ARG0003345 - FIRSTJ161534.5+095709 - J161534.52+095709.9 - commented by HAndernach 790kpc
ARG0002nuw - FIRSTJ103339.2+150821 - J103348.22+150815.3 - commented by HAndernach 1.8Mpc
ARG00039p1 - FIRSTJ105453.8+074004 - J105452.42+074006.7 - commented by HAndernach possible 750 kpc
ARG0002pgv - FIRSTJ165657.6+143011 - J165655.59+142928.3r - 1237665232137486800 commented by HAndernach 1Mpc
ARG00003ge - FIRSTJ142446.3+611416 - J142451.84+611307.3 - commented by HAndernach 1.4Mpc
ARG00025ot - FIRSTJ082025.4+231017 - J082028.42+231108.8 - commented by HAndernach 820kpc
ARG0003l5y - FIRSTJ211544.4+034229 - PKS 2113+035 - commented by HAndernach 720kpc
ARG00031v6 - FIRSTJ222818.9+102011 - J222816.53+102008.5 - commented by HAndernach 1.12 Mpc
ARG0002q90 - FIRSTJ084633.8+141320 - J084636.15+141307.6 - commented by HAndernach 900kpc here http://radiotalk.galaxyzoo.org/#/subjects/ARG0002qa6
ARG00025lu - FIRSTJ090429.3+231220
This one has to be here:
ARG0003k9d - FIRSTJ000340.2+040116 - J000331.50+035111.0
ARG0003o6c looks like 2 doubles (FRIIs), the southern one almost N-S and the northern one E-W? Looking for IDs for the S pair: SDSS J112506.74+023229.0 seems a spiral and off
radio axis; close pair SDSS J112506.31+023250.6/SDSS J112506.12+023249.8, but they have strange colors+shapes and no z_phot; for the northern one, looking at the FIRST
image, I'm not sure I would relate them...
ARG0001182 - FIRSTJ170259.9+421754 - J170256.86+421731.7
ARG0000g6g - FIRSTJ111543.8+524559 - J111537.44+524642.6?
ARG0000j6g - FIRSTJ095609.4+510954 - J095610.30+510959.8
http://radiotalk.galaxyzoo.org/#/subjects/ARG0000j6g - commented by HAndernach, maybe 2,6Mpc
ARG00017f7 - FIRSTJ162808.0+390718 -
ARG0001c76 - FIRSTJ125621.4+363834
ARG0000xai - FIRSTJ123857.3+440830 - B3 1236+444B - commented by HAndernach, 1Mpc
ARG0003gy6 - FIRSTJ011435.6+051026 - PMN J0114+0508 - commented by HAndernach, 1Mpc
ARG0003cyv - FIRSTJ113054.3+062805 - J113051.73+062953.3 - commented by HAndernach, 1.3Mpc
ARG0003nl3 - FIRSTJ120022.3+024751 - J120024.13+024630.1 - 1237651736830739004
ARG0001w15 - FIRSTJ095419.2+271600 - SDSS J095419.19+271559.9 - 1237667112799306517
IGR J17488–2338: a newly discovered giant radio galaxy arXiv:1403.1400v1 [astro-ph.HE] 6 Mar 2014, M. Molina, L. Bassani et al.
NVSS J174839-233517 ,
IGR J17488–2338,~ra,dec 17 48 38.9 -23 35 26.8, has a projected linear extent of 1.4Mpc,
cited GRG: 4C74.26 1237663228536619092 ra,dec 310.65543, 75.13401 or 20:42:37.30, +75:08:02.43, size 1.9Mpc
SDSS J134415.75+331719.1 1237665128551612579 z_spec=0.686
ARG0003fo2 - FIRSTJ135608.6+053434 - maybe J135613.49+053422.1 - 1237655126630532138
ARG00011r7 - FIRSTJ121600.8+420131 - maybe J121609.60+415928.3
ARG0002hlk - FIRSTJ132743.3+174937 - maybe J132743.50+174837.3
ARG00028ra - FIRSTJ075705.8+215429 - maybe J075710.61+215319.7
ARG0000usd - FIRSTJ145328.1+451802 - J145328.17+451801.1
ARG0002156- FIRSTJ155637.9+250025 - SDSS
ARG00009ec z_ph 2.165 QSO host SDSS J105848.67+564800.7 Asymmetric triple radio source. lobe-lobe distance ~1.5' -> ~760 kpc (per Ned Wright, 71/27/73 cosmology). FIRST image centered on NE lobe:
ARG0000da3 z_sp 0.351 SDSS J103556.67+542612.5 possibly messy merger/spiral host. Triple ~symmetric radio source, lobe-lobe distance ~3.5' (on FIRST image) -> ~1 Mpc (per Ned Wright, 71/27/73 cosmology). FIRST image centered on NE lobe:
Lobe-lobe distance ~2.8' (per FIRST image). If host is z_sp 0.418 SDSS J101620.19+101258.2 (I agree with WizardHowl on this), then it's ~920 kpc (per Ned Wright, 71/27/73 cosmology). Spectrum has strong [OII] and [OIII] emission; SDSS image suggests possible major merger, and maybe at least one disk galaxy:
No SDSS spectrum; z_ph given as 0.555 ± 0.1963 and 0.324 ± 0.2156. I measure the lobe-lobe distance as ~2' (per RGZ image); this is ~550 kpc (z=0.32) to ~780 kpc (z=0.56), per Ned Wright (71/27/73 cosmology).
by raynorris scientist
Sorry I've been out of this conversation for quite a while. Can someone fill me in on what's happening? How many of these #giant galaxies do we have now? Are there plans to write a paper about them?
(...) How many of these #giant galaxies do we have now? (...)
Below there is the collection of all the images, which have #giant as comment.
I created a tag group.: A collection of a selected hashtag is created and it is updated automatically.:
Currently the collection contains 122 images, but some images show the same source as mentioned in below discussion.:
Sources, source catalogs, overlapping 'classify' fields, etc.:
Could possibly be a triple
ARG00036mo - FIRSTJ121122.1+084357 - J121116.42+084435.3
ARG00018d9 - FIRSTJ121623.4+383822 - J121628.56+383834.9?
ARG0001ak8 - FIRSTJ160416.3+373237 -
ARG0000zoo - FIRSTJ125637.2+430046 - J125637.74+430228.9
ARG0000wiv - FIRSTJ134249.5+442957 - J134310.77+442829.6
Likely a double to the east
ARG0001nln - FIRSTJ100657.4+311339 - J100656.01+311442.3
ARG00020tq - FIRSTJ125541.5+250745 - J125541.50+250744.6
ARG00023yl - FIRSTJ132330.5+235129 - maybe, maybe not
ARG0001inx - FIRSTJ152453.8+333359 - J152457.34+333500.9
ARG00009ht - FIRSTJ090949.0+564446 - J090944.30+564613.0 - 1237651252562297200
ARG0003abf - FIRSTJ154811.9+072650 - J154817.75+072554.8 - 1237662198824567218
ARG0003qsk - FIRSTJ003511.9+013454 - J003510.58+013345.1 - 1237678595946840569
ARG00013ee - FIRSTJ070958.7+410953 - USNO B1.0 1311-0181305
ARG0003m6b - FIRSTJ005913.1+032024 - J005908.24+032015.0
ARG0002tf7 - FIRSTJ134711.4+125302 - J134715.36+125200.3
ARG0000kaq - FIRSTJ125135.9+503400 - J125142.03+503424.6
ARG0003k85 - FIRSTJ220947.8+040159 - J220948.12+040310.9
ARG0002g15 - FIRSTJ091004.1+183046 - J090957.08+183202.6 or J090958.14+183120.5
ARG0002ans - FIRSTJ102936.0+210310 - J102934.00+210345.7 - 1237667783897251981
ARG0000seh - FIRSTJ135258.7+462728 - J135253.12+462520.7 -
A bit of crossover with Galaxy Zoo
Edit Ned gives redshift of 0.161551 for this source .. so around 600 - 700 kpc, I think*
Also visible in VLSSr
z_ph 0.338±0.1249/0.362±0.0991 - but z_sp 0.162, per NED - SDSS J015006.21-164033.2:
With VLSSr contours overlaid:
And NVSS ones too:
Doublelobes associated with a NOT boring elliptical! 😃
Boilerplate: SDSS image per
http://skyservice.pha.jhu.edu/DR10/ImgCutout/getjpeg.aspx, VLSSr (yellow) and NVSS (cyan) contours derived from FITS files produced using SkyView with Python code described in this RGZ Talk thread. Image center (J2000.0) is the galaxy SDSS J015006.21-164033.2; "z_sp" its NED spectroscopic redshift.
ARG0001udg - FIRSTJ160907.8+275937 - J160909.90+275824.0
ARG0000yh8 - FIRSTJ160957.3+433458 - J160953.42+433411.4
ARG0002ans - FIRSTJ102936.0+210310 - J102934.00+210345.7
ARG0002dlq - FIRSTJ163754.4+194003 - J163758.27+193638.6 - 1237662662684902160
ARG0002cxt - FIRSTJ104252.4+195853 - J104251.51+195724.5 - 1237667781751079392
ARG0002vmo - FIRSTJ000038.2+121211 - J000043.82+121608.3 - 1237678859008540876
ARG00024sn - FIRSTJ094420.8+233141 - J094418.84+233119.8 - 1237667210514006071
ARG0000nwn - FIRSTJ105720.4+484259 - for now J105709.25+484040.9 - 1237658613590196405
ARG0002fz0 - FIRSTJ134524.9+183223 - J134521.48+183406.7 - 1237668271900066669
ARG0001xcb - FIRSTJ164424.4+264006 - J164429.24+264019.3 - 1237662504836400134
ARG00024od - FIRSTJ072709.4+233429 - J072714.47+233555.2 - 1237657402406077710
ARG0000f61 - FIRSTJ151843.9+531905 - J151848.47+532006.4 - 1237655464316436589
ARG0003n9v - FIRSTJ025215.4+025511 - J025210.17+025430.1 - 1237678620120973595
ARG000141e - FIRSTJ073045.6+405132 - J073051.33+404950.8 - 1237673705577382031
ARG0002i0o - FIRSTJ090921.8+173918 - J090916.54+173831.5 - 1237667538001920756
ARG0000tkz - FIRSTJ081636.4+455307 - J081640.84+455238.0 - 1237651190817817012
ARG0002ep0 - FIRSTJ082653.3+190832 - J082658.56+190921.5 - 1237667109037604956
ARG0002khw - J075021.33+163259.3
ARG00000uu - FIRSTJ141849.3+633619 - J141849.27+633619.3 - 1237674477585891868
ARG0001ob2 - FIRSTJ102820.7+305235 - J102821.93+305332.6 - 1237665127459849167
ARG0000r68 - FIRSTJ101759.1+470438 - J101754.85+470529.3 - 1237658206113300486
ARG0001gov - FIRSTJ075330.5+343137 - J075341.32+343032.0 - 1237674290755666969
ARG0000upb - FIRSTJ155801.5+452026 - J155806.87+451955.4 - 1237659330311749781
ARG0000gn8 - FIRSTJ104608.9+522953 - J104614.79+522906.5 - 1237657590317252823
ARG000378r - FIRSTJ084444.1+083048 - J084441.51+083059.9 - 1237664285634265421
ARG0000u07 - FIRSTJ151224.4+454042 -J151219.51+454110.3 -1237659131675738619
ARG0000i20 - SDSS J140315.11+514444.7 - 1237658801507991659
ARG0001saz - FIRSTJ142101.6+285813 - J142102.25+285953.5 - 1237665330400658112
ARG0002o0v - J163534.41+150246.8 - 1237668706760066169
ARG0003q5i - J114559.38+015025.7
ARG0000ihe - FIRSTJ095734.1+513120 - J095740.15+512921.4 - 1237657633264370754
ARG0002awu - J112941.68+205642.2 - 1237667781218992852
ARG0000mn5 - J130709.48+492139.0 - 1237658204514878054
ARG0002lgs - J144637.03+160725.2 - 1237668271906555057
ARG0001lnx - J104851.81+320903.0 - 1237665127461814370
ARG0003fyc - J142955.11+053048.2 - 1237655742941889470
ARG0003q3m - J084759.69+014855.7 - 1237653665251001078
ARG00015jq - J092554.70+400414.1 - 1237657873255432210
by nico775 translator
hi guys, i' m a real noob in astrophysics.... i was wondering how you simply mesure the size of these objects ? i saw that you use the distance mesured on first and the Redshift of the host but then ???
Hi nico775. Here's my understanding: it's not the actual, physical, size, but rather the projected physical size that's what's measured.
So if a pair of lobes is viewed 'side on' - i.e. the jets which produced them are going 'sideways', at right angles to our line of sight - the projected size would be the same as the actual, physical size. On the other hand, if we view a pair of lobes 'end on' - we're 'looking down the barrel of jets' - the lobes appear on top of one another (and so we can't tell how far apart they are). At an angle in between? Well, what is measured is the distance between the lobes as we see it 'on the plane of the sky'.
The actual measurement process goes like this:
- measure the distance between the peak emission in each lobe, in terms of an angle (20 arcminutes, say)
- obtain an estimate of the redshift of the host galaxy (this is, obviously, impossible if you don't know the host!); suppose it's 0.1
- using something like Ned Wright's CosmoCalc, convert the angular size to a (projected) physical size
- for this last step, you need to use the "angular size distance", or more directly the "scale"
For example, if the angular distance between the lobes is 20', and z is 0.1, using CosmoCalc (and keeping the default values of the cosmological parameters, such as H0), the scale is 1.857 kpc/" (kiloparsecs per arcsecond). My trusty calculator says that's 2228.4 kpc, or ~2.2 Mpc.
Hope this helps.
thanks JeanTate !!! it's clear, i'll try to mesure the next supposed giant i' ll find.
by nico775 translator
So just to get sure i did it right..... is that calculation right ?
ARG000058b - ALLWISE J073315.34+594707.6
ARG000167q - J085743.54+394528.7 - 1237657629513286288
ARG0000g2a - ALLWISE J074357.50+524944.4 or USNO B1 1428-0224500
ARG0000kfk - J150445.61+503008.5 - 1237661418216358847
ARG00012nb - J100635.61+413440.5 - 1237660342865036115
ARG0001hw6 - J145132.33+335751.2 - 1237662663209648355
ARG0002247 - J171039.99+243834.6 - 1237659120951821438
ARG0003mko - ALLWISE J205152.31+030924.4
ARG0002mp8 - ALLWISE J090114.06+153550.4 - size 2.5'
ARG000128w - FIRSTJ163751.2+414644 - J163752.72+414605.7 - 1237655502420444875
ARG00019d0 - FIRSTJ121306.2+380837 - J121309.46+380928.5 or J121311.49+381005.7
ARG0000mcz - FIRSTJ080242.4+492900 - J080249.20+492710.8 / J080248.50+492725.4 -1237663530257416748 - 1237663530257416749
ARG0001vz5 - FIRSTJ095423.8+271722 - J095419.19+271559.9 - 1237667112799306517
ARG00033ln - FIRSTJ111634.6+094703 - J111638.39+094751.5 - 1237658492811542984
ARG0003lig - : FIRSTJ132428.3+033520 - J132426.58+033627.6 - 1237655123942769174
ARG0001vdh - FIRSTJ095811.3+273419 - J095810.48+273240.3 - 1237667112799700043
ARG0002mcu - FIRSTJ140856.0+154354 - IR only? size 2.2' - ALLWISE J140852.58+154349.3
ARG00018ca - FIRSTJ121640.4+383905 - J121632.19+383844.4 - 1237664820361626167
ARG0002i2k - FIRSTJ083448.1+173814 -J083448.76+173652.5 - 1237667253992883113
ARG00015rz - FIRSTJ072256.2+395829 - J072259.62+395837.3 - 1237673705039790134
ARG0003k3w - FIRSTJ104814.9+040437 - J104810.29+040335.5 - 1237654604789711966
ARG00022jc - FIRSTJ092331.5+242646 - IC 2465 ( 1237667142330548371 )
ARG0002xb5 - FIRSTJ093014.7+114131 - IR only ALLWISE J093016.66+114240.9
ARG0000h3t -FIRSTJ131028.8+521340 - J131028.85+521340.4 - 1237662302429840114
ARG0000ad6 - FIRSTJ160846.6+561121 - J160852.19+561111.5 - 1237662701862191466
Assuming a measured size of 1.2', and the default values in CosmoCalc, I get 490 kpc. If I use the "73/27/73 cosmology" Dolorous Edd does, I get the same value he does (i.e. 470 kpc).
Hope this helps.
Hi JeanTate, i found my mystake.... in CosmoCalc, i used "Open" instead of "flat". But i don't know what these 2 options mean. thanks again for your help.
Hi nico775, glad to hear you sorted it out.
"Open", in CosmoCalc, simply means that the Omegavac parameter is set to zero; i.e. that there is no Dark Energy. "Flat" means Omegavac+OmegaM = 1. In other words, you're making choices as to what you think the geometry of the universe is, at least out to the redshift you are plugging in.
Ned Wright also has a good, if brief, Tutorial on cosmology. It covers the differences between Open, Flat, and General pretty well I think (and a lot more topics too).
Let's continue , shall we?
ARG0000mbj - FIRSTJ155458.0+493011 - possibly J155502.31+493052.1 - 1237655465393128539
ARG00035rb - FIRSTJ205930.8+090153 - J205927.44+090253.2 or J205927.30+090248.8 - 1237678877780345946 or 1237678877780345947
ARG0001lc1 - FIRSTJ113103.6+321905 - J113059.71+321947.4 - 1237665330921603098
ARG0001l9g - FIRSTJ084654.8+322102 - ALLWISE J084704.30+322032.5
ARG0000g0y - FIRSTJ133308.0+525103 - ALLWISE J133259.56+525116.8
ARG0000bix - FIRSTJ140640.3+552756 - ALLWISE J140632.85+552839.8
ARG0002c3k - FIRSTJ083411.9+202245 - ALLWISE J083414.98+202132.4
ARG0000z7r - FIRSTJ161242.4+431314 - J161242.06+431319.8 - 1237659330850128152
ARG00023em - FIRSTJ145329.8+240437
ARG00038kj - FIRSTJ230403.4+080300 - ALLWISE J230403.08+080419.7
ARG00008qg - FIRSTJ073226.9+571528
ARG0000ch1 - FIRSTJ074651.3+545350 - ALLWISE J074655.06+545423.5
ARG0000lx4 - FIRSTJ111249.2+494222 - J111259.53+494227.0 - 1237658614128247137
ARG00014g2 - FIRSTJ104527.2+403958 - J104525.66+404036.9- 1237662195592527969
ARG0000fib - FIRSTJ151350.8+530743 - ALLWISE J151347.88+530834.1
ARG00012w5 - FIRSTJ173011.3+412603 - ALLWISE J173026.54+412436.3 for reference
ARG0001hxk - FIRSTJ115138.0+335618 - J115139.68+335541.4 - 1237665023828754469
ARG0002jys - FIRSTJ154030.9+164832 - J154026.91+164807.5 - 1237668336858105060
ARG00019g9 - FIRSTJ130759.6+380522 - J130805.02+380521.2 - 1237664846121206152
ARG0003n9c - FIRSTJ230341.6+025524 - J230344.85+025735.1 - 1237678619559199661
ARG0001v7l - FIRSTJ165154.8+273821 - SDSS J165159.91+273836.7 - 1237662303524422687
ARG0001z5j - FIRSTJ125835.9+254953 - J125837.86+255005.9 - 1237667448881152865
ARG00032m4 -FIRSTJ091417.6+100625 - J091419.53+100640.5 - 1237661069243318535
ARG000039f - FIRSTJ140129.6+612323 - J140134.90+612330.4 - 1237655371440783651
ARG00022zy - FIRSTJ114055.5+241452 - J114054.77+241619.0 - 1237667911126221270
Created a separate collection for sources with LAS more than 0.5Mpc but less than 1Mpc
ARG00008cz - FIRSTJ124205.9+573056 - J124154.50+573040.8 - 1237661417669984519
ARG00036t9 - FIRSTJ103511.3+084001 - J103516.84+084110.6 -
ARG0000vb9 - FIRSTJ130151.8+450252 - ALLWISE J130153.62+450139.5
ARG0000pm5 - FIRSTJ125052.4+475246 - J125053.56+475221.2 - 588298664112882006
ARG0001kbn -FIRSTJ094319.9+324704 - J094312.59+324647.0 - 1237664092905996918
ARG0000qc5 - AllWISE J165012.99+473115.6
ARG0000qjo - FIRSTJ092628.3+472311 - J092628.90+472236.0 - 1237657632187744422
ARG0000z2d - FIRSTJ081154.3+431751 - J081159.88+431758.9 - 1237673706654598116
ARG0000z2d - FIRSTJ081154.3+431751 - J081159.88+431758.9 - 1237673706654598116
ARG0001vi2 - FIRSTJ113348.3+273050 - J113345.00+273113.4 - 1237667323789378440
ARG0002ite - J115849.49+171719.5 - 1237668624083976403
ARG00029a9 - FIRSTJ142041.5+214013 - J142046.60+214003.3 - 1237667911142343630
ARG0002ksq - FIRSTJ121609.9+162549 - J121615.21+162432.2 - 1237668588648923647
ARG0001g3y - FIRSTJ120052.3+344824 - J120050.10+344912.3 - 1237665024903348877
Nice macro, Edd. 😄 I really like your new icon, too!
ARG00000ic - FIRSTJ112901.9+635551 - J112851.93+635532.5 - 1237654875357905313
ARG00002r6 - FIRSTJ114109.2+614815 - J114113.42+614709.0 - 1237655464303591680
ARG0000p8e - FIRSTJ132911.4+480352 - J132919.41+480300.6 - 1237658203979645304
ARG0003g3 - FIRSTJ162608.4+052651 - ALLWISE J162611.16+052814.6
ARG0002lqq - FIRSTJ164620.8+160032 - J164617.05+155923.4 - 1237662696506917837
ARG000134o - FIRSTJ151501.5+411843 - J151509.64+411836.8 - 1237661212048687148
ARG0002mhz - FIRSTJ142427.7+154044 - J142427.93+154142.2 - 1237668350283874430
ARG0001pjr - FIRSTJ153247.3+301846 - J153250.93+301946.0 - 1237662339472950320
ARG0000qpv - FIRSTJ132718.0+471832 - AllWISE J132716.77+471711.2
ARG0002o7h - FIRSTJ135602.8+145922 - J135605.75+145748.7 - 1237668348133507470
ARG0001mrl - FIRSTJ080533.0+313703 -
ARG0002cu1 - FIRSTJ163122.1+200112 - J163125.73+200224.0 - 1237662698115302857
ARG0000bh3 - FIRSTJ140622.6+552947 - AllWISE J140632.85+552839.8
ARG0000sy3 - FIRSTJ160629.2+461135 - J160621.13+461346.8 - 1237655464321024631
ARG0001rn6 - FIRSTJ170003.7+291809 - J170008.72+291903.7 - 1237661388158664899
ARG0000sjv - FIRSTJ125943.8+462246 - J125951.20+462333.9 1237661360758915636
ARG0003gzb - FIRSTJ091933.5+050952 - J091929.09+051046.1 - 1237658423545037403
ARG0002ajd - FIRSTJ100903.2+210624 - AllWISE J100858.04+210612.2
ARG0001y5r - FIRSTJ091933.5+050952 - J091929.09+051046.1 - 1237658423545037403
ARG0000ni6 - FIRSTJ103303.9+485512 - allwise J103308.08+485417.6
ARG0002asx - FIRSTJ132945.1+205906 -J132940.59+205810.6 - 1237667734515941735
ARG0000ewx - FIRSTJ161539.1+532727 - J161547.80+532828.5 - 1237665356701696338
ARG00005tr - FIRSTJ162155.2+591954 - J162155.13+591954.8 - 1237668505438388325
ARG0002hhx - FIRSTJ093139.4+175227 - J093141.25+175156.4 - 1237667536393535710
ARG00013wn - FIRSTJ085231.5+405453 - J085232.18+405730.3
ARG0001kiy - FIRSTJ144241.7+324200 - J144234.93+324326.9 - 1237664854182985811
ARG0001gj6 - FIRSTJ142424.3+343543 - J142432.58+343645.8 - 1237662661596676591
ARG00030cd - FIRSTJ141934.7+104817 - J141933.38+104706.1 - 1237661949730554100
XDXDXD Great DE
Are we likely to miss a lot of low-z giants?
If we suspect a giant, for whatever reason, we can click on the FIRST and NVSS links under an ARG field. And if in either there's a hint of something that might be a distant lobe or two, we can explore further, make a Comment or start/add to a Discussion, etc.
Buy what if both lobes are entirely outside the FIRST/NVSS fields? We'd only stumble upon such giants if - like Dolorous Edd - we zoomed out (e.g. changing the "&Size=0.15" in the NVSS URL to something like "&Size=0.30", or "&ImageSize=9" in the FIRST URL), or explored the region using Aladin, etc.
So, how big are the low-z giants we'd miss if we relied solely on the FIRST and/or NVSS fields?
Both are 9'x9', per the main RGZ paper, which means we'd miss a giant if the closest lobe were further than ~4.5'-6.5' from the host. Or saying this another way, if the lobes were > ~9' to 13' apart (shorter for N/S or E/W lobes; longer for NE/W or NW/SE ones).
How big is 9' (13') at various redshifts? Here's what I get, for a selection of redshifts (using CosmoCalc, flat universe, default - Planck? - values):
- z=0.2: 1.8-2.6 Mpc ... we'd miss only the truly super-giants!
- z=0.1: 1.0-1.5 Mpc ... marginal chance of catching true giants (i.e. hotspot-hotspot distance > 1.0 Mpc)
- z=0.05: 0.53-0.77 Mpc ... we'd pick these giants up only if the 'tail' of a lobe were rather long
- z=0.02: 0.22-0.32 Mpc ... pure luck we'd spot any true giants! 😮
Of course, we can only measure the projected size, which will always be smaller than the physical size, due to projection (except if we view a doublelobe exactly othogonal to our line of sight).
Easy enough to test this ... what's the redshift vs 'size of giant' distribution of those we've (re-)discovered? Assuming nothing special about local galaxies, what would be the expected distribution (or, asking this another way, what's the space density distribution of giants, by projected size)?
What do you think?
Sorry for the intrusion, newbie question: at these so nearby distances, should not it be easier to identify a lobe like part of an "overedge" for his radio morphology?
I would like to say that at that distance the radio morphology may provide clues to what is the host (for example by its elongation) and therefore in that direction we have to look at doing zoom out. Can it be?
Easy enough to test this ... what's the redshift vs 'size of giant' distribution of those we've (re-)discovered? Assuming nothing special about local galaxies, what would be the expected distribution (or, asking this another way, what's the space density distribution of giants, by projected size)?
I think you should have a look
at these so nearby distances, should not it be easier to identify a lobe like part of an "overedge" for his radio morphology?
Good question! 😃
If the radio emission is from the core (host) and if the both lobes are extended (like a giant teardrop or tadpole), then it should be quite easy, except perhaps for the very nearest cases.
However, if there is no radio emission from the core/host, and if both lobes are nothing more than slightly extended compact sources, then you would need to examine a field considerably bigger than 9'x9' to even see these lobes. And even then it would be quite difficult to be sure they are doublelobes, and even more difficult to identify the host.
That poster almost certainly contains enough data to be able to do the kind of test I suggested, in Figure 1: count the number of GRGs per redshift bin (being careful how these are defined), and plot them vs the volume of the universe they are in (this isn't as straight-forward as it seems, due to selection biases; e.g. FIRST does not cover the whole sky). As the x-axis has a non-linear scale, I think it's impossible to make a gues just by eyeballing ...
ARG000375r - FIRSTJ121357.6+083257 - J121357.15+083202.2 - 1237661972795490410
ARG0001p2r - FIRSTJ085339.6+303117 -
ARG00011dw - FIRSTJ073312.4+421306 - J073312.61+421156.5 - 1237663915724309162
ARG0003n12 - FIRSTJ023504.1+030051 - AllWISE J023506.70+030143.8
ARG00026oe - FIRSTJ082934.5+224728 - J082941.34+224758.4 - 1237664091823931795
ARG00017xe - FIRSTJ100118.4+385140 -
ARG00024kd - FIRSTJ153721.3+233654 - J153731.05+233614.5 - 1237665374404411721
ARG0003qvq - FIRSTJ144448.5+013315 - J144447.58+013211.7 - 1237651735775019975
ARG0001blj - FIRSTJ160334.2+365817 - J160334.12+365952.9 - 1237662302981521413
ARG0002vui - FIRSTJ090312.5+120825 - J090303.53+120858.6 - 1237671124834779509
ARG00021dq - FIRSTJ130445.2+245436 - J130451.41+245445.9 - 1237667447808065554
ARG0001gs4 - FIRSTJ092755.8+342909 - J092751.11+343103.5 - 1237661383844823081
ARG0001r89 - FIRSTJ124703.4+292930 - J124658.73+292928.8 - 1237665441514586799
ARG0000bg0 - FIRSTJ075509.5+553040 - AllWISE J075514.62+553143.5
ARG00037a4 - FIRSTJ090543.2+083019 - J090540.08+082913.6 - 1237660670346724307
ARG000021n - FIRSTJ170849.5+622755 - J170855.71+622644.1 - 1237651226781090672
ARG00031v8 - FIRSTJ083902.6+102010 - J083856.38+102200.9 - 1237671124295155967
Hi all, In terms of local giants, there are few very massive galaxies within the Local Universe (z< 0.05). As such, we do not expect many giant radio galaxies. However there are a handful of radio galaxies that are quite massive such as Centaurus A. Does this help?
ARG0001j5o - FIRSTJ120249.8+331953 - ? - ?
ARG0003pwp - FIRSTJ013152.8+015429 - J013149.64+015430.4 - 1237680099700048835
ARG0003g3x - J162611.16+052814.6
ARG00034jq - FIRSTJ154628.8+092703 - J154624.47+092835.8 - 1237662534359908962
ARG00028u1 - FIRSTJ134925.2+215239 - J134919.17+215251.1 - 1237667783917503293
ARG00034vi - FIRSTJ114332.6+092052 - J114336.65+092137.5 - 1237660613439390074
ARG0003gc8 - FIRSTJ145216.4+052226
ARG0000rqo - FIRSTJ100314.9+464712
ARG00039to - FIRSTJ161201.1+073726 - SDSS J161157.36+073856.1 - 1237662636376785646
ARG00016ar - FIRSTJ155430.1+394342 - J155426.84+394508.6 - 1237659119331639724
ARG0001og2 - FIRSTJ144518.3+304855 - J144527.05+305128.9 - 1237662696493220133
ARG0002ktp - FIRSTJ135122.1+162457 -
ARG0003ft3 - see comments -J155040.58+054040.9 - 1237662263253009726
ARG0003o8b - FIRSTJ092737.3+023240 - J092738.52+023346.2 - 1237654599949222952
ARG00005pp - FIRSTJ173122.8+592500 - J173111.16+592402.5 - 1237659897246647384
ARG0002fsg - J103403.84+184048.9 - 1237670965930360969
ARG0000293 - FIRSTJ152723.7+621554 - AllWISE J152715.91+621619.7
ARG0003hz4 - FIRSTJ133307.0+045048 - J133307.00+045048.5 - 1237671990802841656
ARG0003bss - FIRSTJ085350.9+065448 - J085348.41+065335.5 - 1237661063872250602
ARG00028pd - FIRSTJ115613.8+215555 - SDSS J115609.97+215428.3 - 1237667734506439315
ARG00007ch - FIRSTJ095139.5+581001 - J095146.71+580855.6 - 1237653614798242558
ARG0003k22 - FIRSTJ204654.2+040540 - J204659.34+040526.8 - 1237669762249722935
ARG00009uc - FIRSTJ082827.4+563045 - J082825.47+562906.6 - 1237663531334632351
ARG0001fjr - FIRSTJ110211.0+350416 - J110218.39+350429.1 - 1237664337175249598
ARG0001qkn- FIRSTJ112438.9+294936 - J112441.77+295008.5 - 1237667212134777630
ARG000355j - FIRSTJ112438.9+294936 - J112441.77+295008.5 - 1237667212134777630
ARG0002jrj - FIRSTJ165539.9+165356 - AllWISE J165537.97+165514.4
ARG0001dn1 - FIRSTJ075853.3+355652 - J075858.29+355643.6 - 1237654627325903400
ARG00036r9 - FIRSTJ083711.6+084116 - J083716.07+084048.4
ARG0002vll - FIRSTJ002221.0+121234 - J002223.20+121303.5
ARG0003avm - FIRSTJ131233.4+071454 - AllWISE J131236.97+071507.3
ARG000157b - FIRSTJ163812.9+401642 - J163808.84+401535.5 - 1237655473968513818
ARG00037i5 - FIRSTJ234136.8+082543 -J234137.14+082817.2 - 1237672765522116840
ARG0000lob - FIRSTJ135437.4+494957 - J135443.10+494959.1 - 1237662301896179940
ARG0001eq5 - FIRSTJ072700.9+352637 - J072701.44+352639.0 - 1237651496289567336
ARG0001gkp - FIRSTJ163226.1+343445 - J163220.21+343337.4
ARG0001j9r - FIRSTJ141718.9+331615 - J141721.71+331549.5 - 1237664852570079876
ARG0000tb8 - FIRSTJ122951.7+460127
- J122951.10+455949.7 - 1237661874014913111
ARG0000vio - FIRSTJ112732.6+445655
- J112737.79+445713.1 - 1237661852002222243
ARG0000y0i - FIRSTJ150152.3+434721 - J150148.34+434632.5 - 1237662300828139986
ARG0002i2f - FIRSTJ082005.8+173819 - J082000.65+173912.2 - 1237667142323405681
ARG0000cxf - FIRSTJ072903.3+543825 - AllWISE J072852.95+543709.5 - 2MASS 07285295+5437088
ARG00030bx - FIRSTJ141935.1+104830 - J141933.38+104706.1 - 1237661949730554100
ARG00014we - FIRSTJ112950.8+402552 - J112956.02+402514.4 - 1237664670052057198
ARG00023tp - J072238.37+235530.8 or J072239.56+235535.8
ARG0001p1y - FIRSTJ090416.6+303204 - J090412.36+303141.0
ARG00029xl - FIRSTJ105524.5+212219 - J105528.07+212223.2 - 1237667735574020508
ARG0003qsv - FIRSTJ222429.4+013443 - J222418.93+013457.5 - 1237678596469424521
ARG0001aur - J144031.11+372240.6 -
ARG0001jtj - J121735.84+330131.9 - 1237665330925863795
ARG0002v2e - FIRSTJ224833.9+122133 - J224830.56+122141.8 - 1237678860074615269
ARG0001tww - J113314.76+281159.3 - 1237667431717863430
A casual question... how many GRG was known before RGZ?
Hundreds ... AFAIK over ~500 GRG candidates only in HAndernach collection, not counting published giants
Looks like triple in FIRST
ARG0001jj5 - FIRSTJ100244.4+330855 - AllWISE J100242.99+330730.8
ARG0000q2x - FIRSTJ080125.2+473849 - J080131.96+473616.0 - 1237651274031628444
ARG0002bzg - FIRSTJ151706.6+202601 - J151708.06+202740.0 - 1237665549432586951
ARG00022vu - FIRSTJ132049.4+241809 - J132047.55+241910.6 - 1237667911673053651
ARG0001mbr - FIRSTJ151907.4+314939 - J151903.65+315008.6 - 1237662305121731919
ARG00028xd - J073413.14+214908.9 - 1237657879148102781
ARG0001gg8 - FIRSTJ160454.1+343818 - J160445.89+343816.5 - 1237662300834759819
ARG0000ju1 - J120546.97+504900.0 - 1237658614131983013
ARG0002eqb - J124608.79+190625.5 - 1237668297133064754
ARG0000fid - J123204.94+530627.3 - 1237657857685782689
ARG0000uug - J101213.72+451529.3 - 1237658204501967268
ARG00011yl - J115333.48+415512.5 - 1237661966891089982
ARG0003krr - FIRSTJ034744.1+035029 - J034739.45+035055.3
ARG0000c1y - J162541.29+550835.8 - 1237665582714651453
ARG0003bei - J223141.75+070221.7 - 1237669698373878434
ARG0001i4u - AllWISE J104526.79+335050.7
ARG0001zpy - J085550.79+253151.0 - 1237664878872495072
ARG0002dgw - J122354.84+194241.8 -
ARG00018lk - J084746.06+383139.3 - 1237657775541714969
ARG00027dv -AllWISE 094554.71 +223018.1
ARG0002hll - J154253.94+174942.9 - 1237665548898599815
ARG00037td - J225934.13+082040.7 - 1237678905165349581
ARG0003i5y - J083817.98+044706.9 - 1237658300058305368
ARG0001pia - J153410.75+302021.1 - 1237662305660175366
ARG0000zt3 - J100633.39+425806.4 - 1237661358070890783
ARG00018d1 - J124236.82+383806.1 - 1237662223532556770
ARG0000hkt - J115457.58+515909.9 - 1237657628990636997
ARG0000n32 - J141738.40+490616.9 - 1237661959372145853
ARG0001hrl - near J141739.44+340137.6 - 1237664853643755652
ARG0002e3x - J115141.50+192609.8 - 1237667914880581716
ARG0001cl7 - J122118.88+362546.7 - 1237664671638618349
ARG000237y - J134712.53+240709.4-1237665567140676459
ARG0000nuc - J134415.64+484549.2 or J134414.94+484601.5
ARG00018nj - J080636.79+382924.7 - 1237654653098918490
Some candidates can also be found here : Interesting things from NVSS
ARG0000kxm - AllWISE J071034.72+501111.2
ARG0002cjw - J085934.43+201006.3 - 1237667253995634809
ARG00010tg - J101244.30+422957.1 - 1237661356997541903
ARG00034ns - J222119.62+092544.5 - 1237679010388706139
ARG0001uy8 - J131443.83+273741.3 - 1237667444050100931
ARG0001hxe - AllWISE J142916.11+335537.2
GMRT observations of IC 711 - The longest head-tail radio galaxy known
Shweta Srivastava, Ashok K. Singal
We present low-frequency, Giant Metrewave Radio Telescope (GMRT) observations at 240, 610 and 1300 MHz of IC 711, a narrow angle tail (NAT) radio galaxy. The galaxy lies in Abell cluster 1314 (redshift 0.034) and has a long radio tail of total angular extent 17 arcmin, corresponding to a projected linear size of 700 kpc. This makes it the longest head-tail radio galaxy known. (...)
(Submitted on 25 Oct 2016)
PS: I started a GZ Talk discussion about this paper in the "Journal Club".
PPS: The galaxy is covered by SDSS.
A Selection of Giant Radio Sources from NVSS
Author: D. D. Proctor
Results of the application of pattern recognition techniques to the problem of identifying Giant Radio Sources (GRS) from the data in the NVSS catalog are presented and issues affecting the process are explored. Decision-tree pattern recognition software was applied to training set source pairs developed from known NVSS large angular size radio galaxies. The full training set consisted of 51,195 source pairs, 48 of which were known GRS for which each lobe was primarily represented by a single catalog component. The source pairs had a maximum separation of 20 arc minutes and a minimum component area of 1.87 square arc minutes at the 1.4 mJy level. The importance of comparing resulting probability distributions of the training and application sets for cases of unknown class ratio is demonstrated. The probability of correctly ranking a randomly selected (GRS, non-GRS) pair from the best of the tested classifiers was determined to be 97.8 +/- 1.5%. The best classifiers were applied to the over 870,000 candidate pairs from the entire catalog. Images of higher ranked sources were visually screened and a table of over sixteen hundred candidates, including morphological annotation, is presented. These systems include doubles and triples, Wide-Angle Tail (WAT) and Narrow-Angle Tail (NAT), S- or Z-shaped systems, and core-jets and resolved cores. While some resolved lobe systems are recovered with this technique, generally it is expected that such systems would require a different approach.
(Submitted on 22 Mar 2016 (this version), latest version 10 May 2016 (v2))
KWillett had informed about the paper in following RGZ Talk discussion.:
GZ blog post:
The shoulder of Giants, 31 Dec 2016
LOFAR MSSS: Discovery of a 2.56 Mpc giant radio galaxy associated with a disturbed galaxy group
Authors: A. O. Clarke, G. Heald, T. Jarrett, J. D. Bray, M. J. Hardcastle, T. M. Cantwell, A. M. M. Scaife, M. Brienza, A. Bonafede, R. P. Breton, J. W. Broderick, D. Carbone, J. H. Croston, J. S. Farnes, J. J. Harwood, V. Heesen, A. Horneffer, A. J. van der Horst, M. Iacobelli, W. Jurusik, G. Kokotanekov, J. P. McKean, L. K. Morabito, D. D. Mulcahy, B.S. Nikiel-Wroczynski, E. Orru, R. Paladino, M. Pandey-Pommier, M. Pietka, R. Pizzo, L. Pratley, C. J. Riseley, H. J. A. Rottgering, A. Rowlinson, J. Sabater, K. Sendlinger, A. Shulevski, S. S. Sridhar, A. J. Stewart, C. Tasse, S. van Velzen, R. J. van Weeren, M. W. Wise
We report on the discovery in the LOFAR Multifrequency Snapshot Sky Survey (MSSS) of a giant radio galaxy (GRG) with a projected size of 2.56±0.07 Mpc projected on the sky. It is associated with the galaxy triplet UGC 9555, within which one is identified as a broad-line galaxy in the Sloan Digital Sky Survey (SDSS) at a redshift of 0.05453±1×10 −5 , and with a velocity dispersion of 215.86±6.34 km/s. From archival radio observations we see that this galaxy hosts a compact flat-spectrum radio source, and we conclude that it is the active galactic nucleus (AGN) responsible for generating the radio lobes. The radio luminosity distribution of the jets, and the broad-line classification of the host AGN, indicate this GRG is orientated well out of the plane of the sky, making its physical size one of the largest known for any GRG. Analysis of the infrared data suggests that the host is a lenticular type galaxy with a large stellar mass (log M/M ⊙ =11.56±0.12 ), and a moderate star formation rate (1.2±0.3 M ⊙ /year ). Spatially smoothing the SDSS images shows the system around UGC 9555 to be significantly disturbed, with a prominent extension to the south-east. Overall, the evidence suggests this host galaxy has undergone one or more recent moderate merger events and is also experiencing tidal interactions with surrounding galaxies, which have caused the star formation and provided the supply of gas to trigger and fuel the Mpc-scale radio lobes.
(Submitted on 6 Feb 2017)
It is a SDSS galaxy! Does it have a RGZ object-ID?
https://radiotalk.galaxyzoo.org/#/subjects/ARG0000am0 - J133924.83+560248.5
https://radiotalk.galaxyzoo.org/#/subjects/ARG0000gno - SDSS J084525.51+522915.7 - 1237651191895097848
https://radiotalk.galaxyzoo.org/#/subjects/ARG00022ru - SDSS J132047.31+241945.8 - 1237667911673053639
https://radiotalk.galaxyzoo.org/#/subjects/ARG0001xph - AllWISE J091229.86+262904.0
https://radiotalk.galaxyzoo.org/#/subjects/ARG0000e0a - J094835.60+535946.3 - 1237655108368728513
https://radiotalk.galaxyzoo.org/#/subjects/ARG0000lfs - J161601.72+495634.4 - 1237665356700188682
https://radiotalk.galaxyzoo.org/#/subjects/ARG0001jvm - J114954.32+325652.1 - 1237665227839570609
https://radiotalk.galaxyzoo.org/#/subjects/ARG0000xim - J124505.20+440232.3 - 1237661871868674977 - AllWISE J124505.22+440232.6
9.9.18 AllWISE J103959.97+052320.8 https://radiotalk.galaxyzoo.org/#/subjects/ARG0003g72
An updated catalogue of giant radio sources.
A. Kuźmicz, M. Jamrozy, K. Bronarska, K. Janda-Boczar, D. J. Saikia.
(Submitted on 24 Sep 2018).
We present a catalogue of 349 giant radio sources (GRSs including both galaxies and quasars). The database contains all giants known to date from the literature. (...)
There is a list of the GRSs given in the paper.: Table 1: Pages 11-20.
PS: I started a discussion in the "Journal Club".
July 30 2018 commented by @HAndernach https://radiotalk.galaxyzoo.org/#/subjects/ARG0003pu2
September 13 2018 https://radiotalk.galaxyzoo.org/#/subjects/ARG0000pyl
September 19 2018 speculative https://radiotalk.galaxyzoo.org/#/subjects/ARG00022ro
September 23 2018 speculative https://radiotalk.galaxyzoo.org/#/subjects/ARG0002dll
September 25 2018 https://radiotalk.galaxyzoo.org/#/subjects/ARG0001bts
September 25 2018 commented by @HAndernach https://radiotalk.galaxyzoo.org/#/subjects/ARG00015ys
https://radiotalk.galaxyzoo.org/#/subjects/ARG00021an comented by H. Andernach
https://radiotalk.galaxyzoo.org/#/subjects/ARG00013t3 comented by H. Andernach
Giant radio galaxies in the LOFAR Two-metre Sky Survey-I
P. Dabhade, H. J. A. Rottgering, J. Bagchi, T. W. Shimwell, M. J. Hardcastle, S. Sankhyayan, R. Morganti, M. Jamrozy, A. Shulevski, K. J. Duncan
(...) Here, we report the biggest sample of GRGs identified to date. These objects were found in the LOFAR Two-metre Sky Survey (LoTSS) first data release images, which cover a 424 square degrees region. Of the 240 GRGs found, 228 are new discoveries. (...)
(Submitted on 31 Mar 2019)
PS: I started a Talk discussion in the "Journal Club".