Discovery of rare double-lobe radio galaxies hosted in spiral galaxies

• by zutopian

  Here is a new paper, which showed up on arxiv today!:

  Discovery of rare double-lobe radio galaxies hosted in spiral galaxies

  Double-lobe radio galaxies in the local Universe have traditionally been found to be hosted in elliptical or lenticular galaxies. We report the discovery of four spiral-host double-lobe radio galaxies (J0836+0532, J1159+5820, J1352+3126 and J1649+2635) that are discovered by cross-matching a large sample of 187005 spiral galaxies from SDSS DR7 to the full catalogues of FIRST and NVSS. J0836+0532 is reported for the first time.

  Authors: Veeresh Singh, C. H. Ishwara-Chandra, Jonathan Sievers, Yogesh Wadadekar, Matt Hilton, Alexandre Beelen
  (Submitted on 4 Sep 2015)
  http://arxiv.org/abs/1509.01559

  Posted September 7, 2015 8:25 AM

• by zutopian

  The SDSS Images of the 4 galaxies are shown on page 4 in the paper! I am going to post the SDSS images and links in the following posts! Asking for the missing IDs of the Radio Zoo images! (IDs for 2 galaxies are known)

  Posted September 7, 2015 8:42 AM

• by zutopian

  One of the re-discovered ones:

  
  (b) J1159+5820:
  http://skyserver.sdss.org/dr12/en/tools/explore/Summary.aspx?id=1237661354316726385
  Discussion about a paper about this galaxy: http://radiotalk.galaxyzoo.org/#/boards/BRG0000009/discussions/DRG0000cqz
  Radio Zoo image: ?

  Posted September 7, 2015 9:00 AM

• by zutopian

  Another one of the re-discovered ones:

  
  (c) J1352+3126: http://skyserver.sdss.org/dr12/en/tools/explore/Summary.aspx?id=1237665331471515679
  Radio Zoo images:
  http://radiotalk.galaxyzoo.org/#/subjects/ARG0001n46
  http://radiotalk.galaxyzoo.org/#/subjects/ARG0001n5e
  https://radiotalk.galaxyzoo.org/#/subjects/ARG0001n3v

  Posted September 7, 2015 9:21 AM

• by zutopian

  Another one of the re-discovered ones:

  
  (d) J1649+2635: http://skyserver.sdss.org/dr12/en/tools/explore/Summary.aspx?id=1237662301913940522
  Discussion about a paper about this galaxy: http://radiotalk.galaxyzoo.org/#/boards/BRG0000009/discussions/DRG00008hg
  Radio Zoo image: http://radiotalk.galaxyzoo.org/#/subjects/ARG0001xiw

  Posted September 7, 2015 9:50 AM

• by zutopian

  New discovery:

  
  (a) J0836+0532: http://skyserver.sdss.org/dr12/en/tools/explore/Summary.aspx?id=1237660412109258798
  Radio Zoo image: ? EDIT: http://radiotalk.galaxyzoo.org/#/subjects/ARG0003frv

  Posted September 7, 2015 10:03 AM

• by 42jkb scientist, admin

  Interesting find, thanks for pointing it out.

  Posted September 7, 2015 10:33 AM

• by 42jkb scientist, admin

  Will send this on to Minnie to move the project forward.

  Posted September 7, 2015 10:33 AM

• by JeanTate in response to zutopian's comment.

  Interestingly, this is almost exactly one of the methods I have used/am using to find SDRAGNs! 😃

  [...] are discovered by cross-matching a large sample of 187005 spiral galaxies from SDSS DR7 to the full catalogues of FIRST and NVSS

  Using this method, I have found several candidate SDRGNs (but none of the four in the paper; my search criteria are somewhat different), but cannot write a paper on my discoveries 😦

  Maybe in Singh+'s follow-up paper I can read about the discovery of several of "my" SDRAGN candidates? Maybe such a paper will include some of the other SDRAGNs discovered by zooites (and reported in the Hourglass sources associated with spiral galaxies thread)? Maybe we ordinary zooites should learn how to write papers, good enough to get published on arXiv at least, so our discoveries will be appropriately acknowledged by the astronomical community?

  What do you think?

  Posted September 7, 2015 11:19 AM

• by zutopian

  I wonder, why the new discovery J0836+0532 had been missed by Mao et al., who had discovered J1649+2635 through a systematic search?

  Posted September 7, 2015 12:41 PM

• by 42jkb scientist, admin in response to JeanTate's comment.

  Yes, there is no reason why you can't write your own paper on your discoveries. If this is something you want to pursue send me an email and we can discuss further.

  Posted September 7, 2015 11:41 PM

• by 42jkb scientist, admin in response to zutopian's comment.

  I'm not sure why Minnie missed J0836+0532 and maybe she can respond to this. Anyhow, with this paper coming out now is a good time to get our RGZ SDRAGN paper ready!

  Posted September 7, 2015 11:42 PM

• by JeanTate in response to 42jkb's comment.

  Thanks! Will do.

  Any other ordinary RGZ zooites interested in working with me on such a paper? Or any other GZ- or RGZ-related one? Please send me a PM! 😃

  Posted September 8, 2015 7:09 AM

• by JeanTate in response to zutopian's comment.

  See new Discussion thread I have a position, how do I find which ARG fields contain it (if any)?

  Posted September 8, 2015 9:23 AM

• by mini.mintaka scientist

  Hi All,

  I posted in the SDRAGNs thread about why I think we didn't find 0836+0532 and the others ... I suspect it's due to the different starting catalogues... we used the Galaxy Zoo Super Clean sample whereas Singh et al used Meert et al. (2015)...

  JeanTate, you should TOTALLY work on a paper about your findings 😃

  clear skies

  minnie

  Posted September 16, 2015 6:09 PM

• by JeanTate in response to mini.mintaka's comment.

  I posted in the SDRAGNs thread about why I think we didn't find 0836+0532 and the others ... I suspect it's due to the different starting catalogues... we used the Galaxy Zoo Super Clean sample whereas Singh et al used Meert et al. (2015)...

  The two systematic searches that I know of - 'yours' and that reported in Singh+ (2015) - both start with a particular definition of what a 'spiral galaxy' is. Not surprisingly (no?), it is actually quite difficult to come up with a consistent definition of such a collection of stars, gas, dust, dark matter, etc ... one that can be used in a robust, comprehensive way. And whatever definition one uses, putting it into an astrophysical context is fraught indeed.

  For example, many grand design spirals are such because they are involved in an interaction with another galaxy (usually a smaller one), and many 'distorted' spirals are such because they are also so engaged ('mergers'). What look like quite tranquil, classical spirals may all have been involved in at least one interaction/merger in the past (as likely happened to both M31 and our own galaxy, for example).

  If the astrophysics being studied has to do with the presence of cold gas - with densities typically found in spirals - in/near the nucleus, preventing jets from the SMBH/accretion disk 'breaking through', then perhaps a somewhat different approach may be worth considering?

  Posted September 20, 2015 11:31 PM

• by mini.mintaka scientist

  Hi Jean,

  It's interesting that you discuss the definition of "spiral" galaxy... indeed many astronomy definitions are fuzzy at best 😛

  The spiral classification is ultimately a morphological classification... and the reason we are interested in spiral DRAGNs is because current galaxy formation theories suggest that the formation of a 'DRAGN' requires a major merger (e.g. Chiaberge et al. 2015) ... which a classic 'spiral' morphology should not be able to withstand. And as you correctly point out, many spiral galaxies have undergone interactions such as minor mergers.

  I think that actually the association with DRAGNs with elliptical galaxies is purely an empirical result, which, as we now know, isn't completely correct... which is why you guys are looking for these sources!

  clear skies

  minnie

  ps. What's a good time for a 'live' discussion? Let me know here...

  Posted September 22, 2015 9:02 AM

• by JeanTate in response to mini.mintaka's comment.

  Thanks mini.

  The spiral classification is ultimately a morphological classification... and the reason we are interested in spiral DRAGNs is because current galaxy formation theories suggest that the formation of a 'DRAGN' requires a major merger (e.g. Chiaberge et al. 2015) ... which a classic 'spiral' morphology should not be able to withstand.

  To turn this on its head, if there is a - rare! - class of major merger in which a classic spiral is the end result, does that make the formation of a DRAGN possible? Given that known SDRAGNs are rare^n, perhaps the ones we see are in classic spirals which have withstood a major merger? After all, merger studies are hardly robust enough to rule out the formation of a classic spiral from a major merger in, what, one out of 100k such mergers, are they?

  Then there's the question of when a DRAGN is produced in a major merger ... AGNs are certainly found in spiral-spiral major mergers, sometimes at quite an early phase of the interaction (when one or both still obviously has a disk and even arms); can DRAGNs form as early as this? From the ~100 'not a boring elliptical' SDRAGN candidate hosts posted so far here in RGZ Talk, quite a few may be just such systems.

  Just a couple of things we can discuss during a 'live discussion'! 😃

  Posted September 22, 2015 10:22 PM

• by mini.mintaka scientist in response to JeanTate's comment.

  "Given that known SDRAGNs are rare^n, perhaps the ones we see are in classic spirals which have withstood a major merger? "

  Absolutely!!!

  something that fascinates me is when you start looking for them, there are signs of merger activity is almost every galaxy... spiral or not! I actually find the whole concept of 'blaming' mergers for everything a bit of a cop-out 😃

  I'm looking forward to the live discussion tonight (Sep 23, UTC 2000) !

  Posted September 23, 2015 11:15 AM