SDSS J085354.49+350900.5, the one that got away ...
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JeanTate
SDSS J085354.49+350900.5 is in the center:
Its DR7 ObjId is 588297865252110427, and, not unexpectedly, it is the subject of a lot of discussion in the GZ forum; for example, the OOTD Wednesday 17th June 2009: What is it? (by waveney). In the DR7 image, it's not clear that there's a dustlane across the face of the lower object, so 2009 zooites can be forgiven for thinking that the big, barred spiral is foreground to the train-wreck (the dustlane strongly suggests it's actually background!).
Anyway, why did this "get away"?
Because it's not one of the 3003 "visually selected pairs of merging galaxies from the SDSS" in Darg+(2010a) ("Galaxy Zoo: the fraction of merging galaxies in the SDSS and their morphologies", link is to the Galaxy Zoo data page)! 😮
So, how did they miss it?
Well, it could be because P_MG - the 'merger fraction' - of the GZ1 votes is only 0.292 for this object (Darg+ used 0.4 for their main cut). Really?!? Zooites could not see what a spectacular merger this is? Actually, it's more that they were confused ... P_DK ("Don't know") is 0.597. It would be nice to see if the GZ2 classification is different/better, but unfortunately it's not in GZ2.
But, I can hear you saying, Darg+ were well aware of the possibility of genuine mergers lurking among those with P_MG < 0.4, and as they explain in their paper, they tried a couple of things to nail down how many of these there might be. But, for whatever reason, they missed this one.
588297865252110427 aka ARP 195 and UGC 04653
That's waveney, from the 2009 OOTD. Notice something interesting? This is also called "ARP 195"; in other words, it's in the Arp Atlas of Peculiar Galaxies.
Now that atlas has been known to contain lots of mergers, since it was first published in 1966.
Mystery question: why did none of the 16 authors think to cross-check Arp's atlas (apparently)?
Double mystery: waveney is, in IRL, Richard Proctor, one of the co-authors.
Take away for citizen scientists: it's a big universe, and even professional astronomers very closely involved with Galaxy Zoo can miss some very interesting things. If you want to do your own research, to discover some of these overlooked interesting things, do not hesitate, you will very likely succeed in making a discovery possibly as important as any other for which Galaxy Zoo is already well-known. However, do be clear-eyed about how much support you will likely get.
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Capella05
moderator
Hi Jean,
I am really struggling to find the point of this post, and what you are trying to convey.
Initially I thought you were trying to provoke a reaction from @waveney, but considering he has not been on the zoo for several years, and therefore unable to defend himself - I thought it was unlikely.
Take away for citizen scientists: it's a big universe, and even professional astronomers very closely involved with Galaxy Zoo can miss some very interesting things. If you want to do your own research, to discover some of these overlooked interesting things, do not hesitate, you will very likely succeed in making a discovery possibly as important as any other for which Galaxy Zoo is already well-known. However, do be clear-eyed about how much support you will likely get.
What exactly, are you expecting from GZ?
When we signed up, and started classifying, it was never promised that we would get a PhD or our names in the headlines - only that our contributions would make a difference and our effort was worth it. From my point of view, that promise has been fulfilled. The sacrifice (not really!) of my personal time is well and truly vindicated.
Perhaps you feel differently.
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vrooje
admin, scientist
I definitely agree that professional scientists don't have a monopoly on discovery; far from it.
As far as I know, the sample from Darg et al. has never been represented as the definitive collection of all merging galaxies in the SDSS. It is one sample, with a completeness level and a contamination level, which have both been explored and characterized. Most importantly for the science, the selection is straightforward and described completely in the paper so that it is replicable by other scientists (citizen or otherwise). You, or anyone, can download the GZ catalogs and perform the same selection. Then, should you choose to do so, you can throw that away and/or perform a different selection, including adding the Arp catalog or other merger catalogs. If you do that, you will complicate your analysis of completeness and contamination, but that may be an acceptable tradeoff for you. That is entirely your decision.
You've made an assumption that those involved in the merger papers failed to cross-check with existing catalogs while performing their analysis, instead of, for example, simply not writing up the long list of things they considered and decided not to do. I am not an author on the Darg et al. study, but the authors seem to me to have made a deliberate choice to keep things as simple as possible by not including archival catalogs, each of which has its own selection function. You might make a different choice, but that doesn't mean theirs was a mistake.
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mlpeck
Changing the subject a little bit, Arp 195 was a Spitzer IRAC target. I didn't spend a lot of time on this and didn't try to make them pretty, but here are some pictures. I cropped these to have approximately the same orientation and FOV of SDSS Navigate at default zoom level. The first was prepared from the 3.6, 4.5 and 5.8 μm bands; the second from 3.6,4.5 and 8 μm.
The IR image makes it pretty clear that there are 3 galaxies here. If I'm not mistaken emission at 8μm is from warm dust and molecules called polycyclic aromatic hydrocarbons (PAH) when present and that's a certain indicator of star formation. I deliberately blew out the highlights of the second image to show that there is extensive debris surrounding the entire group.
As an aside, the first redshifts measured for the southern and middle galaxies were made by Keel et al. (1985).
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zutopian
in response to JeanTate's comment.
Anyway, why did this "get away"?
Because it's not one of the 3003 "visually selected pairs of merging galaxies from the SDSS" in Darg+(2010a) ("Galaxy Zoo: the fraction of merging galaxies in the SDSS and their morphologies", link is to the Galaxy Zoo data page)! 😮
So, how did they miss it?
Well, it could be because P_MG - the 'merger fraction' - of the GZ1 votes is only 0.292 for this object (Darg+ used 0.4 for their main cut). Really?!? Zooites could not see what a spectacular merger this is? Actually, it's more that they were confused ... P_DK ("Don't know") is 0.597. It would be nice to see if the GZ2 classification is different/better, but unfortunately it's not in GZ2.
But, I can hear you saying, Darg+ were well aware of the possibility of genuine mergers lurking among those with P_MG < 0.4, and as they explain in their paper, they tried a couple of things to nail down how many of these there might be. But, for whatever reason, they missed this one.
Sorry for belated reply! 😃 Well, I respond to a post, which you had done last year!
Better late than never! 😃Please be informed, that there is following other paper by Darg et al. concerning GZ mergers.:
Galaxy Zoo: Multi-Mergers and the Millennium Simulation
Authors: D. W. Darg, S. Kaviraj, C. J. Lintott, K. Schawinski, J. Silk, S. Lynn, S. Bamford, R. C. Nichol
(Submitted on 19 Dec 2010 (v1), last revised 17 Jan 2011 (this version, v2))
http://arxiv.org/abs/1012.4214In my opinion, it is strange, that it got away, though it is a "multiple merger"! Curiously, it isn't part of the "multiple mergers" sample!
The images of the multiple merger sample (39 mergers) are shown on page 2 of the paper!
There is given following statement on page 7.:(...) and it is plausible to assume that multi-mergers are amongst the types of merger more likely to be classified as ‘merging’ (in the Galaxy Zoo interface) than simple binaries because multi-mergers generally appear quite dramatic, prompting the user to go for the merger button.
Related GZ blog post:
Galaxy Zoo Multi Mergers, Dec 2010
https://blog.galaxyzoo.org/2010/12/22/galaxy-zoo-multi-mergers/GZ Data page:
This sample of merging galaxies is assembled from SDSS Galaxy Zoo 1 data. It is a homogenous sample of galaxies (0.005 < z < 0.1) with spectroscopy for at least one of two merging galaxies in the pair.
I guess, that GZ-1 is related to spectra in DR7! The galaxy in the middle has a spectrum in DR7 (z=0.057).
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