Outliers - summary
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by
JeanTate
In this thread I will list all the outliers - in the Outliers - collect them here! thread - by type.
It will be a work in progress; as I get time I'll go through the main thread, extract objects, and post them into the relevant post in this thread (by editing it).
As it's possible for an object to be an outlier in more than one way, such an object may appear in more than one list.
The lists are (working titles only):
- star
- overlap
- bad spectrum
- flux(es) badly wrong
- not main/central part of the target galaxy
- V_disp too large (etc)
- bad Petro_R50
- color outlier
- (placeholder)
Posted
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by
JeanTate
Star
(explanation goes here; not just 'object=isolated star', but also 'object is primarily a star on line of sight to galaxy, possibly contaminating the spectrum')
Quench Sample
AGS00001dn (587733432461754555)
AGS00001z3 (758878270823858940)
AGS00001ka (587736543633867051)
AGS00002ak (758877274402460510) - may be overlap; may be QSO
Quench Control
AGS00004d5 (587745447095304755)
AGS0000445 (587741505930592407)
Posted
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JeanTate
Overlap
(explanation goes here; not just that the object is a background - rarely, a foreground - galaxy, but also where the morphological classification is likely to be confused, as in some zooites would have thought the background/foreground galaxy was interacting)
Quench Sample
AGS00000wp (587734303806390532)
AGS0000182 (588015510352298194)
AGS000026g (588023668100825363)
AGS00000ds (154189975032692736) - maybe not (an overlap)
Quench Control
AGS00002qp (587726014001578079)
AGS00003ky (587735695913320628) - seen through an inter-arm region of M101
Posted
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JeanTate
Bad spectrum (placeholder for now)
Posted
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by
JeanTate
Flux(es) badly wrong (placeholder for now)
Posted
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JeanTate
Not main/central part of galaxy
(explanation goes here; not always clear what the main, or central, part of a galaxy is; however, objects here are clearly not! May be HII region, star-forming region, some other kind of clump, or ...)
Quench Sample
AGS00000nz (587729752745902407)
AGS000021r (758882025707733014)
AGS00000to (588295842324021329)
AGS000017a (588298664111112243)
AGS00000iz (587731187819937915)
AGS0000272 - (587742060001820696)
AGS00001bl - (588017726012129327) - spectrum only (image is OK)
AGS0000242 - (587742627995058239)
AGS000029c - (587742012757180541)
AGS000017f - (588298664112881826)
AGS0000182 (588015510352298194) - also an overlap
AGS00000wq (587731185657774302) - minor galaxy in a merger
AGS00000ji (587726878885478661) - minor galaxy in a merger
AGS00001w6 (587739811036791074)
AGS0000038 (588848901010686358) - not obvious
Quench Control
AGS00002y7 (587732152572313657)
AGS000034r (587724240151642162)
AGS000048a (587729752206672095)
AGS00002p7 (587738411398070358)
AGS00002ud (587731512614912145)
AGS0000352 (587731891114934425)
AGS00003yw (587736940906872995) - spectrum only (image is OK)
Posted
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by
JeanTate
V_disp too large (etc)
(explanation goes here; unrealistic estimates of V_disp; mainly 800 ± -3 and 400 ± -50, but also 0 ± 0. Only QS so far, because QC has no V_disp field)
Quench Sample
800 ± -3:
AGS00000so (587729387147427913)
AGS00000xe (587731679572852949)
AGS000016a (587735661013500098)
AGS000018i (588015509820801199)
AGS00001ho (587735347501072399)
AGS00001nu (587738615943725169)
AGS000000e (588848899366977698)
AGS00000an (587725073917739155)
AGS00001ka (587736543633867051)
400 ± -50
AGS00000kn (587727223021240473)
AGS00000li (587729387137401043)
AGS00000v8 (587732578312323193)
AGS00000va (587732577238646829)
AGS000016e (588016892250095738)
AGS00001l2 (587730023330021460)
AGS00001yc (587741420560777244)
0 ± 0
AGS00001ta (587739720296693832)
Posted
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by
JeanTate
Bad Petro_R50
(explanation goes here; unrealistic estimates of the size parameter, Petro_R50)
Quench Sample
AGS00000s1 (587732469848015025) - near bright star
AGS000017a (588298664111112243)
AGS000021c (587742062663041028)
AGS00001cm (758881522663490016)
AGS000021r - also non-main
Quench Control
AGS00002qp (587726014001578079) - also overlap
AGS000049f (587728666117603339)
AGS00002o8 (587736619320213712) - also overlap
AGS00003xb (587736813672792218) - near bright star
AGS00002vf (587742551211769895)
AGS0000445 - also overlap
AGS0000352 - also non-main
AGS00004bm - overlap?
AGS000031r - near bright star
Posted
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JeanTate
color outlier
Posted
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JeanTate
(placeholder, for now)
Posted
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mlpeck
One thing I noticed a couple posts up is that the various data processing pipelines have no consistent symbol for indicating missing or unusable data. The SDSS pipeline generally indicates missingness with a negative error estimate, but they also use 0.0 in either the value field or error field sometimes. I've also seen -9999, -99, any negative number (for a field that should be strictly positive) used. As we saw early on the MPA pipeline sometimes just returns wildly unphysical values for emission line fluxes.
All of your vdisp outliers a few posts up are examples of data that should be recorded as missing.
Posted
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zutopian
in response to JeanTate's comment.
I guess, that you mean the galaxies, which are in below topic, also started by you.:
http://quenchtalk.galaxyzoo.org/#/boards/BGS0000008/discussions/DGS00001zlPosted
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JeanTate
in response to zutopian's comment.
Yes, that's where I'd be going to start filling in that post/list. However, I have not gotten around to doing so yet; not everything in that thread is (necessarily) a color outlier; and there may be color outliers which are not in that thread.
Posted
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zutopian
From Goto's paper:
These criteria nicely remove contamination from nearby stars and star-forming regions.
(..)
Our criteria are more strict than previous ones (e.g.,...), suppressing possible contaminations from other populations of galaxies (Goto 2004).http://arxiv.org/abs/0801.1106
Posted