Galaxy Zoo Talk

Interesting interaction galaxies

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR

    This area is crazy 😃 Interaction and tidal debris of two large active / starburst galaxies and an bright compact object that looks intense blue.

    enter image description here

    And the lower galaxy has spectra of a white dwarf with z = 0.00415? 8) How is that even possible?

    enter image description here

    http://cas.sdss.org/dr13/en/tools/explore/Summary.aspx?id=1237661387614650682

    Posted

  • mlpeck by mlpeck in response to Ghost_Sheep_SWR's comment.

    And the lower galaxy has spectra of a white dwarf with z = 0.00415? 8)
    How is that even possible?

    The SDSS spectro pipeline had extreme difficulty correctly classifying spectra with strong Balmer absorption lines and little or no emission. This is a classic K+A (aka post-starburst) spectrum that hasn't been cataloged as such. Which is a shame since these are exceedingly rare in the nearby universe.

    Posted

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR

    Thanks for the explanation, I started to think there was maybe a white dwarf interfering with the spectrum or something similar. And terminology I can Google 😃

    Posted

  • mlpeck by mlpeck in response to Ghost_Sheep_SWR's comment.

    SDSS did accidentally target foreground stars for spectroscopy sometimes, but that's not what happened here. This is a nice catch by the way! It's a pity there will probably be no followup observations in the foreseeable future.

    Posted

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR

    That would be a pity yes, seems to me there is a lot of interesting interaction going on, and the compact blue object also looks interesting.

    If nearby post-starburst galaxies are so rare is it possible / would it be useful to change the classification in SDSS for other research so it pops up with queries meant to find these galaxies?

    Posted

  • mlpeck by mlpeck in response to Ghost_Sheep_SWR's comment.

    If nearby post-starburst galaxies are so rare is it possible / would
    it be useful to change the classification in SDSS for other research
    so it pops up with queries meant to find these galaxies?

    DR12 was the final data release of SDSS-III and there's not likely to be a re-reduction of the data. It's very unlikely anyone at SDSS would modify a classification by hand even if the automated pipeline is obviously wrong.

    Anyway it's possible to get a handle on the likely number of missed candidates. I noticed the galaxy in the OP has a set of line index and flux measurements from the mpa pipeline, so I tried a casjobs query to look for objects of class 'STAR' that meet minimal spectroscopic criteria for being a K+A galaxy. Here is (part of) the SQL query:

    select into mydb.kastar
	s.ra,
	s.dec,
	s.plate,
	s.mjd,
	s.fiberid,
	s.z,
	s.zErr,
	s.class,
	s.subClass,
	s.zWarning,
	gi.lick_hd_a_sub as lick_hd_a,
	gi.lick_hd_a_sub_err as lick_hd_a_err,
	gi.d4000_n,
	gi.d4000_n_err,
	ge.lgm_tot_p16,
	ge.lgm_tot_p50,
	ge.lgm_tot_p84,
	ge.lgm_fib_p16,
	ge.lgm_fib_p50,
	ge.lgm_fib_p84,
	ge.sfr_tot_p16,
	ge.sfr_tot_p50,
	ge.sfr_tot_p84,
	ge.sfr_fib_p16,
	ge.sfr_fib_p50,
	ge.sfr_fib_p84
from specObjAll s
left outer join PhotoObj as p on s.bestObjid = p.Objid
left outer join galSpecline as g on s.specObjid = g.specObjid
left outer join galSpecIndx as gi on s.specObjid = gi.specObjid
left outer join galSpecExtra as ge on s.specObjid = ge.specObjid
where
  (g.h_alpha_eqw >  -5 and g.h_alpha_eqw_err > 0) and
  (gi.lick_hd_a_sub > 5 and gi.lick_hd_a_sub_err > 0) and
  (s.class = 'STAR') and
  (s.z > .001) and
  (s.snMedian > 10) and
  (s.zWarning = 0 or s.zWarning = 16)
order by
  s.plate, s.mjd, s.fiberid

    This should return 260 objects. Of those 25 are actually (parts of) galaxies. Five of the 25 are just small parts of very large disk galaxies, and a 6th samples a large tidally disturbed satellite of a disk galaxy. The remaining 19 are mostly nearby dwarf ellipticals and irregulars. A few of those have been identified as K+A galaxies. Here is a list of those 25.

    ra,dec,plate,mjd,fiberid,z,zErr,class,subClass
146.03,-0.65827367,266,51630,95,0.004153254,-1,STAR,A0p
212.18034,-1.1616541,302,51688,84,0.004153254,-1,STAR,A0
40.50152,0.014523286,408,51821,118,0.003623643,2.26E-05,STAR,G2
153.17187,3.1293863,502,51957,525,0.004153254,-1,STAR,F5
179.39689,2.167784,515,52051,72,0.003140814,5.95E-05,STAR,A0p
212.18039,-1.1616128,916,52378,336,0.004153254,-1,STAR,A0
182.59617,10.188549,1229,52723,556,0.001511551,2.55E-05,STAR,A0
188.30596,9.3973605,1233,52734,305,0.003585183,1.43E-05,STAR,F2
148.87375,8.3906322,1235,52734,496,0.004153254,-1,STAR,A0
176.21705,57.873519,1311,52765,533,0.004153254,-1,STAR,A0
241.44596,41.318255,1335,52824,501,0.004153254,-1,STAR,WD
159.78941,41.686679,1360,53033,621,0.002380651,1.67E-05,STAR,A0
181.49072,43.143313,1448,53120,515,0.002553218,3.83E-05,STAR,F9
187.6315,41.700285,1454,53090,316,0.001438407,2.77E-05,STAR,A0
188.11207,42.704121,1454,53090,393,0.001618862,3.90E-05,STAR,A0
182.6016,13.17061,1612,53149,448,0.004153254,-1,STAR,A0
184.00169,8.2022885,1624,53386,544,0.00238512,1.94E-05,STAR,F2
186.02124,8.2938287,1625,53140,621,0.004153254,-1,STAR,A0p
160.4207,13.824877,1748,53112,634,0.004153254,-1,STAR,G0
170.82949,13.629783,1753,53383,100,0.002275757,4.29E-05,STAR,A0
179.89085,13.887199,1763,53463,96,0.004153254,-1,STAR,A0
189.7696,14.731127,1769,53502,196,0.004153254,-1,STAR,F2
149.08492,69.700112,1879,54478,414,0.001099975,1.83E-05,STAR,G2
190.49979,32.573542,1975,53734,430,0.002546039,1.54E-05,STAR,F5
190.5857,17.509761,2600,54243,517,0.003897684,3.34E-05,STAR,A0

    Note: copy and paste the first two columns into the SDSS image list tool to get a set of thumbnails.

    Unfortunately the MPA software was last run on DR8 data so there's no line index measurements for any BOSS targets, but it looks to me as though there are likely to be fewer than a handful of candidates that were overlooked because they were misclassified as stars.

    Posted

  • c_cld by c_cld

    Somewhat modified query to be copied in Search SQL tool

    select s.bestobjid as name,
 s.ra,
 s.dec
from specObjAll s
left outer join PhotoObj as p on s.bestObjid = p.Objid
left outer join galSpecline as g on s.specObjid = g.specObjid
left outer join galSpecIndx as gi on s.specObjid = gi.specObjid
where
 s.z > .0007
and s.snMedian > 6 
and (s.zWarning =0 or s.zWarning=16) 
and s.class = 'STAR'
and s.scienceprimary = 1
and s.bestobjid > 0
and p.petrorad_r > 2.5
and p.r > 12
and g.h_alpha_eqw > -5 
and g.h_alpha_eqw_err > 0
and gi.lick_hd_a_sub > 5 
and gi.lick_hd_a_sub_err > 0 
order by s.ra

    Results to be copied in List tool

    name	ra	dec
1237663784215117996	40.50152	0.014523286
1237664092892955400	117.4379	17.25408
1237663916810502289	141.50627	66.12985
1237660637065576556	145.92905	41.569159
1237664835934748837	146.45573	30.53415
1237660584442855544	148.87375	8.3906322
1237648720680714566	149.94912	-0.519918
1237654599954137159	153.17187	3.1293863
1237667550877712642	154.32327	22.160929
1237661850387546148	159.78941	41.686679
1237661069789692132	160.4207	13.824877
1237661069789954297	161.147	13.939648
1237660612898980098	167.82961	8.598422
1237657613411352701	169.77042	57.777516
1237664130485387328	170.82949	13.629783
1237661950787452962	175.58554	13.026609
1237657612875923616	176.21705	57.873519
1237668624082993257	177.27311	17.255701
1237664290998976718	177.37932	15.261037
1237661358616150192	178.13934	48.293074
1237657590858645605	178.48731	55.171493
1237667324328345916	178.76751	28.347886
1237651753473212499	179.39689	2.167784
1237661068187336848	179.89085	13.887199
1237661949179396296	181.66954	12.034544
1237664667370979427	182.43399	39.125913
1237671128057184307	182.59617	10.188549
1237661950790402284	182.6016	13.17061
1237661951327338602	182.79147	13.587506
1237661070336131284	183.07911	15.483094
1237658424637980763	184.00169	8.2022885
1237662525765452020	184.04197	15.123688
1237667443507658904	184.28419	27.795267
1237661950254645376	185.25087	12.725771
1237667212677152817	185.56969	30.889869
1237661976547623019	186.02124	8.2938287
1237662193453105379	186.04685	41.581108
1237648720696705262	186.51599	-0.542162
1237648705652195459	186.58038	1.019617
1237661977085018198	187.14137	8.6396185
1237662195064373343	188.11207	42.704121
1237662236930998372	188.30596	9.3973605
1237658629696323758	189.34229	12.28703
1237662525231005777	189.7696	14.731127
1237658629696782445	190.41422	12.247391
1237668590262222941	190.5857	17.509761
1237668623014953102	190.97574	16.547457
1237671266034450561	191.56847	2.0461211
1237667448884494461	203.12637	25.123587
1237662262701326444	203.65745	8.7936046
1237662530061729940	203.90487	14.360954
1237648702979047550	212.18034	-1.1616541
1237662695961067828	232.45083	26.087876
1237662267540439293	235.27646	4.7528278
1237661387614650682	241.44596	41.318255
1237652599564665412	320.13321	-7.20274

    Posted

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR in response to mlpeck's comment.

    Wow that is amazing and far beyond my skillset. Well +/- 25 isn't that much I guess, and looking at the galaxies in the list most have a fair amount of references so shouldn't be a problem then.

    Thanks for your extensive answer mlpeck.

    Spectra of nearby post-starburst (part of) galaxies classified by SDSS as Star.

    EDIT: c_cld pointed me to SDSS DR7 for the three 'missing' spectra, added below.

    enter image description here
    http://cas.sdss.org/dr7/en/tools/explore/obj.asp?ra=190.49979&dec=32.573542

    enter image description here
    http://cas.sdss.org/dr7/en/tools/explore/obj.asp?ra=187.6315&dec=41.700285

    enter image description here
    http://cas.sdss.org/dr7/en/tools/explore/obj.asp?ra=146.03&dec=-0.65827367

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=212.18034&dec=-1.1616541

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=40.50152&dec=0.014523286

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=153.17187&dec=3.1293863

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=179.39689&dec=2.167784

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=212.18039&dec=-1.1616128

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=182.59617&dec=10.188549

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=188.30596&dec=9.3973605

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=148.87375&dec=8.3906322

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=176.21705&dec=57.873519

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=241.44596&dec=41.318255

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=159.78941&dec=41.686679

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=181.49072&dec=43.143313

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=188.11207&dec=42.704121

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=182.6016&dec=13.17061

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=184.00169&dec=8.2022885

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=186.02124&dec=8.2938287

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=160.4207&dec=13.824877

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=170.82949&dec=13.629783

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=179.89085&dec=13.887199

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=189.7696&dec=14.73112

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=149.08492&dec=69.700112

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=190.5857&dec=17.509761

    @c_cld : Could you explain what you modified in the query and why?

    Posted

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR in response to mlpeck's comment.

    I would have thought all galaxies would have had some interaction in the distant past, but that doesn't seems to be the case (visually nearby galaxies) for all.

    Hmm one additional question; is the extremely common z = 0.00415 part of the SQL query? 11 out of 22 spectra have this z value. All I can see from the (part of) query is z > 0.001.

    All values are z = 0.00415 z error -1.00000 which is a huge error margin. Maybe 0.00415 zError -1.00000 is some sort of system error in SDSS? Some have no redshift flags either.

    EDIT: actually it is 12 out of 25 galaxies from the selection have an exact z=0.004153254 zErr -1. Which is even more implausible from a semi-random set of galaxies with a random distribution of redshifts.

    Posted

  • c_cld by c_cld in response to Ghost_Sheep_SWR's comment.

    @c_cld : Could you explain what you modified in the query and why?

    main modification on signal/noise (snmedian) for #lsb (low surface brightness) objects

    Posted

  • c_cld by c_cld in response to Ghost_Sheep_SWR's comment.

    NO SPECTRA
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=146.03&dec=-0.65827367

    NO SPECTRA
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=187.6315&dec=41.700285

    DOES NOT EXIST IN DATABASE RA Dec 190.49979,32.573542

    no one missing in SDSS DR7!

    http://cas.sdss.org/dr7/en/tools/explore/obj.asp?ra=146.03&dec=-0.65827367 specObjID 75094093364985856 mjd 51630 plate 266 fiberID 95

    http://cas.sdss.org/dr7/en/tools/explore/obj.asp?ra=187.6315&dec=41.700285 specObjID 409492637276438528 mjd 53090 plate 1454 fiberID 316

    http://cas.sdss.org/dr7/en/tools/explore/obj.asp?ra=190.49979&dec=32.573542 specObjID 556143866579779584 mjd 53734 plate 1975 fiberID 430

    Posted

  • c_cld by c_cld in response to Ghost_Sheep_SWR's comment.

    SDSS pipelines could be wrong in many ways as in this example

    tweet from @vrooje
    https://twitter.com/vrooje/status/823965242736529408

    This background spiral in my @Hubble_Live data is classified by SDSS
    as a star, because it’s so small & the nucleus (AGN?) is so bright:

    ![1237661967971385470](https://pbs.twimg.com/media/C29P995UsAAPIFO.jpg =558x242)

    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?id=1237661967971385470

    Posted

  • c_cld by c_cld in response to Ghost_Sheep_SWR's comment.

    Even BOSS spec pipeline could be worse than old DR7 spec

    http://skyserver.sdss.org/dr12/en/tools/explore/Summary.aspx?id=1237651539794526303

    1237651539794526303 7860138255206510592

    1237651539794526303

    Posted

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR in response to c_cld's comment.

    no one missing in SDSS DR7!

    Great, forgot to check there thanks, will add them to the rest!

    SDSS pipelines could be wrong in many ways as in this example

    Even BOSS spec pipeline could be worse than old DR7 spec

    SDSS 415 Mystery

    Great example nice! But still, isn't an exact z=0.004153254 zErr -1 for 12 of 25 'random' galaxies statistically impossible? There must be something strange happening in the pipeline to get such a result don't you think?

    Posted

  • c_cld by c_cld in response to Ghost_Sheep_SWR's comment.

    SDSS 415 Mystery Great example nice! But still, isn't an exact
    z=0.004153254 zErr -1 for 12 of 25 'random' galaxies statistically
    impossible?

    It's certainly coded in the spec pipeline. I've not the details but I queried these parameters and got results of more than 70 #LSB classified wrongly "star"

    Use query to fill form with

    select
bestobjid as name
,ra
,dec
from specobjall
where
z = 0.004153254
and zErr = -1
and zWarning = 0
and class = 'STAR'
and scienceprimary = 1
and bestobjid > 0

    then "submit" and "send to list" giving 75 thumbnails:

    name,ra,dec
1237648705652195459,186.58038,1.019617
1237666406847283275,35.309003,-0.88671181
1237654030327873820,170.0129,2.6896607
1237654030865793233,172.37485,3.2287052
1237651754011132274,181.89377,2.6400986
1237671764250591319,191.39695,1.9886684
1237651736850465224,225.13762,2.2303162
1237655371429707919,156.98848,60.634126
1237654610141642924,183.10157,65.174181
1237655126630072488,207.92879,5.4465009
1237657630065623292,183.27033,53.105602
1237657613411352701,169.77042,57.777516
1237660637065576556,145.92905,41.569159
1237658303281693091,171.60813,59.293712
1237658422476538141,151.85023,5.3252825
1237658802035621935,175.61338,54.819016
1237658424618320052,138.7389,6.0051681
1237658491208466612,186.69678,8.8845779
1237658492818817135,186.02192,10.067747
1237662238540890247,186.72731,10.665856
1237658492820324459,189.52828,10.082355
1237660584442855544,148.87375,8.3906322
1237660962943271189,146.99358,39.086147
1237657612338331761,173.11535,57.36176
1237657612875923616,176.21705,57.873519
1237661387614650682,241.44596,41.318255
1237661873482367232,201.36497,44.437787
1237661949179396296,181.66954,12.034544
1237661950790402284,182.6016,13.17061
1237658628621467733,186.68509,11.379734
1237661950255235091,186.52787,12.860985
1237661951328977047,186.63497,13.578786
1237658630232604761,187.96393,12.656991
1237661971722797834,185.90375,7.5954803
1237661976547623019,186.02124,8.2938287
1237654786779906160,187.52114,8.0733212
1237661971722993682,186.26243,7.5037617
1237661976011538458,187.7547,7.7232201
1237660558672855083,69.8827,25.4053
1237660760536645797,70.0873,25.7153
1237661949728719071,210.73497,11.225665
1237661069789692132,160.4207,13.824877
1237661068187336848,179.89085,13.887199
1237664289929232469,186.90648,14.455583
1237664291539189997,185.41162,15.745123
1237662525767221450,188.17849,15.036137
1237664291539845408,186.89492,15.739491
1237662525231005777,189.7696,14.731127
1237664289934737472,199.87775,14.026978
1237662238542725396,190.97208,10.745656
1237662238006182033,191.73117,10.182416
1237661971725156432,191.31429,7.6156712
1237671991338401886,202.37952,7.781093
1237662238017388882,217.52989,8.7044687
1237662267540439293,235.27646,4.7528278
1237663916810502289,141.50627,66.12985
1237664835934748837,146.45573,30.53415
1237665129609429002,162.04573,33.744541
1237665532788211961,220.46724,23.784493
1237662695961067828,232.45083,26.087876
1237667549804036495,154.67032,21.380483
1237667550877712642,154.32327,22.160929
1237667782823248162,156.90627,20.078678
1237668294982369408,166.09727,19.917124
1237668496853106774,169.90957,17.869327
1237667735043309662,179.01447,22.208276
1237670964851703877,147.21113,15.643606
1237668623012593981,185.33,16.609295
1237668565027127373,186.35025,18.139822
1237668625161453608,188.64475,18.202684
1237668623014953102,190.97574,16.547457
1237668589190054127,194.2145,16.506724
1237668623020524254,204.18421,15.598399
1237663783139410271,36.00158,-0.8193354
1237666209787937902,283.33096,18.120831

    Posted

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR in response to c_cld's comment.

    That's a nice query / method to retrieve the thumbnails fast! Weird, 75 LSB galaxies with the same z value and classification Star.

    I've checked several galaxies in NED and as would be expected all have different redshifts, SDSS redshifts might mess up certain galaxy statistics. Some sort of 'default' z value when the pipeline has trouble establishing redshift perhaps?

    For example the last object on page 3 has a NED redshift of z = ~3.9

    Posted

  • mlpeck by mlpeck in response to Ghost_Sheep_SWR's comment.

    The SDSS spectro pipeline did a search on a discrete grid of redshift values to get the best match to sets of star, galaxy and QSO templates, and I guessed that the redshift values being reported here were at the high end of the search grid for 'STAR's. The problem with that guess is that according to the DR8 release paper the limits for stars were ±1200 km/sec. and 1200/c = 0.00400, not 0.004153...

    Anyway, I ran this simple query in casjobs:

    select into mydb.allstars
	s.z,
	s.zErr,
	s.elodieZ,
	s.elodieZErr,
	s.zWarning
from specObjAll s
where
  (s.class = 'STAR') and
  (s.zWarning = 0 or s.zWarning = 16)

    This returns 760,294 hits when run in DR10 context. At the blue shifted end of the redshift distribution there are 49 spectra with z = -0.004136078 or z = -0.004136076 (rounded to 9 digits). There are only 2 objects more blue shifted.

    At the redshifted end 128 have z = +0.004153253 or z = +0.004153254 and again there are only 2 that are more red shifted.

    On superficial eyeball inspection I don't see any tendency for redshifts to cluster around any other discrete values. So my first guess might be right after all.

    Here's something I think might be worth looking into: all of the misclassified examples you, c_cld and I found seem to be local dwarf galaxies (either spheroidal or irregular). Is it possible any of these have been completely overlooked? Adding even one or two to the census of known local dwarf galaxies would be a useful (i.e probably publishable) discovery. Just a thought that I'm not going to be able to follow up on for a while.

    Posted

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR in response to mlpeck's comment.

    What would be needed to confirm it is (likely) overlooked as a local dwarf galaxy?

    A different or not existing redshift in NED / SIMBAD, different NED classification or no mention in any paper as such?

    And do you mean the misclassified examples of this thread including your last 49 + 128 or inspection of over 760,000 hits?

    Posted

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR

    Hmm I think I can work with this. Take the objects that are clustered around said redshift (either blueshift or redshift) so it is a manageable number. Should visibly be galaxies because there stars included in that selection. If there is another (correct) redshift in NED they are probably not overlooked so can be dismissed.

    Selection criteria for candidates AFAIK should result in possible overlooked local dwarf galaxies from a first selection of SDSS objects classified as STAR and clustered around z = + or - 0.004153254;

    • visual galaxy morphology to exclude stars

    • no redshift value in NED

    • No dwarf classifications in NED + SIMBAD

    • no mentions in papers concerning (local) dwarf galaxies

    Comments / corrections on criteria are very welcome!

    Posted

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR

    After making a list of 118 objects from this thread (after removing duplicates ofcourse) I ran through them all and below is what remained of it, and a couple of sizes for fun. Can't judge if the first three are overlooked as local dwarfs.

    enter image description here
    http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=141.50627&dec=66.12985

    Has a (probably correct) NED redshift z = 0.005818 but without a proper dwarf classification or size indication, is explicitly classified in SIMBAD as white dwarf star and is referenced in SDSS DR7 White Dwarf Catalog in ADS.

    enter image description here http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=190.97574&dec=16.547457

    A bit confusing one. Has a NED redshift z = 0.004041 without dwarf classification or size indication, and when going to SIMBAD from the SDSS Object page doesn't seems to be included in SIMBAD because I can only select two other nearby objects.

    enter image description here http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=217.52989&dec=8.7044687

    NED redshift z = 0.004751 no dwarf classification or size indication, no included in SIMBAD, no reference to dwarf galaxy papers.

    enter image description here http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=175.58554&dec=13.026609

    Looks mighty purple but might be optical artifact, no redshift data besides SDSS redshift, not included in SIMBAD.

    These are just for fun, the 3 smallest dwarfs of the set, for reference the Milky Way is roughly 31-55 x 0.6 kpc.

    enter image description here 0.47 x 0.31 kpc http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=177.27311&dec=17.255701

    enter image description here 0.61 x 0.30 kpc http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=184.04197&dec=15.123688

    enter image description here 0.70 x 0.55 http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=189.34229&dec=12.28703

    And due to a probably wrong redshift, here are two 'NED giant galaxies', for reference the Milky Way is roughly 31-55 x 0.6 kpc, IC 1101 has a halo of around radius 600 kpc.

    enter image description here 254.45 x 132.31 kpc http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=156.90627&dec=20.078678

    enter image description here 174.75 x 152.03 kpc http://skyserver.sdss.org/dr13/en/tools/explore/Summary.aspx?ra=185.90375&dec=7.5954803

    Well that's it for me for these objects, if you have additional data on above galaxies or if you think there might be an overlooked local dwarf galaxy among them please post here and let me know!

    Posted

  • mlpeck by mlpeck in response to Ghost_Sheep_SWR's comment.

    I think there might actually be something here. I don't have time right now to look at these in detail, but take a look at the very last example. It was in the "Virgo Cluster Catalog" of Binggeli, Sandage & Tammann (1985) based on photometric properties, but listed as a dropped candidate in the "Extended Virgo Cluster Catalog" of Kim et al. (2014). That was based on an erroneous redshift of z = 2.2 (from SDSS DR7 or earlier?). A correct redshift measurement should put it back in the Virgo Cluster.

    Next question is how to proceed. I'd suggest trying to contact (via Twitter most likely) a GZ scientist (not Lintott, someone less senior), perhaps klmasters or one of the graduate students/postdocs, or just @GalaxyZoo. I'd also suggest going private with further posts.

    Posted

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR

    That would be great 😃 With such strange redshifts there's bound to be something odd in there.

    Thanks for the feedback! and suggestion, but I feel Talk should be the place where volunteers and scientists discuss possible finds. If that doesn't happen then there are still the moderators who do a great job of flagging up interesting things to the scientists. If nothing else maybe when you do find some time you can look at these in detail. Besides without the input from you and c_cld I definitely wouldn't be able to compile a list of objects.

    In case I missed something here is the complete list with some notes.

    ra dec

    141.50627 66.12985 NO WD NED Z 0.005818

    190.97574 16.547457 ???

    217.52989 8.7044687 No NED REF SIMBAD

    175.58554 13.026609 Purple Point

    177.27311 17.255701 0.47 x 0.31

    184.04197 15.123688 0.61 x 0.30

    189.34229 12.28703 0.70 x 0.55

    156.90627 20.078678 Big NED size

    185.90375 7.5954803 Big NED size VCC 0653

    036.00158 -0.8193354 Point

    069.8827 25.4053 Point

    070.0873 25.7153 Point

    117.4379 17.25408 Point

    146.03 -0.65827367 UGC 5205

    147.21113 15.643606 Point / Star

    148.87375 8.3906322 UGCA 188

    149.08492 69.700112 M82

    149.94912 -0.519918 Point

    153.17187 3.1293863 NGC 3156

    151.85023 5.3252825 NEDz

    159.78941 41.686679 NGC 3319

    167.82961 8.598422 Point

    179.01447 22.208276 QSO / Point

    181.49072 43.143313 UGC 7089

    185.41162 15.745123 IC 783

    186.51599 -0.542162 Point

    186.69678 8.8845779 UGC 7546

    199.87775 14.026978 QSO / Point

    202.37952 7.781093 Star / Point

    204.18421 15.598399 Star / Point

    210.73497 11.225665 Star / Point

    220.46724 23.784493 Point

    283.33096 18.120831 Point

    320.13321 -7.20274 Point

    187.6315 41.700285 NGC 4485

    188.11207 42.704121 UGC 7690

    188.64475 18.202684 NGC 4539

    190.49979 32.573542 NGC 4631 companion

    212.18039 -1.1616128 IC 976

    035.309003 -0.88671181

    040.50152 0.014523286

    138.7389 6.0051681

    145.92905 41.569159

    146.45573 30.53415

    146.99358 39.086147

    154.32327 22.160929

    154.67032 21.380483

    156.98848 60.634126

    160.4207 13.824877

    162.04573 33.744541

    166.09727 19.917124

    169.77042 57.777516

    169.90957 17.869327

    170.0129 2.6896607

    171.60813 59.293712

    172.37485 3.2287052

    173.11535 57.36176

    175.61338 54.819016

    176.21705 57.873519

    170.82949 13.629783 IC 2787

    178.13934 48.293074

    178.48731 55.171493

    179.39689 2.167784

    179.89085 13.887199

    181.66954 12.034544

    181.89377 2.6400986

    182.43399 39.125913

    183.07911 15.483094

    183.10157 65.174181

    183.27033 53.105602

    184.00169 8.2022885

    184.28419 27.795267

    185.25087 12.725771

    182.59617 10.188549 IC 3025

    182.6016 13.17061

    182.79147 13.587506 IC 3033

    185.33 16.609295

    186.02192 10.067747

    186.26243 7.5037617

    186.35025 18.139822

    186.52787 12.860985

    186.58038 1.019617

    186.63497 13.578786 IC 3344

    186.68509 11.379734

    186.72731 10.665856

    186.89492 15.739491

    186.90648 14.455583

    187.14137 8.6396185 UGC 7596

    187.52114 8.0733212

    187.7547 7.7232201

    187.96393 12.656991 IC 3457

    188.17849 15.036137

    188.30596 9.3973605 IC 3487

    189.52828 10.082355 IC 3602

    189.7696 14.731127 IC 3612

    190.41422 12.247391 IC 3663

    190.5857 17.509761

    190.97208 10.745656

    191.31429 7.6156712

    191.39695 1.9886684

    191.73117 10.182416 IC 3767

    194.2145 16.506724

    201.36497 44.437787

    203.12637 25.123587

    203.65745 8.7936046

    203.90487 14.360954

    207.92879 5.4465009

    225.13762 2.2303162

    232.45083 26.087876

    235.27646 4.7528278

    241.44596 41.318255

    161.147 13.939648 1.03 x 0.88

    177.37932 15.261037 0.84 x 0.36

    178.76751 28.347886 0.75 x 0.36

    185.56969 30.889869 1.03 x 0.72

    186.02124 8.2938287 1.26 x 0.99

    186.04685 41.581108 1.37 x 0.94

    191.56847 2.0461211 0.84 x 0.65

    Posted

  • JeanTate by JeanTate

    I second what mlpeck wrote, especially the bit about there possibly being something interesting here.

    General comments (nothing really new):

    • faint fuzzy local-dwarf-looking galaxies with SDSS spectroscopic redshifts (zsp) are not at all rare
    • it is highly likely that a significant subset of these have zsps which are wrong (i.e. are well outside the stated value ± the stated error)
    • (ditto almost any other class of faint SDSS objects with zsps)
    • NED (and SIMBAD) don't do much other than collect what's found in catalogs and papers; in particular, there's no concerted attempt made to ensure sources are consistent (this is perhaps too broad, but a good working assumption)

    My own experience, of several years' ago now, is that you will almost certainly find some interesting objects! 😃 However, there will likely be considerable work needed to understand what you've found, which would almost certainly have to be done before getting time on a big telescope (or the HST).

    Besides without the input from you and c_cld I definitely wouldn't be able to compile a list of objects.

    Would you like to learn how to be able to do this sort of thing yourself? Perhaps it would be of considerable value to other GZ zooites (here is an RGZ thread that's similar, in a way).

    Posted

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

    My own experience, of several years' ago now, is that you will almost certainly find some interesting objects! 😃 However, >there will likely be considerable work needed to understand what you've found, which would almost certainly have to be >done before getting time on a big telescope (or the HST).

    No doubt that's alot of work! That's why I hope some things might be interesting enough for a (GZ) scientist to put time and effort in follow-up research. Beyond my scope. In the case of a 'false' redshift it might be relatively easy perhaps, one good spectrum might clear up any confusion.

    Would you like to learn how to be able to do this sort of thing yourself? Perhaps it would be of considerable value to other >GZ zooites (here is an RGZ thread that's similar, in a way).

    I guess it wouldn't hurt if someone started a thread with simple starting examples, the SDSS example queries don't seem very helpful to me.

    On the RGZ thread; could it be outdated? Recently I've found out it is very simple to make a NVSS contour overlay in Aladin, not sure about FIRST though.

    Posted

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

    That's why I hope some things might be interesting enough for a (GZ) scientist to put time and effort in follow-up research. Beyond my scope.

    No doubt you are aware of the recent Zooniverse AMA section, and the thread Are there more serendipidous discoveries waiting to be followed up ?; I think it's worth repeating something the zookeeper (Chris Lintott) wrote:

    On the broader question - I think @JeanTate is right to highlight the gap between 'spotting something unusual' and getting enough people with enough skills to focus on what's been found to get it to the point where we can write a paper or apply for telescope time. At present, despite heroic efforts from a few Zooites, that gap is I think too large for most people to cross. It's something we'd like to work on.

    IOW, perhaps it's more fruitful to teach someone how to fish than to give them handouts of fish.

    I guess it wouldn't hurt if someone started a thread with simple starting examples, the SDSS example queries don't seem very helpful to me.

    Indeed.

    Who do you think could start such a thread (besides c_cld, mlpeck, and me)?

    On the RGZ thread; could it be outdated? Recently I've found out it is very simple to make a NVSS contour overlay in Aladin, not sure about FIRST though.

    Indeed.

    And that Aladin capability existed long before I decided to teach myself Python (let alone work out how to produce contour overlay images). It's equally simple to produce such contour overlays with FIRST data, and with both FIRST and NVSS.

    However, I'd like to suggest that while the Aladin outputs can look nice, their scientific value is very limited (or, saying the same thing another way, to produce scientifically useful overlays using Aladin is not at all "very simple"). In fact, the Aladin shortcomings were one of my motivators for developing the Python code (other motivators included encouragement from a PI, and requests from fellow zooites to learn how I did it).

    Here's another example, also from RGZ: I have a position, how do I find which ARG fields contain it (if any)?. Note the date (September 8 2015). And the date when the solution was posted (November 10 2015).

    Posted

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

    Ofcourse there is also

    Work on the Voorwerpjes continues in many ways. Galaxy Zoo participants still find possible clouds (and the moderators have been excellent about making sure we see them)

    https://blog.galaxyzoo.org/2016/12/20/new-hubblegemini-results-history-of-fading-agn/

    So I'm hopeful 😃 . Too bad a gap has grown, the question is which side will bridge it? I think I've learned alot the last years and really try finding out more about potential interesting things to either dismiss them or present them in a more interesting way.

    But in the end how much could be realistically expected of non-scientist volunteers? Time is best spent classifying and in the meantime looking out for the odd thing IMHO. A couple of new serendipitous discoveries would clear the way for more scientist time and attention. Pull not push 😃

    Posted

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

    Of course there is also [...]

    Yes, once a new class of object has been definitively identified, and that new class is seen as likely able to help address one or more important questions in contemporary astrophysics, the professional community is quite good at diligently following up.

    Too bad a gap has grown, the question is which side will bridge it? I think I've learned alot the last years and really try finding out more about potential interesting things to either dismiss them or present them in a more interesting way.

    And this is terrific! 😃 Is there a way to create a dozen, a hundred clones of Ghost_Sheep_SWR? 😉

    But in the end how much could be realistically expected of non-scientist volunteers?

    Excellent question! 😄

    Time is best spent classifying and in the meantime looking out for the odd thing IMHO.

    Maybe diversity too?

    For most, time is best spent like that. But as there will always be far fewer professional astronomers than interesting, possibly revolutionary, new objects, maybe some effort to encourage a cadre of non-scientist volunteers who can do at least the first part of follow-up investigations on their own might be an investment that pays big (this is what Chris L is hinting at, I think)? After all, studies have shown that the "non-scientist volunteers" include rather a lot of people with PhDs, MScs, and BScs. So they surely have the requisite foundations, and their participation surely indicates interest ...

    A couple of new serendipitous discoveries would clear the way for more scientist time and attention.

    Let's hope so.

    However, the history of GZ - or even any astronomy Zooniverse project - since GPs and the Voorwerp is rather lacking in such serendipitous discoveries (can you cite any?). Since GPs and the voorwerpjes, there have been quite a few new astronomy PhD students (and PhDs) whose work leverages GZ+ results or uses new GZ+ data, Mel G for example. However, AFAIK, none have worked on any new serendipitous discoveries. And if you compare the incidence of posts by GZ scientists here in GZ Talk with that in the old GZ forum, what do you find?

    Posted

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

    Hmm I don't know what Chris L. is hinting at, might be something the other way around, or even something completely different like a zooite flagging system for objects.

    Well maybe a new class of objects surely is a bridge too far, but for me the chance of finding a new Voorwerpje / unreported transient / other serendipitous discovery etc. is worth the hunt.

    For getting (new) zooites to search for information on their own and preventing them from getting discouraged one suggestion is to put these 3 great resources central on top of the Talk page in BIG letters;

    #1 How do I : Find out more information about the galaxy I have classified?
    https://talk.galaxyzoo.org/#/boards/BGZ0000005/discussions/DGZ0000lv2

    Astrophysics for Galaxy Zoo Talk - redshift z PhotoZ spectra emissions AGN
    https://talk.galaxyzoo.org/#/boards/BGZ0000001/discussions/DGZ0000ulp?page=1

    Index for Galaxy Zoo Talk (links and images )
    https://talk.galaxyzoo.org/?_ga=1.244656832.476670387.1443719759#/boards/BGZ0000001/discussions/DGZ0000wrb

    A very simple change like this could mean a big difference, especially the first one for first time exploration of SDSS.
    I remember when I started here I found it very difficult to learn how to find out more and even finding these useful pages among all other resources / pages.

    I'm also willing to create a more up-to-date 'How do I: Find out more...' page so zooites can learn step by step to answer most questions they have themselves, such as are these galaxies interacting? How big is this galaxy? Etc. Regarding SDSS, redshift, NED and some other resources.

    Posted

  • Budgieye by Budgieye moderator

    How can we make it simpler? All people have to do is look around on the Recent page, and start clicking on featured discussions. When I started contributing to Galaxy Zoo Forum in 2008, there was little information. Even though I "lurked" for 3 days first, my first questions were the supernova and the cosmic ray hit.

    We shall probably "soon" be getting the new version of Talk, and maybe we will make changes at the same time. If you want to practice making a self help discussion now, the moderators could put it in the featured discussion. Talk is for all of us, contributors don't have to be a moderator.

    Posted

  • mlpeck by mlpeck

    Hi Jean:

    I for one am thinking small here. We aren't talking about anything categorically new. Almost everything turned up so far in this topic is a nearby, low surface brightness, dwarf spheroidal (+some irregulars) galaxy. The questions I have, in no particular order are

    • How many of them have no accurate redshift measurement in the literature and are previously unrecognized as galaxies? There's already at least one example of a galaxy found and then lost.
    • Is there a database query that will produce a reasonably high purity sample of galaxies misclassified as stars? Simply looking at the high redshift end of the distribution of stars does produce a sample that's heavily contaminated with galaxies and that might be sufficient.
    • Is there a database query that will produce a high completeness sample of galaxies? That might be a problem. I'd expect galaxies to be scattered along the full range of stellar redshifts probed by the SDSS spectro pipeline and there could be a tiny percentage of misclassified spectra at any redshift.
    • What's the significance of z=0.004153... anyway? A statistical excess of objects at exactly this redshift makes no sense given the available documentation of how the spectro pipeline works (which is basically in a couple of data release papers and buried somewhere in the SDSS-III website).

    Finally:

    Suppose we identify some number (≥1) of galaxies that are misclassified in SDSS, have no accurate redshift measurement in the literature, and are unrecognized as galaxies. Suppose also we can produce accurate redshifts, some line index measurements, and perhaps refine the photometry. Is there a publication in this? I'm guessing maybe yes this might be suitable for MNRAS /Apj Letters -- what we would be doing is adding to the census of known dwarf galaxies in the greater Virgo Cluster and perhaps some nearby galaxy groups.

    Some feedback from an actual scientist might be helpful at this point, which is why I suggested contacting some directly. I wouldn't count on a mod to act as intermediary or expect a scientist just to happen upon this topic. And even though I don't have a lot of use for Twitter I do find it's an effective way to get peoples' attention.

    Posted

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR

    Well after this crisp reply I have absolutely nothing more to add, except for some clickbait paper titles;

    Lost And Found: Not Too Bright Dwarfs

    Leave No Dwarf Behind!

    Faint Dwarfs: Or How To Become A Star

    Thanks mlpeck!

    PS. no twitter or anything fancy like that for me...

    Posted

  • mlpeck by mlpeck

    I'm going to do two followup posts and then I'm done with this topic I think. First, getting back to the galaxy in the OP: I get a redshift using my own template fitting procedure of z = 0.006682±8.9e-06. That's within about 12 km/sec. of the brighter galaxy to the north. There's also a much fainter galaxy to the north of these two with the same redshift. I don't think that one has been noticed before:

    enter image description here

    Posted

  • mlpeck by mlpeck

    Followup #2.

    I did some queries in CasJobs on spectroscopic objects classified as stars in DR12. For all of these I restricted the ZWarning flag to be either 0 or "many outliers" (the latter warning according to SDSS documentation rarely indicates a problem; in retrospect it might have been good to include the warning flag "small delta chisq" as well. Maybe next time). Following an example c_cld posted earlier I also tried setting limits on petrosian radius, reasoning that an extended photometric radius might signal that the target is actually something other than a star. Here are counts of the number of hits:

    all SpecObj     875778
primary only    762997
R_petro > 2.5"   22955
R_petro > 5"      4707

    So even the most restrictive query produces more candidates than I care to look at. From a look at a small sample of the "extended" objects there were clearly many false positives: mostly glare from nearby bright stars and targets that were actually stars in the foreground of galaxies.

    Since one of the interesting finds so far was a galaxy that was in the original Virgo Cluster Catalog but excluded from the more recent Extended Virgo Cluster catalog I decided to try crossmatching the results of the second query with Table 3 of the EVCC. That turns out to be easy in Topcat, which can do a crossmatch on any table online at Vizier. That query produced 8 hits, which are listed in the table below. Seven of those are (probably) dwarf spheroidal systems.

    I ran my own redshift estimation routine on all 8 spectra, and those are listed along with the SDSS measurements in the table below. I also list formal error estimates. Notes on individual objects:

    1. IC 3039: Spectroscopic target was a foreground star. NED lists the galaxy as having redshift z≈0.02, which is likely correct and which puts it in the background of Virgo.

    2-5. These are all very low surface brightness galaxies with low S/N spectra. I have no confidence at all in either the SDSS redshift measurements or mine. I rather doubt that a more sophisticated algorithm could get a more accurate redshift. So, in the unlikely event that someone in a position to get telescope time reads this, these objects really could use additional spectroscopy.

    6-8. These three have reasonably robust redshift measurements, and all three are likely Virgo Cluster members. For some reason NED has no redshift data for any of them.

    So there we have it: there are 3 galaxies that should be added back to the census of Virgo Cluster members and another 4 that need confirmation.

    I don't really have any great ideas about how to get additional likely candidates out of the (at least) thousands of possibles.

    name ra dec z_sdss z_err_sdss z_mlp z_err_mlp
    IC 3039 183.1357 12.3099 0.000198371 1.75753e-05 0.000159094 1.09244e-05
    VCC 0653 185.9038 7.5955 0.00415325 -1 -0.00949819 4.90965e-05
    VCC 0414 185.1016 14.6908 -0.000111712 5.60178e-06 -0.00978367 5.19651e-05
    VCC 1604 188.7934 13.9862 -0.00333485 0.151176 -0.00797457 3.1324e-05
    VCC 1879 190.3641 11.1459 0.00356829 1.11342e-05 -0.00745789 3.30958e-05
    VCC 1238 187.4746 10.3380 0.00217841 1.65791e-05 0.00218661 1.01423e-05
    IC 3442 187.8341 14.1152 0.00415325 -1 0.00418043 1.64866e-05
    IC 3634 190.0469 9.8475 0.00105169 5.34377e-05 0.00115792 2.8664e-06

    Posted

  • mlpeck by mlpeck

    I guess I wasn't quite ready to let this go. I did a position crossmatch of the second query in the previous post (that is all science primary 'STARS') with the "Catalog of Principal Galaxies" (aka HYPERLEDA) of Paturel et al. (2003). That produced 880 hits. I browsed through thumbnail images using the SDSS image list tool and it appears to me that the majority (maybe overwhelmingly) of objects are foreground stars or stars nearby to galaxies. Some objects appear just to be stars with no galaxy nearby. But there are galaxies in there too.

    The list is a little long for this forum so I uploaded a copy to my dropbox account. The file name is pgcxmatch.csv.

    Of course by construction everything on this list has been cataloged as a galaxy somewhere, so there aren't any discoveries to be made here. But there must be some objects without accurate redshifts in NED (for example the three identified in the previous post). Another possible project would be to identify the dual redshift spectra and try to get accurate redshifts for the background galaxies.

    Posted

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR in response to mlpeck's comment.

    I sense...... something is nagging you :p

    Maybe GZ scientists will see an oppurtunity in this thread eg. "GZ volunteers discover lost galaxies", but I'm afraid if you aren't able to take this further it will probably not happen.

    So far I've done everything possible within my abilities, and can't add to what you're posting about now. But there were some priceless 'Hey that's odd' moments I greatly enjoy, finding odd things when you're not even searching 😃 Just to let you know I'm still enjoying your follow-up posts and explanations of how you think and construct cross-matches etc.

    After the list of 118 objects I got a sense of the numbers and time involved; 880 is really too large a number to work with.. (And also a bit distracted by a new obscure GZ project involving brown dwarfs).

    Another possible project would be to identify the dual redshift
    spectra and try to get accurate redshifts for the background galaxies.

    If I understand correctly you mean spectra that are contaminated by foreground stars right?

    Posted

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR

    AGZ000d69g

    SDSS star

    NED z = 0.003153 +/- 0.000135 (dwarf)

    enter image description here enter image description here

    http://skyserver.sdss.org/dr9/en/tools/explore/obj.asp?ra=181.67507814405568&dec=39.009642455652376

    http://ned.ipac.caltech.edu/cgi-bin/objsearch?search_type=Obj_id&objid=2565219&objname=1&img_stamp=YES&hconst=73.0&omegam=0.27&omegav=0.73&corr_z=1

    Posted