Author Topic: Saturday,22nd Feburary,2014:Double OotD,arc+ring around ellipticals  (Read 1765 times)

Tony Wei

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Hello,everyone!
Today's OOTD is for two objects,one is about an arc around a elliptical,the other is for a unique 'HOAG' ring candidate.
OBJECT 1:LEDA 194158


What's that on the side of the elliptical?
This question is being discussed in TALK.
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Are these two galaxies or somewhat else?
by Sekundenschlaf 21 hours ago

Two galaxies; the central one has a very bright core. The one to the right is severly distubred
by ElisabethB MODERATOR 21 hours ago

#SO next to a radio source that looks like a lens
by joi2cjoi 20 hours ago

third oppinion to this maybe? also thought that's a lens
by Sekundenschlaf 20 hours ago

No, it is not a lens. It is too diffused and the lens galaxy does not have enough mass to cause an arc of that size.
by Capella05 MODERATOR 19 hours ago
Indeed,that arc is too wide for a lens.The arc is [HBW2011] J225222.66+010701.0(May be associated with 2MASX J22522239+0107002.)1Obviously it's also different from AGN clouds.
Can we assume that the arc is a dying spiral galaxy,just like that one in HCG 0902?But the shape is much too weird!What's going on?OK,we need your views!
Some data of the ring:
Log (Flux Density S in mJy): -0.23
Frequency                  :  1.4  GHz
For the host galaxy
Distance:Luminosity: 305 Mpc Angular-Size: 267 Mpc
Helio. Radial Velocity     :     21505±59 km/s     
Redshift                   :  0.071734±0.000197
Major Diameter (arcmin)    :  0.28
Minor Diameter (arcmin)    :  0.193
Magnitude and Filter       : 17.4g
4 5

1according to NED.
2see http://www.galaxyzooforum.org/index.php?topic=281574.105
3It means it's between E3&E4
4widefield view:

5That also reminds me another object:

possible lens in UKIDSS images.
I'll have to give koedooder credit for it, however.


OBJECT 2:'the Scream'SDSSCGB 11347 with a ring around 2MASX J11384282+1207587.The ring is 588017703465058498
This object is posted by Pat as a 'HOAG' ring candidate,it's also mentioned by zutopian in Re: Possible strong gravitational lensesBut the bizarre1 shape doesn't agree.And as a HOAG ring,its shape is so weird.The other hand,there are two ellipticals inside the ring.So waveney included it in an OOTD for weird rings.But other rings in it do not contain more than 1 object like 'the Scream',or the ring is not so integral as it.

This is widely discussed in 2008,but,however,it's got 'no real explanation yet'2.So I'd like to 'revisit' it for we may learn a lot from it.
The scream is in a Compact Group of Galaxies3,with 7 members4.Its redshift is 0.177000 and the Helio. Radial Velocity is 53063 km/s.Magnitude is 16.82 from NED5 6.It's also a GIG7.8
To understand how the ring forms,we need some pictures of higher quality and wider discussion.
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So,

1Blog post for Classifying Ring Galaxies
2see Terminology - Names you may not find in an Astronomy textbook (yet)
3SIMBAD
4SIMBAD
5Other info:

Calculated and Corrected Velocities
V (Heliocentric)           :   53063  km/s
V (Kinematic LSR)          :   53064  km/s
V (Galactocentric GSR)     :   52984 +/-      3 km/s
V (Local Group)            :   52930 +/-      8 km/s
V (3K CMB)                 :   53411 +/-     24 km/s
V (Virgo Infall only)      :   53129 +/-     16 km/s
V (Virgo + GA only)        :   53356 +/-     23 km/s
V (Virgo + GA + Shapley)   :   53434 +/-     23 km/s

Hubble Flow Distance and Distance Modulus (where Ho =   73.0 +/- 5 km/sec/Mpc)
D (Galactocentric GSR)     :   725.8 +/-   50.8 Mpc      (m-M) = 39.30 +/- 0.15 mag
D (Local Group)            :   725.1 +/-   50.8 Mpc      (m-M) = 39.30 +/- 0.15 mag
D (3K CMB)                 :   731.7 +/-   51.2 Mpc      (m-M) = 39.32 +/- 0.15 mag
D (Virgo Infall only)      :   727.8 +/-   50.9 Mpc      (m-M) = 39.31 +/- 0.15 mag
D (Virgo + GA only)        :   730.9 +/-   51.2 Mpc      (m-M) = 39.32 +/- 0.15 mag
D (Virgo + GA + Shapley)   :   732.0 +/-   51.2 Mpc      (m-M) = 39.32 +/- 0.15 mag

Scale at Hubble Flow Distances
Scale (Galactocentric GSR) :    3519 pc/arcsec =  3.519 kpc/arcsec = 211.13 kpc/arcmin =  12.67 Mpc/degree
Scale (Local Group)        :    3515 pc/arcsec =  3.515 kpc/arcsec = 210.92 kpc/arcmin =  12.65 Mpc/degree
Scale (3K CMB)             :    3547 pc/arcsec =  3.547 kpc/arcsec = 212.83 kpc/arcmin =  12.77 Mpc/degree
Scale (Virgo Infall only)  :    3528 pc/arcsec =  3.528 kpc/arcsec = 211.71 kpc/arcmin =  12.70 Mpc/degree
Scale (Virgo + GA only)    :    3544 pc/arcsec =  3.544 kpc/arcsec = 212.61 kpc/arcmin =  12.76 Mpc/degree
Scale(Virgo + GA + Shapley):    3549 pc/arcsec =  3.549 kpc/arcsec = 212.92 kpc/arcmin =  12.78 Mpc/degree
Luminosity Distance        : 830 Mpc      (m-M) = 39.59 mag
Angular-Size Distance      : 598 Mpc      (m-M) = 38.88 mag
Co-Moving Radial Distance  : 704 Mpc      (m-M) = 39.24 mag
Co-Moving Tangential Dist. : 704 Mpc      (m-M) = 39.24 mag
Co-Moving Volume           : 1.46 Gpc^3
Light Travel-Time          :    2.116 Gyr
Age at Redshift 0.178161   :   11.183 Gyr
Age of Universe            :   13.299 Gyr
Scale (Cosmology Corrected):    2898 pc/arcsec =  2.898 kpc/arcsec = 173.88 kpc/arcmin =  10.43 Mpc/degree
Surface Brightness Dimming : Flux Density per Unit Area =  0.51902; Magnitude per Unit Area = 0.712 mag
6UKIRT image,shows some active parts of the ring:

7from SIMBAD
8SEE OOTD Saturday, 15 February, 2014: Publication = Discovery
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After looking through Terao et al.'s "Genuine Irregular Galaxy" list (thanks c_cld for pasting the list of positions!) I noticed a couple things:

The galaxy you led off your OOTD post is a confirmed member of Hickson Compact Group (HCG) 59, and therefore does not meet their main criterion for a "GIG". All you have to do is zoom out a bit to see that it's a group member!



This thread is also for those unusual things on the side of those ellipticals,like that object above I mentioned before.So you can also put your similar objects here.
Our greatest glory is not in never falling ,but in rising every time we fall.
——Nelson Rolihlahla Mandela

AlexandredOr

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Re: Saturday,22nd Feburary,2014:Double OotD,arc+ring around ellipticals
« Reply #1 on: February 22, 2014, 03:00:04 pm »
Brilliant. Great OotD  :)

Baby star opening its eyes on the Universe.

JeanTate

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Re: Saturday,22nd Feburary,2014:Double OotD,arc+ring around ellipticals
« Reply #2 on: February 26, 2014, 02:02:02 pm »
Very interesting OOTD, Tony!  8)