Author Topic: Friday, 21 February, 2014: Very Strange Spirals?  (Read 22271 times)

JeanTate

  • OotD posters
  • Hero Member
  • *****
  • Posts: 2976
    • View Profile
Re: Friday, 21 February, 2014: Very Strange Spirals?
« Reply #30 on: June 10, 2014, 02:13:22 am »
{holding pen, independent discovery of an already known source (?): "One previously known case (NGC 3079) has also turned up: http://radiotalk.galaxyzoo.org/#/subjects/ARG0000b5m"

also ARG00004w0

and ARG00010mw - 3C285}

(to be continued/edited)
« Last Edit: June 12, 2014, 05:50:29 pm by JeanTate »

JeanTate

  • OotD posters
  • Hero Member
  • *****
  • Posts: 2976
    • View Profile
ARG00018d0 SDSS J164652.71+383845.3 (zutopian)
« Reply #31 on: June 10, 2014, 07:27:01 am »
ARG00018d0 | SDSS J164652.71+383845.3 | zutopian | discovery (June 9 2014 8:58 AM) | | ~0.2 ph

The disk galaxy - an Eos (edge-on spiral) or at least a highly inclined one, possibly an early-type (Sa?) - is in the center of this SDSS DR10 image, which is 100"x100" (500x500 pix @ 0.2"/pix):



Per Aladin's pre-packaged 'SDSS9 colored' background with FIRST emission displayed as contours on top:



So this may be a core (SMBH in the nucleus of the host galaxy, the Eos) plus a single lobe (i.e. a one-sided FRII source); or the host (galaxy hosting the SMBH) may be the faint smudge, SDSS J164652.14+383839.9, and the alignment with the edge-on disk galaxy mere chance:



I recently downloaded Aladin Sky Atlas, and have started using it in "Aladin on your machine" mode.

JeanTate

  • OotD posters
  • Hero Member
  • *****
  • Posts: 2976
    • View Profile
ARG00027yg SDSS J170525.98+221617.9 (WizardHowl)
« Reply #32 on: June 10, 2014, 10:28:09 am »
ARG00027yg  | SDSS J170525.98+221617.9 | WizardHowl | discovery (January 20 2014 7:56 PM) | | 0.048 sp
SDSS J170525.98+221617.9, the nice face-on spiral in the center:



Here is a composite with FIRST, in red (a fair bit of image processing, so it's more artist than scientific):



As it's nigh on impossible to find anything in Talk, here's what's been posted about this candidate (in RGZ Talk):

WizardHowl: "spiral with spectrum of elliptical?"

Ivywong: "@kevinschawinski and I had a look at the spiral's spectrum below and we agree that it's fairly normal one for an old dusty spiral. some hints of optical AGN activity in the lines but [oiii] and Hb lines are too weak to tell"

WizardHowl: "The host [...] seems to be SDSS J170525.98+221617.9 Z_sp=0.048 a smooth spiral but with a spectrum more closely resembling an elliptical. Maybe it could be an elliptical that has been disturbed by an encounter (with the larger elliptical next door that also is a radio source) and now has a spiral shape? If so then it is not a 'true' spiral but the recent blog post about red spirals found in Galaxy Zoo Hubble suggests that the view of which galaxies may really be disks may be changing anyway, which will impact radio classifications... (discussion for another day...)"

A couple of additional composites:



« Last Edit: June 12, 2014, 09:02:16 pm by JeanTate »

JeanTate

  • OotD posters
  • Hero Member
  • *****
  • Posts: 2976
    • View Profile
ARG0002j29 SDSS J135817.73+171236.7 & J135818.74+171300.6 (WizardHowl)
« Reply #33 on: June 10, 2014, 01:15:33 pm »
  • ARG0002j29 | SDSS J135817.73+171236.7 | WizardHowl | discovery (January 21 2014 6:46 PM) | | 0.095 sp
  • ARG0002j29 | SDSS J135818.74+171300.6 | WizardHowl | discovery (January 21 2014 6:46 PM) | | 0.095 sp

SDSS J135817.73+171236.7 in the center; SDSS J135818.74+171300.6 in upper-left quadrant.



A composite with FIRST, in red (a fair bit of image processing - different from the last one - and it's more artist than scientific):



WizardHowl: "2 spiral galaxies with hourglass emission or corejets at Z_sp=0.095 EoS SDSS J135817.73+171236.7 barred spiral SDSS J135818.74+171300.6"

Quote from: WizardHowl
Today I also found two candidates and am adding them to this thread to keep track of them - they are both in the same image and at the same redshift of Z_sp=0.095, so their morphology is clearer and their spectra cleaner:

http://radiotalk.galaxyzoo.org/#/subjects/ARG0002j29

almost edge-on disk SDSS J135817.73+171236.7

barred spiral SDSS J135818.74+171300.6

The barred spiral has much weaker emission that barely generates a contour and both seem to be corejets, although it is also possible that the stronger source is a triple and the barred galaxy just has weak activity near its core; the orientation makes it ambiguous and without seeing detail in the jets the triple scenario is more likely as it invokes only one source rather than two.

UPDATE: I'm revisiting the objects I'd posted earlier, with a view to applying the two criteria consistently.

Start with the DR10 image, scale 0.18"/pix, 108"x108", centered on the "almost edge-on disk SDSS J135817.73+171236.7"



One galaxy is certainly not a boring elliptical, but the other? Stay tuned.

SkyView composite, DR7 SDSS r-band (faded to all-but invisibility) with FIRST contours (0 min, 8 levels, contour smoothing 8 ) and above DR10 image:



Radio emission is/extends beyond optical boundary of galaxy? For the galaxy in the center, check; for the other one? "maybe" at best, but more likely "can't really tell"

Is this galaxy in the center the likely host of the radio emission? Yes! What about the other one? Well, it has nuclear radio activity ...

For the barred spiral, then, poor.

Applying the same ellipticity and inverse concentration ratio (c) tests as I introduced with ARG0000da3 (see this post), "almost edge-on disk SDSS J135817.73+171236.7" is an E4 elliptical, with c below the threshold value (0.385) in all bands (except u, but the error for petroR90_u is off the scale). Subjectively, I'd class it as an elliptical. So, poor.
« Last Edit: June 16, 2014, 03:27:28 pm by JeanTate »

JeanTate

  • OotD posters
  • Hero Member
  • *****
  • Posts: 2976
    • View Profile
Re: Friday, 21 February, 2014: Very Strange Spirals?
« Reply #34 on: June 10, 2014, 04:23:21 pm »
I'm about to make some major edits to the post I'm quoting - which I'm using to record what 'very strange spirals' zooites have found, in RGZ - and I want to preserve a copy of where I had gotten up to before I start to make those edits.

Catch up, and collection. I'll edit/update this post periodically. Current status: first pass at collecting all candidates done (includes IDs, discoverer/timestamp/link, and redshift). Some loose ends to be tidied up. Images already posted in RGZ Talk to be added in this thread, one per candidate.

In this post: possible lobe/jet radio source apparently associated with disk galaxies (a.k.a. spirals), as identified independently by zooites, and posted in the Hourglass sources associated with spiral galaxies RGZ Talk thread. Together with discoverer, link to discovery RGZ comment/post/thread, and link(s) to nice composite images.

Quasi-columns: RGZ ID, SDSS ID, zooite, discovery link (and date of discovery), image(s) link(s), redshift ("ph"= photometric, "sp" = spectroscopic), note (if any); | character as separator. Order is per appearance in the RGZ thread (which, of course, may not be the order of discovery) ETA: now that I have all the timestamps, I may have re-ordered this by date/time (almost).

  • ARG0001uiz | SDSS J120339.20+275537.2 | WizardHowl | discovery (January 6 2014 12:45 PM) | images | ~0.165 ph
  • ARG0002fud | SDSS J160458.97+183547.7 | antikodon | discovery (and images) (January 9 2014 6:57 PM) | 0.1222 sp
  • ARG0003qg8 | SDSS J112526.53+014301.5 |  firejuggler | discovery (January 10 2014 7:16 PM) | | 0.434 sp
  • ARG0002esa | SDSS J140535.56+190612.9 | infobservador | discovery (January 14 2014 9:43 PM) | image | 0.057 sp
  • ARG0002zck | SDSS J154336.07+110512.9 | infobservador | discovery (January 14 2014 10:38 PM) | images | 0.084 sp
  • ARG0001zj8 | SDSS J122640.22+253855.5 | WizardHowl | discovery (January 17 2014 3:52 PM) | image | 0.134 sp
  • ARG00007yo | SDSS J083136.46+574545.9 | WizardHowl | discovery | | unlikely
  • ARG00027yg  | SDSS J170525.98+221617.9 | WizardHowl | discovery (January 20 2014 7:56 PM) | image | 0.048 sp
  • ARG0002j29 | SDSS J135817.73+171236.7 | WizardHowl | discovery (January 21 2014 6:46 PM) | image | 0.095 sp
  • ARG0002j29 | SDSS J135818.74+171300.6 | WizardHowl | discovery (January 21 2014 6:46 PM) | image | 0.095 sp
  • ARG00036hs | SDSS J132435.81+084635.5 | antikodon | discovery (January 27 2014 8:11 PM) | images | 0.044 sp
  • ARG00022wh | SDSS J112811.63+241746.9 | WizardHowl | discovery (January 30 2014 4:00 PM) | image | ~0.16 ph
  • ARG0002y6c | SDSS J080217.94+112535.0 | WizardHowl | discovery (January 31 2014 5:09 PM) | | 0.060 sp
  • ARG0002ozz | SDSS J144039.86+144122.6 | WizardHowl | discovery (February 21 2014 7:18 PM) | | ~0.08 ph
  • ARG0001kwr | SDSS J121659.93+323106.0 | WizardHowl | discovery (February 23 2014 2:01 PM) | | 0.125 sp
  • ARG00028nb | SDSS J142305.86+215735.5 | WizardHowl | discovery (February 24 2014 1:01 PM) | | ~0.13 ph
  • ARG0003o7j | SDSS J022612.45+023307.4 | WizardHowl | discovery (February 25 2014 8:08 PM) | | 0.145 sp
  • ARG0000x3e | SDSS J092132.98+441345.2 | c_cld | discovery (March 1 2014 9:28 PM) | | 0.247 sp | 4C 44.18
  • ARG0002oyw | SDSS J104434.63+144204.0 | c_cld | discovery (March 2 2014 3:26 PM) | | 0.155 sp | DR8/9 ObjId 1237661070863761563
  • ARG000328n | SDSS J124256.34+101305.9 | WizardHowl | discovery (March 6 2014 4:14 PM) | | ~0.17 ph
  • ARG0003jjg | SDSS J212804.10+041738.4 | sharqua | discovery (March 16 2014 4:14 PM) | | ?
  • ARG0002whf | SDSS J080259.73+115709.7 | WizardHowl | discovery (March 26 2014 4:10 PM) | | ~0.13 ph
  • ARG0000css | SDSS J102733.29+544227.9 | WizardHowl | discovery (April 2 2014 5:52 PM) | | ~0.26 ph
  • ARG00012kb | SDSS J091445.53+413714.3 | zutopian | discovery (May 2 2014 7:58 AM) | | ?
  • ARG0000qmw | SDSS J101536.14+472044.1 | Jean Tate | discovery (May 6 2014 7:58 PM) | | ~0.2 ph
  • ARG0002g0s | SDSS J130140.93+183104.9 | WizardHowl | discovery (May 21 2014 3:01 PM) | | 0.146 sp
  • ARG00025v9 | SDSS J120110.64+230519.2 | antikodon | discovery (June 6 2014 12:35 AM) | image | 0.049 sp
  • ARG00018d0 | SDSS J164652.71+383845.3 | zutopian | discovery (June 9 2014 8:58 AM) | image | ~0.2 ph

Anything else to add?

Please let me know of any mistakes you fell I made, or any corrections, or additions I should make; comments, suggestions: all are welcome!  :)

(to be continued/edited)

JeanTate

  • OotD posters
  • Hero Member
  • *****
  • Posts: 2976
    • View Profile
ARG0002y6c SDSS J080217.94+112535.0 (WizardHowl)
« Reply #35 on: June 12, 2014, 12:32:55 pm »
ARG0002y6c | SDSS J080217.94+112535.0 | WizardHowl | discovery (January 31 2014 5:09 PM) | | 0.060 sp

The galaxy is in the center of this DR10 cutout, 126"x122" (526x510 pix @0.24"/pix):



Per Aladin's pre-packaged 'SDSS9 colored' background with FIRST emission displayed as contours on top:



The association - galaxy/radio emission - seems excellent; and the galaxy seems to have a dustlane, or possibly stubby arms (or does it?). But what sort of radio emission is it, corejet? And is the fainter emission - to the SW - real? associated with the galaxy?

UPDATE: A SkyView composite, SDSS DR7 r-band (DR10 wouldn't load, strange) with FIRST contours (0 min, 3 levels, contour smoothing 8 ) and a DR10 image (108"x108", 600x600 pix @0.18"/pix):



Is this galaxy (still) not a boring elliptical? yes
Radio emission is/extends beyond optical boundary of galaxy? Check.
Is this galaxy the likely host of the radio emission (possible corejet, hint of a detached lobe?)? yes

good
« Last Edit: June 17, 2014, 08:51:46 am by JeanTate »

JeanTate

  • OotD posters
  • Hero Member
  • *****
  • Posts: 2976
    • View Profile
ARG0002ozz SDSS J144039.86+144122.6 (WizardHowl)
« Reply #36 on: June 12, 2014, 12:59:30 pm »
ARG0002ozz | SDSS J144039.86+144122.6 | WizardHowl | discovery (February 21 2014 7:18 PM) | | ~0.08 ph

The "galaxy" (it's actually a blue STAR) is in the center of this DR10 cutout, 121"x117" (526x510 pix @0.23"/pix):



Per Aladin's pre-packaged 'SDSS9 colored' background with FIRST emission displayed as contours on top:



Whatever the host galaxy is, which is producing this nice hourglass emission, it is not a local spiral.  :(
« Last Edit: June 12, 2014, 01:46:15 pm by JeanTate »

JeanTate

  • OotD posters
  • Hero Member
  • *****
  • Posts: 2976
    • View Profile
ARG0002nfj SDSS J105743.81+151740.3 (zutopian)
« Reply #37 on: June 12, 2014, 01:31:40 pm »
ARG0002nfj | SDSS J105743.81+151740.3 | zutopian | discovery (May 8 2014 2:47 PM) | image | ~0.076 ph | similarities with objects featured in DocR's Remarkable Discoveries Underway – Citizen Scientists fire up Radio Galaxy Zoo blog post

The galaxy - an inclined white spiral with brilliant white nucleus - is in the center of this DR10 cutout, 121"x117" (526x510 pix @0.23"/pix):



Per Aladin's pre-packaged 'SDSS9 colored' background with FIRST emission displayed as contours on top:



The NW bent triple (a "wat", wide-angle tail) - "Starship Enterprise"  ;) - has the ETG ("elliptical") z_ph ~0.243 SDSS J105742.10+151804.1 as its host.

The NE radio source, the nucleus of the disturbed spiral z_sp=0.037 SDSS J105744.80+151826.8 is typical of spirals (fairly weak radio emission, confined to the nuclear region).

The central source is the ETG z_sp=0.222 SDSS J105743.38+151748.9. Chance alignment? Both white spiral and z=0.222 elliptical are unrelated sources? Spiral is radio quiet, and just happens to lie in the apparent path of the (far in the background) nascent jet from the super-massive black hole in the elliptical?

Oh, and why "Starship Enterprise"? Judge for yourself!  ;D



UPDATE: SkyView composite, SDSS DR7 r-band (DR10 wouldn't load, strange) with FIRST contours (0 min, 10 levels, contour smoothing 8 ) and DR10 image (108"x108" (600x600 pix @0.18"/pix)):



Is this galaxy - the white spiral with the dazzling AGN - the likely host of the radio emission? Of the nuclear emission, certainly. Of any of the radio emission which extends well beyond the optical boundary? I'm going for "can't really tell".

poor.
« Last Edit: June 17, 2014, 01:50:36 pm by JeanTate »

JeanTate

  • OotD posters
  • Hero Member
  • *****
  • Posts: 2976
    • View Profile
ARG0001pl7 SDSS J161358.61+301809.4 (antikodon)
« Reply #38 on: June 12, 2014, 02:03:43 pm »
ARG0001pl7 | SDSS J161358.61+301809.4 | antikodon | discovery (May 22 2014 1:07 AM) | image | ~0.105 ph

The galaxy - small inclined white disk - is in the center of this DR10 cutout, 174"x168" (526x510 pix @0.33"/pix):



Per Aladin's pre-packaged 'SDSS9 colored' background with FIRST emission displayed as contours on top:



Perhaps the host is one of the faint z_ph ~0.66 red splodges, such as SDSS J161358.01+301812.3?



That would make this double lobe a real giant!  :P

Later, I'll add a composite with the FIRST emission in red ...

Now is later: The galaxy is in the center of this DR10 cutout, 216"x2116" (600x600 pix @0.36"/pix):



Is this galaxy not a boring elliptical? Yes!

SkyView composite, FIRST, in red, with contours (0 min, 9 levels, contour smoothing 8 ) and above DR10 image:



Radio emission is/extends beyond optical boundary of galaxy? Check.
Is this galaxy the likely host of the radio emission (doublelobe)? yes.

Good  :)
« Last Edit: June 16, 2014, 09:17:42 pm by JeanTate »

JeanTate

  • OotD posters
  • Hero Member
  • *****
  • Posts: 2976
    • View Profile
ARG0001kwr SDSS J121659.93+323106.0 (WizardHowl)
« Reply #39 on: June 12, 2014, 02:26:13 pm »
ARG0001kwr | SDSS J121659.93+323106.0 | WizardHowl | discovery (February 23 2014 2:01 PM) | | 0.125 sp

The galaxy is in the center of this DR10 cutout, 121"x117" (526x510 pix @0.23"/pix):



Per Aladin's pre-packaged 'SDSS9 colored' background with FIRST emission displayed as contours on top:



No doubt about the association. Nor that the galaxy has an AGN; here's the spectrum:



But is it a disk galaxy?  ???

JeanTate

  • OotD posters
  • Hero Member
  • *****
  • Posts: 2976
    • View Profile
ARG00028nb SDSS J142305.86+215735.5 (WizardHowl)
« Reply #40 on: June 12, 2014, 02:40:57 pm »
ARG00028nb | SDSS J142305.86+215735.5 | WizardHowl | discovery (February 24 2014 1:01 PM) | | ~0.13 ph

The galaxy is in the center of this DR10 cutout, 121"x117" (526x510 pix @0.23"/pix):



Per Aladin's pre-packaged 'SDSS9 colored' background with FIRST emission displayed as contours on top:



Yes, it's very likely the host, and the radio emission extends far beyond the optical boundary (at least in this SDSS image) ... but is it a disk galaxy?  ???  Zooming in a bit:



What do you think?

JeanTate

  • OotD posters
  • Hero Member
  • *****
  • Posts: 2976
    • View Profile
About 3C 285...
« Reply #41 on: June 12, 2014, 06:03:54 pm »
Still from that thread:

SDSS J132117.81+423515.2 1237662196142047400 z spec=0.079
3C 285 -- Active Galaxy Nucleus



FIRST #double lobe




Superposition SDSS/FIRST


Also posted, by c_cld, in the RGZ Talk thread Did any GZ zooites discover unusual radio galaxies?1 Some discussion ensued:

Quote from:  me (February 23 2014 3:14 PM)
Morphologically, the host seems to me to be a disturbed disk galaxy, likely a merger. It's an AGN, and it clearly has two radio lobes, making it a DRAGN. It would thus seem to meet raynorris (scientist)'s criterion for being a radio-loud spiral. Yet as it's a 3C object, it's surely been investigated to death a long time ago, so what are we missing?

Here's the DR10 image, zoomed in:


Quote from: c_cld (February 23 2014 3:56 PM)
3C 285

The Interaction between Radio Lobes and Hot Gas in the Nearby Radio Galaxies 3C 285 and 3C 442A

paper related to proposal OPTICAL EMISSION IN DOUBLE RADIO GALAXY LOBES: CYCLE 4, HST Proposal 5156, Philippe Crane, NASA Headquarters

Quote from: WizardHowl (February 23 2014 3:57 PM)
I wouldn't assume that just because a radio-loud galaxy is in 3C it means we won't learn anything from looking them up in SDSS - there's always the possibility the association between the radio and optical has not been made before. This applies especially to strange radio morphologies as well as galaxies that are very faint in optical. As an example look at 3C 343, which appears in RGZ as http://radiotalk.galaxyzoo.org/#/subjects/ARG00001qs and has an optical host in SDSS: I could not find a spectrum for the host galaxy in NED/SDSS! By all means add the above DRAGN spiral to the list of objects in the thread started by raynorris :)

1 Link takes you to the thread; while you can sometimes find a way to get the URL of an individual post in a v2 Talk thread, in this case I couldn't, so you'll just have to wade through the whole thread to find the posts I am referring to.  :P

The existence of a disk in 3C 285 (the host galaxy of the radio emission) has been known for quite a while.

In one of its main outputs, NED provides a list, with columns like "Object Name", "Object Type", "Velocity/Redshift", ... and "Refs", and "Notes".

For 3C285, there are (today) 203 Refs  8) :o and 6 Notes. All six are worth copy/pasting here (my added bold):

Quote from: 1
Re:3C 285
A14. 3C 285 - Ours is the first X-ray spectrum to be measured for the nucleus of this source. A two-component model with absorbed and unabsorbed power laws and a strong Gaussian component with rest-frame energy 6.42+/-0.05 keV are required, although the data are not good enough to constrain the photon indices of the power-law components.
(2006MNRAS.370.1893H)

Quote from: 2
Re:3C 285
Irregular clumps of emission linked to star formation are detected in the ultraviolet image of this galaxy (Allen et al. 2002). The near-infrared image shows a flattened galaxy elongated southeast to northwest. The dust lane perpendicular to the elongation of the galaxy is visible in both the WFPC2 and NICMOS images. A faint arclike source is present approximately 5.1" to the southeast; see zoom image.
(2006ApJS..164..307M)

Quote from: 3
Re:3C 285
3C285.-Figure 18 shows the optical and UV images of 3C 285. This galaxy has a very chaotic morphology, with multiple large- and small-scale irregular dust lanes. There appears to be two main dust systems which are elongated perpendicular to one another. The smaller system, aligned roughly along P.A. = 5deg, obscures the nucleus. The larger system aligned along P.A. = 330deg intersects the smaller system at about 2" distance from the nucleus and defines a large ridge of extinction which crosses the entire PC chip (Fig. 18h). The UV image reveals clumps of emission which are predominantly located along the edges of both the small and large-scale dust lanes. These clumps are suggestive of star formation along the edges of dust lanes. Faint diffuse emission is also detected in the UV image, and the dust lanes are apparent in a smoothed version of the image.
(2002ApJS..139..411A)

Quote from: 4
Re:3C 285
5.4 3C 285
The host galaxy of 3C 285 has been identified with the brightest member of a group of galaxies (Sandage 1972). Optical imaging of the galaxy reveals an elliptical main body and a distorted S-shaped envelope aligned with a companion galaxy ~40 arcsec to the north-west (Heckman et al. 1986). Narrow-band imaging shows that the S-shaped extension is the result of continuum-emitting structures (Heckman et al. 1986; Baum et al. 1988). The narrow emission lines are originated by photoionization with a high-ionization parameter (Saunders et al. 1989; Baum et al. 1992). Sandage (1972) found that the B - V colour of 3C 285 is much bluer than that of a normal elliptical galaxy. Our observations show that the blue light of the nucleus (inner 2 arcsec) is dominated by a burst which contains A2I stars, and thus has an age of 10-12 Myr. Saslaw, Tyson & Crane (1978) identified a bright blue slightly resolved object halfway between the nucleus and the eastern radio lobe, which they denoted 3C 285/09.6. Optical spectra and imaging obtained by van Breugel & Dey (1993) showed that the knot is at the same redshift as the galaxy, and its UBV colours and 4000-A break are consistent with a burst of 70 Myr, which they interpreted as being induced by the radio jet. 3C 285 is a classical double-lobed radio galaxy of 190 arcsec total extension at 4.86 GHz, with two hotspots and an eastern ridge showing curvature roughly along the line to the optical companion (Leahy & Williams 1984; Hardcastle et al. 1998). The source has not been detected by the Einstein satellite in X-rays, at a flux level f(0.5-3 keV) < 1.5 x 10^-13^ erg cm^-2^ s^-1^ or L_X_ = 4.4 x 10^42^ erg s^-1^ (Fabbiano et al. 1984).
(2001MNRAS.325..636A)

Quote from: 5
Re:3C 285
5.3 3C 285 (z=0.0794)
This relatively blue galaxy appears in both passbands to be a nucleated disc interacting with a less luminous (V = 17.36 mag) and slightly redder (U - V = 1.37) neighbour (G2), 39.9 arcsec away at PA -249 (Fig. 6). Both galaxies show tidal distortion of their outer isophotes. The galaxy is mildly asymmetric in the V band and more obviously so in the U band, where the nucleus is less prominent but appears to lie within a large (radius ~ 3-4 arcsec, ~ 6-8 kpc), off-centre ring structure (Fig. 7). Baum et al. (1988) found radio-axis aligned H{alpha} emission extending ~ 5.5 arcsec either side of the nucleus, but this is not visible in our images. We do detect a known hotspot (H1) with V = 20.64 mag and U - V = 0.39, 48.2 arcsec from 3C 285 at PA 840, which is within the east radio lobe. It is less blue than our starburst model (U - V = -0.50), but this can be explained by post-starburst reddening. Van Breugel & Dey (1993) previously confirmed that H1 is at the radio galaxy redshift and best fitted its spectrum with an instantaneous starburst model at an age 0.07 +/- 0.03 Gyr. They concluded that it is a kpc-sized object in which star formation had been triggered by the earlier passage of the radio jet.
(2000MNRAS.317..120R)

Quote from: 6
Re:3C 285
3C 285.--This elliptical galaxy has a peculiar optical morphology (Heckman et al. 1986). It displays dramatic isophotal twisting and has a blue color but a red nucleus (Smith 1988). It also has an S-shaped emission-line gas running due east-west along the direction of the radio axis (Baum et al. 1988). Van Breugel & Dey (1993) report the presence of a blue star-forming region in the eastern lobe of 3C 285. This region is apparently elongated along the radio source axis, and its optical line emission, and possibly its optical continuum emission, appear to be edge-brightened on the side facing the nucleus. Van Breugel & Dey suggest that the star formation in this region is triggered by the passage of the radio lobe the intergalactic medium. The UV image of the F342W filter shows the southeastern part of the galaxy. It appears to have a high ellipticity and no nuclear UV component. It matches the optical image (F702W) reasonably well, which implies that the extended UV emission is due to starlight. The F702W image also shows a disklike structure.
(1998ApJS..114..177Z)

So, RGZ zooites finding that the host of 3C 285 - an obvious double-lobe radio galaxy - has dust lanes, a disk, and generally looks quite different from an elliptical galaxy is an independent (re)discovery, not anything new.

It may be that when professional astronomers refer to just a handful (two, three) of spirals having hourglass or doublelobe radio morphologies, they are excluding 3C 285. Kinda an important consideration for our search ... what, exactly, do professional astronomers mean?
« Last Edit: June 12, 2014, 06:15:18 pm by JeanTate »

JeanTate

  • OotD posters
  • Hero Member
  • *****
  • Posts: 2976
    • View Profile
ARG0002whf SDSS J080259.73+115709.7 (WizardHowl)
« Reply #42 on: June 13, 2014, 01:08:40 am »
ARG0002whf | SDSS J080259.73+115709.7 | WizardHowl | discovery (March 26 2014 4:10 PM) | | ~0.13 ph

The galaxy is in the center of this DR10 cutout, 108"x108" (500x500 pix @0.216"/pix):



Is this galaxy not a boring elliptical? Yes!

SkyView composite, SDSS r-band (faded to all-but invisibility) with FIRST contours (0 min, 6 levels, contour smoothing 8 ) and above DR10 image:



Radio emission is/extends beyond optical boundary of galaxy? Check.
Is this galaxy the likely host of the radio emission (a nice, albeit asymmetric hourglass + hint of a core)? Yes!

Excellent!  8)
« Last Edit: June 13, 2014, 09:58:38 am by JeanTate »

JeanTate

  • OotD posters
  • Hero Member
  • *****
  • Posts: 2976
    • View Profile
Re: Friday, 21 February, 2014: Very Strange Spirals?
« Reply #43 on: June 13, 2014, 07:26:25 am »
Here's the OP (opening post) of the RGZ Talk thread, Hourglass sources associated with spiral galaxies:

Quote from: raynorris
Keep an eye out for any #hourglass sources that seem to be hosted by galaxies that look spiral in the infrared. These objects are incredibly rare in the local Universe (only 2 or 3 known) and we may not see any in Radio Galaxy Zoo, but if someone does find one, that would be worth writing a paper about (with the discoverer as co-author, of course). The rarity of radio-loud spirals is thought to be because the radio jets heat up and disrupt the gas in the spiral, switching off star formation, and turning the galaxy into a "red dead" elliptical. But we might find one or two where the jets have only just switched on and haven't yet destroyed the spiral. See http://adsabs.harvard.edu/abs/2012MNRAS.422.1453N for another example of this process in its very early stage. So keep your eyes peeled and yell out (very loudly) if you find one!

I'm quoting this because it's about the best place I can think of to try to write some criteria for a) deciding if an RGZ object may be the kind of thing we're looking out for here, and b) what scientific merit such objects might have. Here's the abstract of that paper:

Quote from: Norris+
F00183-7111 is one of the most extreme ultraluminous infrared galaxies known, with a bolometric luminosity of 9 × 1012 L. Here we present a very long baseline interferometry (VLBI)_ image which shows a compact core-jet active galactic nucleus (AGN) in its core, with a radio luminosity (L2.3 GHz= 6 × 1025 W Hz-1) typical of powerful radio galaxies. Although already radio loud, the quasar jets are only 1.7 kpc long, boring through the dense gas and starburst activity that confine them. This source therefore appears to be powered by a combination of a compact radio-loud AGN surrounded by vigorous starburst activity.

That the textbook perfect Sb and Sc spiral galaxies, with their blue arms and disks, do not have radio jets, lobes, giant plumes, ... nor x-ray or optical jets, nor ... is well-established. And this is so whether or not such galaxies have AGNs (e.g. Seyferts), even when such AGNs are blindingly bright (i.e. when the host galaxy of a quasar - radio-loud or not - is a spiral).

So maybe this is because such perfect spirals have so much gas and dust that even though jets get started near the accretion disk around the SMBH (super-massive black hole), they simply go nowhere.

If that's the hypothesis, then the following sorts of objects would be well worth finding, to study in detail, to test the hypothesis (no particular order):
  • irregulars with jet(s)/lobe(s)/plume(s): irregulars do not have SMBH, so how could they produce jets etc?
  • red spirals with doublelobes (shorthand for 'jet(s)/lobe(s)/plume(s)//etc'): red spirals seem to lack gas and dust (at least, they have far less of it than ordinary, blue, spirals), but some still have AGNs, so they should have more doublelobes
  • lenticulars with doublelobes: lenticulars are just red spirals without arms, bars, or rings
  • Eos (edge-on spirals) with doublelobes: perhaps jets can 'break out' more easily if they shoot perpendicular (or nearly so) to the disk plane? And if accretion disks have random orientations with respect to the disk plane, the distribution of Eos doublelobe orientations can test this idea
  • dwarf galaxies with doublelobes: like irregulars, dwarf galaxies do not have SMBH, so how could they produce doublelobes?
  • 'dustlane' galaxies with doublelobes: dust is thought to have a very short life, except in dense molecular clouds; if there's obviously copious quantities of dust and also doublelobes, does that mean there are no molecular clouds? or that jets can punch through dust but not gas?
  • {interested readers: please add your own questions!  :)}

So a first-pass criterion for selecting 'spirals with doublelobes', in order for them to be used to test various hypotheses concerning AGNs and jets, might be something like "any galaxy other than a boring elliptical which seems to have radio emission outside the optical boundary, or extending beyond that boundary". The "seems to have" can be graded, with symmetric triples where the core coincides perfectly with the nucleus being A+, to a faint blob of radio emission far from the galaxy (and no other radio emission) D (or even F?). How to decide if a likely host galaxy is 'a boring elliptical' or not? The usual zooite method (but blue ellipticals as hosts are definitely to be noted! they likely contain gas and dust), plus astronomers' tests (e.g. concentration ratio, color, Sérsic profile index).

In short, a simple two-part test, taken independently/in parallel: is this galaxy
  • the likely host of the radio emission?
  • not a boring elliptical?

This thread seems to have had a lot of readers lately, and not just me with my endless edits and new posts. How about some of you readers write a post or two? What do you think of all the stuff I've been posting this last week?
« Last Edit: June 13, 2014, 08:10:03 am by JeanTate »

JeanTate

  • OotD posters
  • Hero Member
  • *****
  • Posts: 2976
    • View Profile
ARG0003o7j SDSS J022612.45+023307.4 (WizardHowl)
« Reply #44 on: June 13, 2014, 09:27:34 am »
ARG0003o7j | SDSS J022612.45+023307.4 | WizardHowl | discovery (February 25 2014 8:08 PM) | | 0.145 sp

The galaxy is in the center of this DR10 cutout, 108"x108" (500x500 pix @0.216"/pix):



Is this galaxy not a boring elliptical? Yes!

SkyView composite, SDSS r-band (faded to all-but invisibility) with FIRST contours (0 min, 6 levels, contour smoothing 8 ) and above DR10 image:



Radio emission is/extends beyond optical boundary of galaxy? Check.
Is this galaxy the likely host of the radio emission (a nice, not-quite symmetric hourglass)? Yes!

Excellent!  8)
« Last Edit: June 13, 2014, 09:59:45 am by JeanTate »