NGC 5972: Galaxy with known voorwerpje and known doublelobe
-
by
zutopian
http://skyserver.sdss3.org/public/en/tools/explore/summary.aspx?id=1237665566615666691It is NGC 5972., which has a known voorwerpje (ionized gas cloud). Ref.: GZ paper by Keel et al..
One of the other NED Refs is as follows.:.Title: The Hubble type of the double lobe radio galaxy NGC 5972.
We found in the literature a single example of a spiral galaxy associated with a classical extended double lobe radio source: NGC 5972 classified as an S0-a by Lauberts (1982). We show that it is rather an E galaxy which may possibly be the result of a merger event. It has an emission line spectrum typical of a Seyfert 2 galaxy.
Authors: Veron, P.; Veron-Cetty, M.-P.
Publication: Astronomy and Astrophysics, v.296, p.315 (A&A Homepage)
Publication Date: 04/1995
Origin: CDS; KNUDSEN
Bibliographic Code: 1995A&A...296..315V
http://adsabs.harvard.edu/cgi-bin/bib_query?1995A%26A...296..315VThe paper was cited in following paper.:
Title: An Unusual Radio Galaxy in Abell 428: A Large, Powerful FR I Source in a Disk-dominated Host
Authors: Ledlow, Michael J.; Owen, Frazer N.; Keel, William C.
Bibliographic Code: 1998ApJ...495..227L
http://adsabs.harvard.edu/abs/1998ApJ...495..227LHere is the GZ blog post about the observation by the HST.:
Something rich and strange – Hubble eyes NGC 5972
(...)This is a galaxy with active nucleus, large double radio source, and the most extensive ionized gas we turned up in the Voorwerpje project. (...)
http://blog.galaxyzoo.org/2012/07/12/something-rich-and-strange-hubble-eyes-ngc-5972/
Posted
-
by
zutopian
Curiously, NGC 5972 is classified just as S0/a* in NED! :
There are following 3 Refs for the morphology.:
- 1991RC3.9.C...0000d
- 1973UGC...C...0000N
- 1994AJ....107.1629T
http://ned.ipac.caltech.edu/cgi-bin/NEDatt?objname=NGC+5972
Curiously, the paper 1995A&A...296..315V isn't listed as Ref. for the morphology! As mentioned in previous post, according to the paper "The Hubble type of the double lobe radio galaxy NGC 5972" it is an elliptical ! Curiously, the paper by Lauberts (1982) is also not listed as Ref. for the morphology class in NED.
Title: The Hubble type of the double lobe radio galaxy NGC 5972
We found in the literature a single example of a spiral galaxy associated with a classical extended double lobe radio source: NGC 5972 classified as an S0-a by Lauberts (1982). We show that it is rather an E galaxy which may possibly be the result of a merger event. It has an emission line spectrum typical of a Seyfert 2 galaxy.
Authors: Veron, P.; Veron-Cetty, M.-P.
Publication: Astronomy and Astrophysics, v.296, p.315 (A&A Homepage)
Publication Date: 04/1995
Origin: CDS; KNUDSEN
Bibliographic Code: 1995A&A...296..315V
http://adsabs.harvard.edu/cgi-bin/bib_query?1995A%26A...296..315V' * Lenticular/Spiral transition type, Hubble stage between S0 and Sa.
Posted
-
by
zutopian
In the GZ voorwerpje paper the morphology of NGC 5972 is given as follows.:
Table 9: Morphologies of AGN hosts with extended clouds:
SDSS designation z Sy type Name rmax, kpc Morphology cone angle disc/cloud angle Sides
(...)
SDSS J153854.16+170134.2 0.0297 2 NGC 5972 33 Warped disc and tails 35 18 2
(...)http://arxiv.org/abs/1110.6921
PS: The paper was published prior to the observation by the HST.
Posted
-
by
JeanTate
Very cool, zutopian! 😄
A nearby object which may connect EELRs (a.k.a. voorwerpjes) with radio lobes/jets with disk galaxies, and merger activity and a quenching of star-formation, all in one object ... how cool would that be?!? Not to mention that zooites played an important role ...
Posted
-
by
zutopian
in response to JeanTate's comment.
Well, it is unclear to me, if is an elliptical or a disk galaxy.: In the Veron et al.paper it is stated, that it is actually an elliptical, but in the voorwerpje paper it is classified however as a disc. I wonder, if the HST observation, which was done later, is useful to clarify the morphology? When will the paper about the voorwerpje observations by the HST be available?
In the GZ forum Mr Keel had written in the introduction of the topic "Hubble and Voorwerpjes" following.:
NGC 5972 attracted some interest as possibly being a spiral with a giant double-lobed radio source, which would be quite rare. In a study published in 1995, Phillippe Veron and Mira Veron-Cetty showed that the "spiral arms" are filaments of gas ionized by the central AGN, whose motions are mostly smooth rotation about the core.
After the observation by the HST, c_cld asked following.:
May be you could already confirm the tentative conclusion of this 1995 paper:
"The analysis of the images of NGC 5972 shows that it is an E galaxy rather than an SO-a; this galaxy however shows some structures which are not identifiable with spiral arms but could perhaps be the result of a merger event."Would NGC 5972 be a polar ring candidate?
Mr Keel replied as follows.:
I think we entirely support the idea that NGC 5972 has undergone a merger - we see tidal streams, and the dust and gas are in multiple planes and twisted. It might end up as a polar ring, if we are really patient.
http://www.galaxyzooforum.org/index.php?topic=279219.msg610041#msg610041
So in addition "Polar ring galaxy formation", which is also interesting ! 😃
Posted
-
by
zutopian
Jean informed about a new paper, which might be useful to determine its morphology.:
There's a paper just out which may help us a lot: A Catalogue of Two-Dimensional Photometric Decompositions in the SDSS-DR7 Spectroscopic Main Galaxy Sample: Preferred Models and Systematics, Meert+ 2014:
(...)
By getting the results of these 2D model fits, for candidate hosts in SDSS DR7, we would (will) have a more objective basis for classifying the host's optical morphology, and hopefully enough data to formulate hypotheses concerning late-type vs early-type, signs of merger/interaction, and may even be able to extrapolate to better classifications of more distant/fainter candidate hosts.
And when raynorris returns, he can tells us how any of this relates to PRONGS! 😃http://radiotalk.galaxyzoo.org/#/boards/BRG0000003/discussions/DRG00000rz
EDIT:
I am not sure, if the catalog helps to distinguish between elliptical and disc galaxy.Posted
-
by
NGC3314
(Bill Keel here, actually preferring to dispense with honorifics)
The Hubble images (as seen in the post linked above by zutopian )show crossing dust lanes in front of the galaxy core in NGC 5907, making it a good candidate for the kind of warped disk that would result from a merger involving a gas-rich galaxy (which precession warps in a complex way over time). The main light distribution, however, is typical of an elliptical galaxy near the core, and it's not clear that we see a significant amount of starlight associated with the gas and dust disk. There are certainly a couple of narrow tidal tails, adding to the evidence that the smaller merging galaxy had a disk. The is almost no star formation in the system now, with only a handful of possible star clusters seen in the Hubble images. (Trying to finish the paper on that now).
In other news, Megan Argo led Westerbork-array observations of this object, which show some evidence that the radio jets may have twisted to more nearly line up with the emission-line clouds in the inner parts of the galaxy.
Posted
-
by
JeanTate
Hot off the press (well, it was on Thursday last week), Keel+ 2014: "HST Imaging of Fading AGN Candidates I: Host-Galaxy Properties and Origin of the Extended Gas"! 😄
It contains lots of material on NGC 5972, including GALFIT profile fits to all eight objects (only one is disk-dominated, though four others have quite substantial disks). Perhaps the most intriguing part is in the intro:
Companion papers deal with the implications of these data for these AGN and their histories (Lintott et al., in preparation),
and with the two sample AGN whose double radio sources and giant ionized clouds violate the usual alignment pattern for radio jets and ionization cones (Maksym et al., in preparation).Looking forward to Maksym+ 2014! 😃
Posted