Galaxy Zoo Talk

NGC 5252 + Voorwerp [OIII] images

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR

    Here are two [OIII] images of Voorwerp galaxy NGC 5252;

    enter image description here

    enter image description here

    Please guess the year of publication of the paper they were published in 😄

    Bonuspoints if you name the correct author!

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  • CeciliaB by CeciliaB

    NGC 5252 was observed 23 Feb. 1998. Perhaps the paper was published the same year. Author: V.L. Afanasiev.

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  • Ghost_Sheep_SWR by Ghost_Sheep_SWR

    Ooh nice, how'd you find out?

    (Not correct year / lead author btw)

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  • CeciliaB by CeciliaB

    I just googled the galaxy and saw the image above among the pictures available. From the picture I got the article. But I didn't manage to find when the paper was published.

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  • Ghost_Sheep_SWR by Ghost_Sheep_SWR

    Ah yes ofcourse, I see it too now, and more 😃

    Anyone else? Adds a surprising mystery twist to the Voorwerp saga.

    Posted

  • Ghost_Sheep_SWR by Ghost_Sheep_SWR

    Well I'll just spill the beans then;

    These were published in

    The structure and kinematics of AGN with ionization cones

    by A. Moiseev+ on 22 june 2000. (v1) / 11 july 2000 (v2) and describes the findings of spectral observations of four galaxies: MRK 3, MRK 573, NGC 3516 and NGC 5252. That's 7 years before Hanny's Voorwerp was found. You might recall A. Moiseev from supplying the confirmation data for the latest Voorwerp or as co-author on GZ papers.

    Abstract

    Results of 2D spectral observations for 4 Sy galaxies with ionization
    cones are presented. Images in the [OIII] line, velocity fields of the
    ionized gas, stellar velocity and velocity dispersion fields were
    obtained at the SAO RAS 6m telescope. Non-circular gas motions and
    Z-shaped emission filaments could be explained as helical waves
    located in the ionization cone. This waves are generated by the
    hydrodynamical instability due to the velocity break between galactic
    ISM and outflowing matter from the AGN engine. The axis of cone lies
    close to the direction of a nuclear mini bar.

    To my layman eyes these [OIII] images have excuisite detail and clarity that can rival even with the Hubble images of NGC 5252 from the Voorwerp follow-up papers. So very strange this paper is unknown.

    enter image description here

    enter image description here

    But even a bit more strange is that the images and data from this paper isn't used, mentioned or referenced in any of the Voorwerp papers. Not in the 2009 Hanny's Voorwerp paper, not in the 2012 follow-up paper, and not even in the 2014 and 2016 follow-up papers both of which A. Moiseev is co-author.


    So now I have the following questions;

    • Why isn't this paper and the data on NGC 5252 mentioned or referenced in the Voorwerp papers that include NGC 5252 as Voorwerp galaxy, two of which A. Moiseev is co-author? Was the data and images not good enough, or the paper unknown(?)?

    • Does this maybe mean A. Moiseev+ actually found the first Voorwerp 17 years ago, 7 years before Hanny's Voorwerp? Or is that dependent on the 'Fading' interpretation of AGN-ionized clouds?

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  • Ghost_Sheep_SWR by Ghost_Sheep_SWR

    HST Imaging of Fading AGN Candidates I: Host-Galaxy Properties and Origin of the Extended Gas W.C. Keel+ does seem to reference a 2002 paper by A. V. Moiseev+ on page 11, which looks like a short NGC 5252 follow-up on the above mentioned 2000 paper by A.V. Moiseev+:

    In addition, we re-reduced the similar [O iii] data for NGC 5252 originally presented by Moiseev et al. (2002), Afanasiev et al. (2007a), and Afanasiev et al. (2007b).

    Integral-Field Spectroscopy of the Ionized Cones in Seyfert Galaxies A.V. Moiseev+ 01/2002

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