Galaxy Zoo Talk

A weird angular galaxy-like thing.

  • Artman40 by Artman40

    I found this galaxy-type thing while I was doing Disk Detective project instead of Galaxy Zoo project. Can anyone tell me what is happening here?

    http://talk.diskdetective.org/#/subjects/AWI0000gdt

    SIMBAD does not tell me anything.

    http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=&-out.add=_r&-out.add=_RAJ%2C_DEJ&-sort=_r&-to=&-out.max=20&-meta.ucd=2&-meta.foot=1&-c=48.2928043-24.1090727&-c.rs=5

    This is what VizieR says.

    Posted

  • Capella05 by Capella05 moderator in response to artman40's comment.

    Hi and welcome @artman40

    I do not think it is a galaxy. You might have better luck posting over on Disk Detectives.

    Posted

  • Artman40 by Artman40

    http://talk.diskdetective.org/#/boards/BWI0000002/discussions/DWI000079b

    Here's a topic a few months ago. They showed that it's likely a galaxy or multiple galaxies. Is there any higher-resolution image of that object? But what kind of galaxy it is, remains unknown.

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  • ElisabethB by ElisabethB moderator

    Do you have the coordinates of this system ?

    Posted

  • Artman40 by Artman40

    RA 48.2928043 DEC-24.1090727

    By the way, galaxies show up commonly in Disk Detective project, especially in the first batch of data.

    Posted

  • ElisabethB by ElisabethB moderator

    As far as i can see, this 'galaxy' is out of the SDSS footprint ! 😦

    Posted

  • Artman40 by Artman40

    Shame. So it looks just like an ordinary galaxy or merger?

    By the way, does the Galaxy Zoo use VizieR to check interesting objects and if Galaxy Zoo project have spectral energy distribution diagram like Disk Detective does (in order to make the separation of stars, galaxies, quasars and other objects from each other much easier)?

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  • ElisabethB by ElisabethB moderator

    As long as I don't have an SDSS kind of image I don't really know what I'm looking at ! Sorry !

    And I have no idea what you are talking about (VizieR) ! 😄

    Posted

  • Artman40 by Artman40

    http://vizier.u-strasbg.fr/

    VizieR is a tool that basically allows you to search for astronomical objects in given co-ordinates. It then lists all catalogues where objects in the given co-ordinates within a given radius have appeared. It's great for checking how bright the object is in various bands from visual light to WISE magnitudes as long as these are listed there.

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  • Budgieye by Budgieye moderator

    The southern stars... Let me muddle through this. Just skip to the end.

    We use SDSS almost all the time, but it doesn't have the southern stars.

    I looked up the area in Google Sky, but there was just a red smudge.

    https://www.google.com/sky/#latitude=48.292804&longitude=-24.109072999999967&zoom=14&Spitzer=0.00&ChandraXO=0.00&Galex=0.00&IRAS=0.00&WMAP=0.00&Cassini=0.00&slide=1&mI=-1&oI=-1

    It might be in GEMS or GOODS south patch of sky, but these are small patches. We looked at this several years ago using Hubble Space Telescope data.

    Tues Jan 11 2011 Finding more information about a galaxy http://www.galaxyzooforum.org/index.php?topic=278750.msg520491#msg520491

    Survey: GEMS and GOODS-S
    image reference stars with 9.........
    images are in 2 colours: red and blue
    http://www.galaxyzooforum.org/index.php?topic=271742.msg520137#msg520137
    In the southern skies
    Right ascension 3 hours, declination -27
    http://www.galaxyzooforum.org/index.php?topic=277646.msg460938#msg460938
    SPECTRUM
    use Chandra Deep Field South http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=II/253
    use the last 5 digits only in the recno box, has estimates of redshift
    NAVIGATION
    GEMS navigator http://archive.stsci.edu/prepds/gems/browser.html but it has no co-ordinates
    GEMS SkyWalker
    Use this site as a template
    http://www.ugastro.berkeley.edu/~rgriffit/ACS-GC_jpeg_atlas/12027896_info_bw.jpg
    and substitute the ID of the galaxy you want to look at.
    SDSS doesn't see the southern stars, declination: -27.6146,
    so you can't use SDSS DR7 Navigate Tool 😦

    http://www.universetoday.com/63607/goods-under-astronomers-aegis-produce-gems/ by Jean Tate

    enter image description here

    http://d1jqu7g1y74ds1.cloudfront.net/wp-content/uploads/2010/04/GEMS.jpg

    co-ordinates RA 48.2928043 DEC-24.1090727, looks like it is outside of GEMS area

    http://vizier.u-strasbg.fr/viz-bin/VizieR-5?-ref=VIZ5323dd4d0c46&-out.add=.&-source=VII/237/pgc&recno=190709

    Disk Detective ; there is an optical image in discussion but maybe you saw that and are hoping for a better image.

    http://talk.diskdetective.org/#/boards/BWI0000002/discussions/DWI000079b

    PGC 793497 image from the discussion post.

    enter image description here

    What do I think so far?

    The orange colour is similar to a distant galaxy. I don't know what filters this telescope is using, so I am assuming it is like the SDSS telescope.

    The white objects could be 4 stars in our galaxy. They seem to make a bent line because of the pixellation of the image.

    The white objects could be lensed quasars, though I would expect them to be blue.

    Disk Detective help http://talk.diskdetective.org/#/boards/BWI0000004/discussions/DWI0000574

    http://aladin.u-strasbg.fr/java/alapre.pl?-c=PGC+793497&button=RGB

    enter image description here

    This looks like a galaxy and three stars.

    I've worked for an hour on this and have no good answers. Anyone else have any ideas?

    Posted

  • Artman40 by Artman40

    Wow! This is really interesting. We also know that it is much brighter in mid-infrared than in near-infrared.

    Posted

  • Budgieye by Budgieye moderator

    Galaxies that are far away will have a lot of infrared, but wouldn't it be because of redshift rather than what it is? This assumes that this orange thing is a galaxy.

    Here is an example of a similar galaxy.

    http://skyserver.sdss3.org/dr10/en/tools/explore/summary.aspx?id=0x112d0538a02301cc&spec=0x057c13c6f4006800&apid=ra=257.669489889234&dec=61.4902994783907&scale=0.2&width=200&height=200&opt=G)

    1237651213359710668

    enter image description here

    Posted

  • Artman40 by Artman40

    Very interesting. Are lensed quasars very common or less common?

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  • JeanTate by JeanTate in response to artman40's comment.

    It's an asterism, or in zooite-speak, a platterpillar: three (four? five?) stars close together on the sky. Or at least sources that are effectively points in all relevant bands.

    enter image description here

    This image shows what you already know from the DD images; that the W point source is a different color, in the DSS2 bands, than the others. What is curious is that the E source brightens between the 2MASS K and WISE 1 bands, becoming the brightest source (again; it was brightest in the DSS2 B band) by WISE band 2.

    Why did this asterism get a PGC ID? Perhaps because when that catalog was being prepared, the individual point sources were not resolved ...

    Boilerplate: "Luptonized" image produced from DSS2 FITS files (B, R, and IR plates) obtained from SkyView with Python code described in this RGZ Talk post. Image center (J2000.0) is (48.2928043, -24.1090727).

    Posted

  • Budgieye by Budgieye moderator in response to artman40's comment.

    Nice image Jean.

    Lensed quasars are not common. Here are 10 examples. Part 3 Double quasars in SDSS,... and triple, and quadruple.http://www.galaxyzooforum.org/index.php?topic=275811.msg355411#msg355411

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  • Artman40 by Artman40

    So is the background object galaxy or a quasar? SED definitely suggests that it outshines the stars.

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  • Budgieye by Budgieye moderator

    I would think the background object is a galaxy. Quasars are usually bright blue. and always look like stars, from which the name came Quasi Stellar Objects.

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  • Artman40 by Artman40

    Weird that I don't see any sign of a star from its SED even when it comes to foreground objects. Is it because the stars are faint or the ones in the foreground are not stars after all?

    Posted

  • Budgieye by Budgieye moderator

    There are billions of stars in our galaxy, and they haven't all been given a number yet. Give it a couple of years.

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  • JeanTate by JeanTate in response to artman40's comment.

    Can we agree on what we're referring to?

    Within the Disk Detective red circle, there are one or two point sources, except in DSS2 B (where there's a faint third), and WISE band 1 (which has an elongated source). Within the apparent limits of the resolution of each image/source, there are two underlying point sources*; call them W and E.

    Because neither W nor E is resolved, in any image, we cannot say either is a galaxy, based on morphology alone. And the SED provided on the AWI0000gdt page is not much help; it's the SED of the combined E and W, in all bands.

    To me, the W source is not particularly odd; it's just a cool star, right? Or perhaps an unresolved binary.

    The E source has an odd SED: bright at both blue (DSS2 B ) and red (WISE band 4) ends. What sorts of extra-galactic objects are point sources and bright at both blue and red ends (dim in between)? AGNs/QSOs; the accretion disk is blue, even emitting copious x-rays; the dusty torus (etc) is red. Also, AGNs are, cosmologically speaking, non-conformists; just when you think you've got them nicely pigeon-holed, a new class appears, and upsets your nice classification system (examples: FeLoBALs, BL Lac objects).

    Can galactic stars with debris disks appear both blue and red too?

    *again, except for the faint third point source in DSS2 B

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  • Budgieye by Budgieye moderator

    I think the combination of star + red galaxy fooled the Disk Detective robot into selecting the image because it looked like star+ debris disk. The straight line of 3 stars is just a coincidence.

    Can source E be a spectrographic binary star system ?, they are red and blue at the same time.

    Posted

  • planetaryscience by planetaryscience

    It seems I'm somewhat late to this, but I know a number of different surveys accessible for any part of the sky. There's DSS, as you all seem to have found:

    enter image description here

    and also GALEX

    enter image description here

    and 2MASS

    enter image description here

    and WISE

    http://irsa.ipac.caltech.edu/applications/wise/#id=Hydra_wise_wise_1&RequestClass=ServerRequest&DoSearch=true&intersect=CENTER&subsize=0.16666666800000002&mcenter=mcen&schema=allwise-multiband&dpLevel=3a&band=1,2,3,4&UserTargetWorldPt=48.292791666666666;-24.10913888888889;EQ_J2000&SimpleTargetPanel.field.resolvedBy=nedthensimbad&preliminary_data=no&coaddId=&projectId=wise&searchName=wise_1&shortDesc=Position&isBookmarkAble=true&isDrillDownRoot=true&isSearchResult=true (the images don't have an image URL)

    and a few more, but based on this I'm inclined to believe that the object on the left of the group is a galaxy, as is the fourth, and faintest, object down, and the other 3 are stars.

    Also visible in the WISE images are 3 small stars (too small to see in any of the other survey) to the left of the galaxy.

    Posted