Galaxy Zoo Talk

question on 2MASX J16341450+2634129 (data from DSS2)

  • NenovMir by NenovMir

    While exploring 2MASX J16341450+2634129 in Aladin I found something looking like burst or jet (see attached picture). This can be seen only in DDS2/DDS2red but not in DDS2blue.

    DDS2 collage

    Posted

  • NenovMir by NenovMir

    Here is the link to Aladin to anyone who wants to check it

    Aladin

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  • Rick_Nowell by Rick_Nowell

    Do you mean this? 2MASX J16341450+2634129 DDS2 red filter. Artefact?-unlikely. The image is a bit squashed sideways as it is from a screenshot. The blob at the topmost part of the target galaxy is a star in our galaxy and probably should be discounted. The objects do seem to follow the general shape of the arm to my eye. Anticlockwise two arm barred spiral with two jets at 90 degrees to each other and a channel of activity in between the jets on one arm? Hhhmmm...

    2MASX_J163414

    (credit on picture)

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  • Budgieye by Budgieye moderator

    DSS sky survey was made by scanning photographic plates. This might be a dust particle on the plate?

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  • Rick_Nowell by Rick_Nowell in response to Budgieye's comment.

    If it is a dust particle, then shouldn't it be visible in the blue filter as well? It does look like a hair on the lens, but the object does seem to be behind the foreground star (at the top).

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  • Budgieye by Budgieye moderator

    Wouldn't the red plate and the blue plate be totally separate?Directly behind the telescope, one plate made using a red filter, and then one using a blue filter.

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  • Rick_Nowell by Rick_Nowell

    A more colourful version. The object seems to be behind the blue patch (foreground star). The dust/fibre could physically be on the back red filter after the blue filter. Do they get dust on filters? Coincidental line-of-sight, but there is a yellowing.

    2MASX%20J16341450

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  • Budgieye by Budgieye moderator

    I meant the dust was on the "photograph" not on the filter. The photograph with dust speck was then scanned, [The "photographs" are usually black and white glass plates.]

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  • NenovMir by NenovMir

    Hi, thanks for the discussion! So, it means that most likely it is an artifact, if I understand the conclusion in a correct way?

    Just one small question - what is the chance that this artifact could result in increased intensity on right arm of the galaxy as it is seen in a DDR2 red channel (picture uploaded by Rick_Nowell)?

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  • Rick_Nowell by Rick_Nowell

    You mean the 'yellowing' of the dust/fibre/event- an increase in intensity by chance? A good question, but I'm not familiar with the process of scanning the plates. Probably few are. There are also similarities in pixel colours at high res between the dust/fibre/event and the galaxy, but I really don't know.

    Personally, I tried to locate the galaxy in as many sources as possible, but could not find any other image like that. Until another version of that image is located that shows the features above then it will remain a piece of dust on a plate. Sorry!

    Posted

  • Rick_Nowell by Rick_Nowell

    As can be seen from the Image Headers on the original FITS files below, the Plate A0ZQ was made in 1993-07-11 with an exposure time of 80:00 minutes at the Oschin Schmidt (Palomar) telescope. The scanning takes a little under seven hours per plate to complete using Perkin-Elmer PDS 2020G microdensitometers. https://en.wikipedia.org/wiki/Digitized_Sky_Survey and https://en.wikipedia.org/wiki/Samuel_Oschin_telescope . See also link below for filter datails: this plate uses the red filter IIIa-F + RG610.

    J16341459 (screenshot)

    A GIF image is available here: http://archive.stsci.edu/cgi-bin/dss_search?v=poss2ukstu_red&r=16%3A34%3A14.47&d=%2B26%3A34%3A13.17&e=J2000&h=15.0&w=15.0&f=gif&c=none&fov=NONE&v3=

    J16341459_FITS

    SURVEY = 'POSSII-F'

    DATE = '2016-10-25 ' /FITS: Creation Date

    ORIGIN = 'STScI/MAST' /GSSS: STScI Digitized Sky Survey

    SURVEY = 'POSSII-F' /GSSS: Sky Survey

    REGION = 'XP517 ' /GSSS: Region Name

    PLATEID = 'A0ZQ ' /GSSS: Plate ID

    SCANNUM = '01 ' /GSSS: Scan Number

    DSCNDNUM= '00 ' /GSSS: Descendant Number

    TELESCID= 3 /GSSS: Telescope ID

    BANDPASS= 35 /GSSS: Bandpass Code

    COPYRGHT= 'Caltech/Palomar' /GSSS: Copyright Holder

    SITELAT = 33.356 /Observatory: Latitude

    SITELONG= 116.863 /Observatory: Longitude

    TELESCOP= 'Oschin Schmidt - D' /Observatory: Telescope

    INSTRUME= 'Photographic Plate' /Detector: Photographic Plate

    EMULSION= 'IIIaF ' /Detector: Emulsion

    FILTER = 'RG610 ' /Detector: Filter

    PLTSCALE= 67.20 /Detector: Plate Scale arcsec per mm

    PLTSIZEX= 355.000 /Detector: Plate 0X Dimension mm

    PLTSIZEY= 355.000 /Detector: Plate Y Dimension mm

    PLATERA = 248.002480000 /Observation: Field centre RA degrees

    PLATEDEC= 24.9465910000 /Observation: Field centre Dec degrees

    PLTLABEL= 'SF05281 ' /Observation: Plate Label

    DATE-OBS= '1993-07-11T04:82:00' /Observation: Date/Time

    EXPOSURE= 80.0 /Observation: Exposure Minutes

    PLTGRADE= 'C1 ' /Observation: Plate G

    POSS11 Filter details

    https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0074180900046969

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  • Rick_Nowell by Rick_Nowell

    I should write that I emailed the MAST DSS Archive this a'noon after reading this on the MAST DSS FAQ:

    IMAGE ANOMALIES

    "What's this funny line/feature/UFO in my scan?"
    These images were scanned from photographic plates, so every once in a while, you will encounter a scratch, internal telescope reflection, fingerprint, etc. in your image. So far, none have turned out to be aliens. I'm compiling an informal catalog of regions with plate anomalies, so if you run across one, let us know. "

    They've replied with an email sent with 'High Importance'. It says: " Hi, we are working closely with an expert team to investigate your question." They're the only ones who can be sure and at the least, NenovMir will have pointed out an anomaly! Cool...

    MAST_ImageAnomaliesLink

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  • NenovMir by NenovMir

    Hi Rick_Nowell, many thanks for your thoughtful investigation! Based on the evidence provided by you I think it is most likely an artifact or as MAST DSS people classify it - anomaly. Still very interesting coincident since it is sitting right on the galaxy arm:-)! The probability gives a chance to everything:-)!

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  • Rick_Nowell by Rick_Nowell in response to NenovMir's comment.

    Coincidental is an understatement! ALL the various DSS2 views I've seen have the object behind the foreground star (link for star below). This probably shows best on the more extreme colour versions on the original Aladin page- try "DSS Colored cubehelix" by using the 'manage layers' on the DSS2 image (link below). All available choices seem to place the object behind the star.

    So, using only a red filter (as shown above on the FITS Image Headers), the anomaly is presumably on one side of a bespoke curved Kodak photographic plate, otherwise it would be on top of the foreground star. It might be on the front of the plate, but the anomaly would then have to be on it before the image was taken. Logical? The anomaly can only be on one side of the photographic plate; the back or on the original plate before imaging. It can't be on the red filter.

    So, an object possibly on the back side of a curved plate happens to be inline with a galaxy, so much so it follows the line of the arm. The ends of the object (the original possible jet(s)?) are at at exactly 90 degrees to each other and, if extended, meet very near the centre of the galaxy. There also appears to be some interaction between the object and the image.

    But it looks so much like dust or artefacts! No other non-DSS2 picture I've seen has anything like it! It is completely vacant from SDSS 9, DECaLS or GALEX. What could it be? Let the experts sort it out, if they can.

    SDSS J163414.28+263426.4 http://skyserver.sdss.org/dr9/en/tools/explore/obj.asp?id=1237662337332937074

    http://aladin.u-strasbg.fr/AladinLite/?target=2MASX J16341450%2B2634129&fov=0.03&survey=P/DSS2/color

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  • Rick_Nowell by Rick_Nowell

    Just some fun... Is the object behind the star on the right hand picture?

    2MASX J16341450+2634129

    2MASX J16341450+2634129

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  • zookeeper by zookeeper admin, scientist

    I've just had a chance to scan this thread - thanks Rick for the alert. If the object only shows up in one of the two DSS colours, it's almost certainly an artefact - probably a scratch on the plate, which is worth knowing about. The two DSS plates are completely separate so it's not unlikely that damage to one is replicated on the other. It does show the power of sorting through these things by eye - even the unusual coincidences get thrown up!

    Chris

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  • zutopian by zutopian

    There are also this kind of DECaLS artifacts, which show up on GZ images.:

    A collection of DECaLS artifacts
    https://talk.galaxyzoo.org/#/collections/CGZL00006l

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  • Rick_Nowell by Rick_Nowell in response to zutopian's comment.

    Coincidentally, there's one of those DECaLS artefacts as well! Not as spectacular though. Funny that...

    DECaLS_DR£_Artefact

    J16341450+2634129 DECaLS Image

    http://legacysurvey.org/viewer?ra=248.5603303719662&dec=26.57032299816654&zoom=14&layer=decals-dr2

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  • Rick_Nowell by Rick_Nowell

    It's difficult to fathom with a HD laptop like mine, but try this: You'll need a some software called The ESA/ESO/NASA FITS Liberator 3 (link below). This installs very quickly and will help open a type of file called FITS.

    Next, go to the The STScI Digitized Sky Survey (link below). This is where we will get the file from. About half way down the page there is a box 'retrieve from' with options. Click on "HST Phase2 (GSC1)". Next, below that box add these coordinates: RA 16:34:14.470 or DEC +26:34:13.00 to the relevant box. Further down, click on the box RETRIEVE IMAGE. The file will take ten or so seconds to generate.

    The FITS file box should be in front of you. Zoom in to 200% and use the black and white to adjust contrast. I have it on: Black - 3645; White 6000 as I look at it. This image was made in 1982 by the same telescope as above. Toggle between the 100% and 300% Zoom values. Inconclusive but good fun.

    The STScI Digitized Sky Survey
    http://archive.stsci.edu/cgi-bin/dss_form

    The ESA/ESO/NASA FITS Liberator 3
    https://www.spacetelescope.org/projects/fits_liberator/

    1982-05-21

    TELESCOP= 'Palomar Schmidt ' /Observatory: Telescope

    INSTRUME= 'Photographic Plate' /Detector: Photographic Plate

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  • Rick_Nowell by Rick_Nowell

    Latest email from STScI: "I'm sorry for the delay. Our DSS scientist does have your inquiry; unfortunately he has been extremely busy and hasn't had a chance to reply. Hopefully you will hear something from him soon. Please let me know if you have any other questions. Regards, Deborah Kenny, Archive Hotseat."

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  • Rick_Nowell by Rick_Nowell

    Email from Dr. Brian McLean, Observatory Scientist, Archive Sciences Branch, Operations and Engineering Division, Space Telescope Science Institute: "Thanks for the comments – I’ll add them to a page that I started a while back. Unfortunately, our web folks are so overworked they haven’t made it public yet but that may change as they may give us scientists permissions to edit some pages soon! Cheers, Brian."

    The anomaly has been reported and registered.

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  • zutopian by zutopian

    @Rick_Nowell

    You or someone else might want to report also below anomaly!:

    Unknown object / cosmic ray hit, not geostationary satellite /guide star
    https://talk.galaxyzoo.org/#/boards/BGZ0000006/discussions/DGZ0001y94

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