Author Topic: Spectrum class differences:DR7 versus DR8  (Read 7984 times)

zutopian

  • Hero Member
  • *****
  • Posts: 2852
  • REOPEN this forum!!!
    • View Profile
Re: Spectrum class differences:DR7 versus DR8
« Reply #15 on: August 02, 2012, 08:55:27 pm »
Star    : http://skyserver.sdss.org/dr7/en/tools/explore/obj.asp?id=588015508739063842     <click> "All Spectra"
Galaxy: http://skyserver.sdss3.org/dr8/en/tools/explore/obj.asp?id=1237663783667040348
Good find zutopian!  ;D

This is an overlap. DR8 picked out one redshift system (z=0.19558), probably of the yellow elliptical/lenticular. Whether the blue is local star (per DR7) or something else I can't say (just by looking at the spectrum).

It's not in the overlapping galaxy pairs catalog, so it may be that NGC3314 decided it's a star. Of course, it's also possible he hasn't seen it before ..

If it is a galaxy, it is a merger! The big galaxy has also a spectrum and same redshift.
« Last Edit: August 02, 2012, 08:58:15 pm by zutopian »

zutopian

  • Hero Member
  • *****
  • Posts: 2852
  • REOPEN this forum!!!
    • View Profile
Re: Spectrum class differences:DR7 versus DR8
« Reply #16 on: June 25, 2014, 07:01:18 am »
Different spectral classes and redshifts: DR7 says Galaxy z=0.079, but according to DR10 it is a QSO, which has z=0.414.

DR7  : http://cas.sdss.org/dr7/en/tools/explore/obj.asp?id=587739843769794627
DR10: http://skyserver.sdss3.org/dr10/en/tools/explore/summary.aspx?id=1237667910066569343

It looks like a Galaxy-QSO overlap. The Galaxy isn't a photometric object. I guess, that it is a double-redshift spectrum.

PS: I posted it also in the Overlap topic.
« Last Edit: June 25, 2014, 07:42:00 am by zutopian »