News and updates
DR6 paper in print
The DR6 paper (Adelman-McCarthy,
J.K. et al. 2008, ApJS, 175, 297-313) has appeared in print.
Old "news"
Proper motions update announcement.
Proper motions are not correct.
Bug in SEGUE primTarget flag
PrimTarget flag in SEGUE plates is trunctated in the CAS
SDSS-III announced
A new collaboration based on the legacy of SDSS and SDSS-II has
been formed to pursue a number of new science goals. See the SDSS-III web site at www.sdss3.org.
Patch applied to DR6
This patch, applied the week of Aug 27,2007, corrects several
bugs in the database.
The list of patches to DR6 is as follows:
- 6 segments in Stripe 36 had a bug in their
startMu/endMu, resulting in ~1500 duplicate primary
objects in the main database. This has been corrected,
and the previously duplicate primaries have been made
secondary.
- The 'Propermotions' table has been incremented for BESTDR6 from
DR5 to the full DR6 dataset. Additionally, propermotions have
been added for a large number of objects which previously
had been missed because they were targeted as galaxies (but turned
out to be stars). Additionally, propermotions have
been added for Segue imaging to the SEGUEDR6 database context
in a parallel propermotions table.
Note that all these propermotions have been
're-zeropointed' from their USNO-B source by matching to
the SDSS positions for objects with zero proper motion (distant
galaxies and quasars), and thus are of overall higher accuracy than
those in the 'USNO' table.
- The 'Match' and 'MatchHead' tables in the CAS,
which connects duplicate measurements of the
same physical object on the sky, observed at
different times (for instance, objects in the overlap
between scanlines), were incompletely populated prior
to Aug 31, 2007. They have now been updated.
- The sppParams table incorrectly computed the derived
parameter velgal (the velocity of a star in
the Galactic frame of reference, subtracting out
the suns motion of (v_x,v_y,v_z) = (7,224,10) km/s
prior to Aug 31, 2007. The table is now correct.
The velgal velocities now also reflect the 7.3 km/s offset
determined by absolute reference to known globular clusters
and other Radial velocity standards. The best
radial velocity for stars in the DR6 dataset is the
'rva' value in the sppParams table. It is reliable when
the rvaerr is strictly > 0.
- A view (subset) of the sppParams table, called 'spbsparams'
has been generated for easy access to Galaxy spectral parameters,
including redshift (along with redshift confidence) and
velocity dispersion (measured two different ways). These
parameters are available on a plate-by-plate basis
in the DAS as part of the spZbest* binary FITS tables, and on a
fiber-by-fiber basis in the spSpec* FITS spectra as header
keywords, but they are gathered here in a SQL searchable table.
- Documentation has been updated on matching photometry to
spectroscopy on the SEGUE
website. Magnitudes in the sppParams table are 'PSF target' magnitudes,
the best available at the time an object was targetted for
spectroscopic followup. Since then, the imaging data for
an object may be remeasured (recorded as the best photometry).
Finally, ubercal photometry is also available for many
objects.
- The prepackaged tarballs of spectra, organized by object
category (galaxy, qso, star, etc), are now available again,
and include updates for DR6.
DR6 is available
About DR6 explains what is
new in DR6.
SEGUE spectroscopic parameters available
DR6 includes a slew of new SEGUE data, including new stellar atmospheric
parameters ([Fe/H], log g, Teff) and line indices in
the CAS BESTDR6 database. See About
SEGUE.
DRsup - Data Release Supplemental - is available
DRsup contains additional SEGUE, M31/Perseus and stripe 82 imaging. About DRsup explains what DRsup is
and how to get it.
SDSS acknowledgements updated
The SDSS has entered a second phase of funding and operations, SDSS-II,
with new participating institutions. Please use the updated SDSS acknowledgement
statement in your publications using SDSS data.
DAS hardware is up and healthy.
Last modified: Mon Mar 31 17:06:47 CEST 2008
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