Table information for 'ppmxl.main'

General

This table is available for ADQL queries and through the TAP endpoint.

Resource Description: PPMXL is a catalog of positions, proper motions, 2MASS- and optical photometry of 900 million stars and galaxies, aiming to be complete down to about V=20 full-sky. It is the result of a re-reduction of USNO-B1 together with 2MASS to the ICRS as represented by PPMX.

For a list of all services and tables belonging to this table's resource, see Information on resource 'ppmxl/q'

Citing this table

@MISC{vo:ppmxl_main,
  year=2009,
  title={Untitled Resource},
  author={Röser, S.; Demleitner, M.; Schilbach, E.},
  url={http://data.xao.ac.cn/tableinfo/ppmxl.main},
  howpublished={{VO} resource provided by the {XAO} Data Center}
}

Resource Documentation

To query this data, you can use

• a web form (mainly for cone searches)
• the equivalent SCS service using your favourite VO client (e.g., topcat)
• our web-based crossmatcher to retrieve PPMXL data (e.g., proper motions and photometry) for your object list
• web-based ADQL or, preferentially,
• TAP for more advanced queries.

You can retrieve also the whole data set as a gzipped text file from http://vo.ari.uni-heidelberg.de/ppmxl (39.4 GiB). The columns in the text file are in database order as documented in the table info in DB order with columns separated by vertical bars ("|").

David Tholen kindly provided code to convert this into a collection of files for easy consumption by FORTRAN programs.

Columns

Sorted alphabetically. [Sort by DB column index]

Columns that are parts of indices are marked like this.

VOResource

VO nerds may sometimes need VOResource XML for this table.

Notes

• Note 1

  Magnitudes from USNO-B should be used with care. Photometric calibration may be severely off for some plates.

  For objects from PPMX (bit 1 set in flags), these magnitudes have a special meaning as per the following table:

  PPMXL column	PPMX column	PPMX content
  b1mag	Cmag	Catalogue magnitude from source
  b2mag	Bmag	Johnson B magnitude
  r1mag	Rmag	calc. Ru magnitude from source
  r2mag	N/A	always None
  imag	Vmag	Johnson V magnitude

• Note 2

  magSurveys is built by concatenating the digits assigned to the surveys for b1mag, b2mag, r1mag, r2mag, and imag (in this sequence). The digits are those of given in Note h to Table 3 in 2003AJ....125..984M, except we do not distinguish POSS-II N and SERC-I as a part of POSS-I-N (i.e., both 7 and 9 are 7 here).

  From this field, you can also see which of the surveys contributing to USNO-B had positions for the object.

• Note 3

  The flags column contains a bitwise or of warnings and similar conditions. The bit's meaning is as follows:

  bit 0:	If set, one of the coordinates had an excessively large chisquare.
  bit 1:	Row is from PPMX. These objects are mostly Tycho stars that were masked out of USNO-B. For these, the USNO magnitudes (b1mag through imag) have special meanings. See the note on magnitudes.
  bit 2:	Row is from PPMX and replaces a single row from USNO-B. This is done when the astrometry from PPMX was better (in terms of error estimates) than the astrometry of the corresponding PPMXL object.
  bit 3:	Row replaces multiple USNO-B1.0 objects. When PPMX contains an object that has more than one counterpart in PPMX-L, all such counterparts are discarded on the assumption that they should have been matched in USNO-B1.0 or result from erroneous matches. For these rows, bit 1 is always 1.

• Note 4

  nobs may be NULL for stars coming from ARIHIP or Tycho-2 via PPMX (i.e., bit 1 is set in flags).