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Further access options are discussed below

Information on Service 'PPMXL Cone Search'

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. This service additionally provides improved proper motions computed according to 2016AJ....151...99V.

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

Service Documentation

To query this data, you can use

You can retrieve also the whole data set as a gzipped text file from http://vo.ari.uni-heidelberg.de/ppmxl (43.5 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 ("|").

If you run DaCHS yourself, you can use a C booster kindly provided by Hailong Zhang. Instructions on usage are at the head of the file.

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

In 2016, John Vickers provided a global correction of the PPMXL proper motions based on extragalactic objects (2016AJ....151...99V). The results are given in the vickers_pmra and vickers_pmde columns. The coefficients we used are available at pmr-coefficients.csv and pmd-coefficients.csv. When used with the Code we actually used to compute the corrected values (adding healpix interpolation to the upstream from https://github.com/johnjvickers/PPMXL_Correction), these files have to be renamed pmr.csv and pmd.csv, respectively.

Overview

You can access this service using:

This service is published as follows:

local means it is listed on our front page, ivo_managed means it has a record in the VO registry, gavo means it is within GAVO's service registry.

Other services provided on the underlying data include:

Input Fields

The following fields are available to provide input to the service (with some renderers, some of these fields may be unavailable):

NameTable Head DescriptionUnitUCD
DEC Delta (ICRS) Declination (ICRS decimal) deg pos.eq.dec
hscs_pos Position/Name Coordinates (as h m s, d m s or decimal degrees), or SIMBAD-resolvable object N/A N/A
hscs_sr Search radius Search radius in arcminutes N/A N/A
ipix Id Identifier (Q3C ipix of the USNO-B 1.0 object) N/A meta.id;meta.main
MAXREC Match limit Maximum number of records returned. Pass 0 to retrieve service parameters. N/A N/A
RA Alpha (ICRS) Right Ascension (ICRS decimal) deg pos.eq.ra
RESPONSEFORMAT Output Format File format requested for output. N/A meta.code.mime
SR Search Radius Search radius deg N/A
VERB Verbosity Exhaustiveness of column selection. VERB=1 only returns the most important columns, VERB=2 selects the columns deemed useful to the average user, VERB=3 returns a table with all available columns. N/A N/A

Default Output Fields

The following fields are contained in the output by default. More fields may be available for selection; these would be given below in the VOTable output fields.

NameTable Head DescriptionUnitUCD
_r Dist. Distance to cone center deg pos.distance
b1mag USNO mag (B1) B mag from USNO-B, first epoch Note 1 N/A phot.mag;em.opt.B
b2mag USNO mag (B2) B mag from USNO-B, second epoch Note 1 N/A phot.mag;em.opt.B
dej2000 Dec Declination J2000.0, epoch 2000.0 deg pos.eq.dec;meta.main
e_deepDE E_deepde Mean error in Dec at mean epoch deg stat.error;pos.eq.dec;meta.main
e_pmDE Err. PM(Dec) Mean error in pmDE deg/yr stat.error;pos.pm;pos.eq.dec
e_pmRA Err. PM(RA) Mean error in pmRA*cos(delta) deg/yr stat.error;pos.pm;pos.eq.ra
e_raepRA E_raepra Mean error in RA*cos(delta) at mean epoch deg stat.error;pos.eq.ra;meta.main
Hmag m_H H selected default magnitude from 2MASS mag phot.mag;em.IR.H
imag USNO mag (I) I mag from USNO-B Note 1 N/A phot.mag;em.opt.I
ipix Id Identifier (Q3C ipix of the USNO-B 1.0 object) N/A meta.id;meta.main
Jmag m_J J selected default magnitude from 2MASS mag phot.mag;em.IR.J
Kmag m_K_s K_s selected default magnitude from 2MASS mag phot.mag;em.IR.K
pmDE PM(Dec) Proper Motion in Dec deg/yr pos.pm;pos.eq.dec
pmRA PM(RA) Proper Motion in RA*cos(delta) deg/yr pos.pm;pos.eq.ra
r1mag USNO mag (R1) R mag from USNO-B, first epoch Note 1 N/A phot.mag;em.opt.R
r2mag USNO mag (R2) R mag from USNO-B, second epoch Note 1 N/A phot.mag;em.opt.R
raj2000 RA Right Ascension J2000.0, epoch 2000.0 deg pos.eq.ra;meta.main

VOTable Output Fields

The following fields are available in VOTable output. The verbosity level is a number intended to represent the relative importance of the field on a scale of 1 to 30. The services take a VERB argument. A field is included in the output if their verbosity level is less or equal VERB*10.

NameTable Head DescriptionUnitUCD Verb. Level
raj2000 RA Right Ascension J2000.0, epoch 2000.0 deg pos.eq.ra;meta.main 1
dej2000 Dec Declination J2000.0, epoch 2000.0 deg pos.eq.dec;meta.main 1
pmRA PM(RA) Proper Motion in RA*cos(delta) deg/yr pos.pm;pos.eq.ra 1
pmDE PM(Dec) Proper Motion in Dec deg/yr pos.pm;pos.eq.dec 1
ipix Id Identifier (Q3C ipix of the USNO-B 1.0 object) N/A meta.id;meta.main 5
_r Dist. Distance to cone center deg pos.distance 10
vickers_pmra PM'(RA) Proper motion in RA as re-corrected according to 2016AJ....151...99V, cos(delta) applied. This is only available for objects with 2MASS J magnitudes. e_pmRA still is suitable as an error estimate. N/A pos.pm;pos.eq.ra 10
vickers_pmde PM'(Dec) Proper motion in Dec as re-corrected according to 2016AJ....151...99V. This is only available for objects with 2MASS J magnitudes. e_pmDE still is suitable as an error estimate. N/A pos.pm;pos.eq.dec 10
e_raepRA E_raepra Mean error in RA*cos(delta) at mean epoch deg stat.error;pos.eq.ra;meta.main 15
e_deepDE E_deepde Mean error in Dec at mean epoch deg stat.error;pos.eq.dec;meta.main 15
e_pmRA Err. PM(RA) Mean error in pmRA*cos(delta) deg/yr stat.error;pos.pm;pos.eq.ra 15
e_pmDE Err. PM(Dec) Mean error in pmDE deg/yr stat.error;pos.pm;pos.eq.dec 15
Jmag m_J J selected default magnitude from 2MASS mag phot.mag;em.IR.J 15
Hmag m_H H selected default magnitude from 2MASS mag phot.mag;em.IR.H 15
Kmag m_K_s K_s selected default magnitude from 2MASS mag phot.mag;em.IR.K 15
nobs #obs Number of observations used Note 4 N/A meta.number;obs 20
e_Jmag Err(m_J) J total magnitude uncertainty mag stat.error;phot.mag;em.IR.J 20
b1mag USNO mag (B1) B mag from USNO-B, first epoch Note 1 N/A phot.mag;em.opt.B 25
b2mag USNO mag (B2) B mag from USNO-B, second epoch Note 1 N/A phot.mag;em.opt.B 25
imag USNO mag (I) I mag from USNO-B Note 1 N/A phot.mag;em.opt.I 25
r1mag USNO mag (R1) R mag from USNO-B, first epoch Note 1 N/A phot.mag;em.opt.R 25
r2mag USNO mag (R2) R mag from USNO-B, second epoch Note 1 N/A phot.mag;em.opt.R 25
epRA Epra Mean Epoch (RA) yr time.epoch;pos.eq.ra 25
epDE Epde Mean Epoch (Dec) yr time.epoch;pos.eq.dec 25
e_Hmag Err(m_H) H total magnitude uncertainty mag stat.error;phot.mag;em.IR.H 25
e_Kmag Err(m_K_s) K_s total magnitude uncertainty mag stat.error;phot.mag;em.IR.K 25
magSurveys USNO Mag src. Surveys the USNO-B magnitudes are taken from Note 2 N/A meta.code 28
flags Flags Flags Note 3 N/A meta.code 28

VOResource XML (that's something exclusively for VO nerds)

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

See also the PPMX table info .

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).