TABLE twomass_psc

Contains the parameters provided for each source in the TWOMASS All Sky Release PSC.

This table contains brief descriptions of the parameters provided for
each source in the TWOMASS All Sky Release PSC. The table is organized
according to the broad function and utility of the parameters: positional
information, photometric information, and source quality information.
WFAU gratefully acknowledges help from IPAC at Caltech in enabling a
bulk download of the entire catalogue for local deployment in the VSA/WSA.
Any issues encountered or questions raised in use of this incarnation of
the IPAC IRSA catalogue should be communicated to the vsa- or wsa-support helpdesks
in the first instance. For a complete description please see the
user's guide to the 2MASS PSC all-sky data release

Required constraints:
Primary key is (pts_key)
(ext_key) references twomass_xsc(ext_key)
(scan_key) references twomass_scn(scan_key)

Name Type Length Unit Description Default Value Unified Content Descriptor

cx float 8 unit vector of spherical co-ordinates pos.distance;pos.cartesian.x

cy float 8 unit vector of spherical co-ordinates pos.distance;pos.cartesian.y

cz float 8 unit vector of spherical co-ordinates pos.distance;pos.cartesian.z

htmID bigint 8 Hierarchical Triangular Mesh (HTM) index, 20 deep, for equatorial co-ordinates pos.eq

ra float 8 degrees J2000 right ascension with respect to the ICRS pos.eq.ra;meta.main

dec float 8 degrees J2000 declination with respect to the ICRS pos.eq.dec;meta.main

err_maj real 4 arcsec Semi-major axis length of the one sigma position uncertainty ellipse phys.angSize;src

err_min real 4 arcsec Semi-minor axis length of the one sigma position uncertainty ellipse phys.angSize;src

err_ang smallint 2 degrees Position angle on the sky of the semi-major axis of the position uncertainty ellipse (East of North) pos.posAng

designation varchar 17 Sexagesimal, equatorial position-based source name in the form: hhmmssss+ddmmsss[ABC...]. NAME

j_m real 4 mag Default J-band magnitude phot.flux

j_cmsig real 4 mag Corrected photometric uncertainty for the default J-band magnitude. J-band phot.flux

j_msigcom real 4 mag Combined, or total photometric uncertainty for the default J-band magnitude. J-band phot.flux

j_snr real 4 mag J-band "scan" signal-to-noise ratio. instr.det.noise

h_m real 4 mag Default H-band magnitude phot.flux

h_cmsig real 4 mag Corrected photometric uncertainty for the default H-band magnitude. H-band phot.flux

h_msigcom real 4 mag Combined, or total photometric uncertainty for the default H-band magnitude. H-band phot.flux

h_snr real 4 mag H-band "scan" signal-to-noise ratio. instr.det.noise

k_m real 4 mag Default Ks-band magnitude phot.flux

k_cmsig real 4 mag Corrected photometric uncertainty for the default Ks-band magnitude. Ks-band phot.flux

k_msigcom real 4 mag Combined, or total photometric uncertainty for the default Ks-band magnitude. Ks-band phot.flux

k_snr real 4 mag Ks-band "scan" signal-to-noise ratio. instr.det.noise

ph_qual varchar 3 Photometric quality flag. meta.code.qual

rd_flg varchar 3 Read flag. meta.code

bl_flg varchar 3 Blend flag. meta.code

cc_flg varchar 3 Contamination and confusion flag. meta.code

ndet varchar 6 Frame detection statistics. meta.number

prox real 4 arcsec Proximity. pos.angDistance

pxpa smallint 2 degrees The position angle on the sky of the vector from the source to the nearest neighbor in the PSC, in degrees East of North. pos.posAng

pxcntr int 4 The pts_key value of the nearest source in the PSC. meta.number

gal_contam smallint 2 Extended source "contamination" flag. meta.code

mp_flg smallint 2 Minor Planet Flag. meta.code

pts_key int 4 A unique identification number for the PSC source. meta.id

hemis varchar 1 Hemisphere code for the TWOMASS Observatory from which this source was observed. meta.code;obs

date datetime 8 yyyy-mm-dd The observation reference date for this source expressed in ISO standard format. (YYYY-MM-DD) time.epoch

scan smallint 2 The nightly scan number in which the source was detected. meta.number

glon real 4 degrees Galactic longitude rounded to 0.001 deg. pos.galactic.lon

glat real 4 degrees Galactic latitude rounded to 0.001 deg. pos.galactic.lat

x_scan real 4 arcsec Mean cross-scan focal plane position of the source in the Universal scan (U-scan) coordinate system. pos.cartesian;instr.det

jdate float 8 Julian days The Julian Date of the source measurement accurate to +-30 seconds. time.epoch

j_psfchi real 4 Reduced chi-squared goodness-of-fit value for the J-band profile-fit photometry made on the 1.3 s "Read_2" exposures. stat.fit.param

h_psfchi real 4 Reduced chi-squared goodness-of-fit value for the H-band profile-fit photometry made on the 1.3 s "Read_2" exposures. stat.fit.param

k_psfchi real 4 Reduced chi-squared goodness-of-fit value for the Ks-band profile-fit photometry made on the 1.3 s "Read_2" exposures. stat.fit.param

j_m_stdap real 4 mag J-band "standard" aperture magnitude. phot.flux

j_msig_stdap real 4 mag Uncertainty in the J-band standard aperture magnitude. phot.flux

h_m_stdap real 4 mag H-band "standard" aperture magnitude. phot.flux

h_msig_stdap real 4 mag Uncertainty in the H-band standard aperture magnitude. phot.flux

k_m_stdap real 4 mag Ks-band "standard" aperture magnitude. phot.flux

k_msig_stdap real 4 mag Uncertainty in the Ks-band standard aperture magnitude. phot.flux

dist_edge_ns int 4 arcsec The distance from the source to the nearest North or South scan edge. pos;arith.diff

dist_edge_ew int 4 arcsec The distance from the source to the nearest East or West scan edge. pos;arith.diff

dist_edge_flg varchar 2 Two character flag that specifies to which scan edges a source lies closest, and to which edges the dist_edge_ns and dist_edge_ew values refer. pos;arith.diff

dup_src smallint 2 Duplicate source flag. meta.code

use_src smallint 2 Use source flag. meta.code

a varchar 1 Catalog identifier of an optical source from either the Tycho 2 or USNO-A2.0 catalog that falls within ~5" of the TWOMASS source position. meta.id

dist_opt real 4 arcsec Distance separating TWOMASS source position and associated optical source within 5". pos;arith.diff

phi_opt smallint 2 degrees Position angle on the sky of the vector from the the associated optical source to the TWOMASS source position, in degrees East of North. pos.posAng

b_m_opt real 4 mag Blue magnitude of associated optical source. phot.flux

vr_m_opt real 4 mag Visual or red magnitude of the associated optical source. phot.flux

nopt_mchs smallint 2 The number of USNO-A2.0 or Tycho 2 optical sources found within a 5" radius of the TWOMASS position. meta.number

ext_key int 4 Unique identification number of the record in the XSC that corresponds to this point source. meta.id

scan_key int 4 Unique identification number of the record in the Scan Information Table that corresponds to the survey scan in which this source was detected. meta.id

coadd_key int 4 Unique identification number of the record in the Atlas Image Data Table (NOT YET AVAILABLE) that corresponds to Image in which the position of this source falls. meta.id

coadd smallint 2 Sequence number of the Atlas Image in which the position of this source falls. meta.number

Total length 271

Name	Type	Length	Unit	Description	Default Value	Unified Content Descriptor
cx	float	8		unit vector of spherical co-ordinates		pos.distance;pos.cartesian.x
cy	float	8		unit vector of spherical co-ordinates		pos.distance;pos.cartesian.y
cz	float	8		unit vector of spherical co-ordinates		pos.distance;pos.cartesian.z
htmID	bigint	8		Hierarchical Triangular Mesh (HTM) index, 20 deep, for equatorial co-ordinates		pos.eq
ra	float	8	degrees	J2000 right ascension with respect to the ICRS		pos.eq.ra;meta.main
dec	float	8	degrees	J2000 declination with respect to the ICRS		pos.eq.dec;meta.main
err_maj	real	4	arcsec	Semi-major axis length of the one sigma position uncertainty ellipse		phys.angSize;src
err_min	real	4	arcsec	Semi-minor axis length of the one sigma position uncertainty ellipse		phys.angSize;src
err_ang	smallint	2	degrees	Position angle on the sky of the semi-major axis of the position uncertainty ellipse (East of North)		pos.posAng
designation	varchar	17		Sexagesimal, equatorial position-based source name in the form: hhmmssss+ddmmsss[ABC...].		NAME
j_m	real	4	mag	Default J-band magnitude		phot.flux
j_cmsig	real	4	mag	Corrected photometric uncertainty for the default J-band magnitude.	J-band	phot.flux
j_msigcom	real	4	mag	Combined, or total photometric uncertainty for the default J-band magnitude.	J-band	phot.flux
j_snr	real	4	mag	J-band "scan" signal-to-noise ratio.		instr.det.noise
h_m	real	4	mag	Default H-band magnitude		phot.flux
h_cmsig	real	4	mag	Corrected photometric uncertainty for the default H-band magnitude.	H-band	phot.flux
h_msigcom	real	4	mag	Combined, or total photometric uncertainty for the default H-band magnitude.	H-band	phot.flux
h_snr	real	4	mag	H-band "scan" signal-to-noise ratio.		instr.det.noise
k_m	real	4	mag	Default Ks-band magnitude		phot.flux
k_cmsig	real	4	mag	Corrected photometric uncertainty for the default Ks-band magnitude.	Ks-band	phot.flux
k_msigcom	real	4	mag	Combined, or total photometric uncertainty for the default Ks-band magnitude.	Ks-band	phot.flux
k_snr	real	4	mag	Ks-band "scan" signal-to-noise ratio.		instr.det.noise
ph_qual	varchar	3		Photometric quality flag.		meta.code.qual
rd_flg	varchar	3		Read flag.		meta.code
bl_flg	varchar	3		Blend flag.		meta.code
cc_flg	varchar	3		Contamination and confusion flag.		meta.code
ndet	varchar	6		Frame detection statistics.		meta.number
prox	real	4	arcsec	Proximity.		pos.angDistance
pxpa	smallint	2	degrees	The position angle on the sky of the vector from the source to the nearest neighbor in the PSC, in degrees East of North.		pos.posAng
pxcntr	int	4		The pts_key value of the nearest source in the PSC.		meta.number
gal_contam	smallint	2		Extended source "contamination" flag.		meta.code
mp_flg	smallint	2		Minor Planet Flag.		meta.code
pts_key	int	4		A unique identification number for the PSC source.		meta.id
hemis	varchar	1		Hemisphere code for the TWOMASS Observatory from which this source was observed.		meta.code;obs
date	datetime	8	yyyy-mm-dd	The observation reference date for this source expressed in ISO standard format. (YYYY-MM-DD)		time.epoch
scan	smallint	2		The nightly scan number in which the source was detected.		meta.number
glon	real	4	degrees	Galactic longitude rounded to 0.001 deg.		pos.galactic.lon
glat	real	4	degrees	Galactic latitude rounded to 0.001 deg.		pos.galactic.lat
x_scan	real	4	arcsec	Mean cross-scan focal plane position of the source in the Universal scan (U-scan) coordinate system.		pos.cartesian;instr.det
jdate	float	8	Julian days	The Julian Date of the source measurement accurate to +-30 seconds.		time.epoch
j_psfchi	real	4		Reduced chi-squared goodness-of-fit value for the J-band profile-fit photometry made on the 1.3 s "Read_2" exposures.		stat.fit.param
h_psfchi	real	4		Reduced chi-squared goodness-of-fit value for the H-band profile-fit photometry made on the 1.3 s "Read_2" exposures.		stat.fit.param
k_psfchi	real	4		Reduced chi-squared goodness-of-fit value for the Ks-band profile-fit photometry made on the 1.3 s "Read_2" exposures.		stat.fit.param
j_m_stdap	real	4	mag	J-band "standard" aperture magnitude.		phot.flux
j_msig_stdap	real	4	mag	Uncertainty in the J-band standard aperture magnitude.		phot.flux
h_m_stdap	real	4	mag	H-band "standard" aperture magnitude.		phot.flux
h_msig_stdap	real	4	mag	Uncertainty in the H-band standard aperture magnitude.		phot.flux
k_m_stdap	real	4	mag	Ks-band "standard" aperture magnitude.		phot.flux
k_msig_stdap	real	4	mag	Uncertainty in the Ks-band standard aperture magnitude.		phot.flux
dist_edge_ns	int	4	arcsec	The distance from the source to the nearest North or South scan edge.		pos;arith.diff
dist_edge_ew	int	4	arcsec	The distance from the source to the nearest East or West scan edge.		pos;arith.diff
dist_edge_flg	varchar	2		Two character flag that specifies to which scan edges a source lies closest, and to which edges the dist_edge_ns and dist_edge_ew values refer.		pos;arith.diff
dup_src	smallint	2		Duplicate source flag.		meta.code
use_src	smallint	2		Use source flag.		meta.code
a	varchar	1		Catalog identifier of an optical source from either the Tycho 2 or USNO-A2.0 catalog that falls within ~5" of the TWOMASS source position.		meta.id
dist_opt	real	4	arcsec	Distance separating TWOMASS source position and associated optical source within 5".		pos;arith.diff
phi_opt	smallint	2	degrees	Position angle on the sky of the vector from the the associated optical source to the TWOMASS source position, in degrees East of North.		pos.posAng
b_m_opt	real	4	mag	Blue magnitude of associated optical source.		phot.flux
vr_m_opt	real	4	mag	Visual or red magnitude of the associated optical source.		phot.flux
nopt_mchs	smallint	2		The number of USNO-A2.0 or Tycho 2 optical sources found within a 5" radius of the TWOMASS position.		meta.number
ext_key	int	4		Unique identification number of the record in the XSC that corresponds to this point source.		meta.id
scan_key	int	4		Unique identification number of the record in the Scan Information Table that corresponds to the survey scan in which this source was detected.		meta.id
coadd_key	int	4		Unique identification number of the record in the Atlas Image Data Table (NOT YET AVAILABLE) that corresponds to Image in which the position of this source falls.		meta.id
coadd	smallint	2		Sequence number of the Atlas Image in which the position of this source falls.		meta.number
Total length		271