Table information for 'cars.srccat'

General

Table Description: Extracted sources from the CARS survey, comprising positions and multiband photometry.

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

Resource Description: Images and data from from the CFHTLS archive research survey, a multi-band dataset spanning 37 square degrees of sky in high galactic latitudes.

For a list of all services and tables belonging to this table's resource, see Information on resource 'CARS survey data'

Citing this table

This table has an associated publication. If you use data from it, it may be appropriate to reference 2009A&A...493.1197E (ADS BibTeX entry for the publication) either in addition to or instead of the service reference.

To cite the table as such, we suggest the following BibTeX entry:

@MISC{vo:cars_srccat,
  year=2009,
  title={{CARS} survey data},
  author={Erben, T. and Hildebrandt, H. and Lerchster, M. and Hudelot, P. and Benjamin, J. and van Waerbeke, L. and Schrabback, T. and Brimioulle, F. and Cordes, O. and Dietrich, J. P. and Holhjem, K. and Schirmer, M. and Schneider, P.},
  url={http://dc.zah.uni-heidelberg.de/tableinfo/cars.srccat},
  howpublished={{VO} resource provided by the {GAVO} Data Center}
}

Resource Documentation

These services deliver products from the CFHTLS-Archive-Research Survey (CARS). The survey currently offers derived products from 37 sq. degrees of the Wide part from the Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). The main documentation for the products, its creation and its content is the publication 2009A&A...493.1197E. Here, we discuss some points which are not evident from this publication.

AVAILABLE DATA PRODUCTS

For each 1 sq. deg. CARS pointing we currently offer the following products (we discuss them on the example of the CARS pointing W1m0p1); a typical file is named W1m0p1_izrgu.V1.7A.final.cat. The name contains the following information:

The individual files we offer are:

W1m0p1_izrgu.V1.7A.final.cat
object catalogue in FITS binary format; beware that they are very big and cumbersome to handle if you do not have efficient tools to work on big FITS binary tables! (typical file size per field: 0.5GB!)
W1m0p1_izrgu.V1.7A.final.asc.gz
An ASCII version of W1m0p1_izrgu.V1.7A.final.cat containing a subset of the most important catalogue quantities. This catalogue should be sufficient for most users. The main content of the catalogue can also be queried in the cat service. (typical gzipped file size per field: 20MB)
W1m0p1_izrgu.V1.7A.final.reg.gz

An ASCII ds9 region file containing saoimage/ds9 polygon entries (in pixel coordinates). They represent the CARS image masks described in Sect. 3.4 of 2009A&A...493.1197E. Polygons originating from different masking procedures are encoded with different colours (look at expressions such as '# color=yellow' at the end of each line). We offer this file so that interested users can construct own masks containing only parts of our global MASK key. (typical gzipped file size per field: 1MB)

The colour coding in these files is as follows:

  • yellow: masks from our object density analysis and stars identified in the USNO-A2 catalogue
  • green: stars identified in the GSC1 and GSC2 cataogues
  • magenta: masks around extended haloes of bright stars
  • red: masks from our asteroid track analysis

W1m0p1_irg.V1.7A.truecol.jpg

low resolution true colour i', r' and g' JPG image of the CARS field. These images allow a quick look at the data but they are probably not suitable for high-quality poster print-outs. (typical file size per field: 10MB)
W1m0p1_izrgu.V1.7A.masks.obj.jpg

low resolution JPG image showing object positions and object masks overlayed on the i'-band image. It allows a quick-look at field-layout and object positions. (typical file size per field: 3MB)

The colour coding in this is:

  • green: areas excluded from scientific analysis by our MASK key
  • yellow: stellar sources (SExtractor CLASS_STAR >=0.95)
  • red: galaxies with high-confidence photo-z estimates: (SExtractor CLASS_STAR < 0.95; reliable object photometry in five bands; BPZ ODDS quality parameter > 0.9); see also Sect. 4 of 2009A&A...493.1197E
  • blue: all other galaxies (SExtractor CLASS_STAR < 0.95)

CATALOGUE QUANTITIES

See 2009A&A...493.1197E, in particular Sect. 4, and the SExtractor Users manual for a description of most catalogue entries. Also see the table notes.

CURRENT COVERAGE

CARS coverage

Fields

Sorted by DB column index. [Sort alphabetically]

NameTable Head DescriptionUnitUCD
carsid Id CARS object ID N/A meta.id;meta.main
SeqNr No Running object number (in field) N/A meta.id
raj2000 RA Right ascension of barycenter (J2000) deg pos.eq.ra;meta.main
dej2000 Dec Declination of barycenter (J2000) deg pos.eq.dec;meta.main
xpos X Object position on exposure along x pix pos.cartesian.x;instr.det
ypos Y Object position on exposure along y pix pos.cartesian.y;instr.det
magAuto Auto. mag. Kron-like elliptical aperture magnitude [Note 1] mag phot.mag
magErrAuto Err. Auto. mag. Error in Kron-like elliptical aperture magnitude mag stat.error;phot.mag
magisoU Iso. mag. u* Isophotal magnitude in the u* band [Note 1] mag phot.mag;em.opt
magisoErrU Err. iso. mag. u* RMS error of isophotal magnitude in the u* band mag stat.error;phot.mag;em.opt
magaprU F.a. mag. u* Fixed aperture magnitude in the u* band [Note 1] mag phot.mag;em.opt
magaprErrU Err. F.a. mag. u* RMS error of fixed aperture magnitude in the u* band mag stat.error;phot.mag;em.opt
maglimU Lim. mag. u* Limiting magnitude at object's position in u* band [Note 4] mag N/A
magisoG Iso. mag. g' Isophotal magnitude in the g' band [Note 1] mag phot.mag;em.opt
magisoErrG Err. iso. mag. g' RMS error of isophotal magnitude in the g' band mag stat.error;phot.mag;em.opt
magaprG F.a. mag. g' Fixed aperture magnitude in the g' band [Note 1] mag phot.mag;em.opt
magaprErrG Err. F.a. mag. g' RMS error of fixed aperture magnitude in the g' band mag stat.error;phot.mag;em.opt
maglimG Lim. mag. g' Limiting magnitude at object's position in g' band [Note 4] mag N/A
magisoR Iso. mag. r' Isophotal magnitude in the r' band [Note 1] mag phot.mag;em.opt
magisoErrR Err. iso. mag. r' RMS error of isophotal magnitude in the r' band mag stat.error;phot.mag;em.opt
magaprR F.a. mag. r' Fixed aperture magnitude in the r' band [Note 1] mag phot.mag;em.opt
magaprErrR Err. F.a. mag. r' RMS error of fixed aperture magnitude in the r' band mag stat.error;phot.mag;em.opt
maglimR Lim. mag. r' Limiting magnitude at object's position in r' band [Note 4] mag N/A
magisoI Iso. mag. i' Isophotal magnitude in the i' band [Note 1] mag phot.mag;em.opt
magisoErrI Err. iso. mag. i' RMS error of isophotal magnitude in the i' band mag stat.error;phot.mag;em.opt
magaprI F.a. mag. i' Fixed aperture magnitude in the i' band [Note 1] mag phot.mag;em.opt
magaprErrI Err. F.a. mag. i' RMS error of fixed aperture magnitude in the i' band mag stat.error;phot.mag;em.opt
maglimI Lim. mag. i' Limiting magnitude at object's position in i' band [Note 4] mag N/A
magisoZ Iso. mag. z' Isophotal magnitude in the z' band [Note 1] mag phot.mag;em.opt
magisoErrZ Err. iso. mag. z' RMS error of isophotal magnitude in the z' band mag stat.error;phot.mag;em.opt
magaprZ F.a. mag. z' Fixed aperture magnitude in the z' band [Note 1] mag phot.mag;em.opt
magaprErrZ Err. F.a. mag. z' RMS error of fixed aperture magnitude in the z' band mag stat.error;phot.mag;em.opt
maglimZ Lim. mag. z' Limiting magnitude at object's position in z' band [Note 4] mag N/A
fwhm FWHM Full width half max assuming a gaussian core deg phys.angSize
fluxRadius Flux rad. Fraction-of-light radius pix N/A
majorAxis RMS major Profile RMS along major axis deg phys.angSize.smajAxis
minorAxis RMS minor Profile RMS along minor axis deg phys.angSize.sminAxis
theta Pos. Ang. Position angle (east of north) (J2000) deg pos.posAng
sgclass S/G S/G classifier output (0..1) N/A src.class.starGalaxy
extflags Ext. Flags Extraction Flags N/A N/A
mask In mask True if object is within an object mask N/A meta.code
z_b Z_B Photometric redshift N/A N/A
t_b T_B Mask value N/A N/A
odds z odds Confidence parameter for photometric redshift N/A N/A
NgoodFilters #Good Number of filters with good photometry for BPZ [Note 2] N/A meta.code.qual
NbadFilters #Bad Number of filters with bad photometry for BPZ [Note 2] N/A meta.code.qual
NfaintFilters #Faint Number of filters with faint photometry for BPZ [Note 2] N/A meta.code.qual
goodFilters Good Filters with faint photometry for BPZ [Note 3] N/A N/A
badFilters Bad Filters with bad photometry for BPZ [Note 3] N/A N/A
faintFilters Faint Filters with faint photometry for BPZ [Note 3] N/A N/A
fieldKey Field CARS field designation N/A meta.id

Columns that are parts of indices are marked like this.

Other

The following services may use the data contained in this table:

VOResource

VO nerds may sometimes need VOResource XML for this table.

Notes

Copyright and such:

If you use the CARS products for your own research, please give proper acknowledgment to CADC, the CFHTLS project and the publication 2009A&A...493.1197E