B/denis             The DENIS database            (DENIS Consortium, 1998)
The DENIS (DEep Near-Infrared Survey)
     Epchtein N. et al.
     <The DENIS Consortium (1998)>
ADC_Keywords: Infrared sources ; Photometry, infrared ; Surveys


    DENIS is a project to survey the all-southern sky in three wavelength
    bands (Gunn-i 0.82 µm; J, 1.25 µm; and K_s, 2.15 µm) with 
    limiting magnitudes 18.5, 16.5 and 14.0, respectively. The observations 
    are performed with the 1m-ESO telescope at La Silla (Chile). 
    The DENIS instrument is made up of a 3-channel camera built
    of commercially available detector arrays by the Observatoire de Paris
    and with major contributions from other European Institutes, notably:
    the IAS in Frascati, the Observatoire de Grenoble, the University of
    Innsbruck, the Observatoire de Lyon, and the IAC in Tenerife. The
    survey is carried out by observing strips of 30 ° in declination
    and 12 arcminutes in Right Ascension with an overlap of 2 arcminutes
    between consecutive strips. The survey started at the end of
    1995 and is expected to be completed in 2000. The data are reduced
    in two consecutive steps, the first at the Institut d'Astrophysique de
    Paris and the second at the Leiden Observatory. The position of a
    general extracted point source is provided with an accuracy better
    than 1 arcsec and its magnitude to better than 0.1 mag. The data will
    be made publicly available as soon as possible after completing the
    data reduction. The Centre de Donnees Astronomiques de Strasbourg (CDS) 
    is implementing the final databases and is providing access 
    of the processed and calibrated data to the worldwide community.

    The principal investigator of the DENIS project is N. Epchtein
    (Observatoire de la Cote d'Azur); scientists and engineers from
    seven European countries and from Brazil are involved.

File Summary:

FileName Lrecl Records Explanations
ReadMe 80 . The present file. denis.sam 354 1000 Sample of DENIS output.
See also: http://cdsweb.u-strasbg.fr/denis.html : DENIS documentation Nomenclature Notes: The recommended way to designate the DENIS sources is JHHMMSS.s-DDMMSS Byte-by-byte Description of file: denis.sam
Bytes Format Units Label Explanations
1- 16 A16 --- Name DENIS identifier: JHHMMSS.s-DDMMSS 18- 21 I4 --- Strip DENIS strip number 23- 29 I7 --- SeqNr Object sequence number (from make_ssc) 31- 40 F10.6 deg RAdeg Right ascension (J2000) 42- 51 F10.6 deg DEdeg Declination (J2000) 53- 60 F8.6 deg ErrPos Random Position Error -------------------------------------------------------------------------------- 62- 67 F6.3 mag Ap7mag_I ?Magnitude from FLUX_APER 7'' 69- 74 F6.3 mag eAp7magI ?Magnitude error from FLUXERR_APER 7'' 76- 81 F6.3 mag Ap15mag_I ?Magnitude from FLUX_APER 15'' 83- 88 F6.3 mag eAp15magI ?Magnitude error from FLUXERR_APER 15'' 90- 95 F6.3 mag Automag_I ?Magnitude from FLUX_AUTO 97-102 F6.3 mag eAutomagI ?Magnitude error from FLUXERR_AUTO 104-111 F8.6 deg MajAxis_I ?Major axis object ellipse 113-120 F8.6 deg MinAxis_I ?Minor axis object ellipse 122-129 F8.6 --- ell_I [0,1]? Ellipticity of object (1) 131-136 F6.2 deg Theta_I [-90,+90]? Position angle of ellipse (2) 138-141 F4.2 --- Stellar_I [0,1]? "Stellarity" of object (3) 143-145 I3 --- Extr_I ?Extraction flags (4) 147-148 I2 --- Ima_I ?Image flags (5) 150 I1 --- Arti_I ?Image Artifact marker (6) 152-154 I3 --- Merged_I [0,127]? Merged objects indicator (7) 156-158 I3 --- Field_I ?Field position reference (8) -------------------------------------------------------------------------------- 160-165 F6.3 mag Ap7mag_J ?Magnitude from FLUX_APER 7'' 167-172 F6.3 mag eAp7magJ ?Magnitude error from FLUXERR_APER 7'' 174-179 F6.3 mag Ap15mag_J ?Magnitude from FLUX_APER 15'' 181-186 F6.3 mag eAp15magJ ?Magnitude error from FLUXERR_APER 15'' 188-193 F6.3 mag Automag_J ?Magnitude from FLUX_AUTO 195-200 F6.3 mag eAutomagJ ?Magnitude error from FLUXERR_AUTO 202-209 F8.6 deg MajAxis_J ?Major axis object ellipse 211-218 F8.6 deg MinAxis_J ?Minor axis object ellipse 220-227 F8.6 --- ell_J [0,1]? Ellipticity of object (1) 229-234 F6.2 deg Theta_J [-90,+90]? Position angle of ellipse (2) 236-239 F4.2 --- Stellar_J [0,1]? "Stellarity" of object (3) 241-243 I3 --- Extr_J ?Extraction flags (4) 245-246 I2 --- Ima_J ?Image flags (5) 248 I1 --- Arti_J ?Image Artifact marker (6) 250-252 I3 --- Merged_J [0,127]? Merged objects indicator (7) 254-256 I3 --- Field_J ?Field position reference (8) -------------------------------------------------------------------------------- 258-263 F6.3 mag Ap7mag_K ?Magnitude from FLUX_APER 7'' 265-270 F6.3 mag eAp7magK ?Magnitude error from FLUXERR_APER 7'' 272-277 F6.3 mag Ap15mag_K ?Magnitude from FLUX_APER 15'' 279-284 F6.3 mag eAp15magK ?Magnitude error from FLUXERR_APER 15'' 286-291 F6.3 mag Automag_K ?Magnitude from FLUX_AUTO 293-298 F6.3 mag eAutomagK ?Magnitude error from FLUXERR_AUTO 300-307 F8.6 deg MajAxis_K ?Major axis object ellipse 309-316 F8.6 deg MinAxis_K ?Minor axis object ellipse 318-325 F8.6 --- ell_K [0,1]? Ellipticity of object (1) 327-332 F6.2 deg Theta_K [-90,+90]? Position angle of ellipse (2) 334-337 F4.2 --- Stellar_K [0,1]? "Stellarity" of object (3) 339-341 I3 --- Extr_K ?Extraction flags (4) 343-344 I2 --- Ima_K ?Image flags (5)nomenclature 346 I1 --- Arti_K ?Image Artifact marker (6) 348-350 I3 --- Merged_K [0,127]? Merged objects indicator (7) 352-354 I3 --- Field_K ?Field position reference (8)
Note (1): the ellipticity is defined by: e = (sqrt(a2-b2))/a i.e. a value of zero means a circle, a value close to one corresponds to a line. Note (2): the angle theta is zero in the East and rotates anti-clockwise; the "classical" position angle PA is therefore (90°-theta) Note (3): a value of 1 identifies the object as a star, and a value 0f 0 indicates a galaxy. Note (4): the extraction flag, defined by SExtractor: 1: the object has neighbours, bright and close enough to significantly bias the MAG_AUTO photometry, or bad pixels; 2: the object was originally blended with another one; 4: at least one pixel of the object is saturated (or very close to); 8: the object is truncated (too close to an image boundary); 16: object's aperture data are incomplete or corrupted; 32: object's isophotal data are incomplete or corrupted; 64: a memory overflow occurred during deblending; 128: a memory overflow occurred during extraction. Note (5): the image flag is defined according to the flag.fits file. 1: regression failed for this pixel; 2: flat derived is less than 0.01; 3: abnormaly high flat; 4: abnormaly high residual after adjustment; 5: bias away from mean by more than 5 sigmas; 9: insufficient pixels left after iterative clipping. Caution: different values of these flags may occur in one stellar image. Because these flags do not have binary exclusive values the ORing of these flags causes loss of information! This ORing takes place both inside an isophotal area and for merging of multiple detections of the same source. Note (6): the Artifact flag: it identifies detector/instrument specific conditions. The flag can assume the following values: 1: Glitch; 2: Optical Ghost; 4: Saturation in I. Note (7): the Merged objects indicator takes the values: 0 = no detection, 1 = good detection, 2(+?) = object merge Note (8): the Field position reference refers back to the frame sequence number (2MUFIELD) of the frame from which the particular source was extracted. In case of a merge, one of the frame numbers in the merge is given.
Acknowledgements: DENIS is the result of a joint effort involving human and financial contributions of several Institutes mostly located in Europe. It has been supported financially mainly by the French Institut National des Sciences de l'Univers, CNRS, and French Education Ministry, the European Southern Observatory, the State of Baden-Württemberg, and the European Commission under a network of the Human Capital and Mobility program. Reference: The DENIS Consortium (December 1998) ================================================================================ (End) Sebastien Derriere, Francois Ochsenbein [CDS] 28-Oct-1998