|What's VOS/ADP||ESO Data Products||Contacts|
|Overview and field layout||Data format|
|Notes on the v1.0 Data Release||Data retrieval|
This data release includes broad band and narrow band imaging of a one-square degree region around the 30 Doradus complex in the Large Magellanic Cloud. These data products are based on observations carried out by Joao Alves, Benoit Vandame and Yuri Bialetski with the Wide Field Imager (WFI) at the 2.2m telescope on La Silla (Programme ID 076.C-0888). These data consist of a 2x2 WFI mosaic in the bands B, V, and narrow band Hα and [OIII]. A spectacular colour composite image resulting from these observations is also included in this release and is the subject of an ESO Press Release. Note that observations were carried out in good seeing but non-photometric conditions; scientific applications will therefore require cross-photometric calibration.
||Positions of the 4 fields overlayed on a colour mosaic derived from the FITS files in this release (an 8x8k pixel version (half the size of the full mosaic) is included in this release). All fields are covered in the bands [OIII], B, V and Hα. [Click to get a bigger size layout]|
|The released optical WFI images from the 30 Doradus region reduced with the ESO/MVM pipeline are tabulated to the right, consisting of 16 astrometrically calibrated images in B/123 (4), OIII/8 (4), V/89 (4) and Halpha/7 (4) filters. The table gives: in column (1) the field; in column (2) the filter; in columns (3) and (4) the centre coordinates in RA and Dec; in column (5) the total integration time in seconds; in column (6) the number of frames that make up the final image; in column (7) the average FWHM measured on the image in arcsec ("seeing"); in column (8) the observation date. The same table is also available in ASCII format.||
[click to see the full table]
Each field is the co-addition of a number of sky-subtracted frames (NCOMBINE in the image header). Images are registered using an astrometric grid defined by the Two Micron All Sky Survey (2MASS) catalogue. After co-addition a constant sky value is substracted from each image.
In addition, an 8x8k (half-size) colour mosaic image has been created, derived from the data files in this release. Mosaic FITS images for the individual filters were created with ESO/MVM and then combined to create an RGB image (see also the ESO press release). The Hα mosaic was used for the R channel, the V and [OIII] mosaics were combined to form the G channel and the B mosaic was used for the B channel. Finally, a FITS RGB cube was created from this RGB image with proper WCS information added, which can be loaded directly into DS9 (e.g. 'ds9 -rgbcube ADP_WFI_30Dor_RGB_v1.0.fits') or Aladin.
The following file naming convention has been adopted for the data files:
for the field name <xx>
in the filter <f> and the
respective weight map.
Additionally, field names can be found in the OBJECT keywords in the FITS headers.
The 8x8k RGB mosaic is included in FITS cube and JPG formats:
See here the complete list of data files belonging to this release as they can be retrieved via the data request page.
comments to <firstname.lastname@example.org>
Last update: Dec 20, 2006