| Description: The Cosmic Lens All-Sky Survey (CLASS) is an international collaborative program which has obtained high-resolution radio images of over 10000 flat-spectrum radio sources in order to create the largest and best studied statistical sample of radio-loud gravitationally lensed systems. With this survey, combined with detailed studies of the lenses found therein, constraints can be placed on the expansion rate, matter density, and dark energy (e.g. cosmological constant, quintessence) content of the Universe that are complementary to and independent of those obtained through other methods. CLASS is aimed at identifying lenses where multiple images are formed from compact flat-spectrum radio sources, which should be easily identifiable in the radio maps. Because CLASS is radio-based, dust obscuration in lensing galaxies is not a factor, and the relative insensitivity of the instrument to environmental conditions leads to nearly uniform sensitivity and resolution over the entire survey. |
| Completely compliant |
| Service URL |
| Input Parameter | Required | Present |
|---|---|---|
| Regular parameters: | ||
| POS | MUST | Yes |
| SIZE | MUST | Yes |
| INTERSECT | MAY | No |
| NAXIS | MAY | No |
| CFRAME | MAY | No |
| EQUINOX | MAY | No |
| CRPIX | MAY | No |
| CRVAL | MAY | No |
| CDELT | MAY | No |
| ROTANG | MAY | No |
| PROJ | MAY | No |
| FORMAT | MUST | Yes |
| Service specific parameters | ||
| VERB | MAY | Yes |
| Field UCD | Required | Present | Required datatype |
Actual datatype |
|---|---|---|---|---|
| Regular fields: | ||||
| VOX:Image_Title | MUST | Yes | char | char |
| INST_ID | SHOULD | No | char | |
| VOX:Image_MJDateObs | SHOULD | No | double | |
| POS_EQ_RA_MAIN | MUST | Yes | double | double |
| POS_EQ_DEC_MAIN | MUST | Yes | double | double |
| VOX:Image_Naxes | MUST | Yes | int | int |
| VOX:Image_Naxis | MUST | Yes | int | int |
| VOX:Image_Scale | MUST | Yes | double | double |
| VOX:Image_Format | MUST | Yes | char | char |
| VOX:STC_CoordRefFrame | SHOULD | No | char | |
| VOX:STC_CoordEquinox | MAY | No | double | |
| VOX:WCS_CoordProjection | SHOULD | No | char | |
| VOX:WCS_CoordRefPixel | SHOULD | No | double | |
| VOX:WCS_CoordRefValue | SHOULD | No | double | |
| VOX:WCS_CDMatrix | SHOULD | No | double | |
| VOX:BandPass_ID | SHOULD | No | char | |
| VOX:BandPass_Unit | SHOULD | No | char | |
| VOX:BandPass_RefValue | SHOULD | No | double | |
| VOX:BandPass_HiLimit | SHOULD | No | double | |
| VOX:BandPass_LoLimit | SHOULD | No | double | |
| VOX:Image_PixFlags | SHOULD | No | char | |
| VOX:Image_AccessReference | MUST | Yes | char | char |