| Preview: | Currently blank. On hover-over this will show you the preview image for a given observation. Clicking on it will open a new page showing you a larger version of the preview images. The preview images show the maps produced by ORAC-DR for SCUBA-2 data, and either an integrated map, a representative spectrum or both for the ACSIS data. |
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| Collection: | Currently all JCMT data is labelled JCMT. Eventually, we may have additional JCMT collections for Survey-produced products and PI produced products. |
| Obs ID: | Observation ID. For the raw files and reduced data from one observation the format should be fairly recognisable to JCMT users: instrumentName ___ObsNum__Datestamp. Composite reductions – reduced data using more than one observation – have a more complex ID, which includes a long alphanumeric string and is not easily usable. |
| RA(J2000): | Approximate RA of map centre. Can be shown in decimal degrees or ‘H:M:S’ by selecting the drop down option. |
| Dec(J2000): | Approximate Dec of map centre. Can be shown in decimal degrees or ‘D:M:S’ by selecting the drop down option. |
| Start Date: | UT time of start of observation, in MJD or Calendar format (Calendar by default). |
| Instrument: | JCMT instrument name. Continuum instrumentation naming should be obvious. For heterodyne instrumentation, we’ve chosen to use FRONTEND-BACKEND as a naming scheme, or POLARIMETER-FRONTEND-BACKEND for polarimetry observations. However, not all data has been re-ingested following this change, so you will currently find some HARP data labelled as HARP-ACSIS and some as ACSIS. Some older (pre-ACSIS and pre-SCUBA-2) observations are also present in the database, but they are not very discoverable through this interface. Large amounts of information has not yet been migrated to this database for these older observations, and the older instrument names may not be in a standardised form. |
| Int. Time: | Integration time, by default in seconds. This is the integration time of the whole map. |
| Target Name: | The target name as it was set in the JCMT Observing Tool by the project who carried out the observation. This is usually useful and recognisable, but particularly in projects that observe multiple scans nearby each other you may see names such as ‘Region 1’ or ‘Box N’; this is of less use to other astronomers. The target name can be searched directly from the search pane by unsetting the ‘Resolve object name to coordinates’ tick box in the spatial constraints->Target section of the search pane. |
| Filter: | For continuum observations, this indicates the wavelength. The SCUBA-2 filters are named 450um-SCUBA-2 and 850um-SCUBA-2, to indicate they are not exactly the same filter profile as was used by SCUBA (currently at least, SCUBA filters are named only by the wavelength). This column is not set for spectral observations. It can be used as a constraint on the search page as well as used to filter results shown in the results table. |
| Cal level: |
The calibration level be used as a constraint on the search page |
| Obs Type: | The type of observation — e.g. grid/jiggle/scan for HARP science observations, or scan/setup/noise etc. for SCUBA-2 observations. Can be pre filtered on the query page as well as here — you can view the full list of options for a given instrument in the search pane. |
| Min Wavelength: | Minimum wavelength or frequency of observation. A drop down menu at the top of the column allows you to use various standard frequency and wavelength units. |
| Max Wavelength: | Maximum wavelength or frequency of observation. A drop down menu at the top of the column allows you to use various standard frequency and wavelength units. |
| Proposal ID: | The JCMT proposal ID of the project. Can be preselected on query page, and that page will also autocomplete from the possible options for you. |
| PI Name: | The name of the PI the observation was taken under. This can be preselected in query page which will also autocomplete for you from the possible options. |
| Product ID: | This tells you the type of file. E.g. SCUBA-2 data could be raw_450 or reduced_850 . ACSIS data is in form raw_X, cube_X and reduced_X, where X is the frequency and bandwidth mode, and raw, cube and reduced correspond to the Cal levels 0, 1 and 2. |
| Data Release: | Date this raw observation or reduced file was or will be made public. Data that are not yet public are only viewable if your CADC ID is associated with your JCMT OMP ID and attached to the project in question. This appears to be set correctly but display with the wrong month (always January instead of February or August). |
| Field of View: | The area of the map, in square degrees (default), arcminutes or arcseconds. |
| Pixel Scale: | Spatial size of pixels, in arcseconds by default but convertible to other angular units. Not set for raw SCUBA-2 data or raw ACSIS data. |
| Data Type: | This indicates if the line in the results table represents a cube, image or spectra. This is not set for raw data (i.e., calibration level 0 or a Product ID that begins with raw_). |
| Time dependent: | This should be 0 or 1 to indicate if data is time dependent or not. This is currently broken and is never visibly set at CADC. |
| Intent: | Set to Science or Calibration. Can be set on query page as well as filtered here. Note that observations of a calibration source taken as part of a science msb are labelled science, and SCUBA-2 pointings are always labelled science. |
| Target Type: | This column is not set for JCMT data. For some telescopes a string will be set here similar to the Simbad object type, indicating if it is a star, part of a cloud, a galaxy etc. |
| Target Standard: | Observations of telescope standards are flagged with a 1 here (whether science or calibration), otherwise we set a 0. |
| Sequence Number: | The observation or scan number of the original observation (as listed in the OMP or the JCMT observation log for the night). Not set for composite reductions of multiple observations. |
| Algorithm Name: | Indicates the grouping algorithm used to determine which observations were included in this object, whether single or composite. Possible values are exposure for any object consisting of one observation, night for a night reduction, project for project reductions (where they exist) and eventually public for the tiled JCMT Science Archive generic reductions. |
| Proposal Title: | The title from the original observing proposal. These can be very long. |
| Proposal Keywords: | Not set by the JCMT for any observations/composites. |
| Band: | The waveband — should be millimetre for all of JCMT data. Currently, some older observations have the wrong wavelength bounds set which results in it having a wrong or unknown band. |
| Prov. Version: | This long alphanumeric string tells you which version of reduction software produced this object. For JCMT observations, this is the git commit ID for the version of starlink software used to perform the reduction (see https://github.com/Starlink/starlink) |
| Prov. Name: | For reduced data it is the name of the ORAC-DR recipe used for the reduction. This is not set for raw data. |
| Prov. Project: | Indicates what carried out the data reduction process. At the moment this should be set to the JCMT_STANDARD_PIPELINE for all our data. Eventually we may have other options, for e.g. PI produced data products. |
| Prov. Run ID: | Not generally useful for users, this is a hash indicating the specific run of the software which produced this object. |
| Prov. Last Executed: | Day the processing for this object was carried out. |
| Rest frame spectral coverage: | The rest-frame wavelength/frequency of the observation. A drop down menu lets you select from various wavelength or frequency units. |
| DOWNLOADABLE: | The CADC URI for the downloadable file. This is an unique resource indicator (URI) used by CADC to denote the location of a file available to download. This is not not a clickable link, nor is it a web URL. |
| CAOM Plane Uri: | This is exactly the same as the DOWNLOADABLE column. |
| Molecule: | For spectral observations, this is the observed molecule. This is not set for all data, as observers may have manually specified a frequency. |
| Transition: | For spectral observations, this is the observed transition. This is not set for all data, as observers may have manually specified a frequency. |
| IQ: | Median spatial resolution, i.e. the FWHM of the beam. This is not currently set for JCMT results. |
| Quality: | This is blank if the observation is labelled as GOOD within the JCMT’s OMP system, or will say Fail if the observation was marked as either BAD or QUESTIONABLE in the OMP. Observations marked as JUNK in the OMP are not shown through the Advanced Search interface. |