Help Page for ESO Data Product Query Forms

Allows to constrain your search to data products resulting from a particular programme. The list of programmes to select from includes data from all the ESO public surveys, and from other ESO observing programmes. The full list is available via the page hosting all the available Phase 3 release descriptions.

In the course of the Phase 3 process, the PI of an ESO programme organises the data products according to appropriate high-level criteria into self-consistent groups, called "data collections", which, subsequently, the archive user can browse and access. Later on the PI may issue further data releases to add more data or to update already released data products.

The data collection consists of a series of *data releases* tagged by incremental numbers starting from one, each of which may be considered one particular version of the data collection. Leave this field empty to operate in default mode, i.e. to always obtain the most recent data release for any collection. If you want to request the data of a specific release, enter an integer number (1, 2, ..) to obtain the data of a specific release, usually a previous version of the selected data collection.

Name of the person who delivered the datasets to ESO through the Phase 3 process.

ESO public survey region name.

Read the documentation on the ESO programme identification code.

Name of the ESO telescope. For more information, please check ESO telescope web page..

Name of the instrument. For more information on ESO instrumentation, please check ESO instrumentation web page.

Technique used during the observation.

• IMAGE (any picture)
• SPECTRUM (single-order spectrum)
• ECHELLE (cross-dispersed spectrum)
• MOS (observation with spectra of several objects)
• MXU (observation with spectra of several objects using a pre-manufactured mask)
• IFU (Integral Field Unit observation)
• POLARIMETRY (polarimetric exposure)
• CORONOGRAPHY (coronography exposure)
• INTERFEROMETRY (coherent exposure with more than one telescope beam)

Target name for SIMBAD, NED or OBJECT name in FITS header, depending on the setting of the selector.

• SIMBAD: SIMBAD http://simbad.u-strasbg.fr/simbad/ will be used to find coordinates of the target.

  Examples:

  • Orion
  • M17

• NED: The NASA Extragalactic Database (nedwww.ipac.caltech.edu) will be used to find coordinates of target.

  Examples:

  • 3C273

• Phase3 target name. The target name will be searched in the Phase 3 database. In this case, it is a constraint against the OBJECT keyword information (case insensitive string match, no coordinates involved).

  Examples:

  • d020
  • XMMU J2235.3-2557

• either a Name (a name must contain at least one letter);
• or a set of RA and DEC TAB-separated coordinates;
• or a set of RA and DEC sign-separated coordinates, that is, the sign (+ or -) of the declination must be present as it acts as a separator.

If so wished, a comment can be provided on each line, following a '#' character

Coordinates can be provided as decimal degrees (both RA and DEC) or as sexagesimal hours (RA) and sexagesimal degrees (DEC).

Valid sexagesimal separators are both the blank and the colon, as in: 01:23:45.678, 01 23 45.678.

Example of input target list:

15: +08:                        # sexagesimal, sign separated
15 +08                          # decimal, sign separated -> degrees!
BD +8 4236                      # name which will be resolved using the chosen name resolver (default SIMBAD)
15:30 +08:23                    # sexagesimal, sign separated
15:30:41.1 +08:23:38.1          # sexagesimal, sign separated
15 30 41.1	08 23 38.2      # sexagesimal, tab separated
15:30:41.1	+08:23:38.3     # sexagesimal, tab separated
15:30:41.1 -08 23 38.4          # sexagesimal, sign separated
15 30 41.1 -08:23:38.5          # sexagesimal, sign separated
eta car                         # name which will be resolved using the chosen name resolver (default SIMBAD)
232.67208333	8.393916666     # decimal, tab separated
232.67208333+8.393916666        # decimal, sign separated
b212                            # name which can be matched against an existing Phase 3 target name
                                # by setting the Phase3 Target Name as name resolver (see NAME).

15 30 41.2 08 23 38.4          # no separator
15 30 41 08 23 38              # no separator
15 30 08 23                    # no separator

The right ascension of the target in hours or degrees, depending on the selected format. The values can be expressed as decimal (e.g., 8.2) or sexagesimal values where minutes and seconds are blank or colon separated (e.g., 8 12 or 8:12). If a Search Box is specified, the search will be in a box around the given coordinates. Ranges can be specified with " .. " in which case the box size will not be used.

Examples:

• 12:19:35.934
• > 190.3
  if RA(deg) DEC(deg) is selected.
• 12:15 .. 12:30

The galactic longitude of the target in decimal degrees.

Examples:

• > 45
• 180 .. 270

The declination of the target in degrees. The values can be expressed as decimal (e.g., 8.2) or sexagesimal values where minutes and seconds are blank or colon separated (e.g., 8 12 or 8:12). If a Search Box is specified, the search will be in a box around the given coordinates. Ranges can be specified with " .. " in which case the box size will not be used.

Examples:

• +47:19:19.85
• < 0
• 60 .. 80

The galactic latitude of the target in decimal degrees.

Examples:

• < 0
• 60 .. 80

Survey tile RA in decimal degrees.

Survey tile Declination in decimal degrees.

Tile rotator offset angle as defined using the Survey Area Definition Tool (in degrees).
Note: Orientation on the sky, opposite sign convention than the position angle on the sky.

Selects Equatorial(FK5) or Galactic coordinates as input.

Choose here the output format for coordinates: either sexagesimal hours or decimal degrees.

If you search by coordinates or target name to be resolved by SIMBAD/NED, enter here the size of the search box around the target.
Different query forms use different default search box sizes, so to adapt to the different science use cases.

• In the imaging case, the default value is set to "02:09:00" so to make sure to cover the size of a VIRCAM tile.
• In the spectral case, the default value is set to 2 arcmin.

Enter the UT of interests in YYYY-MM-DDTHH:MM:SS.S format and the system returns all products that potentially cover this UT, i.e. the selected products have start of observation before and end of observation after the given UT.

The stop time of a product can be displayed on the tabular output by selecting (highlighting) it in the Extra Columns section at the bottom of the query form. It specifies the end of the observation, or the end of the last observation if the product resulted from the combination of multiple observations.

Same as "Date OBS" but using the Modified Julian Date (MJD) instead.

Total integration time per pixel (in seconds).
For an imaging data product resulting from the co-addition of multiple exposures pointing at the same sky position (with a tolerance given by a small fraction of the instrumental field of view), EXPTIME represents the total integration time per pixel obtained in the centre of the image.
A common case are imaging observations using the jitter technique, for which EXPTIME=DIT*NDIT*NJITTER, the VISTA/VIRCAM pawprint images being an example. If the product has been constructed from exposures whose positions were offset from each other in order to sample a region of the sky being larger than the instrumental FOV (also known as mosaicing) then the total integration time may vary across the image array. In this case EXPTIME represents the nominal total integration time obtained in at least 50% of the image array taking into account the chosen offset pattern.
For a VISTA tile image being filled using the standard pattern of 6 pointed observations with fixed offsets with NJITTER exposures per pointing, EXPTIME is set to the product 2*NJITTER*NDIT*DIT. The factor 2 reflects that most of the pixels of the final co-added image receive the contributions of at least two observations except for two narrow stripes along the edges, which receive just ‘single’ exposure time.

Total integration time per product (in seconds).
Arithmetic sum of the integration time of all exposures included in the product.
For a VISTA tile being filled using the standard pattern of 6 pointed observations with fixed offsets with NJITTER exposures per pointing, TEXPTIME is set to the product 6*NJITTER*NDIT*DIT. If individual exposures were rejected before combination into the tile, TEXPTIME should be adjusted accordingly.

Flag to indicate that the data product includes observations obtained in more than one epoch. The exact definition of an epoch, particularly the associated time scale, depends on the scientific goals and is at the discretion of the programme P.I. The VISTA public survey programmes UltraVISTA, VIDEO and VVV are expected to deliver multi-epoch data products.

You can identify data products originating from a specific Observation Block ID or a list of OB ID vlues separated with commas, without any blank spaces.

Users can request or exclude data products obtained by combining observations from several Observing Blocks.

The wavelength coverage of any Phase 3 1D spectrum is characterised by 2 parameters: its minimum and maximum wavelengths in nanometers (from the WAVELMIN and WAVELMAX FITS keywords)⁽¹⁾. Using those two parameters an overlap criterion (for 1D spectra only) is implemented, as if gaps were not present in the data:

• 656 - a single wavelength matches any spectrum that contains it (i.e., WAVELMIN ≤ 656 ≤ WAVELMAX);
• 393 AND 656 - two AND-ed wavelengths match any spectrum that contains both wavelengths, that is, the spectrum covers the entire wavelength range between 393 and 656
• 320..420 - a wavelength range matches any spectrum whose wavelengths cover the provided range partially (at least). Example of wavelength extents of the matching spectra: i) 400-500 ii) 500-700 iii) 200-400 iv) 200-700
• < 555 - a '<' inequality matches any spectrum whose min wavelength is < than 555;
• > 555 - a '>' inequality matches any spectrum whose max wavelength is > than 555.
• 656 OR (393 AND 397) - Multiple conditions can be logically ORed and/or ANDed together.

The spectral resolving power (unitless).

The spectral bin size, that is, the wavelength sampling size in units of nanometers.

The signal-to-noise ratio of the spectrum (unitless).

It characterises the quality of the flux calibration in terms of two possible values: ‘ABSOLUTE’ or ‘UNCALIBRATED’. For imaging data, it certifies the validity of PHOTZP if set to ‘ABSOLUTE’, otherwise ‘UNCALIBRATED’. For spectroscopic data, it represents the type of flux calibration, whether ‘ABSOLUTE’ or ‘UNCALIBRATED’ e.g. when normalised to the continuum.

The slit width or the fiber diameter expressed in arcsec.

The name of the dispersive element.

A flag set to T (true) if the spectrum refers to an extended object, F (false) if it is point-like.

A flag set to T (true) if the spectrum is normalised to the continuum, F (false) otherwise.

T (true) indicates that the flux data represent the total source flux if, for instance, observations were obtained under photometric conditions and measures were taken to capture the total source flux e.g. by choosing a slit sufficiently wide with respect to the seeing. It applies to spectroscopic data having FLUXCAL = ‘ABSOLUTE’.

Detector Integration Time. Any query by DIT (detector integration time) includes all data product that have keyword DIT properly defined in the primary HDU.

Number of sub-integration.

Number of jitter positions per observation.

Number of offset positions per observation.

The field of view on the sky sampled by the image in the largest dimension in units of degree.

The sky coverage in units of square degrees.

The image product's typical pixel size in units of arcsec.

The image product's typical resolution or FWHM of the PSF including the effect of atmospheric blurring if applicable (in units of arcsec).

Average ellipticity of point sources defined as (1-b/a) with a and b denoting major and minor axes of the source profile, resp.

Filter name (imaging only).

The ESO archive is directly searchable for science data products. This field allows to constrain the search to one specific data product format:

• image (it includes both SCIENCE.IMAGE and SCIENCE.MEFIMAGE)
• source table (SCIENCE.SRCTBL)
• spectrum (SCIENCE.SPECTRUM)
• (*) Single image (SCIENCE.IMAGE)
• (*) Multiple Extension FITS image (SCIENCE.MEFIMAGE)

The Data Product Format is specified by the Phase 3 FITS keyword PRODCATG='SCIENCE.*'.
If you wish to find source list only, then select only 'SCIENCE.SRCTBL' from the menu.

See the VISTA/VIRCAM paragraph of the Phase3 user documentation "ESO Science Data Products Standard" for the list of VISTA product types.

Type of imaging product: TILE, PAWPRINT, VSTRIPES as defined in the keyword IMATYPE.

Flag to indicate if DP represents a contiguous area of the sky or a sampling thereof (depends on type of product).

Typical 5-sigma limiting depth for point-sources (AB mag, total flux, approximately, that is +-0.1 mag).

AB mag of point sources that appear to be saturated on the image.

Number of raw science data files that were combined in the data product.

Number of micro step positions per observation.

The value of the P3ORIG FITS keyword of the product, which describes the origin of a Phase 3 data product. Can either be:

• EDP – External Data Product, for data processed by an ESO user, typically the P.I. of an ESO observing programme, or
• IDP – Internal Data Product, for data which has been processed by ESO in the course of operations.

It is the date before which the product is under a proprietary period (and downloadable only by the PI or delegates), and after which the product is publicly available.

The date when the product became available through the Phase 3 system.

The Original file name is given by the PI and corresponds to the FITS keyword ORIGFILE.

The Dataset ID is the name under which the data product is stored in the ESO Archive. The Dataset ID corresponds to the FITS keyword ARCFILE, without the extension.

Bibliographic reference to the primary scientific publication associated to the data product describing content, coverage, process of creation and scientific quality, when defined (in the REFERENC FITS keyword of the product).

The VOTable format is a Virtual Observatory XML standard for tabular data. More about the VOTable description is available at http://www.ivoa.net/Documents/latest/VOT.html.
The VOTable format allows you to easily load into any VO-enabled application the results of your search among ESO's collection of advanced data products.
You can also easily convert the VOTable results of your query into any kind of file format (e.g. ascii, CSV) using e.g. the tcopy command-line tool of the STIL Tool Set (STILTS).