NED is an extragalactic database, hence galactic targets should be resolved by SIMBAD.

If you match the target name against the OBJECT FITS keyword value, it will be wildcarded and the search will be case insensitive: car might return eta car, Cartwheel,... To change this default behaviour, use the following operands:

• =car* will match carina,... but not eta car nor Carina.
• ~car* will match carina, Carina, Cartwheel,... but not eta car.
• ==carina will match exactly.

Solar System bodies cannot be resolved. Thus, if you would like to search for moving targets, enter a target name (e.g. neptune) and do not select any name resolver but instead choose the option 'OBJECT - FITS keyword' from the pull-down menu.

• either a Name
• or a set of RA and DEC coordinates being Tab-separated

A few notes regarding the syntax of the input file:

• Lines starting with a single hash '#' are not recognized as targets, but they will be displayed on the query result screen as comments.
• Comments may contain HTML tags.
• You may add your own input notes or comments as an additional column in the query results. Simply add a hash '#' after the target, followed by your input comments. Here are some examples:
  
  • HD 93308 # Variable Star
  • 10 45 03.591 \tab -59 41 04.26 # eta car
  The strings Variable Star and eta car will then get added to the query results in the first column, named Note. It is useful for further processing of the query results, especially with formatted results like TSV or VOTable.
• Blank lines are ignored, as well as lines starting with a double hash '##'.

The observation time is in UTC. To query it is possible to either enter:

• a single day (format: YYYY-MM-DD (or blank separated), no time) e.g. 2020-02-01 all observations taken that day will be returned
• a single instant in time (format: YYYY-MM-DDTHH:MM:SS) e.g. 2020-01-20T08:34:30 all observations taken within 24 hours starting from the provided UTC value will be returned
• a range constraint, either using > or < or the range operator '..' e.g.: 2020-01-31..2020-02-03

Please note that APEX uses the TAI time scale. An observation day at APEX begins at 00:00 TAI.

• Normal Programs (NP)
• Guaranteed Time Observations (GTO)
• Director's Discretionary Time (DDT)
• Target of Opportunity (ToO)
• Large Programs (LP)
• Short Programs
• Calibration Programs
• Monitoring Programs

The pull-down menu lists commonly used Mode values. It is not intended as a complete list of allowed values. Instead, it is intended as guidelines showing what type of information is included in those parameters.

Alternatively, user defined input may be given in the text field below the pull-down menu.
Indeed, the Mode can take more than one value. The values are separated with commas, without any blank spaces. This provides the means to describe a wide range of observations. If more than one value is present, it follows the general-to-specific order, i.e. a general term describing the type of technique, followed by qualifiers describing more specific details. For instance, a jittered NACO polarimetry observation with the Wollaston prism would be described as POLARIMETRY,WOLLASTON,JITTER.

Principal values and qualifiers are listed below. More details are available from the ESO data interface web page.

Principal Values:
IMAGE	Any picture
SPECTRUM	Single-order spectrum
ECHELLE	Cross-dispersed spectrum
MOS	Frame with spectra of several objects
MXU	Frame with spectra of several objects using a pre-manufactured mask
IFU	Integral Field Unit observation
POLARIMETRY	Polarimetric exposure
CORONOGRAPHY	Coronographic exposure
INTERFEROMETRY	Coherent exposure with more than one telescope beam
Qualifiers:
TEL-THROUGH	Telescope through-focus sequence
INS-THROUGH	Instrument through-focus sequence
WEDGE	Focus wedge frame
HARTMANN	Hartmann focus test
ABSORPTION-CELL	Absorption lines included (e.g. Iodine cell)
DRIFTSCAN	Drift scanning exposure
WOLLASTON	Wollaston polarimetry
WIRE_GRID	Wire grid polarimetry
DIRECT	Qualifier indicating direct imaging/spectroscopy
CHOPPING	Exposure utilising M2 chopping
NODDING	Exposure utilising telescope nodding
CHOPNOD	Exposure utilising both chopping and nodding
JITTER	Exposure utilising source jittering technique
SLIC#<i>	Observation using image slicer #i (UVES)
HIT	High time resolution mode (FORS)
FILTERCURVE	Spectroscopic flatfield with a narrowband filter included (FORS)
SPIDER	Exposure using SkySpider (SINFONI)
...	...

• 25 07 2005 .. 26 07 2005 will retrieve frames with a release date set to July 25th 2005.
• > 25 07 2005 will retrieve frames with a release date greater than or equal to July 25th 2005.

• Within a instrument-specific query form (except VIRCAM) the Exptime corresponds to the averaged exposure time. This is because the counts of a single raw frame are averaged over a number (NDIT) of exposures, hence the EXPTIME FITS keyword, and consequently the Exptime value in the query form, corresponds to the value of the DIT keyword in the FITS header.
• Within the main raw query form it corresponds to the total integration time (DIT * NDIT). For VIRCAM, the EXPTIME is always (i.e. in all contexts) defined to be the total integration time.

For LABOCA, the exposure time may be underestimated due to the continuous data taking setup, which records only exptime of the first subscan.

Note that there is an known issue on the main raw query form, when querying for an infrared instrument (except VIRCAM): while the total integration time is shown in the result page, in input (when the user places a constraint on the Exptime field) the user's condition is applied to the averaged exposure time instead. This behaviour will be corrected soon.

The list of filters' spectral coverages currently characterised is available here.

Limitations:
L1) Spectral coverage characterization effort is currently limited to Imaging raw frames. About 95% of all the raw imaging frames with of category SCIENCE (as opposed to ACQUISITION or CALIB) have been characterised

L2) the raw user interface defines (in the blue panel) various observational modes: Imaging, Spectroscopy, Polarimetry, Coronagraphy, etc. Please note that when querying for Imaging, the query does not return some coronagraphy images (this is the case e.g. for EFOSC), nor some polarimetry images (this is the case e.g. for NACO). The reason for that is that different instruments encode differently the same information. Similarly, the current characterization effort is considering Imaging in that very same sense, leaving out some coronagraphy and polarimetry observations. Those will be approached in a second phase.

The Interface

The user finds 2 fields to set constraints on the filter bandpasses:

• Filter bandpass
• Bandpass FWHM

As usual, constraints on different fields are combined with a logical AND.

I1) first field: Filter bandpass
The first field allows the user to query by:

1. An ESO filter name (e.g. R_BESS or MB#516/16_ESO871, etc.)
2. A wavelength in nm (e.g. 555)
3. A wavelength range in nm (e.g. 380..730)
4. A standard bandpass name (see below for the list of supported standard bandpass names)
5. or any combination of the above using a logical or (e.g. R_BESS or stdB or 555)

Correspondingly, the expected output would be:

1. Raw frames matching the provided ESO filter name(*)
2. Imaging raw frames whose spectral characterization overlaps the provided wavelength
3. Imaging raw frames whose spectral characterization overlaps the provided wavelength interval
4. Imaging raw frames which pass the bandpass similarity criterion
5. or any combination of the above using a logical or

Bandpass similarity criterion:
The bandpass similarity criterion is composed of two constraints:

• the central wavelength^(*) of the raw frame's bandpass lies within the central wavelength of the standard bandpass plus or minus half the FWHM of the standard bandpass
  AND
  
• The FWHM of the raw frame's bandpass lies between 0.5 and 1.5 of the standard bandpass FWHM

I2) second field: Bandpass FWHM
The second field allows the user to define a constraint on the FWHM of the searched bandpass in 2 possible ways:

• A single number in nm (e.g.: 90)
• An operator (either > or <) and a number (in nm) (e.g.: > 60)

Expected output:

• Raw frames whose FWHM would be similar (between 0.5 and 1.5) to the provided number (e.g.: betweem 45 and 135 in the example above)
• Raw frames whose FWHM match the provided constraint (e.g. > 50)

If the second field is defined, the bandpass similarity criterion changes accordingly.
When is this useful?
This is useful for example in the case of thetwo WFI filters: U/50 and U/30.
The standard filter name stdU would match U/50 not U/30,
but Filter: stdU and FWHM: <50 would match U/30 and not U/50.

Standard bandpass names currently supported:
As said above, the Filter bandpass field accepts in input standard bandpass names.

The names of the standard bandpasses supported by the service are reported here below, along with their characterisation, and bibliographic references.

(*) The names are chosen to avoid clashes with actual ESO filter names
(**) Names are case-insensitive (both ESO filter names and standard band pass names)

1. Allen, C.W.: Astrophysical Quantities, The Athlone Press (1973)
2. Wamsteker, W., Astron. Astrophys., 97, 329 (1981)
3. IVOA Recommendation, Resource Metadata for the Virtual Observatory, v1.12(2007)

standard bandpass name (*) (**)	wavelength coverage	reference
Halpha	656.2 ± 3.05 nm	Balmer H-alpha
uprime	358 ± 17 nm	SDSS u'
gprime	475.4 ± 69.4 nm	SDSS g'
rprime	620.4 ± 62 nm	SDSS r'
iprime	769.8 ± 65.2 nm	SDSS i'
zprime	966.5 ± 127.9 nm	SDSS z'
stdU	365 ± 34 nm	Allen1
stdB	440 ± 49 nm	"
stdV	550 ± 44.5 nm	Wamsteker2
stdR	700 ± 110 nm	Allen1
stdI	900 ± 120 nm	"
stdJ	1250 ± 150 nm	Wamsteker2
stdH	1650 ± 200 nm	"
stdK	2200 ± 300 nm	"
stdL	3600 ± 600 nm	"
stdM	4800 ± 400 nm	"
millimeter	0.1..10 mm	IVOA Recommmendation3
infrared	1..100 μm	"
optical	300..1000 nm	"
ultraviolet	10..300 nm	"

Please note that the Cumulative Exposure Time is overestimated for multi-chip instruments (e.g. FORS2, VIMOS, XSHOOTER).

Each matching source displayed in Aladin is colour-coded by instrument and is linked back to the ESO Archive by clicking in the Aladin measurement window:

• on the appropriate RequestData link to request the dataset file from the ESO Archive (you will be asked for your ESO User Portal credentials -- username and password -- to reach the Request Submission Setup)
• on the appropriate Dataset ID (you will get full ESO Archive information for this record)
• on the Program ID (you will get full observing program and scheduling information)

• ascii fixed length display
• ascii fixed length download
• ascii csv download
• votable display (only available for some query forms)
• votable download (only available for some query forms)

• to download together with the selected files other related files (if they exist)
  

  Files related to raw data	Raw calibration files needed to process the raw science data Processed calibration files needed to process the raw science data Night log reports Reduced products generated from the selected raw science frames
  Files related to reduced products	Ancillary files (e.g. weightmaps, tar balls, 2d-spectra, etc.)

  Some of the related files need to be dynamically discovered, in which case a "Run association" button must be clicked to activate the discovery process, which usually runs very fast, in few cases lasting about a minute or so.

• to chose which categories of files to download
  E.g.:
  • science products
  • ancillary files
  • raw data
  • calibration files
  • night log reports
  Please utilise the checkbox on the left of each category to include or exclude that type of files from your request.

• to chose whether to apply a cutout to the products

• to chose a download method
  E.g.:
  • Download script
  • File list
  • ZIP

As the user activates or deactivates the various checkboxes, the total number of files, the total size, what goes into the download script, in the file list, and in the zip file, are all updated instantaneously.

To download the files, click on one of the three options on the right hand side.

• The Download shell script button allows you to download the download-shell-script, which you can run on your terminal.
• The Show file list provides, in a new web page, the list of all the download-links to the various files part of your request; each link will make you download a file, but more likely you will use a download manager browser extension (like DownThemAll! which downloads all links found on the page.
• The Download ZIP file button initiates the ZIP download: the browser will open a pop-up window to allow you to control how to download the ZIP file with all the files in your request.

• the acquired science data have the exposure level requested by the PI,
• the user-defined observational constraints have been matched during the observation.