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The instructions below are mainly aimed at PIs who will request assistance to:
weave_open_time_support@ing.iac.es |
Communication with the PI
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General assistance can be provided at the following email:
weave_open_time_support@ing.iac.es |
Phase 2:
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A short guide
The purpose of the phase 2 is the upload of a FITS catalog containing fiber positions on sky, and observing blocks (OB) written in XML describing the necessary observations to the submission platform WASP, maintained by CASU in Cambrige (IoA). At the beginning of every trimester, the uploaded, validated and selected OBs are ingested into the observing queue at the WHT.
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Below we provide an example of real observations made from a simple OB which consists of 3 exposures 1020s each following a 3-point dithering pattern in LIFU low-resolution mode and arbitrary position angle:
CSV catalog:
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PROGTEMP, OBSTEMP: use the OBSTEMP and the PROGTEMP builders to generate them.
IFU_DITHER: it is set to 0 if not specified (no dithering). Standard dithering patterns for 3, 4, 5 and 6 points are available for selection (read more information on IFU_DITHER below).
The position angle (PA, as measured from North to East) is automatically set to 180º, for declinations North to 28.7º, and to 0º, for declinations South to 28.7º. Note that these PAs could be slightly different to allow for finding a suitable acquisition and guiding star. For any other PAs, read more information on requested PA below. Not all values are posible given the rotator limits, and similarly to the above, it can change for finding a suitable acquisition and guiding star.
CSV catalog:
TARGID,TARGNAME,GAIA_RA,GAIA_DEC,PROGTEMP,OBSTEMP,IFU_DITHER |
Validated FITS catalog on WASP: WS2022A2-002.fits
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3. Filling in a simplified CSV version of the catalogue template. Below it's an example of this simplified template and 4 catalogue rows that each describe an OB definition:
<filename: WS2023B2-001_target_list.csv> TARGID,TARGNAME,GAIA_RA,GAIA_DEC,PROGTEMP,OBSTEMP,IFU_DITHER |
Filling out the catalogue template with targets
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It defines how the time within the OB that you wish to observe the target is divided up, by specifying the number of exposures and exposure time within the stipulated OB length. The listed options of exposure time splits correspond to science open-shutter times (note that every exposure incur a 3-minute overhead).
IMPORTANT: It is not recommended unlocking the arms. Note that different exposure splits (unlocking the arms) in the red and the blue arms will have two consequences: firstly, no dithering will be possible, and secondly, OB length will increase as the observing system cannot execute different exposure splits simultaneously but one only exposure in both arms at a time. For example, requesting one exposure in red, and 12 in blue would cause a significant mismatch in overheads between the two arms. |
Binning in the spectral direction
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IFU_PA_REQUEST allows the catalogue provider to specify a rotation angle (position angle) of the LIFU, if this is required. Any dithering requested for the field is applied to the rotated LIFU frame. If a specific PA value is not requested, then the following defaults are applied: IFU_PA=0° (for declinations lower than 28.7°) and IFU_PA=180° (for declinations higher than 28.7°). Note that the requested IFU_PA could be changed by the IFU workflow software if a suitable guiding star cannot be found at the requested PA. Below it's a plot which shows how the PA is changed to find a suitable guiding star.
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IMPORTANT: During the IFU observation preparation using the IFU workflow software, an analysis is performed on putative LIFU pointings to determine if a rotation is required and provides the optimal value IFU_PA should take. Rotation is generally used in cases where the default or requested PA results in no viable guide stars falling within the autoguider field of view, or when the rotation during an exposure is likely to exceed the angular limits of the rotator. This means that it's not always possible that the IFU workflow software can provide the IFU_PA_REQUEST |
value in the catalogue. The table below shows the allowed IFU_PA_REQUEST (=PA in the table) ranges PIs can safely apply for. Maximum value of PA is 360º. |
The table below shows the allowed values for the PA depending on minimum elevation requested in the OB and the target’s declination. Following are plots showing two cases, for better understanding of the PA ranges in the table.
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PA range (°) | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Dec (°) | h_min=50. | 28 28º(X=1.3) | h_min=45. | 58 58º(X=1.4) | h_min=41. | 81 81º(X=1.5) | h_min=38. | 68 68º(X=1.6) | h_min=33. | 75 75º(X=1.8) | h_min=25. | 00 00º(X=2.4) |
Dec (°) | PA range (°) | PA range (°) | PA range (°) | PA range (°) | PA range (°) | PA range (°) | ||||||
] | ||||||||||||
-25 | 225<PA<135 | 245<PA<115 | ||||||||||
-10 | 220<PA<140 | 235<PA<125 | 245<PA<115 | 245<PA<115 | 250<PA<110 | 260<PA<100 | ||||||
0 | 250<PA<110 | 255<PA<105 | 255<PA<105 | 260<PA<100 | 260<PA<100 | 270<PA<90 | ||||||
+15 | 270<PA<90 | 270<PA<90 | 270<PA<90 | 270<PA<90 | 275<PA<85 | 275<PA<85 | ||||||
+28.70 | 295<PA<65 | 295<PA<65 | 295<PA<65 | 295<PA<65 | 295<PA<65 | 295<PA<65 | ||||||
+30 | 130<PA<230 | 130<PA<230 | 130<PA<230 | 130<PA<230 | 135<PA<225 | 135<PA<225 | ||||||
+40 | 115<PA<245 | 120<PA<240 | 120<PA<240 | 120<PA<240 | 130<PA<230 | 135<PA<225 | ||||||
+50 | 105<PA<255 | 100<PA<260 | 115<PA<245 | 120<PA<240 | 120<PA<240 | 135<PA<225 | ||||||
+60 | 80<PA<280 | 95<PA<265 | 105<PA<255 | 110<PA<250 | 120<PA<240 | 130<PA<230 | ||||||
+70 | 65<PA<295 | 85<PA<275 | 95<PA<265 | 110<PA<250 | 120<PA<240 | |||||||
+80 | 35<PA<325 | 90<PA<270 | 140<PA<220 | |||||||||
IFU_DITHER
IFU_DITHER allows the PI to specify the dithering strategy for their observations, but may alternatively request not to dither their observations, with the understanding that this will not provide full spatial coverage of their requested field. PIs may request the preset -3, 3, 4, 5 and 6-dither patterns. The LIFU preset patterns will be properly rotated according to the position angle of the observation.
IMPORTANT: Exposure options for which fixed dither patterns are available in IFU modes are 3x, 4x, 5x, 6x. |
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For custom dither patterns, constraints on the dither step size are imposed by the WASP to ensure that the guide star remains within the guiding camera field of view. From the perspective of IFU users, careful consideration of the dithering options should be made. Below it's an example of custom dithering. Note that pointings are provided for each dither, rather than the dither pointings from an initial position. The three pointings provided in the example below would be executed as part of one only OB.
# A custom 3-dither pattern LIFU pointing |
Summary of table columns and examples
Column | Description | Format | Length | Value(s) | Units | Example |
|---|---|---|---|---|---|---|
TARGPRO | Optional description of programme | ASCII | ≤40 | WS2023B2-010_001 | ||
TARGNAME | The target name | ASCII | ≤30 | M33 | ||
TARGID | The identifier of the target assigned for this programme | ASCII | ≤30 | M33_NE | ||
PROGTEMP | Observing Programme Template | ASCII | 8 (fixed) | 41331.3+ | ||
OBSTEMP | Observing Constraints Template | ASCII | 5 (fixed) | FAACA | ||
GAIA_ID | GAIA Source Identifier | ASCII | 19 | 1463976195968535680 | ||
GAIA_DR | GAIA Data Release version | I1 | 2, 3 | 3 | ||
GAIA_RA | Gaia RA of target | F11.7 | 0...360 | degrees | 178.221875 | |
GAIA_DEC | Gaia Dec of target | F11.7 | -90...90 | degrees | 44.123919 | |
GAIA_EPOCH | Gaia Epoch of target | F6.1 | 2015.5 (DR2), 2016.0 (DR3) | Julian year | 2016.0 | |
GAIA_PMRA | Gaia Proper Motion of target in RA | F11.3 | mas/yr | 12.1 | ||
GAIA_PMDEC | Gaia Proper Motion of target in Dec | F11.3 | mas/yr | 0.01 | ||
GAIA_PARAL | Gaia Parallax of target | F10.3 | mas | 0.002 | ||
IFU_PA_REQUEST | Position Angle of IFU bundle | F11.7 | -180...180 | degrees | 106.701 | |
IFU_DITHER | IFU dither pattern code | I2 | -3, -1, 0, 3, 4, 5, 6 | 3 |
Aladin overlays of the LIFU footprints
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Download the vot files linked below.
Open Aladin and enter an object name in the command field, ex. 'M51'.
File → Load instrument FoV.
In the emerging window, click on 'File' and browse for a suitable vot file.
Click to submit. The vot file will load as a layer with a given colour.
Description and VOT file | LIFU FoV and sky bundles | LIFU FoV |
|---|---|---|
Photo of a real view of the LIFU unit using fibre back illumination. |  |  |
No dithering (as seen in Aladin) Download VOT file: |  | |
3-pointing dithering (as seen in Aladin) Download VOT file: |  | |
6-pointing dithering (as seen in Aladin) Download VOT file: |  |  |
Catalogue upload to WASP
The edited catalogue must go through the IFU workflow, a set of scripts which will make a version of the FITS catalogue suitable for uploading to WASP (http://wasp.ast.cam.ac.uk/catsubmit/upload) for validation. First log on using the provided credentials (the ones emailed from WASP), note that you need to register your IP at http://wasp.ast.cam.ac.uk/ipsubmit/upload first. See below the tab used for uploading the catalogue.
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At ING, we can provide assistance in guiding you through the different stages of the IFU workflow package, or we can even process your catalogue provided in any of the formats described above, on your behalf. In this latter case, simply email your catalogue to the contact below:
weave_open_time_support@ing.iac.es |
LIFU mode: OB preparation
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At ING, we can provide assistance in generating the OBs from the CNAMEd catalogue, please contact:
weave_open_time_support@ing.iac.es |
OB upload to WASP
The processed OBs can be then uploaded, as a tar file if many, to http://wasp.ast.cam.ac.uk/xmlsubmit/upload (see below). Remember to log on first.
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In the figure below we show an example of 6 OBs uploaded whose validation failed (the generated report will tell you why). The "Submission Management" button gives access you to all the catalogue and OB uploads made by the user. Note that if you have requested OB repetitions (for instance, PROGTEMP=41331.5, or 5 OB copies), then only one OB is validated on WASP (not 5 OBs following the example). The OB copies are actually made at the time they are ingested into the observing queue according to the information encoded in PROGTEMP.
IMPORTANT: Don't forget to select the right OBs in the submission maganement! Otherwise, they won't be queued. |
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Observations and follow up
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