The Science Verification observations are part of a very important check of the entire operational procedures and a verification of the scientific status of the VISTA telescope and camera. Furthermore, these observations will provide the first comprehensive self-contained scientific data-sets from VISTA and the data will be immediately available world-wide. In this way, the entire astronomical community will be able to exploit the data scientifically, and use them to plan future observations with VISTA.

VISTA Science Verification (SV) observations were carried out on 15 nights between October 15 - November 02, 2009. Here we provide the details of the two approved VISTA Science Verification programmes, including: information on the phase2, the actually executed observation and the data obtained.

Please also have a look at the Science Verification policies and useful VISTA links.

Table of Content

• Approved Science Verification Programmes
• Phase2 Information
• Phase2 Information for NGC253
• Phase2 Information for Orion
• Observing logs and data packages
• Additional observations requested by Public Survey PIs
• Data products and results

Approved Science Verification Programmes

• Extragalactic mini-survey: deep survey of the stellar halo in the nearby edge-on spiral galaxy NGC 253
  Prog.ID: 60.A-9285(A)
• Galactic Mini-Survey in Orion
  Prog.ID: 60.A-9285(B)
  

Phase2 information (Observing Strategy, Observing Blocks)

60.A-9285(A) Extra-galactic Mini-Survey

Target: NGC 253
RA=00:47:33.1, DEC=-25:17:18

Survey geometry configuration parameters:
X-overlap (2x sampled) = 60 arcsec
Y-overlap (2x sampled) = 60 arcsec
Maximum jitter amplitude=15"
Backtrack step = 100.0

Area definition:
Survey area defined as geodesic rectangle, RA=00:46:30, Dec=-25:17:40, Width=1.2, Height=1.0, Angle=52. The target field is covered with one tile only.

This survey will use three different tile patterns. Tile patterns with 3 pawprints will be used for the "shallow survey" which aims to observe the bright disk of NGC 253. The 6 pawprint tile pattern will be used for deep survey which aims to resolve the brightest red giant branch stars in the halo.

1. Tile pattern VIRCAM_Tile3px: avoids the disk entirely, 2 stripes above and 2 stripes below the galaxy plane. The SADT output file is NGC253_SV_tile3px.xml.
2. Tile pattern VIRCAM_Tile3nx: due to lack of guide and wave-front sensing stars at the given tile center position the SADT output file NGC253_SV_tile3nx.xml was slightly shifted after backtracking.
3. Tile pattern VIRCAM_Tile6zz: tile covering the bright disk and halo of NGC 253. The SADT output file is NGC253_SV_tile6zz.xml.

Deep survey observation description
Only two filters will be used with the following parameters for OBs:

The total exposure time and total execution time will be verified after the final observing strategy and parameters have been confirmed for different parts of the extragalactic mini-survey.

One VIRCAM pointing (tile) covering NGC 253: the longer axis of the camera is aligned with the disk polar axis.
North is up and East to the left; the horizontal bar indicates 30 arcmin length.

The users can download the gzipped-tar file with the full set of OBs for the NGC 253 Z,J deep imaging here.

Shallow survey observation description
The shallow coverage of NGC 253 is intended as a complement to the deeper survey of this galaxy. The intent is to create fields in which the central galaxy is not over-exposed (as is the case for the longer exposures of the deep survey). In this way, the bright regions of the galaxy (bulge and central disk) can be studied and characterized, and very reliable photometry can be done. The photometric solution of the shallow survey can be used to bootstrap a solution to the deep survey.

The shallow survey geometry consists of three fields, two on-source and one on-sky, all of which are rotated along the axis of NGC253 (i.e. 52^o). For each filter the following strategy will be followed: The first object exposure is centered on NGC253 and uses the tile pattern tile3px. The subsequent exposure is located ~2^o to the northwest of the source and consists of a single tile (tile1_00) of equivalent exposure time on sky. The final OB returns to the source, offset by the size of the vertical detector gap and fills in the galaxy coverage using the tile3nx pattern. To ensure good sky characterization, these three OBs must be executed consecutively. As such, they are contained in a p2pp concatenation.

The order of filter preference is J, K, H, and Y. The Z-band will be taken by the deep survey.

Area definition:

Survey area = GEODESIC RECTANGLE (HEIGHT =1.0 and ANGLE = 52^o)

Filters and exposure times

NOTE: * filters are in order of priority; ** extrapolated from the IR colours.

The first set of NGC 253 shallow OBs is available in this gzipped tar file.

During the SV run a bug in the SADT definition of tile3px has been discovered. Therefore subsequently additional OBs have been defined which use tile6zz pattern also for the shallow observations of NGC253. These new OBs can be downloaded from here.

Narrow band survey observation description

Deep exposures with NB118 filter centered on NGC 253 using the same Tile6 pattern as the main deep survey.

The full set of narrow-band OBs is available as a tar file.

60.A-9285(B): Galactic Mini-Survey

Target: Orion

Coverage: RA=05:20 to 05:50, DEC=-03 to +03 (approximately)

Survey area definition for the Galactic mini-survey in the Orion.

Survey geometry configuration parameters:
Position angle: 15deg
X-overlap (2x sampled) = 60 arcsec
Y-overlap (2x sampled) =100 arcsec
Maximum jitter amplitude=30"

General Description
The main goal is a deep ZYJHKs survey of ~30square deg in the Orion OB association. The area is covered by 20 overlapping tiles.
The secondary goal is the photometric monitoring of sources contained in tile 19.
Each of the 20 tiles, except tiles 4 and 8, shall be observed with 2 OBs with the following parameters:

Strategy:
Concatenation of OB1 and OB2 will ensure that the observations are nearly simultaneous, and will therefore minimize the effects of variability of the sources. Sky background will be estimated by stacking the individual pawprints and jittered exposures taken in each tile. The total execution time is 01:57:22.0 per tile.

Tile 4 and Tile 8
Tile 4 contains the bright nebulous cluster NGC 2024, and therefore additional offset sky images will be taken. In addition, the sky will be estimated from its neighbouring Tile 8. Observations will alternate between offset sky, tile 4 and tile 8: with a sequence (Sky field) - (Tile4) - (Tile8) for each filter.

Sky coverage and tiling of the Galactic mini-survey in the Orion.

Strategy for variability monitoring of Tile 19:
Tile 19 will be monitored for variability with 1-2 observations per night in J and H-band, with a minimum time delay of 1h between subsequent observations. An irregular sampling coverage should be performed. OBs used for this variability monitoring will have the following parameters:

The full set of OBs planned to be executed is available in a gzipped tar file.
NOTE: During the SV run a bug was found for the template VIRCAM_img_obs_tile6 when using it with PFJME Nesting and a filter list that has identical filters. Therefore, some slightly modified OBs were added during the SV run.

Observing logs and data packages

The observing log for all the nights during which VISTA observations for the Orion or NGC253 survey have been carried out is available here

Useful additional information can also be found in the VISTA SV Report II 

All data taken during the VISTA SV run is publicly available from the ESO Science Archive and can be requested using the links listed below.

IMPORTANT: Please note that due to the size of the VISTA images, the data packages are LARGE! If these data are used for testing purposes, we suggest to download only selected images, from the file-by-file links available below. Note also that all the raw data are tile-compressed using Rice compression alogithm. Most of the tools based on recent versions of CFITSIO library should handle tile-compressed files transparently.

The data packages contain science and associated calibration data.

• VISTA-SV raw data package containing NGC253 Deep Z, J observations can be downloaded from here
  or on a file-by-file basis from here
• VISTA-SV raw data package containing NGC253 NarrowBand observations can be downloaded from here
  or on a file-by-file basis from here
• VISTA-SV raw data package containing NGC253 Shallow observations can be downloaded from here
  or on a file-by-file basis from here


• Orion Tile1 raw data package can be downloaded from here
  or on a file-by-file basis from here
• Orion Tile2 raw data package can be downloaded from here
  or on a file-by-file basis from here
• Orion Tile3 raw data package can be downloaded from here
  or on a file-by-file basis from here
• Orion Tile4+Tile8 raw data package can be downloaded from here
  or on a file-by-file basis from here
• Orion Tile5 raw data package can be downloaded from here
  or on a file-by-file basis from here
• Orion Tile6 raw data package can be downloaded from here
  or on a file-by-file basis from here
• Orion Tile7 raw data package can be downloaded from here
  or on a file-by-file basis from here
• Orion Tile9 raw data package can be downloaded from here
  or on a file-by-file basis from here
• Orion Tile10 raw data package can be downloaded from here
  or on a file-by-file basis from here
• Orion Tile11 raw data package can be downloaded from here
  or on a file-by-file basis from here
• Orion Tile12 raw data package can be downloaded from here
  or on a file-by-file basis from here
• Orion Tile13 raw data package can be downloaded from here
  or on a file-by-file basis from here
• Orion Tile14 raw data package can be downloaded from here
  or on a file-by-file basis from here
• Orion Tile15 raw data package can be downloaded from here
  or on a file-by-file basis from here
• Orion Tile16 raw data package can be downloaded from here
  or on a file-by-file basis from here
• Orion Tile17 raw data package can be downloaded from here
  or on a file-by-file basis from here
• Orion Tile18 raw data package can be downloaded from here
  or on a file-by-file basis from here
• Orion Tile19 raw data package can be downloaded from here
  or on a file-by-file basis from here
• Orion Tile20 raw data package can be downloaded from here
  or on a file-by-file basis from here

Additional observations requested by Public Survey PIs

During the VISTA SV run, some observations for testing purposes were carried out for the Public Surveys Video, Ultra Vista, VMC and VVV. A brief description of these data is given in the VISTA SV Report II .

These data can be downloaded as full data packages or as single files below:

• Download the VISTA-SV VMC full raw data package
  or download VISTA-SV VMC raw data file-by-file
• Download the VISTA-SV VIDEO and Ultra-VISTA full raw data package
  or download VISTA-SV VIDEO and Ultra-VISTA raw data file-by-file.
• Download the VISTA-SV VVV full raw data package
  or download VISTA-SV VVV raw data file-by-file.

Data products and results

Data will be reduced with the VISTA Data Flow System and will be available as Advanced Data Products (ADPs) from the dedicated web pages, that will be added soon. Here we make available stacked dithered pawprints of one tile (taken with one filter) for each VISTA SV mini-survey:

• Tar file containing 6 stacked paw print images of NGC 253 J-band - Observation from 2009-10-29, OB_ID 428094
• Tar file containing 6 stacked pawprint images of Orion Tile16 J-band<./a> - Observation from 2009-10-20, OB_ID 428810