Information on Service 'M) Apertif DR1 - HI spectral cubes'

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Further access options are discussed below

This service queries the HI spectral cubes of the Apertif DR1 data collection. This data release contains continuum images, HI cubes, polarization cubes and other ancillary data (e.g. raw and calibrated visibilities). The imaging survey is split into two tiers: a wide-shallow tier consisting of a single observation per field and a medium-deep tier consisting of ten observations per field. The imaging survey footprint can be found in the Imaging Survey overview while the area covered by the DR1 can be found in the Apertif DR1 dataproducts description . In this service query, for each observation there are four line sets of cubes of four different frequency ranges (1292.5-1337.1 MHz, 1333.1-1377.7 MHz, 1373.8-1418.4 MHz and 1414.5-1429.3 MHz). Each cube is saved as a fits file for each beam. These images are 1.1°×1.1°(661×661 pixels, with 6′′/pixel). The angular resolution of the imaging survey observations is ∼ 15′′×15′′/sin(δ). Please find more details in the Apertif DR1 Documentation.

For a list of all services and tables belonging to this service's resource, see Information on resource 'Apertif DR-1'

Overview

You can access this service using:

This service is published as follows:

local means it is listed on our front page, ivo_managed means it has a record in the VO registry.

Other services provided on the underlying data include:

Spatial Coverage

Input Fields

The following fields are available to provide input to the service (with some renderers, some of these fields may be unavailable):

NameTable Head DescriptionUnitUCD
beam_number Beam number Beam number N/A meta.id;instr.beam
cube_key Frequency band Observed frequency band N/A meta.id
FORMAT Output format Requested format of the image data N/A N/A
hFORMAT Output format Requested format of the image data N/A N/A
hINTERSECT Intersection type Relation of image and specified Region of Interest. N/A N/A
hPOS Position ICRS Position, RA,DEC, or Simbad object (e.g., 234.234,-32.45) deg pos.eq
hSIZE Field size Size in decimal degrees (e.g., 0.2 or 1,0.1) deg N/A
INTERSECT Intersection type Relation of image and specified Region of Interest. N/A N/A
max_d Max distance from the center Maximum distance to the center of the images deg N/A
MAXREC Match limit Maximum number of records returned. Pass 0 to retrieve service parameters. N/A N/A
obsid ObsId Observation id N/A meta.id
POS Position ICRS Position, RA,DEC decimal degrees (e.g., 234.234,-32.46) deg pos.eq
RESPONSEFORMAT Output Format File format requested for output. N/A meta.code.mime
SIZE Field size Size in decimal degrees (e.g., 0.2 or 1,0.1) deg N/A
target Field Name Name of the field. Matches also partial input (e.g. m1403+5324 or 1403+5324). N/A meta.id
VERB Verbosity Exhaustiveness of column selection. VERB=1 only returns the most important columns, VERB=2 selects the columns deemed useful to the average user, VERB=3 returns a table with all available columns. N/A N/A

Default Output Fields

The following fields are contained in the output by default. More fields may be available for selection; these would be given below in the VOTable output fields.

NameTable Head DescriptionUnitUCD
_r Dist Distance of the queried position to the center of the image arcmin pos.distance
accref Product key The quantity displayed is expressed in the following formula \bar{c} = \frac{\sum_{i=0}^N (i/N - 1/2) \cdot I_i }{\sum_{i=0}^{N} I_i} where N is the number of channels and I_i is the intensity at the i-th channel. N/A N/A
accsize File size Size of the data in bytes byte VOX:Image_FileSize
beam_number Beam Number of the beam N/A meta.id;instr.beam
centerAlpha Ctr. RA Approximate center of image, RA deg POS_EQ_RA_MAIN
centerDelta Ctr. Dec Approximate center of image, Dec deg POS_EQ_DEC_MAIN
cube_key Cube key N/A N/A meta.id
dateObs Obs. date Epoch at midpoint of observation d VOX:Image_MJDateObs
f_ex F ex Fraction of pixels with a value > 6.75 sigma N/A stat.value
freqMax max. Frequency Maximum frequency MHz em.freq
freqMin min. Frequency Minimum frequency MHz em.freq
imageTitle Title Synthetic name of the image N/A VOX:Image_Title
instId Instrument Identifier of the originating instrument N/A INST_ID
mime Type MIME type of the file served N/A meta.code.mime
n_channels # channels Number of channels N/A em.bin
obsid ObsId Unique id N/A meta.id
p_08 P_{0.8} ratio between the sigma and the .8 percent of the maximum of the pixel intensity N/A stat.value
pixelScale Scales The pixel scale on each image axis deg/pix VOX:Image_Scale
pub_did P. DID Dataset identifier assigned by the publisher N/A meta.id;meta.main
related_products Related products Link related products for the observation N/A meta.ref.url
sigma Sigma RMS N/A stat.value
target Field Name of the field N/A meta.id
valid Passed validation Whether or not the dataset has passed validation N/A meta.code.qual

VOTable Output Fields

The following fields are available in VOTable output. The verbosity level is a number intended to represent the relative importance of the field on a scale of 1 to 30. The services take a VERB argument. A field is included in the output if their verbosity level is less or equal VERB*10.

NameTable Head DescriptionUnitUCD Verb. Level
centerAlpha Ctr. RA Approximate center of image, RA deg POS_EQ_RA_MAIN 0
centerDelta Ctr. Dec Approximate center of image, Dec deg POS_EQ_DEC_MAIN 0
imageTitle Title Synthetic name of the image N/A VOX:Image_Title 0
dateObs Obs. date Epoch at midpoint of observation d VOX:Image_MJDateObs 0
accref Product key Access key for the data N/A N/A 1
target Field Name of the field N/A meta.id 1
related_products Related products Link related products for the observation N/A meta.ref.url 1
f_ex F ex Fraction of pixels with a value > 6.75 sigma N/A stat.value 8
p_08 P_{0.8} ratio between the sigma and the .8 percent of the maximum of the pixel intensity N/A stat.value 8
sigma Sigma RMS N/A stat.value 8
bandpassId Bandpass Freeform name of the bandpass used N/A VOX:BandPass_ID 10
accsize File size Size of the data in bytes byte VOX:Image_FileSize 11
pixelScale Scales The pixel scale on each image axis deg/pix VOX:Image_Scale 12
instId Instrument Identifier of the originating instrument N/A INST_ID 15
pixelSize Axes Lengths Number of pixels along each of the axes pix VOX:Image_Naxis 15
pub_did P. DID Dataset identifier assigned by the publisher N/A meta.id;meta.main 15
_r Dist Distance of the queried position to the center of the image arcmin pos.distance 20
mime Type MIME type of the file served N/A meta.code.mime 20
nAxes #axes Number of axes in data N/A VOX:Image_Naxes 20
refFrame Ref. Frame Coordinate system reference frame N/A VOX:STC_CoordRefFrame 20
wcs_equinox Equinox Equinox of the given coordinates yr VOX:STC_CoordEquinox 20
wcs_projection Proj. FITS WCS projection type N/A VOX:WCS_CoordProjection 20
wcs_refPixel Ref. pixel WCS reference pixel pix VOX:WCS_CoordRefPixel 20
wcs_refValues Ref. values World coordinates at WCS reference pixel deg VOX:WCS_CoordRefValue 20
wcs_cdmatrix CD matrix FITS WCS CDij matrix deg/pix VOX:WCS_CDMatrix 20
bandpassUnit Bandpass unit Unit of bandpass specifications (always m). N/A VOX:BandPass_Unit 20
bandpassRefval Band Ref. Characteristic quantity for the bandpass of the image m VOX:BandPass_RefValue 20
bandpassHi Band upper Upper limit of the bandpass (in BandPass_Unit units) m VOX:BandPass_HiLimit 20
bandpassLo Band lower Lower limit of the bandpass (in BandPass_Unit units) m VOX:BandPass_LoLimit 20
pixflags P. Flags Flags specifying the processing done (C-original; F-resampled; Z-fluxes valid; X-not resampled; V-for display only N/A VOX:Image_PixFlags 20
coverage Coverage Field covered by the image deg N/A 20
obsid ObsId Unique id N/A meta.id 20
valid Passed validation Whether or not the dataset has passed validation N/A meta.code.qual 20
task_id Task id ID of the task N/A meta.id 20
beam_number Beam Number of the beam N/A meta.id;instr.beam 20
freqMin min. Frequency Minimum frequency MHz em.freq 20
freqMax max. Frequency Maximum frequency MHz em.freq 20
n_channels # channels Number of channels N/A em.bin 20
pipeline_name Pipeline name Name of the used pipeline N/A N/A 20
pipeline_version Pipeline version Version of the used pipeline N/A N/A 20
cube_key Cube key N/A N/A meta.id 20

Copyright, License, Acknowledgements

APERTIF-DR1 is licensed under the Creative Commons Attribution 3.0 License

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VOResource XML (that's something exclusively for VO nerds)