The SKADS sky and databases

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The SKADS sky and databases

• F. Levrier, R. Wilman, D. Obreschkow, H.-R.
  Klöckner, S. Rawlings
• (Oxford Astrophysics)
• D. Olteanu, S. Young
• (Oxford e-Research Center)

DS2-T1 MEETING LISBON JANUARY 7, 2008
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Output from continuum and line simulations

• ASCII files
• large quantities of data (45 Gb)

Example continuum simulations - 235,301,766
sources
Source type Sources Components
Radio-quiet AGN 36,132,566 1
FRI 23,853,134 3
FRII 2,354 5
Normal galaxies 168,046,330 1
Starburst galaxies 7,267,382 1
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Data distribution and map making

• Query data based on position, source type, flux
  limit...
• Requires database structure (MySQL / PostgreSQL)
• Continuum simulations database HI line
  simulations database
• For each database source tables cluster table

Example continuum simulations database
Source table
Cluster table

• Unique source index per substructure
• NULL values for Q,U,V fluxes
• Max. number of entries per table 1,000,000

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Making the SKADS continuum sky
Input map parameters
region - source types - resolution - frequency -
flux limit
Query databases
Read structure information
position - size - orientation - reference fluxes
Build template image
Compute flux
Scale template image
Paste into full map
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Making the SKADS HI line sky (I)
First approach _at_ low resolution synthetic
spectra
HI flux
Synthetic double-peaked shape
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Making the SKADS HI line sky (II)
Second approach _at_ high resolution template
cubes from R. Boomsma

• Galaxy models made of clouds
• Placed according to density profile
• Orbiting according to velocity curve
• 5 galaxy types (spirals and irregulars)
• 46 inclination values (0-90 degrees)
• 5 asymptotic velocities

scale / rotate / paste
S0-Sab
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Map Maker

• Standalone application in Python / IDL
• SQL/Python interface
• FITS output

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Central square degree of the continuum simulations
Radio-quiet AGN
FR I
FR II
Normal galaxies
Starburst
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Where we stand, where were going

• Database implementation
• IDL to python conversion of Map Maker
• Release of central square degree data in the test
  phase (100 Mb)
  http//webmail.jb.man.ac.uk/skadswiki/ContsimVersi
  on4
• Testing of simulation output (T. Mauch, F.
  Abdalla, T. Kitching)
• Hosting of the database server by OeRC
• Implementation of web interface for database and
  imaging queries
• Release of Map Maker
• Release of the full simulations
• Interface with a MeqTrees sky model

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Measurement Set Generator

• MeqTrees interfaces with AIPS Measurement Sets,
  but it doesnt build them from scratch
• Local MS generator python interface to a glish
  script from T. Willis
• Can use existing configurations or generate
  random ones