SED Builder
David Floyd
August Muench
Tara Murphy
Paresh Prema
Rita Sinha
Motivation
Need for federating NVO clients
Utility of spectral energy distributions for
most niches of astrophysical research:
stars, galaxies, QSOs
Goal: Build a broad band SED for an
object using NVO web services.
Focus on SkyNodes.
Algorithm
GetSed.py:
– Written in python;
– Uses Kwok volib python libraries;
– Implemented GetSedSkyNode module;
– Queries SkyPortal directly with ADQL/s;
– Uses lookup dictionary to identify photometry and
perform conversions.
Calls IDL procedure to fit spectrum and
estimate bolometric luminosity.
Algorithm (cont): Work Flow.
Problems
SkyNodes!
– Some include column names like “min”, or
“confuse?” that trip the ADQL query;
– Some (e.g., GOODS) have essentially no curation
information;
– Some (e.g., GALEX, FUSE) simply didn’t respond.
Manual parsing of table metadata using a
dictionary instead of on the fly UCD parsing.
Future Work
Improved SED Modeling.
Output Proper VOTables w/SSAP.
GetSedTab
– Queries tabular sky services;
– WCSCatFix checks/fixes astrometry of tables;
– Requires (extensive) UCD parsing.
GetSedSIAP
– Derive upper limits on NVSS/FIRST cutouts;
– Process other image archive services.
Targets
587733412056465497
3C293
– 213.75159 52.116272
NGC1068 – 0.424
587733412056530956
M31 – 213.89122 52.09946
– 0.986
M33
587733399708172309
Mrk78 – 214.17679 52.30352
– 1.284
Persson’s Star 587733399171301410
FU Ori – 213.965 52.007126
– 1.514