||Iris: The VAO SED Application
||461, Astronomical Data Analysis Software and Systems XXI
||Doe, S.; Bonaventura, N.; Busko, I.; D'Abrusco, R.; Cresitello-Dittmar, M.; Ebert, R.; Evans, J.; Laurino, O.; McDowell, J.; Pevunova, O.; Refsdal, B.
||We present Iris, the VAO (Virtual Astronomical Observatory)
application for analyzing SEDs (spectral energy distributions). Iris
is the result of one of the major science initiatives of the VAO, and
the first version was released in September 2011. Iris seamlessly
combines key features of several existing astronomical software
applications to streamline and enhance the SED analysis process. With
Iris, users may read in and display SEDs, select data ranges for
analysis, fit models to SEDs, and calculate confidence limits on
best-fit parameters. SED data may be uploaded into the application
from IVOA-compliant VOTable
and FITS format files, or retrieved
directly from NED (the NASA/IPAC Extragalactic Database).
written in unsupported formats may be converted for upload using
a new application provided with the package. The
components of Iris have been contributed by members of the VAO.
contributed by STScI (the Space Telescope Science
Institute), provides a GUI for reading, editing, and displaying SEDs,
as well as defining model expressions and setting initial model
parameter values. Sherpa,
contributed by the Chandra project at SAO
(the Smithsonian Astrophysical Observatory), provides a library of
models, fit statistics, and optimization methods for analyzing SEDs;
the underlying I/O library, SEDLib,
is a VAO product written by SAO to
current IVOA (International Virtual Observatory Alliance)
standards. NED is a service provided by IPAC (the Infrared Processing
and Analysis Center) at Caltech for easy location of data for a given
extragalactic astronomical source, including SEDs. SedImporter is a
new tool for converting non-standard SED data files into a format
supported by Iris. We demonstrate the use of SedImporter to retrieve
SEDs from a variety of sources–from the NED SED service, from the
user's own data, and from other VO applications using SAMP (Simple
Application Messaging Protocol).
We also demonstrate the use of Iris
to read, display, select ranges from, and fit models to SEDs.
Finally, we discuss the architecture of Iris, and the use of IVOA
standards so that Specview, Sherpa, SEDLib and SedImporter work