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		| Paper: | 
		Iris: The VAO SED Application | 
	 
	
		| Volume: | 
		461, Astronomical Data Analysis Software and Systems XXI | 
	 
	
		| Page: | 
		893 | 
	 
	
		| Authors: | 
		Doe, S.; Bonaventura, N.; Busko, I.; D'Abrusco, R.; Cresitello-Dittmar, M.; Ebert, R.; Evans, J.; Laurino, O.; McDowell, J.; Pevunova, O.; Refsdal, B. | 
	 
	
	
		| Abstract: | 
		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).  
  Data
 written in unsupported formats may be converted for upload using
 SedImporter, 
 a new application provided with the package. The
 components of Iris have been contributed by members of the VAO.
 Specview, 
 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) 
 data model
 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
 together seamlessly. | 
	 
	
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