astronomical spectroscopy in the vo era: vospec pedro osuna
DESCRIPTION
Astronomical Spectroscopy in the VO era: VOSpec Pedro Osuna Isa Barbarisi, Jesus Salgado, Andrea Laruelo European Space Astronomy Centre (ESAC) Science Archives and VO Team. Making data available in the Internet. WEB SERVER. Create document. robots. Making data available in the VO. - PowerPoint PPT PresentationTRANSCRIPT
ESAVO/European Space Astronomy Centre (ESAC)Villafranca del Castillo, MADRID (SPAIN)Pedro OsunaASVOWS 21-23 Mar 2007 ESAC
Astronomical Spectroscopy in the VO era: VOSpec
Pedro OsunaIsa Barbarisi, Jesus Salgado, Andrea Laruelo
European Space Astronomy Centre (ESAC)Science Archives and VO Team
ESAVO/European Space Astronomy Centre (ESAC)Villafranca del Castillo, MADRID (SPAIN)Pedro OsunaASVOWS 21-23 Mar 2007 ESAC
Making data available in the Internet
Create document
WEB SERVER
robots
ESAVO/European Space Astronomy Centre (ESAC)Villafranca del Castillo, MADRID (SPAIN)Pedro OsunaASVOWS 21-23 Mar 2007 ESAC
Making data available in the VO
Create service
SSA SERVER
ESAVO/European Space Astronomy Centre (ESAC)Villafranca del Castillo, MADRID (SPAIN)Pedro OsunaASVOWS 21-23 Mar 2007 ESAC
Making data available in VO: DAL Toolkit
Config Files
SpectraFITS Files
Ingestor
DB
ServerDAL Request
VOTable
File Sys
ESAVO/European Space Astronomy Centre (ESAC)Villafranca del Castillo, MADRID (SPAIN)Pedro OsunaASVOWS 21-23 Mar 2007 ESAC
VOSpec Main Features• Handle SSAP spectra• Open local Spectra (Fits or VOTable)• Create a SED of spectra coming from a
wide range of different providers registered in the VO Registry (http://esavo.esa.int/registry) and also coming from local data
• Create SSAP Wrapper with your own set of local spectra and immediately display it
• Graphic options like color modification, zoom, unzoom, change spectra visualization, change units etc..
• Save results as Image/VOTable• Math operations like Polynomial,
BlackBody fitting, Gaussian, Nomalization, DeReddening, Red-shift, Luminosity Differences etc.
• Access to Theoretical Spectra through TSAP and Spectral Atomic Lines through SLAP
• Interoperability with other vo-aware tools through Plastic Technology
ESAVO/European Space Astronomy Centre (ESAC)Villafranca del Castillo, MADRID (SPAIN)Pedro OsunaASVOWS 21-23 Mar 2007 ESAC
De-Reddening
• Interstellar reddening is a phenomenon associated with interstellar extinction where the spectrum of electromagnetic radiation from a radiation source changes characteristics from that which was emitted.
• Reddening occurs due to the light scattering off dust and other matter in the interstellar medium. It preferentially removes shorter wavelength photons from a radiated spectrum while leaving behind the longer wavelength photons (in the optical, light that is redder), leaving the spectroscopic lines unchanged
• VOSpec povides support to this phenomenon allowing to apply the Calzetti, Cardelli O’Donnel or LMC formula, depending by the case.
• Please visit the VOSpec User Manual to see the video of the De-Reddening functionality.
ESAVO/European Space Astronomy Centre (ESAC)Villafranca del Castillo, MADRID (SPAIN)Pedro OsunaASVOWS 21-23 Mar 2007 ESAC
De-Reddening – IRAS 10178-5958 case
ESAVO/European Space Astronomy Centre (ESAC)Villafranca del Castillo, MADRID (SPAIN)Pedro OsunaASVOWS 21-23 Mar 2007 ESAC
Theoretical Spectra Access in VOSpec
• VOSpec allows the user to rescale theoretical spectra using real spectral data for the object to be studied.
• Even if there are many differences between theoretical and real spectra, it’s been studied a solution to unify them in a common access protocol in order to visualize them in the same plot
• Main differences between both kind of spectra are the following:
- Models have specific input parameters- Theoretical Spectra are not normalized
ESAVO/European Space Astronomy Centre (ESAC)Villafranca del Castillo, MADRID (SPAIN)Pedro OsunaASVOWS 21-23 Mar 2007 ESAC
Simple Line Access through VOSpec
• There is a scientific need to have access to spectral line databases in the VO. Many science cases could make use of this kind of access
• VOSpec provides access to Atomic Line Databases through the Simple Line Access Protocol (SLAP)
• Please visit the VOSpec User Manual to see the video of the SLAP functionality.
ESAVO/European Space Astronomy Centre (ESAC)Villafranca del Castillo, MADRID (SPAIN)Pedro OsunaASVOWS 21-23 Mar 2007 ESAC
Best Fit fitting toolMOTIVATION MOTIVATION
Currently, to find the model that best fits a given SED:•Choose parameters manually•Inspect result visually (“Chi-by-eye”)•Modify parameters manually•Reinspect visually•Loop… GOAL
Best Fit finds thebest fit modelautomatically
METHOD
Levenberg-Marquardt Chi-squareminimization algorithm
ESAVO/European Space Astronomy Centre (ESAC)Villafranca del Castillo, MADRID (SPAIN)Pedro OsunaASVOWS 21-23 Mar 2007 ESAC
Best Fit step by step
Selecting TSA server
Initial model
Best fit model
minimizationproccess
Select TSA server
Select initial parameters
ESAVO/European Space Astronomy Centre (ESAC)Villafranca del Castillo, MADRID (SPAIN)Pedro OsunaASVOWS 21-23 Mar 2007 ESAC
Plastic Technology and Applications
• PLASTIC is a protocol for communication between client-side astronomy applications. Through PLASTIC applications can do tasks such as instruct each other to load Spectra, VOTables, highlight a subset of rows or load an image of a particular area of sky. Although such operations are quite simple, they enable powerful collaborations between tools. The philosophy is that the astronomer should have a suite of interoperating tools at his disposal, each of which does one thing well and which can be composed according to his particular needs.
• VOSpec allows registration to the Plastic Hub and it can interoperate with other VO-aware tools like Aladin, Astroscope, VOQuest etc
• Please visit http://plastic.sourceforge.net for more details about the project
Sending spectra from Astroscope to VOSpec through Plastic
Sending spectra from Aladin to VOSpec through Plastic
ESAVO/European Space Astronomy Centre (ESAC)Villafranca del Castillo, MADRID (SPAIN)Pedro OsunaASVOWS 21-23 Mar 2007 ESAC
Future implementations on VOSpec
You name it, we implement it.
See VOSpec at work: http://esavo.esac.esa.int/vospec/
And the User Manual at: http://esavo.esac.esa.int/VOSpecManual/