ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 Astronomical spectroscopy and the Virtual Observatory: a user-oriented perspective Matteo Guainazzi 1, Andrea Laruelo, Jesus Salgado, Isa Barbarisi, Pedro Osuna ESA-VO, Science Operations Department European Space Astronomy Center of ESA Villafranca del Castillo, Spain 1 also EURO-VO astronomer

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 Outline  Why do we care? Spectroscopic surveys in the past and in the future  Which added value can VO bring to the analysis of spectroscopic data?  What does the VO currently offer? Data models Data access protocols Spectral services Spectral VO applications  Adds-on Access to atomic and molecular lines databases Access to theoretical models

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 Spectroscopic surveys: the past Number of redshifts in surveys as a function of time (Yip et al. 2007) YearNumberRzMagnitude Limit FBS19652x V<17.5 SBS19913x V<19 Case V<18 HQS19972x to 3.5V<19 HES x to 3.2V<18 LCRS x to 0.2R<17 2dF x to 2.2b<21 SDSS to 0.3r < (galaxies) to 6r < 19.1 (quasars) DEEP220025x to 1.5I < 24 VVDS x to 4.0I < x to 4.0I < to 4.0I < 26 zCosmos20052x to 1.2I < x to 3.0color selection

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 Evolution of survey source numbers (Cropper 2007)

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 What do we gain with the VO? We should be able to largely gain in efficiency (from “it would take my whole lifetime to do it” to “it can be done by my Ph.D. student”) for tasks like:  Building spectral energy distributions (spectra+photometry) by combining large datasets from different sources  Comparing spectra and images (footprint, contamination …)  Analysis and clever visualization of large datasets  Correlation of spectrally-derived parameters from different sources  Automatic classification (and outliers discovery)  Multi-parameter connectedness (M.Cropper)  Selection of sub-samples on the basis of a multi-parameter space  Access to ancillary information useful for the interpretation of the data: existing object classification, publications

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 What should VO tools be also able to do?  Basic display tools: superposition, rebinning, smoothing, dynamical spectra  Radial velocity measurements and superposition of spectral region in the velocity parameter space  Rectification  Fits (Gaussian, Maxwellian, Voigt profiles)  Measurement of line profile asymmetry and broadening  Time analysis (periodograms, Fourier analysis, Doppler imaging)  Spectral deconvolution in energy and Fourier space  Comparison between observed spectra and spectral templates  Comparison between observed spectra and theoretical models  Not all functionalities must be simultaneously present in a given tool!

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 What does the VO offer?  Data models and data access protocols: Simple Spectral Access (SSA; Tody et al. 2007) Based on the concept of a “1-D” spectrum: spectral coordinates, flux, error, quality flag, etc, Virtual data generation: cut-out, reprojection, dynamic extraction etc. Support to multiple data format: VOTable, FITS binary, CSV, native XML, HTML Spectrum Data Model (Mc Dowell et al. 2007)  Spectral services  Applications Specview (STScI) SPLAT (AstroGrid) VOSpec (ESA-VO)

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 What does the VO offer?  Data models and data access protocols: Simple Spectral Access (SSA; Tody et al. 2007) Based on the concept of a “1-D” spectrum: spectral coordinates, flux, error, quality flag, etc, Virtual data generation: cut-out, reprojection, dynamic extraction etc. Support to multiple data format: VOTable, FITS binary, CSV, native XML, HTML Spectrum Data Model (Mc Dowell et al. 2007)  Spectral services  Applications Specview (STScI) SPLAT (AstroGrid) VOSpec (ESA-VO)

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 EURO-VO spectroscopic tools SPLAT-VO VOSpec

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 Basic working scheme Collect spectra Build SED Local files Remote servers Prepare spectra Data screening Rebinning Filtering De-noising De-reddening Units conversion Spectra arithmentic Convolutions Analyse spectra EW Flux Fit Bisectoring Mirroring Interpolation Line identification Theory Publish results Paper-quality plots Export analysis Units?

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 SED generation and graphics  Access to spectra from: Local files (FITS, ASCII, NDF …) Files available on the Internet Simple Spectral Access Protocol compatible servers: (CDF-S, EUVE, FUSE, Giraffe, HST, HUT, Integral/OMC, ISO, IUE, SDSS, XMM-Newton/RGS, WHS, WUPE …)  Units handling Most of the standard units on the frequency/energy/wavelength axis, and on the flux density axis can be hadled automatically VOSpec also handles automatically any units via dimensional analysis  Plotting Single- and multi-spectra plotting, with various standard graphical facilities SPLAT allows the co-existence of different plotting windows, a “drag the file name” function to display a new spectrum, and movie generation VOSpec allows interactive mouse-driven zooming

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 Analysis tools: SPLAT Conversion to velocity, redshift or Lorentz factor space Spectral arithmetic for spectra (limited to strictly overlapping frequency ranges) –Pairs of spectra –Spectra and a constant Cut and removal of spectral ranges Fit of continua and emission/absorption lines Generation of a spectrum from an interpolated line (needed to evaluate the continuum level underneath a fitted line) Filtering Flipping/translating SPEFO (legacy software from Ondřeov Observatory)

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 VOSpec: spectral analysis functionalities I. Arithmetic and convolution between spectra Line fitting Best Fit of theoretical models Fit of theoretical models to an observed spectrum (see later) Fit of an absorption line profile with different models (Gaussian, Loretntzian Voigt)

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 VOSpec: spectral analysis functionalities II. Mirroring, bisector Interactive integrated flux and equivalent width Filtering Discrete wavelet analysis Wavelength-to-velocity conversion Dereddening: Calzetti law Cardelli-O’Donnel law LMC law Calculation of luminosity differences between observational spectra and models

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 The power of interoperability I. GB 2MASS SDSS ROSAT Chandra AstroScope: catalogue search Aladin: multipanel imaging VOSpec: generation of SEDs TOPCAT: tabular data plotting/manipulation

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 Community efforts I.: EZ and GOSSIP EZ: Automatic calculation of spectroscopic redshifts GOSSIP: Spectrophotometric analysis through SED fitting (not VO yet) (Franzetti 2007; Garilli 2007)

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 Simple Line Access through VOSpec VOSpec provides access to atomic and molecular line Databases throuh a specific VO access protocol (SLAP): –NIST –CHIANTI (X-rays) –CIELO (XMM-Newton) –IASD (ISO) –LERMA (molecular) This allows on-the-fly identification of transitions associated to a given observed feature SPLAT includes a hardcoded line identification facility on the basis of standard sets of lines

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 Easy access to theoretical models (TSAP) SVO web server implementation ( ESA-VO VOSpec implementation

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 Thoretical models fit step by step  Selecting TSA server Initial model Best fit model minimization proccess Select TSA server Select initial parameters

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 A typical session …

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 Will we ever have X-ray data in the VO? Traditional wisdom: no! Spectra in X-ray archives are in instrumental counts Conversion into physical units is strongly model dependent due to non- linearity of the redistribution matrix “We” X-ray astronomers know how to do it: ask us! Little, little, twinkling star … ? XMM-Newton EPIC redistribution function

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 Yes! XMM-Newton/RGS However, high-resolution instruments are now flying: XMM-Newton RGS (R≈ ) The redistribution function is very close to linear Model independent fluxed spectra can be produced Soon availabe as VO server (the first all-sky spectral X-ray server ever) –Pilot project on Seyfert 2 galaxies available since 1 year (CIELO-AGN) No general solution yet for moderate- resolution spectra (XMM-Newton/EPIC, Chandra/ACIS, Suzaku/XIS, Swift …) RGS redistribution function (Gonzalez-Riestra & Rodriguez-Pascal 2007) ABDor

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 Conclusions: wher do we stand?  On-the-fly SED generation: Spectra access from SSAP-compatible server Automatic handling of units  Spectral analysis tools Growing suite of spectral analysis tools available in the “mainstream” tools Multi-component fit possible Community-based web-services start appearing for more specialized tasks  Interoperability All tools use PLASTIC First steps to export via PLASTIC also the analysis results  Usage on massive sets of data Mainly designed to handle one source at the time → highly interactive

ESAVO/European Space Astronomy Centre (ESAC) Villafranca del Castillo, MADRID (SPAIN) Matteo Guainazzi “Astronomy with Virtual Observatories” Pune, 17 October 2007 (Brandt et al. 2001) Science highlight from spectroscopic surveys (Le Fèvre et al. 2006) VVDS Discovery of high-redshift dusty galaxy population with strong star formation SDSS High-redshift QSOs XMM-Newton SDSS: New stellar streams and satellites of the Milky Way (Belokurov et al. 2006) SDSS, z~0.1 DEEP2, 0.75<z<1.05 SDSS+DEEP2 Red galaxy environment (Cooper et al. 2006)