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Deblending issues working report

Deblending issues working report. Main Task  Obtain a clean spectrum for every observed source, resolved in the astrometric field. DU11 in CU5: Leiden (NL), Cambridge (UK), Roma,Teramo (IT). INAF - Teramo Observatory: Anna Piersimoni, Giorgia Busso

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Deblending issues working report

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  1. Deblending issues working report Main Task  Obtain a clean spectrum for every observed source, resolved in the astrometric field DU11 in CU5: Leiden (NL), Cambridge (UK), Roma,Teramo (IT) INAF - Teramo Observatory: Anna Piersimoni, Giorgia Busso INAF - Rome Observatory (Monte Porzio Catone): Giacinto Iannicola, Luigi Pulone, Marco Castellani ASI – ASDC (Frascati) : Licia Troisi, Roberto Buonanno, Giuliano Giuffrida MontePorzio 16-04-08 CU5#DU11 Luigi Pulone@ INAF-OA Roma

  2. Data Processing and Analysis Consortium ESA Gaia project team ESA Ground segment oversight GAIA Science Team DPAC CU3 Core processing CU1 System architecture CU4 Object analysis CU2 Simulazioni CU7 Variability analysis CU5 Photometric processing CU8 Astrophysical parameters CU6 Spectroscopic processing

  3. Coordination Unit 5 Riduzione fotometrica e calibrazione sia in banda G che negli spettri • Estrazione dei parametri delle identificazioni per ogni passaggio nel campo astrometrico • Elaborazione ed accumulazione dei dati in banda G, RP, BP • Identificazione stelle standard, variabili, analisi oggetti multipli • Calibrazione interna ed esterna dati fotometrici • Photometric science alerts

  4. Gli obbiettivi di GAIA Accuratezza • 4 μarcsec a V=10 10 μarcsec a V=15 0.2 marcsec a V=20 • Velocità radiali con accuratezza di qualche km/s complete fino a V=17.5 • Survey celeste con risoluzione spaziale di 0.1 arcsec fino a V=20 • spettrofotometria multi-epoca fino a V=20 • definizione di un sistema inerziale legato ai quasar più lontani Risultati - GAIA posizionerà 300 milioni di stelle nello spazio delle fasi a 6 dimensioni e 1 miliardo di stelle nello spazio delle fasi a 5 dimensioni

  5. Astrofisica stellare Formazione stellare nella Via Lattea Struttura Galattica Binarie e nane brune Fisica fondamentale Sistema di riferimento Sistema solare Pianeti extrasolari

  6. Confronto fra Hipparcos e GAIA Oggetti galassie quasar Supernovae extrag. Nuovi asteroidi binarie Nane bianche Nane brune Sistemi planetari

  7. Schedule 2020 2004 2008 2016 2000 2012 Concept & Technology Study ESA SCI 2000(4) Acceptance Re-Assessment: Ariane  Soyuz Technology Development Design, Build, Test Launch To L2 Observations Assumed start of Phase B2 Analysis Catalogue Early Data

  8. Satellite and System ESA only mission Launch date: 2011 Lifetime: 5 years Launcher: FREGAT Orbit: L2 Ground station: Perth or Madrid Data rate: 1 Mbps Mass: 1700 kg (payload 800 kg) Power: 2000 W (payload 1200 W)

  9. Il percorso ottico

  10. GAIA– Simulazione campo stellare media densità spettrofotometro R spettrofotometro B

  11. OA Teramo OA Roma, ASI-ASDC

  12. Teramo group • Background modelling • Studying relationships between AL and AC size of the source and APs • Source crowding evaluation at source and transit level • Create connected groups on the basis of the contamination degree • Individuate isolated objects

  13. BP photometer: AC width vs. G mag BP photometer: AL length vs. G mag AC AL

  14. High density regions, like Galactic bulge low-extinction regions and central regions of the Large Magellanic Cloud, present a challenge both for board data-handling and for the ground-based reduction while being crucial for the Gaia science case. A recent result: expected frequency of the deblending procedure for the whole mission lifetime (~10%) taking into account the overlapping of the two field of view. Figures from Marrese & Busso 2007

  15. Rome group • Deblending of connected groups due to: • overlapping of spectra of different sources in connected windows • objects in nearby windows whose spectra extend into the program window • objects for which the on-board detection software has not assigned a window • barely detectable sources beyond the survey magnitude limit (20 < G < 22).

  16. The numerical approach The analytical approach, has shown some limitations in reproducing high metallicity and low temperature spectra. The Rome group is now developing and testing a new deblending technique based a Marquardt-like method for non linear least square minimization. This approach is much more straightforward and makes use of the entire morphology of the spectrum simultaneously in both the Blue and Red bands. First results appear encouraging.

  17. new approach • template library 3500 < Teff < 20000°K, -5.00 < [M/H] < 1.00 • comparison between templates and input spectrum • models interpolation

  18. OLD ANALYTICAL vs NEW NUMERICAL APPROACH M/H = -5 T=8000 K Logg=4.5 Av=0. OLD NEW

  19. testT = 9250°K, [M/H]= -4.5, -0.2, 1.0

  20. Two blended spectra in the same window • Teff=20000°K, [M/H]=-4.5 + Teff=9000°K, [M/H]=0.00 • Shift: 10 pixel

  21. Recovering of blended spectra • Teff=20000°K, [M/H]=-4.5 + Teff=9000°K, [M/H]=0.00 • Shift 10 pixel

  22. Central star: V=13 T=6000 [M/H]=0 Blended 1: V=14 T=10000 [M/H]=0.5 dX=15 px dY=2 px Blended 2: V=15 T=8000 [M/H]=-0.5 dX=13 dY=3

  23. Next steps: • Include log g into the reference theoretical template • Take into account the Av • Consider the paving strategy, cut windows etc. to rebuild connected and contaminated spectra

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