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Testing the AGN unified model using spectropolarimetry

Testing the AGN unified model using spectropolarimetry. Cristina Ramos Almeida Andrés Asensio Ramos, María Jesús Martínez González, Rafael Manso Sáinz, José Antonio Acosta Pulido & the CanariCam AGN team “Los Piratas”.

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Testing the AGN unified model using spectropolarimetry

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  1. Testing the AGN unified model using spectropolarimetry Cristina Ramos Almeida Andrés Asensio Ramos, María Jesús Martínez González, Rafael Manso Sáinz, José Antonio Acosta Pulido & the CanariCam AGN team “Los Piratas”

  2. Modeling Clumpy Torus Models • Torus dust grains absorb optical & UV photons from matter accretion  re-emission in the infrared (peaking at mid-IR  5-30 μm). • Dust distributed in clumps instead of homogeneously filling torus volume (Nenkova et al. 2002; Hönig et al. 2006; Schartmann et al. 2008). Nenkova et al. (2002) 16th October - Polarization & AGN Cristina Ramos Almeida

  3. Observations IR range (mid-IR) key to constrain parameters of torus models. Goal: isolation of torus emission (Ro< 10 pc; interferometry & mid-IR). Large aperture data (e.g. ISO, Spitzer, IRAS) contaminated with circunnuclear stellar emission. High-spatial resolution infrared observations (e.g., CanariCam, T-ReCS, Michelle, VISIR) key to isolate torus emission. Isolation of Torus emission 16th October - Polarization & AGN Cristina Ramos Almeida

  4. Observations Isolation of Torus emission 8 m Gemini 85 cm Spitzer 16th October - Polarization & AGN Cristina Ramos Almeida

  5. Mid-IR imaging: space (Spitzer/IRAC) vs. ground (Gemini/T-ReCS) observations Díaz-Santos (2009, PhD)

  6. Observations RA et al. 2009, 2011; Alonso-Herrero et al. 2011 • Ground-based subarcsecond resolution mid-IR imaging data for 21 nearby Seyfert galaxies. • Compilation of near-IR nuclear fluxes from the literature of similar resolutions as mid-IR data. • Herschel far-IR data also available (GT + GO programmes). AGN-dominated SEDs = torus emission (Sy2) & torus+AGN emission (Sy1). 16th October - Polarization & AGN Cristina Ramos Almeida

  7. Results NIR + MIR spectral energy distributions 16th October - Polarization & AGN Cristina Ramos Almeida

  8. SED modelling BayesClumpy • Bayesian code to fit the clumpy models of Nenkova et al. 2008a,b. • PCA decomposition + Neural networks to approximate Clumpy Database (6 parameters-based models). • Solution to the Clumpy Database degeneracy  • Possibility of interpolating within the database  • Simultaneous fit of both SED + spectrum  • Prediction of next observation to add to SED  • Available for the astrophysical community  Asensio Ramos & Ramos Almeida 2009, 2012 16th October - Polarization & AGN Cristina Ramos Almeida

  9. 16th October - Polarization & AGN Cristina Ramos Almeida

  10. Circinus NIR data from NACO / VLT (Prieto et al. 2010) NGC 7469 16th October - Polarization & AGN Cristina Ramos Almeida MIR data from T-ReCS /Gemini-South (Packham et al. 2005; RA et al. 2011)

  11. Results Are the obscuring tori of Type 1 and 2 Seyferts different? NIR+MIR emission reproduced with small tori (Ro< 6 pc) 16th October - Polarization & AGN Cristina Ramos Almeida

  12. Results Are the obscuring tori of Type 1 and 2 Seyferts different? Sy1 tori covering factors < Sy2 tori covering factors Sy1 Sy1 Sy2 Sy2 Sy1 photon escape prob. > Sy2 photon escape prob. 16th October - Polarization & AGN Cristina Ramos Almeida

  13. Results Are the obscuring tori of Type 1 and 2 Seyferts different? -Expected from warped disk torus models (Lawrence & Elvis 2010) -also from X-ray observations of Seyfert galaxies (Ricci et al. 2011) Lawrence & Elvis (2010) • -Highly inclined Seyfert 1 tori: • Bi-conical outflows (SINFONI; Müller-Sanchez et al. 2011) • Accretion disk orientation from X-ray data (Nandra et al. 2007) 16th October - Polarization & AGN Cristina Ramos Almeida

  14. Results Are the obscuring tori of Type 1 and 2 Seyferts different? If all Seyfert nuclei are identical, as simple unification predicts, only the viewing angle determines the classification. Our results suggest that the classification as Type-1 or Type-2 may also depend on the intrinsic properties of the torus. Schartmann et al. (2008) 16th October - Polarization & AGN Cristina Ramos Almeida

  15. Project Are the obscuring tori of Type 1 and 2 Seyferts different? • Origin of unification scheme for Seyfert galaxies (Antonucci & Miller 1985) detection of polarized broad lines in NGC 1068 nuclei. • Only 30-50% of nearby Sy2s show a Sy1-type polarized spectrum (Tran 2001). Implications? • 1) not all Seyferts harbour a hidden BLR (Tran 2001, 2003; Gu & Huang 2002) • 2) distribution of dust within the torus and its inclination not as simple as predicted by the unified model. 16th October - Polarization & AGN Cristina Ramos Almeida

  16. Project Are the obscuring tori of Type 1 and 2 Seyferts different? Results from our modelling with torus models could explain lack of polarized broad lines in 50-70% of nearby Seyfert 2 galaxies. The torus has to have a determined orientation (close to edge-on) and enough clumps to make the broad lines visible in polarized light. GALAXY NGC 7582 IC 5063 POLARIZED BROAD LINES✗ ✔ i FROM MODELLING43°±19°22° 81°±5°8° 16th October - Polarization & AGN Cristina Ramos Almeida

  17. Project Are the obscuring tori of Type 1 and 2 Seyferts different? Results from our modelling with torus models could explain lack of polarized broad lines in 50-70% of nearby Seyfert 2 galaxies. The torus has to have a determined orientation (close to edge-on) and enough clumps to make the broad lines visible in polarized light. NGC 7582 ✗ IC 5063 ✔ POLARIZED BROAD LINES✔✗ i FROM MODELLING81°±5°8° 43°±19°22° 16th October - Polarization & AGN Cristina Ramos Almeida

  18. Project Are the obscuring tori of Type 1 and 2 Seyferts different? Results from our modelling with torus models could explain lack of polarized broad lines in 50-70% of nearby Seyfert 2 galaxies. The torus has to have a determined orientation (close to edge-on) and enough clumps to make the broad lines visible in polarized light. Comparison between RA11+AH11 results and a homogeneous data set of spectropolarimetric data. 16th October - Polarization & AGN Cristina Ramos Almeida

  19. Futre observations Are the obscuring tori of Type 1 and 2 Seyferts different? • Homogeneous dataset of polarized optical spectra of a representative sample of Seyfert galaxies for which we have constraints on their torus properties. • ISIS/WHT observations scheduled in Jan 2013  16 objects. • FORS2/VLT observations requested in 2013A  18 objects. • Sample contains similar numbers of Seyfert 1, 1.2, 1.5, 1.9 and 2 types  study how polarization signal varies between types. 16th October - Polarization & AGN Cristina Ramos Almeida

  20. Futre observations GOALS • Analize in a consistent way linear polarization signal and high angular resolution infrared data using torus models. • Confirm whether or not the lack of polarized broad lines in 50-70% of Sy2 population due to low torus inclinations and/or small covering factors. • Directly compare between linear polarization signal in Sy1s and Sy2s. 16th October - Polarization & AGN Cristina Ramos Almeida

  21. Thanks!

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