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arXiv · 1107.2420

Resolving the nuclear dust distribution of the Seyfert 2 galaxy NGC 3081

C. Ramos Almeida·M. Sanchez-Portal·A. M. Perez-Garcia·J. A. Acosta-Pulido·M. Castillo·A. Asensio Ramos·J. I. Gonzalez-Serrano·A. Alonso-Herrero·J. M. Rodriguez Espinosa·E. Hatziminaoglou·D. Coia·I. Valtchanov·M. Povic·P. Esquej·C. Packham·B. Altieri
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Abstract

We report far-infrared (FIR) imaging of the Seyfert 2 galaxy NGC 3081 in the range 70-500 micron, obtained with an unprecedented angular resolution, using the Herschel Space Observatory instruments PACS and SPIRE. The 11 kpc (~70 arcsec) diameter star-forming ring of the galaxy appears resolved up to 250 micron. We extracted infrared (1.6-500 micron) nuclear fluxes, that is active nucleus-dominated fluxes, and fitted them with clumpy torus models, which successfully reproduce the FIR emission with small torus sizes. Adding the FIR data to the near- and mid-infrared spectral energy distribution (SED) results in a torus radial extent of Ro=4(+2/-1) pc, as well as in a flat radial distribution of the clouds (i.e. the q parameter). At wavelengths beyond 200 micron, cold dust emission at T=28+/-1 K from the circumnuclear star-forming ring of 2.3 kpc (~15 arcsec) in diameter starts making a contribution to the nuclear emission. The dust in the outer parts of the galaxy is heated by the interstellar radiation field (19+/-3 K).

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C. Ramos Almeida, M. Sanchez-Portal, A. M. Perez-Garcia, J. A. Acosta-Pulido, M. Castillo, A. Asensio Ramos, J. I. Gonzalez-Serrano, A. Alonso-Herrero, J. M. Rodriguez Espinosa, E. Hatziminaoglou, D. Coia, I. Valtchanov, M. Povic, P. Esquej, C. Packham, B. Altieri. 2011-07-12. Resolving the nuclear dust distribution of the Seyfert 2 galaxy NGC 3081. https://doi.org/10.1111/j.1745-3933.2011.01117.x

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