Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The parsec scale region of Active Galactic Nuclei in the IR   First results from the AGN-Heidelberg program aimed at spatially resolving
the central pc region of the closest Active Galactic Nuclei are presented. The
core region of prototype active nuclei are clearly unveiled at IR waves and at
distances from the nucleus - few pc- where circumnuclear starforming regions
appear not to be present. Within that perspective, classical active nuclei as
Circinus and NGC 1097, reveal with unprecedented detail clear channels of
material being driven to the core whereas others as Centaurus A and NGC 1566,
show a "clean" core environment. At the very center, a central compact region
of about 2 pc scale is resolved in Circinus but not in the other cases
challenging thus the universal presence of the putative obscuring torus.

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The categories of this paper are: alg-geom
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The categories of this paper are: patt-sol
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The categories of this paper are: chao-dyn
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The categories of this paper are: chem-ph
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The categories of this paper are: q-alg
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The categories of this paper are: cmp-lg
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The categories of this paper are: atom-ph
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The categories of this paper are: physics
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The categories of this paper are: hep-ex
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The categories of this paper are: q-fin
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The categories of this paper are: math
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The categories of this paper are: acc-phys
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The categories of this paper are: eess
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The categories of this paper are: cond-mat
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The categories of this paper are: hep-lat
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The categories of this paper are: ao-sci