Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The double AGN in NGC 6240 revealed through 3-5 micron spectroscopy   We present 3-5 micron spectroscopy of the interacting system NGC 6240,
showing the presence of two active galactic nuclei. The brightest (southern)
nucleus shows up with a starburst-like emission, with a prominent 3.3 micron
emission feature. However, the presence of an AGN is revealed by the detection
of a broad Br alpha emission line, with a width of ~1,800 km/s. The spectrum of
the faintest (northern) nucleus shows typical AGN features, such as a steep
continuum and broad absorption features in the M-band. We discuss the physical
properties of the dusty absorbers/emitters, and show that in both nuclei the
AGN is dominant in the 3-5 micron band, but its contribution to the total
luminosity is small (a few percent of the starburst emission).

15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math