Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spectroscopy of H II Regions in the Late-Type Spiral Galaxy NGC 6946   We present the results of spectroscopy of 39 H II regions in the spiral
galaxy NGC 6946. The spectral observations were carried out at the 6-m BTA
telescope of the SAO RAS with the SCORPIO focal reducer in the multi-slit mode
with the dispersion of 2.1A/px and spectral resolution of 10A. The absorption
estimates for 39 H II regions were obtained. Using the "strong line" method
(NS-calibration) we determined the electron temperature, and the abundances of
oxygen and nitrogen for 30 H II regions. The radial gradients of O/H and N/H
were constructed.

27
The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
7
The categories of this paper are: hep-th
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
5
The categories of this paper are: gr-qc
15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
29
The categories of this paper are: funct-an
25
The categories of this paper are: patt-sol