Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: First detection and characterization of symbiotic stars in M31   Symbiotic binaries are putative progenitors of type Ia supernovae. The census
of Galactic symbiotic binaries is so incomplete that we cannot reliably
estimate the total population of these stars, and use it to check whether that
number is consistent with the observed type Ia supernova rate in spiral
galaxies. We have thus begun a survey of the nearest counterpart of our own
Galaxy, namely M31, where a relatively complete census of symbiotic stars is
achievable. We report the first detections and spectrographic characterizations
of 35 symbiotic binaries in M31, and compare these stars with the symbiotic
population in the Milky Way. These newly detected M31 symbiotic binaries are
remarkably similar to galactic symbiotics, though we are clearly only sampling
(in this feasibility study) the most luminous symbiotics in M31. We have also
found, in M31, the symbiotic star (M31SyS J004233.17+412720.7) with the highest
ionization level known amongst all symbiotics. An optical outburst of the M31
symbiotic star M31SyS J004322.50+413940.9 was probably a nova-like outburst,
the first symbiotic outburst detected outside the Milky Way and Magellanic
Clouds.

8
The categories of this paper are: hep-ex
36
The categories of this paper are: cmp-lg
17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
27
The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat
10
The categories of this paper are: q-bio
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
30
The categories of this paper are: q-alg
2
The categories of this paper are: math