Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Census of Self-Obscured Massive Stars in Nearby Galaxies with Spitzer:
  Implications for Understanding the Progenitors of SN 2008S-Like Transients   A new link in the causal mapping between massive stars and potentially fatal
explosive transients opened with the 2008 discovery of the dust-obscured
progenitors of the luminous outbursts in NGC 6946 and NGC 300. Here we carry
out a systematic mid-IR photometric search for massive, luminous, self-obscured
stars in four nearby galaxies: M33, NGC 300, M81, and NGC 6946. For detection,
we use only the 3.6 micron and 4.5 micron IRAC bands, as these can still be
used for multi-epoch Spitzer surveys of nearby galaxies (=<10 Mpc). We combine
familiar PSF and aperture-photometry with an innovative application of image
subtraction to catalog the self-obscured massive stars in these galaxies. In
particular, we verify that stars analogous to the progenitors of the NGC 6946
(SN 2008S) and NGC 300 transients are truly rare in all four galaxies: their
number may be as low as ~1 per galaxy at any given moment. This result
empirically supports the idea that the dust-enshrouded phase is a very
short-lived phenomenon in the lives of many massive stars and that these
objects constitute a natural extension of the AGB sequence. We also provide
mid-IR catalogs of sources in NGC 300, M81, and NGC 6946.

5
The categories of this paper are: gr-qc
10
The categories of this paper are: q-bio
28
The categories of this paper are: alg-geom
23
The categories of this paper are: solv-int
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
3
The categories of this paper are: physics
2
The categories of this paper are: math
4
The categories of this paper are: cond-mat