Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Beyond Str\"omgren Spheres and Wind-Blown Bubbles: An Observational
  Perspective on H II Region Feedback   Massive stars produce copious quantities of ultraviolet radiation beyond the
Lyman limit, photoionizing the interstellar medium (ISM) and producing H II
regions. As strong sources of recombination- and forbidden-line emission,
infrared continuum, and thermal (free-free) radio continuum, H II regions serve
as readily-observable beacons of massive star formation in the Milky Way and
external galaxies. Along with supernovae, H II regions are dominant sources of
feedback in star-forming galaxies, injecting radiative and mechanical
luminosity into the ISM. H II regions may prove more important than supernovae
as triggers of star formation through localized compression of cold cloud
cores. In this review, I give a broad overview of the structure and
time-evolution of H II regions, emphasizing complications to the theoretical
picture revealed by multiwavelength observations. I discuss a recent
controversy surrounding the dominant feedback mechanism in 30 Doradus, the most
luminous H II region in the Local Group. I summarize the first results from the
Milky Way Project (MWP), which has produced a new catalog of several thousand
candidate Galactic H II regions by enlisting >35,000 "citizen scientists" to
search Spitzer Space Telescope survey images for bubble-shaped structures. The
MWP and similar large catalogs enable empirical studies of Galactic H II region
evolution across the full range of luminosities and statistical studies of
triggered star formation.

27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
25
The categories of this paper are: patt-sol
0
The categories of this paper are: hep-ph
9
The categories of this paper are: nlin
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
33
The categories of this paper are: plasm-ph
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
19
The categories of this paper are: eess
12
The categories of this paper are: nucl-th