Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Optical and X-ray Studies of Ten X-ray Selected Cataclysmic Binaries   We report on ground-based optical observations of ten cataclysmic binaries
that were discovered through their X-ray emission. Time-resolved radial
velocity spectroscopy yields unambiguous orbital periods for eight objects and
ambiguous results for the remaining two. The orbital periods range from 87 min
to 9.38 hr. We also obtained time-series optical photometry for six targets,
four of which have coherent pulsations. These periods are 1218 s for 1RXS
J045707.4+452751, 628 s for AX J1740.2-2903, 477 s for AX J1853.3-0128, and 935
s for IGR J19267+1325. A total of seven of the sources have coherent
oscillations in X-rays or optical, indicating that they are intermediate polars
(DQ Herculis stars). Time-resolved spectroscopy of one object, Swift
J2218.4+1925, shows that it is an AM Herculis star, or polar, and IGR
J19552+0044 may also be in that class. For another object, Swift J0476.2-1611,
we find an orbital period of 9.384 hr and detect the spectrum of the secondary
star. The secondary's spectral contribution implies a distance of 900 (+190,
-150) pc, where the error bars are estimated using a Monte Carlo technique to
account for correlated uncertainties.

14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
22
The categories of this paper are: chao-dyn
24
The categories of this paper are: dg-ga
13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
3
The categories of this paper are: physics
20
The categories of this paper are: acc-phys
17
The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
5
The categories of this paper are: gr-qc