Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The imprint of the crustal magnetic field on the thermal spectra and
  pulse profiles of isolated neutron stars   Isolated neutron stars (NSs) show a bewildering variety of astrophysical
manifestations, presumably shaped by the magnetic field strength and topology
at birth. Here, using state-of-the art calculations of the coupled magnetic and
thermal evolution of NSs, we compute the thermal spectra and pulse profiles
expected for a variety of initial magnetic field configurations. In particular,
we contrast models with purely poloidal magnetic fields to models dominated by
a strong internal toroidal component. We find that, while the former displays
double peaked profiles and very low pulsed fractions, in the latter, the
anisotropy in the surface temperature produced by the toroidal field often
results in a single pulse profile, with pulsed fractions that can exceed the
50-60% level even for perfectly isotropic local emission. We further use our
theoretical results to generate simulated "observed" spectra, and show that
blackbody (BB) fits result in inferred radii that can be significantly smaller
than the actual NS radius, even as low as ~ 1-2 km for old NSs with strong
internal toroidal fields and a high absorption column density along their line
of sight. We compute the size of the inferred BB radius for a few
representative magnetic field configurations, NS ages, and magnitudes of the
column density. Our theoretical results are of direct relevance to the
interpretation of X-ray observations of isolated NSs, as well as to the
constraints on the equation of state of dense matter through radius
measurements.

17
The categories of this paper are: q-fin
4
The categories of this paper are: cond-mat
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
2
The categories of this paper are: math
24
The categories of this paper are: dg-ga
18
The categories of this paper are: econ
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
23
The categories of this paper are: solv-int
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
3
The categories of this paper are: physics
12
The categories of this paper are: nucl-th
5
The categories of this paper are: gr-qc