Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Probing X-ray emission in different modes of PSR J1023+0038 with a radio
  pulsar scenario   Transitional pulsars provide us with a unique laboratory to study the physics
of accretion onto a magnetic neutron star. PSR J1023+0038 (J1023) is the best
studied of this class. We investigate the X-ray spectral properties of J1023 in
the framework of a working radio pulsar during the active state. We modelled
the X-ray spectra in three modes (low, high, and flare) as well as in
quiescence, to constrain the emission mechanism and source parameters. The
emission model, formed by an assumed pulsar emission (thermal and
magnetospheric) plus a shock component, can account for the data only adding a
hot dense absorber covering ~30% of the emitting source in high mode. The
covering fraction is similar in flaring mode, thus excluding total enshrouding,
and decreases in the low mode despite large uncertainties. This provides
support to the recently advanced idea of a mini-pulsar wind nebula (PWN), where
X-ray and optical pulsations arise via synchrotron shock emission in a very
close (~100 km, comparable to a light cylinder), PWN-like region that is
associated with this hot absorber. In low mode, this region may expand,
pulsations become undetectable, and the covering fraction decreases.

32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
27
The categories of this paper are: comp-gas
21
The categories of this paper are: adap-org
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
2
The categories of this paper are: math
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
36
The categories of this paper are: cmp-lg
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
16
The categories of this paper are: stat
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg