Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The properties and origin of magnetic fields in white dwarfs   A significant fraction of white dwarfs harbour a magnetic field with
strengths ranging from a few kG up to about 1000 MG. The fraction appears to
depend on the specific class of white dwarfs being investigated and may hold
some clues to the origin of their magnetic field. The number of white dwarfs
with variable fields as a function of their rotation phase have revealed a
large field structure diversity, from a simple offset dipole to structures with
spots or multipoles. A review of the current challenges in modelling white
dwarf atmospheres in the presence of a magnetic field is presented, and the
proposed scenarios for the formation of magnetic fields in white dwarfs are
examined.

17
The categories of this paper are: q-fin
15
The categories of this paper are: nucl-ex
0
The categories of this paper are: hep-ph
30
The categories of this paper are: q-alg
22
The categories of this paper are: chao-dyn
8
The categories of this paper are: hep-ex
31
The categories of this paper are: ao-sci
13
The categories of this paper are: quant-ph
9
The categories of this paper are: nlin
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph