Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Spinning dust emission from ultrasmall silicates: emissivity and
  polarization spectrum   Anomalous microwave emission (AME) is an important Galactic foreground of
Cosmic Microwave Background (CMB) radiation. It is believed that the AME arises
from rotational emission by spinning polycyclic aromatic hydrocarbons (PAHs) in
the interstellar medium (ISM). In this paper, we assume that a population of
ultrasmall silicate grains may exist in the ISM, and quantify rotational
emissivity from these tiny particles and its polarization spectrum. We found
that spinning silicate nanoparticles can produce strong rotational emission
when those small grains follow a log-normal size distribution. The polarization
fraction of spinning dust emission from tiny silicates increases with
decreasing the dipole moment per atom ($\beta$) and can reach $P\sim 20\%$ for
$\beta\sim 0.1$D at grain temperature of 60 K. We identify a parameter space
$(\beta,Y_{Si})$ for silicate nanoparticles in which its rotational emission
can adequately reproduce both the observed AME and the polarization of the AME,
without violating the observational constraints by the ultraviolet extinction
and polarization of starlight. Our results reveal that rotational emission from
spinning silicate may be an important source of the AME.

18
The categories of this paper are: econ
10
The categories of this paper are: q-bio
8
The categories of this paper are: hep-ex
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs
17
The categories of this paper are: q-fin
16
The categories of this paper are: stat
37
The categories of this paper are: supr-con
4
The categories of this paper are: cond-mat
14
The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
26
The categories of this paper are: bayes-an
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol