Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Revisiting the analysis of axion-like particles with the Fermi-LAT
  gamma-ray observation of NGC1275   In this work, we re-analyze the Fermi-LAT observation of NGC 1275 to search
for axion-like particle (ALP) effects and constrain ALP parameters. Instead of
fitting the observed spectrum with ALP models, we adopt an alternative method
for the analysis of this source which calculates the irregularity of the
spectrum. With the newly used method, we find no spectral oscillation for the
NGC 1275 and rule out couplings $g_{a\gamma}>3\times10^{-12}\,{\rm GeV^{-1}}$
around ALP mass of $m_a\sim$ 1 neV at 95\% confidence level, which is more
stringent than the previous results. We also show that the constraints can be
further improved by combining the observation of PKS 2155-304. We suggest that
with more sources taken into account, we could obtain a much wider exclusion
region.

32
The categories of this paper are: atom-ph
0
The categories of this paper are: hep-ph
10
The categories of this paper are: q-bio
37
The categories of this paper are: supr-con
24
The categories of this paper are: dg-ga
29
The categories of this paper are: funct-an
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
2
The categories of this paper are: math
27
The categories of this paper are: comp-gas
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
20
The categories of this paper are: acc-phys
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph