Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Resolving the Host Galaxy of a Distant Blazar with LBT/LUCI1 + ARGOS   BL Lac objects emitting in the Very High Energy (VHE) regime are unique tools
to peer into the properties of the Extragalactic Background Light (EBL).
However, due to the typical absence of features in their spectra, the
determination of their redshifts has proven challenging. In this work we
exploit the superb spatial resolution delivered by the new Advanced Rayleigh
guided Ground layer adaptive Optics System (ARGOS) at the Large Binocular
Telescope to detect the host galaxy of HESS J1943+213, a VHE emitting BL Lac
shining through the Galaxy. Deep H-band imaging collected during the ARGOS
commissioning allowed us to separate the contribution of the nuclear emission
and to unveil the properties of the host galaxy with unprecedented detail. The
host galaxy is well fitted by a S\'ersic profile with index of n~2 and total
magnitude of H~16.15 mag. Under the assumption that BL Lac host galaxies are
standard candles, we infer a redshift of z~0.21. In the framework of the
current model for the EBL, this value is in agreement with the observed dimming
of the VHE spectrum due to the scatter of energetic photons on the EBL.

7
The categories of this paper are: hep-th
23
The categories of this paper are: solv-int
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
37
The categories of this paper are: supr-con
18
The categories of this paper are: econ
3
The categories of this paper are: physics
16
The categories of this paper are: stat
15
The categories of this paper are: nucl-ex
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
14
The categories of this paper are: math-ph
20
The categories of this paper are: acc-phys
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The categories of this paper are: gr-qc
32
The categories of this paper are: atom-ph