Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Clustering of galaxies around GRB sight-lines   There is evidence of an overdensity of strong intervening MgII absorption
line systems distributed along the lines of sight towards GRB afterglows
relative to quasar sight-lines. If this excess is real, one should also expect
an overdensity of field galaxies around GRB sight-lines, as strong MgII tends
to trace these sources. In this work, we test this expectation by calculating
the two point angular correlation function of galaxies within
120$^{\prime\prime}$ ($\sim470~h_{71}^{-1}~\mathrm{Kpc}$ at $\langle z\rangle
\sim0.4$) of GRB afterglows. We compare the Gamma-ray burst Optical and
Near-infrared Detector (GROND) GRB afterglow sample -- one of the largest and
most homogeneous samples of GRB fields -- with galaxies and AGN found in the
COSMOS-30 photometric catalog. We find no significant signal of anomalous
clustering of galaxies at an estimated median redshift of $z\sim0.3$ around GRB
sight-lines, down to $K_{\mathrm{AB}}<19.3$. This result is contrary to the
expectations from the MgII excess derived from GRB afterglow spectroscopy,
although many confirmed galaxy counterparts to MgII absorbers may be too faint
to detect in our sample -- especially those at $z>1$. We note that the addition
of higher sensitivity Spitzer IRAC or HST WFC3 data for even a subset of our
sample would increase this survey's depth by several orders of magnitude,
simultaneously increasing statistics and enabling the investigation of a much
larger redshift space.}

15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
33
The categories of this paper are: plasm-ph
8
The categories of this paper are: hep-ex
7
The categories of this paper are: hep-th
28
The categories of this paper are: alg-geom
32
The categories of this paper are: atom-ph
11
The categories of this paper are: hep-lat
3
The categories of this paper are: physics
2
The categories of this paper are: math
22
The categories of this paper are: chao-dyn
37
The categories of this paper are: supr-con
21
The categories of this paper are: adap-org
12
The categories of this paper are: nucl-th