Constraining Dark matter annihilation with Dark Energy Survey Y3 LSBG
  sample
  To reveal natures of the dark matter (DM) particles, a gamma-ray signal
produced in annihilation processes of DM into the standard model particles has
been one of the major probes. The cross-correlation between highly DM dominated
structures, such as local dwarf galaxies, and observed photons in the direction
of the structures, has been explored and provided stringent constraints on the
annihilation rate. In our previous work, we have shown that it is sufficient to
know the distance distribution of the galaxy sample and individual distance
measurement is not required for constraining the annihilation rate. In this
work, we apply the method to low-surface brightness galaxies (LSBGs) with
unknown individual redshifts provided from the Dark Energy Survey (DES) Year 3
data. With all DES-LSBGs of about 24,000 objects, we find that the upper limits
of the cross section for bb channel with 95% C.L. is 3*10^-25 cm^3/s at DM mass
of 100 GeV. To be more conservative, we remove about 7000 LSBGs within 1 degree
from resolved gamma-ray point sources and then the constraint becomes 30 %
weaker than the one with all samples in all DM mass ranges.
