Multiwavelength analysis of low surface brightness galaxies to study possible dark matter signature. (arXiv:1911.00369v2 [astro-ph.HE] UPDATED)
<a href="http://arxiv.org/find/astro-ph/1/au:+Bhattacharjee_P/0/1/0/all/0/1">Pooja Bhattacharjee</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Majumdar_P/0/1/0/all/0/1">Pratik Majumdar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Das_M/0/1/0/all/0/1">Mousumi Das</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Das_S/0/1/0/all/0/1">Subinoy Das</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Joarder_P/0/1/0/all/0/1">Partha S. Joarder</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Biswas_S/0/1/0/all/0/1">Sayan Biswas</a>
Low Surface Brightness (LSB) galaxies have very diffuse, low surface density
stellar disks which appear faint in optical images. They are very rich in
neutral hydrogen (HI) gas, which extends well beyond the stellar disks. Their
extended HI rotation curves and stellar disks indicate that they have very
massive dark matter (DM) halos compared to normal bright galaxies. Hence, LSB
galaxies may represent valuable laboratories for the indirect detection of DM.
In this paper, we search for WIMP annihilation signatures in four LSB galaxies
and present an analysis of nearly nine years of data from the Fermi Large Area
Telescope (LAT). Above 500 MeV, no excess emission was detected from the LSB
galaxies. We obtain constraints on the DM cross-section for different
annihilation channels, for both individual and stacked targets. In addition to
this, we use radio data from the Very Large Array (VLA) radio telescope in
order to derive DM constraints, following a multiwavelength approach. The
constraints obtained from the four considered LSB galaxies are nearly 3 orders
of magnitude weaker than the predicted limits for the thermal relic abundances
and the combined limits achieved from Fermi-LAT observations of dwarf
spheroidal galaxies. Finally, we discuss the possibility of detecting emission
from LSB galaxies using the upcoming ground-based $gamma$-ray and radio
observatories, namely the Cherenkov Telescope Array (CTA) and the Square
Kilometre Array (SKA).
Low Surface Brightness (LSB) galaxies have very diffuse, low surface density
stellar disks which appear faint in optical images. They are very rich in
neutral hydrogen (HI) gas, which extends well beyond the stellar disks. Their
extended HI rotation curves and stellar disks indicate that they have very
massive dark matter (DM) halos compared to normal bright galaxies. Hence, LSB
galaxies may represent valuable laboratories for the indirect detection of DM.
In this paper, we search for WIMP annihilation signatures in four LSB galaxies
and present an analysis of nearly nine years of data from the Fermi Large Area
Telescope (LAT). Above 500 MeV, no excess emission was detected from the LSB
galaxies. We obtain constraints on the DM cross-section for different
annihilation channels, for both individual and stacked targets. In addition to
this, we use radio data from the Very Large Array (VLA) radio telescope in
order to derive DM constraints, following a multiwavelength approach. The
constraints obtained from the four considered LSB galaxies are nearly 3 orders
of magnitude weaker than the predicted limits for the thermal relic abundances
and the combined limits achieved from Fermi-LAT observations of dwarf
spheroidal galaxies. Finally, we discuss the possibility of detecting emission
from LSB galaxies using the upcoming ground-based $gamma$-ray and radio
observatories, namely the Cherenkov Telescope Array (CTA) and the Square
Kilometre Array (SKA).
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