The millisecond pulsar MAXI J1816--195 was recently discovered by MAXI in
2022 May. We have studied different properties of the pulsar using data from
NuSTAR and NICER observations. The position of the source is measured by NuSTAR
as RA = 18h16m52s.40, Dec = −19o37′58′′.35. The unstable
burning of accreted material on the surface of neutron stars induces
thermonuclear (Type-I) bursts. Several thermonuclear bursts have been detected
from the source during the outburst. We study the evolution of burst profile
with flux and energy using NuSTAR and NICER observations. During the NuSTAR
observation, a total of four bursts were detected from the source. The duration
of each burst was around ∼ 30 s and the ratio of peak to persistent count
rate is ∼ 26 as seen from the NuSTAR data. The thermonuclear bursts are
modeled to determine the burst timing parameters using a sharp linear rise and
exponential decay function. The burst profiles show a relatively long tail in
lower energies. The hardness ratio during the thermonuclear bursts shows
significant variation as observed by NuSTAR. We successfully model the
broadband burst-resolved spectra with a combination of an absorbed blackbody
along with a non-thermal component to account for the persistent emission. The
burst-resolved spectral parameters show significant evolution during the burst.
During the peak of the burst, the Eddington luminosity is found to be ∼3.7×1038 erg s−1. The burst-resolved spectral parameters provide a
source distance of 8.5±1.2 kpc for isotropic burst emission.Comment: 13 pages, 9 figures, 4 tables, comments are welcom