Speaker
Description
We present a detailed analysis of the dark matter distribution and disk
stability of the dwarf irregular galaxy NGC 3741 using multi-wavelength
observations. HI, optical, and near-ultraviolet (NUV) imaging data were
retrieved from the SkyView Virtual Observatory, providing a comprehen
sive view of both the gaseous and stellar components.
Using the HI surface density and rotation curve data available from
the literature, we estimate the dynamical mass distribution, revealing a
total dark matter mass of ∼ 3.1 × 109M⊙ within the observed HI disk,
corresponding to a dark matter to baryon ratio of ∼ 18. The extended HI
disk permits the calculation of the Toomre stability parameter, showing
that the gas disk is globally stable against axisymmetric collapse (Q > 1).
Turbulent pressure, estimated from the observed HI velocity dispersion
(σg ∼ 8kms−1), contributes significantly to this stability, consistent with
the low star formation efficiency observed in this system.
Our results demonstrate that NGC 3741 is strongly dark matter dom
inated, and that turbulence and differential rotation provide sufficient
support to stabilize its extended gaseous disk. This study highlights the
importance of multi-wavelength observations in understanding the dy
namical structure and internal pressure support mechanisms in gas-rich
dwarf irregular galaxies.