NuSTAR and AstroSat observations of GX 9$+$1: Spectral and temporal studies

We have studied the spectro-temporal properties of the neutron star low mass X-ray binary GX 9$+$1 using data from $\mathit{\text{NuSTAR/FPM}}$ and $\mathit{\text{AstroSat/SXT}}$ and $\mathit{\text{LAXPC}}$. The hardness-intensity diagram of the source showed it to be in the soft spectral state during both observations. $\mathit{\text{NuSTAR}}$ spectral analysis yielded an inclination angle ($\theta$) $=$ 29${\begin{array}{c}+3\\ -4\end{array}}^{\circ }$ and inner disk radius ($R_{in}$) $\le$ 19.01 km. Assuming that the accretion disk was truncated at the Alfvén radius during the observation, the upper limit of the magnetic dipole moment ($\mu$) and the magnetic field strength ($B$) at the poles of the neutron star in GX 9$+$1 were calculated to be 1.45$\times$${10}^{26}$ G cm${}^3$ and 2.08$\times$${10}^8$ G, respectively (for $k_A$ $=$ 1). Flux resolved spectral analysis with $\mathit{\text{AstroSat}}$ data showed the source to be in the soft spectral state ($F_{disk}$/$F_{total}$ $\sim$0.9) with a monotonic increase in mass accretion rate ($\dot{m}$) along the banana branch. The analysis also showed the presence of absorption edges at $\sim$1.9 and $\sim$2.4 keV, likely due to Si XIII and S XV, respectively. Temporal analysis with $\mathit{\text{LAXPC-20}}$ data in the 0.02 $-$ 100 Hz range revealed the presence of noise components, which could be characterized with broad Lorentzian components.