Galactic black hole candidate MAXI~J1348-630 was recently discovered by { \it MAXI} and { \it Swift}/BAT satellites during its first outburst in 2019 January which continued for $\sim4$ months. We study the spectral and timing properties of the source in detail. The combined $1-150$ keV { \it Swift}/XRT, { \it Swift}/BAT and { \it MAXI}/GSC spectra are investigated with the two component advective flow (TCAF) solution. Physical flow parameters of TCAF, such as the Keplerian disk accretion rate, the sub-Keplerian halo accretion rate, the shock location and the shock compression ratio are estimated from our spectral fits. Based on the variation of flux in soft and hard X-ray ranges, the hardness ratio, TCAF model fitted accretion rates and accretion rate ratio (ARR), we show how the sources evolved through four spectral states viz. hard, hard-intermediate, soft-intermediate and soft states in rising and declining states. Low-frequency quasi-periodic oscillations (QPO) are observed in two observations during the rising phase of the outburst. From the spectral analysis, we estimate the mass of the black hole to be $9.1^{ +1.6}_{ -1.2}$ $M_{ \odot}$. We also find that the viscous timescale in this outburst is $\sim 3.5$ days. The distance of the source is also estimated as $5-10$ kpc from state transition luminosity.
Categories: astro-ph.HE