2010AJ....139.2241M

We present measurements of carbon monoxide emission in the central region of the nearby starburst NGC 6000 taken with the Submillimeter Array. The J = 2-1 transition of ¹²CO, ¹³CO, and C¹⁸O were imaged at a resolution of ∼3''x2'' (450x300 pc). We accurately determine the dynamical center of NGC 6000 at α_J2000.0= 15^h49^m49.^s5 and δ_J2000.0 = -29°23'13'' which agrees with the peak of molecular emission position. The observed CO dynamics could be explained in the context of the presence of a bar potential affecting the molecular material, likely responsible for the strong nuclear concentration where more than 85% of the gas is located. We detect a kinematically detached component of dense molecular gas at relatively high velocity which might be fueling the star formation. A total nuclear dynamical mass of 7x10⁹ M_☉ is derived and a total mass of gas of 4.6x10⁸ M_☉, yielding a M_gas/M_dyn∼ 6%, similar to other previously studied barred galaxies with central starbursts. We determined the mass of molecular gas with the optically thin isotopologue C¹⁸O and we estimate a CO-to-H₂ conversion factor X_CO= 0.4x10²⁰/cm2(K km/s)^–1 in agreement with that determined in other starburst galaxies.