Struttura iperfina della Via Lattea a 1420 MHz

The purpose of this work is to obtain the curve of rotation of the Milky Way, to map the spiral structure of the Galaxy in the I and II quadrant with a thin division and to determine the integral mass; all this is done through the study of the galactic hydrogen concentration.
The data, obtained by the radio telescope Salsa Onsala in Sweden, refer to several observations done between December 2012 and April 2013. For the elaboration of those data, which were the spectrum of the radiation, the software SalsaJ was used.
The result of this study confirms that the matter velocity, far away from the galactic center, does not decrease, but remains the same. The distribution of the hydrogen is not uniform: it is concentrated in filamentary structures, which are considered an evidence of the presence of a spiral structure. And the mass of the Galaxy is confront with historical data.