2018 21st International Conference of Computer and Information Technology (ICCIT), 21-23 December, 2018 SALSA is an ICT based educational tool for Astrophysics students to study structure and dynamics of Milky Way Galaxy 1 st Mir Sakhawat Hossain Department of Mathematics Kabi Nazrul Government College Dhaka, Bangladesh s.hossain18@gmail.com 2 nd Banrupa Mallik Department of Physics Begum Badrunnessa Govt. Girls College Dhaka, Bangladesh banrupamallik@gmail.com Abstract—After the discovery of radiation from Galactic Hy- drogen gas clouds in 1951, the 21cm wavelength HI line had become the best marker to study spectral profiles in radio astronomy. It has been utilized as an important tracer for the distribution and velocity of molecular gas clouds in the Interstel- lar that has helped enormously in the understanding of galactic structure. ICT based astronomy and astrophysics tools have been developed for decades for undergraduate level use including radio telescopes controllable over the Internet at minimal cost. These radio telescopes can effectively be used to study galactic structure and dynamics. This paper presents an observation to study galaxy dynamics and map its spiral structure which was carried out between galactic coordinate longitudes 6° to 225° and latitudes 0° to 35° with two low cost 2.3 meters Haystack model type radio frequency receiving systems called SALSA radio telescopes at Onsala Space Observatory in Sweden which is maintained by Chalmers University of Technology. Components of the velocity of Hydrogen gas clouds were calculated using different galactic longitudes and latitudes as a function of galactic distance from the center to plot spiral galactic arms and rotation curves. This radio observational experiment was done by remote operation over the Internet in frequency switching mode. Our project aims to prove the quality and importance of this type of ICT based tools for astronomical education and citizen science. Index Terms—Open Educational Resources, STEM, Educa- tional technology, Physics education, Student experiments I. I NTRODUCTION Neutral Hydrogen(HI) at the ground state level is an abundant and uniformly distributed element throughout the interstellar medium(ISM). It is the most ubiquitous element in interstellar low-density regions but can be detected in λ ≈ 21 cm or ≈ 1420 MHz where H 2 is symmetric but not detectable at the radio frequencies [1]. In 1933, Karl Guthe Jansky detected first extraterrestrial radio frequency [2]. In 1945 then Van de Hulst predicted 21 cm wavelength emission [3]. The same frequency line is also detected by Muller and Oort [4] in the same year. A preliminary survey was made by Christiansen and Hindman [5] in Australia. They made this survey with a 7.5-m paraboloid and movable radio antenna that had a beam width between half power with direction of 1.9° horizontally Chalmers University of Technology, Onsala, Sweden. and 2.7° vertically and it covered galactic longitudes -10° to +10° in the galactic plane. In Netherlands, Muller and West- erhout [6] took an extended neutral HI line profile survey and made a catalog approximately in galactic latitude ±20° and longitude 318° to 220°. Within these periods angular resolution has been developed from 30° to 30 -µas [7], [8]. Recently all- sky mapping in HI line based on EBHIS and GASS has been completed [9] with angular resolution 16.2 ′′ and sensitivity σ rms = 43 mK. Santo and Ashraf carried out a galactic survey to map the Milky Way galaxy in galactic longitudes 0° to 225° in the galactic plane [10] using SALSA radio telescope which was built for EU HOU project [11]. Considering this observation we have accomplished our observation using the SALSA radio telescope in extended galactic coordinates i.e., galactic longitudes 6° to 225° and latitudes 0° to 35°. We have discussed here SALSA Radio Telescope, Basic block diagram of a SALSA type telescope, galactic geometry for observable parameters, observation details, data analysis and results with plotting and importance of this project. II. SALSA RADIO TELESCOPE A. Basic Details of SALSA SALSA is a part of the European Hands-On Universe project(EU-HOU) [12] designed to bring interactive lessons of astronomy to the classroom [13]. There are two SALSA telescopes with the same specification see Table I [14]. Anyone can control these telescopes using Internet browser by log in https://vale.oso.chalmers.se/salsa/ for free at any time. The telescope is composed of several main components: • A 2.3 meter satellite dish on a fully steerable, motorized azimuth-elevation mount • A rotor controller to run the motors which steer the telescope • A feed composed of a helical antenna backed by a cavity • A super-heterodyne receiver providing 10 MHz band- width centered on the 1420.4 MHz (21-cm) hydrogen line • A low-noise amplifier • A/D conversion on a dedicated PCI card 978-1-5386-9242-4/18/$31.00 ©2018 IEEE