ALMA (Atacama Large Millimeter/sub-millimeter Array) is by far the largest project of current ground-based observational facilities in astronomy and astrophysics. It is built and operated as a world-wide cooperation (ESO, NRAO, NAOJ) at an altitude of 5000m in the Atacama desert, Chile. Because of its unprecedented capabilities, ALMA is considered as a cutting-edge research device in astrophysics with potential for many breakthrough discoveries in the next decade and beyond. Despite not being a facility dedicated for solar research, science observations of the Sun are now possible and have already started in the current observing Cycle 4 (2016-2017). Recent commissioning of this specific solar ALMA observing mode should be counted as an achievement of the international development team.
In order to facilitate user access to this top-class, but at the same moment very complicated device to researchers lacking technical expertise, a network of three ALMA Regional Centers (ARCs) has been formed in Europe (EU ARC), North America (NA ARC), and East Asia (EA ARC) as a user support infrastructure and interface between the observatory and the community. The EU ARC has been formed as a distributed network of seven nodes coordinated from ESO. The Czech node located at the Astronomical Institute in Ondrejov has a unique expertise in the solar research among the EU ARC network and the achievement mentioned above has been accomplished with significant contributions of its researchers.
After a short introduction to ALMA we will present the roles of ARC nodes and give hints on how to best use their services. The peculiarities of solar observations that required the development of specific Solar ALMA Observing Modes will be discussed and the results of science verification observing campaigns (solar ALMA maps) will be shown. Finally, a first analysis of the publicly available science verification data will be presented.