TUIMP: The Universe In My Pocket. Free astronomy booklets in all languages

TUIMP (www.tuimp.org) is an international project to produce little astronomy booklets. These booklets, folded from just one sheet of paper, can be used in classrooms, at open public conferences, or during visits of observatories and planetariums. They are free to download from the internet, the only thing which is needed is a color printer (in absence of a printer, the booklets can also be directly consulted on line, even with just a mobile phone). The booklets are intended for children from nine years old and for anyone curious of astronomy. They are written in a simple language, amply illustrated, revised and translated by professional astronomers. So far, they are being published in six languages, others languages are to come. Everyone is invited to download the booklets and use them in their outreach activities.Comment: to be published in the proceedings of the CAP2018 conference Communicating astronomy with the public in Fukuoka, Japa

The effects of spatially distributed ionisation sources on the temperature structure of HII region

Spatially resolved studies of star forming regions show that the assumption of spherical geometry is not realistic in most cases, with a major complication posed by the gas being ionised by multiple non-centrally located stars or star clusters. We try to isolate the effects of multiple non-centrally located stars on the temperature and ionisation structure of HII regions, via the construction of 3D photoionisation models using the 3D Monte Carlo photoionisation code MOCASSIN. We find that the true temperature fluctuations due to the stellar distribution (as opposed to the large-scale temperature gradients due to other gas properties) are small in all cases and not a significant cause of error in metallicity studies. Strong emission lines from HII regions are often used to study the metallicity of star-forming regions. We compare integrated emission line spectra from our models and quantify any systematic errors caused by the simplifying assumption of a single, central location for all ionising sources. We find that the dependence of the metallicity indicators on the ionisation parameter causes a clear bias, due to the fact that models with a fully distributed configuration of stars always display lower ionisation parameters than their fully concentrated counterparts. The errors found imply that the geometrical distribution of ionisation sources may partly account for the large scatter in metallicities derived using model-calibrated empirical methods.Comment: 13 pages, 6 figures, Accepted by MNRA