Neutron stars and pulsars are associated with

it is very well related to a lot of things but with my limited knowledge i can confidently say that the answer is space.

i guess that visual aids present persuasive examples to what you are presenting, some factors would be theme (does it fit with the color, information, what you are presenting), size (can you see it, is it a big enough span of data/information), and overall look of the visual aid.

hope this : )