Sentence:  From the brightness of the F <WSD>component</WSD> of the solar corona and the brightness of the zodiacal light , an estimate of the particle sizes , concentrations , and spatial distribution can be derived for regions of space near the ecliptic plane . 
Meaning of the word marked with <WSD> tags:  an artifact that is one of the individual parts of which a composite entity is made up; especially a part that can be separated from or attached to a system