▁Several ▁types ▁of ▁ast ro phys ical ▁objects ▁emit , ▁flu ores ce , ▁or ▁reflect ▁X - ray s , ▁from ▁galax y ▁clusters , ▁through ▁black ▁holes ▁in ▁active ▁gal actic ▁nuc lei ▁( AG N ) ▁to ▁gal actic ▁objects ▁such ▁as ▁super n ova ▁rem n ants , ▁stars , ▁and ▁binary ▁stars ▁containing ▁a ▁white ▁d war f ▁( c ata c ly sm ic ▁variable ▁stars ▁and ▁super ▁soft ▁X - ray ▁sources ), ▁neut ron ▁star ▁or ▁black ▁hole ▁( X - ray ▁bin aries ). ▁Some ▁solar ▁system ▁bodies ▁emit ▁X - ray s , ▁the ▁most ▁notable ▁being ▁the ▁Moon , ▁although ▁most ▁of ▁the ▁X - ray ▁bright ness ▁of ▁the ▁Moon ▁ar ises ▁from ▁reflected ▁solar ▁X - ray s . ▁A ▁combination ▁of ▁many ▁un resol ved ▁X - ray ▁sources ▁is ▁thought ▁to ▁produce ▁the ▁observed ▁X - ray ▁background . ▁The ▁X - ray ▁continu um ▁can ▁arise ▁from ▁bre ms stra hl ung , ▁black - body ▁radiation , ▁syn ch ro tr on ▁radiation , ▁or ▁what ▁is ▁called ▁inverse ▁Com pton ▁scatter ing ▁of ▁lower - energy ▁phot ons ▁by ▁relativ istic ▁electrons , ▁knock - on ▁coll isions ▁of ▁fast ▁pro tons ▁with ▁atomic ▁electrons , ▁and ▁atomic ▁recom bin ation , ▁with ▁or ▁without ▁additional ▁electron ▁trans itions . ▁ ▁An ▁intermediate - mass ▁X - ray ▁binary ▁( IM X B ) ▁is ▁a ▁binary ▁star ▁system ▁where ▁one ▁of ▁the ▁components ▁is