Bremsstrahlung radiation | COSMOS - Centre for Astrophysics ...

The word “Bremsstrahlung” is a German word meaning “braking radiation,” which refers to the way in which electrons are “braked” when they hit a metal target. Swinburne CentreforAstrophysicsandSupercomputing SwinburneAstronomyOnline Search Index ABCDE FGHIJ KLMNO PQRST UVWXY ZAll COSMOS-TheSAOEncyclopediaofAstronomy›B Bremsstrahlungradiation Bremsstrahlungradiationistheradiationgivenoffbyachargedparticle(mostoftenanelectron)duetoitsaccelerationcausedbyanelectricfieldofanotherchargedparticle(mostoftenaprotonoranatomicnucleus).Theword“Bremsstrahlung”isaGermanwordmeaning“brakingradiation,”whichreferstothewayinwhichelectronsare“braked”whentheyhitametaltarget.Theincidentelectronsarefree,meaningthey’renotboundtoanatomorion,bothbeforeandafterthebraking.Consequently,thiskindofradiation’sspectrumiscontinuous(unlikeatomicspectra,whichcontainsharpspectrallines)andsometimesreferredtoas“free-free”radiation.Iftheenergyoftheincidentelectronsishighenough,theyemitX-raysaftertheyhavebeenbraked. OneofthemostinterestingexamplesofBremsstrahlungradiationintheuniverseisthatcomingfromthehotintraclustergasofgalaxyclusters.Inthiscase,theelectronsdon’tbounceoffametaltargetbutaredeflectedbytheelectricfieldofprotons.ThegashasX-rayluminositiesoftoW(roughly10billionto1trilliontimestheluminosityofthesun!)andtemperaturesontheorderof10millionK.X-raytelescopescandetectthisradiationasdiffuselight,asseenintheimageoftheComacluster(belowleft). ChandraX-rayimageoftheComaclusterofgalaxies.Thetwolargewhitedotsintheimagearethetwobigellipticalgalaxiesseenintheopticalimage(right).Credit:NASA/CXC/SAO/A.Vikhlininetal. HubbleimageofComa.Credit:OmarLopez-Cruz&IanShelton/NOAO/AURA/NSF StudyAstronomyOnlineatSwinburneUniversity Allmaterialis©SwinburneUniversityofTechnologyexceptwhereindicated.