Quasars. Chapter 17. Topics. Quasars characteristics what are they? what is their energy source? where are they? how old are they? interactions of quasars and their light with other objects. Furthest known quasar (April, 2000) -- red shift 5.8
Age ~ less than 1 billion years after the universe began
High redshift! (Hmm...)
Luminosities up to1000 times normal galaxies
In visible light, they are brighter than brightest giant elliptical galaxies
Brighter than all other types of galaxies in gamma rays, X-rays, and infrared radiation
First discovered because of high radio emission; “radio quiet” quasars actually outnumber the “radio loud” quasars
Many exhibit emissions that vary in periods of days or weeks (Hmm...
Spectrum shows emission lines of elements such as carbon, magnesium, oxygen, helium, and hydrogen
Most also possess narrow absorption lines, usually with redshifts less than or equal to those of emission lines (Hmm...)
Discovered in 1960sQuasar Characteristics
was not ejected but just happens to appear along the same
line of sight.
Time delays of the light forming the four images produced by the gravitation of the red elliptical galaxy can be used to calculate the Hubble constant.