Chapter14:Galaxies withActive Nuclei有活动核的星系2006Brooks/Cole-Thomson
Galaxies with Active Nuclei 有活动核的星系 Chapter 14:
ActiveGalaxies活动星系Galaxies with extremely violent energy release intheirnuclei (pl.of nucleus)核区活动剧烈（释放巨大能量→“activegalacticnuclei"(=AGN)活动星系核Uptomanythousandtimesmoreluminousthanthe entire Milky Wayenergyreleased withinaregionapprox.thesizeof our solarsystem!在太阳系大小的范围内，释放的能量可达银河系总能量的几千倍Quasar3c175YLA6cmimage(C)NRAO 1996
Active Galaxies 活动星系 Galaxies with extremely violent energy release in their nuclei (pl. of nucleus). 核区活动剧烈（释放巨大能量） → “active galactic nuclei” (= AGN) 活动星系核 Up to many thousand times more luminous than the entire Milky Way; energy released within a region approx. the size of our solar system! 在太阳系大小的范围内，释放的能量 可达银河系总能量的几千倍
LineSpectraofGalaxies星系线光谱Takingaspectrumofthelightfromanormal galaxy:正常星系的光谱LangWoaelgsgocunThe light fromthegalaxy should bemostly starlight,and should thuscontainmanyabsorptionlinesfromtheindividualstellarspectra多是恒星光，有很多吸收线
Line Spectra of Galaxies 星系线光谱 Taking a spectrum of the light from a normal galaxy: 正常星系的光谱 The light from the galaxy should be mostly star light, and should thus contain many absorption lines from the individual stellar spectra. 多是恒星光，有很多吸收线
Seyfert GalaxiesUnusualspiralgalaxies不寻常的漩涡星系·Verybrightcores非常亮的核·Emissionlinespectra发射线光谱·Variability:~50%in a fewmonths光变Most likelypowersourceNGC1566最可能的能源：Accretiononto a supermassive blackhole (~107-108Msun)超大质量黑洞吸积物质Circinus GalaxyNGC7742
Seyfert Galaxies NGC 1566 Circinus Galaxy Unusual spiral galaxies: 不寻常的漩涡星系 • Very bright cores 非常亮的核 • Emission line spectra 发射线光谱 • Variability: ~ 50 % in a few months 光变 Most likely power source 最可能的能源: Accretiononto a supermassive black hole (~107 – 108 Msun) 超大质量黑洞吸积物质 NGC 7742
相互作用星系InteractingGalaxiesSeyfertgalaxyNGC7674SeyfertgalaxyNGC7674isSeyfertgalaxy3C219distortedwithfainttidaltailsTidal tailVisual (blue)+radio(redandyellow)9100km/s8620km/sSeyfertgalaxy3C219isejectingmatterinjetsfromatinyactivenucleus8700km/s8200km/sActivegalaxiesareoftenassociatedwithinteractinggalaxies,possiblyresultofrecentgalaxymergers活动星系经常和相互作用星系有联系
Interacting Galaxies 相互作用星系 Seyfert galaxy NGC 7674 Active galaxies are often associated with interacting galaxies, possibly result of recent galaxy mergers. 活动星系经常和相互作用星 系有联系 Seyfert galaxy 3C219