Planetary Nebulae Shane Fogerty AST453 - PowerPoint PPT Presentation

Planetary Nebulae Shane Fogerty AST453 10/25/2012

Outline ● History ● Basics of PN ● Simple Model ● Forbidden Lines ● Morphology

His History tory ● Famously sly, W , Will lliam He Hersch schel sa saw w th these fu fuzz zzy o y objects cts th through h his te telesco cope in in 1785. S Since ce t they l y looked si simila lar to to pla lanets ts, , he d dubbed th these se objects “ cts “Planeta tary N Nebula lae” ● The fi first P st PN we N were d disco covered b by Messie sier ● The n name “ “Pla laneta tary Ne Nebula” i is a a m misn isnomer ● Emiss ission l lin ines we s were th theorized a as a an o obse serva vati tion o of f a n new w ele lement: t: “nebuliu ium” ( (500.7 n nm) ● 60 ye years l later, , Ir Ira S S. B . Bowe wen d demonstr trate tes th s this l s lin ine co comes s fr from Oxy Oxygen in in sp special cir circumsta stance ces ( s (fo forbidden li line) ● In In th the 1 1930s, W Wil ilso son o obse serve ves th s the Do Dopple ler shift ft o of f PN t N to co conclude t that t th they are e expanding ● An understa standing of n f nucle cleosy synth thesis and ste stella lar e evo volutio ion help co complete te th the p pictu icture o of f planeta tary n y nebula lae

Basics of Planetary Nebulae

Basics of Planetary Nebulae

Forbidden Lines ● Ions like OIII get excited into a metastable state ● In a very rarefied medium, this ion will be able to release energy by emitting a photon

Simple Wind Model ● A fast(~1000km/s) wind catches up to and interacts with the AGB star's previous slow(10- 15km/s), more dense wind Kwok ok et et al al (1978) 1978)

Morphologies

Morphologies ● Supe uper-w r-wind ind is is no not sp t spher herica ically lly sym symmetr etric ic ● What hat co could uld ca caus use th e this? is? M Mag ag field fields? s? B Bina inaries ries?

Morphologies – Magnetic Fields? ● Garci arcia-S a-Seg egura ura (1 (1999 999) sh ) show ow th that m at magne gnetic tic fiel fields ds co could uld sh shap ape ou e outfl tflows ows, p , prov rovide ided la d larg rge-sc e-scale ale fie fields lds or or lots lots of of rot rotatio ation ● No Nordh rdhau aus e s et al t al. (2 . (2007 007) a ) and nd So Soker ker (20 (2006 06) ad ) adde ded d feedb fee dback ack to to the these se m mode odels a ls and nd sh show ow tha that th t thes ese e fie fields lds mu must st be be sho short- rt-live lived (~ d (~100 00 ye years ars) ● Singl ingle e AGB GB s stars tars ar are c e con onside sidered red un unab able t le to o ma maint intain ain the the m mag agneti netic fi c field elds n s nece ecess ssary ary to to co collim llimat ate th e the o e outf utflow lows to s to m matc atch o h obs bserva ervatio tions ns

Morphologies – Binaries? ● A companion star could shape the outflowing material in an axisymmetric way ● There are many different scenarios (close companion, far, merger...) that have been theoretically investigated (Blackman, Nordhaus, Frank)

Binaries or Single Stars? ● Both. oth. O Obse bserva rvatio tional nal sur surve veys i ys inve nvesti stigat gated ed cen centra tral l st stars ars wi within thin PN PN a and nd fou found nd bin binarie aries s <2 <25% 5% ● Ma Many ny of of the the co comp mpani anions ons h had p ad peri eriod ods o s of < f <3 d 3 day ays ● Co Collim llimat ation ion is is mo more re corr correla elated ted wi with th cen central tral st star ar mass ma ss th than b an bina inarity rity ● Theo eorie ries m s must ust ex expla plain P in PN for forma matio tion fo n for bo r both th bi binari naries es and and si sing ngle s le stars tars

References ● Ba Balic lick 1987 87, “The e evolu olution ion of of pla planet etary ry ne nebula ulae e I: St Structure res, io ioniz izat ation ions, an and d mor orph pholog logic ical al seq equen ences es”, Ap ApJ ● Ku Kudrit ritzki i & & Pu Puls ls 200 000, “Wind inds from om ho hot stars rs”, ARAA AA ● De Marc rco o 200 009, “The e orig rigin in and d shap aping ing of of pla planet etary ry ne nebula ulae: e: Pu Puttin ing g the e bina inary ry hypo pothe hesis is to the e test”, Public licatio ions ns of of the he As Astro rono nomic ical l So Societ iety of the he Pa Pacif ific ic ● Ba Balic lick & & Frank nk 200 002, 2, “S “Sha hape pes and d Sh Shap aping ing of of plan lanet etary ry neb ebula ulae”, ”, AR ARAA AA ● Corr rrad adi i & & Sc Schwarz rz 19 1995 95, “M “Mor orph pholog logic ical al pro roge genit itors of pla lane netar ary nebu bulae lae: whic hich h pro rogen enit itor ors? ? I. Compar arit itiv ive e pro roper erties of of bipolar lar ne nebu bula lae” e”, A&A A&A ● Kw Kwok & & Pu Purt rton n 197 978, 8, “On On the origin igin of of pl plan anet etary ry neb ebula ulae” e”, ApJ ApJ ● Vide ideos fro rom http: p://www.cas astler lerock.wed ednet et.ed edu/HS/ S/stello ello/As Astron onomy/ TEXT EXT/CHAISSO SSON/BG3 G312 12/HTML/BG3 BG312 1203. 3.htm ● Images es fro rom Wik ikipe ipedia ht http://en. n.wik ikipe ipedi dia. a.or org/wik iki/ i/Plan Planetary_n _neb ebula ula, Bru Bruce e Ba Balic lick's 's pag age http: p://www.astro. o.washin hingt gton. n.edu du/us users rs/ba balic lick/WFPC PC2/ 2/ind index.html, l, http://skyser erver er.sds dss.or org/ g/dr1 r1/en/ n/as astro/ o/star ars/stars rs.as asp, and d http://www.uc ucl. l.ac.uk/star/ r/res esear arch/ h/star ars_g _galaxie ies/PN PNe