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

• bse

serva vati tion o

• f

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

• bse

serve ves th s the Do Dopple ler shift ft o

• f

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

• f

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

• k 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

• w th

that m at magne gnetic tic fiel fields ds co could uld sh shap ape ou e outfl tflows

• ws, p

, prov rovide ided la d larg rge-sc e-scale ale fie fields lds

• r
• r lots

lots of

• f 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 fee feedb dback ack to to the these se m mode

• dels a

ls and nd sh show

• w 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

• nside

sidered red un unab able t le to

• 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.
• th. 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

• f the

the co comp mpani anions

• ns h

had p ad peri eriod

• ds 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 ma mass 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

• lution

ion of

• f pla

planet etary ry ne nebula ulae e I: St Structure res, io ioniz izat ation ions, an and d mor

• rph

pholog logic ical al seq equen ences es”, Ap ApJ

• Ku

Kudrit ritzki i & & Pu Puls ls 200 000, “Wind inds from

• m ho

hot stars rs”, ARAA AA

• De Marc

rco

• 200

009, “The e orig rigin in and d shap aping ing of

• f 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

• f 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

• f plan

lanet etary ry neb ebula ulae”, ”, AR ARAA AA

• Corr

rrad adi i & & Sc Schwarz rz 19 1995 95, “M “Mor

• rph

pholog logic ical al pro roge genit itors of pla lane netar ary nebu bulae lae: whic hich h pro rogen enit itor

• rs?

? I. Compar arit itiv ive e pro roper erties of

• f 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

• f 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

• nomy/

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

• rg/wik

iki/ i/Plan Planetary_n _neb ebula ula, Bru Bruce e Ba Balic lick's 's pag age http: p://www.astro.

• .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

• rg/

g/dr1 r1/en/ n/as astro/

• /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