Eruptive Mass Loss in Massive Stars Nathan Smith - University of Arizona
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Transcript of Eruptive Mass Loss in Massive Stars Nathan Smith - University of Arizona
Eruptive Mass Loss in Massive StarsEruptive Mass Loss in Massive StarsNathan Smith Nathan Smith - University of Arizona - University of Arizona
OUTLINE
Intro: Mass Loss in Massive-Star EvolutionWinds vs. Eruptions: Mass/Metallicity dependence?
Lessons from Eta Carinae:1843 Eruption: Poster child for episodic mass loss events
Diversity of LBVs and Extragalactic Transients:
LBVs: Diversity of winds, eruptions, spectra.
Type IIn Supernovae and Circumstellar Gas: Pre-SN mass loss: Evidence for precursor LBV-like
eruptions.
Dust formation/survival in Type IIn SNe:Special circumstances: Dense CSM.
Intro: Mass Loss in Massive-Star EvolutionWinds vs. Eruptions: Mass/Metallicity dependence?
Lessons from Eta Carinae:1843 Eruption: Poster child for episodic mass loss events
Diversity of LBVs and Extragalactic Transients:
LBVs: Diversity of winds, eruptions, spectra.
Type IIn Supernovae and Circumstellar Gas: Pre-SN mass loss: Evidence for precursor LBV-like
eruptions.
Dust formation/survival in Type IIn SNe:Special circumstances: Dense CSM.
Single-star mass-loss(STELLAR WINDS and ERUPTIONS)
Binary-star mass-transfer(ROCHE LOBE OVERFLOW)
END FATES of MASSIVE STARS: What type of supernovafrom which type of star?
Type II-P II-L
IIb
Type Ib
Type Ic (GRB)
Mass loser
Mass gainer
Mass gainer
Heger et al.Woosley et al.Maeder & Meynet
Paczynski et al. 67; Podsiadlowski et al. 92Image courtesy M. Modjaz
Type IIn /Ibn
60 M
120 MLBV
WR
Mass loss and stellar evolution:
LBV winds/eruptions
SN Ib/cSN Ib/c
= L/4GMc
SUPER EDDINGTONCONTINUUM-DRIVENWINDS/OUTBURSTS
Smith & Owocki 2006Owocki et al. 2004Shaviv et al. 2001
SUPER EDDINGTONCONTINUUM-DRIVENWINDS/OUTBURSTS
Smith & Owocki 2006Owocki et al. 2004Shaviv et al. 2001
?
Theorists don’t know what makes LBVs erupt
??
120120
20 20
M/MM/M
t = 0t = 0 2.5-3 Myr2.5-3 Myr
WRWR
MS clumpedMS clumped
MS homogeneous
MS homogeneous
zero metallicity?zero metallicity?
(consequences of overestimated mass loss rates)
Evolutionary tracks for massive stars depend on adopted steady mass loss rates (e.g., Maeder & Meynet 1994, 2000, 2003; Heger et al. 2003).
Problem: more recent modeling of spectra of O stars winds find LOWER mass-loss rates than “standard” by factors of 3-10 or more. (Factor of >3; Bouret et al. 2005; Factor of >10; Fullerton et al. 2005).
Evolutionary tracks for massive stars depend on adopted steady mass loss rates (e.g., Maeder & Meynet 1994, 2000, 2003; Heger et al. 2003).
Problem: more recent modeling of spectra of O stars winds find LOWER mass-loss rates than “standard” by factors of 3-10 or more. (Factor of >3; Bouret et al. 2005; Factor of >10; Fullerton et al. 2005).
Why are O-star winds clumpy? See papers by Owocki & Rybicki and this morning’s talk by Sunqvist
Why are O-star winds clumpy? See papers by Owocki & Rybicki and this morning’s talk by Sunqvist
Smith & Owocki2006
Smith & Owocki2006
Single-Star Evolution
120120
20 20
M/MM/M
t = 0t = 0 2.5-3 Myr2.5-3 Myr
WRWR
MS clumpedMS clumped
MS homogeneous
MS homogeneous
LBVsLBVs
zero metallicity?zero metallicity?
Type IIn
Type Ib/c
Type IIn
Type Ib/c
Smith & Owocki2006
Smith & Owocki2006
(consequences of overestimated mass loss rates)
Single-Star Evolution
Evolutionary tracks for massive stars depend on adopted steady mass loss rates (e.g., Maeder & Meynet 1994, 2000, 2003; Heger et al. 2003).
Problem: more recent modeling of spectra of O stars winds find LOWER mass-loss rates than “standard” by factors of 3-10 or more. (Factor of >3; Bouret et al. 2005; Factor of >10; Fullerton et al. 2005).
Evolutionary tracks for massive stars depend on adopted steady mass loss rates (e.g., Maeder & Meynet 1994, 2000, 2003; Heger et al. 2003).
Problem: more recent modeling of spectra of O stars winds find LOWER mass-loss rates than “standard” by factors of 3-10 or more. (Factor of >3; Bouret et al. 2005; Factor of >10; Fullerton et al. 2005).
Ejected mass = 10-15 M
KE = 1049.6 - 1050 ergErad = 1049.7 erg
Ejected mass = 10-15 M
KE = 1049.6 - 1050 ergErad = 1049.7 erg
Eta Carinae’s1843 eruption:Eta Carinae’s1843 eruption:
Range of Ejecta Speed = 40 - 650 km/s
Follows a Hubble law
Range of Ejecta Speed = 40 - 650 km/s
Follows a Hubble law
2.122 m H2 1-0 S(1)1.644 m [Fe II]
Gemini South/Phoenix R=60,000
Smith (2006) ApJ, 644, 1151Smith (2006) ApJ, 644, 1151
KE/Erad ≈ 1KE/Erad ≈ 1 Wind or Explosion?Wind or Explosion?
DUST MASS
Md ~ 0.1-0.15 M in one event! (Smith et al.)
Up to Md ~ 0.4 M including previous events? (Gomez et al. 2011)
DUST MASS
Md ~ 0.1-0.15 M in one event! (Smith et al.)
Up to Md ~ 0.4 M including previous events? (Gomez et al. 2011)
Massive Dusty Molecular Shell
Smith & Ferland (2007, ApJ, 655, 911)Smith & Ferland (2007, ApJ, 655, 911)
CLOUDY models: survival of H2 requires a density of nH = 106.7-7 cm-3 in the outer shell, implying a total gas mass of 17-35 M.
CLOUDY models: survival of H2 requires a density of nH = 106.7-7 cm-3 in the outer shell, implying a total gas mass of 17-35 M.
Outer shellCool dust 140 K
Molecular hydrogenThin shell
Inner ShellWarm dust 200 K
[Fe II] emission, etc.Thick shellne=104 cm-3
Outer shellCool dust 140 K
Molecular hydrogenThin shell
Inner ShellWarm dust 200 K
[Fe II] emission, etc.Thick shellne=104 cm-3
Ammonia in the outer H2 shell of Eta Carinae (Smith et al. 2006, ApJL, 645, L41)
Ammonia in the outer H2 shell of Eta Carinae (Smith et al. 2006, ApJL, 645, L41)
Despite Eta Car being an extremely luminous hot star, several molecules have been detected:
Near-IR H2 lines – first detection of molecules (Smith & Davidson 2001; Smith 2002; Smith 2006)
NH3 (3,3) - Ammonia detected with ATCA (Smith et al. 2006)
CH, OH detected in UV absorption with STIS (Verner et al. 2006; Nielsen et al.; Gull et al.)
CO, 13CO, CN, HCO+, HCN, HNC, H13CN, N2H+ detected with APEX (Loinard et al. 2012; arXiv:1203.1559)
Eta Car is unique laboratory for rapid molecule and dust formation in N-rich ejecta around hot stars.
Will the Dust & Molecules survive the SN?
Despite Eta Car being an extremely luminous hot star, several molecules have been detected:
Near-IR H2 lines – first detection of molecules (Smith & Davidson 2001; Smith 2002; Smith 2006)
NH3 (3,3) - Ammonia detected with ATCA (Smith et al. 2006)
CH, OH detected in UV absorption with STIS (Verner et al. 2006; Nielsen et al.; Gull et al.)
CO, 13CO, CN, HCO+, HCN, HNC, H13CN, N2H+ detected with APEX (Loinard et al. 2012; arXiv:1203.1559)
Eta Car is unique laboratory for rapid molecule and dust formation in N-rich ejecta around hot stars.
Will the Dust & Molecules survive the SN?
Massive Dusty Molecular Shell
CHEMICAL ABUNDANCE CHANGES IN THE OUTER EJECTA
Smith & Morse 2004
HST/WFPC2 F502N [O III] F658N [N II]
HST/WFPC2 F502N [O III] F658N [N II]
LBV eruptions can trigger sudden changes in chemical abundances…LBV eruptions can trigger sudden changes in chemical abundances…
Multiple eruptions…Multiple eruptions…
[O III]H[O II]
N/O ≥ 20
N/O ≈ 1
N/O ≈ 0.1
Nitrogen enrichment gets weaker at larger radii.Nitrogen enrichment gets weaker at larger radii.
Eta Carinae had multiple previous eruptions.
Another generation of stars is still forming nearby…
Most massive stars live fast, die young, etc.This might actually matter in starburst regions, early universe, proto-GC’s …
Eta Carinae had multiple previous eruptions.
Another generation of stars is still forming nearby…
Most massive stars live fast, die young, etc.This might actually matter in starburst regions, early universe, proto-GC’s …
1600 AD shell:
From [Fe II] lines:
M = 0.1-0.2 M .M = 0.01 M/yr
KE = 1047 ergs
Mass and KE similar to 1890 outburst of Eta Car’s Little Homunculus.
1600 AD shell:
From [Fe II] lines:
M = 0.1-0.2 M .M = 0.01 M/yr
KE = 1047 ergs
Mass and KE similar to 1890 outburst of Eta Car’s Little Homunculus.
The historical light curveof P Cygni (de Groot 1983)
[Fe II] 1.644 um
NICFPSGinsburg, Smith, & Bally (in prep.)
[Fe II] 1.644 um
NICFPSGinsburg, Smith, & Bally (in prep.)
P Cygni:
the only other nebula from a Galactic giant LBV eruption that was actually observed.
P Cygni:
the only other nebula from a Galactic giant LBV eruption that was actually observed.
Smith & Hartigan2006, ApJ, 638, 1045 Smith & Hartigan2006, ApJ, 638, 1045
400 yr {
~1200 yr old
ERad = 2.51048 ergs
OBSERVED MASSES OF LBV NEBULAE
In LBV shells, mass of ~10 M is typical for L* > 106 L.
In LBV shells, mass of ~10 M is typical for L* > 106 L.
Smith & Owocki (2006)ApJ Letters, 645, L45Smith & Owocki (2006)ApJ Letters, 645, L45
Pistol Star (Figer+99) Eta Car
P Cygni
AG Car(S. White)
HD 168625
(Smith 2007)
Sher 25
(Brandner+97)
Mass-loss rates of 0.01-1 M/yr……beyond limitations of a line-driven wind (~10-4 M/yr * L6)
Requires continuum driving or hydrodynamic explosions. Both are insensitive to metallicity.
Observing Giant Eruptions of Massive StarsObserving Giant Eruptions of Massive StarsReview of giant eruption light curves and spectra
(see Smith et al. 2011, MNRAS, 415, 773)
Unpredictable, violent, and erratic variability
+
Smith, Vink, & de Koter (2004)Smith, Vink, & de Koter (2004)
. Sher 25
• Eta Car
~ 0.9
~ 0.5
Wolf-Rayet(WC, WN)
MS
• Pistol *
RSGs
WNH
Lower-LuminosityLBV-like
ERUPTIONS?
Lower-LuminosityLBV-like
ERUPTIONS?
. SN1987A
Luminous Blue Variables(a.k.a. Hubble-Sandage variables)H&S ’53
“giant eruptions”
. SN1987A
• Eta Car
M.S.
• Pistol *
RSG
Explosions / eruptions / winds
Surface instability? …or deep energy deposition?
Covering a wider range of initial Mass
Don’t have good observational constraints on brief and relatively faint eruptive events.
(so far, just tip of the iceberg…)
…PTF, Pan-STARRS, LSST
Explosions / eruptions / winds
Surface instability? …or deep energy deposition?
Covering a wider range of initial Mass
Don’t have good observational constraints on brief and relatively faint eruptive events.
(so far, just tip of the iceberg…)
…PTF, Pan-STARRS, LSSTAGB
?
Main Lesson: LBVs and related phenomena are more diverse than we thought
Broad spectrum of energy, luminosity, duration, spectral properties…
PNe
also: binary mergers, electron capture SNe, etc. also: binary mergers, electron capture SNe, etc.
Massive Star Eruptions Create Dense and Dusty Circumstellar Shells…
What happens when they explode as Supernovae?
Massive Star Eruptions Create Dense and Dusty Circumstellar Shells…
What happens when they explode as Supernovae?
Type IInSupernovae
(n = narrow H lines)
Efficient conversion of KE Light
CONSTRAINTS FROM SUPERNOVA PROGENITOR STARS CONSTRAINTS FROM SUPERNOVA PROGENITOR STARS
II-P IIn
IIbIIb
II-L
Smith et al. (2011)MNRAS, 412, 1522Smith et al. (2011)MNRAS, 412, 1522
Type IIn supernovae are seen over a range of metallicity, including low-Z dwarf galaxies.
PROPERTIES OF SN2006gy’s CSMPROPERTIES OF SN2006gy’s CSM
A Massive LBV-like Shell: Clues from Spectral EvolutionA Massive LBV-like Shell: Clues from Spectral Evolution
.Time evolution of narrow H(Smith et al. 2010, ApJ, 709, 856)
• Narrow absorption gets weaker... …running out of CSM?• Narrow absorption gets broader... …faster CSM at larger radii?
.Time evolution of narrow H(Smith et al. 2010, ApJ, 709, 856)
• Narrow absorption gets weaker... …running out of CSM?• Narrow absorption gets broader... …faster CSM at larger radii?
NarrowNarrow Int.Int. BroadBroad
PROPERTIES OF SN2006gy’s CSMPROPERTIES OF SN2006gy’s CSM
A Massive LBV-like Shell: Clues from Spectral EvolutionA Massive LBV-like Shell: Clues from Spectral Evolution
NarrowNarrow Int.Int. BroadBroad
Hubble Flow at 150-500 km/s
Suggests 1049 erg ejection~8 yr before SN (fall 1998)
Hubble Flow at 150-500 km/s
Suggests 1049 erg ejection~8 yr before SN (fall 1998)
.Time evolution of narrow H(Smith et al. 2010, ApJ, 709, 856)
• Narrow absorption gets weaker... …running out of CSM?• Narrow absorption gets broader... …faster CSM at larger radii?
.Time evolution of narrow H(Smith et al. 2010, ApJ, 709, 856)
• Narrow absorption gets weaker... …running out of CSM?• Narrow absorption gets broader... …faster CSM at larger radii?
IR/optical echo: Massive dust shell at R=0.5-1 light year (ejected 1500 yr before SN).
Requires at least 0.1 M of dust ( > 10 M total mass).
IR/optical echo: Massive dust shell at R=0.5-1 light year (ejected 1500 yr before SN).
Requires at least 0.1 M of dust ( > 10 M total mass).
PROPERTIES OF SN2006gy’s CSMPROPERTIES OF SN2006gy’s CSM
Smith et al. 2008, ApJ, 686, 485Smith et al. 2010, ApJ, 709, 856Miller et al. 2010, AJ, 139, 2218
Smith et al. 2008, ApJ, 686, 485Smith et al. 2010, ApJ, 709, 856Miller et al. 2010, AJ, 139, 2218
1-2 Years Later…IR Echo from dusty outer shell1-2 Years Later…IR Echo from dusty outer shell
KeckLGS/AOinfrared
visual
PROPERTIES OF SN2006gy’s CSMPROPERTIES OF SN2006gy’s CSM
1-2 Years Later…IR Echo from dusty outer shell1-2 Years Later…IR Echo from dusty outer shell
KeckLGS/AOinfrared
visual
Multiple massive shell ejections.Multiple massive shell ejections.
Dusty light echo:Outer massive shell, R ~ 1 lyejected ~1000-2000 yr earlier…another 10 M
Dusty light echo:Outer massive shell, R ~ 1 lyejected ~1000-2000 yr earlier…another 10 M
Inner massive shell, H-rich, 10-20 M, 100-600 km/s, Hubble lawInner massive shell, H-rich, 10-20 M, 100-600 km/s, Hubble law
SN2006jc
Foley et al. 200, ApJ, 657, L105Pastorello et al. 2007, Nature, 447, 829
Smith, Foley, & Filippenko 2008, ApJ, 680, 568
Foley et al. 200, ApJ, 657, L105Pastorello et al. 2007, Nature, 447, 829
Smith, Foley, & Filippenko 2008, ApJ, 680, 568
SN 2006jc had an observed precursoreruption 2 yr before exploding as a supernova…
SN 2006jc had an observed precursoreruption 2 yr before exploding as a supernova…
2 yr2 yr
Dust Formation Dust Formation
Explosion of WR star with dense CSM Explosion of WR star with dense CSM
Surprising Dust Formation in SN 2006jc
3 lines of evidence:
#1 Rapid fading
#2 Infrared emission from hot dust
#3 Far side blocked
Foley et al. (2007)Foley et al. (2007)
…faster than 56Co decay…faster than 56Co decay
Smith, Foley, & Filippenko 2008Smith, Foley, & Filippenko 2008
Surprising Dust Formation in SN 2006jc
3 lines of evidence:
#1 Rapid fading
#2 Infrared emission from hot dust
#3 Far side blocked
Day51
Day75
Day102
Day128
Smith et al. 2008Smith et al. 2008
Hot dust at ~1600 K.
Dust cools fast and piles up downstream. Total dust formed:
Md 0.01 M (Smith et al. 2008)
From later near/mid-IR obs:
Md 0.008 M (Matilla et al. 2008)
Smith, Foley, & Filippenko 2008Smith, Foley, & Filippenko 2008
Surprising Dust Formation in SN 2006jc
3 lines of evidence:
#1 Rapid fading
#2 Infrared emission from hot dust
#3 Far side blockedVel. (103 km/s)Vel. (103 km/s)
…but only seen in the narrow He I lines in the post-shock gas (swept-up CSM)…but only seen in the narrow He I lines in the post-shock gas (swept-up CSM)
Smith, Foley, & Filippenko 2008Smith, Foley, & Filippenko 2008
This is Wavelength-Dependent (stronger inblue em. lines)
CSM
He-rich
CSM
He-rich
SNejecta
C-rich?
SNejecta
C-rich?
Type IcSN
Type IcSN
SN2006jc.
Where did the dust form?
Blueshifted narrow He I lines: also from Zone 2
DUST FORMED IN THE SHOCK• Shocked CSM gas? (forward shock)• Shocked SN ejecta? (reverse shock)
Dust in/around Type IIn Supernovae
• IR Echoes from Pre-existing dust SN 2006gy ~0.1 M (Smith+08; Miller+10) SN2010jl 0.03-0.35 M ( Andrews+11)
several SNe IIn (Fox et al. 2009. 2011)
• Blueshifts suggest some new dust formation in post-shock gas as well.
SN 1995N (Fransson+02)SN 1998S (Pozzo+04;
molecules - Gerardy+00) SN 2005ip, 2006tf, 2008iy, 2010jl, others… (Smith+2008,2009,2012; Miller et al. 2010)
Dust in/around Type IIn Supernovae
• IR Echoes from Pre-existing dust SN 2006gy ~0.1 M (Smith+08; Miller+10) SN2010jl 0.03-0.35 M ( Andrews+11)
several SNe IIn (Fox et al. 2009. 2011)
• Blueshifts suggest some new dust formation in post-shock gas as well.
SN 1995N (Fransson+02)SN 1998S (Pozzo+04;
molecules - Gerardy+00) SN 2005ip, 2006tf, 2008iy, 2010jl, others… (Smith+2008,2009,2012; Miller et al. 2010)
dust formation in post-shock shell.dust formation in post-shock shell.
1.2 mm observations of z>6 quasars reveal huge amounts of dust. (Bertoldi et al. 2003, AA, 406, L55)
MD = few 108 M
Dust production of ~1 M/yr.
~0.01 M per SN…
1.2 mm observations of z>6 quasars reveal huge amounts of dust. (Bertoldi et al. 2003, AA, 406, L55)
MD = few 108 M
Dust production of ~1 M/yr.
~0.01 M per SN…
Massive star eruptions: Potential sources of dust in the early Universe?
Pre-SN Eruptions enable dust production in 2 ways:
1.Pre-existing dust seen as IR echoes.LOTS of dust – of order 0.01-0.2 M
2. New dust formation in post-shock gas when SN collides with dense CSM.
Radiative cooling and collapse of post-shock shell facilitates efficient dust formation.
Key questions:
1.Will that new dust survive?SNe IIn: slower shocks
no UV flash from shock breakoutdust already behind shock
2.Are there enough eruptive stars to do it?? … Early universe, low-Z, etc.
SUMMARY
Intro: Mass Loss in Massive-Star EvolutionEruptions: Dominate mass return, work at low-Z
Eruptions of LBVs - Eta Carinae et al.:Lots of mass return: CNO processed, dusty, molecule rich
Luminous Type IIn Supernovae and Circumstellar Gas: Pre-SN mass loss: Evidence for precursor LBV-like eruptions.
9% of all ccSNe: probably large fraction of very massive stars.
Dust formation/survival in Type IIn SNe:Special circumstances: Dense CSM, more dust than other
SNe.Qualitatively different from normal SNe: post-shock dust,
no (or weak) UV flash from shock breakout…
Intro: Mass Loss in Massive-Star EvolutionEruptions: Dominate mass return, work at low-Z
Eruptions of LBVs - Eta Carinae et al.:Lots of mass return: CNO processed, dusty, molecule rich
Luminous Type IIn Supernovae and Circumstellar Gas: Pre-SN mass loss: Evidence for precursor LBV-like eruptions.
9% of all ccSNe: probably large fraction of very massive stars.
Dust formation/survival in Type IIn SNe:Special circumstances: Dense CSM, more dust than other
SNe.Qualitatively different from normal SNe: post-shock dust,
no (or weak) UV flash from shock breakout…