mass transfer in binary starsrgi/doc/talks/lund-2010.pdf · 1. why do we care about binary stars?...
TRANSCRIPT
Mass Transfer in Binary Stars
Robert Izzard
AIfA, Bonn
Co-conspirators
Tyl Dermine,
ULB
Ross Church,
Lund
Shazrene Mohamed,Bonn
Selma de Mink,Utrecht/Bonn/STScI
Ines Brott,Utrecht
Norbert Langer,Utrecht/Bonn
Sung-Chul Yoon,Bonn
VLT/FLAMES teamULB (Jorissen)
EU
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 2 / 64
1. Why do we care about Binary Stars?
2. Single vs Binary Evolution
3. RLOF vs Wind Accretion
4. e.g. Wind mass transfer: Barium Stars
5. e.g. RLOF in Massive Stars
6. Where do I (we?) go next?
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 3 / 64
Night Sky
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Yale Bright Star Catalogue, Stars Brighter than 5th Mag
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 4 / 64
Night Sky Binaries
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Night Sky Binaries
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AlgolCapella
RigelSirius
Castor
ProcyonRegulus
Mizar
Arcturus
Antares
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Useful numbers
Stars brighter than 5th magnitude in Yale catalogue
◮ 1618 star systems
◮ 825 single-star systems
◮ 793 binary-star systems
◮ Binary System Fraction = 7931618
= 49%◮ 51 single stars : 98 stars in binaries
◮ Binary Star Fraction
= 793×2825+793×2
= 15862411
= 66%
◮ Most stars are in binaries!
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 7 / 64
Why Binaries?
◮ Accurate stellar masses, radii, luminosities
◮ Gamma-ray bursts:long and short, very old! (z ∼ 8)
◮ Type Ia supernovae: Standard candles (?)Tell us Universe is expanding?
◮ Galactic Chemical Evolution: SN Ia, Ic, novae
◮ Stellar mergers
◮ X-ray binaries, CVs, AM CVns (grav waves)
◮ Chemically peculiar stars (my favourites!)
◮ Vital to understanding galaxies, stellar clusters,star formation, even cosmology. . .
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 8 / 64
Why Binaries?
◮ Accurate stellar masses, radii, luminosities
◮ Gamma-ray bursts:long and short, very old! (z ∼ 8)
◮ Type Ia supernovae: Standard candles (?)Tell us Universe is expanding?
◮ Galactic Chemical Evolution: SN Ia, Ic, novae
◮ Stellar mergers
◮ X-ray binaries, CVs, AM CVns (grav waves)
◮ Chemically peculiar stars (my favourites!)
◮ Vital to understanding galaxies, stellar clusters,star formation, even cosmology. . .
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 8 / 64
Why Binaries?
◮ Accurate stellar masses, radii, luminosities
◮ Gamma-ray bursts:long and short, very old! (z ∼ 8)
◮ Type Ia supernovae: Standard candles (?)Tell us Universe is expanding?
◮ Galactic Chemical Evolution: SN Ia, Ic, novae
◮ Stellar mergers
◮ X-ray binaries, CVs, AM CVns (grav waves)
◮ Chemically peculiar stars (my favourites!)
◮ Vital to understanding galaxies, stellar clusters,star formation, even cosmology. . .
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 8 / 64
Why Binaries?
◮ Accurate stellar masses, radii, luminosities
◮ Gamma-ray bursts:long and short, very old! (z ∼ 8)
◮ Type Ia supernovae: Standard candles (?)Tell us Universe is expanding?
◮ Galactic Chemical Evolution: SN Ia, Ic, novae
◮ Stellar mergers
◮ X-ray binaries, CVs, AM CVns (grav waves)
◮ Chemically peculiar stars (my favourites!)
◮ Vital to understanding galaxies, stellar clusters,star formation, even cosmology. . .
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 8 / 64
Why Binaries?
◮ Accurate stellar masses, radii, luminosities
◮ Gamma-ray bursts:long and short, very old! (z ∼ 8)
◮ Type Ia supernovae: Standard candles (?)Tell us Universe is expanding?
◮ Galactic Chemical Evolution: SN Ia, Ic, novae
◮ Stellar mergers
◮ X-ray binaries, CVs, AM CVns (grav waves)
◮ Chemically peculiar stars (my favourites!)
◮ Vital to understanding galaxies, stellar clusters,star formation, even cosmology. . .
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 8 / 64
Why Binaries?
◮ Accurate stellar masses, radii, luminosities
◮ Gamma-ray bursts:long and short, very old! (z ∼ 8)
◮ Type Ia supernovae: Standard candles (?)Tell us Universe is expanding?
◮ Galactic Chemical Evolution: SN Ia, Ic, novae
◮ Stellar mergers
◮ X-ray binaries, CVs, AM CVns (grav waves)
◮ Chemically peculiar stars (my favourites!)
◮ Vital to understanding galaxies, stellar clusters,star formation, even cosmology. . .
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 8 / 64
Why Binaries?
◮ Accurate stellar masses, radii, luminosities
◮ Gamma-ray bursts:long and short, very old! (z ∼ 8)
◮ Type Ia supernovae: Standard candles (?)Tell us Universe is expanding?
◮ Galactic Chemical Evolution: SN Ia, Ic, novae
◮ Stellar mergers
◮ X-ray binaries, CVs, AM CVns (grav waves)
◮ Chemically peculiar stars (my favourites!)
◮ Vital to understanding galaxies, stellar clusters,star formation, even cosmology. . .
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 8 / 64
Why are binaries so different?
Why are binaries so different?
Compare:
Single starevolution
Binary starevolution
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 9 / 64
Why are binaries so different?
Single Star Evolution
Time/Gyr →Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 10 / 64
Why are binaries so different?
Single Star Evolution
Time/Gyr →Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 11 / 64
Why are binaries so different?
Single Star Evolution
Time/Gyr →Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 12 / 64
Why are binaries so different?
Single Star Evolution
Time/Gyr →Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 13 / 64
Why are binaries so different?
Single Star Evolution
Time/Gyr →Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 14 / 64
Why are binaries so different?
Binary Star Evolution
Time/Gyr →Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 15 / 64
Why are binaries so different?
Binary Star Evolution
Time/Gyr →Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 16 / 64
Why are binaries so different?
Binary Star Evolution
Time/Gyr →Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 17 / 64
Why are binaries so different?
Binary Star Evolution
Time/Gyr →Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 18 / 64
Binary Interaction
What happens next?Transfer of
1. Mass M
2. Angular Momentum J
0 2 4 6 8 10log10 Period/days
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 19 / 64
Binary Interaction RLOF
What happens next?1. Close binary: Roche-lobe overflow
2. . . .
0 2 4 6 8 10log10 Period/days
RocheLobeOverFlow
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 20 / 64
Binary Interaction RLOF
Close binary: Roche-lobe Overflow
Roche Lobe
overflow
∆M and ∆Jspin up+tides
Play Ross Church’s movies
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 21 / 64
Binary Interaction RLOF
Often not “conservative”: Common Envelope
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 22 / 64
Binary Interaction RLOF
Chemical peculiarities ???
White Dwarf +
Chemically Normal? Star
Massive stars: WD→NS or BH
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 23 / 64
Binary Interaction Wind accretion
What happens next?1. Close binary: Roche-lobe overflow
2. Distant binary: Wind accretion
0 2 4 6 8 10log10 Period/days
WindAccretion
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 24 / 64
Binary Interaction Wind accretion
Distant Binary: Wind Accretion
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 25 / 64
Binary Interaction Wind accretion
Wind Accretion: Giant Wind
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 26 / 64
Binary Interaction Wind accretion
Wind Accretion: Gravitational Focusing
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 27 / 64
Binary Interaction Wind accretion
Wind Accretion: Accretion
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 28 / 64
Binary Interaction Wind accretion
Wind Accretion 6: Primary Death
White Dwarf +
Chemically Peculiar Star
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 29 / 64
Binary Interaction Oh dear
So we understand it all?
◮ At a qualitative level, yes. . . (perhaps)
◮ But quantitatively . . .little agreement between models and observations!
Two examples for you:
1. Barium stars
◮ Low mass 1 − 3 M⊙
◮ Wind accretion◮ Complete observation set: [Ba/Fe], P and e
2. Massive main sequence stars
◮ High mass > 10 M⊙
◮ Roche lobe overflow◮ Observation set expanding rapidly
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 30 / 64
Barium Stars
What is a barium star?
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 31 / 64
Barium Stars
How to make a Ba star?
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 32 / 64
Barium Stars
The barium star now
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 33 / 64
Barium Stars
Tidal Circulari[sz]ation τ ∼ (separation/radius)8
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 34 / 64
Barium Stars
Observations: GK giants (Jorissen data)
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Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 35 / 64
Barium Stars
Expected result for Ba stars
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Circularization!
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 36 / 64
Barium Stars
Not what we see! They are eccentric
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Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 37 / 64
Barium Stars
Confirmed in canonical model
2 3 4 5log10(Period/days)
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Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 38 / 64
Barium Stars
What is happening?
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Ecc
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Time
TPAGB
EndAGB
Tides
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 39 / 64
Barium Stars
What is happening?
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EndAGB
Tides
e-pumping
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 40 / 64
Barium Stars
What is happening?
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e-pumping
Kick ?
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 41 / 64
Barium Stars
Solution 1: Kick The WD
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 42 / 64
Barium Stars
Not Crazy! Seen in GCs (Davis et al.)
Single
andbinary stars!
Old WD/MS
Young WD
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 43 / 64
Barium Stars
Apply WD kick 4 kms−1
2 3 4 5log10(Period/days)
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Still Problems!
Period gap!
Long-P tail
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 44 / 64
Barium Stars
4km/s kick+efficient CE ejection
2 3 4 5log10(Period/days)
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Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 45 / 64
Barium Stars
4km/s kick + efficient CEE and −∆Jorb
2 3 4 5log10(Period/days)
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Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 46 / 64
Barium Stars
Solution 1: How To Make Ba Stars. . . ?
Izzard, Church and Dermine 2010 (A&A accepted)
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 47 / 64
Barium Stars
Solution 2: Circumbinary Disk?
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 48 / 64
Barium Stars
Some eccentricity, same old problems?
100 1000 104 105
Period/days
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Dermine et al. (in preparation)
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 49 / 64
Barium Stars
Wind Mass Transfer? e.g. Mira
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 50 / 64
Barium Stars
Play movies
Play Shazrene Mohamed’s movies
Morris et al. 2004, Mauron & Huggins 2006
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 51 / 64
Barium Stars
Wind OverFlow?
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RocheLobeOverFlow
WindAccretion
WOF?WOF?
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 52 / 64
Massive Stars
RLOF (in Massive Stars)
L1
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 53 / 64
Massive Stars
RLOF (in Massive Stars)◮ Often “conservative”: Spin up is important!
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crit
M2/M⊙
M1=20 M⊙
M2=16 M⊙
P=4 daysCase A RLOF
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 54 / 64
Massive Stars
Spun Up Massive Stars
Why are they interesting?
Rotation→Instabilities→Mixing
In low-mass stars:τrotational mixing ≪ τH-burning
In massive stars:τrotationalmixing ∼ τH-burning
1. H-burnt material (He,N) at the surface!“Chemically homogeneous”
2. Smaller stars
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 55 / 64
Massive Stars
Sung-Chul Yoon’s Movies
Single stars, M = 20M⊙, Z = 0.05Z⊙
v/vcrit = 15% v/vcrit = 60%
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 56 / 64
Massive Stars
At Critical Rotation
Mass cannot be accreted → lost to interstellar medium!
unprocessed
mildly processed
processed
Ejected material:He, N, Na, Al ↑
C, O, Mg ↓
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 57 / 64
Massive Stars
Consequences for Globular ClustersStars in Globular Clusters have O-Na and Al-Mg anticorrelations
Caretta et al. 2009
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 58 / 64
Massive Stars
Are massive binaries responsible?
De Mink et al. 2009
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 59 / 64
Observations→Problems
Before you get comfortable
1. We do not understand mixing, e.g.:
◮ rotation◮ magnetic fields◮ thermohaline etc.
2. We do not understand how binaries affectthe big picture:
◮ Spin Up: RLOF, tides, more mixing?◮ Spin Down: Wind, tides, less mixing?
3. Main sequence models are wrong
4. We cannot always see that they are binaries
5. CONNECTED PROBLEMS:all related to each other
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 60 / 64
Observations→Problems
e.g. Nitrogen in B type starsObs: VLT-FLAMES survey of Massive (B/MS) Stars (Hunter et al. 2008/9)vs Models of rotating single stars from Ines Brott (et al. in preparation)
6.8
7
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8
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12 +
log
[N/H
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v sini [km/s]M ≤ 10 Msun10 < M ≤ 12 Msun
12 < M ≤ 15 Msun15 < M ≤ 20 Msun
M > 20 Msunbinary
�
�
�
�ADVERTISEMENT: VLT Tarantula survey coming out soon: 103 stars!
Binaries?
MassTransfer?
These areMain SequenceStars:“Understood”!
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 61 / 64
Observations→Problems
Close binary evolution: 20M⊙+15M⊙
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Tim
e (
Myr)
onset mass transfer
and spin up of accretor
1. m
erg
ers:
ongo
ing
mas
s tr
ansf
er
low mass He star companion
3. single rapid rotator /
rapid rotator + NS companion
detached binaries
2. rapid rotator +
Calculated by Selma de Mink withbinary_c/nucsyn population synthesis code.
http://www.astro.uni-bonn.de/~izzard/binary_c.html
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 62 / 64
Observations→Problems
Close binary evolution: 20M⊙+15M⊙
1 2 3 4 5
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18
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Initial orbital period (days)
Time (Myr)
pre mass transfer
Post mass transfer
fast rotating accretor
ongoing
mass
transfe
r
Mer
gers
tidal spin up
Detectable as binary by
radial velocity variationsOne or both stars
are fast rotators
M1 = 20 Msun
M2 = 15 Msun
Calculated by Selma de Mink withbinary_c/nucsyn population synthesis code.
http://www.astro.uni-bonn.de/~izzard/binary_c.html
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 63 / 64
Observations→Problems
Where do I/we go from here?
New Observations
VLT Tarantula etc.
Hydro models:
Mass Transfer
Stellar Mergers
Stellar models:
Mixing
Nucleosynthesis
Understand
Physics of
Stars
Robert Izzard (AIfA, Bonn) Mass Transfer in Binary Stars 64 / 64