The Role of Massive Binaries in the Universe
Ed P.J.van den Heuvel
University of Amsterdam
“Cataclysmic
Variables”
M< Msun
11
10 L
MICRO QUASARS
Main sources of X-rays
from normal galaxies
Coalescence: Prime
Grav. Wave sources
Long GRBs seen to beyond z= 9
Adriaan Blaauw (1914-2010) and
Massive stars and Binaries
He discovered in the 1950s:
- Expansion of OB associations: ages only a few million years
- Existence of Runaway OB Stars, and in 1961:
- Gave consistent theory for the Origin of Runaway Stars in the
form of binary interactions: the Binary Supernova Model.
Later Poveda et al.(1967) also suggested: dynamical interactions
in compact stellar groups.
The latter was worked out by Blaauw’s PhD student T. v. Albada (1968)
Blaauw and Morgan
ApJ 119, 625, 1954:
RUNAWAY OB STARS
AE Aur (B0V) and
μ Col (O9.5V) were
shot out of Orion
with v=130 Km/s
some 2,6 million yrs
ago
Blaauw, Scientific
American
February 1956
In close binaries:
• Mass transfer causes the exploding star to be the
least massive of the two when it explodes
• The two stars then stay together in an eccentric
orbit and the system becomes a runaway star (for
spherically symmetric SN mass ejection)
Newton (1687) showed:
MasS m inside a shell of mass M
Mass m outside shell of mass M
m experiences no force
from M
m experiences attraction as though M
is concentrated in its centre
Porb = 2.08
days, M > 16Msun
Plaatje HMXB Blauwe
superreus
star
Ppulse = 4.84 sec
NS: v(orb) = 420 km/s
(Discovered by Schreier et al, 1972)
Example of the evolution of a massive Close Binary into a runaway
High Mass X-ray Binary (e.g. vdH & Heise 1972; Tutukov and Yungelson 1973)
System is “runaway star”
runaway, v= 75 km/s
Star > 16Msun
P = 2.08 d
P= 3.4 d
P = 5.6d
High-Mass X-ray Binaries
(O6f to B0.5 Ia or Ib blue
supergiants + X-ray pulsars
or black holes)
runaway, v= 45
km/s
23xsun
P= 8.97 d
ISM Bow shock of Vela X-1
Kaper et al.1997 (came
from Vela OB1 2-3 Myr ago)
B1.5 Iae supergiant
M> 40 Msun
runaway
v> 84 km/s
4U 1538-55
P= 3.73 d
z(gal) = 260 pc
Ppulse = 529s
Companion of 4U1700-37 is the 6,5 mag O6.5f star HD 153919 (>40 Msun)
V(run) = 75 km/s
Ankay, Kaper et al.
A&A, 2001
Hoogerwerf de Bruijne and de Zeeuw (2001), from Hipparcos
observations:
2/3 of the runaway O-stars probably due to the Supernova effect
Blaauw (1993) over 50 per cent of massive runaways are Heliumenhanced; indicates: binary mass transfer
Fuiji &Portegies Zwart et al.(2011): also a fraction must come
from dynamical cluster interactions, also involving binaries.
Extra Complication to the “Blaauw model” for OB runaways
(Gunn and Ostriker 1970, Lyne and co-workers,
particularly Hobbs et al. 2005) <v> ~ 400 km/s
10
10
100
1000
100
1000
3-D speed
(km/sec)
3-D speed
(km/sec
Neutron-star kick may disrupt the system, producing a single
OB runaway star
SNR Semeis 147, d = 0.8 to 1.8 kpc
Runaway B0.3V star HD 37424 ( V= 9.0 magn, M ~ 15 Msun),
v(pec)= 74 ± 7.5 km/s, d = 1.3 kpc (B.Dinҫel et al. 2014, Jena Univ.)
Pulsar PSRJ 0538+2817, v = 383± 1 km/s, d = 1.3 kpc, kin. age 30 000 yr
P(pulse) =143ms
x = center SNR
+ = pulsar
System disrupted
by Blaauw effect +
birth-kick to NS
Without NS kick it
would not have
disrupted
+
x
Frequency of Binaries AMONG Massive Stars:
T.S. van Albada , B.A.N. 20, 47-56 ,1968 [PhD Thesis with A. Blaauw]
G.P.Kuiper (1935) suggested a mass-ratio q= (m2/m1) distribution
f(q) = 2/(1+q)²
Science 337,444,2012
Sana et al. 2012, Science 337, 444ff
Types of X-ray Binaries
HMXBs
Supergiant systems
Donor mass > 20Msun
NS
Wind
driven
(slow PSRs)
LMXBs
Be/X-ray Binaries
compact*
Donor mass 10 – 20 Msun
NS
BH
Disk
driven
(fast PSRs)
M Donor < M
Transients, mostly
(slow) pulsars;
Wide binaries
High Form. Rate : 1/ 1000 yr
BH-
NS-LMXBs
LMXBs
(“X-ray
Novae”)
often X-bursts
and/or
millisec PSRs
Low form. Rate: <1/10 5-6yr
HMXBs observed by Integral-IBIS
Source: Peter Kretschmar, 2010
Be-star
~ 15M sun
He star
~ 3M sun
NS
“Standard” scenario for forming
a double neutron star, starting
from a B-emission X-ray binary,
Orbital Period > 1 year
Involves a COMMON-ENVELOPE
phase: requires WIDE initial system
First-born NS is “recycled”:
it underwent much accretion,
weakening its magnetic field
(Drawing from Dewi, Podsiadlowski
and Pols, 2005)
2nd He-star
2nd NS
orbital P= a few hours]
Double neutron star
e.g: Cyg X-3, P(orb)=4.8h
WN7+NS /BH (microQSO)
The “Blaauw-effect”
in double neutron stars
(15 systems known now)
Hulse-Taylor
Hulse-Taylor binary
Binary pulsar
pulsarPSR
PRS 1913+16 (1974), Porb = 7.75 h, e =0.615
The eccentricity was induced by
the second SN explosion, which produced the (unseen) NS companion
All Double Neutron Stars have eccentric orbits, due to the second SN.
5 AU
A big unsolved problem
When a neutron star in a HMXB
with an orbital period of less
than a few years spirals in, the
two stars will merge and form a
Thorne-Zytkow star: a red
supergiant with e neutron star
core.
Such stars should form at a rate
of about once per 1000 years in
the Galaxy.
Remnants of such systems must
be all around us. Where are they
and how do they look like?
PSRJ0737-3039AB, P(orb) = 2,4 hours
“In the universe, anything NOT forbidden is
COMPULSORY”
Jerry Ostriker
Making a short Gamma Ray Burst and a Gravitational wave Burst:
Double Neutron Star Merger: rate: ~one in 100 000 yr per galaxy
Main producers of r-process elements (e.g. Au, U) in the universe
Long GRB 980425 (Galama, Vreeswijk et al.1998) Type Ic peculiar, no H
and He in spectrum: collapsing CO core of > 5 solar masses: makes BH;
V ( SN shell)= 40 000 km/s
Long GRB MODEL:
Rapidly Rotating
Disk of NUCLEAR
matter around a
recently-formed
BLACK HOLE
produces JETS
(radiation- or EM or
neutrino-driven)
perpendicular to
the disk.
(Woosley,
1993, and
MacFadyan
& Woosley
1998)
“Hypernova”
or
“Collapsar”
Requires high angular momentum of collapsing core (rapid rotation)
Black Hole X-ray Binaries
(25 known) exhibit many of
the same phenomena
as AGNs:
Relativistic jets, X- and
gamma-ray emission,
outbursts, etc.
(e.g. see Mirabel et al.
many papers)
Long GRBs: Can Binaries make them?
Ideas (Izzard et al 2004, Podsiadlowski et al. 2004):
To get rapidly rotating core by tidal spinup , deep spiral-in of a low-mass
companion needed.
So: also Long GRBs likely require binaries.
LGRB-Supernova then produces a
Black-Hole plus low-mass companion
later becomes a Low-mass BH X-ray
binary
V404 Cygni went in outburst
15 June 2015 and reached 30x Crab
Alternative possibility
Progenitors of Long GRBs are close Helium star + compact star
binaries, with Massive helium stars (≥ 6 solar masses) ,
resembling Cyg X-3 ( here the He-star is a WR star: type WN7).
WR wind
6
If P(orb) ~ a few hours, tidal torques are strong enough to keep
the Helium star in rapid synchronous rotation, and J is large enough
for making a collapsar (vdH and Yoon, 2007, Ap & Sp.Science;
Bogamosov, 2014, Astronomy Reports)
Single Star progenitors (Quasi-homogeneous Evolution; Yoon and
Langer):
Must be very rapidly rotating (break-up) O stars. Such stars are
result only from mergers of close binaries (de Koter et al, 2015)
They go through homohemeous evolution and then produce a
Type Ic-peculiar SN/long GRB
So: This model ALSO requires a binary progenitor
Most distant Long GRB: GRB 090429B, redshift 9.4
GRB 090423, z= 8.2
Afterglow can be a
million times
brighter than a
Supernova.
In principle visible
to z=20
IMPORTANCE OF MASSIVE BINARIES IN THE UNIVERSE:
1. Probes for testing fundamental physics:
A. Double neutron stars:
- Testbeds for general relativity (e.g.1973 Nobel prize for Taylor and
Hulse)
- mergers are (the only) sure source for detectable GravitationalWave bursts for LIGO, VIRGO, etc.
- Main source of r-process elements in Universe
B. Black-hole XRBs allow precise study of BH-accretion and jet
formation, important for understanding AGNs and QSOs
2. Importance for (study of) evolution of Universe:
- HMXBs in young galaxies are main source of ionizing X-ray
radiation for intergalactic medium (EoR).
- Long GRBs are products of massive binary evolution and probe the
universe to beyond z= 9.4, and presumably up to z= 20.
No other objects known out to such redshifts.
PROBLEMS THAT MAY KEEP ME (AND YOU) AWAKE AT NIGHT:
1. If Cyg X-3 is a BH, then later it may become a double BH or a NS+BH
(Belczynski et al. 2013)
What is the birth rate of such objects? It lives ~ 500 000 yrs,
so birth rate is 2 per million yrs(?) per galaxy(?) ± ∞ .
2. What will happen with the bulk of the HMXBs: The ones with orb.
period below about one year will become Thorne- Zytkow objects.
What will happen to Neutron-star ones among them? How will their
remnants look like?
They form once per 1000 yrs in the Galaxy, so they must be common!!
3. Where are the (Be + Helium star)- binaries (partly: progenitors of
Be/X-ray binaries and thus of double neutron stars)?
4. How do massive binaries become LBVs? ( Nathan Smith)