Black Hole Formation and Black Hole Formation and KicksKicks

Vicky KalogeraPhysics & Astronomy Dept

withBart Willems

Mike HenningerTodd Levin

Natasha Ivanovaand

Chris Fryer (LANL)Frank Timmes (LANL)

Observed sample of BH X-ray binaries:

Growing in number Exciting recent measurements of proper motion

give us with radial velocity unique information on kinematic history (see F. Mirabel’s talk)

BH formation: some open questions …

What is the mass relation between progenitors and BHs ? Are asymmetric birth kicks imparted to BHs ? How do their magnitudes compare to NS kicks ?

courtesy Sky & TelescopeFeb 2003 issue

How do BHX-ray binaries form ?

primordial binary

X-ray binary at Roche-lobe overflow

Common Envelope:orbital contractionand mass loss

BH formation

Use ALL observational constraints:

Currently: donordonor position on the H-R diagramH-R diagram BH and donor massesmasses *orbital periodperiod *3-D center-of-mass velocityvelocity

Calculations: 1. Identify MT sequencesMT sequences that satisfysatisfy

H-R, masses, periodH-R, masses, period constraintsconstraints > obtain timetime of BH formationBH formation 2. Follow motion in the Galaxy > obtain post-collapse Vcmpost-collapse Vcm 3. Follow tidal evolution prior to XRB phase

> obtain post-collapse A, epost-collapse A, e4. Analyze collapse dynamics:

constrainconstrain BH XRB progenitor and kickprogenitor and kick

Example case: GRO J1655-40

Two sets of binary properties from:Beer & Podsiadlowski 2002 (BP)

Greene, Bailyn, & Orosz 2001 (GBO)

BH (Mo) Donor (Mo) SpT

BP 5.4+-0.3 1.45+-0.35 F5-G0

GBO 6.3+-0.5 2.4+-0.4 F6III

Porb = 2.62 d

GRO J1655-40 (with BP parameters)

Conservative MT:

Sequences must satisfy constraints on current H-R position of the donorand …

GRO J1655-40

Conservative MT:

Sequences must satisfy constraints on current H-R position of the donorand …

… satisfy constraintson current BH anddonor masses and most importantly orbital period

GRO J1655-40

time since BHformation: ~830Myr

chosen MT seq:4.4Mo BH2.4Mo donor1.4d period

BH

donor

GRO J1655-40 : MT seq. that satisfy all constraints

BP conservativeBP non-conservativeGBO conservativeGBO non-conservative

GRO J1655-40 : MT seq. that satisfy all constraints

BP conservativeBP non-conservativeGBO conservativeGBO non-conservative

BH

donor

GRO J1655-40: Motion in the Galaxy (for BP conservative MT seq.)

BH age ~ 830Myr ---> VPEC = 63-78 km/s

GRO J1655-40 VPEC, MBH, Mdonor, Aorb (or Porb), and e at BH formation constrain pre-collapse Apre-collapse Aorborb as well as the BH-progenitor massBH-progenitor mass and the possible BH kickpossible BH kick magnitude

(for BP conservative MT seq.)

BH kick magnitude

BH

pro

geni

tor

mas

s

GRO J1655-40 (for BP conservative MT seq.)

MBH = 4.4 Mo

from core-collapsehydro simulations:

BH formation: delayed

M0 >~ 6 Mo

GRO J1655-40

conservative MT non-conservative MT

BP

GBO

Work in progress:

Analysis for XTE J1118-480 and Cyg X-1 is underway …

Are BH kicks correlated with either BH mass or mass loss at BH formation ?

Comparison with NS systemsSco X-1, 4U1700-37, LS 5039 and more …

Conclusions on J1655-40:

BH progenitor in the range 4.5 - 14 Mo

BH kicks necessary; in the range of 30 - 200 km/s

delayed BH formation through fallback