Populations of (bright) compact sources in galaxies

Populations of (bright) compact sources in galaxies

Marat GilfanovMPA, Garching

Marat Gilfanov X-rays from nearby galaxies, 5/9/2007

Hans-Jakob Grimm (CfA)

Igor Prokopenko (IKI)

Pavel Shtykovskiy (IKI/MPA)

Rashid Sunyaev (MPA/IKI)

Rasmus Voss (MPA, MPE)

Akos Bogdan (MPA)


Binary evolution“primordial”

binaryMS+MS

BH/NS+MS

wind accretion orRoche lobe overflow

Roche lobe overflow

stellar evolution

SN explosion

massive star: stellar evolution

low-mass star:stellar evolution

ororbital decay

~2-40 Myrs50 Myrs

1-10 Gyrs

HMXB

LMXB


Lx-mass relation for LMXBsnumber of sources total X-ray

luminosity


Lx-SFR relation for HMXBsnumber of sources total X-ray

luminosity

Lx~SFR

Nx~SFR

Non-physicaleffect of statisticsof small numbers

Ltot=Lk


Total luminosity of XRBs

Lx ~ 2•1039SFR 8•1038M*

Nx(Lx>1037) ~ 7SFR 10M*

[SFR]= M/yr[M*]=1010 M


Luminosity functions


HMXBsX-ray luminosity functions:

SFR~0.15-7 Msun/yr


HMXBsX-ray luminosity functions scaled to the same SFR

SFR~0.15-7 Msun/yr


HMXB & LMXB luminosity functions

• different shapes - different accretion regimes:

• HMXB - wind accretion• LMXB - Roche-lobe overflow

• “true” ULXs are associated with star-formation

• no features at LEdd for NS - ???


HMXB XLF & IMF slopeaccretion of radiation pressure driven stellar wind

€

˙ M wind ∝ L*

L* ∝ M*3

⎫ ⎬ ⎭⇒ ˙ M wind ∝ M*

3 ⇒ ˙ M acc ∝ ˙ M wind ∝ M*3

more accurate consideration (Bondi accr. etc) :˙ M acc ∝ M*

2.5 ⇒ Lx ∝ M*2.5 (Postnov, 2004)

dNdLx

= dNdM*

× dLx

dM*

⎛ ⎝ ⎜

⎞ ⎠ ⎟−1

⇒ α IMF = 2.5 ×α XLF −1.5

α IMF ,α XLF − IMF and XLF slopes : dNdLX

= M*−α XLF ; dN

dM*

= M*−α IMF

α XLF =1.6 ± 0.15⇒ α IMF = 2.5 ± 0.4 (Salpeter : α IMF = 2.35)


LMXB XLF

Evolved companionand/or

Gravitational braking inultracompact binariesNS+WD, Porb~10 min

short life-time problem

magnetic braking(Sco X-1 etc.)

gravitational brakingin longer Porb systems

King, Bildsten,Postnov and others


Faint sources (old populations)

Sazonov et al., 2006Revnivtsev et al., 2006

number of sources

contribution to total luminosity

~3%


How abundant are X-ray binaries?

Nx(Lx>1037) ~ 7SFR 10M*


Abundance of HMXBs

€

N HMXB ~ ˙ N *(M > 8Msun ) × f HMXB × τ HMXB

number of HMXBs observed at any given time:

birth rate of compactobjects

HMXBfraction

duration ofHMXB phasenumber

of HMXB

€

f HMXB ∝ fbin × f surv ...


Abundance of HMXBs

€

N HMXB ~ ˙ N *(M > 8Msun ) × f HMXB × τ HMXB

number of HMXBs observed at any given time :

€

˙ N *(M > 8Msun ) ≈ 7.4 ⋅10−3 ×SFR

€

N HMXB (L >1034 ) ≈ 500 ×SFR

Salpeter IMF:

Nx-SFR relation:

€

f HMXB × τ HMXB ~ 0.07 Myr


Abundance of HMXBs

€

f HMXB × τ HMXB ≥ 0.07 Myr

O,B binaries: HMXB~104-105 yrsX/Be binaries: HMXB~105-106 (?) yrs

€

f HMXB ≥ 0.7 × τ HMXB

0.1 Myr ⎛ ⎝ ⎜

⎞ ⎠ ⎟−1


Abundance of LMXBs

€

fLMXB ~ 7 ⋅10−6 f tr

0.1 ⎛ ⎝ ⎜

⎞ ⎠ ⎟−1

Per 1010 Msun:Salpeter IMF: ~7.4107 BH & NSLMXB-Mstar relation: NLMXB(LX>1035)~50 LMXBs


Time dependence of XRB populations

HMXB LMXB

LX , NX

log(time)SF event

50-100 Myr >1 Gyr

has been measured(Pavel Shtykovsky’s talk)


HMXBs and the spiral structure

HST image of M51

Beckwith, 2005

X-ray sources in M51 (Chandra) distance to spiral arms

(low stat. significance)

stars


X-ray binaries and CXB


X-ray binaries and CXBCosmic star formation stellar mass

€

LX = 2.5 ⋅1039 ˙ ρ * + 8 ⋅1039 ρ* [erg/sec/Mpc3]

(from Nagamine et al., 2006)


X-ray binaries and CXB

<zHMXB> ~ 1.5<zLMXB> ~ 0.5

2-10 keV:HMXB ~7-10%LMXB <1-2%


HMXBs & unresolved part of CXB

HMXB contribution can explain ~50% of the unresolved part of the CXB (via contribution of faint normal galaxies)


LMXBs: primordial and dynamically

formed (talk of Rasmus Voss for details)


LMXBs in M31

primordial

tidal capturein the bulge

total

GC


LMXBs in M31primordi

al

dynamical interaction

GCs inner bulge

~60 ~20 ~20


LMXBs in M31luminosity functions


Andromeda galaxy (M31)


The End

Populations of (bright) compact sources in galaxies

Documents

xray sources

nxsfr relation

cxbxray binaries

b binaries

yrsxbe binaries

stellar evolutionlowmass

given time

salpeter imf