Populations of (bright) compact sources in galaxies
description
Transcript of 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)
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
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
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
Lx-mass relation for LMXBsnumber of sources total X-ray
luminosity
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
Lx-SFR relation for HMXBsnumber of sources total X-ray
luminosity
Lx~SFR
Nx~SFR
Non-physicaleffect of statisticsof small numbers
Ltot=Lk
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
Total luminosity of XRBs
Lx ~ 2•1039SFR 8•1038M*
Nx(Lx>1037) ~ 7SFR 10M*
[SFR]= M/yr[M*]=1010 M
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
Luminosity functions
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
HMXBsX-ray luminosity functions:
SFR~0.15-7 Msun/yr
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
HMXBsX-ray luminosity functions scaled to the same SFR
SFR~0.15-7 Msun/yr
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
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 - ???
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
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)
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
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
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
Faint sources (old populations)
Sazonov et al., 2006Revnivtsev et al., 2006
number of sources
contribution to total luminosity
~3%
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
How abundant are X-ray binaries?
Nx(Lx>1037) ~ 7SFR 10M*
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
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 ...
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
Abundance of HMXBs
€
N HMXB ~ ˙ N *(M > 8Msun ) × f HMXB × τ HMXB
number of HMXBs observed at any given time :
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˙ 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
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
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
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
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
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
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)
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
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
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
X-ray binaries and CXB
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
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)
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
X-ray binaries and CXB
<zHMXB> ~ 1.5<zLMXB> ~ 0.5
2-10 keV:HMXB ~7-10%LMXB <1-2%
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
HMXBs & unresolved part of CXB
HMXB contribution can explain ~50% of the unresolved part of the CXB (via contribution of faint normal galaxies)
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
LMXBs: primordial and dynamically
formed (talk of Rasmus Voss for details)
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
LMXBs in M31
primordial
tidal capturein the bulge
total
GC
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
LMXBs in M31primordi
al
dynamical interaction
GCs inner bulge
~60 ~20 ~20
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
LMXBs in M31luminosity functions
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
Andromeda galaxy (M31)
Marat Gilfanov X-rays from nearby galaxies, 5/9/2007
The End