X-Rays�Λ= 1-100 Å Plasma Temp

Home , Hakucho, Hinode (satellite), Suzaku (satellite), Yohkoh

Violent Universe Explored by Japanese X-ray Satellites�

Hideyo Kunieda Nagoya University

Asia Academic Seminar CPS 8th International School of Planetary Science September 30, 2011 at Awaji� Lecture Plan September 30, 9:00-10:15 I. Basic processes in High energy astronomy I-1: Why X-ray astronomy? I-2: Emission mechanisms I-3: Energy sources II. High energy phenomena II-1: Stellar X-ray emission September 30, 10:45-12:00 II-2: Supernova remnants (SNR) II-3: Neutron stars and blackholes II-4: Active Galactic Nuclei II-5: Cluster of galaxies and Cosmology I-1. Why X-ray astronomy?

1. Sun http://swc.nict.go.jp/sunspot/� Optical Image Photosphere : Black body radiation �T = 6430°K λpeak~4500 A Wien’s law λT = 2800 micron K Density ~1014 atom/cc (10-6 g/cc) http://swc.nict.go.jp/sunspot/� X-ray Image by Yohkoh Corona : Thin thermal emission + lines 6 T = 10 °Kλpeak ~30 A (if BB) Density ~106-8 atom/cc http://hinode.nao.ac.jp/latest/�

http://hinode.nao.ac.jp/latest/� I-1. Why X-ray astronomy? Optical Image 2. Cluster of Galaxies Optical image : Component galaxies Emission from stars Visible mass ~ M X-ray image : Hot plasma T ~ 107-8°K Virgo X-ray Image by Plasma mass ~ 1-5 M Cluster ASCA Mass to bind hot gas in clusters Dark matter Mass ~ 5-20 M Radiation and related physical processes

Radio�λ= 0.1 - 100 mm FM Radio frequency Molecular emission 80.7 MHz Vibration, rotation λ=3x1010cm/8.07x107 = 4 x102 cm Infrared�λ= 1-100 micron Dust emission Black body radiation 37℃ => 310 °K Low temp. stars ~ 9 micron

Optical�λ=4000-7000Å H Ly-α 1215Å Main sequence stars Ly limit 912Å

T= 6430°K λpeak~4500 A H Ba-α (H-α) 6562Å Absorption & emission lines from excited atoms Radiation and related physical processes

Ultra-violet�λ= 100-4000Å Binding energy Early type stars(<7000°K) (Outer most electron) H (13.6 eV), He (24.6 eV), Emission lines Li (5.4eV), Be(9.3eV) X-rays�λ= 1-100 Å Plasma temp. 105-8 K Binding energy (Inner most electron) Emission lines C(280eV), O(550eV) (transition between levels) Ar(3.1keV), Fe(7.1keV)

Gamma rays�λ< 1Å Nuclear transition Synchrotron rad. High energy particles Compton rad. Radiation mechanisms of X-rays

Magnetic Sun, Stars Field High energy Nuclear Electrons Fusion Supernovae Energy Neutron stars Source Light X-rays X-rays Gravity Blackholes Cluster galaxies Hot Plasama Electrons Ion

Optical UV X-ray X-rays IR Radio

100K 10,000 1M 100M Life cycle of stars

Molecular Cloud Rado & Infrared Black Observations holes Birth of X-rays Stars Planetary nebula

Supernova Sun explosion Visible stars Red giant Narrow window X-rays are observable at Visible light from out side atmosphere UV X-ray

IR Visible γ-ray Radio Altitude for 1/100 of Io(km) 1/100 Altitude for

Wavelength X-ray Telescope� Japanese X-ray Satellites

Hakucho (1979)! Tenma (1983)! Ginga (1987)! 90kg! 200kg! 420kg! Suzaku (2005) 1700kg! ASCA (1993) 420kg!

JAXA� II-2: Emission mechanisms 1. Black body radiation Thermometry of steel furnaces based on the radiation

E(ν) d ν = 2 Z(ν)kT d ν Z(ν): lattice points in phase space (1) Long wave side：Rayleigh-Jeans distribution 4πL３ Z(ν) d ν = ------ν ２ d ν C３� E(ν) d ν 8πkT U(ν) d ν = ------= ------ν ２ d ν L3 C３ When ν --> small, it well represents observed spectra but when ν is large, U will become inﬁnity. II-2: Emission mechanisms 1. Black body radiation

(2) Short Wave side：Wien distribution

4πL３ Z(ν) d ν = ------ν 2 exp(-h ν /kT)d ν C３

2 Z(ν) hν d ν 8πh U(ν) d ν = ------= ------ν 3 exp(-h ν /kT) d ν L３ c３�

When h ν /kT >>1, it well represents observed spectra but does not match with the data when h ν /kT <<1 II-2: Emission mechanisms 1. Black body radiation

(3) Interpolation：Planck distribution 8πh 1 U(ν) = ------ν 3 d ν Planck distribution c3 exp(h ν /kT) –1 When h ν /kT <<1, exp(- h ν /kT) =1 + h ν /kT 8πkT U(ν) d ν = ------ν 2 d ν Rayleigh-Jeans c3 When h ν /kT >>1, exp(h ν /kT) >>1 8πkT U(ν) d ν = ------ν 3 exp(-h ν /kT) d ν Wein c3 II-2: Emission mechanisms 1. Black body radiation Planck distribution ) ν Wien∝ R-J exp(-h ν /kT) ∝ν 2 Log B( Log

John D. Kraus, 1986: logν Radio Astronomy, Cygnus-Quasar Books ,81� II-2: Emission mechanisms 1. Black body radiation Peak frequency : derivative of Planck’s eq. = 0 8πh 1 U(ν) = ------ν 3 d ν Planck distribution c3 exp(h ν /kT) –1 x３ f (x) = ------when x= hν/kT ex –1 ∂ f 3x2(ex – 1) –x3ex ------= ------= 0 ∂ x (ex –1)２ 3(1- ex) = x left term = 0(x=0), =1.8(x=1), =2.4(x=2), =3(x=∞) x=2.812 hνmax=2.82 kT λmaxT = 2900(µm・K) Wien’s law II-2: Emission mechanisms 1. Black body radiation Total brightness : Integration of Planck’s eq. U(ν) c B(ν) = ------4π 2πh 1 ∫ B(ν)d ν = ------∫ ------ν 3 d ν c2 exp(h ν /kT) – 1 When x= hν/kT 2h kT x３ π４ B = ------(------)4 ∫ ------dx  = ------c2 h ex –1 15 2π５k４ = ------T４ = σ T４ 15c2h3

σ= 5.67 x 10-5 erg cm-2 deg-4 s-1 ：Stefan-Boltzmann constant II-2: Emission mechanisms 1. Black body radiation

Planck distribution λmaxT=2900(µm・K)

Wien’s law ) ν Wien∝ R-J exp(-h ν /kT) ∝ν 2 B =σ T４� B( Log

John D. Kraus, 1986: logν Radio Astronomy, Cygnus-Quasar Books ,81� II-2: Emission mechanisms 2. Line emission and absorption Emission from Fe atoms

0 k eV ER C = EC - EK 0 .0 5 k eV M > 7. 1 1 ke V ( ＜1 . 7 4 3 Å ） 0 .7 1 k eV L E = E - E Kβ Kβ M K = 7. 06 ke V ( 1. 75 7 Å ） Kα K X- r a y s EK α = EL - EK = 6. 40 ke V ( 1. 93 7 Å ） 7 .1 1 k eV K-shell Characteristic X-rays

Analysis of elements II-2: Emission mechanisms 2. Line emission and absorption Absorption by Fe atom Absorption edge E = E - E 0 k eV R C C K > 7 .1 1 k eV (＜ 1 .7 4 3 Å ） 0 .0 5 k eV M 0 .7 1 k eV L E K β = E - E K β M K = 7 .0 6 k eV ( 1 .7 5 7 Å ） K α E K α = E L - E K = 6 .4 0 k eV ( 1 .9 3 7 Å ） 7 .1 1 k eV K-shell Absorption lines If outer electrons are ionized II-2: Emission mechanisms 2. Line emission and absorption Absorption by Fe atom Absorption edge

E > EK = 7.11 keV (1.743 Å)�

EK β =EM -EK ∝E-3 =7.06 ke V (1.75 7 Å ）

EK α=EL -EK =6.40 keV (1.93 7 Å ） Absorption lines

Absorption cross section If outer electrons are ionized

EK X-ray energy II-2: Emission mechanisms Emission from hot plasmas Ionization state �Electron collision/Photo ionization Free electrons �Recombination Equilibrium Lines from ionized ions �Binding energy increases after the removal of outer electrons �Fe XVII(16 electrons are removed)�Fe Kα X-ray ~ 6.4 keV �Fe XVIII -XXV ~ 6.7 keV �Fe XXVI ~ 6.9 keV Line energy ---> Ionization state Line ratio of an element ---> Tion, Te (Balance of ionization/recomb.) Line ratio ----> Atomic abundance II-2: Emission mechanisms Emission from hot plasmas Galactic Center

Suzaku:�180 ksec

Fe abs. Edge�

FeI FeXXV FeXXVI� Neutral Fe @6.4 keV He like Fe @6.7 keV H like Fe @6.9 keV Resolved by

Koyama et al, 2007: Publ. Astron. Soc. Japan, 59, 221 ΔE~140 eV of CCD Koyama et al, 2007: Publ. Astron. Soc. Japan, 59, 245� II-2: Emission mechanisms Emission from hot plasmas

0 XIS

-0.2

-0.4

-0.2

-0.4 Koyama, 2006: Journal of Physics ; Conference Series, 54, 95� 0.8 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 II-2: Emission mechanisms 3. Bremsstrahlung .. n Dipole d Radiation into the unit solid angle Ωd 2 .. θ dP d2 ----- = ------sin2 θ dΩ 4πc3 dW e2 . ----- = ------∫ dΩ (n(t) x (n(t) x β(t)))2 2 dt 16π ε0c . If θ is the angle between β(t)and n, e2 . = ------∫ dΩ sin2 θ (β(t))2 - 2 16π ε0c Max. at perpendicular direction

e2 . . = ------(v(t))2 ∫ dΩ sin2 θ (β(t))2 2 16π ε0c β=v/c II-2: Emission mechanisms 3. Bremsstrahlung When dΩ = sinθ dθ dψ dW e2 . ----- = ------(v(t))2 3 dt 6πε0c

dW e2 v2 (t) sin θ ----- = ------∫ dΩ ------2 5 dt 16π ε0c (1-v(t) cos θ／ c )

When β= v/c  1 Isotropic in the rest frame  Lorentz transformation  Beaming 1 γ= ------√(1 – v2/c2) II-2: Emission mechanisms 3. Bremsstrahlung Lorentz transformation 1 x’=γ(x-vt) x=γ(x’+vt) γ= ------√(1 – v2/c2) y’=y y=y’ z’=z z=z’ 2 t’=γ(t-vx/c ) t=γ(t’+vx’/c2)

γ(dx’+vdt’) u ’+v u =dx/dt= ------= ------x x 2 2 γ(dt’+vdx/c ) 1 + vux’/c u ’ u =------y v (x, y, z) y 2 γ(1+vux’/c ) u ’ u =------z z 2 γ(1+vux’/c ) II-2: Emission mechanisms 3. Bremsstrahlung Measured in the moving system 1 γ Velocity u’, direction θ’, = ------√(1 – v2/c2) Parallel component to v is affected by the motion v u||’+v u ’ u || = ------2 u = ------2 1 + vu||’/c γ( 1 + vu||’ /c ) In the moving system, light direction is θ‘ is changed to θ u sin θ= ----- = ------c sinθ’ c c γ( 1 + v cosθ /c) z z’ Here, u’=c, u|| =c cosθ, u =c sinθ If θ=π/2, sinθ=1/γ u u’ θ’ v 1/γ II-2: Emission mechanisms 3. Bremsstrahlung Thermal bremsstralung e V Impact parameter b b dW 2e2 R ------= ------｜ΔV｜2 ωτ<< 1 τ= b / v Z e dω 3πc3 Ze2 b dt 2Ze2 ΔV = ----- ∫ ------= ------m (b2 + v2t2)3/2 mbV

dW(b) 8Z2e6 ------= ------b<

6 16e bmax 2 = ------ne ni Z ln(------) 3 2 3c m v bmin 16πe6 2 = ------ne ni Z gff(v, ω) (eq 5.11) 3 3 c3m2v √ George B. Rybicki, Alan P. Lightman, 1979: Radiative Processes in Astrophysics, Wiley-VC, 158� II-2: Emission mechanisms 3. Bremsstrahlung Thermal bremsstralung e V Thermal distribution of electrons dP ∝ exp(-E/kT) d3v = exp( - mv2/2kT) d3v b R

∞ dW(v, ω) Z ∫ ------v2 exp(-mv2/2kT) dv e dW vmin dωdVdt ------= ------dVdtdω ∞ ∫ v2 exp(-mv2/2kT) dv dω=2πdν 0 dW 2π 25πe6 1/2 1/2 2 -hν/kT ------= (------) ------T Z ne ni e g (eq. 5.14a) dV dt dν 3km 3mc3

George B. Rybicki, Alan P. Lightman, 1979: Radiative Processes in Astrophysics, Wiley-VC, 160� II-2: Emission mechanisms 3. Bremsstrahlung Thermal bremsstralung e V Thermal distribution of electrons dP ∝ exp(-E/kT) d3v = exp( - mv2/2kT) d3v b R ∞ dW(v, ω) ∫ ------v2 exp(-mv2/2kT) dv Z e dW vmin dωdVdt ------= ------dVdtdω ∞ ∫ v2 exp(-mv2/2kT) dv dω=2πdν 0

dW 2π 25πe6 1/2 1/2 2 -hν/kT ------= (------) ------T Z ne ni e g (eq. 5.14a) dV dt dν 3km 3mc3 dW 2πkT 25πe6 1/2 2 ------= (------) ------Z ne ni g (eq. 5.15a) 3 dV dt 3m 3hmc George B. Rybicki, Alan P. Lightman, 1979: Radiative Processes in Astrophysics, Wiley-VC, 160-161� Emission from hot plasmas Galactic Center

Thermal Bremsstrahlung� Suzaku:�180 ksec

Fe abs. Edge�

FeI FeXXV FeXXVI� Neutral Fe @6.4 keV He like Fe @6.7 keV H like Fe @6.9 keV Resolved by

Koyama et al, 2007: Publ. Astron. Soc. Japan, 59, 221 ΔE~140 eV of CCD Koyama et al, 2007: Publ. Astron. Soc. Japan, 59, 245� Thermal radiation from SNR

Si Fe

名古屋大学 Ux研＠研究プロジェクト http://www.u.phys.nagoya-u.ac.jp/r_e/r_e3_4.html� II-2: Emission mechanisms 4. Synchrotron radiation

q d ---- v x B = mrω2 = --- (γmv) B c dt F V qB qB ω= ------Cyclotron frequency = ------mc γmc

2 2 2 2 q v⊥ ω < P > = ------γ=(1-v2/c2)-1/2 3 c3 4 dp/dt= 2 2 P = ---- σTh cβ γ UB (eq. 6. 7b) 3

2 UB = B ／8π : Energy density of B

George B. Rybicki, Alan P. Lightman, 1979: Radiative Processes in Astrophysics, Wiley-VC, 169� II-2: Emission mechanisms 4. Synchrotron radiation

３ —１ Typical frequency Δt = (γ ωB sinα) 3 3γ2qB sinα ３ ωC= ----γ ωB sinα = ------2 2mc

2 q4B2 γ2β2sin2α P = ------2 3 3m c (eq. 6. 17b) 1/γ

If energy spectrum of electrons is power law, -P N(γ) dγ= C２γ dγ

-(p-1)/2 (p-3)/2 Ptot(ω) ∝ ω ∫ F(x) x dx (eq. 6. 22a)

p-1 s = ------2 George B. Rybicki, Alan P. Lightman, 1979: Radiative Processes in Astrophysics, Wiley-VC, 173-174� II-2: Emission mechanisms 5. Compton scattering

dσT 1 2 2 ------= ---- ro (1+cos θ) dΩ 2 8π 2 σT = ----- ro 3 In relativistic cases, ε ε -- = 1 + ------(1 – cosθ) 2 ε1 mc

2 2 dσ ro ε1 ε ε1 ----- = ------( --- + ---- - sin2θ) eq(7.4) 2 dΩ 2 ε ε1 ε

George B. Rybicki, Alan P. Lightman, 1979: Radiative Processes in Astrophysics, Wiley-VC, 197� II-2: Emission mechanisms 5. Compton scattering Inverse ε 1= h ν 1

If Εel is large (>> mec2), ε =h ν observer frame has to be θ referred to the incident photon Eelectron ε’= ε γ (1-β cosθ) hν<< hν’ δΕ1 =h 2 2 ~ E ε1 ν1 ----- = cσTγ ∫ (1 – βcosθ) εn dε electron dt ε =h ν θ 4 2 2 U = ∫ ε n dε P = -----σT cγ β UPH PH 3 Energy density E of radiation electron II-2: Emission mechanisms Radiation Processes Line emissions Thermal Bremsstrahlung ------> Blackbody radiation

dW 2πkT 25πe6 1/2 2 ------= (------) ------Z ne ni g (eq. 5.15a) dV dt 3m 3hmc3 Synchrotron 4 2 2 P = ---- σTh cβ γ UB (eq. 6. 7b) 3 Inverse Compton 4 σ γ2β2 P = ----- T c UPH George B. Rybicki, Alan P. Lightman, 1979: 3 Radiative Processes in Astrophysics, Wiley-VC, 161� II-2: Emission mechanisms of high energy photons Synchrotron-self-Compton Model for a Blazer�

Synchrotron� Inverse Compton�

Macomb, D, J, 1995: The AstroPhysical Journal, 449,99� II-2: Emission mechanisms of high energy photons

SN1006

SN 1006

Power law

2 /arcmin 2

Thermal Counts/s/kev/cm

Energy (keV) I-3: Energy sources of high energy phenomena

Energy release of X-ray sources

33 Sun Lopt~10 erg/s Nuclear fusion 27 LX~10 erg/s SN E ~ 1051 erg Gravitational Energy AGN L~1041-47 erg/sec Gravitational Energy Cluster E~1060 erg Dynamical+G Energy γ burst E~1052 erg/sec Hypernovae? 1. Nuclear energy SUN Energy release of the Sun --> Black body radiation kT=6430°K、r = 600,000 km、σ= 5.67x10-5

L = 4πr2 σT4 = 4.4 x 1033 erg/s

t = 3600 s/h x 24 h/d x 365 d/y x 46 x 108 y = 1.45 x 1017 sec (3.15 x 107 sec/y) E = L x t = 6 x 1050 erg 1. Nuclear energy SUN Nuclear reactions 2 + P-P chain (I) p +p  H + e +νe0.16MeV 2H + p  3He + γ [6.7MeV/3H] for kT > 8 106K 3He + 3He  4He + 2p [26.1MeV/4H] (II) kT > 2 107Kになると

3He + 4He  7Be +γ 7Be + p  8B + γ 8 8 + B  Be + e νe7 MeV Solar neutrino 8Be  24He CNO cycle He burning C O burning---> Fe 2. Gravitational energy

Sun 3.8 x 1048 erg Mechanical E of Expanding shell Supernova Neutron stars R = 106 cm 1% E = 2 x 1053 erg Neutrino Blackholes R = 3 x 105 cm 99% 53 1 MSolar E = 7 x 10 erg Escape KAMIOKANDE

Escape velocity At Rg, ves = c 2 2 ves = 2GM/R Then Rg = 2GM/c E=GM2/R = 3 (M/M ) km solar ~ Mc2 II. High energy phenomena II-1 : Stellar X-ray emission 1. Stellar X-ray emission (1) Evolution and X-ray emission from proto-stars Contraction of molecular cloud Release of angular Momentum Class 0 Accretion disk I Bipolar flow X-rays emission discovered by ASCA II Central star III Central star (Nuclear reaction)

Gravitational E --> Heating --> Rotation --> B -->Hot plasmas High energy electrons Hard X-rays

Star forming region

Optical image Radio image (Extinction) (Molecular cloud X-ray blinking of proto stars in SFR (2) Solar X-rays

Main sequence stars Core Temp. and Density --> Ignition of Nuclear reaction Photo-sphere: T ~ 6000°K Blackbody Corona: T ~ 106-7 K --> several keV --> X-rays

Nuclear energy --> Convection/Rotation --> B Solar magnetic ﬁeld --> Extends into the atmosphere

Reconnection --> E -->Acceleration of e-

Thermalization Hard X-rays Soft X-rays Soft X-ray Movie of the Sun by Yohkoh

http://www.isas.jaxa.jp/home/solar/yohkoh/� Solar Flare observed by Yohkoh� 軟 X線像 � 温度� � Hard Soft References�

• George B. Rybicki, Alan P. Lightman, 1979: Radiative Processes in Astrophysics, Wiley-VCH, 158,160-161,169,173-174,197 • John D. Kraus, 1986: Radio Astronomy, Cygnus-Quasar Books ,81� • Koyama et al, 2007: Discoveries of Diffuse Iron Line Sources from the Sgr B Region, Publ. Astron. Soc. Japan, 59, 221 • Koyama et al, 2007: Iron and Nickel Line Diagnostic for the Garactic Center Diffuse Emission, Publ. Astron. Soc. Japan, 59, 245� • Koyama, 2006: New X-ray view of the Galactic Center observed with Suzaku, Journal of Physics ; Conference Series, 54, 95 • Macomb, D, J, 1995: Multiwavelength Observatons of Markarian 421 During a TeV/X-Ray Flare The AstroPhysical Journal, 449,99� References�

• Sun - optical image - http://swc.nict.go.jp/sunspot/ • Sun - X-ray Image - http://hinode.nao.ac.jp/latest/� • 名古屋大学 Ux研＠研究プロジェクト (Cassiopeia A) http://www.u.phys.nagoya-u.ac.jp/r_e/r_e3_4.html • ようこう http://www.isas.jaxa.jp/home/solar/yohkoh/� References� • http://www.u.phys.nagoya-u.ac.jp/r_e/r_e3_4.html • Furuzawa et al., 2009, Doppler-Broadened Iron X-Ray Lines From Tycho's Supernova Remnant : ApJ...693L.. • Hayato et al., 2010, Expansion Velocity of Ejecta in Tycho's Supernova Remnant Measured by Doppler Broadened X-ray Line Emission : ApJ...725..894H • Ishihara et al., 2010, Origin of the dust emission from Tycho's SNR : A&A...521L..61I • http://www.astro.isas.ac.jp/xjapan/asca/3/agn/ • "James N, Reeves et al, 2007, Revealing the High Energy Emission from theObscyred seyfert Galaxy MCG-5-23-16 with Suzaku, Publ. Astron. Soc.Japan, 59, 301" • Fabian et al, 1989, X-ray ﬂuorescence from the inner disc in Cygnus:X-1, Mon. Not. R. astr. Soc, 238, 729 • Tanaka et al, 1995, Gravitationally redshifted emission implying an accretion disc and massive black hole in the active galaxy MCG-6-30-15,Natur., 375, 659 • Miniutti et al, 2007, The Long Suzaku Observation of MCG-6-30-15,Progress of Theoretical Physics Supplement, 169, 260 • Koyama et al., 2007: Iron and Nickel Line Diagnostic for the Garactic Center Diffuse emission, Publ. Astron. Soc. Japan, 59, 245 • Murakami et al, 2003, Reﬂected X-ray Emissions on Molecular Clouds -Evidence of the Past Actives of Sgr A*, Astron. Nachr, 324, 125 • Koyama et al., 2008: A time-Variable X-Ray Echo; Indication of past Flare of Garactic-Center Black Hole, Publ. Astron. Soc. Japan, 60, 201 • Shibata et al., 2001, Temperature Map of the Virgo Cluster of Galaxies Observed with ASCA: ApJ... 549...228 • Ezawa et al., 1997, Discovery of a Large-Scale Abundance Gradient in the Cluster of Galaxies AWM 7 with ASCA: ApJ...490L..33E • Lubin et al., 1996, The Baryon Fraction and Velocity--Temperature Relation in Galaxy Clusters : Models versus Observations : ApJ...460...10 �