High-z Galaxy Formation
and Feedback「フィードバック機構」

Ken Nagamine
Osaka / UNLV
長峯健太郎
（大阪大学）
Recent Collaborators on this topic:
Jun-Hwan Choi (UT Austin)
Jason Jaacks (UT Austin)
Emilio Romano-Diaz (Bonn)

Isaac Shlosman (Kentucky)
Robert Thompson (W. Cape)
Keita Todoroki (Kansas)
Hide Yajima (Tohoku)

Outline• フィードバック機構とは？ (by MS, SNe, AGN, …)• Effects on Cosmological Quantities• Effects on Galaxy Statistics• Downsizing, Galaxy Morphologies, Elliptical Gals.
• Conclusions

フィードバック機構とは？
（銀河形成における）• エネルギー(光、物質）が放出され、その後の系の進化に影響を与えること。

• What, Who, Where, When, Why, How ?
• Who?：超新星、SMBH (AGN)、大質量星(MS)• Where? : galaxy, star-forming region, black hole
• When, Why, How?

``Concordance ΛCDM model ”
WMAP, Planck:SN Ia(⌦M , ⌦⇤ , ⌦b , h,8 , ns ) ⇡ (0.3, 0.7, 0.04, 0.7, 0.8, 0.96)956

http://www.roe.ac.uk

Fig. 7. – Evolution of the density of luminous quasars based on the SDSS and 2dF
strong decline of quasar number density suggests the quasar/AGN population isprovide enough UV photons to ionize the Universe at z > 6.

neutral fraction

Understand• Reionization process• Galaxy Formation• statistics (LF, MF)• SFRD, SMD• Mass-metallicity(Fund. Plane?)• Gas fractions•…
Illiev+ ’06

Fan+ ’08

Fig. 8. – The volume-averaged neutral fraction of the IGM vs. redshift using variou

Prevalence of Galactic Wind Feedback-- Pollution of Intergalactic Medium by metals

M82 Purple: Hα+NII

Blue: HST, optical

NGC3079
Blue: Chandra (X-ray)
Red Green: HST (optical)

Supernova(SN) Feedback• Source of radiation, metals,cosmic rays•• —> E ~10 erg, —> E , E• Outflows, Suppression of SF
51
Etot~10 erg (mostly to “ν”)
49fbkth(White & Rees 78; Dekel & Silk ’86)

Crab Nebula — SN 1054 (NASA, ESA)VwSPH
mesh codes• Kinetic energy & momentum• Thermal energy• Type I, IIComputational Cosmology
Self-consistent galaxy formation scenario
from first principles (as much as possible)
z~1100

Radiative
cooling/heating,Star formation,& Feedback

z=100

Initial conditions

z=10

Cosmological params,
Dark energy, Dark matter,
Baryons(+expanding universe)

Gravity + Hydrodynamics

z=3z=0100 cMpc
z=0
T < 104.5 K (blue)
104.5 K < T < 105.5 K(green)
T > 105.5 K (red)EAGLE sim:
Schaye+ ‘15

Cosmic Star Formation History
EAGLE sim: Schaye+ ‘15

No SN feedback

With SN feedback

No metal cooling

Too many stars are produced without SN FB.

Temperature

Metallicity

Galactic Wind (Kinetic) Feedback
Need to specify

Ṁw and Vw“Energy-driven” vs. “Momentum-driven”: mass-loading factor

ṀW = Ṁ ,Energy-driven:

12ṀW VW
20=ĖSNSF RVW20gal

Momentum-driven:ṀW VW=0gal

ṖradVescgal

300 km s 1

SF R

Radiation pressure from massive stars
and SNe is applied to the dust
particles, which entrains the wind

Higher mass-loading factor for lower mass galaxies.

Murray+ ’05

Figure 3. Same as in Fig. 2, but for the projected inte
right-hand panel. The IGM temperature is significantly
Figure 3. Same as in Fig. 2, but for the projected intehardly heat the IGM on large scales.
right-hand panel. The IGM temperature is significantly
hardly heat the IGM on large scales.

Impact of Momentum-driven Wind on IGM
2584
2584

J.-H. Choi and K. Nagamine
J.-H. Choi and K. Nagamine
Temperature

Projected metal density

10 Mpc/h

Energy-driven wind(constant Vw)

Momentum-driven

Choi & KN ’10

UV LFs at z=4-8: Obs vs. Sim
HUDF09+HUDF12, ERS, CANDELS, BORG/HIPPIESSimulations

DM halo MF + M/L evol.
α=-1.64 (z=4)α=-2.06 (z=6)

dα/dz= -0.13
dα/dz= -0.17(Bouwens+ ’14)

Steepening of the faint-end slope
towards high-z even to α≲-2(cf., Dunlop+, Ellis+, Finkelstein+, McLure+, Oesch+, Ouchi+, Schenker+, Trenti+, etc.)

SFR fcn w/ H2-SF model
H2 -BASED STAR FORMATION MODEL, z ≥ 6 LUMINOSITY FUNCTION, & REIONIZTION

Previous pressure-SF model

5

Jaacks, Thompson, KN ’13

Jaacks, Thompson, & Nagaminez = 6, 7, 8 (red triangles, blue circles and green squares,
H2-SF
respectively). We find good agreement with the observed
results (Smit et al. 2012, cyan diamonds), especially atz = 7. Deviation at low-SFR end of z = 6 is expected,
given a similar deviation in the LF at the low-end shownin Jaacks et al. (2012a,b). This deviation could either
indicate that our simulation is still overproducing stars
at z = 6, or it could also be due to uncertainties in thefaint-end observations (i.e., missed faint galaxies) and/or
assumptions regarding extinction.
The SFRF has a similar functional form as the LF,
therefore we utilize the same Schechter+ function to fit
it: φ(SFR) ≡ dn/d log(SFR) = ln(10)SFR Φ(SFR), and"(1+α)"!
!
SFRSFRThe observational
Figure 3. SFRF of simulated galaxies at z = 6, 7, & 8, shown as red triangles, blue circles
green squares, respectively.
∗ andφ(SFR)=ln(10)φexp−estimates (Smit et al. 2012) are shown by filled cyan diamonds. Solid red, blue and green lines ∗represent the best-fit Schechter+
functions∗SFR
SFR(Equation 2) to the simulation data.
#"β $−1!
SFR×1+, (2)ulation is suﬃcient to maintain reionization,
we utilize
SFRt
the theoretical prescription presented in Madau et al.
the minimum
required
where φ∗(1999),, SFR∗ whichand α quantifies
are the usual
Schechter SFRD
parameto keep the intergalactic
medium (IGM) ionized (shadedt
2. Redshift evolution of Schechter+ parameters for bothters as in gray
Equation
(1);
SFR
is
thelocation of the secondcontour):ulated LF (red squares) and simulated SFRF (blue diaturnover, and β is related to the low-SFR end power-law
at z = 6, 7, & 8, shown with 1σ error bars. The SFRF β!
"!
"3tslope which is proportionalto(1+α−β)
atSFR≪SFR.
oﬀset by ∆z = 0.1 for readability. The horizontal dashC
1+z−3−3−1ρ̇⋆ ≈2 × 10to all five parameters[MMpcin ]. (3)ne in the top panel represents the approximate JWST⊙ yr
The best-fit
results
areshown
f10escle limit (Muv ≈ −16).
Figure 3 with solid lines. Similarly
to the rest-frame UV
LF, the right-mostpanel
shows theThis depends
on redshift
and increase
the ratioinof normalIGM clumping

Modified Schechter SFR fcn:

Agrees well with current obs constraints at z=6 & 7 (Smit+ ’12).

SFR fcn provides more direct comparison btw sim & obs.

CGM baryon budget(Circum-galactic Medium)• HST COS. 44 quasarspectra• multiphase CGM in L* gal

Total: 45-100% ofcosmic fraction(r<160kpc)• CLOUDY modelling• More sophisticated models

25-45%>5%
14-24%of stellar FB is needed.

2-6%

Werk+ ‘14

Multi-phase CGM in high-z galaxies

Stellar Feedback(in addition to SN feedback)• stellar winds from young stars (“early” FB)• radiation pressure• dust absorption of UV —> IR emission+ photo-electric heating• photo-ionization(alters future heating/cooilng rates)

Hopkins+ ’13

Galaxy Merger Simulations
Stellar Feedback:radiation pressure, direct
momentum (stellar wind),photoionization heating

But, this is not incosmological context.
Resolution:
mp≲1000M⦿, ε~3pc
Hopkins+ ’13(GADGET SPH)

(Springel+ ’05, …, Hopkins+’13)

Stellar Feedback in Zoom-in Sim(Cosmological Initial Condition)• Star formation is episodic.
• Outflows sweep up CGM.
Inflow

Hopkins+’13; Muratov+ ’14

Stellar Feedback in Zoom-in Sim
Mass Loading Factor : η(≈ Momentum-driven)

Wind Velocity

Hopkins+’13; Muratov+ ’14

Circum-galactic medium (CGM)(probed by quasar absorption lines)

proper
500 kpc/h

z=2.8 Eris2 zoom-in simulation (Shen+ ’13)z=10.2
Romano-Diaz+ ‘11
resolution ~ 30 pc (proper)

Massive disk gal already at z~10
Mtot ∼ 1.1 × 1010 h−1 M⊙
total disk mass is ∼2.9 × 109 h−1 M⊙

Mstar,disk ~ 8 × 108 h−1 M⊙

Mgas ∼ 4.8 × 1010 M⊙

Mstar ∼ 4.1 × 1010 M⊙

z=6.3
Yajima+ ‘14

Mdust/Mmetal = 0.4,i.e. Mdust = 0.008 Mgas (Z/Z⊙ )Escape Fraction of Ionizing Photons
6Yajima et al.

Figure 2. Escape fraction as a Yajima,function of Choi,
halo massat z’11= 3−6
KNfor the N144L10 Fiducial UVB run. Diﬀerent colors are used for
diﬀerent redshifts (red: z = 3, blue: z = 5, green: z = 6). The
triangles in the bottom right panel show the mean values in eachmass bin with 1-σ error bars. The data points with log fesc < −2.5
are shown at log fesc = −2.5 for plotting purposes.

Figure 3. Mean escape fraction in each mass bin of Fig. 2 asa function of redshift. Diﬀerent symbols indicate diﬀerent halo
mass ranges (filled circles: 108.75 − 109.25Yajima+M⊙ , stars: ’14
109.25 −109.75 M⊙ , filled triangles: 109.75 − 1010.25 M⊙ , open squares:
1010.25 − 1010.75 M⊙ , crosses: 1010.75 − 1011.25 M⊙ , open triangles: 1011.25 − 1011.75 M⊙ , and open circle: 1011.75 − 1012.25 M⊙ ).

Elliptical Galaxies,Downsizing,& Feedback

Naab+’12; Oser+’14：zoom-in cosmo hydro sim

AGE [Gyr]Two-phase Formation& Downsizing

Lowmass

7.0 × 1011–1.3 × 1012 M⊙ h−1

Formed at high-z outside,
but accreted later on.

AGE [Gyr]late in-situ SF

Massive
4.5 × 1012–2.7 × 1013 M⊙ h−1

In-situ SF dominant @ high-zlog (R/Rvir)

http://www.illustris-project.org/

10 cMpc volume; w/ AGN feedback (quasar + radio mode)

Stellar Light

Gas Density

Formation of massive elliptical, “red & dead” gal.

Which is the true HUDF observation?

Conclusions, Keywords & Future• `Feedback’ continues to be the focus of galaxy formation &evolution.

• “Early Feedback” from young stars: rad pressure, momentum,thermal energy, photoionization,• Dust! (couple w/ radiation)• Morphology, Downsizing. Color bimodality?
• Orientation effect; Escape Fraction; Reionization• AGN FB, gal-SMBH co-evolution.