EAYAM 2017 at Ishigaki, Japan on Nov 14, 2017

Is there a maximum mass forsupermassive black holes (SMBHs) ?
See Ichikawa & Inayoshi (2017b), ApJL, 840, L9

Kohei Ichikawa (市川幸平)
JSPS fellow at Columbia Univ./NAOJ
1

EAYAM 2017 at Ishigaki, Japan on Nov 14, 2017

Is there a maximum mass forsupermassive black holes (SMBHs) ?
See Ichikawa & Inayoshi (2017b), ApJL, 840, L9

10
A: Yes. And the value is ~10 M

Kohei Ichikawa (市川幸平)
JSPS fellow at Columbia Univ./NAOJ
2sun

EAYAM 2017 at Ishigaki, Japan on Nov 14, 2017

Is there a maximum mass forsupermassive black holes (SMBHs) ?
See Ichikawa & Inayoshi (2017b), ApJL, 840, L9

AGN JetSMBHADAF disk

Kohei Ichikawa (市川幸平)
JSPS fellow at Columbia Univ./NAOJ
3

AcHve GalacHc Nuclei (AGN)
Rees 84;Antonucci & Miller 85; Urry & Padovani95

GalaxySupermassive Black Hole (SMBH)

AGN

dusty torus<10 kpc<10 pc(see Ichikawa+15, Burtscher+13)

Why do we observe AGN for SMBH studies?

☑ AGN is a growing phase of SMBH
☑ easy to esFmate BH mass (e.g., single-epoch method; Kaspi+00,05)☑ Very, very bright in opFcal/UV (and also X-ray, IR!)
Lbol >= 1047 erg/s; which canbe observable up to z~7!
4

Maximum mass of SMBHs

Maximum mass of SMBHs
1010Msun !

☑ Maximum mass of SMBHs: Mmax ˜ 1010-11 Msun ?
☑ Mmax seems independent of redshic
See McConnell+11; Kormandy & Ho ’13 for the local SMBHs, and see Netzer+03; Trakhtenbrot’14; Wu+15 for high-z sources

What mass limit of SMBHs tells us?
1010Msun !

☑ e-folding Hme: only 40 Myr☑ Max MBH exists already at z~6
But no ultra-massive MBH w/ 1012-13 Msun at z<6 !

Something regulates SMBH growth at 1010 Msun
(and, it seems to be z-independent)

What mass limit of SMBHs tells us?
1010Msun !

☑ e-folding Hme: only 40 Myr☑ Max MBH exists already at z~6
But no ultra-massive MBH w/ 1012-13 Msun at z<6 !

Something regulates SMBH growth at 1010 Msun
(and, it seems to be z-independent)

Theory: Let’s calculate the mass accreHon rate

Inayoshi & Haiman ‘16

Theory: Let’s calculate the mass accreHon rate

Inayoshi & Haiman ‘160.3☑ Ṁacc / MBH

Theory: Let’s calculate the mass accreHon rate(ADAF)

0.3 and1.0 =>☑ Ṁacc / MBH
ṀEdd / MBH
Ṁacc /ṀEdd / MBH0.7☑ All accreHon disks become ADAF at MBH ~ 1010-11 Msun
☑ most of the mass is expelled as jet/ounlows=> Let’s check radio-loud AGN fracHon as a funcHon of MBH

ObservaHons: SDSS AGN/Quasars (QSOs)
orange: radio detected sources
gray: radio upper-limit sources

Our RL/RQ boundary

convenHonal RL/RQ boundary

SDSS DR7 QSO catalog contains 76,000 QSOs at z<2☑ MBH, radio-loudness R=f1.5GHz/f2500Å, (R>10; radio-loud QSO)
☑ we used the conservaHve value of R>100 for RL QSOs

Radio Loud (RL) fracHon vs. MBH
Jets should be associated with ADAFs ≈ RL fracHon increase
KI2 (K. Ichikawa & K. Inayoshi) ‘17
w/76,000 sources from SDSS QSO catalog

theoreHcal
ADAF area☑ RL fracHon starts to increase at MBH ~ 2x109 Msun
☑ RL fracHon = tjet/(tjet + tacc)

What does the RL fracHon tell us?
☑ RL fracHon = tjet/(tjet + tacc) <=> tjet =KI2 (K. Ichikawa & K. Inayoshi) ‘17(Thompson+05)

0.7 yrn)usMH/B
8 (Mt acc =

01x
5
4.

act=t jetcL)
Rf1(/LfR

What does the RL fracHon tell us?
☑ RL fracHon = tjet/(tjet + tacc) <=> tjet =KI2 (K. Ichikawa & K. Inayoshi) ‘17(Thompson+05)

0.7 yrn)usMH/B
8 (Mt acc =01x54.

act=t jetcL)
Rf
1(/LfR☑ tjet >= tacc at log (MBH/Msun) > 10.3
SMBH cannot get the mass at log (MBH/Msun) > 10.3

Summary & Conclusion✓ SMBHs seem to have mass limit to 1010-11 Msun and z independent✓ This suggests SMBHs have self regulaFon system at the max mass

✓ Theory suggests all AGN fall in ADAF state at the max mass end✓ mainly done by Inayoshi & Haiman ‘16✓ ObservaFonally, the ouZlow/jets are expected at the mass mass

✓ Radio-loud QSO increases at MBH ~ 2x109 Msun (Ichikawa & Inayoshi ’17)
✓ Using 76,000 SDSS DR7 QSOs w/ conservaFve RL criterion of R>100✓ RL fracFon = tjet/(tjet + tacc) <=> tjet =✓ tjet >= tacc at log (MBH/Msun) > 10.3

SMBH cannot get the mass at log (MBH/Msun) > 10.3
Auto-quenching of SMBH growth occurs at log (MBH/Msun) > 10.3

Appendix

z dependence of RL fracHon

KI & KI 2017

Eddington raHo vs. MBH☑ λEdd increases at MBH ~ 2x109 Msun

MBH vs. z

EsHmaHon of BH mass