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VLBI
observations of jets in
M87
Avery E. Broderick Sheperd Doeleman (MIT Haystack)
Vincent Fish (MIT Haystack)
Alan Rogers (MIT Haystack)
Dimitrios Psaltis (Arizona)
Tim Johannsen (Arizona/UW-PI-CITA)
Avi Loeb (Harvard)
Ramesh Narayan (Harvard)
Mark Reid (Smithsonian)
Mareki Honma (NAOJ)
Fermi Bubbles Workshop 12.4.2013
mm-VLBI
observations of jets in
M87
Avery E. Broderick Sheperd Doeleman (MIT Haystack)
Vincent Fish (MIT Haystack)
Alan Rogers (MIT Haystack)
Dimitrios Psaltis (Arizona)
Tim Johannsen (Arizona/UW-PI-CITA)
Avi Loeb (Harvard)
Ramesh Narayan (Harvard)
Mark Reid (Smithsonian)
Mareki Honma (NAOJ)
Fermi Bubbles Workshop 12.4.2013
mm-VLBI
observations of jets in
M87 & Sgr A*
Avery E. Broderick Sheperd Doeleman (MIT Haystack)
Vincent Fish (MIT Haystack)
Alan Rogers (MIT Haystack)
Dimitrios Psaltis (Arizona)
Tim Johannsen (Arizona/UW-PI-CITA)
Avi Loeb (Harvard)
Ramesh Narayan (Harvard)
Mark Reid (Smithsonian)
Mareki Honma (NAOJ)
Fermi Bubbles Workshop 12.4.2013
SGR A* & M87 ARE THE SAME!
• Very sub-Eddington: 𝑳/𝑳𝑬𝒅𝒅~𝟏𝟎−𝟗 & 𝟏𝟎−𝟔 ≪ 𝟎. 𝟎𝟏
• Flat radio spectrum with spectral break at ~1mm
• Similar 𝒏𝒆, 𝑩~𝟏𝟎𝟎 G
Fermi Bubbles Workshop 12.4.2013
Sgr A*
(Zhao & Goss, 1998)
M87
VLA (NRAO)
What ingredient in jet production is missing in Sgr A*?
(Is an ingredient missing?)
SGR A* & M87 ARE DIFFERENT!
Fermi Bubbles Workshop 12.4.2013
SMA,
JCMT
ARO-SMT
CARMA
APEX,
ASTE,
ALMA Plateau de
Bure
IRAM
30m
SPT
LMT • Earth-sized mm/sub-mm VLBI array
• Existing and Planned telescopes.
• Accesses resolutions of ~10 mas,
Sufficient to resolve horizons of M87 & Sgr A*
Haystack
APEX,
ASTE,
ALMA
SPT
Fermi Bubbles Workshop 12.4.2013
SMA,
JCMT
SMT
CARMA
Data already exists on
Hawaii-CARMA-SMT
• Doeleman et al., Nature, 455, 78 (2008)
𝐷~37 ± 14 𝜇𝑎𝑠~0.7 𝐷𝐻
• Fish et al., ApJ, 727, 36 (2011)
• Doeleman et al., Science, 338, 355 (2012)
FIRST DATA!
SMA,
JCMT
ARO-SMT
CARMA
APEX,
ASTE,
ALMA Plateau de
Bure
IRAM
30m
SPT
LMT
Haystack
APEX,
ASTE,
ALMA
SPT
7 8 9 10 11 12 13
Courtesy of Vincent Fish Fermi Bubbles Workshop 12.4.2013
M87
-
Sgr A* M87
THE STATE OF EHT DATA TODAY
Fermi Bubbles Workshop 12.4.2013
PHYSICAL MODELS FOR LOW-LUMINOSITY AGN Modeling Priors Empirical Priors
SPIN OF SGR A*
Fermi Bubbles Workshop 12.4.2013
PHYSICAL MODELS FOR LOW-LUMINOSITY AGN Modeling Priors Empirical Priors
Low Spin High Spin
SPIN OF SGR A*
Fermi Bubbles Workshop 12.4.2013
GETTING AT SGR A*’S SPIN
a~0+0.64+0.86
q=68+5+8-20-28 deg.
x=-52+17+33-15-24 deg.
Incl
ina
tion
Spin Magnitude
Our accretion
model is wrong!
Observations are easy to fit
Non-accretion physics is
important!
Fermi Bubbles Workshop 12.4.2013
SPIN OF SGR A*
Fermi Bubbles Workshop 12.4.2013
SPIN OF SGR A*
Fermi Bubbles Workshop 12.4.2013
SPIN OF SGR A*
Fermi Bubbles Workshop 12.4.2013
SPIN OF SGR A*
𝜗, 𝜑 , Θ, Φ0 ,
ro, a, dir
SPIN/INCLINATION FROM
DISK LENSE-THIRRING PRECESSION
Fermi Bubbles Workshop 12.4.2013
SPIN OF SGR A*
𝜗, 𝜑 , Θ, Φ0 ,
ro, a, dir
SPIN/INCLINATION FROM
DISK LENSE-THIRRING PRECESSION
Fermi Bubbles Workshop 12.4.2013
SPIN OF SGR A*
SGR A*’S NATURAL PRECESSION RATE
𝑇𝑝𝑟𝑒𝑐~𝐿𝑑𝑖𝑠𝑘
𝜏𝐿𝑇~
𝐺𝑀
𝑐3
𝑟𝑖1/2𝑟𝑜
5/2
10 𝑎 sin Θ~
2
𝑎
𝑟𝑜
103
5/2
yr
SPIN OF SGR A*
S2 periapse ~3 × 103 𝐺𝑀/𝑐2
Comparable to timescales
already probed by the EHT!
Fermi Bubbles Workshop 12.4.2013
SPIN-DISK SIZE POSTERIOR PROBABILITY
Fermi Bubbles Workshop 12.4.2013
SPIN OF SGR A*
Sgr A*:
Low spin (if at all)!
MODELING M87: GRMHD JETS
• Blanford-Znajek/Blandford-Payne:
Electromagnetic extraction of black
hole spin/disk angular momentum.
• Large-scale ordered magnetic fields
• Canonical Structure:
• MHD Disk
• Magnetically dominated wind
• Force-free, roughly parabolic jet
McKinney & Blandford (2009)
SPIN OF M87
Fermi Bubbles Workshop 12.4.2013
𝐷 = 40 ± 2 𝜇𝑎𝑠
MODELING M87: GRMHD JETS
• Blanford-Znajek/Blandford-Payne:
Electromagnetic extraction of black
hole spin/disk angular momentum.
• Large-scale ordered magnetic fields
• Canonical Structure:
• MHD Disk
• Magnetically dominated wind
• Force-free, roughly parabolic jet
McKinney & Blandford (2009)
SPIN OF M87
Fermi Bubbles Workshop 12.4.2013
M87 Jet Widths
𝐷 = 40 ± 2 𝜇𝑎𝑠
MODELING M87: GRMHD JETS
• Blanford-Znajek/Blandford-Payne:
Electromagnetic extraction of black
hole spin/disk angular momentum.
• Large-scale ordered magnetic fields
• Canonical Structure:
• MHD Disk
• Magnetically dominated wind
• Force-free, roughly parabolic jet
McKinney & Blandford (2009)
SPIN OF M87
Fermi Bubbles Workshop 12.4.2013
M87 Jet Widths
𝐷 = 40 ± 2 𝜇𝑎𝑠
Hada et al. (2011)
SPIN OF M87: ROUGH CUT
Give non-spinning black holes best chance:
• Jets are disk driven
• Jets turn on (nearly) immediately
Jets start out slow (𝚪~𝟏 − 𝟐), emission scale ~ ISCO
SPIN OF M87
Chris Fach
Fermi Bubbles Workshop 12.4.2013
SPIN OF M87: ROUGH CUT
Give non-spinning black holes best chance:
• Jets are disk driven
• Jets turn on (nearly) immediately
Jets start out slow (𝚪~𝟏 − 𝟐), emission scale ~ ISCO
SPIN OF M87
Chris Fach
EHT size limit
Fermi Bubbles Workshop 12.4.2013
MODELING M87: GRMHD JETS
• Blanford-Znajek/Blandford-Payne:
Electromagnetic extraction of black
hole spin/disk angular momentum.
• Large-scale ordered magnetic fields
• Canonical Structure:
• MHD Disk
• Magnetically dominated wind
• Force-free, roughly parabolic jet
McKinney & Blandford (2009)
SPIN OF M87
Fermi Bubbles Workshop 12.4.2013
“SIMPLE” JET MODELS
• Axisymmetric & Stationary (+poloidal struc)
• Particle inertia irrelevant:
• + Boundary conditions at disk/black hole!
𝑭𝐿 = 𝜌𝑬 + 𝒋 × 𝑩 = 0
SPIN OF M87
Fermi Bubbles Workshop 12.4.2013
“SIMPLE” JET MODELS
• Axisymmetric & Stationary (+poloidal struc)
• Particle inertia irrelevant:
• + Boundary conditions at disk/black hole!
𝑭𝐿 = 𝜌𝑬 + 𝒋 × 𝑩 = 0
SPIN OF M87
Fermi Bubbles Workshop 12.4.2013
low RΩ
“SIMPLE” JET MODELS
• Axisymmetric & Stationary (+poloidal struc)
• Particle inertia irrelevant:
• + Boundary conditions at disk/black hole!
𝑭𝐿 = 𝜌𝑬 + 𝒋 × 𝑩 = 0
SPIN OF M87
Fermi Bubbles Workshop 12.4.2013
intermediate RΩ
“SIMPLE” JET MODELS
• Axisymmetric & Stationary (+poloidal struc)
• Particle inertia irrelevant:
• + Boundary conditions at disk/black hole! 𝜃
Choosing BCs
= choosing Ω(r) & Γ∞
𝑭𝐿 = 𝜌𝑬 + 𝒋 × 𝑩 = 0
SPIN OF M87
Fermi Bubbles Workshop 12.4.2013
tan 𝜃 ~𝑣𝐴
𝑅Ω~
𝐵𝑃
𝐵𝜙~𝛽∞
−1
large RΩ
“SIMPLE” JET MODELS
• Axisymmetric & Stationary (+poloidal struc)
• Particle inertia irrelevant:
• + Boundary conditions at disk/black hole!
Choosing BCs
= choosing Ω(r) & Γ∞
𝑭𝐿 = 𝜌𝑬 + 𝒋 × 𝑩 = 0
SPIN OF M87
Fermi Bubbles Workshop 12.4.2013
tan 𝜃 ~𝑣𝐴
𝑅Ω~
𝐵𝑃
𝐵𝜙~𝛽∞
−1
large RΩ
𝜃
Ω
𝑟
High spin
low spin
Disk Friendly!
FULL MHD VS. SIMPLE FORCE FREE
Disk
Wind
Jet
Fermi Bubbles Workshop 12.4.2013
SPIN OF M87
FROM STRUCTURE TO EMISSION
Particle acceleration
in the jet!
AEB & Loeb (2009) Dexter, McKinney & Agol (2012)
SPIN OF M87
Fermi Bubbles Workshop 12.4.2013
RESOLUTION, COOLING TIMES &
PARAMETERIZING IGNORANCE
Cooling
length from
injection at
100 G
Lensed Horizon size
• Particle acceleration
smoothed over jet on EHT
scales!
• Places lower limit on
density of nonthermal
electrons
• Parameterize by typical
load radius, and conserve
thereafter.
SPIN OF M87
Fermi Bubbles Workshop 12.4.2013
EMPIRICAL PRIORS
• Optical super-luminal motion of “knots” (6c at >1”, Γ∞~𝟓)
• Radio super-luminal motion of “knots” (~2.3c at few mas)
• Orientation of large-scale jet (E-W)
• Core Dominance
• Spectra?
Courtesy of Craig Walker
SPIN OF M87
Fermi Bubbles Workshop 12.4.2013
EMPIRICAL PRIORS: SPECTRA OF WHAT?
>1”
0.1”-1”
1 mas-0.1”
<1 mas
SPIN OF M87
Fermi Bubbles Workshop 12.4.2013
EMPIRICAL PRIORS: SPECTRA OF WHAT?
Strong non-VLBI
constraint on jet
models!
>1”
0.1”-1”
1 mas-0.1”
<1 mas
SPIN OF M87
Fermi Bubbles Workshop 12.4.2013
A MODEL FAMILY FOR M87
Load radius
SPIN OF M87
Fermi Bubbles Workshop 12.4.2013
A MODEL FAMILY FOR M87
Load radius Black hole spin
SPIN OF M87
Fermi Bubbles Workshop 12.4.2013
FIRST FITS: EXISTENCE
20
2
10
0
𝜒2
97
102 min 𝜒^2/DOF ~ 97/180!
(cf. Gaussian ~ 130/184!)
Loading
Radius in
𝐺𝑀/𝑐2
Black hole spin Fermi Bubbles Workshop 12.4.2013
FIRST FITS: SOME CHECKS
Loading radius
Jet position angle
(E of N), from
mm-VLBI alone! 𝑃 𝑅, 𝜉
𝑃
~70∘!
SPIN OF M87
Fermi Bubbles Workshop 12.4.2013
FIRST FITS: SOME CHECKS
Fermi Bubbles Workshop 12.4.2013
FIRST FITS: THE SPIN OF M87
M87:
(Very) high spin!
Caution:
spin calibration not
good near a~1
SPIN OF M87
Fermi Bubbles Workshop 12.4.2013
A TALE OF TWO BLACK HOLES
SGR A*
• Low accretion rate RIAF
• Flat radio spectra
+ break at 1mm
• 𝐵~102 G
• Well fit by physically
motivated models
• No prominent jet
• Low spin!
M87
Fermi Bubbles Workshop 12.4.2013
• Low accretion rate RIAF
• Flat radio spectra
+ break at 1mm
• 𝐵~102 G
• Well fit by (surprisingly simple)
physically motivated models
• Prominent jet
• High spin!
First empirical evidence that black
hole spin is important in AGN jets!
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