ALMA and SMA polarimetric observation towards M87
ALMA band3 image of M87
ALMA band 3 image of M87, not VLA
(Heavily self-calibrated)
Contour: Total intensity
Color: Polarized intensity
Bar: EVPA+90
Introduction
Astrophysical Jets
YSO jets
μ-QSO jets
SS 433
Mioduszewski+
Central Object: proto star
velocity : Γ ~ 1
size: ~ pc
GRB 030329
Taylor+
GRB jets ?
Central Object: ?
velocity : Γ ~ 100?
size: ~ ?
Central Object: Black hole/Nuetron Star
velocity : Γ ~ 2 - 3?( < 10 M◎ )
size: ~ 10 pc
Cyg A
Perley+
AGN jets
Central Object: Super Massive Black Hole
velocity : Γ ~ 30 ? (107-9 M◎)
size: ~ 106 pc
Towards Complete Understanding of AGN Jets
Two fundamental questions:
1. Essential question - What are AGN jets? How are the jets formed?
How are the jets accelerated?
How are the jets collimated?
What are the contents of AGN jet?
2. Philosophical question - Why do AGN jets exist? -
Why do some AGN (~ 10 %) have jets, some (~ 90%) do not?
What are the jets triggered by?
What is the role of AGN jets as a member of the universe?
Towards Complete Understanding of AGN Jets
Two fundamental questions:
1. Essential question - What are AGN jets? How are the jets formed?
How are the jets accelerated?
How are the jets collimated?
What are the contents of AGN jet?
2. Philosophical question - Why do AGN jets exist? -
Why do some AGN (~ 10 %) have jets, some (~ 90%) do not?
What are the jets triggered by?
What is the role of AGN jets as a member of the universe?
Importance of M 87
□ M 87 (Virgo A*)
- 1st discovered relativistic jet
Curtis 1918, Publications of Lick
Observatory 13, 31
- Low-Luminosity AGN:
~1042 erg s-1 (~ 10-6 Ledd)
Typical AGN with radiatively inefficient
accretion flow (RIAF)
- High Energy activities
Up to TeV gamma-ray
Miss-aligned BL Lac?
- 2nd largest apparent size of rs ( = 8 uas)
MBH = 6.6 (3.5) x 109 Msun; D = 16.7 Mpc
Best Source to understand AGN jet !!
Collimation profile of M87 jet
Asada & Nakamura 2012, Doeleman+2012,
Nakamura & Asada 2013, Hada+2013
Re-collimation?
Stawarz et al. 2006
Conical Jet
Z ~ r1
(Semi-)Parabolic Jet
Z ~ r1.7
Collimation profile of M87 jet
EVN 1.6 GHzAsada & Nakamura 2012, Doeleman+2012,
VLBA 5 GHz Nakamura & Asada 2013, Hada+2013
VLBA 8.4 GHz
Asada+ 2016, Asada+ in prep.
VLBA 15 GHz
VLBA 22 GHz
VLBA 43 GHz
VLBA 86 GHz
VLBI core
VSOP 5 GHz
VSOP 1.6 GHz
Jet width of M87 is in good agreement with
the expectation of GRMHD jet solutions
Nakamura+ in prep.
Acceleration and Collimation of the M 87 jet
Asada & Nakamura 2012, ApJ, 745, 28
Asada, K. et al. 2014, ApJL, 781, 2
HST-1
D E ABC
Z (α-1)/α
Vz ∝ Z 2/α
In relativistic regime,
α: power-law index of streamline (= 1.7)
Γ ∝ Z (α-1)/α
Komissarov et al. 2009 MNRAS, 394, 1182
In non- relativistic regime,
Vz ∝ Z 2/α
Nakamura & Asada 2013, ApJ,
Simultaneous acceleration and
collimation
of jet within re-collimation shock region.
Acceleration and Collimation of the M 87 jet
Asada & Nakamura 2012, ApJ, 745, 28
Asada, K. et al. 2014, ApJL, 781, 2
HST-1
D E ABC
Detection of fast motions
Z (α-1)/α
Vz ∝ Z 2/α
In relativistic regime,
α: power-law index of streamline (= 1.7)
Γ ∝ Z (α-1)/α
Komissarov et al. 2009 MNRAS, 394, 1182
In non- relativistic regime,
Vz ∝ Z 2/α
Nakamura & Asada 2013, ApJ,
Simultaneous acceleration and
collimation
of jet within re-collimation shock region.
What do we want to know more?
- Current our (my?) understanding:
Generally, both collimation profile and velocity field are
in good agreement with the expectation by GRMHD jet
- Next Objective:
How about energy budget?
Li+ 2009, ApJ, 699, 513
Ljet ( ~ 1044 erg s-1) vs Pacc (ηMc2)
It may imply very important question: BZ jet or BP jet?
How to probe mass accretion?
Probing Accretion Flow with FRM
Observer
Magnetized Plasma
(RIAF) ~ 107-9 K
Agol 2000, Quataert & Gruzinov 2000, Bower et al. 2003, Marrone et
al. 2006, Macquart et al. 2006
With RIAF model:
BH
Polarized emission
(innermost AF or Jet) ~ 1012 K
Marrone et al. 2006, ApJ, 640, 308
SMA Polarimetry towards Sgr A*
Marrone et al. 2006, ApJ, 640, 308
RM observation with SMA towards Sgr A*
- RM = (5.6 ± 0.7) × 105 rad m-2
M = 2 × 10-7 - 2 × 10-9 M yr-1
In the case of M 87
- Apply the same scheme to M 87
Back light would be innermost jet,
not AF
See Nagai’s
talk
On Per
A/3C84/NGC12
75
See also.
Plambeck+
2014 for
- With Chandra Observation
- rB ~ 230 pc (3 × 105 rs)
- PB ~ 7 × 1045 erg s-1
- MB ~ 0.12 M yr-1
Di Matteo et al. 2003, ApJ, 582,133
SMA observations
SMA observations
2013, Jan. 23
SMA images
2014, Jan. 09
2014, Feb. 28
2014, May 13
RM fitting towards M 87
1.5 × 105 rad m-2
2014, Jan. 09
EVPA [degree]
12 mon.
-2.1 × 105 rad m-2
2013, Jan. 27
-1.9 × 105 rad m-2
1.5 mon.
2014, Feb. 28
-3.2 × 105 rad m-2
3 mon.
2014, May 13
λ2 [mm2]
Mean RM and Mass accretion rate
Assuming no time variation,
<RM> = (-0.2 ± 1.3) × 105 rad m-2 !!
|RM| < 4.1 × 105 rad m-2 !!
M < 6.2 × 10-4 M yr-1 (at 21 rs)
M < 4.9 × 10-3 MB (at 21 rs)
Humm, SMA would not be sufficient….
Let’s go to longer wavelength (as λ2) and higher sensitivity
ALMA observations
ALMA observations
ALMA CY2 & CY3 observations:
CY2 obs.
Date: Sep, 19, 2015
Freq.: 90.5, 92.5 102.5 104.5
Resolution: 0.3 arcsec
CY3 obs.
Date: Nov, 11, 2015
Freq.: 90.5, 92.5 102.5 104.5
Resolution: 0.06 arcsec
Contour: Total intensity
Color: Polarized intensity
Bar: EVPA+90
SMA
ALMA observations
90.5 GHz
Without self calibration
QPOL
UPOL
Core (BH)
Core (BH)
~ 20 mJy
~ 30 mJy
Fractional Polarization ~ 1.5 %
(c.f., Fractional Polarization @ SMA ~ 1.5 %)
ALMA CY2 observations
92.5
QPOL
UPOL
102.5
104.5
RM with ALMA
Preliminary
RM = -2.5 × 104 rad m-2 !!
M = 9.9 × 10-5 M yr-1 (at 21 rs)
RM fitting towards M 87
Pang et al. 2011, MNRAS, 415, 1228
Yuan et al. 2012, ApJ, 761, 130
ALMA
M = 9.9 × 10-5 M yr-1 (at 21 rs)
M = 7.6 × 10-4 MB (at 21 rs)
Substantial decrease of the mass accretion rate.
Probably very strong constraint on RIAF !!
Figure courtesy: Masa Nakamura (ASIAA)
Comparison with Jet Power
Accreting Power :Pacc (= Mc2) ~ 5 × 1042 erg s-1
Ljet ~ (60 – 1000 %) x Pacc
Li+ 2009, ApJ, 699, 513
Jet would be supported by “BH spin” ?
But, η could be too large? (e.g., upto ~100% for GRMHD jet)
Tchekhovskoy and McKinney 2012
Ljet is overestimated? (pdV and Pacc at different epoch?)
Pacc is underestimated? (viewing angle of 16 °?)
See, Moscibrodzka’s talk
Summary
Summary
- Collimation profile and Velocity field of M87 jet is
in good agreement w
- We conducted mm polarimetry to measure RM.
- Estimated M of M87 to be 9.9 × 10-5 M yr-1
- M is substantially decreased, consistent with ADIOS
- Accreting Power may not be sufficient
to support Kinetic Power of Jet
- RM studies with EHT/GLT+ALMA will reveal AF structure
EVPAs of M87
Time variation of PAcore
T ~ 6 weeks.
P.A. of extend jet
EVPAs of M87 with HST
Abramowski et al. 2012
- Frac P with SMA ~ 1- 2 %
(c.f., Frac P with HST ~ 2 %
(occasionally 10 %))
Avachat et al. 2016
- SMA may see the fastest time variation
- Probably see the same region
Origin of the polarization emission
□ Polarized flux towards core with ALMA ~ 35 mJy
( ~ a few mJy? with VLBA at 86 GHz)
□ Fractional polarization towards core ~ 1 – 2 %
□ Current VLBI at 86 GHz missing most of the flux:
-> Diffuse and extended structure?
(Note: epochs of observations are different)
Hada et al. 2016
0.4 mas (= 200 Rs)
0.05 mas (= 40 Rs)
Origin of the polarization emission
□ SMA/ALMA and HST may see the same region
□ OTOH, Core show the rapid time variation;
shortest time sale we detected ~ 6 weeks,
corresponds to light crossing time of 0.04 pc (~ 60 Rs)
Hada et al. 2016
0.4 mas (= 200 Rs)
0.05 mas (= 40 Rs)
M 87 and its Accretion Flows
- Low-Luminosity AGNs are subclass of AGN. (L < 10-3 Ledd)
- LLAGNs (Ho et al. 1997) are considered to accommodate RIAF
- M 87 is categorized as LLAGN.
LLAGN
No Big Blue Bump
(Ho et al. 2009)
Accretion flow of LLAGNs
Three types of RIAFs:
ADAF
ADIOS
CDAF
(Ichimaru 1977;
Narayan & Yi 1995)
(Blandford & Begelman
1999)
(Igumenshchev &
Abramowicz 1999)
~ (r/rB)0
~ (r/rB)0-1
~ (r/rB)1
Structure
M
rB: Bondi radius (~ 104-6 rs)
- Substantial decrease of the mass accretion rate
can be expected for ADIOS and CDAF !!
Mass Accretion Rate is fundamental parameter to consider
energy balance between Lacc and Lrad or Ljet.
EVPAs of M87
P.A. of extend jet
EVPAs of M87
2014, Feb. 28
Knot A
Knot C
2014, May 13
P.A. of extendKnot
jet C
Knot A
Knot B
Knot B
EVPAs of M87
Knot A
Knot C
Knot B
Perlman+
P.A. of extend jet
EVPAs of M87
Time variation of PAcore
T ~ 6 weeks.
P.A. of extend jet
EVPAs of M87 with HST
Abramowski et al. 2012
- Frac P with SMA ~ 1- 2 %
(c.f., Frac P with HST ~ 2 %
(occasionally 10 %))
Avachat et al. 2016
- SMA may see the fastest time variation
- Probably see the same region
Issues
Presentation by Monika Moscibrodzka et al. @ EHT2016
Issues
Presentation by Monika Moscibrodzka et al. @ EHT2016