First M87 Event Horizon Telescope Results:
Shadow of the Supermassive Black Hole

Geoffrey C. Bower
EHT Project Scientist(ASIAA, Hilo)M87

42 μas
MBH=6.5 +/- 0.7 x 109 Msun

First Image of a Black HoleGlobal Team at the EHT 2018 Conference

EHT-M87 24 September 2019

Members of the EHT team at Telescopes

EHT-M87 24 September 2019

EHT-M87 24 September 2019

Board Institutions
EHT-M87 24 September 2019

Funders
EHT-M87 24 September 2019

Affiliates
EHT-M87 24 September 2019

EHT-M87 24 September 2019

Publications

Meerkat+GBT

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Strong Evidence for a Black HoleGRAVITY Collaboration 2018
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The Largest Black Holes on the Sky

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Distance and Mass of M87

D=16.8 +/- 0.8 Mpc

Walsh et al 2013, Gebhardt et al 2011

à 𝜃shadow ~ 20 – 40 μas
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Curtis 1918

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EHT-M87 24 September 2019

Light Bent by the Black Hole

Bardeen 1973

Luminet 1979

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The Black Hole Shadow

𝜃shadow ~ 10 GM/Dc2 ~ 50 μas

Falcke, Melia, Agol 2000
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Shiokawa et alEHT-M87 24 September 2019

MM VLBI Imaging of M87

Doeleman et al 2012

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ALMAEHT-M87 24 September 2019

EHT – 4x Mk664 Gbps

Whitney et al 2012
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Event Horizon Telescope in 2017

• Atacama Large Millimeter Array (ALMA), Chile• ALMA Pathfinder Experiment (APEX), Chile• James Clerk Maxwell Telescope (JCMT), Hawaii• Large Millimeter Telescope (LMT), Mexico• IRAM 30-meter Telescope, Spain• South Pole Telescope (SPT), South Pole• Submillimeter Telescope (SMT), Arizona

M. Johnson/SAO• Submillimeter Array (SMA), Hawaii

eht-hops

CASA

AIPS

Calibrateeht-im

SMILI

CLEAN

Image

KORAL

Simulate

Image

Modelbhac

iharm3dH-AMRgeometric

GRMHD

EHT-M87 24 September 2019

0.6

HOPS-CASA

0.8

506/1677
223/1198

0.8

CASA-AIPS

524/1672
392/1133

0.4
0.2
3

HOPS-AIPS

03474/1669
382/1123

0.6

0.6

0.4

0.4

0.2

0.2

303

303C279
M87

Scaled Frequency

0.8

HOPS-CASA

0.8

0.8

245/2227
5/928

0.6
0.4
0.2

330.8
0.6

HOPS-CASA

0.8

299/5628
14/14210.8

210/5524
26/1047

0.4
0.2
3HOPS-AIPS

0030.6

0.4

0.4

0.2

0.2

3CASA-AIPS
236/5487
17/10230.6

03ln AC/ ln AC

3HOPS-AIPS

0.8

202/2185
11/789
0.6

0.4

0.4

0.2

0.2

303

CASA-AIPS 3C279
M87

192/2180
8/780

0.6

|V |/
Scaled Frequency

Scaled Frequency

Extensive Cross-Comparisons

0C/3

303C

3C279
M87

3EHT-M87 24 September 2019

April 6

April 10

April 1165432150 µas

Brightness Temp. (109 K)

April 50EHT-M87 24 September 2019Representative GRMHD Model Image of M87
EHT2017 image

Simulated image
from GRMHD model

Simulated image
convolved with20 𝜇as beam

EHT-M87 24 September 2019

EHT-M87 24 September 2019

Visibility Amplitude (Jy)100

10 110 2• Ring-like structure• Some asymmetry02• Large-scale structure resolved

4Baseline (G )68

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M87

Circular
Flux depression > 10:1
Asymmetric brightness
Minor variability

42 μas
MBH=6.5 +/- 0.7 x 109 Msun

First Image of a Black HoleEHT Future• Sgr A*!
• Polarimetry• AGN• 2018 & 2020 Epochs• Multi-wavelength Data
• Movies• Higher image fidelity• More sources
EHT-M87 24 September 2019