Shocking News from Galaxy Clusters Marcus Brggen Franco Vazza - - PowerPoint PPT Presentation

▶
shocking news from galaxy clusters
SMART_READER_LITE
LIVE PREVIEW

Shocking News from Galaxy Clusters Marcus Brggen Franco Vazza - - PowerPoint PPT Presentation

Mar 22, 2023 534 likes •922 views

Shocking News from Galaxy Clusters Marcus Brggen Franco Vazza (Hamburg) Francesco De Gasperin (Hamburg) Annalisa Bonafede (Hamburg) Reinout van Weeren (CfA) Georgiana Ogrean (CfA) Huub Rttgering (Leiden) Will Dawson (UC Davis) David

slide-1
SLIDE 1

U of Hamburg M Brüggen

Shocking News from Galaxy Clusters

Marcus Brüggen

Franco Vazza (Hamburg) Francesco De Gasperin (Hamburg) Annalisa Bonafede (Hamburg) Reinout van Weeren (CfA) Georgiana Ogrean (CfA) Huub Röttgering (Leiden) Will Dawson (UC Davis) David Wittman (UC Davis) James Jee (UC Davis) Andra Stroe (Leiden)

slide-2
SLIDE 2

U of Hamburg M Brüggen

What can mergers between galaxy clusters teach us about:

  • 1. Particle acceleration (and generation of B fields)?
  • 2. The nature of Dark Matter?
  • 3. Galaxy Evolution?
slide-3
SLIDE 3

U of Hamburg M Brüggen

Merger%Scenario%

Key%

Dark% Ma0er% Gas% Dark%Ma0er% +%Gas% Galaxies%

S" N"

slide-4
SLIDE 4

Merger%Scenario%

Key%

Dark% Ma0er% Gas% Dark%Ma0er% +%Gas% Galaxies%

S" N"

Gravita8onal%A0rac8on%

slide-5
SLIDE 5

U of Hamburg M Brüggen

Merger%Scenario%

Key%

Dark% Ma0er% Gas% Dark%Ma0er% +%Gas% Galaxies%

S" N"

11/14/2012%

slide-6
SLIDE 6

Merger%Scenario%

Key%

Dark% Ma0er% Gas% Dark%Ma0er% +%Gas% Galaxies%

S" N"

11/14/2012%

slide-7
SLIDE 7

U of Hamburg M Brüggen

Merger%Scenario%

Key%

Dark% Ma0er% Gas% Dark%Ma0er% +%Gas% Galaxies%

N+S$

11/14/2012%

slide-8
SLIDE 8

U of Hamburg M Brüggen

Merger%Scenario%

Key%

Dark% Ma0er% Gas% Dark%Ma0er% +%Gas% Galaxies%

N S

Momentum% Momentum% 11/14/2012%

slide-9
SLIDE 9

Merger%Scenario%

Key%

Dark% Ma0er% Gas% Dark%Ma0er% +%Gas% Galaxies%

N S C$

11/14/2012%

Shocks%%%%%%%Radio%relics%

slide-10
SLIDE 10

U of Hamburg M Brüggen

What are radio relics?

PSZ1 G108.18-11.53

colour: X-ray contours: radio

De Gasperin 14

ZwCl 0008.8+5215

van Weeren et al. 11

slide-11
SLIDE 11

U of Hamburg M Brüggen

The sausage: CIZA J2242.8+5301

GMRT 610 MHz, resolution of 4.8 arcsec×3.9 arcsec. total on source time 9 hrs, bandwidth of 32 MHz.

2 Mpc 50 kpc 1.5 Mpc

van Weeren, Röttgering, Brüggen, Hoeft, Science, 330, 347 (2010)

slide-12
SLIDE 12

Akamatsu, van Weeren, Kawahara, Röttgering, MB, Hoeft, Sobral, Ogrean, Kaastra 2014

slide-13
SLIDE 13

Dawson et al. 2014

Smoothed galaxy luminosity density map of CIZA Subaru data red sequence selection

slide-14
SLIDE 14

U of Hamburg M Brüggen

Problem #1: Efficient electron acceleration at low Mach numbers

1

slide-15
SLIDE 15

U of Hamburg M Brüggen

Shock-Drift Acceleration

slide-16
SLIDE 16

U of Hamburg M Brüggen

Shock-Drift Acceleration

up down

shock normal

θ

B field

Need:

θ ≥ 60o Ms ≤ 6 β ≥ 20 106K ≤ Te ≤ 109K

Guo et al. 2014

slide-17
SLIDE 17

polarisation @ 2.2 GHz: 50 % E-vectors and why is it so smooth?

slide-18
SLIDE 18

U of Hamburg M Brüggen

slide-19
SLIDE 19

U of Hamburg M Brüggen

Still some questions...

slide-20
SLIDE 20

Abell 2146 puzzle

Mach numbers:

M = 2.1 +/- 0.2 M = 1.6 +/- 0.1

Chandra 0.3-7 .0 keV , Russell et al. 2011

GMRT 325 MHz

Why do we not observe radio emission from these shocks?

Tuesday, March 26, 13

Slide from Reinout

slide-21
SLIDE 21

Bonafede et al 2014

PLCKG287.0 +32.9

Connection AGN relic?

red: XMM blue: 325 MHz

slide-22
SLIDE 22

PLCKG287.0 +32.9

slide-23
SLIDE 23

U of Hamburg M Brüggen

Problem #2: Where are the protons?

2

slide-24
SLIDE 24

U of Hamburg M Brüggen

Where are the protons?

slide-25
SLIDE 25

Vazza, Eckert & Brüggen (in prep.)

Fermi-upper limits (stacked) Ackermann et al (2013)

slide-26
SLIDE 26

U of Hamburg M Brüggen

Caprioli et al. 2014

slide-27
SLIDE 27

U of Hamburg M Brüggen

Problem #3: Where does the B field come from?

3

slide-28
SLIDE 28

Magnetic field amplification by cosmic rays

precursor exerts a force on the upstream plasma not proportional to gas density Density fluctuations acceleration fluctuations density fluctuations

FCR

upstream downstream CR

density fluctuations

shock

slide-29
SLIDE 29

Cosmic-ray driven turbulence

Brüggen 2013

slide-30
SLIDE 30

Magnetic field amplification

Brüggen 2013

max av par perp M=100 M=3 M=2

can be probed with Faraday rotation...

slide-31
SLIDE 31

U of Hamburg M Brüggen B field shock many shocks

  • f different M

strong shocks align fields and amplify strong shocks also dominate radio emission(?)

slide-32
SLIDE 32

U of Hamburg M Brüggen

https://lofar.physik.uni-bielefeld.de//

Hamburg LOFAR station just completed

slide-33
SLIDE 33

LOFAR

10 hrs GMRT @ 150 MHz

10 hrs LOFAR @150 MHz

  • 0.3 % of the data
  • 1/

4 of the resolution available

Toothbrush cluster

22 Tuesday, March 26, 13

Slide from Reinout

slide-34
SLIDE 34

van Weeren et al in prep

slide-35
SLIDE 35

Stroe, Sobral, Dawson, Jee, Hoekstra, Brüggen, et al. 2014

H alpha Luminosity Function

slide-36
SLIDE 36

U of Hamburg M Brüggen

Conclusions

  • Relativistic plasma is great for finding shocks in cluster outskirts and

learn about B-fields

  • Some cluster shocks show relics, some do not.
  • Relics show best evidence to date for shock acceleration at low M
  • Efficient electron acceleration at low-M shocks at high beta via SDA
  • Why are there no gamma rays detected?
  • Look for offset between DM and galaxy centroid - SIDM?
  • Star formation increased behind shock in CIZA 2242 but not in

toothbrush

  • First LOFAR observations of relics are becoming available
slide-37
SLIDE 37

U of Hamburg M Brüggen

Thank you!