Coma Cluster

ira.inaf.it

Coma Cluster

Probing the Off-State of Cluster Radio Halos

Shea Brown

Bolton Postdoctoral Fellow

CSIRO, Astronomy & Space Science

12 September, 2011


Cluster Stacking

Coma Cluster

Bridge

Brown et al. (2011)


The Paradigm:

Relic

Bridge

Halo

Relic

Halo fronts

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Physics of Non-thermal Processes

Pfrommer et al. 2008

4


Physics of Non-thermal Processes

Halos

Halos?

(mini)

Pfrommer et al. 2008

5


Cluster Radio Sources: Halos, & Relics

Coma Cluster

Bridge

Brown & Rudnick (2011)

6


Physics of Non-thermal Processes

Halos

Halos?

(mini)

Pfrommer et al. 2008

7


Physics of Non-thermal Processes

Halos ?

Pfrommer et al. 2008

8


Physics of Non-thermal Processes

Brunetti &

Lazarian

Brunetti &

Lazarian

Brunetti &

Lazarian

Pfrommer et al. 2008

9


Physics of Non-thermal Processes

Relics

Relics

Pfrommer et al. 2008

10


Physics of Non-thermal Processes

Relics

Relics

Pfrommer et al. 2008

11


Probing the low surface-brightness universe

Where are the frontiers?

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Probing the low surface-brightness universe

Brunetti et al. 2009

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Probing the low surface-brightness universe

1)

Brunetti et al. 2009

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2)


Stack X-ray Luminous Clusters

• SUMSS

• Good surface-brightness sensitivity

• Retains large angular scales

• Sample

• In SUMSS

• L_x [0.1-2.4 keV] > 1.0E+44 erg/s

• z < 0.2

• Procedure

• Convolve each to 300 kpc beam (redshift dependent)

• Filter out emission smaller than 600 kpc

• Regrid/rescale to common physical pixel scale

• “Quality Control”

• Stack

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Stacking: SUMSS

SUMSS

• Work harder to find the optimal method

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Stack X-ray Luminous Clusters

• SUMSS

• Good surface-brightness sensitivity

• Retains large angular scales

• Sample

• In SUMSS

• L_x [0.1-2.4 keV] > 1.0E+44 erg/s

• z < 0.2

• Procedure

• Convolve each to 300 kpc beam (redshift dependent)

• Filter out emission smaller than 600 kpc

• Regrid/rescale to common physical pixel scale

• “Quality Control”

• Stack

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Cluster Stacking

Coma Cluster

Bridge

Brown et al. (2011)


Cluster Stacking

Coma Cluster

Bridge

Brown et al. (2011)


Cluster Distribution

Coma Cluster

Bridge

Brown et al. (2011)


Cluster Stacking

Coma Cluster

Bridge

Brown et al. (2011)


Cluster Stacking

Coma Cluster

Bridge

Brown et al. (2011)


Cluster Stacking

Coma Cluster

Bridge

Brown et al. (2011)


Cluster Stacking

Coma Cluster

Bridge

Brown et al. (2011)


Cluster Stacking

Coma Cluster

Bridge

Brown et al. (2011)


Where is the Flux coming from?

Coma Cluster

KS-Test

5%

“On-Correlation” Halos

Monte-Carlo

13±5% (none >39%)

Small “Off-Correlation”

Flux added to all

91% (5.0E+23 W/Hz)

Brown et al. (2011)


Where is the Flux coming from?

Coma Cluster

KS-Test

5%

“On-Correlation” Halos

Monte-Carlo

13±5% (none >39%)

Small “Off-Correlation”

Flux added to all

91% (5.0E+23 W/Hz)

Brown et al. (2011)


Distribution of Luminosity

Coma Cluster

Bridge

Brown et al. (2011)


What does this mean?

Coma Cluster

25

24

Bridge

23

Brown et al. (2011)

44.4 44.6 44.8 45 45.2 45.4


What does this mean?

1: Confirmation Coma of Cluster

bi-modality

25

1a: Confirmed down to

lower Lx

24

Bridge

23

Brown et al. (2011)

44.4 44.6 44.8 45 45.2 45.4


What does this mean?

1: Confirmation Coma of Cluster

bi-modality

25

1a: Confirmed down to

lower Lx

2: “Off-State”

Detected

2a: Lx and C

dependent

24

Bridge

23

Brown et al. (2011)

44.4 44.6 44.8 45 45.2 45.4


What does this mean?

1: Confirmation Coma of Cluster

bi-modality

25

1a: Confirmed down to

lower Lx

2: “Off-State”

Detected

2a: Lx and C

dependent

24

3: UNAMBIGUOUS: Most/All

massive clusters have magnetic

Bridge

fields…B 23 min ~ 1 µG

Brown et al. (2011)

44.4 44.6 44.8 45 45.2 45.4


Physics of Non-thermal Processes

Off-state?

Off-state?

Off-state?

Pfrommer et al. 2008

33


What does this mean?

Coma Cluster

25

24

Bridge

23

EMU Land

Brown et al. (2011)

44.4 44.6 44.8 45 45.2 45.4


Probing the low surface-brightness universe

Random things an EMU can do

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Hight Redshift Clusters: El Gordo

Coma Cluster

Bridge

Brown et al. (2011)


El Gordo

Coma Cluster

Bridge

Brown et al. (2011)


El Gordo

Coma Cluster

Bridge

Brown et al. (2011)


El Gordo

Coma Cluster

1.4 Mpc

Bridge

Brown et al. (2011)


Stacking: SUMSS

SUMSS

• Work harder to find the optimal method

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Large Scale Structure Probes

using tailed radio galaxies

PREMISES

! Tailed radio galaxies are formed by the relative motion

of AGN & external medium (ICM or WHIM)

! Gravitational collapse does NOT separate the AGN

motion (coupled to DM) and the gas motion

! Baryon physics (MHD) will yield shocks, turbulence and

separate the two motions, leading to tailed sources

Shocks from accretion

onto filaments & clusters

heat and stir up gas on

much larger scales than

cluster cores

Skillman et al. 2008

ApJ 689, 1063

Density

Temperature

32 Mpc

Rudnick & Brown 2011


Examples of tails+ over large distances

Virial

radius

SUMSS + ROSAT

12 Mpc superstructure

M. Mao, ATLAS 2010

Large WAT

• Objectives:

– Characterize relative velocity structure

of DM vs. gas

– Look for accretion shock

– Where/when do RG turn on?

Rudnick & Brown 2011


CSIRO Astronomy & Space Science

Shea Brown

Bolton Postdoctoral Fellow

Email: Shea.Brown@csiro.au

Web: http://www.atnf.csiro.au/people/Shea.Brown/

Thank you


EMU:

• Lx > 10 45 erg/s

• 107 clusters in the EMU sky

• Lx =5-10 *10 44 erg/s

• 142 clusters in the EMU sky

• Lx 1-5 *10 44 erg/s

• 532 clusters in the EMU sky

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