Post on 12-Jan-2016
transcript
Thermal / Non-thermal plasmaInteractions in Clusters
The Good, the Bad & the Puzzling
L. Rudnick, MN Inst. for Astrophysics, Zeldovich 100
The BIG Questions
• How can relativistic plasmas, seen through synchrotron radiation, reveal the dynamics and evolution of clusters? SYNCHROTRON, clues to DYNAMICS ?
• How does the dynamics of the thermal plasma affect the growth of the magnetic field and the acceleration of relativistic particles?
DYNAMICS causes B field and CRs ?
L. Rudnick, MN Inst. for Astrophysics, Zeldovich 100
Key Messages
L. Rudnick MN Inst. for Astrophysics Zeldovich 100
GOOD NEWS: хорошие новости • AGN influences on thermal X-ray plasma are welldocumented (heating, cavities, etc) • Shocks seen in radio, sometimes in X-ray & S-Z, are consistent with expectations from theory, connected to cluster mergers • Radio halos likely result from expected turbulence in mergers
BAD NEWS: плохие новости • Mach numbers expected from simulations and measured in X-ray inconsistent with spectral index of radio emission. • Missing shocks, either radio or X-ray
PUZZLING NEWS: головоломки • Mild mergers with no shocks also produce giant radio halos. • 3D structure of giant shock in Abell 2256 is not simple to explain • Radio galaxies sometimes seen at edge of shocks – why?
Юрий Никулин
Max Otto von StierlitzМаксим Максимович Исаев
with support from U.S. NSF, AST112195
The GOOD News
Radio galaxy ICM interactions
L. Rudnick, MN Inst. for Astrophysics, Zeldovich 100
ACTIVEPASSIVE
The GOOD News• Merger shocks: simulations and observed relics
L. Rudnick, MN Inst. for Astrophysics, Zeldovich 100
Vazz
a et
al.
2012
, MN
RAS
421
1868
The GOOD News
L. Rudnick, MN Inst. for Astrophysics, Zeldovich 100
Keeping electrons energized: CRe lifetimes ~ 108 y
CRe diffusion times ~ 1010 y
W. Couch
M. O
wers
Merger-driven turbulence
The GOOD News
• Radio halos mergers
L. Rudnick, MN Inst. for Astrophysics, Zeldovich 100
Cassano+ 2011
HalosDISTURBED
RELAXE
D
The GOOD News
L. Rudnick, MN Inst. for Astrophysics, Zeldovich 100
A. S
imio
nesc
u et
al.
2013
ApJ
775
4
Planck intermediate results. X. Physics of the hot gas in the Coma cluster, 2013
Consistent shock story - Radio, X-ray, S-Z
Brown & Rudnick, 2011
RADIO
X-RAY
S-Z
Mismatched Mach numbers ?
M < 2
3.3 < M < 4.6
X-ray shock
radio spectrum
The BAD NewsO
grea
n+20
13
X-ra
y sh
ock
radi
o sp
ectr
umva
n W
eere
n+ 1
2 ainj= -0.6 to -0.7
Do shocks look too efficient?
Tension with g-ray limits?
The BAD News
The BAD NewsX-ray shock
Radio shock
Where’s the radio shock?
Why theoffset?
The PUZZLING Newsголоволомки
L. Rudnick, MN Inst. for Astrophysics, Zeldovich 100
Expl
orin
g
low s
urfa
ce b
right
ness
radi
o em
ission
Farnsworth+2013
Can MILD mergers Giant Radio Halos?
Farnsworth+ 2013
The PUZZLING News
RADIOX-Ray
Rossetti+ 2013Abell 2142
Abell 2256 – where’s the shock?
with F. Owen, NRAO & J. Eilek, NMIMT
RadioX-ray
The PUZZLING News
Abell 2256 – where’s the shock?
with F. Owen, NRAO & J. Eilek, NMIMT
The PUZZLING News
Flat spectrum
Steep spectrum
The PUZZLING NewsRadio Galaxy – relic/shock connection?
Bonafede+14
van Weeren+ 2010
Pizzo+2010
Key Messages
L. Rudnick MN Inst. for Astrophysics Zeldovich 100
GOOD NEWS: хорошие новости • AGN influences on thermal X-ray plasma are welldocumented (heating, cavities, etc) • Shocks seen in radio, sometimes in X-ray & S-Z, are consistent with expectations from theory, connected to cluster mergers • Radio halos likely result from expected turbulence in mergers
BAD NEWS: плохие новости • Mach numbers expected from simulations and measured in X-ray inconsistent with spectral index of radio emission. • Missing shocks, either radio or X-ray
PUZZLING NEWS: головоломки • Mild mergers with no shocks also produce giant radio halos. • 3D structure of giant shock in Abell 2256 is not simple to explain • Radio galaxies sometimes seen at edge of shocks – why?
Юрий Никулин
Max Otto von StierlitzМаксим Максимович Исаев
with support from U.S. NSF, AST112195
radio.galaxyzoo.org