Transcript Solar ~Axions

Solar ~axions
K. Zioutas
Università di Patrasso & CERN
 EU-ILIAS AXIONS
 brillante idea!
INFN Sezione di Trieste
Università di Trieste - Dipartimento di Fisica
3 ottobre 2006
 u?
The CAST collaboration  LLNL
 P. Sikivie
 Istanbul
Profit / encouraged from :
E. Arik / TU
M. Asplund / Au
K. Dennerl / MPE
L. Di Lella / CERN
M. Grande / RAL-UK
Th. Hackman / UH-FI
D.H.H. Hoffmann / TU-Darmstadt
J. Huovelin / UH-FI
J. Jacoby / U. Frankfurt
B. Lakic / RBI - Zagreb
S. Orlando / INAF-Palermo
A. Ortiz / USA
Th. Papaevangelou / CERN
Y. Semertzidis / BNL-USA
Sp. Tzamarias / HOU-GR
O. Vilhu / UH-FI
….m.m.
CAST motivated work
 beyond(?) CAST
 feedback!
Thanks to PVLAS:
Axion searches in the spotlight

Attempts to reconcile
PVLAS result with
CAST and other
limits…
And others…
Axion searches in the spotlight
• The interest on axions reaches also
string theorists…
Motivation?
Alvaro de Rujula
< 1998
Axion  Dark Matter particle candidate  new physics
http://www.fnal.gov/directorate/Longrange/PartAstro1003_Talks/Bauer.pdf
The Primakoff Effect
1951
H. Primakoff
g
behind all present axion work
×
B
before CAST:
 BNL & Tokyo
 axion-Bragg @ Ge, NaI, …
CAST
Axion - source
↓
P. Sikivie
Axion - detection
↓
α
gvirtual
X
B
g
 Inner Sun imaging!
new
Solar axion spectrum
Ea  4.2 keV
2
g aγγ



  10
1 
10
GeV


Paγ  1.710-17 
2004 data analysis
CCD/Telescope
• Spot position well
determined
• Full sensitivity of telescope
exploited
• Counts inside the spot
compatible with background
Tracking data
new
Signal simulation
•No axion signal detected
X ← PVLAS
CAST
2004
• x7 improvement.
• competes with best
astrophysical limit @
coherence masses.
for
?
bridge the gap PVLAS ↔ CAST
 demanding + inspiring new experiments
K. van Bibber et al.
 1989
CAST Phase II (4He)
Present
progress
Present
progress
Cosmological limit
~4 mbar
~0.215 eV
Hannestad etal, JCAP 0507 (05) 002
OFF-resonance axion-converted analog spectrum
new
2nd X-ray optic
• Measured effective area (throughput)
very different than simulations
• Several factors at play
mimic CAST

(in)direct axion-signals ?
Challenging questions @ Sun
 11 years cycle!?
 Solar corona heating
 Flares  instantaneous particle acceleration
 Dynamo(s)  B⊙
 Sunspots heating
 Neon composition
 “Solar Model problem”!
 » smoking-gun signatures for new physics?
 solar ~axions 
1st
axion ⇄ photon
 oscillations
┌► X-rays, visible, …
Unexpected (dis)appearance of photons
Lx ~ B2
à la Sikivie
à la van Bibber
~ρ
 dynamical behaviour  transient effects
2nd
axion → 2γ
 ubiquitous @ Sun, …
 decay of gravitationally trapped
massive ~axions, e.g. KK-type  generic
▼
unexpectedly hot “plasma”
▼
Lx ≈ constant
 solar observations require both components 
Solar temperature distribution
 solar corona problem
Grotrian (1939)
 The enigma of coronal heating represents… one of the
outstanding puzzles of stellar astronomy + one of the
most challenging problems in astrophysics.
S.M. Jefferies, McIntosh, Armstrong, Bogdan, Cacciani, Fleck, ApJL. 648 (10.9.2006)151
E R Priest, D W Longcope, J Heyvaerts, ApJ. 624 (2005) 1057
 The mechanism that heats the solar corona remains elusive.
 Everything above the photosphere …would not be there at all.
M.J. Aschwanden, A.I. Poland, D.M. Rabin, A.R.A.A. 39 (2001) 75
C.J. Schrijver, A.A. van Ballegooijen, ApJ. 630 (2005) 552
Stellar observations + theory on stellar evolution
↛ stars might possess atmospheres … that produce X-rays.
L.W. Acton, Magnetodynamic Phenomena in the Solar Atm. (1996) 3
 The magnetic field plays a crucial role in heating the solar
corona (this has been known for many years) 
the exact energy release mechanism(s) is(are) still unknown.
 the process by which it is converted into heat and other forms
remains a nagging unsolved problem.
K. Galsgaard, C.E. Parnell, A.& A. 439 (August 2005) 335
R.B. Dahlburg, J.A. Klimchuk, S.K. Antiochos, ApJ. 622 (2005) 1191
On solving the Coronal Heating Problem
▼
“one of the most important problems in astrophysics”
“There are many different heating mechanisms operating in the corona ”
J.A. Klimchuk, Solar Physics 234 (2006) 41
 invited review
↛
 2nd component
B-modified solar
axion spectrum?
2005-  RHESSI
SMART_1
La ≈0.16Lsolar ≈ 106 t/s  Ltrapped ≈ 200 g/s ≈ 1019 g  now
http://science.nasa.gov/headlines/y2006/10may_longrange.htm

Solar seismic models + the ν-predictions
103-104 T
2-3 T
30-50 T
...seismic models are
very close to the real
Sun in the regions of
concern.
But 
… as far as the internal
rotation
profile
is
not
included in the study, new
surprises may appear …
- - - - - Bahcall etal.
Magnetic fields simulated. Normalized amplitudes by
their maximum intensity.
S Couvidat, S Turck-Chieze, AG Kosovichev. ApJ. 599 (2003) 1434
~105 Tesla
 change significantly
solar ν-fluxes
OFFPOINTING:
1992
2005-
 YOHKOH
 RHESSI
 33 days
←
PVLAS  Solar KK-axions
≠ QCD axions
?
DiLella, Z., Astropart. Phys.19 (2003)145
http://www.unine.ch/phys/corpus/tpc2002/zioutas.ppt
2006
Values in 3-12 keV correlate with GOES implying signal!
How is this energetic e- population created in the Quiet Corona ?
 more offpointing 2006 thru 2007
http://sprg.ssl.berkeley.edu/~hannah/presentations/pdf_spd_06.pdf
not ≠ reconstructed solar X-ray spectrum
see DiLella + Z. (2003)
What produces solar flares?  μflares, nanoflares,..
 The precise causes of solar flares & CMEs
is one of the great solar mysteries. (2003)
 flare-quiet ≈ flare-imminent regions
↓
… storage and release of the energy that powers solar flares
is generally believed to be in the coronal magnetic field …
+ magnetic reconnection necessary for solar flares to occur.
G. Barnes, K.D. Leka, ApJ. 646 (August 2006) 1303,
ibid. 595 (2003) 1277
DH Hathaway, http://science.msfc.nasa.gov/ssl/pad/solar/quests.html (2003)
Electrical Current Issue in Flares
Rate of e- acceleration  1037e-/s  1018 A

B ≈ 104 T
G. Emslie (2005)
http://www.astro.auth.gr/~vlahos/ascona/memberstalks/energeticsEmslie.ppt#368,9,Electrical
axion→γ
(transient) trigger!?
 1st component
~B 2
 4 cases ~ consistent with B2
 with “some” σ’s each
 combined + more findings
> σ’s
One key issue to understand the coronal heating problem is to know
how magnetic energy can be stored and then released in a solar
magnetic configuration.
S Regnier, RC Canfield, Proc. SOHO 15 Workshop - Coronal Heating,
St. Andrews, Scotland, 6-9 September 2004, ESA SP-575 (2004) 255
In the axion scenario 
B = catalyst
⊗ ρlocal,Δt ~ ωplasma=maxion
the magnetic field can transform out streaming
~axions-to-photons + vice versa
+
 transient brightenings!
 CAST @ Sun
The long-term evolution of AR 7978 (S10o)  Yohkoh / SXT
st
1
Lx

Lx  B1.94±.12
 ~ filter independent
Eγ < 4 keV
RHESSI :
often hard X-ray
emission from
non-flaring ARs.
 ≳ 5 keV
Hannah, Hurford,
Hudson,
Abstract:
2005AGUFMSH11A0242H
AGU Fall meeting,
5-9/12/2005
B [Gauss]
<X-ray flux> / cm2 vs. <B>
July-Nov. 1996
From: L. van Driel-Gesztelyi, P. Démoulin, C.H. Mandrini, L. Harra, J.A. Klimchuk, ApJ. 586 (2003) 579
K. Zioutas, K. Dennerl, M. Grande, D.H.H. Hoffmann, J. Huovelin, B. Lakic, S. Orlando, A.Ortiz,
Th. Papaevangelou, Y. Semertzidis, Sp. Tzamarias, O. Vilhu J. Phys. Conf. Ser. 39 (2006) 103
nd
2
Power-law index n of Lx ~ Bn =(time)
 YOHKOH / XRT
The relation between the solar soft X-ray flux (below ~4.4keV) …and B can
be approximated by a power law with an averaged index close to 2.
Benevolenskaya, Kosovichev, Lemen, Scherrer, Slater ApJ. 571 (2002) L181
Note:
axion-to-photon oscillation ∝ B2

e.g., in CAST
DHH Hoffmann, K. Z., Nucl. Phys. B Suppl. 151 (2006) 359
 11 years solar cycle? 
FLARES
 origin?
3rd
Lx
↑
The Electron “Problem”
e- flux~105 hard X-rays
from Bremsstrahlung!
 Bmax
Rebinned peak flare X-ray intensity vs. Bmax
D. Mason et al., ApJ. 645 (10.7.2006)1543
 B2 correlation
G. Emslie (2005)
http://www.astro.auth.gr/%7Evlahos/ascona/memberstalks/energeticsEmslie.ppt#366,8
SUNSPOTS
 origin?
relative to Photosphere
(=Quiet Sun)
50% of the quiet Sun
th
4
K. Zioutas, K. Dennerl, M. Grande, D.H.H. Hoffmann, J. Huovelin, B. Lakic, S. Orlando, A.Ortiz,
Th. Papaevangelou, Y. Semertzidis, Sp. Tzamarias, O. Vilhu J. Phys. Conf. Ser. 39(2006)103
Plot reconstructed from : SK Solanki A.&A. Rev.11 (2003) 153 
• fundamental questions remain unanswered.
• is an additional mechanism needed?

SUNSPOTS
Yohkoh - XRTelescope
 TAUP2005
Solar Corona Problem
<1.3 MK> quiet Sun
Sunspots = “dark spots”  T
⇩
 photosphere
~ 4500K  heat flux problem
in umbra + penumbra
Spruit, Scharmer, A.&A. (2005), astro-ph/0508504
<1.8 MK> Umbra
 Corona
Soft X-ray fluxes
Penumbra
<2.4 MK>
T
⇧
Sunspots: ~ 50 - 190 DN/s
Quiet Sun: ~ 10 - 50 DN/s
(ARs:
~ 500 - 4000 DN/s)
 sunspot plasma parameters
are higher than @ quiet-Sun
 B ~ 2 kG above most sunspots !
Temperature distributions
A.Nindos, M.R.Kundu, S.M.White, K.Shibasaki, N.Gopalswamy,
ApJ. SUPPL. 130 (2000) 485
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
 “… sunspots remain mysterious”.
 The penumbral mystery … the very reason for its existence unknown.
http://www.solarphysics.kva.se/NatureNov2002/background.html
Long-lasting sunspots appear in this sequence of drawings made by
Galileo himself as he observed the Sun from June 2nd to 26th, 1612.
http://science.nasa.gov/headlines/y2001/ast07nov_1.htm
more?
Standard Solar Model problem with:
Solar metallicity
 manifestation of 2 opposite effects?
M. Asplund et al., astro-ph/200410214 :
measured photospheric abundances of
C, N, O, Ne 25-35% below prediction!
To rescue the agreement between the SS
Model and Helioseismology the radiative
opacity reduction by the downward
revision of the C,N,O,Ne abundances
(which provide a major source of opacity
for the solar interior, which determines the
internal solar structure and the depth of
the
convection
zone)
must
be
compensated by other elements. Ne is
the only suitable element, since its
photospheric abundance is not well
determined due to absence of strong
lines; the Ne solar abundance is obtained
either from solar energetic particles or
from coronal X-rays or EUV. Also above
20 quiet solar Active Regions:
Quiet ARs: Ne/O also at ~0.15.
Flares: enhanced Ne detection (~2x),
Ne/O abundance ratios vs. coronal activity.
models incorrectly predict
• the depth of the convection zone,
• the depth profiles of sound speed and density,
• the helium abundance
J.J. Drake, P. Testa, Nature 436 (2005) 525
Stellar spectra are likely dominated by photons from
intense flares. Therefore flare enhanced Ne/O ratios
 no solution of the problem!
J.T. Schmelz et al., ApJ. 634 (2005) L197
i.e., some mechanism would preferentially dredge up Ne from the photosphere!
Ne/O = 0.52 would reconcile low C,N,O
abundances with helioseismology.
Solution: stellar values!?
The problem: find a truly solar-like star.
 None star known has such a low Ne/O
ratio as observed for the Sun.
 Why the Sun is so special?
C.Liefke, JHMM. Schmitt, A&A L. (2006)
Martin ASPLUND,
private communication, 11/9/2006
“the most promising aspect in my opinion is not the increase in
radiation pressure, but rather the extra heating from absorption
of axions in the atmosphere which might increase the
temperature in the spectral line formation region of the Sun.”
▼
!Solar axion surface effects at work!
… changing diffusion locally.
 No problem for the Solar Model
• Solar atmosphere:
 differential rotation
• Solar ν’s & X-rays
 oscillations / correlations

Soft X-ray Corona
 WL K-Corona?
mm
 photosphere
Why this occurs is unclear!
D. Altrock,
Private communication
The rotation profile across latitude for all years averaged.
Short solid line: sunspot groups; thin solid line: Mt. Wilson Doppler
measurements of the photosphere; dashed line: the WL K-corona.
M.A. Weber, L.W. Acton, D. Alexander, S. Kubo, H. Hara, Sol. Phys. 189 (1999) 271
X-rays
SXT S60o N60o
Yohkoh
SXT equator
ν’s
Comparison of normalized probability distribution functions formed from power
spectra of data from SXT equator (red), SXT N60-S60 (green), Homestake (black),
and GALLEX (blue). Note that the SXT (red) and GALLEX data are equatorial, and
the other two are not. Frequencies are given in cycles per year.
D.O. Caldwell, P.A. Sturrock, Astroparticle Phys. 23 (2005) 543
Yohkoh
X-rays
SXT S60o N60o
SXT equator
Homestake
GALLEX
ν’s
Comparison of normalized probability distribution functions formed from power
spectra of data from SXT equator (red), SXT N60-S60 (green), Homestake (black),
and GALLEX (blue). Note that the SXT (red) and GALLEX data are equatorial, and
the other two are not. Frequencies are given in cycles per year.
D.O. Caldwell, P.A. Sturrock, Astroparticle Phys. 23 (2005) 543
Conclusion towards 
Conclusion towards 
Every solar puzzle is due to ~axions!
Mamma mia che fortuna!