Solar Solar ~~axionsaxions

K. ZioutasK. Zioutas

Università di Patrasso Università di Patrasso && CERN CERN EU-ILIAS AXIONS EU-ILIAS AXIONS

INFN Sezione di TriesteUniversità di Trieste - Dipartimento di Fisica

3 ottobre 2006

brillante ideabrillante idea!!

The CAST collaboration LLNLLLNL

P. SikivieP. Sikivie

IstanbulIstanbul

uu??

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.

Profit / encouraged from :

CASTCAST motivated workmotivated work

beyond(?) beyond(?) CASTCAST feedbackfeedback!!

Thanks to PVLAS:Axion searches in the spotlight

Attempts to Attempts to reconcile PVLAS reconcile PVLAS result with CAST result with CAST and other limits…and other limits…

And others…And others…

Axion searches in the spotlight

• The interest on axions reaches also The interest on axions reaches also string theorists…string theorists…

MotivationMotivation?

< 1998

Alvaro de Rujula

http://www.fnal.gov/directorate/Longrange/PartAstro1003_Talks/Bauer.pdf

Axion Dark Matter particle candidate new physics

The Primakoff Effect 1951

×B

H. Primakoff

behind all present axion work

before CAST:

BNL & Tokyo

axion-Bragg @ Ge, NaI, …

CASTCAST

Axion - source Axion - detection

↓ ↓

P. Sikivie

BXvirtual

α

Inner Sun imaging!

newnew

keV4.2Ea

Solar axion spectrum

Paγ 1.710-17

2

GeV10

g110

aγγ

2004 data analysisCCD/Telescope

• Spot position well determined• Full sensitivity of telescope

exploited• Counts inside the spot

compatible with background

Tracking data Signal simulation

•No axion signal detectedNo axion signal detected

newnew

CAST 2004

for

XX ←← PVLASPVLAS

??

• x7x7 improvement. improvement.

• competes with best competes with best astrophysical limit astrophysical limit @@ coherence masses.coherence masses.

bridge the gap PVLAS PVLAS ↔↔ CASTCAST

demandingdemanding + inspiring new experimentsinspiring new experiments

CAST Phase II (4He)

Cosmological limit Cosmological limit Hannestad etal, JCAP 0507 (05) Hannestad etal, JCAP 0507 (05)

002002

PresentPresentprogressprogress

PresentPresentprogresprogresss

~4 mbar~4 mbar~0.215 eV~0.215 eV

K. van Bibber et al.

19891989

OFF-resonance axion-converted analog spectrum

newnew

22ndnd X-ray optic 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”“Solar Model problem”!

» smoking-gun signatures for new physics?

solarsolar ~~axionsaxions

ubiquitous @@ Sun, …

11st st

┌►┌► X-rays, visible, …

Unexpected (dis)appearance of photonsUnexpected (dis)appearance of photons

Lx ~ B2 à la Sikivie ~ ρ à la van Bibber

dynamical behaviour transient effects

axion ⇄ photon oscillations

22ndnd axion → 2γ

decay of gravitationally trapped massive ~axions, e.g. KK-type generic

▼ unexpectedly hot “plasma” ▼ Lx ≈ constant

solar observations require both componentssolar observations require both components

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

Solar temperature distribution

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

K. Galsgaard, C.E. Parnell, A.& A. 439 (August 2005) 335 R.B. Dahlburg, J.A. Klimchuk, S.K. Antiochos, ApJ. 622 (2005) 1191

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.

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

The mechanism that heats the solar corona remains elusive.

Everything above the photosphere …would not be there at all.

On solving the Coronal Heating ProblemOn solving the Coronal Heating Problem

▼▼

“one of the most important problems in astrophysicsone 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

→X→X

22ndnd component component

2005- RHESSI SMART_1

B-modified solar axion spectrum?

La ≈0.16Lsolar ≈ 106 t/s Ltrapped ≈ 200 g/s ≈ 1019 g now

Magnetic fields simulated. Normalized amplitudes by

their maximum intensity.

S Couvidat, S Turck-Chieze, AG Kosovichev. ApJ. 599 (2003) 1434

Solar seismic models + the ν-predictions

103-104 T

30-50 T

2-3 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.

http://science.nasa.gov/headlines/y2006/10may_longrange.htm

~105 Tesla change significantly solar ν-fluxes

OFFPOINTING:OFFPOINTING:

1992 YOHKOH 2005- RHESSI 33 days

http://www.unine.ch/phys/corpus/tpc2002/zioutas.ppt

←← PVLASPVLAS Solar KK-axions ≠ QCD axions

DiLella, Z., Astropart. Phys.19 (2003)145

??

http://sprg.ssl.berkeley.edu/~hannah/presentations/pdf_spd_06.pdf

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

not ≠ reconstructed solar X-ray spectrum see DiLella + Z. (2003)

20062006

What produces solar flaresWhat produces solar flares? ? μμflares, nanoflares,..flares, nanoflares,..

The precise causes of solar flares & CMEs is one of the great solar mysteries. (20032003)

flare-quiet ≈≈ flare-imminent regions

↓↓ … storage and release of the energy that powers solar flares is generally believedbelieved to be in the coronal magnetic fieldmagnetic field … + magnetic reconnectionmagnetic 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 (20032003)

Electrical Current Issue in Flares

Rate of e- acceleration 1037e-/s 1018 A

B B ≈≈ 10 104 4 TT G. Emslie (2005)http://www.astro.auth.gr/~vlahos/ascona/memberstalks/energeticsEmslie.ppt#368,9,Electrical

axionaxion→→γγ (transient) trigger(transient) trigger!?!?

11stst component component ~~BB22

4 cases4 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 howhow 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

the magnetic field can transform out streaming

~axions-to-photons + vice versavice versa

++ transient brightenings!

In the axion scenarioIn the axion scenario

B B = catalyst = catalyst ⊗⊗ ρρlocal,local,ΔΔtt ~ ~ ωωplasmaplasma=m=maxionaxion

CASTCAST @@ SunSun

<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

The long-term evolution of AR 7978 (S10o) Yohkoh / SXT

Lx B1.94±.12

~ filter independent

Eγ < 4 keV

B [Gauss]

Lx

11stst

RHESSI :often hard X-rayemission from non-flaring ARs.

≳ ≳ 5 keV5 keV Hannah, Hurford, Hudson, Abstract: 2005AGUFMSH11A0242HAGU Fall meeting, 5-9/12/2005

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 cycle11 years solar cycle??

22ndnd

33rdrd

Rebinned peak flare X-ray intensity vs. Bmax

D. Mason et al., ApJ. 645 (10.7.2006)1543 B2 correlation

Lx

↑

Bmax

The Electron “Problem”The Electron “Problem”

e- flux~105 hard X-raysfrom Bremsstrahlung!!

FLARES FLARES origin?origin?

G. Emslie (20052005)http://www.astro.auth.gr/%7Evlahos/ascona/memberstalks/energeticsEmslie.ppt#366,8

44ththSUNSPOTSSUNSPOTS originorigin??

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

rela

tive

to

Ph

oto

sph

ere

(=Q

uie

t S

un

)

50% of the quiet Sun

SK Solanki A.&A. Rev.11 (2003) 153 Plot reconstructed from : • fundamental questions remain unanswered.fundamental questions remain unanswered.• is an additional mechanism neededis an additional mechanism needed??

SUNSPOTS Yohkoh - XRTelescope

<1.3 MK> quiet Sun

<1.8 MK> Umbra

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

Sunspots = “dark spots” T ⇩⇩

photospherephotosphere ~ 4500K heat flux problem in umbra + penumbra Spruit, Scharmer, A.&A. (2005), astro-ph/0508504

CoronaCorona

Soft X-ray fluxes 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 kGB ~ 2 kG above most sunspots !

Sola

r C

oron

a P

rob

lem

Penumbra<2.4 MK>

TAUP2005

Long-lasting sunspots appear in this sequence of drawings made by

Galileo himself as he observed the Sun from June 2nd to 26th, 16121612. http://science.nasa.gov/headlines/y2001/ast07nov_1.htm

more?

manifestation of 2 opposite effectsmanifestation of 2 opposite effects??

Solar metallicitySolar metallicity

Standard Solar Model problem with:Standard Solar Model problem with:

Ne/O abundance ratios vs. coronal activity.

To rescue the agreement between the SSModel 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:Quiet ARs: Ne/ONe/O also at ~0.15 also at ~0.15..Flares:Flares: enhanced Ne detection enhanced Ne detection (~2x),

i.e., some mechanism would preferen-tially 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 specialWhy the Sun is so special??

C.Liefke, JHMM. Schmitt, A&A L. (2006)

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 fromintense flares. Therefore flare enhanced Ne/O ratios no solution of the problem! J.T. Schmelz et al., ApJ. 634 (2005) L197

measured photospheric abundances of

C, N, O, Ne 25-35% below prediction!

M. Asplund et al., astro-ph/200410214 :

!!Solar axion surface effects at workSolar axion surface effects at work!!

… changing diffusion locally.

No problem for the Solar Model

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 the extra heating from absorption of axions in the atmosphere which might increase the of axions in the atmosphere which might increase the temperature in the spectral line formation region of the Sun.” temperature in the spectral line formation region of the Sun.”

▼▼

• Solar atmosphere:Solar atmosphere: differential rotation

• SolarSolar ν’ν’s s && X X--raysrays oscillations / correlations

WL K-Corona?

mm

Soft X-ray Corona

photosphere

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

Why this occurs is unclear!D. Altrock, Private communication

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

ν’s

X-rays Yohkoh

SXT equatorSXT S60o N60o

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

ν’s

X-rays Yohkoh

SXT equatorSXT S60o N60o

Homestake GALLEX

Conclusion towardsConclusion towards

Conclusion towardsConclusion towards

Every solar puzzle is due to Every solar puzzle is due to ~~axionsaxions!!

Mamma mia che fortunaMamma mia che fortuna!!