Solar ~axions K. Zioutas Università di Patrasso & CERN EU-ILIAS AXIONS brillante idea! INFN Sezione di TriesteUniversità di Trieste - Dipartimento di Fisica 3 ottobre 2006
The CAST collaboration LLNL P. Sikivie Istanbul u?
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. CASTmotivated 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…
Alvaro de Rujula < 1998
AxionDark Matter particle candidate new physics http://www.fnal.gov/directorate/Longrange/PartAstro1003_Talks/Bauer.pdf
H. Primakoff g behind all present axion work × B The Primakoff Effect 1951
beforeCAST: BNL & Tokyo axion-Bragg@ Ge, NaI, …
CAST Axion - sourceAxion - detection ↓ ↓ P. Sikivie
α g virtual X B
Solar axion spectrum Paγ 1.710-17
new 2004 data analysis CCD/Telescope Tracking data Signal simulation • Spot position well determined • Full sensitivity of telescope exploited • Counts inside the spot compatible with background • No axion signal detected
X ←PVLAS ? for CAST 2004 • x7 improvement. • competes with best astrophysical limit @ coherence masses.
bridge the gap PVLAS ↔CAST demanding+inspiring new experiments
K. van Bibber et al. CAST Phase II(4He) Present progress Cosmological limit Hannestad etal, JCAP 0507 (05) 002 1989 Present progress ~4 mbar ~0.215 eV
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 ~ ρà la van Bibber dynamical behaviour transient effects ubiquitous @ Sun, … 2nd decay of gravitationally trapped massive ~axions, e.g. KK-type generic ▼ unexpectedly hot “plasma” ▼ Lx ≈ constant axion→ 2γ 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
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 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 The magnetic field plays a crucial role in heating the solar corona (this has been known for many years) the exactenergy release mechanism(s)is(are) still unknown. the process by which it is converted into heat and other forms remainsa 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
B-modified solar axion spectrum? 2005-RHESSI SMART_1 La≈0.16Lsolar≈ 106 t/s Ltrapped≈ 200 g/s≈1019 gnow
Solar seismic models + the ν-predictions http://science.nasa.gov/headlines/y2006/10may_longrange.htm ...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 … 103-104 T 2-3 T 30-50 T - - - - -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 YOHKOH 2005-RHESSI 33 days
←PVLASSolar 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)
G. Emslie (2005) http://www.astro.auth.gr/~vlahos/ascona/memberstalks/energeticsEmslie.ppt#368,9,Electrical axion→γ(transient) trigger!? Electrical Current Issue in Flares Rate of e- acceleration 1037e-/s1018A B ≈ 104 T
1stcomponent ~B2 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 knowhow 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 1st Lx Lx B1.94±.12 RHESSI : often hard X-ray emission from non-flaring ARs. ≳ 5 keV ~ filter independent Eγ < 4 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. VilhuJ. Phys. Conf. Ser. 39 (2006) 103
2nd 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 to2. Benevolenskaya, Kosovichev, Lemen, Scherrer, Slater ApJ. 571 (2002) L181 Note:axion-to-photon oscillation ∝ B2 e.g., inCAST DHH Hoffmann, K. Z., Nucl. Phys. B Suppl. 151 (2006) 359 11 years solar cycle?
3rd Lx ↑ Bmax Rebinned peak flare X-ray intensity vs. Bmax D. Mason et al., ApJ. 645 (10.7.2006)1543 B2 correlation FLARES origin? The Electron “Problem” e- flux~105 hard X-rays from Bremsstrahlung! G. Emslie (2005) http://www.astro.auth.gr/%7Evlahos/ascona/memberstalks/energeticsEmslie.ppt#366,8
SUNSPOTSorigin? 4th 50% of the quiet Sun relative to Photosphere (=Quiet Sun) 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?
SUNSPOTSYohkoh - XRTelescope TAUP2005 <1.3 MK> quiet Sun Sunspots =“dark spots” T⇩ photosphere ~ 4500K heat flux problem inumbra+ penumbra Spruit, Scharmer, A.&A. (2005), astro-ph/0508504 Corona 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 kGabove most sunspots! Solar Corona Problem <1.8 MK>Umbra Penumbra <2.4 MK> Temperature distributionsA.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
Standard Solar Model problem with: Solar metallicity manifestation of 2 opposite effects?
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), 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 special? C.Liefke, JHMM. Schmitt, A&A L. (2006) M. Asplund et al., astro-ph/200410214 : measured photospheric abundances of C, N, O, Ne 25-35% below prediction! • 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 Ne/O abundance ratios vs. coronal activity.
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 • Solarν’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