printlogo
http://www.ethz.ch/index_EN
Welcome to Institute for Astronomy
 
print
  

Stenflo, Jan O., Prof. (Emeritus)

Research Groups

Extragalactic Astrophysics
(Lead: Prof. Carollo)
Observational Cosmology
(Lead: Prof. Lilly)
Star and Planet Formation
(Lead: Prof. Meyer)
Cosmology
(Lead: Prof. Refregier)
Black Holes
(Lead: Prof. Schawinski)
jstenflo
ETH Zurich
Institute for Astronomy
HIT Floor G 12.4
Wolfgang-Pauli-Strasse 27
8093 Zurich
Switzerland

+41 44 632 3804 phone
+41 44 633 1238 fax

stenflo@astro.phys.ethz.ch


Research Activities
Solar magnetic fields, polarization physics, high-precision spectro-polarimetry.


Short CV
Jan Olof Stenflo became full Professor in astronomy at the ETH and the University of Zurich (dual professorship) in 1980 and was head of the Institute of Astronomy 1980-2006. This institute was founded in 1980 in connection with the appointment of Professor Stenflo. He officially retired end of November 2007 but continues his research activities.

Education:

Ph.D. in Astronomy, Lund, Sweden 1968

A more complete CV is available here

Publications
  • Selected papers and other publications with J.O. Stenflo as author or co-author. A more complete list of publications is available here.


  • Solar magnetic fields as revealed by Stokes polarimetry
  • J.O. Stenflo
  • A&A Rev. 21:66 (2013)

  • Calibration of the 6302/6301 Stokes V line ratio in terms of the 5250/5247 ratio
  • J.O. Stenflo, M.L. Demidov, M. Bianda, R. Ramelli
  • A&A 556, A113 (2013)

  • Horizontal or vertical magnetic fields on the quiet Sun: Angular distributions and their height variations
  • J.O. Stenflo
  • A&A 555, A132 (2013)

  • Line-interlocking effects on polarization in spectral lines by Rayleigh and Raman scattering
  • M. Sampoorna, K.N. Nagendra, J.O. Stenflo
  • ApJ 770, 92 (2013)

  • Modeling the quantum interference signatures of the Ba II D2 4554 Å line in the Second Solar Spectrum
  • H.N. Smitha, K.N. Nagendra, J.O. Stenflo, M. Sampoorna
  • ApJ 768, 163 (2013)

  • Bipolar magnetic regions on the Sun: Global analysis of the SOHO/MDI data set
  • J.O. Stenflo, A.G. Kosovichev
  • ApJ 745, 129 (2012)

  • Polarized line transfer with F-state interference in a non-magnetic medium: partial frequency redistribution effects in the collisionless regime
  • H.N. Smitha, K. Sowmya, K.N. Nagendra, M. Sampoorna,
  • J.O. Stenflo
  • ApJ 758, 112 (2012)

  • J-state interference signatures in the second solar spectrum: Modeling the Cr I triplet at 5204 - 5208 Å
  • H.N. Smitha, K.N. Nagendra, J.O. Stenflo, M. Bianda, M. Sampoorna,R. Ramelli, L.S. Anusha
  • A&A 541, A24 (2012)

  • Collapsed, uncollapsed, and hidden magnetic flux on the quiet Sun
  • J.O. Stenflo
  • A&A 529, A42 (2011)

  • Magnetic fields on the quiet Sun
  • J.O. Stenflo
  • Proc. Xth Hvar Astrophysical Colloquium,
  • Central European Astrophysical Bulletin 35, 1-18 (2011)

  • Polarized line formation with J-state interference in the presence of magnetic fields I: Partial frequency redistribution in the collisionless regime
  • H.N. Smitha, M. Sampoorna, K.N. Nagendra, J.O. Stenflo
  • ApJ 733, A4 (2011)

  • Analysis of the forward scattering Hanle effect in the Ca I 4227 A line
  • L.S. Anusha, K.N. Nagendra, M. Bianda, J.O. Stenflo, R. Holzreuter, M. Sampoorna, H. Frisch, R. Ramelli, H.N. Smitha
  • ApJ 737, 95 (2011)


  • Observations of forward scattering Hanle effect in the
  • Ca I 4227 A line
  • M. Bianda, R. Ramelli, L.S. Anusha, J.O. Stenflo, K.N. Nagendra, R. Holzreuter, M. Sampoorna, H. Frisch, H.N. Smitha
  • A&A 530, L13 (2011)

  • Unsolved problems in solar polarization
  • J.O. Stenflo
  • in J.R. Kuhn, D.M. Harrington, H. Lin, S.V. Berdyugina, J. Trujillo-Bueno, S.L. Keil, T. Rimmele (eds.),
  • Proc. 6th International Workshop on Solar Polarization,
  • ASP Conf. Ser. 437, 3-17 (2011)

  • Summary talk
  • J.O. Stenflo
  • in J.R. Kuhn, D.M. Harrington, H. Lin, S.V. Berdyugina, J. Trujillo-Bueno, S.L. Keil, T. Rimmele (eds.),
  • Proc. 6th International Workshop on Solar Polarization,
  • ASP Conf. Ser. 437, 501-508 (2011)

  • Distribution functions for magnetic fields on the quiet Sun
  • J.O. Stenflo
  • A&A 517, A37 (2010)

  • Stokes Polarimetry of the Zeeman and Hanle Effects
  • J.O. Stenflo
  • in M.C.E. Huber, A. Pauluhn, J. Len Culhane, J. Gethyn Timothy, K. Wilhelm, A. Zehnder (eds.),
  • Observing Photons in Space,
  • ISSI Scientific Report 9, 543-558 (2010)

  • Probability distribution functions for solar and stellar magnetic fields
  • J.O. Stenflo
  • in A. Kosovichev, A. Andrei, J.-P. Rozelot (eds.),
  • Solar and Stellar Variability - Impact on Earth and Planets,
  • IAU Symp. 264, 191-196 (2010)

  • Generalization of the last scattering approximation for the Second Solar Spectrum modeling: the Ca I 4227 A line as a case study
  • L.S. Anusha, K.N. Nagendra, J.O. Stenflo, M. Bianda, M. Sampoorna, H. Frisch, R. Holzreuter, R. Ramelli
  • ApJ 718, 988-1000 (2010)

  • Magnetic structuring at spatially unresolved scales
  • J.O. Stenflo
  • in K.N. Nagendra, H.-G. Ludwig, P. Bonifacio (eds.),
  • 3D views on cool stellar atmospheres: theory meets observation,
  • Memorie della Societa Astronomica Italiana 80, 690-695 (2009)

  • The second solar spectrum and the hidden magnetism
  • J.O. Stenflo
  • in K.G. Strassmeier,A.G. Kosovichev, J. Beckmann (eds.),
  • Cosmic Magnetic Fields: from Planets, to Stars and Galaxies,
  • IAU Symp. 259, 211-222 (2009)

  • Small-scale solar magnetic fields
  • A.G. de Wijn, J.O. Stenflo, S.K. Solanki, S. Tsuneta
  • in M.J. Thompson, A. Balogh, J.L. Culhane, A. Nordlund, S.K. Solanki, J.-P. Zahn (eds.),
  • Space Sci. Rev. 144, 275-315 (2009)

  • Origin of Spatial Variations of Scattering Polarization in the Wings of the Ca I 4227 A Line
  • M. Sampoorna, J.O. Stenflo, K.N. Nagendra, M. Bianda, R. Ramelli, L.S. Anusha
  • ApJ 699, 1650-1659 (2009)

  • The photosphere as a laboratory for quantum physics
  • J.O. Stenflo
  • Proc. IXth Hvar Astrophysical Colloquium,
  • Central European Astrophysical Bulletin 33, 1-18 (2009)

  • The Sun as a Rosetta Stone for polarization physics
  • J.O. Stenflo
  • in S. Berdyugina, K.N. Nagendra, R. Ramelli (eds.),
  • Proc. 5th International Workshop on Solar Polarization,
  • ASP Conf. Ser. 405, 3-16 (2009)

  • Magnetic Field Dependence of Polarized Scattering on Potassium
  • C. Thalmann, J.O. Stenflo, A. Feller, A. Cacciani
  • in S. Berdyugina, K.N. Nagendra, R. Ramelli (eds.),
  • Proc. 5th International Workshop on Solar Polarization,
  • ASP Conf. Ser. 405, 113-118 (2009)

  • Spectropolarimetry of Ca II 8542: probing the chromospheric magnetic field
  • L. Kleint, K. Reardon, J.O. Stenflo, H. Uitenbroek, A. Tritschler
  • in S. Berdyugina, K.N. Nagendra, R. Ramelli (eds.),
  • Proc. 5th International Workshop on Solar Polarization,
  • ASP Conf. Ser. 405, 247-250 (2009)

  • Theory of polarized scattering in the mixed Hanle-Zeeman regime
  • M. Sampoorna, K.N. Nagendra, J.O. Stenflo
  • in S. Berdyugina, K.N. Nagendra, R. Ramelli (eds.),
  • Proc. 5th International Workshop on Solar Polarization,
  • ASP Conf. Ser. 405, 93-100 (2009)

  • Zeeman line formation in solar magnetic fields.
  • Studies with empirical probability distribution functions
  • M. Sampoorna, K.N. Nagendra, H. Frisch, J.O. Stenflo
  • A&A 485, 275-287 (2008)

  • Hanle-Zeeman redistribution matrix.
  • III. Solution of the polarized line formation problem
  • M. Sampoorna, K.N. Nagendra, J.O. Stenflo
  • ApJ 679, 889-899 (2008)

  • Hanle-Zeeman redistribution matrix.
  • II. Comparison of classical and quantum electrodynamic approaches
  • M. Sampoorna, K.N. Nagendra, J.O. Stenflo
  • ApJ 670, 1485-1503 (2007)

  • Hanle-Zeeman redistribution matrix.
  • I. Classical theory expressions in the laboratory frame
  • M. Sampoorna, K.N. Nagendra, J.O. Stenflo
  • ApJ 663, 625-642 (2007)

  • Solar Magnetic Fields
  • J.O. Stenflo
  • in R. Jain, P. Venkatakrishnan, J.T. Karpen (eds.),
  • Challenges for Solar Cycle - 24,
  • Proc. Conf. at PRL, Ahmedabad, 22-25 January 2007
  • J. Astrophys. Astr. (India) 29, 19-28 (2008)


  • Scattering polarization in strong chromospheric lines.
  • III. Spatial fluctuations of the polarized Ca II K line profiles
  • R. Holzreuter, J.O. Stenflo
  • A&A 472, 919-928 (2007)

  • Scattering polarization in strong chromospheric lines.
  • II. Influence of the temperature curve on the Ca II K line
  • R. Holzreuter, J.O. Stenflo
  • A&A 467, 695-702 (2007)

  • Solar polarimetry with ZIMPOL: Plans for the future
  • J.O. Stenflo
  • in V. Bommier, S. Sahal-Brechot (eds.),
  • Proc. Solar magnetism and dynamics & THEMIS users meeting,
  • Meudon, 15-17 November 2006,
  • Memorie della Societa Astronomica Italiana 78, 181-190 (2007) 

  • Ca II K polarization as a diagnostic of temperature bifurcation
  • R. Holzreuter, D.M. Fluri, J.O. Stenflo
  • A&A 449, L41-L44 (2006)

  • First polarimetric measurements and modeling of the
  • Paschen-Back effect in CaH transitions
  • S.V. Berdyugina, D.M. Fluri, R. Ramelli,
  • M. Bianda, D. Gisler, J.O. Stenflo
  • ApJ 649, L49-L52 (2006)

  • The Sun's Magnetism
  • J.O. Stenflo
  • Nuncio Siderio III, No. 4, 2-3 
  • IAU GA Newspaper, Prague, August 17, 2006

  • Polarization at the extreme limb of the Sun
  • and the role of eclipse observations
  • J.O. Stenflo
  • in R. Ramelli, O. Shalabiea, Ibrahim M. Saleh, J.O. Stenflo (eds.),
  • Proc. Intern. Symp. on Solar Physics and Solar Eclipses (SPSE2006),
  • Sebha Univ. publ., Sebha, Libya, 1-14 (2007) 

  • Second Solar Spectrum: A brief overview
  • J.O. Stenflo
  • in R. Casini, B.W. Lites (eds.),
  • Proc. 4th International Workshop on Solar Polarization,
  • ASP Conf. Ser. 358, 215-224 (2006) 

  • Laboratory experiment for polarized scattering at potassium vapor
  • C. Thalmann, J.O. Stenflo, A. Feller, A. Cacciani
  • in R. Casini, B.W. Lites (eds.),
  • Proc. 4th International Workshop on Solar Polarization,
  • ASP Conf. Ser. 358, 323-328 (2006) 

  • Tunable narrow-band filter for imaging polarimetry
  • A. Feller, A. Boller, J.O. Stenflo
  • in R. Casini, B.W. Lites (eds.),
  • Proc. 4th International Workshop on Solar Polarization,
  • ASP Conf. Ser. 358, 155-160 (2006) 

  • Polarized scattering in strong chromospheric lines:
  • theory and its confrontation with observations
  • D.M. Fluri, R. Holzreuter, J.O. Stenflo
  • in R. Casini, B.W. Lites (eds.),
  • Proc. 4th International Workshop on Solar Polarization,
  • ASP Conf. Ser. 358, 237-244 (2006) 

  • Hanle effect in the Paschen-Back regime
  • A.I. Shapiro, D.M. Fluri, S.V. Berdyugina, J.O. Stenflo
  • in R. Casini, B.W. Lites (eds.),
  • Proc. 4th International Workshop on Solar Polarization,
  • ASP Conf. Ser. 358, 311-316 (2006) 

  • Spectropolarimetric observations of filaments
  • in Halpha and He D3
  • M. Bianda, R. Ramelli, J. Trujillo Bueno, J.O. Stenflo
  • in R. Casini, B.W. Lites (eds.),
  • Proc. 4th International Workshop on Solar Polarization,
  • ASP Conf. Ser. 358, 454-458 (2006) 

  • Spectropolarimetry of solar prominences
  • R. Ramelli, M. Bianda, J. Trujillo Bueno, L. Merenda, J.O. Stenflo
  • in R. Casini, B.W. Lites (eds.),
  • Proc. 4th International Workshop on Solar Polarization,
  • ASP Conf. Ser. 358, 471-474 (2006) 

  • Evolution and rotation of large-scale photospheric
  • magnetic fields of the Sun during cycles 21-23.
  • Periodicities, north-south asymmetries and r-mode signatures
  • R. Knaack, J.O. Stenflo, S.V. Berdyugina
  • A&A 438, 1067-1082 (2005)

  • Spherical harmonic decomposition of solar magnetic fields
  • R. Knaack, J.O. Stenflo
  • A&A 438, 349-363 (2005)

  • Absence of linear polarization in Halpha emission of solar flares
  • M. Bianda, A.O. Benz, J.O. Stenflo, G. Kueveler, R. Ramelli
  • A&A 434, 1183-1189 (2005)

  • Scattering polarization in strong chromospheric lines.
  • I. Explanation of the triplet peak structure
  • R. Holzreuter, D.M. Fluri, J.O. Stenflo
  • A&A 434, 713-724 (2005)

  • Polarization of the Sun's continuous spectrum
  • J.O. Stenflo
  • A&A 429, 713-730 (2005)

  • Hidden magnetism
  • J.O. Stenflo
  • Nature 430, 304-305 (2004)

  • The new world of scattering physics seen by
  • high-precision imaging polarimetry
  • J.O. Stenflo
  • Reviews in Modern Astronomy 17, 269-296 (2004) 

  • Periodic oscillations in the north-south asymmetry
  • of the solar magnetic field
  • R. Knaack, J.O. Stenflo, S.V. Berdyugina
  • A&A 418, L17-L20 (2004)

  • Spectro-polarimetric observations: What's next ?
  • J.O. Stenflo
  • in J. Trujillo Bueno, J. Sanchez Almeida (eds.), "Solar Polarization",
  • Proc. 3rd International Workshop on Solar Polarization,
  • ASP Conf. Ser. 307, 583-592 (2003) 

  • Scattering polarization in magnetic fields: Anomalies, surprises, and enigmas
  • J.O. Stenflo
  • in J. Trujillo Bueno, J. Sanchez Almeida (eds.), "Solar Polarization",
  • Proc. 3rd International Workshop on Solar Polarization,
  • ASP Conf. Ser. 307, 385-398 (2003) 

  • Depolarizing lines in the Sun's spectrum
  • D.M. Fluri, J.O. Stenflo
  • A&A 398, 763-773 (2003)

  • Spectro-polarimetry
  • J.O. Stenflo
  • in B.N. Dwivedi (ed.), "Dynamic Sun",
  • Cambridge Univ. Press, 128-147 (2003)

  • Imaging polarimetry: Opportunities and limitations
  • J.O. Stenflo
  • in S. Fineschi (ed.), "Polarimetry in Astronomy" SPIE 4843, 76-88 (2003) 

  • Flux tubes or fractal distributions -
  • on the nature of photospheric magnetic fields
  • J.O. Stenflo, R. Holzreuter
  • Astron. Nachr. 324, 397 (2003)

  • Distribution of magnetic fields at scales beyond the spatial resolution limit
  • J.O. Stenflo, R. Holzreuter
  • in A.A. Pevtsov, H. Uitenbroek (eds.), "Current Theoretical Models
  • and Future High Resolution Solar Observations: Preparing for ATST"
  • ASP Conf. Ser. 286, 169-176 (2003) 

  • Empirical view of magnetoconvection
  • J.O. Stenflo, R. Holzreuter
  • in H. Sawaya-Lacoste (ed.), "Magnetic Coupling of the Solar Atmosphere"
  • ESA Publ. SP-505, 101-104 (2002) 

  • Enigmatic magnetic field effects in the scattering polarization
  • of the Ca I 4227 A line
  • M. Bianda, J.O. Stenflo, A. Gandorfer, D. Gisler
  • in A.A. Pevtsov, H. Uitenbroek (eds.), "Current Theoretical Models
  • and Future High Resolution Solar Observations: Preparing for ATST"
  • ASP Conf. Ser. 286, 61-68 (2003) 

  • Harmonic analysis of solar magnetic fields
  • R. Knaack, J.O. Stenflo
  • in H. Sawaya-Lacoste (ed.), "Magnetic Coupling of the Solar Atmosphere"
  • ESA Publ. SP-505, 453-456 (2002) 

  • Spatial mapping of the Hanle and Zeeman effects on the Sun
  • J.O. Stenflo, A. Gandorfer, R. Holzreuter,
  • D. Gisler, C.U. Keller, M. Bianda
  • A&A 389, 314-324 (2002)

  • Molecular line scattering and magnetic field effects:
  • Resolution of an enigma
  • S.V. Berdyugina, J.O. Stenflo, A. Gandorfer
  • A&A 388, 1062-1078 (2002)

  • Polarized radiation diagnostics of solar magnetic fields
  • J.O. Stenflo
  • in J. Trujillo Bueno, F. Moreno Insertis, F. Sanchez (eds.),
  • "Astrophysical Spectropolarimetry". Lectures given at
  • XII Canary Islands Winter School of Astrophysics ,
  • Cambridge Univ. Press, pp. 55-100 (2002)

  • Limitations and opportunities for the
  • diagnostics of solar and stellar magnetic fields
  • J.O. Stenflo
  • in G. Mathys, S.K. Solanki, D.T. Wickramasinghe (eds.),
  • "Magnetic Fields across the Hertzsprung-Russel Diagram"
  • ASP Conf. Ser. 248, 639-650 (2001)

  • Observations of scattering polarization and the Hanle effect
  • J.O. Stenflo
  • in M. Sigwarth (ed.), "Advanced Solar Polarimetry:
  • Theory, Observation, and Instrumentation"
  • ASP Conf. Ser. 236, 97-108 (2001) 

  • Influence of magnetic fields on the coherence effects
  • in the Na I D1 and D2 lines
  • J.O. Stenflo, A. Gandorfer, T. Wenzler, C.U. Keller
  • A&A 367, 1033-1048 (2001)

  • Center-to-limb variation of the enigmatic Na I D1 and D2
  • polarization profiles
  • J.O. Stenflo, A. Gandorfer, C.U. Keller
  • A&A 355, 781-788 (2000)

  • Anomalous polarization effects due to coherent scattering
  • in the solar spectrum
  • J.O. Stenflo, C.U. Keller, A. Gandorfer
  • A&A 355, 789-803 (2000)

  • What can we learn about the corona from polarization meaurements
  • J.O. Stenflo
  • in W.C. Livingston, A. Ozguc (eds.), "The last total solar eclipse
  • of the millennium in Turkey"
  • ASP Conf. Ser. 205, 41-50 (2000) 

  • Hanle effect observations with the Ca I 4227 A line
  • M. Bianda, J.O. Stenflo, S.K. Solanki
  • A&A 350, 1060-1070 (1999)

  • Partial frequency redistribution with Hanle and Zeeman effects
  • V. Bommier, J.O. Stenflo
  • A&A 350, 327-333 (1999)

  • Solar Polarization
  • K.N. Nagendra, J.O. Stenflo (eds.)
  • Proc. 2nd International Workshop on Solar Polarization,
  • Bangalore, India, 12-16 October 1998. ASSL 243,
  • Kluwer Acad. Publ. (1999)

  • Continuum polarization in the solar spectrum
  • D.M. Fluri, J.O. Stenflo
  • A&A 341, 902-911 (1999)

  • Hanle-Zeeman scattering matrix
  • J.O. Stenflo
  • A&A 338, 301-310 (1998)

  • Hanle diagnostics of solar magnetic fields: The Sr II 4078 A line
  • M. Bianda, J.O. Stenflo, S.K. Solanki
  • A&A 337, 565-578 (1998)

  • Hanle depolarisation in the solar chromosphere:
  • The Ca I 4227 A line
  • M. Bianda, S.K. Solanki, J.O. Stenflo
  • A&A 331, 760-770 (1998)

  • Differential Hanle effect and the spatial variation of
  • turbulent magnetic fields on the Sun
  • J.O. Stenflo, C.U. Keller, A. Gandorfer
  • A&A 329, 319-328 (1998)

  • Quantum interferences, hyperfine structure, and
  • Raman scattering on the Sun
  • J.O. Stenflo
  • A&A 324, 344-356 (1997)

  • Center-to-limb variation of the second solar spectrum
  • J.O. Stenflo, M. Bianda, C.U. Keller, S.K. Solanki
  • A&A 322, 985-994 (1997)

  • The second solar spectrum.
  • A new window for diagnostics of the Sun
  • J.O. Stenflo, C.U. Keller
  • A&A 321, 927-934 (1997)

  • New window for spectroscopy
  • J.O. Stenflo, C.U. Keller
  • Nature 382, 588 (1997)

  • Scattering physics
  • J.O. Stenflo
  • Solar Phys. 164,1-20 (1996)

  • Solar polarization
  • J.O. Stenflo, K.N. Nagendra (eds.)
  • Solar Phys. 164 1-432 (1996)

  • Small Scale Magnetic Structures on the Sun
  • J.O. Stenflo
  • A&A Rev. 1, 3-48 (1989)

  • Solar Magnetic Fields - Polarized Radiation Diagnostics
  • J.O. Stenflo
  • Monograph, Kluwer Acad. Publ. (1994)
  • Contents
  • Chapter 1. Solar magnetism - an overview
  • Chapter 2. Theory of polarized radiation
  • Chapter 3. Interaction of matter with radiation
  • Chapter 4. Radiative transfer without scattering
  • Chapter 5. Classical scattering and the Hanle effect
  • Chapter 6. Non-LTE radiative transfer: phenomenological treatment
  • Chapter 7. Introduction to quantum field theory of polarized radiative transfer
  • Chapter 8. Multi-level radiative transfer with coherence effects
  • Chapter 9. Rayleigh and Raman scattering
  • Chapter 10. Collisions, partial redistribution, and turbulent magnetic fields
  • Chapter 11. Solutions of the polarized transfer equation
  • Chapter 12. Diagnostics of small-scale magnetic fields
  • Chapter 13. Instrumentation for solar polarimetry
  • References
  • Index



 

Wichtiger Hinweis:
Diese Website wird in älteren Versionen von Netscape ohne graphische Elemente dargestellt. Die Funktionalität der Website ist aber trotzdem gewährleistet. Wenn Sie diese Website regelmässig benutzen, empfehlen wir Ihnen, auf Ihrem Computer einen aktuellen Browser zu installieren. Weitere Informationen finden Sie auf
folgender Seite.

Important Note:
The content in this site is accessible to any browser or Internet device, however, some graphics will display correctly only in the newer versions of Netscape. To get the most out of our site we suggest you upgrade to a newer browser.
More information

© 2014 ETH Zurich | Imprint | Disclaimer | 28 September 2013
top