Zobrazeno 1 - 10
of 828
pro vyhledávání: '"Ramelli, R"'
Publikováno v:
A&A 659, A179 (2022)
We present novel spectropolarimetric observations of the hydrogen H$\alpha$ line taken with the Z\"urich Imaging Polarimeter (ZIMPOL) at the Gregory Coud\'e Telescope of the Istituto Ricerche Solari Locarno (IRSOL). The linear polarization is clearly
Externí odkaz:
http://arxiv.org/abs/2201.03815
Publikováno v:
A&A 641, A63 (2020)
Several strong resonance lines, such as H I Ly-$\alpha$, Mg II k, Ca II K, Ca I 4227 \AA\, which are characterized by deep and broad absorption profiles in the solar intensity spectrum, show conspicuous linear scattering polarization signals when obs
Externí odkaz:
http://arxiv.org/abs/2006.13653
Autor:
Bianda, M., Berdyugina, S., Gisler, D., Ramelli, R., Belluzzi, L., Carlin, E. S., Stenflo, J. O., Berkefeld, T.
Publikováno v:
A&A 614, A89 (2018)
Context. The scattering polarization signal observed in the photospheric Sr i 4607 {\AA} line is expected to vary at granular spatial scales. This variation can be due to changes in the magnetic field intensity and orientation (Hanle effect), but als
Externí odkaz:
http://arxiv.org/abs/1803.03531
Autor:
Ramelli, R., Setzer, M., Engelhard, M., Bianda, M., Paglia, F., Stenflo, J. O., Küveler, G., Plewe, R.
The solar limb darkening function is well known and is widely employed in models of the solar atmosphere. However, there has been a lack of systematic spectrally resolved measurements. Therefore we recently decided to start an observing campaign with
Externí odkaz:
http://arxiv.org/abs/1708.03284
The Sc II 4247 A line formed in the chromosphere is one of the lines well known, like the Na I D_2 and Ba II D_2, for its prominent triple peak structure in Q/I and the underlying quantum interference effects governing it. In this paper, we try to st
Externí odkaz:
http://arxiv.org/abs/1408.4247
Autor:
Supriya, H. D., Smitha, H. N., Nagendra, K. N., Stenflo, J. O., Bianda, M., Ramelli, R., Ravindra, B., Anusha, L. S.
The observed center-to-limb variation (CLV) of the scattering polarization in different lines of the Second Solar Spectrum can be used to constrain the height variation of various atmospheric parameters, in particular the magnetic fields via the Hanl
Externí odkaz:
http://arxiv.org/abs/1407.5461
Four decades ago the Stokes V line ratio in the Fe I 5247.06 and 5250.22 {\AA} lines was introduced as a powerful means of exploring the intrinsic field strengths at sub-pixel scales, which led to the discovery that most of the photospheric flux is i
Externí odkaz:
http://arxiv.org/abs/1307.1117
Autor:
Smitha, H. N., Nagendra, K. N., Stenflo, J. O., Bianda, M., Sampoorna, M., Ramelli, R., Anusha, L. S.
The scattering polarization in the solar spectrum is traditionally modeled with each spectral line treated separately, but this is generally inadequate for multiplets where J-state interference plays a significant role. Through simultaneous observati
Externí odkaz:
http://arxiv.org/abs/1203.4934
Autor:
Bianda, M., Ramelli, R., Anusha, L. S., Stenflo, J. O., Nagendra, K. N., Holzreuter, R., Sampoorna, M., Frisch, H., Smitha, H. N.
Chromospheric magnetic fields are notoriously diffcult to measure. The chromospheric lines are broad, while the fields are producing a minuscule Zeeman-effect polarization. A promising diagnostic alternative is provided by the forward-scattering Hanl
Externí odkaz:
http://arxiv.org/abs/1105.2157
The solar surface magnetic field is connected with and even controls most of the solar activity phenomena. Zeeman effect diagnostics allow for measuring only a small fraction of the fractal-like structured magnetic field. The remaining hidden magneti
Externí odkaz:
http://arxiv.org/abs/1103.2524