A simple model of circular polarization dependence on Mn delta-layer position in LED heterostructures with InGaAs/GaAs quantum well is proposed, being able to explain quite accurately recent fascinating experimental results [S.V. Zaitsev, et al., Physica E (2009), doi:10.1016/j.physe.2008.11.003]. The model emphasizes the role of position-dependent exchange interaction between injected holes an...

Here we report the first detection of polarization signals induced by the Zeeman effect in spectral lines of the system of FeH located around 1.6 mm. Motivated by the tentative detection of this band in the intensity 4 4 E P–A P spectrum of late-type dwarfs, we have investigated the full Stokes sunspot spectrum and have found circular and linear polarization signatures that we associate with th...

Following a BeppoSAX alert (Piro 1999a) and the discovery of the OT at SAAO (Vreeswijk et al. 1999a), we observed GRB990510 with the FORS instrument on ESO’s VLT Unit 1 (‘Antu’). The burst is unremarkable in gamma rays, but in optical is the first one to show good evidence for jet-like outflow (Stanek et al. 1999, Harrison et al. 1999). We report the detection of significant linear polarization...

Observations of the afterglows of γ-ray bursts (GRBs) have revealed that they lie at cosmological distances, and so correspond to the release of an enormous amount of energy. The nature of the central engine that powers these events and the prompt γ-ray emission mechanism itself remain enigmatic because, once a relativistic fireball is created, the physics of the afterglow is insensitive to the...

Refraction and polarization transfer in an ultrarelativistic highly magnetized pulsar plasma are considered. Normal waves in the pulsar plasma are linearly polarized however circular polarization arises in the polarization limiting region if radiation propagates at an angle to the plane of the magnetic field lines. The rays go off this plane due to refraction or (and) due to rotation of the mag...

We have studied the nonlinear Faraday effect with intense linear polarized light in an optically thick atomic rubidium vapor. We demonstrate that the polarization rotation rate rotation angle per unit magnetic field, in the limit of low field has a maximum value as the intensity and density are increased. We also show that the optimal sensitivity of an optical magnetometer based on this system ...

The recently detected linear polarization in the optical lightcurve of GRB 990510 renewed the interest on how polarization can be produced in gamma–ray burst fireballs. Here we present a model based on the assumption that we are seeing a collimated fireball, observed slightly off–axis. This introduces some degree of anisotropy, and makes it possible to observe a linearly polarized flux even if ...

The recent detection of significant linear polarization at mm and sub-mm wavelengths in the spectrum of Sgr A* (if confirmed) will be a useful probe of the conditions within several Schwarzschild radii (rS) of the event horizon at the Galactic Center. Hydrodynamic simulations of gas flowing in the vicinity of this object suggest that the infalling gas circularizes when it approaches within 5− 2...

We present results of optical linear polarization measurements of stars in the region of the relatively isolated cometary globule CG 12 in Centaurus at a galactic latitude b 21◦. A polarization map representing the geometry of the magnetic field in the cloud is produced. In the lower-density outer parts of the cloud, the field is more or less parallel to the cometary tail and other elongated st...

We study time delay in atomic photoionization by circularly polarized light. By considering the Li atom in an excited 2p state, we demonstrate a strong time delay asymmetry between the photoemission of the target electrons that are coand counter-rotating with the electromagnetic field in the polarization plane. In addition, we observe the time delay sensitivity to the polar angle of the photoel...