We investigate the formation of polarization profiles induced by a magnetic field in the He I multiplet at 10830 Å. Our analysis considers the Zeeman splitting in the incomplete Paschen-Back regime. The effects turn out to be important and produce measurable signatures on the profiles, even for fields significantly weaker than the level-crossing

The intergalactic magnetic field within filaments should be less polluted by magnetized outflows from active galaxies than magnetic fields in clusters. Therefore, filaments may be a better laboratory to study magnetic field amplification by structure formation than galaxy clusters, which typically host many more active galaxies. We present highly

We report on the results of two coordinated multiwavelength campaigns that focused on the blazar Markarian 421 during its 2006 and 2008 outbursts. These campaigns obtained UV and X-ray data using the XMM-Newton satellite, while the gamma-ray data were obtained utilizing three imaging atmospheric Cerenkov telescopes, the Whipple 10 m telescope and

SN 1988A is (with exception of the well-observed SN 1987A) the only type II SN for which observations of the late tail of the light curve are presently available. This SN showed a brief spike in the early visual light curve followed by a long plateau lasting for about 3 months. Spectra taken during both the plateau and the postplateau phases

Observations of SN 1988A in M58 are presented which show a remarkable departure from Co-56 decay in the optical light curve starting about 700 days since explosion. It is shown that the departure cannot be explained by the contribution from other radioactive isotopes to the late luminosity, and fluorescence in nearby clouds can be excluded as the

We present the detection at 89 μm (observed frame) of the Herschel-selected gravitationally lensed starburst galaxy HATLAS J1429-0028 (also known as G15v2.19) in 15 minutes with the High-resolution Airborne Wideband Camera-plus (HAWC+) onboard the Stratospheric Observatory for Infrared Astronomy (SOFIA). The spectacular lensing system consists of