Related papers: Extended Red Emission: Observational constraints f…
Extended radio emission detected around a sample of GHz Peaked Spectrum (GPS) radio sources is discussed. Evidence for extended emission which is related to the GPS source is found in 6 objects out of 33. Three objects are associated with…
The current studies of cosmic rays are focused on most energetic particles entering the atmosphere and producing a single Extensive Air Shower (EAS). There are, however, models predicting that interactions of high energy particles may…
Cosmic rays (CRs) are ubiquitous in the interstellar medium (ISM) of nearby galaxies, but many of their properties are not well-constrained. Gamma-ray observations provide a powerful tool in this respect, allowing us to constrain both the…
Massive young stellar objects are known to undergo an evolutionary phase in which high mass accretion rates drive strong outflows. A class of objects believed to trace this phase accurately is the GLIMPSE Extended Green Object (EGO) sample,…
To date, the ability for observers to reveal the composition or thermal structure of an exoplanet's atmosphere has rested on two techniques: high-contrast direct imaging and time-series observations of transiting exoplanets. The former is…
Most modeling attempts of blazars use a small emission zone located close to the central black hole in order to explain the broad-band spectral energy distribution. Here we present a case where additionally to the small region a…
Despite major advances in climate science over the last 30 years, persistent uncertainties in projections of future climate change remain. Climate projections are produced with increasingly complex models which attempt to represent key…
We consider the effect of electron scattering on lines emitted as a result of supernova interaction with a circumstellar medium, assuming that the scattering occurs in ionized gas in the preshock circumstellar medium. The single scattering…
We report Chandra ACIS observations of the fields of 4 QSOs showing strong extended optical emission-line regions. Two of these show no evidence for significant extended X-ray emission. The remaining two fields, those of 3C 249.1 and 4C…
The GALPROP model for cosmic-ray propagation is able to make explicit predictions for the distribution of galactic diffuse gamma-rays. We compare different propagation models with gamma-ray spectra measured by EGRET for various regions of…
``Extremely red quasars'' (ERQs) are a non-radio-selected, intrinsically luminous population of quasars at cosmic noon selected by their extremely red colour from rest-frame UV to mid-IR. ERQs are uniquely associated with exceptionally…
The Galactic plane is a strong hard x-ray emitter and the emission forms a narrow continuous ridge. The currently known hard x-ray sources are far too few to explain the ridge x-ray emission, and the fundamental question as to whether the…
Optical and near-IR observations of the halos of disk galaxies and blue compact galaxies have revealed a very red spectral energy distribution, which cannot easily be reconciled with a normal, metal-poor stellar population like that in the…
Since their first observation in 1962, the existence of Ultra High Energy Cosmic Rays (UHECR) remains a mystery in modern astrophysics. Those cosmic rays, with energies well above 50 EeV ($50\times 10^{18}$eV), can hardly be accelerated,…
The Extragalactic Background Light (EBL) causes attenuation of the VHE spectra of extragalactic sources, via pair-production. The amount of attenuation depends on the distance of the source, i.e. on the integration over the line of sight…
The Red Planet has fascinated humans for millennia, especially for the last few centuries, and particularly during the Space Age. The nagging suspicion of extant Martian life is both fed by, and drives the many space missions to Mars and…
The interpretation of experimental data of ultra-high energy cosmic rays (UHECRs) above 10^17 eV is still under controversial debate. The development and improvement of numerical tools to propagate UHECRs in galactic and extragalactic space…
(Abridged) We constrain simulated all-sky maps in total intensity, linear polarization, and rotation measure (RM) by observations. We test a number of large-scale magnetic field configurations and take the properties of the warm…
We consider an astrophysical system with a population of sources and a population of lenses. For each pair of source and lens, there is a thin on-axis tube-like volume behind the lens in which the radiation flux from the source is greatly…
Many of the basic problems in the astrophysics of charged Cosmic Rays remain on principle unresolved by in situ observations in the Solar System due to the chaotic nature of the propagation of these particles in Interstellar space. This…