Related papers: What is the Broad Line Region?
A solid observational characterization of cluster regions around the virial radius would allow us to improve considerably our understanding of the physics of galaxy clusters as a whole: sadly current and planned experiments will not allow…
Substantial progress in the field of the Local Interstellar Medium has been largely due to recent launches of space missions, mostly in the UV and X-ray domains, but also to ground-based observations, mainly in high resolution spectroscopy.…
The success of Deep Learning methods is not well understood, though various attempts at explaining it have been made, typically centered on properties of stochastic gradient descent. Even less clear is why certain neural network…
The study of topological information of spatial objects has for a long time been a focus of research in disciplines like computational geometry, spatial reasoning, cognitive science, and robotics. While the majority of these researches…
Recent work on the dyadosphere of a black hole is reviewed with special emphasis on the explanation of gamma ray bursts. A change of paradigm in the observations of black holes is presented.
Fine structure of giant resonances (GR) has been established in recent years as a global phenomenon across the nuclear chart and for different types of resonances. A quantitative description of the fine structure in terms of characteristic…
We discuss the polarization of broad emission lines in the type 1 active galactic nuclei (AGNs). The polarization depends on the geometry of the broad line region (BLR), and also on the polarization mechanism, or distribution of the…
The recent discovery of universal principles underlying many complex networks occurring across a wide range of length scales in the biological world has spurred physicists in trying to understand such features using techniques from…
Information-theoretic arguments are used to obtain a link between the accurate linearity of Schrodinger's equation and Lorentz invariance: A possible violation of the latter at short distances would imply the appearance of nonlinear…
In order to shed light on the characteristics of the broad line region (BLR) in a narrow-line Seyfert 1 galaxy, we present an analysis of X-ray, UV, and optical spectroscopic observations of the broad emission lines in Mrk 110. For the…
Current reverberation mapping (RM) studies primarily focus on single emission lines, particularly the \hb\ line, which may not fully reveal the geometry and kinematic properties of the broad-line region (BLR). To overcome this limitation,…
The Broad Emission Lines (BELs) in spectra of type 1 Active Galactic Nuclei (AGN) can be very complex, indicating a complex Broad Line Region (BLR) geometry. According to the standard unification model one can expect an accretion disk…
'Downwards drifting' structures observed in fast radio bursts (FRBs) could naturally arise from a screen occurring after a small initial dispersion measure region. The screen imprints temporally sharp but broadband structure on the pulse…
We analyze the ratios of the broad hydrogen Balmer emission lines (from H\alpha to H\epsilon) in the context of estimating the physical conditions in the broad line region (BLR) of active galactic nuclei (AGN). The Balmer emission lines are…
The cosmic ray energy distributions contain spectral features, that is narrow energy regions where the slope of the spectrum changes rapidly. The identification and study of these features is of great importance to understand the…
Location information is often used as a proxy to guarantee the performance of a wireless communication link. However, localization errors can result in a significant mismatch with the guarantees, particularly detrimental to users operating…
This is a brief, non-exhaustive review of Fast Radio Burst (FRB), a new category of radio transients originating from extragalactic distances. We discuss the key observational properties known so far and the scientific applications of FRBs.…
Line broadening and variability are observational hallmarks of active galactic nuclei which allow us to measure supermassive black hole masses as well as constrain the geometry and kinematics of the emitting gas, with the most precise…
We introduce new geometric objects called spectral networks. Spectral networks are networks of trajectories on Riemann surfaces obeying certain local rules. Spectral networks arise naturally in four-dimensional N=2 theories coupled to…
The optical/near-IR stellar continuum carries unique information about the stellar population in a galaxy, its mass function and star-formation history. Star-forming regions display rich emission-line spectra from which we can derive the…