相关论文: Radio Spectroscopy of Active Galactic Nuclei
Active Galactic Nuclei (AGN) can be probed by at different regions of the electromagnetic spectrum: e.g., radio observations reveal the nature of their relativistic jets and their magnetic fields, and complementarily, X-ray observations…
Active galactic nuclei (AGN) are one of the most luminous objects in the Universe, emitting powerful continuum and line emission across all wavelength bands. They represent an important link in the investigations of the galaxy evolution and…
Active Galactic Nuclei (AGN) are ideal sources for multi-wavelength studies as their emission can cover almost 20 orders of magnitude in frequency from the radio to the gamma-ray band. After reviewing their basic properties, I will assess…
Nuclear physics offers us a powerful tool: using nuclear resonance absorption lines to infer the physical conditions in astrophysical settings which are otherwise difficult to deduce. Present-day technology provides an increase in…
Over the last five decades, AGN studies have produced a number of spectacular examples of synergies and multifaceted approaches in astrophysics. The field of AGN research now spans the entire spectral range and covers more than twelve…
Infrared spectroscopy in the mid- and far-infrared provides powerful diagnostics for studying the emission regions in active galaxies. The large variety of ionic fine structure lines can probe gas conditions in a variety of physical…
The spectra of Active Galactic Nuclei (AGNs) are often characterized by a wealth of emission lines with different profiles and intensity ratios that led to a complicated classification. Their electro-magnetic radiation spans more than 10…
We propose to advance investigations of electromagnetic radiation originating in atomic nuclei beyond its current infancy to a true astronomy. This nuclear emission is independent from conditions of gas, thus complements more traditional…
Astrophysical gamma-ray spectroscopy is an invaluable tool for studying nuclear astrophysics, supernova structure, recent star formation in the Milky Way and mixing of nucleosynthesis products in the interstellar medium. After a short,…
Variability of radio-emitting active galactic nuclei can be used to probe both intrinsic variations arising from shocks, flares, and other changes in emission from regions surrounding the central supermassive black hole, as well as…
In preparation for a study of their circumnuclear gas we have surveyed 60% of a complete sample of elliptical galaxies within 75 Mpc that are radiosources. Some 20% of our nuclear spectra have infrared emission lines, mostly Paschen lines,…
Active Galactic Nuclei (AGN) are highly energetic astrophysical sources powered by accretion onto supermassive black holes in galaxies, which present unique observational signatures covering the full electromagnetic spectrum (and more) over…
The black-hole/accretion-disk paradigm for active galactic nuclei (AGNs) is now reasonably secure, but there are still important unresolved issues, some of which will require the capabilities of an 8 to 10-m class UV/optical space-based…
The recent availability of wideband receivers and high sensitivity instruments in the mm and submm wavelengths has opened the possibility of studying in detail the chemistry of the interstellar medium in extragalactic objects. Within the…
In the framework of the study of extragalactic radio sources, we will focus on the importance of the spatial resolution at different wavelengths, and of the combination of observations at different frequency bands. In particular, a…
Active Galactic Nuclei (AGN) are remarkable astronomical sources emitting over the whole electromagnetic spectrum, with different bands providing unique windows on distinct sub-structures and their related physics. AGN come in a large…
We present a model for the inverted radio spectra of active active galactic nuclei as well as the central regions of normal galaxies. The model is based on the unified scenario for active galaxies, stating that the central engines of active…
We first review some basic properties of the most important classes of active galactic nuclei (AGN), including quasars, blazars, Seyfert galaxies and radio galaxies. The most commonly accepted type of scheme designed to individually unify…
Although rare, massive stars, being the main sources of ionizing radiation, chemical enrichment and mechanical energy in the Galaxy, are the most important objects of the stellar population. This review presents the many different aspects…
High-resolution imaging and long-slit spectroscopy obtained with HST, combined with ground-based integral-field spectroscopy, provides the kinematics of stars and gas in nearby galactic nuclei with sufficient accuracy to derive the…