Related papers: Active Galactic Nuclei and their Role in Galaxy Ev…
This overview provides a historical perspective highlighting the pioneering role which the fairly modest observational facilities of ARIES have played since the 1990s in systematically characterizing the optical variability on hour-like…
Non-blazar Active Galactic Nuclei (AGN) have emerged as a new gamma-ray emitting source class on the extragalactic sky and started to deepen our understanding of the physical processes and the nature of AGN in general. The detection of…
We present a 5-8 micron analysis of the Spitzer-IRS spectra of 71 ultraluminous infrared galaxies (ULIRGs) with redshift z < 0.15, devoted to the study of the role of active galactic nuclei (AGN) and starbursts (SB) as the power source of…
We present the results of a 5-8 micron spectral analysis performed on the largest sample of local ultraluminous infrared galaxies (ULIRGs) selected so far, consisting of 164 objects up to a redshift of ~0.35. The unprecedented sensitivity…
Active Galactic Nuclei (AGN) are axisymmetric systems to first order; their observed properties are likely strong functions of inclination with respect to our line of sight, yet the specific inclinations of all but a few AGN are generally…
We explore the connections between the infrared and X-ray properties of AGNs. Using the well constrained infrared SEDs of a sample of local (i.e., z < 0.1) sample of X-ray AGNs, we develop new diagnostics that exploit 24um and 70um flux…
Feedback, in particular from active galactic nuclei (AGN), is believed to play a crucial role in the evolution of galaxies. In the local Universe, many galaxies with an AGN are indeed observed to reside in the so-called green valley,…
Extragalactic X-ray surveys over the past decade have dramatically improved understanding of the majority populations of active galactic nuclei (AGNs) over most of the history of the Universe. Here we briefly highlight some of the exciting…
The Chandra Deep Fields (CDFs), being a major thrust among extragalactic X-ray surveys and complemented effectively by multiwavelength observations, have critically contributed to our dramatically improved characterization of the 0.5-8 keV…
Understanding the infrared emission of galaxies is critical to observational and theoretical investigations of the condensation of galaxies out of the intergalactic medium and the conversion of gas into stars over cosmic time. From an…
AGN are among the most energetic phenomena in the Universe and in the last two decades INTEGRAL's contribution in their study has had a significant impact. Thanks to the INTEGRAL extragalactic sky surveys, all classes of soft X-ray detected…
Submillimetre (sub-mm) galaxies have very high infrared (IR) luminosities and are thousands of times more numerous at z~2 than local ultra-luminous IR galaxies. They therefore represent a key phase in galaxy evolution which can be missed in…
Active Galactic Nuclei (AGN) are intertwined with galaxy evolution, injecting energy into the interstellar medium (ISM) that could regulate star formation as a galaxy evolves. However, the phenomena through which we observe AGN are…
A proper analysis of the evolution of sources emitting in the Mid-Infrared is strongly dependent on their broad-band spectral properties (SEDs) at different redshifts and luminosities and on a reliable classification allowing to disentangle…
In the framework of a systematic ALMA study of IR-selected main-sequence and starburst galaxies at z~1-1.7 at typical ~1" resolution, we report on the effects of mid-IR- and X-ray-detected active galactic nuclei (AGN) on the reservoirs and…
Deep field observations are an essential tool to probe the cosmological evolution of galaxies. In this context, X-ray deep fields provide information about some of the most energetic cosmological objects: active galactic nuclei (AGN).…
The last few years have seen gamma-ray astronomy maturing and advancing in the field of time-domain astronomy, utilizing source variability on timescales over many orders of magnitudes, from a decade down to a few minutes and shorter,…
We briefly review how X-ray observations of high-redshift active galactic nuclei (AGNs) at z = 4-7 have played a critical role in understanding their basic demographics as well as their physical processes; e.g., absorption by nuclear…
In this paper we summarise the research that is currently going on in Ethiopia and East-Africa in extragalactic astronomy and physics of active galaxies and active galactic nuclei (AGN). The study is focused on some of the still open…
The main focus of this thesis is the IR spectral regime, which since the 70's and 80's has revolutionised our understanding of the Universe. A multi-wavelength analysis on Extremely Red Galaxy populations is first presented in one of the…