In this work, we study the properties of galaxies that are showing the inside-out assembly (which we call inside-out assembled galaxies; IOAGs), with the main aim to understand better their properties and morphological transformation. We analysed a sample of galaxies from the Sloan Digital Sky Survey (SDSS) Data Release 8 (DR8), with stellar masses in the range log M* = 10.73 – 11.03 M⊙ at at z < 0.1, and analyze their location in the stellar mass-SFR and the color-stellar mass diagram. We found that IOAGs have different spectroscopic properties, most of them being classified either as AGN or composite. We found that the majority of our sources are located below the main sequence of star formation in the SFR-stellar mass diagram, and in the green valley or red sequence in the color-stellar mass diagram. We argue that IOAGs seem to correspond to the transition area where the galaxies are moving from star-forming to quiescent, and from the blue cloud to the red sequence and/or to recently quenched galaxies.

We have made a spectroscopic survey of luminous AGNs and quasars selected in the mid-infrared from Spitzer IRAC surveys. Mid-infrared selection is less affected by dust obscuration, and we find more high redshift quasars than are found in optical or hard X-ray surveys. We have derived luminosity functions for obscured and unobscured quasar populations, and we use these and spectral energy distribution fits to place constraints on host galaxy properties and quasar lifetimes.

We present 1-second cadence, precise optical observations from SOFIA and Palomar of a sample of nearby supermassive black holes. The observations were taken to identify the shortest timescale variability in the nuclear photometry which may be associated with instabilities in the accretion flow in the immediate vicinity of the black hole. The shortest timescale variability, if associated with the radius of the innermost stable circular orbit (ISCO), can then be used to estimate the spin of the black hole. Despite 1% precision photometry, we obtained a non-detection of any significant variability in the nucleus of M32 (Mbh ∼ 2.5 × 106 Mȯ). Given the density of the stellar cusp, this argues for a scenario where 1000 Msun seed black holes formed from the coalescence of less massive black holes, which then accrete the gas produced by stellar interactions/winds. In more luminous systems however, we find a significant deection of variability and present hypotheses to explain the signal and thereby the origin of supermassive black holes.

Host galaxy morphology studies of jetted narrow-line Seyfert 1 galaxies (NLS1) are scarce. Although it seems that they are mostly hosted by late-type galaxies the results remain inconclusive, mostly due to the small sample size. Increasing the number of studied sources is crucial to achieve statistically significant results and to establish a preferred host type for jetted NLS1s. To this end we observed the host galaxies of nine NLS1s in near-infrared using NOTCam at the Nordic Optical Telescope. Seven of these sources are jetted based on the 37 GHz observations at Metsähovi Radio Observatory, Finland. To determine the morphological types of the hosts we performed photometric decomposition of the near-infrared images using GALFIT. Here we present the results of the host galaxy modelling, discuss the importance of this study to our understanding of the nature of the diverse NLS1 population, as well as its significance and implications for active galactic nuclei research in general.

We aim to leverage the transformational science enabled by the Event Horizon Telescope (EHT) to study the physics of, and near, the black holes in a sample of galaxies covering a large parameter space in SMBH mass, accretion rate, and jet power. To this end, we work on a sample of nearby galaxies whose directly measured black hole masses and distances imply that 40 micro-arcsec EHT observations will resolve the central engine at < 100 Schwarzschild radius resolution. As an EHT member, I will present the results from the study of M87 and will discuss the impact of this finding on the study of nearby AGNs. The study of the SMBHs in these systems using molecular and ionised gas kinematics will also be presented.

In April 2017 Event Horizon Telescope (EHT) has delivered first resolved images of a shadow of a supermassive black hole. Apart from black hole sources in M87 and in the Galactic Center, observed with resolution comparable to the Schwarzschild radius scale, EHT observed multiple AGN sources during the 2017 campaign. These include 3C279, Centaurus A, OJ287 and more. For most of the considered sources EHT 2017 data set should allow to reconstruct images with highest angular resolution in the history of their observations, approaching 20 uas. While the analysis of these data is still ongoing, I will talk about the scientific opportunities related to observing AGN sources with the extreme resolution of the EHT as well as about the astrophysical questions that these observations may help answering.

This study focuses on spectral energy distributions and light-curves of blazars and radio galaxies, and the testing of the existing models with a view to appropriately predict a new model that will nearly accurately present the nature of the energy outflows of these super-massive bodies. Understanding blazar emission is very important as it relates more directly to the physics of the AGN’s central black hole. X-ray, radio and gamma-ray wavelength range data on blazars and radio galaxies from archived data has been collected and a detailed investigation of the spectral energy distribution patterns of the blazars and radio galaxies carried out so as to fit the data in the various models. The results of this investigation will be discussed in detail in this presentation.

Bright quasars at low z have generally been found in massive, evolved host galaxies, consistent with formation at early epochs. However, deep, high resolution, multicolor imaging of some quasar hosts have found morphological evidence of tidal tails and colors indicative of active star formation. These results are consistent with theories of galaxy formation and evolution in which merger processes trigger the activation of the quasar phase, and energetic feedback is essential. Understanding the role the black hole population plays in the galaxy formation process is important, but imaging the host galaxies around bright quasars is difficult because of the contribution of the bright nuclei. Very high resolution, deep imaging is necessary to successfully remove the nuclear component. We made high-resolution near-infrared images of several bright z ˜ 0.3 BL Lacs with the Gemini Multi-Conjugate Adaptive Optics System (GeMS)/GSAOI in order to study their host galaxies. We will present the results of this imaging with the 1 arcmin AO-corrected field provided by GeMS/GSAOI and compare with available HST imaging available in the archive.

Active Galactic Nuclei (AGN), accreting supermassive black holes at the centers of galaxies, are believed to produce powerful outflows – often observed as radio jets – which significantly influence the evolution of the surrounding galaxy and inter-galactic medium. However, how these jets – which are produced in the central parsecs of the AGN – impact gas on scales thousands to millions times larger is poorly understood. Doing so requires measuring the properties on all the relevant size scales. In this talk I will present initial results from the deepest-ever radio VLBI survey of an extragalactic field, whose milli-arcsecond angular resolution allows us to probe the central parsecs around these AGN. By comparing the radio properties of the detected radio jets with the multi-wavelength properties of their host galaxies, we are better to understand what galaxies generate powerful radio jets, and how do these outflows affect their host galaxies.

We analyze the molecular and atomic gas data from the GALEX Arecibo SDSS Survey (xGASS) and the extended CO Legacy Database (xCOLD GASS) IRAM survey using novel survival analysis techniques to identify a small number of stellar properties that best correlate with the gas mass. We find that the dust absorption, AV, and the stellar half-light radius, R50, are likely the two best secondary parameters than improve the Kennicutt - Schmidt type relation between the gas mass and the star formation rate, SFR. We fit multiple regression, taking into account gas mass upper limits, to summarize the median, mean, and the 0.15/0.85 quantile multivariate relationships between the gas mass (atomic or molecular hydrogen), SFR, AV and/or R50. In particular, we find that the AV of both the stellar continuum and nebular gas emission shows a significant partial correlation with the molecular hydrogen after controlling for the effect of SFR. The partial correlation between the AV and the atomic gas, however, is weak and their zero-order correlation may be explained by SFR. This is expected since in poorly dust-shielded regions molecular hydrogen is dissociated by the far ultraviolet photons and HI is the dominant phase. Similarly, R50 shows significant partial correlations with both atomic and molecular gas masses. This hints at the importance of environment (e.g., galacto-centric distance) on the gas contents galaxies and on the interplay between gas and star formation rate. We apply the gas scaling relations we found to a large sample of type 2 and type 1 AGNs and infer that the gas mass correlates with AGN luminosity. This correlation is inconsistent with the prediction of AGN feedback models that strong AGNs remove or heat cold gas in their host galaxies.

The astrophysics of Active Galactic Nuclei (AGN) is one of the long outstanding issues in searches among the scientific communities raised with diverse perspectives like nebula, quasars, etc some decades ago. Currently, this exotic system is at least understood as the center of an active galaxy. Thus, the consensus of this recent theory has opened up a number of research issues for the progress of astrophysical science including how the hosting galaxy evolves with the AGN, how matter and energy flow towards and outwards, etc. Moreover, most of the AGNs possess Supermassive Black Holes (SMBHs) and accrete matter at a very high rate as current observations report. Consequently, both observations of electromagnetic (EM) spectrum and Gravity Waves (GWs) will considered to provide complementary information about the AGNs and the roles in their environments including black holes in their centers, outflow and inflow of matter-energy. Interested with this background rationale, we study the mechanisms of AGN interaction with its environment and flow of relativistic jets where General Relativistic (GR) Magneto-Hydrodynamic (MHD) equations are being considered. The solutions of the field equations are treated with a metric that involves charged systems for the possible relativistic jets including accretions. Then, numerical data is being generated using the latest version Mathematic software. Finally, the theoretical data is being compared with that of observation for validation of the model.

3C 294 is a powerful FR II type radio galaxy at z = 1.786. Due to its proximity of a bright star, it has been subject to several adaptive optics supported imaging studies. The system shows a clumpy structure indicative of a merging system. There is even tentative evidence that 3C 294 hosts a dual AGN. In order to distinguish between the various scenarios for 3C 294 we performed deep high-resolution adaptive optics imaging and optical spectroscopy of 3C 294 with the Large Binocular Telescope. We resolve the 3C 294 system in three distinct components separated by a few tenths of an arcsecond. One of them is compact, the other two are extended. The nature of the latter is unclear. They could be a single galaxy with an internal dust absorption feature, a galaxy merger, or two galaxies at different redshifts. We can now uniquely associate the radio source of 3c 294 with one of the extended components. Based on our spectroscopy, we determine a slightly different redshift of z = 1.784. We find, however, in addition a single emission line at a wavelength of 6745 AA, which might be identified with Lyα at z = 4.56. It thus appears unlikely that 3C294 hosts a dual AGN; it might rather be a pair of AGNs with very small projected separation.

The presence of a super massive BH in almost all galaxies in the Universe is an accepted paradigm in astronomy. How these BHs form and how they co-evolve with the host galaxy is one of the most intriguing unanswered problems in modern Cosmology and of extreme relevance to understand the issue of galaxy formation. Clustering measurements can powerfully test theoretical model predictions of BH triggering scenarios and put constraints on the typical environment where AGN live in, through the connection with their host dark matter halos. In this talk, I will present some recent results on the AGN clustering dependence on host galaxy properties, such as galaxy stellar mass, star formation rate and specific BH accretion rate, based on X-ray selected Chandra COSMOS Legacy Type 2 AGN. We found no significant AGN clustering dependence on galaxy stellar mass and specif BHAR for Type 2 COSMOS AGN at mean z ∼ 1.1, with a stellar - halo mass relation flatter than predicted for non active galaxies in the Mstar range probed by our sample. We also observed a negative clustering dependence on SFR, with AGN hosting halo mass increasing with decreasing SFR. Mock catalogs of active galaxies in hosting dark matter halos with logMh[Msun] > 12.5, matched to have the same X-ray luminosity, stellar mass and BHAR of COSMOS AGN predict the observed Mstar - Mh, BHAR - Mh and SFR-Mh relations, at z ∼ 1.

Connection between star formation and AGN activity has been studied widely over the past years, which shown to be very important for understanding better the role of AGN in galaxy evolution. In this context, what are the stellar ages and average stellar populations of AGN host galaxies, and if there are any differences depending on AGN type, are still open questions that brought many inconsistencies, very often due to different selection criteria used. The AGN sample detected in the ultra-hard X-rays (14–195 keV) by the Swift BAT telescope is not affected by obscuration nor is it contaminated by stellar emission, and presents some of the most unbiased samples. In this talk we will present the results obtained on AGN stellar populations and ages through spectral fittings by using the Swift-BAT AGN Spectroscopic Survey (BASS) which gives us an unique opportunity to understand better the connection between AGN and their host galaxies.

The RadioAstron Space VLBI mission utilized the 10-m radio telescope on board the dedicated Spektr-R spacecraft to observe cosmic radio sources with an unprecedented angular resolution at centimeter wave lengths in total and polarized light. The longest baseline of the space-ground interferometer is about 350000 km. It operated in 2011–2019 together with 58 largest ground radio telescopes. Resolution as high as 10 microarcsec has been achieved. An overview of its AGN science results will be presented in the talk. It includes a probe of jet emission mechanism through brightness temperature measurements, reconstruction of magnetic field structure close to the jet origin using polarization data, jet formation and collimation study for well resolved nearby AGN, as well as observations and analysis of jet precession and plasma instabilities. We will also discuss a new scattering effect which was discovered by RadioAstron to affect high resolution radio measurements of AGN and SgrA*.

In this talk I will show that multi-wavelength observations can provide novel constraints on the properties of ionized gas outflows in AGN. I will present evidence that the infrared emission in active galaxies includes a contribution from dust which is mixed with the outflow and is heated by the AGN. We detect this infrared component in thousands of AGN for the first time, and use it to constrain the outflow location. By combining this with optical emission lines, we constrain the mass outflow rates and energetics in a sample of 234 type II AGN, the largest such sample to date. The key ingredient of our new outflow measurements is a novel method to estimate the electron density using the ionization parameter and location of the flow. The inferred electron densities, ∼104.5 cm−3, are two orders of magnitude larger than found in most other cases of ionized outflows. We argue that the discrepancy is due to the fact that the commonly-used [SII]-based method underestimates the true density by a large factor. As a result, the inferred mass outflow rates and kinetic coupling efficiencies are 1–2 orders of magnitude lower than previous estimates, and 3–4 orders of magnitude lower than the typical requirement in hydrodynamic cosmological simulations. These results have significant implications for the relative importance of ionized outflows feedback in this population.

In order to construct accurate Galaxy Evolution models, a more thorough understanding of the high SFRs seen at z > 2 is needed. To better understand AGNs at higher redshifts, we have conducted a multi-wavelength of 38 of the most luminous AGNs found in the SDSS catalogue at redshift z ∼ 4.8, powered by fast-growing supermassive black holes (SMBHs). Using Herschel/SPIRE observations, we found star formation rates (SFRs) of up to 4000 Solar masses per year. We believe that both the AGN and star formation of these objects are fed by a common reservoir of cold gas, and that this cold gas is due to in-falling matter from major mergers. In this talk, we present ALMA band-7 data of the [CII] λ157.74 m emission line and underlying far-infrared (FIR) continuum of twelve luminous quasars at z∼4.8 in our search for dynamically interacting companions.