Paola Marziani’s research while affiliated with National Institute of Astrophysics and other places

Contamination from singly ionized iron emission is one of the greatest obstacles to determining the intensity of emission lines in the UV and optical wavelength ranges. This study presents a comprehensive analysis of the ii emission in the bright quasar RM 102, based on the most recent version of the CLOUDY software, with the goal of understanding the nature and the origin of the emission. We employ a constant pressure model for the emitting clouds, instead of the customary constant density assumption. The allowed parameter range is broad, with metallicity up to 50 times the solar value and turbulent velocity up to 100 km s^-1 for a subset of models. We also consider geometrical effects that could enhance the visibility of the non-illuminated faces of the clouds, as well as the presence of additional mechanical heating. Our investigation reveals that the broad line region of RM 102 is characterized by highly metallic gas. The observed ii features provide strong evidence for an inflow pattern geometry that favours the dark sides of clouds over isotropic emission if the heating is predominantly radiative. Solutions with mechanical heating are also an interesting option, but they require further self-consistent analysis. This study underscores the critical role of the dark versus bright side interpretation for reproducing the strong ii features in RM 102, highlighting both the geometry of the emitting region and the presence of chemically enriched gas as fundamental factors. Additionally, we report that CLOUDY currently still lacks certain transitions in its atomic databases, which prevents it from fully reproducing some observed ii features in quasar spectra.

The physical origins of the diverse emission-line asymmetries observed in the spectra of active galactic nuclei (AGNs) remain incompletely understood. Monitoring the temporal variations of line profiles offers a promising approach to investigating the underlying physics. In this study, we present an analysis of the broad H$\beta$ emission line profiles of eight AGNs observed from the end of 2016 to May 2023 as part of the reverberation mapping campaign titled "Monitoring AGNs with H$\beta$ Asymmetry" (MAHA), utilizing data obtained from the Wyoming Infrared Observatory (WIRO) 2.3-meter telescope. We measure the temporal variations of line asymmetry, width, and central velocity shift for the eight objects. Our findings reveal that the variation in asymmetry is positively correlated with H$\beta$ flux in five of the eight objects, while the remaining objects exhibit negative or complex correlations. Furthermore, we observe anti-correlations between line width and H$\beta$ flux for most objects, indicating the presence of the "breathing" phenomenon in their H$\beta$ emission lines. In contrast, two objects demonstrate an "anti-breathing" phenomenon or complex behavior. We discuss the physical origins of the temporal variations in line profiles and propose the possibility of decomposing the variations in H$\beta$ asymmetry and width into components: one that corresponds to short-term variations in H$\beta$ flux and another that reflects long-term variations in continuum light curves, perhaps driven by radiation pressure.

Supermassive binary black holes (SMBBHs) are the anticipated byproducts of galaxy mergers and play a pivotal role in shaping galaxy evolution, gravitational wave emissions, and accretion physics. Despite their theoretical prevalence, direct observational evidence for SMBBHs remains elusive, with only a handful of candidates identified to date. This paper explores optimal strategies and key environments for locating SMBBHs, focusing on observational signatures in the broad Balmer lines. We present a preliminary analysis on a flux-limited sample of sources belonging to an evolved spectral type along the quasar main sequence, and we discuss the spectroscopic clues indicative of binary activity and highlight the critical role of time-domain spectroscopic surveys in uncovering periodic variability linked to binary systems.

Supermassive binary black holes (SMBBHs) are the anticipated byproducts of galaxy mergers and play a pivotal role in shaping galaxy evolution, gravitational wave emissions, and accretion physics. Despite their theoretical prevalence, direct observational evidence for SMBBHs remains elusive, with only a handful of candidates identified to date. This paper explores optimal strategies and key environments for locating SMBBHs, focusing on observational signatures in the broad Balmer lines. We present a preliminary analysis on a flux-limited sample of sources belonging to an evolved spectral type along the quasar main sequence, and we discuss the spectroscopic clues indicative of binary activity and highlight the critical role of time-domain spectroscopic surveys in uncovering periodic variability linked to binary systems.

This review provides an observational perspective on the fundamental properties of super-Eddington accretion onto supermassive black holes in quasars. It begins by outlining the selection criteria, particularly focusing on optical and UV broad-line intensity ratios, used to identify a population of unobscured super-Eddington candidates. Several defining features place these candidates at the extreme end of the Population A in main sequence of quasars: among them are the highest observed singly-ionized iron emission, extreme outflow velocities in UV resonance lines, and unusually high metal abundances. These key properties reflect the coexistence of a virialized sub-system within the broad-line region alongside powerful outflows, with the observed gas enrichment likely driven by nuclear or circumnuclear star formation. The most compelling evidence for the occurrence of super-Eddington accretion onto supermassive black holes comes from recent observations of massive black holes at early cosmic epochs. These black holes require rapid growth rates that are only achievable through radiatively inefficient super-Eddington accretion. Furthermore, extreme Eddington ratios, close to or slightly exceeding unity, are consistent with the saturation of radiative output per unit mass predicted by accretion disk theory for super-Eddington accretion rates. The extreme properties of super-Eddington candidates suggest that these quasars could make them stable and well-defined cosmological distance indicators, leveraging the correlation between broad-line width and luminosity expected in virialized systems. Finally, several analogies with accretion processes around stellar-mass black holes, particularly in the high/soft state, are explored to provide additional insight into the mechanisms driving super-Eddington accretion.

Contamination from singly ionized iron emission is one of the greatest obstacles to determining the intensity of emission lines in the UV and optical wavelength ranges. This study presents a comprehensive analysis of the FeII emission in the bright quasar RM 102, based on the most recent version of the CLOUDY software, with the goal of simultaneously reproducing UV and optical FeII emission. We employ a constant pressure model for the emitting clouds, instead of the customary constant density assumption. The allowed parameter range is broad, with metallicity up to 50 times the solar value and turbulent velocity up to 100 km s$^{-1}$ for a subset of models. We also consider geometrical effects that could enhance the visibility of the non-illuminated faces of the clouds, as well as additional mechanical heating. Our investigation reveals that the broad line region of RM 102 is characterized by highly metallic gas. The observed FeII features provide strong evidence for an inflow pattern geometry that favours the dark sides of clouds over isotropic emission. This study confirms the presence of chemically enriched gas in the broad line region of bright quasars, represented by RM 102, which is necessary to explain the strong FeII emission and its characteristic features. Additionally, we report that CLOUDY currently still lacks certain transitions in its atomic databases which prevents it from fully reproducing some observed FeII features in quasar spectra.

Context. Despite the increasing prevalence of radio-loud (RL) sources at cosmic noon, our understanding of the underlying physics that governs the accretion disc outflows in these particular sources and its dissimilarity with radio-quiet (RQ) quasars remains somewhat limited. Aims. Disentangling the real impact of the radio-loudness and accretion on the outflow parameters remains a challenge to this day. We present ten new spectra of high-redshift and high-luminosity quasars and combine these with previous data at both high and low redshift with the aim being to evaluate the role of the feedback from RL and RQ AGN. The final high-redshift (1.5 ≲ z ≲ 3.9), high-luminosity (47.1 ≤ log(L) ≤ 48.5) sample consists of a combination of 60 quasars from our ISAAC and the Hamburg-ESO surveys. The low-redshift ( z ≤ 0.8) sample has 84 quasars that have been analyzed in the optical and with the Faint Object Spectrograph (FOS) data in the UV. Methods. We perform a multicomponent analysis of optical and UV emission line profiles along the quasar main sequence, and provide a relation that can be used to estimate the main outflow parameters (mass rate, thrust, and kinetic power) in both the BLR and NLR through the analysis of the [O III ] λ 5007 and C IV λ 1549 emission lines. Results. Spectrophotometric properties and line profile measurements are presented for H β +[O III ] λλ 4959,5007, Si IV λ 1397+O IV ] λ 1402, C IV λ 1549+He II λ 1640, and the 1900 Å blend. High-ionization lines, such as C IV λ 1549 and [O III ] λ 5007, usually present a significant asymmetry toward the blue, especially in radio-quiet sources. This is strong evidence of outflow motions. In the ISAAC sample, 72% of the quasars where [O III ] is clearly detected present significant outflows, with centroid velocity at half intensity blueshifted to values of greater than ∼250 km s ⁻¹ . Radio-loud quasars tend to present slightly more modest blueshifted components in both the UV and optical ranges. The behavior of [O III ] λ 5007 mirrors that of C IV λ 1549, with blueshift amplitudes between the two lines showing a high degree of correlation, which appears unaffected by the presence of radio emission. Conclusions. In contrast to the situation at low redshift, both RL and RQ AGN outflow parameters at high luminosity appear in the range needed to provide feedback effects on their host galaxies. Both high- and low- z RL quasars exhibit smaller outflows compared to RQ quasars, suggesting a potential role of radio-loudness in mitigating outflow effects. Nevertheless, the radio-loudness effect on AGN feedback is much less significant than the effect of accretion, with this latter emerging as the main driver of nuclear outflows.

In this work we discuss the correlation between luminosity L and velocity dispersion σ observed in different astrophysical contexts, in particular that of early-type galaxies (ETGs; Faber–Jackson (FJ) law) and that of active galactic nuclei (AGN). Our data for the ETGs confirm the bending of the FJ at high masses and the existence of similar curvatures in the projections of the Fundamental Plane (FP) approximately at the mass scale of ∼1010M⊙. We provide an explanation for such curvatures and for the presence of the Zone of Exclusion (ZoE) in these diagrams. The new prospected theory for the FJ law introduces a new framework to understand galaxy evolution in line with the hierarchical structure of the Universe. The classic analysis carried out for a class of type 1 AGN accreting gas at very high rates, confirms that a FJ law of the form L=L0σ4 is roughly consistent with the observations, with a slope quite similar to that of ETGs. We discuss the physics behind the FJ law for the AGN in different contexts and also examine the biases affecting both the luminosity and the velocity dispersion, paying particular attention to the effects induced by the spherical symmetry of the emitting sources on the accuracy of the luminosity estimates.