Dominik Schelicher (Univ. Sapienza) & Matias Liempi (Univ. Sapienza):
Title: Formation of massive black holes via collisions: validation and statistical predictions
Abstract: “During the last years it was shown that the collision-based formation of very massive objects is an important formation channel of supermassive black holes. We present here the main criteria under which this channel may operate including a validation of these criteria through the comparison with numerical N-body simulations and Nuclear Star Cluster observations. Our formation criteria have been implemented in the semi-analytic galaxy evolution model GALACTICUS. We present here the main implementation and its first results, as well as the plans for future work to expand this model..”
Lorenzo Battistini (Univ. Roma Tre):
Title: Properties of an X-ray selected sample of dual AGN candidates with XMM-Newton and Chandra
Abstract: “We present the study of an X-ray selected sample of dual AGN candidates at projected spatial separations 0.5 < rp < 100 kpc up to z ∼ 0.1, using XMM-Newton and Chandra data. The total sample is composed by both AGN-AGN pairs and AGN-galaxy pairs. The main goal of our study was to highlight the absorption properties and the AGN activity during the merger phases, and to compare them with a sample of isolated AGN. Among all the X-ray selected AGN, we found that ∼ 11% of them shows a companion (either a galaxy or another AGN). The majority of the AGN in pair is found to be at separation rp < 30 kpc, suggesting that the merger do have an impact on the AGN activity, which is triggered at the closer separations between the nuclei. These results will be discussed in details through the spectral analysis, together with the absorption properties of the dual sample.”
Location: dipartimento di fisica dell’Università “La Sapienza”, Aula Careri, , edificio Marconi, primo piano
Tommaso Zana (Univ. Sapienza):
Title: Super-critical accretion of seed black holes in gaseous protogalactic nuclei: hints from high-resolution simulations
Abstract: “To shed light on the mystery of the exceptionally massive (> 10⁹ Msun) black holes observed at high redshift (z~6-7), we have explored the impact of super Eddington accretion onto black hole seeds of different masses, when they are located at the center of a gas-rich proto-galaxy at z~15. For this purpose, we have run various high-resolution smoothed-particle hydrodynamical simulations including star formation, photoionization non-equilibrium cooling of primordial species, and an accretion prescription based on the slim disc scheme, one of the most efficient models in terms of accretion. We tested the effect of the seed mass on the accretion efficiency, since lower mass seeds would be more easily scattered away from the centre of the galactic potential, where a lower content of gas could hinder the accretion process.Preliminary results indicate that our model can significantly grow black hole seeds regardless of their initial mass, with only a marginal dependence on the strength of their feedback. However, the surrounding environment, as represented by the initial conditions, plays a dominant role in shaping the growth efficiency.”
Alessandro Trinca (Univ. Sapienza):
Title: Seeking the rise of the first Massive Black Holes in the JWST era
Abstract: “The advent of JWST has revolutionized our understanding of the high-redshift Universe, enabling the exploration of Active Galactic Nuclei (AGN) in unprecedented detail and extending observations to fainter and more distant objects. Early JWST campaigns uncovered a ubiquitous population of AGNs at z∼5, representing up to 10–20% of UV-detected galaxies, and identified several extreme candidates at z≳10. Many of these AGNs are powered by black holes (BHs) that appear overmassive relative to their host galaxies, showing BH-to-stellar mass ratios that are orders of magnitude higher than those predicted by local scaling relations. This poses a significant challenge to current theoretical models of early galaxy evolution. To investigate this population of early massive BHs, we developed the Cosmic Archaeology Tool (CAT), a semi-analytical model designed to reconstruct the co-evolution of the first galaxies and AGNs within a full cosmological framework. We explore different possible BH evolutionary pathways against JWST AGNs to test whether their properties can already shed some light on the nature and early rise of massive BHs. Preliminary results suggest an early BH growth dominated by short, efficient phases of super-Eddington accretion, driven by the frequent dynamical interactions that characterize the first galaxies. This scenario not only explains their overmassiveness but also provides a natural mechanism to realign these systems with the local population at later times..”
Ivano Saccheo (Univ. Roma Tre):
Title: Shedding light on QSOs at EoR via X-ray-to-NIR spectral energy distribution modelings
Abstract: “In this talk, I will present the results of the first systematic investigation of the multi-wavelength emission of a sample of Titan QSOs at the Epoch of Reionization. These QSOs at 6 ≲ z ≲ 7.5 have been selected to have massive SMBHs, which required initial black hole seeds larger than 10^3 Msun, making them a challenge for SMBH formation theories. I focused on SED to get insights into their intrinsic physical properties (accretion rate, energy budget and relative prominence of the primary continuum emission components). Remarkably the UV-to-optical SED of the Titans closely resembles that of other luminous QSOs both at z>6 and at Cosmic Noon (z=2-3) despite their extreme SMBH selection criterion and clear differences in X-ray spectral properties compared to luminous QSOs at lower redshifts. This finding will be discussed in the light of determining the average properties of the continuum emission of QSOs shining in the first Gyr of the Universe. In addition, I will report on the UV/optical bolometric corrections for z > 6 QSOs and compare them with those derived for the bulk of the QSO population. Accurate measurements of Kbol are crucial for robustly estimating the bolometric luminosity for large samples of high-z QSOs collected in upcoming Rubin/Euclid surveys.”
Vittoria Elvezia Gianolli (Univ. Roma Tre):
Title: UFOs in AGNs
Abstract: “The detection of blue-shifted absorption lines likely associated with ionized Iron K-shell transitions in the X-ray spectra of many Active Galactic Nuclei (AGN) suggests the presence of a highly ionized gas outflowing with mildly relativistic velocities (0.03 c - 0.6 c), named Ultra-Fast Outflow (UFO). Within the SUBWAYS project we characterized these winds starting from a sample of 22 radio-quiet quasars at 0.1 < z < 0.4, and compared the results with similar studies in the literature on samples of 42 local radio-quiet Seyfert galaxies and 14 high redshift radio-quiet quasars. The scope of our work is a statistical study of UFO parameters and incidence, considering key physical properties of the sources, e.g. supermassive black hole (SMBH) mass, bolometric luminosity, accretion rates and Spectral Energy Distribution, with the aim of gaining new insights into the UFO launching mechanisms. We find indications that highly luminous AGN with steeper X-ray/UV ratio, are more likely to host UFO. The presence of UFO is not significantly related to any other AGN property in our sample. These findings suggest that the UFO phenomenon may be transient. Focusing on AGN with UFO, other important results are: (1) faster UFO have larger ionization parameters and column densities; (2) X-ray radiation plays a more crucial role in driving highly ionized winds compared to UV; (3) the correlation between outflow velocity and luminosity is significantly flatter than what expected for radiatively driven winds; (4) more massive BH experience higher wind mass-losses, suppressing accretion of matter onto the BH; (5) the UFO launching radius is positively correlated with the Eddington ratio. Furthermore, our analysis suggest the involvement of multiple launching mechanisms, including radiation pressure and magneto-hydrodynamic processes, rather than pointing to a single, universally applicable mechanism.”
Pierpaolo Condò (Univ. Tor Vergata):
Title: Advanced X-ray modeling of supermassive black hole winds: the case of IRAS 13224-3809
Abstract: "Recent studies have advanced our understanding of ultra-fast outflows (UFOs) in active galactic nuclei (AGN) and highlighted their crucial role in galactic evolution through AGN feedback mechanisms. The Narrow-Line Seyfert 1 galaxy IRAS 13224-3809 has been extensively studied and has served as a key example in various, often conflicting, theoretical models. Our study tries to synthesize and refine existing attempts in analyzing this target in the X-rays to better understand its UFO and its impact on the AGN environment. We employed a detailed analysis of the XMM-Newton and NuSTAR archival data focusing on time-resolved and flux-resolved X-ray spectroscopy in the 0.3-15 keV band. In our study, we endeavored to capture the broad-band continuum shape as accurately as possible. Alongside this effort, we introduced tailored photo-ionization simulations, specifically designed to model the outflow, enriching our comprehensive analysis of its complex dynamics. The complexity of the broad-band continuum modeling suggests multiple potential interpretations, underscoring the need for further research. Nevertheless, our analysis confirms the presence of a rapidly variable outflow in IRAS 13224-3809, with spectral features that change on timescales shorter than 50 ks, opening the floor to explore driving mechanisms and dynamics of powerful AGN outflows."
PROPOSALS DISCUSSION:
Federica Ricci - ALMA: re-submission followup SUBWAYS;
Alessia Tortosa - Chandra: IRAS 04416+1215;
Vittoria Gianolli - Chandra: A candidate Optical/X-ray mismatched quasar;
Elias Kammoun - Chandra+HST+(ESO): Luminous QSOs at z~0.8;
Roberto Serafinelli - Chandra: A jet-driven outflow in the z=2.2 blazar TON 618?;
Roberto Serafinelli - HST: Probing the variability of ionized absorbers in an obscured state of PG 1114+445;
Angela Bongiorno - ESO - (JWST): scaling relations ty2 at z~1-2;
Francesco Tombesi - XRISM: 3C120/3C111;
Alessia Tortosa - XRISM : IC4329A;
Akke Viitanen (OAR):
Title: Building a realistic, empirical photometric AGN/galaxy/star catalog for LSST
Abstract: "Realistic photometric catalogs including AGN, galaxies, and stars are essential tools in assessing the performance and systematics of a large-scale survey such as Rubin-LSST (to be online September 2023/early 2024), which is set to observe half of the sky in six photometric bands (ugrizy) approximately 2000 times within ten years of time. As part of the Italian LSST in-kind contribution, I will present the INAF-OAR approach for creating an end-to-end LSST simulation pipeline. Namely, we have created an empirical X-ray/optical AGN catalog by populating EGG galaxies with accretion rates up to high redshift (z ~ 5) and low stellar mass (logM/Msun ~ 8.5), with host stellar masses, SFRs, morphologies, as well as AGN variability, optical/near-IR SEDs and broad-band photometry. Using the catalog, synthetic LSST images are created which take into account the LSST observing strategy (cadence), as well as instrumental and optical effects. Finally, we use the official LSST Science Pipelines to process the simulated images in order to extract photometric catalogs similar to how it will be done in practice in operations. The end-to-end pipeline presented here will serve as a paramount tool within LSST for understanding AGN selection and scientific yield of AGN variability studies."
Roberto Serafinelli (OAR):
Title: Ionized absorbers in Active Galactic Nuclei
Abstract: "Ionized gas in active galactic nuclei can be detected by means of absorption or emission features in their X-ray or optical/UV spectra. As ionized gas could be indicative of outflows, which are thought to be the main mechanism through which the black hole transfers its energy to the surrounding environment, its study is one of the hot topics in modern astrophysics. I will review the current understanding of observational signatures of ionized absorbers, with particular emphasis on the recent results obtained with the quasar PG 1114+445, in which nearly all these observational features are observed. I will also present preliminary results on the nearby Seyfert galaxy NGC 4051, for which we are preparing to test the Time-Evolving Photo-Ionization Device (TEPID) model, in order to open the way for future high-resolution spectra from the recently launched X-ray telescope XRISM."
Location: Istituto di Astrofisica e Planetologia Spaziali (INAF - IAPS) Aula IB09
Gabriele Bruni (IAPS):
Title: The GRACE project: high-energy giant radio galaxies and their duty cycle
Abstract: "The advent of new generation radio telescopes is opening new possibilities on the classification and study of extragalactic high-energy sources, specially the underrepresented ones like radio galaxies. Among these, Giant Radio Galaxies (GRG, larger than 0.7 Mpc) are among the most extreme manifestations of the accretion/ ejection processes on supermassive black holes. Our recent studies have shown that GRG can be up to four times more abundant in hard X-ray selected (i.e. from INTEGRAL/IBIS and Swift/BAT at >20 keV) samples and, most interestingly, the majority of them present signs of restarted radio activity. This makes them the ideal testbed to study the so far unknown duty cycle of jets in active galactic nuclei. Open questions in the field include: How and when jets are restarted? How jets evolve and what’s their dynamic? What is the jet's duty cycle and what triggers them? Our group has recently collected a wealth of radio data on these high-energy selected GRGs, allowing us to study their jet formation and evolution from the pc to kpc scales, across different activity epochs. Furthermore, we are devoting an effort to the exploitation of new radio surveys data for the discovery of new classes of counterparts of Fermi/LAT and ANTARES catalogues. In particular, we are unveiling the hidden population of radio galaxies associated with gamma-ray sources, and possibly with neutrino events."
Luigi Spinoglio (IAPS):
Title: The spectral energy distributions and the bolometric luminosities of local AGN
Abstract: "We measure the bolometric luminosity of a complete and unbiased sample of AGN in the local universe, the 12 micron selected AGN sample. For each galaxy we used a 10-bands spectral energy distribution, from the radio to the hard X-rays with the main purpose of isolating the nonstellar nuclear component, originating from the AGN, in each energy band, by using sub-arcsecond photometric data, where available, and correcting those contaminated by stellar light from the host galaxy. We derive the median Spectral Energy Distributions (SED) of each type of AGN, namely Seyfert type 1, Hidden Broad Line Region galaxies, Seyfert type 2 and LINERs.
We find that the 12um and the K-band nuclear luminosities have good linear correlations with the bolometric luminosity, similar to those in the X-rays. We derive bolometric corrections for either continuum bands (2.2um K-band, 12um, 2-10keV and 14-195keV) and emission lines (mid-IR high ionisation lines of [OIV] and [NeV]) and optical [OIII]5007A) as well as for combinations of IR continuum and line emission.
We find that fixed combinations of the 12um nuclear luminosity plus the [OIV]26um, or the [NeV]14.3um line luminosities, provide accurate predictors of the bolometric luminosity, at least up to quasar luminosities (10^46 erg s-1). This result reflects the fact that in the mid-IR includes a large fraction of (and is proportional to) the bolometric luminosity of the AGN, through both the nuclear continuum emission from hot dust/torus and the gas emission from the NLR. The James Webb Space Telescope will be able to measure this bolometric luminosity in virtually any AGN in the local universe. For AGN at redshifts z<1 the [NeV]14.3um line can also be used."
Federica Ricci (Roma Tre University) :
Title: The near-infrared view of the BLR in X-ray selected local AGN: BASS DR2
Abstract: "Virial black hole mass (Mbh) determination involves directly knowing the broad line region (BLR) clouds velocity distribution, their distance from the central supermassive black hole R_BLR and the virial factor f. Understanding whether biases arise in Mbh estimation with increasing obscuration is possible only by studying a large statistical sample of obscuration unbiased (hard) X-ray selected AGN in the rest-frame near-infrared (NIR, 0.8-2.5μm) since it penetrates deeper into the BLR than the optical. We present a detailed analysis of 314 high spectral resolution (R~5000) unique NIR spectra of local (z<0.1) BAT-selected Seyfert galaxies as part of the BAT AGN spectroscopic survey (BASS) DR2. This represents the largest and least biased NIR AGN database assembled yet, a benchmark for next-generation surveys in X-rays and NIR. These observations have allowed us to assess the presence of correlations between f and AGN properties for the first time in a complete (both obscured and unobscured) statistical sample of AGN with rich ancillary information (e.g., column density Nh, Lx, Mbh, stellar velocity dispersion sigma_star), and to verify systematics in Mbh determination by comparing the BLR characterisation in the optical (based on Hα) and NIR (based on HeI, Paβ, Paα). Our results show the critical impact obscuration can have on BLR characterisation and the importance of the X-rays and NIR for a less biased view of the BLR."
Daniele Tagliacozzo (Roma Tre University) :
Title: The geometry of the hot corona in MCG-05-23-16 constrained by X-ray polarimetry
Abstract: "The AGNs X-Ray spectra are dominated by radiation emitted by the accretion disc and energized via comptonization in a hot and compact medium close to the SMBH, with unknown geometry and enigmatic physical origin: the corona. Now, with IXPE we have for the first time the chance to unveil the X-Ray polarization properties of these objects, aligning a new tool to spectroscopical analysis. In this talk I will present the IXPE view of the radio-quiet and Compton-thin Seyfert galaxy MCG-05-23-16, discussing the results of our analysis and trying to point out the hints we got on the morphology of the AGNs comptonizing corona obtained through a comparison with simulations performed with the Monte Carlo code MONK. Finally, I will briefly review the other main IXPE results on radio-quiet, unobscured AGNs, trying to point out a complete depiction of the state of the art."