Publications (2024)
Total peer-reviewed articles: 132
Quantum origin of anomalous Floquet phases in cavity-QED materials
Authors: Perez-Gonzalez, Beatriz; Platero, Gloria; Gomez-Leon, Alvaro
Journal: COMMUNICATIONS PHYSICS
Publication date: 2024/12/21
DOI: 10.1038/s42005-024-01908-y
Abstract: Anomalous Floquet topological phases are unique to periodically driven systems, lacking a static analog. Inspired by Floquet Engineering with classical electromagnetic radiation, Quantum Floquet Engineering has emerged as a promising tool to tailor the properties of quantum materials using quantum light. While the latter recovers the physics of Floquet materials in its semi-classical limit, the mapping between these two scenarios remains mysterious in many aspects. In this work, we discuss the emergence of quantum anomalous topological phases in cavity-QED materials, linking the topological phase transitions in the electron-photon spectrum with those in the 0- and pi-gaps of Floquet quasienergies. Our results establish the microscopic origin of an emergent discrete time-translation symmetry in the matter sector, and link isolated c-QED materials with periodically driven ones. Finally, we discuss the bulk-edge correspondence in terms of hybrid light-matter topological invariants.
Photodissociation of the CH2Cl radical: A high-level ab initio study
Authors: Charfeddine, F.; Yazidi, O.; Zanchet, A.; Banares, L.; Garcia-Vela, A.
Journal: JOURNAL OF CHEMICAL PHYSICS
Publication date: 2024/12/21
DOI: 10.1063/5.0243800
Abstract: Photodissociation of the CH2Cl radical is investigated by using high-level multireference configuration interaction ab initio methods, including the spin-orbit coupling. All possible fragmentation pathways, namely, CH2Cl + h nu -> CH2 + Cl, HCCl + H, and CCl + H-2, have been analyzed. The potential-energy curves of the ground and several excited electronic states along the corresponding dissociating bond distance of each pathway have been calculated. Inclusion of the spin-orbit couplings is found to be crucial because it strongly determines the shape of the curves of the different excited states and, therefore, their photodissociation dynamics behavior. Analysis of the potential curves indicates that the pathways producing CH2 + Cl and HCCl + H can occur through a fast direct dissociation mechanism, while the pathway leading to CCl + H-2 involves much slower dissociation mechanisms such as internal conversion between electronic states, predissociation, or tunneling through exit barriers. The main implications are that the two faster channels are predicted to be dominant, while the slower pathway is expected to be very unlikely and rather irrelevant. Appreciable actinic fluxes of solar irradiation are available at stratospheric altitudes where ozone is abundant, in the wavelength range where absorption of the first low-lying excited states of CH2Cl has been observed experimentally. Our results show that in this excitation energy range, the above-mentioned two dominant dissociation pathways are open and then could contribute to stratospheric ozone depletion.
Toward a robust physical and chemical characterization of heterogeneous lines of sight: The case of the Horsehead nebula
Authors: Segal, Leontine; Roueff, Antoine; Pety, Jerome; Gerin, Maryvonne; Roueff, Evelyne; Goicoechea, Javier R.; Beslic, Ivana; Coude, Simon; Einig, Lucas; Mazurek, Helena; Orkisz, Jan H.; Palud, Pierre; Santa-Maria, Miriam G.; Zakardjian, Antoine; Bardeau, Sebastien; Bron, Emeric; Chainais, Pierre; Demyk, Karine; Magalhaes, Victor de Souza; Gratier, Pierre; Guzman, Viviana V.; Hughes, Annie; Languignon, David; Levrier, Francois; Le Bourlot, Jacques; Le Petit, Franck; Lis, Dariusz C.; Liszt, Harvey S.; Peretto, Nicolas; Sievers, Albrecht; Thouvenin, Pierre-Antoine
Journal: ASTRONOMY & ASTROPHYSICS
Publication date: 2024/12/12
DOI: 10.1051/0004-6361/202451567
Abstract: Context. Dense and cold molecular cores and filaments are surrounded by an envelope of translucent gas. Some of the low-J emission lines of CO and HCO+ isotopologues are more sensitive to the conditions either in the translucent environment or in the dense and cold one because their intensities result from a complex interplay of radiative transfer and chemical properties of these heterogeneous lines of sight (LoSs). Aims. We extend our previous single-zone modeling with a more realistic approach that introduces multiple layers to take account of possibly varying conditions along the LoS. We used the IRAM-30m data from the ORION-B large program toward the Horsehead nebula in order to demonstrate our method’s capability and effectiveness. Methods. We propose a cloud model composed of three homogeneous slabs of gas along each LoS, representing an outer envelope and a more shielded inner layer. We used the non-LTE radiative transfer code RADEX to model the line profiles from the kinetic temperature (T-kin), the volume density (n(H2)), kinematics, and chemical properties of the different layers. We then used a fast and robust maximum likelihood estimator to simultaneously fit the observed lines of the CO and HCO+ isotopologues. To limit the variance on the estimates, we propose a simple chemical model by constraining the column densities. Results. A single-layer model cannot reproduce the spectral line asymmetries that result from a combination of different radial velocities and absorption effects among layers. A minimal heterogeneous model (three layers only) is sufficient for the Horsehead application, as it provides good fits of the seven fitted lines over a large part of the studied field of view. The decomposition of the intensity into three layers allowed us to discuss the distribution of the estimated physical or chemical properties along the LoS. About 80% of the (CO)-C-12 integrated intensity comes from the outer envelope, while similar to 55% of the integrated intensity of the (1 – 0) and (2 – 1) lines of (CO)-O-18 comes from the inner layer. For the lines of the (CO)-C-13 and the HCO+ isotopologues, integrated intensities are more equally distributed over the cloud layers. The estimated column density ratio N((CO)-C-13)/N((CO)-O-18) in the envelope increases with decreasing visual extinction, and it reaches 25 in the pillar outskirts. While the inferred T-kin of the envelope varies from 25 to 40 K, that of the inner layer drops to similar to 15 K in the western dense core. The estimated n(H2) in the inner layer is similar to 3 x 10(4) cm(-3) toward the filament, and it increases by a factor of ten toward dense cores. Conclusions. Our proposed method correctly retrieves the physical and chemical properties of the Horsehead nebula. It also offers promising prospects for less supervised model fits of wider-field datasets.
SNe Ia Twins for Life: Toward a Precise Determination of H0
Authors: Ruiz-Lapuente, P.; Hernandez, J. I. Gonzalez
Journal: ASTROPHYSICAL JOURNAL
Publication date: 2024/12/01
Abstract: Here we present an approach to the measurement of extragalactic distances using twin SNe Ia, taken from the early down to the nebular phase. The approach is purely empirical, although we can give a theoretical background on why the method is reliable. By studying those twins in galaxies where peculiar velocities are relatively unimportant, we can tackle the H-0 tension problem. Here we apply the method to the determination of the distances to NGC 7250 and NGC 2525, who hosted, respectively, SN 2013dy and SN 2018gv, twins of two different SNe Ia prototypes: SN 2013aa/SN 2017cbv and SN 2011fe. From the study of the SN 2013aa and SN 2017cbv twin pair, by comparing it with SN 2011fe and applying the difference between the SN 2013aa/2017cbv and the SN 2011fe class, we also find a good estimate of the distance to NGC 5643. We have just started to measure distances with the method for the samples in W.L Freedman et al. and A. G. Riess et al. There are differences in measured distances to the same galaxy using Cepheids or TRGBs. In this context of discrepancy, the twins for life method is very competitive because it can provide distance estimates with a modulus error of sigma(mu) = 0.04 mag. Our findings called for a revision of the distances measured with Cepheids in A. G. Riess et al. (2022). NGC 7250 and NGC 2525 needed better measurements with Cepheids. We have noticed that the Cepheids-based distance obtained with the JWST in A. G. Riess et al. (2024a) for NGC 5643 is in good agreement with what we find, unlike their previous estimate in A. G. Riess et al. (2022). The Hubble tension can arise from the way in which the local SNe Ia sample is linked to the SNe Ia Hubble flow sample. A good calibration of SNe Ia in the local sample is needed and we have started to gather it. We also expect to apply the twin SNe Ia comparison from the local sample to that in galaxies with z >0.02-0.03 well into the Hubble flow to obtain a reliable value for H-0. Those distant SNe Ia can be observed with the ELT or the JWST.
Proposed Importance of HOCO Chemistry: Inefficient Formation of CO2 from CO and OH Reactions on Ice Dust
Authors: Ishibashi, Atsuki; Molpeceres, German; Hidaka, Hiroshi; Oba, Yasuhiro; Lamberts, Thanja; Watanabe, Naoki
Journal: ASTROPHYSICAL JOURNAL
Publication date: 2024/12/01
Abstract: With the advent of JWST ice observations, dedicated studies on the formation reactions of detected molecules are becoming increasingly important. One of the most interesting molecules in interstellar ice is CO2. Despite its simplicity, the main formation reaction considered, CO + OH -> CO2 + H through the energetic HOCO* intermediate on ice dust, is subject to uncertainty because it directly competes with the stabilization of HOCO as a final product, which is formed through energy dissipation of HOCO* to the water ice. When energy dissipation to the surface is effective during the reaction, HOCO can be a dominant product. In this study, we experimentally demonstrate that the major product of the reaction is indeed not CO2, but rather the highly reactive radical HOCO. The HOCO radical can later evolve into CO2 through H-abstraction reactions, but these reactions compete with additional reactions, leading to the formation of carboxylic acids (R-COOH). Our results highlight the importance of HOCO chemistry and encourage further exploration of the chemistry of this radical.
The Electron-Phonon Interaction in Non-Stoichiometric Bi2Sr2CaCu2O8+? Superconductor Obtained from the Diffuse Elastic Scattering of Helium Atoms
Authors: Benedek, Giorgio; Manson, Joseph R.; Miret-Artes, Salvador; Schmicker, Detlef; Toennies, Jan Peter
Journal: CONDENSED MATTER
Publication date: 2024/12/01
Abstract: Previously, helium atom scattering (HAS) has been shown to probe the electron-phonon interaction at conducting crystal surfaces via the temperature dependence of the specular peak intensity. This method is now extended to non-stoichiometric superconductors. The electron-phonon interaction, as expressed by the mass-enhancement factor lambda, is derived from the temperature dependence of the diffuse elastic scattering intensity, which specifically depends on the non-stoichiometric component responsible for superconductivity. The measured value of the mass-enhancement factor for Bi2Sr2CaCu2O8+delta at the optimal doping delta = 0.16 is lambda = 0.55 +/- 0.08 is in good agreement with values of lambda recently estimated with other methods. This also confirms the relevant role of electron-phonon interaction in high-temperature non-stoichiometric cuprate superconductors.
Borophene nanoclusters: Energetics and structures from analytical potentials
Authors: Zergani, Farideh; Marques, Jorge M. C.; Bartolomei, Massimiliano; Pirani, Fernando
Journal: JOURNAL OF CHEMICAL PHYSICS
Publication date: 2024/11/28
DOI: 10.1063/5.0239149
Abstract: Boron shows a variety of properties, determining a chemistry rich and complementary to that of carbon, the neighbor atom in the Periodic Table. In this work, we investigated the strength and nature of the interaction involving B-12 or B-36 monomer, which represent molecular prototypes of borophene, the two-dimensional allotrope of elemental boron. For the representation of the intermolecular interaction, we developed new potential energy surfaces (PESs) that are based on accurate ab initio or density functional theory data. It is shown that borophene molecules are bound by weak intermolecular interactions of van der Waals nature, perturbed by antiaromatic effects. Moreover, the proposed PESs are given in an analytical form proper to investigate the structures and energetics of (B-12)(n) and (B-36)(n) clusters (with n = 2-10) by applying a global geometry optimization procedure. It is found that the most stable structures of (B-12)(n) favor close contacts between the edges of the monomers, leading to cage-like clusters as n increases, and conversely, (B-36)(n) clusters are mainly composed of stacked or herringbone structures. These results suggest the possibility to produce a novel class of two-dimensional borophene materials, exhibiting different features compared to graphene like structures, which could be of interest for the nanotechnology.
The Galaxy Activity, Torus, and Outflow Survey (GATOS): V. Unveiling PAH survival and resilience in the circumnuclear regions of AGNs with JWST
Authors: Garcia-Bernete, I.; Rigopoulou, D.; Donnan, F. R.; Alonso-Herrero, A.; Pereira-Santaella, M.; Shimizu, T.; Davies, R.; Roche, P. F.; Garcia-Burillo, S.; Labiano, A.; Hermosa Munoz, L.; Zhang, L.; Audibert, A.; Bellocchi, E.; Bunker, A.; Combes, F.; Delaney, D.; Esparza-Arredondo, D.; Gandhi, P.; Gonzalez-Martin, O.; Honig, S. F.; Imanishi, M.; Hicks, E. K. S.; Fuller, L.; Leist, M.; Levenson, N. A.; Lopez-Rodriguez, E.; Packham, C.; Ramos Almeida, C.; Ricci, C.; Stalevski, M.; Martin, M. Villar; Ward, M. J.
Journal: ASTRONOMY & ASTROPHYSICS
Publication date: 2024/11/11
DOI: 10.1051/0004-6361/202450086
Abstract: This study analyses JWST MIRI/MRS observations of the infrared (IR) polycyclic aromatic hydrocarbon (PAH) bands in the nuclear (similar to 0.4 ” at 11 mu m; similar to 75 pc) and circumnuclear regions (inner similar to kpc) of local active galactic nuclei (AGNs) from the Galactic Activity, Torus, and Outflow Survey (GATOS). We examine the PAH properties in the circumnuclear regions of AGNs and the projected direction of AGN-outflows and compare them to those in star-forming regions and the innermost regions of AGNs. This study employs 4.9-28.1 mu m sub-arcsecond angular resolution data to investigate the properties of PAHs in three nearby sources (D-L similar to 30 – 40 Mpc). Our findings are aligned with previous JWST studies, demonstrating that the central regions of AGNs display a larger fraction of neutral PAH molecules (i.e. elevated 11.3/6.2 and 11.3/7.7 mu m PAH ratios) in comparison to star-forming galaxies. We find that AGNs might affect not only the PAH population in the innermost region, but also in the extended regions up to similar to kpc scales. By comparing our observations to PAH diagnostic diagrams, we find that, in general, regions located in the projected direction of the AGN-outflow occupy similar positions on the PAH diagnostic diagrams as those of the innermost regions of AGNs. Star-forming regions that are not affected by the AGNs in these galaxies share the same part of the diagram as star-forming galaxies. We also examined the potential of the PAH-H-2 diagram to disentangle AGN-versus-star-forming activity. Our results suggest that in Seyfert-like AGNs, the illumination and feedback from the AGN might affect the PAH population at nuclear and kpc scales, particularly with respect to the ionisation state of the PAH grains. However, PAH molecular sizes are rather similar. The carriers of the ionised PAH bands (6.2 and 7.7 mu m) are less resilient than those of neutral PAH bands (11.3 mu m), which might be particularly important for strongly AGN-host coupled systems. Therefore, caution must be applied when using PAH bands as star-formation rate indicators in these systems even at kpc scales, with the effects of the AGN being more important for ionised ones.
Quantifying the informativity of emission lines to infer physical conditions in giant molecular clouds: I. Application to model predictions
Authors: Einig, Lucas; Palud, Pierre; Roueff, Antoine; Pety, Jerome; Bron, Emeric; Le Petit, Franck; Gerin, Maryvonne; Chanussot, Jocelyn; Chainais, Pierre; Thouvenin, Pierre-Antoine; Languignon, David; Beslic, Ivana; Coude, Simon; Mazurek, Helena; Orkisz, Jan H.; Santa-Maria, Miriam G.; Segal, Leontine; Zakardjian, Antoine; Bardeau, Sebastien; Demyk, Karine; de Souza Magalhaes, Victor; Goicoechea, Javier R.; Gratier, Pierre; Guzman, Viviana V.; Hughes, Annie; Levrier, Francois; Le Bourlot, Jacques; Lis, Dariusz C.; Liszt, Harvey S.; Peretto, Nicolas; Roueff, Evelyne; Sievers, Albrecht
Journal: ASTRONOMY & ASTROPHYSICS
Publication date: 2024/11/11
DOI: 10.1051/0004-6361/202451588
Abstract: Context. Observations of ionic, atomic, or molecular lines are performed to improve our understanding of the interstellar medium (ISM). However, the potential of a line to constrain the physical conditions of the ISM is difficult to assess quantitatively, because of the complexity of the ISM physics. The situation is even more complex when trying to assess which combinations of lines are the most useful. Therefore, observation campaigns usually try to observe as many lines as possible for as much time as possible. Aims. We have searched for a quantitative statistical criterion to evaluate the full constraining power of a (combination of) tracer(s) with respect to physical conditions. Our goal with such a criterion is twofold. First, we want to improve our understanding of the statistical relationships between ISM tracers and physical conditions. Secondly, by exploiting this criterion, we aim to propose a method that helps observers to make their observation proposals; for example, by choosing to observe the lines with the highest constraining power given limited resources and time. Methods. We propose an approach based on information theory, in particular the concepts of conditional differential entropy and mutual information. The best (combination of) tracer(s) is obtained by comparing the mutual information between a physical parameter and different sets of lines. The presented analysis is independent of the choice of the estimation algorithm (e.g., neural network or chi(2) minimization). We applied this method to simulations of radio molecular lines emitted by a photodissociation region similar to the Horsehead Nebula. In this simulated data, we considered the noise properties of a state-of-the-art single dish telescope such as the IRAM 30m telescope. We searched for the best lines to constrain the visual extinction, A(V)(tot), or the ultraviolet illumination field, G(0). We ran this search for different gas regimes, namely translucent gas, filamentary gas, and dense cores. Results. The most informative lines change with the physical regime (e.g., cloud extinction). However, the determination of the optimal (combination of) line(s) to constrain a physical parameter such as the visual extinction depends not only on the radiative transfer of the lines and chemistry of the associated species, but also on the achieved mean signal-to-noise ratio. The short integration time of the CO isotopologue J = 1 – 0 lines already yields much information on the total column density for a large range of (A(V)(tot), G(0)) space. The best set of lines to constrain the visual extinction does not necessarily combine the most informative individual lines. Precise constraints on the radiation field are more difficult to achieve with molecular lines. They require spectral lines emitted at the cloud surface (e.g., [CII] and [CI] lines). Conclusions. This approach allows one to better explore the knowledge provided by ISM codes, and to guide future observation campaigns.
Gapless deconfined phase in a Z N-symmetric Hamiltonian created in a cold-atom setup
Authors: Rakov, Mykhailo, V; Tagliacozzo, Luca; Lewenstein, Maciej; Zakrzewski, Jakub; Chanda, Titas
Journal: PHYSICAL REVIEW B
Publication date: 2024/11/05
DOI: 10.1103/PhysRevB.110.195114
Abstract: We investigate a quasi-two-dimensional system consisting of two species of alkali atoms confined in a specific optical lattice potential [Phys. Rev. A 95 , 053608 (2017)]. In the low-energy regime, this system is governed by a unique ZN gauge theory, where field theory arguments have suggested that it may exhibit two exotic gapless deconfined phases, namely a dipolar liquid phase and a Bose liquid phase, along with two gapped (confined and deconfined) phases. We address these predictions numerically by using large-scale density matrix renormalization group simulations. Our findings provide conclusive evidence for the existence of a gapless Bose liquid phase for N 7. We demonstrate that this gapless phase shares the same critical properties as one-dimensional critical phases, resembling weakly coupled chains of Luttinger liquids. In the range of ladder and cylinder geometries and N considered, the gapless dipolar phase predicted theoretically is still elusive and its characterization will probably require a full two-dimensional treatment.
Synthesis and Spectroscopic Characterization of Interstellar Candidate Ethynyl Thiocyanate: HCCSCN
Authors: Alonso, Elena R.; Insausti, Aran; Kolesnikova, Lucie; Leon, Iker; Mcguire, Brett A.; Shingledecker, Christopher N.; Agundez, Marcelino; Cernicharo, Jose; Rivilla, Victor M.; Cabezas, Carlos; Jimenez-Serra, Izaskun; Martin-Pintado, Jesus; Guillemin, Jean-Claude
Journal: ASTROPHYSICAL JOURNAL
Publication date: 2024/11/01
Abstract: This work aims to spectroscopically characterize and provide for the first time direct experimental frequencies of the ground vibrational state and two excited states of the simplest alkynyl thiocyanate (HCCSCN) for astrophysical use. Both microwave (8-16 GHz) and millimeter-wave regions (50-120 GHz) of the spectrum have been measured and analyzed in terms of Watson’s semirigid rotor Hamiltonian. A total of 314 transitions were assigned to the ground state of HCCSCN, and a first set of spectroscopic constants have been accurately determined. Spectral features of the molecule were then searched for in Sgr B2(N), NGC 6334I, G+0.693-0.027, and TMC-1 molecular clouds. Upper limits to the column density are provided.
AGN feeding along a one-armed spiral in NGC 4593: A study using ALMA CO(2-1) observations
Authors: Kianfar, K.; Andreani, P.; Fernandez-Ontiveros, J. A.; Combes, F.; Spinoglio, L.; Hatziminaoglou, E.; Ricci, C.; Bewketu-Belete, A.; Imanishi, M.; Pereira-Santaella, M.; Slater, R.; Malheiro, M.
Journal: ASTRONOMY & ASTROPHYSICS
Publication date: 2024/11/01
DOI: 10.1051/0004-6361/202451185
Abstract: Context. We investigate active galactic nuclei (AGN) feeding through the molecular gas (CO(2-1) emission) properties of the local Seyfert 1 galaxy NGC 4593, using Atacama Large Millimeter Array (ALMA) observations and other multi-wavelength data. Aims. Our study aims to understand the interplay between the AGN and the interstellar medium (ISM) in this galaxy, examining the role of the AGN in steering gas dynamics within its host galaxy, evaluating the energy injected into the ISM, and determining whether gas is inflowing or outflowing from the galaxy. Methods. After reducing the ALMA CO(2-1) images, we employed two models, 3D-BAROLO and DISCFIT, to construct a disc model and fit its emission to the ALMA data. Additionally, we used photometric data to build a spectral energy distribution (SED) and apply the CIGALE code to derive key physical properties of the AGN and its host. Results. Our analysis reveals a complex interplay within NGC 4593, including a clear rotational pattern, the influence of a non-axisymmetric bar potential, and a central molecular zone (CMZ)-like ring. We observe an outflow of CO(2-1) gas along the minor axis, at a distance of similar to 220 pc from the nucleus. The total molecular gas mass is estimated to be 1 – 5 x 10(8) M-circle dot, with non-circular motions contributing 10%. Our SED analysis indicates an AGN fraction of 0.88 and a star formation rate (SFR) of 0.42 M-circle dot yr(-1). Conclusions. These findings highlight the complex dynamics in the centre of NGC 4593, which are significantly influenced by the presence of the AGN. The overall physical properties of this system suggest that the AGN has a substantial impact on the evolution of NGC 4593.
Polycyclic Aromatic Hydrocarbon Emission in the Central Regions of Three Seyferts and the Implication for Underlying Feedback Mechanisms
Authors: Zhang, Lulu; Garcia-Bernete, Ismael; Packham, Chris; Donnan, Fergus R.; Rigopoulou, Dimitra; Hicks, Erin K. S.; Davies, Ric I.; Shimizu, Taro T.; Alonso-Herrero, Almudena; Almeida, Cristina Ramos; Pereira-Santaella, Miguel; Ricci, Claudio; Bunker, Andrew J.; Leist, Mason T.; Rosario, David J.; Garcia-Burillo, Santiago; Munoz, Laura Hermosa; Combes, Francoise; Imanishi, Masatoshi; Labiano, Alvaro; Esparza-Arredondo, Donaji; Bellocchi, Enrica; Audibert, Anelise; Fuller, Lindsay; Gonzalez-Martin, Omaira; Honig, Sebastian; Izumi, Takuma; Levenson, Nancy A.; Lopez-Rodriguez, Enrique; Rouan, Daniel; Stalevski, Marko; Ward, Martin J.
Journal: ASTROPHYSICAL JOURNAL LETTERS
Publication date: 2024/11/01
Abstract: We analyze JWST Mid-Infrared Instrument/Medium Resolution Spectrograph integral field unit observations of three Seyferts from the Galactic Activity, Torus, and Outflow Survey (GATOS) and showcase the intriguing polycyclic aromatic hydrocarbon (PAH) and emission-line characteristics in regions of similar to 500 pc scales over or around their active galactic nuclei (AGN). Combing the measurements and model predictions, we find that the central regions containing a high fraction of neutral PAHs with small sizes, e.g., those in ESO137-G034, are in highly heated environments, due to collisional shock heating, with hard and moderately intense radiation fields. Such environments are proposed to result in inhibited growth or preferential erosion of PAHs, decreasing their average size and overall abundance. We additionally find that the central regions containing a high fraction of ionized PAHs with large sizes, e.g., those in MCG-05-23-016, are likely experiencing severe photoionization because of the radiative effects from the radiative shock precursor besides the AGN. The severe photoionization can contribute to the ionization and further destruction of PAHs. Overall, different Seyferts, even different regions in the same galaxy, e.g., those in NGC 3081, can contain PAH populations of different properties. Specifically, Seyferts that exhibit similar PAH characteristics to ESO137-G034 and MCG-05-23-016 also tend to have similar emission-line properties to them, suggesting that the explanations for PAH characteristics of ESO137-G034 and MCG-05-23-016 may also apply generally. These results have promising application in the era of JWST, especially in diagnosing different (i.e., radiative and kinetic) AGN feedback modes.
Optimal quantum circuit generation for pixel segmentation in multiband images
Authors: Altares-Lopez, Sergio; Garcia-Ripoll, Juan Jose; Ribeiro, Angela
Journal: APPLIED SOFT COMPUTING
Publication date: 2024/11/01
DOI: 10.1016/j.asoc.2024.112175
Abstract: A novel approach is proposed for multiband image processing via quantum models in real situations. Quantum circuits are automatically generated ad-hoc for each use case via multiobjective genetic algorithms. Using this universal method, image processing tasks such as segmentation can be carried out by considering the properties that constitute each pixel. The generated circuits present a low level of correlation between qubits, and thus can be considered quantum-inspired machine learning models. The effectiveness of this methodology has been validated by applying it to different segmentation use cases. Comparisons are made between optimized classical kernel methods and the generated quantum-inspired models to understand their behaviors. The results show that quantum models for multiband image processing achieve accuracies similar to those of classical methods.
A biconical ionised gas outflow and evidence of positive feedback in NGC 7172 uncovered by MIRI/JWST
Authors: Munoz, L. Hermosa; Alonso-Herrero, A.; Pereira-Santaella, M.; Garcia-Bernete, I.; Garcia-Burillo, S.; Garcia-Lorenzo, B.; Davies, R.; Shimizu, T.; Esparza-Arredondo, D.; Hicks, E. K. S.; Haidar, H.; Leist, M.; Lopez-Rodriguez, E.; Ramos Almeida, C.; Rosario, D.; Zhang, L.; Audibert, A.; Bellocchi, E.; Boorman, P.; Bunker, A. J.; Combes, F.; Campbell, S.; Diaz-Santos, T.; Fuller, L.; Gandhi, P.; Gonzalez-Martin, O.; Hoenig, S.; Imanishi, M.; Izumi, T.; Labiano, A.; Levenson, N. A.; Packham, C.; Ricci, C.; Rigopoulou, D.; Rouan, D.; Stalevski, M.; Villar-Martin, M.; Ward, M. J.
Journal: ASTRONOMY & ASTROPHYSICS
Publication date: 2024/10/22
DOI: 10.1051/0004-6361/202450262
Abstract: We present observations of the type-2 Seyfert NGC 7172 obtained with the medium-resolution spectrometer (MRS) of the Mid-Infrared Instrument (MIRI) on board the James Webb Space Telescope (JWST). This galaxy hosts one of the lowest ionised gas mass outflow rates (M-out similar to 0.005 M-circle dot yr(-1)) in a sample of six active galactic nuclei (AGN) with similar bolometric luminosities (log L-bol similar to 44 erg s(-1)) within the Galactic Activity, Torus, and Outflow Survey (GATOS). We aim to understand the properties of the ionised gas outflow and its impact on the host galaxy. We mainly used the ionised gas emission lines from the neon transitions, which cover a broad range of ionisation potentials (IPs) from similar to 20 eV to similar to 130 eV. We applied parametric and non-parametric methods to characterise the line emission and kinematics. The low excitation lines (IP < 25 eV, e.g. [Ne II]) trace the rotating disc emission. The high excitation lines (IP > 90 eV, e.g. [Ne V]), which are likely photoionised exclusively by the AGN, are expanding in the direction nearly perpendicular to the disc of the galaxy, with maximum projected velocities in the range of similar to 350-500 km s(-1). In particular, [Ne V] and [Ne VI] lines reveal a biconical ionised gas outflow emerging north-south from the nuclear region, extending at least similar to 2.5 ” N and 3.8 ” S (projected distance of similar to 450 and 680 pc, respectively). Most of the emission arising in the northern part of the cone was not previously detected due to obscuration. Given the almost face-on orientation of the outflow and the almost edge-on orientation of the galaxy, NGC 7172 may be a case of weak coupling. Nevertheless, we found evidence of positive feedback in two distinct outflowing clumps at projected distances of 3.1 ” and 4.3 ” (i.e. similar to 560 and 780 pc) south-west of the AGN. We estimated a star formation rate in these regions using the [Ne II] and [Ne III] luminosities of 0.08 M-circle dot yr(-1), which is similar to 10% of that found in the circumnuclear ring. The star formation activity might have been triggered by the interaction between the ionised gas outflow and the interstellar medium of the galaxy.