@article{17557, abstract = {The black hole (BH) binaries in active galactic nuclei (AGN) are expected to form mainly through scattering encounters in the ambient gaseous medium. Recent simulations, including our own, have confirmed this formation pathway is highly efficient. We perform 3D smoothed particle hydrodynamics (SPH) simulations of BH scattering encounters in AGN discs. Using a range of impact parameters, we probe the necessary conditions for binary capture and how different orbital trajectories affect the dissipative effects from the gas. We identify a single range of impact parameters, typically of width ∼0.86−1.59 binary Hill radii depending on AGN disc density, that reliably leads to binary formation. The periapsis of the first encounter is the primary variable that determines the outcome of the initial scattering. We find an associated power law between the energy dissipated and the periapsis depth to be ΔE ∝ r−b with b = 0.42 ± 0.16, where deeper encounters dissipate more energy. Excluding accretion physics does not significantly alter these results. We identify the region of parameter space in initial energy versus impact parameter where a scattering leads to binary formation. Based on our findings, we provide a ready-to-use analytic criterion that utilizes these two pre-encounter parameters to determine the outcome of an encounter, with a reliability rate of >90 per cent. As the criterion is based directly on our simulations, it provides a reliable and highly physically motivated criterion for predicting binary scattering outcomes which can be used in population studies of BH binaries and mergers around AGN.}, author = {Rowan, Connar and Whitehead, Henry and Boekholt, Tjarda and Kocsis, Bence and Haiman, Zoltán}, issn = {0035-8711}, journal = {Monthly Notices of the Royal Astronomical Society}, number = {4}, pages = {10448--10468}, publisher = {Oxford University Press (OUP)}, title = {{Black hole binaries in AGN accretion discs – II. Gas effects on black hole satellite scatterings}}, doi = {10.1093/mnras/stad3641}, volume = {527}, year = {2023}, } @article{17558, abstract = {The detection of starlight from the host galaxies of quasars during the reionization epoch (z > 6) has been elusive, even with deep Hubble Space Telescope observations1,2. The current highest redshift quasar host detected3, at z = 4.5, required the magnifying effect of a foreground lensing galaxy. Low-luminosity quasars4,5,6 from the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP)7 mitigate the challenge of detecting their underlying, previously undetected host galaxies. Here we report rest-frame optical images and spectroscopy of two HSC-SSP quasars at z > 6 with the JWST. Using near-infrared camera imaging at 3.6 and 1.5 μm and subtracting the light from the unresolved quasars, we find that the host galaxies are massive (stellar masses of 13 × and 3.4 × 1010 M☉, respectively), compact and disc-like. Near-infrared spectroscopy at medium resolution shows stellar absorption lines in the more massive quasar, confirming the detection of the host. Velocity-broadened gas in the vicinity of these quasars enables measurements of their black hole masses (1.4 × 109 and 2.0 × 108 M☉, respectively). Their location in the black hole mass–stellar mass plane is consistent with the distribution at low redshift, suggesting that the relation between black holes and their host galaxies was already in place less than a billion years after the Big Bang.}, author = {Ding, Xuheng and Onoue, Masafusa and Silverman, John D. and Matsuoka, Yoshiki and Izumi, Takuma and Strauss, Michael A. and Jahnke, Knud and Phillips, Camryn L. and Li, Junyao and Volonteri, Marta and Haiman, Zoltán and Andika, Irham Taufik and Aoki, Kentaro and Baba, Shunsuke and Bieri, Rebekka and Bosman, Sarah E. I. and Bottrell, Connor and Eilers, Anna-Christina and Fujimoto, Seiji and Habouzit, Melanie and Imanishi, Masatoshi and Inayoshi, Kohei and Iwasawa, Kazushi and Kashikawa, Nobunari and Kawaguchi, Toshihiro and Kohno, Kotaro and Lee, Chien-Hsiu and Lupi, Alessandro and Lyu, Jianwei and Nagao, Tohru and Overzier, Roderik and Schindler, Jan-Torge and Schramm, Malte and Shimasaku, Kazuhiro and Toba, Yoshiki and Trakhtenbrot, Benny and Trebitsch, Maxime and Treu, Tommaso and Umehata, Hideki and Venemans, Bram P. and Vestergaard, Marianne and Walter, Fabian and Wang, Feige and Yang, Jinyi}, issn = {0028-0836}, journal = {Nature}, number = {7977}, pages = {51--55}, publisher = {Springer Science and Business Media LLC}, title = {{Detection of stellar light from quasar host galaxies at redshifts above 6}}, doi = {10.1038/s41586-023-06345-5}, volume = {621}, year = {2023}, } @article{17573, abstract = {The Laser Interferometer Space Antenna (LISA) will be a transformative experiment for gravitational wave astronomy, and, as such, it will offer unique opportunities to address many key astrophysical questions in a completely novel way. The synergy with ground-based and space-born instruments in the electromagnetic domain, by enabling multi-messenger observations, will add further to the discovery potential of LISA. The next decade is crucial to prepare the astrophysical community for LISA’s first observations. This review outlines the extensive landscape of astrophysical theory, numerical simulations, and astronomical observations that are instrumental for modeling and interpreting the upcoming LISA datastream. To this aim, the current knowledge in three main source classes for LISA is reviewed; ultra-compact stellar-mass binaries, massive black hole binaries, and extreme or interme-diate mass ratio inspirals. The relevant astrophysical processes and the established modeling techniques are summarized. Likewise, open issues and gaps in our understanding of these sources are highlighted, along with an indication of how LISA could help making progress in the different areas. New research avenues that LISA itself, or its joint exploitation with upcoming studies in the electromagnetic domain, will enable, are also illustrated. Improvements in modeling and analysis approaches, such as the combination of numerical simulations and modern data science techniques, are discussed. This review is intended to be a starting point for using LISA as a new discovery tool for understanding our Universe.}, author = {Amaro-Seoane, Pau and Andrews, Jeff and Arca Sedda, Manuel and Askar, Abbas and Baghi, Quentin and Balasov, Razvan and Bartos, Imre and Bavera, Simone S. and Bellovary, Jillian and Berry, Christopher P. L. and Berti, Emanuele and Bianchi, Stefano and Blecha, Laura and Blondin, Stéphane and Bogdanović, Tamara and Boissier, Samuel and Bonetti, Matteo and Bonoli, Silvia and Bortolas, Elisa and Breivik, Katelyn and Capelo, Pedro R. and Caramete, Laurentiu and Cattorini, Federico and Charisi, Maria and Chaty, Sylvain and Chen, Xian and Chruślińska, Martyna and Chua, Alvin J. K. and Church, Ross and Colpi, Monica and D’Orazio, Daniel and Danielski, Camilla and Davies, Melvyn B. and Dayal, Pratika and De Rosa, Alessandra and Derdzinski, Andrea and Destounis, Kyriakos and Dotti, Massimo and Duţan, Ioana and Dvorkin, Irina and Fabj, Gaia and Foglizzo, Thierry and Ford, Saavik and Fouvry, Jean-Baptiste and Franchini, Alessia and Fragos, Tassos and Fryer, Chris and Gaspari, Massimo and Gerosa, Davide and Graziani, Luca and Groot, Paul and Habouzit, Melanie and Haggard, Daryl and Haiman, Zoltán and Han, Wen-Biao and Istrate, Alina and Johansson, Peter H. and Khan, Fazeel Mahmood and Kimpson, Tomas and Kokkotas, Kostas and Kong, Albert and Korol, Valeriya and Kremer, Kyle and Kupfer, Thomas and Lamberts, Astrid and Larson, Shane and Lau, Mike and Liu, Dongliang and Lloyd-Ronning, Nicole and Lodato, Giuseppe and Lupi, Alessandro and Ma, Chung-Pei and Maccarone, Tomas and Mandel, Ilya and Mangiagli, Alberto and Mapelli, Michela and Mathis, Stéphane and Mayer, Lucio and McGee, Sean and McKernan, Berry and Miller, M. Coleman and Mota, David F. and Mumpower, Matthew and Nasim, Syeda S. and Nelemans, Gijs and Noble, Scott and Pacucci, Fabio and Panessa, Francesca and Paschalidis, Vasileios and Pfister, Hugo and Porquet, Delphine and Quenby, John and Ricarte, Angelo and Röpke, Friedrich K. and Regan, John and Rosswog, Stephan and Ruiter, Ashley and Ruiz, Milton and Runnoe, Jessie and Schneider, Raffaella and Schnittman, Jeremy and Secunda, Amy and Sesana, Alberto and Seto, Naoki and Shao, Lijing and Shapiro, Stuart and Sopuerta, Carlos and Stone, Nicholas C. and Suvorov, Arthur and Tamanini, Nicola and Tamfal, Tomas and Tauris, Thomas and Temmink, Karel and Tomsick, John and Toonen, Silvia and Torres-Orjuela, Alejandro and Toscani, Martina and Tsokaros, Antonios and Unal, Caner and Vázquez-Aceves, Verónica and Valiante, Rosa and van Putten, Maurice and van Roestel, Jan and Vignali, Christian and Volonteri, Marta and Wu, Kinwah and Younsi, Ziri and Yu, Shenghua and Zane, Silvia and Zwick, Lorenz and Antonini, Fabio and Baibhav, Vishal and Barausse, Enrico and Bonilla Rivera, Alexander and Branchesi, Marica and Branduardi-Raymont, Graziella and Burdge, Kevin and Chakraborty, Srija and Cuadra, Jorge and Dage, Kristen and Davis, Benjamin and de Mink, Selma E. and Decarli, Roberto and Doneva, Daniela and Escoffier, Stephanie and Gandhi, Poshak and Haardt, Francesco and Lousto, Carlos O. and Nissanke, Samaya and Nordhaus, Jason and O’Shaughnessy, Richard and Portegies Zwart, Simon and Pound, Adam and Schussler, Fabian and Sergijenko, Olga and Spallicci, Alessandro and Vernieri, Daniele and Vigna-Gómez, Alejandro}, issn = {1433-8351}, journal = {Living Reviews in Relativity}, number = {1}, publisher = {Springer Science and Business Media LLC}, title = {{Astrophysics with the laser interferometer space antenna}}, doi = {10.1007/s41114-022-00041-y}, volume = {26}, year = {2023}, } @article{17584, abstract = {Some Seyfert galaxies are detected in high-energy gamma rays, but the mechanism and site of gamma-ray emission are unknown. Also, the origins of the cosmic high-energy neutrino and MeV gamma-ray backgrounds have been veiled in mystery since their discoveries. We propose emission from stellar-mass BHs (sBHs) embedded in disks of active galactic nuclei as their possible sources. These sBHs are predicted to launch jets due to the Blandford–Znajek mechanism, which can produce intense electromagnetic, neutrino, and cosmic-ray emissions. We investigate whether these emissions can be the sources of cosmic high-energy particles. We find that emission from internal shocks in the jets can explain gamma rays from nearby radio-quiet Seyfert galaxies including NGC 1068, if the Lorentz factor of the jets (Γj) is high. On the other hand, for moderate Γj, the emission can significantly contribute to the background gamma-ray and neutrino intensities in the ~MeV and ≲PeV bands, respectively. Furthermore, for moderate Γj with efficient amplification of the magnetic field and cosmic-ray acceleration, the neutrino emission from NGC 1068 and the ultrahigh-energy cosmic rays can be explained. These results suggest that the neutrino flux from NGC 1068 as well as the background intensities of MeV gamma rays, neutrinos, and the ultrahigh-energy cosmic rays can be explained by a unified model. Future MeV gamma-ray satellites will test our scenario for neutrino emission.}, author = {Tagawa, Hiromichi and Kimura, Shigeo S. and Haiman, Zoltán}, issn = {0004-637X}, journal = {The Astrophysical Journal}, number = {1}, publisher = {American Astronomical Society}, title = {{High-energy electromagnetic, neutrino, and cosmic-ray emission by stellar-mass black holes in disks of active galactic nuclei}}, doi = {10.3847/1538-4357/ace71d}, volume = {955}, year = {2023}, } @article{17594, abstract = {The origin of stellar-mass black hole mergers discovered through gravitational waves is being widely debated. Mergers in the disks of active galactic nuclei (AGNs) represent a promising source of origin, with possible observational clues in the gravitational-wave data. Beyond gravitational waves, a unique signature of AGN-assisted mergers is electromagnetic emission from the accreting black holes. Here we show that jets launched by accreting black holes merging in an AGN disk can be detected as peculiar transients by infrared, optical, and X-ray observatories. We further show that this emission mechanism can explain the possible associations between gravitational-wave events and the optical transient ZTF 19abanrhr and the proposed gamma-ray counterparts GW150914-GBM and LVT151012-GBM. We demonstrate how these associations, if genuine, can be used to reconstruct the properties of these events’ environments. Searching for infrared and X-ray counterparts to similar electromagnetic transients in the future, once host galaxies are localized by optical observations, could provide a smoking-gun signature of the mergers’ AGN origin.}, author = {Tagawa, Hiromichi and Kimura, Shigeo S. and Haiman, Zoltán and Perna, Rosalba and Bartos, Imre}, issn = {0004-637X}, journal = {The Astrophysical Journal}, number = {1}, publisher = {American Astronomical Society}, title = {{Observable signature of merging stellar-mass black holes in active galactic nuclei}}, doi = {10.3847/1538-4357/acc4bb}, volume = {950}, year = {2023}, } @article{17602, abstract = {Motivated by the increasing number of detections of merging black holes by LIGO-VIRGO-KAGRA, black hole (BH) binary mergers in the discs of active galactic nuclei (AGNs) is investigated as a possible merger channel. In this pathway, BH encounters in the gas disc form mutually bound BH binary systems through interaction with the gas in the disc and subsequently inspiral through gravitational torques induced by the local gas. To determine the feasibility of this merger pathway, we present the first three-dimensional global hydrodynamic simulations of the formation and evolution of a stellar-mass BH binaries AGN discs with three different AGN disc masses and five different initial radial separations. These 15 simulations show binary capture of prograde and retrograde binaries can be successful in a range of disc densities including cases well below that of a standard radiatively efficient alpha disc, identifying that the majority of these captured binaries are then subsequently hardened by the surrounding gas. The eccentricity evolution depends strongly on the orbital rotation where prograde binaries are governed by gravitational torques form their circumbinary mini disc, with eccentricities being damped, while for retrograde binaries the eccentricities are excited to >∼ 0.9 by accretion torques. In two cases, retrograde binaries ultimately undergo a close periapsis passage which results in a merger via gravitational waves after only a few thousand binary orbits. Thus, the merger time-scale can be far shorter than the AGN disc lifetime. These simulations support an efficient AGN disc merger pathway for BHs.}, author = {Rowan, Connar and Boekholt, Tjarda and Kocsis, Bence and Haiman, Zoltán}, issn = {0035-8711}, journal = {Monthly Notices of the Royal Astronomical Society}, number = {2}, pages = {2770--2796}, publisher = {Oxford University Press}, title = {{Black hole binary formation in AGN discs: from isolation to merger}}, doi = {10.1093/mnras/stad1926}, volume = {524}, year = {2023}, } @article{17606, abstract = {We present the first results from the JWST ASPIRE program (A SPectroscopic survey of biased halos In the Reionization Era). This program represents an imaging and spectroscopic survey of 25 reionization-era quasars and their environments by utilizing the unprecedented capabilities of NIRCam Wide Field Slitless Spectroscopy (WFSS) mode. ASPIRE will deliver the largest (∼280 arcmin^2) galaxy redshift survey at 3-4 μm among JWST Cycle-1 programs and provide extensive legacy values for studying the formation of the earliest supermassive black holes (SMBHs), the assembly of galaxies, early metal enrichment, and cosmic reionization. In this first ASPIRE paper, we report the discovery of a filamentary structure traced by the luminous quasar J0305-3150 and ten [OIII] emitters at z=6.6. This structure has a 3D galaxy overdensity of δgal=12.6 over 637 cMpc3, one of the most overdense structures known in the early universe, and could eventually evolve into a massive galaxy cluster. Together with existing VLT/MUSE and ALMA observations of this field, our JWST observations reveal that J0305-3150 traces a complex environment where both UV-bright and dusty galaxies are present, and indicate that the early evolution of galaxies around the quasar is not simultaneous. In addition, we discovered 31 [OIII] emitters in this field at other redshifts, 5.3