Astronomy & Astrophysics最新文献

{"title":"Discovery of three magnetic helium-rich hot subdwarfs with SALT","authors":"M. Dorsch, C. S. Jeffery, A. Philip Monai, C. A. Tout, E. J. Snowdon, I. Monageng, L. J. A. Scott, B. Miszalski, V. M. Woolf","doi":"10.1051/0004-6361/202451306","DOIUrl":"https://doi.org/10.1051/0004-6361/202451306","url":null,"abstract":"Magnetic fields with strengths ranging from 300 to 500 kG have recently been discovered in a group of four extremely similar helium-rich hot subdwarf (He-sdO) stars. In addition to their strong magnetic fields, these He-sdO stars are characterised by common atmospheric parameters, clustering around <i>T<i/><sub>eff<sub/> = 46 500 K, a log <i>ɡ<i/>/cm s<sup>−1<sup/> close to 6, and intermediate helium abundances. Here we present the discovery of three additional magnetic hot subdwarfs, J123359.44–674929.11, J125611.42-575333.45, and J144405.79–674400.93. These stars are again almost identical in terms of atmospheric parameters, but, at <i>B<i/> ≈ 200 kG, their magnetic fields are somewhat weaker than those previously known. The close similarity of all known He-sdOs implies a finely tuned formation channel. We propose the merging of a He white dwarf with a H+He white dwarf. A differential rotation at the merger interface may initiate a toroidal magnetic field that evolves via a magnetic dynamo to produce a poloidal field. This field is either directly visible at the surface or might diffuse towards the surface if initially buried. We further discuss a broad absorption line centred at about 4630 Å that is common to all magnetic He-sdOs. This feature may not be related to the magnetic field but instead to the intermediate helium abundances in these He-sdO stars, allowing the strong He II 4686 Å line to be perturbed by collisions with hydrogen atoms.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"54 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142598286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Probing the magnetic fields of starspots with transit mapping","authors":"Fabian Menezes, Alexandre Araújo, Adriana Valio","doi":"10.1051/0004-6361/202452071","DOIUrl":"https://doi.org/10.1051/0004-6361/202452071","url":null,"abstract":"<i>Context.<i/> Starspots, regions of strong magnetic fields, serve as indicators of stellar activity and the dynamo mechanism at play in the interior of stars. The magnetic fields of main-sequence stars play a crucial role in driving stellar activity. An effective approach to better understanding stellar magnetic fields and activity lies in the detailed characterisation of starspot properties.<i>Aims.<i/> We propose a new method for estimating the magnetic fields of starspots that employs modelling techniques of planetary transit mapping, which provides estimates of the size, intensity, and location of spots on the stellar photosphere.<i>Methods.<i/> A starspot’s maximum magnetic field was calculated using the linear relationship with the spot flux deficit, Δ<i>F<i/><sub>spot<sub/> (the spot’s brightness times its area) and the well-characterised relation for sunspots determined in this work, <i>B<i/><sub>spot<sub/> = 1170 + 844log Δ​<i>F<i/><sub>spot<sub/> (G).<i>Results.<i/> Applying this relationship to previously mapped spots on the photospheres of 14 FGK and M stars yields spot maximum magnetic fields ranging from 2700 G to 4600 G, with an overall average of 3900 ± 400 G. We looked for correlations between starspot magnetic fields and stellar properties. We did not find any correlation between a spot’s mean extreme magnetic field and effective temperature, nor the differential shear. However, a weak anti-correlation is seen between the spots’ magnetic field and stellar age as well as between the magnetic field and the rotation period.<i>Conclusions.<i/> When compared with previous results of small-scale magnetic field measurements, the B values obtained here are basically constant and near the saturation limit found for rapid rotators. This implies that it is not the intensity of the magnetic field of starspots that decreases with age but rather the filling factor. This result offers a unique window into the magnetic dynamo of stars.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"34 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142598501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Origin of transition disk cavities","authors":"Shuo Huang, Nienke van der Marel, Simon Portegies Zwart","doi":"10.1051/0004-6361/202451511","DOIUrl":"https://doi.org/10.1051/0004-6361/202451511","url":null,"abstract":"<i>Context<i/>. Protoplanetary disks surrounding young stars are the birth places of planets. Among them, transition disks with inner dust cavities of tens of au are sometimes suggested to host massive companions. Yet, such companions are often not detected.<i>Aims<i/>. Some transition disks exhibit a large amount of gas inside the dust cavity and relatively high stellar accretion rates, which contradicts typical models of gas-giant-hosting systems. Therefore, we investigate whether a sequence of low-mass planets can create the appearance of cavities in the dust disk.<i>Methods<i/>. We evolve the disks with low-mass growing embryos in combination with 1D dust transport and 3D pebble accretion, to investigate the reduction of the pebble flux at the embryos’ orbits. We vary the planet and disk properties to understand the resulting dust profile.<i>Results<i/>. We find that multiple pebble-accreting planets can efficiently decrease the dust surface density, resulting in dust cavities consistent with transition disks. The number of low-mass planets necessary to sweep up all pebbles decreases with decreasing turbulent strength and is preferred when the dust Stokes number is 10<sup>−2<sup/> − 10<sup>−4<sup/>. Compared to dust rings caused by pressure bumps, those by efficient pebble accretion exhibit more extended outer edges. We also highlight the observational reflections: the transition disks with rings featuring extended outer edges tend to have a large gas content in the dust cavities and rather high stellar accretion rates.<i>Conclusions<i/>. We propose that planet-hosting transition disks consist of two groups. In Group A disks, planets have evolved into gas giants, opening deep gaps in the gas disk. Pebbles concentrate in pressure maxima, forming dust rings. In Group B, multiple Neptunes (unable to open deep gas gaps) accrete incoming pebbles, causing the appearance of inner dust cavities and distinct ring-like structures near planet orbits. The morphological discrepancy of these rings may aid in distinguishing between the two groups using high-resolution ALMA observations.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"5 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142598504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Counting stars from the integrated spectra of galaxies","authors":"I. Martín-Navarro, A. Vazdekis","doi":"10.1051/0004-6361/202451604","DOIUrl":"https://doi.org/10.1051/0004-6361/202451604","url":null,"abstract":"Over the last few decades, evolutionary population synthesis models have powered an unmatched leap forward in our understanding of galaxies. From dating the age of the first galaxies in the Universe to providing detailed measurements of the chemical composition of nearby galaxies, the success of this approach built upon simple stellar population (SSP) spectro-photometric models is unquestionable. However, the internal constraints inherent to the construction of SSP models can hinder our ability to analyze the integrated spectra of galaxies in situations where the SSP assumption does not sufficiently hold. Thus, here we revisit the possibilities of fitting galaxy spectra as a linear combination of stellar templates without assuming any a priori knowledge on stellar evolution. We showcase the sensitivity of this alternative approach to changes in the stellar population properties, in particular the direct connection to variations in the stellar initial mass function, as well as its advantages when dealing with noncanonical integrated populations and semi-resolved observations. Furthermore, our analysis demonstrates that the absorption spectra of galaxies can be used to independently constrain stellar evolution theory beyond the limited conditions of the solar neighborhood.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"80 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142598502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The radial distribution of radio emission from SN 1993J: Magnetic field amplification due to the Rayleigh-Taylor instability","authors":"I. Martí-Vidal, C.-I. Björnsson, M. A. Pérez-Torres, P. Lundqvist, J. M. Marcaide","doi":"10.1051/0004-6361/202450329","DOIUrl":"https://doi.org/10.1051/0004-6361/202450329","url":null,"abstract":"<i>Context.<i/> Observations of radio emission from young core-collapse supernovae (CCSNe) allow one to study the history of the pre-supernova stellar wind, trace the density structure of the ejected material, and probe the magnetohydrodynamics that describe the interaction between the two, as the forward shock expands into the circumstellar medium. The radio shell of supernova SN 1993J has been observed with very long baseline interferometry (VLBI) for ∼20 years, giving one of the most complete pictures of the evolution of a CCSN shock. However, different results about the expansion curve and properties of the radio-emitting structure have been reported by different authors, likely due to systematics in the data calibration and/or model assumptions made by each team.<i>Aims.<i/> We aim to perform an analysis of the complete set of VLBI observations of SN 1993J that accounts for different instrumental and source-intrinsic effects, in order to retrieve robust conclusions about the shock expansion and physics in SN 1993J.<i>Methods.<i/> We have explored the posterior probability distribution of a complete data model, using a technique based on Markov chains. Our model accounts for antenna calibration effects, as well as different kinds of radio-emission structures for the supernova.<i>Results.<i/> The posterior parameter distributions strongly favor a spherical shell-like radio structure with a nonuniform radial intensity profile, with a broad brightness distribution that peaks close to or just above the region where the contact discontinuity is expected to be located. Regarding the shell expansion, the full dataset can be well described using one single deceleration parameter, <i>β<i/> ∼ 0.80, being the shell outer radius <i>R<i/> ∝ <i>t<i/><sup><i>β<i/><sup/>. There is clear evidence of a relative widening of the shell width beyond day 2600−3300 after the explosion, which is due to an increased deceleration of the inner shell boundary. This is similar to findings previously reported by other authors.<i>Conclusions.<i/> The radial intensity profile and the late evolution of the shell suggest a scenario in which the magnetic field is amplified mainly by the Rayleigh-Taylor instability, which emanates from the contact discontinuity. Furthermore, the increased deceleration of the inner boundary indicates that the reverse shock enters a region of the ejecta at around 3000 days, where the density distribution is substantially flatter. Such a weakening of the reverse shock can also explain the achromatic break in the radio light curves, which occurs at the same time. The deduced radial intensity distribution for SN 1993J is quite similar to that observed in the spatially well-resolved supernova remnant Cassiopeia A.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"28 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142598506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of the internal temperature on vertical mixing and on cloud structures in ultra-hot Jupiters","authors":"Pascal A. Noti, Elspeth K. H. Lee","doi":"10.1051/0004-6361/202451823","DOIUrl":"https://doi.org/10.1051/0004-6361/202451823","url":null,"abstract":"<i>Context.<i/> The vertical mixing in hot-Jupiter atmospheres plays a critical role in the formation and spacial distribution of cloud particles in their atmospheres. This affects the observed spectra of a planet through cloud opacity, which can be influenced by the degree of cold trapping of refractory species in the deep atmosphere.<i>Aims.<i/> We aim to isolate the effects of the internal temperature on the mixing efficiency in the atmospheres of ultra-hot Jupiters (UHJs) and the spacial distribution of cloud particles across the planet.<i>Methods.<i/> We combined a simplified tracer-based cloud model, a picket fence radiative-transfer scheme, and a mixing length theory to the Exo-FMS general circulation model. We ran the model for five different internal temperatures at typical UHJ atmosphere system parameters.<i>Results.<i/> Our results show the convective eddy diffusion coefficient remains low throughout the vast majority of the atmosphere, with mixing dominated by advective flows. However, some regions can show convective mixing in the upper atmosphere for colder interior temperatures. The vertical extent of the clouds is reduced as the internal temperature is increased. Additionally, a global cloud layer gets formed below the radiative-convective boundary (RCB) in the cooler cases.<i>Conclusions.<i/> Convection is generally strongly inhibited in UHJ atmospheres above the RCB due to their strong irradiation. Convective mixing plays a minor role compared to advective mixing in keeping cloud particles aloft in UHJs with warm interiors. Higher vertical turbulent heat fluxes and the advection of potential temperature inhibit convection in warmer interiors. Our results suggest that isolated upper atmosphere regions above cold interiors may exhibit strong convective mixing in isolated regions around Rossby gyres, allowing aerosols to be better retained in these areas.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"2 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142596914","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The masses of open star clusters and their tidal tails and the stellar initial mass function","authors":"Henriette Wirth, František Dinnbier, Pavel Kroupa, Ladislav Šubr","doi":"10.1051/0004-6361/202347839","DOIUrl":"https://doi.org/10.1051/0004-6361/202347839","url":null,"abstract":"<i>Context.<i/> Unresolved binaries have a strong influence on the observed parameters of stellar clusters (SCs).<i>Aims.<i/> We quantify this influence and compute the resulting mass underestimates and stellar mass function (MF).<i>Methods. N<i/>-body simulations of realistic SCs were used to investigate the evolution of the binary population in a SC and its tidal tails. Together with an empirically gauged stellar mass-luminosity relation, the results were then used to determine how the presence of binaries changes the photometric mass and MF of the SC and its tails as deduced from observations.<i>Results.<i/> Tail 1 (T1), which is the tidal tail caused by gas expulsion, contains a larger fraction of binaries than both the SC and Tail 2 (T2), which forms after gas expulsion. Additionally, T1 has a larger velocity dispersion. Using the luminosity of an unresolved binary, an observer would underestimate its mass. This bias sensitively depends on the companion masses due to the structure of the stellar mass-luminosity relation. Combining the effect of all binaries in the simulation, the total photometric mass of the SC is underestimated by 15%. Dark objects (black holes and neutron stars) increase the difference between the real and observed mass of the SC further. For both the SC and the tails, the observed power-law index of the MF between a stellar mass of 0.3 and 0.7 <i>M<i/><sub>⊙<sub/> is smaller by up to 0.2 than the real one, the real initial mass function (IMF) being steeper by this amount. This difference is larger for stars with a larger velocity dispersion or binary fraction.<i>Conclusions.<i/> Since the stars formed in SCs are the progenitors of the Galactic field stars, this work suggests that the binary fractions of different populations of stars in the Galactic disc will differ as a function of the velocity dispersion. However, the direction of this correlation is currently unclear, and a complete population synthesis will be needed to investigate this effect. Variations in the binary fractions of different clusters can lead to perceived variations of the deduced stellar MFs.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"196 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142597311","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel scaling laws to derive spatially resolved flare and CME parameters from sun-as-a-star observables","authors":"Atul Mohan, Natchimuthuk Gopalswamy, Hemapriya Raju, Sachiko Akiyama","doi":"10.1051/0004-6361/202451072","DOIUrl":"https://doi.org/10.1051/0004-6361/202451072","url":null,"abstract":"Coronal mass ejections (CMEs) are often associated with X-ray (SXR) flares powered by magnetic reconnection in the low corona, while the CME shocks in the upper corona and interplanetary (IP) space accelerate electrons often producing the type II radio bursts. The CME and the reconnection event are part of the same energy release process as highlighted by the correlation between reconnection flux (<i>ϕ<i/><sub>rec<sub/>) that quantifies the strength of the released magnetic free energy during the SXR flare, and the CME kinetic energy that drives the IP shocks leading to type II bursts. Unlike the Sun, these physical parameters cannot be directly inferred in stellar observations. Hence, scaling laws between unresolved sun-as-a-star observables, namely SXR luminosity (<i>L<i/><sub>X<sub/>) and type II luminosity (<i>L<i/><sub>R<sub/>), and the physical properties of the associated dynamical events are crucial. Such scaling laws also provide insights into the interconnections between the particle acceleration processes across low-corona to IP space during solar-stellar “flare-CME-type II” events. Using long-term solar data in the SXR to radio waveband, we derived a scaling law between two novel power metrics for the flare and CME-associated processes. The metrics of “flare power” ( ) and “CME power” ( ), where <i>V<i/><sub>CME<sub/> is the CME speed, scale as . In addition, <i>L<i/><sub>X<sub/> and <i>ϕ<i/><sub>rec<sub/> show power-law trends with <i>P<i/><sub>CME<sub/> with indices of 1.12 ± 0.05 and 0.61 ± 0.05, respectively. These power laws help infer the spatially resolved physical parameters, <i>V<i/><sub>CME<sub/> and <i>ϕ<i/><sub>rec<sub/>, from disk-averaged observables, <i>L<i/><sub>X<sub/> and <i>L<i/><sub>R<sub/> during solar-stellar flare-CME-type II events.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"28 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142594702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evolution of lithium in the disc of the Galaxy and the role of novae","authors":"Sviatoslav Borisov, Nikos Prantzos, Corinne Charbonnel","doi":"10.1051/0004-6361/202451321","DOIUrl":"https://doi.org/10.1051/0004-6361/202451321","url":null,"abstract":"<i>Context.<i/> Lithium plays a crucial role in probing stellar physics, stellar and primordial nucleosynthesis, and the chemical evolution of the Galaxy. Stars are considered to be the main source of Li, yet the identity of its primary stellar producer has long been a matter of debate.<i>Aims.<i/> In light of recent theoretical and observational results, we investigate in this study the role of two candidate sources of Li enrichment in the Milky Way, namely asymptotic giant branch (AGB) stars and, in particular, novae.<i>Methods.<i/> We utilised a one-zone Galactic chemical evolution (GCE) model to assess the viability of AGB stars and novae as stellar sources of Li. We used recent theoretical Li yields for AGB stars, while for novae we adopted observationally inferred Li yields and recently derived delay time distributions (DTDs). Subsequently, we extended our analysis by using a multi-zone model with radial migration to investigate spatial variations in the evolution of Li across the Milky Way disc and compared the results with observational data for field stars and open clusters.<i>Results.<i/> Our analysis shows that AGB stars clearly fail to reproduce the meteoritic Li abundance. In contrast, novae appear as promising candidates within the adopted framework, allowing us to quantify the contribution of each Li source at the Sun’s formation and today. Our multi-zone model reveals the role of the differences in the DTDs of Type Ia supernovae and novae in shaping the evolution of Li in the various galactic zones. Its results are in fair agreement with the observational data for most open clusters, but small discrepancies appear in the outer disc.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"3 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142594700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Blazar S 0528+134 is possibly the most powerful emitter in the Universe, including in the range of gravitational waves","authors":"A. E. Volvach, L. N. Volvach, M. G. Larionov","doi":"10.1051/0004-6361/202451911","DOIUrl":"https://doi.org/10.1051/0004-6361/202451911","url":null,"abstract":"<i>Aims.<i/> A new method of determining the parameters of close binary systems of supermassive black holes (SMBHs) and the level of gravitational waves (GWs) on the Earth’s surface are proposed.<i>Methods.<i/> Data are presented from long-term monitoring of possibly the most powerful emitter in the Universe, S 0528+134, at five frequencies in the radio range from 4.8 GHz to 37 GHz, obtained by the RT-22 radio telescope of the Radio Astronomy Laboratory CrAO in Simeiz, the RT-26 radio telescope at Michigan Observatory, and the 40 m radio telescope of the Owens Valley Radio Observatory.<i>Results.<i/> The dynamics of powerful flares that have occurred in the object since its discovery in a sky survey in 1970 were considered. The main physical characteristics of binary SMBHs located in the central regions of the system were obtained. These data were used to find the masses of the SMBH companions, the parameters of their orbits, the energy reserve of the system, and the lifetime of the object before the SMBHs’ merger. The level of GWs on the Earth’s surface was determined and the possibility of their detection by International Pulsar Timing Array (IPTA) GW detectors was considered.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"95 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142594699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}