Pub Date : 2024-12-17DOI: 10.1051/0004-6361/202348339
Ludwig M. Böss, Klaus Dolag, Ulrich P. Steinwandel, Elena Hernández-Martínez, Ildar Khabibullin, Benjamin Seidel, Jenny G. Sorce
Aims. Detecting diffuse synchrotron emission from the cosmic web is still a challenge for current radio telescopes. We aim to make predictions about the detectability of cosmic web filaments from simulations.Methods. We present the first cosmological magnetohydrodynamic simulation of a 500 h−1c Mpc volume with an on-the-fly spectral cosmic ray (CR) model. This allows us to follow the evolution of populations of CR electrons and protons within every resolution element of the simulation. We modeled CR injection at shocks, while accounting for adiabatic changes to the CR population and high-energy-loss processes of electrons. The synchrotron emission was then calculated from the aged electron population, using the simulated magnetic field, as well as different models for the origin and amplification of magnetic fields. We used constrained initial conditions, which closely resemble the local Universe, and compared the results of the cosmological volume to a zoom-in simulation of the Coma cluster, to study the impact of resolution and turbulent reacceleration of CRs on the results.Results. We find a consistent injection of CRs at accretion shocks onto cosmic web filaments and galaxy clusters. This leads to diffuse emission from filaments of the order Sν ≈ 0.1 μJy beam−1 for a potential LOFAR observation at 144 MHz, when assuming the most optimistic magnetic field model. The flux can be increased by up to two orders of magnitude for different choices of CR injection parameters. This can bring the flux within a factor of ten of the current limits for direct detection. We find a spectral index of the simulated synchrotron emission from filaments of α ≈ −1.0 to –1.5 in the LOFAR band.
{"title":"Simulating the LOcal Web (SLOW)","authors":"Ludwig M. Böss, Klaus Dolag, Ulrich P. Steinwandel, Elena Hernández-Martínez, Ildar Khabibullin, Benjamin Seidel, Jenny G. Sorce","doi":"10.1051/0004-6361/202348339","DOIUrl":"https://doi.org/10.1051/0004-6361/202348339","url":null,"abstract":"<i>Aims.<i/> Detecting diffuse synchrotron emission from the cosmic web is still a challenge for current radio telescopes. We aim to make predictions about the detectability of cosmic web filaments from simulations.<i>Methods.<i/> We present the first cosmological magnetohydrodynamic simulation of a 500 <i>h<i/><sup>−1<sup/> <i>c<i/> Mpc volume with an on-the-fly spectral cosmic ray (CR) model. This allows us to follow the evolution of populations of CR electrons and protons within every resolution element of the simulation. We modeled CR injection at shocks, while accounting for adiabatic changes to the CR population and high-energy-loss processes of electrons. The synchrotron emission was then calculated from the aged electron population, using the simulated magnetic field, as well as different models for the origin and amplification of magnetic fields. We used constrained initial conditions, which closely resemble the local Universe, and compared the results of the cosmological volume to a zoom-in simulation of the Coma cluster, to study the impact of resolution and turbulent reacceleration of CRs on the results.<i>Results.<i/> We find a consistent injection of CRs at accretion shocks onto cosmic web filaments and galaxy clusters. This leads to diffuse emission from filaments of the order <i>S<i/><sub><i>ν<i/><sub/> ≈ 0.1 μJy beam<sup>−1<sup/> for a potential LOFAR observation at 144 MHz, when assuming the most optimistic magnetic field model. The flux can be increased by up to two orders of magnitude for different choices of CR injection parameters. This can bring the flux within a factor of ten of the current limits for direct detection. We find a spectral index of the simulated synchrotron emission from filaments of <i>α<i/> ≈ −1.0 to –1.5 in the LOFAR band.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"22 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841373","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}
Pub Date : 2024-12-17DOI: 10.1051/0004-6361/202452252
Yasuhiro Hasegawa, Riouhei Nakatani, Isabel Rebollido, Meredith MacGregor, Björn J. R. Davidsson, Dariusz C. Lis, Neal Turner, Karen Willacy
Context. Debris disks contain the formation and evolution histories of planetary systems. Recent detections of gas in these disks have received considerable attention, as the origin of the gas sheds light on ongoing disk evolution and the current composition of planet-forming materials.Aims. Observations of CO gas alone, however, cannot reliably differentiate between two leading and competing hypotheses: (1) that the observed gas is a leftover of protoplanetary disk gas, and (2) that the gas is the outcome of collisions between icy bodies. We propose that such a differentiation may become possible by observing cold water vapor.Methods. We performed order-of-magnitude analyses and compared these with existing observations.Results. We show that different hypotheses lead to different masses of water vapor. This occurs because, for both hypotheses, the presence of cold water vapor is attributed to photodesorption from dust particles by attenuated interstellar UV radiation. Cold water vapor cannot be observed by current astronomical facilities as most of its emission lines fall in the far-IR (FIR) range.Conclusions. This work highlights the need for a future FIR space observatory to reveal the origin of gas in debris disks and the evolution of planet-forming disks in general.
{"title":"Water vapor as a probe of the origin of gas in debris disks","authors":"Yasuhiro Hasegawa, Riouhei Nakatani, Isabel Rebollido, Meredith MacGregor, Björn J. R. Davidsson, Dariusz C. Lis, Neal Turner, Karen Willacy","doi":"10.1051/0004-6361/202452252","DOIUrl":"https://doi.org/10.1051/0004-6361/202452252","url":null,"abstract":"<i>Context<i/>. Debris disks contain the formation and evolution histories of planetary systems. Recent detections of gas in these disks have received considerable attention, as the origin of the gas sheds light on ongoing disk evolution and the current composition of planet-forming materials.<i>Aims<i/>. Observations of CO gas alone, however, cannot reliably differentiate between two leading and competing hypotheses: (1) that the observed gas is a leftover of protoplanetary disk gas, and (2) that the gas is the outcome of collisions between icy bodies. We propose that such a differentiation may become possible by observing cold water vapor.<i>Methods<i/>. We performed order-of-magnitude analyses and compared these with existing observations.<i>Results<i/>. We show that different hypotheses lead to different masses of water vapor. This occurs because, for both hypotheses, the presence of cold water vapor is attributed to photodesorption from dust particles by attenuated interstellar UV radiation. Cold water vapor cannot be observed by current astronomical facilities as most of its emission lines fall in the far-IR (FIR) range.<i>Conclusions<i/>. This work highlights the need for a future FIR space observatory to reveal the origin of gas in debris disks and the evolution of planet-forming disks in general.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"64 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841423","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}
Pub Date : 2024-12-17DOI: 10.1051/0004-6361/202450958
Alexey Potapov, Robin T. Garrod
Context. The solid-state reaction C + H2O → H2CO has recently been studied experimentally and claimed as a new ‘non-energetic’ pathway to complex organic and prebiotic molecules in cold astrophysical environments.Aims. We compared results of astrochemical network modelling with and without the C + H2O surface reaction.Methods. A typical, generic collapse model in which a dense core forms from initially diffuse conditions was used along with the astrochemical kinetics model MAGICKAL.Results. The inclusion of the reaction does not notably enhance the abundance of formaldehyde itself; however, it significantly enhances the abundance of methanol (formed by the hydrogenation of formaldehyde) on the dust grains at early times, when the high gas-phase abundance of atomic C leads to relatively rapid adsorption onto the grain surfaces. As a result, the gas-phase abundance of methanol is also increased due to chemical desorption, quickly reaching abundances close to ∼10−9 nH, which decline strongly under late-time, high-density conditions. The reaction also influences the abundances of simple ice species, with the CO2 abundance increased in the earliest, deepest ice layers, while the water-ice abundance is somewhat depressed. The abundances of various complex organic molecules are also affected, with some species becoming more abundant and others less. When gas-phase atomic carbon becomes depleted, the grain-surface chemistry returns to behaviour that would be expected if there had been no new reaction.Conclusions. Our results show that fundamental reactions involving the simplest atomic and molecular species can be of great importance for the evolution of astrochemical reaction networks, thus providing motivation for future experimental and theoretical studies.
{"title":"Influence of the C + H2O → H2CO solid-state reaction on astrochemical networks and the formation of complex organic molecules","authors":"Alexey Potapov, Robin T. Garrod","doi":"10.1051/0004-6361/202450958","DOIUrl":"https://doi.org/10.1051/0004-6361/202450958","url":null,"abstract":"<i>Context<i/>. The solid-state reaction C + H<sub>2<sub/>O → H<sub>2<sub/>CO has recently been studied experimentally and claimed as a new ‘non-energetic’ pathway to complex organic and prebiotic molecules in cold astrophysical environments.<i>Aims<i/>. We compared results of astrochemical network modelling with and without the C + H<sub>2<sub/>O surface reaction.<i>Methods<i/>. A typical, generic collapse model in which a dense core forms from initially diffuse conditions was used along with the astrochemical kinetics model MAGICKAL.<i>Results<i/>. The inclusion of the reaction does not notably enhance the abundance of formaldehyde itself; however, it significantly enhances the abundance of methanol (formed by the hydrogenation of formaldehyde) on the dust grains at early times, when the high gas-phase abundance of atomic C leads to relatively rapid adsorption onto the grain surfaces. As a result, the gas-phase abundance of methanol is also increased due to chemical desorption, quickly reaching abundances close to ∼10<sup>−9<sup/> n<sub><i>H<i/><sub/>, which decline strongly under late-time, high-density conditions. The reaction also influences the abundances of simple ice species, with the CO<sub>2<sub/> abundance increased in the earliest, deepest ice layers, while the water-ice abundance is somewhat depressed. The abundances of various complex organic molecules are also affected, with some species becoming more abundant and others less. When gas-phase atomic carbon becomes depleted, the grain-surface chemistry returns to behaviour that would be expected if there had been no new reaction.<i>Conclusions<i/>. Our results show that fundamental reactions involving the simplest atomic and molecular species can be of great importance for the evolution of astrochemical reaction networks, thus providing motivation for future experimental and theoretical studies.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"47 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142840908","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}
Pub Date : 2024-12-17DOI: 10.1051/0004-6361/202452139
Yuhong Gao, Bo Li, Mijie Shi, Shaoxia Chen, Hui Yu
Aims. We aim to provide more insights into the applicability of the much-studied discrete leaky modes (DLMs) in classic analyses to solar coronal seismology.Methods. Under linear ideal pressureless magnetohydrodynamics (MHD), we examined 2D axial fundamental kink motions that arise when localized velocity exciters impact some symmetric slab equilibria. Continuous structuring is allowed. A 1D initial value problem (IVP) is formulated in conjunction with an eigenvalue problem (EVP) for laterally open systems, with no strict boundary conditions (BCs) at infinity. The IVP is solved by eigenfunction expansion, allowing a clear distinction between the contributions from proper eigenmodes and improper continuum eigenmodes. Example solutions are offered for parameters typical of active region loops.Results. Our solutions show that the system evolves toward long periodicities due to proper eigenmodes (on the order of the axial Alfvén time), whereas the interference of the improper continuum may lead to short periodicities initially (on the order of the lateral Alfvén time). Specializing to the slab axis, we demonstrate that the proper contribution strengthens with the density contrast, but may occasionally be stronger for less steep density profiles. Short periodicities are not guaranteed in the improper contribution, the details of the initial exciter being key. When identifiable, these periodicities tend to agree with the oscillation frequencies expected for DLMs, despite the differences in the BCs between our EVP and classic analyses. The eigenfunction expansion approach enables all qualitative features to be interpreted as the interplay between the initial exciter and some response function, the latter being determined solely by the equilibria.Conclusions. Classic theories for DLMs can find seismological applications, with time-dependent studies offering additional ways for constraining initial exciters.
{"title":"Temporal evolution of axially standing kink motions in solar coronal slabs: An eigenfunction expansion approach","authors":"Yuhong Gao, Bo Li, Mijie Shi, Shaoxia Chen, Hui Yu","doi":"10.1051/0004-6361/202452139","DOIUrl":"https://doi.org/10.1051/0004-6361/202452139","url":null,"abstract":"<i>Aims.<i/> We aim to provide more insights into the applicability of the much-studied discrete leaky modes (DLMs) in classic analyses to solar coronal seismology.<i>Methods.<i/> Under linear ideal pressureless magnetohydrodynamics (MHD), we examined 2D axial fundamental kink motions that arise when localized velocity exciters impact some symmetric slab equilibria. Continuous structuring is allowed. A 1D initial value problem (IVP) is formulated in conjunction with an eigenvalue problem (EVP) for laterally open systems, with no strict boundary conditions (BCs) at infinity. The IVP is solved by eigenfunction expansion, allowing a clear distinction between the contributions from proper eigenmodes and improper continuum eigenmodes. Example solutions are offered for parameters typical of active region loops.<i>Results.<i/> Our solutions show that the system evolves toward long periodicities due to proper eigenmodes (on the order of the axial Alfvén time), whereas the interference of the improper continuum may lead to short periodicities initially (on the order of the lateral Alfvén time). Specializing to the slab axis, we demonstrate that the proper contribution strengthens with the density contrast, but may occasionally be stronger for less steep density profiles. Short periodicities are not guaranteed in the improper contribution, the details of the initial exciter being key. When identifiable, these periodicities tend to agree with the oscillation frequencies expected for DLMs, despite the differences in the BCs between our EVP and classic analyses. The eigenfunction expansion approach enables all qualitative features to be interpreted as the interplay between the initial exciter and some response function, the latter being determined solely by the equilibria.<i>Conclusions.<i/> Classic theories for DLMs can find seismological applications, with time-dependent studies offering additional ways for constraining initial exciters.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"14 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142840910","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}
Pub Date : 2024-12-17DOI: 10.1051/0004-6361/202451265
V. Gustafsson, M. Brüggen, T. Enßlin
Context. Faraday rotation contains information about the magnetic field structure along the line of sight and is an important instrument in the study of cosmic magnetism. Traditional Faraday spectrum deconvolution methods such as RMCLEAN face challenges in resolving complex Faraday dispersion functions and handling large datasets.Aims. We developed a deep learning deconvolution model to enhance the accuracy and efficiency of extracting Faraday rotation measures from radio astronomical data, specifically targeting data from the MeerKAT Galaxy Cluster Legacy Survey (MGCLS).Methods. We used semi-supervised learning, where the model simultaneously recreates the data and minimizes the difference between the output and the true signal of synthetic data. Performance comparisons with RMCLEAN were conducted on simulated as well as real data for the galaxy cluster Abell 3376.Results. Our semi-supervised model is able to recover the Faraday dispersion for extended rotation measure (RM) components, while accounting for bandwidth depolarization, resulting in a higher sensitivity for high-RM signals, given the spectral configuration of MGCLS. Applied to observations of Abell 3376, we find detailed magnetic field structures in the radio relics, and several active galactic nuclei. We also applied our model to MeerKAT data of Abell 85, Abell 168, Abell 194, Abell 3186, and Abell 3667.Conclusions. We have demonstrated the potential of deep learning for improving RM synthesis deconvolution, providing accurate reconstructions at a high computational efficiency. In addition to validating our data against existing polarization maps, we find new and refined features in diffuse sources imaged with MeerKAT.
{"title":"Semi-supervised rotation measure deconvolution and its application to MeerKAT observations of galaxy clusters","authors":"V. Gustafsson, M. Brüggen, T. Enßlin","doi":"10.1051/0004-6361/202451265","DOIUrl":"https://doi.org/10.1051/0004-6361/202451265","url":null,"abstract":"<i>Context.<i/> Faraday rotation contains information about the magnetic field structure along the line of sight and is an important instrument in the study of cosmic magnetism. Traditional Faraday spectrum deconvolution methods such as RMCLEAN face challenges in resolving complex Faraday dispersion functions and handling large datasets.<i>Aims.<i/> We developed a deep learning deconvolution model to enhance the accuracy and efficiency of extracting Faraday rotation measures from radio astronomical data, specifically targeting data from the MeerKAT Galaxy Cluster Legacy Survey (MGCLS).<i>Methods.<i/> We used semi-supervised learning, where the model simultaneously recreates the data and minimizes the difference between the output and the true signal of synthetic data. Performance comparisons with RMCLEAN were conducted on simulated as well as real data for the galaxy cluster Abell 3376.<i>Results.<i/> Our semi-supervised model is able to recover the Faraday dispersion for extended rotation measure (RM) components, while accounting for bandwidth depolarization, resulting in a higher sensitivity for high-RM signals, given the spectral configuration of MGCLS. Applied to observations of Abell 3376, we find detailed magnetic field structures in the radio relics, and several active galactic nuclei. We also applied our model to MeerKAT data of Abell 85, Abell 168, Abell 194, Abell 3186, and Abell 3667.<i>Conclusions.<i/> We have demonstrated the potential of deep learning for improving RM synthesis deconvolution, providing accurate reconstructions at a high computational efficiency. In addition to validating our data against existing polarization maps, we find new and refined features in diffuse sources imaged with MeerKAT.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"23 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841300","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}
Pub Date : 2024-12-17DOI: 10.1051/0004-6361/202452170
Barbara Keresztes, Sándor Góbi, Anita Schneiker, Gábor Bazsó, György Tarczay
Aims. Icy mantles on interstellar dust grains are considered key contributors to the chemical complexity of the interstellar medium (ISM). Gas-phase molecules in the ISM can adsorb onto these icy surfaces, where chemical reactions can be induced by ultraviolet (UV) or cosmic ray (CR) irradiation. The resulting molecules can subsequently desorb, thereby altering the composition of the gas phase in the ISM. Therefore, studying astrochemically relevant reactions within ices is essential for advancing our understanding of astrochemistry.Methods. We conducted experiments with pure methanol (CH3OH), pure methylamine (CH3NH2), and CH3OH:CH3NH2 ices. To simulate CR effects, ices were irradiated with 5 keV electrons. We integrated the advantages of ice experiments and noble gas matrix experiments by performing two distinct investigations on each sample. During temperature-programmed desorption (TPD), chemical changes in the ice samples were monitored using Fourier transform infrared (FTIR) spectroscopy. In addition, the desorbing molecules were trapped in an Ar matrix through a following experiment. This TPD-matrix-isolation (TPD-MI) redeposition process enabled FTIR spectroscopic identification of the desorbed species.Results. The results obtained from experiments with CH3OH and CH3NH2 ices are consistent with previous studies. Additionally, the TPD-MI redeposition process enabled the identification of several species previously not detected clearly and directly in pure CH3OH or CH3NH2 ices, including molecules such as HCOOH, HCN, and CH2CHNH. Our experiments with CH3OH:CH3NH2 mixtures revealed the formation of several nitrogen- and oxygen-containing organic species (CH3NHCH2OH, NH2CH2OH, NH2CH2CH2OH, and HNCO), which are potential precursors to prebiotic molecules in the ISM. Therefore, these experiments provide valuable insights into the chemical evolution in space.
{"title":"Cosmic-ray-induced chemical processes in CH3OH, CH3NH2, and CH3OH:CH3NH2 ices","authors":"Barbara Keresztes, Sándor Góbi, Anita Schneiker, Gábor Bazsó, György Tarczay","doi":"10.1051/0004-6361/202452170","DOIUrl":"https://doi.org/10.1051/0004-6361/202452170","url":null,"abstract":"<i>Aims.<i/> Icy mantles on interstellar dust grains are considered key contributors to the chemical complexity of the interstellar medium (ISM). Gas-phase molecules in the ISM can adsorb onto these icy surfaces, where chemical reactions can be induced by ultraviolet (UV) or cosmic ray (CR) irradiation. The resulting molecules can subsequently desorb, thereby altering the composition of the gas phase in the ISM. Therefore, studying astrochemically relevant reactions within ices is essential for advancing our understanding of astrochemistry.<i>Methods.<i/> We conducted experiments with pure methanol (CH<sub>3<sub/>OH), pure methylamine (CH<sub>3<sub/>NH<sub>2<sub/>), and CH<sub>3<sub/>OH:CH<sub>3<sub/>NH<sub>2<sub/> ices. To simulate CR effects, ices were irradiated with 5 keV electrons. We integrated the advantages of ice experiments and noble gas matrix experiments by performing two distinct investigations on each sample. During temperature-programmed desorption (TPD), chemical changes in the ice samples were monitored using Fourier transform infrared (FTIR) spectroscopy. In addition, the desorbing molecules were trapped in an Ar matrix through a following experiment. This TPD-matrix-isolation (TPD-MI) redeposition process enabled FTIR spectroscopic identification of the desorbed species.<i>Results.<i/> The results obtained from experiments with CH<sub>3<sub/>OH and CH<sub>3<sub/>NH<sub>2<sub/> ices are consistent with previous studies. Additionally, the TPD-MI redeposition process enabled the identification of several species previously not detected clearly and directly in pure CH<sub>3<sub/>OH or CH<sub>3<sub/>NH<sub>2<sub/> ices, including molecules such as HCOOH, HCN, and CH<sub>2<sub/>CHNH. Our experiments with CH<sub>3<sub/>OH:CH<sub>3<sub/>NH<sub>2<sub/> mixtures revealed the formation of several nitrogen- and oxygen-containing organic species (CH<sub>3<sub/>NHCH<sub>2<sub/>OH, NH<sub>2<sub/>CH<sub>2<sub/>OH, NH<sub>2<sub/>CH<sub>2<sub/>CH<sub>2<sub/>OH, and HNCO), which are potential precursors to prebiotic molecules in the ISM. Therefore, these experiments provide valuable insights into the chemical evolution in space.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"258 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841304","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}
Pub Date : 2024-12-17DOI: 10.1051/0004-6361/202451003
S. Czesla, F. Nail, A. Lavail, D. Cont, L. Nortmann, F. Lesjak, M. Rengel, L. Boldt-Christmas, D. Shulyak, U. Seemann, P. C. Schneider, A. Hatzes, O. Kochukhov, N. Piskunov, A. Reiners, D. J. Wilson, F. Yan
Transmission spectroscopy is a prime method to study the atmospheres of extrasolar planets. We obtained a high-resolution spectral transit time series of the hot Jupiter WASP-121 b with CRIRES+ to study its atmosphere via transmission spectroscopy of the He I λ10833 triplet lines. Our analysis shows a prominent He I λ10833 absorption feature moving along with the planetary orbital motion, which shows an observed, transit-averaged equivalent width of approximately 30 mÅ, a slight redshift, and a depth of about 2%, which can only be explained by an atmosphere overflowing its Roche lobe. We carried out 3D hydrodynamic modeling to reproduce the observations, which favors asymmetric mass loss with a more pronounced leading tidal tail, possibly also explaining observational evidence for additional absorption stationary in the stellar rest frame. A trailing tail is not detectable. From our modeling, we derived estimates of ≥2 × 1013 g s−1 for the stellar and 5.4 × 1012 g s−1 for the planetary mass loss rate, which is consistent with X-ray and extreme-ultraviolet (XUV) driven mass loss in WASP-121 b.
透射光谱法是研究太阳系外行星大气层的主要方法。我们利用CRIRES+获得了热木星WASP-121 b的高分辨率光谱过境时间序列，通过He I λ10833三重线的透射光谱对其大气层进行了研究。我们的分析表明，一个突出的 He I λ10833 吸收特征随着行星轨道运动而移动，其观测到的过境平均等效宽度约为 30 米埃，有轻微的红移，深度约为 2%，这只能用大气溢出其罗氏叶来解释。我们进行了三维流体力学建模来重现观测结果，结果表明质量损失是不对称的，具有更明显的潮汐前尾，这也可能解释了恒星静止轨道上额外吸收静止的观测证据。后尾是检测不到的。通过建模，我们估计恒星质量损失率≥2 × 1013 g s-1，行星质量损失率为5.4 × 1012 g s-1，这与WASP-121 b中X射线和极紫外（XUV）驱动的质量损失是一致的。
{"title":"The overflowing atmosphere of WASP-121 b","authors":"S. Czesla, F. Nail, A. Lavail, D. Cont, L. Nortmann, F. Lesjak, M. Rengel, L. Boldt-Christmas, D. Shulyak, U. Seemann, P. C. Schneider, A. Hatzes, O. Kochukhov, N. Piskunov, A. Reiners, D. J. Wilson, F. Yan","doi":"10.1051/0004-6361/202451003","DOIUrl":"https://doi.org/10.1051/0004-6361/202451003","url":null,"abstract":"Transmission spectroscopy is a prime method to study the atmospheres of extrasolar planets. We obtained a high-resolution spectral transit time series of the hot Jupiter WASP-121 b with CRIRES+ to study its atmosphere via transmission spectroscopy of the He I <i>λ<i/>10833 triplet lines. Our analysis shows a prominent He I <i>λ<i/>10833 absorption feature moving along with the planetary orbital motion, which shows an observed, transit-averaged equivalent width of approximately 30 mÅ, a slight redshift, and a depth of about 2%, which can only be explained by an atmosphere overflowing its Roche lobe. We carried out 3D hydrodynamic modeling to reproduce the observations, which favors asymmetric mass loss with a more pronounced leading tidal tail, possibly also explaining observational evidence for additional absorption stationary in the stellar rest frame. A trailing tail is not detectable. From our modeling, we derived estimates of ≥2 × 10<sup>13<sup/> g s<sup>−1<sup/> for the stellar and 5.4 × 10<sup>12<sup/> g s<sup>−1<sup/> for the planetary mass loss rate, which is consistent with X-ray and extreme-ultraviolet (XUV) driven mass loss in WASP-121 b.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"78 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841424","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}
Pub Date : 2024-12-17DOI: 10.1051/0004-6361/202452274
K. Abd El Dayem, R. Abuter, N. Aimar, P. Amaro Seoane, A. Amorim, J. Beck, J. P. Berger, H. Bonnet, G. Bourdarot, W. Brandner, V. Cardoso, R. Capuzzo Dolcetta, Y. Clénet, R. Davies, P. T. de Zeeuw, A. Drescher, A. Eckart, F. Eisenhauer, H. Feuchtgruber, G. Finger, N. M. Förster Schreiber, A. Foschi, F. Gao, P. Garcia, E. Gendron, R. Genzel, S. Gillessen, M. Hartl, X. Haubois, F. Haussmann, G. Heißel, T. Henning, S. Hippler, M. Horrobin, L. Jochum, L. Jocou, A. Kaufer, P. Kervella, S. Lacour, V. Lapeyrère, J.-B. Le Bouquin, P. Léna, D. Lutz, F. Mang, N. More, T. Ott, T. Paumard, K. Perraut, G. Perrin, O. Pfuhl, S. Rabien, D. C. Ribeiro, M. Sadun Bordoni, S. Scheithauer, J. Shangguan, T. Shimizu, J. Stadler, O. Straub, C. Straubmeier, E. Sturm, L. J. Tacconi, I. Urso, F. Vincent, S. D. von Fellenberg, F. Widmann, E. Wieprecht, J. Woillez, F. Zhang
Studying the orbital motion of stars around Sagittarius A* in the Galactic center provides a unique opportunity to probe the gravitational potential near the supermassive black hole at the heart of our Galaxy. Interferometric data obtained with the GRAVITY instrument at the Very Large Telescope Interferometer (VLTI) since 2016 has allowed us to achieve unprecedented precision in tracking the orbits of these stars. GRAVITY data have been key to detecting the in-plane, prograde Schwarzschild precession of the orbit of the star S2 that is predicted by general relativity. By combining astrometric and spectroscopic data from multiple stars, including S2, S29, S38, and S55 – for which we have data around their time of pericenter passage with GRAVITY – we can now strengthen the significance of this detection to an approximately 10σ confidence level. The prograde precession of S2’s orbit provides valuable insights into the potential presence of an extended mass distribution surrounding Sagittarius A*, which could consist of a dynamically relaxed stellar cusp comprising old stars and stellar remnants, along with a possible dark matter spike. Our analysis, based on two plausible density profiles – a power-law and a Plummer profile – constrains the enclosed mass within the orbit of S2 to be consistent with zero, establishing an upper limit of approximately 1200 M⊙ with a 1σ confidence level. This significantly improves our constraints on the mass distribution in the Galactic center. Our upper limit is very close to the expected value from numerical simulations for a stellar cusp in the Galactic center, leaving little room for a significant enhancement of dark matter density near Sagittarius A*.
{"title":"Improving constraints on the extended mass distribution in the Galactic center with stellar orbits","authors":"K. Abd El Dayem, R. Abuter, N. Aimar, P. Amaro Seoane, A. Amorim, J. Beck, J. P. Berger, H. Bonnet, G. Bourdarot, W. Brandner, V. Cardoso, R. Capuzzo Dolcetta, Y. Clénet, R. Davies, P. T. de Zeeuw, A. Drescher, A. Eckart, F. Eisenhauer, H. Feuchtgruber, G. Finger, N. M. Förster Schreiber, A. Foschi, F. Gao, P. Garcia, E. Gendron, R. Genzel, S. Gillessen, M. Hartl, X. Haubois, F. Haussmann, G. Heißel, T. Henning, S. Hippler, M. Horrobin, L. Jochum, L. Jocou, A. Kaufer, P. Kervella, S. Lacour, V. Lapeyrère, J.-B. Le Bouquin, P. Léna, D. Lutz, F. Mang, N. More, T. Ott, T. Paumard, K. Perraut, G. Perrin, O. Pfuhl, S. Rabien, D. C. Ribeiro, M. Sadun Bordoni, S. Scheithauer, J. Shangguan, T. Shimizu, J. Stadler, O. Straub, C. Straubmeier, E. Sturm, L. J. Tacconi, I. Urso, F. Vincent, S. D. von Fellenberg, F. Widmann, E. Wieprecht, J. Woillez, F. Zhang","doi":"10.1051/0004-6361/202452274","DOIUrl":"https://doi.org/10.1051/0004-6361/202452274","url":null,"abstract":"Studying the orbital motion of stars around Sagittarius A* in the Galactic center provides a unique opportunity to probe the gravitational potential near the supermassive black hole at the heart of our Galaxy. Interferometric data obtained with the GRAVITY instrument at the Very Large Telescope Interferometer (VLTI) since 2016 has allowed us to achieve unprecedented precision in tracking the orbits of these stars. GRAVITY data have been key to detecting the in-plane, prograde Schwarzschild precession of the orbit of the star S2 that is predicted by general relativity. By combining astrometric and spectroscopic data from multiple stars, including S2, S29, S38, and S55 – for which we have data around their time of pericenter passage with GRAVITY – we can now strengthen the significance of this detection to an approximately 10<i>σ<i/> confidence level. The prograde precession of S2’s orbit provides valuable insights into the potential presence of an extended mass distribution surrounding Sagittarius A*, which could consist of a dynamically relaxed stellar cusp comprising old stars and stellar remnants, along with a possible dark matter spike. Our analysis, based on two plausible density profiles – a power-law and a Plummer profile – constrains the enclosed mass within the orbit of S2 to be consistent with zero, establishing an upper limit of approximately 1200 <i>M<i/><sub>⊙<sub/> with a 1<i>σ<i/> confidence level. This significantly improves our constraints on the mass distribution in the Galactic center. Our upper limit is very close to the expected value from numerical simulations for a stellar cusp in the Galactic center, leaving little room for a significant enhancement of dark matter density near Sagittarius A*.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"27 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142840860","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}
Pub Date : 2024-12-17DOI: 10.1051/0004-6361/202451068
J.-V. Harre, A. M. S. Smith, S. C. C. Barros, V. Singh, J. Korth, A. Brandeker, A. Collier Cameron, M. Lendl, T. G. Wilson, L. Borsato, Sz. Csizmadia, J. Cabrera, H. Parviainen, A. C. M. Correia, B. Akinsanmi, N. Rosario, P. Leonardi, L. M. Serrano, Y. Alibert, R. Alonso, J. Asquier, T. Bárczy, D. Barrado Navascues, W. Baumjohann, W. Benz, N. Billot, C. Broeg, M.-D. Busch, P. E. Cubillos, M. B. Davies, M. Deleuil, A. Deline, L. Delrez, O. D. S. Demangeon, B.-O. Demory, A. Derekas, B. Edwards, D. Ehrenreich, A. Erikson, A. Fortier, L. Fossati, M. Fridlund, D. Gandolfi, K. Gazeas, M. Gillon, M. Güdel, M. N. Günther, A. Heitzmann, Ch. Helling, K. G. Isaak, L. L. Kiss, K. W. F. Lam, J. Laskar, A. Lecavelier des Etangs, D. Magrin, P. F. L. Maxted, B. Merín, C. Mordasini, V. Nascimbeni, G. Olofsson, R. Ottensamer, I. Pagano, E. Pallé, G. Peter, D. Piazza, G. Piotto, D. Pollacco, D. Queloz, R. Ragazzoni, N. Rando, H. Rauer, I. Ribas, N. C. Santos, G. Scandariato, D. Ségransan, A. E. Simon, S. G. Sousa, M. Stalport, S. Sulis, Gy. M. Szabó, S. Udry, B. Ulmer, V. Van Grootel, J. Venturini, E. Villaver, V. Viotto, N. A. Walton, R. West, K. Westerdorff
Context. Hot Jupiters (HJs) with close-by planetary companions are rare, with only a handful of them having been discovered so far. This could be due to their suggested dynamical histories, which lead to the possible ejection of other planets. TOI-2109 b is special in this regard because it is the HJ with the closest relative separation from its host star, being separated by less than 2.3 stellar radii. Unexpectedly, transit timing measurements from recently obtained CHEOPS observations show low-amplitude transit-timing variations (TTVs).Aims. We aim to search for signs of orbital decay and to characterise the apparent TTVs in an attempt to gain information about a possible companion.Methods. We fitted the newly obtained CHEOPS light curves using TLCM and extracted the resulting mid-transit timings. Successively, we used these measurements in combination with TESS and archival photometric data and radial velocity (RV) data to estimate the rate of tidal orbital decay of TOI-2109 b, and also to characterise the TTVs using the N-body code TRADES and the photo-dynamical approach of PyTTV.Results. We find tentative evidence at 3σ for orbital decay in the TOI-2109 system when we correct the mid-transit timings using the best-fitting sinusoidal model of the TTVs. We do not detect additional transits in the available photometric data, but find evidence supporting the authenticity of the apparent TTVs, indicating a close-by, outer companion with Pc > 1.125 d. Due to the fast rotation of the star, the new planetary candidate cannot be detected in the available RV measurements, and its parameters can only be loosely constrained by our joint TTV and RV modelling.Conclusions. TOI-2109 could join a small group of rare HJ systems that host close-by planetary companions, only one of which (WASP-47 b) has an outer companion. More high-precision photometric measurements are necessary to confirm the existence of this planetary companion.
{"title":"Hints of a close outer companion to the ultra-hot Jupiter TOI-2109 b★","authors":"J.-V. Harre, A. M. S. Smith, S. C. C. Barros, V. Singh, J. Korth, A. Brandeker, A. Collier Cameron, M. Lendl, T. G. Wilson, L. Borsato, Sz. Csizmadia, J. Cabrera, H. Parviainen, A. C. M. Correia, B. Akinsanmi, N. Rosario, P. Leonardi, L. M. Serrano, Y. Alibert, R. Alonso, J. Asquier, T. Bárczy, D. Barrado Navascues, W. Baumjohann, W. Benz, N. Billot, C. Broeg, M.-D. Busch, P. E. Cubillos, M. B. Davies, M. Deleuil, A. Deline, L. Delrez, O. D. S. Demangeon, B.-O. Demory, A. Derekas, B. Edwards, D. Ehrenreich, A. Erikson, A. Fortier, L. Fossati, M. Fridlund, D. Gandolfi, K. Gazeas, M. Gillon, M. Güdel, M. N. Günther, A. Heitzmann, Ch. Helling, K. G. Isaak, L. L. Kiss, K. W. F. Lam, J. Laskar, A. Lecavelier des Etangs, D. Magrin, P. F. L. Maxted, B. Merín, C. Mordasini, V. Nascimbeni, G. Olofsson, R. Ottensamer, I. Pagano, E. Pallé, G. Peter, D. Piazza, G. Piotto, D. Pollacco, D. Queloz, R. Ragazzoni, N. Rando, H. Rauer, I. Ribas, N. C. Santos, G. Scandariato, D. Ségransan, A. E. Simon, S. G. Sousa, M. Stalport, S. Sulis, Gy. M. Szabó, S. Udry, B. Ulmer, V. Van Grootel, J. Venturini, E. Villaver, V. Viotto, N. A. Walton, R. West, K. Westerdorff","doi":"10.1051/0004-6361/202451068","DOIUrl":"https://doi.org/10.1051/0004-6361/202451068","url":null,"abstract":"<i>Context<i/>. Hot Jupiters (HJs) with close-by planetary companions are rare, with only a handful of them having been discovered so far. This could be due to their suggested dynamical histories, which lead to the possible ejection of other planets. TOI-2109 b is special in this regard because it is the HJ with the closest relative separation from its host star, being separated by less than 2.3 stellar radii. Unexpectedly, transit timing measurements from recently obtained CHEOPS observations show low-amplitude transit-timing variations (TTVs).<i>Aims<i/>. We aim to search for signs of orbital decay and to characterise the apparent TTVs in an attempt to gain information about a possible companion.<i>Methods<i/>. We fitted the newly obtained CHEOPS light curves using TLCM and extracted the resulting mid-transit timings. Successively, we used these measurements in combination with TESS and archival photometric data and radial velocity (RV) data to estimate the rate of tidal orbital decay of TOI-2109 b, and also to characterise the TTVs using the <i>N<i/>-body code TRADES and the photo-dynamical approach of PyTTV.<i>Results<i/>. We find tentative evidence at 3<i>σ<i/> for orbital decay in the TOI-2109 system when we correct the mid-transit timings using the best-fitting sinusoidal model of the TTVs. We do not detect additional transits in the available photometric data, but find evidence supporting the authenticity of the apparent TTVs, indicating a close-by, outer companion with <i>P<i/><sub>c<sub/> > 1.125 d. Due to the fast rotation of the star, the new planetary candidate cannot be detected in the available RV measurements, and its parameters can only be loosely constrained by our joint TTV and RV modelling.<i>Conclusions<i/>. TOI-2109 could join a small group of rare HJ systems that host close-by planetary companions, only one of which (WASP-47 b) has an outer companion. More high-precision photometric measurements are necessary to confirm the existence of this planetary companion.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"144 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142841307","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}
Pub Date : 2024-12-17DOI: 10.1051/0004-6361/202451163
S. Gallo, N. Aghanim, C. Gouin, D. Eckert, M. Douspis, J. Paste, T. Bonnaire
Filaments connected to galaxy clusters are crucial environments for studying the build up of cosmic structures as they funnel matter towards the clusters’ deep gravitational potentials. Identifying gas in filaments is a challenge, due to their lower density contrast, which produces faint signals. Therefore, the best opportunity to detect these signals is in the outskirts of galaxy clusters. We revisited the X-ray observation of the cluster Abell 2744, using statistical estimators of the anisotropic matter distribution to identify filamentary patterns around it. We report, for the first time, the blind detection of filaments connected to a galaxy cluster from X-ray emission using a filament-finder technique and a multipole decomposition technique. We compare this result with filaments extracted from the distribution of spectroscopic galaxies using the same two approaches. This allowed us to demonstrate the robustness and reliability of our techniques in tracing the filamentary structure of three and five filaments connected to Abell 2744, in two and three dimensions, respectively.
{"title":"Tracing gaseous filaments connected to galaxy clusters: The case study of Abell 2744","authors":"S. Gallo, N. Aghanim, C. Gouin, D. Eckert, M. Douspis, J. Paste, T. Bonnaire","doi":"10.1051/0004-6361/202451163","DOIUrl":"https://doi.org/10.1051/0004-6361/202451163","url":null,"abstract":"Filaments connected to galaxy clusters are crucial environments for studying the build up of cosmic structures as they funnel matter towards the clusters’ deep gravitational potentials. Identifying gas in filaments is a challenge, due to their lower density contrast, which produces faint signals. Therefore, the best opportunity to detect these signals is in the outskirts of galaxy clusters. We revisited the X-ray observation of the cluster Abell 2744, using statistical estimators of the anisotropic matter distribution to identify filamentary patterns around it. We report, for the first time, the blind detection of filaments connected to a galaxy cluster from X-ray emission using a filament-finder technique and a multipole decomposition technique. We compare this result with filaments extracted from the distribution of spectroscopic galaxies using the same two approaches. This allowed us to demonstrate the robustness and reliability of our techniques in tracing the filamentary structure of three and five filaments connected to Abell 2744, in two and three dimensions, respectively.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"39 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142840909","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}
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