Pub Date : 2026-01-26DOI: 10.1051/0004-6361/202555469
M. Ould-Elhkim, C. Moutou, J.-F. Donati, P. Cortés-Zuleta, X. Delfosse, É. Artigau, C. Cadieux, P. Charpentier, A. Carmona, I. Boisse, C. Reylé, E. Gaidos, R. Cloutier, G. Hébrard, L. Arnold, J.-D. do Nascimento, N. J. Cook, R. Doyon
Context. M dwarfs are prime targets in the search for exoplanets because of their prevalence and because low-mass planets can be better detected with radial velocity (RV) methods. In particular, the near-infrared (NIR) spectral domain offers an increased RV sensitivity and potentially reduced stellar activity signals. Precise NIR RV measurements are strongly affected by telluric absorption lines from the Earth’s atmosphere, however.Aims. We searched for planets orbiting Gl 725 B, a nearby late-M dwarf located at 3.5 pc, using high-precision SPIRou RV observations. We also assessed the effect of telluric contamination on these measurements and evaluated the performance of the weighted principal component analysis reconstruction (wapiti) method, which is a weighted principal component analysis (wPCA) approach designed to mitigate these systematics and to improve the sensitivity of planet detections.Methods. Using synthetic and observational SPIRou data, we simulated the effect of telluric lines on RV data under varying barycentric Earth radial velocity (BERV) conditions. We then applied the wapiti method for identifying and correcting telluric-induced systematics in line-by-line RVs. The method was tested through an injection-recovery test on simulated data and was subsequently applied to real SPIRou observations of Gl 725 B.Results. wapiti successfully corrects telluric contamination in simulated and real datasets. This enhances the detectability and accuracy of planetary signals. In the corrected Gl 725 B dataset, we identified a two-planet system composed of a candidate inner planet (Gl 725 Bb), with periods of 4.765 ± 0.004 days and a semi-amplitude of 1.4 ± 0.3 m s−1, and a confirmed planet Gl 725 Bc, with a period of 37.90 ± 0.17 days and a semi-amplitude of 1.7 ± 0.3 m s−1. Their minimum mass is 1.5 ± 0.4 M⊕ and of 3.5 ± 0.7 M⊕, respectively, and the outer planet is located in the habitable zone of its host star. Using a multi-dimensional Gaussian process framework to model and correct for stellar activity, we also recovered a stellar rotation period of 105.1 ± 3.3 days.
上下文。M矮星是寻找系外行星的主要目标，因为它们普遍存在，而且用径向速度（RV）方法可以更好地探测到低质量的行星。特别是，近红外（NIR）光谱域提供了增加的RV灵敏度和潜在的减少恒星活动信号。然而，精确的近红外RV测量受到来自地球大气的大地吸收线的强烈影响。我们利用SPIRou RV的高精度观测，寻找围绕Gl 725b运行的行星，Gl 725b是一颗距地球3.5英里的晚m矮星。我们还评估了大地污染对这些测量的影响，并评估了加权主成分分析重建（wapiti）方法的性能，这是一种加权主成分分析（wPCA）方法，旨在减轻这些系统性并提高行星探测的灵敏度。利用合成SPIRou资料和观测SPIRou资料，模拟了不同地球质心径向速度（BERV）条件下大地线对RV资料的影响。然后，我们应用wapiti方法在逐行rv中识别和校正构造诱导的系统。该方法通过模拟数据的注入-回收测试进行了测试，随后应用于Gl 725 b的真实SPIRou观测结果。Wapiti成功地校正了模拟和真实数据集的大地污染。这提高了行星信号的可探测性和准确性。在修正后的Gl 725 B数据集中，我们确定了一个由候选内行星（Gl 725 Bb）组成的双行星系统，周期为4.765±0.004天，半振幅为1.4±0.3 m s−1，确认行星Gl 725 Bc，周期为37.90±0.17天，半振幅为1.7±0.3 m s−1。它们的最小质量分别为1.5±0.4 M⊕和3.5±0.7 M⊕，外行星位于其主星的宜居带。利用多维高斯过程框架对恒星活动进行建模和校正，我们还恢复了恒星自转周期为105.1±3.3天。
{"title":"The SPIRou Legacy Survey","authors":"M. Ould-Elhkim, C. Moutou, J.-F. Donati, P. Cortés-Zuleta, X. Delfosse, É. Artigau, C. Cadieux, P. Charpentier, A. Carmona, I. Boisse, C. Reylé, E. Gaidos, R. Cloutier, G. Hébrard, L. Arnold, J.-D. do Nascimento, N. J. Cook, R. Doyon","doi":"10.1051/0004-6361/202555469","DOIUrl":"https://doi.org/10.1051/0004-6361/202555469","url":null,"abstract":"<i>Context<i/>. M dwarfs are prime targets in the search for exoplanets because of their prevalence and because low-mass planets can be better detected with radial velocity (RV) methods. In particular, the near-infrared (NIR) spectral domain offers an increased RV sensitivity and potentially reduced stellar activity signals. Precise NIR RV measurements are strongly affected by telluric absorption lines from the Earth’s atmosphere, however.<i>Aims<i/>. We searched for planets orbiting Gl 725 B, a nearby late-M dwarf located at 3.5 pc, using high-precision SPIRou RV observations. We also assessed the effect of telluric contamination on these measurements and evaluated the performance of the weighted principal component analysis reconstruction (wapiti) method, which is a weighted principal component analysis (wPCA) approach designed to mitigate these systematics and to improve the sensitivity of planet detections.<i>Methods<i/>. Using synthetic and observational SPIRou data, we simulated the effect of telluric lines on RV data under varying barycentric Earth radial velocity (BERV) conditions. We then applied the wapiti method for identifying and correcting telluric-induced systematics in line-by-line RVs. The method was tested through an injection-recovery test on simulated data and was subsequently applied to real SPIRou observations of Gl 725 B.<i>Results<i/>. wapiti successfully corrects telluric contamination in simulated and real datasets. This enhances the detectability and accuracy of planetary signals. In the corrected Gl 725 B dataset, we identified a two-planet system composed of a candidate inner planet (Gl 725 Bb), with periods of 4.765 ± 0.004 days and a semi-amplitude of 1.4 ± 0.3 m s<sup>−1<sup/>, and a confirmed planet Gl 725 Bc, with a period of 37.90 ± 0.17 days and a semi-amplitude of 1.7 ± 0.3 m s<sup>−1<sup/>. Their minimum mass is 1.5 ± 0.4 M<sub>⊕<sub/> and of 3.5 ± 0.7 M<sub>⊕<sub/>, respectively, and the outer planet is located in the habitable zone of its host star. Using a multi-dimensional Gaussian process framework to model and correct for stellar activity, we also recovered a stellar rotation period of 105.1 ± 3.3 days.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"102 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146044749","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 : 2026-01-23DOI: 10.1051/0004-6361/202556224
A. Lemière, G. Castelletti, N. L. Maza
We present the first detection of GeV γ-ray emission potentially associated with the pulsar wind nebula (PWN) hosted by the young core-collapse supernova remnant G292.0+1.8, based on a detailed, time-resolved analysis of Fermi-LAT data. By isolating the unpulsed component from the dominant magnetospheric radiation of PSR J1124-5916, we successfully disentangled a candidate nebular emission in the GeV range, characterized its morphology, and extracted its spectrum. This identification places G292.0+1.8 among the few systems in which the pulsar and PWN contributions have been spectrally resolved at high energies, offering new insight into their respective emission mechanisms. We characterized the γ-ray spectrum of the pulsar and modeled the broadband spectral energy distribution (SED) of the PWN using radio, X-ray, and GeV data. The emission is well described by a single electron population with two spectral breaks: one intrinsic to the injection spectrum and another produced by synchrotron cooling in a magnetic field of ∼15μG. Notably, the inferred magnetic field and the low TeV flux of the nebula resemble those of 3C 58, suggesting that similar low-field environments can arise in young PWNe. The high-energy portion of the SED is now tightly constrained by our GeV detection and the existing TeV upper limits. Compared to our model, earlier predictions tend to underpredict the γ-ray flux, whereas others that succeed in reproducing the GeV component often overpredict the TeV emission. This mismatch underscores the challenges in modeling particle acceleration and radiation processes in young PWNe and establishes G292.0+1.8 as a valuable benchmark for testing and refining such models.
{"title":"Unlocking the radio- γ spectrum of the pulsar wind nebula around PSR J1124–5916 in SNR G292.0+1.8","authors":"A. Lemière, G. Castelletti, N. L. Maza","doi":"10.1051/0004-6361/202556224","DOIUrl":"https://doi.org/10.1051/0004-6361/202556224","url":null,"abstract":"We present the first detection of GeV γ-ray emission potentially associated with the pulsar wind nebula (PWN) hosted by the young core-collapse supernova remnant G292.0+1.8, based on a detailed, time-resolved analysis of <i>Fermi<i/>-LAT data. By isolating the unpulsed component from the dominant magnetospheric radiation of PSR J1124-5916, we successfully disentangled a candidate nebular emission in the GeV range, characterized its morphology, and extracted its spectrum. This identification places G292.0+1.8 among the few systems in which the pulsar and PWN contributions have been spectrally resolved at high energies, offering new insight into their respective emission mechanisms. We characterized the γ-ray spectrum of the pulsar and modeled the broadband spectral energy distribution (SED) of the PWN using radio, X-ray, and GeV data. The emission is well described by a single electron population with two spectral breaks: one intrinsic to the injection spectrum and another produced by synchrotron cooling in a magnetic field of ∼15μG. Notably, the inferred magnetic field and the low TeV flux of the nebula resemble those of 3C 58, suggesting that similar low-field environments can arise in young PWNe. The high-energy portion of the SED is now tightly constrained by our GeV detection and the existing TeV upper limits. Compared to our model, earlier predictions tend to underpredict the γ-ray flux, whereas others that succeed in reproducing the GeV component often overpredict the TeV emission. This mismatch underscores the challenges in modeling particle acceleration and radiation processes in young PWNe and establishes G292.0+1.8 as a valuable benchmark for testing and refining such models.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"30 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146044747","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 : 2026-01-23DOI: 10.1051/0004-6361/202556672
P. Samarth, G. Fedoseev, M. Bulak, S. Ioppolo, L. Hornekær, E. F. van Dishoeck, H. Linnartz, K.-J. Chuang
Context. Acetylene (C2H2) has been commonly observed in various astronomical objects, including star-forming regions, young stellar objects, and our Solar System. Theoretical and laboratory studies have proposed multiple mechanisms that link this simplest alkyne to volatile hydrocarbons and polycyclic aromatic hydrocarbons through UV- or cosmic-ray-induced energetic processes. However, it is still unclear whether refractory material can be efficiently formed through solid-state reactions involving C2H2 on dust grains.Aims. In this work, we aim to experimentally study the chemical complexity induced by the UV irradiation of pure C2H2 ice and characterize both volatile and nonvolatile photoproducts to better understand the evolution of simple hydrocarbons under astronomically relevant conditions.Methods. Experiments were performed using MATRI2CES, an ultra-high vacuum, cryogenic setup to investigate the C2H2 ice chemistry induced by UV photons between 7.2 and 10.2 eV at 15 K. The UV-processed ice samples were monitored in situ by laser desorption post-ionization reflection time-of-flight mass spectrometry (LDPI ReTOF-MS) in combination with the pulsed ion deflection (PID) technique. The mass spectrometric data of volatiles and refractory residues produced upon VUV photolysis of C2H2 ice were collected in situ at 15 and 300 K, respectively, minimizing uncertainties associated with external analytical methods used in previous studies.Results. The experimental results obtained after photolysis of pure C2H2 ice with a fluence of 3 × 1017 photons cm−2 (106 years in dense clouds, show the formation of large saturated and unsaturated hydrocarbons containing up to 13 carbon atoms, including molecules identified in previous similar studies. After the sublimation of these volatile products, measurements of the residue at 300 K revealed a rich and distinct mass spectrum suggesting the synthesis of refractories composed of conjugated triple bonds (-C≡C-) and double (-C=C−) bonds. The astrochemical implications and the possible connection of the produced residues with unidentified infrared emission bands are discussed.
{"title":"In situ characterization of volatile and refractory hydrocarbons produced by UV photolysis of interstellar C2H2 ice","authors":"P. Samarth, G. Fedoseev, M. Bulak, S. Ioppolo, L. Hornekær, E. F. van Dishoeck, H. Linnartz, K.-J. Chuang","doi":"10.1051/0004-6361/202556672","DOIUrl":"https://doi.org/10.1051/0004-6361/202556672","url":null,"abstract":"<i>Context<i/>. Acetylene (C<sub>2<sub/>H<sub>2<sub/>) has been commonly observed in various astronomical objects, including star-forming regions, young stellar objects, and our Solar System. Theoretical and laboratory studies have proposed multiple mechanisms that link this simplest alkyne to volatile hydrocarbons and polycyclic aromatic hydrocarbons through UV- or cosmic-ray-induced energetic processes. However, it is still unclear whether refractory material can be efficiently formed through solid-state reactions involving C<sub>2<sub/>H<sub>2<sub/> on dust grains.<i>Aims<i/>. In this work, we aim to experimentally study the chemical complexity induced by the UV irradiation of pure C<sub>2<sub/>H<sub>2<sub/> ice and characterize both volatile and nonvolatile photoproducts to better understand the evolution of simple hydrocarbons under astronomically relevant conditions.<i>Methods<i/>. Experiments were performed using MATRI<sup>2<sup/>CES, an ultra-high vacuum, cryogenic setup to investigate the C<sub>2<sub/>H<sub>2<sub/> ice chemistry induced by UV photons between 7.2 and 10.2 eV at 15 K. The UV-processed ice samples were monitored in situ by laser desorption post-ionization reflection time-of-flight mass spectrometry (LDPI ReTOF-MS) in combination with the pulsed ion deflection (PID) technique. The mass spectrometric data of volatiles and refractory residues produced upon VUV photolysis of C<sub>2<sub/>H<sub>2<sub/> ice were collected in situ at 15 and 300 K, respectively, minimizing uncertainties associated with external analytical methods used in previous studies.<i>Results<i/>. The experimental results obtained after photolysis of pure C<sub>2<sub/>H<sub>2<sub/> ice with a fluence of 3 × 10<sup>17<sup/> photons cm<sup>−2<sup/> (10<sup>6<sup/> years in dense clouds, show the formation of large saturated and unsaturated hydrocarbons containing up to 13 carbon atoms, including molecules identified in previous similar studies. After the sublimation of these volatile products, measurements of the residue at 300 K revealed a rich and distinct mass spectrum suggesting the synthesis of refractories composed of conjugated triple bonds (-C≡C-) and double (-C=C−) bonds. The astrochemical implications and the possible connection of the produced residues with unidentified infrared emission bands are discussed.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"7 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146044748","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 : 2026-01-23DOI: 10.1051/0004-6361/202555280
Nelvy Choque-Challapa, Rory Smith, Ivan Lacerna, J. Alfonso L. Aguerri, Daniela Palma
The Virgo cluster is one of the closest clusters to us where we can further study the evolution of galaxies, with several infalling substructures and several filaments around it that have been reported. Therefore, it makes this cluster and its surrounding area an interesting place to study the spatial distribution of the population of dwarf and bright giant galaxies. We analysed the dwarf fraction (DF) in different regions of the cluster, inside the virial radius, in its surrounding area, and in the filamentary structure surrounding it using available catalogues with the aim of measuring whether the DF changes in different environments. Although the total dwarf fraction within the cluster is ∼0.8, significant local variations are measured throughout the cluster; there are regions with a relatively higher concentration of giant or dwarf galaxies. The fact that Virgo is embedded in a rich environment surrounded by several filaments that feed the cluster with new substructures could imply changes in the DF locally. When we analysed the DF variation at further distances from the cluster we observe some regions with few or no giant galaxies at all, with a local DF ranging from 0.8−1.0. Additionally, when comparing the dwarf fraction in different environments, overall the DF is larger in regions further away from denser regions such as the Virgo cluster and its filamentary structure surrounding it. When comparing the filament and the cluster area, the DF is slightly higher in the filaments, but from filament to filament, the DF changes depending on the presence of groups.
{"title":"The spatial distribution of dwarf and giant galaxies in and around the Virgo cluster","authors":"Nelvy Choque-Challapa, Rory Smith, Ivan Lacerna, J. Alfonso L. Aguerri, Daniela Palma","doi":"10.1051/0004-6361/202555280","DOIUrl":"https://doi.org/10.1051/0004-6361/202555280","url":null,"abstract":"The Virgo cluster is one of the closest clusters to us where we can further study the evolution of galaxies, with several infalling substructures and several filaments around it that have been reported. Therefore, it makes this cluster and its surrounding area an interesting place to study the spatial distribution of the population of dwarf and bright giant galaxies. We analysed the dwarf fraction (DF) in different regions of the cluster, inside the virial radius, in its surrounding area, and in the filamentary structure surrounding it using available catalogues with the aim of measuring whether the DF changes in different environments. Although the total dwarf fraction within the cluster is ∼0.8, significant local variations are measured throughout the cluster; there are regions with a relatively higher concentration of giant or dwarf galaxies. The fact that Virgo is embedded in a rich environment surrounded by several filaments that feed the cluster with new substructures could imply changes in the DF locally. When we analysed the DF variation at further distances from the cluster we observe some regions with few or no giant galaxies at all, with a local DF ranging from 0.8−1.0. Additionally, when comparing the dwarf fraction in different environments, overall the DF is larger in regions further away from denser regions such as the Virgo cluster and its filamentary structure surrounding it. When comparing the filament and the cluster area, the DF is slightly higher in the filaments, but from filament to filament, the DF changes depending on the presence of groups.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"1 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146044764","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 : 2026-01-22DOI: 10.1051/0004-6361/202556146
C. Moutou, P. Petit, P. Charpentier, P. Cristofari, C. Baruteau, P. Thébault, L. Arnold, E. Artigau, A. Carmona, N. J. Cook, F. Debras, X. Delfosse, J.-F. Donati, L. Malo, M. Ould-Elhkim
One of the first exoplanet hosts, discovered about thirty years ago, the star 55 Cnc has been continuously observed ever since. It is now known to host at least five planets with orbital periods ranging from 17 hours to 15 years. It is also one of the most extreme metal-rich stars in the neighbourhood, and it has a low-mass secondary star. In this article, we present data obtained at the Canada-France-Hawai’i Telescope with the SPIRou spectropolarimeter on both components of the 55 Cnc stellar system. We revisit the long-period radial-velocity signals of 55 Cnc A, with a focus on the role of the magnetic cycle, and propose the existence of a sixth planet candidate, whose period falls close to that of the magnetic cycle, or half of it. The other massive outer planet has a revised period of 13.15 years and a minimum mass of 3.8 MJup. Although some uncertainty remains about these outer planets, the characterisation of the four inner planets is very robust through the combination of many different datasets, and all signals are consistent in the near-infrared (nIR) and optical domains. In addition, the magnetic topology of the solar-type primary component of the system was observed by SPIRou at the minimum of its activity cycle, characterised by an amplitude ten times smaller than observed that during its maximum in 2017. For the low-mass component 55 Cnc B, we report the discovery of two exoplanets in the system, with a period of 6.799 ± 0.0014 and 33.75 ± 0.04 days and a minimum mass of 3.5 ± 0.8 and 5.3 ± 1.4 M⊕, respectively. The secondary magnetic field is very weak, and the current dataset does not allow its precise characterisation, setting an upper limit of 10 G. The system 55 Cnc stands out as the sixth binary system with planetary systems around both components and the first one with non-equal-mass stellar components.
{"title":"Characterising planetary systems with SPIRou: Questions about the magnetic cycle of 55 Cnc A and two new planets around B★","authors":"C. Moutou, P. Petit, P. Charpentier, P. Cristofari, C. Baruteau, P. Thébault, L. Arnold, E. Artigau, A. Carmona, N. J. Cook, F. Debras, X. Delfosse, J.-F. Donati, L. Malo, M. Ould-Elhkim","doi":"10.1051/0004-6361/202556146","DOIUrl":"https://doi.org/10.1051/0004-6361/202556146","url":null,"abstract":"One of the first exoplanet hosts, discovered about thirty years ago, the star 55 Cnc has been continuously observed ever since. It is now known to host at least five planets with orbital periods ranging from 17 hours to 15 years. It is also one of the most extreme metal-rich stars in the neighbourhood, and it has a low-mass secondary star. In this article, we present data obtained at the Canada-France-Hawai’i Telescope with the SPIRou spectropolarimeter on both components of the 55 Cnc stellar system. We revisit the long-period radial-velocity signals of 55 Cnc A, with a focus on the role of the magnetic cycle, and propose the existence of a sixth planet candidate, whose period falls close to that of the magnetic cycle, or half of it. The other massive outer planet has a revised period of 13.15 years and a minimum mass of 3.8 M<sub>Jup<sub/>. Although some uncertainty remains about these outer planets, the characterisation of the four inner planets is very robust through the combination of many different datasets, and all signals are consistent in the near-infrared (nIR) and optical domains. In addition, the magnetic topology of the solar-type primary component of the system was observed by SPIRou at the minimum of its activity cycle, characterised by an amplitude ten times smaller than observed that during its maximum in 2017. For the low-mass component 55 Cnc B, we report the discovery of two exoplanets in the system, with a period of 6.799 ± 0.0014 and 33.75 ± 0.04 days and a minimum mass of 3.5 ± 0.8 and 5.3 ± 1.4 M<sub>⊕<sub/>, respectively. The secondary magnetic field is very weak, and the current dataset does not allow its precise characterisation, setting an upper limit of 10 G. The system 55 Cnc stands out as the sixth binary system with planetary systems around both components and the first one with non-equal-mass stellar components.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"32 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146021936","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 : 2026-01-22DOI: 10.1051/0004-6361/202555476
Vincenzo Mariani, Agnès Fienga, Zachary Murray, Mickaël Gastineau, Jacques Laskar
Context. One of the main bottlenecks in assessing the accuracy of the Mars orbit is the unknown value of the asteroids in the main asteroid belt. A modeling with 343 asteroids as point masses is used today, with the relative masses fit to observational data.Aims. We propose an innovative method for reducing the number of asteroids implemented as point masses, which in turn reduces the number of parameters to be fit without a significant degradation of the postfit residuals.Methods. We used boosting decision trees to obtain a ranking by relative importance of the 343 asteroids of the current main belt modeling.Results. We were able to remove more than 100 of these asteroids without significantly degrading the postfit residuals and with a significant improvement of the uncertainties. Furthermore, we verified that the postfit masses found with the new modeling (INPOP25c) are consistent with respect to the mass estimation from an independent approach by means of the albedo properties of the asteroids.
{"title":"Boosting decision trees for the selection of main belt asteroids in planetary ephemerides: An alternative model","authors":"Vincenzo Mariani, Agnès Fienga, Zachary Murray, Mickaël Gastineau, Jacques Laskar","doi":"10.1051/0004-6361/202555476","DOIUrl":"https://doi.org/10.1051/0004-6361/202555476","url":null,"abstract":"<i>Context<i/>. One of the main bottlenecks in assessing the accuracy of the Mars orbit is the unknown value of the asteroids in the main asteroid belt. A modeling with 343 asteroids as point masses is used today, with the relative masses fit to observational data.<i>Aims<i/>. We propose an innovative method for reducing the number of asteroids implemented as point masses, which in turn reduces the number of parameters to be fit without a significant degradation of the postfit residuals.<i>Methods<i/>. We used boosting decision trees to obtain a ranking by relative importance of the 343 asteroids of the current main belt modeling.<i>Results<i/>. We were able to remove more than 100 of these asteroids without significantly degrading the postfit residuals and with a significant improvement of the uncertainties. Furthermore, we verified that the postfit masses found with the new modeling (INPOP25c) are consistent with respect to the mass estimation from an independent approach by means of the albedo properties of the asteroids.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"269 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146022062","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 : 2026-01-21DOI: 10.1051/0004-6361/202557253
L. P. Chitta, D. I. Pontin, E. R. Priest, D. Berghmans, E. Kraaikamp, L. Rodriguez, C. Verbeeck, A. N. Zhukov, S. Krucker, R. Aznar Cuadrado, D. Calchetti, J. Hirzberger, H. Peter, U. Schühle, S. K. Solanki, L. Teriaca, A. S. Giunta, F. Auchère, L. Harra, D. Müller
Solar flares are the most powerful, magnetically driven, explosions in the heliosphere. The nature of magnetic energy release in the solar corona that heats the plasma and accelerates particles in a flare, however, remains poorly understood. Here, we report high-resolution coronal observations of a flare by the Solar Orbiter mission that reveal initially weaker but rapid reconnection events, on timescales of a few seconds at most, leading to a more prominent activity of a similar nature that explosively causes a flare. Signatures of this process are further imprinted on the widespread raining plasma blobs with short lifetimes, giving rise to the characteristic ribbon-like emission pattern associated with the flare. Our observations unveil the central engine of a flare and emphasize the crucial role of an avalanche-like magnetic energy release mechanism at work.
{"title":"A magnetic avalanche as the central engine powering a solar flare","authors":"L. P. Chitta, D. I. Pontin, E. R. Priest, D. Berghmans, E. Kraaikamp, L. Rodriguez, C. Verbeeck, A. N. Zhukov, S. Krucker, R. Aznar Cuadrado, D. Calchetti, J. Hirzberger, H. Peter, U. Schühle, S. K. Solanki, L. Teriaca, A. S. Giunta, F. Auchère, L. Harra, D. Müller","doi":"10.1051/0004-6361/202557253","DOIUrl":"https://doi.org/10.1051/0004-6361/202557253","url":null,"abstract":"Solar flares are the most powerful, magnetically driven, explosions in the heliosphere. The nature of magnetic energy release in the solar corona that heats the plasma and accelerates particles in a flare, however, remains poorly understood. Here, we report high-resolution coronal observations of a flare by the Solar Orbiter mission that reveal initially weaker but rapid reconnection events, on timescales of a few seconds at most, leading to a more prominent activity of a similar nature that explosively causes a flare. Signatures of this process are further imprinted on the widespread raining plasma blobs with short lifetimes, giving rise to the characteristic ribbon-like emission pattern associated with the flare. Our observations unveil the central engine of a flare and emphasize the crucial role of an avalanche-like magnetic energy release mechanism at work.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"58 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146006175","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 : 2026-01-20DOI: 10.1051/0004-6361/202556855
P. Weber, S. Pérez, C. Baruteau, S. Marino, F. Castillo, M. R. Jankovic, T. Pearce, M. C. Wyatt, A. A. Sefilian, J. Olofsson, G. Cataldi, J. B. Lovell, C. del Burgo, A. M. Hughes, S. Mac Manamon, A. Brennan, L. Matrà, J. Milli, B. Zawadzki, E. Chiang, M. A. MacGregor, D. J. Wilner, M. Bonduelle, J. M. Carpenter, Y. Han, Á. Kóspál, P. Luppe
Context. Debris discs were long considered to be largely gas-free environments, where dynamical evolution is governed primarily by collisional fragmentation, gravitational stirring, and radiative forces. Recent detections of CO molecular line emission in debris discs demonstrate that gas is present, but its abundance and origin are still uncertain. The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) observed both the gas and dust of several debris discs at high resolution and revealed a narrow ring of gas and dust in the disc HD 121617, with an asymmetric arc-like feature that is 40% brighter than the rest of the ring.Aims. An important open question is how representative the estimated CO masses are for the total gas mass in debris discs. We aim to constrain the total gas mass in HD 121617 using numerical models under the assumption that the dust arc is produced by hydrodynamical processes involving the gas.Methods. We used the hydrodynamical code Dusty FARGO-ADSG, in which dust is modelled as Lagrangian particles. We explored the effects of radiation pressure and dust feedback, as well as of varying the total gas mass on the dynamical evolution of the system. We compared these simulations with observations via radiative transfer calculations.Results. We find that an unstable gas ring can create a size-dependent radial and azimuthal dust trap. The total gas mass dictates the efficiency of particle trapping as a function of grain size. We find that two of our models, Mgas=50 M⊕ and Mgas=5 M⊕, can simultaneously reproduce the observed arc in the ALMA band 7 continuum image and the radial outward offset of the VLT/SPHERE scattered light ring, driven by the combined effects of gas drag and radiation pressure. We further find a conservative lower limit of Mgas>2.5 M⊕ and a conservative upper limit of Mgas<250 M⊕.Conclusions. If the ALMA band 7 asymmetry is caused by gas drag, reconciling the required gas mass with the observed 12CO emission suggests the presence of significant amounts of H2, consistent with the gas being primordial, that is, long-lived remnant material from the protoplanetary disc phase. In this scenario, HD 121617 would represent a hybrid disc, bridging the protoplanetary and debris disc stages. As an arc-shaped emission can alternatively be reproduced by a planet’s gravitational forcing, future observations are crucial to distinguish between these two scenarios.
{"title":"The ALMA survey to Resolve exoKuiper belt Substructures (ARKS)","authors":"P. Weber, S. Pérez, C. Baruteau, S. Marino, F. Castillo, M. R. Jankovic, T. Pearce, M. C. Wyatt, A. A. Sefilian, J. Olofsson, G. Cataldi, J. B. Lovell, C. del Burgo, A. M. Hughes, S. Mac Manamon, A. Brennan, L. Matrà, J. Milli, B. Zawadzki, E. Chiang, M. A. MacGregor, D. J. Wilner, M. Bonduelle, J. M. Carpenter, Y. Han, Á. Kóspál, P. Luppe","doi":"10.1051/0004-6361/202556855","DOIUrl":"https://doi.org/10.1051/0004-6361/202556855","url":null,"abstract":"<i>Context<i/>. Debris discs were long considered to be largely gas-free environments, where dynamical evolution is governed primarily by collisional fragmentation, gravitational stirring, and radiative forces. Recent detections of CO molecular line emission in debris discs demonstrate that gas is present, but its abundance and origin are still uncertain. The <i>ALMA survey to Resolve exoKuiper belt Substructures (ARKS)<i/> observed both the gas and dust of several debris discs at high resolution and revealed a narrow ring of gas and dust in the disc HD 121617, with an asymmetric arc-like feature that is 40% brighter than the rest of the ring.<i>Aims<i/>. An important open question is how representative the estimated CO masses are for the total gas mass in debris discs. We aim to constrain the total gas mass in HD 121617 using numerical models under the assumption that the dust arc is produced by hydrodynamical processes involving the gas.<i>Methods<i/>. We used the hydrodynamical code Dusty FARGO-ADSG, in which dust is modelled as Lagrangian particles. We explored the effects of radiation pressure and dust feedback, as well as of varying the total gas mass on the dynamical evolution of the system. We compared these simulations with observations via radiative transfer calculations.<i>Results<i/>. We find that an unstable gas ring can create a size-dependent radial and azimuthal dust trap. The total gas mass dictates the efficiency of particle trapping as a function of grain size. We find that two of our models, <i>M<i/><sub>gas<sub/>=50 <i>M<i/><sub>⊕<sub/> and <i>M<i/><sub>gas<sub/>=5 <i>M<i/><sub>⊕<sub/>, can simultaneously reproduce the observed arc in the ALMA band 7 continuum image and the radial outward offset of the VLT/SPHERE scattered light ring, driven by the combined effects of gas drag and radiation pressure. We further find a conservative lower limit of <i>M<i/><sub>gas<sub/>>2.5 <i>M<i/><sub>⊕<sub/> and a conservative upper limit of <i>M<i/><sub>gas<sub/><250 <i>M<i/><sub>⊕<sub/>.<i>Conclusions<i/>. If the ALMA band 7 asymmetry is caused by gas drag, reconciling the required gas mass with the observed <sup>12<sup/>CO emission suggests the presence of significant amounts of H<sub>2<sub/>, consistent with the gas being primordial, that is, long-lived remnant material from the protoplanetary disc phase. In this scenario, HD 121617 would represent a hybrid disc, bridging the protoplanetary and debris disc stages. As an arc-shaped emission can alternatively be reproduced by a planet’s gravitational forcing, future observations are crucial to distinguish between these two scenarios.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"63 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146006171","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 : 2026-01-20DOI: 10.1051/0004-6361/202556568
J. B. Lovell, A. S. Hales, G. M. Kennedy, S. Marino, J. Olofsson, A. M. Hughes, E. Mansell, B. C. Matthews, T. D. Pearce, A. A. Sefilian, D. J. Wilner, B. Zawadzki, M. Booth, M. Bonduelle, A. Brennan, C. del Burgo, J. M. Carpenter, G. Cataldi, E. Chiang, A. Fehr, Y. Han, Th. Henning, A. V. Krivov, P. Luppe, J. P. Marshall, S. Mac Manamon, J. Milli, A. Moór, M. C. Wyatt, S. Ertel, M. R. Jankovic, Á. Kóspál, M. A. MacGregor, L. Matrà, S. Pérez, P. Weber
<i>Context<i/>. Asymmetries in debris discs provide unique clues to understand the evolution and architecture of planetary systems. Previous studies of debris discs at (sub)millimetre wavelengths have suggested the presence of asymmetries in a wide variety of systems, yet the lack of sufficiently sensitive high-resolution observations means that the typical properties of debris disc asymmetries have not been studied at the population level. The aim of the ALMA survey to Resolve exoKuiper belt Substructures (ARKS) is to expand our understanding of radial and vertical dust structures, as well as gas distributions and kinematics, in debris discs. The ARKS sample of 24 highly resolved targets in ALMA’s Bands 6 and 7 (1.1–1.4 mm and 0.8–1.1 mm, respectively) provided a unique opportunity to study their asymmetries.<i>Aims<i/>. Here, in ARKS VI, we present a systematic analysis of the asymmetries and stellocentric offsets present in the ALMA continuum data for the ARKS survey. Our aims are to (i) identify asymmetries in debris disc dust distributions, (ii) quantify debris disc asymmetry properties, and (iii) discuss the potential origins of debris disc asymmetries. This work is the first systematic analysis of asymmetries in a large sample of well-resolved discs at (sub)millimetre wavelengths.<i>Methods<i/>. We utilised empirical methods to identify emission asymmetries (relative to disc major and minor axes, and azimuthal disc locations) and the presence of offset emission between disc centres and the locations of the host stars, via an analysis of their calibration procedures and disc properties. We associated observational asymmetry types (offset, major and/or minor axis, azimuthal) and plausible physical classes (arcs, eccentricities, and possible clumps and warps) associated with each source.<i>Results<i/>. We show that there are ten systems, almost half of the ARKS sample, that host either a continuum emission asymmetry or offset emission. Three systems host offsets (HD 15115, HD 32297, and HD 109573 (HR 4796)), four host azimuthal asymmetries (HD 9672 (49 Ceti), HD 92945, HD 107146, and HD 121617), two host an asymmetry in their major axis (HD 10647 (q<sup>1<sup/> Eri), and HD 39060 (<i>β<i/> Pic)), and one hosts an asymmetry in their minor axis (HD 61005). We attribute the offset asymmetries to non-zero eccentricities, and three of the azimuthal asymmetries to arcs. The presence of an asymmetry or offset in the ARKS sample appears to be correlated with the fractional luminosity of cold dust. We tentatively suggest that continuum asymmetries are more prevalent in CO-rich debris discs, suggesting that gas interactions may drive debris dust asymmetries. We identify seven other tentative asymmetries, including four in distinct ARKS systems and three in systems with otherwise significant asymmetries.<i>Conclusions<i/>. This study demonstrates that debris disc asymmetries in the ARKS sample are common, and plausibly so in the wider population of debr
上下文。碎片盘的不对称性为理解行星系统的演化和结构提供了独特的线索。先前对（亚）毫米波长的碎片盘的研究表明，在各种各样的系统中都存在不对称，但缺乏足够敏感的高分辨率观测意味着碎片盘不对称的典型特性尚未在种群水平上进行研究。ALMA调查外柯伊伯带亚结构（ARKS）的目的是扩大我们对径向和垂直尘埃结构的理解，以及碎片盘中的气体分布和运动学。ARKS采样了ALMA波段6和7（分别为1.1-1.4 mm和0.8-1.1 mm）的24个高分辨率目标，为研究它们的不对称性提供了独特的机会。这里，在ARKS VI中，我们对ARKS调查中ALMA连续体数据中的不对称性和星心偏移进行了系统分析。我们的目标是(i)确定碎片盘尘埃分布中的不对称性，（ii）量化碎片盘的不对称性特性，以及（iii）讨论碎片盘不对称性的潜在起源。这项工作是第一次系统地分析（亚）毫米波长下高分辨率圆盘的不对称性。我们利用经验方法来识别发射不对称性（相对于盘主轴和小轴，以及盘的方位角位置），以及盘中心和主星位置之间存在的偏移发射，通过分析它们的校准程序和盘的特性。我们将观测到的不对称类型（偏移、主轴和/或小轴、方位角）和与每个源相关的合理物理类别（弧线、偏心、可能的团块和翘曲）联系起来。我们表明，有10个系统，几乎一半的ARKS样本，宿主连续发射不对称或抵消发射。三个系统主机偏移（HD 15115， HD 32297和HD 109573 (HR 4796)），四个主机方位角不对称（HD 9672 (49 Ceti), HD 92945， HD 107146和HD 121617），两个主机在其长轴上具有不对称（HD 10647 （q1 Eri）和HD 39060 (β Pic)），一个主机在其小轴上具有不对称（HD 61005）。我们将偏移不对称归因于非零偏心，并将三个方位角不对称归因于弧。ARKS样品中不对称或偏移的存在似乎与冷尘埃的分数光度有关。我们初步认为，连续体不对称在富含co的碎片盘中更为普遍，这表明气体相互作用可能导致碎片尘埃不对称。我们确定了其他7个暂定不对称，包括4个不同的ARKS系统和3个具有其他显著不对称的系统。这项研究表明，ARKS样本中的碎片盘不对称是常见的，而且在（亚）毫米波长的更广泛的碎片盘中似乎也是如此。这意味着，当我们以更高的灵敏度和分辨率探测这些碎片盘时，（亚）毫米的不对称可能会等待发现。在整个过程中，我们强调了未来的研究，以进一步调查碎片盘不对称的起源，并建立在这里提出的工作。
{"title":"The ALMA survey to Resolve exoKuiper belt Substructures (ARKS)","authors":"J. B. Lovell, A. S. Hales, G. M. Kennedy, S. Marino, J. Olofsson, A. M. Hughes, E. Mansell, B. C. Matthews, T. D. Pearce, A. A. Sefilian, D. J. Wilner, B. Zawadzki, M. Booth, M. Bonduelle, A. Brennan, C. del Burgo, J. M. Carpenter, G. Cataldi, E. Chiang, A. Fehr, Y. Han, Th. Henning, A. V. Krivov, P. Luppe, J. P. Marshall, S. Mac Manamon, J. Milli, A. Moór, M. C. Wyatt, S. Ertel, M. R. Jankovic, Á. Kóspál, M. A. MacGregor, L. Matrà, S. Pérez, P. Weber","doi":"10.1051/0004-6361/202556568","DOIUrl":"https://doi.org/10.1051/0004-6361/202556568","url":null,"abstract":"<i>Context<i/>. Asymmetries in debris discs provide unique clues to understand the evolution and architecture of planetary systems. Previous studies of debris discs at (sub)millimetre wavelengths have suggested the presence of asymmetries in a wide variety of systems, yet the lack of sufficiently sensitive high-resolution observations means that the typical properties of debris disc asymmetries have not been studied at the population level. The aim of the ALMA survey to Resolve exoKuiper belt Substructures (ARKS) is to expand our understanding of radial and vertical dust structures, as well as gas distributions and kinematics, in debris discs. The ARKS sample of 24 highly resolved targets in ALMA’s Bands 6 and 7 (1.1–1.4 mm and 0.8–1.1 mm, respectively) provided a unique opportunity to study their asymmetries.<i>Aims<i/>. Here, in ARKS VI, we present a systematic analysis of the asymmetries and stellocentric offsets present in the ALMA continuum data for the ARKS survey. Our aims are to (i) identify asymmetries in debris disc dust distributions, (ii) quantify debris disc asymmetry properties, and (iii) discuss the potential origins of debris disc asymmetries. This work is the first systematic analysis of asymmetries in a large sample of well-resolved discs at (sub)millimetre wavelengths.<i>Methods<i/>. We utilised empirical methods to identify emission asymmetries (relative to disc major and minor axes, and azimuthal disc locations) and the presence of offset emission between disc centres and the locations of the host stars, via an analysis of their calibration procedures and disc properties. We associated observational asymmetry types (offset, major and/or minor axis, azimuthal) and plausible physical classes (arcs, eccentricities, and possible clumps and warps) associated with each source.<i>Results<i/>. We show that there are ten systems, almost half of the ARKS sample, that host either a continuum emission asymmetry or offset emission. Three systems host offsets (HD 15115, HD 32297, and HD 109573 (HR 4796)), four host azimuthal asymmetries (HD 9672 (49 Ceti), HD 92945, HD 107146, and HD 121617), two host an asymmetry in their major axis (HD 10647 (q<sup>1<sup/> Eri), and HD 39060 (<i>β<i/> Pic)), and one hosts an asymmetry in their minor axis (HD 61005). We attribute the offset asymmetries to non-zero eccentricities, and three of the azimuthal asymmetries to arcs. The presence of an asymmetry or offset in the ARKS sample appears to be correlated with the fractional luminosity of cold dust. We tentatively suggest that continuum asymmetries are more prevalent in CO-rich debris discs, suggesting that gas interactions may drive debris dust asymmetries. We identify seven other tentative asymmetries, including four in distinct ARKS systems and three in systems with otherwise significant asymmetries.<i>Conclusions<i/>. This study demonstrates that debris disc asymmetries in the ARKS sample are common, and plausibly so in the wider population of debr","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"45 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146006174","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 : 2026-01-20DOI: 10.1051/0004-6361/202556523
J. Milli, J. Olofsson, M. Bonduelle, R. Bendahan-West, J. P. Marshall, E. Choquet, A. A. Sefilian, Y. Han, B. Zawadzki, S. Mac Manamon, E. Mansell, C. del Burgo, J. M. Carpenter, A. M. Hughes, M. Booth, E. Chiang, S. Ertel, Th. M. Esposito, Th. Henning, J. Hom, M. R. Jankovic, A. V. Krivov, J. B. Lovell, P. Luppe, M. A. MacGregor, S. Marino, B. C. Matthews, L. Matrà, A. Moór, N. Pawellek, T. D. Pearce, S. Pérez, V. Squicciarini, P. Weber, D. J. Wilner, M. C. Wyatt
Context. Debris discs are analogues to our own Kuiper belt around main-sequence stars and are therefore referred to as exoKuiper belts. They have been resolved at high angular resolution at wavelengths spanning the optical/near-infrared to the submillimetre-millimetre regime. Short wavelengths can probe the light scattered by such discs, which is dominated by micron-sized dust particles, while millimetre wavelengths can probe the thermal emission of millimetre-sized particles. Determining differences in the dust distribution between millimetre- and micron-sized dust is fundamental to revealing the dynamical processes affecting the dust in debris discs.Aims. We aim to compare the scattered light from the discs of the ‘ALMA survey to Resolve exoKuiper belt Substructures’ (ARKS) with the thermal emission probed by ALMA. We focus on the radial distribution of the dust, and we also put constraints on the presence of giant planets in those systems.Methods. We used high-contrast scattered light observations obtained with VLT/SPHERE, GPI, and the HST to uniformly study the dust distribution in those systems and compare it to the dust distribution extracted from the ALMA observations carried out in the course of the ARKS project. We also set constraints on the presence of planets by using these high-contrast images combined with exoplanet evolutionary models.Results. Fifteen of the 24 discs comprising the ARKS sample are detected in scattered light, with TYC 9340-437-1 being imaged for the first time at near-infrared wavelengths. For six of those 15 discs, the dust surface density seen in scattered light peaks farther out compared to that observed with ALMA. These six discs except one are known to also host cold CO gas. Conversely, the systems without significant offsets are not known to host gas, except one. Moreover, with our scattered light near-infrared images, we achieve typical sensitivities to planets from 1 to 10 MJup beyond 10 to 20 au, depending on the system age and distance.Conclusions. This observational study suggests that the presence of gas in debris discs may affect the small and large grains differently, pushing the small dust to greater distances where the gas is less abundant.
{"title":"The ALMA survey to Resolve exoKuiper belt Substructures (ARKS)","authors":"J. Milli, J. Olofsson, M. Bonduelle, R. Bendahan-West, J. P. Marshall, E. Choquet, A. A. Sefilian, Y. Han, B. Zawadzki, S. Mac Manamon, E. Mansell, C. del Burgo, J. M. Carpenter, A. M. Hughes, M. Booth, E. Chiang, S. Ertel, Th. M. Esposito, Th. Henning, J. Hom, M. R. Jankovic, A. V. Krivov, J. B. Lovell, P. Luppe, M. A. MacGregor, S. Marino, B. C. Matthews, L. Matrà, A. Moór, N. Pawellek, T. D. Pearce, S. Pérez, V. Squicciarini, P. Weber, D. J. Wilner, M. C. Wyatt","doi":"10.1051/0004-6361/202556523","DOIUrl":"https://doi.org/10.1051/0004-6361/202556523","url":null,"abstract":"<i>Context<i/>. Debris discs are analogues to our own Kuiper belt around main-sequence stars and are therefore referred to as exoKuiper belts. They have been resolved at high angular resolution at wavelengths spanning the optical/near-infrared to the submillimetre-millimetre regime. Short wavelengths can probe the light scattered by such discs, which is dominated by micron-sized dust particles, while millimetre wavelengths can probe the thermal emission of millimetre-sized particles. Determining differences in the dust distribution between millimetre- and micron-sized dust is fundamental to revealing the dynamical processes affecting the dust in debris discs.<i>Aims<i/>. We aim to compare the scattered light from the discs of the ‘ALMA survey to Resolve exoKuiper belt Substructures’ (ARKS) with the thermal emission probed by ALMA. We focus on the radial distribution of the dust, and we also put constraints on the presence of giant planets in those systems.<i>Methods<i/>. We used high-contrast scattered light observations obtained with VLT/SPHERE, GPI, and the HST to uniformly study the dust distribution in those systems and compare it to the dust distribution extracted from the ALMA observations carried out in the course of the ARKS project. We also set constraints on the presence of planets by using these high-contrast images combined with exoplanet evolutionary models.<i>Results<i/>. Fifteen of the 24 discs comprising the ARKS sample are detected in scattered light, with TYC 9340-437-1 being imaged for the first time at near-infrared wavelengths. For six of those 15 discs, the dust surface density seen in scattered light peaks farther out compared to that observed with ALMA. These six discs except one are known to also host cold CO gas. Conversely, the systems without significant offsets are not known to host gas, except one. Moreover, with our scattered light near-infrared images, we achieve typical sensitivities to planets from 1 to 10 <i>M<i/><sub>Jup<sub/> beyond 10 to 20 au, depending on the system age and distance.<i>Conclusions<i/>. This observational study suggests that the presence of gas in debris discs may affect the small and large grains differently, pushing the small dust to greater distances where the gas is less abundant.","PeriodicalId":8571,"journal":{"name":"Astronomy & Astrophysics","volume":"32 1","pages":""},"PeriodicalIF":6.5,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146006198","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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