Pub Date : 2024-07-22DOI: 10.1038/s41550-024-02324-6
Jonathan O’Callaghan
NASA’s Mars Sample Return mission faces an uncertain future, with funding issues pushing back the crucial final phase into late next decade. If a solution could be found, the scientific return would be immense.
{"title":"Why scientists are longing for samples from Mars","authors":"Jonathan O’Callaghan","doi":"10.1038/s41550-024-02324-6","DOIUrl":"10.1038/s41550-024-02324-6","url":null,"abstract":"NASA’s Mars Sample Return mission faces an uncertain future, with funding issues pushing back the crucial final phase into late next decade. If a solution could be found, the scientific return would be immense.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"8 8","pages":"940-942"},"PeriodicalIF":12.9,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141736957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-07-22DOI: 10.1038/s41550-024-02327-3
Eirini Angeloudi, Jesús Falcón-Barroso, Marc Huertas-Company, Alina Boecker, Regina Sarmiento, Lukas Eisert, Annalisa Pillepich
The hierarchical model of galaxy evolution suggests that mergers have a substantial impact on the intricate processes that drive stellar assembly within a galaxy. However, accurately measuring the contribution of accretion to a galaxy’s total stellar mass and its balance with in situ star formation poses a persistent challenge, as it is neither directly observable nor easily inferred from observational properties. Using data from MaNGA, we present theory-motivated predictions for the fraction of stellar mass originating from mergers in a statistically significant sample of nearby galaxies. Employing a robust machine learning model trained on mock MaNGA analogues (MaNGIA) obtained from a cosmological simulation (TNG50), we unveil that in situ stellar mass dominates almost across the entire stellar mass spectrum (109 M⊙ < M⋆ < 1012 M⊙). Only in more massive galaxies (M⋆ > 1011 M⊙) does accreted mass become a substantial contributor, reaching up to 35–40% of the total stellar mass. Notably, the ex situ stellar mass in the nearby Universe exhibits notable dependence on galaxy characteristics, with higher accreted fractions favoured being by elliptical, quenched galaxies and slow rotators, as well as galaxies at the centre of more massive dark matter haloes. The contribution of accreted stars to a galaxy’s total stellar mass is hard to determine directly from observations. Here constraints are placed on the ex situ stellar mass for ~10,000 galaxies using a cosmological simulation and machine learning.
{"title":"Constraints on the in situ and ex situ stellar masses in nearby galaxies obtained with artificial intelligence","authors":"Eirini Angeloudi, Jesús Falcón-Barroso, Marc Huertas-Company, Alina Boecker, Regina Sarmiento, Lukas Eisert, Annalisa Pillepich","doi":"10.1038/s41550-024-02327-3","DOIUrl":"10.1038/s41550-024-02327-3","url":null,"abstract":"The hierarchical model of galaxy evolution suggests that mergers have a substantial impact on the intricate processes that drive stellar assembly within a galaxy. However, accurately measuring the contribution of accretion to a galaxy’s total stellar mass and its balance with in situ star formation poses a persistent challenge, as it is neither directly observable nor easily inferred from observational properties. Using data from MaNGA, we present theory-motivated predictions for the fraction of stellar mass originating from mergers in a statistically significant sample of nearby galaxies. Employing a robust machine learning model trained on mock MaNGA analogues (MaNGIA) obtained from a cosmological simulation (TNG50), we unveil that in situ stellar mass dominates almost across the entire stellar mass spectrum (109 M⊙ < M⋆ < 1012 M⊙). Only in more massive galaxies (M⋆ > 1011 M⊙) does accreted mass become a substantial contributor, reaching up to 35–40% of the total stellar mass. Notably, the ex situ stellar mass in the nearby Universe exhibits notable dependence on galaxy characteristics, with higher accreted fractions favoured being by elliptical, quenched galaxies and slow rotators, as well as galaxies at the centre of more massive dark matter haloes. The contribution of accreted stars to a galaxy’s total stellar mass is hard to determine directly from observations. Here constraints are placed on the ex situ stellar mass for ~10,000 galaxies using a cosmological simulation and machine learning.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"8 10","pages":"1310-1320"},"PeriodicalIF":12.9,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141736970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-07-22DOI: 10.1038/s41550-024-02320-w
Julie Nekola Nováková
An IAU meeting on extraterrestrial life tackled some ageless questions from a variety of unusual perspectives, including the media and science fiction, and was refreshingly explicit about degrees of uncertainty in the answers.
{"title":"Toward discovery of life beyond Earth and its impact","authors":"Julie Nekola Nováková","doi":"10.1038/s41550-024-02320-w","DOIUrl":"10.1038/s41550-024-02320-w","url":null,"abstract":"An IAU meeting on extraterrestrial life tackled some ageless questions from a variety of unusual perspectives, including the media and science fiction, and was refreshingly explicit about degrees of uncertainty in the answers.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"8 7","pages":"799-800"},"PeriodicalIF":12.9,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141750309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-07-22DOI: 10.1038/s41550-024-02333-5
Exoplanetary science has been advancing in leaps and bounds since its beginnings almost 30 years ago. This issue of Nature Astronomy celebrates its progress with a range of papers that sample the breadth of this booming discipline.
{"title":"The continued growth of exoplanets","authors":"","doi":"10.1038/s41550-024-02333-5","DOIUrl":"10.1038/s41550-024-02333-5","url":null,"abstract":"Exoplanetary science has been advancing in leaps and bounds since its beginnings almost 30 years ago. This issue of Nature Astronomy celebrates its progress with a range of papers that sample the breadth of this booming discipline.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"8 7","pages":"797-798"},"PeriodicalIF":12.9,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41550-024-02333-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141750283","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-22DOI: 10.1038/s41550-024-02330-8
Bishwanath Gaire
{"title":"Subchromospheric magnetic reconnection on the Sun","authors":"Bishwanath Gaire","doi":"10.1038/s41550-024-02330-8","DOIUrl":"10.1038/s41550-024-02330-8","url":null,"abstract":"","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"8 7","pages":"807-807"},"PeriodicalIF":12.9,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141750345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-07-22DOI: 10.1038/s41550-024-02317-5
Jacob L. Bean, Madison Brady
Most data for extrasolar rocky planets comes from observations of objects significantly larger than the Earth. The newly discovered SPECULOOS-3 b is a good target for efforts to characterize exoplanets closer in size to the solar system terrestrial planets.
关于太阳系外岩质行星的大多数数据都来自于对比地球大得多的天体的观测。新发现的 SPECULOOS-3 b 是一个很好的目标，可以用来描述大小更接近太阳系陆地行星的系外行星。
{"title":"Earth-sized planet spotted around a nearby small star","authors":"Jacob L. Bean, Madison Brady","doi":"10.1038/s41550-024-02317-5","DOIUrl":"10.1038/s41550-024-02317-5","url":null,"abstract":"Most data for extrasolar rocky planets comes from observations of objects significantly larger than the Earth. The newly discovered SPECULOOS-3 b is a good target for efforts to characterize exoplanets closer in size to the solar system terrestrial planets.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"8 7","pages":"805-806"},"PeriodicalIF":12.9,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141750333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-07-19DOI: 10.1038/s41550-024-02323-7
Justin L. Ripley, Abhishek Hegade K R, Rohit S. Chandramouli, Nicolás Yunes
The gravitational waves emitted by neutron star binaries probe the physics of matter at supranuclear densities. During the late inspiral, tidal deformations raised on each star by the gravitational field of its companion depend crucially on the star’s internal properties. The misalignment of a star’s tidal bulge with its companion’s gravitational field encodes the strength of internal dissipative processes, which imprint onto the phase of the gravitational waves emitted. Here, we analyse gravitational wave data from the GW170817 (binary neutron star) event detected by LIGO and Virgo and find a constraint on the dissipative tidal deformability of a neutron star. From this constraint, assuming a temperature profile for each star in the binary, we obtain an order of magnitude bound on the averaged bulk (ζ) and shear (η) viscosity of each star during the inspiral: ζ ≲ 1031 g cm−1 s−1 and η ≲ 1028 g cm−1 s−1. We forecast that these bounds could be improved by two orders of magnitude with third-generation detectors, like Cosmic Explorer, using inspiral data. These constraints already inform nuclear physics models and motivate further theoretical work to better understand the interplay between viscosity and temperature in the late inspiral of neutron stars. An analysis of the gravitational waves emitted from the neutron star binary merger GW170817 provides constraints on the out-of-equilibrium (viscous) properties of neutron star matter.
中子星双星发出的引力波探测了超核密度物质的物理学。在吸气晚期，伴星引力场对每颗恒星产生的潮汐变形在很大程度上取决于恒星的内部特性。恒星的潮汐隆起与其伴星引力场的错位编码了内部耗散过程的强度，而这些耗散过程会影响到所发射引力波的相位。在这里，我们分析了 LIGO 和室女座探测到的 GW170817（双中子星）事件的引力波数据，并找到了中子星耗散潮汐变形能力的约束条件。根据这一约束条件，假设双星中的每颗恒星都有一个温度曲线，我们得到了每颗恒星在吸气过程中的平均体积粘度（ζ）和剪切粘度（η）的数量级约束：ζ ≲ 1031 g cm-1 s-1，η ≲ 1028 g cm-1 s-1。我们预测，利用第三代探测器（如宇宙探测器）的吸气数据，这些界限可以提高两个数量级。这些约束条件已经为核物理模型提供了信息，并推动了进一步的理论工作，以更好地理解中子星吸气后期粘度和温度之间的相互作用。
{"title":"A constraint on the dissipative tidal deformability of neutron stars","authors":"Justin L. Ripley, Abhishek Hegade K R, Rohit S. Chandramouli, Nicolás Yunes","doi":"10.1038/s41550-024-02323-7","DOIUrl":"10.1038/s41550-024-02323-7","url":null,"abstract":"The gravitational waves emitted by neutron star binaries probe the physics of matter at supranuclear densities. During the late inspiral, tidal deformations raised on each star by the gravitational field of its companion depend crucially on the star’s internal properties. The misalignment of a star’s tidal bulge with its companion’s gravitational field encodes the strength of internal dissipative processes, which imprint onto the phase of the gravitational waves emitted. Here, we analyse gravitational wave data from the GW170817 (binary neutron star) event detected by LIGO and Virgo and find a constraint on the dissipative tidal deformability of a neutron star. From this constraint, assuming a temperature profile for each star in the binary, we obtain an order of magnitude bound on the averaged bulk (ζ) and shear (η) viscosity of each star during the inspiral: ζ ≲ 1031 g cm−1 s−1 and η ≲ 1028 g cm−1 s−1. We forecast that these bounds could be improved by two orders of magnitude with third-generation detectors, like Cosmic Explorer, using inspiral data. These constraints already inform nuclear physics models and motivate further theoretical work to better understand the interplay between viscosity and temperature in the late inspiral of neutron stars. An analysis of the gravitational waves emitted from the neutron star binary merger GW170817 provides constraints on the out-of-equilibrium (viscous) properties of neutron star matter.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"8 10","pages":"1277-1283"},"PeriodicalIF":12.9,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141725759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 : 2024-07-17DOI: 10.1038/s41550-024-02326-4
Gabrielle dos Santos Ilha, Marianne Boix, Jürgen Knödlseder, Philippe Garnier, Ludovic Montastruc, Pierre Jean, Giovanni Pareschi, Alexander Steiner, François Toussenel
Astronomical observatories have been identified as substantial contributors to the carbon footprint of astrophysical research. Being part of the collaboration that is currently developing the medium-sized telescopes in the Cherenkov Telescope Array, a ground-based observatory for very-high-energy γ-rays that will comprise 64 telescopes deployed on two sites, we assessed the environmental impacts of one medium-sized telescope on the northern site with a life-cycle assessment. We identified resource use and climate change as having the most significant impacts due to telescope manufacturing and energy consumption during operations. We estimate life-cycle greenhouse gas emissions of 2,660 ± 274 tCO2e for the telescope, 44% of which arise from construction, 1% from on-site assembly and commissioning and 55% from operations over 30 yr. The environmental impacts could be reduced by using renewable energy during construction and operations, using fewer electronic components and metal casting and using recycled materials. We propose complementing the project requirements with environmental budgets as an effective measure for impact management and reductions. According to a life-cycle analysis, the main environmental impacts of building and operating an astronomical telescope are greenhouse gas emissions and the use of mineral resources. Impacts can be reduced by using renewable energy and by making design changes.
{"title":"Assessment of the environmental impacts of the Cherenkov Telescope Array mid-sized telescope","authors":"Gabrielle dos Santos Ilha, Marianne Boix, Jürgen Knödlseder, Philippe Garnier, Ludovic Montastruc, Pierre Jean, Giovanni Pareschi, Alexander Steiner, François Toussenel","doi":"10.1038/s41550-024-02326-4","DOIUrl":"10.1038/s41550-024-02326-4","url":null,"abstract":"Astronomical observatories have been identified as substantial contributors to the carbon footprint of astrophysical research. Being part of the collaboration that is currently developing the medium-sized telescopes in the Cherenkov Telescope Array, a ground-based observatory for very-high-energy γ-rays that will comprise 64 telescopes deployed on two sites, we assessed the environmental impacts of one medium-sized telescope on the northern site with a life-cycle assessment. We identified resource use and climate change as having the most significant impacts due to telescope manufacturing and energy consumption during operations. We estimate life-cycle greenhouse gas emissions of 2,660 ± 274 tCO2e for the telescope, 44% of which arise from construction, 1% from on-site assembly and commissioning and 55% from operations over 30 yr. The environmental impacts could be reduced by using renewable energy during construction and operations, using fewer electronic components and metal casting and using recycled materials. We propose complementing the project requirements with environmental budgets as an effective measure for impact management and reductions. According to a life-cycle analysis, the main environmental impacts of building and operating an astronomical telescope are greenhouse gas emissions and the use of mineral resources. Impacts can be reduced by using renewable energy and by making design changes.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"8 11","pages":"1468-1477"},"PeriodicalIF":12.9,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141631345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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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