Pub Date : 2024-09-27DOI: 10.1038/s41550-024-02373-x
Jianxun Shen, Chuanzhou Liu, Yongxin Pan, Wei Lin
One of the main goals of most ongoing and future space exploration missions is to search for habitable conditions and potential signs of extraterrestrial life on Solar System bodies. Space Agencies have usually implemented this by ‘following’ a specific diagnostic that has an important role in life, with ‘following the water’ being the most famous — but by no means the only — indication. However, the use of only one life-essential element has limitations. Here we propose to follow the serpentine as a way to integrate multiple aspects of habitable conditions as we know them, given that the presence of serpentine implies a water supply, organic molecules, bioavailable essential elements, energy sources, greenhouse gases and preservable environments. Serpentine minerals are associated with the complex process called serpentinization, a subtype of water–rock interactions. Serpentinization and its products are therefore likely to provide insights into where to find potential life-inhabited niches on celestial bodies such as Mars and icy moons. Serpentinization — the metamorphism of rocks involving large amounts of water — includes many different aspects linked to habitability and offers a more reliable indicator of habitable conditions in the Solar System than a single diagnostic, such as water.
{"title":"Follow the serpentine as a comprehensive diagnostic for extraterrestrial habitability","authors":"Jianxun Shen, Chuanzhou Liu, Yongxin Pan, Wei Lin","doi":"10.1038/s41550-024-02373-x","DOIUrl":"10.1038/s41550-024-02373-x","url":null,"abstract":"One of the main goals of most ongoing and future space exploration missions is to search for habitable conditions and potential signs of extraterrestrial life on Solar System bodies. Space Agencies have usually implemented this by ‘following’ a specific diagnostic that has an important role in life, with ‘following the water’ being the most famous — but by no means the only — indication. However, the use of only one life-essential element has limitations. Here we propose to follow the serpentine as a way to integrate multiple aspects of habitable conditions as we know them, given that the presence of serpentine implies a water supply, organic molecules, bioavailable essential elements, energy sources, greenhouse gases and preservable environments. Serpentine minerals are associated with the complex process called serpentinization, a subtype of water–rock interactions. Serpentinization and its products are therefore likely to provide insights into where to find potential life-inhabited niches on celestial bodies such as Mars and icy moons. Serpentinization — the metamorphism of rocks involving large amounts of water — includes many different aspects linked to habitability and offers a more reliable indicator of habitable conditions in the Solar System than a single diagnostic, such as water.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"8 10","pages":"1230-1236"},"PeriodicalIF":12.9,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142325446","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 : 2024-09-27DOI: 10.1038/s41550-024-02381-x
Dirk Schulze-Makuch
In hyperarid environments, life can obtain water through salts that draw moisture from the atmosphere. These salts, then, should be a focus of searches for life on Mars. The experiments performed by NASA’s Viking landers may have accidentally killed Martian life by applying too much water.
{"title":"We may be looking for Martian life in the wrong place","authors":"Dirk Schulze-Makuch","doi":"10.1038/s41550-024-02381-x","DOIUrl":"10.1038/s41550-024-02381-x","url":null,"abstract":"In hyperarid environments, life can obtain water through salts that draw moisture from the atmosphere. These salts, then, should be a focus of searches for life on Mars. The experiments performed by NASA’s Viking landers may have accidentally killed Martian life by applying too much water.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"8 10","pages":"1208-1210"},"PeriodicalIF":12.9,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142325443","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 : 2024-09-25DOI: 10.1038/s41550-024-02357-x
Tomas Cassanelli, Calvin Leung, Pranav Sanghavi, Juan Mena-Parra, Savannah Cary, Ryan Mckinven, Mohit Bhardwaj, Kiyoshi W. Masui, Daniele Michilli, Kevin Bandura, Shami Chatterjee, Jeffrey B. Peterson, Jane Kaczmarek, Mubdi Rahman, Kaitlyn Shin, Keith Vanderlinde, Sabrina Berger, Charanjot Brar, P. J. Boyle, Daniela Breitman, Pragya Chawla, Alice P. Curtin, Matt Dobbs, Fengqiu Adam Dong, Emmanuel Fonseca, B. M. Gaensler, Adaeze Ibik, Victoria M. Kaspi, Kholoud Khairy, Adam E. Lanman, Mattias Lazda, Hsiu-Hsien Lin, Jing Luo, Bradley W. Meyers, Nikola Milutinovic, Cherry Ng, Gavin Noble, Aaron B. Pearlman, Ue-Li Pen, Emily Petroff, Ziggy Pleunis, Brendan Quine, Masoud Rafiei-Ravandi, Andre Renard, Ketan R. Sand, Eve Schoen, Paul Scholz, Kendrick M. Smith, Ingrid Stairs, Shriharsh P. Tendulkar
Fast radio bursts (FRBs) are millisecond-duration radio transients whose origins remain unknown. As the vast majority of bursts are one-off events, it is necessary to pinpoint FRBs precisely within their host galaxies at the time of detection. Here we use two purpose-built outrigger telescopes to localize FRB 20210603A at the time of its detection by the Canadian Hydrogen Intensity Mapping Experiment (CHIME). Our very-long-baseline interferometry stations localized the burst to a 0.2" × 2" final ellipse in the disk of its host galaxy SDSS J004105.82+211331.9. A spatially resolved spectroscopic follow-up revealed recent star formation (Hα emission) on kiloparsec scales near the burst position. The excess dispersion measure is consistent with expectations from the nearly edge-on disk of the host galaxy, demonstrating the utility of FRBs as probes of the interstellar medium in distant galaxies. The excess dispersion measure, rotation measure and scattering are consistent with expectations for a pulse travelling from deep within its host galactic plane, strengthening the link between the local environment of FRB 20210603A and the disk of its host galaxy. Finally, this technique demonstrates a way to overcome the trade-off between angular resolution and field of view in FRB instrumentation, paving the way towards plentiful and precise FRB localizations. Two ‘outrigger’ telescopes were added to CHIME, leading to the localization at detection of FRB 20210603A. The burst originated from deep within the star-forming disk of its host galaxy.
{"title":"A fast radio burst localized at detection to an edge-on galaxy using very-long-baseline interferometry","authors":"Tomas Cassanelli, Calvin Leung, Pranav Sanghavi, Juan Mena-Parra, Savannah Cary, Ryan Mckinven, Mohit Bhardwaj, Kiyoshi W. Masui, Daniele Michilli, Kevin Bandura, Shami Chatterjee, Jeffrey B. Peterson, Jane Kaczmarek, Mubdi Rahman, Kaitlyn Shin, Keith Vanderlinde, Sabrina Berger, Charanjot Brar, P. J. Boyle, Daniela Breitman, Pragya Chawla, Alice P. Curtin, Matt Dobbs, Fengqiu Adam Dong, Emmanuel Fonseca, B. M. Gaensler, Adaeze Ibik, Victoria M. Kaspi, Kholoud Khairy, Adam E. Lanman, Mattias Lazda, Hsiu-Hsien Lin, Jing Luo, Bradley W. Meyers, Nikola Milutinovic, Cherry Ng, Gavin Noble, Aaron B. Pearlman, Ue-Li Pen, Emily Petroff, Ziggy Pleunis, Brendan Quine, Masoud Rafiei-Ravandi, Andre Renard, Ketan R. Sand, Eve Schoen, Paul Scholz, Kendrick M. Smith, Ingrid Stairs, Shriharsh P. Tendulkar","doi":"10.1038/s41550-024-02357-x","DOIUrl":"10.1038/s41550-024-02357-x","url":null,"abstract":"Fast radio bursts (FRBs) are millisecond-duration radio transients whose origins remain unknown. As the vast majority of bursts are one-off events, it is necessary to pinpoint FRBs precisely within their host galaxies at the time of detection. Here we use two purpose-built outrigger telescopes to localize FRB 20210603A at the time of its detection by the Canadian Hydrogen Intensity Mapping Experiment (CHIME). Our very-long-baseline interferometry stations localized the burst to a 0.2\" × 2\" final ellipse in the disk of its host galaxy SDSS J004105.82+211331.9. A spatially resolved spectroscopic follow-up revealed recent star formation (Hα emission) on kiloparsec scales near the burst position. The excess dispersion measure is consistent with expectations from the nearly edge-on disk of the host galaxy, demonstrating the utility of FRBs as probes of the interstellar medium in distant galaxies. The excess dispersion measure, rotation measure and scattering are consistent with expectations for a pulse travelling from deep within its host galactic plane, strengthening the link between the local environment of FRB 20210603A and the disk of its host galaxy. Finally, this technique demonstrates a way to overcome the trade-off between angular resolution and field of view in FRB instrumentation, paving the way towards plentiful and precise FRB localizations. Two ‘outrigger’ telescopes were added to CHIME, leading to the localization at detection of FRB 20210603A. The burst originated from deep within the star-forming disk of its host galaxy.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"8 11","pages":"1429-1442"},"PeriodicalIF":12.9,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142317282","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 : 2024-09-23DOI: 10.1038/s41550-024-02363-z
A magnetic halo featuring coherent magnetized ridges several kiloparsecs above and below the Galactic Disk, and a gamma-ray counterpart, are revealed. They probably arise from outflows that are driven by star-forming regions in the Galactic Disk, 3–5 kiloparsecs from the Galactic Centre.
{"title":"Non-thermal outflows of the Milky Way traced by radio polarization and gamma-ray emission","authors":"","doi":"10.1038/s41550-024-02363-z","DOIUrl":"10.1038/s41550-024-02363-z","url":null,"abstract":"A magnetic halo featuring coherent magnetized ridges several kiloparsecs above and below the Galactic Disk, and a gamma-ray counterpart, are revealed. They probably arise from outflows that are driven by star-forming regions in the Galactic Disk, 3–5 kiloparsecs from the Galactic Centre.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"8 11","pages":"1357-1358"},"PeriodicalIF":12.9,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142276758","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 : 2024-09-23DOI: 10.1038/s41550-024-02362-0
He-Shou Zhang, Gabriele Ponti, Ettore Carretti, Ruo-Yu Liu, Mark R. Morris, Marijke Haverkorn, Nicola Locatelli, Xueying Zheng, Felix Aharonian, Hai-Ming Zhang, Yi Zhang, Giovanni Stel, Andrew Strong, Michael C. H. Yeung, Andrea Merloni
Magnetic halos of galaxies are crucial for understanding galaxy evolution, galactic-scale outflows and feedback from star formation activity. Identifying the magnetized halo of the Milky Way is challenging because of the potential contamination from foreground emission arising in local spiral arms. In addition, it is unclear how our magnetic halo is influenced by recently revealed large-scale structures such as the X-ray-emitting eROSITA Bubbles detected by the extended Roentgen Survey with an Imaging Telescope Array (eROSITA). Here we report the identification of several kiloparsec-scale magnetized structures on the basis of their polarized radio emission and their gamma-ray counterparts, which can be interpreted as the radiation of relativistic electrons in the Galactic magnetic halo. These non-thermal structures extend far above and below the Galactic plane and are spatially coincident with the thermal X-ray emission from the eROSITA Bubbles. The morphological consistency of these structures suggests a common origin, which can be sustained by Galactic outflows driven by active star-forming regions located in the Galactic Disk at 3–5 kpc from the Galactic Centre. These results reveal how X-ray-emitting and magnetized halos of spiral galaxies can be related to intense star formation activities and suggest that the X-shaped coherent magnetic structures observed in their halos can stem from galactic outflows. A magnetic galactic halo featuring coherent ridges several kiloparsecs above and below the Galactic Disk has been detected in multi-wavelength observations. The halo is probably a consequence of outflows driven by active star-forming regions in the disk.
星系的磁晕对于了解星系演化、星系尺度外流和恒星形成活动的反馈至关重要。识别银河系的磁晕具有挑战性，因为可能会受到当地旋臂产生的前景发射的污染。此外，目前还不清楚我们的磁晕是如何受到最近揭示的大尺度结构的影响的，比如由扩展伦琴巡天成像望远镜阵列（eROSITA）探测到的发射 X 射线的 eROSITA 气泡。在这里，我们报告了根据其偏振射电发射及其伽马射线对应物识别出的几个千帕秒级磁化结构，它们可以被解释为银河系磁晕中相对论电子的辐射。这些非热结构延伸到银河平面上下很远的地方，与 eROSITA 气泡的热 X 射线辐射在空间上是重合的。这些结构在形态上的一致性表明它们有一个共同的起源，那就是位于距银河中心 3-5 kpc 的银河盘中的活跃恒星形成区所驱动的银河外流。这些结果揭示了螺旋星系的X射线发射和磁化晕如何与激烈的恒星形成活动有关，并表明在其晕中观测到的X形相干磁性结构可能源于银河外流。
{"title":"A magnetized Galactic halo from inner Galaxy outflows","authors":"He-Shou Zhang, Gabriele Ponti, Ettore Carretti, Ruo-Yu Liu, Mark R. Morris, Marijke Haverkorn, Nicola Locatelli, Xueying Zheng, Felix Aharonian, Hai-Ming Zhang, Yi Zhang, Giovanni Stel, Andrew Strong, Michael C. H. Yeung, Andrea Merloni","doi":"10.1038/s41550-024-02362-0","DOIUrl":"10.1038/s41550-024-02362-0","url":null,"abstract":"Magnetic halos of galaxies are crucial for understanding galaxy evolution, galactic-scale outflows and feedback from star formation activity. Identifying the magnetized halo of the Milky Way is challenging because of the potential contamination from foreground emission arising in local spiral arms. In addition, it is unclear how our magnetic halo is influenced by recently revealed large-scale structures such as the X-ray-emitting eROSITA Bubbles detected by the extended Roentgen Survey with an Imaging Telescope Array (eROSITA). Here we report the identification of several kiloparsec-scale magnetized structures on the basis of their polarized radio emission and their gamma-ray counterparts, which can be interpreted as the radiation of relativistic electrons in the Galactic magnetic halo. These non-thermal structures extend far above and below the Galactic plane and are spatially coincident with the thermal X-ray emission from the eROSITA Bubbles. The morphological consistency of these structures suggests a common origin, which can be sustained by Galactic outflows driven by active star-forming regions located in the Galactic Disk at 3–5 kpc from the Galactic Centre. These results reveal how X-ray-emitting and magnetized halos of spiral galaxies can be related to intense star formation activities and suggest that the X-shaped coherent magnetic structures observed in their halos can stem from galactic outflows. A magnetic galactic halo featuring coherent ridges several kiloparsecs above and below the Galactic Disk has been detected in multi-wavelength observations. The halo is probably a consequence of outflows driven by active star-forming regions in the disk.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"8 11","pages":"1416-1428"},"PeriodicalIF":12.9,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142276760","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 : 2024-09-18DOI: 10.1038/s41550-024-02316-6
Lauren Schurmeier, Andrew J. Dombard
Ceres’s surface is ice-rich and warm, so we expect craters to viscously flow. Yet most of Ceres’s craters are not shallow. A new model that includes a stronger, progressively dirtier icy crust, frozen from an ancient ocean, may reconcile this discrepancy.
{"title":"Unrelaxed craters muddy the waters of the dwarf planet Ceres","authors":"Lauren Schurmeier, Andrew J. Dombard","doi":"10.1038/s41550-024-02316-6","DOIUrl":"10.1038/s41550-024-02316-6","url":null,"abstract":"Ceres’s surface is ice-rich and warm, so we expect craters to viscously flow. Yet most of Ceres’s craters are not shallow. A new model that includes a stronger, progressively dirtier icy crust, frozen from an ancient ocean, may reconcile this discrepancy.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"8 11","pages":"1352-1353"},"PeriodicalIF":12.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142236171","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 : 2024-09-18DOI: 10.1038/s41550-024-02379-5
Nature Astronomy is a selective journal whose editors examine submissions for advances in scientific understanding, robustly supported conclusions and broad relevance. Here we expound upon these criteria to help authors maximize their publication chances.
{"title":"Tips for submission success","authors":"","doi":"10.1038/s41550-024-02379-5","DOIUrl":"10.1038/s41550-024-02379-5","url":null,"abstract":"Nature Astronomy is a selective journal whose editors examine submissions for advances in scientific understanding, robustly supported conclusions and broad relevance. Here we expound upon these criteria to help authors maximize their publication chances.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"8 9","pages":"1069-1069"},"PeriodicalIF":12.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.com/articles/s41550-024-02379-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142245506","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 : 2024-09-18DOI: 10.1038/s41550-024-02360-2
Paul Woods
Adam Carnall’s BAGPIPES code grew out of necessity and has since developed into a widely used tool for fitting the spectra and photometry of galaxies, especially in the JWST era.
Adam Carnall 的 BAGPIPES 代码是在必要的情况下开发出来的，后来发展成为一种广泛使用的拟合星系光谱和光度测量的工具，尤其是在 JWST 时代。
{"title":"BAGPIPES","authors":"Paul Woods","doi":"10.1038/s41550-024-02360-2","DOIUrl":"10.1038/s41550-024-02360-2","url":null,"abstract":"Adam Carnall’s BAGPIPES code grew out of necessity and has since developed into a widely used tool for fitting the spectra and photometry of galaxies, especially in the JWST era.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"8 9","pages":"1205-1205"},"PeriodicalIF":12.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142245507","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 : 2024-09-18DOI: 10.1038/s41550-024-02339-z
P. Padovani, E. Resconi, M. Ajello, C. Bellenghi, S. Bianchi, P. Blasi, K.-Y. Huang, S. Gabici, V. Gámez Rosas, H. Niederhausen, E. Peretti, B. Eichmann, D. Guetta, A. Lamastra, T. Shimizu
We present a comprehensive multi-messenger study of NGC 1068, the prototype Seyfert II galaxy associated with high-energy neutrinos following a detection by the IceCube Neutrino Observatory. Various aspects of the source, including its nuclear activity, jet, outflow and starburst region, are analysed in detail using a multi-wavelength approach and relevant luminosities are derived. We then explore its γ-ray and neutrino emissions and investigate the potential mechanisms underlying these phenomena and their relations with the different astrophysical components to try to understand which is responsible for the IceCube neutrinos. By first using simple order-of-magnitude arguments and then applying specific theoretical models, we infer that only the region close to the accretion disk around the supermassive black hole has the right density of both the X-ray photons needed to provide the targets for protons to sustain neutrino production and the optical/infrared photons required to absorb the associated, but unobserved, γ-rays. We conclude by highlighting ongoing efforts to constrain a possible broad connection between neutrinos and active galactic nuclei, as well as future synergies between astronomical and neutrino facilities. Observations of the galaxy NGC 1068 in different wavebands are brought together in a multi-messenger case study, exploring the potential origin and mechanisms responsible for the recently detected neutrino emission from this source.
冰立方中微子天文台（IceCube Neutrino Observatory）探测到一个与高能中微子有关的赛弗特II星系原型--NGC 1068，我们将对该星系进行全面的多信使研究。我们采用多波长方法详细分析了该源的各个方面，包括其核活动、喷流、流出和星爆区域，并得出了相关光度。然后，我们探究了它的γ射线和中微子辐射，并研究了这些现象的潜在机制及其与不同天体物理成分的关系，试图了解冰立方中微子是由哪些因素引起的。通过首先使用简单的量级论证，然后应用具体的理论模型，我们推断出只有靠近超大质量黑洞周围吸积盘的区域才同时拥有适当密度的 X 射线光子和光学/红外光子，前者需要为质子提供目标以维持中微子的产生，后者需要吸收相关但未被观测到的γ 射线。最后，我们将重点介绍目前正在努力探索中微子与活动星系核之间可能存在的广泛联系，以及未来天文设施与中微子设施之间的协同作用。
{"title":"High-energy neutrinos from the vicinity of the supermassive black hole in NGC 1068","authors":"P. Padovani, E. Resconi, M. Ajello, C. Bellenghi, S. Bianchi, P. Blasi, K.-Y. Huang, S. Gabici, V. Gámez Rosas, H. Niederhausen, E. Peretti, B. Eichmann, D. Guetta, A. Lamastra, T. Shimizu","doi":"10.1038/s41550-024-02339-z","DOIUrl":"10.1038/s41550-024-02339-z","url":null,"abstract":"We present a comprehensive multi-messenger study of NGC 1068, the prototype Seyfert II galaxy associated with high-energy neutrinos following a detection by the IceCube Neutrino Observatory. Various aspects of the source, including its nuclear activity, jet, outflow and starburst region, are analysed in detail using a multi-wavelength approach and relevant luminosities are derived. We then explore its γ-ray and neutrino emissions and investigate the potential mechanisms underlying these phenomena and their relations with the different astrophysical components to try to understand which is responsible for the IceCube neutrinos. By first using simple order-of-magnitude arguments and then applying specific theoretical models, we infer that only the region close to the accretion disk around the supermassive black hole has the right density of both the X-ray photons needed to provide the targets for protons to sustain neutrino production and the optical/infrared photons required to absorb the associated, but unobserved, γ-rays. We conclude by highlighting ongoing efforts to constrain a possible broad connection between neutrinos and active galactic nuclei, as well as future synergies between astronomical and neutrino facilities. Observations of the galaxy NGC 1068 in different wavebands are brought together in a multi-messenger case study, exploring the potential origin and mechanisms responsible for the recently detected neutrino emission from this source.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"8 9","pages":"1077-1087"},"PeriodicalIF":12.9,"publicationDate":"2024-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142245508","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 : 2024-09-18DOI: 10.1038/s41550-024-02350-4
I. F. Pamerleau, M. M. Sori, J. E. C. Scully
Ceres is a key object in understanding the evolution of small bodies and is the only dwarf planet to have been orbited by a spacecraft, NASA’s Dawn mission. Dawn data paint an inconclusive picture of Ceres’ internal structure, composition and evolutionary pathway: crater morphology and gravity inversions suggest an ice-rich interior, while a lack of extensive crater relaxation argues for low ice content. Here we resolve this discrepancy by applying an ice rheology that includes effects of impurities on grain boundary sliding to finite element method simulations of Cerean craters. We show that Ceres can maintain its cratered topography while also having an ice-rich crust. Our simulations show that a crust with ~90% ice near the surface, which gradually decreases to 0% at 117 km depth, simultaneously matches the observed lack of crater relaxation, observed crater morphology and gravity inversions. This crustal structure results from a frozen ocean that became more impurity rich as it solidified top-down. Therefore, the Dawn data are consistent with an icy Ceres that evolved through freezing of an ancient, impure ocean. An ice-rich crust with increasing silicate content with depth is consistent with Ceres’ crater morphology, lack of crater relaxation and gravity inversions. This structure has a higher ice content than previously expected and could form from a relic ocean.
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