Nature Astronomy最新文献_第6页

Deimos’s shape and geology explained by a subcatastrophic impact 火卫二的形状和地质可以用次灾难性撞击来解释

IF 14.1 1区物理与天体物理

Nature Astronomy Pub Date : 2026-08-18 DOI: 10.1038/s41550-026-02956-w

S. D. Raducan, H. F. Agrusa, E. Asphaug, C. M. Ernst, M. Jutzi, P. Michel, M. Popescu, S. Sugita

{"title":"Deimos’s shape and geology explained by a subcatastrophic impact","authors":"S. D. Raducan, H. F. Agrusa, E. Asphaug, C. M. Ernst, M. Jutzi, P. Michel, M. Popescu, S. Sugita","doi":"10.1038/s41550-026-02956-w","DOIUrl":"https://doi.org/10.1038/s41550-026-02956-w","url":null,"abstract":"Small planetary bodies record the processes that shaped the Solar System, but their surfaces and interiors often evolve in unexpected ways. Deimos, the potato-shaped, 12-km-diameter outer satellite of Mars, has a strikingly smooth surface covered by fine regolith, in contrast to its heavily cratered and grooved sibling, 22-km-diameter Phobos. Moreover, Deimos’s topography is dominated by a single large south-polar depression, whose formation we simulate to constrain the moon’s interior and surface geomechanical properties and to explain the origin and distribution of its regolith. Here we find that an oblique impact by a 320-m-diameter projectile can quantitatively account for this depression, the global regolith layer and surface features such as bright streaks and crater infill. Our results show that Deimos’s upper layers are extremely weak and that its interior is highly porous and dissipative, resembling the recently visited rubble-pile asteroids rather than lunar regolith. This suggests that small dark moons and asteroids, despite their specific histories, may converge on similar physical states.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"20 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148769288","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}

引用次数: 0

Hidden mass in early galaxies revealed by bottom-heavy initial mass functions 由底重初始质量函数揭示的早期星系中的隐藏质量

IF 14.1 1区物理与天体物理

Nature Astronomy Pub Date : 2026-08-18 DOI: 10.1038/s41550-026-02932-4

Chloe M. Cheng, Martje Slob, Mariska Kriek, Aliza G. Beverage, Pieter G. van Dokkum, Rachel Bezanson, Gabriel Brammer, Charlie Conroy, Anna de Graaff, Elham Eftekhari, Robert Feldmann, Wout M. Goesaert, Meng Gu, Joel Leja, Brian Lorenz, Pavel E. Mancera Piña, Ignacio Martín-Navarro, Andrew B. Newman, Sedona H. Price, Alice E. Shapley, Piyush Sharda, Katherine A. Suess, Arjen van der Wel, Daniel R. Weisz

{"title":"Hidden mass in early galaxies revealed by bottom-heavy initial mass functions","authors":"Chloe M. Cheng, Martje Slob, Mariska Kriek, Aliza G. Beverage, Pieter G. van Dokkum, Rachel Bezanson, Gabriel Brammer, Charlie Conroy, Anna de Graaff, Elham Eftekhari, Robert Feldmann, Wout M. Goesaert, Meng Gu, Joel Leja, Brian Lorenz, Pavel E. Mancera Piña, Ignacio Martín-Navarro, Andrew B. Newman, Sedona H. Price, Alice E. Shapley, Piyush Sharda, Katherine A. Suess, Arjen van der Wel, Daniel R. Weisz","doi":"10.1038/s41550-026-02932-4","DOIUrl":"https://doi.org/10.1038/s41550-026-02932-4","url":null,"abstract":"James Webb Space Telescope (JWST) observations have revealed that massive galaxies formed and evolved faster than predicted by galaxy formation models, with many having already assembled a large mass in stars approximately 12 billion years ago. However, masses of distant galaxies are uncertain, as they assume a distribution of stellar birth masses (the initial mass function (IMF)) similar to that in the Milky Way. Specifically, the contribution from low-mass stars, which make up the bulk of stellar mass, is not directly observed but inferred on the basis of an extrapolation of the Milky Way IMF. Here, we provide robust constraints on the low-mass IMF beyond the local Universe from full-spectrum models. Using ultra-deep spectra of nine massive quiescent galaxies at redshift z ≈ 0.7 from the JWST Initial Mass Function of Early Red NIRSpec Objects program, extended to bluer wavelengths with deep Very Large Telescope Large Early Galaxy Astrophysics Census spectra, we find that the most massive galaxies have excess low-mass stars. Remarkably, our oldest galaxy (formation redshift, zform > 5) has the most bottom-heavy IMF. This galaxy may be a descendant of JWST’s ‘impossibly early’ galaxies, implying that the latter may have had similarly bottom-heavy IMFs, increasing their masses by a factor of approximately 4 ± 1. Our findings may thus amplify the tension with galaxy formation models.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"31 1","pages":""},"PeriodicalIF":14.1,"publicationDate":"2026-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148769289","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}

引用次数: 0

Evidence of a massive accretion event 1.8 billion years before the Gaia-Sausage-Enceladus merger 盖亚-香肠-土卫二合并前18亿年前的一次大规模吸积事件的证据

IF 15.2 1区物理与天体物理

Nature Astronomy Pub Date : 2026-08-17 DOI: 10.1038/s41550-026-02931-5

Davide Massari, Chiara Zerbinati, Cristiano Fanelli, Amina Helmi, Edoardo Ceccarelli, Fernando Aguado-Agelet, Santi Cassisi, Ewoud Wempe, Matteo Monelli, Andrea Bellini, Thomas M. Callingham, Hanneke C. Woudenberg, Roger E. Cohen, Carme Gallart, Elena Pancino, Sara Saracino, Maurizio Salaris, Alessio Mucciarelli

{"title":"Evidence of a massive accretion event 1.8 billion years before the Gaia-Sausage-Enceladus merger","authors":"Davide Massari, Chiara Zerbinati, Cristiano Fanelli, Amina Helmi, Edoardo Ceccarelli, Fernando Aguado-Agelet, Santi Cassisi, Ewoud Wempe, Matteo Monelli, Andrea Bellini, Thomas M. Callingham, Hanneke C. Woudenberg, Roger E. Cohen, Carme Gallart, Elena Pancino, Sara Saracino, Maurizio Salaris, Alessio Mucciarelli","doi":"10.1038/s41550-026-02931-5","DOIUrl":"10.1038/s41550-026-02931-5","url":null,"abstract":"The merger history of the Galaxy has been traced back firmly to a redshift of 2 (10 billion years ago). While evidence for the existence of at least one more substantial merger before this time has been presented, its interpretation is yet to be fully established. Here we show that the population of globular clusters around the Galaxy depicts three distinct age–metallicity sequences, one associated with the progenitor of the Milky Way, one with the merger with Gaia-Sausage-Enceladus 10 billion years ago and a third intermediate sequence associated with at least one merger that we estimate took place about 1.8 billion years before Gaia-Sausage-Enceladus. This discovery has been possible thanks to exquisite Hubble Space Telescope data and sophisticated analysis that enables very precise relative age determination of globular clusters. The newly identified sequence reveals that this merger took place with an object of a similar stellar mass to that of Gaia-Sausage-Enceladus (≃5 × 108 stellar masses, M⊙) that deposited most of its mass in the inner 6 kpc of the Milky Way. The identification of a third merger event in the inner Galaxy puts to rest earlier debates and, honouring previous works, we name the progenitor system Low-energy-Kraken-Heracles, or LKH for short. By studying the dynamical properties, age and metallicity of globular clusters in the inner Galaxy, the authors found evidence of a massive dwarf galaxy that was accreted by the Milky Way 1.8 billion years earlier than the Gaia-Sausage-Enceladus merger.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"10 10","pages":"1570-1577"},"PeriodicalIF":15.2,"publicationDate":"2026-08-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.nature.comhttps://www.nature.com/articles/s41550-026-02931-5.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149177771","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}

引用次数: 0

Astro-tourism as a model for participatory science engagement 作为参与式科学参与模式的天文旅游

IF 15.2 1区物理与天体物理

Nature Astronomy Pub Date : 2026-08-14 DOI: 10.1038/s41550-026-02944-0

Anton Binneman

引用次数: 0

Author Correction: Detection of a four-carbon sugar in interstellar space 作者更正：在星际空间检测到一种四碳糖

IF 15.2 1区物理与天体物理

Nature Astronomy Pub Date : 2026-08-14 DOI: 10.1038/s41550-026-02974-8

Izaskun Jiménez-Serra, Juan García de la Concepción, Herma M. Cuppen, Marta Rey-Montejo, Miguel Sanz-Novo, Víctor M. Rivilla, Jesús Martín-Pintado, Andrés Megías, Carlos Briones, David San Andrés, Laura Colzi, Shaoshan Zeng, Sergio Martín, Joseph Salaris, Antonio Martínez-Henares, Álvaro López-Gallifa, Miguel Angel Requena-Torres, Belén Tercero, Pablo de Vicente, Aran Insausti, Elena R. Alonso, Emilio J. Cocinero

引用次数: 0

No kinematics, no problem 没有运动学，没有问题

IF 15.2 1区物理与天体物理

Nature Astronomy Pub Date : 2026-08-14 DOI: 10.1038/s41550-026-02960-0

Lindsay Oldham

引用次数: 0

The CosmoCube lunar mission for probing the dark ages and cosmic dawn via 21-cm cosmology “宇宙立方体”月球任务，通过21厘米宇宙学探测黑暗时代和宇宙黎明

IF 15.2 1区物理与天体物理

Nature Astronomy Pub Date : 2026-08-14 DOI: 10.1038/s41550-026-02946-y

Eloy de lera Acedo, David Bacon, Will Grainger, Dominic Anstey, Harry Bevins, Lucinda King, Kaan Artuc, Mohammed Al-Badri, Chris Pearson, Suresh Balaji, Richard Holdaway, Judd Bowman, Daniel Jacobs, Theodora Varelidi-Strati, Steve Eckersley, Abigail Harvey, Andrea Turconi, Ana-Maria Dorobat, Andri M. Gretarsson, Yabin Liao, Xan Morice-Atkinson, Olugbenga Olumodimu

{"title":"The CosmoCube lunar mission for probing the dark ages and cosmic dawn via 21-cm cosmology","authors":"Eloy de lera Acedo, David Bacon, Will Grainger, Dominic Anstey, Harry Bevins, Lucinda King, Kaan Artuc, Mohammed Al-Badri, Chris Pearson, Suresh Balaji, Richard Holdaway, Judd Bowman, Daniel Jacobs, Theodora Varelidi-Strati, Steve Eckersley, Abigail Harvey, Andrea Turconi, Ana-Maria Dorobat, Andri M. Gretarsson, Yabin Liao, Xan Morice-Atkinson, Olugbenga Olumodimu","doi":"10.1038/s41550-026-02946-y","DOIUrl":"10.1038/s41550-026-02946-y","url":null,"abstract":"The Universe between recombination (redshift z ≈ 1,000 or 400,000 years after the Big Bang) and the later formation of the first generation of stars at z ≈ 30 to 12 (~100 to 300 million years after the Big Bang) remains largely unexplored. During these epochs, the Universe was filled with diffuse neutral hydrogen. Studying this ‘dark age’ and ‘cosmic dawn’ before the reionization by early galaxies is crucial for understanding fundamental cosmological concepts, including dark matter and cosmic structure formation. Observations of the 21-cm line emitted by neutral hydrogen are key, but ground-based radio telescopes face challenges such as radiofrequency interference and atmospheric effects, which effectively prevent observations below ~45 MHz, thereby missing the dark ages. Here we propose the cost-effective CosmoCube lunar mission, which could overcome these limitations by conducting observations from the far side of the Moon’s orbit launching in only a few years, before the spectrum from the far side of the Moon is contaminated by human-made radio signals. The cost-effective CosmoCube mission is proposed to observe the 21-cm line emitted by neutral hydrogen from the relatively uncontaminated radio environment of the far side of the Moon.","PeriodicalId":18778,"journal":{"name":"Nature Astronomy","volume":"10 8","pages":"1097-1106"},"PeriodicalIF":15.2,"publicationDate":"2026-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"148754325","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}

引用次数: 0

A lunar radio astronomy array built in Africa 在非洲建造的月球射电天文阵列

IF 15.2 1区物理与天体物理

Nature Astronomy Pub Date : 2026-08-14 DOI: 10.1038/s41550-026-02949-9

Adriana Marais, Carla Sharpe Mitchell, Eugene Avenant, Hendrik Burger, Michael Johnston, Thomas Küsel, Japie Ludick, Oleg Smirnov

引用次数: 0

What are you doing here? 你在这里做什么？

IF 15.2 1区物理与天体物理

Nature Astronomy Pub Date : 2026-08-14 DOI: 10.1038/s41550-026-02963-x

引用次数: 0

A hidden companion on Orion’s shoulder 一个隐藏在猎户座肩膀上的同伴

IF 15.2 1区物理与天体物理