IF 2.5 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus

Pub Date : 2024-09-23 DOI: 10.1016/j.icarus.2024.116323

Hannah R. Sanderson , James F.J. Bryson , Claire I.O. Nichols , Christopher J. Davies

The thermal and magnetic histories of planetesimals provide unique insights into the formation and evolution of Earth’s building blocks. These histories can be gleaned from meteorites by using numerical models to translate measured properties into planetesimal behaviour. In this paper, we present a new 1D planetesimal thermal evolution and dynamo generation model. This magnetic field generation model is the first of a differentiated, mantled planetesimal that includes both mantle convection and sub-eutectic core solidification. We have improved fundamental aspects of mantle heat transport by including a more detailed viscosity model and stagnant lid convection parametrisations consistent with internal heating. We have also added radiogenic heating from ⁶⁰Fe in the metallic Fe-FeS core. Additionally, we implement a combined thermal and compositional buoyancy flux, as well as the latest magnetic field scaling laws to predict magnetic field strengths during the planetesimal’s thermal evolution until core solidification is complete. We illustrate the consequences of our model changes with an example run for a 500 km radius planetesimal. These effects include more rapid erosion of core thermal stratification and longer duration of mantle convection compared to previous studies. The additional buoyancy from core solidification has a marginal effect on dynamo strength, but for some initial core sulfur contents it can prevent cessation of the dynamo when mantle convection ends. Our model can be used to investigate the effects of individual parameters on dynamo generation and constrain properties of specific meteorite parent bodies. Combined, these updates mean this model can predict the most reliable and complete magnetic field history for a planetesimal to date, so is a valuable tool for deciphering planetesimal behaviour from meteorite properties.

行星碎块的热历史和磁性历史为了解地球组成元素的形成和演变提供了独特的视角。通过使用数值模型将测量到的特性转化为行星的行为，可以从陨石中收集到这些历史。在本文中，我们提出了一个新的一维行星热演化和动力生成模型。这个磁场生成模型是第一个包含地幔对流和亚共晶内核凝固的分化幔状行星模型。我们改进了地幔热传输的基本方面，包括一个更详细的粘度模型和与内部加热一致的停滞盖对流参数。我们还增加了金属铁-铁-硒内核中 60Fe 的辐射加热。此外，我们还采用了热浮力通量和成分浮力通量的组合，以及最新的磁场缩放定律来预测行星热演化过程中的磁场强度，直到内核凝固完成。我们以一个半径为 500 公里的行星为例，说明了模型变化的后果。与以前的研究相比，这些影响包括内核热分层侵蚀更快，地幔对流持续时间更长。内核凝固产生的额外浮力对动力强度的影响微乎其微，但对于某些初始内核硫含量，它可以防止地幔对流结束时动力停止。我们的模型可用于研究单个参数对动力生成的影响，并约束特定陨石母体的属性。这些更新意味着这个模型可以预测迄今为止最可靠和最完整的行星磁场历史，因此是一个从陨石特性来解读行星行为的宝贵工具。

{"title":"Unlocking planetesimal magnetic field histories: A refined, versatile model for thermal evolution and dynamo generation","authors":"Hannah R. Sanderson , James F.J. Bryson , Claire I.O. Nichols , Christopher J. Davies","doi":"10.1016/j.icarus.2024.116323","DOIUrl":"10.1016/j.icarus.2024.116323","url":null,"abstract":"<div><div>The thermal and magnetic histories of planetesimals provide unique insights into the formation and evolution of Earth’s building blocks. These histories can be gleaned from meteorites by using numerical models to translate measured properties into planetesimal behaviour. In this paper, we present a new 1D planetesimal thermal evolution and dynamo generation model. This magnetic field generation model is the first of a differentiated, mantled planetesimal that includes both mantle convection and sub-eutectic core solidification. We have improved fundamental aspects of mantle heat transport by including a more detailed viscosity model and stagnant lid convection parametrisations consistent with internal heating. We have also added radiogenic heating from <sup>60</sup>Fe in the metallic Fe-FeS core. Additionally, we implement a combined thermal and compositional buoyancy flux, as well as the latest magnetic field scaling laws to predict magnetic field strengths during the planetesimal’s thermal evolution until core solidification is complete. We illustrate the consequences of our model changes with an example run for a 500km radius planetesimal. These effects include more rapid erosion of core thermal stratification and longer duration of mantle convection compared to previous studies. The additional buoyancy from core solidification has a marginal effect on dynamo strength, but for some initial core sulfur contents it can prevent cessation of the dynamo when mantle convection ends. Our model can be used to investigate the effects of individual parameters on dynamo generation and constrain properties of specific meteorite parent bodies. Combined, these updates mean this model can predict the most reliable and complete magnetic field history for a planetesimal to date, so is a valuable tool for deciphering planetesimal behaviour from meteorite properties.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"425 ","pages":"Article 116323"},"PeriodicalIF":2.5,"publicationDate":"2024-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142356766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Low temperature phase transitions in the visible and near-infrared (VNIR) reflectance spectra of (NH4)2HPO4 and (NH4)HSO4 salts (NH4)2HPO4 和 (NH4)HSO4 盐的可见光和近红外 (VNIR) 反射光谱中的低温相变

IF 2.5 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus

Pub Date : 2024-09-21 DOI: 10.1016/j.icarus.2024.116321

M. Fastelli , B. Schmitt , P. Beck , O. Poch , A. Zucchini , P. Comodi

The detection of ammonium bearing crystalline solids in salt-water systems on icy bodies and solar system bodies could provide information about the ascent of these salts from a deep reservoir within the hydrosphere. Due to their chemical-physical properties, NH₄⁺ compounds play a key role both in the internal dynamics of celestial bodies and in the potential habitability of ocean worlds. In this work we analysed the reflectance spectra of two synthetic NH₄⁺ salts: ammonium hydrogen phosphate (NH₄)₂HPO₄ and ammonium hydrogen sulphate (NH₄)HSO₄ in the 1–4.2 μm spectral range at low temperature, between 110 and 290 K. For (NH₄)₂HPO₄ we also examined the effect of three different grain sizes (150–125 μm; 125–80 μm; 80–32 μm). The collected reflectance spectra show absorption features related to NH₄⁺ group overtone and combination modes in the 1–2.5 μm range. In particular, the bands located at ∼1.09 μm (3ν₃), ∼1.30 μm (2ν₃ + ν₄), ∼1.58 μm (2ν₃), ∼2.02 μm (ν₂ + v₃) and ∼ 2.2 μm (v₃ + v₄) could be useful to discriminate these salts. The low temperature spectra, compared to those at ambient temperature, reveal finer structures, displaying sharper and narrower absorption bands. The selected NH₄⁺-bearing salts are subjected to reversible low temperature phase transitions, which are revealed in the spectra by a progressive growth and shift of the bands toward shorter wavelengths with a drastic change of their depth. We performed laboratory measurements of ammonium (NH₄⁺) compounds to address the limited data available expanding the existing database. The collected cryogenic spectra can be directly compared with remote sensing data from planetary missions of the upcoming decade such as NASA's Europa Clipper, and ESA's JUICE and the newly launched James Webb Space Telescope expanding the existing database of ammonium compounds at cryogenic temperature.

在冰冻天体和太阳系天体的盐水系统中探测到含铵的结晶固体，可以提供有关这些盐类从水圈内的深层水库上升的信息。由于其化学物理特性，NH4+化合物在天体内部动力学和海洋世界的潜在可居住性方面都发挥着关键作用。在这项研究中，我们分析了两种合成 NH4+ 盐类的反射光谱：磷酸氢铵 (NH4)2HPO4 和硫酸氢铵 (NH4)HSO4，它们在 110 至 290 K 低温条件下的 1-4.2 μm 光谱范围内。收集到的反射光谱显示出与 1-2.5 μm 范围内 NH4+ 族泛音和组合模式有关的吸收特征。尤其是位于 ∼1.09 μm (3ν3)、∼1.30 μm (2ν3 + ν4)、∼1.58 μm (2ν3)、∼2.02 μm (ν2 + v3) 和 ∼ 2.2 μm (v3 + v4) 处的波段可用于区分这些盐类。与环境温度下的光谱相比，低温光谱显示出更精细的结构，显示出更清晰和更窄的吸收带。被选中的含 NH4+ 的盐类会发生可逆的低温相变，这在光谱中表现为波段的逐渐增长和向短波长的移动，以及波段深度的急剧变化。我们对铵（NH4+）化合物进行了实验室测量，以解决现有数据库中数据有限的问题。收集到的低温光谱可直接与未来十年行星任务（如美国国家航空航天局的欧罗巴号快船、欧空局的 JUICE 和新发射的詹姆斯-韦伯太空望远镜）的遥感数据进行比较，从而扩展现有的低温铵化合物数据库。

{"title":"Low temperature phase transitions in the visible and near-infrared (VNIR) reflectance spectra of (NH4)2HPO4 and (NH4)HSO4 salts","authors":"M. Fastelli , B. Schmitt , P. Beck , O. Poch , A. Zucchini , P. Comodi","doi":"10.1016/j.icarus.2024.116321","DOIUrl":"10.1016/j.icarus.2024.116321","url":null,"abstract":"<div><div>The detection of ammonium bearing crystalline solids in salt-water systems on icy bodies and solar system bodies could provide information about the ascent of these salts from a deep reservoir within the hydrosphere. Due to their chemical-physical properties, NH<sub>4</sub><sup>+</sup> compounds play a key role both in the internal dynamics of celestial bodies and in the potential habitability of ocean worlds. In this work we analysed the reflectance spectra of two synthetic NH<sub>4</sub><sup>+</sup> salts: ammonium hydrogen phosphate (NH<sub>4</sub>)<sub>2</sub>HPO<sub>4</sub> and ammonium hydrogen sulphate (NH<sub>4</sub>)HSO<sub>4</sub> in the 1–4.2 μm spectral range at low temperature, between 110 and 290 K. For (NH<sub>4</sub>)<sub>2</sub>HPO<sub>4</sub> we also examined the effect of three different grain sizes (150–125 μm; 125–80 μm; 80–32 μm). The collected reflectance spectra show absorption features related to NH<sub>4</sub><sup>+</sup> group overtone and combination modes in the 1–2.5 μm range. In particular, the bands located at ∼1.09 μm (3ν<sub>3</sub>), ∼1.30 μm (2ν<sub>3</sub> + ν<sub>4</sub>), ∼1.58 μm (2ν<sub>3</sub>), ∼2.02 μm (ν<sub>2</sub> + v<sub>3</sub>) and ∼ 2.2 μm (<em>v</em><sub>3</sub> + v<sub>4</sub>) could be useful to discriminate these salts. The low temperature spectra, compared to those at ambient temperature, reveal finer structures, displaying sharper and narrower absorption bands. The selected NH<sub>4</sub><sup>+</sup>-bearing salts are subjected to reversible low temperature phase transitions, which are revealed in the spectra by a progressive growth and shift of the bands toward shorter wavelengths with a drastic change of their depth. We performed laboratory measurements of ammonium (NH<sub>4</sub><sup>+</sup>) compounds to address the limited data available expanding the existing database. The collected cryogenic spectra can be directly compared with remote sensing data from planetary missions of the upcoming decade such as NASA's Europa Clipper, and ESA's JUICE and the newly launched James Webb Space Telescope expanding the existing database of ammonium compounds at cryogenic temperature.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"425 ","pages":"Article 116321"},"PeriodicalIF":2.5,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142326803","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}

引用次数: 0

Refined 70-cm earth-based lunar radar maps and a new interpretation of the Cruger-Sirsalis cryptomare 经改进的 70 厘米地基月球雷达图和对 Cruger-Sirsalis 隐星的新解释

IF 2.5 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus

Pub Date : 2024-09-21 DOI: 10.1016/j.icarus.2024.116324

Bruce A. Campbell , Erica R. Jawin , Gareth A. Morgan

We present a new processing approach for Earth-based, 70-cm wavelength, dual-polarization radar data collected using the Arecibo and Green Bank Telescopes. Earth-based data represent the only view of the Moon at this wavelength. This methodology greatly improves the synthetic aperture focusing of the images to their best possible spatial resolution, with a concurrent improvement in signal-to-noise ratio and multi-look summing. Image coverage is also expanded to the full illuminated beam area. Registration to a visible image basemap reduces RMS geographic placement errors to less than ∼2 km. Images collected after the first Planetary Data System archive delivery are also included. Analysis of the circular polarization ratio (CPR) suggests an uncertainty of ∼20 %, based on the likely ∼1 dB error in estimating the background noise in a radar look. We use the new 70-cm maps with topography and 12.6-cm radar images to revisit an initial study of cryptomare units in the Cruger-Sirsalis region, and find that mare contamination of the Orientale ejecta must be well-mixed with highland material, as opposed to the earlier hypothesis of a highland-dominated blanket over mare-rich regolith. This result shows that the two radar wavelengths provide a more complete view of the cryptomare regolith cross section, and that radar signatures can delineate ilmenite contamination of highlands areas where multi-spectral methods are limited by other factors.

我们介绍了一种新的处理方法，用于处理利用阿雷西博望远镜和绿岸望远镜收集的基于地球的 70 厘米波长双极化雷达数据。地基数据是该波长唯一的月球观测数据。这种方法大大提高了合成孔径聚焦图像的空间分辨率，同时改善了信噪比和多视角求和。图像覆盖范围也扩大到整个光束照射区域。与可见光图像基图配准后，地理位置的均方根误差减小到 2 千米以下。首次行星数据系统档案交付后收集的图像也包括在内。对圆偏振比（CPR）的分析表明，根据雷达观测中估计背景噪声可能存在的∼1 dB误差，其不确定性为∼20%。我们利用新的 70 厘米地形图和 12.6 厘米雷达图像，重新审视了对 Cruger-Sirsalis 地区隐粒岩单元的初步研究，发现东方谷喷出岩的母岩污染必须与高地物质充分混合，而不是像以前假设的那样，在富含母岩的碎屑岩上覆盖着一层以高地为主的毯子。这一结果表明，两种波长的雷达能够更全面地观察隐伏累加岩的横截面，雷达特征能够在多光谱方法受到其他因素限制的情况下，确定高地地区的钛铁矿污染情况。

{"title":"Refined 70-cm earth-based lunar radar maps and a new interpretation of the Cruger-Sirsalis cryptomare","authors":"Bruce A. Campbell , Erica R. Jawin , Gareth A. Morgan","doi":"10.1016/j.icarus.2024.116324","DOIUrl":"10.1016/j.icarus.2024.116324","url":null,"abstract":"<div><div>We present a new processing approach for Earth-based, 70-cm wavelength, dual-polarization radar data collected using the Arecibo and Green Bank Telescopes. Earth-based data represent the only view of the Moon at this wavelength. This methodology greatly improves the synthetic aperture focusing of the images to their best possible spatial resolution, with a concurrent improvement in signal-to-noise ratio and multi-look summing. Image coverage is also expanded to the full illuminated beam area. Registration to a visible image basemap reduces RMS geographic placement errors to less than ∼2 km. Images collected after the first Planetary Data System archive delivery are also included. Analysis of the circular polarization ratio (CPR) suggests an uncertainty of ∼20 %, based on the likely ∼1 dB error in estimating the background noise in a radar look. We use the new 70-cm maps with topography and 12.6-cm radar images to revisit an initial study of cryptomare units in the Cruger-Sirsalis region, and find that mare contamination of the Orientale ejecta must be well-mixed with highland material, as opposed to the earlier hypothesis of a highland-dominated blanket over mare-rich regolith. This result shows that the two radar wavelengths provide a more complete view of the cryptomare regolith cross section, and that radar signatures can delineate ilmenite contamination of highlands areas where multi-spectral methods are limited by other factors.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"425 ","pages":"Article 116324"},"PeriodicalIF":2.5,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142356762","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}

引用次数: 0

Morphometry and kinematics correlation of wrinkle ridges on Mars: Insights from Trishear modelling 火星皱纹脊的形态和运动学相关性：特里谢尔建模的启示

IF 2.5 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus

Pub Date : 2024-09-21 DOI: 10.1016/j.icarus.2024.116330

F. Carboni, O. Karagoz, T. Kenkmann

Wrinkle ridges are among the most common and controversial compressional tectonic structures on terrestrial planets. While their origins are well inferred to be related to crustal shortening driven by compressional stress, their subsurface characterization is still a matter of debate. Open questions remain about the geometry, number, structural style and kinematics of faults promoting wrinkle ridges. We use the Trishear and Fault-Parallel-Flow integrated forward kinematic modelling to model wrinkle ridges related faults. This is achieved through a series of balanced cross sections and a consequent set of narrow 3D models. We perform a detail kinematic analysis on nine wrinkle ridges: six are located in the circum-Tharsis regions of Lunae Planum and Solis Planum, while three are located in the Hellas Planitia, Hesperia Planum and Syrtis Major Planum, respectively. The applied methodology allows us to quantitatively assess wrinkle ridges geometry and kinematics, and to correlate them with morphometric parameters (i.e., width and relief). Our results indicate how wrinkle ridges tectonics can be characterized by a more complex array of faults than previously modelled. This leads to a total amount of horizontal shortening accommodated differently depending on the number and type of faults (i.e., main fault, backthrust, synthetic faults). The location and geometry of the modelled faults suggest the presence of multiple detachments at different depths and with different mechanical behaviors such as weaker and more frictional décollements, which are likely found within sedimentary interlayers. The amount of shortening, the fault geometry and spacing, as well as the upper faults tips depth are positively correlated with major morphometric parameters of wrinkle ridges topography.

皱褶脊是陆地行星上最常见也是最有争议的压缩构造结构之一。虽然它们的起源被很好地推断为与压缩应力驱动的地壳缩短有关，但它们的地下特征仍然是一个有争议的问题。关于促进皱纹脊的断层的几何形状、数量、结构风格和运动学，仍有许多问题有待解决。我们采用特里舍尔（Trishear）和断层-平行流（Fault-Parallel-Flow）综合前向运动学模型来模拟与皱脊有关的断层。这是通过一系列平衡截面和随之产生的一组狭窄三维模型来实现的。我们对 9 条皱脊进行了详细的运动学分析：其中 6 条位于 Lunae Planum 和 Solis Planum 的环塔西斯地区，另外 3 条分别位于 Hellas Planitia、Hesperia Planum 和 Syrtis Major Planum。应用该方法，我们可以对皱脊的几何形状和运动学进行定量评估，并将它们与形态测量参数（即宽度和起伏）联系起来。我们的研究结果表明，皱脊构造的特点是断层阵列比以前的模型更为复杂。这导致水平缩短的总量因断层的数量和类型（即主断层、反推断层、合成断层）的不同而不同。模拟断层的位置和几何形状表明，在不同深度存在多个脱离层，且具有不同的力学行为，如摩擦力较弱和摩擦力较大的脱离层，这些脱离层很可能存在于沉积夹层中。缩短量、断层几何形状和间距以及上断层尖端深度与皱脊地形的主要形态参数呈正相关。

{"title":"Morphometry and kinematics correlation of wrinkle ridges on Mars: Insights from Trishear modelling","authors":"F. Carboni, O. Karagoz, T. Kenkmann","doi":"10.1016/j.icarus.2024.116330","DOIUrl":"10.1016/j.icarus.2024.116330","url":null,"abstract":"<div><div>Wrinkle ridges are among the most common and controversial compressional tectonic structures on terrestrial planets. While their origins are well inferred to be related to crustal shortening driven by compressional stress, their subsurface characterization is still a matter of debate. Open questions remain about the geometry, number, structural style and kinematics of faults promoting wrinkle ridges. We use the Trishear and Fault-Parallel-Flow integrated forward kinematic modelling to model wrinkle ridges related faults. This is achieved through a series of balanced cross sections and a consequent set of narrow 3D models. We perform a detail kinematic analysis on nine wrinkle ridges: six are located in the circum-Tharsis regions of Lunae Planum and Solis Planum, while three are located in the Hellas Planitia, Hesperia Planum and Syrtis Major Planum, respectively. The applied methodology allows us to quantitatively assess wrinkle ridges geometry and kinematics, and to correlate them with morphometric parameters (i.e., width and relief). Our results indicate how wrinkle ridges tectonics can be characterized by a more complex array of faults than previously modelled. This leads to a total amount of horizontal shortening accommodated differently depending on the number and type of faults (i.e., main fault, backthrust, synthetic faults). The location and geometry of the modelled faults suggest the presence of multiple detachments at different depths and with different mechanical behaviors such as weaker and more frictional décollements, which are likely found within sedimentary interlayers. The amount of shortening, the fault geometry and spacing, as well as the upper faults tips depth are positively correlated with major morphometric parameters of wrinkle ridges topography.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"425 ","pages":"Article 116330"},"PeriodicalIF":2.5,"publicationDate":"2024-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Chandrayaan-3 landing site evolution by South Pole-Aitken basin and other impact craters 按南极-艾特肯盆地和其他撞击坑划分的钱德拉雅安-3 号着陆点演变情况

IF 2.5 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus

Pub Date : 2024-09-20 DOI: 10.1016/j.icarus.2024.116329

S. Vijayan , K.B. Kimi , Anil Chavan , R. Aditi , U. Thahira , V. Rama Subramanian , Rishitosh K. Sinha , Amitabh , Santosh Vadawale , M. Shanmugam , N.P.S. Mithun , Arpit R. Patel , Amit Basu Sarbadhikari , K.V. Iyer , K. Suresh , Ajay Prashar , G. Rima , Anil Bhardwaj

The Chandrayaan-3 mission with the Vikram-lander and the Pragyan rover landed in the high latitude highland region near the south pole of the Moon. The landing site is located ∼350 km from the South Pole-Aitken basin rim, an ancient and highly cratered terrain. This site has undergone the complex emplacement sequence of SPA basin ejecta followed by the nearby and distant impact basins and crater ejecta materials. To evaluate the source of individual basin and crater ejecta emplacement over this landing site, we carefully demarcated the nearby and distal basins and craters that could have contributed to the source regolith material. We found that the SPA basin is the major contributor, which deposited nearly ∼1400 m of ejecta materials, and 11 other basins deposited ∼580 m of ejecta. The other complex craters contributed up to ∼90 m of ejecta. Meanwhile, secondary craters of a few km in diameter located adjacent to the landing site contributed to ∼0.5 m ejecta, which are crucial target materials for the Pragyan rover insitu analysis. Pragyan rover images revealed the landing site is devoid of >1 m boulders along the traverse revealing typical highland terrain. The Pragyan rover Navcam and Orbital High Resolution Camera regional images revealed linear distal ejecta rays possibly from the distant impacts as insitu evidence of foreign material at the CH-3 landing site. We found a semi-circular, heavily degraded structure encompassed around the landing site, which is interpreted as a buried impact crater ∼160 km in diameter probably formed before the SPA basin. The erasure of pre-SPA basin craters is caused by both the direct burial by SPA basin ejecta, high seismic shaking during SPA formation, and then followed by various post-SPA craters and its associated some of the degradation processes. Overall, Chandrayaan-3 landed within an ancient region that hosts some of the most deeply excavated materials on the Moon.

携带维克拉姆着陆器和普拉扬漫游车的 "月壤-3 号 "任务在月球南极附近的高纬度高原地区着陆。着陆点距离南极-艾特肯盆地边缘约 350 千米，这是一个古老的火山口地形。该着陆点经历了南极-艾特肯盆地喷出物、附近和远处的撞击盆地以及陨石坑喷出物的复杂喷出顺序。为了评估该着陆点上各个撞击盆地和陨石坑喷出物的来源，我们仔细划分了附近和远处的撞击盆地和陨石坑，这些盆地和陨石坑都可能是碎屑材料的来源。我们发现，SPA盆地是主要的喷出物质来源，沉积了近∼1400米的喷出物质，其他11个盆地沉积了∼580米的喷出物质。其他复杂的陨石坑则沉积了多达 ∼90 米的喷出物质。同时，着陆点附近直径为几公里的次级陨石坑产生了 ∼0.5 米的喷出物，这些喷出物是普拉扬漫游车原位分析的重要目标材料。Pragyan 漫游车图像显示，着陆点沿线没有 1 米长的巨石，显示了典型的高原地形。Pragyan 漫游车导航摄像头和轨道高分辨率照相机的区域图像显示了可能来自远距离撞击的线性远端喷出射线，这是 CH-3 着陆点异物的现场证据。我们在着陆点周围发现了一个半圆形的严重退化结构，据解释，这是一个直径为 160 千米的埋藏式撞击坑，可能形成于 SPA 盆地之前。SPA盆地之前的陨石坑的侵蚀是由SPA盆地喷出物的直接掩埋、SPA形成过程中的高地震震动以及SPA盆地之后的各种陨石坑及其相关的一些退化过程造成的。总之，"钱德拉雅安3号 "着陆在一个古老的区域内，该区域拥有月球上挖掘最深的一些物质。

{"title":"Chandrayaan-3 landing site evolution by South Pole-Aitken basin and other impact craters","authors":"S. Vijayan , K.B. Kimi , Anil Chavan , R. Aditi , U. Thahira , V. Rama Subramanian , Rishitosh K. Sinha , Amitabh , Santosh Vadawale , M. Shanmugam , N.P.S. Mithun , Arpit R. Patel , Amit Basu Sarbadhikari , K.V. Iyer , K. Suresh , Ajay Prashar , G. Rima , Anil Bhardwaj","doi":"10.1016/j.icarus.2024.116329","DOIUrl":"10.1016/j.icarus.2024.116329","url":null,"abstract":"<div><div>The Chandrayaan-3 mission with the Vikram-lander and the Pragyan rover landed in the high latitude highland region near the south pole of the Moon. The landing site is located ∼350 km from the South Pole-Aitken basin rim, an ancient and highly cratered terrain. This site has undergone the complex emplacement sequence of SPA basin ejecta followed by the nearby and distant impact basins and crater ejecta materials. To evaluate the source of individual basin and crater ejecta emplacement over this landing site, we carefully demarcated the nearby and distal basins and craters that could have contributed to the source regolith material. We found that the SPA basin is the major contributor, which deposited nearly ∼1400 m of ejecta materials, and 11 other basins deposited ∼580 m of ejecta. The other complex craters contributed up to ∼90 m of ejecta. Meanwhile, secondary craters of a few km in diameter located adjacent to the landing site contributed to ∼0.5 m ejecta, which are crucial target materials for the Pragyan rover insitu analysis. Pragyan rover images revealed the landing site is devoid of >1 m boulders along the traverse revealing typical highland terrain. The Pragyan rover Navcam and Orbital High Resolution Camera regional images revealed linear distal ejecta rays possibly from the distant impacts as insitu evidence of foreign material at the CH-3 landing site. We found a semi-circular, heavily degraded structure encompassed around the landing site, which is interpreted as a buried impact crater ∼160 km in diameter probably formed before the SPA basin. The erasure of pre-SPA basin craters is caused by both the direct burial by SPA basin ejecta, high seismic shaking during SPA formation, and then followed by various post-SPA craters and its associated some of the degradation processes. Overall, Chandrayaan-3 landed within an ancient region that hosts some of the most deeply excavated materials on the Moon.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"425 ","pages":"Article 116329"},"PeriodicalIF":2.5,"publicationDate":"2024-09-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142323117","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}

引用次数: 0

Survey of remnant seasonal ice patches at southern polar Mars 南极火星残余季节性冰斑调查

IF 2.5 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus

Pub Date : 2024-09-20 DOI: 10.1016/j.icarus.2024.116331

M. Gergacz , A. Kereszturi

On Mars after the recession of the seasonal polar ice cap, small icy patches in shady and/or low thermal conductivity places are left behind. These regions are then illuminated by direct sunlight during the summer, warm up and in an ideal case a liquid phase could emerge. This work is surveying HiRISE images for such ice patches and found 148 images with ice patches on them out of the 730 images that fit the selection criteria of location and season. Their separation of ice from other bright patches, like clouds or lighter shades of surface layers and rocks was possible by their bluish color and strong connection to local topography Images with ice patches ranged between 140° and 200° solar longitude in the latitude band between −40° and − 60°. The diameter of the ice patches ranges between 1.5 and 300 m, and they remain on the surface even after the seasonal polar cap has passed over the area for at least the duration range of 1.5–139 Martian days. This range of duration indicates not ephemerally formed ice in the night but longer presence at the surface.

在火星上，季节性极地冰盖消退后，会在阴暗和/或热传导率低的地方留下小块冰层。这些区域在夏季受到阳光直射，温度升高，在理想情况下会出现液相。这项研究正在对 HiRISE 图像进行调查，以寻找此类冰斑，并在 730 幅符合地点和季节选择标准的图像中找到了 148 幅带有冰斑的图像。这些图像的颜色偏蓝，与当地地形密切相关，因此可以将冰与其他亮斑（如云层或浅色地表层和岩石）区分开来。冰斑的直径在 1.5 米到 300 米之间，即使在季节性极冠掠过该区域后，冰斑仍留在地表，持续时间至少在 1.5-139 个火星日之间。这一持续时间范围表明冰不是在夜间短暂形成的，而是在地表存在较长时间。

引用次数: 0

The direction of core solidification in asteroids: Implications for dynamo generation 小行星内核凝固的方向：对发电机产生的影响

IF 2.5 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus

Pub Date : 2024-09-19 DOI: 10.1016/j.icarus.2024.116319

K.H. Dodds , J.F.J. Bryson , J.A. Neufeld , R.J. Harrison

Paleomagnetic studies of meteorites over the past two decades have revealed that the cores of multiple meteorite parent bodies, including those of certain chondritic groups, generated dynamo fields as they crystallised. However, uncertainties in the direction and mode of core solidification in asteroid-sized bodies have meant using the timings and durations of these fields to constrain parent body properties, such as size, is challenging. Here, we use updated equations of state and liquidus relationships for Fe-FeS liquids at low pressures to calculate the locations at which solids form in these cores. We perform these calculations for core-mantle boundary (CMB) pressures from 0–2 GPa, and Fe-FeS liquid concentrations on the iron-rich side of the eutectic, as well as two values of iron thermal expansivity that cover the measured uncertainties in this parameter, and adiabatic and conductive cooling of these cores. We predict inward core crystallisation from the CMB in asteroids due to their low

< 0.5 GPa

pressures regardless of the uncertainties in other key core parameters. However, due to low internal pressures in these cores, remelting of any iron snow, as proposed to generate Ganymede’s present-day field, may be unlikely as the cores are approximately isothermal. Therefore a different mode of inward core solidification is possibly required to explain compositionally-driven dynamo action in asteroids. Additionally, we identify possible regimes at higher

> 0.6 − 2 GPa

pressures in which crystallisation can occur concurrently at the CMB and the centre.

过去二十年来对陨石进行的古地磁研究显示，多个陨石母体（包括某些软玉群的母体）的内核在结晶过程中会产生动力场。然而，小行星大小的陨石核心凝固方向和模式的不确定性，意味着利用这些场的时间和持续时间来约束母体的属性（如大小）是具有挑战性的。在这里，我们使用低压下 Fe-FeS 液体的最新状态方程和液相关系来计算这些内核中固体形成的位置。我们针对 0-2 GPa 的岩心-岩幔边界（CMB）压力、共晶富铁一侧的 Fe-FeS 液体浓度、涵盖该参数测量不确定性的两个铁热膨胀率值以及这些岩心的绝热和传导冷却进行了计算。由于小行星的内压较低，我们预测它们的内核会向内结晶，与其他关键内核参数的不确定性无关。然而，由于这些内核的内部压力较低，任何铁雪的重熔（如产生木卫二现今磁场的提议）都不太可能发生，因为这些内核大致处于等温状态。因此，可能需要一种不同的内核凝固模式来解释小行星中由成分驱动的动力作用。此外，我们还确定了在较高的 > 0.6 - 2 GPa 压力下的可能状态，在这种状态下，结晶可在 CMB 和中心同时发生。

{"title":"The direction of core solidification in asteroids: Implications for dynamo generation","authors":"K.H. Dodds , J.F.J. Bryson , J.A. Neufeld , R.J. Harrison","doi":"10.1016/j.icarus.2024.116319","DOIUrl":"10.1016/j.icarus.2024.116319","url":null,"abstract":"<div><div>Paleomagnetic studies of meteorites over the past two decades have revealed that the cores of multiple meteorite parent bodies, including those of certain chondritic groups, generated dynamo fields as they crystallised. However, uncertainties in the direction and mode of core solidification in asteroid-sized bodies have meant using the timings and durations of these fields to constrain parent body properties, such as size, is challenging. Here, we use updated equations of state and liquidus relationships for Fe-FeS liquids at low pressures to calculate the locations at which solids form in these cores. We perform these calculations for core-mantle boundary (CMB) pressures from 0–2 GPa, and Fe-FeS liquid concentrations on the iron-rich side of the eutectic, as well as two values of iron thermal expansivity that cover the measured uncertainties in this parameter, and adiabatic and conductive cooling of these cores. We predict inward core crystallisation from the CMB in asteroids due to their low <span><math><mi>< 0.5 GPa</mi></math></span> pressures regardless of the uncertainties in other key core parameters. However, due to low internal pressures in these cores, remelting of any iron snow, as proposed to generate Ganymede’s present-day field, may be unlikely as the cores are approximately isothermal. Therefore a different mode of inward core solidification is possibly required to explain compositionally-driven dynamo action in asteroids. Additionally, we identify possible regimes at higher <span><math><mi>> 0.6 − 2 GPa</mi></math></span> pressures in which crystallisation can occur concurrently at the CMB and the centre.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"425 ","pages":"Article 116319"},"PeriodicalIF":2.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142319303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Coupled tidal tomography and thermal constraints for probing Mars viscosity profile 用于探测火星粘度分布的潮汐层析成像和热约束耦合技术

IF 2.5 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus

Pub Date : 2024-09-19 DOI: 10.1016/j.icarus.2024.116318

Alex Guinard, Agnès Fienga, Anthony Mémin, Clément Ganino

Computing the tidal deformations of Mars, we explored various Mars spherically symmetric internal structures with different types of interface between the mantle and the liquid core. By assessing their compatibility with a diverse set of geophysical observations we show that despite the very short periods of excitation, tidal deformation is very efficient to constrain Mars interior. We calculated densities and thicknesses for Martian lithosphere, mantle, core–mantle boundary layers and core and found them consistent with preexisting results from other methods. We also estimated new viscosities for these layers. We demonstrated that the geodetic records associated with thermal constraints are very sensitive to the presence of a 2-layered interface on the top of the liquid core in deep Martian mantle. This interface is composed by 2 layers of similar densities but very different viscosity and rheology: the layer on the top of the core is liquid (Newtonian, NBL) and the one at the base of the mantle, overlaying the liquid one, is an Andrade layer (ABL) with a viscosity in average 10 orders of magnitude greater than the Newtonian layer. Our results also indicate that the existence of this 2-layered interface significantly impacts the viscosity profiles of the mantle and the lithosphere. More precisely, models including the 2-layered interface do not display significant viscosity contrast between the mantle and the lithosphere, preventing mechanical decoupling between a lithosphere and the mantle immediately below. Such models are in favor of a stagnant lid regime that can be supported by the current absence of an Earth-like plate tectonics on Mars. Finally, in our results, the presence of liquid Newtonian layer at the top of the liquid core is incompatible with the existence of a solid inner core.

通过计算火星的潮汐变形，我们探索了地幔和液态内核之间具有不同类型界面的各种火星球形对称内部结构。通过评估这些结构与各种地球物理观测数据的兼容性，我们发现尽管激发周期很短，但潮汐形变对约束火星内部非常有效。我们计算了火星岩石圈、地幔、地核-地幔边界层和地核的密度和厚度，发现它们与其他方法的已有结果一致。我们还为这些层估算了新的粘度。我们证明，与热约束相关的大地测量记录对火星地幔深处液态内核顶部存在的两层界面非常敏感。该界面由两层密度相似但粘度和流变性迥异的物质组成：地核顶部的物质层为液态（牛顿层，NBL），地幔底部覆盖液态物质层的物质层为安德拉德层（ABL），其粘度平均比牛顿层大 10 个数量级。我们的研究结果还表明，这两层界面的存在极大地影响了地幔和岩石圈的粘度分布。更确切地说，包含两层界面的模型不会在地幔和岩石圈之间显示出明显的粘度对比，从而阻止岩石圈和紧接其下的地幔之间的机械解耦。这种模型有利于停滞的盖层机制，目前火星上没有类似地球的板块构造也可以支持这种机制。最后，根据我们的研究结果，液态内核顶部存在液态牛顿层与固态内核的存在是不相容的。

{"title":"Coupled tidal tomography and thermal constraints for probing Mars viscosity profile","authors":"Alex Guinard, Agnès Fienga, Anthony Mémin, Clément Ganino","doi":"10.1016/j.icarus.2024.116318","DOIUrl":"10.1016/j.icarus.2024.116318","url":null,"abstract":"<div><div>Computing the tidal deformations of Mars, we explored various Mars spherically symmetric internal structures with different types of interface between the mantle and the liquid core. By assessing their compatibility with a diverse set of geophysical observations we show that despite the very short periods of excitation, tidal deformation is very efficient to constrain Mars interior. We calculated densities and thicknesses for Martian lithosphere, mantle, core–mantle boundary layers and core and found them consistent with preexisting results from other methods. We also estimated new viscosities for these layers. We demonstrated that the geodetic records associated with thermal constraints are very sensitive to the presence of a 2-layered interface on the top of the liquid core in deep Martian mantle. This interface is composed by 2 layers of similar densities but very different viscosity and rheology: the layer on the top of the core is liquid (Newtonian, NBL) and the one at the base of the mantle, overlaying the liquid one, is an Andrade layer (ABL) with a viscosity in average 10 orders of magnitude greater than the Newtonian layer. Our results also indicate that the existence of this 2-layered interface significantly impacts the viscosity profiles of the mantle and the lithosphere. More precisely, models including the 2-layered interface do not display significant viscosity contrast between the mantle and the lithosphere, preventing mechanical decoupling between a lithosphere and the mantle immediately below. Such models are in favor of a stagnant lid regime that can be supported by the current absence of an Earth-like plate tectonics on Mars. Finally, in our results, the presence of liquid Newtonian layer at the top of the liquid core is incompatible with the existence of a solid inner core.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"425 ","pages":"Article 116318"},"PeriodicalIF":2.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0019103524003786/pdfft?md5=0c0e6dd63f31d5726acabf1dd61b4e68&pid=1-s2.0-S0019103524003786-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142315818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Seasonality of aeolian landforms on Meridiani Planum, Mars 火星子午线上风化地貌的季节性

IF 2.5 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus

Pub Date : 2024-09-19 DOI: 10.1016/j.icarus.2024.116325

J. Kozakiewicz , D. Maj , S. Mol , M. Sobucki , T. Michaels , N. Frodyma

The wind interacts with the surface of Mars, forming aeolian landforms. The orientation of these landforms informs us about the formative wind directions. The observations of the orientation of aeolian landforms on Meridiani Planum between Mars years 26 and 38 indicated that there is a seasonality of formative wind directions in this region. The studied landforms were shaped by a predominant SE wind during summer, while during winter several wind directions played a role in their formation. Throughout the Mars year, the most formative were the NW winds. The presence of dark wind streaks oriented toward the west during winter indicates that E winds occur in this season on Meridiani Planum, as previously predicted by numerical simulations. It was also found that aeolian deflation led to complete erosion of smaller dunes, and that the relatively strong deflation was responsible for the scarcity of fine-grained ripples on Meridiani Planum. In this region, fine-grained ripples were found only in a few locations, and they were mainly small bedforms with wavelengths up to several centimeters.

风与火星表面相互作用，形成风化地貌。这些地貌的方位告诉我们形成风的方向。对火星年 26 至 38 年间子午线上风化地貌方位的观测表明，该地区的形成风向具有季节性。所研究的地貌在夏季主要由东南风形成，而在冬季则由多个风向共同作用形成。在整个火星年中，最主要的形成风向是西北风。冬季出现的朝向西方的暗风条纹表明，正如之前数值模拟所预测的那样，子午线在这个季节会出现东风。研究还发现，风化放气导致较小的沙丘被完全侵蚀，而相对强烈的放气是造成子午线上细粒波纹稀少的原因。在这一地区，仅在少数几个地点发现了细粒波纹，它们主要是波长达几厘米的小床层。

{"title":"Seasonality of aeolian landforms on Meridiani Planum, Mars","authors":"J. Kozakiewicz , D. Maj , S. Mol , M. Sobucki , T. Michaels , N. Frodyma","doi":"10.1016/j.icarus.2024.116325","DOIUrl":"10.1016/j.icarus.2024.116325","url":null,"abstract":"<div><div>The wind interacts with the surface of Mars, forming aeolian landforms. The orientation of these landforms informs us about the formative wind directions. The observations of the orientation of aeolian landforms on Meridiani Planum between Mars years 26 and 38 indicated that there is a seasonality of formative wind directions in this region. The studied landforms were shaped by a predominant SE wind during summer, while during winter several wind directions played a role in their formation. Throughout the Mars year, the most formative were the NW winds. The presence of dark wind streaks oriented toward the west during winter indicates that E winds occur in this season on Meridiani Planum, as previously predicted by numerical simulations. It was also found that aeolian deflation led to complete erosion of smaller dunes, and that the relatively strong deflation was responsible for the scarcity of fine-grained ripples on Meridiani Planum. In this region, fine-grained ripples were found only in a few locations, and they were mainly small bedforms with wavelengths up to several centimeters.</div></div>","PeriodicalId":13199,"journal":{"name":"Icarus","volume":"425 ","pages":"Article 116325"},"PeriodicalIF":2.5,"publicationDate":"2024-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142318535","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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

Size-based spectrophotometric analysis of the Polana-Eulalia Complex 基于粒度的波拉纳-尤利亚综合体分光光度分析

IF 2.5 2区物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS

Icarus

Pub Date : 2024-09-19 DOI: 10.1016/j.icarus.2024.116322

L.T. McClure , J.P. Emery , C.A. Thomas , K.J. Walsh , R.K. Williams

The Polana-Eulalia Complex (PEC) is an Inner Main Belt, C-complex asteroid population that may be the source of the near-Earth asteroid spacecraft mission targets (101955) Bennu and (162173) Ryugu. Here, we report a size-based investigation of the visible (VIS; 0.47 —0.89 μm) spectrophotometric slopes of the PEC's constituent families, the “New Polana” and Eulalia Families. Using two releases of the Sloan Digital Sky Survey's Moving Object Catalog as well as the 3rd data release of the Gaia catalog, we present evidence of size-based slope variability within each family. We find that Eulalia family members exhibit lower average slopes than Polana family members in all catalogs' samples, particularly for objects <9 km in diameter. We are unable to conclude that VIS slope distinguishability between the families is statistically significant, but we explore a potential cause of the bulk slope differences between the PEC families, in addition to providing commentary on size-slope trends generally.

波拉纳-尤利亚复合体（Polana-Eulalia Complex，PEC）是一个内主带C复合体小行星群，可能是近地小行星任务目标（101955）贝努（Bennu）和（162173）龙宫（Ryugu）的来源。在此，我们报告了对 PEC 的组成家族--"新波拉纳 "家族和欧拉利亚家族--的可见光（VIS；0.47 -0.89 μm）分光光度斜率进行的基于尺寸的调查。利用两次发布的斯隆数字巡天活动天体目录以及第三次发布的盖亚星表数据，我们提出了每个科内基于大小的斜率变化证据。我们发现，在所有星表样本中，尤拉莉亚家族成员的平均斜率都低于波拉纳家族成员，尤其是直径为9千米的天体。我们无法断定各族之间的VIS斜率差异具有统计学意义，但我们探讨了PEC各族之间斜率差异的潜在原因，并对尺寸-斜率的总体趋势进行了评述。

引用次数: 0

Icarus最新文献