首页 > 最新文献

Publications of the Astronomical Society of the Pacific最新文献

英文 中文
Two-photon Production in Low-velocity Shocks 低速冲击中的双光子产生
IF 3.5 3区 物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS Pub Date : 2023-12-28 DOI: 10.1088/1538-3873/acff85
S. R. Kulkarni, J. Michael Shull
The Galactic interstellar medium abounds in shocks with low velocities vs ≲ 70 km s−1. Some are descendants of higher velocity shocks, while others start off at low velocity (e.g., stellar bow shocks, intermediate velocity clouds, spiral density waves). Low-velocity shocks cool primarily via Lyα and two-photon continuum, augmented by optical recombination lines (e.g., Hα), forbidden lines of metals and free-bound emission, free–free emission. The dark far-ultraviolet (FUV) sky, aided by the fact that the two-photon continuum peaks at 1400 Å, makes the FUV band an ideal tracer of low-velocity shocks. GALEX FUV images reaffirm this expectation, discovering faint and large interstellar structure in old supernova remnants and thin arcs stretching across the sky. Interstellar bow shocks are expected from fast stars from the Galactic disk passing through the numerous gas clouds in the local interstellar medium within 15 pc of the Sun. Using the bests atomic data available to date, we present convenient fitting formulae for yields of Lyα, two-photon continuum, and Hα for pure hydrogen plasma in the temperature range of 104–105 K. The formulae presented here can be readily incorporated into time-dependent cooling models as well as collisional ionization equilibrium models.
银河系星际介质中存在大量低速 vs ≲ 70 km s-1 的冲击波。有些是高速冲击波的后代,有些则是从低速冲击波开始的(如恒星弓形冲击波、中速云、螺旋密度波)。低速冲击主要通过 Lyα 和双光子连续波来冷却,并通过光学重组线(如 Hα)、金属禁线和自由束缚发射、自由发射来增强。暗色的远紫外(FUV)天空,加上双光子连续波在 1400 Å 处达到峰值,使得 FUV 波段成为低速冲击的理想示踪波段。GALEX 的 FUV 图像再次证实了这一预期,在古老的超新星遗迹和延伸至整个天空的细弧中发现了微弱而巨大的星际结构。星际弓形冲击预计是来自银河盘的快速恒星穿过太阳周围 15 pc 范围内的本地星际介质中的大量气体云时产生的。利用迄今为止最好的原子数据,我们提出了温度范围在 104-105 K 的纯氢等离子体的 Lyα、双光子连续光和 Hα 产量的便捷拟合公式。
{"title":"Two-photon Production in Low-velocity Shocks","authors":"S. R. Kulkarni, J. Michael Shull","doi":"10.1088/1538-3873/acff85","DOIUrl":"https://doi.org/10.1088/1538-3873/acff85","url":null,"abstract":"The Galactic interstellar medium abounds in shocks with low velocities <italic toggle=\"yes\">v</italic>\u0000<sub>\u0000<italic toggle=\"yes\">s</italic>\u0000</sub> ≲ 70 km s<sup>−1</sup>. Some are descendants of higher velocity shocks, while others start off at low velocity (e.g., stellar bow shocks, intermediate velocity clouds, spiral density waves). Low-velocity shocks cool primarily via Ly<italic toggle=\"yes\">α</italic> and two-photon continuum, augmented by optical recombination lines (e.g., H<italic toggle=\"yes\">α</italic>), forbidden lines of metals and free-bound emission, free–free emission. The dark far-ultraviolet (FUV) sky, aided by the fact that the two-photon continuum peaks at 1400 Å, makes the FUV band an ideal tracer of low-velocity shocks. GALEX FUV images reaffirm this expectation, discovering faint and large interstellar structure in old supernova remnants and thin arcs stretching across the sky. Interstellar bow shocks are expected from fast stars from the Galactic disk passing through the numerous gas clouds in the local interstellar medium within 15 pc of the Sun. Using the bests atomic data available to date, we present convenient fitting formulae for yields of Ly<italic toggle=\"yes\">α</italic>, two-photon continuum, and H<italic toggle=\"yes\">α</italic> for pure hydrogen plasma in the temperature range of 10<sup>4</sup>–10<sup>5</sup> K. The formulae presented here can be readily incorporated into time-dependent cooling models as well as collisional ionization equilibrium models.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":"21 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-12-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139096132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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
SDSS-IV from 2014 to 2016: A Detailed Demographic Comparison over Three Years 从 2014 年到 2016 年的 SDSS-IV:三年来的详细人口统计比较
IF 3.5 3区 物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS Pub Date : 2023-12-21 DOI: 10.1088/1538-3873/ad0d7b
Amy M. Jones, Rachael L. Beaton, Brian A. Cherinka, Karen L. Masters, Sara Lucatello, Aleksandar M. Diamond-Stanic, Sarah A. Bird, Michael R. Blanton, Katia Cunha, Emily E. Farr, Diane Feuillet, Peter M. Frinchaboy, Alex Hagen, Karen Kinemuchi, Britt Lundgren, Mariarosa L. Marinelli, Adam D. Myers, Alexandre Roman-Lopes, Ashley J. Ross, José R. Sánchez-Gallego, Sarah J. Schmidt, Jennifer Sobeck, Keivan G. Stassun, Jamie Tayar, Mariana Vargas-Magaña, J. C. Wilson, Gail Zasowski
The Sloan Digital Sky Survey (SDSS) is one of the largest international astronomy organizations. We present demographic data based on surveys of its members from 2014, 2015 and 2016, during the fourth phase of SDSS (SDSS-IV). We find about half of SDSS-IV collaboration members were based in North America, a quarter in Europe, and the remainder in Asia and Central and South America. Overall, 26%–36% are women (from 2014 to 2016), up to 2% report non-binary genders. 11%–14% report that they are racial or ethnic minorities where they live. The fraction of women drops with seniority, and is also lower among collaboration leadership. Men in SDSS-IV were more likely to report being in a leadership role, and for the role to be funded and formally recognized. SDSS-IV collaboration members are twice as likely to have a parent with a college degree, than the general population, and are ten times more likely to have a parent with a PhD. This trend is slightly enhanced for female collaboration members. Despite this, the fraction of first generation college students is significant (31%). This fraction increased among collaboration members who are racial or ethnic minorities (40%–50%), and decreased among women (15%–25%). SDSS-IV implemented many inclusive policies and established a dedicated committee, the Committee on INclusiveness in SDSS. More than 60% of the collaboration agree that the collaboration is inclusive; however, collaboration leadership more strongly agree with this than the general membership. In this paper, we explain these results in full, including the history of inclusive efforts in SDSS-IV. We conclude with a list of suggested recommendations based on our findings, which can be used to improve equity and inclusion in large astronomical collaborations, which we argue is not only moral, but will also optimize their scientific output.
斯隆数字巡天(SDSS)是最大的国际天文学组织之一。我们根据2014年、2015年和2016年SDSS第四阶段(SDSS-IV)期间对其成员的调查提供了人口统计数据。我们发现,大约一半的SDSS-IV合作成员在北美,四分之一在欧洲,其余在亚洲、中美洲和南美洲。总体而言,26%-36%为女性(从2014年到2016年),多达2%报告为非二元性别。11%-14%的人称自己在居住地属于少数种族或少数族裔。女性比例随着资历的增加而下降,在合作领导层中也较低。在 SDSS-IV 中,男性更有可能担任领导职务,并且其职务得到资助和正式认可。与普通人相比,SDSS-IV 合作成员的父母拥有大学学位的可能性是普通人的两倍,父母拥有博士学位的可能性是普通人的十倍。女性合作成员的这一趋势略有增强。尽管如此,第一代大学生的比例仍然很高(31%)。在少数种族或族裔的合作成员中,这一比例有所上升(40%-50%),而在女性合作成员中则有所下降(15%-25%)。SDSS-IV 实施了许多包容性政策,并成立了一个专门委员会,即 SDSS 包容性委员会。超过 60% 的合作者同意合作具有包容性;但是,合作领导层比一般成员更强烈地同意这一点。在本文中,我们将全面解释这些结果,包括 SDSS-IV 包容性工作的历史。最后,我们根据研究结果提出了一系列建议,这些建议可用于提高大型天文合作组织的公平性和包容性,我们认为这不仅符合道义,还能优化其科学产出。
{"title":"SDSS-IV from 2014 to 2016: A Detailed Demographic Comparison over Three Years","authors":"Amy M. Jones, Rachael L. Beaton, Brian A. Cherinka, Karen L. Masters, Sara Lucatello, Aleksandar M. Diamond-Stanic, Sarah A. Bird, Michael R. Blanton, Katia Cunha, Emily E. Farr, Diane Feuillet, Peter M. Frinchaboy, Alex Hagen, Karen Kinemuchi, Britt Lundgren, Mariarosa L. Marinelli, Adam D. Myers, Alexandre Roman-Lopes, Ashley J. Ross, José R. Sánchez-Gallego, Sarah J. Schmidt, Jennifer Sobeck, Keivan G. Stassun, Jamie Tayar, Mariana Vargas-Magaña, J. C. Wilson, Gail Zasowski","doi":"10.1088/1538-3873/ad0d7b","DOIUrl":"https://doi.org/10.1088/1538-3873/ad0d7b","url":null,"abstract":"The Sloan Digital Sky Survey (SDSS) is one of the largest international astronomy organizations. We present demographic data based on surveys of its members from 2014, 2015 and 2016, during the fourth phase of SDSS (SDSS-IV). We find about half of SDSS-IV collaboration members were based in North America, a quarter in Europe, and the remainder in Asia and Central and South America. Overall, 26%–36% are women (from 2014 to 2016), up to 2% report non-binary genders. 11%–14% report that they are racial or ethnic minorities where they live. The fraction of women drops with seniority, and is also lower among collaboration leadership. Men in SDSS-IV were more likely to report being in a leadership role, and for the role to be funded and formally recognized. SDSS-IV collaboration members are twice as likely to have a parent with a college degree, than the general population, and are ten times more likely to have a parent with a PhD. This trend is slightly enhanced for female collaboration members. Despite this, the fraction of first generation college students is significant (31%). This fraction increased among collaboration members who are racial or ethnic minorities (40%–50%), and decreased among women (15%–25%). SDSS-IV implemented many inclusive policies and established a dedicated committee, the Committee on INclusiveness in SDSS. More than 60% of the collaboration agree that the collaboration is inclusive; however, collaboration leadership more strongly agree with this than the general membership. In this paper, we explain these results in full, including the history of inclusive efforts in SDSS-IV. We conclude with a list of suggested recommendations based on our findings, which can be used to improve equity and inclusion in large astronomical collaborations, which we argue is not only moral, but will also optimize their scientific output.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":"21 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139053449","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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
The Large Array Survey Telescope—Pipeline. I. Basic Image Reduction and Visit Coaddition 大型阵列巡天望远镜管道。I. 基本图像缩减和访问叠加
IF 3.5 3区 物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS Pub Date : 2023-12-21 DOI: 10.1088/1538-3873/ad0977
E. O. Ofek, Y. Shvartzvald, A. Sharon, C. Tishler, D. Elhanati, N. Segev, S. Ben-Ami, G. Nir, E. Segre, Y. Sofer-Rimalt, A. Blumenzweig, N. L. Strotjohann, D. Polishook, A. Krassilchtchikov, A. Zenin, V. Fallah Ramazani, S. Weimann, S. Garrappa, Y. Shanni, P. Chen, E. Zimmerman
The Large Array Survey Telescope (LAST) is a wide-field telescope designed to explore the variable and transient sky with a high cadence and to be a test-bed for cost-effective telescope design. A LAST node is composed of 48 (32 already deployed), 28 cm f/2.2 telescopes. A single telescope has a 7.4 deg2 field of view and reaches a 5σ limiting magnitude of 19.6 (21.0) in 20 (20 × 20) s (filter-less), while the entire system provides a 355 deg2 field of view. The basic strategy of LAST is to obtain multiple 20 s consecutive exposures of each field (a visit). Each telescope carries a 61 Mpix camera, and the system produces, on average, about 2.2 Gbit s−1. This high data rate is analyzed in near real-time at the observatory site, using limited computing resources (about 700 cores). Given this high data rate, we have developed a new, efficient data reduction and analysis pipeline. The LAST data pipeline includes two major parts: (i) Processing and calibration of single images, followed by a coaddition of the visit’s exposures. (ii) Building the reference images and performing image subtraction and transient detection. Here we describe in detail the first part of the pipeline. Among the products of this pipeline are photometrically and astrometrically calibrated single and coadded images, 32 bit mask images marking a wide variety of problems and states of each pixel, source catalogs built from individual and coadded images, Point-Spread Function photometry, merged source catalogs, proper motion and variability indicators, minor planets detection, calibrated light curves, and matching with external catalogs. The entire pipeline code is made public. Finally, we demonstrate the pipeline performance on real data taken by LAST.
大型阵列巡天望远镜(LAST)是一台宽视场望远镜,旨在高频率地探索变星和瞬变天空,并作为成本效益望远镜设计的试验平台。LAST 节点由 48 台(32 台已部署)28 厘米 f/2.2 望远镜组成。单台望远镜的视场为 7.4 平方分米,在 20 (20 × 20) 秒(无滤波器)内达到 19.6 (21.0) 的 5σ 极限星等,而整个系统的视场为 355 平方分米。LAST 的基本策略是对每个视场进行多次 20 秒的连续曝光(访问)。每台望远镜携带一台 6100 万像素的相机,系统平均产生约 2.2 Gbit s-1。观测站利用有限的计算资源(约 700 个内核)对这一高数据率进行近乎实时的分析。鉴于如此高的数据传输率,我们开发了一种新的、高效的数据还原和分析管道。LAST 数据管道包括两个主要部分:(i) 处理和校准单幅图像,然后对访问的曝光进行共同加法。(ii) 建立参考图像并进行图像减法和瞬态检测。在此,我们将详细介绍该流程的第一部分。该流水线的产品包括:经过光度和天体测量校准的单幅图像和共加图像、标记了各种问题和每个像素状态的 32 位掩膜图像、根据单幅图像和共加图像建立的源星表、点散布函数光度测量、合并源星表、适当运动和变率指标、小行星探测、校准光曲线,以及与外部星表的匹配。整个管道代码都是公开的。最后,我们在 LAST 拍摄的真实数据上演示了该管道的性能。
{"title":"The Large Array Survey Telescope—Pipeline. I. Basic Image Reduction and Visit Coaddition","authors":"E. O. Ofek, Y. Shvartzvald, A. Sharon, C. Tishler, D. Elhanati, N. Segev, S. Ben-Ami, G. Nir, E. Segre, Y. Sofer-Rimalt, A. Blumenzweig, N. L. Strotjohann, D. Polishook, A. Krassilchtchikov, A. Zenin, V. Fallah Ramazani, S. Weimann, S. Garrappa, Y. Shanni, P. Chen, E. Zimmerman","doi":"10.1088/1538-3873/ad0977","DOIUrl":"https://doi.org/10.1088/1538-3873/ad0977","url":null,"abstract":"The Large Array Survey Telescope (LAST) is a wide-field telescope designed to explore the variable and transient sky with a high cadence and to be a test-bed for cost-effective telescope design. A LAST node is composed of 48 (32 already deployed), 28 cm <italic toggle=\"yes\">f</italic>/2.2 telescopes. A single telescope has a 7.4 deg<sup>2</sup> field of view and reaches a 5<italic toggle=\"yes\">σ</italic> limiting magnitude of 19.6 (21.0) in 20 (20 × 20) s (filter-less), while the entire system provides a 355 deg<sup>2</sup> field of view. The basic strategy of LAST is to obtain multiple 20 s consecutive exposures of each field (a visit). Each telescope carries a 61 Mpix camera, and the system produces, on average, about 2.2 Gbit s<sup>−1</sup>. This high data rate is analyzed in near real-time at the observatory site, using limited computing resources (about 700 cores). Given this high data rate, we have developed a new, efficient data reduction and analysis pipeline. The LAST data pipeline includes two major parts: (i) Processing and calibration of single images, followed by a coaddition of the visit’s exposures. (ii) Building the reference images and performing image subtraction and transient detection. Here we describe in detail the first part of the pipeline. Among the products of this pipeline are photometrically and astrometrically calibrated single and coadded images, 32 bit mask images marking a wide variety of problems and states of each pixel, source catalogs built from individual and coadded images, Point-Spread Function photometry, merged source catalogs, proper motion and variability indicators, minor planets detection, calibrated light curves, and matching with external catalogs. The entire pipeline code is made public. Finally, we demonstrate the pipeline performance on real data taken by LAST.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":"80 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139053845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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
AstroSer: Leveraging Deep Learning for Efficient Content-based Retrieval in Massive Solar-observation Images AstroSer:利用深度学习在海量太阳观测图像中实现基于内容的高效检索
IF 3.5 3区 物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS Pub Date : 2023-12-12 DOI: 10.1088/1538-3873/ad0e7e
Shichao Wu, Yingbo Liu, Lei Yang, Xiaoying Liu, Xingxu Li, Yongyuan Xiang, Yunyu Gong
Rapid and proficient data retrieval is an essential component of modern astronomical research. In this paper, we address the challenge of retrieving astronomical image content by leveraging state-of-the-art deep learning techniques. We have designed a retrieval model, HybridVR, that integrates the capabilities of the deep learning models ResNet50 and VGG16 and have used it to extract key features of solar activity and solar environmental characteristics from observed images. This model enables efficient image matching and allows for content-based image retrieval (CBIR). Experimental results demonstrate that the model can achieve up to 98% similarity during CBIR while exhibiting adaptability and scalability. Our work has implications for astronomical research, data management, and education, and it can contribute to optimizing the utilization of astronomical image data. It also serves as a useful example of the application of deep learning technology in the field of astronomy.
快速而熟练的数据检索是现代天文研究的重要组成部分。在本文中,我们利用最先进的深度学习技术来应对检索天文图像内容的挑战。我们设计了一个检索模型 HybridVR,它集成了深度学习模型 ResNet50 和 VGG16 的功能,并利用它从观测图像中提取太阳活动和太阳环境特征的关键特征。该模型可实现高效的图像匹配,并支持基于内容的图像检索(CBIR)。实验结果表明,该模型在基于内容的图像检索(CBIR)中的相似度高达 98%,同时表现出良好的适应性和可扩展性。我们的工作对天文研究、数据管理和教育具有重要意义,有助于优化天文图像数据的利用。它也是深度学习技术在天文学领域应用的一个有益实例。
{"title":"AstroSer: Leveraging Deep Learning for Efficient Content-based Retrieval in Massive Solar-observation Images","authors":"Shichao Wu, Yingbo Liu, Lei Yang, Xiaoying Liu, Xingxu Li, Yongyuan Xiang, Yunyu Gong","doi":"10.1088/1538-3873/ad0e7e","DOIUrl":"https://doi.org/10.1088/1538-3873/ad0e7e","url":null,"abstract":"Rapid and proficient data retrieval is an essential component of modern astronomical research. In this paper, we address the challenge of retrieving astronomical image content by leveraging state-of-the-art deep learning techniques. We have designed a retrieval model, HybridVR, that integrates the capabilities of the deep learning models ResNet50 and VGG16 and have used it to extract key features of solar activity and solar environmental characteristics from observed images. This model enables efficient image matching and allows for content-based image retrieval (CBIR). Experimental results demonstrate that the model can achieve up to 98% similarity during CBIR while exhibiting adaptability and scalability. Our work has implications for astronomical research, data management, and education, and it can contribute to optimizing the utilization of astronomical image data. It also serves as a useful example of the application of deep learning technology in the field of astronomy.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":"1 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138684285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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
The Impact of Serpentinization on the Initial Conditions of Satellite Forming Collisions of Large Kuiper Belt Objects 蛇形化对柯伊伯带大型天体卫星形成碰撞初始条件的影响
IF 3.5 3区 物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS Pub Date : 2023-12-08 DOI: 10.1088/1538-3873/ad0f9a
A. Farkas-Takács, Csaba Kiss
Kuiper Belt objects are thought to be formed at least a few million years after the formation of calcium–aluminum-rich inclusions (CAIs), at a time when the 26Al isotope—the major source of radiogenic heat in the early solar system—had significantly depleted. The internal structure of these objects is highly dependent on any additional source that can produce extra heat in addition to that produced by the remaining, long-lasting radioactive isotopes. In this paper, we explore how serpentinization, the hydration of silicate minerals, can contribute to the heat budget and to what extent it can modify the internal structure of large Kuiper Belt objects. We find that the extent of restructuring depends very strongly on the start time of the formation process, the size of the object, and the starting ice-to-rock ratio. Serpentinization is able to restructure most of the interior of all objects in the whole size range (400–1200 km) and ice-to-rock ratio range investigated if the process starts early, ∼3 Myr after CAI formation, potentially leading to a predominantly serpentine core much earlier than previously thought (≤5 Myr versus several tens of million years). While the ratio of serpentinized material gradually decreases with the increasing formation time, the increasing ice-to-rock ratio, and the increasing start time of planetesimal formation in the outer solar system, in the case of the largest objects a significant part of the interior will be serpentinized even if the formation starts relatively late, ∼5 Myr after CAI formation. Therefore it is feasible that the interior of planetesimals may have contained a significant amount of serpentine, and in some cases, it could have been a dominant constituent, at the time of satellite-forming impacts.
柯伊伯带天体被认为是在富钙铝包裹体(CAIs)形成至少几百万年后形成的,当时26Al同位素——早期太阳系中放射性热的主要来源——已经明显耗尽。这些物体的内部结构高度依赖于任何可以产生额外热量的额外来源,除了剩余的、持久的放射性同位素产生的热量。在本文中,我们探讨了蛇纹石化,硅酸盐矿物的水化作用,如何有助于热收支,以及它在多大程度上可以改变大型柯伊伯带天体的内部结构。我们发现,重构的程度在很大程度上取决于形成过程的开始时间、物体的大小和开始的冰岩比。蛇纹石化能够在整个尺寸范围(400-1200公里)内重构所有物体的大部分内部,如果这一过程开始得早,在CAI形成后约3 Myr,可能导致以蛇纹石为主的核心比以前认为的要早得多(≤5 Myr,而不是几千万年前)。蛇纹石化物质的比例随着形成时间的增加、冰岩比的增加和外太阳系星子形成开始时间的增加而逐渐减少,但对于最大的天体来说,即使形成开始得相对较晚,在CAI形成后约5 Myr,内部也有很大一部分会被蛇纹石化。因此,小星子的内部可能含有大量的蛇纹石,在某些情况下,在形成卫星的撞击中,蛇纹石可能是主要成分。
{"title":"The Impact of Serpentinization on the Initial Conditions of Satellite Forming Collisions of Large Kuiper Belt Objects","authors":"A. Farkas-Takács, Csaba Kiss","doi":"10.1088/1538-3873/ad0f9a","DOIUrl":"https://doi.org/10.1088/1538-3873/ad0f9a","url":null,"abstract":"Kuiper Belt objects are thought to be formed at least a few million years after the formation of calcium–aluminum-rich inclusions (CAIs), at a time when the 26Al isotope—the major source of radiogenic heat in the early solar system—had significantly depleted. The internal structure of these objects is highly dependent on any additional source that can produce extra heat in addition to that produced by the remaining, long-lasting radioactive isotopes. In this paper, we explore how serpentinization, the hydration of silicate minerals, can contribute to the heat budget and to what extent it can modify the internal structure of large Kuiper Belt objects. We find that the extent of restructuring depends very strongly on the start time of the formation process, the size of the object, and the starting ice-to-rock ratio. Serpentinization is able to restructure most of the interior of all objects in the whole size range (400–1200 km) and ice-to-rock ratio range investigated if the process starts early, ∼3 Myr after CAI formation, potentially leading to a predominantly serpentine core much earlier than previously thought (≤5 Myr versus several tens of million years). While the ratio of serpentinized material gradually decreases with the increasing formation time, the increasing ice-to-rock ratio, and the increasing start time of planetesimal formation in the outer solar system, in the case of the largest objects a significant part of the interior will be serpentinized even if the formation starts relatively late, ∼5 Myr after CAI formation. Therefore it is feasible that the interior of planetesimals may have contained a significant amount of serpentine, and in some cases, it could have been a dominant constituent, at the time of satellite-forming impacts.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":"41 46","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-12-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138588727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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
Staring at the Sun with the Keck Planet Finder: An Autonomous Solar Calibrator for High Signal-to-noise Sun-as-a-star Spectra 用凯克行星探测器凝视太阳:用于高信噪比太阳即恒星光谱的自主太阳校准器
IF 3.5 3区 物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS Pub Date : 2023-12-04 DOI: 10.1088/1538-3873/ad0b30
Ryan A. Rubenzahl, Samuel Halverson, Josh Walawender, Grant M. Hill, Andrew W. Howard, Matthew Brown, Evan Ida, Jerez Tehero, Benjamin J. Fulton, Steven R. Gibson, Marc Kassis, Brett Smith, Truman Wold, Joel Payne
Extreme precision radial velocity (EPRV) measurements contend with internal noise (instrumental systematics) and external noise (intrinsic stellar variability) on the road to 10 cm s−1 “exo-Earth” sensitivity. Both of these noise sources are well-probed using “Sun-as-a-star” RVs and cross-instrument comparisons. We built the Solar Calibrator (SoCal), an autonomous system that feeds stable, disk-integrated sunlight to the recently commissioned Keck Planet Finder (KPF) at the W. M. Keck Observatory. With SoCal, KPF acquires signal-to-noise ratio (S/N) ∼ 1200, R = 98,000 optical (445–870 nm) spectra of the Sun in 5 s exposures at unprecedented cadence for an EPRV facility using KPF’s fast readout mode (<16 s between exposures). Daily autonomous operation is achieved by defining an operations loop using state machine logic. Data affected by clouds are automatically flagged using a reliable quality control metric derived from simultaneous irradiance measurements. Comparing solar data across the growing global network of EPRV spectrographs with solar feeds will allow EPRV teams to disentangle internal and external noise sources and benchmark spectrograph performance. To facilitate this, all SoCal data products are immediately available to the public on the Keck Observatory Archive. We compared SoCal RVs to contemporaneous RVs from NEID, the only other immediately public EPRV solar data set. We find agreement at the 30–40 cm s−1 level on timescales of several hours, which is comparable to the combined photon-limited precision. Data from SoCal were also used to assess a detector problem and wavelength calibration inaccuracies associated with KPF during early operations. Long-term SoCal operations will collect upwards of 1000 solar spectra per six-hour day using KPF’s fast readout mode, enabling stellar activity studies at high S/N on our nearest solar-type star.
极精密径向速度(EPRV)测量在通往 10 cm s-1 "外地球 "灵敏度的道路上要与内部噪声(仪器系统性)和外部噪声(恒星内在变异性)作斗争。利用 "太阳即恒星 "的 RV 和跨仪器比较可以很好地探测这两种噪声源。我们建造了太阳校准器(SoCal),它是一个自主系统,向 W. M. 凯克天文台最近投入使用的凯克行星探测器(KPF)提供稳定的磁盘积分太阳光。利用SoCal,KPF以5秒的曝光时间获取信噪比(S/N)∼1200,R = 98,000的太阳光学(445-870 nm)光谱,对于使用KPF的快速读出模式(曝光间隔16秒)的EPRV设备来说,这种速度是前所未有的。通过使用状态机逻辑定义操作循环,实现了每日自主运行。利用同步辐照度测量得出的可靠质量控制指标,受云层影响的数据会被自动标记。在不断扩大的 EPRV 光谱仪全球网络中,通过太阳馈源对太阳数据进行比较,将使 EPRV 团队能够区分内部和外部噪声源,并对光谱仪的性能进行基准测试。为了便于进行这项工作,所有 SoCal 数据产品都可以立即在凯克天文台档案库中向公众提供。我们将 SoCal RV 与 NEID 的同期 RV 进行了比较,后者是唯一一个立即公开的 EPRV 太阳数据集。我们发现在 30-40 cm s-1 的水平上,两者在几个小时的时间尺度上是一致的,这与光子限制的综合精度相当。来自 SoCal 的数据还被用来评估早期运行期间与 KPF 有关的探测器问题和波长校准误差。SoCal 的长期运行将利用 KPF 的快速读出模式,每天 6 小时收集多达 1000 多条太阳光谱,从而能够对离我们最近的太阳型恒星进行高信噪比的恒星活动研究。
{"title":"Staring at the Sun with the Keck Planet Finder: An Autonomous Solar Calibrator for High Signal-to-noise Sun-as-a-star Spectra","authors":"Ryan A. Rubenzahl, Samuel Halverson, Josh Walawender, Grant M. Hill, Andrew W. Howard, Matthew Brown, Evan Ida, Jerez Tehero, Benjamin J. Fulton, Steven R. Gibson, Marc Kassis, Brett Smith, Truman Wold, Joel Payne","doi":"10.1088/1538-3873/ad0b30","DOIUrl":"https://doi.org/10.1088/1538-3873/ad0b30","url":null,"abstract":"Extreme precision radial velocity (EPRV) measurements contend with internal noise (instrumental systematics) and external noise (intrinsic stellar variability) on the road to 10 cm s<sup>−1</sup> “exo-Earth” sensitivity. Both of these noise sources are well-probed using “Sun-as-a-star” RVs and cross-instrument comparisons. We built the Solar Calibrator (SoCal), an autonomous system that feeds stable, disk-integrated sunlight to the recently commissioned Keck Planet Finder (KPF) at the W. M. Keck Observatory. With SoCal, KPF acquires signal-to-noise ratio (S/N) ∼ 1200, <italic toggle=\"yes\">R</italic> = 98,000 optical (445–870 nm) spectra of the Sun in 5 s exposures at unprecedented cadence for an EPRV facility using KPF’s fast readout mode (&lt;16 s between exposures). Daily autonomous operation is achieved by defining an operations loop using state machine logic. Data affected by clouds are automatically flagged using a reliable quality control metric derived from simultaneous irradiance measurements. Comparing solar data across the growing global network of EPRV spectrographs with solar feeds will allow EPRV teams to disentangle internal and external noise sources and benchmark spectrograph performance. To facilitate this, all SoCal data products are immediately available to the public on the Keck Observatory Archive. We compared SoCal RVs to contemporaneous RVs from NEID, the only other immediately public EPRV solar data set. We find agreement at the 30–40 cm s<sup>−1</sup> level on timescales of several hours, which is comparable to the combined photon-limited precision. Data from SoCal were also used to assess a detector problem and wavelength calibration inaccuracies associated with KPF during early operations. Long-term SoCal operations will collect upwards of 1000 solar spectra per six-hour day using KPF’s fast readout mode, enabling stellar activity studies at high S/N on our nearest solar-type star.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":"51 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138684481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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
The Abrupt Resumptions of Pulsations in α Cygni (Deneb) α天鹅座(Deneb)脉冲的突然恢复
IF 3.5 3区 物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS Pub Date : 2023-12-01 DOI: 10.1088/1538-3873/ad1118
H. Abt, J. Guzik, J. Jackiewicz
Paddock’s 1927–1935 radial velocities of α Cygni (Deneb) show semi-regular pulsations with a dominant period of about 12 days. Lucy found many periods of lesser amplitude. In Paddock’s data and subsequent 1956 data from Abt, after the large-amplitude pulsations seemed to damp down, abruptly new sets of pulsations started within a fraction of a day. Five of those resumptions occurred with intervals averaging 72.4 ± 0.3 days. These resumptions seem to start at any phase during the pulsations. We are unaware of this behavior in any other star. We also find evidence of this behavior in the 1977–1982 radial velocity data of Parthasarathy & Lambert and the 1997–2001 photometry/radial velocity data of Richardson et al., as well as in photometric data from the NASA Transiting Exoplanet Survey Satellite (TESS) spacecraft and ground-based visual observations in the AAVSO International Database. The ground-based data have too infrequent sampling intervals to confirm the ∼70-day resumption intervals or to pinpoint the day and phase of abrupt amplitude increase. The TESS data, with 2-minute cadence, shows one instance of pulsation resumption, but does not have a long enough time series to confirm a 70-day interval. Without any evidence for duplicity, we cannot explain this behavior as being due to a companion in a highly eccentric orbit. α Cygni is one of the Luminous Blue Variables (supergiants) and these resumptions may be related to the microvariations produced in convective layers below their atmospheres, pulsation-driven shocks and rarefactions, or pulsation-convection interactions. We encourage further observations by ground-based observers and using the TESS spacecraft to confirm the ∼70-day resumption interval and lack of correlation with pulsation phase in both radial velocity and light curve data.
帕多克(Paddock)1927-1935 年对α 天鹅座(Deneb)的径向速度研究显示,α 天鹅座的脉动是半规则的,主要周期约为 12 天。露西发现了许多振幅较小的周期。在帕多克的数据和后来 1956 年阿伯特的数据中,大振幅脉动似乎减弱后,新的脉动又在一天之内突然开始。其中五次恢复的时间间隔平均为 72.4 ± 0.3 天。这些恢复似乎可以在脉动过程中的任何阶段开始。我们没有在其他恒星中发现过这种现象。我们还在 Parthasarathy 和 Lambert 1977-1982 年的径向速度数据、Richardson 等人 1997-2001 年的测光/径向速度数据,以及 NASA Transiting Exoplanet Survey Satellite(TESS)航天器的测光数据和 AAVSO 国际数据库中的地基目视观测数据中找到了这种行为的证据。地基数据的采样间隔太短,无法确认 70 天的恢复间隔,也无法确定振幅突然增大的日期和相位。TESS 的数据以 2 分钟为一周期,显示了一次脉动恢复,但没有足够长的时间序列来确认 70 天的间隔。α天鹅座是发光蓝变星(超巨星)之一,这些脉动恢复可能与其大气层下对流层产生的微变、脉动驱动的冲击和稀有效应或脉动与对流的相互作用有关。我们鼓励地面观测者和 TESS 航天器进行进一步观测,以证实恢复间隔为 70 天,且径向速度和光曲线数据与脉冲相位缺乏相关性。
{"title":"The Abrupt Resumptions of Pulsations in α Cygni (Deneb)","authors":"H. Abt, J. Guzik, J. Jackiewicz","doi":"10.1088/1538-3873/ad1118","DOIUrl":"https://doi.org/10.1088/1538-3873/ad1118","url":null,"abstract":"Paddock’s 1927–1935 radial velocities of α Cygni (Deneb) show semi-regular pulsations with a dominant period of about 12 days. Lucy found many periods of lesser amplitude. In Paddock’s data and subsequent 1956 data from Abt, after the large-amplitude pulsations seemed to damp down, abruptly new sets of pulsations started within a fraction of a day. Five of those resumptions occurred with intervals averaging 72.4 ± 0.3 days. These resumptions seem to start at any phase during the pulsations. We are unaware of this behavior in any other star. We also find evidence of this behavior in the 1977–1982 radial velocity data of Parthasarathy & Lambert and the 1997–2001 photometry/radial velocity data of Richardson et al., as well as in photometric data from the NASA Transiting Exoplanet Survey Satellite (TESS) spacecraft and ground-based visual observations in the AAVSO International Database. The ground-based data have too infrequent sampling intervals to confirm the ∼70-day resumption intervals or to pinpoint the day and phase of abrupt amplitude increase. The TESS data, with 2-minute cadence, shows one instance of pulsation resumption, but does not have a long enough time series to confirm a 70-day interval. Without any evidence for duplicity, we cannot explain this behavior as being due to a companion in a highly eccentric orbit. α Cygni is one of the Luminous Blue Variables (supergiants) and these resumptions may be related to the microvariations produced in convective layers below their atmospheres, pulsation-driven shocks and rarefactions, or pulsation-convection interactions. We encourage further observations by ground-based observers and using the TESS spacecraft to confirm the ∼70-day resumption interval and lack of correlation with pulsation phase in both radial velocity and light curve data.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":"65 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138993791","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 Proof of Concept Balanced Mixer with the use of a Digital IF Power Combiner to Improve LO Noise Rejection 利用数字中频功率合路器改进 LO 噪声抑制的概念验证平衡混频器
IF 3.5 3区 物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS Pub Date : 2023-12-01 DOI: 10.1088/1538-3873/ad0789
D. Monasterio, Sebastian Jorquera, F. Curotto, Camilo Espinoza, R. Finger, L. Bronfman
In this work we present a novel digital technique, that allows local oscillator (LO) noise cancellation using a digital power combiner in a balanced mixer receiver architecture. A theoretical analysis of the noise cancellation using the proposed technique is derived and a proof of concept experiment is made for the Ku-Band. This experiment includes the design and construction of a custom balanced mixer and an artificial noise source. Experimental results show a consistent noise temperature reduction in comparison with a full analog mixer, and in some cases reaching noise temperature levels similar to the receiver operating without the artificial LO noise.
在这项工作中,我们提出了一种新的数字技术,该技术允许在平衡混频器接收器架构中使用数字功率合成器来消除本振(LO)噪声。对所提出的降噪技术进行了理论分析,并对ku波段进行了概念验证实验。本实验包括定制平衡混频器和人工噪声源的设计和构造。实验结果表明,与全模拟混频器相比,噪声温度降低一致,并且在某些情况下达到与没有人工LO噪声的接收器工作相似的噪声温度水平。
{"title":"A Proof of Concept Balanced Mixer with the use of a Digital IF Power Combiner to Improve LO Noise Rejection","authors":"D. Monasterio, Sebastian Jorquera, F. Curotto, Camilo Espinoza, R. Finger, L. Bronfman","doi":"10.1088/1538-3873/ad0789","DOIUrl":"https://doi.org/10.1088/1538-3873/ad0789","url":null,"abstract":"In this work we present a novel digital technique, that allows local oscillator (LO) noise cancellation using a digital power combiner in a balanced mixer receiver architecture. A theoretical analysis of the noise cancellation using the proposed technique is derived and a proof of concept experiment is made for the Ku-Band. This experiment includes the design and construction of a custom balanced mixer and an artificial noise source. Experimental results show a consistent noise temperature reduction in comparison with a full analog mixer, and in some cases reaching noise temperature levels similar to the receiver operating without the artificial LO noise.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":" 5","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138615499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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
Photometry, Centroid and Point-spread Function Measurements in the LSST Camera Focal Plane Using Artificial Stars 利用人造恒星测量 LSST 相机焦平面的光度、中心点和点散布函数
IF 3.5 3区 物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS Pub Date : 2023-12-01 DOI: 10.1088/1538-3873/ad0a73
Johnny H. Esteves, Yousuke Utsumi, Adam Snyder, Theo Schutt, Alex Broughton, Bahrudin Trbalic, Sidney Mau, Andrew Rasmussen, Andrés A. Plazas Malagón, Andrew Bradshaw, Stuart Marshall, Seth Digel, James Chiang, Eli Rykoff, Chris Waters, Marcelle Soares-Santos, Aaron Roodman
The Vera C. Rubin Observatory’s LSST Camera (LSSTCam) pixel response has been characterized using laboratory measurements with a grid of artificial stars. We quantify the contributions to photometry, centroid, point-spread function size, and shape measurement errors due to small anomalies in the LSSTCam CCDs. The main sources of those anomalies are quantum efficiency variations and pixel area variations induced by the amplifier segmentation boundaries and “tree-rings”—circular variations in silicon doping concentration. This laboratory study using artificial stars projected on the sensors shows overall small effects. The residual effects on point-spread function (PSF) size and shape are below 0.1%, meeting the ten-year LSST survey science requirements. However, the CCD mid-line presents distortions that can have a moderate impact on PSF measurements. This feature can be avoided by masking the affected regions. Effects of tree-rings are observed on centroids and PSFs of the artificial stars and the nature of the effect is confirmed by a study of the flat-field response. Nevertheless, further studies of the full-focal plane with stellar data should more completely probe variations and might reveal new features, e.g., wavelength-dependent effects. The results of this study can be used as a guide for the on-sky operation of LSSTCam.
Vera C. Rubin天文台的LSST相机(LSSTCam)的像素响应是通过实验室测量人造恒星网格来确定的。我们量化了 LSSTCam CCD 的微小异常对光度、中心点、点散布函数大小和形状测量误差的影响。这些异常的主要来源是放大器分割边界和 "树环"(硅掺杂浓度的圆形变化)引起的量子效率变化和像素面积变化。这项使用投射到传感器上的人造星进行的实验室研究显示,总体影响较小。对点散射函数(PSF)大小和形状的残余影响低于 0.1%,符合 LSST 十年巡天科学要求。不过,CCD 中线的扭曲会对 PSF 测量产生一定影响。可以通过遮挡受影响区域来避免这一问题。在人造星的中心点和 PSF 上观测到了树环效应,对平场响应的研究证实了这种效应的性质。不过,利用恒星数据对全焦面的进一步研究应该能更全面地探查各种变化,并可能揭示出新的特征,例如与波长有关的效应。本研究的结果可作为 LSSTCam 在天空中运行的指导。
{"title":"Photometry, Centroid and Point-spread Function Measurements in the LSST Camera Focal Plane Using Artificial Stars","authors":"Johnny H. Esteves, Yousuke Utsumi, Adam Snyder, Theo Schutt, Alex Broughton, Bahrudin Trbalic, Sidney Mau, Andrew Rasmussen, Andrés A. Plazas Malagón, Andrew Bradshaw, Stuart Marshall, Seth Digel, James Chiang, Eli Rykoff, Chris Waters, Marcelle Soares-Santos, Aaron Roodman","doi":"10.1088/1538-3873/ad0a73","DOIUrl":"https://doi.org/10.1088/1538-3873/ad0a73","url":null,"abstract":"The Vera C. Rubin Observatory’s LSST Camera (LSSTCam) pixel response has been characterized using laboratory measurements with a grid of artificial stars. We quantify the contributions to photometry, centroid, point-spread function size, and shape measurement errors due to small anomalies in the LSSTCam CCDs. The main sources of those anomalies are quantum efficiency variations and pixel area variations induced by the amplifier segmentation boundaries and “tree-rings”—circular variations in silicon doping concentration. This laboratory study using artificial stars projected on the sensors shows overall small effects. The residual effects on point-spread function (PSF) size and shape are below 0.1%, meeting the ten-year LSST survey science requirements. However, the CCD mid-line presents distortions that can have a moderate impact on PSF measurements. This feature can be avoided by masking the affected regions. Effects of tree-rings are observed on centroids and PSFs of the artificial stars and the nature of the effect is confirmed by a study of the flat-field response. Nevertheless, further studies of the full-focal plane with stellar data should more completely probe variations and might reveal new features, e.g., wavelength-dependent effects. The results of this study can be used as a guide for the on-sky operation of LSSTCam.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":"28 1","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138684133","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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
Rotational Phase Dependent J − H Colour of the Dwarf Planet Eris 矮行星厄里斯的旋转相位相关 J - H 颜色
IF 3.5 3区 物理与天体物理 Q2 ASTRONOMY & ASTROPHYSICS Pub Date : 2023-12-01 DOI: 10.1088/1538-3873/ad0b31
R. Szakáts, Csaba Kiss
The largest bodies—or dwarf planets—constitute a different class among Kuiper Belt objects and are characterized by bright surfaces and volatile compositions remarkably different from that of smaller trans-Neptunian objects. These compositional differences are also reflected in the visible and near-infrared colors, and variegations across the surface can cause broadband colors to vary with rotational phase. Here we present near-infrared J and H-band observations of the dwarf planet (136199) Eris obtained with the GuideDog camera of the Infrared Telescope Facility. These measurements show that—as suspected from previous J − H measurements—the J − H color of Eris indeed varies with rotational phase. This suggests notable surface heterogenity in chemical composition and/or other material properties despite the otherwise quite homogeneous, high albedo surface, characterized by a very low amplitude visible range light curve. While variations in the grain size of the dominant CH4 may in general be responsible for notable changes in the J − H color, in the current observing geometry of the system it can only partially explain the observed J − H variation.
最大的天体——或矮行星——在柯伊伯带天体中构成了不同的类别,其特征是明亮的表面和挥发性成分,与较小的海王星外天体明显不同。这些成分的差异也反映在可见光和近红外颜色上,并且表面上的变化会导致宽带颜色随旋转相位而变化。在这里,我们介绍了用红外望远镜设施的导盲犬相机获得的矮行星(136199)Eris的近红外J和h波段观测结果。这些测量结果表明——正如之前的J−H测量所怀疑的那样——阋神星的J−H颜色确实随着旋转相位的变化而变化。这表明表面在化学成分和/或其他材料性质上存在显著的不均匀性,尽管表面具有相当均匀的高反照率,其特征是可见范围光曲线的振幅非常低。虽然主要CH4的晶粒尺寸的变化通常可能导致J−H颜色的显著变化,但在目前观察到的系统几何结构中,它只能部分解释观察到的J−H变化。
{"title":"Rotational Phase Dependent J − H Colour of the Dwarf Planet Eris","authors":"R. Szakáts, Csaba Kiss","doi":"10.1088/1538-3873/ad0b31","DOIUrl":"https://doi.org/10.1088/1538-3873/ad0b31","url":null,"abstract":"The largest bodies—or dwarf planets—constitute a different class among Kuiper Belt objects and are characterized by bright surfaces and volatile compositions remarkably different from that of smaller trans-Neptunian objects. These compositional differences are also reflected in the visible and near-infrared colors, and variegations across the surface can cause broadband colors to vary with rotational phase. Here we present near-infrared J and H-band observations of the dwarf planet (136199) Eris obtained with the GuideDog camera of the Infrared Telescope Facility. These measurements show that—as suspected from previous J − H measurements—the J − H color of Eris indeed varies with rotational phase. This suggests notable surface heterogenity in chemical composition and/or other material properties despite the otherwise quite homogeneous, high albedo surface, characterized by a very low amplitude visible range light curve. While variations in the grain size of the dominant CH4 may in general be responsible for notable changes in the J − H color, in the current observing geometry of the system it can only partially explain the observed J − H variation.","PeriodicalId":20820,"journal":{"name":"Publications of the Astronomical Society of the Pacific","volume":" 606","pages":""},"PeriodicalIF":3.5,"publicationDate":"2023-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138610794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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
期刊
Publications of the Astronomical Society of the Pacific
全部 Acc. Chem. Res. ACS Applied Bio Materials ACS Appl. Electron. Mater. ACS Appl. Energy Mater. ACS Appl. Mater. Interfaces ACS Appl. Nano Mater. ACS Appl. Polym. Mater. ACS BIOMATER-SCI ENG ACS Catal. ACS Cent. Sci. ACS Chem. Biol. ACS Chemical Health & Safety ACS Chem. Neurosci. ACS Comb. Sci. ACS Earth Space Chem. ACS Energy Lett. ACS Infect. Dis. ACS Macro Lett. ACS Mater. Lett. ACS Med. Chem. Lett. ACS Nano ACS Omega ACS Photonics ACS Sens. ACS Sustainable Chem. Eng. ACS Synth. Biol. Anal. Chem. BIOCHEMISTRY-US Bioconjugate Chem. BIOMACROMOLECULES Chem. Res. Toxicol. Chem. Rev. Chem. Mater. CRYST GROWTH DES ENERG FUEL Environ. Sci. Technol. Environ. Sci. Technol. Lett. Eur. J. Inorg. Chem. IND ENG CHEM RES Inorg. Chem. J. Agric. Food. Chem. J. Chem. Eng. Data J. Chem. Educ. J. Chem. Inf. Model. J. Chem. Theory Comput. J. Med. Chem. J. Nat. Prod. J PROTEOME RES J. Am. Chem. Soc. LANGMUIR MACROMOLECULES Mol. Pharmaceutics Nano Lett. Org. Lett. ORG PROCESS RES DEV ORGANOMETALLICS J. Org. Chem. J. Phys. Chem. J. Phys. Chem. A J. Phys. Chem. B J. Phys. Chem. C J. Phys. Chem. Lett. Analyst Anal. Methods Biomater. Sci. Catal. Sci. Technol. Chem. Commun. Chem. Soc. Rev. CHEM EDUC RES PRACT CRYSTENGCOMM Dalton Trans. Energy Environ. Sci. ENVIRON SCI-NANO ENVIRON SCI-PROC IMP ENVIRON SCI-WAT RES Faraday Discuss. Food Funct. Green Chem. Inorg. Chem. Front. Integr. Biol. J. Anal. At. Spectrom. J. Mater. Chem. A J. Mater. Chem. B J. Mater. Chem. C Lab Chip Mater. Chem. Front. Mater. Horiz. MEDCHEMCOMM Metallomics Mol. Biosyst. Mol. Syst. Des. Eng. Nanoscale Nanoscale Horiz. Nat. Prod. Rep. New J. Chem. Org. Biomol. Chem. Org. Chem. Front. PHOTOCH PHOTOBIO SCI PCCP Polym. Chem.
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1