发布求助
文献互助 智能选刊 最新文献

Proceedings of the International Astronomical Union. International Astronomical Union最新文献

筛选
英文 中文
The structure of the Milky Way from period-luminosity relations. 从周期-光度关系看银河系的结构
Proceedings of the International Astronomical Union. International Astronomical Union Pub Date : 2024-02-06 DOI: 10.1017/S1743921323003083
Dorota M Skowron
{"title":"The structure of the Milky Way from period-luminosity relations.","authors":"Dorota M Skowron","doi":"10.1017/S1743921323003083","DOIUrl":"10.1017/S1743921323003083","url":null,"abstract":"<p><p>Disentangling the structural components of the Milky Way requires knowledge of distances to various classes of objects, both young, which trace the Galactic disk, and old, which trace the Galactic bulge and halo. Variable stars that obey period-luminosity relations are perfect distance indicators for such studies. Here we discuss recent findings on the structure of our galaxy, inferred from period-luminosity relations for both young, old and intermediate-age variable stars, including Cepheids, RR Lyrae stars, <i>δ</i> Scuti stars, and long-period variables.</p>","PeriodicalId":74548,"journal":{"name":"Proceedings of the International Astronomical Union. International Astronomical Union","volume":"18 Suppl 376","pages":"180-194"},"PeriodicalIF":0.0,"publicationDate":"2024-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7615664/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139974918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Multiplicity of Northern bright O-type stars with optical long baseline interferometry. Results of the pilot survey. 用光学长基线干涉测量法观测北半球明亮的o型星的多样性。试点调查结果。
Proceedings of the International Astronomical Union. International Astronomical Union Pub Date : 2023-04-01 DOI: 10.1051/0004-6361/202245364
Cyprien Lanthermann
{"title":"Multiplicity of Northern bright O-type stars with optical long baseline interferometry. Results of the pilot survey.","authors":"Cyprien Lanthermann","doi":"10.1051/0004-6361/202245364","DOIUrl":"https://doi.org/10.1051/0004-6361/202245364","url":null,"abstract":"<p><p>The study of the multiplicity of massive stars gives hints of their formation processes and their evolution path. Optical interferometry is mandatory to fulfill our knowledge of their multiplicity by probing the separation gap between 1 and 50 mas. We demonstrated the capability of the new interferometric instrument MIRC-X, located at the CHARA array, to study a large sample of more than 120 (H < 7.5) O-type stars. We observed 29 O-type star systems, including a couple of systems in average atmospheric conditions around a magnitude of H = 7.5. Out of these 29 systems, we detected 18 companions in 16 different systems, resulting in a multiplicity fraction f <sub><i>m</i></sub> = 16 / 29 = 0.55, and a companion fraction of f <sub><i>c</i></sub> = 18 / 29 = 0.62. We observed for the first time 11 of these detected companions. This study concludes that a large survey on more than 120 Northern O-type stars is possible with MIRC-X.</p>","PeriodicalId":74548,"journal":{"name":"Proceedings of the International Astronomical Union. International Astronomical Union","volume":"672 ","pages":"A6"},"PeriodicalIF":0.0,"publicationDate":"2023-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7614368/pdf/EMS152562.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9227878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Hybrid magnetic structures around spinning black holes connected to a surrounding accretion disk. 与周围吸积盘相连的旋转黑洞周围的混合磁结构。
Proceedings of the International Astronomical Union. International Astronomical Union Pub Date : 2023-01-23 DOI: 10.1017/S1743921322001715
I El Mellah, B Cerutti, B Crinquand, K Parfrey
{"title":"Hybrid magnetic structures around spinning black holes connected to a surrounding accretion disk.","authors":"I El Mellah, B Cerutti, B Crinquand, K Parfrey","doi":"10.1017/S1743921322001715","DOIUrl":"10.1017/S1743921322001715","url":null,"abstract":"<p><p>The hot accretion flow around Kerr black holes is strongly magnetized. Magnetic field loops sustained by a surrounding accretion disk can close within the event horizon. We performed particle-in-cell simulations in Kerr metric to capture the dynamics of the electromagnetic field and of the ambient collisionless plasma in this coupled configuration. We find that a hybrid magnetic topology develops with a closed magnetosphere co-existing with open field lines threading the horizon reminiscent of the Blandford-Znajek solution. Further in the disk, highly inclined open magnetic field lines can launch a magnetically-driven wind. While the plasma is essentially force-free, a current sheet forms above the disk where magnetic reconnection produces macroscopic plasmoids and accelerates particles up to relativistic Lorentz factors. A highly dynamic Y-point forms on the furthest closed magnetic field line, with episodic reconnection events responsible for transient synchrotron emission and coronal heating.</p>","PeriodicalId":74548,"journal":{"name":"Proceedings of the International Astronomical Union. International Astronomical Union","volume":"16 Suppl 362","pages":"184-189"},"PeriodicalIF":0.0,"publicationDate":"2023-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7614309/pdf/EMS144710.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9854008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Hierarchical star formation in the Magellanic Clouds with the VMC survey. 麦哲伦星云中的分层恒星形成与VMC调查。
Proceedings of the International Astronomical Union. International Astronomical Union Pub Date : 2021-08-01 DOI: 10.1017/S1743921322005038
Amy E Miller, Maria-Rosa L Cioni, Richard de Grijs, Ning-Chen Sun
{"title":"Hierarchical star formation in the Magellanic Clouds with the VMC survey.","authors":"Amy E Miller,&nbsp;Maria-Rosa L Cioni,&nbsp;Richard de Grijs,&nbsp;Ning-Chen Sun","doi":"10.1017/S1743921322005038","DOIUrl":"https://doi.org/10.1017/S1743921322005038","url":null,"abstract":"<p><p>The VISTA Magellanic Clouds Survey (VMC) is a near-infrared survey of the Magellanic system. The VMC data has been exploited to detect and study statistically correlated young groups of stars - also known as \"young stellar structures\" - in the Large and Small Magellanic Clouds (LMC and SMC). We showcase the ~ 3000 recently detected young stellar structures in the LMC and their similarity to the fractal interstellar medium. We discuss how their properties indicate their formation mechanisms and that there are no preferred scales of star formation in the LMC.</p>","PeriodicalId":74548,"journal":{"name":"Proceedings of the International Astronomical Union. International Astronomical Union","volume":"17 Suppl 373","pages":"11-14"},"PeriodicalIF":0.0,"publicationDate":"2021-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7614645/pdf/EMS158215.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9656048","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
The rotation of low mass stars at 30 Myr in the cluster NGC 3766. NGC 3766星团中30myr低质量恒星的旋转。
Proceedings of the International Astronomical Union. International Astronomical Union Pub Date : 2019-06-01 Epub Date: 2020-09-24 DOI: 10.1017/S1743921319009797
Julia Roquette, Jerome Bouvier, Estelle Moraux, Herve Bouy, Jonathan Irwin, Suzanne Aigrain, Régis Lachaume
{"title":"The rotation of low mass stars at 30 Myr in the cluster NGC 3766.","authors":"Julia Roquette,&nbsp;Jerome Bouvier,&nbsp;Estelle Moraux,&nbsp;Herve Bouy,&nbsp;Jonathan Irwin,&nbsp;Suzanne Aigrain,&nbsp;Régis Lachaume","doi":"10.1017/S1743921319009797","DOIUrl":"https://doi.org/10.1017/S1743921319009797","url":null,"abstract":"<p><p>Together with the stellar rotation, the spotted surfaces of low-mass magnetically active stars produce modulations in their brightness. These modulations can be resolved by photometric variability surveys, allowing direct measurements of stellar spin rates. In this pro-ceedings, we present results of a multisite photometric survey dedicated to the measurement of spin rates in the 30 Myr cluster NGC 3766. Inside the framework of the Monitor Project, the cluster was monitored during 2014 in the i-band by the Wide Field Imager at the MPG/ESO 2.2-m telescope. Data from Gaia-DR2 and <i>griz</i> Y photometry from DECam/CTIO were used to identify cluster members. We present spin rates measured for ∼200 cluster members.</p>","PeriodicalId":74548,"journal":{"name":"Proceedings of the International Astronomical Union. International Astronomical Union","volume":"15 Suppl 354","pages":"200-203"},"PeriodicalIF":0.0,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S1743921319009797","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38451863","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
SOWAT: High-resolution imaging with only partial AO correction. SOWAT：仅进行部分 AO 校正的高分辨率成像。
Proceedings of the International Astronomical Union. International Astronomical Union Pub Date : 2019-05-01 Epub Date: 2020-03-11 DOI: 10.1017/S1743921319007026
Felix Bosco, Jörg-Uwe Pott, Rainer Schödel
{"title":"SOWAT: High-resolution imaging with only partial AO correction.","authors":"Felix Bosco, Jörg-Uwe Pott, Rainer Schödel","doi":"10.1017/S1743921319007026","DOIUrl":"10.1017/S1743921319007026","url":null,"abstract":"<p><p>Observations of dense stellar systems such as globular clusters (GCs) are limited in resolution by the optical aberrations induced by atmospheric turbulence (atmospheric seeing). At the example of holographic speckle imaging, we now study, to which degree image reconstruction algorithms are able to remove residual aberrations from a partial adaptive optics (AO) correction, such as delivered from ground-layer AO (GLAO) systems. Simultaneously, we study, how such algorithms benefit from being applied to pre-corrected instead of natural point-spread functions (PSFs). We find that using partial AO corrections already lowers the demands on the holography reference star by ∼ 3 mag, what makes more fields accessible for this technique, and also that the discrete integration times may be chosen about 2 - 3× longer, since the effective wavefront evolution is slowed down by removing the perturbation power.</p>","PeriodicalId":74548,"journal":{"name":"Proceedings of the International Astronomical Union. International Astronomical Union","volume":"14 Suppl 351","pages":"185-188"},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7115986/pdf/EMS92595.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38325631","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Using cold plasma to investigate the mechanisms involved in cosmic dust formation: role of the C/O ratio and metals. 利用冷等离子体研究宇宙尘埃形成的机制：C/O 比率和金属的作用。
Proceedings of the International Astronomical Union. International Astronomical Union Pub Date : 2019-04-01 Epub Date: 2020-10-12 DOI: 10.1017/S1743921319008457
Rémi Bérard, Kremena Makasheva, Hassan Sabbah, Karine Demyk, Christine Joblin
{"title":"Using cold plasma to investigate the mechanisms involved in cosmic dust formation: role of the C/O ratio and metals.","authors":"Rémi Bérard, Kremena Makasheva, Hassan Sabbah, Karine Demyk, Christine Joblin","doi":"10.1017/S1743921319008457","DOIUrl":"10.1017/S1743921319008457","url":null,"abstract":"<p><p>Using a cold plasma reactor in which we inject an organosilicon molecular precursor, we investigate chemical mechanisms that can be involved in dust formation in evolved stars. By injecting metal atoms into the gas-phase, we investigate the role of metals on dust composition. We show the formation of composite particles made of pure metal (silver) nanoparticles embedded in an organosilicon dust. We study the impact of oxygen and show that it can inhibit dust formation, likely through the destruction of nucleation seeds.</p>","PeriodicalId":74548,"journal":{"name":"Proceedings of the International Astronomical Union. International Astronomical Union","volume":"15 Suppl 350","pages":"397-300"},"PeriodicalIF":0.0,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7116203/pdf/EMS92592.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38604837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Evolution of Solids in Planet Forming Disks: The Interplay of Experiments, Simulations, and Observations. 行星形成盘中固体的演化:实验、模拟和观测的相互作用。
Proceedings of the International Astronomical Union. International Astronomical Union Pub Date : 2019-04-01 Epub Date: 2020-10-12 DOI: 10.1017/S1743921319009608
T Birnstiel
{"title":"Evolution of Solids in Planet Forming Disks: The Interplay of Experiments, Simulations, and Observations.","authors":"T Birnstiel","doi":"10.1017/S1743921319009608","DOIUrl":"https://doi.org/10.1017/S1743921319009608","url":null,"abstract":"<p><p>Circumstellar dust analogues can be studied experimentally to determine their col- lisional behavior and their optical properties. These results affect simulations of circumstellar disks in various, substantial ways: Collision results determine how dust aggregates grow and how their aerodynamic properties change with time. This determines how solids move throughout the disk, how they accumulate, and how planetesimals might be formed. The optical properties determine the observational signature of these effects and allow us to constrain the spatial distribution of dust in disks, the sizes of the aggregates, as well as the temperature and optical depth of the dust emission. In this contribution, it is discussed how theoretical models and their predictions depend on laboratory results and what we learned about disks from high spatial resolution radio interferometry.</p>","PeriodicalId":74548,"journal":{"name":"Proceedings of the International Astronomical Union. International Astronomical Union","volume":"15 Suppl 350","pages":"200-204"},"PeriodicalIF":0.0,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S1743921319009608","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38604834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Photoprocessing of large PAH cations. 大的多环芳烃阳离子的光处理。
Proceedings of the International Astronomical Union. International Astronomical Union Pub Date : 2019-04-01 Epub Date: 2020-10-12 DOI: 10.1017/S1743921319007063
Gabi Wenzel, Sarah Rodriguez Castillo, Giacomo Mulas, Ming-Chao Ji, Anthony Bonnamy, Hassan Sabbah, Alexandre Giuliani, Laurent Nahon, Christine Joblin
{"title":"Photoprocessing of large PAH cations.","authors":"Gabi Wenzel,&nbsp;Sarah Rodriguez Castillo,&nbsp;Giacomo Mulas,&nbsp;Ming-Chao Ji,&nbsp;Anthony Bonnamy,&nbsp;Hassan Sabbah,&nbsp;Alexandre Giuliani,&nbsp;Laurent Nahon,&nbsp;Christine Joblin","doi":"10.1017/S1743921319007063","DOIUrl":"https://doi.org/10.1017/S1743921319007063","url":null,"abstract":"<p><p>In cosmic environments, polycyclic aromatic hydrocarbons (PAHs) strongly interact with vacuum ultraviolet (VUV) photons emitted by young stars. Trapped PAH cations ranging in size from 30 to 48 carbon atoms were irradiated by tunable synchrotron light (DESIRS beamline at SOLEIL). Their ionization and dissociation cross sections were determined and compared with TD-DFT computed photoabsorption cross sections. Evidence for radiative cooling is reported.</p>","PeriodicalId":74548,"journal":{"name":"Proceedings of the International Astronomical Union. International Astronomical Union","volume":"15 Suppl 350","pages":"388-389"},"PeriodicalIF":0.0,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/S1743921319007063","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"38604836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Deuteration of C60 on a highly oriented pyrolytic graphite surface. 高取向热解石墨表面的 C60 Deuteration。
Proceedings of the International Astronomical Union. International Astronomical Union Pub Date : 2019-04-01 Epub Date: 2020-10-12 DOI: 10.1017/S1743921320000344
G Pantazidis, M Scheffler, F D S Simonsen, A Cassidy, P A Jensen, L Hornekær, J D Thrower
{"title":"Deuteration of C<sub>60</sub> on a highly oriented pyrolytic graphite surface.","authors":"G Pantazidis, M Scheffler, F D S Simonsen, A Cassidy, P A Jensen, L Hornekær, J D Thrower","doi":"10.1017/S1743921320000344","DOIUrl":"10.1017/S1743921320000344","url":null,"abstract":"<p><p>Reactions on carbonaceous surfaces play an important role in processes such as H<sub>2</sub> formation in the interstellar medium. We have investigated the adsorption of C<sub>60</sub> molecules on a highly oriented pyrolytic graphite (HOPG) surface and then exposed them to a beam of deuterium atoms in order to investigate the formation of deuterated fullerenes. Scanning tunneling microscopy (STM) was used to probe the adsorbed molecules and their deuteration. Deuteration of C<sub>60</sub> films results in increased thermal stability of the film, relative to films of pristine C<sub>60</sub>, along with an evolution towards higher deuterated species. The STM data provide confirmatory evidence for the formation of deuterated fullerene species.</p>","PeriodicalId":74548,"journal":{"name":"Proceedings of the International Astronomical Union. International Astronomical Union","volume":"15 Suppl 350","pages":"458-459"},"PeriodicalIF":0.0,"publicationDate":"2019-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7610475/pdf/EMS120223.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"25532196","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
下一页 尾页
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
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
请完成安全验证×
相关产品
×
本文献相关产品
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 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号：481959085
Book学术官方微信