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Chemical Evolution via Dilution of an Initial Reservoir of Heavy Elements 通过稀释初始重元素储层实现化学演化
Research notes of the AAS Pub Date : 2024-06-24 DOI: 10.3847/2515-5172/ad5a8d
Graeme H. Smith
{"title":"Chemical Evolution via Dilution of an Initial Reservoir of Heavy Elements","authors":"Graeme H. Smith","doi":"10.3847/2515-5172/ad5a8d","DOIUrl":"https://doi.org/10.3847/2515-5172/ad5a8d","url":null,"abstract":"As a possible analog to the type of environment that might have produced the first low-mass metal-containing stars, a model is outlined in which a reservoir of gas containing the first metals begins forming stars upon an inflow of metal-free gas from a surrounding environment. The mass of gas in the reservoir is assumed to initially increase, reach a maximum, and then follow an exponential decline. The stellar metallicity distribution brought about is an example of chemical evolution via dilution of an initial source of metals.","PeriodicalId":74684,"journal":{"name":"Research notes of the AAS","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Determination of the Abundance of Mercury from the Hg ii Line at 5677.10 Å in Late B-type Stars. III. HD 145389 (ϕ Her) and HD 186122 (46 Aql) 通过 B 型晚期恒星中位于 5677.10 Å 处的 Hg ii 线确定汞的丰度。III.HD 145389 (ϕ Her) 和 HD 186122 (46 Aql)
Research notes of the AAS Pub Date : 2024-06-24 DOI: 10.3847/2515-5172/ad5a8e
Richard Monier
{"title":"Determination of the Abundance of Mercury from the Hg ii Line at 5677.10 Å in Late B-type Stars. III. HD 145389 (ϕ Her) and HD 186122 (46 Aql)","authors":"Richard Monier","doi":"10.3847/2515-5172/ad5a8e","DOIUrl":"https://doi.org/10.3847/2515-5172/ad5a8e","url":null,"abstract":"The weak line of Hg ii located at 5677.10 Å is used to measure the mercury abundance in two HgMn stars, HD 145389 (ϕ Her) and HD 186122 (46 Aql). This line is detected at 3σ above the noise in the adjacent continuum in ϕ Her but not detected in 46 Aql. The synthesis of this line, using the current atomic parameters available in NIST, confirms a large overabundance of mercury in HD 143807, about 4.08 dex, which is actually smaller than the excess derived from the 3983.93 Å line in earlier studies. The synthesis of other lines close to the Hg ii line yields excesses in scandium (+1.9 dex), chromium (+1.0 dex) and yttrium (+3.34 dex) in ϕ Her.","PeriodicalId":74684,"journal":{"name":"Research notes of the AAS","volume":"209 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141524955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Einasto Gravitational Potentials have Difficulty to Hold Spherically Symmetric Stellar Systems with Cores 艾纳斯托引力势难以保持球心对称恒星系统
Research notes of the AAS Pub Date : 2024-06-23 DOI: 10.3847/2515-5172/ad5a0f
Jorge Sánchez Almeida
{"title":"Einasto Gravitational Potentials have Difficulty to Hold Spherically Symmetric Stellar Systems with Cores","authors":"Jorge Sánchez Almeida","doi":"10.3847/2515-5172/ad5a0f","DOIUrl":"https://doi.org/10.3847/2515-5172/ad5a0f","url":null,"abstract":"It was known that an ideal spherically symmetric stellar system with isotropic velocities and an inner core cannot reside in a Navarro, Frenk, and White (NFW) gravitational potential. The incompatibility can be pinned down to the radial gradient of the NFW potential in the very center of the system, which differs from zero. The gradient is identically zero in an Einasto potential, also an alternative representation of the dark matter (DM) halos created by the kind of cold DM defining the current cosmological model. Here we show that, despite the inner gradient being zero, stellar cores are also inconsistent with Einasto potentials. This result may have implications to constrain the nature of DM through interpreting the stellar cores often observed in dwarf galaxies.","PeriodicalId":74684,"journal":{"name":"Research notes of the AAS","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501645","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Gnuastro: Generating Polar Plots in Astronomical Images Gnuastro：在天文图像中生成极坐标图
Research notes of the AAS Pub Date : 2024-06-23 DOI: 10.3847/2515-5172/ad5a6c
Sepideh Eskandarlou and Mohammad Akhlaghi
{"title":"Gnuastro: Generating Polar Plots in Astronomical Images","authors":"Sepideh Eskandarlou and Mohammad Akhlaghi","doi":"10.3847/2515-5172/ad5a6c","DOIUrl":"https://doi.org/10.3847/2515-5172/ad5a6c","url":null,"abstract":"When a structure displays dependence on distance and azimuthal angle from a center (for example the spiral arms of galaxies or the diffraction spikes of stars), projecting the pixels to polar coordinates greatly simplifies their study. This projection from one pixel grid to another is known as a “polar plot.” For this purpose, a new option has been added to the GNU Astronomy Utilities (Gnuastro) in version 0.23 to “astscript-radial-profile” script, which we describe in this research note. The figures of this research note are reproducible with Maneage, on the Git commit 5d34243.","PeriodicalId":74684,"journal":{"name":"Research notes of the AAS","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141524956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Observations of the 2024 May 14 X8.7 Solar Flare with the Goldstone-Apple Valley Radio Telescope (GAVRT) 利用金石-苹果谷射电望远镜（GAVRT）观测 2024 年 5 月 14 日 X8.7 级太阳耀斑
Research notes of the AAS Pub Date : 2024-06-20 DOI: 10.3847/2515-5172/ad5a0d
Thangasamy Velusamy, Ryan Dorcey, Nancy Kreuser-Jenkins, Lisa Nichole Lamb, Erica Pagano, Marin M. Anderson, Joseph Lazio and Steven Levin
{"title":"Observations of the 2024 May 14 X8.7 Solar Flare with the Goldstone-Apple Valley Radio Telescope (GAVRT)","authors":"Thangasamy Velusamy, Ryan Dorcey, Nancy Kreuser-Jenkins, Lisa Nichole Lamb, Erica Pagano, Marin M. Anderson, Joseph Lazio and Steven Levin","doi":"10.3847/2515-5172/ad5a0d","DOIUrl":"https://doi.org/10.3847/2515-5172/ad5a0d","url":null,"abstract":"The Goldstone-Apple Valley Radio Telescope (GAVRT) project conducts a regular monitoring program of the Sun. The GAVRT Solar Patrol project uses a 34 m diameter antenna to produce raster-scan maps of the Sun simultaneously at 4 frequencies ranging from approximately 3 to 14 GHz. On 2024 May 14, as part of regular GAVRT Solar Patrol observations, raster maps were produced when an X8.7 solar flare occurred in active region AR13664. Here we present the GAVRT maps of the May 14 flare along with microwave flux density spectra showing the non-thermal microwave burst emission from mildly relativistic electrons produced in this largest flare of Solar Cycle 25 to date. AR13664 reappeared as AR13697 and continued to be very active, producing X flares while GAVRT monitored its activity. GAVRT microwave data provide a powerful complement to the energetic electrons tracked by X-ray, millimeter-wave and γ-ray emissions.","PeriodicalId":74684,"journal":{"name":"Research notes of the AAS","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141531964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A Comment on the Solar Activity Level in 1791 by Lorenzo Hervás y Panduro 洛伦佐-埃尔瓦斯-潘杜罗对 1791 年太阳活动水平的评论
Research notes of the AAS Pub Date : 2024-06-20 DOI: 10.3847/2515-5172/ad5960
A. J. P. Aparicio and J. M. Vaquero
{"title":"A Comment on the Solar Activity Level in 1791 by Lorenzo Hervás y Panduro","authors":"A. J. P. Aparicio and J. M. Vaquero","doi":"10.3847/2515-5172/ad5960","DOIUrl":"https://doi.org/10.3847/2515-5172/ad5960","url":null,"abstract":"Past solar activity is of great interest for astrophysical and geophysical studies. Systematic searches over the last four centuries have detailed the evolution of the solar cycle. Brief comments on solar activity for periods with sparse records, such as the year 1791, are crucial. Lorenzo Hervás y Panduro, a Jesuit intellectual, noted in his 1793 book that sunspots were seen almost daily from 1791 January 1 to April 20. This would suggest a solar activity level estimated at a sunspot number of around 70.","PeriodicalId":74684,"journal":{"name":"Research notes of the AAS","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Absorption in the Spectrum of a Background AGN by C ii* by the Supernova Remnant G354-33 超新星残留物 G354-33 在背景 AGN 光谱中对 C ii* 的吸收
Research notes of the AAS Pub Date : 2024-06-20 DOI: 10.3847/2515-5172/ad58e3
John C. Raymond and Connor Griscom
{"title":"Absorption in the Spectrum of a Background AGN by C ii* by the Supernova Remnant G354-33","authors":"John C. Raymond and Connor Griscom","doi":"10.3847/2515-5172/ad58e3","DOIUrl":"https://doi.org/10.3847/2515-5172/ad58e3","url":null,"abstract":"A number of very large, very faint supernova remnants (SNRs) have been discovered in the past few years. Those in the Galactic halo occur in low density gas, so they might be more easily observed in absorption than in emission. The SNR G354-33 is a shell of faint UV and optical filaments about 10° in diameter. Here we point out that a spectrum of the QSO J2017-4516 used study the galaxy cluster J2016-4517 shows an absorption line from the excited fine structure level of C ii at −50 km s−1. Absorption features of Si ii and Si iii are also seen at this velocity. The observed column density compares well with shock wave models. Doppler shifted C ii* absorption features provide an excellent means to find and characterize SNR shocks because they arise from compressed gas.","PeriodicalId":74684,"journal":{"name":"Research notes of the AAS","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141524957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
A Lack of Mass-gap Compact Object Binaries in APOGEE APOGEE中缺乏质量间隙紧凑的天体双星
Research notes of the AAS Pub Date : 2024-06-20 DOI: 10.3847/2515-5172/ad5964
Meir Schochet, Jamie Tayar and Jeff J. Andrews
{"title":"A Lack of Mass-gap Compact Object Binaries in APOGEE","authors":"Meir Schochet, Jamie Tayar and Jeff J. Andrews","doi":"10.3847/2515-5172/ad5964","DOIUrl":"https://doi.org/10.3847/2515-5172/ad5964","url":null,"abstract":"Depending principally on mass, the compact object remnant left behind after a star’s life may be a white dwarf, neutron star (NS), or black hole (BH). While we have large samples of each of these remnants, we lack knowledge of the exact conditions separating these outcomes. The boundary between low-mass BHs and massive NSs is particularly poorly understood, as few objects between 2 and 5 M⊙ are known. To probe this regime, we search the Apache Point Observatory Galactic Evolution Experiment 17th Data Release data set of 657,000 unique stars for binary systems with one stellar component that exhibit large radial velocity shifts over multiple observations. We identify 4751 likely binary systems, and estimate a minimum mass for each system’s “invisible companion” under the assumption of tidal synchronization. Two systems have companion masses ≳2 M⊙, although we conclude that neither are good candidates for possessing a mass-gap NS or BH companions.","PeriodicalId":74684,"journal":{"name":"Research notes of the AAS","volume":"56 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141524959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Do We Finally Know all Stellar and Substellar Neighbors within 10 pc of the Sun? 我们终于知道距离太阳 10 pc 范围内的所有恒星和子恒星邻居了吗？
Research notes of the AAS Pub Date : 2024-06-17 DOI: 10.3847/2515-5172/ad5844
Ralf-Dieter Scholz and Alexey Mints
{"title":"Do We Finally Know all Stellar and Substellar Neighbors within 10 pc of the Sun?","authors":"Ralf-Dieter Scholz and Alexey Mints","doi":"10.3847/2515-5172/ad5844","DOIUrl":"https://doi.org/10.3847/2515-5172/ad5844","url":null,"abstract":"Our knowledge on the closest solar neighbors gradually improved over a long time with the help of new methods and the recognition of new stellar and substellar species. The latest burst of discoveries since 1997, in which the first author participated, seemingly filled the gap of missing systems within 10 pc from the Sun. However, previous estimates of the population relied on two assumptions: that the sample was complete within 5 pc and that the density was uniform out to 10 pc. The first of these is not true, and the second in question. Otherwise, up to about 90 systems could be still missing within 10 pc. We find no indication for missing brown dwarfs within 10 pc, but strongly increasing deficits from early-M to late-M dwarfs hint at some still hidden late-M dwarf neighbors. They may have already been detected by Gaia but published so far without or with incorrect parallax measurements, because of close companions or their location in the Galactic plane.","PeriodicalId":74684,"journal":{"name":"Research notes of the AAS","volume":"75 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141524958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Disproving the High-eccentricity Planet HD 220773b 反驳高同心度行星HD 220773b
Research notes of the AAS Pub Date : 2024-06-16 DOI: 10.3847/2515-5172/ad57b5
Ilaria Carleo, Silvano Desidera, Alessandro Sozzetti, Serena Benatti, Riccardo Claudi, Mario Damasso, Matteo Pinamonti and Alessandro Ruggeri
{"title":"Disproving the High-eccentricity Planet HD 220773b","authors":"Ilaria Carleo, Silvano Desidera, Alessandro Sozzetti, Serena Benatti, Riccardo Claudi, Mario Damasso, Matteo Pinamonti and Alessandro Ruggeri","doi":"10.3847/2515-5172/ad57b5","DOIUrl":"https://doi.org/10.3847/2515-5172/ad57b5","url":null,"abstract":"HD 220773 has been announced to host a giant planet in an eccentric orbit. Global Architecture of Planetary Systems collaboration followed this target up with the HARPS-N spectrograph at Telescopio Nazionale Galileo, in order to search for additional small planets in the system. This radial velocity monitoring produced approximately 130 HARPS-N data points, leading to the refutation of the announced planet.","PeriodicalId":74684,"journal":{"name":"Research notes of the AAS","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141501652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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