{"title":"关于ngc4147暗物质形成的场景","authors":"Andrés E. Piatti","doi":"10.1007/s12036-025-10079-3","DOIUrl":null,"url":null,"abstract":"<div><p>We report results on the radial velocity dispersion profile built out to the outskirts of NGC 4147, a Milky Way globular cluster with detected strong tidal tails. The cluster was chosen to probe, from an observational point of view, recent simulations that suggest that rising velocity dispersion profiles at large distances from the clusters’ centers would be seen in globular clusters without tidal tails. From GEMINI@GMOS spectra, centered in the infrared Ca II triplet region, of selected stars located along the onset of NGC 4147’s tidal tails, we measured their radial velocities and overall metallicities. The derived metallicities were used to ultimately assess the highly-ranked cluster candidates of 9 stars, located between <span>\\(\\sim \\)</span>7 and 33 pc from the cluster’s center, suitable for testing the aforementioned simulation. We complemented the present radial velocities with others available in the literature for the cluster’s members, and built a cluster velocity dispersion profile, which suggests a mostly flat or slightly rising profile at large distances from the cluster’s center. This outcome confirms that kinematically hot outermost cluster stars are seen in NGC 4147, which disproves the recent model predictions. Nevertheless, the mean velocity dispersion of the outermost cluster’s stars agrees with NGC 4147 being formed in a <span>\\(10^8\\)</span>–<span>\\(10^9\\)</span> <span>\\(\\hbox {M}_\\odot \\)</span> dwarf galaxy with a cored dark matter profile that was later accreted to the Milky Way.</p></div>","PeriodicalId":610,"journal":{"name":"Journal of Astrophysics and Astronomy","volume":"46 2","pages":""},"PeriodicalIF":1.6000,"publicationDate":"2025-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"On the dark matter formation scenario of NGC 4147\",\"authors\":\"Andrés E. Piatti\",\"doi\":\"10.1007/s12036-025-10079-3\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>We report results on the radial velocity dispersion profile built out to the outskirts of NGC 4147, a Milky Way globular cluster with detected strong tidal tails. The cluster was chosen to probe, from an observational point of view, recent simulations that suggest that rising velocity dispersion profiles at large distances from the clusters’ centers would be seen in globular clusters without tidal tails. From GEMINI@GMOS spectra, centered in the infrared Ca II triplet region, of selected stars located along the onset of NGC 4147’s tidal tails, we measured their radial velocities and overall metallicities. The derived metallicities were used to ultimately assess the highly-ranked cluster candidates of 9 stars, located between <span>\\\\(\\\\sim \\\\)</span>7 and 33 pc from the cluster’s center, suitable for testing the aforementioned simulation. We complemented the present radial velocities with others available in the literature for the cluster’s members, and built a cluster velocity dispersion profile, which suggests a mostly flat or slightly rising profile at large distances from the cluster’s center. This outcome confirms that kinematically hot outermost cluster stars are seen in NGC 4147, which disproves the recent model predictions. Nevertheless, the mean velocity dispersion of the outermost cluster’s stars agrees with NGC 4147 being formed in a <span>\\\\(10^8\\\\)</span>–<span>\\\\(10^9\\\\)</span> <span>\\\\(\\\\hbox {M}_\\\\odot \\\\)</span> dwarf galaxy with a cored dark matter profile that was later accreted to the Milky Way.</p></div>\",\"PeriodicalId\":610,\"journal\":{\"name\":\"Journal of Astrophysics and Astronomy\",\"volume\":\"46 2\",\"pages\":\"\"},\"PeriodicalIF\":1.6000,\"publicationDate\":\"2025-07-26\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Astrophysics and Astronomy\",\"FirstCategoryId\":\"101\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s12036-025-10079-3\",\"RegionNum\":4,\"RegionCategory\":\"物理与天体物理\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"ASTRONOMY & ASTROPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Astrophysics and Astronomy","FirstCategoryId":"101","ListUrlMain":"https://link.springer.com/article/10.1007/s12036-025-10079-3","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
We report results on the radial velocity dispersion profile built out to the outskirts of NGC 4147, a Milky Way globular cluster with detected strong tidal tails. The cluster was chosen to probe, from an observational point of view, recent simulations that suggest that rising velocity dispersion profiles at large distances from the clusters’ centers would be seen in globular clusters without tidal tails. From GEMINI@GMOS spectra, centered in the infrared Ca II triplet region, of selected stars located along the onset of NGC 4147’s tidal tails, we measured their radial velocities and overall metallicities. The derived metallicities were used to ultimately assess the highly-ranked cluster candidates of 9 stars, located between \(\sim \)7 and 33 pc from the cluster’s center, suitable for testing the aforementioned simulation. We complemented the present radial velocities with others available in the literature for the cluster’s members, and built a cluster velocity dispersion profile, which suggests a mostly flat or slightly rising profile at large distances from the cluster’s center. This outcome confirms that kinematically hot outermost cluster stars are seen in NGC 4147, which disproves the recent model predictions. Nevertheless, the mean velocity dispersion of the outermost cluster’s stars agrees with NGC 4147 being formed in a \(10^8\)–\(10^9\)\(\hbox {M}_\odot \) dwarf galaxy with a cored dark matter profile that was later accreted to the Milky Way.
期刊介绍:
The journal publishes original research papers on all aspects of astrophysics and astronomy, including instrumentation, laboratory astrophysics, and cosmology. Critical reviews of topical fields are also published.
Articles submitted as letters will be considered.