T. Bridges, M. Beasley, F. Faifer, D. Forbes, J. Forte, K. Gebhardt, D. Hanes, R. Sharples, S. Zepf
{"title":"具有GMOS的早期型星系中的球状星团","authors":"T. Bridges, M. Beasley, F. Faifer, D. Forbes, J. Forte, K. Gebhardt, D. Hanes, R. Sharples, S. Zepf","doi":"10.1017/S1539299600015501","DOIUrl":null,"url":null,"abstract":"We present recent results from our long-term Gemini/GMOS study of globular clusters (GCs) in early-type galaxies. To date, we have obtained photometry and spectroscopy for GCs in NGCs 3379, 4649, 524, 7332, and IC 1459. We find a clear bimodality in the NGC 4649 GC color distribution, with the fraction of blue/red clusters increasing with galacto-centric radius. We derive ages and metallicities for 22 GCs in NGC 3379, finding that most of the clusters appear old (10–15 Gyr); however, there is a group of 4 metal-rich, younger clusters with ages of 2–6 Gyr. The NGC 3379 GC velocity dispersion decreases with radius, as does the inferred (local) mass-to-light ratio: there is no evidence for a dark matter halo in NGC 3379 based on our GC data.","PeriodicalId":422890,"journal":{"name":"Highlights of Astronomy","volume":"664 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2003-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Globular Clusters in Early-Type Galaxies with GMOS\",\"authors\":\"T. Bridges, M. Beasley, F. Faifer, D. Forbes, J. Forte, K. Gebhardt, D. Hanes, R. Sharples, S. Zepf\",\"doi\":\"10.1017/S1539299600015501\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"We present recent results from our long-term Gemini/GMOS study of globular clusters (GCs) in early-type galaxies. To date, we have obtained photometry and spectroscopy for GCs in NGCs 3379, 4649, 524, 7332, and IC 1459. We find a clear bimodality in the NGC 4649 GC color distribution, with the fraction of blue/red clusters increasing with galacto-centric radius. We derive ages and metallicities for 22 GCs in NGC 3379, finding that most of the clusters appear old (10–15 Gyr); however, there is a group of 4 metal-rich, younger clusters with ages of 2–6 Gyr. The NGC 3379 GC velocity dispersion decreases with radius, as does the inferred (local) mass-to-light ratio: there is no evidence for a dark matter halo in NGC 3379 based on our GC data.\",\"PeriodicalId\":422890,\"journal\":{\"name\":\"Highlights of Astronomy\",\"volume\":\"664 1\",\"pages\":\"0\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2003-10-13\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Highlights of Astronomy\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1017/S1539299600015501\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Highlights of Astronomy","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1017/S1539299600015501","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
Globular Clusters in Early-Type Galaxies with GMOS
We present recent results from our long-term Gemini/GMOS study of globular clusters (GCs) in early-type galaxies. To date, we have obtained photometry and spectroscopy for GCs in NGCs 3379, 4649, 524, 7332, and IC 1459. We find a clear bimodality in the NGC 4649 GC color distribution, with the fraction of blue/red clusters increasing with galacto-centric radius. We derive ages and metallicities for 22 GCs in NGC 3379, finding that most of the clusters appear old (10–15 Gyr); however, there is a group of 4 metal-rich, younger clusters with ages of 2–6 Gyr. The NGC 3379 GC velocity dispersion decreases with radius, as does the inferred (local) mass-to-light ratio: there is no evidence for a dark matter halo in NGC 3379 based on our GC data.