arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1602.01649astro-ph.SR
收藏

MUSE crowded field 3D spectroscopy of over 12,000 stars in the globular cluster NGC 6397 - I. The first comprehensive spectroscopic HRD of a globular cluster

Tim-Oliver Husser, Sebastian Kamann, Stefan Dreizler, Martin Wendt, Nina Wulff, Roland Bacon, Lutz Wisotzki, Jarle Brinchmann, Peter M. Weilbacher, Martin M. Ro… 展开作者

Tim-Oliver Husser, Sebastian Kamann, Stefan Dreizler, Martin Wendt, Nina Wulff, Roland Bacon, Lutz Wisotzki, Jarle Brinchmann, Peter M. Weilbacher, Martin M. Roth, Ana Monreal-Ibero

英文摘要:

Aims. We demonstrate the high multiplex advantage of crowded field 3D spectroscopy using the new integral field spectrograph MUSE by means of a spectroscopic analysis of more than 12,000 individual stars in the globular cluster NGC 6397. Methods. The stars are deblended with a PSF fitting technique, using a photometric reference catalogue from HST as prior, including relative positions and brightnesses. This catalogue is also used for a first analysis of the extracted spectra, followed by an automatic in-depth analysis using a full-spectrum fitting method based on a large grid of PHOENIX spectra. Results. With 18,932 spectra from 12,307 stars in NGC 6397 we have analysed the largest sample so far available for a single globular cluster. We derived a mean radial velocity of vrad=17.84+-0.07 km/s and a mean metallicity of [Fe/H]=-2.120+-0.002, with the latter seemingly varying with temperature for stars on the RGB. We determine T_eff and [Fe/H] from the spectra, and log g from HST photometry. This is the first very comprehensive HRD for a globular cluster based on the analysis of several thousands of stellar spectra, ranging from the main sequence to the tip of the RGB. Furthermore, two interesting objects were identified with one being a post-AGB star and the other a possible millisecond-pulsar companion.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑