Utilizza questo identificativo per citare o creare un link a questo documento:
http://hdl.handle.net/20.500.12386/26304
Titolo: | Detailed Abundance Analysis of a Metal-poor Giant in the Galactic Center | Autori: | Ryde, N. Fritz, T. K. Rich, R. M. Thorsbro, B. Schultheis, M. ORIGLIA, Livia Chatzopoulos, S. |
Data pubblicazione: | 2016 | Rivista: | THE ASTROPHYSICAL JOURNAL | Numero: | 831 | Fascicolo: | 1 | Da pagina:: | 40 | Abstract: | We report the first results from our program to examine the metallicity distribution of the Milky Way nuclear star cluster connected to Sgr A*, with the goal of inferring the star formation and enrichment history of this system, as well as its connection and relationship with the central 100 pc of the bulge/bar system. We present the first high-resolution (R ∼ 24,000), detailed abundance analysis of a K = 10.2 metal-poor, alpha-enhanced red giant projected at 1.5 pc from the Galactic center, using NIRSPEC on Keck II. A careful analysis of the dynamics and color of the star locates it at about {26}<SUB>-16</SUB><SUP>+54</SUP> pc line-of-sight distance in front of the nuclear cluster. It probably belongs to one of the nuclear components (cluster or disk), not to the bar/bulge or classical disk. A detailed spectroscopic synthesis, using a new line list in the K band, finds [Fe/H] ∼ -1.0 and [α/Fe] ∼ +0.4, consistent with stars of similar metallicity in the bulge. As known giants with comparable [Fe/H] and alpha enhancement are old, we conclude that this star is most likely to be a representative of the ∼10 Gyr old population. This is also the most metal-poor-confirmed red giant yet discovered in the vicinity of the nuclear cluster of the Galactic center. We consider recent reports in the literature of a surprisingly large number of metal-poor giants in the Galactic center, but the reported gravity of {log}g∼ 4 for these stars calls into question their reported metallicities. | URI: | http://hdl.handle.net/20.500.12386/26304 | URL: | https://iopscience.iop.org/article/10.3847/0004-637X/831/1/40 | ISSN: | 0004-637X | DOI: | 10.3847/0004-637X/831/1/40 | Bibcode ADS: | 2016ApJ...831...40R | Fulltext: | open |
È visualizzato nelle collezioni: | 1.01 Articoli in rivista |
File in questo documento:
File | Descrizione | Dimensioni | Formato | |
---|---|---|---|---|
Ryde_2016_ApJ_831_40.pdf | Pdf editoriale | 1.05 MB | Adobe PDF | Visualizza/apri |
Page view(s)
68
controllato il 20-lug-2024
Download(s)
16
controllato il 20-lug-2024
Google ScholarTM
Check
Altmetric
Altmetric
Tutti i documenti in DSpace sono pubblicati ad Accesso Aperto, salvo diversa indicazione per alcuni documenti specifici.