Spectroscopic Detection of a Cusp of Late-type Stars around the Central Black Hole in the Milky Way
| Autor: | O. Pfuhl, Feng Gao, Maryam Habibi, Felix Widmann, T. Ott, Frank Eisenhauer, A. Jiménez-Rosales, P. T. de Zeeuw, Jason Dexter, P. M. Plewa, Idel Waisberg, M. Bauboeck, Reinhard Genzel, S. von Fellenberg, Stefan Gillessen |
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| Jazyk: | angličtina |
| Rok vydání: | 2019 |
| Předmět: |
Physics
Red giant Milky Way Galactic Center FOS: Physical sciences Astronomy and Astrophysics Astrophysics Star count Astrophysics::Cosmology and Extragalactic Astrophysics Giant star Stellar classification Astrophysics - Astrophysics of Galaxies Galaxy Stars Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics Solar and Stellar Astrophysics (astro-ph.SR) Astrophysics::Galaxy Astrophysics |
| Popis: | In a dynamically relaxed cluster around a massive black hole a dense stellar cusp of old stars is expected to form. Previous observations showed a relative paucity of red giant stars within the central 0.5 pc in the Galactic Center. By co-adding spectroscopic observations taken over a decade, we identify new late-type stars, including the first five warm giants (G2-G8III), within the central 1 arcsec 2 (0.04 {\times} 0.04 pc^2) of the Galaxy. Our findings increase the number of late-type stars to 21, of which we present deep spectra for 16. The updated star count, based on individual spectral classification, is used to reconstruct the surface density profile of giant stars. Our study, for the first time, finds a cusp in the surface number density of the spectroscopically identified old (>3 Gyr) giants population (m K ApJ Letters, in press |
| Databáze: | OpenAIRE |
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