Constraining the population of isolated massive stars within the Central Molecular Zone
| Autor: | Lee Patrick, Chris Evans, M. E. Lohr, Francisco Najarro, J. S. Clark |
|---|---|
| Přispěvatelé: | Unidad de Excelencia Científica María de Maeztu Centro de Astrobiología del Instituto Nacional de Técnica Aeroespacial y CSIC, MDM-2017-0737, Generalitat Valenciana, Agencia Estatal de Investigación (AEI), Universidad de Alicante. Departamento de Física Aplicada, Astrofísica Estelar (AE) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Initial mass function
Milky Way Population FOS: Physical sciences Context (language use) Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics Stellar classification 01 natural sciences early-type [Stars] 0103 physical sciences Astrophysics::Solar and Stellar Astrophysics education 010303 astronomy & astrophysics Solar and Stellar Astrophysics (astro-ph.SR) Astrophysics::Galaxy Astrophysics Astronomía y Astrofísica early type [Stars] Physics education.field_of_study 010308 nuclear & particles physics Star formation Astronomy and Astrophysics center [Galaxy] Evolution [Stars] Astrophysics - Astrophysics of Galaxies Galaxy Stars Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Astrophysics of Galaxies (astro-ph.GA) Astrophysics::Earth and Planetary Astrophysics |
| Zdroj: | RUA. Repositorio Institucional de la Universidad de Alicante Universidad de Alicante (UA) DIGITAL.INTA Repositorio Digital del Instituto Nacional de Técnica Aeroespacial instname |
| ISSN: | 0004-6361 |
| Popis: | Many galaxies host pronounced circumnuclear starbursts, fuelled by infalling gas. Such activity is expected to drive the secular evolution of the nucleus and generate super winds, while the intense radiation fields and extreme gas and cosmic ray densities present may act to modify the outcome of star formation with respect to more quiescent galactic regions. The centre of the Milky Way is the only example of this phenomenon where, by virtue of its proximity, individual stars may be resolved. Previous studies have revealed that it hosts a rich population of massive stars; these are located within three clusters, with an additional contingent dispersed throughout the Central Molecular Zone (CMZ). We employed VLT+KMOS to obtain homogeneous, high S/N spectroscopy of the later cohort for classification and quantitative analysis. Including previously identified examples, we found a total of 83 isolated massive stars within the Galactic Centre, which are biased towards objects supporting powerful stellar winds and/or extensive circumstellar envelopes. No further stellar clusters, or their tidally stripped remnants, were identified, although an apparent stellar overdensity was found to be coincident with the Sgr B1 star forming region. The cohort of isolated massive stars within the CMZ is comparable in size to that of the known clusters but, due to observational biases, is likely highly incomplete at this time. Combining both populations yields over 320 spectroscopically classified stars that are expected to undergo core collapse within the next 20Myr. Given that this is presumably an underestimate of the true number, the population of massive stars associated with the CMZ appears unprecedented amongst star formation complexes within the Milky Way, and one might anticipate that they play a substantial role in the energetics and evolution of the nuclear region. Comment: 28 pages, 14 figures, accepted for publication in Astronomy and Astrophysics |
| Databáze: | OpenAIRE |
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