INSPIRE: INvestigating Stellar Population In RElics – IV. The initial mass function slope in relics
| Autor: | Ignacio Martín-Navarro, C Spiniello, C Tortora, L Coccato, G D’Ago, A Ferré-Mateu, C Pulsoni, J Hartke, M Arnaboldi, L Hunt, N R Napolitano, D Scognamiglio, M Spavone |
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| Rok vydání: | 2023 |
| Předmět: | |
| Zdroj: | Monthly Notices of the Royal Astronomical Society. 521:1408-1414 |
| ISSN: | 1365-2966 0035-8711 |
| DOI: | 10.1093/mnras/stad503 |
| Popis: | In the last decade, growing evidence has emerged supporting a non-universal stellar Initial Mass Function (IMF) in massive galaxies, with a larger number of dwarf stars with respect to the Milky-Way (bottom-heavy IMF). However, a consensus about the mechanisms that cause IMF variations is yet to be reached. Recently, it has been suggested that stars formed early-on in cosmic time, via a star formation burst, could be characterised by a bottom-heavy IMF. A promising way to confirm this is to use relics, ultra-compact massive galaxies, almost entirely composed by these "pristine" stars. The INSPIRE Project aims at assembling a large sample of confirmed relics, that can serve as laboratory to investigate on the conditions of star formation in the first 1-3 Gyr of the Universe. In this third INSPIRE paper, we build a high signal-to-noise spectrum from five relics and one from five galaxies with similar sizes, masses, and kinematical properties, but characterised by a more extended star formation history (non-relics). Our detailed stellar population analysis suggests a systematically bottom-heavier IMF slope for relics than for non-relics, adding new observational evidence for the non-universality of the IMF at various redshifts and further supporting the above proposed physical scenario. Accepted for publication in MNRAS. 8 pages, 5 figures |
| Databáze: | OpenAIRE |
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