تقرير
Insights into formation scenarios of massive Early-Type galaxies from spatially resolved stellar population analysis in CALIFA
| العنوان: | Insights into formation scenarios of massive Early-Type galaxies from spatially resolved stellar population analysis in CALIFA |
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| المؤلفون: | Zibetti, Stefano, Gallazzi, Anna R., Hirschmann, Michaela, Consolandi, Guido, Falcón-Barroso, Jesús, van de Ven, Glenn, Lyubenova, Mariya |
| سنة النشر: | 2019 |
| المجموعة: | Astrophysics |
| مصطلحات موضوعية: | Astrophysics - Astrophysics of Galaxies |
| الوصف: | We perform spatially resolved stellar population analysis for a sample of 69 early-type galaxies (ETGs) from the CALIFA integral field spectroscopic survey, including 48 ellipticals and 21 S0's. We generate and quantitatively characterize profiles of light-weighted mean stellar age and metallicity within $\lesssim 2R_e$, as a function of radius and stellar-mass surface density $\mu_*$. We study in detail the dependence of profiles on galaxies' global properties, including velocity dispersion $\sigma_e$, stellar mass, morphology. ETGs are universally characterized by strong, negative metallicity gradients ($\sim -0.3\,\text{dex}$ per $R_e$) within $1\,R_e$, which flatten out moving towards larger radii. A quasi-universal local $\mu_*$-metallicity relation emerges, which displays a residual systematic dependence on $\sigma_e$, whereby higher $\sigma_e$ implies higher metallicity at fixed $\mu_*$. Age profiles are typically U-shaped, with minimum around $0.4\,R_e$, asymptotic increase to maximum ages beyond $\sim 1.5\,R_e$, and an increase towards the centre. The depth of the minimum and the central increase anti-correlate with $\sigma_e$. A possible qualitative interpretation of these observations is a two-phase scenario. In the first phase, dissipative collapse occurs in the inner $1\,R_e$, establishing a negative metallicity gradient. The competition between the outside-in quenching due to feedback-driven winds and some form of inside-out quenching, possibly caused by central AGN feedback or dynamical heating, determines the U-shaped age profiles. In the second phase, the accretion of ex-situ stars from quenched and low-metallicity satellites shapes the flatter stellar population profiles in the outer regions. Comment: Accepted version to appear in MNRAS. Improved discussion with respect to original submission and additional tests included |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1093/mnras/stz3205 |
| URL الوصول: | http://arxiv.org/abs/1906.02209 |
| رقم الأكسشن: | edsarx.1906.02209 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1093/mnras/stz3205 |
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