SDSS-IV MaNGA: stellar rotational support in disc galaxies versus central surface density and stellar population age

Journal Article · 12 August 2024 · Monthly Notices of the Royal Astronomical Society

DOI: https://doi.org/10.1093/mnras/stae1939 · OSTI ID:2437800

Wang, Xiaohan ; Luo, Yifei ; Faber, S. M. ; Koo, David C.; Mao, Shude ; Westfall, Kyle B. ; Lu, Shengdong ; Wang, Weichen ; Bundy, Kevin; Boardman, N.; Avila-Reese, Vladimir ; Fernández-Trincado, José G. ; Lane, Richard R.

ABSTRACT We investigate how the stellar rotational support changes as a function of spatially resolved stellar population age ($$D_n4000$$) and relative central stellar surface density ($$\Delta \Sigma _1$$) for MaNGA isolated/central disc galaxies. We find that the galaxy rotational support indicator $$\lambda _{R_\mathrm{e}}$$ varies smoothly as a function of $$\Delta \Sigma _1$$ and $$D_n4000$$. $$D_n4000$$ versus $$\Delta \Sigma _1$$ follows a ‘J-shape’, with $$\lambda _{R_\mathrm{e}}$$ contributing to the scatters. In this ‘J-shaped’ pattern rotational support increases with central $$D_n4000$$ when $$\Delta \Sigma _1$$ is low but decreases with $$\Delta \Sigma _1$$ when $$\Delta \Sigma _1$$ is high. Restricting attention to low-$$\Delta \Sigma _1$$ (i.e. large-radius) galaxies, we suggest that the trend of increasing rotational support with $$D_n4000$$ for these objects is produced by a mix of two different processes, a primary trend characterized by growth in $$\lambda _{R_\mathrm{e}}$$ along with mass through gas accretion, on top of which disturbance episodes are overlaid, which reduce rotational support and trigger increased star formation. An additional finding is that star-forming galaxies with low $$\Delta \Sigma _1$$ have relatively larger radii than galaxies with higher $$\Delta \Sigma _1$$ at fixed stellar mass. Assuming that these relative radii rankings are preserved while galaxies are star forming then implies clear evolutionary paths in central $$D_n4000$$ versus $$\Delta \Sigma _1$$. The paper closes with comments on the implications that these paths have for the evolution of pseudo-bulges versus classical bulges. The utility of using $$\rm D_n4000$$–$$\Delta \Sigma _1$$ to study $$\lambda _{R_\mathrm{e}}$$ reinforces the notion that galaxy kinematics correlate both with structure and with stellar-population state, and indicates the importance of a multidimensional description for understanding bulge and galaxy evolution.

• Sponsoring Organization: USDOE
• OSTI ID: 2437800
• Journal Information: Monthly Notices of the Royal Astronomical Society, Journal Name: Monthly Notices of the Royal Astronomical Society Journal Issue: 2 Vol. 533; ISSN 0035-8711
• Publisher: Oxford University PressCopyright Statement
• Country of Publication: United Kingdom
• Language: English