Details

Autor(en) / Beteiligte

• Ellison, Sara L.
• Sánchez, Sebastian F.
• Ibarra-Medel, Hector
• Antonio, Braulio
• Mendel, J. Trevor
• Barrera-Ballesteros, Jorge

Titel

Star formation is boosted (and quenched) from the inside-out: radial star formation profiles from MaNGA

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2018-02, Vol.474 (2), p.2039-2054

Ort / Verlag

London: Oxford University Press

Erscheinungsjahr

2018

Quelle

EZB Free E-Journals

Beschreibungen/Notizen

• Abstract The tight correlation between total galaxy stellar mass and star formation rate (SFR) has become known as the star-forming main sequence. Using ∼487 000 spaxels from galaxies observed as part of the Sloan Digital Sky Survey Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, we confirm previous results that a correlation also exists between the surface densities of star formation (ΣSFR) and stellar mass (Σ⋆) on kpc scales, representing a ‘resolved’ main sequence. Using a new metric (ΔΣSFR), which measures the relative enhancement or deficit of star formation on a spaxel-by-spaxel basis relative to the resolved main sequence, we investigate the SFR profiles of 864 galaxies as a function of their position relative to the global star-forming main sequence (ΔSFR). For galaxies above the global main sequence (positive ΔSFR) ΔΣSFR is elevated throughout the galaxy, but the greatest enhancement in star formation occurs at small radii (<3 kpc, or 0.5Re). Moreover, galaxies that are at least a factor of 3 above the main sequence show diluted gas phase metallicities out to 2Re, indicative of metal-poor gas inflows accompanying the starbursts. For quiescent/passive galaxies that lie at least a factor of 10 below the star-forming main sequence, there is an analogous deficit of star formation throughout the galaxy with the lowest values of ΔΣSFR in the central 3 kpc. Our results are in qualitative agreement with the ‘compaction’ scenario in which a central starburst leads to mass growth in the bulge and may ultimately precede galactic quenching from the inside-out.