The initial mass function of a massive relic galaxy

Abstract

Massive relic galaxies formed the bulk of their stellar component before z~2 and have remained unaltered since then. Therefore, they represent a unique opportunity to study in great detail the frozen stellar population properties of those galaxies that populated the primitive Universe. We have combined optical to near-infrared line-strength indices in order to infer, out to 1.5 Reff, the IMF of the nearby relic massive galaxy NGC 1277. The IMF of this galaxy is bottom-heavy at all radii, with the fraction of low-mass stars being at least a factor of two larger than that found in the Milky Way. The excess of low-mass stars is present throughout the galaxy, while the velocity dispersion profile shows a strong decrease with radius. This behaviour suggests that local velocity dispersion is not the only driver of the observed IMF variations seen among nearby early-type galaxies. In addition, the excess of low-mass stars shown in NGC 1277 could reflect the effect on the IMF of dramatically different and intense star formation processes at z~2, compared to the less extreme conditions observed in the local Universe.

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Cited by in corpus (18)

• Black Hole Mass Scaling Relations for Early-Type Galaxies: $M_{BH}$-$M_{\ast ,sph}$ and $M_{BH}$-$M_{\ast ,gal}$
• Timing the formation and assembly of early-type galaxies via spatially resolved stellar populations analysis
• IMF and [Na/Fe] abundance ratios from optical and NIR Spectral Features in Early-type Galaxies
• The Stellar Initial Mass Function in Early-Type Galaxies From Absorption Line Spectroscopy. IV. A Super-Salpeter IMF in the center of NGC 1407 from Non-Parametric Models
• The Fornax 3D project: a two-dimensional view of the stellar initial mass function in the massive lenticular galaxy FCC 167
• INSPIRE: INvestigating Stellar Population In RElics -- I. Survey presentation and pilot program
• Radial gradients in initial mass function sensitive absorption features in the Coma brightest cluster galaxies
• A Black Hole Mass Determination for the Compact Galaxy Mrk 1216
• Is it possible to reconcile extragalactic IMF variations with a universal Milky Way IMF?
• Stellar populations across the black hole mass - velocity dispersion relation
• Stellar population properties of individual massive early-type galaxies at 1.4 < z < 2
• Star formation quenching imprinted on the internal structure of naked red nuggets
• What does (not) drive the variation of the low-mass end of the stellar initial mass function of early-type galaxies
• Nature versus nurture: relic nature and environment of the most massive passive galaxies at $z<0.5$
• Globular Cluster Systems of Relic Galaxies
• Unravelling the Origin of the Counter-Rotating Core in IC 1459 with KMOS and MUSE
• Ultra-massive black hole feedback in compact galaxies
• Comparing IMF-sensitive indices of intermediate-mass quiescent galaxies in various environments