IMF–METALLICITY: A TIGHT LOCAL RELATION REVEALED BY THE CALIFA SURVEY

Journal Article · Sat Jun 20 00:00:00 EDT 2015 · Astrophysical Journal Letters

DOI:https://doi.org/10.1088/2041-8205/806/2/L31· OSTI ID:22518951

Martín-Navarro, Ignacio; Vazdekis, Alexandre; Falcón-Barroso, Jesús ^[1]; La Barbera, Francesco ^[2]; Lyubenova, Mariya; Trager, S. C. ^[3]; Ven, Glenn van de ^[4]; Ferreras, Ignacio ^[5]; Sánchez, S. F. ^[6]; García-Benito, R.; Mendoza, M. A. ^[7]; Mast, D. ^[8]; others, and

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1. Instituto de Astrofísica de Canarias, c/Vía Láctea s/n, E-38205—La Laguna, Tenerife (Spain)
2. INAF—Osservatorio Astronomico di Capodimonte, Napoli (Italy)
3. Kapteyn Astronomical Institute, University of Groningen, Postbus 800, 9700 AV Groningen (Netherlands)
4. Max Planck Institute for Astronomy, Königstuhl 17, D-69117 Heidelberg (Germany)
5. Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT (United Kingdom)
6. Instituto de Astronomía, Universidad Nacional Autonóma de México, A.P. 70-264, 04510 México, D.F., México (Mexico)
7. Instituto de Astrofísica de Andalucía (CSIC), Glorieta de la Astronomía s/n, Aptdo. 3004, E-18080 Granada (Spain)
8. Instituto de Cosmologia, Relatividade e Astrofísica—ICRA, Centro Brasileiro de Pesquisas Físicas, Rua Dr.Xavier Sigaud 150, CEP 22290-180, Rio de Janeiro, RJ (Brazil)

Variations in the stellar initial mass function (IMF) have been invoked to explain the spectroscopic and dynamical properties of early-type galaxies (ETGs). However, no observations have yet been able to disentangle the physical driver. We analyze here a sample of 24 ETGs drawn from the CALIFA survey, deriving in a homogeneous way their stellar population and kinematic properties. We find that the local IMF is tightly related to the local metallicity, becoming more bottom-heavy toward metal-rich populations. Our result, combined with the galaxy mass–metallicity relation, naturally explains previous claims of a galaxy mass–IMF relation, derived from non-IFU spectra. If we assume that—within the star formation environment of ETGs—metallicity is the main driver of IMF variations, a significant revision of the interpretation of galaxy evolution observables is necessary.

• OSTI ID: 22518951
• Journal Information: Astrophysical Journal Letters, Vol. 806, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTROPHYSICS
COSMOLOGY AND ASTRONOMY
GALACTIC EVOLUTION
GALAXIES
MARINE SURVEYS
MASS
METALLICITY
STAR EVOLUTION
STARS
VARIATIONS