The role of the Galactic bar in the chemical evolution of the Milky Way

Author(s)

Cavichia, O. ^[1] ; Molla, M. ^[2] ; Costa, R. D. D. ^[1] ; Maciel, W. J. ^[1]

Affiliation

^[1] Univ Sao Paulo, IAG, BR-05508900 Sao Paulo - Brazil

^[2] CIEMAT, E-28040 Madrid - Spain

• Document type: Journal article
• Source: Monthly Notices of the Royal Astronomical Society; v. 437, n. 4, p. 3688-3701, FEB 2014.
• Web of Science Citations: 25

Abstract

In the absence of an interaction, central bars might be the most effective mechanism for radial motions of gas in barred spiral galaxies, which represent two-thirds of disc galaxies. The dynamical effects induced by bars in the first few kpc of discs might play an important role in the disc profiles in this region. In this work, a chemical evolution model with radial gas flows is proposed in order to mimic the effects of the Milky Way bar in the bulge and inner disc. The model is an update of a chemical evolution model with the inclusion of radial gas flows in the disc and bulge. The exchange of gas between the cylindrical concentric regions that form the Galaxy is modelled considering the flows of gas from and to the adjacent cylindrical regions. The most recent data for the bulge metallicity distribution are reproduced by means of a single and longer bulge collapse time-scale (2 Gyr) than other chemical evolution models predict. The model is able to reproduce the peak in the present star formation rate at 4 kpc and the formation of the molecular gas ring. The model with a bar predicts a flattening of the oxygen radial gradient of the disc. Additionally, models with radial gas flows predict a higher star formation rate during the formation of the bulge. This is in agreement with the most recent observations of the star formation rate at the centre of massive barred spiral galaxies. (AU)

• FAPESP's process: 07/07704-2 - Populations and evolution of the bulge and the central region of the Galaxy
• Grantee: Oscar Cavichia de Moraes
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 09/54006-4 - A computer cluster for the Astronomy Department of the University of São Paulo Institute of Astronomy, Geophysics and Atmospheric Sciences and for the Cruzeiro do Sul University Astrophysics Center
• Grantee: Elisabete Maria de Gouveia Dal Pino
• Support Opportunities: Multi-user Equipment Program
• FAPESP's process: 12/01017-1 - Chemical evolution of barred spiral galaxies and chemical abundances of planetary nebula towards the center of the Milky Way
• Grantee: Oscar Cavichia de Moraes
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 10/18835-3 - Planetary nebulae, stars and chemical evolution of stellar systems
• Grantee: Roberto Dell'Aglio Dias da Costa
• Support Opportunities: Research Projects - Thematic Grants