Accretion of low-metallicity gas by the Milky Way

B. P. Wakker (), J. C. Howk, B. D. Savage, H. van Woerden, S. L. Tufte, U. J. Schwarz, R. Benjamin, R. J. Reynolds, R. F. Peletier and P. M. W. Kalberla
Additional contact information
B. P. Wakker: Department of Astronomy
J. C. Howk: The Johns Hopkins University
B. D. Savage: Department of Astronomy
H. van Woerden: Kapteyn Institute
S. L. Tufte: Lewis & Clark College
U. J. Schwarz: Kapteyn Institute
R. Benjamin: University of Wisconsin
R. J. Reynolds: Department of Astronomy
R. F. Peletier: University of Durham
P. M. W. Kalberla: Radio-astronomisches Institüt Universität Bonn

Nature, 1999, vol. 402, issue 6760, 388-390

Abstract: Abstract Models of the chemical evolution of the Milky Way suggest that the observed abundances of elements heavier than helium (‘metals’) require a continuous infall of gas with metallicity (metal abundance) about 0.1 times the solar value. An infall rate integrated over the entire disk of the Milky Way of ∼1 solar mass per year can solve the ‘G-dwarf problem’—the observational fact that the metallicities of most long-lived stars near the Sun lie in a relatively narrow range1,2,3. This infall dilutes the enrichment arising from the production of heavy elements in stars, and thereby prevents the metallicity of the interstellar medium from increasing steadily with time. However, in other spiral galaxies, the low-metallicity gas needed to provide this infall has been observed only in associated dwarf galaxies4 and in the extreme outer disk of the Milky Way5,6. In the distant Universe, low-metallicity hydrogen clouds (known as ‘damped Lyα absorbers’) are sometimes seen near galaxies7,8. Here we report a metallicity of 0.09 times solar for a massive cloud that is falling into the disk of the Milky Way. The mass flow associated with this cloud represents an infall per unit area of about the theoretically expected rate, and ∼0.1–0.2 times the amount required for the whole Galaxy.

Date: 1999
References: Add references at CitEc
Citations:

Downloads: (external link)
https://www.nature.com/articles/46498 Abstract (text/html)
Access to the full text of the articles in this series is restricted.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:nat:nature:v:402:y:1999:i:6760:d:10.1038_46498

Ordering information: This journal article can be ordered from
https://www.nature.com/

DOI: 10.1038/46498

Access Statistics for this article

Nature is currently edited by Magdalena Skipper

More articles in Nature from Nature
Bibliographic data for series maintained by Sonal Shukla () and Springer Nature Abstracting and Indexing ().