Observational Evidence for the Infall of Low-Metallicity Gas onto the Milky Way

Wakker, B. P., Howk, J. C., Savage, B. D., Tufte, S. L., Reynolds, R. J., van Woerden, H., Schwarz, U. J., Peletier, R. F. & Kalberla, P. M. W., 1999, In : Bulletin of the American Astronomical Society. 31, p. 887

Research output: Contribution to journalArticleAcademicpeer-review

We find evidence for a hitherto unknown component of the Milky Way: infalling gas with low heavy element abundances. Infall of metal-poor matter has been the preferred solution to the long-standing ``G-dwarf problem'', the fact that the abundance distribution of unevolved stars is narrower than expected in a simple model (e.g. Pagel 1997). Our conclusion is based on the metallicity we measure for the high-velocity cloud complex C of 0.070+/-0.020 times solar, using the Seyfert galaxy Mark 290 as a background probe. We also determine a lower limit of 5 kpc to its distance and argue that it is likely that D3 Gyr ago (Toomre, in Kerr & Sullivan 1969). This work was supported by NASA under grant #GO6590.01-95A
Original languageEnglish
Pages (from-to)887
JournalBulletin of the American Astronomical Society
Publication statusPublished - 1999

ID: 25645873