The Gaia-ESO Survey: radial metallicity gradients and age-metallicity relation of stars in the Milky Way disk

We study the relationship between age, metallicity, and α-enhancement of FGK stars in the Galactic disk. The results are based upon the analysis of high-resolution UVES spectra from the Gaia-ESO large stellar survey. We explore the limitations of the observed dataset, i.e. the accuracy of stellar parameters and the selection effects that are caused by the photometric target preselection. We find that the colour and magnitude cuts in the survey suppress old metal-rich stars and young metal-poor stars. This suppression may be as high as 97% in some regions of the age-metallicity relationship. The dataset consists of 144 stars with a wide range of ages from 0.5 Gyr to 13.5 Gyr, Galactocentric distances from 6 kpcto 9.5 kpc, and vertical distances from the plane 0 < |Z| < 1.5 kpc. On this basis, we find that i) the observed age-metallicity relation is nearly flat in the range of ages between 0 Gyr and 8 Gyr; ii) at ages older than 9 Gyr, we see a decrease in [Fe/H] and a clear absence of metal-rich stars; this cannot be explained by the survey selection functions; iii) there is a significant scatter of [Fe/H] at any age; and iv) [Mg/Fe] increases with age, but the dispersion of [Mg/Fe] at ages >9 Gyr is not as small as advocated by some other studies. In agreement with earlier work, we find that radial abundance gradients change as a function of vertical distance from the plane. The [Mg/Fe] gradient steepens and becomes negative. In addition, we show that the inner disk is not only more α-rich compared to the outer disk, but also older, as traced independently by the ages and Mg abundances of stars.

Relation of the invertebrate to the vertebrate faunal zones of the Etchegoin and Jacalitos in the Coalinga oil district California /

Thesis (M.S. in Geology)--University of California, Berkeley, 1914.

The relation of quickness of learning to retentiveness,

Published also as thesis (PH. D.) Columbia University, 1917.

What is the relation of academic preparation, experience, intelligence, achievement, and sex of rural teachers in Mississippi to their pay?

Thesis note on label mounted on p.2 of cover.

A relation of the second voyage to Guiana.

S.T.C. no. 14947.

Relation of the discovery and conquest of the kingdoms of Peru /

Reprint. Originally published: New York : The Cortes Society, 1921, in series: Documents and narratives concerning the discovery and conquest of Latin America ; no. 4, v. 1.

Preliminary report on relation of structure to uranium mineralization in the Todilto limestone, Grants District, New Mexico /

"September 10, 1952."

Charts: relation of pastures, feed production, and butterfat price ratios to dairy production ....

Mimeographed.

Relation of soil type to the income and crops on farms in Tompkins County, New York.

Thesis (M.S. in Agr.)--Cornell Univ., 1917.

Interests in relation to intelligence: a study of the relation of the mental status of school children to their motivation as shown in the choices of school plans and occupational preferences,

Mode of access: Internet.

Some factors in the relation of stream and valley sedimentation to flood-control problems.

Mode of access: Internet.

The narrative of the Honourable John Byron (Commodore in a late expedition round the world) : containing an account of the great distresses suffered by himself and his companions on the coasts of Patagonia from the year 1740, till their arrival in England, 1746. With a description of St. Jago de Chili, and the manners and customs of the inhabitants. Also a relation of the loss of the Wager man of war...

MTSD 38.

Sir Francis Drake revived : who is or may be a pattern to stirre up all heroicke and active spirits of these times, to benefit their countrey and eternize their names by like noble attempts : Being a summary and true relation of foure severall voyages made by the said Sir Francis Drake to the West-Indies ... His voyage made with Chistopher Carleill, Martin Frobusher, Francis Knollis, and others, Their taking the townes of Saint Jago, Sancto Domingo, Carthagena and Saint Augustine : His last voyage (in which he dyed) being accompanied with Sir John Hawkins, Sir Thomas Baskerfield, Sir Nicholas Clifford, with others : His manner of buriall /

La primera obra relata el viaje de 1572-1573, la segunda el viaje de 1577-1580, la tercera el de 1585-1586 y la última del viaje de 1595-1596, en el que murió.

An essay on the relation of the several parts of a mathematical science to the fundamental idea therein contained; the substance of which was read before the Ashmolean Society on the evening of May 14, 1849,

Mode of access: Internet.