Observations of Very Metal-Poor Stars in the Galaxy

نویسنده

  • Timothy C. Beers
چکیده

I report on recent results from observations of stars with metallicities [Fe/H] ≤ −2.0. These include a substantial new sample of objects with high-resolution observations obtained as part of a follow-up of the HK Survey, The Hamburg/ESO Survey, and the ongoing survey SEGUE: Sloan Extension for Galactic Understanding and Exploration. Perspectives on the next directions are also provided.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

ساخت و تحلیل فهرست ستارهای از کهکشان M33

In this study, 1200 images and catalogues of M33 spiral galaxy taken by WFCAM camera at UKIRT telescope in J, H and K bands. Cross correlation methods were employed to identify stars in overlapping regions from among images taken in different dates. Careful astrometric and photometric analysis was made to calibrate stellar positions and magnitudes using their 2MASS near infra red survey. The fi...

متن کامل

Pulsating red giant and supergiant stars in the Local Group dwarf galaxy Andromeda I

We have conducted an optical long-term monitoring survey of the majority of dwarf galaxies in the Local Group, with the Isaac Newton Telescope (INT), to identify the long period variable (LPV) stars. LPV stars vary on timescales of months to years, and reach the largest amplitudes of their brightness variations at optical wavelengths, due to the changing temperature. They trace stellar populati...

متن کامل

Stellar Populations in the Central Galaxies of Fossil Groups

It is inferred from the symmetrical and luminous X-ray emission of fossil groups that they are mature, relaxed galaxy systems. Cosmological simulations and observations focusing on their dark halo and inter-galactic medium properties confirm their early formation. Recent photometric observations suggest that, unlike the majority of non-fossil brightest group galaxies (BGGs), the central early-t...

متن کامل

The effect of variation of stellar dispersion velocities by the galactic latitude in interpreting gravitational microlensing observations

Our galaxy is a spiral galaxy and its stars are mostly in a thin disk and rotate around the galactic center. The vertical component of the dispersion velocity of stars is a function of the galactic latitude and decreases with increasing it. In the galactic Besancon model, this dependence is ignored and they just consider the dependence of dispersion velocity on the stellar age. Becanson model i...

متن کامل

Metallicity distribution of halo stars and minor merger processes of the Galaxy

In this paper, a possible relation between the high dispersion in metallicity of metal-poor halo stars and the minor merger processes in the history of the Galaxy is presented. Observations show that satellite galaxies have been falling into the gravitational well of the Galaxy and then disrupted by the tidal force through minor merger processes. As a result, the foreign populations of stars in...

متن کامل

Very young massive stars in the Small Magellanic Cloud, revealed by HST

High spatial resolution imaging with the Hubble Space Telescope allowed us to resolve the compact H ii region N 81 lying in the Small Magellanic Cloud (SMC). We show the presence of a tight cluster of newborn massive stars embedded in this nebular “blob” of ∼ 10′′across. This is the first time the stellar content and internal morphology of such an object is uncovered. These are among the younge...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2008