ar X iv : a st ro - p h / 01 01 43 8 v 1 2 4 Ja n 20 01 NUCLEAR

نویسنده

  • J. J. COWAN
چکیده

Observations of metal-poor Galactic halo stars indicate that the abundance pattern of the (heaviest) neutron-capture elements is consistent with the scaled solar system r-process abundances. Utilizing the radioactive (r-process) element thorium, age determinations have been made for several of these same stars, placing constraints on both Galactic and cosmological age estimates.

برای دانلود رایگان 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

ar X iv : a st ro - p h / 01 01 31 5 v 1 1 8 Ja n 20 01 Signal Characteristics from Electromagnetic Cascades in Ice

We investigate the development of electromagnetic cascades in ice using a GEANT Monte Carlo simulation. We examine the Cherenkov pulse that is generated by the charge excess that develops and propagates with the shower. This study is important for the RICE experiment at the South Pole, as well as any test beam experiment which seeks to measure coherent Cherenkov radiation from an electromagneti...

متن کامل

ar X iv : a st ro - p h / 96 01 12 9 v 1 2 3 Ja n 19 96 Is Her X - 1 a strange star

The possible identification of Her X-1 with a strange star (Li et al. 1995) is shown to be incorrect.

متن کامل

ar X iv : a st ro - p h / 04 01 12 2 v 2 1 9 Ja n 20 04 High Energy Gamma - Ray Astronomy

The physics results of high energy γ-ray astronomy are reported, emphasizing recent achievements with ground-based detectors. This includes some of the instrumental developments and latest projects. The fundamental contribution of the field to the question of Cosmic Ray origin is highlighted.

متن کامل

ar X iv : a st ro - p h / 02 01 31 6 v 1 1 8 Ja n 20 02 New Approach to Sgr A * Problem

The hypothesis that radiation of Sgr A* is caused by accretion onto a supermassive compact object without the events horizon is studied. The main equations of the accretion and a relativistic equation of the trasfer radiation are obtained. The synchrotron spectrum in the vicinity of the maximum is considered.

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

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2001