Inferring the age of the universe with globular clusters
نویسندگان
چکیده
منابع مشابه
Did Globular Clusters Reionize the Universe ?
A problem still unsolved in cosmology is the identification of the sources of radiation able to reionize H i in the intergalactic medium (IGM) by z ∼ 6. Theoretical works and observations seem to indicate that the fraction, 〈fesc〉, of H i ionizing radiation emitted from galaxies that escapes into the IGM is small in the local universe (〈fesc〉 < ∼ 10%). At high redshift galaxies are more compact...
متن کاملThe Age of Globular Clusters
I review here recent developments which have affected our understanding of both the absolute age of globular clusters and the uncertainties in this age estimate, and comment on the implications for cosmological models. This present estimate is in agreement with the range long advocated by David Schramm. The major uncertainty in determining ages of globular clusers based upon the absolute magnit...
متن کاملthe evaluation of language related engagment and task related engagment with the purpose of investigating the effect of metatalk and task typology
abstract while task-based instruction is considered as the most effective way to learn a language in the related literature, it is oversimplified on various grounds. different variables may affect how students are engaged with not only the language but also with the task itself. the present study was conducted to investigate language and task related engagement on the basis of the task typolog...
15 صفحه اولGlobular clusters, Hipparcos, and the age of the galaxy.
We discuss the impact of the results from the recent Hipparcos astrometric satellite on distance estimates of galactic globular clusters. Recalibrating the clusters not only implies a relatively small change in the distance to the Large Magellanic Cloud, and hence a rescaling of several estimates of the Hubble constant, but also leads to significantly younger cluster ages. Although the data are...
متن کاملdeterminant of the hankel matrix with binomial entries
abstract in this thesis at first we comput the determinant of hankel matrix with enteries a_k (x)=?_(m=0)^k??((2k+2-m)¦(k-m)) x^m ? by using a new operator, ? and by writing and solving differential equation of order two at points x=2 and x=-2 . also we show that this determinant under k-binomial transformation is invariant.
15 صفحه اولذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Cosmology and Astroparticle Physics
سال: 2020
ISSN: 1475-7516
DOI: 10.1088/1475-7516/2020/12/002