2 Dark a world, now some more light!

流浪行星

行星一定要绕着恒星转吗?不!天文学家最新发现了一些孤立行星,它们在宇宙中漂流,不围绕任何行星。

从2006-2007年间日本-新西兰的银心联合巡天观测中,天文学家发现了10颗木星(太阳系最大行星)大小的流浪行星。这几个流浪儿距离地球平均一两万光年。据估计,宇宙中木星大小的流浪行星的数目大概是恒星的两倍!当然,现有观测并没有完全排除这几颗行星有恒星相伴的可能,但这种可能性很低。

菜单分类: 
研究方法: 
学术分类: 

On the Origin and Evolution of Life in the Galaxy

A simple stochastic model for evolution, based upon the need to pass a
sequence of n critical steps (Carter 1983, Watson 2008) is applied to both
terrestrial and extraterrestrial origins of life. In the former case, the time
at which humans have emerged during the habitable period of the Earth suggests

N-body simulations of gravitational dynamics (Dehnen&Read,2011)

Abstract: We describe the astrophysical and numerical basis of N-body simulations, both
of collisional stellar systems (dense star clusters and galactic centres) and

星系动物园:公众科学工程

SETI项目利用公众的闲置计算机资源来进行数据分析寻找外星生命,而Galaxy Zoo则利用公众闲置的大脑来进行模式识别、数据分类,汇总后进行统计处理,研究星系形成和宇宙学。

Galaxy Zoo: Morphological Classification and Citizen Science

菜单分类: 
研究方法: 
学术分类: 

Lemaître首先发现了哈博定律

The linear redshift-distance relationship: Lemaître beats Hubble by two years

 

Lemaître在1927年的一篇法文论文中首先从理论和观测上同时给出距离-红移关系,比Hubble1929年的结果早了两年。

 

菜单分类: 
研究方法: 
学术分类: 

Title: LCDM: Triumphs, Puzzles and Remedies

Authors:
L. Perivolaropoulos (U. of Ioannina)

Abstract: The consistency level of LCDM with geometrical data probes has been
increasing with time during the last decade. Despite of these successes, there
are some puzzling conflicts between LCDM predictions and dynamical data probes

暗物质照耀的可居星球

尽管暗物质本身不会被照亮,也没有温度,不会发热,但它们会发光!当然,它们并不发射可见光,而是发射伽玛射线。暗物质粒子间相互碰撞会有一定几率发生湮灭反应,转化成伽玛光子。对一些大型行星,这种伽玛光子可能足够多从而使行星上保持液态水,进而孕育生命。

Dark Matter And The Habitability of Planets

研究方法: 

What do we really know about Dark Energy? (Ruth Durrer 11)

Authors:
Ruth Durrer

Abstract: In this paper I discuss what we truly know about dark energy. I shall argue
that up to date our single indication for the existence of dark energy comes
from distance measurements and their relation to redshift
. Supernovae, CMB

What do we really know about Dark Energy? (Ruth Durrer 11)

Authors:
Ruth Durrer

Abstract: In this paper I discuss what we truly know about dark energy. I shall argue
that up to date our single indication for the existence of dark energy comes
from distance measurements and their relation to redshift. Supernovae, CMB

Introduction to Early Universe Cosmology (R. Brandenberger 2011)

Authors:
Robert H. Brandenberger (McGill University)

Abstract: Observational cosmology is in its "golden age" with a vast amount of recent
data on the distribution of matter and light in the universe. This data can be
used to probe theories of the very early universe. It is small amplitude

Pages

Subscribe to 2DARK天文志 RSS