De_Rossi 发表于 2012-7-30 09:54

晕族大质量致密天体(MACHOs)为什么不可能是暗物质?

In the 1990s, astronomers watched millions of stars towards the Galactic
Centre and the Large and Small Magellanic Clouds, tracking their
brightness each night for several years. They sought stars that suddenly
brightened and then quickly faded in a characteristic way, due to the
amplification of a foreground mass. A team observing in Australia found
tens of these events, which they attributed to dead stars or rogue gas planets
of about Jupiter’s mass.Most were seen towards the Galactic Centre, rather
than the Magellanic Clouds, suggesting that more of these planetary-sized
objects lay within our galaxy than in the Milky Way’s outer regions. So the
contribution of such MACHOs to the Milky Way’s dark matter budget was
small.
朝向麦哲伦星云的行星相比,观测到的朝向银心的现象占绝大多数;这表明存在于银河系内部的这些大小与行星接近的天体数量要多于那些银河系外部区域内此类天体的数量。因此,这样的晕族大质量致密天体对于银河系内暗物质数量的贡献很小。
这个逻辑关系不成立啊,怎么贡献小了?

DSMelody 发表于 2012-7-30 11:14

:Q看不懂:Q

天空★下着沙 发表于 2012-7-30 19:38



1。或许只是银河系的特例,并不代表其它河外星系的machos 质量贡献也小

2。 如果是大尺度形态普遍存在的现象,那么至少可以说明MACHOS现在已经不是有力的候选

3。 究竟是不是有力候选,还需要更多的观测证据来说明,现阶段的资料还太少,不能妄下定论
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