The Cosmic Energy Inventory: Construction and Consistency Investigations II

2015 Fiscal Year Final Research Report

• Project/Area Number: 23540288
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Particle/Nuclear/Cosmic ray/Astro physics
• Research Institution: The University of Tokyo
• Principal Investigator: FUKUGITA Masataka 東京大学, カブリ数物連携宇宙研究機構, 特任教授 (40100820)
• Project Period (FY): 2011-04-28 – 2016-03-31
• Keywords: 宇宙科学 / 宇宙物理 / 光学赤外線天文学

Outline of Final Research Achievements

Galaxies are not closed entities as depicted by the term ``Island Universe''. The matter associated with the galaxy is distributed extending far beyond its gravitational radius. This is illuminated by dark matter and dust: those associated with galaxies are less than their global values. In the present work we studied the distribution of cosmic dust, for which observational information can passively be obtained. We showed that while 1/3 of dust roduced in star forming activity in galaxies remains in the galactic disc, 2/3 are expelled from galaxies: its half is captured in Mg II clouds. The rest 1/3 is expelled to intergalactic space. We detected dust in damped Lyman alpha absorbers, while the total amount is smaller than in Mg II clouds. Heavy elements in the clouds are inferred to be produced in star forming activities in galaxies, carried away and deposited in those clouds.

Free Research Field

天体物理学