Open AccessLyman α systems within hot galactic haloes
Author(s) -
Viegas Sueli M.,
Friaça Amâncio C. S.,
Gruenwald Ruth
Publication year - 1999
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.1999.02818.x
Subject(s) - physics , astrophysics , halo , galaxy , galactic halo , astronomy , line (geometry) , thermal , intergalactic medium , redshift , geometry , mathematics , meteorology
A hot‐gas halo is predicted by chemodynamical models during the early evolution of spheroidal galaxies. Cold condensations, arising from thermal instabilities in the hot gas, are expected to be embedded in the hot halo. In the early phases of the galaxy ( t ≲1 Gyr), a strong X‐ray and EUV emission is produced by the extended hot‐gas distribution, ionizing the cold clouds. This self‐irradiating two‐phase halo model successfully explains several line ratios observed in QSO absorption‐line systems, and reproduces the temperature distribution of Lyman α clouds.