Astronomy and Astrophysics – Astrophysics
Scientific paper
1994-06-16
Astronomy and Astrophysics
Astrophysics
14 pages,1 figure,uuencoded,compressed,ps file,accepted by MNRAS
Scientific paper
Motivated by recent observation of Lanzetta et al. that most luminous galaxies at low redshifts produce $\lya$ absorption at impact parameter $l\lsim 160 \kpch$, we propose that these absorbers are clouds confined by the pressure of ambient hot gas in galactic haloes. We determine the properties of this hot gas and of the absorption systems on the basis of observational and theoretical constraints. The absorbing clouds need to be replenished on about one orbital time ($\sim 10^9$ yrs) in the galactic halo. The pressure and temperature of the gas at radius $r\sim 100\kpc$ are $P=(10-100){\rm cm^{-3} K}$, $T=10^{(5.5-6.5)}{\rm K}$. The model requires that about 10 per cent of the gas in low-redshift galactic haloes is in the hot phase. Such gas in galactic haloes emits x-ray with bolometric luminosity of the order $10^{37-40}{\rm erg\,s^{-1}}$. The plausibility for such gas to exist in current models of galaxy formation is discussed.
No associations
LandOfFree
Lyman alpha absorption at low redshifts and hot gas in galactic haloes does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Lyman alpha absorption at low redshifts and hot gas in galactic haloes, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Lyman alpha absorption at low redshifts and hot gas in galactic haloes will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-615944