Аннотация
We investigate the relative importance of two galactic outflow suppression
mechanisms : a) Cosmological infall of the intergalactic gas onto the galaxy,
and b) the existence of a hot circumgalactic medium (CGM). Considering only
radial motion, the infall reduces the speed of outflowing gas and even halts
the outflow, depending on the mass and redshift of the galaxy. For star forming
galaxies there exists an upper mass limit beyond which outflows are suppressed
by the gravitational field of the galaxy. We find that infall can reduce this
upper mass limit approximately by a factor of two (independent of the
redshift). Massive galaxies ($10^12 M_ødot$) host large reservoir
of hot, diffuse CGM around the central part of the galaxy. The CGM acts as a
barrier between the infalling and outflowing gas and provides an additional
source of outflow suppression. We find that at low redshifts ($złesssim3.5$),
the CGM is more effective than the infall in suppressing the outflows.
Together, these two processes give a mass range in which galaxies are unable to
have effective outflows. We also discuss the impact of outflow suppression on
the enrichment history of the galaxy and its environment.
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