Constraint on intergalactic dust from thermal history of intergalactic medium
نویسندگان
چکیده
We present a new constraint on the amount of dust in the intergalactic medium (IGM) at high redshift. We derive the thermal history of the IGM by taking account of the photoelectric heating by dust grains, and compare it with the thermal history suggested by observations of Lyman α forests. As a result, if the IGM grain size is & 100 Å, the dust-gas mass ratio of the IGM at z & 2 is . 1/100 Galactic value corresponding to Ω dust . 10. If the grain size is as small as ∼ 10 Å, which is suggested to be the primary grain size produced in the ejecta of supernovae, the dustgas ratio is . 1/1000 Galactic value corresponding to Ω dust . 10. In addition, we show that the photoelectric heating by dust can be the most important heating mechanism for the IGM even if the grain size is as large as 0.1 μm.
منابع مشابه
Amount of intergalactic dust: constraints from distant supernovae and thermal history of intergalactic medium
This paper examines the allowed amount of IG (intergalactic) dust, which is constrained by extinction and reddening of distant SNe and thermal history of IGM (intergalactic medium) affected by dust photoelectric heating. Based on the observational cosmic star formation history, we find an upper bound of χ, the mass ratio of the IG dust to the total metal in the Universe, as χ . 0.1 for 10Å . a ...
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