Dust growth via accretion of gas species has been proposed as the dominant
process to increase the amount of dust in galaxies. We show here that this
hypothesis encounters severe difficulties that make it unfit to explain the
observed UV and IR properties of such systems, particularly at high redshifts.
Dust growth in the diffuse ISM phases is hampered by (a) too slow accretion
rates; (b) too high dust temperatures, and (c) the Coulomb barrier that
effectively blocks accretion. In molecular clouds these problems are largely
alleviated. Grains are cold (but not colder than the CMB temperature). However,
in dense environments accreted materials form icy water mantles, perhaps with
impurities. Mantles are immediately (1 yr) photo-desorbed as grains return to
the diffuse ISM at the end of the cloud lifetime, thus erasing any memory of
the growth. We conclude that dust attenuating stellar light at high-z must be
ready-made stardust largely produced in supernova ejecta.
Description
[1606.07214] The problematic growth of dust in the interstellar medium
%0 Generic
%1 ferrara2016problematic
%A Ferrara, Andrea
%A Viti, Serena
%A Ceccarelli, Cecilia
%D 2016
%K dust growth ism
%T The problematic growth of dust in the interstellar medium
%U http://arxiv.org/abs/1606.07214
%X Dust growth via accretion of gas species has been proposed as the dominant
process to increase the amount of dust in galaxies. We show here that this
hypothesis encounters severe difficulties that make it unfit to explain the
observed UV and IR properties of such systems, particularly at high redshifts.
Dust growth in the diffuse ISM phases is hampered by (a) too slow accretion
rates; (b) too high dust temperatures, and (c) the Coulomb barrier that
effectively blocks accretion. In molecular clouds these problems are largely
alleviated. Grains are cold (but not colder than the CMB temperature). However,
in dense environments accreted materials form icy water mantles, perhaps with
impurities. Mantles are immediately (1 yr) photo-desorbed as grains return to
the diffuse ISM at the end of the cloud lifetime, thus erasing any memory of
the growth. We conclude that dust attenuating stellar light at high-z must be
ready-made stardust largely produced in supernova ejecta.
@misc{ferrara2016problematic,
abstract = {Dust growth via accretion of gas species has been proposed as the dominant
process to increase the amount of dust in galaxies. We show here that this
hypothesis encounters severe difficulties that make it unfit to explain the
observed UV and IR properties of such systems, particularly at high redshifts.
Dust growth in the diffuse ISM phases is hampered by (a) too slow accretion
rates; (b) too high dust temperatures, and (c) the Coulomb barrier that
effectively blocks accretion. In molecular clouds these problems are largely
alleviated. Grains are cold (but not colder than the CMB temperature). However,
in dense environments accreted materials form icy water mantles, perhaps with
impurities. Mantles are immediately (1 yr) photo-desorbed as grains return to
the diffuse ISM at the end of the cloud lifetime, thus erasing any memory of
the growth. We conclude that dust attenuating stellar light at high-z must be
ready-made stardust largely produced in supernova ejecta.},
added-at = {2016-06-24T08:44:01.000+0200},
author = {Ferrara, Andrea and Viti, Serena and Ceccarelli, Cecilia},
biburl = {https://www.bibsonomy.org/bibtex/26a79e2a271ffd187b81f59b48771c430/miki},
description = {[1606.07214] The problematic growth of dust in the interstellar medium},
interhash = {53910f3d454a4dd54f63a36ba07c68ae},
intrahash = {6a79e2a271ffd187b81f59b48771c430},
keywords = {dust growth ism},
note = {cite arxiv:1606.07214Comment: 6 pages, MNRAS Letter. Comments welcome},
timestamp = {2016-06-24T08:44:01.000+0200},
title = {The problematic growth of dust in the interstellar medium},
url = {http://arxiv.org/abs/1606.07214},
year = 2016
}