Interpreting ALMA Observations of the ISM During the Epoch of
Reionisation
H. Katz, T. Kimm, D. Sijacki, and M. Haehnelt. (2016)cite arxiv:1612.01786Comment: 32 Pages, 25 figures, Submitted to MNRAS, Abstract abridged for arXiv.
Abstract
We present cosmological, radiation-hydrodynamics simulations of galaxy
formation during the epoch of reionisation in an effort towards modelling the
interstellar medium (ISM) and interpreting ALMA observations. Simulations with
and without stellar radiation are compared at large (Mpc), intermediate (tens
of kpc), and small (sub kpc) scales to highlight the differences local stellar
radiation can make for the distribution of neutral hydrogen internally to
galaxy and externally on the surrounding filaments and intergalactic medium
(IGM). At large scales, we find that the dense regions around galaxies reionise
first before UV photons penetrate the voids; however, there remains a
considerable amount of neutral gas present within the galaxies. The spatial
distribution of neutral gas is highly dynamic and is anti-correlated with the
presence of stars older than a few Myrs. Likewise, H$_2$ masses in the galaxies
are extremely time variable and sensitive to the presence of these same stars.
For our specific feedback implementation, most of the metals remain inside the
virial radii of galaxies and they are proportionally distributed over the
ionised and neutral medium by mass. For our most massive galaxy with $\rm
M_h\sim10^11$M$_ødot$, we find that the majority of the CII mass in the
galaxy is associated with cold neutral clumps, similar to OI. NII is more
diffuse and arises in warmer gas while OIII is associated with the hotter gas
produced by photo-heating and supernovae that has a higher ionisation
parameter. If small pockets of high metallicity gas exist in the ISM, the
emission from these ions may be observable by ALMA while the naturally low
metallicity of the galaxy will cause these systems to fall below the local
CII-SFR relation. abridged
Description
[1612.01786] Interpreting ALMA Observations of the ISM During the Epoch of Reionisation
%0 Generic
%1 katz2016interpreting
%A Katz, Harley
%A Kimm, Taysun
%A Sijacki, Debora
%A Haehnelt, Martin
%D 2016
%K ALMA ISM simulation
%T Interpreting ALMA Observations of the ISM During the Epoch of
Reionisation
%U http://arxiv.org/abs/1612.01786
%X We present cosmological, radiation-hydrodynamics simulations of galaxy
formation during the epoch of reionisation in an effort towards modelling the
interstellar medium (ISM) and interpreting ALMA observations. Simulations with
and without stellar radiation are compared at large (Mpc), intermediate (tens
of kpc), and small (sub kpc) scales to highlight the differences local stellar
radiation can make for the distribution of neutral hydrogen internally to
galaxy and externally on the surrounding filaments and intergalactic medium
(IGM). At large scales, we find that the dense regions around galaxies reionise
first before UV photons penetrate the voids; however, there remains a
considerable amount of neutral gas present within the galaxies. The spatial
distribution of neutral gas is highly dynamic and is anti-correlated with the
presence of stars older than a few Myrs. Likewise, H$_2$ masses in the galaxies
are extremely time variable and sensitive to the presence of these same stars.
For our specific feedback implementation, most of the metals remain inside the
virial radii of galaxies and they are proportionally distributed over the
ionised and neutral medium by mass. For our most massive galaxy with $\rm
M_h\sim10^11$M$_ødot$, we find that the majority of the CII mass in the
galaxy is associated with cold neutral clumps, similar to OI. NII is more
diffuse and arises in warmer gas while OIII is associated with the hotter gas
produced by photo-heating and supernovae that has a higher ionisation
parameter. If small pockets of high metallicity gas exist in the ISM, the
emission from these ions may be observable by ALMA while the naturally low
metallicity of the galaxy will cause these systems to fall below the local
CII-SFR relation. abridged
@misc{katz2016interpreting,
abstract = {We present cosmological, radiation-hydrodynamics simulations of galaxy
formation during the epoch of reionisation in an effort towards modelling the
interstellar medium (ISM) and interpreting ALMA observations. Simulations with
and without stellar radiation are compared at large (Mpc), intermediate (tens
of kpc), and small (sub kpc) scales to highlight the differences local stellar
radiation can make for the distribution of neutral hydrogen internally to
galaxy and externally on the surrounding filaments and intergalactic medium
(IGM). At large scales, we find that the dense regions around galaxies reionise
first before UV photons penetrate the voids; however, there remains a
considerable amount of neutral gas present within the galaxies. The spatial
distribution of neutral gas is highly dynamic and is anti-correlated with the
presence of stars older than a few Myrs. Likewise, H$_2$ masses in the galaxies
are extremely time variable and sensitive to the presence of these same stars.
For our specific feedback implementation, most of the metals remain inside the
virial radii of galaxies and they are proportionally distributed over the
ionised and neutral medium by mass. For our most massive galaxy with ${\rm
M_h}\sim10^{11}$M$_{\odot}$, we find that the majority of the CII mass in the
galaxy is associated with cold neutral clumps, similar to OI. NII is more
diffuse and arises in warmer gas while OIII is associated with the hotter gas
produced by photo-heating and supernovae that has a higher ionisation
parameter. If small pockets of high metallicity gas exist in the ISM, the
emission from these ions may be observable by ALMA while the naturally low
metallicity of the galaxy will cause these systems to fall below the local
[CII]-SFR relation. [abridged]},
added-at = {2016-12-07T09:39:09.000+0100},
author = {Katz, Harley and Kimm, Taysun and Sijacki, Debora and Haehnelt, Martin},
biburl = {https://www.bibsonomy.org/bibtex/26b1a962942f6740752a7e4549b42eab5/miki},
description = {[1612.01786] Interpreting ALMA Observations of the ISM During the Epoch of Reionisation},
interhash = {1d6223759bc05b93727f88464d05dae0},
intrahash = {6b1a962942f6740752a7e4549b42eab5},
keywords = {ALMA ISM simulation},
note = {cite arxiv:1612.01786Comment: 32 Pages, 25 figures, Submitted to MNRAS, Abstract abridged for arXiv},
timestamp = {2016-12-07T09:39:09.000+0100},
title = {Interpreting ALMA Observations of the ISM During the Epoch of
Reionisation},
url = {http://arxiv.org/abs/1612.01786},
year = 2016
}