We investigate whether strong molecular and atomic emission lines at
far-infrared wavelengths can influence the identification and derived
properties of galaxies selected from broad-band, far-infrared or submillimetre
observations. Several of these lines, e.g. CII158um, have been found to be
very bright in some high-redshift galaxies, with fluxes of >0.1-1% of the total
far-infrared luminosity, and may be even brighter in certain populations at
high redshifts. At redshifts where these lines fall in instrument pass-bands
they can significantly increase the broad-band flux measurements. We estimate
that the contributions from line emission could boost the apparent broad-band
flux by >20-40% in the Herschel and SCUBA-2 bands. Combined with the steep
source counts in the submillimetre and far-infrared bands, line contamination
has potentially significant consequences for the properties of sources detected
in flux-limited continuum surveys, biasing the derived redshift distributions
and bolometric luminosities. Indeed, it is possible that some z>4 sources found
in 850-um surveys are being identified in part due to line contamination from
strong CII emission. These biases may be even stronger for less-luminous and
lower-metallicity populations at high redshifts which are observable with ALMA
and which may have even stronger line-to-continuum ratios.
Описание
[1104.1758] The potential influence of far-infrared emission lines on the selection of high-redshift galaxies
%0 Generic
%1 Smail2011
%A Smail, Ian
%A Swinbank, A. M.
%A Ivison, R. J.
%A Ibar, E.
%D 2011
%K [CII] high-z molecules
%T The potential influence of far-infrared emission lines on the selection
of high-redshift galaxies
%U http://arxiv.org/abs/1104.1758
%X We investigate whether strong molecular and atomic emission lines at
far-infrared wavelengths can influence the identification and derived
properties of galaxies selected from broad-band, far-infrared or submillimetre
observations. Several of these lines, e.g. CII158um, have been found to be
very bright in some high-redshift galaxies, with fluxes of >0.1-1% of the total
far-infrared luminosity, and may be even brighter in certain populations at
high redshifts. At redshifts where these lines fall in instrument pass-bands
they can significantly increase the broad-band flux measurements. We estimate
that the contributions from line emission could boost the apparent broad-band
flux by >20-40% in the Herschel and SCUBA-2 bands. Combined with the steep
source counts in the submillimetre and far-infrared bands, line contamination
has potentially significant consequences for the properties of sources detected
in flux-limited continuum surveys, biasing the derived redshift distributions
and bolometric luminosities. Indeed, it is possible that some z>4 sources found
in 850-um surveys are being identified in part due to line contamination from
strong CII emission. These biases may be even stronger for less-luminous and
lower-metallicity populations at high redshifts which are observable with ALMA
and which may have even stronger line-to-continuum ratios.
@misc{Smail2011,
abstract = { We investigate whether strong molecular and atomic emission lines at
far-infrared wavelengths can influence the identification and derived
properties of galaxies selected from broad-band, far-infrared or submillimetre
observations. Several of these lines, e.g. [CII]158um, have been found to be
very bright in some high-redshift galaxies, with fluxes of >0.1-1% of the total
far-infrared luminosity, and may be even brighter in certain populations at
high redshifts. At redshifts where these lines fall in instrument pass-bands
they can significantly increase the broad-band flux measurements. We estimate
that the contributions from line emission could boost the apparent broad-band
flux by >20-40% in the Herschel and SCUBA-2 bands. Combined with the steep
source counts in the submillimetre and far-infrared bands, line contamination
has potentially significant consequences for the properties of sources detected
in flux-limited continuum surveys, biasing the derived redshift distributions
and bolometric luminosities. Indeed, it is possible that some z>4 sources found
in 850-um surveys are being identified in part due to line contamination from
strong [CII] emission. These biases may be even stronger for less-luminous and
lower-metallicity populations at high redshifts which are observable with ALMA
and which may have even stronger line-to-continuum ratios.
},
added-at = {2011-04-12T15:35:38.000+0200},
author = {Smail, Ian and Swinbank, A. M. and Ivison, R. J. and Ibar, E.},
biburl = {https://www.bibsonomy.org/bibtex/213710c18da3c1361ccb4e29a5eb2bd0a/miki},
description = {[1104.1758] The potential influence of far-infrared emission lines on the selection of high-redshift galaxies},
interhash = {7b1f7fa60e5d9238f4eaaaa648fe1b86},
intrahash = {13710c18da3c1361ccb4e29a5eb2bd0a},
keywords = {[CII] high-z molecules},
note = {cite arxiv:1104.1758
Comment: MNRAS letter, in press},
timestamp = {2011-04-12T15:35:38.000+0200},
title = {The potential influence of far-infrared emission lines on the selection
of high-redshift galaxies},
url = {http://arxiv.org/abs/1104.1758},
year = 2011
}