We present new results on CII158$\mu$ m emission from four galaxies in the
reionization epoch. These galaxies were previously confirmed to be at redshifts
between 6.6 and 7.15 from the presence of the Ly$\alpha$ emission line in their
spectra. The Ly$\alpha$ emission line is redshifted by 100-200 km/s compared to
the systemic redshift given by the CII line. These velocity offsets are
smaller than what is observed in z~3 Lyman break galaxies with similar UV
luminosities and emission line properties. Smaller velocity shifts reduce the
visibility of Ly$\alpha$ and hence somewhat alleviate the need for a very
neutral IGM at z~7 to explain the drop in the fraction of Ly$\alpha$ emitters
observed at this epoch.
The galaxies show CII emission with LCII=0.6-1.6 x10$^8 L_ødot$: these
luminosities place them consistently below the SFR-LCII relation observed for
low redshift star forming and metal poor galaxies and also below z =5.5 Lyman
break galaxies with similar star formation rates. We argue that previous
undetections of CII in z~7 galaxies with similar or smaller star formation
rates are due to selection effects: previous targets were mostly strong
Ly$\alpha$ emitters and therefore probably metal poor systems, while our
galaxies are more representative of the general high redshift star forming
population .
Описание
[1608.08837] Tracing the reionization epoch with ALMA: [CII] emission in z~7 galaxies
%0 Generic
%1 pentericci2016tracing
%A Pentericci, L.
%A Carniani, S.
%A Castellano, M.
%A Fontana, A.
%A Maiolino, R.
%A Guaita, L.
%A Vanzella, E.
%A Grazian, A.
%A Santini, P.
%A Yan, H.
%A Cristiani, S.
%A Conselice, C.
%A Giavalisco, M.
%A Hathi, N.
%A Koekemoer, A.
%D 2016
%K [CII] detection high-z
%T Tracing the reionization epoch with ALMA: CII emission in z~7 galaxies
%U http://arxiv.org/abs/1608.08837
%X We present new results on CII158$\mu$ m emission from four galaxies in the
reionization epoch. These galaxies were previously confirmed to be at redshifts
between 6.6 and 7.15 from the presence of the Ly$\alpha$ emission line in their
spectra. The Ly$\alpha$ emission line is redshifted by 100-200 km/s compared to
the systemic redshift given by the CII line. These velocity offsets are
smaller than what is observed in z~3 Lyman break galaxies with similar UV
luminosities and emission line properties. Smaller velocity shifts reduce the
visibility of Ly$\alpha$ and hence somewhat alleviate the need for a very
neutral IGM at z~7 to explain the drop in the fraction of Ly$\alpha$ emitters
observed at this epoch.
The galaxies show CII emission with LCII=0.6-1.6 x10$^8 L_ødot$: these
luminosities place them consistently below the SFR-LCII relation observed for
low redshift star forming and metal poor galaxies and also below z =5.5 Lyman
break galaxies with similar star formation rates. We argue that previous
undetections of CII in z~7 galaxies with similar or smaller star formation
rates are due to selection effects: previous targets were mostly strong
Ly$\alpha$ emitters and therefore probably metal poor systems, while our
galaxies are more representative of the general high redshift star forming
population .
@misc{pentericci2016tracing,
abstract = {We present new results on [CII]158$\mu$ m emission from four galaxies in the
reionization epoch. These galaxies were previously confirmed to be at redshifts
between 6.6 and 7.15 from the presence of the Ly$\alpha$ emission line in their
spectra. The Ly$\alpha$ emission line is redshifted by 100-200 km/s compared to
the systemic redshift given by the [CII] line. These velocity offsets are
smaller than what is observed in z~3 Lyman break galaxies with similar UV
luminosities and emission line properties. Smaller velocity shifts reduce the
visibility of Ly$\alpha$ and hence somewhat alleviate the need for a very
neutral IGM at z~7 to explain the drop in the fraction of Ly$\alpha$ emitters
observed at this epoch.
The galaxies show [CII] emission with L[CII]=0.6-1.6 x10$^8 L_\odot$: these
luminosities place them consistently below the SFR-L[CII] relation observed for
low redshift star forming and metal poor galaxies and also below z =5.5 Lyman
break galaxies with similar star formation rates. We argue that previous
undetections of [CII] in z~7 galaxies with similar or smaller star formation
rates are due to selection effects: previous targets were mostly strong
Ly$\alpha$ emitters and therefore probably metal poor systems, while our
galaxies are more representative of the general high redshift star forming
population .},
added-at = {2016-09-01T10:08:14.000+0200},
author = {Pentericci, L. and Carniani, S. and Castellano, M. and Fontana, A. and Maiolino, R. and Guaita, L. and Vanzella, E. and Grazian, A. and Santini, P. and Yan, H. and Cristiani, S. and Conselice, C. and Giavalisco, M. and Hathi, N. and Koekemoer, A.},
biburl = {https://www.bibsonomy.org/bibtex/223df1c17080a24e722fe5753b563e64a/miki},
description = {[1608.08837] Tracing the reionization epoch with ALMA: [CII] emission in z~7 galaxies},
interhash = {905eb8706a5acd2dd23f99eae4a088c8},
intrahash = {23df1c17080a24e722fe5753b563e64a},
keywords = {[CII] detection high-z},
note = {cite arxiv:1608.08837Comment: To appear in ApJL},
timestamp = {2016-09-01T10:08:14.000+0200},
title = {Tracing the reionization epoch with ALMA: [CII] emission in z~7 galaxies},
url = {http://arxiv.org/abs/1608.08837},
year = 2016
}