We make use of ALMA continuum observations of $15$ luminous Lyman-break
galaxies at $z$$\sim$$7$$-$$8$ to probe their dust-obscured star-formation.
These observations are sensitive enough to probe to obscured SFRs of $20$
$M_ødot$$/$$yr$ ($3\sigma$). Six of the targeted galaxies show significant
($\geq$$3$$\sigma$) dust continuum detections, more than doubling the number of
known dust-detected galaxies at $z$$>$$6.5$. Their IR luminosities range from
$2.7$$\times$$10^11$ $L_ødot$ to $1.1$$\times$$10^12$ $L_ødot$,
equivalent to obscured SFRs of $20$ to $105$ $M_ødot$$/$$yr$. We use our
results to quantify the correlation of the infrared excess IRX on the
UV-continuum slope $\beta_UV$ and stellar mass. Our results are most
consistent with an SMC attenuation curve for intrinsic $UV$-slopes
$\beta_UV,intr$ of $-2.63$ and most consistent with an attenuation curve
in-between SMC and Calzetti for $\beta_UV,intr$ slopes of $-2.23$, assuming a
dust temperature $T_d$ of $50$ K. Our fiducial IRX-stellar mass results at
$z$$\sim$$7$$-$$8$ are consistent with marginal evolution from $z$$\sim$$0$. We
then show how both results depend on $T_d$. For our six dust-detected sources,
we estimate their dust masses and find that they are consistent with dust
production from SNe if the dust destruction is low ($<$$90$%). Finally we
determine the contribution of dust-obscured star formation to the star
formation rate density for $UV$ luminous ($<$$-$$21.5$ mag:
$\gtrsim$$1.7$$L_UV ^*$) $z$$\sim$$7$$-$$8$ galaxies, finding that the total
SFR density at $z$$\sim$$7$ and $z$$\sim$$8$ from bright galaxies is
$0.18_-0.10^+0.08$ dex and $0.20_-0.09^+0.05$ dex higher, respectively,
i.e. $\sim$$13$ of the star formation in $\gtrsim$$1.7$$L_UV ^*$
galaxies at $z$$\sim$$7$$-$$8$ is obscured by dust.
Description
Significant Dust-Obscured Star Formation in Luminous Lyman-break Galaxies at $z$$\sim$$7$$-$$8$
%0 Generic
%1 schouws2021significant
%A Schouws, Sander
%A Stefanon, Mauro
%A Bouwens, Rychard J.
%A Smit, Renske
%A Hodge, Jacqueline A.
%A Labbé, Ivo
%A Algera, Hiddo S.
%A Boogaard, Leindert
%A Carniani, Stefano
%A Fudamoto, Yoshi
%A Holwerda, Benne W.
%A Illingworth, Garth D.
%A Maiolino, Roberto
%A Maseda, Michael V.
%A Oesch, Pascal A.
%A van der Werf, Paul P.
%D 2021
%K library
%T Significant Dust-Obscured Star Formation in Luminous Lyman-break
Galaxies at $z$$\sim$$7$$-$$8$
%U http://arxiv.org/abs/2105.12133
%X We make use of ALMA continuum observations of $15$ luminous Lyman-break
galaxies at $z$$\sim$$7$$-$$8$ to probe their dust-obscured star-formation.
These observations are sensitive enough to probe to obscured SFRs of $20$
$M_ødot$$/$$yr$ ($3\sigma$). Six of the targeted galaxies show significant
($\geq$$3$$\sigma$) dust continuum detections, more than doubling the number of
known dust-detected galaxies at $z$$>$$6.5$. Their IR luminosities range from
$2.7$$\times$$10^11$ $L_ødot$ to $1.1$$\times$$10^12$ $L_ødot$,
equivalent to obscured SFRs of $20$ to $105$ $M_ødot$$/$$yr$. We use our
results to quantify the correlation of the infrared excess IRX on the
UV-continuum slope $\beta_UV$ and stellar mass. Our results are most
consistent with an SMC attenuation curve for intrinsic $UV$-slopes
$\beta_UV,intr$ of $-2.63$ and most consistent with an attenuation curve
in-between SMC and Calzetti for $\beta_UV,intr$ slopes of $-2.23$, assuming a
dust temperature $T_d$ of $50$ K. Our fiducial IRX-stellar mass results at
$z$$\sim$$7$$-$$8$ are consistent with marginal evolution from $z$$\sim$$0$. We
then show how both results depend on $T_d$. For our six dust-detected sources,
we estimate their dust masses and find that they are consistent with dust
production from SNe if the dust destruction is low ($<$$90$%). Finally we
determine the contribution of dust-obscured star formation to the star
formation rate density for $UV$ luminous ($<$$-$$21.5$ mag:
$\gtrsim$$1.7$$L_UV ^*$) $z$$\sim$$7$$-$$8$ galaxies, finding that the total
SFR density at $z$$\sim$$7$ and $z$$\sim$$8$ from bright galaxies is
$0.18_-0.10^+0.08$ dex and $0.20_-0.09^+0.05$ dex higher, respectively,
i.e. $\sim$$13$ of the star formation in $\gtrsim$$1.7$$L_UV ^*$
galaxies at $z$$\sim$$7$$-$$8$ is obscured by dust.
@misc{schouws2021significant,
abstract = {We make use of ALMA continuum observations of $15$ luminous Lyman-break
galaxies at $z$$\sim$$7$$-$$8$ to probe their dust-obscured star-formation.
These observations are sensitive enough to probe to obscured SFRs of $20$
$M_{\odot}$$/$$yr$ ($3\sigma$). Six of the targeted galaxies show significant
($\geq$$3$$\sigma$) dust continuum detections, more than doubling the number of
known dust-detected galaxies at $z$$>$$6.5$. Their IR luminosities range from
$2.7$$\times$$10^{11}$ $L_{\odot}$ to $1.1$$\times$$10^{12}$ $L_{\odot}$,
equivalent to obscured SFRs of $20$ to $105$ $M_{\odot}$$/$$yr$. We use our
results to quantify the correlation of the infrared excess IRX on the
UV-continuum slope $\beta_{UV}$ and stellar mass. Our results are most
consistent with an SMC attenuation curve for intrinsic $UV$-slopes
$\beta_{UV,intr}$ of $-2.63$ and most consistent with an attenuation curve
in-between SMC and Calzetti for $\beta_{UV,intr}$ slopes of $-2.23$, assuming a
dust temperature $T_d$ of $50$ K. Our fiducial IRX-stellar mass results at
$z$$\sim$$7$$-$$8$ are consistent with marginal evolution from $z$$\sim$$0$. We
then show how both results depend on $T_d$. For our six dust-detected sources,
we estimate their dust masses and find that they are consistent with dust
production from SNe if the dust destruction is low ($<$$90$%). Finally we
determine the contribution of dust-obscured star formation to the star
formation rate density for $UV$ luminous ($<$$-$$21.5$ mag:
$\gtrsim$$1.7$$L_{UV} ^*$) $z$$\sim$$7$$-$$8$ galaxies, finding that the total
SFR density at $z$$\sim$$7$ and $z$$\sim$$8$ from bright galaxies is
$0.18_{-0.10}^{+0.08}$ dex and $0.20_{-0.09}^{+0.05}$ dex higher, respectively,
i.e. $\sim$$\frac{1}{3}$ of the star formation in $\gtrsim$$1.7$$L_{UV} ^*$
galaxies at $z$$\sim$$7$$-$$8$ is obscured by dust.},
added-at = {2021-05-27T05:44:27.000+0200},
author = {Schouws, Sander and Stefanon, Mauro and Bouwens, Rychard J. and Smit, Renske and Hodge, Jacqueline A. and Labbé, Ivo and Algera, Hiddo S. and Boogaard, Leindert and Carniani, Stefano and Fudamoto, Yoshi and Holwerda, Benne W. and Illingworth, Garth D. and Maiolino, Roberto and Maseda, Michael V. and Oesch, Pascal A. and van der Werf, Paul P.},
biburl = {https://www.bibsonomy.org/bibtex/26aab353125e7716a5003eaff830182e3/gpkulkarni},
description = {Significant Dust-Obscured Star Formation in Luminous Lyman-break Galaxies at $z$$\sim$$7$$-$$8$},
interhash = {d4c810cd5e51ad469092463c083533e9},
intrahash = {6aab353125e7716a5003eaff830182e3},
keywords = {library},
note = {cite arxiv:2105.12133Comment: 21 pages, 12 figures, 2 tables. Submitted to ApJ},
timestamp = {2021-05-27T05:44:27.000+0200},
title = {Significant Dust-Obscured Star Formation in Luminous Lyman-break
Galaxies at $z$$\sim$$7$$-$$8$},
url = {http://arxiv.org/abs/2105.12133},
year = 2021
}