The ALPINE-ALMA [C II] Survey: [C II]158micron Emission Line Luminosity Functions at $z sim 4-6$. (arXiv:2006.04835v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Yan_L/0/1/0/all/0/1">Lin Yan</a> (Caltech), <a href="http://arxiv.org/find/astro-ph/1/au:+Sajina_A/0/1/0/all/0/1">A. Sajina</a> (Tufts University), <a href="http://arxiv.org/find/astro-ph/1/au:+Loiacono_F/0/1/0/all/0/1">F. Loiacono</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lagache_G/0/1/0/all/0/1">G. Lagache</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bethermin_M/0/1/0/all/0/1">M. Bèthermin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Faisst_A/0/1/0/all/0/1">A. Faisst</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ginolfi_M/0/1/0/all/0/1">M. Ginolfi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fevre_O/0/1/0/all/0/1">O. Le Fèvre</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gruppioni_C/0/1/0/all/0/1">C. Gruppioni</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Capak_P/0/1/0/all/0/1">P.L. Capak</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cassata_P/0/1/0/all/0/1">P. Cassata</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schaerer_D/0/1/0/all/0/1">D. Schaerer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Silverman_J/0/1/0/all/0/1">J.D. Silverman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bardelli_S/0/1/0/all/0/1">S. Bardelli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dessauges_Zavadsky_M/0/1/0/all/0/1">M. Dessauges-Zavadsky</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cimatti_A/0/1/0/all/0/1">A. Cimatti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hathi_N/0/1/0/all/0/1">N.P. Hathi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lemaux_B/0/1/0/all/0/1">B.C. Lemaux</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ibar_E/0/1/0/all/0/1">E. Ibar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jones_G/0/1/0/all/0/1">G.C. Jones</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Koekemoer_A/0/1/0/all/0/1">A.M. Koekemoer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Oesch_P/0/1/0/all/0/1">P.A. Oesch</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Talia_M/0/1/0/all/0/1">M. Talia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pozzi_F/0/1/0/all/0/1">F. Pozzi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Riechers_D/0/1/0/all/0/1">D.A. Riechers</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tasca_L/0/1/0/all/0/1">L.A. Tasca</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Toft_S/0/1/0/all/0/1">S. Toft</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vallini_L/0/1/0/all/0/1">L. Vallini</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vergani_D/0/1/0/all/0/1">D. Vergani</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zamorani_G/0/1/0/all/0/1">G. Zamorani</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zucca_E/0/1/0/all/0/1">E. Zucca</a>
We present the [CII]158$mu$m line luminosity functions (LFs) at $zsim 4-6$
using the ALMA observations of 118 sources, which are selected to have UV
luminosity $M_{1500A} < -20.2$ and optical spectroscopic redshifts in COSMOS
and ECDF-S. Of the 118 targets, 75 have significant [C II] detections and 43
are upper limits. With this UV-selected sample, we set stringent lower bounds
to the volume density of [C II] emitters at $zsim4-6$. Our derived LFs are
consistent with the $zsim0$ [C II] LF at $leq 10^9L_odot$, but show a hint
of an excess of [C II] emitters at the luminous end ($>10^9L_odot$) compared
to $zsim0$. This excess is consistent with a potential population of [C
II]-bright UV-faint sources that are largely excluded from the ALPINE target
selection. To further constrain such sources, in a companion analysis, Loiacono
et al. (2020) estimate the [C II] LF based on serendipitous [C II] sources in
the ALPINE maps. Their resulting single data point is consistent with the
excess we observe at high-L. Combined, these studies suggest possible redshift
evolution in the [C II] LFs at high luminosity between $zsim 5$ and $0$. This
conclusion is further supported by the inferred [C II] LFs from the far-IR and
CO LFs at $zsim4-6$. Integrating our estimate on the best-fit [C II] LF, we
set a constraint on molecular gas mass density at $zsim4-6$, with $rho_{mol}
sim (2-7)times10^7M_odot$ Mpc$^{-3}$. This is broadly consistent with
previous studies, although the uncertainties span more than an order of
magnitude. Finally, we find that available model predictions tend to
underestimate the number densities of [C II] emitters at $zsim5$.
We present the [CII]158$mu$m line luminosity functions (LFs) at $zsim 4-6$
using the ALMA observations of 118 sources, which are selected to have UV
luminosity $M_{1500A} < -20.2$ and optical spectroscopic redshifts in COSMOS
and ECDF-S. Of the 118 targets, 75 have significant [C II] detections and 43
are upper limits. With this UV-selected sample, we set stringent lower bounds
to the volume density of [C II] emitters at $zsim4-6$. Our derived LFs are
consistent with the $zsim0$ [C II] LF at $leq 10^9L_odot$, but show a hint
of an excess of [C II] emitters at the luminous end ($>10^9L_odot$) compared
to $zsim0$. This excess is consistent with a potential population of [C
II]-bright UV-faint sources that are largely excluded from the ALPINE target
selection. To further constrain such sources, in a companion analysis, Loiacono
et al. (2020) estimate the [C II] LF based on serendipitous [C II] sources in
the ALPINE maps. Their resulting single data point is consistent with the
excess we observe at high-L. Combined, these studies suggest possible redshift
evolution in the [C II] LFs at high luminosity between $zsim 5$ and $0$. This
conclusion is further supported by the inferred [C II] LFs from the far-IR and
CO LFs at $zsim4-6$. Integrating our estimate on the best-fit [C II] LF, we
set a constraint on molecular gas mass density at $zsim4-6$, with $rho_{mol}
sim (2-7)times10^7M_odot$ Mpc$^{-3}$. This is broadly consistent with
previous studies, although the uncertainties span more than an order of
magnitude. Finally, we find that available model predictions tend to
underestimate the number densities of [C II] emitters at $zsim5$.
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