The ALPINE-ALMA [CII] Survey: data processing, catalogs, and statistical source properties

Abstract

The ALPINE-ALMA large program targets the [CII] 158 µm line and the far-infrared continuum in 118 spectroscopically confirmed star-forming galaxies between z=4.4 and z=5.9. It represents the first large [CII] statistical sample built in this redshift range. We present details of the data processing and the construction of the catalogs. We detected 23 of our targets in the continuum. To derive accurate infrared luminosities and obscured star formation rates, we measured the conversion factor from the ALMA 158 µm rest-frame dust continuum luminosity to the total infrared luminosity (L IR ) after constraining the dust spectral energy distribution by stacking a photometric sample similar to ALPINE in ancillary single-dish far-infrared data. We found that our continuum detections have a median L IR of 4.4×10 11 L . We also detected 57 additional continuum sources in our ALMA pointings. They are at lower redshift than the ALPINE targets, with a mean photometric redshift of 2.5±0.2. We measured the 850 µm number counts between 0.35 and 3.5 mJy, improving the current interferometric constraints in this flux density range. We found a slope break in the number counts around 3 mJy with a shallower slope below this value. More than 40 % of the cosmic infrared background is emitted by sources brighter than 0.35 mJy. Finally, we detected the [CII] line in 75 of our targets. Their median [CII] luminosity is 4.8×10 8 L and their median full width at half maximum is 252 km/s. After measuring the mean obscured SFR in various [CII] luminosity bins by stacking ALPINE continuum data, we find a good agreement between our data and the local and predicted SFR-L [CII] relations of De Looze et al. (2014) and Lagache et al. (2018).

The ALPINE-ALMA [CII] Survey: Size of Individual Star-Forming Galaxies at z=4-6 and their Extended Halo Structure

“…Overview ALPINE is an ALMA large program (Project ID: 2017.1.00428.L; PI: O. Le Fèvre; see also : e.g., Le Fèvre et al 2019;Faisst et al 2019;Bethermin et al 2020), aimed at measuring [C ii] 158 µm and rest-frame FIR continuum emission from a representative sample of 118 main-sequence galaxies at 4.4 < z < 5.8. Observations were carried out between May 2018 and February 2019.…”

“…The details of data calibration, reduction, and [C ii] line extractions are described in Bethermin et al (2020).…”

“…The major steps were performed with the scripts provided by the ALMA Observatory. We applied additional flags, especially for a few bad antennas with suspicious behaviors (see Bethermin et al 2020). With the CASA task tclean, continuum maps were produced by utilizing the line-free channels in all spectral windows, while [C ii] line cubes were generated after continuum subtraction from the observed visibility data with uvcontsub.…”

A puzzling non-detection of [O III] and [C II] from a $z \approx 7.7$ galaxy observed with ALMA

“…They do, however, find a possible deviation at lower SFR. Schaerer et al (2020) also find good agreement between z ∼ 4 -6 star-forming galaxies from the APLINE-ALMA survey (Le Fèvre et al 2019;Bethermin et al 2020;Faisst et al 2020) and local galaxies. When combined with earlier measurements at z > 6, they find only a slightly steeper [C ii]-SFR relation than the local one.…”

The ALPINE-ALMA [C II] Survey: [C II]158micron Emission Line Luminosity Functions at $z \sim 4-6$

“…The goal of this paper is to address these questions, using a unique set of observations taken by the ALMA Large Program to INvestigate C II at Early times (ALPINE) survey (Le Fèvre et al 2019;Faisst et al 2020;Bethermin et al 2020).…”