ALMA-IMF

Context. Over the past few years the Atacama Large Millimeter Array (ALMA) has detected dust-rich galaxies whose cold dust emission is spatially disconnected from the ultraviolet (UV) rest-frame emission. This represents a challenge for modeling their spectral energy distributions (SED) with codes based on an energy budget between the stellar and dust components. This could potentially weaken the solidity of the physical parameters measured with these modeling tools. Aims. We want to verify the validity of energy balance modeling on a sample of galaxies observed from the UV to the sub-millimeter rest frame with ALMA and decipher what information can be reliably retrieved from the analysis of the full SED and from subsets of wavelengths. Methods. We select 17 sources at z ≃ 2 in the Hubble Ultra-Deep Field (HUDF) and in the GOODS-South field detected with ALMA and Herschel and for which UV to near-infrared rest-frame ancillary data are available. We fit the data with CIGALE exploring different configurations for dust attenuation and star formation histories, considering either the full dataset or one that is reduced to the stellar and dust emission. We compare estimates of the dust luminosities, star formation rates, and stellar masses. Results. The fit of the stellar continuum alone with the starburst attenuation law can only reproduce up to 50% of the total dust luminosity observed by Herschel and ALMA. This deficit is found to be marginally consistent with similar quantities estimated in the COSMOS field and is found to increase with the specific star formation rate. The combined stellar and dust SEDs are well fitted when different attenuation laws are introduced. Shallow attenuation curves are needed for the galaxies whose cold dust distribution is very compact compared to starlight. The stellar mass estimates are affected by the choice of the attenuation law. The star formation rates are robustly estimated as long as dust luminosities are available. The large majority of the galaxies are above the average main sequence of star forming galaxies and one source is a strong starburst.

Aims. The sulfur content in dense molecular regions is highly depleted in comparison to diffuse clouds. The reason for this phenomenon is unclear, and it is therefore necessary to carry out observational studies of sulfur-bearing species toward dense regions, mainly in early evolution stages. In this context, the analysis of sulfur-bearing molecules in a large sample of dense starless molecular cores is of great importance to help us uncover the early sulfur chemistry in these regions. Methods. From the Atacama Large Millimeter Array (ALMA) data archive, we selected a project in Band 7 (275-373 GHz), which contains the emission of several sulfur-bearing species. The observations were performed toward a sample of 37 dense cores that are embedded in the most massive infrared-quiet molecular clumps from the ATLASGAL survey. The lines of 34SO, SO2, NS, SO, SO+, and H2CS were analyzed, and the column densities of each molecular species were obtained. Based on the continuum emission and two CH3OH lines, the 37 cores were characterized in density and temperature, and the corresponding H2 column densities were derived. The abundances of these sulfur-bearing species were derived and studied. Results. We find that the abundances of the analyzed sulfur-bearing species increase with increasing gas temperature. Based on the correlation between abundances and temperature, we suggest that the chemistry involved in the formation of each of the analyzed molecules may similarly depend on Tk in the range 20–100 K. Additionally, we find that the comparisons among abundances are highly correlated in general. Taking into account that this correlation decreases in more evolved sources, we suggest that the sulfur-bearing species we analyzed have a similar chemical origin. Our observational results show that the X(SO2)/X(SO) ratio can be used as a chemical clock of molecular cores. Based on the line widths of the molecular lines, we point out that molecules with an oxygen content (34SO, SO2, SO, and SO+) may be associated with warmer and more turbulent gas than the other molecules. H2CS and NS are associated with more quiescent gas, probably in the external envelopes of the cores, which trace similar physical and chemical conditions. We complement recent similar works done toward more evolved sources with a large sample of sources, but also provide quantitative information about abundances that might be useful in chemical models for explaining the sulfur chemistry in the interstellar medium.

The Atacama Large Millimeter/submillimeter Array (ALMA) (The Enhanced Atacama Large Millimeter/submillimeter Array (known as ALMA) is an international astronomy facility. ALMA is a partnership between North America, Europe, and Japan/Taiwan, in cooperation with the Republic of Chile, and is funded in Europe by the European Southern Observatory (ESO) and Spain, in North America by the U.S. National Science Foundation (NSF) in cooperation with the National Research Council of Canada (NRC), and in Japan by the National Institutes of Natural Sciences (NINS) in cooperation with the Academia Sinica in Taiwan. ALMA construction and operations are led on behalf of Japan/Taiwan by the National Astronomical Observatory of Japan (NAOJ), on behalf of North America by the National Radio Astronomy Observatory (NRAO), which is managed by Associated Universities, Inc. (AUI), and on behalf of Europe by ESO) combines large collecting area and location on a high dry site to provide it with unparalleled potential for sensitive millimeter/submillimeter spectral line observations. Its wide frequency coverage, superb receivers and flexible spectrometer will ensure that its potential is met. Since the 1999 meeting on ALMA Science (Wootten, ASP Conf. Ser. 235, 2001), the ALMA team has substantially enhanced its capability for line observations. ALMA’s sensitivity increased when Japan joined the project, bringing the 16 antennas of the Atacama Compcat Array (ACA), equivalent to eight additional 12 m telescopes. The first four receiver cartridges for the baseline ALMA (Japan’s entry has brought two additional bands to ALMA’s receiver retinue) have been accepted, with performance above the already-challenging specifications. ALMA’s flexibility has increased with the enhancement of the baseline correlator with additional channels and flexibility, and with the addition of a separate correlator for the ACA. As an example of the increased flexibility, ALMA is now capable of multi-spectral-region and multi-resolution modes. With the former, one might observe e.g. four separate transitions anywhere within a 2 GHz band with a high resolution bandwidth. With the latter, one might simultaneously observe with low spectral resolution over a wide bandwidth and with high spectral resolution over a narrow bandwidth; this mode could be useful for observations of pressure-broadened lines with narrow cores, for example. Several science examples illustrate ALMA’s potential for transforming millimeter and submillimeter astronomy.

The ALMA (Atacama Large Millimeter/submillimeter Array) project is an international collaboration between Europe, East Asia and North America in cooperation with the Republic of Chile. The ALMA Array Operations Site (AOS) is located at Chajnantor, a plateau at an altitude of 5000 m in the Atacama desert in Chile, and the ALMA Operations Support Facility (OSF) is located near the AOS at an altitude of 2900 m. ALMA will consist of an array of 66 antennas, with baselines up to 16 km and state-of-the-art receivers that cover all the atmospheric windows up to 1 THz. An important component of ALMA is the compact array of twelwe 7-m and four 12-m antennas (the Atacama Compact Array, ACA), which will greatly enhance ALMA's ability to image extended sources. Construction of ALMA started in 2003 and will be completed in 2013. Commissioning started in January 2010 and Early Science Operations is expected to start during the second half of 2011. ALMA science operations is provided by the Joint ALMA Observatory (JAO) in Chile, and the three ALMA Regional Centers (ARCs) located in each ALMA region - Europe, North America and East Asia. ALMA observations will take place 24h per day, interrupted by maintenance periods, and will be done in service observing mode with flexible (dynamic) scheduling. The observations are executed in the form of scheduling blocks (SBs), each of which contains all information necessary to schedule and execute the observations. The default output to the astronomer will be pipeline-reduced images calibrated according to the calibration plan. The JAO is responsible for the data product quality. All science and calibration raw data are captured and archived in the ALMA archive, a distributed system with nodes at the OSF, the Santiago central office and the ARCs. Observation preparation will follow a Phase 1/Phase 2 process. During Phase 1, observation proposals will be created using software tools provided by the JAO and submitted for scientific and technical review. Approved Phase 1 proposals will be admitted to Phase 2 where all observations will be specified as SBs using software tools provided by the JAO. User support will be done at the ARCs through a helpdesk system as well as face-to-face support.

We describe the calibration and imaging heuristics developed and deployed in the Atacama Large Millimeter/submillimeter Array (ALMA) interferometric data processing pipeline, as of ALMA Cycle 9 operations. The pipeline software framework is written in Python, with each data reduction stage layered on top of tasks and toolkit functions provided by the Common Astronomy Software Applications package. This framework supports a variety of tasks for observatory operations, including science data quality assurance, observing mode commissioning, and user reprocessing. It supports ALMA and Very Large Array interferometric data along with ALMA and NRO 45 m single dish data, via different stages and heuristics. In addition to producing calibration tables, calibrated measurement sets, and cleaned images, the pipeline creates a WebLog which serves as the primary interface for verifying the quality assurance of the data by the observatory and for examining the contents of the data by the user. Following the adoption of the pipeline by ALMA Operations in 2014, the heuristics have been refined through annual prioritized development cycles, culminating in a new pipeline release aligned with the start of each ALMA Cycle of observations. Initial development focused on basic calibration and flagging heuristics (Cycles 2–3), followed by imaging heuristics (Cycles 4–5). Further refinement of the flagging and imaging heuristics, including the introduction of parallel processing, proceeded for Cycles 6–7. In the 2020 release, the algorithm to identify channels to use for continuum subtraction and imaging was substantially improved by the addition of a moment difference analysis. A spectral renormalization stage was added for the 2021 release (Cycle 8) to correct high spectral resolution visibility data acquired on targets exhibiting strong celestial line emission in their autocorrelation spectra. The calibration heuristics used in the low signal-to-noise regime were improved for the 2022 release (Cycle 9). In the two most recent Cycles, 97% of ALMA data sets were calibrated and imaged with the pipeline, ensuring long-term automated reproducibility of results. We conclude with a brief description of plans for future additions, including a self-calibration stage, support for multi-configuration imaging, and complete calibration and imaging of full polarization data.

We present the first results of the Galaxy Activity, Torus, and Outflow Survey (GATOS), a project aimed at understanding the properties of the dusty molecular tori and their connection to the host galaxy in nearby Seyfert galaxies. Our project expands the range of active galactic nuclei (AGN) luminosities and Eddington ratios covered by previous surveys of Seyferts conducted by the Atacama Large Millimeter Array (ALMA), allowing us to study the gas feeding and feedback cycle in a combined sample of 19 Seyferts. We used ALMA to obtain new images of the emission of molecular gas and dust using the CO(3–2) and HCO+(4–3) lines as well as their underlying continuum emission at 870 μm with high spatial resolutions (0.1″ ∼ 7 − 13 pc) in the circumnuclear disks (CND) of ten nearby (D < 28 Mpc) Seyfert galaxies selected from an ultra-hard X-ray survey. Our new ALMA observations detect 870 μm continuum and CO line emission from spatially resolved disks located around the AGN in all the sources. The bulk of the 870 μm continuum flux can be accounted for by thermal emission from dust in the majority of the targets. For most of the sources, the disks show a preponderant orientation perpendicular to the AGN wind axes, as expected for dusty molecular tori. The median diameters and molecular gas masses of the tori are ∼42 pc and ∼6 × 105 M⊙, respectively. We also detected the emission of the 4–3 line of HCO+in four GATOS targets. The order of magnitude differences found in the CO/HCO+ratios within our combined sample point to a very different density radial stratification inside the dusty molecular tori of these Seyferts. We find a positive correlation between the line-of-sight gas column densities responsible for the absorption of X-rays and the molecular gas column densities derived from CO toward the AGN in our sources. Furthermore, the median values of both column densities are similar. This suggests that the neutral gas line-of-sight column densities of the dusty molecular tori imaged by ALMA significantly contribute to the obscuration of X-rays. The radial distributions of molecular gas in the CND of our combined sample show signs of nuclear-scale molecular gas deficits. We also detect molecular outflows in the sources that show the most extreme nuclear-scale gas deficits in our sample. These observations find for the first time supporting evidence that the imprint of AGN feedback is more extreme in higher luminosity and/or higher Eddington ratio Seyfert galaxies.

Using the Atacama Large Millimeter/submillimeter Array (ALMA), we report high angular-resolution observations of the redshift z = 3.63 galaxy H-ATLAS J083051.0+013224 (G09v1.97), one of the most luminous strongly lensed galaxies discovered by the Herschel-Astrophysical Terahertz Large Area Survey (H-ATLAS). We present 0.″2−0.″4 resolution images of the rest-frame 188 and 419 μm dust continuum and the CO(6–5), H2O(211−202), and Jup = 2 H2O+ line emission. We also report the detection of H2O(211−202) in this source. The dust continuum and molecular gas emission are resolved into a nearly complete ∼1.″5 diameter Einstein ring plus a weaker image in the center, which is caused by a special dual deflector lensing configuration. The observed line profiles of the CO(6–5), H2O(211−202), and Jup = 2 H2O+ lines are strikingly similar. In the source plane, we reconstruct the dust continuum images and the spectral cubes of the CO, H2O, and H2O+ line emission at sub-kiloparsec scales. The reconstructed dust emission in the source plane is dominated by a compact disk with an effective radius of 0.7 ± 0.1 kpc plus an overlapping extended disk with a radius twice as large. While the average magnification for the dust continuum is μ ∼ 10−11, the magnification of the line emission varies from 5 to 22 across different velocity components. The line emission of CO(6–5), H2O(211−202), and H2O+ have similar spatial and kinematic distributions. The molecular gas and dust content reveal that G09v1.97 is a gas-rich major merger in its pre-coalescence phase, with a total molecular gas mass of ∼1011 M⊙. Both of the merging companions are intrinsically ultra-luminous infrared galaxies (ULIRGs) with infrared luminosities LIR reaching ≳4 × 1012 L⊙, and the total LIR of G09v1.97 is (1.4 ± 0.7)×1013 L⊙. The approaching southern galaxy (dominating from V = −400 to −150 km s−1 relative to the systemic velocity) shows no obvious kinematic structure with a semi-major half-light radius of as = 0.4 kpc, while the receding galaxy (0 to 350 km s−1) resembles an as = 1.2 kpc rotating disk. The two galaxies are separated by a projected distance of 1.3 kpc, bridged by weak line emission (−150 to 0 km s−1) that is co-spatially located with the cold dust emission peak, suggesting a large amount of cold interstellar medium (ISM) in the interacting region. As one of the most luminous star-forming dusty high-redshift galaxies, G09v1.97 is an exceptional source for understanding the ISM in gas-rich starbursting major merging systems at high redshift.

The interaction between radio jets and quasar host galaxies plays a paramount role in quasar and galaxy co-evolution. However, very little is known at present about this interaction at very high−z. Here, we present new Atacama Large Millimeter/submillimeter Array (ALMA) observations in Bands 7 and 3 of six radio-loud (RL) quasar host galaxies at z > 5. We recovered [C II] 158 μm line and underlying dust continuum emission at > 2σ for five sources, while we obtained upper limits for the CO(6-5) emission line and continuum for the remaining source. At the spatial resolution of our observations (∼1″​​.0–1″​​.4), we did not recover any perturbed or extended morphologies or kinematics, which are known signatures of potential mergers. These galaxies already host large quantities of gas (∼1010 M⊙), with [C II] luminosities of L[C II] ∼ 108 − 9 L⊙ and [C II]-based star formation rates of 30 − 400 M⊙ yr−1. In building their radio/submillimeter (radio/submm) spectral energy distributions (SEDs), we found that in at least four cases, the 1 mm continuum intensity arises from a combination of synchrotron and dust emission. The initial estimation of synchrotron contribution at 300 GHz in these cases is of ≳10%. Assuming a scenario where the continuum emission is solely due to cold dust as an upper limit, we obtained infrared (IR) luminosities of LIR ∼ 1011 − 12 L⊙. We compared the properties of the sources inspected here with a large collection of radio-quiet sources from the literature, as well as a sample of RL quasars from previous studies at comparable redshifts. We recovered a mild potential decrease in L[C II] for the RL sources, which might be due to a suppression of the cool gas emission due to the radio jets. We did not find any [C II] emitting companion galaxy candidate around the five RL quasars observed in Band 7. Given the depth of our dataset, this result is still consistent with what has been observed around radio-quiet quasars. Future higher spatial-resolution observations, over a broader frequency range, of high−z RL quasars hosts will allow us to further improve our understanding of the physics of these sources.

We present high-resolution (≲160 au) Atacama Large Millimeter/submillimeter Array (ALMA) 1.3 mm observations of the high-mass prestellar core candidate G11.92−0.61 MM2, which reveal that this source is in fact a protobinary system with a projected separation of 505 au. The binary components, MM2E and MM2W, are compact (radii <140 au) sources within the partially optically thick dust emission with α 0.9 cm−1.3 mm = 2.47–2.94. The 1.3 mm brightness temperatures, T b = 68.4/64.6 K for MM2E/MM2W, imply internal heating and minimum luminosities L * > 24.7 L ⊙ for MM2E and L * > 12.6 L ⊙ for MM2W. The compact sources are connected by a “bridge” of lower-surface-brightness dust emission and lie within more extended emission that may correspond to a circumbinary disk. The circumprotostellar gas mass, estimated from ∼0.″2 resolution VLA 0.9 cm observations assuming optically thin emission, is 6.8 ± 0.9 M ⊙. No line emission is detected toward MM2E and MM2W in our high-resolution 1.3 mm ALMA observations. The only line detected is 13CO J = 2–1, in absorption against the 1.3 mm continuum, which likely traces a layer of cooler molecular material surrounding the protostars. We also report the discovery of a highly asymmetric bipolar molecular outflow that appears to be driven by MM2E and/or MM2W in new deep, ∼0.″5 resolution (1685 au) ALMA 0.82 mm observations. This outflow, traced by low-excitation CH3OH emission, indicates ongoing accretion onto the protobinary system. Overall, the super-Alfvénic models of Mignon-Risse et al. agree well with the observed properties of the MM2E/MM2W protobinary, suggesting that this system may be forming in an environment with a weak magnetic field.

Wide, deep, blind continuum surveys at submillimetre/millimetre (submm/mm) wavelengths are required to provide a full inventory of the dusty, distant Universe. However, conducting such surveys to the necessary depth, with sub-arcsec angular resolution, is prohibitively time-consuming, even for the most advanced submm/mm telescopes. Here, we report the most recent results from the ALMACAL project, which exploits the ‘free’ calibration data from the Atacama Large Millimetre/submillimetre Array (ALMA) to map the lines of sight towards and beyond the ALMA calibrators. ALMACAL has now covered 1001 calibrators, with a total sky coverage around 0.3 deg2, distributed across the sky accessible from the Atacama desert, and has accumulated more than 1000 h of integration. The depth reached by combining multiple visits to each field makes ALMACAL capable of searching for faint, dusty, star-forming galaxies (DSFGs), with detections at multiple frequencies to constrain the emission mechanism. Based on the most up-to-date ALMACAL data base, we report the detection of 186 DSFGs with flux densities down to S870 µm ∼ 0.2 mJy, comparable with existing ALMA large surveys but less susceptible to cosmic variance. We report the number counts at five wavelengths between 870 μm and 3 mm, in ALMA bands 3, 4, 5, 6, and 7, providing a benchmark for models of galaxy formation and evolution. By integrating the observed number counts and the best-fitting functions, we also present the resolved fraction of the cosmic infrared background (CIB) and the CIB spectral shape. Combining existing surveys, ALMA has currently resolved about half of the CIB in the submm/mm regime.

We present new multifrequency Atacama Large Millimeter/submillimeter Array (ALMA) continuum observations of the massive [$\log _{10}(M_\star /\mathrm{M}_\odot) = 10.3_{-0.2}^{+0.1}$], UV-luminous [$M_\mathrm{UV} = -21.7 \pm 0.2$] $z=7.31$ galaxy REBELS-25 in Bands 3, 4, 5, and 9. Combining the new observations with previously taken data in Bands 6 and 8, we cover the dust continuum emission of the galaxy in six distinct bands – spanning rest-frame $50-350\, \mu$m – enabling simultaneous constraints on its dust mass ($M_\mathrm{dust}$), temperature ($T_\mathrm{dust}$), and emissivity index ($\beta _\mathrm{IR}$) via modified blackbody fitting. Given a fiducial model of optically thin emission, we infer a cold dust temperature of $T_\mathrm{dust} = 32_{-6}^{+9}\,$ K and a high dust mass of $\log _{10}(M_\mathrm{dust}/\mathrm{M}_\odot) = 8.2_{-0.4}^{+0.6}$, and moderately optically thick dust does not significantly alter these estimates. If we assume dust production is solely through supernovae (SNe), the inferred dust yield would be high, $y = 0.7_{-0.4}^{+2.3}\, \mathrm{M}_\odot$ per SN. Consequently, we argue grain growth in the interstellar medium of REBELS-25 also contributes to its dust build-up. This is supported by the steep dust emissivity index $\beta _\mathrm{IR} = 2.5 \pm 0.4$ we measure for REBELS-25, as well as by its high stellar mass, dense interstellar medium, and metal-rich nature. Our results suggest that constraining the dust emissivity indices of high-redshift galaxies is important not only to mitigate systematic uncertainties in their dust masses and obscured star formation rates, but also to assess if dust properties evolve across cosmic time. We present an efficient observing set-up to do so with ALMA, combining observations of the peak and Rayleigh–Jeans tail of the dust emission.

ALMA (Atacama Large Millimeter/submillimeter Array) is the world's largest ground-based facility for observations in the millimeter/submillimeter regime. One of ALMA's outstanding characteristics is the large effort dedicated to the quality assurance (QA) of the calibrated and imaged data products offered to the astronomical community. The Data Management Group (DMG), in charge of the data processing, review, and delivery of the ALMA data, consists of approximately 60 experts in data reduction, from the ALMA Regional Centers (ARCs) and the Joint ALMA Observatory (JAO), distributed in fourteen countries. With a throughput of more than 3,000 datasets per year, meeting the goal of delivering the pipeline-able data products within 30 days after data acquisition is a huge challenge. This paper presents (a) the history of data processing at ALMA, (b) the challenges our team had and is still facing, (c) the methodology followed to mitigate the operational risks, (d) the ongoing optimization initiatives, (e) the current data processing status, (f) the strategy which is being followed so that, in a few Cycles from now, a team of approximately 10 data reducers (DRs) at JAO can process and review some 80% of the datasets collected during an observing cycle, and, finally, (g) the important role of the ARCs for processing the remaining datasets.

We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of 85.69- and 99.02-GHz continuum emission and H42α and H40α lines emission from the central 1 kpc of NGC 1808. These forms of emission are tracers of photoionizing stars but unaffected by dust obscuration that we use to test the applicability of other commonly star formation metrics. An analysis of the spectral energy distributions shows that free–free emission contributes about 60–90 per cent of the continuum emission in the 85–100-GHz frequency range, dependent on the region. The star formation rate (SFR) derived from the ALMA free–free emission is 3.1 ± 0.3 M⊙ yr−1. This is comparable to the SFRs measured from the infrared emission, mainly because most of the bolometric energy from the heavily obscured region is emitted as infrared emission. The radio 1.5-GHz emission yields an SFR 25 per cent lower than the ALMA value, probably because of the diffusion of the electrons producing the synchrotron emission beyond the star-forming regions. The SFRs measured from the extinction-corrected H α line emission are about 40–65 per cent of the SFR derived from the ALMA data, likely because this metric was not calibrated for high-extinction regions. Some SFRs based on extinction-corrected ultraviolet emission are similar to those from ALMA and infrared data, but given that the ultraviolet terms in the extinction correction equations are very small, these metrics seem inappropriate to apply to this dusty starburst.

(Abridged) Transition disks are recognized by the absence of emission of small dust grains inside a radius of up to several 10s of AUs. Due to the lack of angular resolution and sensitivity, the gas content of such dust holes has not yet been determined, but is of importance to constrain the mechanism leading to the dust holes. Transition disks are thought to currently undergo the process of dispersal, setting an end to the giant planet formation process. We present new high-resolution observations with the Atacama Large Millimeter/ submillimeter Array (ALMA) of gas lines towards the transition disk Oph IRS 48 previously shown to host a large dust trap. ALMA has detected the $J=6-5$ line of $^{12}$CO and C$^{17}$O around 690 GHz (434 $\mu$m) at a resolution of $\sim$0.25$''$ corresponding to $\sim$30 AU (FWHM). The observed gas lines are used to set constraints on the gas surface density profile. New models of the physical-chemical structure of gas and dust in Oph IRS 48 are developed to reproduce the CO line emission together with the spectral energy distribution (SED) and the VLT-VISIR 18.7 $\mu$m dust continuum images. Integrated intensity cuts and the total spectrum from models having different trial gas surface density profiles are compared to observations. Using the derived surface density profiles, predictions for other CO isotopologues are made, which can be tested by future ALMA observations of the object. The derived gas surface density profile points to the clearing of the cavity by one or more massive planet/companion rather than just photoevaporation or grain-growth.

Aims.We investigate the dust attenuation of 122 heavily dust-obscured galaxies detected with the Atacama Large Millimeter Array (ALMA) andHerschelin the COSMOS field. We search for correlations between dust attenuation recipes and the variation of physical parameters, namely, the effective radii of galaxies, their star formation rates, and stellar masses. We aim to understand which of the commonly used laws best describes dust attenuation in dusty star-forming galaxies (DSFGs) at high redshift.Methods.We made use of the extensive photometric coverage of the COSMOS data combined with highly resolved dust continuum maps from ALMA. We usedCIGALEto estimate various physical properties of these dusty objects, namely: their star formation rates (SFR), their stellar masses, and their attenuation at short wavelengths. We inferred the effective radii (Re) of galaxies using GALFIT in theYband of HSC and ALMA continuum maps. We used these radii to investigate the relative compactness of the dust continuum and the extension of the rest-frame UV/optical Re(y)/Re(ALMA).Results.We find that the physical parameters calculated from our models strongly depend on the assumption of the dust attenuation curve. As expected, the most impacted parameter is the stellar mass, which leads to a change in the “starburstiness” of the objects. We find that taking into account the relative compactness of star-to-dust emission prior to SED fitting is crucial, especially when studying dust attenuation of dusty star-forming galaxies. Shallower attenuation curves do not show a clear preference of compactness with attenuation, while the Calzetti attenuation curve is shown to prefer a comparable spatial extent of unattenuated stellar light and dust emission. The evolution of theRe(UV)/Re(ALMA) ratio with redshift peaks around the cosmic noon in our sample of DSFGs, showing that this compactness is correlated with the cosmic SFR density of these dusty sources.