dataesr/scientific-paragraphs-categorization huggingface dataset:
Timing of the events As a first investigation of the specificities of NPF in plume conditions, we performed a simple analysis of the starting time of the NPF events on plume and non-plume days. The starting time of an event was defined by a visual inspection at the time when the 1. 5-2. 5 nm ions concentration measured with the AIS significantly increased. Only the events simultaneously detected with the AIS and the DMPS were included in this analysis, and the dataset was not limited to May-August-September-October, but included instead all available AIS data between mid-May and the end of October. In total, 36 events observed on non-plume days and 10 events detected in plume conditions were documented. The median starting time of NPF in non-plume conditions was found at 08:36 LT (25th percentile: 08:15 LT; 75th percentile: 09:06 LT).
(2019)  based on aircraft measurements conducted in the passive plume of Etna (k = 1. 84 × 10 -8 , a = 1. 12), despite slight differences in the analysis. Indeed,  Sahyoun et al. (2019)  used direct measurements of [H 2 SO 4 ] and investigated the link between [H 2 SO 4 ] and J 2. 5 instead of J 2. Also, instead of fitting all derived J 2. 5 , the dataset was first binned with respect to [H 2 SO 4 ] (bins of equal length, 0. 25 × 10 8 cm -3 ), after which median J 2. 5 was calculated for each bin and finally fitted using a power model. As a sensitivity study, and in order to provide a more consistent comparison with the results reported by  Sahyoun et al. (2019) , we applied a similar fitting method; the only difference was in the binning procedure, as we used bins with an equal number of data points instead of equal length.
(2018)  was run for each NPF event, with the corresponding temperature, relative humidity and CS levels. Figure  5b  shows, for the same dataset as in Fig. 5a , the ratio between J 2 derived from DMPS measurements (referred to as J meas ) and J 2 predicted by the pa-  rameterization (referred to as J param ), which included both neutral and ion-induced nucleation pathways. In addition, we also binned the data with respect to [H 2 SO 4 ] (10 bins with equal number of points) and calculated the median ratio J meas /J param in each bin. As evidenced in Fig. 5b , 64 % of the calculated ratios were < 1, which was unexpected since particle formation rates resulting from the binary nucleation of H 2 SO 4 -H 2 O should not exceed J meas. This result was most likely related to (1) the use of proxy-derived [H 2 SO 4 ] in the calculation of J param and (2) the fact that J meas was not derived from direct measurement of 2 nm particles but from J 12 and GR 12-19 , which might have led to additional uncertainty.
Altogether, these results suggest that higher SO 2 mixing ratios observed on plume days did contribute to the NPF events observed in such conditions, in agreement with earlier results from  Boulon et al. (2011b)  and  Sahyoun et al. (2019). However, the contribution of other compounds to the process could not be excluded based on the available dataset, and additional measurements would be needed to further investigate this aspect, including in specific direct measurement of the chemical composition of the clusters as well as their precursors. Such measurements would also allow more detailed evaluation of the proxy by  Mikkonen et al. (2011)  for the prediction of [H 2 SO 4 ] in volcanic eruption plume conditions. Together with direct measurements of sub-3 nm cluster ions and particles, the identification of the precursors would finally favour a more robust investigation of the actual mechanisms responsible for cluster formation in volcanic plumes.
Summary and conclusions We investigated the occurrence of NPF in volcanic plume conditions at the Maïdo observatory based on measurements conducted between 1 January and 31 December 2015. During this time period, four effusive eruptions of the Piton de la Fournaise, located ∼ 39 km away from the station, were observed, and we were able to detect volcanic plume conditions at Maïdo during three of the four eruptions. In total, 29 "plume days" were identified according to SO 2 mixing ratios measured during morning hours (06:00-11:00 LT, i. e. including usual nucleation hours), among which 14 days were classified as "strong plume days", and were compared with 250 "non-plume days". This dataset is, to our knowledge, the largest ever reported for the investigation of NPF in volcanic plume conditions and allowed for the first time a statistical approach to characterizing the process and also assessing its relevance with respect to non-plume conditions.
Acknowledgements. We would like to thank  ATMO Réunion  for providing SO 2 data. Financial support. This research has been supported by the  European Commission ,  H2020 Research Infrastructures (ACTRIS-2  (grant no. 654109 )), and by the  ANR  (grant no. ANR-14-CE03-0004-04 ). This work has received financial support from the  French programme SNO-CLAP ; it has also been funded by  OM-NCG/OSUR program  from  La Réunion University. Review statement. This paper was edited by  Veli-Matti Kerminen  and reviewed by two anonymous referees.
THEMIS integrates the life-cycle inventory database ecoinvent 2. 2  22, 84  , which has been adapted to represent selected regional and future technology characteristics, and extended with extra electricity technology inventories unavailable in the original database. The version used in this analysis was augmented compared to the original version of THEMIS to also include nuclear power and biomass with and without CCS. It now includes 11 technology groups (photovoltaics, concentrated solar power, coal without/with CCS, natural gas without/with CCS, hydropower, wind power, nuclear power, biopower without/with CCS) represented by 43 different systems with their own life-cycle inventories  26, 31, 85. The adaptations to ecoinvent consist of two main elements. First, the electricity mixes were changed according to the generic IEA Baseline and BLUE Map climate policy scenarios  83  for the years 2010, 2030 and 2050.
IAM regions are matched to the THEMIS region with the best regional fit. The power systems' environmental impacts were calculated for each IAM model region, scenario and technology by multiplying the capacity additions and operation as derived from the IAMs with LCA impact coefficients derived with THEMIS and then aggregated to the global totals shown in the analysis of the paper. Our combined IAM and LCA analysis captures the different timing of infrastructure and operational effects, allowing us to apply LCA impact data (e. g. , emission factors) to the appropriate years when activities occur. It also allows us to capture the need to make upfront infrastructure investments for electricity generation later, the relevance of which has been noted by others  88, 89. Further, by decomposing LCA coefficients into four energy carriers (solid, liquid and gaseous fuels, and electricity) and assigning them to IAM scenario-specific emission intensities (for fuels and electricity), we are able to consistently account impacts related to indirect energy requirements  26.
Acknowledgements The research leading to these results has received funding from the  European Union 's  Seventh Programme   FP7/2007-2013  under grant agreement no. 308329  (ADVANCE). Additional financial support came from the  Research Council of Norway  (grant  209697  for A. A. and  E. G. H. , and grant  288047  for A. A. , G. L. , F. H. and A. P. ), and the  Luxembourg National Research Fund for T. G. (grant  INTER/RCN/18/12772313 ), the  European Union 's  Horizon 2020 research and innovation program  under grant agreement no. 730403  ( INNOPATHS ) for R. C. P. , G. L. and M. P. , as well as grant agreement no. 730035  ( REINVENT ) for H. S. d. B. and D. v. V. We would like to thank  Sebastian Rauner  for valuable discussions and helpful feedback.
The CALYPSO survey The Continum And Lines in Young ProtoStellar Objects (CALYPSO, see http://irfu. cea. fr/Projets/Calypso/) IRAM Large Program is a survey of 16 Class 0 protostars, carried out with the IRAM Plateau de Bure (PdBI) interferometer in three spectral setups  (around 94 GHz, 219 GHz, and 231 GHz). CALYPSO was crafted as an effort to make progress in our understanding of the angular momentum problem for Article number, page 2 of 47 A. J. Maury et al. : CALYPSO view   Notes. The sources are ordered by increasing right ascension of the targeted core (see phase centers of our observations in Table  A. 1). Column 1: Name of the protostar. Column 2: Distance of the cloud where the protostar lies. The Taurus distance is taken from a VLBA measurement estimating distances from 130 pc to 160 pc  (Torres et al.
Goals and plan of the present paper This paper is the first of a series of statistical analyses  (Belloche et al. in prep. , Maret et al. in prep. , Podio et al. in prep, Gaudel et al. in prep. )  that are carried out for the whole CALYPSO sample. They address the three cornerstone questions described above that lie at the heart of the scientific motivations of CALYPSO. This paper focuses on the inner density structure(s) of the CALYPSO Class 0 protostars, analyzing the dual-frequency dust continuum emission visibilities to probe the structure of protostellar envelopes down to radii ∼ 30 au (for the Taurus sources) to ∼ 90 au (for the Serpens Main sources), with special emphasis on characterizing candidate protostellar disks and multiple systems. We show the dust continuum emission datasets, obtained at 1.
37 mm and 3. 18 mm, for the whole CALYPSO sample (see Table 1) in Sect. 2 and the dust continuum sources detected in our maps in Sect. 3. Section 4 is dedicated to describing the analysis of the dust continuum visibility dataset we performed to test whether candidate disk components are detected in each of the primary targets of our sample. In Sect. 5. 1 we discuss the occur-Article number, page 3 of 47 A&A proofs: manuscript no. ms-langedit-arxiv rence and properties of the candidate embedded disks in Class 0 protostellar envelopes from our sample and the literature. In Sect. 5. 2 we explore current predictions from theoretical models of protostellar collapse, and the constraints our results bring to these models. Finally, we briefly discuss in Sect. 5. 3 the multiplicity of Class 0 protostars in our sample and in the literature and compare them to the multiplicity properties of YSOs at more advanced evolutionary stages.
A higher spectral resolution correlator was placed onto a handful of molecular emission lines, but we present here only the analysis of the continuum emission extracted from the WideX dataset. The proximity of some of the sources on the sky allowed us to use common gain calibrators for several groups of sources and therefore to time-share a total of 37 tracks of ∼8 hr on the 16 sources. Each track was divided unequally among the sources, roughly in inverse proportion to the source luminosities so as to obtain the most homogeneous signal-to-noise ratios (S/N) in the sample. For each track, nearby amplitude and phase calibrators were observed to determine the time-dependent complex antenna gains. The calibration was performed in the GILDAS/CLIC 2  environment. The correlator bandpass was calibrated on strong quasars (e.
g. , 3C273 and 3C454. 3), while the absolute flux density scale was usually derived from observations of MWC349 and 3C84. The absolute flux calibration uncertainty is estimated to be ∼10% at 94 GHz and ∼15% at 231 GHz. For sources where the peak of the dust continuum emission is detected at >40 σ (roughly equivalent to all sources with peak flux > 80 mJy/beam at 231 GHz, see Table  2 ), we also carried out self-calibration of the continuum emission visibility dataset to improve the S/N at the longest baselines.
PdBI continuum emission maps After a cross-check of the absolute flux calibration consistency of the observing dates, the visibility datasets obtained with the A and C configuration were combined, for each of the three frequency setups independently. The continuum visibilities were generated from the WideX units, avoiding channels in which line emission was detected at a level > 5 σ in the spectrum integrated over 2 around the peaks of the continuum emission reported in Table  3. Examples of wide-band spectra are shown in  Maury et al. (2014) , while the analysis of the molecular content of the whole sample will be presented in  Belloche et al. (in prep). In order to produce images and visibility curves with optimum sensitivity and best uv-coverage at 1. 3 mm, we merged the continuum visibility data that were independently obtained at 219 GHz and 231 GHz: we used the spectral index computed from the shortest common baseline of our PdBI observations at 94 GHz and 231 GHz (α 20kλ , see Col.
Dust continuum sources in the CALYPSO maps Dust continuum emission was successfully detected at 231 GHz and 94 GHz toward all the Class 0 protostars we targeted in our survey: the positions and flux densities of the continuum sources detected in the fields observed with the PdBI are reported in Table 3. The target Class 0 protostars are labeled as "primary protostars" in the "source nature" column. Multiple dust continuum emission components are sometimes detected in our PdBI maps. For each field that was observed with CALYPSO, we built a first sample of millimeter continuum sources from our 231 GHz PdBI dataset and selected components whose dust continuum emission was detected above the 5σ level in the maps (within the 21 FWHM primary beam). This detection threshold was chosen so as to limit contamination from spurious sources created by deconvolution of data sampling only partially the uv-plane.
The blue and red arrows show the direction of the protostellar jet(s) either as found in our CALYPSO dataset or from the literature (see Table  1 ). to resolve them (the synthesized beam of the 94 GHz data is 2. 5 times larger than the beam of the 231 GHz data). Moreover, since the PdBI 94 GHz maps have a larger primary beam than the 231 GHz maps, four sources detected at A&A proofs: manuscript no. ms-langedit-arxiv Fig. 2. Same as Fig. 1  for the SVS13 region. The dashed pink contour shows the PdBI primary beam at each frequency. The contours show levels of -3σ (dashed), 5σ, and 10σ, then from 20σ in steps of 20σ (see Table  2 ). The blue and red arrows show the direction of the protostellar jets from our CALYPSO data for SVS13A/B  (Podio et al. in prep. ) , while the SVS13C outflow P. A.
Building a proper visibility dataset for each primary target protostar Each secondary source reported in Table  3  was removed from the visibility data by subtracting a Gaussian source model with FWHM at most twice the synthesized beam size (to remove only compact components and avoid affecting the envelope emission), or a point source if separated from the primary continuum component by less than two synthesized beams. During this subtraction process, the coordinates and peak fluxes of secondary components were fixed to the values reported in Cols. 2 and 3 of Table 3. Subtracting the visibilities that are due to secondary components allowed us to perform a focused analysis of the contin-uum emission that originates from each main protostar that was targeted by our observing program. We stress, however, that this operation does not preclude the possible presence of tighter multiple components at scales that cannot be resolved with PdBI.
4 south of IRAS2A is detected with VLA  (Tobin et al. 2015a ) and ALMA  (Maury et al. in prep)  but is not detected with our CALYPSO data because the high resolution data for IRAS2A was obtained prior to the CALYPSO program (see Appendix C. 4). Article number, page 7 of 47 Fig. 4. Examples of radial intensity profiles from single-dish maps obtained at the IRAM-30m telescope that are used as large-scale constraint for the envelope modeling. These profiles were obtained from the dust continuum emission maps acquired using the IRAM-30m and are published in  Motte & André (2001)  and  Kaas et al. (2004). significantly lower than the flux measured at the 20 kλ baselines. This illustrates the difficulty of reliably reconstructing interferometric maps from data with incomplete uv-coverage, and it justifies our approach to carry out modeling in the uv-plane rather than in the image plane.
The resulting extrapolated total envelope fluxes and peak flux densities at 231 GHz are reported in Cols. 13 and 14 of Table  4 , respectively, for the sources that are resolved by single-dish observations. Val-ues for the total fluxes at 94 GHz were obtained by scaling the 231 GHz fluxes assuming the spectral index indicated in Col. 6. Because single-dish continuum observations are broadband and the spectral index of the dust continuum emission in the envelope at larger scales is not well constrained by our PdBI dualfrequency observations (since the minimum common baseline at 94 and 231 GHz only probes scales up to < ∼ 6 ), the fluxes at baselines < 10kλ extrapolated from single-dish data are uncertain. When we used them in our modeling of the envelope emission, we therefore allowed the total envelope flux to vary within a range ±30%.
Comparison to protostellar envelope models From the continuum visibility dataset constructed for each primary protostar (see Sect. 4. 1), we extracted the flux density of the protostellar dust continuum emission as a function of spatial frequency by averaging the real parts of the observed visibilities in bins of baseline lengths (bin widths of 20kλ at 231 GHz, and bin widths of 10kλ at 94 GHz). We obtained visibility curves sampling baselines  kλ at 231  kλ at 94 GHz. Error bars on visibility amplitudes were estimated from the individual weights (w i ) of the interferometric visibility amplitudes (y i ), which were then averaged in bins of uv-distance: the error bar is the error on the mean value in an individual bin (y err = Σ(w 2 i × (y i -w mean ) 2 )/(Σw i ) 2 and w mean = Σ(y i × w i )/Σw i ).
Comparison with envelope models including a disk-like component For three protostars in our sample (L1448-C, L1448-NB1, and L1527; see Table  6 ), no single Plummer envelope model was able to satisfactorily reproduce the continuum emission data at both 231 GHz and 94 GHz (reduced χ 2 > 3). At these two frequencies, the curvature of the radial intensity profile for these sources does not follow a simple power-law trend, or at uvdistances longer than 100 kλ, their PdBI visibility curve does not decrease quickly enough to be reproduced by one envelope model alone. In addition, while the 94 GHz visibility profiles of IRAS4B and GF92 are satisfactorily described by singleenvelope models, their 231 GHz visibility profiles are inconsistent with single Plummer-like envelope models. This suggests that emission at baselines probed only by the 231 GHz data (250-550 kλ) differs from the best-fit envelope model we found to reproduce the 94 GHz continuum emission.
Recent SMA observations of the Class 0 protostar BHR7 suggest a compact dust continuum component at r ∼ 120 au, although the kinematics obtained within the same dataset do not confirm Keplerian rotation at similar scales  (Tobin et al. 2018). Gerin et al. (2017)  analyzed ALMA 0. 8mm dust continuum observations of two Class 0 protostars, B1b-N and B1b-S. They found that compact disk-like components could only contribute to the intensity profiles at scales < ∼ 50 au. The 0. 87mm ALMA observations by  Tokuda et al. (2017)  enabled the detection of a small 10 au radius disk in L1521F. For the B335 protostar, observations of the kinematics in the inner envelope with ALMA provided an upper limit to the disk radius of B335 < 15 au  (Yen et al. 2015b ). The two Class 0 protostars IRAS16253 and IRAS15398 have been observed with ALMA by  Yen et al.
Our highest angular resolution data for IRAS2A (configuration A of the PdBi at 231 GHz) was obtained as part of the pilot R068 project  (Maury et al. 2010) : the lower sensitivity of these earlier observations (obtained before the installation of the WideX correlator) explains the non-detection of a separated compact source at the secondary position. To build robust estimates of the upper-limit MF from our sample, and considering that a secondary source is detected with ALMA and the VLA, we count IRAS2A as a binary system in our multiplicity analysis. -Candidate disk For the sake of clarity and brevity, we do not report this model here, but the best-fit model is still the Plummer-only model, with very similar parameters as were found as best fits for the whole visibility dataset, which is reported in Table  6.
The low S/N of the binned visibilities from our PdBI dataset for L1521F make it difficult to robustly model them in detail, but it is possible to extrapolate the outer envelope properties to establish constraints on the maximum disk-like component (i. e. , maximum radius and flux) that can be added while reproducing the dust continuum interferometric fluxes obtained in L1521F. The 231 GHZ profile is best modeled using a PG model that includes an unresolved Gaussian component (FWHM 0. 13 , see Fig. C. 10): this suggests that a candidate disk of radius ∼< 20 au and flux ∼ 1. 3 ± 0. 4 mJy may be detected in L1521F. However, as in the case of IRAM04191,.
Acknowledgements. We thank the  IRAM  staff for their support in carrying out the CALYPSO observations, and the anonymous referee for a detailed reading that significantly helped us to improve the paper. We thank  Kees Dullemond ,  Ralf Klessen ,  Sandrine Bottinelli ,  Benoit Commercon , and  Ralf Launhardt  for their participation to the preparation of the  CALYPSO  project. This work has benefited from the support of the  European Research Council  under the European Union's  Seventh Framework Programme  ( Advanced Grant ORISTARS  with grant agreement no. 291294  and  Starting Grant MagneticYSOs  with grant agreement no. 679937 ).
Visibility profiles of the 231 GHz (black dots) and 94 GHz (gray triangles) continuum emission from L1448-C. In each visibility curve, we show both the best Plummer-only model (Pl, black curve) and the best Plummer+Gauss (PG, red curve) model. The PG model that includes a marginally resolved 0. 16 -FWHM Gaussian component reproduces the 231 GHz profile better than the Plummer-only (Pl) model (see Table6for more information on the two models). Moreover, the PG model that includes an unresolved additional Gaussian component reproduces the 94 GHz visibility profile better. -Multiplicity In our CALYPSO maps, shown in Fig. B. 3, a single proto- star is detected. The two continuum sources IRAS2A2 and IRAS2A3, reported in Maury et al. (2014); Codella et al. (2014b), are now shown to originate from an envelope struc- ture that is detected by the interferometer: our improved dataset after self-calibration (which improved the rms noise and the imaging fidelity) allows us to recover the lower sur- face brightness emission that surrounds them, and they are found to reconnect with the main source envelope emission.
B. 6). We show that the PG model that includes an unresolved Gaussian component (FWHM ∼ 24 au) is better than the Pl model at 231 GHz (see TableC. 10), while the 94 GHz profile can be well modeled with a Plummer-only model. The flat profile of the 231 GHz dust continuum emission observed at baselines > 300kλ strongly suggest that an unresolved candidate disk is responsible for the dust continuum emission at scales < 50au, but our limited S/N cannot provide a robust characterization of the protostellar disk size in IRAM04191 (all error bars on the fluxes overlap in the baseline range 300-600 kλ). Although the current CALYPSO observations do not allow us to firmly establish the size of the disk-like component in IRAM04191, the 231 GHz visibility curve (seeFig. C. 9 -Candidate disk The low S/N of the binned visibilities from our PdBI dataset for IRAM04191 makes it difficult to robustly model them in detail.