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We present the results of the ALMA Large Program Early Planet Formation in Embedded disks observations of the Class 0 protostar GSS30 IRS3. Our observations included 1.3 mm continuum with a resolution of 0.''05 (7.8 au) and several molecular species including $^{12}$CO, $^{13}$CO, C$^{18}$O, H$_{2}$CO and c-C$_{3}$H$_{2}$. The dust continuum analysis unveiled a disk-shaped structure with a major axis size of $\sim$200 au. We observed an asymmetry in the minor axis of the continuum emission suggesting that the emission is optically thick and the disk is flared. On the other hand, we identified two prominent bumps along the major axis located at distances of 26 and 50 au from the central protostar. The origin of the bumps remains uncertain and might be due to an embedded substructure within the disk or the result of the temperature distribution instead of surface density due to optically thick continuum emission. The $^{12}$CO emission reveals a molecular outflow consisting of three distinct components: a collimated one, an intermediate velocity component exhibiting an hourglass shape, and a wider angle low-velocity component. We associate these components with the coexistence of a jet and a disk-wind. The C$^{18}$O emission traces both a Keplerian rotating circumstellar disk and the infall of the rotating envelope. We measured a stellar dynamical mass of 0.35$\pm$0.09 M$_{\odot}$., Comment: 25 pages, 19 figures. Accepted for publication in A&A

We present Atacama Large Millimeter/submillimeter Array (ALMA) observations of the binary Class 0 protostellar system BHR 71 IRS1 and IRS2 as part of the Early Planet Formation in Embedded Disks (eDisk) ALMA Large Program. We describe the $^{12}$CO ($J$=2--1), $^{13}$CO ($J$=2--1), C$^{18}$O ($J$=2--1), H$_2$CO ($J=3_{2,1}$--$2_{2,0}$), and SiO ($J$=5--4) molecular lines along with the 1.3 mm continuum at high spatial resolution ($\sim$0.08" or $\sim$5 au). Dust continuum emission is detected toward BHR 71 IRS1 and IRS2, with a central compact component and extended continuum emission. The compact components are smooth and show no sign of substructures such as spirals, rings or gaps. However, there is a brightness asymmetry along the minor axis of the presumed disk in IRS1, possibly indicative of an inclined geometrically and optically thick disk-like component. Using a position-velocity diagram analysis of the C$^{18}$O line, clear Keplerian motions were not detected toward either source. If Keplerian rotationally-supported disks are present, they are likely deeply embedded in their envelope. However, we can set upper limits of the central protostellar mass of 0.46 M$_\odot$ and 0.26 M$_\odot$ for BHR 71 IRS1 and BHR 71 IRS2, respectively. Outflows traced by $^{12}$CO and SiO are detected in both sources. The outflows can be divided into two components, a wide-angle outflow and a jet. In IRS1, the jet exhibits a double helical structure, reflecting the removal of angular momentum from the system. In IRS2, the jet is very collimated and shows a chain of knots, suggesting episodic accretion events., Comment: 38 pages, 29 figures, accepted in ApJ

(abridged) Protostellar outflows exhibit large variations in their structure depending on the observed gas emission. This study analyzes the atomic jet and molecular outflow in the Class I protostar, TMC1A to characterize morphology and identify previously undetected spatial features with JWST's NIRSpec IFU. In addition to identifying a large number of Fe II and H2 lines, we have detected the bipolar Fe jet by revealing, for the first time, the presence of a red-shifted atomic jet. Similarly, the red-shifted component of the H2 slower wide-angle outflow is observed. Both Fe II and H2 red-shifted emission exhibit significantly lower flux densities compared to their blue-shifted counterparts. Additionally, we report the detection of a collimated high-velocity (100 km s-1), blue-shifted H2 outflow, suggesting the presence of a molecular jet in addition to the well-known wider angle low-velocity structure. The Fe II and H2 jets show multiple intensity peaks along the jet axis, which may be associated with ongoing or recent outburst events. In addition to the variation in their intensities, the H2 wide-angle outflow exhibits a "ring"-like structure. The blue-shifted H2 outflow also shows a left-right brightness asymmetry likely due to interactions with the surrounding ambient medium and molecular outflows. Using the Fe II line ratios, the extinction along the atomic jet is estimated to be between Av = 10-30 on the blue-shifted side, with a trend of decreasing extinction with distance from the protostar. A similar Av is found for the red-shifted side, supporting the argument for an intrinsic red-blue outflow lobe asymmetry rather than environmental effects such as extinction. This intrinsic difference revealed by the unprecedented sensitivity of JWST, suggests that younger outflows already exhibit the red-blue side asymmetry more commonly observed towards jets associated with Class II disks., Comment: 16 pages, 11 figures

Young protostellar binary systems, with expected ages less than $\sim$10$^5$ years, are little modified since birth, providing key clues to binary formation and evolution. We present a first look at the young, Class 0 binary protostellar system R CrA IRAS 32 from the Early Planet Formation in Embedded Disks (eDisk) ALMA large program, which observed the system in the 1.3 mm continuum emission, $^{12}$CO (2-1), $^{13}$CO (2-1), C$^{18}$O (2-1), SO (6$_5$-5$_4$), and nine other molecular lines that trace disk, envelope, shocks, and outflows. With a continuum resolution of $\sim$0.03$^{\prime\prime}$ ($\sim$5 au, at a distance of 150 pc), we characterize the newly discovered binary system with a separation of 207 au, their circumstellar disks, and a circumbinary disk-like structure. The circumstellar disk radii are 26.9$\pm$0.3 and 22.8$\pm$0.3 au for sources A and B, respectively, and their circumstellar disk dust masses are estimated as 22.5$\pm$1.1 and 12.4$\pm$0.6 M$_{\Earth}$. The circumstellar disks and the circumbinary structure have well aligned position angles and inclinations, indicating formation in a smooth, ordered process such as disk fragmentation. In addition, the circumstellar disks have a near/far-side asymmetry in the continuum emission suggesting that the dust has yet to settle into a thin layer near the midplane. Spectral analysis of CO isotopologues reveals outflows that originate from both of the sources and possibly from the circumbinary disk-like structure. Furthermore, we detect Keplerian rotation in the $^{13}$CO isotopologues toward both circumstellar disks and likely Keplerian rotation in the circumbinary structure; the latter suggests that it is probably a circumbinary disk., Comment: 33 pages, 29 figures, 6 tables

Molecular abundances in protoplanetary disks are highly sensitive to the local physical conditions, including gas temperature, gas density, radiation field, and dust properties. Often multiple factors are intertwined, impacting the abundances of both simple and complex species. We present a new approach to understanding these chemical and physical interdependencies using machine learning. Specifically we explore the case of CO modeled under the conditions of a generic disk and build an explanatory regression model to study the dependence of CO spatial density on the gas density, gas temperature, cosmic ray ionization rate, X-ray ionization rate, and UV flux. Our findings indicate that combinations of parameters play a surprisingly powerful role in regulating CO compared to any singular physical parameter. Moreover, in general, we find the conditions in the disk are destructive toward CO. CO depletion is further enhanced in an increased cosmic ray environment and in disks with higher initial C/O ratios. These dependencies uncovered by our new approach are consistent with previous studies, which are more modeling intensive and computationally expensive. Our work thus shows that machine learning can be a powerful tool not only for creating efficient predictive models, but also for enabling a deeper understanding of complex chemical processes., Comment: Accepted in ApJ, 17 pages, 13 figures, 5 tables

We present ALMA observations of the Class I source Oph IRS63 in the context of the Early Planet Formation in Embedded Disks (eDisk) large program. Our ALMA observations of Oph IRS63 show a myriad of protostellar features, such as a shell-like bipolar outflow (in $^{12}$CO), an extended rotating envelope structure (in $^{13}$CO), a streamer connecting the envelope to the disk (in C$^{18}$O), and several small-scale spiral structures seen towards the edge of the dust continuum (in SO). By analyzing the velocity pattern of $^{13}$CO and C$^{18}$O, we measure a protostellar mass of $\rm M_\star = 0.5 \pm 0.2 $~$\rm M_\odot$ and confirm the presence of a disk rotating at almost Keplerian velocity that extends up to $\sim260$ au. These calculations also show that the gaseous disk is about four times larger than the dust disk, which could indicate dust evolution and radial drift. Furthermore, we model the C$^{18}$O streamer and SO spiral structures as features originating from an infalling rotating structure that continuously feeds the young protostellar disk. We compute an envelope-to-disk mass infall rate of $\sim 10^{-6}$~$\rm M_\odot \, yr^{-1}$ and compare it to the disk-to-star mass accretion rate of $\sim 10^{-8}$~$\rm M_\odot \, yr^{-1}$, from which we infer that the protostellar disk is in a mass build-up phase. At the current mass infall rate, we speculate that soon the disk will become too massive to be gravitationally stable., Comment: 26 pages and 17 figures

We present the first results from the Early Planet Formation in Embedded Disks (eDisk) ALMA Large Program toward Oph IRS43, a binary system of solar mass protostars. The 1.3 mm dust continuum observations resolve a compact disk, ~6au radius, around the northern component and show that the disk around the southern component is even smaller, <~3 au. CO, 13CO, and C18O maps reveal a large cavity in a low mass envelope that shows kinematic signatures of rotation and infall extending out to ~ 2000au. An expanding CO bubble centered on the extrapolated location of the source ~130 years ago suggests a recent outburst. Despite the small size of the disks, the overall picture is of a remarkably large and dynamically active region., Comment: Paper 10 of the ALMA eDisk Large Program. Accepted for publication in ApJ

Protostellar disks are a ubiquitous part of the star formation process and the future sites of planet formation. As part of the Early Planet Formation in Embedded Disks (eDisk) large program, we present high-angular resolution dust continuum ($\sim40\,$mas) and molecular line ($\sim150\,$mas) observations of the Class 0 protostar, IRAS 15398-3359. The dust continuum is small, compact, and centrally peaked, while more extended dust structures are found in the outflow directions. We perform a 2D Gaussian fitting to find the deconvolved size and $2\sigma$ radius of the dust disk to be $4.5\times2.8\,\mathrm{au}$ and $3.8\,\mathrm{au}$, respectively. We estimate the gas+dust disk mass assuming optically thin continuum emission to be $0.6-1.8\,M_\mathrm{jup}$, indicating a very low-mass disk. The CO isotopologues trace components of the outflows and inner envelope, while SO traces a compact, rotating disk-like component. Using several rotation curve fittings on the PV diagram of the SO emission, the lower limits of the protostellar mass and gas disk radius are $0.022\,M_\odot$ and $31.2\,\mathrm{au}$ from our Modified 2 single power-law fitting. A conservative upper limit of the protostellar mass is inferred to be $0.1\,M_\odot$. The protostellar mass-accretion rate and the specific angular momentum at the protostellar disk edge are found to be between $1.3-6.1\times10^{-6}\,M_\odot\,\mathrm{yr^{-1}}$ and $1.2-3.8\times10^{-4}\,\mathrm{km\,s^{-1}\,pc}$, respectively, with an age estimated between $0.4-7.5\times10^{4}\,$yr. At this young age with no clear substructures in the disk, planet formation would likely not yet have started. This study highlights the importance of high-resolution observations and systematic fitting procedures when deriving dynamical properties of deeply embedded Class 0 protostars., Comment: 28 pages, 16 figures. Accepted for publication in ApJ as one of the first-look papers of the eDisk ALMA Large Program

We present observations of the Class 0 protostar IRAS 16544-1604 in CB 68 from the ''Early Planet Formation in Embedded Disks (eDisk)'' ALMA Large program. The ALMA observations target continuum and lines at 1.3-mm with an angular resolution of $\sim$5 au. The continuum image reveals a dusty protostellar disk with a radius of $\sim$30 au seen close to edge-on, and asymmetric structures both along the major and minor axes. While the asymmetry along the minor axis can be interpreted as the effect of the dust flaring, the asymmetry along the major axis comes from a real non-axisymmetric structure. The C$^{18}$O image cubes clearly show the gas in the disk that follows a Keplerian rotation pattern around a $\sim$0.14 $M_{\odot}$ central protostar. Furthermore, there are $\sim$1500 au-scale streamer-like features of gas connecting from North-East, North-North-West, and North-West to the disk, as well as the bending outflow as seen in the $^{12}$CO (2-1) emission. At the apparent landing point of NE streamer, there are SO (6$_5$-5$_4$) and SiO (5-4) emission detected. The spatial and velocity structure of NE streamer can be interpreted as a free-falling gas with a conserved specific angular momentum, and the detection of the SO and SiO emission at the tip of the streamer implies presence of accretion shocks. Our eDisk observations have unveiled that the Class 0 protostar in CB 68 has a Keplerian rotating disk with flaring and non-axisymmetric structure associated with accretion streamers and outflows., Comment: 30 pages, 24 figures, accepted for publication in The Astrophysical Journal as one of the first-look papers of the eDisk ALMA Large Program

Studying the physical and chemical conditions of young embedded disks is crucial to constrain the initial conditions for planet formation. Here, we present Atacama Large Millimeter/submillimeter Array (ALMA) observations of dust continuum at $\sim$0.06" (8 au) resolution and molecular line emission at $\sim$0.17" (24 au) resolution toward the Class 0 protostar L1527 IRS from the Large Program eDisk (Early Planet Formation in Embedded Disks). The continuum emission is smooth without substructures, but asymmetric along both the major and minor axes of the disk as previously observed. The detected lines of $^{12}$CO, $^{13}$CO, C$^{18}$O, H$_2$CO, c-C$_3$H$_2$, SO, SiO, and DCN trace different components of the protostellar system, with a disk wind potentially visible in $^{12}$CO. The $^{13}$CO brightness temperature and the H$_2$CO line ratio confirm that the disk is too warm for CO freeze out, with the snowline located at $\sim$350 au in the envelope. Both molecules show potential evidence of a temperature increase around the disk-envelope interface. SO seems to originate predominantly in UV-irradiated regions such as the disk surface and the outflow cavity walls rather than at the disk-envelope interface as previously suggested. Finally, the continuum asymmetry along the minor axis is consistent with the inclination derived from the large-scale (100" or 14,000 au) outflow, but opposite to that based on the molecular jet and envelope emission, suggesting a misalignment in the system. Overall, these results highlight the importance of observing multiple molecular species in multiple transitions to characterize the physical and chemical environment of young disks., Comment: 27 pages, 16 figures, 2 tables, 10 pages appendix with 12 figures. Accepted for publication in ApJ as one of the first-look papers of the eDisk ALMA Large Program

We present an overview of the Large Program, ``Early Planet Formation in Embedded Disks (eDisk)'', conducted with the Atacama Large Millimeter/submillimeter Array (ALMA). The ubiquitous detections of substructures, particularly rings and gaps, in protoplanetary disks around T Tauri stars raise the possibility that at least some planet formation may have already started during the embedded stages of star formation. In order to address exactly how and when planet formation is initiated, the program focuses on searching for substructures in disks around 12 Class 0 and 7 Class I protostars in nearby ($< $200 pc) star-forming regions through 1.3 mm continuum observations at a resolution of $\sim7$ au (0.04"). The initial results show that the continuum emission, mostly arising from dust disks around the sample protostars, has relatively few distinctive substructures, such as rings and spirals, in marked contrast to Class II disks. The dramatic difference may suggest that substructures quickly develop in disks when the systems evolve from protostars to Class II sources or alternatively that high optical depth of the continuum emission could obscure internal structures. Kinematic information obtained through CO isotopologue lines and other lines reveals the presence of Keplerian disks around protostars, providing us with crucial physical parameters, in particular, the dynamical mass of the central protostars. We describe the background of the eDisk program, the sample selection and their ALMA observations, the data reduction, and also highlight representative first-look results., Comment: This is a publication of a series of eDisk ALMA large program first-look papers

Previous observations of B335 have presented evidence of ongoing infall in various molecular lines, e.g., HCO$^+$, HCN, CO. There have been no confirmed observations of a rotationally supported disk on scales greater than ~12~au. The presence of an outflow in B335 suggests that also a disk should be present or in formation. To constrain the earliest stages of protostellar evolution and disk formation, we aim to map the region where gas falls inwards and observationally constrain its kinematics. Furthermore, we aim to put strong limits on the size and orientation of any disk-like structure in B335. We use high angular resolution $^{13}$CO data from ALMA, and combine it with shorter-baseline archival data to produce a high-fidelity image of the infall in B335. We also revisit the imaging of high-angular resolution Band 6 continuum data to study the dust distribution in the immediate vicinity of B335. Continuum emission shows an elliptical structure (10 by 7 au) with a position angle 5 degrees east of north, consistent with the expectation for a forming disk in B335. A map of the infall velocity (as estimated from the $^{13}$CO emission), shows evidence of asymmetric infall, predominantly from the north and south. Close to the protostar, infall velocities appear to exceed free-fall velocities. 3D radiative transfer models, where the infall velocity is allowed to vary within the infall region, can explain the observed kinematics. The data suggests that a disk has started to form in B335 and that gas is falling towards that disk. However, kinematically-resolved line data towards the disk itself is needed to confirm the presence of a rotationally supported disk around this young protostar. The measured high infall velocities are not easily reconcilable with a magnetic braking scenario and suggest that there is a pressure gradient that allows the infall velocity to vary in the region., Comment: 14 pages, 11 figures

Outflows and winds launched from young stars play a crucial role in the evolution of protostars and the early stages of planet formation. However, the specific details of the mechanism behind these phenomena, including how they affect the protoplanetary disk structure, are still debated. We present {\it JWST} NIRSpec Integral Field Unit (IFU) observations of atomic and H$_2$ lines from 1 -- 5.1 $\mu$m toward the low-mass protostar TMC1A. For the first time, a collimated atomic jet is detected from TMC1A in the [Fe II] line at 1.644 $\mu$m along with corresponding extended H$_2$ 2.12 $\mu$m emission. Towards the protostar, we detected spectrally broad H I and He I emissions with velocities up to 300 km/s that can be explained by a combination of protostellar accretion and a wide-angle wind. The 2$\mu$m continuum dust emission, H I, He I, and O I all show emission from the illuminated outflow cavity wall and scattered line emission. These observations demonstrate the potential of {\it JWST} to characterize and reveal new information about the hot inner regions of nearby protostars. In this case, a previously undetected atomic wind and ionized jet in a well-known outflow., Comment: Accepted for publication on ApJL, 10 pages, 6 figures including appendix

In this Letter, we report Very Long Baseline Array observations of 22 GHz water masers toward the protostar CARMA-6, located at the center of the Serpens South young cluster. From the astrometric fits to maser spots, we derive a distance of 440.7+/-3.5 pc for the protostar (1% error). This represents the best direct distance determination obtained so far for an object this young and deeply embedded in this highly obscured region. Taking into account depth effects, we obtain a distance to the cluster of 440.7+/-4.6 pc. Stars visible in the optical that have astrometric solutions in the Gaia Data Release 3 are, on the other hand, all located in the periphery of the cluster. Their mean distance of 437 (+51, -41) pc is consistent within 1-sigma with the value derived from maser astrometry. As the maser source is just at the center of Serpens South, we finally solve the ambiguity of the distance to this region that has prevailed over the years., Comment: Accepted to A&A Letters; Co-author spelling name corrected

Modern interferometers routinely provide radio-astronomical images down to subarcsecond resolution. However, interferometers filter out spatial scales larger than those sampled by the shortest baselines, which affects the measurement of both spatial and spectral features. Complementary single-dish data are vital for recovering the true flux distribution of spatially resolved astronomical sources with such extended emission. In this work, we provide an overview of the prominent available methods to combine single-dish and interferometric observations. We test each of these methods in the framework of the CASA data analysis software package on both synthetic continuum and observed spectral data sets. We develop a set of new assessment tools that are generally applicable to all radio-astronomical cases of data combination. Applying these new assessment diagnostics, we evaluate the methods' performance and demonstrate the significant improvement of the combined results in comparison to purely interferometric reductions. We provide combination and assessment scripts as add-on material. Our results highlight the advantage of using data combination to ensure high-quality science images of spatially resolved objects., Comment: 29 pages, 20 figures. Accepted for publication in PASP. Code repository available at: github.com/teuben/DataComb

We present Atacama Large Millimeter/submillimeter Array observations of the $\sim$10 kAU environment surrounding 21 protostars in the Orion A molecular cloud tracing outflows. Our sample is composed of Class 0 to flat-spectrum protostars, spanning the full $\sim$1 Myr lifetime. We derive the angular distribution of outflow momentum and energy profiles and obtain the first two-dimensional instantaneous mass, momentum, and energy ejection rate maps using our new approach: the Pixel Flux-tracing Technique (PFT). Our results indicate that by the end of the protostellar phase, outflows will remove $\sim$2 to 4 M$_\odot$ from the surrounding $\sim$1 M$_\odot$ low-mass core. These high values indicate that outflows remove a significant amount of gas from their parent cores and continuous core accretion from larger scales is needed to replenish core material for star formation. This poses serious challenges to the concept of ``cores as well-defined mass reservoirs", and hence to the simplified core-to-star conversion prescriptions. Furthermore, we show that cavity opening angles, and momentum and energy distributions all increase with the protostar evolutionary stage. This is clear evidence that even garden-variety protostellar outflows: (a) effectively inject energy and momentum into their environments on $10$ kAU scales, and (b) significantly disrupt their natal cores, ejecting a large fraction of the mass that would have otherwise fed the nascent star. Our results support the conclusion that protostellar outflows have a direct impact on how stars get their mass, and that the natal sites of individual low-mass star formation are far more dynamic than commonly accepted theoretical paradigms., Comment: 76 pages, 43 figures. Accepted by ApJ 2023.2.6

Science archives are cornerstones of modern astronomical facilities. In this paper we describe the version 1.0 milestone of the Atacama Large Millimeter/submillimeter Array Science Archive. This version features a comprehensive query interface with rich metadata and visualisation of the spatial and spectral locations of the observations, a complete set of virtual observatory services for programmatic access, text-based similarity search, display and query for types of astronomical objects in SIMBAD and NED, browser-based remote visualisation, interactive previews with tentative line identification and extensive documentation including video and Jupyter Notebook tutorials. The development is regularly evaluated by means of user surveys and is entirely focused on providing the best possible user experience with the goal of helping to maximise the scientific productivity of the observatory., Comment: 6 pages, 7 figues

We present high resolution Karl G. Jansky Very Large Array (VLA) observations of the protostar L1527 IRS at 7 mm, 1.3 cm, and 2 cm wavelengths. We detect the edge-on dust disk at all three wavelengths and find that it is asymmetric, with the southern side of the disk brighter than the northern side. We confirm this asymmetry through analytic modeling and also find that the disk is flared at 7 mm. We test the data against models including gap features in the intensity profile, and though we cannot rule such models out, they do not provide a statistically significant improvement in the quality of fit to the data. From these fits, we can however place constraints on allowed properties of any gaps that could be present in the true, underlying intensity profile. The physical nature of the asymmetry is difficult to associate with physical features due to the edge-on nature of the disk, but could be related to spiral arms or asymmetries seen in other imaging of more face-on disks., Comment: 20 pages, 5 figures, 3 tables; accepted for publication in the Astrophysical Journal

In response to the challenges presented by high reviewer workloads in traditional panel reviews and increasing numbers of submitted proposals, ALMA implemented distributed peer review to assess the majority of proposals submitted to the Cycle 8 Main Call. In this paper, we present an analysis of this review process. Over 1000 reviewers participated in the process to review 1497 proposals, making it the largest implementation of distributed peer review to date in astronomy, and marking the first time this process has been used to award the majority of observing time at an observatory. We describe the process to assign proposals to reviewers, analyze the nearly 15,000 ranks and comments submitted by reviewers to identify any trends and systematics, and gather feedback on the process from reviewers and Principal Investigators (PIs) through surveys. Approximately 90% of the proposal assignments were aligned with the expertise of the reviewer, as measured both by the expertise keywords provided by the reviewers and the reviewers' self-assessment of their expertise on their assigned proposals. PIs rated 73% of the individual review comments as helpful, and even though the reviewers had a broad range of experience levels, PIs rated the quality of the comments received from students and senior researchers similarly. The primary concerns raised by PIs were the quality of some reviewer comments and high dispersions in the ranks. The ranks and comments are correlated with various demographics to identify the main areas in which the review process can be improved in future cycles., Comment: 57 pages, 48 figures; accepted for publication in BAAS. [v2] is a minor revision, clarifying that we describe the largest implementation of distributed peer review to date in astronomy

We present an updated analysis of systematics in the Atacama Large Millimeter/submillimeter Array (ALMA) proposal ranks from Carpenter (2020) to include the last two ALMA cycles, when significant changes were introduced in the proposal review process. In Cycle 7, the investigator list on the proposal cover sheet was randomized such that the reviewers were aware of the overall proposal team but did not know the identity of the principal investigator (PI). In Cycle 8, ALMA adopted distributed peer review for most proposals and implemented dual-anonymous review for all proposals, in which the identity of the proposal team was not revealed to the reviewers. The most significant change in the systematics in Cycles 7 and 8 compared to previous cycles is related to the experience of PIs in submitting ALMA proposals. PIs that submit a proposal every cycle tend to have ranks that are consistent with average in Cycles 7 and 8 whereas previously they had the best overall ranks. Also, PIs who submitted a proposal for the second time show improved ranks over previous cycles. These results suggest some biases related to the relative prominence of the PI have been present in the ALMA review process. Systematics related to regional affiliation remain largely unchanged in that PIs from Chile, East Asia, and non-ALMA regions tend to have poorer overall ranks than PIs from Europe and North America. The systematics of how one region ranks proposals from another region are also investigated. No significant differences in the overall ranks based on gender of the PI are observed., Comment: 16 pages, 13 figures. Accepted for publication in PASP

We have conducted mapping observations toward the n3 and n5 positions in the NGC\,2264-D cluster-forming region with the Atacama Compact Array (ACA) of the Atacama Large Millimeter/submillimeter Array (ALMA) in Band 3. Observations with 10000 au scale beam reveal the chemical composition at the clump scale. The spatial distributions of the observed low upper-state-energy lines of CH$_{3}$OH are similar to those of CS and SO, and the HC$_{3}$N emission seems to be predominantly associated with clumps containing young stellar objects. The turbulent gas induced by the star formation activities produces large-scale shock regions in NGC\,2264-D, which are traced by the CH$_{3}$OH, CS and SO emissions. We derive the HC$_{3}$N, CH$_{3}$CN, and CH$_{3}$CHO abundances with respect to CH$_{3}$OH. Compared to the n5 field, the n3 field is farther (in projected apparent distance) from the neighboring NGC\,2264-C, yet the chemical composition in the n3 field tends to be similar to that of the protostellar candidate CMM3 in NGC\,2264-C. The HC$_{3}$N/CH$_{3}$OH ratios in the n3 field are higher than those in the n5 field. We find an anti-correlation between the HC$_{3}$N/CH$_{3}$OH ratio and their excitation temperatures. The low HC$_{3}$N/CH$_{3}$OH abundance ratio at the n5 field implies that the n5 field is an environment with more active star formation compared with the n3 field., Comment: 16 pages, 10 figures, 6 tables, Accepted by Publications of the Astronomical Society of Japan (PASJ)

We have analyzed Atacama Large Millimeter/submillimeter Array (ALMA) Cycle 4 Band 6 data toward two young stellar objects (YSOs), Oph-emb5 and Oph-emb9, in the Ophiuchus star-forming region. The YSO Oph-emb5 is located in a relatively quiescent region, whereas Oph-emb9 is irradiated by a nearby bright Herbig Be star. Molecular lines from $cyclic$-C$_{3}$H$_{2}$ ($c$-C$_{3}$H$_{2}$), H$_{2}$CO, CH$_{3}$OH, $^{13}$CO, C$^{18}$O, and DCO$^{+}$ have been detected from both sources, while DCN is detected only in Oph-emb9. Around Oph-emb5, $c$-C$_{3}$H$_{2}$ is enhanced at the west side, relative to the IR source, whereas H$_{2}$CO and CH$_{3}$OH are abundant at the east side. In the field of Oph-emb9, moment 0 maps of the $c$-C$_{3}$H$_{2}$ lines show a peak at the eastern edge of the field of view, which is irradiated by the Herbig Be star. Moment 0 maps of CH$_{3}$OH and H$_{2}$CO show peaks farther from the bright star. We derive the $N$($c$-C$_{3}$H$_{2}$)/$N$(CH$_{3}$OH) column density ratios at the peak positions of $c$-C$_{3}$H$_{2}$ and CH$_{3}$OH near each YSO, which are identified based on their moment 0 maps. The $N$($c$-C$_{3}$H$_{2}$)/$N$(CH$_{3}$OH) ratio at the $c$-C$_{3}$H$_{2}$ peak is significantly higher than at the CH$_{3}$OH peak by a factor of $\sim 19$ in Oph-emb9, while the difference in this column density ratio between these two positions is a factor of $\sim2.6 $ in Oph-emb5. These differences are attributed to the efficiency of the photon-dominated region (PDR) chemistry in Oph-emb9. The higher DCO$^{+}$ column density and the detection of DCN in Oph-emb9 are also discussed in the context of UV irradiation flux., Comment: 20 pages, 14 figures, 4 tables, Accepted by The Astrophysical Journal. We changed continuum images (Figure 2). We show the continuum images with only 12-m array data in this version. Since there are unknown issues when we combined 12-m and 7-m array data for the continuum image, the scales were wrong in the previous versions

Using the Karl G. Jansky Very Large Array (VLA), we have conducted a survey for 22 GHz, 6_{1,6}-5_{2,3} H2O masers toward the Serpens South region. The masers were also observed with the Very Long Baseline Array (VLBA) following the VLA detections. We detect for the first time H2O masers in the Serpens South region that are found to be associated to three Class 0-Class I objects, including the two brightest protostars in the Serpens South cluster, known as CARMA-6 and CARMA-7. We also detect H2O masers associated to a source with no outflow or jet features. We suggest that this source is most probably a background AGB star projected in the direction of Serpens South. The spatial distribution of the emission spots suggest that the masers in the three Class 0-Class I objects emerge very close to the protostars and are likely excited in shocks driven by the interaction between a protostellar jet and the circumstellar material. Based on the comparison of the distributions of bolometric luminosity of sources hosting 22 GHz H2O masers and 162 YSOs covered by our observations, we identify a limit of L_Bol ~ 10 L_Sun for a source to host water masers. However, the maser emission shows strong variability in both intensity and velocity spread, and therefore masers associated to lower-luminosity sources may have been missed by our observations. We also report 11 new sources with radio continuum emission at 22 GHz., Comment: Published in AJ

Angular momentum is one of the most important physical quantities that govern star formation. The initial angular momentum of a core may be responsible for its fragmentation and can have an influence on the size of the protoplanetary disk. To understand how cores obtain their initial angular momentum, it is important to study the angular momentum of filaments where they form. While theoretical studies on filament rotation have been explored, there exist very few observational measurements of the specific angular momentum in star-forming filaments. We present high-resolution N2D+ ALMA observations of the LBS 23 (HH24-HH26) region in Orion B, which provide one of the most reliable measurements of the specific angular momentum in a star-forming filament. We find the total specific angular momentum ($4 \times 10^{20} cm^2s^{-1}$), the dependence of the specific angular momentum with radius (j(r) $\propto r^{1.83}$), and the ratio of rotational energy to gravitational energy ($\beta_{rot} \sim 0.04$) comparable to those observed in rotating cores with sizes similar to our filament width ($\sim$ 0.04 pc) in other star-forming regions. Our filament angular momentum profile is consistent with rotation acquired from ambient turbulence and with simulations that show cores and their host filaments develop simultaneously due to the multi-scale growth of nonlinear perturbation generated by turbulence., Comment: accepted by ApJ, 2020.12.1

We have carried out mapping observations of molecular emission lines of HC$_{3}$N and CH$_{3}$OH toward two massive cluster-forming clumps, NGC2264-C and NGC2264-D, using the Nobeyama 45-m radio telescope. We derive an $I$(HC$_{3}$N)/$I$(CH$_{3}$OH) integrated intensity ratio map, showing a higher value at clumps including 2MASS point sources at the northern part of NGC2264-D. Possible interpretations of the $I$(HC$_{3}$N)/$I$(CH$_{3}$OH) ratio are discussed. We have also observed molecular emission lines from CCS and N$_{2}$H$^{+}$ toward five positions in each clump. We investigate the $N$(N$_{2}$H$^{+}$)/$N$(CCS) and $N$(N$_{2}$H$^{+}$)/$N$(HC$_{3}$N) column density ratios among the ten positions in order to test whether they can be used as chemical evolutionary indicators in these clumps. The $N$(N$_{2}$H$^{+}$)/$N$(CCS) ratio shows a very high value toward a bright embedded IR source (IRS1), whereas the $N$(N$_{2}$H$^{+}$)/$N$(HC$_{3}$N) ratio at IRS1 is comparable with those at the other positions. These results suggest that UV radiation affects the chemistry around IRS1. We find that there are positive correlations between these column density ratios and the excitation temperatures of N$_{2}$H$^{+}$, which implies the chemical evolution of clumps. These chemical evolutionary indicators likely reflect the combination of evolution along the filamentary structure and evolution of each clump., Comment: 5 figures, 9 tables, and 3 figures in appendix, 19 pages, Accepted by the Monthly Notices of the Royal Astronomical Society

We present a new package for joint deconvolution of ALMA 12m, 7m, and Total Power (TP) data, dubbed ``Total Power Map to Visibilities (TP2VIS)". It converts a TP (single-dish) map into visibilities on the CASA platform, which can be input into deconvolvers (e.g., CLEAN) along with 12m and 7m visibilities. A manual is presented in the Github repository (https://github.com/tp2vis/distribute). Combining data from the different ALMA arrays is a driver for a number of science topics, namely those that probe size scales of extended and compact structures simultaneously. We test TP2VIS using model images, one with a single Gaussian and another that mimics the internal structures of giant molecular clouds. The result shows that the better uv coverage with TP2VIS visibilities helps the deconvolution process and reproduces the model image within errors of only 5% over two orders of magnitude in flux., Comment: Accepted to PASP. Software distribution: https://github.com/tp2vis/distribute

We investigated the central mass distribution of the luminous infrared galaxy NGC 3256 at a distance of 35 Mpc by using CO(1-0) observations of the Atacama Large Millimeter and sub-millimeter Array (ALMA) and near-IR data of the Two Micron Sky Survey (2MASS). We found that there is a huge amount of invisible dynamical mass ($4.84 \times 10^{10} M_{\odot}$) in the central region of the galaxy. The invisible mass is likely caused by some dark matter, which might have a cuspy dark matter profile. We note that this dark matter is difficult to explain with the conventional Modified Newtonian Dynamics (MOND) model, which is only applicable at a low acceleration regime, whereas the acceleration at the central region of the galaxy is relatively strong. Therefore, this discovery might pose a challenge to the conventional MOND models., Comment: 26 pages, 7 figures, accepted by Sains Malaysiana

Aims: We investigated the masses and spatial distributions of pre-stellar and protostellar candidates in the young, low-mass star forming region Serpens South, where active star formation is known to occur along a predominant filamentary structure. Previous observations used to study these distributions have been limited by two important observational factors: (1) sensitivity limits that leave the lowest-mass sources undetected, or (2) resolution limits that cannot distinguish binaries and/or cluster members in close proximity. Methods: Recent millimeter-wavelength interferometry observations can now uncover faint and/or compact sources in order to study a more complete population of protostars, especially in nearby ($D<500$ pc) clusters. Here we present ALMA observations of 1 mm (Band 6) continuum in a $3 \times 2$ arcminutes region at the center of Serpens South. Our angular resolution of $\sim1$ arcsec is equivalent to $\sim400$ au, corresponding to scales of envelopes and/or disks of protostellar sources. Results: We detect 52 sources with 1 mm continuum, and we measure masses of $0.002 - 0.9$ solar masses corresponding to gas and dust in the disk and/or envelope of the protostellar system. For the deeply embedded (youngest) sources with no IR counterparts, we find evidence of mass segregation and clustering according to: the Minimum Spanning Tree method, distribution of projected separations between unique sources, and concentration of higher-mass sources near to the dense gas at the cluster center. Conclusions: The mass segregation of the mm sources is likely primordial rather than dynamical given the young age of this cluster, compared with segregation time. This is the first case to show this for mm sources in a low-mass protostellar cluster environment., Comment: Accepted to A&A, FITS data to be available at CDS

We aim at studying the causal link between the knotty jet structure in CARMA 7, a young Class 0 protostar in the Serpens South cluster, and episodic accretion in young protostellar disks. We used numerical hydrodynamics simulations to derive the protostellar accretion history in gravitationally unstable disks around solar-mass protostars. We compared the time spacing between luminosity bursts \Delta\tau_mod, caused by dense clumps spiralling on the protostar, with the differences of dynamical timescales between the knots \Delta\tau_obs in CARMA 7. We found that the time spacing between the bursts have a bi-modal distribution caused by isolated and clustered luminosity bursts. The former are characterized by long quiescent periods between the bursts with \Delta\tau_mod = a few * (10^3-10^4) yr, whereas the latter occur in small groups with time spacing between the bursts \Delta\tau_mod= a few * (10-10^2) yr. For the clustered bursts, the distribution of \Delta\tau_mod in our models can be fit reasonably well to the distribution of \Delta\tau_obs in the protostellar jet of CARMA 7, if a certain correction for the (yet unknown) inclination angle with respect to the line of sight is applied. The K-S test on the model and observational data sets suggests the best-fit values for the inclination angles of 55-80 deg., which become narrower (75-80 deg.) if only strong luminosity bursts are considered. The dynamical timescales of the knots in the jet of CARMA 7 are too short for a meaningful comparison with the long time spacings between isolated bursts in our models. The exact sequences of time spacings between the luminosity bursts in our models and knots in the jet of CARMA 7 were found difficult to match. (abridged), Comment: Accepted for publication in Astronomy & Astrophysics

We present new Submillimeter Array (SMA) observations of CO(2-1) outflows toward young, embedded protostars in the Perseus molecular cloud as part of the Mass Assembly of Stellar Systems and their Evolution with the SMA (MASSES) survey. For 57 Perseus protostars, we characterize the orientation of the outflow angles and compare them with the orientation of the local filaments as derived from $Herschel$ observations. We find that the relative angles between outflows and filaments are inconsistent with purely parallel or purely perpendicular distributions. Instead, the observed distribution of outflow-filament angles are more consistent with either randomly aligned angles or a mix of projected parallel and perpendicular angles. A mix of parallel and perpendicular angles requires perpendicular alignment to be more common by a factor of $\sim$3. Our results show that the observed distributions probably hold regardless of the protostar's multiplicity, age, or the host core's opacity. These observations indicate that the angular momentum axis of a protostar may be independent of the large-scale structure. We discuss the significance of independent protostellar rotation axes in the general picture of filament-based star formation., Comment: Accepted to ApJ

We present a 3 mm spectral line and continuum survey of L1451 in the Perseus Molecular Cloud. These observations are from the CARMA Large Area Star Formation Survey (CLASSy), which also imaged Barnard 1, NGC 1333, Serpens Main and Serpens South. L1451 is the survey region with the lowest level of star formation activity---it contains no confirmed protostars. HCO+, HCN, and N2H+ (J=1-0) are all detected throughout the region, with HCO+ the most spatially widespread, and molecular emission seen toward 90% of the area above N(H_2) column densities of 1.9x10^21 cm^-2. HCO+ has the broadest velocity dispersion, near 0.3 km/s on average, compared to ~0.15 km/s for the other molecules, thus representing a range from supersonic to subsonic gas motions. Our non-binary dendrogram analysis reveals that the dense gas traced by each molecule has similar hierarchical structure, and that gas surrounding the candidate first hydrostatic core (FHSC), L1451-mm, and other previously detected single-dish continuum clumps have similar hierarchical structure; this suggests that different sub-regions of L1451 are fragmenting on the pathway to forming young stars. We determined the three-dimensional morphology of the largest detectable dense gas structures to be relatively ellipsoidal compared to other CLASSy regions, which appeared more flattened at largest scales. A virial analysis shows the most centrally condensed dust structures are likely unstable against collapse. Additionally, we identify a new spherical, centrally condensed N2H+ feature that could be a new FHSC candidate. The overall results suggest L1451 is a young region starting to form its generation of stars within turbulent, hierarchical structures., Comment: Accepted to The Astrophysical Journal (ApJ), 45 pages, 24 figures (some with reduced resolution in this preprint); Project website is at http://carma.astro.umd.edu/classy

The loss of mass from protostars, in the form of a jet or outflow, is a necessary counterpart to protostellar mass accretion. Outflow ejection events probably vary in their velocity and/or in the rate of mass loss. Such `episodic' ejection events have been observed during the Class 0 protostellar phase (the early accretion stage), and continue during the subsequent class I phase that marks the first one million years of star formation. Previously observed episodic-ejection sources were relatively isolated; however, the most common sites of star formation are clusters. Outflows link protostars with their environment and provide a viable source of turbulence that is necessary for regulating star formation in clusters, but it is not known how an accretion-driven jet or outflow in a clustered environment manifests itself in its earliest stage. This early stage is important in establishing the initial conditions for momentum and energy transfer to the environment as the protostar and cluster evolve. Here we report that an outflow from a very young class 0 protostar, at the hub of the very active and filamentary Serpens South protostellar cluster, shows unambiguous episodic events. The $^{12}$CO (J=2-1) emission from the protostar reveals 22 distinct features of outflow ejecta, the most recent having the highest velocity. The outflow forms bipolar lobes --- one of the first detectable signs of star formation --- which originate from the peak of 1-mm continuum emission. Emission from the surrounding C$^{18}$O envelope shows kinematics consistent with rotation and an infall of material onto the protostar. The data suggest that episodic accretion-driven outflow begins in the earliest phase of protostellar evolution, and that the outflow remains intact in a very clustered environment, probably providing efficient momentum transfer for driving turbulence., Comment: Accepted for publication as a "Letter" in Nature. 6 figures

Molecular outflows driven by protostellar cluster members likely impact their surroundings and contribute to turbulence, affecting subsequent star formation. The very young Serpens South cluster consists of a particularly high density and fraction of protostars, yielding a relevant case study for protostellar outflows and their impact on the cluster environment. We combined CO $J=1-0$ observations of this region using the Combined Array for Research in Millimeter-wave Astronomy (CARMA) and the Institut de Radioastronomie Millim\'{e}trique (IRAM) 30 m single dish telescope. The combined map allows us to probe CO outflows within the central, most active region at size scales of 0.01 pc to 0.8 pc. We account for effects of line opacity and excitation temperature variations by incorporating $^{12}$CO and $^{13}$CO data for the $J=1-0$ and $J=3-2$ transitions (using Atacama Pathfinder Experiment and Caltech Submillimeter Observatory observations for the higher CO transitions), and we calculate mass, momentum, and energy of the molecular outflows in this region. The outflow mass loss rate, force, and luminosity, compared with diagnostics of turbulence and gravity, suggest that outflows drive a sufficient amount of energy to sustain turbulence, but not enough energy to substantially counter the gravitational potential energy and disrupt the clump. Further, we compare Serpens South with the slightly more evolved cluster NGC 1333, and we propose an empirical scenario for outflow-cluster interaction at different evolutionary stages., Comment: 26 pages, 15 figures, accepted for publication in the Astrophysical Journal

We are conducting a Jansky VLA Ka-band (8 mm and 1 cm) and C-band (4 cm and 6.4 cm) survey of all known protostars in the Perseus Molecular Cloud, providing resolution down to $\sim$0.06'' and $\sim$0.35" in Ka-band and C-band, respectively. Here we present first results from this survey that enable us to examine the source NGC 1333 IRAS2A in unprecedented detail and resolve it into a proto-binary system separated by 0.621"$\pm$0.006" ($\sim$143 AU) at 8 mm, 1 cm, and 4 cm. These 2 sources (IRAS2A VLA1 and VLA2) are likely driving the two orthogonal outflows known to originate from IRAS2A. The brighter source IRAS2A VLA1 is extended perpendicular to its outflow in the VLA data, with a deconvolved size of 0.055" ($\sim$13 AU), possibly tracing a protostellar disk. The recently reported candidate companions (IRAS2A MM2 and MM3) are not detected in either our VLA data, CARMA 1.3 mm data, or SMA 850 $\mu$m data. SMA CO ($J=3\rightarrow2$), CARMA CO ($J=2\rightarrow1$), and lower resolution CARMA CO ($J=1\rightarrow0$) observations are used to examine the outflow origins and the nature of the candidate companions to IRAS2A VLA1. The CO ($J=3\rightarrow2$) and ($J=2\rightarrow1$) data show that IRAS2A MM2 is coincident with a bright CO emission spot in the east-west outflow, and IRAS2A MM3 is within the north-south outflow. In contrast, IRAS2A VLA2 lies at the east-west outflow symmetry point. We propose that IRAS2A VLA2 is the driving source of the East-West outflow and a true companion to IRAS2A VLA1, whereas IRAS2A MM2 and MM3 may not be protostellar., Comment: Accepted to ApJ, 27 pages, 6 Figures, 2 Tables

We present observations of N2H+(1-0), HCO+(1-0), and HCN(1-0) toward the Serpens Main molecular cloud from the CARMA Large Area Star Formation Survey (CLASSy). We mapped 150 square arcminutes of Serpens Main with an angular resolution of 7 arcsecs. The gas emission is concentrated in two subclusters (the NW and SE subclusters). The SE subcluster has more prominent filamentary structures and more complicated kinematics compared to the NW subcluster. The majority of gas in the two subclusters has subsonic to sonic velocity dispersions. We applied a dendrogram technique with N2H+(1-0) to study the gas structures; the SE subcluster has a higher degree of hierarchy than the NW subcluster. Combining the dendrogram and line fitting analyses reveals two distinct relations: a flat relation between nonthermal velocity dispersion and size, and a positive correlation between variation in velocity centroids and size. The two relations imply a characteristic depth of 0.15 pc for the cloud. Furthermore, we have identified six filaments in the SE subcluster. These filaments have lengths of 0.2 pc and widths of 0.03 pc, which is smaller than a characteristic width of 0.1 pc suggested by Herschel observations. The filaments can be classified into two types based on their properties. The first type, located in the northeast of the SE subcluster, has larger velocity gradients, smaller masses, and nearly critical mass-per-unit-length ratios. The other type, located in the southwest of the SE subcluster, has the opposite properties. Several YSOs are formed along two filaments which have supercritical mass per unit length ratios, while filaments with nearly critical mass-per-unit-length ratios are not associated with YSOs, suggesting that stars are formed on gravitationally unstable filaments., Comment: Accepted to ApJ. 38 pages, 16 figures, 5 tables

We present observations of outflows in the star-forming region NGC 1333 using the Combined Array for Research in Millimeter-Wave Astronomy (CARMA). We combined the 12CO and 13CO (1-0) CARMA mosaics with data from the 14-m Five College Radio Astronomy Observatory (FCRAO) to probe the central, most dense and active region of this protostellar cluster at scales from 5'' to 7' (or 1000 AU to 0.5 pc at a distance of 235 pc). We map and identify 12CO outflows, and along with 13CO data we estimate their mass, momentum and energy. Within the 7'x7' map, the 5'' resolution allows for a detailed study of morphology and kinematics of outflows and outflow candidates, some of which were previously confused with other outflow emission in the region. In total, we identify 22 outflow lobes, as well as 9 dense circumstellar envelopes marked by continuum emission, of which 6 drive outflows. We calculate a total outflow mass, momentum and energy within the mapped region of 6 Msun, 19 Msun km/s, and 7x10^44 erg, respectively. Within this same region, we compare outflow kinematics with turbulence and gravitational energy, and we suggest that outflows are likely important agents for the maintenance of turbulence in this region. In the earliest stages of star formation, outflows do not yet contribute enough energy to totally disrupt the clustered region where most star formation is happening, but have the potential to do so as the protostellar sources evolve. Our results can be used to constrain outflow properties, such as outflow strength, in numerical simulations of outflow-driven turbulence in clusters., Comment: 24 pages, 9 figures, 5 tables, accepted for publication in ApJ

The Wilkinson Microwave Anisotropy Probe (WMAP) free-free foreground emission map is used to identify diffuse ionized regions (DIR) in the Galaxy (Rahman & Murray 2010). It has been found that the 18 most luminous WMAP sources produce more than half of the total ionizing luminosity of the Galaxy. We observed radio recombination lines (RRLs) toward the luminous WMAP source G49.75-0.45 with the Green Bank Telescope near 1.4 GHz. Hydrogen RRL is detected toward the source but no helium line is detected, implying that n_He+/n_H+ < 0.024. This limit puts severe constraint on the ionizing spectrum. The total ionizing luminosity of G49 (3.05 x 10^51 s^-1) is ~ 2.8 times the luminosity of all radio HII regions within this DIR and this is generally the case for other WMAP sources. Murray & Rahman (2010) propose that the additional ionization is due to massive clusters (~ 7.5 x10^3 Msun for G49) embedded in the WMAP sources. Such clusters should produce enough photons with energy \geq 24.6 eV to fully ionize helium in the DIR. Our observations rule out a simple model with G49 ionized by a massive cluster. We also considered 'leaky' HII region models for the ionization of the DIR, suggested by Lockman and Anantharamaiah, but these models also cannot explain our observations. We estimate that the helium ionizing photons need to be attenuated by > ~10 times to explain the observations. If selective absorption of He- ionizing photons by dust is causing this additional attenuation, then the ratio of dust absorption cross sections for He- and H- ionizing photons should be > ~6., Comment: Accepted for publication in the ApJ; 14 pages, 3 figures