19 research outputs found

    Early Planet Formation in Embedded Disks (eDisk) X: Compact Disks, Extended Infall, and a Fossil Outburst in the Class I Oph IRS43 Binary

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    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 Ap

    Early Planet Formation in Embedded Disks (eDisk). VIII. A Small Protostellar Disk around the Extremely Low-Mass and Young Class 0 Protostar, IRAS 15398-3359

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    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 (40\sim40\,mas) and molecular line (150\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 2σ2\sigma radius of the dust disk to be 4.5×2.8au4.5\times2.8\,\mathrm{au} and 3.8au3.8\,\mathrm{au}, respectively. We estimate the gas+dust disk mass assuming optically thin continuum emission to be 0.61.8Mjup0.6-1.8\,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 0.022M0.022\,M_\odot and 31.2au31.2\,\mathrm{au} from our Modified 2 single power-law fitting. A conservative upper limit of the protostellar mass is inferred to be 0.1M0.1\,M_\odot. The protostellar mass-accretion rate and the specific angular momentum at the protostellar disk edge are found to be between 1.36.1×106Myr11.3-6.1\times10^{-6}\,M_\odot\,\mathrm{yr^{-1}} and 1.23.8×104kms1pc1.2-3.8\times10^{-4}\,\mathrm{km\,s^{-1}\,pc}, respectively, with an age estimated between 0.47.5×1040.4-7.5\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 Progra

    Early Planet Formation in Embedded Disks (eDisk) VI: Kinematic Structures around the Very Low Mass Protostar IRAS 16253-2429

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    Precise estimates of protostellar masses are crucial to characterize the formation of stars of low masses down to brown-dwarfs (BDs; M* < 0.08 Msun). The most accurate estimation of protostellar mass uses the Keplerian rotation in the circumstellar disk around the protostar. To apply the Keplerian rotation method to a protostar at the low-mass end, we have observed the Class 0 protostar IRAS 16253-2429 using the Atacama Large Millimeter/submillimeter Array (ALMA) in the 1.3 mm continuum at an angular resolution of 0.07" (10 au), and in the 12CO, C18O, 13CO (J=2-1), and SO (J_N = 6_5-5_4) molecular lines, as part of the ALMA Large Program Early Planet Formation in Embedded Disks (eDisk). The continuum emission traces a non-axisymmetric, disk-like structure perpendicular to the associated 12CO outflow. The position-velocity (PV) diagrams in the C18O and 13CO lines can be interpreted as infalling and rotating motions. In contrast, the PV diagram along the major axis of the disk-like structure in the 12CO line allows us to identify Keplerian rotation. The central stellar mass and the disk radius are estimated to be ~0.12-0.17 Msun and ~13-19 au, respectively. The SO line suggests the existence of an accretion shock at a ring (r~28 au) surrounding the disk and a streamer from the eastern side of the envelope. IRAS 16253-2429 is not a proto-BD but has a central stellar mass close to the BD mass regime, and our results provide a typical picture of such very low-mass protostars.Comment: 41 pages, 14 figure

    Early Planet Formation in Embedded Disks (eDisk) XII: Accretion streamers, protoplanetary disk, and outflow in the Class I source Oph IRS63

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    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^{12}CO), an extended rotating envelope structure (in 13^{13}CO), a streamer connecting the envelope to the disk (in C18^{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^{13}CO and C18^{18}O, we measure a protostellar mass of M=0.5±0.2\rm M_\star = 0.5 \pm 0.2 ~M\rm M_\odot and confirm the presence of a disk rotating at almost Keplerian velocity that extends up to 260\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 C18^{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 106\sim 10^{-6}~Myr1\rm M_\odot \, yr^{-1} and compare it to the disk-to-star mass accretion rate of 108\sim 10^{-8}~Myr1\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 figure

    Early Planet Formation in Embedded Disks (eDisk) III: A first high-resolution view of sub-mm continuum and molecular line emission toward the Class 0 protostar L1527 IRS

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    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 \sim0.06" (8 au) resolution and molecular line emission at \sim0.17" (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^{12}CO, 13^{13}CO, C18^{18}O, H2_2CO, c-C3_3H2_2, SO, SiO, and DCN trace different components of the protostellar system, with a disk wind potentially visible in 12^{12}CO. The 13^{13}CO brightness temperature and the H2_2CO line ratio confirm that the disk is too warm for CO freeze out, with the snowline located at \sim350 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 Progra

    Early Planet Formation in Embedded Disks (eDisk). IV. The Ringed and Warped Structure of the Disk around the Class I Protostar L1489 IRS

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    Constraining the physical and chemical structure of young embedded disks is crucial to understanding the earliest stages of planet formation. As part of the Early Planet Formation in Embedded Disks Atacama Large Millimeter/submillimeter Array Large Program, we present high spatial resolution (\sim0.\!\!^{\prime\prime}1 or \sim15 au) observations of the 1.3 mm continuum and 13^{13}CO J=J= 2-1, C18^{18}O J=J= 2-1, and SO JN=J_N= 656_5-545_4 molecular lines toward the disk around the Class I protostar L1489 IRS. The continuum emission shows a ring-like structure at 56 au from the central protostar and a tenuous, optically thin emission extending beyond \sim300 au. The 13^{13}CO emission traces the warm disk surface, while the C18^{18}O emission originates from near the disk midplane. The coincidence of the radial emission peak of C18^{18}O with the dust ring may indicate a gap-ring structure in the gaseous disk as well. The SO emission shows a highly complex distribution, including a compact, prominent component at \lesssim30 au, which is likely to originate from thermally sublimated SO molecules. The compact SO emission also shows a velocity gradient along a slightly (15\sim15^\circ) tilted direction with respect to the major axis of the dust disk, which we interpret as an inner warped disk in addition to the warp around \sim200 au suggested by previous work. These warped structures may be formed by a planet or companion with an inclined orbit, or by a gradual change in the angular momentum axis during gas infall.Comment: 24 pages, 12 figures. Accepted for publication in The Astrophysical Journal as one of the first-look papers of the eDisk ALMA Large Progra

    Early Planet Formation in Embedded Disks (eDisk). VII. Keplerian Disk, Disk Substructure, and Accretion Streamers in the Class 0 Protostar IRAS 16544-1604 in CB 68

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    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 \sim5 au. The continuum image reveals a dusty protostellar disk with a radius of \sim30 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 C18^{18}O image cubes clearly show the gas in the disk that follows a Keplerian rotation pattern around a \sim0.14 MM_{\odot} central protostar. Furthermore, there are \sim1500 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^{12}CO (2-1) emission. At the apparent landing point of NE streamer, there are SO (65_5-54_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 Progra

    Early Planet Formation in Embedded Disks (eDisk). I. Overview of the Program and First Results

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    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 7\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 paper

    Fludarabine, cytarabine, granulocyte colony-stimulating factor, and idarubicin with gemtuzumab ozogamicin improves event-free survival in younger patients with newly diagnosed aml and overall survival in patients with npm1 and flt3 mutations

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    Purpose To determine the optimal induction chemotherapy regimen for younger adults with newly diagnosed AML without known adverse risk cytogenetics. Patients and Methods One thousand thirty-three patients were randomly assigned to intensified (fludarabine, cytarabine, granulocyte colony-stimulating factor, and idarubicin [FLAG-Ida]) or standard (daunorubicin and Ara-C [DA]) induction chemotherapy, with one or two doses of gemtuzumab ozogamicin (GO). The primary end point was overall survival (OS). Results There was no difference in remission rate after two courses between FLAG-Ida + GO and DA + GO (complete remission [CR] + CR with incomplete hematologic recovery 93% v 91%) or in day 60 mortality (4.3% v 4.6%). There was no difference in OS (66% v 63%; P = .41); however, the risk of relapse was lower with FLAG-Ida + GO (24% v 41%; P < .001) and 3-year event-free survival was higher (57% v 45%; P < .001). In patients with an NPM1 mutation (30%), 3-year OS was significantly higher with FLAG-Ida + GO (82% v 64%; P = .005). NPM1 measurable residual disease (MRD) clearance was also greater, with 88% versus 77% becoming MRD-negative in peripheral blood after cycle 2 (P = .02). Three-year OS was also higher in patients with a FLT3 mutation (64% v 54%; P = .047). Fewer transplants were performed in patients receiving FLAG-Ida + GO (238 v 278; P = .02). There was no difference in outcome according to the number of GO doses, although NPM1 MRD clearance was higher with two doses in the DA arm. Patients with core binding factor AML treated with DA and one dose of GO had a 3-year OS of 96% with no survival benefit from FLAG-Ida + GO. Conclusion Overall, FLAG-Ida + GO significantly reduced relapse without improving OS. However, exploratory analyses show that patients with NPM1 and FLT3 mutations had substantial improvements in OS. By contrast, in patients with core binding factor AML, outcomes were excellent with DA + GO with no FLAG-Ida benefit
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