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
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
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 (mas) and molecular line (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 radius of the dust disk to be
and , respectively. We estimate the gas+dust disk mass
assuming optically thin continuum emission to be ,
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
and from our Modified 2 single power-law
fitting. A conservative upper limit of the protostellar mass is inferred to be
. The protostellar mass-accretion rate and the specific angular
momentum at the protostellar disk edge are found to be between
and
, respectively, with an age
estimated between 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
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
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 CO), an extended rotating envelope
structure (in CO), a streamer connecting the envelope to the disk (in
CO), and several small-scale spiral structures seen towards the edge of
the dust continuum (in SO). By analyzing the velocity pattern of CO and
CO, we measure a protostellar mass of ~ and confirm the presence of a disk rotating at almost Keplerian
velocity that extends up to 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 CO
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 ~ and compare it to the disk-to-star mass accretion rate of ~, 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
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 0.06" (8 au) resolution and molecular line emission at
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
CO, CO, CO, HCO, c-CH, SO, SiO, and DCN trace
different components of the protostellar system, with a disk wind potentially
visible in CO. The CO brightness temperature and the HCO line
ratio confirm that the disk is too warm for CO freeze out, with the snowline
located at 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 Progra
Early Planet Formation in Embedded Disks (eDisk). IV. The Ringed and Warped Structure of the Disk around the Class I Protostar L1489 IRS
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 (0.\!\!^{\prime\prime}1 or 15 au) observations of the
1.3 mm continuum and CO 2-1, CO 2-1, and SO
- 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
300 au. The CO emission traces the warm disk surface, while the
CO emission originates from near the disk midplane. The coincidence of
the radial emission peak of CO 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 30
au, which is likely to originate from thermally sublimated SO molecules. The
compact SO emission also shows a velocity gradient along a slightly
() 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
200 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
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 5 au. The continuum image reveals a dusty
protostellar disk with a radius of 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 CO image cubes clearly show the gas in the disk that follows a
Keplerian rotation pattern around a 0.14 central protostar.
Furthermore, there are 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 CO (2-1) emission. At the
apparent landing point of NE streamer, there are SO (6-5) 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
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 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
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