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Stella S. R. Offner

Publications and source records attributed to Stella S. R. Offner.

At least 19 recordsLinked to original sources
arXiv2026

Uncovering the Origin of Slow Rotators among Intermediate-Mass Stars in the Star-Forming Cluster Trumpler 14

Intermediate-mass (about 1.5-8 M$_{\odot}$) stars exhibit a wide range of rotation rates and have gained attention for their roles in the extended main-sequence turnoffs (eMSTO) seen in some young and intermediate-age clusters (ages $< 2$ Gyr). Although rapid rotation is expected due to their radiative envelopes, the presence of slow rotators remains puzzling. In this study, we examine disk and X-ray signatures among the intermediate-mass members of the star-forming cluster Trumpler 14. Of the 118 intermediate-mass members, 24 are considered disk-bearing on the basis of their infrared spectral indices derived from spectral energy distributions. The majority of these reside outside the heavily irradiated cluster core and are all slow rotators ($\lessapprox 100$ km s$^{-1}$) except for three fast-rotating Class III objects. Additionally, in the same sample of 118, 37 are X-ray sources, and 22 having available $v \sin i$ data show a systematically slower rotation than X-ray quiet sources. Our findings suggest that, while young stellar disks in intermediate-mass stars contribute to early spin-down, high-energy processes traced by X-ray emission during this phase could be an additional channel for angular-momentum loss in these stars.

astro-ph.SR↗
arXiv2026

The ALMA EGO-10 Survey of Massive Protoclusters: Correlation of 1.3 mm Continuum Source Clustering with Evolutionary State

Massive stars characteristically form in clustered environments. Characterising young massive 'protoclusters' is therefore crucial to constraining the mechanism(s) of massive star formation, and of the assembly of stellar clusters. We present 1.3 mm continuum results from the ALMA EGO-10 imaging survey, targeting ten Spitzer GLIMPSE Extended Green Objects (EGOs) - massive protostars with active outflows traced by extended 4.5 $μ$m emission. Our sensitive 1'.6$\times$1'.6 mosaics reveal rich protoclusters associated with all targets. With a mean spatial resolution 2200$\times$1600 AU, we identify 570 cores - between 13 and 135 per field. We quantify protocluster structure with the $Q$-parameter, finding structural diversity with 0.5 $\lesssim Q \lesssim$ 0.9. The sample is notable for the wealth of complementary high-resolution multiwavelength data available. Correlating our cores with these observations, we find only 2%, 5% and 4% of cores host 6.7 GHz CH$_3$OH masers, 22 GHz H$_2$O masers and cm-$λ$ continuum sources, respectively. The massive protostars traced by 6.7 GHz masers typically reside near protocluster centres (median offset 0.045 pc), and all at $d<$ 3 kpc are found in clustered locales, with $>$10 cores within 10,000 AU. Using VLA cm-$λ$ continuum observations, we construct a new evolutionary indicator: the ratio of protocluster cm-$λ$ continuum luminosity to the mass of the associated ATLASGAL clump ($L_\text{cm}/M_\text{AGAL}$). This ratio correlates positively with $Q$, with the correlation driven primarily by the cm-$λ$ continuum emission from MYSOs. This suggests dynamic protocluster structure, evolving from subclustered to centrally condensed, consistent with the global collapse in hierarchical, clump-fed models of massive star formation.

astro-ph.GA↗
arXiv2026

Non-ideal MHD and protostellar feedback effects on disc formation and evolution in numerical simulations of star cluster formation

While recent surveys have resolved hundreds of nearby protostellar discs, numerical simulations assuming ideal magnetohydrodynamics (MHD) have historically struggled to achieve disc formation due to efficient angular momentum removal by magnetic torques. Non-ideal MHD effects, relevant at the low ionization fractions typical of molecular clouds, have been shown to reduce the effectiveness of magnetic braking and promote disc formation. In this work, we present the results from a suite of calculations following the gravitational collapse of 50 $M_{\odot}$ turbulent molecular cloud cores down to the formation and evolution of stellar systems and protostellar discs. We use the radiation-MHD code GIZMO including non-ideal MHD (Ohmic resistivity, ambipolar diffusion, and the Hall effect) and the STARFORGE numerical framework for modeling star formation and stellar feedback. We compare the effects of assuming ideal vs. non-ideal MHD and including sub-grid protostellar jet feedback on disc formation and evolution. Discs form in all of our models but are least massive in the model with ideal MHD and sub-grid jet feedback. Apart from the ideal MHD$+$jets model, we do not observe any significant differences in disc properties between the ideal and non-ideal MHD models; however, ideal MHD discs are embedded in smaller rotating envelopes. Disc sizes are in general agreement with those of observed discs. Jet feedback increases core fragmentation and reduces final stellar masses. Our results suggest that magnetic braking does not efficiently suppress disc formation, regardless of whether ideal or non-ideal MHD is assumed, under the dynamical conditions in which multiple stellar systems form.

astro-ph.SR↗
arXiv2026

ALMA High-resolution Observation of the HH46/47 Outflow/disk/envelope System

We present $0.1^{\prime\prime}$ ($\sim 50$ au) resolution Atacama Large Millimeter/submillimeter Array (ALMA) observations of the HH 46/47 molecular outflow and its envelope-disk system. The 1.3 mm continuum emission reveals a compact central source surrounded by a circumbinary disk with substructures. The companion, identified in optical and infrared observations, is not detected in the millimeter continuum but coincides with a local intensity minimum. Two spur-like features extending from the primary source toward the companion are identified and are likely induced by gravitational perturbations from the companion. The envelope-disk system is traced by C$^{18}$O, SO, H$_2$CO, and CH$_3$OH. C$^{18}$O primarily traces the extended envelope, while SO probes the inner envelope, and H$_2$CO and CH$_3$OH trace compact, faster-rotating structures near the centrifugal barrier. The observations are well reproduced by a rotating-infalling envelope transitioning to an inner disk at a radius of $\sim 30$ au around a $0.3~M_\odot$ protostar. The $^{12}$CO emission, together with JWST NIRCam images, reveals multiple shell structures in the outflow. Using C$^{18}$O and $^{13}$CO to correct for optical depth, we derive the spatial distributions of outflow mass, momentum, and kinetic energy, as well as their corresponding rates. A model-independent analysis of a well-defined redshifted shell yields its three-dimensional velocity field, showing that the shell expands radially rather than flowing along its surface. Although a transverse velocity gradient is detected, interpreting it as rotation implies an unphysically large magnetic lever arm, disfavoring a direct disk-wind origin. Instead, the shell kinematics support an entrainment scenario.

astro-ph.GA↗
arXiv2026

Preferential alignment of Class 0, Class I protostellar disks in multiple systems across nine nearby molecular clouds

Protostellar disk orientations in multiple systems provide critical insights into the primary mechanisms that govern the formation of multiple-star systems, their subsequent dynamical evolution, and their impact on planet-forming disks. We present a disk alignment study of 512 Class 0, Class I, and flat-spectrum protostars across nine nearby molecular clouds within 500 pc, utilizing data from the CAMPOS and VANDAM surveys. Our sample includes 74 binaries and 31 high-order multiple systems. We find that multiple systems with projected pair separations up to 6000 au exhibit preferential disk alignment with respect to each other across all evolutionary classes, deviating significantly from the random distribution predicted by turbulent fragmentation models. This suggests that the formation of multiple systems cannot be explained by turbulent fragmentation alone. Disk alignment on scales of a few thousand au is also difficult to explain by disk fragmentation as the dominant origin. We further find that the degree of nearest-neighbor disk alignment in higher-order multiples is comparable to that in binaries. Finally, we identify a significant deficit of flat-spectrum protostellar disks in high-order multiple systems as compared to younger Class 0 and Class I phases. The decline is consistent with rapid dynamical evolution, in which most higher-order systems dissolve by the end of the Class I phase.

astro-ph.SR↗
arXiv2026

VESTA: Visual Exploration with Statistical Tool Agents

Fitting quantitative models to data is a central step in scientific workflows, yet it remains one of the least automated. Recent agent-based systems leverage language and vision-language models (VLMs) to iteratively propose and refine statistical models, but these systems struggle on more challenging modeling tasks. To address these limitations, we introduce VESTA: Visual Exploration with Statistical Tool Agents, a framework that equips VLMs with a dynamically growing exploration toolkit to guide model refinement through data transformations, hypothesis-driven visualizations, and robust statistical tests. Unlike prior systems that rely on iterative critique alone, VESTA actively explores data before and during refinement by selecting or creating diagnostic tools, which accumulate in the model's context and can be reused later. We evaluate VESTA against established baselines in three toolkit configurations: no tools, static expert-written tools, and dynamic model-written tools. To support this evaluation, we introduce DAWN (Dataset for Automated Workflows and Numerical Modeling), a benchmark targeting distribution fitting and time series modeling with varying difficulty tiers, and culminating in real-world astronomy tasks including modeling initial mass functions and gravitational-wave chirp signals. We find that VESTA's dynamic tool creation outperforms prior agentic pipelines, with the largest gains on complex and domain-specific tasks. We further show that dynamically generated tools are substantially more sophisticated than those produced by existing visual tool-creation systems, covering more diagnostic categories per function and strongly preferring visual outputs that the VLM critic can reason over directly.

cs.AI↗
arXiv2026

The Evolution of Star-Forming Gas in STARFORGE: From Clouds, to Cores, to Stars

Star formation occurs within dense regions of giant molecular clouds (GMCs), however, exactly how gas collects and evolves to form individual stars and what role dense cores play remains unclear. We use the Lagrangian cell information in the STARFORGE simulation suite to track star-forming gas in three GMCs with varying magnetic field strengths. We find that, once a protostar forms, the lifetime of the unaccreted gas correlates with the final stellar mass, where low-mass stars ($M_*$ < 0.5 M$_\odot$) accrete for 0.5-0.6 Myr from a relatively local reservoir of gas, and high-mass stars ($M_*$ > 2 M$_\odot$) accrete over 3.3-4.7 Myr from a much larger volume. Although the protostellar accretion time increases weakly with magnetic field strength, the accreting gas radii, velocity dispersions, virial parameters, and magnetic energy ratios are largely insensitive to the global cloud properties. At the time of protostar formation, the unaccreted gas exhibits linewidth-size and mass-size relations characteristic of turbulently regulated, isothermal dense cores, following $σ_v \propto R^{0.47-0.55}$ and $M \propto R^{1.0-1.1}$, respectively. Low- and intermediate-mass stars undergo relatively continuous accretion and their accretion histories are well-fit by either isothermal sphere, turbulent core, or competitive accretion models, where no one model fits all masses. However, many high-mass stars experience intermittent accretion and their accretion histories are not well-fit by any of these models. While the distribution of accreting gas is more extended than typically-defined dense cores, the physical properties and structure of the star-forming gas resemble those of observed cores and are largely regulated by turbulence and feedback.

astro-ph.GA↗
arXiv2026

Gauging the Impact of Cosmic Ray Feedback on the Stellar Initial Mass Function

Cosmic rays (CRs) drive ionization and influence gas dynamics in molecular clouds (MCs), potentially impacting the resulting star formation outcomes. Although previous simulations of individual star formation have included methods for cosmic ray transport (CRT), none have been large enough to resolve the stellar initial mass function (IMF). We conduct numerical simulations following the collapse of a $20000 M_{\odot}$ MC and the subsequent star formation including CRT, both with and without CRs accelerated by winds from the young massive stars, and compare against a non-CRT simulation. We show that after the first massive stars form, the cavity produced by feedback is more pronounced in the CRT simulations because the external CRs are able to propagate inwards and compress the gas into higher density structures. This increases the subsequent star formation in the cloud; by the end of the simulation, the SFE in the CRT simulation including stellar wind CRs is 43 \% higher than the non-CRT simulation. The IMF is also top heavy in comparison, with a slope above 1 $M_{\odot}$ that is shallower by $\sim 20$ \%. These effects are also present in the simulation without wind-accelerated CRs, but they are not as pronounced; the SFE is only 16 \% higher than the non-CRT simulation, and the IMF high-mass slope is shallower by $\sim 10$ \%. These results may explain some of the observed top-heavy IMFs, which typically occur in high-CR environments such as the galactic center.

astro-ph.HE↗
arXiv2026

Investigating the Gamma-Ray Emission from Explosive Dispersal Outflows with Fermi-LAT

We present the first systematic study of explosive dispersal outflows (EDOs) as potential sources of high-energy emission in the Milky Way. EDOs are energetic outflows produced during dynamical interactions in young, massive star-forming regions, and their physical conditions make them promising environments for cosmic-ray acceleration. Using 16 years of $0.2$--$500$ GeV Fermi-LAT observations, we study the gamma-ray properties of seven EDOs. Three EDOs, DR21, G34.26$+$0.15, and G5.89$-$0.39 show spatially coincident GeV emission, while the remaining systems yield non-detections. Among the sample, DR21 stands out as the brightest candidate, with a detection significance $\geq 40σ$. Its spectrum is well described by a power law with an exponential cutoff, and the integrated luminosity in the $0.1$--$500$ GeV band is $L_γ\simeq 2\times10^{35}\ \mathrm{erg\ s^{-1}}$. When compared with the outflow's estimated kinetic energy, the inferred cosmic-ray acceleration efficiency is $\leq 15\%$, consistent with values for shocks in dense molecular environments. The energetics and morphology support an association between the DR21 molecular outflow and the observed gamma rays. Our results demonstrate that EDOs span a wide range of gamma-ray luminosities and efficiencies, suggesting they may contribute to the Galactic cosmic ray budget. This motivates searches for additional EDOs and improved multiwavelength characterization of their environments.

astro-ph.HE↗
arXiv2026

Digging into the Interior of Hot Cores with ALMA (DIHCA). VI. The Formation of Low-mass Multiple Systems in High-mass Cluster-forming Regions

Most stars form in multiple systems, with profound implications in numerous astronomical phenomena intrinsically linked to multiplicity. However, our knowledge about the process on how multiple stellar systems form is incomplete and biased toward nearby molecular clouds forming only low-mass stars, which are unrepresentative of the stellar population in the Galaxy. Most stars form within dense cores in clusters alongside high-mass stars (>8 M$_{\odot}$), as likely the Sun did. Here we report deep ALMA 1.33 mm dust continuum observations at ~160 au spatial resolution, revealing 72 low-mass multiple systems embedded in 23 high-mass cluster-forming regions, as part of the Digging into the Interior of Hot Cores with ALMA (DIHCA) survey. We find that the companion separation distribution presents a distinct peak at ~1200 au, in contrast to the one at ~4000 au observed in nearby low-mass regions. The shorter fragmentation scale can be explained by considering the higher pressure exerted by the surrounding medium, which is higher than the one in low-mass regions, due to the larger turbulence and densities involved. Because the peak of the companion separation distribution occurs at much larger scales than the expected disk sizes, we argue that the observed fragmentation is produced by turbulent core fragmentation. Contrary as predicted, the multiplicity fraction remains constant as the stellar density increases. We propose that in the extremely dense environments where high-mass stars form, dynamical interactions play an important role in disrupting weakly bound systems.

astro-ph.GA↗
arXiv2026

The Timescales of Embedded Star Formation as Observed in STARFORGE

Star formation occurs within dusty molecular clouds that are then disrupted by stellar feedback. However, the timing and physical mechanisms that govern the transition from deeply embedded to exposed stars remain uncertain. Using the STARFORGE simulations, we analyze the evolution of ``embeddedness'', identifying what drives emergence. We find the transition from embedded to exposed is fast for individual stars, within 1.3 Myr after the star reaches its maximum mass. This rapid transition is dominated by massive stars, which accrete while remaining highly obscured until their feedback eventually balances, then overcomes, the local accretion. For these massive stars, their maximum mass is reached simultaneously with their emergence. Once these stars are revealed, their localized, pre-supernova feedback then impacts the cloud, driving gas clearance. Because massive stars dominate the luminosity, their fast, local evolution dominates the light emergence from the dust. We calculate the dependence of these processes on the mass of the cloud and find that emergence always depends on when massive stars form, which scales with the cloud's free-fall time. We also measure the evolution of dust and H$α$ luminosities, where for $\sim$2 Myr, these tracers outshine the emerging stellar continuum, reaching their peak when gas and dust remain tightly coupled to the massive stars. These results closely resemble observationally observed lifetimes, tying the observable dust and line emission directly to the same localized processes that drive stellar emergence, evidence that our simulated de-embedding physics is representative of real star-forming regions. Thus, because the initial embedding of the most luminous stars is highly local, the emergence of stars is a faster, earlier, more local event than the overall disruption of the cloud by gas expulsion.

astro-ph.SR↗
arXiv2025

Further correction to the STARFORGE methods paper: Planck-mean dust opacities

The model for the Planck-mean dust opacity $κ_{P}$ given in Appendix C of the STARFORGE simulations methods paper does not extrapolate well to low radiation temperature $T_{\rm rad}$, so we provide an updated calculation suitable for general use. We also clarify the role of the dust and radiation temperatures in setting the dust opacity, and provide code and calculations of the Planck- and Rosseland- mean dust opacity as a function of both the dust temperature $T_{\rm d}$ and the radiation temperature $T_{\rm rad}$.

astro-ph.GA↗
arXiv2025

AstroVisBench: A Code Benchmark for Scientific Computing and Visualization in Astronomy

Large Language Models (LLMs) are being explored for applications in scientific research, including their capabilities to synthesize literature, answer research questions, generate research ideas, and even conduct computational experiments. Ultimately, our goal is for these to help scientists derive novel scientific insights. In many areas of science, such insights often arise from processing and visualizing data to understand its patterns. However, evaluating whether an LLM-mediated scientific workflow produces outputs conveying the correct scientific insights is challenging to evaluate and has not been addressed in past work. We introduce AstroVisBench, the first benchmark for both scientific computing and visualization in the astronomy domain. AstroVisBench judges a language model's ability to both (1) create astronomy-specific workflows to process and analyze data and (2) visualize the results of these workflows through complex plots. Our evaluation of visualizations uses a novel LLM-as-a-judge workflow, which is validated against annotation by five professional astronomers. Using AstroVisBench we present an evaluation of state-of-the-art language models, showing a significant gap in their ability to engage in astronomy research as useful assistants. This evaluation provides a strong end-to-end evaluation for AI scientists that offers a path forward for the development of visualization-based workflows, which are central to a broad range of domains from physics to biology.

cs.CL↗
arXiv2025

The Green Bank Ammonia Survey: Data Release 2

We present an overview of the final data release (DR2) from the Green Bank Ammonia Survey (GAS). GAS is a Large Program at the Green Bank Telescope to map all Gould Belt star-forming regions with $A_\mathrm{V} \gtrsim 7$~mag visible from the northern hemisphere in emission from NH$_3$ and other key molecular tracers. This final release includes the data for all the regions observed: Heiles Cloud 2 and B18 in Taurus; Barnard 1, Barnard 1-E, IC348, NGC 1333, L1448, L1451, and Per7/34 in Perseus; L1688 and L1689 in Ophiuchus; Orion A (North and South) and Orion B in Orion; Cepheus, B59 in Pipe; Corona Australis (CrA) East and West; IC5146; and Serpens Aquila and MWC297 in Serpens. Similar to what was presented in GAS DR1, we find that the NH$_3$ emission and dust continuum emission from Herschel correspond closely. We find that the NH$_3$ emission is generally extended beyond the typical 0.1 pc length scales of dense cores, and we find that the transition between coherent core and turbulent cloud is a common result. This shows that the regions of coherence are common throughout different star forming regions, with a substantial fraction of the high column density regions displaying subsonic non-thermal velocity dispersions. We produce maps of the gas kinematics, temperature, and NH$_3$ column densities through forward modeling of the hyperfine structure of the NH$_3$ (1,1) and (2,2) lines. We show that the NH$_3$ velocity dispersion, $σ_v$, and gas kinetic temperature, $T_{\rm kin}$, vary systematically between the regions included in this release, with an increase in both the mean value and spread of $σ_v$ and $T_{\rm kin}$ with increasing star formation activity. The data presented in this paper are publicly available via \dataset[DOI: 10.11570/24.0091]{https://doi.org/10.11570/24.0091}.

astro-ph.GA↗
arXiv2025

Detection of a septuple stellar system in formation via disk fragmentation

Stellar multiple systems play a pivotal role in cluster dynamics and stellar evolution, leading to intense astronomical phenomena like X-ray binaries, gamma-ray bursts, Type Ia supernova, and stellar mergers, which are prime sources of gravitational waves. However, their origin remains poorly understood. Here we report the discovery of a septuple protostellar system embedded in a Keplerian disk within the high-mass star-forming region NGC\,6334IN, with close separations of 181-461 AU. The stability analysis reveals that the disk surrounding the septuple system is dynamically unstable, indicating that the septuple system formed via disk fragmentation. Previous studies have typically found only 2--3 members forming via disk fragmentation in both low- and high-mass star-forming regions. Our findings provide compelling observational evidence that the fragmentation of a gravitationally unstable disk is a viable mechanism for the formation of extreme high-order multiplicity, confirming what was previously only a theoretical concept. The results shed new light on the formation of extreme high-order multiplicity in cluster environments.

astro-ph.GA↗
arXiv2025

Modeling turbulent and self-gravitating fluids with Fourier neural operators

Neural Operators (NOs) are a leading method for surrogate modeling of partial differential equations. Unlike traditional neural networks, which approximate individual functions, NOs learn the mappings between function spaces. While NOs have been predominantly tested on simplified 1D and 2D problems, such as those explored in prior works, these studies fail to address the complexities of more realistic, high-dimensional, and high-dynamic range systems. Moreover, many real-world applications involve incomplete or noisy data, which has not been adequately explored in current NO literature. In this work, we present a novel application of NOs to astrophysical data, which involves high-dynamic range projections into an observational space. We train Fourier NO (FNO) models to predict the evolution of incomplete observational proxies with density variations spanning four orders of magnitude. We demonstrate that FNOs can predict the effects of unobserved dynamical variables. Our work lays the groundwork for future studies that forecast direct astronomical observables.

astro-ph.GA↗
arXiv2025

CAMPOS II. The onset of protostellar disk substructures and planet formation

The 1.3 mm CAMPOS survey has resolved 90 protostellar disks with ~15 au resolution across the Ophiuchus, Corona Australis, and Chamaeleon star-forming regions. To address the fundamental question, `When does planet formation begin?', we combined the CAMPOS sample with literature observations of Class 0-II disks (bolometric temperature, $T_{bol} \le 1900 K$). To investigate substructure detection rates as a function of $T_{bol}$, we restricted the sample to disks observed at the 1.3 mm wavelength, with inclinations below 75$^\circ$, linear resolution $\le 20$ au and resolved with at least 4 resolution elements ($θ_{disk}/θ_{res} \ge 4$). We also considered the effects of extinction correction and the inclusion of Herschel Space Telescope data on the $T_{bol}$ measurements to constrain the lower and upper limits of $T_{bol}$ for each source. We find that by $T_{bol}$ ~200-400 K, substructure detection rates increased sharply to ~60%, corresponding to an age of ~0.2-0.4 Myr. No substructures are detected in Class 0 disks. The ratio of disk-averaged brightness temperature to predicted dust temperature shows a trend of increasing values toward the youngest Class 0 disks, suggesting higher optical depths in these early stages. Our statistical analysis confirms that substructures similar to those in Class II disks are already common by the Class I stage, and the emergence of structures at early Class I could represent only an upper limit. Classifying disks with substructures into those with and without large central cavities, we find both populations coexisting across evolutionary stages, suggesting they are not necessarily evolutionarily linked. If protostellar disk substructures do follow an evolutionary sequence, then our results imply that disk substructures evolve very rapidly and thus can be present in all Class I/II stages and/or that they can be triggered at different times.

astro-ph.EP↗
arXiv2025

Stellar populations in STARFORGE II: Comparison with observations

Recent studies suggest that most star-forming regions in our Galaxy form stellar associations rather than bound clusters. We analyse models from the STARFORGE simulation suite, a set of magneto-hydrodynamical simulations that include all key stellar feedback and radiative processes following star formation through cloud dispersal. We create synthetic observations by introducing observational biases such as random spurious measurements, unresolved binaries, and photometric sensitivity. These biases affect the measurement of the group mass, size, and velocity dispersion, introducing uncertainties of up to 100%, with accuracy improving as the number of system members increases. Furthermore, models favouring the formation of groups around massive stars were the most affected by observational biases, as massive stars contribute a larger fraction of the group mass and are often missing from astrometric surveys like Gaia. We compare the simulations to the Cepheus Far North (CFN) region, and show that CFN groups may have formed in a low-density environment similar to those modelled in STARFORGE but with massive stars not located preferentially in groups. We also question the effectiveness of the kinematic traceback method, showing that it is accurate within 20% only for certain associations with actual virial parameters above 2. However, observational biases can artificially raise the virial parameter by up to a factor ten, making it difficult to evaluate the reliability of the traceback age. Additionally, since stars continue to form during the dispersal of the parent cloud, we find no relation between the stellar-dynamical age difference and the length of the embedded phase.

astro-ph.GA↗