相关论文: Resolving the Luminosity Problem in Low-Mass Star …

Motivated by recent observations which detect an outer boundary for starless cores, and evidence for time-dependent mass accretion in the Class 0 and Class I protostellar phases, we reexamine the case of spherical isothermal collapse in the…

A model for massive stars is constructed by piecing together evolutionary algorithms for the protostellar structure, the environment, the inflow and the radiation feedback. We investigate specified accretion histories of constant,…

We present an analysis of the temperature, density, and velocity of the molecular gas in the star-forming core around W51 e2. A previous paper (Ho and Young 1996) describes the kinematic evidence which implies that the core around e2 is…

The mass of a protostar is calculated from the infall and dispersal of an isothermal sphere in a uniform background. For high contrast between peak and background densities and for short dispersal time t_d, the accretion is "self-limiting":…

Molecular clouds are observed to be turbulent, but the origin of this turbulence is not well understood. As a result, there are two different approaches to simulating molecular clouds, one in which the turbulence is allowed to decay after…

Studies of the evolution of massive protostars and the evolution of their host molecular cloud cores are commonly treated as separate problems. However, interdependencies between the two can be significant. Here, we study the simultaneous…

We propose a new analytic model for the initial conditions of protostellar collapse in relatively isolated regions of star formation. The model is non-magnetic, and is based on a Plummer-like radial density profile as its initial condition.…

The bright maser emission produced by several molecular species at centimeter to long millimeter wavelengths provides an essential tool for understanding the process of massive star formation. Unimpeded by the high dust optical depths that…

We present a unified model for molecular core formation and evolution, based on numerical simulations of converging, supersonic flows. Our model applies to star formation in GMCs dominated by large-scale turbulence, and contains four main…

The process of mass accretion onto Young Stellar Objects (YSOs) plays a fundamental role in determining the final stellar mass and setting the initial conditions for planet formation. Despite its critical role, our understanding of…

We discuss problems with some observational estimates indicating long protostellar core lifetimes and large stellar age spreads in molecular clouds. We also point out some additional observational constraints which suggest that protostellar…

Improving our understanding of the initial conditions and earliest stages of star formation is crucial to gain insight into the origin of stellar masses, multiple systems, and protoplanetary disks. We review the properties of low-mass dense…

Star formation generally proceeds inside-out, with overdense regions inside protostellar cores collapsing rapidly and progressively less dense regions following later. Consequently, a small protostar will form early in the evolution of a…

The evolution of star-forming core analogues undergoing inside-out collapse is studied with a multi-point chemodynamical model which self-consistently computes the abundance distribution of chemical species in the core. For several collapse…

We perform calculations of our one-dimensional, two-zone disk model to study the long-term evolution of the circumstellar disk. In particular, we adopt published photoevaporation prescriptions and examine whether the photoevaporative loss…

Following our recent work devoted to the effect of accretion on the pre-main-sequence evolution of low-mass stars, we perform a detailed analysis of episodic excursions of low-mass protostars in the Hertzsprung-Russell (H-R) diagram…

As an initial investigation into the long-term evolution of protostellar disks, we explore the conditions required to explain the large outbursts of disk accretion seen in some young stellar objects. We use one-dimensional time-dependent…

In this Letter we present a theoretical scenario to explain the steep correlation between disk accretion rates and stellar masses observed in pre-main sequence stars. We show that the correlations and spread observed in the two best studied…

The proliferation of high time-resolution and decades-long monitoring of classical T Tauri stars provides a vast opportunity to test the variability of the star-disk connections. However, most monitoring surveys use single broad-band…

We present measurements of the mean dense core lifetimes in numerical simulations of magnetically supercritical, turbulent, isothermal molecular clouds, in order to compare with observational determinations. "Prestellar" lifetimes (given as…