Physics of accretion onto young stars III. Comparisons with observations
نویسندگان
چکیده
We present new evolutionary sequences for long lasting accreting low-mass (0.1 M ≤ M ≤ 2.5M ) pre-main sequence stars. The calculations, performed for two different mass accretion rates, show that accretion accelerates the evolution of the star. The star has a smaller radius and goes down its convective track faster than in a standard scheme. Consequently, the age of a star, as given by its location on the HertzsprungRussell diagram, is lower than that of a non-accreting star. We discuss 2H and 7Li burning and show how accretion affects the surface abundance of these elements. Notably, we point out that deuterium must be present at the surface of accreting intermediate-mass stars. Finally, we estimate the age, mass and radius of a sample of T Tauri stars located in the Taurus Auriga star forming region.
منابع مشابه
Effect of the temperature profile of the accretion disk on the structure of jets and outflows around protostars
Magnetic fields play an important role in creating, driving, and in the evolution of outflows and jets from protostars and accretion disks. On the other hand, the temperature profile of the accretion disks may also affect the structure of the magnetic field and outflows. In this paper, we use the self-similar method in cylindrical coordinates to investigate the effect of the temperature profile...
متن کاملBondi-Hoyle Accretion in Dense Star Clusters: Implications for Stars, Disks, and Planets Draft version: May 22, 2007
We investigate the Bondi-Hoyle accretion of gas from a GMC onto young stardisk systems in a cluster. This post-formation accretionary phase can continue for several Myr after young stars are born, until the gas is heated by massive stars and removed from the cluster, or when low-mass stars are ejected from the cluster. We perform N-body simulations of stars orbiting in young model clusters usin...
متن کامل2 00 8 ‘ Tail - end ’ Bondi - Hoyle Accretion in Young Star Clusters : Implications for Disks , Planets , and Stars Submitted to AJ , 7 - Nov - 2007
Young stars orbiting in the gravitational potential well of forming star clusters pass through the cluster’s dense molecular gas and can experience Bondi-Hoyle accretion from reservoirs outside their individual protostellar cloud cores. Accretion can occur for several million years after the stars form, but before the cluster disperses. This accretion is predominantly onto the disk and not the ...
متن کاملA simple model for accretion disks in the post-Newtonian approximation
p { margin-bottom: 0.1in; direction: ltr; line-height: 120%; text-align: left; }a:link { } In this paper, the evolution of accretion disks in the post-Newtonian limit has been investigated. These disks are formed around gravitational compact objects such as black holes, neutron stars, or white dwarfs. Although most analytical researches have been conducted in this context in the framework o...
متن کاملA Simplified Solution for Advection Dominated Accretion Flows with Outflow
The existence of outflow in the advection dominated accretion flows has been confirmed by both numerical simulations and observations. The outow models for ADAF have been investigated by several groups with a simple self similar solution. But this solution is inaccurate at the inner regions and can not explain the emitted spectrum of the flow; so, it is necessary to obtain a global solution for...
متن کامل