Dust-Gas Instabilities in Protoplanetary Disks: Toward Understanding Planetesimal Formation

This book explores the formation of planetesimals, kilometer-sized bodies that precede planets, through disk instabilities. It addresses how instabilities evolve and presents a new instability driven by dust coagulation. The simulation demonstrates a scenario of planetesimal formation in dusty rings.

Format: Paperback / softback
Length: 116 pages
Publication date: 27 April 2023
Publisher: Springer Verlag, Singapore

The formation of planets is a longstanding and complex topic in astrophysics, particularly when it comes to planetesimals, which are kilometer-sized bodies that are believed to be the precursors of planets. Despite the existence of some promising mechanisms, the exact formation scenarios of planetesimals remain unclear and are subject to ongoing debate. In this book, we focus on disk instabilities, which are believed to play a crucial role in the formation of planetesimals. By employing linear analyses and numerical simulations, we explore how a disk evolves through the development of instabilities and introduce a new instability driven by dust coagulation. Through these simulations, we demonstrate a scenario of planetesimal formation: a sequential progression of multiple instabilities leads to the formation of dusty rings, which eventually give rise to planetesimals.

Disk instabilities are crucial in understanding the formation of planetesimals, as they can provide the necessary conditions for their growth and aggregation. One of the key instabilities that we investigate in this book is the spiral instability, which is driven by the gravitational attraction between particles in a disk. We show that this instability can lead to the formation of clumps, which can eventually merge to form larger bodies known as planetesimals.

In addition to the spiral instability, we introduce a new instability driven by dust coagulation. Dust particles in a disk can collide and stick together, forming larger aggregates known as dust grains. We show that the growth of these dust grains can be enhanced by the presence of gas in the disk, leading to the formation of dust rings. These dust rings can then collapse and form planetesimals, providing a new mechanism for the formation of planets.

Our simulations demonstrate that the formation of planetesimals can be influenced by a variety of factors, including the disk's temperature, density, and the presence of other bodies such as stars and planets. By understanding these factors, we can better predict the formation of planetesimals and the subsequent evolution of planetary systems.

In conclusion, this book provides a comprehensive exploration of disk instabilities and their role in the formation of planetesimals. By employing linear analyses and numerical simulations, we demonstrate a scenario of planetesimal formation that is driven by the sequential development of multiple instabilities. This work contributes to our understanding of the complex processes involved in planet formation and has implications for the search for exoplanets and the study of planetary systems.

Weight: 209g
Dimension: 235 x 155 (mm)
ISBN-13: 9789811917677
Edition number: 1st ed. 2022