Printer Friendly

An Introduction to Star Formation.

An introduction to star formation

By Derek Ward-Thompson and Anthony P. Whitworth

Published by Cambridge University Press, 2011

Hardcover: pp xx + 208xiv, 81 b/w illustrations

ISBN 978-0-521-63030-6

Size: 247 x 174 mm

Mass: 0.6 kg

Price: R600.00 (incl. VAT and postage), available from Cambridge University Press, South Africa, email: cambridge@cup.co.za, postal address: PO Box 50017, Victoria and Alfred Waterfront, Cape Town 8002, South Africa

[ILLUSTRATION OMITTED]

The success of the recent Spitzer and Herschel satellites in extending sensitive observations to the medium-and long-wavelength regions of the infrared has led to many new observations of star-forming regions. Coupling these with the high-resolution millimeter-wave mapping to be expected from the ALMA array telescope in Chile, the field is bound to experience explosive growth in the near future. This book by Ward-Thompson and Whitworth has thus appeared at a very opportune moment.

An Introduction to Star Formation is aimed at the advanced undergraduate or beginning graduate student. The introductory chapter lists some of the aims of research in this area. There are still many unanswered questions. Though star formation takes place in molecular clouds, the minimum requirements for it to occur at all are not completely clear and the efficiency of the processes in converting the available matter into stars is still a matter for investigation. Though the Initial Mass Function (the mass distribution) of stars shows a lot of uniformity from one location to another, the reason why this should be so is not understood. Stars in binary systems constitute the majority of all those formed and theory is also lacking in this area. Then there are the questions around planetary formation, such as what their mass distributions are likely to be.

On a macroscopic scale, interacting galaxies often support extremely high star formation rates, leading to starbursts. Also, a good deal of time on large telescopes is devoted to observing how the rate of star formation has evolved since the early stages of the universe.

A good deal of the book recapitulates the basic physics behind the processes at work--line and continuum radiation mechanisms, the 21-cm line etc. The conditions within molecular clouds--molecular and line radiation, dust content and composition, cooling processes, magnetic fields, fractal structure, turbulence, are all covered. The conditions leading to collapse and the theoretical models of this are gone into, not neglecting the fact that the idealised uniform spherical clouds the models often deal with do not really exist in nature.

The actual formation of protostars and their observational characteristics are covered in Chapter 6. The contraction towards dense cores, which must get rid of their increasing thermal energy through molecular line radiation, is treated, discussing also how development appears on a Hertzsprung-Russell diagram (in the case of low-mass stars)-e.g., the Hayashi and Henyey tracks which are followed before long-term evolution commences along the Main Sequence. The far-infrared is the region where the warming cores are first detected. Further evolution leads to outflows, detectable in molecular line profiles. Jets, believed to be involved in dissipating angular momentum, are often detected and finally the nuclear processes start, leading to T-Tauri and other visible pre-main-sequence stars. Massive stars, on the other hand, form somewhat differently. OB stars are associated with HII regions and, though not mentioned much in this book, PAH (polycyclic aromatic hydrocarbons) emissions. Some of the theory of HII regions and emission measures is incidentally presented here. The definition of column density might usefully have appeared in the index.

I found this book to be a useful compendium of the rather wide-ranging basic theories required to form an understanding of star formation, a subject that sill has many poorly understood areas and that will undoubtedly attract future generations of astrophysicists.

Contents

1 Introduction

2 Probing Star Formation

3 The ISM--the beginnings of star formation

4 Molecular clouds--the sites of star formation

5 Fragmentation and Collapse--the road to star formation

6 Young stars, protostars and accretion--building a typical star

7 The formation of high-mass-stars, and their surroundings

8 By-products and consequences of star formation
COPYRIGHT 2011 Astronomical Society of Southern Africa
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2011 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Author:Glass, Ian
Publication:Monthly Notes of the Astronomical Society of Southern Africa
Article Type:Book review
Date:Aug 1, 2011
Words:674
Previous Article:A Question and Answer Guide to Astronomy.
Next Article:Ophiuchus, the Herb Healer.
Topics:

Terms of use | Copyright © 2018 Farlex, Inc. | Feedback | For webmasters