John Dyson made outstanding research contributions over many years to ourunderstanding of the responses of interstellar media to winds from stars andfrom active galaxies. He had a huge influence on these subjects and his workgained an international reputation. Much of his career was at the University ofManchester where he became Professor of Astronomy and Head of Astrophysics.He moved in 1996 to the University of Leeds, becoming Dean of Research, andwas appointed Emeritus Research Professor in 2006.He died in 2010 and is much missed by friends and colleagues world-widewho valued his scientific insight, quick wit, kindness and generosity.David Williams is currently Emeritus Perren Professor of Astronomy at UniversityCollege London. While at NASA’s Goddard Space Flight Center in the 1960s hebecame interested in interstellar molecules and interstellar dust as potentialprobes of the interstellar medium. When John Dyson and David were bothworking in Manchester, John emphasised the importance of cosmic gas dynamicsin understanding interstellar chemistry and dust, and David built a researchgroup at UMIST to investigate these and other topics. He left Manchester in1994 for UCL and has continued to study problems in interstellar physics andchemistry.

• ContentsPreface to the Third Edition ............................................................................viiSome Relevant Physical and Astronomical Information...................................ixAuthors.............................................................................................................xiChapter 1 Introduction..................................................................................... 1Chapter 2 How We Obtain Information about the Interstellar Medium........... 9Chapter 3 Microscopic Processes in the Interstellar Medium ......................... 31Chapter 4 Interstellar Grains.......................................................................... 51Chapter 5 Radiatively Excited Regions........................................................... 79Chapter 6 Introduction to Gas Dynamics .................................................... 103Chapter 7 Gas Dynamical Effects of Stars on the Interstellar Medium........ 135Chapter 8 Star Formation and Star-Forming Regions.................................. 169Answers to Problems ...................................................................................... 187Index.............................................................................................................. 191

John Dyson made outstanding research contributions over many years to ourunderstanding of the responses of interstellar media to winds from stars andfrom active galaxies. He had a huge influence on these subjects and his workgained an international reputation. Much of his career was at the University ofManchester where he became Professor of Astronomy and Head of Astrophysics.He moved in 1996 to the University of Leeds, becoming Dean of Research, andwas appointed Emeritus Research Professor in 2006.He died in 2010 and is much missed by friends and colleagues world-widewho valued his scientific insight, quick wit, kindness and generosity.David Williams is currently Emeritus Perren Professor of Astronomy at UniversityCollege London. While at NASA’s Goddard Space Flight Center in the 1960s hebecame interested in interstellar molecules and interstellar dust as potentialprobes of the interstellar medium. When John Dyson and David were bothworking in Manchester, John emphasised the importance of cosmic gas dynamicsin understanding interstellar chemistry and dust, and David built a researchgroup at UMIST to investigate these and other topics. He left Manchester in1994 for UCL and has continued to study problems in interstellar physics andchemistry.

• ContentsPreface to the Third Edition ............................................................................viiSome Relevant Physical and Astronomical Information...................................ixAuthors.............................................................................................................xiChapter 1 Introduction..................................................................................... 1Chapter 2 How We Obtain Information about the Interstellar Medium........... 9Chapter 3 Microscopic Processes in the Interstellar Medium ......................... 31Chapter 4 Interstellar Grains.......................................................................... 51Chapter 5 Radiatively Excited Regions........................................................... 79Chapter 6 Introduction to Gas Dynamics .................................................... 103Chapter 7 Gas Dynamical Effects of Stars on the Interstellar Medium........ 135Chapter 8 Star Formation and Star-Forming Regions.................................. 169Answers to Problems ...................................................................................... 187Index.............................................................................................................. 191

John Dyson made outstanding research contributions over many years to ourunderstanding of the responses of interstellar media to winds from stars andfrom active galaxies. He had a huge influence on these subjects and his workgained an international reputation. Much of his career was at the University ofManchester where he became Professor of Astronomy and Head of Astrophysics.He moved in 1996 to the University of Leeds, becoming Dean of Research, andwas appointed Emeritus Research Professor in 2006.He died in 2010 and is much missed by friends and colleagues world-widewho valued his scientific insight, quick wit, kindness and generosity.David Williams is currently Emeritus Perren Professor of Astronomy at UniversityCollege London. While at NASA’s Goddard Space Flight Center in the 1960s hebecame interested in interstellar molecules and interstellar dust as potentialprobes of the interstellar medium. When John Dyson and David were bothworking in Manchester, John emphasised the importance of cosmic gas dynamicsin understanding interstellar chemistry and dust, and David built a researchgroup at UMIST to investigate these and other topics. He left Manchester in1994 for UCL and has continued to study problems in interstellar physics andchemistry.

• ContentsPreface to the Third Edition ............................................................................viiSome Relevant Physical and Astronomical Information...................................ixAuthors.............................................................................................................xiChapter 1 Introduction..................................................................................... 1Chapter 2 How We Obtain Information about the Interstellar Medium........... 9Chapter 3 Microscopic Processes in the Interstellar Medium ......................... 31Chapter 4 Interstellar Grains.......................................................................... 51Chapter 5 Radiatively Excited Regions........................................................... 79Chapter 6 Introduction to Gas Dynamics .................................................... 103Chapter 7 Gas Dynamical Effects of Stars on the Interstellar Medium........ 135Chapter 8 Star Formation and Star-Forming Regions.................................. 169Answers to Problems ...................................................................................... 187Index.............................................................................................................. 191