The Earliest Stages of Massive Clustered Star Formation: Fragmentation of Infrared Dark Clouds

The Earliest Stages of Massive Clustered Star Formation: Fragmentation of Infrared Dark Clouds
Author: Ke Wang
Publisher: Springer
Total Pages: 160
Release: 2014-11-03
Genre: Science
ISBN: 3662449692

This thesis presents an in-depth, high-resolution observational study on the very beginning of the formation process: the fragmentation of dense molecular clouds known as infrared dark clouds (IRDCs). Using the Submillimeter Array (SMA) and Very Large Array (VLA) radio interferometers, the author has discovered a common picture of hierarchical fragmentation that challenges some of the leading theoretical models and suggests a new, observation-driven understanding of how massive star formation in clustered environments may begin: it is initiated by the hierarchical fragmentation of a dense filament from 10 pc down to 0.01 pc, and the stellar mass buildup is simultaneously fed by hierarchical accretion at similar scales. The new scenario points out the importance of turbulence and filamentary structure, which are now receiving increasing attention and further tests from both observers and theorists.

The First Stars

The First Stars
Author: Volker Bromm
Publisher: Springer
Total Pages: 240
Release: 2016-09-07
Genre: Science
ISBN: 9783642119644

The formation of the first stars (Pop III stars) and galaxies is one of the great outstanding challenges in modern astrophysics and cosmology. The first stars are likely key drivers for early cosmic evolution and will be at the center of attention over the next decade. The best available space and ground-based telescopes like the Hubble Space Telescope probe the Universe to high redshifts and provide us with tantalizing hints; but they cannot yet directly detect the first generation of stars and the formation of the first galaxies. This is left as key science for future telecopes like the James Webb Space Telescope. This book is based in part on classroom tested lectures related to Pop III stars, but also draws from the author's review articles of the main physical principles involved. The book will thus combine pedagogical introductory chapters with more advanced ones to survey the cutting-edge advances from the frontier of research. It covers the theory of first star formation, the relation between first stars and dark matter, their impact on cosmology, their observational signatures, the transition to normal star formation as well as the assembly of the first galaxies. It will prepare students for interpreting observational findings and their cosmological implications.

Star Clusters and How to Observe Them

Star Clusters and How to Observe Them
Author: Mark Allison
Publisher: Springer Science & Business Media
Total Pages: 218
Release: 2006-04-04
Genre: Science
ISBN: 1846281989

Astronomy enthusiasts will all appreciate the detailed yet easily-assimilated description of star clusters, how they were formed as our Milky Way galaxy, how they evolved, and how they are classified. The latest research has revealed a vast amount of fascinating information about the clusters, along with some spectacular photographs. Modern commercially-made telescopes enable amateur astronomers to see a surprising amount of detail, and to record – using CCD cameras, video, webcams or even film – some remarkably beautiful and detailed images. Contained here also is detailed information on using refractors, reflectors, and, of course, Meade and Celestron’s ubiquitous range of computer-controlled SCT telescopes.

Dynamical Evolution of Star Clusters - Confrontation of Theory and Observations

Dynamical Evolution of Star Clusters - Confrontation of Theory and Observations
Author: Piet Hut
Publisher: Springer
Total Pages: 0
Release: 1996-06-30
Genre: Science
ISBN: 9780792340706

This volume reviews recent progress in the study of dynamics of star clusters. The meeting focused on the enormous progress of both the observation and the theoretical modeling of star clusters. New results from the refurbished Hubble Space Telescope (HST) include the mass function down to the hydrogen burning limits, white dwarf sequence, and central density profiles of `post-collapse' clusters by star counts. On the theoretical side, this symposium saw the first direct evidence of gravothermal oscillation through N-body simulation, which was made possible by GRAPE-4, the dedicated special-purpose computer for N-body simulation. Numerical techniques to combine stellar evolution and dynamical evolution of the cluster were presented. The book will be of primary interest to astrophysicists.

Open Issues in Local Star Formation

Open Issues in Local Star Formation
Author: Jacques Lépine
Publisher: Springer Science & Business Media
Total Pages: 406
Release: 2006-04-18
Genre: Science
ISBN: 1402026005

The international colloquium Open Issues in Local Star Formation and Early Stellar Evolution was focused on: the physics of young stellar objects, which are observed with increasing angular resolution by the new generation of telescopes; and the processes that triggered large scale star formation in the solar neighbourhood. The scientific presentations were not limited to these two main topics as many new and interesting results related to star formation have been obtained.; The participants presented new findings in the fields of stellar groups and associations; young stellar objects; disks; outflows and jets; the ISM conditions for star formation; and early stages of star formation. The discussions on open issues, representing problems and unanswered questions, should make this book particularly useful for researchers and PhD students.

The Birth of Star Clusters

The Birth of Star Clusters
Author: Steven Stahler
Publisher: Springer
Total Pages: 205
Release: 2017-11-04
Genre: Science
ISBN: 3319228013

All stars are born in groups. The origin of these groups has long been a key question in astronomy, one that interests researchers in star formation, the interstellar medium, and cosmology. This volume summarizes current progress in the field, and includes contributions from both theorists and observers. Star clusters appear with a wide range of properties, and are born in a variety of physical conditions. Yet the key question remains: How do diffuse clouds of gas condense into the collections of luminous objects we call stars? This book will benefit graduate students, newcomers to the field, and also experienced scientists seeking a convenient reference.

Dynamics of Young Star Clusters and Associations

Dynamics of Young Star Clusters and Associations
Author: Cathie Clarke
Publisher: Springer
Total Pages: 356
Release: 2015-09-11
Genre: Science
ISBN: 3662472902

Where do most stars (and the planetary systems that surround them) in the Milky Way form? What determines whether a young star cluster remains bound (such as an open or globular cluster), or disperses to join the field stars in the disc of the Galaxy? These questions not only impact understanding of the origins of stars and planetary systems like our own (and the potential for life to emerge that they represent), but also galaxy formation and evolution, and ultimately the story of star formation over cosmic time in the Universe. This volume will help readers understand our current views concerning the answers to these questions as well as frame new questions that will be answered by the European Space Agency's Gaia satellite that was launched in late 2013. The book contains the elaborated notes of lectures given at the 42nd Saas-Fee Advanced Course “Dynamics of Young Star Clusters & Associations" by Cathie Clarke (University of Cambridge) who presents the theory of star formation and dynamical evolution of stellar systems, Robert Mathieu (University of Wisconsin) who discusses the kinematics of star clusters and associations, and I. Neill Reid (S pace Telescope Science Institute) who provides an overview of the stellar populations in the Milky Way and speculates on from whence came the Sun. As part of the Saas-Fee Advanced Course Series, the book offers an in-depth introduction to the field serving as a starting point for Ph.D. research and as a reference work for professional astrophysicists.

The Initial Conditions of Clustered Star Formation: an Observational Study of Dense Gas in the Ophiuchus Molecular Cloud

The Initial Conditions of Clustered Star Formation: an Observational Study of Dense Gas in the Ophiuchus Molecular Cloud
Author:
Publisher:
Total Pages:
Release: 2005
Genre:
ISBN:

In this dissertation I present a detailed survey of molecular line emission (including NH3, C2S, HC5N, N2H+, N2D+ and H2D+) towards clustered star forming Cores in the nearby Ophiuchus molecular cloud, with the aim of characterizing the distribution and kinematics of the dense gas within a clustered star forming environment and compare these results with those found in more isolated star forming regions. I show that the dense Oph Cores present characteristics of both isolated and clustered star forming regions in several key parameters, including Core kinematics, temperatures and chemistry. At the higher gas densities where the N2H+ emission is excited, I show that the presence of an embedded protostar is correlated with increased gas motions. I additionally present evidence of N2H+ depletion from the gas phase, suggesting that in higher density, clustered environments N2H+ may not accurately trace the physical conditions of the densest core gas. I present the distribution of H2D+ and N2D+ across the Oph B Core, and show the distribution is not simple or easily explained by chemical models of evolving, isolated cores. Finally, I summarize the results of this dissertation, the questions it raises concerning the exploration of how stars form in clusters, and discuss how these questions may be answered through upcoming observational surveys and by new telescope facilities.