What Are Gamma-Ray Bursts?

What Are Gamma-Ray Bursts?

JOSHUA S. BLOOM
Copyright Date: 2011
Pages: 280
https://www.jstor.org/stable/j.ctt7sm0h
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  • Book Info
    What Are Gamma-Ray Bursts?
    Book Description:

    Gamma-ray bursts are the brightest--and, until recently, among the least understood--cosmic events in the universe. Discovered by chance during the cold war, these evanescent high-energy explosions confounded astronomers for decades. But a rapid series of startling breakthroughs beginning in 1997 revealed that the majority of gamma-ray bursts are caused by the explosions of young and massive stars in the vast star-forming cauldrons of distant galaxies. New findings also point to very different origins for some events, serving to complicate but enrich our understanding of the exotic and violent universe.What Are Gamma-Ray Bursts?is a succinct introduction to this fast-growing subject, written by an astrophysicist who is at the forefront of today's research into these incredible cosmic phenomena.

    Joshua Bloom gives readers a concise and accessible overview of gamma-ray bursts and the theoretical framework that physicists have developed to make sense of complex observations across the electromagnetic spectrum. He traces the history of remarkable discoveries that led to our current understanding of gamma-ray bursts, and reveals the decisive role these phenomena could play in the grand pursuits of twenty-first century astrophysics, from studying gravity waves and unveiling the growth of stars and galaxies after the big bang to surmising the ultimate fate of the universe itself.

    What Are Gamma-Ray Bursts?is an essential primer to this exciting frontier of scientific inquiry, and a must-read for anyone seeking to keep pace with cutting-edge developments in physics today.

    eISBN: 978-1-4008-3700-7
    Subjects: Physics

Table of Contents

  1. Front Matter
    (pp. i-vi)
  2. Table of Contents
    (pp. vii-viii)
  3. PREFACE
    (pp. ix-xiv)
    Joshua S. Bloom
  4. 1 INTRODUCTION
    (pp. 1-39)

    BeforeMythbustersandThe A-Teammade big explosions cool, big explosions were decidedlyuncool. The threat of nuclear war between the United States and the USSR (and, perhaps, China)—made blatantly real during the Cuban Missile Crisis in October 1962—had become a fixture in everyday life. One year after the crisis, seeking to diffuse an escalating arms race and the global increase of radioactive fallout from nuclear weapons testing, Soviet Premier Nikita Khrushchev and U.S. President John F. Kennedy agreed to the Partial Test Ban Treaty. Ratifying nations agreed that all nuclear weapons testing would be conducted underground from...

  5. 2 INTO THE BELLY OF THE BEAST
    (pp. 40-71)

    Before the afterglow era, GRBs were essentially defined by observations of their high-energy emission.*The landscape of such observations—the light curves and spectra of the events—exhibits at once great diversity and elements of commonality that bind different events together. As we shall see, GRBs are like fingerprints: no two are alike, but they share common properties. Those common elements provide strong constraints both on the nature of the “engine” that supplies the energy to the event and the physical processes that drive the emission we see.

    The community has been fortunate to have had continuous GRB monitors in...

  6. 3 AFTERGLOWS
    (pp. 72-112)

    Had Ray Klebesadel and his collaborators found convincing evidence for a connection of a GRB to a supernova, the search for late-time emission after a given GRB would have been sharpened and honed from the outset. Instead, the search for afterglows was generally fragmented, unfocused, and, for decades, unmotivated by specific theoretical predictions. In the context of Galactic models of GRBs, the possibility of delayed emission at X-ray wavebands was quickly hypothesized.¹ But until BeppoSAX, there was no X-ray facility that could quickly be trained on new GRB positions to search for afterglows; likewise, no convincing signatures would be seen...

  7. 4 THE EVENTS IN CONTEXT
    (pp. 113-134)

    Prompt and afterglow emission of GRBs are largely driven by the central engine behavior, the explosion properties, and the physics of relativistic shocks. Those seconds, minutes, and days after the main event tell a remarkable story about how the progenitors of GRBs end their life. But it is the context—where GRBs occur inside and out of galaxies and throughout cosmic time—that tell us how the progenitors lived. Indeed, we treat GRB locations like a crime scene, extracting forensic evidence to make a case about the lifecycle of a GRB progenitor; that progenitor, while on the other side of...

  8. 5 THE PROGENITORS OF GAMMA-RAY BURSTS
    (pp. 135-168)

    The physics of the central engine (§2.3) is constrained by basic measurements of GRB variability, inferred luminosity and energy release, and event spectra. This has led to the conclusion that a newly formed black hole or rapidly spinning neutron star lies at the heart of most distant GRBs: popular-level promotions of GRBs have noted, not unreasonably, that a GRB is the birth cry of a newborn black hole. But the tale we spin about GRB central engines may be more aptly seen as the denouement of an epic story about the tragic life cycle of the object(s) that produces the...

  9. 6 GAMMA-RAY BURSTS AS PROBES OF THE UNIVERSE
    (pp. 169-202)

    Until now we have concentrated on the observations and theory of GRBs. The events have shown themselves as a complex, panchromatic phenomenon that can arise from a variety of different progenitors in both the nearby and distant Universe. The GRB community has succeeded in measuring the diversity of basic parameters of the explosions and clearly learned a great deal about the physics of the emission mechanisms. But despite a raft of certainties, we could fill a book with what we do not know. Indeed, filling in these sometimes gaping holes and searching for new insights into the phenomenon keep many...

  10. NOTES
    (pp. 203-226)
  11. SUGGESTIONS FOR FURTHER READING
    (pp. 227-230)
  12. GLOSSARY
    (pp. 231-248)
  13. INDEX
    (pp. 249-256)