Terrestrial Consequences of Spectral and Temporal Variability in Ionizing Photon Events

@article{Ejzak2007TerrestrialCO,
  title={Terrestrial Consequences of Spectral and Temporal Variability in Ionizing Photon Events},
  author={Larissa M. Ejzak and Adrian L. Melott and Mikhail V. Medvedev and Brian C. Thomas},
  journal={The Astrophysical Journal},
  year={2007},
  volume={654},
  pages={373-384}
}
Gamma-ray bursts (GRBs) directed at Earth from within a few kiloparsecs may have damaged the biosphere, primarily through changes in atmospheric chemistry that admit greatly increased solar UV. However, GRBs are highly variable in spectrum and duration. Recent observations indicate that short (~0.1 s) burst GRBs, which have harder spectra, may be sufficiently abundant at low redshift that they may offer an additional significant effect. A much longer timescale is associated with shock breakout… Expand

Figures from this paper

Biological radiation dose from secondary particles in a Milky Way gamma-ray burst
TLDR
Modelled the air showers produced by gamma-ray primaries up to 100 GeV, it is found that the number of muons produced by the electromagnetic component of hypothetical galactic GRBs significantly increases the total muon flux, and the biological radiation dose from secondary muons is negligible. Expand
Astrophysical ionizing radiation and Earth: a brief review and census of intermittent intense sources.
TLDR
This review estimates the intensities and rates of occurrence of many kinds of strong radiation bursts by astrophysical entities, ranging from gamma-ray bursts at cosmological distances to the Sun itself, and notes for the first time that so-called "short-hard" gamma-rays bursts are a substantial threat, comparable in magnitude to supernovae and greater than that of the higher-luminosity long bursts considered in most past work. Expand
Gamma-ray bursts as a threat to life on Earth
  • B. Thomas
  • Physics, Environmental Science
  • International Journal of Astrobiology
  • 2009
Abstract Gamma-ray bursts (GRBs) are likely to have made a number of significant impacts on the Earth during the last billion years. The gamma radiation from a burst within a few kiloparsecs wouldExpand
Terrestrial Effects of High Energy Cosmic Rays
Abstr act: On geological timescales, the Earth is likely to be exposed to higher than the usual flux of high energy cosmic rays (HECRs) from astrophysical sources such as nearby supernovae, gamma rayExpand
Late Ordovician geographic patterns of extinction compared with simulations of astrophysical ionizing radiation damage
TLDR
This work focuses on gamma-ray bursts (Thorsett 1995; Scalo and Wheeler 2002), a proposed causal agent for the end-Ordovician extinction, a threat approximately competitive with, for example, that of nearby supernovae. Expand
Possible role of gamma ray bursts on life extinction in the universe.
TLDR
It is found that the probability of a lethal GRB is much larger in the inner Milky Way (95% within a radius of 4 kpc from the galactic center), making it inhospitable to life, and the safest environments for life are the lowest density regions in the outskirts of large galaxies, and life can exist in only ≈10% of galaxies. Expand
High Energy Cosmic Ray Effects on Terrestrial Atmospheric Chemistry
Washburn University, Department of Physics and Astronomy, Topeka, KS 66621,United States of AmericaE-mail: melott@ku.eduAbstract. A variety of events such as gamma-ray bursts and supernovae mayExpand
Atmospheric Consequences of Cosmic Ray Variability in the Extragalactic Shock Model II: Revised io
[1] It has been suggested that galactic shock asymmetry induced by our galaxy's infall toward the Virgo Cluster may be a source of periodicity in cosmic-ray exposure as the solar system oscillatesExpand
Ground-Level Ozone Following Astrophysical Ionizing Radiation Events: An Additional Biological Hazard?
TLDR
The amount of ozone produced in the lower atmosphere for the case of a gamma-ray burst is examined and it is found that the values are too small to pose a significant additional threat to the biosphere. Expand
TERRESTRIAL EFFECTS OF NEARBY SUPERNOVAE IN THE EARLY PLEISTOCENE.
TLDR
It is found that a supernova at 100 pc can have only a small effect on terrestrial organisms from visible light and that chemical changes such as ozone depletion are weak, but tropospheric ionization right down to the ground, due to the penetration of ⩾TeV CRs, will increase by nearly an order of magnitude for thousands of years, and irradiation by muons on the ground and in the upper ocean will increase twentyfold. Expand
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 51 REFERENCES
Terrestrial implications of cosmological gamma-ray burst models
The observation by the BATSE instrument on the Compton Gamma Ray Observatory that gamma-ray bursts (GRBs) are distributed isotropically around the Earth but nonuniformly in distance has led to theExpand
Transport of Ionizing Radiation in Terrestrial-like Exoplanet Atmospheres
TLDR
It is suggested that transient atmospheric ionization layers can be frequently created at altitudes lower than the equilibrium layers that result from steady irradiation and winds from the parent star, as well as the effects of angle of incidence and a modified twostream approximation solution for the UV transfer. Expand
Terrestrial Ozone Depletion Due to a Milky Way Gamma-Ray Burst
TLDR
The first detailed computation of the effects of a gamma-ray burst in the Earth's atmosphere of one such impulsive event is performed, lending support to the hypothesis that a GRB may have initiated the late Ordovician mass extinction. Expand
Study of Very Short Gamma-Ray Bursts: New Results from BATSE and Konus
Our recent studies of very short gamma-ray bursts (GRBs) of T90 ≤ 100 ms duration have indicated a significant angular asymmetry and a uniform V/Vmax distribution from the BATSE (Burst and TransientExpand
A Gamma-Ray Burst Remnant in Our Galaxy: HESS J1303-631
We present an investigation of the multiwavelength data on HESS J1303-631, an unidentified TeV source serendipitously discovered in the Galactic plane by the HESS collaboration. Our results stronglyExpand
Gamma-Ray Bursts and the Earth: Exploration of Atmospheric, Biological, Climatic, and Biogeochemical Effects
Gamma-ray bursts (GRBs) are likely to have made a number of significant impacts on the Earth during the last billion years. The gamma radiation from a burst within a few kiloparsecs would quicklyExpand
Astrophysical and Astrobiological Implications of Gamma-Ray Burst Properties
Combining results from Schmidt for the local cosmic rate and mean peak luminosity of γ-ray bursts (GRBs) with results on the history of the cosmic star formation rate (SFR), we provide estimates forExpand
BATSE observations of gamma-ray burst spectra. I: Spectral diversity
We studied the time-averaged gamma-ray burst spectra accumulated by the spectroscopy detectors of the Burst and Transient Source Experiment. The spectra are described well at low energy by aExpand
Climatic and biogeochemical effects of a galactic gamma ray burst
TLDR
The results support the hypothesis that the characteristics of the Late Ordovician mass extinction are consistent with GRB initiation, and show the first detailed computation of two other significant effects. Expand
The BATSE Gamma-Ray Burst Spectral Catalog. I. High Time Resolution Spectroscopy of Bright Bursts Using High Energy Resolution Data
This is the first in a series of gamma-ray burst spectroscopy catalogs from the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory, each covering a different aspect ofExpand
...
1
2
3
4
5
...