ICE AGE EPOCHS AND THE SUN'S PATH THROUGH THE GALAXY

@article{Gies2005ICEAE,
  title={ICE AGE EPOCHS AND THE SUN'S PATH THROUGH THE GALAXY},
  author={Douglas R. Gies and J. W. Helsel},
  journal={The Astrophysical Journal},
  year={2005},
  volume={626},
  pages={844-848}
}
We present a calculation of the Sun's motion through the Milky Way over the last 500 million yr. The integration is based on estimates of the Sun's current position and speed from measurements with Hipparcos and on a realistic model for the Galactic gravitational potential. We estimate the times of the Sun's past spiral arm crossings for a range of assumed values of the spiral pattern angular speed. We find that for a difference between the mean solar and pattern speed of Ω☉ - Ωp = 11.9 ± 0.7… Expand

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References

SHOWING 1-10 OF 37 REFERENCES
The spiral structure of the Milky Way, cosmic rays, and ice age epochs on Earth
Abstract The short term variability of the galactic cosmic ray flux (CRF) reaching Earth has been previously associated with variations in the global low altitude cloud cover. This CRF variabilityExpand
Mass extinctions and the sun's encounters with spiral arms
Abstract The terrestrial fossil record shows that the exponential rise in biodiversity since the Precambrian period has been punctuated by large extinctions, at intervals of 40 to 140 Myr. These massExpand
A plausible Galactic spiral pattern and its rotation speed
We report calculations of the stellar and gaseous response to a Milky Way mass distribution model including a spiral pattern with a locus as traced by K-band observations, superimposed on theExpand
Galactic disc dark matter, terrestrial impact cratering and the law of large numbers
A new approach is used to study the old question of missing mass in the Galactic disc. Invoking the law of large numbers, a simple average is formed of the many independent published values of theExpand
Kinematics of young stars. II. Galactic spiral structure
The young star velocity eld is analysed by means of a galactic model which takes into account solar motion, dierential galactic rotation and spiral arm kinematics. We use two samples of HipparcosExpand
Cosmic ray diffusion from the galactic spiral arms, iron meteorites, and a possible climatic connection.
  • N. Shaviv
  • Physics, Medicine
  • Physical review letters
  • 2002
TLDR
Although the geological evidence for the occurrence of iceage epochs in the past eon is not unequivocal, it appears to have a nontrivial correlation with the spiral arm crossings-agreeing in period and phase. Expand
A model of the 8-25 micron point source infrared sky
We present a detailed model for the IR point-source sky that comprises geometrically and physically realistic representations of the Galactic disk, bulge, stellar halo, spiral arms (including theExpand
Local stellar kinematics from Hipparcos data
TLDR
From the parallaxes and proper motions of a kinematically unbiased subsample of the Hipparcos Catalogue, it is re-determined as a function of colour the kinematics of main-sequence stars that spiral arms are responsible for the non-axisymmetry and that R0/Rd ≃ 3 to 3, where Rd is the scalelength of the disc. Expand
Gas dynamics in the Milky Way: second pattern speed and large-scale morphology
We present new gas flow models for the Milky Way inside the solar circle. We use smoothed particles hydrodynamics (SPH) simulations in gravitational potentials determined from the near-infrared (NIR)Expand
Galactic kinematics of Cepheids from Hipparcos proper motions
The Hipparcos proper motions of 220 galactic Cepheids, together with relevant ground-based photometry, have been analysed. The effects of galactic rotation are very clearly seen. Mean values of theExpand
...
1
2
3
4
...