Zobrazeno 41 - 50
of 11 484
pro vyhledávání: '"Katz J"'
Autor:
Katz, J. I.
Asteroidal impact threats to the Earth will be predicted a century or more in advance. Changing an asteroid's albedo changes the force of Solar radiation on it, and hence its orbit. Albedo may be changed by applying a thin ($\sim 0.1\,\mu$) reflectiv
Externí odkaz:
http://arxiv.org/abs/2112.03501
Autor:
Katz, J. I.
FRB 190520B, a repeating FRB near-twin of FRB 121102, was discovered \citep{N21} to have a dispersion measure excess over the intergalactic and Galactic contributions of about 900 pc-cm$^{-3}$, attributable to its host galaxy or near-source environme
Externí odkaz:
http://arxiv.org/abs/2110.10847
Autor:
Katz, J. I.
Can a satellite dodge a collision with untracked orbiting debris? Can a satellite dodge collision with a tracked object, making only the avoidance man{\oe}uvers actually required to avoid collision, despite the uncertainties of predicted conjunctions
Externí odkaz:
http://arxiv.org/abs/2110.03113
Autor:
Katz, J. I.
Most Fast Radio Burst (FRB) models are built from comparatively common astronomical objects: neutron stars, black holes and supernova remnants. Yet FRB sources are rare, and most of these objects, found in the Galaxy, do not make FRB. Special and rar
Externí odkaz:
http://arxiv.org/abs/2106.06066
Autor:
Katz, J. I.
When does the presence of an outlier in some measured property indicate that the outlying object differs qualitatively, rather than quantitatively, from other members of its apparent class? Historical examples include the many types of supernov\ae\ a
Externí odkaz:
http://arxiv.org/abs/2106.05212
Autor:
Belof, J. L., Katz, J. I.
Most measurements of compressive strength of ductile materials have involved Hopkinson-Kolsky bars or Taylor anvils placing samples in uniaxial compression. In these geometries strain is limited by the tendency of the sample to petal, in analogy to n
Externí odkaz:
http://arxiv.org/abs/2106.03767
Autor:
Katz, J. I.
Publikováno v:
Nuclear Technology 207, S326 (2021)
Enrico Fermi estimated the yield of the Trinity test to be about 10 kilotons by dropping small pieces of paper and observing their motion in the blast wave. This is about 40% of the radiochemically derived value of $25 \pm 2$ kilotons that necessaril
Externí odkaz:
http://arxiv.org/abs/2103.05784
Autor:
Katz, J. I.
I summarize evidence against the hypothesis that `Oumuamua is the artificial creation of an advanced civilization. An appendix discusses the flaws and inconsistencies of the "Breakthrough" proposal for laser acceleration of spacecraft to semi-relativ
Externí odkaz:
http://arxiv.org/abs/2102.07871
Autor:
Katz, J. I.
The activity of the repeating FRB 20180916B is periodically modulated with a period of 16.3 days, and FRB 121102 may be similarly modulated with a period of about 160 days. In some models of this modulation the period derivative is insensitive to the
Externí odkaz:
http://arxiv.org/abs/2012.15354
Autor:
Katz, J. I.
Variations of the dispersion (DM) and rotation (RM) measures of FRB 121102 indicate magnetic fields $\sim$ 3--17 mG in the dispersing plasma. The electron density may be $\sim 10^4\,$cm$^{-3}$. The observed time scales $\sim 1$ year constrain the siz
Externí odkaz:
http://arxiv.org/abs/2011.11666