scholarly journals Mapping the three-dimensional dust extinction towards the supernova remnant S147 – the S147 dust cloud

2017 ◽  
Vol 472 (4) ◽  
pp. 3924-3935 ◽  
Author(s):  
B.-Q. Chen ◽  
X.-W. Liu ◽  
J.-J. Ren ◽  
H.-B. Yuan ◽  
Y. Huang ◽  
...  
Keyword(s):  
Supernova Remnant ◽  
Dust Cloud ◽  
Three Dimensional ◽  
Dust Extinction

Three-dimensional models of the zodiacal dust cloud

Icarus ◽  
1989 ◽  
Vol 82 (2) ◽  
pp. 369-378 ◽  
Author(s):  
R.H. Giese ◽  
B. Kneiβel
Keyword(s):  
Dust Cloud ◽  
Three Dimensional ◽  
Zodiacal Dust ◽  
Dimensional Models ◽  
Three Dimensional Models

scholarly journals Dynamics of the Zodiacal Cloud

1992 ◽  
Vol 152 ◽  
pp. 333-347 ◽  
Author(s):  
S. F. Dermott ◽  
R. S. Gomes ◽  
D. D. Durda ◽  
B. Å. S. Gustafson ◽  
S. Jayaraman ◽  
...  
Keyword(s):  
Solar System ◽  
Dust Particle ◽  
Thermal Flux ◽  
Complex Structure ◽  
Dust Cloud ◽  
Three Dimensional ◽  
The Sun ◽  
Particle Orbits ◽  
Analysis Center ◽  
Asteroidal Dust

Advances in infrared astronomy and in computing power have recently opened up an interesting area of the solar system for dynamical exploration. The survey of the sky made by The Infrared Astronomical Satellite (IRAS) in 1983 revealed the complex structure of the zodiacal dust cloud. We now know the inclination and nodes of the plane of symmetry of the cloud with respect to the ecliptic and we have evidence that the cloud is not rotationally symmetric with respect to the Sun. Of even more interest is the discovery by IRAS of prominent dust bands that circle the Sun in planes near-parallel to the ecliptic. In 1984, we suggested (Dermott et al., Nature, 312, 505-509) that the solar system dust bands discovered by IRAS are produced by the gradual comminution of the asteroids in the major Hirayama asteroid families. The confirmation of this hypothesis has involved: (1) The development of a new secular perturbation theory that includes the effects of Poynting-Robertson light drag on the evolution of the dust particle orbits; (2) The production of a new high resolution Zodiacal History File by IPAC (the Infrared Processing and Analysis Center at Caltech); (3) The development of the SIMUL code: a three-dimensional numerical model that allows the calculation of the thermal flux produced by any particular distribution of dust particle orbits. SIMUL includes the effects of planetary perturbations and PR drag on the dust particle orbits and reproduces the exact viewing geometry of the IRAS telescope. We report that these tools allow us to account in detail for the observed structure of the dust bands. They also allow us to show that there is evidence in the IRAS data for the transport of asteroidal dust from the main belt to the Earth by Poynting-Robertson light drag.

scholarly journals Density distribution of a dust cloud in three-dimensional complex plasmas

2016 ◽  
Vol 94 (3) ◽  
Author(s):  
V. N. Naumkin ◽  
D. I. Zhukhovitskii ◽  
V. I. Molotkov ◽  
A. M. Lipaev ◽  
V. E. Fortov ◽  
...  
Keyword(s):  
Density Distribution ◽  
Dust Cloud ◽  
Three Dimensional ◽  
Complex Plasmas

scholarly journals Spectral and morphological study of the gamma radiation of the middle-aged supernova remnant HB 21

2019 ◽  
Vol 623 ◽  
pp. A86 ◽  
Author(s):  
L. Ambrogi ◽  
R. Zanin ◽  
S. Casanova ◽  
E. De Oña Wilhelmi ◽  
G. Peron ◽  
...  
Keyword(s):  
Energy Distribution ◽  
Electron Spectrum ◽  
Supernova Remnant ◽  
Gamma Ray ◽  
Spectral Energy Distribution ◽  
Three Dimensional ◽  
Spectral Energy ◽  
Proton Spectrum ◽  
Middle Aged ◽  
Gamma Ray Emission

Aims. We investigate the nature of the accelerated particles responsible for the production of the gamma-ray emission observed from the middle-aged supernova remnant (SNR) HB 21. Methods. We present the analysis of more than nine years of Fermi LAT data from the SNR HB 21. We performed morphological and spectral analysis of the SNR by means of a three-dimensional binned likelihood analysis. To assess the intrinsic properties of the parent particle models, we fit the obtained gamma-ray spectral energy distribution of the SNR by both hadronic- and leptonic-induced gamma-ray spectrum. Results. We observe an extended emission positionally in agreement with the SNR HB 21. The bulk of this gamma-ray emission is detected from the remnant; photons up to ~10 GeV show clear evidence of curvature at the lower energies. The remnant is characterized by an extension of 0°.83, that is, 30% smaller than claimed in previous studies. The increased statistics allowed us also to resolve a point-like source at the edge of the remnant, in proximity to a molecular cloud of the Cyg OB7 complex. In the southern part of the remnant, a hint of an additional gamma-ray excess in correspondence to shocked molecular clouds is observed. Conclusions. The spectral energy distribution of the SNR shows evidence of a break around 400 MeV, which can be properly fitted within both the hadronic and leptonic scenario. The pion-decay mechanism reproduces well the gamma rays, postulating a proton spectrum with a slope ~2.5 and with a steepening around tens of GeV, which could be explained by the energy-dependent escape of particles from the remnant. In the leptonic scenario the electron spectrum within the SNR matches closely the locally measured spectrum. This remarkable and novel result shows that SNR HB 21 could be a direct contributor to the population of Galactic electrons. In the leptonic scenario, we find that the local electron spectrum with a break around 2 GeV, closely evokes the best-fitting parental spectrum within this SNR. If such a scenario is confirmed, this would indicate that the SNR might be a source of Galactic background electrons.

scholarly journals The Global Distribution of Zodiacal Dust

1990 ◽  
Vol 139 ◽  
pp. 231-232 ◽  
Author(s):  
B. Kneißel
Keyword(s):  
Solar System ◽  
Data Base ◽  
Observational Data ◽  
Dust Cloud ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Zodiacal Light ◽  
Orbital Inclination ◽  
Zodiacal Dust ◽  
Infrared Brightness

From visible or infrared brightness observations of the zodiacal light, a large variety of models of the three-dimensional structure of the zodiacal dust cloud has been proposed. To assess the reliability of these models, we must first investigate their fit to a selected set of observational data. The fit is best for bulge models, which have an appreciable density over the solar poles. Next, we check the orbital inclination distributions predicted by the various models. A comparison of these distributions with those of minor bodies in the solar system does not support the preference for bulge models, but instead supports polar hole models with a negligible density over the solar pole. These uncertainties of modelling have to be kept in mind when models are used to derive the brightness contribution of zodiacal light, particularly in the infrared, where the data base is still limited.

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