1,124 research outputs found
The FluxCompensator: Making Radiative Transfer Models of hydrodynamical Simulations Directly Comparable to Real Observations
When modeling astronomical objects throughout the universe, it is important
to correctly treat the limitations of the data, for instance finite resolution
and sensitivity. In order to simulate these effects, and to make radiative
transfer models directly comparable to real observations, we have developed an
open-source Python package called the FluxCompensator that enables the
post-processing of the output of 3-d Monte-Carlo radiative transfer codes, such
as HYPERION. With the FluxCompensator, realistic synthetic observations can be
generated by modelling the effects of convolution with arbitrary point-spread
functions (PSFs), transmission curves, finite pixel resolution, noise and
reddening. Pipelines can be applied to compute synthetic observations that
simulate observatories, such as the Spitzer Space Telescope or the Herschel
Space Observatory. Additionally, this tool can read in existing observations
(e.g. FITS format) and use the same settings for the synthetic observations. In
this paper, we describe the package as well as present examples of such
synthetic observations.Comment: Accepted by ApJ, 12 pages, 5 figures, 2 tables, code examples,
open-source softwar
On the Earth Microwave Background: Absorption and Scattering by the Atmosphere
The absorption and scattering of microwave radiation by the atmosphere of the Earth
is considered under a steady state scenario. Using this approach, it is demonstrated
that the microwave background could not have a cosmological origin. Scientific
observations in the microwave region are explained by considering an oceanic source,
combined with both Rayleigh and Mie scattering in the atmosphere in the absence
of net absorption. Importantly, at high frequencies, Mie scattering occurs primarily
with forward propagation. This helps to explain the lack of high frequency microwave
background signals when radio antennae are positioned on the Earth’s surface
On the Origins of the CMB: Insight from the COBE, WMAP, and Relikt-1 Satellites
The powerful “Cosmic Microwave Background (CMB)” signal currently associated
with the origins of the Universe is examined from a historical perspective and relative
to the experimental context in which it was measured. Results from the COBE satellite
are reviewed, with particular emphasis on the systematic error observed in determining
the CMB temperature. The nature of the microwave signal emanating from the oceans
is also discussed. From this analysis, it is demonstrated that it is improper for the
COBE team to model the Earth as a 285 K blackbody source. The assignment of
temperatures to objects that fail to meet the requirements set forth in Kirchhoff’s
law constitutes a serious overextension of the laws of thermal emission. Using this
evidence, and the general rule that powerful signals are associated with proximal
sources, the CMB monopole signal is reassigned to the oceans. In turn, through the
analysis of COBE, WMAP, and Relikt-1 data, the dipole signal is attributed to motion
through a much weaker microwave field present both at the position of the Earth and
at the second Lagrange point
Commentary on the Liquid Metallic Hydrogen Model of the Sun: Insight Relative to Coronal Holes, Sunspots, and Solar Activity
While mankind will always remain unable to sample the interior of the Sun, the presence
of sunspots and coronal holes can provide clues as to its subsurface structure. Insight
relative to the solar body can also be gained by recognizing that the Sun must exist in the
condensed state and support a discrete lattice structure, as required for the production
of its continuous spectrum. In this regard, the layered liquid metallic hydrogen lattice
advanced as a condensed model of the Sun (Robitaille P.M. Liquid Metallic Hydrogen:
A Building Block for the Liquid Sun.
Progr. Phys
., 2011, v. 3, 60–74; Robitaille P.M.
Liquid Metallic Hydrogen II: A Critical Assessment of Current and Primordial Helium
Levels in Sun.
Progr. Phys
., 2013, v. 2, 35–47; Robitaille J.C. and Robitaille P.M.
Liquid Metallic Hydrogen III. Intercalation and Lattice Exclusion Versus Gravitational
Settling and Their Consequences Relative to Internal Structure, Surface Activity, and
Solar Winds in the Sun.
Progr. Phys
., 2013, v. 2, in press) provides the ability to add
structure to the solar interior. This constitutes a significant advantage over the gaseous
solar models. In fact, a layered liquid metallic hydrogen lattice and the associated
intercalation of non-hydrogen elements can help to account for the position of sunspots
and coronal holes. At the same time, this model provides a greater understanding of the
mechanisms which drive solar winds and activity
Liquid Metallic Hydrogen: A Building Block for the Liquid Sun
Liquid metallic hydrogen provides a compelling material for constructing a condensed
matter model of the Sun and the photosphere. Like diamond, metallic hydrogen might
have the potential to be a metastable substance requiring high pressures for forma-
tion. Once created, it would remain stable even at lower pressures. The metallic
form of hydrogen was initially conceived in 1935 by Eugene Wigner and Hillard B.
Huntington who indirectly anticipated its elevated critical temperature for liquefaction
(Wigner E. and Huntington H.B. On the possibility of a metallic modification of hydro-
gen.
J. Chem. Phys.
, 1935, v.3, 764–770). At that time, solid metallic hydrogen was
hypothesized to exist as a body centered cubic, although a more energetically accessible
layered graphite-like lattice was also envisioned. Relative to solar emission, this struc-
tural resemblance between graphite and layered metallic hydrogen should not be easily
dismissed. In the laboratory, metallic hydrogen remains an elusive material. However,
given the extensive observational evidence for a condensed Sun composed primarily of
hydrogen, it is appropriate to consider metallic hydrogen as a solar building block. It
is anticipated that solar liquid metallic hydrogen should possess at least some layered
order. Since layered liquid metallic hydrogen would be essentially incompressible, its
invocation as a solar constituent brings into question much of current stellar physics.
The central proof of a liquid state remains the thermal spectrum of the Sun itself. Its
proper understanding brings together all the great forces which shaped modern physics.
Although other proofs exist for a liquid photosphere, our focus remains solidly on the
generation of this light
On the Presence of a Distinct Solar Surface: A Reply to Hervé Faye
In this exposition, the existence of the solar surface will be briefly explored. Within
the context of modern solar theory, the Sun cannot have a distinct surface. Gases are
incapable of supporting such structures. The loss of a defined solar surface occurred in
1865 and can be directly attributed to Herv
́
e Faye (Faye H. Sur la constitution physique
du soleil.
Les Mondes
, 1865, v.7, 293–306). Modern theory has echoed Faye affirming
the absence of this vital structural element. Conversely, experimental evidence firmly
supports that the Sun does indeed possess a surface. For nearly 150 years, astronomy
has chosen to disregard direct observational evidence in favor of theoretical models
The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere II. Continuous Emission and Condensed Matter Within the Corona
The K-corona, a significant portion of the solar atmosphere, displays a continuous spectrum which closely parallels photospheric emission, though without the presence of overlying Fraunhofer lines. The E-corona exists in the same region and is characterized by weak emission lines from highly ionized atoms. For instance, the famous green emission line from coronium (FeXIV) is part of the E-corona. The F-corona exists beyond the K/E-corona and, like the photospheric spectrum, is characterized by Fraunhofer lines. The F-corona represents photospheric light scattered by dust particles in the interplanetary medium. Within the gaseous models of the Sun, the K-corona is viewed as photospheric radiation which has been scattered by relativistic electrons. This scattering is thought to broaden the Fraunhofer lines of the solar spectrum such that they can no longer be detected in the K-corona. Thus, the gaseous models of the Sun account for the appearance of the K-corona by distorting photospheric light, since they are unable to have recourse to condensed matter to directly produce such radiation. Conversely, it is now advanced that the continuous emission of the K-corona and associated emission lines from the E-corona must be interpreted as manifestations of the same phenomenon: condensed matter exists in the corona. It is well-known that the Sun expels large amounts of material from its surface in the form of flares and coronal mass ejections. Given a liquid metallic hydrogen model of the Sun, it is logical to assume that such matter, which exists in the condensed state on the solar surface, continues to manifest its nature once expelled into the corona. Therefore, the continuous spectrum of the K-corona provides the twenty-seventh line of evidence that the Sun is composed of condensed matter
The Liquid Metallic Hydrogen Model of the Sun and the Solar Atmosphere IV. On the Nature of the Chromosphere
The chromosphere is the site of weak emission lines characterizing the flash spectrum observed for a few seconds during a total eclipse. This layer of the solar atmosphere is known to possess an opaque Hα emission and a great number of spicules, which can extend well above the photosphere. A stunning variety of hydrogen emission lines have been observed in this region. The production of these lines has provided the seventeenth line of evidence that the Sun is comprised of condensed matter (Robitaille P.M. Liquid Metallic Hydrogen II: A critical assessment of current and primordial helium levels in Sun. Progr. Phys., 2013, v. 2, 35–47). Contrary to the gaseous solar models, the simplest mechanism for the production of emission lines is the evaporation of excited atoms from condensed surfaces existing within the chromosphere, as found in spicules. This is reminiscent of the chemiluminescence which occurs during the condensation of silver clusters (Konig L., Rabin I., Schultze W., and Ertl G. Chemiluminescence in the Agglomeration of Metal Clusters. Science, v. 274, no. 5291, 1353–1355). The process associated with spicule formation is an exothermic one, requiring the transport of energy away from the site of condensation. As atoms leave localized surfaces, their electrons can occupy any energy level and, hence, a wide variety of emission lines are produced. In this regard, it is hypothesized that the presence of hydrides on the Sun can also facilitate hydrogen condensation in the chromosphere. The associated line emission from main group and transition elements constitutes the thirtieth line of evidence that the Sun is condensed matter. Condensation processes also help to explain why spicules manifest an apparently constant temperature over their entire length. Since the corona supports magnetic field lines, the random orientations associated with spicule formation suggests that the hydrogen condensates in the chromosphere are not metallic in nature. Spicules provide a means, not to heat the corona, but rather, for condensed hydrogen to rejoin the photospheric layer of the Sun. Spicular velocities of formation are known to be essentially independent of gravitational effects and highly supportive of the hypothesis that true condensation processes are being observed. The presence of spicules brings into question established chromospheric densities and provides additional support for condensation processes in the chromosphere, the seventh line of evidence that the Sun is comprised of condensed matter
Commentary Relative to the Emission Spectrum of the Solar Atmosphere: Further Evidence for a Distinct Solar Surface
The chromosphere and corona of the Sun represent tenuous regions which are characterized by numerous optically thin emission lines in the ultraviolet and X-ray bands. When observed from the center of the solar disk outward, these emission lines experience modest brightening as the limb is approached. The intensity of many ultraviolet and X-ray emission lines nearly doubles when observation is extended just beyond the edge of the disk. These findings indicate that the solar body is opaque in this frequency range and that an approximately two fold greater region of the solar atmosphere is being sampled outside the limb. These observations provide strong support for the presence of a distinct solar surface. Therefore, the behavior of the emission lines in this frequency range constitutes the twenty fifth line of evidence that the Sun is comprised of condensed matte
Blackbody Radiation and the Loss of Universality: Implications for Planck's Formulation and Boltzman's Constant
Through the reevaluation of Kirchhoff's law (Robitaille P.M.L. IEEE Trans. Plasma Sci., 2003, v.31(6), 1263-1267), Planck's blackbody equation (Planck M. Ann. der Physik, 1901, v.4, 553-356) loses its universal significance and becomes restricted to perfect absorbers. Consequently, the proper application of Planck's radiation law involves the study of solid opaque objects, typically made from graphite, soot, and carbon black. The extension of this equation to other materials may yield apparent temperatures, which do not have any physical meaning relative to the usual temperature scales. Real temperatures are exclusively obtained from objects which are known solids, or which are enclosed within, or in equilibrium with, a perfect absorber. For this reason, the currently accepted temperature of the microwave background must be viewed as an apparent temperature. Rectifying this situation, while respecting real temperatures, involves a reexamination of Boltzman's constant. In so doing, the latter is deprived of its universal nature and, in fact, acts as a temperature dependent variable. In its revised form, Planck's equation becomes temperature insensitive near 300K, when applied to the microwave background
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