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1.
Juan C. López Vieyra Alexander V. Turbiner Nicolais L. Guevara 《Astrophysics and Space Science》2007,308(1-4):493-497
- The exotic system H 3 ++ (which does not exist without magnetic field) exists in strong magnetic fields:
- In triangular configuration for B≈108–1011?G (under specific external conditions)
- In linear configuration for B>1010?G
- In the linear configuration the positive z-parity states 1σ g , 1π u , 1δ g are bound states
- In the linear configuration the negative z-parity states 1σ u , 1π g , 1δ u are repulsive states
- The H 3 ++ molecular ion is the most bound one-electron system made from protons at B>3×1013?G
2.
Joseph V. Hollweg 《Solar physics》1978,56(2):305-333
We examine the propagation of Alfvén waves in the solar atmosphere. The principal theoretical virtues of this work are: (i) The full wave equation is solved without recourse to the small-wavelength eikonal approximation (ii) The background solar atmosphere is realistic, consisting of an HSRA/VAL representation of the photosphere and chromosphere, a 200 km thick transition region, a model for the upper transition region below a coronal hole (provided by R. Munro), and the Munro-Jackson model of a polar coronal hole. The principal results are:
- If the wave source is taken to be near the top of the convection zone, where n H = 5.2 × 1016 cm?3, and if B ⊙ = 10.5 G, then the wave Poynting flux exhibits a series of strong resonant peaks at periods downwards from 1.6 hr. The resonant frequencies are in the ratios of the zeroes of J 0, but depend on B ⊙, and on the density and scale height at the wave source. The longest period peaks may be the most important, because they are nearest to the supergranular periods and to the observed periods near 1 AU, and because they are the broadest in frequency.
- The Poynting flux in the resonant peaks can be large enough, i.e. P ⊙ ≈ 104–105 erg cm?2s?1, to strongly affect the solar wind.
- ¦δv¦ and ¦δB¦ also display resonant peaks.
- In the chromosphere and low corona, ¦δv ≈ 7–25 kms?1 and ¦δB¦ ≈0.3–1.0 G if P ⊙≈104-105 erg cm?2s?1.
- The dependences of ¦δv¦ and ¦δB¦ on height are reduced by finite wavelength effects, except near the wave source where they are enhanced.
- Near the base, ¦δB¦ ≈ 350–1200 G if P ⊙ ～- 104–105. This means that nonlinear effects may be important, and that some density and vertical velocity fluctuations may be associated with the Alfvén waves.
- Below the low corona most wave energy is kinetic, except near the base where it becomes mostly magnetic at the resonances.
- ?0 < δv 2 > v A or < δB 2 > v A/4π are not good estimators of the energy flux.
- The Alfvén wave pressure tensor will be important in the transition region only if the magnetic field diverges rapidly. But the Alfvén wave pressure can be important in the coronal hole.
3.
In this paper we review the drift theory of charged particles in electric and magnetic fields. No new physical interpretations are added to this classical topic, but through an alternative, simplified derivation of the guiding centre velocity, several complexities are eliminated and possible misconceptions of the theory are clarified. It is shown that:
- The curvature/gradient drift velocity in the magnetic field, averaged over a particle distribution function is to lowest order in the direction of?×B/B 2, while the average particle velocity is in the direction ofB×? P withP the scalar particle pressure.
- These drift directions are correct for first-order expansions of the particle distribution function, and only second-order or higher expansions change these directions.
- The?×B/B 2 drift, which is the standard gradient plus curvature drift, and which is usually considered as a ‘single particle’ drift, need not be ‘reconciled’ with theB×? P, or ‘macroscopic, collective’ drift, as is often asserted in the literature. They are in fact related per definition and we show how.
- When viewed in fixed momentum intervals (p,p+dp), the so-called Compton-Getting factor enters into the electric field (E×B)/B 2 drift term.
- The results are independent of the scale length of variation ofE andB, in contrast to existing drift theory. We discuss the implications of this result for three important cases.
4.
Recent gamma-ray observations of solar flares have provided a better means for estimating the heating of the solar atmosphere by energetic protons. Such heating has been suggested as the explanation of the continuum emission of the white-light flare. We have analyzed the effects on the photosphere of high-energy particles capable of producing the intense gamma-ray emission observed in the 1978 July 11 flare. Using a simple energy-balance argument and taking into account hydrogen ionization, we have obtained the following conclusions:
- Heating near τ5000 = 1 in the input HSRA model atmosphere is negligible, even for very high fluxes of energetic particles.
- Energy deposition increases with height for the inferred proton spectra, and does not depend strongly upon the assumed angle of incidence. The computed energy inputs fall in the range 10–100 ergs (cm3 s)?1 at the top of the photosphere.
- H? continuum dominates for column densities as small as 1022 cm?3, but at greater heights hydrogen ionizes sufficiently for the higher continua to dominate the energy balance.
- The total energy deposited in the ‘photospheric’ region of H? dominance could be within a factor of 3 of the necessary energy deposition, by comparison with the white-light flare of 1972 August 7, but the emergent spectrum is quite red so that the intensity excess in the visible band is insufficient to explain the observations.
5.
J. J. Aly 《Solar physics》1992,138(1):133-162
Some useful properties of a finite energy, constant-α, force-free magnetic field B α occupying a half-space D are presented. In particular:
- Fourier and Green representations of B α are obtained and used to derive conditions for the existence and uniqueness of a B α having a given normal component B z on the boundary ?D.
- The asymptotic behaviour of B α at infinity as well as stability results against changes in the boundary condition on ?D and in the value of α are established.
- The energy of B α is shown to be smaller than the energy of the open field having the same B z on ?D, thus confirming an earlier conjecture (Aly, 1984).
- B α is proved to not be a Taylor-Heyvaerts-Priest state, in spite of the fact that its relative helicity H is finite and that it is the only solution of the Lagrange-Euler equation associated with the problem of minimizing the energy among all the fields having the same value of H and the same B z on ?D.
6.
The radiation fluxes of the NGC 1275 galaxy central region are being observed on the 1.25-m telescope, using a scanning spectrophotometer with the entrance aperture 10″ in three Δλ=80 Å spectral regions: Hβ, 4959+5007 Å [OIII] and continuum. There were 35 nights of observations during 1982–1987. With the time resolution of half an hour 379 measurements were obtained in each spectral region. The analysis of these results shows:
- The standard deviations of measurements in each spectral region 2–3 times exceed the errors of observations.
- The radiation flux distribution resembles to normal one only for Hβ line.
- Two-humps forms of continuum flux distribution curve is like that of radio emission in 8 mm and 2.6 cm wavelengths.
- Various forms of fluxes distribution curves of Hβ and [OIII] lines permit us to suppose that the location of these lines emission regions near the sources of excitation are different.
7.
It is the purpose of this paper to illustrate the interrelation between the problems of the ‘missing mass’, the galactic age and the cosmological constant A (or its equivalent quantum vacuum densityρ v ). The inflationary picture of the early universe predicts that our present universe should have a very nearlyEuclidean metric. If we accept this concept, one would have to discriminate between two rather extreme Euclidean cosmological models:
- The standard model with ∧=0 and a densityρ c = 3H 0 2 8πG. There are difficulties ifH 0≥5- km s?1 Mpc?1 and the galactic aget 0≥14×109 years.
- The Euclidean Friedmann-Lemaître models with ∧>0, i.e., Δgt;0, i.e.,ρ v =ρ c ?ρ o , whereρ o is the present matter density, including the nonrelativistic dark matter. Hereρ v ‘competes’ with the missing mass.
8.
G. A. Krasinsky E. V. Pitjeva M. L. Sveshnikov L. I. Chunayeva 《Celestial Mechanics and Dynamical Astronomy》1993,55(1):1-23
Modern planetary theories may be considered as a realisation of a four-dimensional dynamical reference frame. The existence of secular trends between the dynamical system and the adopted system of the Fundamental Catalogue (as well as between time scales involved) has been studied by discussing planetary observations of different types and by comparison with a numerical theory constructed for the time span 1769–1988. Parameters of the theory were fitted to radar ranging data for 1961–1988 for inner planets and to meridian observations of 18th–20th centuries for outer planets. Then a set of the inner planet optical observations, which includes USNO meridian observations, transits through the solar disk and occultations of fundamental stars are discussed. The main results are the following:
- Radar data were used to estimate the time derivative? of the gravitational constantG (in another interpretation, the secular trend between the atomic and dynamic time scales): $$\dot G/G = (0.37 \pm 0.45) \times 10^{ - 11} /y.$$ This estimation, being statistically insignificant, gives some physically meaningful restriction to?.
- From the same data a new estimation of relativistic effects in the motion of Mercury was obtained, which has confirmed the Einstein value of the perihelion advance with the error 0″.06/cy. So in the frame of Einstein's theory the value of solar dynamic oblateness cannot be larger than 2×10?6.
- The analysis of time behavior of residuals in the inner planet longitudes shows secular trends. It is demonstrated that these trends may be explained by combined action of a linear trenddT of Brouwer's time scale (which is adopted as a standard for reduction of observations before 1959) and the error in Newcomb's value of the constant of precession. From USNO meridian observations fordT the following estimate was obtained:dT=?14.5±2.1 sec/cy with the corresponding correction,dp, to Newcomb's precessiondp=0″.46±0″.13/cy. The estimate ofdT is in good agreement with the value ofdT determined from transits of Mercury and Venus through the solar diskdT=?12.9±1.3 sec/cy which does not depend on any precession error.
- As a by-product, new accurate ephemerides of the outer planets are obtained over the time interval 1769–1988, the average residuals being presented.
9.
J. P. Vallée 《Astrophysics and Space Science》1995,234(1):1-10
A search is made here for possible variations in the behavior of magnetic field valuesB at various gas density valuesn, when comparing low density gas versus high density gas, and when comparing compressed gas versus quiescent gas.
- For thequiescent microturbulent interstellar gas (e.g., clouds, interclumps — see TableI), the statistical relationB ~n k yieldsk = 0.46 ± 0.07 forhigh gas densityn > 100 cm?3, andk = 0.17 ± 0.03 forlow gas densityn < 100 cm?3 (see Figure 1).
- For thecompressed macroturbulent interstellar gas (e.g., masers, expanding shells — see Table II), the statistical relationB ~n K yieldsK = 0.61 ± 0.09 forhigh gas densityn > 100 cm?3, andK = 0.37 ± 0.2 forlow gas densityn < 100 cm?3 (see Figure 2).
- The separation betweenlow density gas andhigh density gas is statistically significant. The 2 different physical behaviors (below and above the break at 100 cm?3) are confirmed statistically (about 2 to 4 sigma away for the quiescent gas alone; about 3 to 6 sigma away for the combined quiescent plus compressed gas).
- The separation betweencompressed gas andquiescent gas is not statistically significant now (see Figure 3). Atn > 100 cm?3, a comparison of quiescent gas versus compressed gas shows no statistically significant differences in behavior (they are only about 1 sigma away). Atn < 100 cm?3, a comparison of quiescent versus compressed gas also shows no statistically significant differences in behavior (less than 1 sigma away).
- A relation between the densityn and the galactic-wide Star Formation Rate (SFR) can be made for galactic magnetic fields, i.e.: (SFR) ~n n . For galactic-wide parameters using quiescent, low densityn < 100 cm?3, and the known relationshipsB ~n k/j withk = 0.17,B ~ (SFR) j withj = 0.13, then one gets here a lawSFR ~n k/j with an exponentk/j = 1.3. This is in rough accord with known data for the Milky Way and for NGC6946.
10.
Hot spots similar to those in the radio galaxy Cygnus A can be explained by the strong shock produced by a supersonic but classical jet \(\left( {u_{jet}< c/\sqrt 3 } \right)\) . The high integrated radio luminosity (L?2×1044 erg s?1) and the strength of mean magnetic field (B?2×10?4 G) suggest the hot spots are the downstream flow of a very strong shock which generates the ultrarelativistic electrons of energy ?≥20 MeV. The fully-developed subsonic turbulence amplifies the magnetic field of the jet up to 1.6×10?4 G by the dynamo effect. If we assume that the post-shock pressure is dominated by relativistic particles, the ratio between the magnetic energy density to the energy density in relativistic particles is found to be ?2×10?2, showing that the generally accepted hypothesis of equipartition is not valid for hot spots. The current analysis allows the determination of physical parameters inside hot spots. It is found that:
- The velocity of the upstream flow in the frame of reference of the shock isu 1?0.2c. Radio observations indicate that the velocity of separation of hot spots isu sep?0.05c, so that the velocity of the jet isu jet=u 1+u sep?0.25c.
- The density of the thermal electrons inside the hot spot isn 2?5×10?3 e ? cm?3 and the mass ejected per year to power the hot spot is ?4M 0yr?1.
- The relativistic electron density is less than 20% of the thermal electron density inside the hot spot and the spectrum is a power law which continues to energies as low as 30 MeV.
- The energy density of relativistic protons is lower than the energy density of relativistic electrons unlike the situation for cosmic rays in the Galaxy.
11.
A clarification and discussion of the energy changes experienced by cosmic rays in the interplanetary region is presented. It is shown that the mean time rate of change of momentum of cosmic rays reckoned for a fixed volume in a reference frame fixed in the solar system is 〈p〉 =p V·G/3 (p=momentum,V is the solar wind velocity andG=cosmic-ray density gradient). This result is obtained in three ways:
- by a rearrangement and reinterpretation of the cosmic-ray continuity equation;
- by using a scattering analysis based on that of Gleeson and Axford (1967);
- by using a special scattering model in which cosmic-rays are trapped in ‘magnetic boxes’ moving with the solar wind.
12.
The main results of a study of a catalogue of physical parameters of 1041 spectroscopic binaries are presented. The distribution of spectroscopic binaries over all main parametersM 1, a, e, M1/M2, P, and certain dependencies between some of them have been found.
- It appears that among bright (m v?3 m –5 m ) stars withM?1M ⊙, about 40% are apparently spectroscopic binaries with comparable masses of components.
- The majority of spectroscopic binaries with the ratio of the large semiaxis of the orbit to the radius of the primarya/R 1?20, have eccentricities close to zero. This is probably a consequence of the tidal circularization of orbits of close binaries by viscous friction.
- The discovery of duplicity of double-line spectroscopic binaries is possible only if the semiamplitude of radial velocityK 1 is almost 10 times higher than the semiamplitude of the radial velocity of a single-line spectroscopic binary of the same mass.
- Double-line spectroscopic binaries witha/R ⊙?6(M 1/M ⊙)1/3,M 1≈M 2?1.5M ⊙ are almost almost absent, and the number of stars witha/R ⊙?6(M 1/M ⊙)1/3,M 1≈1.5M ⊙ is relatively low.
- The distribution of unevolved SB stars over the large semiaxis may be described by the expression d(N d/Nt)≈0.2 d loga for 6(M 1/M ⊙)1/3?a/R ⊙?100.
- The intial mass-function for primaries of spectroscopic binaries is the same Salpeter function dN d≈M 1 ?2.35 dM 1 for 1?M 1/M ⊙?30.
- It is possible to explain the observed ratio of the number of single-line spectroscopic binaries to the number of double-line binaries if one assumes that the average initial mass ratio is close to 1 and that the mass of the postmass-exchange remnant of the primary exceeds the theoretical one and/or that half of the angular momentum of the system is lost during mass-exchange.
- The above-mentioned distributions ofM 1 anda and assumptions on the mass of remnant and/or momentum loss also allow us to explain the observed shapes of dN/dM, dN/dq, and dN/da distributions after some selection effects are taken into account.
13.
J. C. Brown V. A. Carlaw T. V. Cawthorne V. Icke 《Astrophysics and Space Science》1988,143(1):153-161
The jet/grain model proposed by Ramatyet al. (1984, hereafter abbreviated as RKL) for production of the narrow gamma-ray lines reported from SS433 is examined and shown to be untenable on numerous grounds. Most importantly:
- The huge Coulomb collisional losses (W c?2×1041 erg s?1) from the jet, which would necessarily accompany non-thermal production of the gamma rays, demands a jet acceleration/collimation process acting over a very long range and with a power at least 102 times the Eddington limit for any stellar object.
- There is a collisional thick target limit (irrespective of jet mass) to the gamma ray yield per interstellar proton. Consequently, the gamma-ray data demand an improbably high interstellar density (?109 cm?3).
- For the grains to be kept cool enough (?3000 K) to survive the heating rateW c either by radiation or jet expansion would demand a ‘jet’ wider than its length and so inconsistent with narrow lines. In the case of radiative cooling, the resultant IR flux would exceed the observed values by a factor ?104.
- Light scattered on the jet grain mass required would be highly polarized, contrary to observations, unless the jet was optically thick to grains, again precluding their radiative cooling.
- To avoid unacceptable precessional broadening of the gamma-ray lines demands an emitting jet length ?0.5 days atv=0.26c. This increases the necessary mass loss rate by a factor ?10 over the values obtained by RKL who assumed a 4-day ‘flare’.
- The model also predicts rest energy gamma-ray lines which are not observed.
14.
N. Hiotelis 《Astrophysics and Space Science》2008,315(1-4):191-200
We used merger trees realizations, predicted by the extended Press-Schechter theory, in order to study the growth of angular momentum of dark matter haloes. Our results showed that:
- The spin parameter λ′ resulting from the above method, is an increasing function of the present day mass of the halo. The mean value of λ′ varies from 0.0343 to 0.0484 for haloes with present day masses in the range of 109h?1 M ⊙ to 1014h?1 M ⊙.
- The distribution of λ′ is close to a log-normal, but, as it is already found in the results of N-body simulations, the match is not satisfactory at the tails of the distribution. A new analytical formula that approximates the results much more satisfactorily is presented.
- The distribution of the values of λ′ depends only weakly on the redshift.
- The spin parameter of an halo depends on the number of recent major mergers. Specifically the spin parameter is an increasing function of this number.
15.
From a comparative study between stellar and gas data it is seen that turbulent and hydrodynamic motions in the Galaxy are common to both types of materials:
- Galactic clusters have sizes and intrinsic dispersions compatible with the modified form of the Kolmogorov law seen in molecular clouds: undimensional velocities σ(km s?1)=0.54d 0.38 (pc). This indicates that ‘typic’ clusters were born from ‘typic’ dark clouds as these of the Lynds's catalogue (diametersd<10 pc, dispersions σ<1.5 km s?1 hydrogen densitiesn H>200 atom cm?3). These clouds have mass enough to form galactic clusters (1000–3000M ⊙).
- The cluster formation is related to the supersonic range of the Kolmogorov relationship σ(d>1 pc) while the AFGKM stars are related to the subsonic range of the same relationship σ(d<0.3 pc), the intermediate transition zone is probably related to OB stars and/or trapezia.
- The effects of the magnetic fields in the clouds are also discussed. It seems to be that in the clouds the magnetic energy does not exceed the kinetic energy (proportional toσ 2(d)) and that this determinates the freezing criteria. The hypotheses introduced here can be checked with 21 cm Zeeman splitting.
- Low-density globular clusters are also coherent with the Kolmogorov relationship. Some hypotheses about their origin and the type of clouds where they were born are discussed. This last part of the study lets open the possibility of further studies about evolution of globular clusters.
16.
Slobodan Ninković 《Astrophysics and Space Science》1987,136(2):299-314
An analysis of the data concerning high-velocity stars from Eggen's catalogue aimed at a determination of the approximate slope of the mass function for the spherical component of our Galaxy, and at estimating the local circular velocity, as well as the local rotation velocity, as by-products, has been performed. Our conclusions are that:
- A linear dependence of the mass on the radius is very likely;
- the value of the limiting radius is most likely equal to (40±10) kpc;
- the two local velocities are approximately equal to each other, being both equal to (230±30) km s?1;
- the local escape velocity appears to be most likely equal to (520±30) km s?1;
- the total mass of a corona, obtained in this way, is (5±1)×1011 M ⊙.
17.
The properties of small (< 2″) moving magnetic features near certain sunspots are studied with several time series of longitudinal magnetograms and Hα filtergrams. We find that the moving magnetic features:
- Are associated only with decaying sunspots surrounded entirely or in part by a zone without a permanent vertical magnetic field.
- Appear first at or slightly beyond the outer edge of the parent sunspot regardless of the presence or absence of a penumbra.
- Move approximately radially outward from sunspots at about 1 km s?1 until they vanish or reach the network.
- Appear with both magnetic polarities from sunspots of single polarities but appear with a net flux of the same sign as the parent sunspot.
- Transport net flux away from the parent sunspots at the same rates as the flux decay of the sunspots.
- Tend to appear in opposite polarity pairs.
- Appear to carry a total flux away from sunspots several times larger than the total flux of the sunspots.
- Produce only a very faint emmission in the core of Hα.
18.
Halton Arp 《Journal of Astrophysics and Astronomy》1987,8(3):231-239
Image processing performed on a series of photographs of the superluminal Seyfert galaxy, 3C 120, shows the outer optical disc to consist of fragmented segments generally pointing toward the centre. One long arm of peculiar, separated knots comes off to the W and SW. A peculiar companion is seen along the line of the NW radio jet. In the interior, optical jets are detected which are aligned along the direction of the outer radio jets. A region of the sky 45 ×; 25 degrees around 3C120 is investigated. It is found that:
- A nebulous filament about 3/4 degree in length points to 3C 120.
- Hydrogen clouds of redshiftz = ?130 and ?210 km s?1 are situated at 3 and 1 degrees on either side of 3C 120.
- Eleven low-surface-brightness galaxies with 4500 <z < 5300 km s?1 fall within a radius of 8 degrees.
- Seven quasars withz ? 1.35 and radio fluxesS b ? 0.3 fall within a radius of 10 degrees.
19.
I. Lerche 《Astrophysics and Space Science》1977,48(2):335-356
We investigate the ‘equilibrium’ and stability of spherically-symmetric self-similar isothermal blast waves with a continuous post-shock flow velocity expanding into medium whose density varies asr ?ω ahead of the blast wave, and which are powered by a central source (a pulsar) whose power output varies with time ast ω?3. We show that:
- for ω<0, no physically acceptable self-similar solution exists;
- for ω>3, no solution exists since the mass swept up by the blast wave is infinite;
- ? must exceed zero in order that the blast wave expand with time, but ?<2 in order that the central source injects a finite total energy into the blast wave;
- for 3>ωmin(?)>ω>ωmax(?)>0, where $$\begin{gathered} \omega _{\min } (\varphi ){\text{ }} = {\text{ }}2[5{\text{ }} - {\text{ }}\varphi {\text{ }} + {\text{ }}(10{\text{ }} + {\text{ 4}}\varphi {\text{ }} - {\text{ 2}}\varphi ^2 )^{1/2} ]^2 [2{\text{ }} + {\text{ (10 }} + {\text{ 4}}\varphi {\text{ }} - {\text{ 2}}\varphi ^2 {\text{)}}^{{\text{1/2}}} ]^{ - 2} , \hfill \\ \omega _{\max } (\varphi ){\text{ }} = {\text{ }}2[5{\text{ }} - {\text{ }}\varphi {\text{ }} - {\text{ }}(10{\text{ }} + {\text{ 4}}\varphi {\text{ }} - {\text{ 2}}\varphi ^2 )^{1/2} ]^2 [2{\text{ }} - {\text{ (10 }} + {\text{ 4}}\varphi {\text{ }} - {\text{ 2}}\varphi ^2 {\text{)}}^{{\text{1/2}}} ]^{ - 2} , \hfill \\ \end{gathered} $$ two critical points exist in the flow velocity versus position plane. The physically acceptable solution must pass through the origin with zero flow speed and through the blast wave. It must also pass throughboth critical points if \(\varphi > \tfrac{5}{3}\) , while if \(\varphi< \tfrac{5}{3}\) it must by-pass both critical points. It is shown that such a solution exists but a proper connection at the lower critical point (for ?>5/3) (through whichall solutions pass with thesame slope) has not been established;
- for 3>ω>ωmin(?) it is shown that the two critical points of (iv) disappear. However a new pair of critical points form. The physically acceptable solution passing with zero flow velocity through the origin and also passing through the blast wave mustby-pass both of the new critical points. It is shown that the solution does indeed do so;
- for 3>ωmin(?)>ωmax(?)>ω it is shown that the dependence of the self-similar solution on either ω or ? is non-analytic and therefore, inferences drawn from any solutions obtained in ω>ωmax(?) (where the dependence of the solutionis analytic on ω and ?) are not valid when carried over into the domain 3>ωmin(?)>ωmax(?)>ω;
- all of the physically acceptable self-similar solutions obtained in 3>ω>0 are unstable to short wavelength, small amplitude but nonself-similar radial velocity perturbations near the origin, with a growth which is a power law in time;
- the physical self-similar solutions are globally unstable in a fully nonlinear sense to radial time-dependent flow patterns. In the limit of long times, the nonlinear growth is a power law in time for 5<ω+2?, logarithmic in time for 5>ω+2?, and the square of the logarithm in time for 5=ω+2?.
20.
An observational program at the Sacramento Peak Observatory in 1965 provided high-dispersion spectra of the solar chromosphere in several spectral regions simultaneously. These regions included various combinations of the spectral lines Hα, Hβ and H?, the D3-line of Hei, the infrared triplet of Oi, and the H- and K-lines and the infrared triplet of Caii. With the use of an image slicer the observations were made simultaneously at two heights in the solar chromosphere separated by several thousand kilometers. From these data we draw the following conclusions:
- Emission of different lines arises in the same chromospheric features. The intensity ratio of lines of different elements varies significantly from spicule to spicule. For the H- and K-lines of ionized calcium, this ratio remains constant, independent of wavelength throughout the line, overall intensity, and height in the chromosphere. Two rare-earth lines in the wing of the H-line show no spicular structure at all.
- The line-of-sight velocities of many features reverse as a function of time, although most spicules show velocities in only one direction. The simultaneous spectra at two heights show most spicules to have the same line-of-sight velocity at both. There may be an additional class of features, mostly rapidly moving, whose members have line-of-sight velocities that increase with height. These features comprise perhaps 10% of the total. Velocity changes occur simultaneously, to within 20 sec, at two heights separated by 1800 km, indicating velocities of propagation of hundreds of km/sec. The velocity field of individual features is often quite complicated; many spectral features are inclined to the direction of dispersion, implying that differential mass motions are present.
- The existence of anomalously broad H and K profiles is real. Even with high dispersion and the best seeing, such profiles are not resolved into smaller features. The central reversal in K, H and Hα appears to remain unshifted when the wings are displaced in wavelength, indicating that the reversal is non-spicular.