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Cosmic ray positrons and negatrons differential intensities near north geomagnetic pole from balloon flight measurements, noting solar modulation effects
Diffuse background of 2-20 keV X rays over Scorpius to North Galactic Pole sky band by rocket measurements
A two-component model of the local interstellar medium was developed, based on the Radio Astronomy Explorer (RAE-1) satellite observations of the low frequency (0.2 - 10 MHz) galactic radio background spectrum. The model shows evidence for a thick spiral arm and a thick electron disk of 600 and 1200 pc slab thicknesses, respectively. The temperature difference between the north galactic pole and anticenter directions supports the concept of a local positive thermal gradient away from the galactic plane. A preliminary discussion of the influence of the Razin effect on the model is also presented.
An upper limit to the local population II density is derived, in terms of the mass-luminosity ratio, on the basis of U, B, and V photometric observations of several thousand stars with V magnitudes between 12 and 18 in a region near the North Galactic Pole. The photographic and photoelectric photometry and the reduction procedures are discussed. Models of the density distribution and luminosity function of the population II stars are used to predict their distribution in color and apparent magnitude. The derived local density of population II is found to be significantly lower than previous estimates. Possible causes for this discrepancy are considered.
The spatial distribution of sodium emission north and south of Io was observed to have a time-dependent asymmetry correlated with Io's magnetic latitude. The spatial gradient was greatest when Jupiter's north magnetic pole pointed away from Io; this is a configuration of maximum probability of decametric emission. A hypothesis is invoked for explaining the asymmetry and used to calculate preliminary fluxes of low-energy trapped charged particles in the vicinity.
A compact X-ray source near the North Galactic Pole has been detected with the low-energy X-ray telescope aboard the SAS-3 satellite. The spectral temperature of the source is less than 1 million K, and the energy flux at the earth is 3 by 10 to the -10th power erg/sq cm/sec above 0.1 keV. The flux appeared to be constant both on short time scales (10-1000 s), and over the interval from the first SAS-3 observation (June 12, 1975) to the latest (July 15, 1975). The possible identification of this source with the hot white dwarf HZ 43 is discussed.
A clearly established diffuse celestial gamma-ray component was seen by SAS-2 above 35 MeV, after examining several regions of the sky at different latitudes, including the north celestial pole. For energies above 100 MeV the gamma ray results are consistent with an equation of the form I(b)=C1+C2/sin b with the second term being dominant, suggesting that the radiation above 100 MeV comes largely from the local regions of the galactic disk. Between 35 and 100 MeV, a similar equation is also a reasonable representation of the data, but here the two terms are comparable, with the first, or isotropic term, actually being the larger one. In addition to indicating that the diffuse radiation is partially galactic, these results imply a steepness for the energy spectrum of the diffuse isotropic component which places significant constraints on possible theoretical models of this radiation.
While dark adapted, two Apollo-Soyuz astronauts saw eighty-two light flash events during a complete 51 deg orbit which passed near the north magnetic pole and through the South Atlantic Anomaly. The frequency of events at the polar parts of the orbit is 25 times that noted in equatorial latitudes and no increased frequency was noted in the South Atlantic Anomaly at the 225-km altitude. The expected flux of heavy particles at the northern and southern points is 1-2/min per eye, and the efficiency for seeing high Z-high energy (HZE) particles which were below the Cerenkov threshold is 50%.
Real-time N2O measurements have been made in situ at the South Pole, Antarctica, north and south of the equator from on board the Alpha Helix and over the Pacific Ocean on several aircraft flights from the U.S. to New Zealand, Australia and 90 deg S. In addition, an automated EC-GC has been operated for the past year intermittently monitoring N2O in surface air at a rural site in the wheatlands of eastern Washington state. The data obtained are consistent and in agreement with the data obtained from the analyses of a large number of samples collected both from ground stations and a variety of aircraft flights made in the southern and northern hemisphere. The observed global data show no interhemispheric differences. The present concentration of N2O in the troposphere is measured to be 330 + or - 3 ppbv. Its vertical distribution in the troposphere is very uniform. A small decrease (2-3 percent) across the tropopause is characteristically observed in the high-altitude flights.
A survey has been made of a quarter of the celestial sphere from balloon altitudes with a telescope having a 1.6-deg beamwidth and two spectral bands: 3-10 kaysers and 10-25 kaysers. The limiting sensitivity of the survey was 10,000 Jy. The galactic disk was detected from 358 to 45 deg galactic longitude. The total far-infrared flux from several regions on the galactic plane measured in this survey is 5-10 times larger than that observed by others using smaller beamwidths and small-amplitude spatial chopping, indicating that a substantial part of the emission comes from extended sources. Two other extended sources were also observed, one in the Cygnus region and the other a spur running off the galactic plane at 130 deg galactic longitude toward the north celestial pole. In addition, lower limits for the spectral index of interstellar dust emission are presented.
Probabilities are calculated for acquiring suitable guide stars (GS) with the fine guidance system (FGS) of the space telescope. A number of the considerations and techniques described are also relevant for other space astronomy missions. The constraints of the FGS are reviewed. The available data on bright star densities are summarized and a previous error in the literature is corrected. Separate analytic and Monte Carlo calculations of the probabilities are described. A simulation of space telescope pointing is carried out using the Weistrop north galactic pole catalog of bright stars. Sufficient information is presented so that the probabilities of acquisition can be estimated as a function of position in the sky. The probability of acquiring suitable guide stars is greatly increased if the FGS can allow an appreciable difference between the (bright) primary GS limiting magnitude and the (fainter) secondary GS limiting magnitude.
The presence of an emission-line component to the radiation field is suggested by rocket observations, at low resolution, of the spectrum of the diffuse, far-ultraviolet background near the north galactic pole. Removal of the line emission leaves a residual uniform cosmic ultraviolet background radiation of only 150 + or - 50 photons/sq cm s sr A, or about half that previously reported. The lines, which are at the wavelengths of the collisionally-excited atom emissions that have been predicted to arise from a hot galactic corona, suggest that there is no need to explain observed high-ionization states at high galactic latitudes as being due to photoionization caused by neutrino decay.
Sufficient and unambiguous evidences of the intrinsic martian magnetic field are: (1) the independence of the field polarity in Maritan magnetic tail from interplanetary magnetic fields (IMF) polarity inversion, established with the help of Mars-5 data; and (2) the incongruity between the sign of the radial component of the field measured in Martian tail (Mars-2) and that of the draped model with IMF data measured simultaneously (Mars-3) on February 23-24, 1972. Mar's dipole magnetic moment is within the limits (1.5 to 2.2) x 10 to e 22 G cc. The dipole axis is deflected from that of rotation on the angle I 15 deg. The North magnetic pole is located in the South Hemisphere. In the frame of the precession-dinamo model the magnetic fields of the planets Mars and Earth are similar. The Martian magnetic field is the real obstacle for the solar wind near the planet.
It is reaffirmed in this reply that the 'classical' polar wind is based on the thermal escape of the light ions H(+) and He(+). It is asserted that the polar ion flow observations presented in the Gurgiolo and Burch (1985) comment paper, made by the High Altitude Plasma Instrument (HAPI) instrument on Dynamics Explorer-1 (DE), are O(+) and that the probable origin of these ions, which is consistent with the observations, is a highly localized region in the dayside polar cleft; this is a distinctly different source region than that of the polar wind. Velocity and mass selection, as a result of E x B convection acting on ions from a localized source region in the polar cusp or the dayside polar cap boundary, determines the measured HAPI ion distribution. The Retarding Ion Mass Spectrometer instrument on DE, during the same time period, was measuring the light ion polar wind with flow energies of less than 2.5 eV which originated in the polar cap ionosphere very near the north magnetic pole.
A deep far-infrared survey is presented using over 1000 scans made of a 4 to 6 sq. deg. field at the north ecliptic pole by the IRAS. Point sources from this survey are up to 100 times fainter than the IRAS point source catalog at 12 and 25 micrometers, and up to 10 times fainter at 60 and 100 micrometers. The 12 and 25 micrometer maps are instrumental noise-limited, and the 60 and 100 micrometer maps are confusion noise-limited. The majority of the 12 micrometer point sources are stars within the Milky Way. The 25 micrometer sources are composed almost equally of stars and galaxies. About 80% of the 60 micrometer sources correspond to galaxies on Palomar Observatory Sky Survey (POSS) enlargements. The remaining 20% are probably galaxies below the POSS detection limit. The differential source counts are presented and compared with what is predicted by the Bahcall and Soneira Standard Galaxy Model using the B-V-12 micrometer colors of stars without circumstellar dust shells given by Waters, Cote and Aumann. The 60 micrometer source counts are inconsistent with those predicted for a uniformly distributed, nonevolving universe. The implications are briefly discussed.
A single spectrum, of extremely long integration time, is used to place stringent new limits on the diffuse far-UV background in the 500-1200 A region. This spectrum, obtained in the vicinity of the North Galactic Pole with the Voyager 2 UV spectrometer, can be explained solely on the basis of resonant scattering from interplanetary H I and He I. Limits on any additional sources of sky background radiation corresponding to 100-200 photons/sq cm per sec/sr per A for continuum emission and 6000 photons/sq cm per sec/sr for line emission are demonstrated. Comparisons of these upper limits with existing measurements and various potential source mechanisms are discussed. The first detection of resonantly scattered interplanetary H I Ly-gamma (973 A) emission is reported.
The results of two searches for brown dwarfs using IRAS data bases are reviewed. From one survey, it is concluded that all of the 5776 high-latitude point sources in the IRAS Point Source Catalog can be positionally associated with stars or galaxies by simple comparisons with optical catalogs and atlases. Only one object near the north Galactic pole possesses an optical/IR color cool enough to be considered as a candidate; it is found to be an unusual carbon star of 1300 K with a probable distance far out in the Galactic halo. The more sensitive Serendipitous Survey, which detected objects about five times fainter than the other survey, also found no brown dwarfs. This survey found fewer ordinary stars than the number extrapolated from the less sensitive survey.
Redshifts and morphological types are presented for a complete sample of 1093 galaxies with m(pg) less than or equal to 15.5 mag in a 6-deg-wide strip crossing the north Galactic pole. Also presented are redshifts for an additional 92 fainter galaxies in the same strip. Outside of the core of the Coma Cluster, both early- and late-type galaxies trace essentially the same structures in redshift space. Thinner slices illustrate the small velocity dispersion perpendicular to the surfaces in the survey.