The cosmic gamma-ray spectrum near 1 MeV observed by the ERS-18 satellite
Omnidirectional cosmic gamma ray flux near one MeV observed by ERS-18 satellite, plotting spectral energy distribution
Gruber, D.↗
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Standard values for the solar constant and its spectral components
Solar constant and spectral energy distribution standard values by high altitude aircraft, balloon and spacecraft measurements
Drummond, A. J.↗
Ultraviolet reflectivity of Jupiter observed from a rocket
UV spectral energy distribution of Jupiter from rocket-borne Cassegrain telescope observation, computing planet geometric reflectivity in 2100- 3600 A range
Kondo, Y.↗
The infrared object HD 45677
IR stellar object HD 45677, discussing IR spectral energy distribution in terms of black body temperature range
Allen, D. A.↗
The shadow band phenomenon
Shadow band observations during 7 March 1970 solar eclipse, determining spectral energy distribution from magnetic tape recordings of collimated photocells output
Daly, C. J.↗
A compact spectroradiometer for solar simulator measurements
Compact spectral irradiance probe has been designed and built which uses wedge filter in conjunction with silicon cell and operational amplifier. Probe is used to monitor spectral energy distribution of solar simulators and other high intensity sources.
Seward, H. H.↗
Comet Spectra
The nature and chemical composition of comets as determined by their spectral energy distributions and polarization of the scattered radiation are discussed. The study is divided into two parts: (1) a description of the spectra and, (2) a discussion of the excitation mechanisms responsible for their production.
C. Arpigny↗
The infrared sources in M8.
The spectral energy distribution and size of the source of infrared radiation from Herschel 36 in M8 have been investigated. Radiation from the diffuse source in the vicinity of the hourglass has been measured. It is shown that a significant fraction of the 10-microns flux comes from an unresolved source centered on Herschel 36. Other stars in M8 have also been investigated as potential sources of infrared radiation.
Woolf, N. J.↗
Photoelectric spectrophotometry of OQ 172 and OH 471
Absolute spectral energy distributions for the large redshift quasars OQ 172 and OH 471 are discussed along with similar data for two other quasars 4C05.34 and PHL 957. Assuming cosmological redshifts, OQ 172 and OH 471 are not as luminous as PHL 957. If these quasars are basically similar and if radiative processes dominate, the strength of Ly alpha and the behavior of the continuum at the Lyman limit strongly suggest that these objects consist of a central ionizing source surrounded by discrete clouds, filaments or a gaseous structure such as a disk. This gaseous matter does not cover the whole solid angle surrounding the source.
Oke, J. B.↗
Photoelectric spectrophotometry of OQ 172 and OH 471
Absolute spectral energy distributions for the large-redshift quasars OQ 172 and OH 471 are discussed along with similar data for two other quasars: 4C 05.34 and PHL 957. If the redshift are assumed to be cosmological, OQ 172 and OH 471 are not as luminous as PHL 957. If these quasars are basically similar and if radiative processes dominate, the strength of alpha and the behavior of the continuum at the Lyman limit strongly suggest that these objects consist of a central ionizing source surrounded by discrete clouds, filaments, or a gaseous structure such as a disk. This gaseous matter does not cover the whole solid angle surrounding the source.
Oke, J. B.↗
Scanner observations of carbon stars from 5000 to 7000 A
New photoelectric spectral scans of 26 N-type and 11 R-type carbon stars are presented. The spectral energy distributions were also measured to gain new insight into the composition, chemistry, and structure of carbon star atmospheres. Using the best continuum points in the wavelength region from 5000 to 7000 A a color index is defined, taking into account fluxes at 0.57 and 0.68 microns. The new color index correlates well with the widely used (V-R) broad-band color index.-
Fay, T. D., Jr.↗
Ultraviolet spectrophotometry of Sirius from Gemini 12
The spectral energy distribution of Sirius between 2500 and 3700 A at a resolution of 7 A is obtained from plates taken on Gemini 12. The agreement with other observations and the most recent line-blanketed model atmospheres is good. The equivalent width of the Mg II doublet near 2800 A is 6.0 A, if the continuum level is represented by regions near 2650 and 2910 A. This is consistent with expectations for a hot Am star and implies line blocking of up to 15% in this wavelength region.
Spear, G. G.↗
Spectrophotometry of supernovae
Studies were made of a type II supernova (SN 1970g in M 101) and a type I supernova (SN 1972e in NGC 5253) covering the wavelength range from 3200 to 10,000 A. The absolute spectral energy distributions show that both types have a continuum that varies slowly and uniformly with time and carries the bulk of the radiated flux at early epochs. Some lines in both types have P Cygni profiles: broad emissions with broad absorptions at their violet edges. Some lines are common to both types and persist throughout the evolution of the spectrum.
Kirshner, R. P.↗
Further observations of BL Lacertae
Spectrophotometric observations of BL Lac have been obtained under conditions of fair to excellent seeing with BL Lac near the zenith. The nucleus was faint for all observations. Four absorption features identified as the Mg I and MgH band, the 4410-A band, the G-band, and H and K of Ca II, are observed. The redshift is approximately 0.070, in agreement with results in a previous paper. When the effects of the radiation from the central bright source are removed as well as possible, the residual spectral energy distribution is found to be very similar to that of a standard giant elliptical galaxy redshifted by 0.070 and reddened by a factor corresponding to a color excess of 0.28 to 0.40. The absolute visual magnitude of the underlying galaxy is -22.6 if the Hubble constant is 60 km/s per Mpc and the color excess is 0.28.
Thuan, T. X.↗
Seyfert galaxies with strong Fe II emission
Measurements are reported for the spectral energy distributions of the Seyfert galaxies Zw 2130+09 and Zw 0051+12 as well as the quasar 3C 273 over the wavelength range from 3300 to 10,760 A. Absolute emission-line intensities are derived for numerous Fe II blends and the O I line at 8446 A. Several new Fe II emission features are identified, the absence of Fe III emission is noted, and interesting properties of the individual spectra are described. Constraints on the ionizing continuum and on the geometry and velocity field of the emission-line regions are discussed. The observations show that Seyfert galaxies with strong Fe II emission also have strong O I 8446-A emission and that a flat continuum in the near-UV appears to be common in such objects. Assuming photoionization, it is suggested that both the Fe II and the O I emission could result from continuum fluorescence in an outer, optically thick H I zone in an emission-line region about 1 pc in radius and consisting of many small high-velocity filaments.
Oke, J. B.↗
The stellar content of the nuclear regions of Sc galaxies
Stellar-population syntheses based on absolute spectral energy distributions over the wavelength range from 3300 to 10,400 A are used to determine the stellar content of the nuclear regions of seven nearby Sc galaxies (NGC 628, 1073, 1084, 1637, 2903, 4321, and 5194). A linear-programming procedure is employed to construct models of the overall stellar populations whose spectra closely match those of the seven galaxies. Absolute measurements of the emission-line spectra of the nuclear regions are also provided. It is found that: (1) intrinsic reddening is probably present in each nuclear region; (2) the upper main sequence is substantially populated in most of the models; (3) the lower main sequence contributes insignificantly to the luminosity in all optimal solutions; (4) substantial contributions are made by evolved M stars at long wavelengths in all the models; (5) the model photometric M/L ratios are low, of the order of unity; and (6) the O-B stars arising naturally in the population models are just sufficient to provide the observed nuclear ionization in all the galaxies except NGC 5194, which may be collisionally ionized. The properties of the nuclear regions are shown to be consistent with the existence of a common initial mass function for star formation and a variety of time dependences for the star-formation process. A possibly significant correlation is noted between nuclear stellar content and overall dynamical properties in four of the galaxies.
Turnrose, B. E.↗
The spectrum of the halo surrounding the quasar PHL 1070
The quasar PHL 1070 and its surrounding halo of light have been observed with the Palomar multichannel spectrophotometer using circular and annular apertures. The central quasar has a magnitude of 16.6 and an emission-line redshift of 0.076 + or - 0.002. The halo light has a magnitude of 19.0 and a possible absorption-line system with an absorption redshift of 0.067 + or - 0.008. The magnitude, possible absorption lines, and probable spectral energy distribution of the halo are consistent with those of a normal galaxy at the redshift of the quasar.
Morton, D. C.↗
Spectral variations in brightest cluster galaxies
Multichannel-spectrometer scans of 56 of the brightest galaxies in faint clusters have been examined for evidence of color evolution. The dispersion introduced into the sample by some 25% of the galaxies which have unusual spectra is shown to be sufficient to obscure evolutionary variations. On omitting these galaxies it is found that over a time equivalent to a redshift of 0.46, B-V decreases by no more than 0.04 mag. A comparative analysis of the spectral energy distributions suggests that their differences may be due to a combination of the dispersion in metallicity among the members of the sample and to anomalous reddening of individual galaxies.
Wilkinson, A.↗