Magellan In Transition
NASA's Magellan has project mapped 98 percent of Venus' surface with synthetic-aperture imaging radar, microwave radiometry, and radar altimetry.
Magellan↗
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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High-Precision Magellan Orbit Determination For Stereo Image Processing
The magellan spacecraft has systematically imaged the surface of Venus using Synthetic aperture Radar (SAR) for two years. During this time Venus rotated three times under the orbit, causing the ground track to make three cycles across the surface.
Magellan↗
Environmental Quenching of Low-surface-brightness Galaxies Near Hosts from Large Magellanic Cloud to Milky Way Mass Scales
Low-surface-brightness galaxies (LSBGs) are excellent probes of quenching and other environmental processes near massive galaxies. We study an extensive sample of LSBGs near massive hosts in the local universe that are distributed across a diverse range of environments. The LSBGs with surface-brightness ${\mu }_{\mathrm{eff},{g}}\gt 24.2\,\mathrm{mag}\,{\mathrm{arcsec}}^{-2}$ are drawn from the Dark Energy Survey Year 3 catalog while the hosts with masses $9.0\lt \mathrm{log}({{ \mathcal M }}_{\star }/{M}_{\odot })\lt 11.0$ comparable to the Milky Way and the Large Magellanic Cloud are selected from the z0MGS sample. We study the projected radial density profiles of LSBGs as a function of their color and surface brightness around hosts in both the rich Fornax–Eridanus cluster environment and the low-density field. We detect an overdensity with respect to the background density, out to 2.5 times the virial radius for both hosts in the cluster environment and the isolated field galaxies. When the LSBG sample is split by g − i color or surface brightness μ eff, g , we find the LSBGs closer to their hosts are significantly redder and brighter, like their high-surface-brightness counterparts. The LSBGs form a clear “red sequence” in both the cluster and isolated environments that is visible beyond the virial radius of the hosts. This suggests preprocessing of infalling LSBGs and a quenched backsplash population around both host samples. More so, the relative prominence of the “blue cloud” feature implies that preprocessing is ongoing near the isolated hosts compared to the cluster environment where the LSBGs are already well processed.
79 ASTRONOMY AND ASTROPHYSICS↗
Decrease in the high energy X-ray flux from Cen XR-2. Search for X-rays from the large and small Magellanic clouds
High energy X ray sky survey data on decreased intensity of Cen XR-2, and X ray energy flux from Magellanic clouds - Mildura, Australia, October 15 and 24, 1967
Clark, G. W.↗
Search for X-rays from the large and small Magellanic clouds.
Energetic X ray intensities from large and small Magellanic clouds investigated by balloon flight sky survey, noting energy flux upper limits
Clark, G. W.↗
A search for absorption of the soft X-ray diffuse flux by the Small Magellanic Cloud
Extragalactic background soft X ray diffuse flux consistent with absorption by Small Magellanic Cloud
Bunner, A. N.↗
X-ray emission from the Magellanic Clouds observed by Uhuru.
Description of three sources in the Large Magellanic Cloud and one in the Small Cloud which have been discovered by Uhuru. These sources each emit about 10 to the 38th erg/sec in the 2- to 7-keV band, and they account for more than 90% of the total emission from the Clouds. The source in the Small Cloud shows time variability on time scales of hours.
Leong, C.↗
Nucleosynthesis in the Magellanic Clouds and the Galaxy.
Available evidence on the chemical composition of the Magellanic Clouds (when compared to the Galaxy) is not sufficient for a detailed theory of the chemical evolution of the Clouds to be developed at present. However, this evidence is thus far compatible with the view that much of the material of the Clouds went through a considerable amount of nucleosynthesis early in its history. The Clouds could once have been part of the Galaxy, or they could have formed as satellites when the protogalaxy condensed. The general problem of the chemical evolution is tied closely to the problem of galaxy formation which remains unsolved.
Burbidge, G.↗
Soft X-ray survey of the Large Magellanic Cloud
A soft X-ray survey (0.15-1.5 keV) of the Large Magellanic Cloud (LMC) during a sounding rocket flight, reveals possible emission from the centrally located barlike structure. No evidence was seen for absorption of the soft X-ray 'background' in the direction of the LMC. Both of these observations support the hypothesis of a local production of the soft X-ray background.
Rappaport, S.↗
Observations of X-ray sources in the Large Magellanic Cloud by the OSO-7 satellite
Observations of the Large Magellanic Cloud with the 1-40 keV X-ray detectors on the OSO-7 satellite are reported. Results include the discovery of a previously unreported source LMC X-5, measurements of the spectral characteristics of four sources, and observations of their variability on time scales of months.
Markert, T. H.↗
Apollo 16 far-ultraviolet imagery and spectra of the Large Magellanic Cloud
The Large Magellanic Cloud was observed by the far ultraviolet camera spectrograph from the lunar surface during the Apollo 16 mission 22 April 1972. Images were obtained with about 3 arc min resolution, in the 1,050 to 1,600 and 1,250 to 1,600 A wavelength ranges, of nearly the entire LMC. Spectra were also obtained in the 1,050 to 1,600 and 900 to 1,600 A ranges along a strip 1/4 deg wide (determined by the instrument's grid collimator) passing across the LMC. The images and spectra have been scanned with a PDS microdensitometer, and isodensity contour plots have been prepared using the Univac 1108 computer.
Page, T.↗
Soft X-rays from the Large Magellanic Cloud - Implications on the origin of the diffuse X-ray background
A total soft X-ray luminosity of approximately 10 to the 38th power ergs/s was observed from the Large Magellanic Cloud (LMC) during pointed rocket observations in November 1973. Simple spectral parameters are derived and discussed. Upper limits at 1 KeV to several known LMC point sources are presented. A diffuse bar source reported previously was not detected. Strong limits are placed on the fraction of halo and extragalactic diffuse X-ray flux observed in the direction of the LMC due to the lack of correlation of the 0.25-KeV diffuse flux with interstellar hydrogen in the Galaxy and in the LMC.
Long, K. S.↗
Color composite photographs of the Magellanic Clouds
Simulated color photographs of the Large and Small Magellanic Clouds were produced from black and white photographs taken with the Schmidt telescope at Cerro Tololo using multichannel projection techniques. A brief discussion of the techniques employed, the color photographs obtained, and the potential of future work of this type is given.
Dufour, R. J.↗
Apollo 17 far-ultraviolet spectra in the Large Magellanic Cloud
During the Apollo 17 mission, low-resolution far-ultraviolet spectra were obtained for two parts of the Large Magellanic Cloud. The spectra are reasonably well fit by a model of a 30,000-K star reddened by a (B-V) color excess of 0.3 magnitude, but other combinations of temperature and reddening provide equally good fits.
Henry, R. C.↗
Apollo-16 far-ultraviolet spectra in the Large Magellanic Cloud
Spectra in the wavelength ranges from 900 to 1600 A and 1050 to 1600 A of some OB associations in the Large Magellanic Cloud were obtained from the lunar surface by the Apollo-16 far-ultraviolet camera/spectrograph on April 22, 1972. The observed spectral distributions appear consistent with a stellar model having an effective temperature of 30,000 K, reddened by E(B-V) = 0.3, and characterized by the average far-ultraviolet extinction curve of Bless and Savage (1972). However, the absolute intensity of the far-ultraviolet spectrum of the associations NGC 2050 and 2055 seems somewhat too bright in comparison with ground-based photometry.
Carruthers, G. R.↗
Apollo 16 far-ultraviolet imagery and spectra of the Large Magellanic Cloud
The Large Magellanic Cloud (LMC) was observed with a far-ultraviolet camera/spectrograph (Experiment S-201) from the lunar surface during the Apollo 16 mission. Images were obtained with about 3-arcmin resolution, in the 1050-1600- and 1250-1600-A wavelengths ranges, of nearly the entire LMC. Spectra were also obtained in the 1050-1600- and 900-1600-A ranges with 30-40-A resolution along a strip 0.25 deg wide passing across the LMC. The images and spectra have been scanned with a microdensitometer, and analyses of the data to date are discussed.
Page, T. L.↗
Far-infrared observations of Large Magellanic Cloud H II regions
Far-infrared emission has been measured from four Large Magellanic Cloud H II regions: the 30 Doradus nebula, MC75, MC76 and MC77. The far-infrared radiation is thermal emission from dust heated by starlight. The results show that the LMC H II regions, like H II regions in the Galaxy, have far-infrared luminosities comparable to the total luminosity of their exciting stars.
Werner, M. W.↗
On the lack of absorption of 1 keV diffuse X-rays by the Small Magellanic Cloud
The contribution to the diffuse X-ray background near 1 keV cosmic (extragalactic) origin is poorly known. Data from a slow scan across the Small Magellanic Cloud by the Wisconsin soft X-ray experiment on OSO 8 are analyzed to search for absorption of a possible cosmic component to the diffuse flux. No indication of an X-ray shadow near 1 keV is found, setting an upper limit to the intensity of the flux originating beyond the SMC that is inconsistent with a cosmic spectrum of 11 E to the -1.4 photons per (sq cm s sr keV), even allowing for depletion of the absorbing elements in the SMC. Unless emission by the SMC or an upward fluctuation in the galactic or cosmic diffuse flux at the position of the SMC has canceled out the expected absorption, the contribution to the diffuse flux at 1 keV from beyond the SMC must be less than 50% of that expected for an extrapolated E to the -1.4 source spectrum.
Bunner, A. N.↗