Search Publications
The location of the open-closed magnetic field line boundary in the dawn sector auroral ionosphere
Lester, M.; Rème, H.; Bosqued, J. +7 more
As a measure of the degree of coupling between the solar wind-magnetosphere-ionosphere systems, the rate at which the size of the polar cap (the region corresponding to ionospheric termini of open magnetic flux tubes) varies is of prime importance. However, a reliable technique by which the extent of the polar cap might be routinely monitored has …
Energetic neutral atoms from Jupiter measured with the Cassini magnetospheric imaging instrument: Time dependence and composition
Krimigis, S. M.; Mitchell, D. G.; Roelof, E. C. +2 more
During the Cassini spacecraft flyby of Jupiter in late 2000/early 2001, the Ion and Neutral Camera (INCA, one of three sensors that make up the Cassini Magnetospheric Imaging Instrument (MIMI)) obtained the first ever images of Jupiter's magnetosphere in energetic neutral atom (ENA) flux. These emissions are dominated by hydrogen atoms in the ener…
A Hubble Space Telescope Study of Star Formation in the Inner Resonance Ring of NGC 3081
Byrd, Gene G.; Freeman, Tarsh; Buta, Ronald J.
We present Hubble Space Telescope Wide Field Planetary Camera 2 images of the inner regions of NGC 3081, an absolute magnitude MB=-20.0 early-type barred spiral having four well-defined resonance rings: a nuclear ring, an inner ring, an outer R1 ring, and an outer R'2 pseudoring. Here we focus on a photo…
Late-type giant variables in NGC 6522, LMC and SMC. How do they differ?
Glass, I. S.; Schultheis, M.; Cioni, M. -R.
Complete samples of 2MASS stars in three fields of differing metallicities (and possibly differing age distributions) have been extracted and cross-correlated with MACHO and ISO data to determine their variability and mass-loss properties. In each MK histogram a fall-off in numbers is seen above the tip of the RGB. The luminosity of the…
Spectral Classification of Stars in A Supplement to the Bright Star Catalogue
Abt, Helmut A.
MK spectral types are given for about 584 stars in A Supplement to the Bright Star Catalogue. These are compared with Hipparcos parallaxes to check the reliability of those classifications. The estimated errors are +/-1.2 subtypes, and 10% of the luminosity classes may be wrong.
A Chandra View of the Normal S0 Galaxy NGC 1332. I. An Unbroken, Steep Power-Law Luminosity Function for the Low-Mass X-Ray Binary Population
Humphrey, Philip J.; Buote, David A.
Chandra ACIS -S3 observations of the nearby S0 galaxy NGC 1332 resolve much of the X-ray emission into 73 point sources, of which 37 lie within the D25 isophote. The remaining galaxy emission comprises hot, diffuse gas and unresolved sources and is discussed in two companion papers. The point-source X-ray luminosity function (XLF) shows…
Some Like It Hot: The X-Ray Emission of the Giant Star YY Mensae
Skinner, Stephen L.; Güdel, Manuel; Audard, Marc +3 more
We present an analysis of the X-ray emission of the rapidly rotating giant star YY Mensae observed by Chandra HETGS and XMM-Newton. The high-resolution spectra display numerous emission lines of highly ionized species; Fe XVII to Fe XXV lines are detected, together with H-like and He-like transitions of lower Z elements. Although no obvious flare …
Clean Optical Spectrum of the Radio Jet of 3C 120
Christensen, L.; Mediavilla, E.; Sánchez, S. F. +2 more
We present integral field spectroscopy (IFS) of the central region of 3C 120. We have modeled the nuclear and host galaxy three-dimensional spectra using techniques normally applied to imaging, decoupling both components and obtaining a residual data cube. Using this residual data cube, we detected the extended emission line region associated with…
Evidence for temporal change at Uranus' south pole
Hammel, H. B.; Rages, K. A.; Friedson, A. J.
Analysis of Hubble Space Telescope images of Uranus taken between 1994 and 2002 shows evidence for temporal changes in zonal brightness patterns in the south polar region. Between 1994 and 2002, a relatively bright ring developed near 70° S. The pole itself, which was the brightest area of the southern hemisphere in 1994, has become relatively dar…
Evolution of the Martian atmosphere and hydrosphere: Solar wind erosion studied by ASPERA-3 on Mars Express
Lundin, Rickard; Barabash, Stanislav
The evolution of the Martian atmosphere and the potential existence of a past hydrosphere is a scientific issue of great interest in planetary research. Although the first missions to Mars had a focus on surface features and atmospheric properties, some of the missions (e.g., The Soviet Mars 2, 3 and 5) also carried instruments addressing the sola…