Passive instrumentation and stimuli generation for Saturn IB equipment checkout. Volume I - Summary technical report Final technical report, 26 Jun. 1965 - 31 May 1966

Passive instrumentation and stimuli generation for Saturn IB equipment checkout - nondestructive testin

Implementations guidelines, airborne evaluation equipment, advanced system checkout design, phase B Final report, 29 Jun. 1965 - 29 Jul. 1966

Airborne checkout equipment functions and implementation for Saturn IVB stage and instrument uni

X-rays from T Tau: A test case for accreting T Tauri stars

We test models for the generation of X-rays in accreting T Tauri stars (TTS), using X-ray data from the classical TTS T Tau. High-resolution spectroscopy from the Reflection Grating Spectrometers on XMM-Newton is used to infer electron densities, element abundances and the thermal structure of the X-ray source. We also discuss the ultraviolet light curve obtained by the Optical Monitor, and complementary ground-based photometry. A high-resolution image from Chandra constrains contributions from the two companions of T Tau N. The X-ray grating spectrum is rich in emission lines, but shows an unusual mixture of features from very hot (~30 MK) and very cool (1-3 MK) plasma, both emitted by similar amounts of emission measure. The cool plasma confirms the picture of a soft excess in the form of an enhanced OVII/OVIII Lya flux ratio, similar to that previously reported for other accreting TTS. Diagnostics from lines formed by this plasma indicate low electron densities (<~ 1E10 cm-3). The Ne/Fe abundance ratio is consistent with a trend in pre-main sequence stars in which this ratio depends on spectral type, but not on accretion. On the basis of line density diagnostics, we conclude that the density of the cool ``soft-excess'' plasma is orders of magnitude below that predicted for an accretion shock, assuming previously determined accretion rates of (3-6)E-8 M_sun/y. We argue that loading of magnetic field lines with infalling material suppresses the heating process in a part of the corona. We thus suggest that the X-ray production of T Tau is influenced by the accretion process although the X-rays may not form in the bulk of the accretion footpoints.Comment: 12 pages, 7 figures, A&A style. Accepted by A&A, to appear in a special section/issue dedicated to the XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST). See also http://www.issibern.ch/teams/Taurus/papers.htm

A Single Circumbinary Disk in the HD 98800 Quadruple System

We present sub-arcsecond thermal infrared imaging of HD 98800, a young quadruple system composed of a pair of low-mass spectroscopic binaries separated by 0.8'' (38 AU), each with a K-dwarf primary. Images at wavelengths ranging from 5 to 24.5 microns show unequivocally that the optically fainter binary, HD 98800B, is the sole source of a comparatively large infrared excess upon which a silicate emission feature is superposed. The excess is detected only at wavelengths of 7.9 microns and longer, peaks at 25 microns, and has a best-fit black-body temperature of 150 K, indicating that most of the dust lies at distances greater than the orbital separation of the spectroscopic binary. We estimate the radial extent of the dust with a disk model that approximates radiation from the spectroscopic binary as a single source of equivalent luminosity. Given the data, the most-likely values of disk properties in the ranges considered are R_in = 5.0 +/- 2.5 AU, DeltaR = 13+/-8 AU, lambda_0 = 2(+4/-1.5) microns, gamma = 0+/-2.5, and sigma_total = 16+/-3 AU^2, where R_in is the inner radius, DeltaR is the radial extent of the disk, lambda_0 is the effective grain size, gamma is the radial power-law exponent of the optical depth, tau, and sigma_total is the total cross-section of the grains. The range of implied disk masses is 0.001--0.1 times that of the moon. These results show that, for a wide range of possible disk properties, a circumbinary disk is far more likely than a narrow ring.Comment: 11 page Latex manuscript with 3 postscript figures. Accepted for publication in Astrophysical Journal Letters. Postscript version of complete paper also available at http://www.hep.upenn.edu/PORG/web/papers/koerner00a.p

Research on passive instrumentation and stimuli generation for Saturn IB equipment checkout. Volume III - Appendix A, laboratory data Final technical report, 26 Jun. 1965 - 31 May 1966

Passive instrumentation and stimuli generation for Saturn IB equipment checkout - laboratory dat

Research on passive instrumentation and stimuli generation for Saturn IB equipment checkout. Volume IV - Appendix B, instrument unit data sheets Final technical report, 26 Jun. 1965 - 31 May 1966

Passive instrumentation and stimuli generation for Saturn IB equipment checkout - instrument unit data sheet

Research on passive instrumentation and stimuli generation for Saturn IB equipment checkout. Volume II - Detailed technical report Final report, 26 Jun. 1965 - 31 May 1966

Passive instrumentation and stimuli generation for Saturn IB equipment checkout - nondestructive testin