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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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All sourcesNASA NTRSDOE OSTI
NASA NTRS1991

Particle astrophysics

The following scientific areas are reviewed: (1) cosmology and particle physics (particle physics and the early universe, dark matter, and other relics); (2) stellar physics and particles (solar neutrinos, supernovae, and unconventional particle physics); (3) high energy gamma ray and neutrino astronomy; (4) cosmic rays (space and ground observations). Highest scientific priorities for the next decade include implementation of the current program, new initiatives, and longer-term programs. Essential technological developments, such as cryogenic detectors of particles, new solar neutrino techniques, and new extensive air shower detectors, are discussed. Also a certain number of institutional issues (the funding of particle astrophysics, recommended funding mechanisms, recommended facilities, international collaborations, and education and technology) which will become critical in the coming decade are presented.

Sadoulet, Bernard↗
NASA NTRS1991

Research in planetary Astronomy

The focus was on the study, via near infrared observations, of the outer planets and their satellites. In the last year, these observations have emphasized imaging observations using the Cassegrain infrared camera at the f/70 focus of the 200 inch Hale telescope.

Matthews, K.↗
NASA NTRS1994

A multiwavelength study of star formation in the L1495E cloud in Taurus

We have carried out a deep (t = 30,000 s) X-ray search of the eastern portion of the L1495 cloud centered on the well-known weak line T Tauri star (WTTS) V410 Tau using the Roentgen Satellite (ROSAT) PSPC. This deep exposure enabled a search for candidate pre-main-sequence (PMS) objects in this cloud to a limit approximately 20 times more sensitive than that typical of the fields examined with the Einstein searches. Despite assertions that the PMS population in Taurus-Auriga is nearly completely known, this Stet survey revealed eight new PMS objects in a region 50 min in diameter, as compared to a previously known stellar population of 12 objects, including deeply embedded Infrared Astronomy Satellite (IRAS) sources. Spectroscopic and photometric observations enable us to place these objects in the H-R diagram. The newly discovered objects are predominantly stars of spectral-type M0 and later, and a large fraction (6/8) appear to be surrounded by circumstellar accretion disks as judged by their infrared excess and H alpha emission. We combined the data for these Stet-discovered objects with extant and new data for the previously identified PMS stars in this region to examine the history of star formation and the frequency distribution of stellar masses in this cloud. If the 'post-ROSAT' population is either complete or representative, we conclude (1) that star formation in L1495 East took place approximately 1 x 10(exp 6) yr ago and that the spread in ages is small; (2) the frequency distribution of masses, N(M), in this apparently coeval group appears to peak near log M = -0.5 (using masses derived from recently published PMS tracks of D'Antona & Mazzitelli and Swenson et al. and to decline toward lower masses. The derived N(log M) for L1495E compares well with the IMF derived from studies of stars in the solar neighborhood, a result which suggests that the Taurus-Auriga clouds are currently producing stars whose mass spectrum approximates the time/space-averaged IMF for the solar neighborhood.

Strom, Karen M.↗
NASA NTRS1999

High Energy Properties of Galactic Superluminals

Intensive searches across the electromagnetic spectrum have shown that transient X-ray binary systems exhibit properties similar to the central engines of AGNs. Having proven that accretion disks are present in both types of systems, it is now the task to determine the accretion physics which brings about the observed phenomena. The galactic superluminal transient sources, which are strongly suspected of containing black holes, are particularly attractive for studying state changes, jets, quasi-periodic behavior, and flaring/outburst behavior on timescales a million times shorter than those of their extragalactic counterparts. The galactic sources GRS 1915+105, GRO J1655-40 and more recently-detected transients such as XTE J1748-288 have demonstrated a rich variety of spectral and temporal behaviors. I review some of these observations from the perspective of high energy astronomy with emphasis on recent data from the Compton Observatory and Rossi X-ray Timing Explorer.

Alan, Harmon B.↗
NASA NTRS1990

STS-35: Astro-1 BBXRT Problem Area

The primary objective of STS-35 was to conduct observations in ultraviolet and X-ray astronomy with the ASTRO-1 observatory. ASTRO-1 consisted of four telescopes: Hopkins Ultraviolet Telescope (HUT); Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE); Ultraviolet Imaging Telescope (UIT); and Broad Band X-ray Telescope (BBXRT). This videotape shows work on the BBXRT in the clean room. Two days before a scheduled September 1 launch date, the avionics box on the BBXRT malfunctioned and had to be changed and retested.

Source record↗
NASA NTRS2000

Structure of Protoplanetary Environments

Our research focused on the structure and composition of the disks in the T Tau and Haro 6-10 multiple star systems and on the nature of the 'infrared companions' that these systems contain. This work has resulted in two papers, one on T Tau, presently under review at the Astrophysical Journal, and the other, on Haro 6-10, about to be submitted to Astronomy and Astrophysics. In the paper 'Evidence for Extinction and Accretion Variability in T Tau S' by Tracy L. Beck, L. Prato, and M. Simon, we present angularly resolved spectra of T Tau N (the visible star) and T Tau S (the infrared companion, IRC) in the three micrometer water ice-feature and the K-band. Most of the water ice absorption lies along the line of sight to T Tau S, confirming it is seen through stronger obscuration. A decrease in the ice-band absorption toward T Tau S between 12/98 and 1/00, significant, at the two-sigma level, was associated with an increase in its near IR flux. Bracket gamma emission is detected in T Tau N and S, and H2 (2.12 micrometer) emission only toward T Tau S, consistent with previous studies of IRCs. Our results suggest that the near IR variability of T Tau S is probably caused by both variations in accretion rate and extinction. Our paper on Haro 6-10, 'The Near IR and Ice Band Variability of Haro, 6-10' by Ch. Leinert, T.L. Beck, S. Ligori, M. Simon, J. Woitas, and R.R. Howell, represents a fusion of originally independent efforts at the Max Planck Institut fur Astronomie (Heidelberg) and Stony Brook. Our combined observations demonstrate that both Haro 6-10 S (the visible star) and Haro 6-10 N (the IRC) vary significantly in near IR flux on time scales as short as a month. The substantial decrease of Haro 6-10 S in the last four years carries the photometric signature of increased extinction. However, a comparable K-band flux increase of the IRC is associated with a dimming at H so cannot be explained by lower extinction. Absorption in the 3.1 micrometer ice band was always greater toward the IRC during our observations indicating a large amount of obscuring material. We detect variable extinction in the ice-band toward Haro 6-10 S and the IRC, significant at the 3.5-sigma and 2.0-sigma levels, respectively.

Simon, Michal↗
NASA NTRS2001

Exploring the Hot Galactic Halo Using Shadows of High Latitude Clouds

The objective of this proposal was to measure variations in the 1/4 keV emission from the galactic halo, using ROSAT (x-ray astronomy satellite) Position Sensitive Proportional Counters (PSPC) observations toward known enhancements in the absorbing column density along the line-of-sight out of the Galaxy. Target directions were selected to have a low total hydrogen column density but to also show significant gradients in the amount of absorbing material, as traced by Infrared Astronomical Satellite (IRAS) 100 micron emission, on angular scales that would be contained within the PSPC field of view. In addition, we restricted the galactic latitude of the target directions to be greater than 60 degrees or less than -60 degrees in order to enable a cleaner separation of Galactic halo emission from that of the Galactic disk. The observations would also provide a measurement of the brightness of the emission from the Local Bubble.

Juda, M.↗
NASA NTRS1983

Science and technology results from the OSS-1 payload on the Space Shuttle

The OSS-1 Payload of nine experiments was carried on the STS-3 Space Shuttle flight in March of 1982. The OSS-1 Payload contained four instruments that evaluated specific aspects of the Orbiter's environment, including the levels of particulate, gaseous and electromagnetic emissions given off by the Orbiter, and the interactions between the Orbiter and the surrounding plasma. In addition to these environmental observations, these instruments performed scientific investigations in astronomy and in space plasma physics, including active experiments in electron beam propagation. Other experiments were in the areas of solar physics, plant growth, micrometeorite studies and the technology of actively controlled heat pipes. We present the initial results from these experiments, with some implications of these results for future operation of space experiments from the Shuttle payload bay. One major result was the unexpected discovery of a faint surface-induced optical glow created near the Shuttle surfaces by impacts of ambient atmospheric atoms and molecules.

short duration↗
NASA NTRS2009

The Skylab Medical Operations Project: Recommendations to Improve Crew Health and Performance for Future Exploration Missions

From May of 1973 to February of 1974, the National Aeronautics and Space Administration conducted a series of three manned missions to the Skylab space station, a voluminous vehicle largely descendant of Apollo hardware, and America s first space station. The crewmembers of these three manned missions spent record breaking durations of time in microgravity (28 days, 59 days and 84 days, respectively) and gave the U.S. space program its first experiences with long-duration space flight. The program overcame a number of obstacles (including a significant crippling of the Skylab vehicle) to conduct a lauded scientific program that encompassed life sciences, astronomy, solar physics, materials sciences and Earth observation. Skylab has more to offer than the results of its scientific efforts. The operations conducted by the Skylab crews and ground personnel represent a rich legacy of operational experience. As we plan for our return to the moon and the subsequent manned exploration of Mars, it is essential to utilize the experiences and insights of those involved in previous programs. Skylab and SMEAT (Skylab Medical Experiments Altitude Test) personnel have unique insight into operations being planned for the Constellation Program, such as umbilical extra-vehicular activity and water landing/recovery of long-duration crewmembers. Skylab was also well known for its habitability and extensive medical suite; topics which deserve further reflection as we prepare for lunar habitation and missions beyond Earth s immediate sphere of influence. The Skylab Medical Operations Summit was held in January 2008. Crewmembers and medical personnel from the Skylab missions and SMEAT were invited to participate in a two day summit with representatives from the Constellation Program medical operations community. The purpose of the summit was to discuss issues pertinent to future Constellation operations. The purpose of this document is to formally present the recommendations of the Skylab and SMEAT participants.

Polk, James D.↗
NASA NTRS2009

The Skylab Medical Operations Project: Recommendations to Improve Crew Health and Performance for Future Exploration Missions

From May 1973 to February 1974, NASA conducted a series of three human missions to the Skylab space station, which was a voluminous vehicle largely descendant of Apollo hardware and the first U.S. space station. Crew members of these missions spent record-breaking durations of time in microgravity (28, 59, and 84 days, respectively) and gave the U.S. space program its first experiences with long-duration space flight. The program overcame a number of obstacles to conduct a lauded scientific program that encompassed life sciences, astronomy, solar physics, materials sciences, and Earth observation. Yet Skylab has more to offer than the results of these scientific efforts. The operations that were conducted by the crews and ground personnel represent a rich legacy of operational experience. As we plan a return to the moon and subsequent human exploration of Mars, it is essential to use the experiences and insights of those who were involved in previous programs. Skylab and Skylab Medical Experiments Altitude Test personnel possess unique insight into operations that are being planned for the Constellation Program, such as umbilical extravehicular activity and water landing/recovery of long-duration crew members. The Skylab Program was also well known for its habitability and extensive medical suite.

Scheuring, Richard A.↗
NASA NTRSDate not supplied

Fabrication of monocrystalline silicon x-ray mirrors

Progress within the fi eld of x-ray astronomy depends on astronomical x-ray observations of ever-increasing quality and speed. Fast and high-resolution x-ray observations over a broad spectral range promise amazing new discoveries. These observations, however, require a spaceborne x-ray telescope of unprecedented imaging power. Of the numerous technological concerns associated with the design and construction of such a telescope, the x-ray focusing optics present a particularly complex and arduous set of challenges. An x-ray optical assembly comprises many thousands of x-ray mirrors, a most critical element. Our group at NASA Goddard Space Flight Center (GSFC) pursues the development of an x-ray mirror manufacturing process capable of meeting the stringent quality, production time, and cost requirements of the next-generation of x-ray telescopes. The manufacturing process employs monocrystalline silicon: a lightweight, stiff, thermally conductive, and readily available material which is free of internal stress; it is a nearly ideal material for a thin mirror substrate. The process involves various traditional optical fabrication techniques adapted to x-ray mirror geometry. Presently, our process is capable of fabricating sub-arcsecond half-power diameter (HPD) resolution mirror pairs (primary and secondary) at a mirror thickness of 0.5 mm and of virtually any x-ray optical design (e.g. Wolter-I, Wolter-Schwarzschild, etc.). The mirror substrate surface quality is comparable to, and sometimes exceeding, that of the mirrors on the Chandra X-ray Observatory. This paper describes the various manufacturing steps involved in the production of x-ray mirror substrates and a present status report.

Raul E. Riveros↗
DOE OSTI2024

Mitigation of the Brighter-fatter Effect in the LSST Camera

Abstract Thick, fully depleted charge-coupled devices are known to exhibit nonlinear behavior at high signal levels due to the dynamic behavior of charges collecting in the potential wells of pixels, called the brighter-fatter effect (BFE). The effect results in distorted images of bright calibration stars, creating a flux-dependent point-spread function that if left unmitigated, could make up a large fraction of the error budget in Stage IV weak-lensing (WL) surveys such as the Legacy Survey of Space and Time (LSST). In this paper, we analyze image measurements of flat fields and artificial stars taken at different illumination levels with the LSST Camera (LSSTCam) at SLAC National Accelerator Laboratory in order to quantify this effect in the LSSTCam before and after a previously introduced correction technique. We observe that the BFE evolves anisotropically as a function of flux due to higher-order BFEs, which violates the fundamental assumption of this correction method. We then introduce a new method based on a physically motivated model to account for these higher-order terms in the correction, and then we test the modified correction on both data sets. We find that the new method corrects the effect in flat fields better than it corrects the effect in artificial stars, which we suggest is the result of sub-pixel physics not included in this correction model. We use these results to define a new metric for the full-well capacity of our sensors and advise image processing strategies to further limit the impact of the effect on LSST WL science pathways.

47 OTHER INSTRUMENTATION↗
NASA NTRS1981

Medium energy gamma ray astronomy with transpacific balloon flights

Transpacific balloon flights with the University of California, Riverside (UCR) double scatter telescope are discussed. With flight durations from 5 days up to perhaps 15 days the long observation times necessary for medium energy (1-30 MeV) gamma ray astronomy can be obtained. These flights would be made under the auspices of the Joint U.S.-Japan Balloon Flight Program at NASA. It is proposed that flights can provide at least 30 hours of observation time per flight for many discrete source candidates and 120 hours for detecting low intensity cosmic gamma ray bursts.

Zych, A. D.↗
NASA NTRS1974

Skylab observations of Comet Kohoutek

This paper summarizes the special operational procedures developed to observe the Comet Kohoutek from Skylab and the scientific results from these observations. Emphasis is placed on results from Skylab experiments S052, White Light Coronagraph; S201, Far UV Electronographic Camera; S233, Kohoutek Photometric Photography; S019, UV Stellar Astronomy; S183, Ultraviolet Panorama Telescope; and S082B, Ultraviolet Spectrography. Visual observations by the astronaut crew and the significance of these observations are discussed.

Snoddy, W. C.↗
NASA NTRS1987

IRAS and ground-based observations of star formation regions in the Magellanic clouds

The Infrared Astronomy Satellite (IRAS) detected several hundred individual regions of star formation in the Large and Small Magellanic Clouds. Nearly two dozen of the brightest such sources were searched for from the ground at 10 microns; most of these were located and measured at wavelengths from 0.6 to 20 microns. Three principle results emerge from this study: First, the IRAS data show that star formation is considerably less active in the SMC than in the LMC, relative either to mass, luminosity, or H I content. The reduced activity in the SMC is consistent with the smaller amount of molecular material inferred from CO observations. Second, the sizes of the objects range from less than a few arcsecs (objects which look like extremely compact HII regions, with little or no extended radio, optical, or infrared emission) to some tens of arcsecs across (giant HII regions, of which the largest and brightest is 30 Doradus). Third, there are no obvious differences in the characteristics of the central portions of the LMC and SMC sources; all look like Galactic H II regions of similar luminosity.

Elias, Jonathan H.↗
NASA NTRS2019

Search for Intermediate Mass Black Hole Binaries in the First and Second Observing Runs of the Advanced LIGO and VIRGO Network

Gravitational-wave astronomy has been firmly established with the detection of gravitational waves from the merger of ten stellar-mass binary black holes and a neutron star binary. This paper reports on the all-sky search for gravitational waves from intermediate mass black hole binaries in the first and second observing runs of the Advanced LIGO and Virgo network. The search uses three independent algorithms: two based on matched filtering of the data with waveform templates of gravitational-wave signals from compact binaries, and a third, model-independent algorithm that employs no signal model for the incoming signal. No intermediate mass black hole binary event is detected in this search. Consequently, we place upper limits on the merger rate density for a family of intermediate mass black hole binaries. In particular, we choose sources with total masses 𝑀=𝑚1+𝑚2∈[120,800] 𝑀⊙ and mass ratios 𝑞=𝑚2/𝑚1∈[0.1,1.0]. For the first time, this calculation is done using numerical relativity waveforms (which include higher modes) as models of the real emitted signal. We place a most stringent upper limit of 0.20 Gpc−3 yr−1 (in comoving units at the 90% confidence level) for equal-mass binaries with individual masses 𝑚1,2=100 𝑀⊙ and dimensionless spins 𝜒1,2=0.8 aligned with the orbital angular momentum of the binary. This improves by a factor of ∼5 that reported after Advanced LIGO’s first observing run.

B. P. Abbott↗