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C Howard

Publications and source records attributed to C Howard.

4 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2012

GASPS Observations of Herbig Ae/Be Stars with PACS/Herschel: The Atomic and Molecular Content of Their Protoplanetary Discs

We observed a sample of 20 representative Herbig Ae/Be stars and five A-type debris discs with PACS onboard of Herschel. The observations were done in spectroscopic mode, and cover far-IR lines of [O I], [C II], CO, CH+, H2O and OH. We have a [O I] 63 micron detection rate of 100% for the Herbig Ae/Be and 0% for the debris discs. [O I] 145 micron is only detected in 25 %, CO J=18-17 in 45 % (and less for higher J transitions) of the Herbig Ae/Be stars and for [C II] 157 micron, we often found spatially variable background contamination. We show the first detection of water in a Herbig Ae disc, HD 163296, which has a settled disc. Hydroxyl is detected as well in this disc. CH+, first seen in HD 100546, is now detected for the second time in a Herbig Ae star, HD 97048. We report fluxes for each line and use the observations as line diagnostics of the gas properties. Furthermore, we look for correlations between the strength of the emission lines and stellar or disc parameters, such as stellar luminosity, UV and X-ray flux, accretion rate, PAH band strength, and flaring. We find that the stellar UV flux is the dominant excitation mechanism of [O I] 63, with the highest line fluxes found in those objects with a large amount of flaring and greatest PAH strength. Neither the amount of accretion nor the X-ray luminosity has an influence on the line strength. We find correlations between the line flux of [O I] 63 and [O I] 145, CO J = 18-17 and [O I] 6300 A, and between the continuum flux at 63 micron and at 1.3 mm, while we find weak correlations between the line flux of [O I] 63 and the PAH luminosity, the line flux of CO J = 3-2, the continuum flux at 63 micron, the stellar effective temperature and the Br(gamma) luminosity. Finally, we use a combination of the [O I] 63 and CO-12 J = 2-1 line fluxes to obtain order of magnitude estimates of the disc gas masses, in agreement of the values we found from detailed modelling of 2 HAEBEs, HD 163296 and HD 169142.

G Meeus↗
NASA NTRSDate not supplied

PREFIRE at ASDC Revolutionizing Polar System Observations

In the ongoing battle against climate change, early detection is key to minimizing their devastating impact on communities and ecosystems. Hosted by the Atmospheric Science Data Center (ASDC) at NASA's Langley Research Center, PREFIRE mission aims to bridge a critical knowledge gap in climate science by focusing on the far-infrared (FIR) portion of the electromagnetic spectrum, which has been historically under-observed.

Hazem M↗
NASA NTRSDate not supplied

Crew Health and Performance Integrated Data System Platform Project Updates

Future human exploration missions introduce a new paradigm as crews move further from the resupply and near real-time ground support typical of Low Earth Orbit missions today. Without immediate support from ground-based personnel, exploration crews will be more reliant on inflight data and technology to respond to emergencies and anomalies. Today, in-flight data is often siloed, unsynchronized, and largely inaccessible in real time. Many data sets require manual entry and/or data transfer between vehicles and the ground. These issues contribute to risks in supporting crew autonomy for future exploration missions. An integrated data system platform is needed to mitigate these risks by supporting a new generation of technologies and employing advanced analytical and predictive modeling techniques to enable crew autonomy for future exploration missions. The Crew Health and Performance Integrated Data System Platform (CHP-IDSP) project is laying a foundation for future in-flight informatics by providing a back-end architecture for collecting, storing, and integrating multiple sources of data generated by and around the crew. This cohesive integration point will streamline the management of CHP data (e.g., environmental, exercise, medical, sleep, performance, etc.) and facilitate situation awareness and decision support required by the crew and remote support of exploration missions. This presentation will describe the ongoing development effort of the path-to-flight CHP-IDSP software and the demonstration of its core capabilities. This includes a brief history of the project, the human-centered process used to identify data needs and workflows feeding the development of scenarios and requirements, and current subsystem development status. Current integrations, including the Chiron exploration electronic health record application, will be discussed. Future work includes collaboration with additional CHP domains and a flight technology demonstration.

Data integration↗