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Komatsu, T.

Publications and source records attributed to Komatsu, T..

CosmoQuest: Better Citizen Science Through Education

In the modern era, NASA SMD missions and facilities are producing data at a rate too great for the science community to maximally utilize. While software can help, what is really needed is additional eyes, hands, and minds - help we can find in the form of citizen scientist volunteers. The CosmoQuest virtual research facility has demonstrated through published research results that classroom students and the public can, with proper training and support from Subject Matter Experts (SMEs), fill roles more traditionally filled by university students. The research question behind CosmoQuest's creation was simple: if students and the public are provided a properly scaffolded experience that mirrors that of researchers, will they come and perform as well as our students? and can they rise up to be research collaborators? In creating CosmoQuest, we started with a core of citizen science portals, educational materials for both students and life-long learners, and collaboration areas. These three primary focuses mirror the research, courses, and collaboration spaces that form the foundation of a university department. We then went on to add the features that make a center stand out - we added seminars in the form of Google Hangouts on Air, planetarium content through our Science on the Half Sphere program, and even the chance to vicariously attend conferences through live blogging by our team members. With this design for a virtual research facility, the answer to our foundational question has been a resounding yes; the public can aid us in doing science provided they are properly trained. To meet the needs of our population we have developed four areas of engagement: research, education, media, and community.

Gay, P. L.↗

Two Active States of the Narrow-Line Gamma-Ray-Loud AGN GB 1310 + 487

Context. Previously unremarkable, the extragalactic radio source GB1310 487 showed gamma-ray flare on 2009 November 18, reaching a daily flux of approximately 10(exp -6) photons cm(exp -2) s(exp -1) at energies E greater than 100MeV and became one of the brightest GeV sources for about two weeks. Its optical spectrum shows strong forbidden-line emission while lacking broad permitted lines, which is not typical for a blazar. Instead, the spectrum resembles those of narrow emission-line galaxies. Aims. We investigate changes in the object's radio-to-GeV spectral energy distribution (SED) during and after the prominent gamma-ray flare with the aim of determining the nature of the object and of constraining the origin of the variable high-energy emission. Methods. The data collected by the Fermi and AGILE satellites at gamma-ray energies; Swift at X-ray and ultraviolet (UV); the Kanata, NOT, and Keck telescopes at optical; OAGH and WISE at infrared (IR); and IRAM30m, OVRO 40m, Effelsberg 100m, RATAN-600, and VLBA at radio are analyzed together to trace the SED evolution on timescales of months. Results. The gamma-ray radio-loud narrow-line active galactic nucleus (AGN) is located at redshift z = 0.638. It shines through an unrelated foreground galaxy at z = 0.500. The AGN light is probably amplified by gravitational lensing. The AGN SED shows a two-humped structure typical of blazars and gamma-ray-loud narrow-line Seyfert 1 galaxies, with the high-energy (inverse-Compton) emission dominating by more than an order of magnitude over the low-energy (synchrotron) emission during gamma-ray flares. The difference between the two SED humps is smaller during the low-activity state. Fermi observations reveal a strong correlation between the gamma-ray flux and spectral index, with the hardest spectrum observed during the brightest gamma-ray state. The gamma-ray flares occurred before and during a slow rising trend in the radio, but no direct association between gamma-ray and radio flares could be established. Conclusions. If the gamma-ray flux is a mixture of synchrotron self-Compton (SSC) and external Compton (EC) emission, the observed GeV spectral variability may result from varying relative contributions of these two emission components. This explanation fits the observed changes in the overall IR to gamma-ray SED.

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Capture of free-flying payloads with flexible space manipulators

A recently developed control system for capturing free-flying payloads with flexible manipulators is discussed. Three essential points in this control system are, calculating optimal path, using a vision sensor for an external sensor, and controlling active vibration. Experimental results are shown using a planar flexible manipulator.

Komatsu, T.↗