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HelioSwarm (HS) is a NASA Medium-Class Explorer mission of the Heliophysics Division designed to explore the dynamic three-dimensional mechanisms controlling the physics of plasma turbulence, a ubiquitous process occurring in the heliosphere and in plasmas throughout the universe. This will be accomplished by making simultaneous measurements at nine spacecraft with separations spanning magnetohydrodynamic and sub-ion spatial scales in a variety of near-Earth plasmas. In this paper, we describe the scientific background for the HS investigation, the mission goals and objectives, the observatory reference trajectory and instrumentation implementation before the start of Phase B. Through multipoint, multiscale measurements, HS promises to reveal how energy is transferred across scales and boundaries in plasmas throughout the universe., Comment: Submitted to Space Science Reviews, 60 pages, 15 figures, 2 videos

This study extended research on the development of explanatory labels for astronomical images for the non-expert lay public. The research questions addressed how labels with leading questions/metaphors and relevance to everyday life affect comprehension of the intended message for deep space images, the desire to learn more, and the aesthetic appreciation of images. Participants were a convenience sample of 1,921 respondents solicited from a variety of websites and through social media who completed an online survey that used four high-resolution images as stimuli: Sagittarius A*, Solar Flare, Cassiopeia A, and the Pinwheel Galaxy (M101). Participants were randomly assigned initially to 1 of 3 label conditions: the standard label originally written for the image, a label with a leading question containing a metaphor related to the information for the image, or a label that contained a fact about the image relevant to everyday life. Participants were randomly assigned to 1 image and compared all labels for that image. Open-ended items at various points asked participants to pose questions to a hypothetical astronomer. Main findings were that the relevance condition was significantly more likely to increase wanting to learn more; the original label was most likely to increase overall appreciation; and, smart phone users were more likely to want to learn more and report increased levels of appreciation. Results are discussed in terms of the need to examine individual viewer characteristics and goals in creating different labels for different audiences., Comment: 50 pages, 7 tables, 2 figures, accepted by the journal "Psychology of Aesthetics, Creativity, and the Arts"

This study extended research on the development of explanatory labels for astronomical images for the non-expert lay public. The research questions addressed how labels with leading questions/metaphors and relevance to everyday life affect comprehension of the intended message for deep space images, the desire to learn more, and the aesthetic appreciation of images. Participants were a convenience sample of 1,921 respondents solicited from a variety of websites and through social media who completed an online survey that used four high-resolution images as stimuli: Sagittarius A*, Solar Flare, Cassiopeia A, and the Pinwheel Galaxy (M101). Participants were randomly assigned initially to 1 of 3 label conditions: the standard label originally written for the image, a label with a leading question containing a metaphor related to the information for the image, or a label that contained a fact about the image relevant to everyday life. Participants were randomly assigned to 1 image and compared all labels for that image. Open-ended items at various points asked participants to pose questions to a hypothetical astronomer. Main findings were that the relevance condition was significantly more likely to increase wanting to learn more; the original label was most likely to increase overall appreciation; and, smart phone users were more likely to want to learn more and report increased levels of appreciation. Results are discussed in terms of the need to examine individual viewer characteristics and goals in creating different labels for different audiences., Comment: 50 pages, 7 tables, 2 figures, accepted by the journal "Psychology of Aesthetics, Creativity, and the Arts"

The Solar Wind Electrons Alphas and Protons (SWEAP) Investigation on Solar Probe Plus is a four sensor instrument suite that provides complete measurements of the electrons and ionized helium and hydrogen that constitute the bulk of solar wind and coronal plasma. SWEAP consists of the Solar Probe Cup (SPC) and the Solar Probe Analyzers (SPAN). SPC is a Faraday Cup that looks directly at the Sun and measures ion and electron fluxes and flow angles as a function of energy. SPAN consists of an ion and electron electrostatic analyzer (ESA) on the ram side of SPP (SPAN-A) and an electron ESA on the anti-ram side (SPAN-B). The SPAN-A ion ESA has a time of flight section that enables it to sort particles by their mass/charge ratio, permitting differentiation of ion species. SPAN-A and -B are rotated relative to one another so their broad fields of view combine like the seams on a baseball to view the entire sky except for the region obscured by the heat shield and covered by SPC. Observations by SPC and SPAN produce the combined field of view and measurement capabilities required to fulfill the science objectives of SWEAP and Solar Probe Plus. SWEAP measurements, in concert with magnetic and electric fields, energetic particles, and white light contextual imaging will enable discovery and understanding of solar wind acceleration and formation, coronal and solar wind heating, and particle acceleration in the inner heliosphere of the solar system. SPC and SPAN are managed by the SWEAP Electronics Module (SWEM), which distributes power, formats onboard data products, and serves as a single electrical interface to the spacecraft. SWEAP data products include ion and electron velocity distribution functions with high energy and angular resolution. Full resolution data are stored within the SWEM, enabling high resolution observations of structures such as shocks, reconnection events, and other transient structures to be selected for download after the fact. This paper describes t, United States. National Aeronautics and Space Administration (contract NNN06AA01C (Task NNN10AA08T))

Modern society has led many people to become consumers of data unlike previous generations. How this shift in the way information is communicated and received - including in areas of science - and affects perception and comprehension is still an open question. This study examined one aspect of this digital age: perceptions of astronomical images and their labels, on mobile platforms. Participants were n = 2183 respondents to an online survey, and two focus groups (n = 12 astrophysicists; n = 11 lay public). Online participants were randomly assigned to 1 of 12 images, and compared two label formats. Focus groups compared mobile devices and label formats. Results indicated that the size and quality of the images on the mobile devices affected label comprehension and engagement. The question label format was significantly preferred to the fun fact. Results are discussed in terms of effective science communication using technology., Comment: 23 pages, 1 figure; Journal of Science Communication, in press

Modern society has led many people to become consumers of data unlike previous generations. How this shift in the way information is communicated and received - including in areas of science - and affects perception and comprehension is still an open question. This study examined one aspect of this digital age: perceptions of astronomical images and their labels, on mobile platforms. Participants were n = 2183 respondents to an online survey, and two focus groups (n = 12 astrophysicists; n = 11 lay public). Online participants were randomly assigned to 1 of 12 images, and compared two label formats. Focus groups compared mobile devices and label formats. Results indicated that the size and quality of the images on the mobile devices affected label comprehension and engagement. The question label format was significantly preferred to the fun fact. Results are discussed in terms of effective science communication using technology., Comment: 23 pages, 1 figure; Journal of Science Communication, in press

A non-proprietary Mission Concept available for presentation to NASA, providing High Area, High Resolution Imaging Spectroscopy and Timing with Arcmin Angular Resolution Submitted in response to NASA 2011 RFI NNH11ZDA018L 'Concepts for the Next NASA X-ray Astronomy Mission', Comment: 10 pages plus 8 page technical appendix

A non-proprietary Mission Concept available for presentation to NASA, providing High Area, High Resolution Imaging Spectroscopy and Timing with Arcmin Angular Resolution Submitted in response to NASA 2011 RFI NNH11ZDA018L 'Concepts for the Next NASA X-ray Astronomy Mission', Comment: 10 pages plus 8 page technical appendix

Some 400 years after Galileo, modern telescopes have enabled humanity to "see" what the natural eye cannot. Astronomical images today contain information about incredibly large objects located across vast distances and reveal information found in "invisible" radiation ranging from radio waves to X-rays. The current generation of telescopes has created an explosion of images available for the public to explore. This has, importantly, coincided with the maturation of the Internet. Every major telescope has a web site, often with an extensive gallery of images. New and free downloadable tools exist for members of the public to explore astronomical data and even create their own images. In short, a new era of an accessible universe has been entered, in which the public can participate and explore like never before. But there is a severe lack of scholarly and robust studies to probe how people - especially non-experts - perceive these images and the information they attempt to convey. Most astronomical images for the public have been processed (e.g., color choices, artifact removal, smoothing, cropping/field-of-view shown) to strike a balance between the science being highlighted and the aesthetics designed to engage the public. However, the extent to which these choices affect perception and comprehension is, at best, poorly understood. The goal of the studies presented here was to begin a program of research to better understand how people perceive astronomical images, and how such images, and the explanatory material that accompanies them, can best be presented to the public in terms of understanding, appreciation, and enjoyment of the images and the science that underlies them., Comment: 49 pages, 14 figures, Science Communication, in press

The Solar Spectroscopy Explorer (SSE) concept is conceived as a scalable mission, with two to four instruments and a strong focus on coronal spectroscopy. In its core configuration it is a small strategic mission ($250-500M) built around a microcalorimeter (an imaging X-ray spectrometer) and a high spatial resolution (0.2 arcsec) EUV imager. SSE puts a strong focus on the plasma spectroscopy, balanced with high resolution imaging - providing for break-through imaging science as well as providing the necessary context for the spectroscopy suite. Even in its smallest configuration SSE provides observatory class science, with significant science contributions ranging from basic plasma and radiative processes to the onset of space weather events. The basic configuration can carry an expanded instrument suite with the addition of a hard X-ray imaging spectrometer and/or a high spectral resolution EUV instrument - significantly expanding the science capabilities. In this configuration, it will fall at the small end of the medium class missions, and is described below as SSE+. This scalable mission in its largest configuration would have the full complement of these instruments and becomes the RAM (Reconnection And Microscale) mission. This mission has been designed to address key outstanding issues in coronal physics, and to be highly complementary to missions such as Solar Probe Plus, Solar Orbiter, and Solar-C as well as ground-based observatories., Comment: 8 pages, 3 figures, submitted to 2010 Heliophysics Decadal Review

The International X-ray Observatory (IXO) is a joint ESA-JAXA-NASA effort to address fundamental and timely questions in astrophysics: What happens close to a black hole? How did supermassive black holes grow? How does large scale structure form? What is the connection between these processes? To address these questions IXO will employ optics with 3 sq m collecting area and 5 arc sec angular resolution - 20 times more collecting area at 1 keV than any previous X-ray observatory. Focal plane instruments will deliver a 100-fold increase in effective area for high-resolution spectroscopy, deep spectral imaging over a wide field of view, unprecedented polarimetric sensitivity, microsecond spectroscopic timing, and high count rate capability. The mission is being planned for launch in 2021 to an L2 orbit, with a five-year lifetime and consumables for 10 years., Comment: 6 pages, 3 figures, for conference "X-ray Astronomy 2009 Present status, multi-wavelength approach and future perspectives"

The International X-ray Observatory (IXO), a joint NASA-ESA-JAXA effort, will address fundamental and timely questions in astrophysics: What happens close to a black hole? How did supermassive black holes grow? How does large scale structure form? What is the connection between these processes? To address these science questions, IXO will trace orbits close to the event horizon of black holes, measure black hole spin for several hundred active galactic nuclei (AGN), use spectroscopy to characterize outflows and the environment of AGN during their peak activity, search for supermassive black holes out to redshift z = 10, map bulk motions and turbulence in galaxy clusters, find the missing baryons in the cosmic web using background quasars, and observe the process of cosmic feedback where black holes inject energy on galactic and intergalactic scales. IXO will employ optics with 20 times more collecting area at 1 keV than any previous X-ray observatory. Focal plane instruments will deliver a 100-fold increase in effective area for high-resolution spectroscopy, deep spectral imaging over a wide field of view, unprecedented polarimetric sensitivity, microsecond spectroscopic timing, and high count rate capability. The improvement of IXO relative to current X-ray missions is equivalent to a transition from the 200 inch Palomar telescope to a 22m telescope while at the same time shifting from spectral band imaging to an integral field spectrograph., Comment: 19 pages, submitted in response to Astro2010 Decadal Program Prioritization Panel First Request for Information

The International X-ray Observatory (IXO) is a joint NASA-ESA-JAXA effort. X-ray observations will resolve pressing astrophysical questions such as: What happens close to a black hole? How do supermassive black holes grow? How does large scale structure form? What is the connection between these processes? To address these questions requires dramatic increases in collection area combined with sensitive new instrumentation. IXO's spectroscopic, timing, and polarimetric capabilities will probe close to the event horizon of super-massive black holes (SMBH) where strong gravity dominates. IXO will determine the evolution and origin of SMBH by measuring their spin to understand their merger history, surveying them to find their luminosity distribution out to high redshift (z~8), and spectroscopically characterizing their outflows during peak activity. IXO will revolutionize our understanding of galaxy clusters by mapping their bulk motions and turbulence. IXO will observe the process of cosmic feedback where black holes inject energy on galactic and intergalactic scales, and characterize the missing baryons in the cosmic web. Meanwhile, surveys of distant clusters will constrain cosmological models. IXO will be available to all astronomers, taking X-ray astrophysics from an era where high-resolution spectra are a rarity to one with vast numbers of spectra from all types of sources. Powerful spectral diagnostics and large collecting areas will reveal unexpected discoveries, with IXO studying new phenomena as they appear-a key feature of great observatories., Comment: 118 pages, submitted in response to Astro2010 Decadal Program Prioritization Panel Second Request for Information

The Solar Spectroscopy Explorer (SSE) concept is conceived as a scalable mission, with two to four instruments and a strong focus on coronal spectroscopy. In its core configuration it is a small strategic mission ($250-500M) built around a microcalorimeter (an imaging X-ray spectrometer) and a high spatial resolution (0.2 arcsec) EUV imager. SSE puts a strong focus on the plasma spectroscopy, balanced with high resolution imaging - providing for break-through imaging science as well as providing the necessary context for the spectroscopy suite. Even in its smallest configuration SSE provides observatory class science, with significant science contributions ranging from basic plasma and radiative processes to the onset of space weather events. The basic configuration can carry an expanded instrument suite with the addition of a hard X-ray imaging spectrometer and/or a high spectral resolution EUV instrument - significantly expanding the science capabilities. In this configuration, it will fall at the small end of the medium class missions, and is described below as SSE+. This scalable mission in its largest configuration would have the full complement of these instruments and becomes the RAM (Reconnection And Microscale) mission. This mission has been designed to address key outstanding issues in coronal physics, and to be highly complementary to missions such as Solar Probe Plus, Solar Orbiter, and Solar-C as well as ground-based observatories., Comment: 8 pages, 3 figures, submitted to 2010 Heliophysics Decadal Review

Some 400 years after Galileo, modern telescopes have enabled humanity to "see" what the natural eye cannot. Astronomical images today contain information about incredibly large objects located across vast distances and reveal information found in "invisible" radiation ranging from radio waves to X-rays. The current generation of telescopes has created an explosion of images available for the public to explore. This has, importantly, coincided with the maturation of the Internet. Every major telescope has a web site, often with an extensive gallery of images. New and free downloadable tools exist for members of the public to explore astronomical data and even create their own images. In short, a new era of an accessible universe has been entered, in which the public can participate and explore like never before. But there is a severe lack of scholarly and robust studies to probe how people - especially non-experts - perceive these images and the information they attempt to convey. Most astronomical images for the public have been processed (e.g., color choices, artifact removal, smoothing, cropping/field-of-view shown) to strike a balance between the science being highlighted and the aesthetics designed to engage the public. However, the extent to which these choices affect perception and comprehension is, at best, poorly understood. The goal of the studies presented here was to begin a program of research to better understand how people perceive astronomical images, and how such images, and the explanatory material that accompanies them, can best be presented to the public in terms of understanding, appreciation, and enjoyment of the images and the science that underlies them., Comment: 49 pages, 14 figures, Science Communication, in press

The International X-ray Observatory (IXO) is a joint NASA-ESA-JAXA effort. X-ray observations will resolve pressing astrophysical questions such as: What happens close to a black hole? How do supermassive black holes grow? How does large scale structure form? What is the connection between these processes? To address these questions requires dramatic increases in collection area combined with sensitive new instrumentation. IXO's spectroscopic, timing, and polarimetric capabilities will probe close to the event horizon of super-massive black holes (SMBH) where strong gravity dominates. IXO will determine the evolution and origin of SMBH by measuring their spin to understand their merger history, surveying them to find their luminosity distribution out to high redshift (z~8), and spectroscopically characterizing their outflows during peak activity. IXO will revolutionize our understanding of galaxy clusters by mapping their bulk motions and turbulence. IXO will observe the process of cosmic feedback where black holes inject energy on galactic and intergalactic scales, and characterize the missing baryons in the cosmic web. Meanwhile, surveys of distant clusters will constrain cosmological models. IXO will be available to all astronomers, taking X-ray astrophysics from an era where high-resolution spectra are a rarity to one with vast numbers of spectra from all types of sources. Powerful spectral diagnostics and large collecting areas will reveal unexpected discoveries, with IXO studying new phenomena as they appear-a key feature of great observatories., Comment: 118 pages, submitted in response to Astro2010 Decadal Program Prioritization Panel Second Request for Information

The International X-ray Observatory (IXO) is a joint ESA-JAXA-NASA effort to address fundamental and timely questions in astrophysics: What happens close to a black hole? How did supermassive black holes grow? How does large scale structure form? What is the connection between these processes? To address these questions IXO will employ optics with 3 sq m collecting area and 5 arc sec angular resolution - 20 times more collecting area at 1 keV than any previous X-ray observatory. Focal plane instruments will deliver a 100-fold increase in effective area for high-resolution spectroscopy, deep spectral imaging over a wide field of view, unprecedented polarimetric sensitivity, microsecond spectroscopic timing, and high count rate capability. The mission is being planned for launch in 2021 to an L2 orbit, with a five-year lifetime and consumables for 10 years., Comment: 6 pages, 3 figures, for conference "X-ray Astronomy 2009 Present status, multi-wavelength approach and future perspectives"

The International X-ray Observatory (IXO), a joint NASA-ESA-JAXA effort, will address fundamental and timely questions in astrophysics: What happens close to a black hole? How did supermassive black holes grow? How does large scale structure form? What is the connection between these processes? To address these science questions, IXO will trace orbits close to the event horizon of black holes, measure black hole spin for several hundred active galactic nuclei (AGN), use spectroscopy to characterize outflows and the environment of AGN during their peak activity, search for supermassive black holes out to redshift z = 10, map bulk motions and turbulence in galaxy clusters, find the missing baryons in the cosmic web using background quasars, and observe the process of cosmic feedback where black holes inject energy on galactic and intergalactic scales. IXO will employ optics with 20 times more collecting area at 1 keV than any previous X-ray observatory. Focal plane instruments will deliver a 100-fold increase in effective area for high-resolution spectroscopy, deep spectral imaging over a wide field of view, unprecedented polarimetric sensitivity, microsecond spectroscopic timing, and high count rate capability. The improvement of IXO relative to current X-ray missions is equivalent to a transition from the 200 inch Palomar telescope to a 22m telescope while at the same time shifting from spectral band imaging to an integral field spectrograph., Comment: 19 pages, submitted in response to Astro2010 Decadal Program Prioritization Panel First Request for Information

We report an initial study of temperature and emission measure distributions along four steady loops observed with the Transition Region and Coronal Explorer (TRACE) at the limb of the Sun. The temperature diagnostic is the filter ratio of the extreme-ultraviolet 171-angstrom and 195-angstrom passbands. The emission measure diagnostic is the count rate in the 171-angstrom passband. We find essentially no temperature variation along the loops. We compare the observed loop structure with theoretical isothermal and nonisothermal static loop structure., Comment: 10 pages, 3 postscript figures (LaTeX, uses aaspp4.sty). Accepted by ApJ Letters

We report an initial study of temperature and emission measure distributions along four steady loops observed with the Transition Region and Coronal Explorer (TRACE) at the limb of the Sun. The temperature diagnostic is the filter ratio of the extreme-ultraviolet 171-angstrom and 195-angstrom passbands. The emission measure diagnostic is the count rate in the 171-angstrom passband. We find essentially no temperature variation along the loops. We compare the observed loop structure with theoretical isothermal and nonisothermal static loop structure., Comment: 10 pages, 3 postscript figures (LaTeX, uses aaspp4.sty). Accepted by ApJ Letters

We have obtained images of the eclipsing pulsar binary PSR~B1957+20 using the Planetary Camera of the Hubble Space Telescope. The high spatial resolution of this instrument has allowed us to separate the pulsar system from a nearby background star which has confounded ground-based observations of this system near optical minimum. Our images limit the temperature of the backside of the companion to $T \simlt 2800$~K, about a factor of two less than the average temperature of the side of the companion facing the pulsar, and provide a marginal detection of the companion at optical minimum. The magnitude of this detection is consistent with previous work which suggests that the companion nearly fills its Roche lobe and is supported through tidal dissipation., Comment: uuencoded gzip-compressed postscript: 10 pages of text plus 2 postscript figures. This preprint is available in various formats from http://archer.stsci.edu:1024/~fruchter/HST_1957/1957.html or http://electra.stsci.edu:1024/~fruchter/HST_1957/1957.html

We have obtained images of the eclipsing pulsar binary PSR~B1957+20 using the Planetary Camera of the Hubble Space Telescope. The high spatial resolution of this instrument has allowed us to separate the pulsar system from a nearby background star which has confounded ground-based observations of this system near optical minimum. Our images limit the temperature of the backside of the companion to $T \simlt 2800$~K, about a factor of two less than the average temperature of the side of the companion facing the pulsar, and provide a marginal detection of the companion at optical minimum. The magnitude of this detection is consistent with previous work which suggests that the companion nearly fills its Roche lobe and is supported through tidal dissipation., Comment: uuencoded gzip-compressed postscript: 10 pages of text plus 2 postscript figures. This preprint is available in various formats from http://archer.stsci.edu:1024/~fruchter/HST_1957/1957.html or http://electra.stsci.edu:1024/~fruchter/HST_1957/1957.html