Sample records for intergalactic space

  1. Testing a novel method to map the 3D distribution of gas clouds in intergalactic space

    E-print Network

    Bardalez Gagliuffi, Daniella C

    2011-01-01

    We propose a new method to detect intergalactic Lyman a emitter and absorber systems by comparing broadband and narrowband images. The narrowband observations were carried out with the Maryland-Magellan Tunable Filter ...

  2. Scatter broadening of compact radio sources by the ionized intergalactic medium: prospects for detection with Space VLBI and the Square Kilometre Array

    NASA Astrophysics Data System (ADS)

    Koay, J. Y.; Macquart, J.-P.

    2015-01-01

    We investigate the feasibility of detecting and probing various components of the ionized intergalactic medium (IGM) and their turbulent properties at radio frequencies through observations of scatter broadening of compact sources. There is a strong case for conducting targeted observations to resolve scatter broadening (where the angular size scales as ˜?-2) of compact background sources intersected by foreground galaxy haloes and rich clusters of galaxies to probe the turbulence of the ionized gas in these objects, particularly using Space very long baseline interferometry (VLBI) with baselines of 350 000 km at frequencies below 800 MHz. The sensitivity of the Square Kilometre Array (SKA) allows multifrequency surveys of interstellar scintillation (ISS) of ˜ 100 ?Jy sources to detect or place very strong constraints on IGM scatter broadening down to ˜ 1 ?as scales at 5 GHz. Scatter broadening in the warm-hot component of the IGM with typical overdensities of ˜30 cannot be detected, even with Space VLBI or ISS, and even if the outer scales of turbulence have an unlikely low value of ˜1 kpc. None the less, intergalactic scatter broadening can be of the order of ˜ 100 ?as at 1 GHz and ˜ 3 ?as at 5 GHz for outer scales ˜1 kpc, assuming a sufficiently high-source redshift that most sight-lines intersect within a virial radius of at least one galaxy halo (z ? 0.5 and 1.4 for 1010 and 1011 M? systems, following McQuinn 2014). Both Space VLBI and multiwavelength ISS observations with the SKA can easily test such a scenario, or place strong constraints on the outer scale of the turbulence in such regions.

  3. Simulating intergalactic quasar scintillation

    NASA Astrophysics Data System (ADS)

    Pallottini, A.; Ferrara, A.; Evoli, C.

    2013-10-01

    Intergalactic scintillation of distant quasars is sensitive to free electrons and therefore complements Ly? absorption-line experiments probing the neutral intergalactic medium (IGM). We present a new scheme to compute IGM refractive scintillation effects on distant sources in combination with adaptive mesh refinement cosmological simulations. First, we validate our model by reproducing the well-known interstellar scintillation (ISS) of Galactic sources. The simulated cosmic density field is then used to infer the statistical properties of intergalactic scintillation. Contrary to previous claims, we find that the scattering measure of the simulated IGM at z < 2 is = 3.879, i.e. almost 40 times larger than that for the usually assumed smooth IGM. This yields an average modulation index ranging from 0.01 (?s = 5 GHz) up to 0.2 (?s = 50 GHz); above ?s ? 30 GHz the IGM contribution dominates over ISS modulation. We compare our model with data from a 0.3 ? z ? 2 quasar sample observed at ?obs = 8.4 GHz. For this high-frequency (10.92 ? ?s ? 25.2), high-galactic-latitude sample ISS is negligible, and IGM scintillation can reproduce the observed modulation with a 4 per cent accuracy, without invoking intrinsic source variability. We conclude by discussing the possibility of using IGM scintillation as a tool to pinpoint the presence of intervening high-z groups/clusters along the line of sight, thus making it a probe suitably complementing Sunyaev-Zel'dovich data recently obtained by Planck.

  4. Intergalactic HI Clouds

    E-print Network

    F. H. Briggs

    2005-02-16

    Neutral intergalactic clouds are so greatly out numbered by galaxies that their integral HI content is negligible in comparison to that contained in optically luminous galaxies. In fact, no HI cloud that is not associated with a galaxy or grouping of galaxies has yet been identified. This points to a causal relationship that relies on gravitational potentials that bind galaxies also being responsible for confining HI clouds to sufficient density that they can become self-shielding to the ionizing background radiation. Unconfined clouds of low density become ionized, but confined clouds find themselves vulnerable to instability and collapse, leading to star formation.

  5. Telescope for Habitable Exoplanets and Interstellar/Intergalactic Astronomy

    E-print Network

    successor to HST and companion to the James Webb Space Telescope (JWST). With a wide field imagerTHEIA Telescope for Habitable Exoplanets and Interstellar/Intergalactic Astronomy White Paper, Penn State, Princeton University, Space Telescope Science Institute, University of California

  6. On the intergalactic attenuation for high-z galaxies

    NASA Astrophysics Data System (ADS)

    Inoue, Akio K.

    2015-01-01

    Even after the cosmic reionization, neutral hydrogen still remains in the intergalactic space. These intervening hydrogen atoms absorb the radiation from high-z objects and make a numerous absorption lines, the so-called Lyman alpha forest, in the spectra of the objects. To know the absorption amount as a function of redshift is essentially important for studies of the high-z objects, for example, to predict how much reddening occurs in the spectra of the high-z galaxies, which is used as the so-called Lyman break technique. The current standard model for the intergalactic attenuation is Madau (1995). However, the intergalactic absorbers' statistics, which is the ingredient of the model, is largely updated during two decades after Madau (1995). Here, I present an update of this kind model. I also show a preliminary result of the absorption excess in a proto-cluster environment found in a composite spectrum of galaxies behind the proto-cluster.

  7. An Intergalactic Voyage.

    ERIC Educational Resources Information Center

    Wethered, Peggy Ann

    1997-01-01

    Describes an event called Star Week that involved families joining in their children's projects, attending an educational presentation by the National Aeronautics and Space Administration (NASA), and participating in a schoolwide star party. Contains resources for both students and teachers. (JRH)

  8. Ten More New Sightlines for the Study of Intergalactic Helium, and Hundreds of Far-Ultraviolet-Bright Quasars, from the Sloan Digital Sky Survey, Galaxy Evolution Explorer, and Hubble Space Telescope

    NASA Astrophysics Data System (ADS)

    Syphers, David; Anderson, Scott F.; Zheng, Wei; Haggard, Daryl; Meiksin, Avery; Schneider, Donald P.; York, Donald G.

    2009-11-01

    Absorption along quasar sightlines remains among the most sensitive direct measures of He II reionization in much of the intergalactic medium (IGM). Until recently, fewer than a half-dozen unobscured quasar sightlines suitable for the He II Gunn-Peterson test were known; although these handful demonstrated great promise, the small sample size limited confidence in cosmological inferences. We have recently added nine more such clean He II quasars, exploiting Sloan Digital Sky Survey (SDSS) quasar samples, broadband ultraviolet (UV) imaging from Galaxy Evolution Explorer (GALEX), and high-yield UV spectroscopic confirmations from Hubble Space Telescope (HST). Here we markedly expand this approach by cross-correlating SDSS DR7 and GALEX GR4+5 to catalog 428 SDSS and 165 other quasars with z > 2.78 having likely (~70%) GALEX detections, suggesting they are bright into the far-UV. Reconnaissance HST Cycle 16 Supplemental prism data for 29 of these new quasar-GALEX matches spectroscopically confirm 17 as indeed far-UV bright. At least 10 of these confirmations have clean sightlines all the way down to He II Ly?, substantially expanding the number of known clean He II quasars, and reaffirming the order of magnitude enhanced efficiency of our selection technique. Combined confirmations from this and our past programs yield more than 20 He II quasars, quintupling the sample. These provide substantial progress toward a sample of He II quasar sightlines large enough, and spanning a sufficient redshift range, to enable statistical IGM studies that may avoid individual object peculiarity and sightline variance. Our expanded catalog of hundreds of high-likelihood far-UV-bright QSOs additionally will be useful for understanding the extreme-UV properties of the quasars themselves. Based on observations with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

  9. Intergalactic shells at large redshift

    NASA Technical Reports Server (NTRS)

    Shull, J. M.; Silk, J.

    1981-01-01

    The intergalactic shells produced by galactic explosions at large redshift, whose interiors cool by inverse Compton scattering off the cosmic background radiation, have a characteristic angular size of about 1 arcmin at peak brightness. At z values lower than 2, the shells typically have a radius of 0.5 Mpc, a velocity of about 50 km/sec, a metal abundance of about 0.0001 of cosmic values, and strong radiation in H I(Lyman-alpha), He II 304 A, and the IR fine-structure lines of C II and Si II. The predicted extragalactic background emission from many shells, strongly peaked toward the UV, sets an upper limit to the number of exploding sources at z values of about 10. Shell absorption lines of H I, C II, Si II, and Fe II, which may be seen at more recent epochs in quasar spectra, may probe otherwise invisible explosions in the early universe.

  10. INTERGALACTIC 'PIPELINE' FUNNELS MATTER BETWEEN COLLIDING GALAXIES

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This visible-light picture, taken by NASA's Hubble Space Telescope, reveals an intergalactic 'pipeline' of material flowing between two battered galaxies that bumped into each other about 100 million years ago. The pipeline [the dark string of matter] begins in NGC 1410 [the galaxy at left], crosses over 20,000 light-years of intergalactic space, and wraps around NGC 1409 [the companion galaxy at right] like a ribbon around a package. Although astronomers have taken many stunning pictures of galaxies slamming into each other, this image represents the clearest view of how some interacting galaxies dump material onto their companions. These results are being presented today at the 197th meeting of the American Astronomical Society in San Diego, CA. Astronomers used the Space Telescope Imaging Spectrograph to confirm that the pipeline is a continuous string of material linking both galaxies. Scientists believe that the tussle between these compact galaxies somehow created the pipeline, but they're not certain why NGC 1409 was the one to begin gravitationally siphoning material from its partner. And they don't know where the pipeline begins in NGC 1410. More perplexing to astronomers is that NGC 1409 is seemingly unaware that it is gobbling up a steady flow of material. A stream of matter funneling into the galaxy should have fueled a spate of star birth. But astronomers don't see it. They speculate that the gas flowing into NGC 1409 is too hot to gravitationally collapse and form stars. Astronomers also believe that the pipeline itself may contribute to the star-forming draught. The pipeline, a pencil-thin, 500 light-year-wide string of material, is moving a mere 0.02 solar masses of matter a year. Astronomers estimate that NGC 1409 has consumed only about a million solar masses of gas and dust, which is not enough material to spawn some of the star-forming regions seen in our Milky Way. The low amount means that there may not be enough material to ignite star birth in NGC 1409, either. The glancing blow between the galaxies was enough, however, to toss stars deep into space and ignite a rash of star birth in NGC 1410. The arms of NGC 1410, an active, gas-rich spiral galaxy classified as a Seyfert, are awash in blue, the signature color of star-forming regions. The bar of material bisecting the center of NGC 1409 also is a typical byproduct of galaxy collisions. Astronomers expect more fireworks to come. The galaxies are doomed to continue their game of 'bumper cars,' hitting each other and moving apart several times until finally merging in another 200 million years. The galaxies' centers are only 23,000 light-years apart, which is slightly less than Earth's distance from the center of the Milky Way. They are bound together by gravity, orbiting each other at 670,000 miles an hour (1 million kilometers an hour). The galaxies reside about 300 million light-years from Earth in the constellation Taurus. The Hubble picture was taken Oct. 25, 1999. Credits: NASA, William C. Keel (University of Alabama, Tuscaloosa)

  11. The sources of intergalactic metals

    NASA Astrophysics Data System (ADS)

    Scannapieco, E.; Pichon, C.; Aracil, B.; Petitjean, P.; Thacker, R. J.; Pogosyan, D.; Bergeron, J.; Couchman, H. M. P.

    2006-01-01

    We study the clustering properties of metals in the intergalactic medium (IGM) as traced by 619 CIV and 81 SiIV absorption components with N>= 1012cm-2 and 316 MgII and 82 FeII absorption components with N>= 1011.5cm-2 in 19 high signal-to-noise ratio (60-100 pixel-1), high-resolution (R= 45000) quasar spectra. CIV and SiIV trace each other closely and their line-of-sight correlation functions ?(v) exhibit a steep decline at large separations and a flatter profile below ~150 km s-1, with a large overall bias. These features do not depend on absorber column densities, although there are hints that the overall amplitude of ?CIV (v) increases with time over the redshift range detected (1.5-3). Carrying out a detailed smoothed particle hydrodynamic simulation (2 × 3203, 57 Mpc3 comoving), we show that the CIV correlation function cannot be reproduced by models in which the IGM metallicity is constant or a local function of overdensity (Z~?2/3). However, the properties of ?CIV(v) are generally consistent with a model in which metals are confined within bubbles with a typical radius Rs about sources of mass >=Ms. We derive best-fitting values of Rs~ 2 comoving Mpc and Ms~ 1012Msolar at z= 3. Our lower-redshift (0.5-2) measurements of the MgII and FeII correlation functions also uncover a steep decline at large separations and a flatter profile at small separations, but the clustering is even higher than in the z= 1.5-3 measurements, and the turnover is shifted to somewhat smaller distances, ~75 km s-1. Again, these features do not change with column density, but there are hints that the amplitudes of ?MgII(v) and ?FeII(v) increase with time. We describe an analytic `bubble' model for these species, which come from regions that are too compact to be accurately simulated numerically, deriving best-fitting values of Rs~ 2.4 Mpc and Ms~ 1012Msolar. Equally good analytic fits to all four species are found in a similarly biased high-redshift enrichment model in which metals are placed within 2.4 comoving Mpc of Ms~ 3 × 109 sources at z= 7.5.

  12. Intergalactic medium metal enrichment through dust sputtering

    Microsoft Academic Search

    Simone Bianchi; Andrea Ferrara

    2005-01-01

    We study the motion of dust grains into the intergalactic medium (IGM) around redshift z= 3, to test the hypothesis that grains can efficiently pollute the gas with metals through sputtering. We use the results available in the literature for radiation-driven dust ejection from galaxies as initial conditions and follow the motion onwards. Via this mechanism, grains are ejected into

  13. Ludwig Biermann Award Lecture: High-Velocity Clouds and the Local Intergalactic Medium (With 12 Figures)

    NASA Astrophysics Data System (ADS)

    Richter, Philipp

    2006-01-01

    In this article I review recent observations of the gaseous halos of galaxies and the intergalactic medium at low redshift. In the first part I discuss distribution, metal content, and physical properties of the Galactic intermediate- and high-velocity clouds and the hot halo of the Milky Way. Recent absorption and emission measurements show that the Galaxy's tidal interaction with the Magellanic Clouds, the infall of low-metallicity gas, as well as the circulation of gas as part of the galactic fountain contribute to the observed distribution of gas in the halo of the Milky Way. In the second part I give a short overview on the circumgalactic gaseous environment of other nearby spiral galaxies. Multi-wavelength observations demonstrate that neutral and ionized gaseous halos of galaxies are common, and that they extend deep into intergalactic space. These studies suggest that the gaseous material around spiral galaxies is tightly connected to the on-going hierarchical formation and evolution of these galaxies. In the last part of this article I summarize recent quasar absorption-line measurements of the local intergalactic medium. In accordance with cosmological simulations, absorption-line studies in the far-ultraviolet indicate that both the photoionized Ly alpha forest and the shock-heated warm-hot intergalactic medium harbor a substantial fraction of the baryons in the local Universe.

  14. Highly-ionized oxygen absorbers in the intergalactic medium

    Microsoft Academic Search

    S. R. Furlanetto; L. A. Phillips; M. Kamionkowski

    2005-01-01

    Recent ultraviolet and X-ray observations of intergalactic OVI and OVII absorption systems along lines of sight to bright quasars have opened a new window on to the `warm-hot intergalactic medium'. These systems appear to provide a significant reservoir for baryons in the local Universe, and comparison to cosmological simulations suggests that their abundance roughly matches theoretical predictions. Here we use

  15. Intergalactic Propagation of UHE Cosmic Rays

    E-print Network

    Abraham Achterberg; Yves A. Gallant; Colin A. Norman; Donald B. Melrose

    1999-07-05

    We discuss the intergalactic propagation of ultra-high-energy cosmic rays (UHECRs) with energies E \\geq 10^{18.5} eV. We consider the propagation of UHECRs under the influence of the energy-dependent deflection by a weak random magnetic field in the intergalactic medium and energy losses by photo-pion and pair production. We calculate arrival spectra taking full account of the kinematics of photo-pion production and the Poisson statistics of the photo-pion interaction rate. We give estimates for the deflection of UHECRs from the line of sight to the source, time delays with respect to photons from the same source, arrival spectra and source statistics. These estimates are confirmed by numerical simulations of the propagation in energy evolution of UHECRs. These simulations demonstrate that the often-used continuous approximation in the treatment of energy losses due to photo-pion production on the cosmic microwave background (CMWB) cannot be justified for UHECRs. We discuss the implications of these results for the observed flux of particles above the Greisen-Zatsepin-Kuz'min cut-off in two of the scenarios that have been proposed for the production of these particles: continuous production in the large shock waves associated with powerful radio galaxies, or possibly large-scale structure formation, and the impulsive production at relativistic blast waves associated with cosmological gamma-ray bursts.

  16. The Ionization History of The Intergalactic Medium:

    NASA Technical Reports Server (NTRS)

    Madau, Piero

    2003-01-01

    The funded project seeked a unified description of the ionization, physical structure, and evolution of the intergalactic medium (IGM) and quasar intervening absorption systems. We proposed to conduct theoretical studies of the IGM and QSO absorbers in the context of current theories of galaxy formation, developing and using numerical and analytical techniques aimed at a detailed modeling of cosmological radiative transfer, gas dynamics, and thermal and ionization evolution. The ionization history of the IGM has important implications for the metagalactic UV background, intergalactic helium absorption 21-cm tomography, metal absorption systems, fluctuations in the microwave background, and the cosmic rate of structure and star formation. All the original objectives of our program have been achieved, and the results widely used and quoted by the community. Indeed, they remain relevant as the level and complexity of research in this area has increased substantially since our proposal was submitted, due to new discoveries on galaxy formation and evolution, a flood of high-quality data on the distant universe, new theoretical ideas and direct numerical simulations of structure formation in hierarchical clustering theories.

  17. Effects of the Intergalactic Plasma on Supernova Dimming via Photon-Axion Oscillations

    E-print Network

    Csáki, C; Terning, J; Csaki, Csaba; Kaloper, Nemanja; Terning, John

    2002-01-01

    We have recently proposed a mechanism of photon-axion oscillations as a way of rendering supernovae dimmer without cosmic acceleration. Subsequently, it has been argued that the intergalactic plasma may interfere adversely with this mechanism by rendering the oscillations energy dependent. Here we show that this energy dependence is extremely sensitive to the precise value of the free electron density in the Universe. Decreasing the electron density by only a factor of 4 is already sufficient to bring the energy dependence within the experimental bounds. Models of the intergalactic medium show that for redshifts zspace is filled with regions of density significantly lower than the average density. From these models we estimate that the average electron density in most of space is lower by at least a factor of 15 compared to the estimate based on one half of all baryons being uniformly distributed and ionized. Therefore the energy dependence of the photon-axion oscillatio...

  18. Constraints on dark matter from intergalactic radiation

    NASA Technical Reports Server (NTRS)

    Overduin, J. M.; Wesson, P. S.

    1992-01-01

    Several of the dark matter candidates that have been proposed are believed to be unstable to decay, which would contribute photons to the radiation field between galaxies. The main candidates of this type are light neutrinos and axions, primordial mini-black holes, and a nonzero 'vacuum' energy. All of these can be constrained in nature by observational data on the extragalactic background light and the microwave background radiation. Black holes and the vacuum can be ruled out as significant contributors to the 'missing mass'. Light axions are also unlikely candidates; however, those with extremely small rest energies (the so-called 'invisible' axions) remain feasible. Light neutrinos, like those proposed by Sciama, are marginally viable. In general, we believe that the intergalactic radiation field is an important way of constraining all types of dark matter.

  19. Effects of a hot intergalactic medium

    NASA Technical Reports Server (NTRS)

    Taylor, Gregory B.; Wright, Edward L.

    1989-01-01

    One effect a hot intergalactic medium (IGM) would have would be to produce an isotropic X-ray background through thermal bremsstrahlung. Such a background was modeled including both relativistic electron-ion and electron-electron emission; the observed X-ray measurements could be fit with a current temperature of 10.2 keV and Omega (IGM) of 0.27, assuming that the IGM was instantaneously heated at a redshift of 5 and cools by relativistic adiabatic expansion and Compton cooling. Such a hot IGM would also distort the cosmic microwave background spectrum by inverse Compton scattering off relativistic electrons. This distortion was modeled using the relativistic treatment. When including the recent data of Matsumoto et al., an undistorted radiation temperature of 2.86 K and an Omega (IGM) of 0.41 was found.

  20. Intergalactic medium metal enrichment through dust sputtering

    NASA Astrophysics Data System (ADS)

    Bianchi, Simone; Ferrara, Andrea

    2005-04-01

    We study the motion of dust grains into the intergalactic medium (IGM) around redshift z= 3, to test the hypothesis that grains can efficiently pollute the gas with metals through sputtering. We use the results available in the literature for radiation-driven dust ejection from galaxies as initial conditions and follow the motion onwards. Via this mechanism, grains are ejected into the IGM with velocities >100 km s-1 as they move supersonically, grains can be efficiently eroded by non-thermal sputtering. However, Coulomb and collisional drag forces effectively reduce the charged grain velocity. Up-to-date sputtering yields for graphite and silicate (olivine) grains have been derived using the code TRANSPORT OF IONS IN MATTER (TRIM), for which we provide analytic fits. After training our method on a homogeneous density case, we analyse the grain motion and sputtering in the IGM density field as derived from a ? cold dark matter (CDM) cosmological simulation at z= 3.27. We found that only large (a>~ 0.1?m) grains can travel up to considerable distances (few ×100 kpc physical) before being stopped. Resulting metallicities show a well-defined trend with overdensity ?. The maximum metallicities are reached for 10 < ? < 100[corresponding to systems, in quasi-stellar object (QSO) absorption spectra, with 14.5 < log N(HI) < 16]. However the distribution of sputtered metals is very inhomogeneous, with only a small fraction of the IGM volume polluted by dust sputtering (filling factors of 18 per cent for Si and 6 per cent for C). For the adopted size distribution, grains are never completely destroyed; nevertheless, the extinction and gas photoelectric heating effects resulting from this population of intergalactic grains are well below current detection limits.

  1. The Multiphase Intergalactic Medium towards PKS 2155-304

    E-print Network

    J. Michael Shull; Jason Tumlinson; Mark Giroux

    2003-07-25

    We study the cluster of H I and O VI absorption systems and the claimed detection of O VIII absorption from the intergalactic medium at z ~ 0.0567, associated with a group of galaxies toward the BL Lac object PKS 2155-304. As measured by spectrographs on the Hubble Space Telescope, Far Ultraviolet Spectroscopic Explorer, and Chandra, this system appears to contain gas at a variety of temperatures. We analyze this multi-phase gas in a clumpy-infall model. From the absence of C IV and Si III absorption in the Ly-alpha clouds, we infer metallicities less than 2.5-10% of solar values. The only metals are detected in two O VI absorption components, offset by +/- 400 km/s from the group barycenter (cz ~ 16,600 km/s). The O VI components may signify "nearside" and "backside" infall into the group potential well, which coincides with the claimed O VIII absorption. If the claimed O VIII detection is real, our analysis suggests that clusters of strong Ly-alpha and O VI absorbers, associated with groups of galaxies, may be the "signposts" of shock-heated, metal-enriched baryons. Through combined UV and X-ray spectra of H I and O VI, O VII, and O VIII, one may be able to clarify the heating mechanism of this multiphase gas.

  2. Intergalactic stellar populations in intermediate redshift clusters

    NASA Astrophysics Data System (ADS)

    Melnick, J.; Giraud, E.; Toledo, I.; Selman, F.; Quintana, H.

    2012-11-01

    A substantial fraction of the total stellar mass in rich clusters of galaxies resides in a diffuse intergalactic component usually referred to as the intracluster light (ICL). Theoretical models indicate that these intergalactic stars originate mostly from the tidal interaction of the cluster galaxies during the assembly history of the cluster, and that a significant fraction of these stars could have formed in situ from the late infall of cold metal-poor gas clouds on to the cluster. However, these models also overpredict the fraction of stellar mass in the ICL by a substantial margin, something that is still not well understood. The models also make predictions about the age distribution of the ICL stars, which may provide additional observational constraints. Here we present population synthesis models for the ICL of an intermediate redshift (z = 0.29) X-ray cluster that we have extensively studied in previous papers. The advantage of observing intermediate redshift clusters rather than nearby ones is that the former fit the field of view of multi-object spectrographs in 8-m telescopes and therefore permit us to encompass most of the ICL with only a few well-placed slits. In this paper we show that by stacking spectra at different locations within the ICL it is possible to reach sufficiently high signal-to-noise ratios to fit population synthesis models and derive meaningful results. The models provide ages and metallicities for the dominant populations at several different locations within the ICL and the brightest cluster galaxies (BCG) halo, as well as measures of the kinematics of the stars as a function of distance from the BCG. We thus find that the ICL in our cluster is dominated by old metal-rich stars, at odds with what has been found in nearby clusters where the stars that dominate the ICL are old and metal poor. While we see weak evidence of a young, metal-poor component, if real, these young stars would amount to less than 1 per cent of the total ICL mass, much less than the up to 30 per cent predicted by the models. We propose that the very metal-rich (i.e. 2.5× solar) stars in the ICL of our cluster, which comprise ˜40 per cent of the total mass, originate mostly from the central dumb-bell galaxy, while the remaining solar and metal-poor stars come from spiral, post-starburst (E+A) and metal-poor dwarf galaxies. About 16 per cent of the ICL stars are old and metal poor.

  3. The intergalactic medium in the cosmic web

    NASA Astrophysics Data System (ADS)

    Tejos, Nicolas

    2014-10-01

    We request funding to perform a dedicated survey and analysis of theHST archive of COS-G130M quasar spectra to construct anabsorption-line catalog tuned to study the environment {i.e. large-scalestructure, LSS} of the intergalactic medium {IGM}. Specifically, wewill characterize the HI Lyman series absorption at z<0.1 andassociate metals for all absorbers along 100 quasar sightlinespenetrating the SDSS footprint. Using standard line-profile fittingtechniques, we will recover HI column densities and Dopplerparameters. These will be publicly released in a database thatincludes spectral masks identifying spurious spectral features,regions biased by previously known systems, etc. This catalog will beanalyzed in conjunction with the suite of LSS catalogs generated fromthe SDSS footprint {e.g. clusters, groups}, with emphasis on newalgorithms designed to identify and characterize galaxy voids.Through this analysis, we will test the predictions from ourcosmological paradigm that the IGM traces a so-called cosmic web ofLSS.

  4. Giant Radio Galaxies: I. Intergalactic Barometers

    E-print Network

    Malarecki, J M; Saripalli, L; Subrahmanyan, R; Jones, D H; Duffy, A R; Rioja, M

    2013-01-01

    We present new wideband radio observations with the Australia Telescope Compact Array of a sample of 12 giant radio galaxies. The radio observations are part of a larger radio-optical study aimed at relating the radio structures with the ambient medium on large scales. With projected linear sizes larger than 0.7 Mpc, these objects are ideal candidates for the study of the Warm-Hot Intergalactic Medium (WHIM). The sample includes sources with sizes spanning 0.8 to 3.2 Mpc and total powers of 1.2*10^24 to 4.0*10^26 W Hz^-1 at 2.1 GHz. Redshifts were limited to z<0.15 to permit spectroscopic observations of the hosts and neighbouring galaxies, which were obtained using the AAOmega spectrograph on the Anglo-Australian Telescope. We derive lobe energy densities from the radio observations via equipartition arguments. The inferred pressures in the lobes of the giant radio sources, which range from 1.1*10^-15 to 2.0*10^-14 Pa (80 to 1500 cm^-3 K), are lower than previously inferred from X-ray observations of dens...

  5. Quantized Redshifts of Galaxies: Stimulated Raman Scattering in Cold Intergalactic Rydberg Matter

    NASA Astrophysics Data System (ADS)

    Holmlid, Leif

    2004-05-01

    That the redshifts for galaxies in the local supercluster are quantizedwas recently confirmedby Guthrie and Napier(A&A310 (1996) 353). These redshifts are here proposed to be due to stimulatedStokes Raman processes in intergalactic matter in the form of Rydberg Matter (RM). Rydberg Matteris an electronically excited material, as demonstrated by its use as laser medium in a thermally excitedultra-broadband tunable IR laser (Chem. Phys. Lett. 376 (2003) 812). Its existence in interstellar andintergalactic space is demonstrated by several observational results, notably the unidentified IR bands,that agree well with the emission from Rydberg Matter. A stimulated Raman process will allow theH I 21 cm radiation to proceed without deflection, in agreement with observation. Such redshiftswill be additive during the passage through space. The process in Rydberg Matter here proposed togive rise to the Stokes Raman process is excitation of electronic translational modes in the planarclusters forming the matter. The specific cluster sizes found in laboratory experiments give rise toa few differently sized redshift quanta, which is in good agreement with the observed quanta. Anexcitation level (principal quantum number) of Rydberg Matter in intergalactic space between 175and 200 gives the correct size of the redshift quanta.

  6. Galaxy formation in an intergalactic medium dominated by explosions

    Microsoft Academic Search

    J. P. Ostriker; L. L. Cowie

    1981-01-01

    The evolution of galaxies in an intergalactic medium dominated by explosions of star systems is considered analogously to star formation by nonlinearly interacting processes in the interstellar medium. Conditions for the existence of a hydrodynamic instability by which galaxy formation leads to more galaxy formation due to the propagation of the energy released at the death of massive stars are

  7. A Population of Intergalactic Supernovae in Galaxy Clusters

    NASA Astrophysics Data System (ADS)

    Gal-Yam, Avishay; Maoz, Dan; Guhathakurta, Puragra; Filippenko, Alexei V.

    2003-03-01

    We have discovered seven cluster supernovae (SNe) of Type Ia in the course of the Wise Observatory Optical Transients Search in the fields of 0.06-14 mag for SN 1998fc and MR>-11.8 mag for SN 2001al. The fractions of the cluster luminosities in dwarf galaxies fainter than our limits are less than 3×10-3 and less than 3×10-4, respectively. Thus, 2/7 of the SNe would be associated with <=3×10-3 of the luminosity attributed to galaxies. We argue, instead, that the progenitors of both events were probably members of a diffuse population of intergalactic stars recently detected in local clusters via planetary nebulae and red giants. Considering the higher detectability of hostless SNe compared with normal SNe, we estimate that 20+20-12 (20+35-13) percent at the 68% (95%) confidence level of the SN Ia parent stellar population in clusters is intergalactic. This fraction is consistent with other measurements of the intergalactic stellar population and implies that the process that produces intergalactic stars (e.g., tidal disruption of cluster dwarfs) does not disrupt or enhance significantly the SN Ia formation mechanism. Hostless SNe are potentially powerful tracers of the formation of the intergalactic stellar population out to high redshift.

  8. Effects of the Intergalactic Plasma on Supernova Dimming via Photon-Axion Oscillations

    E-print Network

    Csaba Csaki; Nemanja Kaloper; John Terning

    2001-12-17

    We have recently proposed a mechanism of photon-axion oscillations as a way of rendering supernovae dimmer without cosmic acceleration. Subsequently, it has been argued that the intergalactic plasma may interfere adversely with this mechanism by rendering the oscillations energy dependent. Here we show that this energy dependence is extremely sensitive to the precise value of the free electron density in the Universe. Decreasing the electron density by only a factor of 4 is already sufficient to bring the energy dependence within the experimental bounds. Models of the intergalactic medium show that for redshifts zspace is filled with regions of density significantly lower than the average density. From these models we estimate that the average electron density in most of space is lower by at least a factor of 15 compared to the estimate based on one half of all baryons being uniformly distributed and ionized. Therefore the energy dependence of the photon-axion oscillations is consistent with experiment, and the oscillation model remains a viable alternative to the accelerating Universe for explaining the supernova observations. Furthermore, the electron density does give rise to a sufficiently large plasma frequency which cuts off the photon-axion mixing above microwave frequencies, shielding the cosmic microwave photons from axion conversions and significantly relaxing the lower bounds on the axion mass implied by the oscillation model.

  9. Current Status of the DIOS (diffuse intergalactic oxygen surveyor) Mission

    NASA Astrophysics Data System (ADS)

    Tawara, Yuzuru; Mitsuda, Kazuhisa; Yamasaki, Noriko; Takei, Yoh; Ezoe, Yuichiro; Ishisaki, Yoshitaka; Ohashi, Takaya

    The Diffuse Intergalactic Oxygen Surveyor (DIOS) mission will conduct a high-sensitivity soft X-ray survey over a wide solid angle of the sky to search warm hot intergalactic medium using redshifted OVII and OVIII lines. Together with very high spectroscopic capability, DIOS will bring rich science about the dynamics of cosmic hot plasmas in all spatial scales. Key instruments of the DIOS are a 4-stage X-ray telescope (FXT) and an array of TES micro-calorimeter (XSA), cooled with mechanical coolers. FXT uses the conical approximation of the Wolter I optic extended to four-fold reflection, which can provide very short focal length to be suited to small detector of XSA to cover wide field of view. In this paper, hardware development of DIOS and outstanding issues about the payload are described. DIOS will be further developed with international collaboration and will be proposed to the call of JAXA’s scientific satellite.

  10. Bar-driven injection of intergalactic matter into galactic halos

    E-print Network

    M. Lopez-Corredoira

    2007-03-15

    AIMS. The non-conservative gravitational potential of barred galaxies, or of any other non-axisymmetric structure, produces a loss of energy in infalling particles of the intergalactic medium into the galaxy, which are trapped in its potential. This dynamical friction can contribute towards increasing the total mass of barred galaxies. METHODS. Analytical calculations of the energy loss are carried out using the orbits of the particles derived numerically. Theoretical predictions are compared with observations through the statistical analysis of the rotation curves of barred and non-barred galaxies, either in cluster or field galaxies. RESULTS. There is a net effect of accretion, but it is normally very low in relative terms. It is only significant (>10% of the total mass of the dark matter halo in the life of the galaxy) if the density of the intergalactic medium is higher than ~3e13 Msun/Mpc^3 (or considerably lower in cases of motions of the galaxies close to the IGM average motion, or perpendicular to the plane of the galaxy, or when the halo mass is low). Data on rotation curves do not show clear trends towards higher halo mass for barred galaxies, only slight trends for early-type spiral galaxies. In any case, the statistical uncertainties are limited to the detection of differences in masses >~20%, so the effect of bar-driven injection of intergalactic matter into galactic halos might be present with relative contributions to the average mass of these barred galaxies lower than 20%.

  11. High-metallicity, photoionized gas in intergalactic large-scale filaments

    NASA Astrophysics Data System (ADS)

    Aracil, Bastien; Tripp, Todd M.; Bowen, David V.; Prochaska, Jason X.; Chen, Hsiao-Wen; Frye, Brenda L.

    2006-03-01

    We present high-resolution ultraviolet spectra of absorption-line systems towards the low-z quasi-stellar object (QSO) HS 0624+6907 (zQSO= 0.3700). Coupled with ground-based imaging and spectroscopic galaxy redshifts, we find evidence that many of these absorbers do not arise in galaxy haloes but rather are truly intergalactic gas clouds distributed within large-scale structures, and moreover, the gas is cool (T < 105 K) and has relatively high metallicity (Z > 0.9Zsolar). Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) data reveal a dramatic cluster of 13 HI Lyman ? (Ly?) lines within a 1000 km s-1 interval at zabs= 0.0635. We find 10 galaxies at this redshift with impact parameters ranging from ?= 135h-170 kpc to 1.37h-170 Mpc. The velocities and velocity spread of the Ly? lines in this complex are unlikely to arise in the individual haloes of the nearby galaxies; instead, we attribute the absorption to intragroup medium gas, possibly from a large-scale filament viewed along its long axis. Contrary to theoretical expectations, this gas is not the shock-heated warm-hot intergalactic medium (WHIM); the width of the Ly? lines all indicate a gas temperature T<< 105 K, and metal lines detected in the Ly? complex also favour photoionized, cool gas. No OVI absorption lines are evident, which is consistent with photoionization models. Remarkably, the metallicity is near-solar, [M/H]=-0.05 +/- 0.4 (2? uncertainty), yet the nearest galaxy which might pollute the intergalactic medium is at least 135h-170 kpc away. Tidal stripping from nearby galaxies appears to be the most likely origin of this highly enriched, cool gas. More than six Abell galaxy clusters are found within 4° of the sight line suggesting that the QSO line of sight passes near a node in the cosmic web. At z~ 0.077, we find absorption systems as well as galaxies at the redshift of the nearby clusters Abell 564 and Abell 559. We conclude that the sight line pierces a filament of gas and galaxies feeding into these clusters. The absorber at zabs= 0.07573 associated with Abell 564/559 also has a high metallicity with [C/H] > -0.6, but again the closest galaxy is relatively far from the sight line (?= 293h-170 kpc). The Doppler parameters and HI column densities of the Ly? lines observed along the entire sight line are consistent with those measured towards other low-z QSOs, including a number of broad (b > 40kms-1) Ly? lines.

  12. Intergalactic thermonuclear gamma-ray line

    NASA Technical Reports Server (NTRS)

    Clayton, D. D.

    1985-01-01

    The possibility of thermonculear reactions occurring in dilute space is briefly considered. X-ray emission from clusters of galaxies demonstrates that perhaps as much as 10 to the 14th solar masses of hot gas (T of about 100 million K) may often surround galaxies in clusters with a density of perhaps 0.004/cu cm. If the ion temperature is 100 million K, the thermonuclear reaction p + d to He-3 + gamma ray should emit gamma rays at a rate of roughly 4 x 10 to the 41st/sec with energy 5.516 + or -0.016 MeV. Such a source in teh virgo cluster at 15.7 Mpc would present a line flux of 1 x 10 to the -11th/sq cm/sec.

  13. Intergalactic Extinction of High Energy Gamma-Rays

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    1998-01-01

    We discuss the determination of the intergalactic pair-production absorption coefficient as derived by Stecker and De Jager by making use of a new empirically based calculation of the spectral energy distribution of the intergalactic infrared radiation field as given by Malkan and Stecker. We show that the results of the Malkan and Stecker calculation agree well with recent data on the infrared background. We then show that Whipple observations of the flaring gamma-ray spectrum of Mrk 421 hint at extragalactic absorption and that the HEGRA observations of the flaring spectrum of Mrk 501 appear to strongly indicate extragalactic absorption. We also discuss the determination of the y-ray opacity at higher redshifts, following the treatment of Salamon and Stecker. We give a predicted spectrum, with absorption included for PKS 2155-304. This XBL lies at a redshift of 0.12, the highest redshift source yet observed at an energy above 0.3 TeV. This source should have its spectrum steepened by approx. 1 in its spectral index between approx. 0.3 and approx. 3 TeV and should show an absorption cutoff above approx. 6 TeV.

  14. Constraints on the Intergalactic Transport of Cosmic Rays

    E-print Network

    Fred C. Adams; Katherine Freese; Gregory Laughlin; Gregory Tarl{é}; Nathan Schwadron

    1997-10-10

    Motivated by recent experimental proposals to search for extragalactic cosmic rays (including anti-matter from distant galaxies), we study particle propagation through the intergalactic medium (IGM). We first use estimates of the magnetic field strength between galaxies to constrain the mean free path for diffusion of particles through the IGM. We then develop a simple analytic model to describe the diffusion of cosmic rays. Given the current age of galaxies, our results indicate that, in reasonable models, a completely negligible number of particles can enter our Galaxy from distances greater than $\\sim 100$ Mpc for relatively low energies ($E$ $< 10^6$ GeV/n). We also find that particle destruction in galaxies along the diffusion path produces an exponential suppression of the possible flux of extragalactic cosmic rays. Finally, we use gamma ray constraints to argue that the distance to any hypothetical domains of anti-matter must be roughly comparable to the horizon scale.

  15. An Improved Treatment of Cosmological Intergalactic Medium Evolution

    E-print Network

    Manrique, Alberto

    2015-01-01

    The modeling of galaxy formation and reionization, two central issues of modern cosmology, relies on the accurate follow-up of the intergalactic medium (IGM). Unfortunately, owing to the complex nature of this medium, the differential equations governing its ionization state and temperature are only approximate. In this paper, we improve these master equations. We derive new expression for the distinct composite inhomogeneous IGM phases, including all relevant ionizing/recombining and cooling/heating mechanisms, taking into account inflows/outflows into/from halos, and using more accurate recombination coefficients. Furthermore, to better compute the source functions in the equations we provide an analytic procedure for calculating the halo mass function in ionized environments, accounting for the bias due to the ionization state of their environment. Such an improved treatment of IGM evolution is part of a complete realistic model of galaxy formation presented elsewhere.

  16. Search for emission from warm-hot intergalactic medium

    NASA Astrophysics Data System (ADS)

    Takei, Yoh; Ohashi, Takaya; Sato, Kosuke; Mitsuishi, Ikuyuki; Branchini, Enzo; Ursino, Eugenio; Corsi, Alessandra

    About half of the baryons in the local Universe are not yet observed and are thought to reside in the intergalactic medium at temperatures of 0.1-10 million K and densities of 10-6 -10-4 cm-3 . This is called warm-hot intergalactic medium (WHIM). In this paper, we summarize search for emission from the WHIM, and show prospects with future instruments. Using XIS instrument onboard Suzaku, we searched for redshifted OVII and OVIII WHIM emission lines, in cluster outskirts and superclusters: Shapley supercluster, Sculptor supercluster, A2218, A1413, A2142, A2052, and the Coma cluster. The chance for detecting a signal was estimated to be sufficient to motivate our search, given the relatively high density and high temperature expected for the WHIM in these regions. We did not detect the significant emission, but obtained upper limits in OVII and OVIII emission intensities for these clusters and superclusters. The density of the WHIM was constrained based on the upper limits, which is 200-300 times mean baryon density of the Universe. Future instruments such as microcalorimeters have much higher sensitivity for weak lines. In particular a combination of a microcalorimeter and large grasp (effective area times field of view) telescope is ideal for mapping of the WHIM. We created mock spectra that contain the WHIM, cosmic X-ray background and Galactic emission. Here we present our results concerning detectability and expected 3-d maps of the line emitting regions asssociated to the WHIM, with future missions such as EDGE/XENIA.

  17. Parity-odd correlators of diffuse gamma-rays and intergalactic magnetic fields

    NASA Astrophysics Data System (ADS)

    Tashiro, Hiroyuki; Vachaspati, Tanmay

    2015-03-01

    We develop the connection between intergalactic helical magnetic fields and parity-odd signatures in the diffuse gamma-ray sky. We find that the location and the amplitude of a peak in a parity-odd correlator, Q(R), can be used to infer the normal and helical power spectra of the intergalactic magnetic field. When applied to Fermi-LAT data, the amplitude of the observed peak in Q(R) gives ˜10-14 G intergalactic magnetic field strength, which is consistent with an earlier independent estimate that only used the peak location (Tashiro et al. 2014). We discuss features in the observed Q(R) that further support the intergalactic magnetic field hypothesis and make predictions for future tests.

  18. Lyman-alpha scattering in the intergalactic medium during the epoch of reionisation 

    E-print Network

    Higgins, Jonathan

    2012-06-22

    We examine resonant scattering of Ly? (Lyman-alpha) photons in the neutral hydrogen Intergalactic Medium (IGM) at high redshift. Ly? scattering plays a key role in the 21cm emission/absorption against the Cosmic Microwave Background via...

  19. A Study of the Reionization History of Intergalactic Helium with FUSE and the Very Large Telescope

    NASA Astrophysics Data System (ADS)

    Zheng, W.; Kriss, G. A.; Deharveng, J.-M.; Dixon, W. V.; Kruk, J. W.; Shull, J. M.; Giroux, M. L.; Morton, D. C.; Williger, G. M.; Friedman, S. D.; Moos, H. W.

    2004-04-01

    We obtained high-resolution Far Ultraviolet Spectroscopic Explorer (FUSE; R~20,000) and Very Large Telescope (VLT; R~45,000) spectra of the quasar HE 2347-4342 in order to study the properties of the intergalactic medium between redshifts z=2.0 and 2.9. The high-quality optical spectrum allows us to identify approximately 850 H I absorption lines with column densities between N~5×1011 and 1018 cm-2. The reprocessed FUSE spectrum extends the wavelength coverage of the He II absorption down to an observed wavelength of 920 Å. Source flux is detected to rest-frame wavelengths as short as ~237 Å. Approximately 1400 He II absorption lines are identified, including 917 He II Ly? systems and some of their He II Ly?, Ly?, and Ly? counterparts. The ionization structure of He II is complex, with approximately 90 absorption lines that are not detected in the hydrogen spectrum. These features may represent the effect of soft ionizing sources. The ratio ?=N(HeII)/N(HI) varies approximately from unity to more than a thousand, with a median value of 62 and a distribution consistent with the intrinsic spectral indexes of quasars. This provides evidence that the dominant ionizing field is from the accumulated quasar radiation, with contributions from other soft sources such as star-forming regions and obscured active galactic nuclei, which do not ionize helium. We find an evolution in ? toward smaller values at lower redshift, with the gradual disappearance of soft components. At redshifts z>2.7, the large but finite increase in the He II opacity, ?=5+/-1, suggests that we are viewing the end stages of a reionization process that began at an earlier epoch. Fits of the absorption profiles of unblended lines indicate comparable velocities between hydrogen and He+ ions. For line widths bHe+=?bH, we find ?=0.95+/-0.12, indicating a velocity field in the intergalactic medium dominated by turbulence. At hydrogen column densities N<3×1012 cm-2, the number of forest lines shows a significant deficit relative to a power law and becomes negligible below N=1011 cm-2. Based on observations made for the Guaranteed Time Team by the NASA-CNES-CSA FUSE mission; Ultraviolet-Visual Echelle Spectrograph observations performed at the European Southern Observatory, Paranal, Chile, within the program 68.A-0230 and observations with the NASA/ESA Hubble Space Telescope.

  20. Studying the Warm-hot Intergalactic Medium in Emission

    NASA Astrophysics Data System (ADS)

    Takei, Y.; Ursino, E.; Branchini, E.; Ohashi, T.; Kawahara, H.; Mitsuda, K.; Piro, L.; Corsi, A.; Amati, L.; den Herder, J. W.; Galeazzi, M.; Kaastra, J.; Moscardini, L.; Nicastro, F.; Paerels, F.; Roncarelli, M.; Viel, M.

    2011-06-01

    We assess the possibility of detecting the warm-hot intergalactic medium in emission and characterizing its physical conditions and spatial distribution through spatially resolved X-ray spectroscopy, in the framework of the recently proposed DIOS, EDGE, Xenia, and ORIGIN missions, all of which are equipped with microcalorimeter-based detectors. For this purpose, we analyze a large set of mock emission spectra, extracted from a cosmological hydrodynamical simulation. These mock X-ray spectra are searched for emission features showing both the O VII K? triplet and O VIII Ly? line, which constitute a typical signature of the warm-hot gas. Our analysis shows that 1 Ms long exposures and energy resolution of 2.5 eV will allow us to detect about 400 such features per deg2 with a significance >=5? and reveals that these emission systems are typically associated with density ~100 above the mean. The temperature can be estimated from the line ratio with a precision of ~20%. The combined effect of contamination from other lines, variation in the level of the continuum, and degradation of the energy resolution reduces these estimates. Yet, with an energy resolution of 7 eV and all these effects taken into account, one still expects about 160 detections per deg2. These line systems are sufficient for tracing the spatial distribution of the line-emitting gas, which constitute an additional information, independent from line statistics, to constrain the poorly known cosmic chemical enrichment history and the stellar feedback processes.

  1. Equilibration Processes in the Warm-Hot Intergalactic Medium

    NASA Astrophysics Data System (ADS)

    Bykov, A. M.; Paerels, F. B. S.; Petrosian, V.

    2008-02-01

    The Warm-Hot Intergalactic Medium (WHIM) is thought to contribute about 40 50% to the baryonic budget at the present evolution stage of the universe. The observed large scale structure is likely to be due to gravitational growth of density fluctuations in the post-inflation era. The evolving cosmic web is governed by non-linear gravitational growth of the initially weak density fluctuations in the dark energy dominated cosmology. Non-linear structure formation, accretion and merging processes, star forming and AGN activity produce gas shocks in the WHIM. Shock waves are converting a fraction of the gravitation power to thermal and non-thermal emission of baryonic/leptonic matter. They provide the most likely way to power the luminous matter in the WHIM. The plasma shocks in the WHIM are expected to be collisionless. Collisionless shocks produce a highly non-equilibrium state with anisotropic temperatures and a large differences in ion and electron temperatures. We discuss the ion and electron heating by the collisionless shocks and then review the plasma processes responsible for the Coulomb equilibration and collisional ionisation equilibrium of oxygen ions in the WHIM. MHD-turbulence produced by the strong collisionless shocks could provide a sizeable non-thermal contribution to the observed Doppler parameter of the UV line spectra of the WHIM.

  2. On the enrichment of the intergalactic medium by galactic winds

    E-print Network

    Biman Nath; Neil Trentham

    1997-07-16

    Observations of metal lines in $\\lyal$ absorption systems of small H~I column density and their ubiquitous nature suggest that the intergalactic medium (IGM) was enriched to about $Z \\sim 0.01 \\> Z_{\\odot}$ by a redshift $z \\sim 3$. We investigate the role of winds from small star-forming galaxies at high $z$ in enriching the IGM. The existence of large numbers of small galaxies at high $z$ follows naturally from hierarchical clustering theories (e.g. CDM). For analytical simplicity we assume that the galactic winds escape the galaxies at a single characteristic redshift $z_{in}$, and we model the galactic winds as spherical shock waves propagating through the IGM. We then calculate the probability distribution of the metallicity of the IGM, as a function of time (for different values of $z_{in}$), adopting plausible galaxy mass functions (from Press-Schechter formalism), cooling physics, star-formation efficiencies, gas ejection dynamics, and nucleosynthesis yields. We compare this expected distribution with the observed distribution of metallicities in the Ly$\\alpha$ forest at $z=3$, the metal poor stars in the halo of our Galaxy, and with other observational constraints on such a scenario. We find that galactic winds at high $z$ could have enriched the IGM to a mean metallicity of $Z \\sim 0.01 Z_{\\odot}$ at $z \\sim 3$, with a standard deviation of the same order, if $z_{in} \\la 5$, and that this satisfies all the observational constraints.

  3. Cosmological Halos: A Search for the Ionized Intergalactic Medium

    E-print Network

    Robert M. Geller; Robert J. Sault; Robert Antonucci; Neil E. B. Killeen; Ron Ekers; Ketan Desai

    1998-10-01

    Standard big bang nucleosynthesis predicts the average baryon density of the Universe to be a few percent of the critical density. Only about one tenth of the predicted baryons have been seen. A plausible respository for the missing baryons is in a diffuse ionized intergalactic medium (IGM). In an attempt to measure the IGM we searched for Thomson-scattered halos around strong high redshift radio sources. Observations of the radio source 1935-692 were made with the Australia Telescope Compact Array. We assumed a uniform IGM, and isotropic steady emission of 1935-692 for a duration between 10^7 - 10^8 years. A model of the expected halo visibility function was used in \\chi^2 fits to place upper limits on \\Omega_{IGM}. The upper limits varied depending on the methods used to characterize systematic errors in the data. The results are 2/sigma limits of \\Omega_{IGM} < 0.65. While not yet at the sensitivity level to test primordial nucleosynthesis, improvements on the technique will probably allow this in future studies.

  4. Exploring the intergalactic medium with VLT/UVES

    E-print Network

    S. Cristiani; S. Bianchi; S. D'Odorico; T. -S. Kim

    2001-12-12

    The remarkable efficiency of the UVES spectrograph at the VLT has made it possible to push high-resolution, high-S/N ground observations of the Ly-a forest down to z~1.5, gaining new insight into the physical conditions of the intergalactic medium and its evolution over more than 90% of the cosmic time. The universal expansion, the UV ionizing background and the gravitational condensation of structures are the driving factors shaping the number density and the column density distribution of the absorbers. A (limited) contribution of UV photons produced by galaxies is found to be important to reproduce the observed evolutionary pattern at very high and low redshift. The Lyman forest contains most of the baryons, at least at z>1.5, and acts as a reservoir for galaxy formation. The typical Doppler parameter at a fixed column density is measured to slightly increase with decreasing redshift, but the inferred temperature at the mean density is increasing with redshift. The signatures of HeII reionization and feedback from the formation of galactic structures have possibly been detected in the Lyman forest.

  5. Heating of Intergalactic Gas and Cluster Scaling Relations

    E-print Network

    Michael Loewenstein

    1999-10-14

    X-ray observations of galaxy groups and clusters are inconsistent with the predictions of the simplest hierarchical clustering models, wherein non-baryonic and baryonic components are assembled together under the sole influence of gravity. These departures are in the sense that the intergalactic medium is hotter and more extended than expected, and become increasingly strong for less massive systems. I model these effects by constructing baseline sequences of hydrostatic polytropic models normalized to observations of high-temperature clusters and numerical simulations, and then transforming them by adding proscribed amounts of heat per particle at the cluster center. I present sequences with a universal value of this heating parameter that simultaneously reproduce recently published observed (gas and total gravitational) mass-temperature and entropy-temperature relations. The required amount of energy injection is consistent with constraints on the number of supernovae needed to account for observed intracluster silicon abundances, provided that energy injection is centrally concentrated. I argue that most of the heating occurred during or after the assembly of the cluster, and not exclusively in pre-collapse proto-cluster fragments.

  6. A Search for Intergalactic Globular Clusters in the Local Group

    E-print Network

    Zinn, Graziella di Tullio

    2015-01-01

    The whole Sloan Digital Sky Survey (SDSS, 14,555 deg^2 has been searched for intergalactic globular clusters (IGCs) in the Local Group (LG). Using optical, infrared, and ultraviolet photometric selection criteria and photometric redshifts, the 2.1x10^8 of objects in the SDSS Galaxy Catalogue were reduced to only 183,791 brighter than r_o = 19 that might be GCs. Visual examination of their SDSS images recovered 84 percent of the confirmed GCs in M31 and M33 and yielded 17 new GC candidates, 5 of them of high confidence, which we could confirm as GCs in MegaPrime images from the Canada, France, Hawaii Telescope. These 5 GCs are within M31's halo, but the other 12 candidates are not close to LG galaxies or galaxies within 3 Mpc of the LG. Even though this search covers only one-third of the sky and some GCs could have been missed, it suggests that the LG does not contain a large population of IGCs more luminous than Mv ~ -6. In the direction of the M81 Group, the search yielded five candidate GCs, probable membe...

  7. A Search for Intergalactic Globular Clusters in the Local Group

    NASA Astrophysics Data System (ADS)

    di Tullio Zinn, Graziella; Zinn, Robert

    2015-04-01

    The whole Sloan Digital Sky Survey (SDSS, 14,555 {{deg }2}) has been searched for intergalactic globular clusters (IGCs) in the Local Group (LG). Using optical, infrared, and ultraviolet photometric selection criteria and photometric redshifts, the 2.1× {{10}8} objects in the SDSS Galaxy Catalog were reduced to only 183,791 brighter than {{r}0}=19 that might be GCs. Visual examination of their SDSS images recovered 84% of the confirmed GCs in M31 and M33 and yielded 17 new GC candidates, 5 of them of high confidence, which we could confirm as GCs in MegaPrime images from the Canada-France-Hawaii Telescope. These 5 GCs are within M31's halo, but the other 12 candidates are not close to LG galaxies or galaxies within 3 Mpc of the LG. Even though this search covers only one-third of the sky and some GCs could have been missed, it suggests that the LG does not contain a large population of IGCs more luminous than {{M}V}˜ -6. In the direction of the M81 Group, the search yielded five candidate GCs, probable members of that group.

  8. Exploring the intergalactic magnetic field by means of Faraday tomography

    NASA Astrophysics Data System (ADS)

    Akahori, Takuya; Kumazaki, Kohei; Takahashi, Keitaro; Ryu, Dongsu

    2014-06-01

    Unveiling the intergalactic magnetic field (IGMF) in filaments of galaxies is a very important and challenging subject in modern astronomy. In order to probe the IGMF from rotation measures (RMs) of extragalactic radio sources, we need to separate RMs due to other origins such as the source, intervening galaxies, and our Galaxy. In this paper, we discuss observational strategies for the separation by means of Faraday tomography (Faraday RM synthesis). We consider an observation of a single radio source such as a radio galaxy or a quasar viewed through the Galaxy and the cosmic web. We then compare the observation with another observation of a neighboring source with a small angular separation. Our simulations with simple models of the sources suggest that it would be not easy to detect the RM due to an IGMF of order ˜ 1 rad m-2, an expected value for the IGMF through a single filament. Contrary to this, we find that an RM of at least ˜ 10 rad m-2 could be detected with the Square Kilometre Array or its pathfinders/precursors, if we achieve selection of ideal sources. These results would be improved if we incorporated decomposition techniques such as RMCLEAN and QU-fitting. We discuss the feasibility of the strategies for cases with complex Galactic emissions as well as with effects of observational noise and radio frequency interferences.

  9. Galaxy formation in an intergalactic medium dominated by explosions

    NASA Technical Reports Server (NTRS)

    Ostriker, J. P.; Cowie, L. L.

    1981-01-01

    The evolution of galaxies in an intergalactic medium dominated by explosions of star systems is considered analogously to star formation by nonlinearly interacting processes in the interstellar medium. Conditions for the existence of a hydrodynamic instability by which galaxy formation leads to more galaxy formation due to the propagation of the energy released at the death of massive stars are examined, and it is shown that such an explosive amplification is possible at redshifts less than about 5 and stellar system masses between 10 to the 8th and 10 to the 12th solar masses. Explosions before a redshift of about 5 are found to lead primarily to the formation of massive stars rather than galaxies, while those at a redshift close to 5 will result in objects of normal galactic scale. The model also predicts a dusty interstellar medium preventing the detection of objects of redshift greater than 3, numbers and luminosities of protogalaxies comparable to present observations, unvirialized groups of galaxies lying on two-dimensional surfaces, and a significant number of black holes in the mass range 1000-10,000 solar masses.

  10. A COS Survey of the Low-Redshift Intergalactic Medium

    NASA Astrophysics Data System (ADS)

    Danforth, Charles; Pieri, M.; Shull, J. M.; Keeney, B. A.; Stevans, M. L.; Stocke, J. T.; Savage, B. D.; Green, J. C.

    2013-01-01

    In three years of science operations onboard HST, the Cosmic OriginsSpectrograph has generated an archive of far-ultraviolet AGN spectra of unprecedented breadth, depth, and quality. COS was designed to be sensitive to many important diagnostic lines in the far-UV (1135-1800A) in the low-redshift, "local" universe: Lya (z<0.47), Lyb (0.1intergalactic absorption along ~200 extragalactic sight lines. This significant cornerstone of the scientific legacy of COS is at least an order-of-magnitude improvement over previous low-z IGM surveys in total observed pathlength and number of absorbers as well as substantial improvements in sensitivity and uniformity. Of particular interest is the sensitivity of COS to weak and broad absorption. We discuss the scope of and methodology behind the catalog, several initial discoveries, and the overall statistical findings of the survey. Finally, we discuss the new areas of cosmology enabled by this expanded study.

  11. Navy Space and Astronautics Orientation.

    ERIC Educational Resources Information Center

    Herron, R. G.

    Fundamental concepts of the spatial environment, technologies, and applications are presented in this manual prepared for senior officers and key civilian employees. Following basic information on the atmosphere, solar system, and intergalactic space, a detailed review is included of astrodynamics, rocket propulsion, bioastronautics, auxiliary…

  12. Can the intergalactic medium cause a rapid drop in Ly? emission at z > 6?

    NASA Astrophysics Data System (ADS)

    Mesinger, Andrei; Aykutalp, Aycin; Vanzella, Eros; Pentericci, Laura; Ferrara, Andrea; Dijkstra, Mark

    2015-01-01

    The large cross-section of the Ly? line makes it a sensitive probe of the ionization state of the intergalactic medium (IGM). Here, we present the most complete study to date of the IGM Ly? opacity, and its application to the redshift evolution of the `Ly? fraction', i.e. the fraction of colour-selected galaxies with a detectable Ly? emission line. We use a tiered approach, which combines large-scale seminumeric simulations of reionization with moderate-scale hydrodynamic simulations of the ionized IGM. This allows us to simultaneously account for evolution in both: (i) the opacity from an incomplete (patchy) reionization, parametrized by the filling factor of ionized regions, QH II; and (ii) the opacity from self-shielded systems in the ionized IGM, parametrized by the average photoionization rate inside H II regions, H II. In contrast to recent empirical models, attenuation from patchy reionization has a unimodal distribution along different sightlines, while attenuation from self-shielded systems is more bimodal. We quantify the average IGM transmission in our (QH II, H II) parameter space, which can easily be used to interpret new data sets. Our new, improved models highly disfavour an evolution in H II as the sole driver of a large change in IGM opacity. Using current observations, we predict that the Ly? fraction cannot drop by more than a factor of ?2 with IGM attenuation alone, even for H II filling factors as low as QH II ? 0.1. Larger changes in the Ly? fraction could result from a co-evolution with galaxy properties. Marginalizing over H II, we find that current observations constrain QH II(z ? 7) ? 0.6, at a 68 per cent confidence level (CL). However, all of our parameter space is consistent with observations at 95 per cent CL, highlighting the need for larger observational samples at z ? 6.

  13. The faint intergalactic redshifted emission balloon and the cosmic web imager : two integral field spectrographs designed to study emission from the intergalactic medium

    NASA Astrophysics Data System (ADS)

    Matuszewski, Mateusz Konrad

    Gas in the intergalactic medium serves as the fuel for galaxies. It carries signatures of galactic feedback, including matter and energy outflows. Understanding the morphology, thermodynamics, chemistry, and kinematics of this gas is key to understanding galaxy formation and evolution. The principal method of characterizing this gas has been the study of the Lyman ? forest and associated metal systems. While this work has yielded deep insights into the nature of intergalactic matter, the scarcity of suitable background sources does allow for a full three-dimensional picture. Numerical simulations and theoretical work indicate that this gas produces faint and extended recombinant line emission. Its signatures in Ly?(1216 Å), OVI(1033 Å), CIV(1550 Å) are expected to be the strongest. Recent advances in technology and fresh ideas in instrumentation are allowing access to the predicted surface brightness of intergalactic emission. The Faint Intergalactic Redshifted Emission Balloon (FIREBall) and the Cosmic Web Imager (CWI) are two integral field spectrographs probing different redshift regimes, which have been designed for the specific purpose of detecting and mapping emission from the intergalactic medium. FIREBall, operating in the balloon ultraviolet window around 2000 Å, probes the redshift range 0.3 < z < 1, while CWI, a ground-based optical instrument, studies the Universe at 2.5 < z < 7.0. Both instruments collected their first science data in mid-2009. This manuscript discusses the science case for the spectrographs, focuses on their designs, construction, testing, first light, target selection, observations, data reduction, and analysis. Initial results are presented and discussed.

  14. Metallicity of the intergalactic medium using pixel statistics: III. Silicon

    E-print Network

    Anthony Aguirre; Joop Schaye; Tae-Sun Kim; Tom Theuns; Michael Rauch; Wallace L. W. Sargent

    2004-01-13

    (Modified) We study the abundance of silicon in the intergalactic medium by analyzing the statistics of SiIV, CIV, and HI pixel optical depths in a sample of 19 high-quality quasar absorption spectra spanning redshifts z ~ 2 - 4, which we compare to realistic spectra drawn from a hydrodynamical simulation. We find that silicon is highly overabundant relative to carbon and that the scatter in Si/C is much smaller than that in C/H, implying a common origin for Si and C. The inferred [Si/C] depends upon the shape of the UV background (UVB) (harder backgrounds leading to higher [Si/C]), ranging from [Si/C] ~ 1.5 for a quasar-only UVB, to [Si/C] ~ 0.25 for a UVB including both galaxies and an artificial softening. For our fiducial UVB, which includes both quasars and galaxies, we find [Si/C]=0.77 +/- 0.05, with a possible systematic error of ~ 0.1 dex. There is no evidence for evolution in [Si/C] and the data are inconsistent with previous claims of a sharp change in the SiIV/CIV ratio (or the UVB) at z ~ 3. Comparisons with low-metallicity halo stars and nucleosynthetic yields suggest that either our fiducial UVB is too hard or that supermassive Pop III stars might have to be included. The inferred [Si/C] corresponds to a contribution to the cosmic Si abundance of [Si/H] = -2.0, a significant fraction of all Si production expected by z ~ 3.

  15. TEMPORAL SMEARING OF TRANSIENT RADIO SOURCES BY THE INTERGALACTIC MEDIUM

    SciTech Connect

    Macquart, Jean-Pierre; Koay, Jun Yi, E-mail: J.Macquart@curtin.edu.au [ICRAR/Curtin University, Curtin Institute of Radio Astronomy, Perth WA 6845 (Australia)

    2013-10-20

    The temporal smearing of impulsive radio events at cosmological redshifts probes the properties of the ionized intergalactic medium (IGM). We relate the degree of temporal smearing and the profile of a scattered source to the evolution of a turbulent structure in the IGM as a function of redshift. We estimate the degree of scattering expected by analyzing the contributions to the scattering measure of the various components of baryonic matter embedded in the IGM, including the diffuse IGM, intervening galaxies, and intracluster gas. These estimates predict that the amount of temporal smearing expected at 300 MHz is typically as low as ?1 ms and suggests that these bursts may be detectable with low-frequency widefield arrays. A generalization of the dispersion-measure-scattering-measure relation observed for Galactic scattering to the densities and turbulent conditions relevant to the IGM suggests that scattering measures on the order of 10{sup –6} kpc m{sup –20/3} would be expected at z ? 1. This scattering is sufficiently low enough that its effects would not, for most lines of sight, be manifested in existing observations of the scatter broadening in images of extragalactic compact sources. The redshift dependence on the temporal smearing discriminates between scattering that occurs in the host galaxy of the burst and the IGM, with ?{sub host}?(1 + z){sup –3} if the scattering probes length scales below the inner scale of the turbulence or ?{sub host}?(1 + z){sup –17/5} if the turbulence follows a Kolmogorov spectrum. This differs strongly from the expected IGM scaling ?{sub IGM} ? z {sup 2} for z ?< 1 and (1 + z){sup 0.2–0.5} for z ?> 1.

  16. How Neutral Is the Intergalactic Medium at z ~ 6?

    NASA Astrophysics Data System (ADS)

    Lidz, Adam; Hui, Lam; Zaldarriaga, Matias; Scoccimarro, Roman

    2002-11-01

    Recent observations of high-redshift quasar spectra reveal long gaps with little flux. A small or no detectable flux does not by itself imply that the intergalactic medium (IGM) is neutral. Inferring the average neutral fraction from the observed absorption requires assumptions about clustering of the IGM, which the gravitational instability model supplies. Our most stringent constraint on the neutral fraction at z~6 is derived from the mean Ly? transmission measured from the z=6.28 Sloan Digital Sky Survey quasar of Becker and coworkers; the neutral hydrogen fraction at mean density has to be larger than 4.7×10-4. This is substantially higher than the neutral fraction of ~(3-5)×10-5 at z=4.5-5.7, suggesting that dramatic changes take place around or just before z~6, even though current constraints are still consistent with a fairly ionized IGM at z~6. These constraints also translate into constraints on the ionizing background, subject to uncertainties in the IGM temperature. An interesting alternative method to constrain the neutral fraction is to consider the probability of having many consecutive pixels with little flux, which is small unless the neutral fraction is high. It turns out that this constraint is slightly weaker than the one obtained from the mean transmission. We show that while the derived neutral fraction at a given redshift is sensitive to the power-spectrum normalization, the size of the jump around z~6 is not. We caution that the main systematic uncertainties include spatial fluctuations in the ionizing background and the continuum placement. Tests are proposed. In particular, the sight line-to-sight line dispersion in mean transmission might provide a useful diagnostic. We express the dispersion in terms of the transmission power spectrum and develop a method to calculate the dispersion for spectra that are longer than the typical simulation box.

  17. STUDYING THE WARM-HOT INTERGALACTIC MEDIUM IN EMISSION

    SciTech Connect

    Takei, Y.; Mitsuda, K. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan); Ursino, E.; Branchini, E. [Dipartimento di Fisica, Universita degli Studi 'Roma Tre' via della Vasca Navale 84, I-00146 Roma (Italy); Ohashi, T.; Kawahara, H. [Department of Physics, School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397 (Japan); Piro, L.; Corsi, A. [INAF-Istituto di Astrofisica Spaziale Fisica Cosmica, Via del Fosso del Cavaliere 100, I-00133 Roma (Italy); Amati, L. [INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica Bologna, via P. Gobetti 101, I-40129 Bologna (Italy); Den Herder, J. W.; Kaastra, J. [SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht (Netherlands); Galeazzi, M. [Physics Department of University of Miami, 319 Knight Physics Building, Coral Gables, FL 33164 (United States); Moscardini, L.; Roncarelli, M. [Dipartimento di Astronomia, Universita di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Nicastro, F. [INAF-Osservatorio Astronomico di Roma, via Frascati 33, I00040 Monteporzio-Catone (RM) (Italy); Paerels, F. [Columbia Astrophysics Laboratory and Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States); Viel, M., E-mail: takei@astro.isas.jaxa.jp [INAF-Osservatorio Astronomico di Trieste, via Tiepolo 11, I-34131 Trieste (Italy)

    2011-06-20

    We assess the possibility of detecting the warm-hot intergalactic medium in emission and characterizing its physical conditions and spatial distribution through spatially resolved X-ray spectroscopy, in the framework of the recently proposed DIOS, EDGE, Xenia, and ORIGIN missions, all of which are equipped with microcalorimeter-based detectors. For this purpose, we analyze a large set of mock emission spectra, extracted from a cosmological hydrodynamical simulation. These mock X-ray spectra are searched for emission features showing both the O VII K{alpha} triplet and O VIII Ly{alpha} line, which constitute a typical signature of the warm-hot gas. Our analysis shows that 1 Ms long exposures and energy resolution of 2.5 eV will allow us to detect about 400 such features per deg{sup 2} with a significance {>=}5{sigma} and reveals that these emission systems are typically associated with density {approx}100 above the mean. The temperature can be estimated from the line ratio with a precision of {approx}20%. The combined effect of contamination from other lines, variation in the level of the continuum, and degradation of the energy resolution reduces these estimates. Yet, with an energy resolution of 7 eV and all these effects taken into account, one still expects about 160 detections per deg{sup 2}. These line systems are sufficient for tracing the spatial distribution of the line-emitting gas, which constitute an additional information, independent from line statistics, to constrain the poorly known cosmic chemical enrichment history and the stellar feedback processes.

  18. Intergalactic globular clusters and the faint end of the galaxy number counts in A1656 (Coma)

    E-print Network

    A. Marin-Franch; A. Aparicio

    2002-11-26

    The existence of an intergalactic globular cluster population in the Coma cluster of galaxies has been tested using surface-brightness fluctuations. The main result is that the intergalactic globular cluster surface density ($N_{\\rm IGC}$) does not correlate with the distance to the center of Coma and hence with the environment. Furthermore, comparing these results with different Coma mass-distribution model predictions, it is suggested that $N_{\\rm IGC}$ must in fact be zero all over Coma. On the other hand, the results for $N_{\\rm IGC}$ and the faint end of the galaxy number counts (beyond $m_R=23.5$) are connected. So $N_{\\rm IGC}=0$ settles the slope of this function, which turns out to be $\\gamma=0.36\\pm0.01$ down to $m_R=26.5$. The fact that $N_{\\rm IGC}=0$ all over Coma suggests that globular clusters were formed only, or almost only, from protogalactic clouds. None, or perhaps very few, could have formed in isolated regions. It also seems inappropriate to advocate a relationship between intergalactic globular clusters and dark matter distributions, although it is true that the relationship could still exist but not be strong enough to have been detected. Finally, since our conclusion is that intergalactic globular clusters do not exist in Coma, accretion of intergalactic globular clusters might not be significant in galaxy formation and evolutionary processes in the Coma galaxies.

  19. Multifrequency survey of the intergalactic cloud in the M96 group

    NASA Technical Reports Server (NTRS)

    Schneider, Stephen E.; Skrutskie, M. F.; Hacking, Perry B.; Young, Judith S.; Dickman, Robert L.

    1989-01-01

    The intergalactic cloud of neutral hydrogen in the M96 group are examined for signs of emission over a wide range of frequencies, from radio waves to X rays. Past or present stellar activity in the gas might have been expected to produce detectable visual infrared, CO, OH, or radio recombination-line emission. None was detected. The limits are used to study physical conditions in the intergalactic gas. In particular, B and V band limits on starlight and IRAS limits on the presence of dust strongly constrain the presence of stars or stellar by-products. However, given the uncertainties about physical conditions in the intergalactic environment, it is difficult to rule out entirely the presence of stellar-processed materials. Results of neutral hydrogen mapping from a large-scale survey of the intergalactic cloud and surrounding region are also presented. These observations confirm that the gas is confined to a large ringlike structure. The simplest interpretation remains that the intergalactic gas in Leo is primordial.

  20. Multifrequency survey of the intergalactic cloud in the M96 group

    SciTech Connect

    Schneider, S.E.; Skrutskie, M.F.; Hacking, P.B.; Young, J.S.; Dickman, R.L.

    1989-03-01

    The intergalactic cloud of neutral hydrogen in the M96 group are examined for signs of emission over a wide range of frequencies, from radio waves to X rays. Past or present stellar activity in the gas might have been expected to produce detectable visual infrared, CO, OH, or radio recombination-line emission. None was detected. The limits are used to study physical conditions in the intergalactic gas. In particular, B and V band limits on starlight and IRAS limits on the presence of dust strongly constrain the presence of stars or stellar by-products. However, given the uncertainties about physical conditions in the intergalactic environment, it is difficult to rule out entirely the presence of stellar-processed materials. Results of neutral hydrogen mapping from a large-scale survey of the intergalactic cloud and surrounding region are also presented. These observations confirm that the gas is confined to a large ringlike structure. The simplest interpretation remains that the intergalactic gas in Leo is primordial. 36 references.

  1. Studying the Warm Hot Intergalactic Medium with Gamma-Ray Bursts

    NASA Astrophysics Data System (ADS)

    Branchini, E.; Ursino, E.; Corsi, A.; Martizzi, D.; Amati, L.; den Herder, J. W.; Galeazzi, M.; Gendre, B.; Kaastra, J.; Moscardini, L.; Nicastro, F.; Ohashi, T.; Paerels, F.; Piro, L.; Roncarelli, M.; Takei, Y.; Viel, M.

    2009-05-01

    We assess the possibility of detecting and characterizing the physical state of the missing baryons at low redshift by analyzing the X-ray absorption spectra of the gamma-ray burst (GRB) afterglows, measured by a microcalorimeter-based detector with 3 eV resolution and 1000 cm2 effective area and capable of fast repointing, similar to that on board of the recently proposed X-ray satellites EDGE and XENIA. For this purpose we have analyzed mock absorption spectra extracted from different hydrodynamical simulations used to model the properties of the warm hot intergalactic medium (WHIM). These models predict the correct abundance of O VI absorption lines observed in UV and satisfy current X-ray constraints. According to these models space missions such as EDGE and XENIA should be able to detect ~60 WHIM absorbers per year through the O VII line. About 45% of these have at least two more detectable lines in addition to O VII that can be used to determine the density and the temperature of the gas. Systematic errors in the estimates of the gas density and temperature can be corrected for in a robust, largely model-independent fashion. The analysis of the GRB absorption spectra collected in three years would also allow to measure the cosmic mass density of the WHIM with ~15% accuracy, although this estimate depends on the WHIM model. Our results suggest that GRBs represent a valid, if not preferable, alternative to active galactic nuclei to study the WHIM in absorption. The analysis of the absorption spectra nicely complements the study of the WHIM in emission that the spectrometer proposed for EDGE and XENIA would be able to carry out thanks to its high sensitivity and large field of view.

  2. STUDYING THE WARM HOT INTERGALACTIC MEDIUM WITH GAMMA-RAY BURSTS

    SciTech Connect

    Branchini, E.; Ursino, E.; Martizzi, D. [Dipartimento di Fisica, Universita degli Studi 'Roma Tre' via della Vasca Navale 84, I-00146 Roma (Italy); Corsi, A.; Piro, L. [INAF-Istituto di Astrofisica Spaziale Fisica Cosmica, Via del Fosso del Cavaliere 100, I-00133 Roma (Italy); Amati, L. [INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica Bologna, via P. Gobetti 101, I-40129 Bologna (Italy); Den Herder, J. W.; Kaastra, J.; Paerels, F.; Takei, Y. [SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht (Netherlands); Galeazzi, M. [Physics Department of University of Miami, 319 Knight Physics Building, Coral Gables, FL 33164 (United States); Gendre, B. [Laboratoire d'Astrophysique de Marseille/CNRS/Universite de Provence, 38 Rue Joliot-Curie, 13388 Marseille CEDEX 13 (France); Moscardini, L. [Dipartimento di Astronomia, Universita degli Studi di Bologna, via Ranzani 1, I-40127 Bologna (Italy); Nicastro, F.; Roncarelli, M. [INAF-Osservatorio Astronomico di Roma, via Frascati 33, I00040 Monteporzio-Catone (Italy); Ohashi, T. [Department of Physics, School of Science, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397 (Japan); Viel, M. [INAF-Osservatorio Astronomico di Trieste, via Tiepolo 11, I-34131 Trieste (Italy)], E-mail: branchin@fis.uniroma3.it

    2009-05-20

    We assess the possibility of detecting and characterizing the physical state of the missing baryons at low redshift by analyzing the X-ray absorption spectra of the gamma-ray burst (GRB) afterglows, measured by a microcalorimeter-based detector with 3 eV resolution and 1000 cm{sup 2} effective area and capable of fast repointing, similar to that on board of the recently proposed X-ray satellites EDGE and XENIA. For this purpose we have analyzed mock absorption spectra extracted from different hydrodynamical simulations used to model the properties of the warm hot intergalactic medium (WHIM). These models predict the correct abundance of O VI absorption lines observed in UV and satisfy current X-ray constraints. According to these models space missions such as EDGE and XENIA should be able to detect {approx}60 WHIM absorbers per year through the O VII line. About 45% of these have at least two more detectable lines in addition to O VII that can be used to determine the density and the temperature of the gas. Systematic errors in the estimates of the gas density and temperature can be corrected for in a robust, largely model-independent fashion. The analysis of the GRB absorption spectra collected in three years would also allow to measure the cosmic mass density of the WHIM with {approx}15% accuracy, although this estimate depends on the WHIM model. Our results suggest that GRBs represent a valid, if not preferable, alternative to active galactic nuclei to study the WHIM in absorption. The analysis of the absorption spectra nicely complements the study of the WHIM in emission that the spectrometer proposed for EDGE and XENIA would be able to carry out thanks to its high sensitivity and large field of view.

  3. Cosmic far-ultraviolet background radiation - Probe of a dense hot intergalactic medium

    NASA Technical Reports Server (NTRS)

    Sherman, R. D.; Silk, J.

    1979-01-01

    Line and continuum radiation fluxes have been computed for a wide range of enriched intergalactic medium (IGM) models. Observations of the diffuse extragalactic light at optical and far-ultraviolet wavelengths are found to provide a potentially important probe of a dense hot intergalactic medium. If the diffuse X-ray background is produced by this gas, the models constrain the cosmological density parameter (Omega) to be less than 0.4. The associated Compton distortions of the cosmic blackbody background radiation and the optical depths to distant quasars at X-ray wavelengths are also evaluated.

  4. Tracing the Cosmic Metal Evolution in the Low-redshift Intergalactic Medium

    NASA Astrophysics Data System (ADS)

    Shull, J. Michael; Danforth, Charles W.; Tilton, Evan M.

    2014-11-01

    Using the Cosmic Origins Spectrograph aboard the Hubble Space Telescope, we measured the abundances of six ions (C III, C IV, Si III, Si IV, N V, and O VI) in the low-redshift (z <= 0.4) intergalactic medium (IGM). Both C IV and Si IV have increased in abundance by a factor of ~10 from z ? 5.5 to the present. We derive ion mass densities, ?ion ? ?ion?cr, with ?ion expressed relative to the closure density. Our models of mass-abundance ratios, (Si III/Si IV) = 0.67+0.35-0.19, (C III/C IV) = 0.70+0.43-0.20, and (? C \\scriptsize{III} + ? C \\scriptsize{IV}) / (? _Si \\scriptsize{III} + ? _Si \\scriptsize{IV}) = 4.9+2.2-1.1, are consistent with the photoionization parameter log U = -1.5 ± 0.4, hydrogen photoionization rate ?H = (8 ± 2) × 10-14 s-1 at z < 0.4, and specific intensity I 0 = (3 ± 1) × 10-23 erg cm-2 s-1 Hz-1 sr-1 at the Lyman limit. Consistent ionization corrections for C and Si are scaled to an ionizing photon flux ?0 = 104 cm-2 s-1, baryon overdensity ? b ? 200 ± 50, and "alpha-enhancement" (Si/C enhanced to three times its solar ratio). We compare these metal abundances to the expected IGM enrichment and abundances in higher photoionized states of carbon (C V) and silicon (Si V, Si VI, and Si VII). Our ionization modeling infers IGM metal densities of (5.4 ± 0.5) × 105 M ? Mpc-3 in the photoionized Ly? forest traced by the C and Si ions and (9.1 ± 0.6) × 105 M ? Mpc-3 in hotter gas traced by O VI. Combining both phases, the heavy elements in the IGM have mass density ? Z = (1.5 ± 0.8) × 106 M ? Mpc-3 or ? Z ? 10-5. This represents 10% ± 5% of the metals produced by (6 ± 2) × 108 M ? Mpc-3 of integrated star formation with yield ym = 0.025 ± 0.010. The missing metals at low redshift may reside within galaxies and in undetected ionized gas in galactic halos and circumgalactic medium. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA Contract NAS5-26555.

  5. Confirmation of X-ray Absorption by Warm-hot Intergalactic Medium in the Sculptor Wall

    E-print Network

    Fang, Taotao

    In a previous paper, we reported a 3? detection of an absorption line from the warm-hot intergalactic medium (WHIM) using the Chandra and XMM X-ray grating spectra of the blazar H2356-309, the sight line of which intercepts ...

  6. Intergalactic Photon Spectra from the Far-IR to the UV Lyman Limit for 0 < z < 6 and the Optical Depth of the Universe to High-Energy Gamma Rays

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.; Malkan, M. A.; Scully, S. T.

    2006-01-01

    We calculate the intergalactic photon density as a function of both energy and redshift for 0intergalactic photon densities to extend previous work on the absorption of high-energy Gamma-rays in intergalactic space owing to interactions with low-energy photons and the 2.7 K cosmic microwave background radiation. We calculate the optical depth of the universe, Tau , for Gamma-rays having energies from 4 GeV to 100 TeV emitted by sources at redshifts from 0 to 5. We also give an analytic fit with numerical coefficients for approximating (E(Gamma), z). As an example of the application of our results, we calculate the absorbed spectrum of the blazar PKS 2155-304 at z=0.117 and compare it with the spectrum observed by the HESS air Cerenkov Gamma-ray telescope array.

  7. Space

    NSDL National Science Digital Library

    2014-09-18

    This unit begins by introducing students to the historical motivation for space exploration. They learn about the International Space Station, including current and futuristic ideas that engineers are designing to propel space research. Then they learn about the physical properties of the Moon, and think about what types of products engineers would need to design in order for humans to live on the Moon. Lastly, students learn some descriptive facts about asteroids, such as their sizes and how that relates to the potential danger of an asteroid colliding with the Earth.

  8. THE RELATIONSHIP BETWEEN INTERGALACTIC H I/O VI AND NEARBY (z < 0.017) GALAXIES

    SciTech Connect

    Wakker, B. P.; Savage, B. D. [Department of Astronomy, University of Wisconsin, 475 N. Charter St, Madison, WI 53706 (United States)

    2009-05-15

    We analyze intergalactic H I and O VI absorbers with v < 5000 km s{sup -1} in Hubble Space Telescope and Far Ultraviolet Spectroscopic Explorer spectra of 76 active galactic nuclei. The baryons traced by H I/O VI absorption are clearly associated with the extended surroundings of galaxies; for impact parameters <400 kpc they are 2-4 times more numerous as those inside the galaxies. This large reservoir of matter likely plays a major role in galaxy evolution. We tabulate the fraction of absorbers having a galaxy of a given luminosity within a given impact parameter ({rho}) and velocity difference ({delta}v), as well as the fraction of galaxies with an absorber closer than a given {rho} and {delta}v. We identify possible 'void absorbers' ({rho} > 3 Mpc to the nearest L{sub *} galaxy), although at v < 2500 km s{sup -1} all absorbers are within 1.5 Mpc of an L>0.1 L{sub *} galaxy. The absorber properties depend on {rho}, but the relations are not simple correlations. For four absorbers with {rho} = 50-350 kpc from an edge-on galaxy with known orientation of its rotation, we find no clear relation between absorber velocities and the rotation curve of the underlying galaxy. For {rho} < 350 kpc, the covering factor of Ly{alpha} (O VI) around L>0.1 L {sub *} galaxies is 100% (70%) for field galaxies and 65% (10%) for group galaxies; 50% of galaxy groups have associated Ly{alpha}. All O VI absorbers occur within 550 kpc of an L>0.25 L{sub *} galaxy. The properties of three of 14 O VI absorbers are consistent with photoionization, for five the evidence points to collisional ionization; the others are ambiguous. The fraction of broad Ly{alpha} lines increases from z = 3 to z = 0 and with decreasing impact parameter, consistent with the idea that gas inside {approx}500 kpc from galaxies is heating up, although alternative explanations cannot be clearly excluded.

  9. Intergalactic Hydrogen Clouds at Low Redshift: Connections to Voids and Dwarf Galaxies

    NASA Technical Reports Server (NTRS)

    Shull, J. Michael; Stocke, John T.; Penton, Steve

    1996-01-01

    We provide new post-COSTAR data on one sightline (Mrk 421) and updated data from another (I Zw 1) from our Hubble Space Telescope (HST) survey of intergalactic Ly(alpha) clouds located along sightlines to four bright quasars passing through well-mapped galaxy voids (16000 km/s pathlength) and superclusters (18000 km/s). We report two more definite detections of low-redshift Ly(alpha) clouds in voids: one at 3047 km/s (heliocentric) toward Mrk 421 and a second just beyond the Local Supercluster at 2861 km/s toward I Zw 1, confirming our earlier discovery of Ly(alpha) absorption clouds in voids (Stocke et al., ApJ, 451, 24). We have now identified ten definite and one probable low-redshift neutral hydrogen absorption clouds toward four targets, a frequency of approximately one absorber every 3400 km/s above 10(exp 12.7/sq cm column density. Of these ten absorption systems, three lie within voids; the probable absorber also lies in a void. Thus, the tendency of Ly(alpha) absorbers to 'avoid the voids' is not as clear as we found previously. If the Ly(alpha) clouds are approximated as homogeneous spheres of 100 kpc radius, their masses are approximately 10(exp 9)solar mass (about 0.01 times that of bright L* galaxies) and they are 40 times more numerous, comparable to the density of dwarf galaxies and of low-mass halos in numerical CDM simulations. The Ly(alpha) clouds contribute a fraction Omega(sub cl)approximately equals 0.003/h(sub 75) to the closure density of the universe, comparable to that of luminous matter. These clouds probably require a substantial amount of nonbaryonic dark matter for gravitational binding. They may represent extended haloes of low-mass protogalaxies which have not experienced significant star formation or low-mass dwarf galaxies whose star formation ceased long ago, but blew out significant gaseous material.

  10. The Carbon Content of Intergalactic Gas at Z=4.25 and Its Evolution toward Z=2.4

    E-print Network

    Simcoe, Robert A.

    This paper presents ionization-corrected measurements of the carbon abundance in intergalactic gas at 4.0 < z < 4.5, using spectra of three bright quasars obtained with the Magellan Inamori Kycocera Echelle spectrograph ...

  11. The ultimate fate of cosmic rays from galaxies and their role in the intergalactic medium

    NASA Astrophysics Data System (ADS)

    Lacki, Brian C.

    2015-03-01

    The majority of cosmic rays (CRs) generated by star-forming galaxies escape them and enter the intergalactic medium (IGM). Galactic wind termination shocks might also accelerate CRs. I show that the mean pressure of these CRs can reach to within an order of magnitude of the mean Lyman ? forest thermal pressure. At z ? 1, their pressure may have even been dominant. I also demonstrate that, whichever IGM phase the CRs reside in, they contribute significantly to its pressure if its temperature is ˜104 K, as long as pionic and Coulomb losses are negligible. Where CRs end up depends on the structure and strength of intergalactic magnetic fields. I argue that CRs end up at least 30 kpc from their progenitor galaxies. CRs may self-confine in the IGM to the sound speed, generating ? 10- 13 G magnetic fields. These considerations imply the existence and importance of a non-thermal IGM.

  12. Constraints on the Sunyaev-Zel'dovich signal from the warm-hot intergalactic medium from WMAP and SPT data

    NASA Astrophysics Data System (ADS)

    Génova-Santos, Ricardo; Suárez-Velásquez, I.; Atrio-Barandela, F.; Mücket, J. P.

    2013-07-01

    The fraction of ionized gas in the warm-hot intergalactic medium induces temperature anisotropies on the cosmic microwave background similar to those of clusters of galaxies. The Sunyaev-Zel'dovich (SZ) anisotropies due to these low-density, weakly non-linear, baryon filaments cannot be distinguished from that of clusters using frequency information, but they can be separated since their angular scales are very different. To determine the relative contribution of the WHIM SZ signal to the radiation power spectrum of temperature anisotropies, we explore the parameter space of the concordance ? cold dark matter model using Monte Carlo Markov chains and the Wilkinson Microwave Anisotropy Probe 7 yr and South Pole Telescope data. We find marginal evidence of a contribution by diffuse gas, with amplitudes of AWHIM = 10-20 ?K2, but the results are also compatible with a null contribution from the WHIM, allowing us to set an upper limit of AWHIM < 43 ?K2 (95.4 per cent CL). The signal produced by galaxy clusters remains at ACL = 4.5 ?K2, a value similar to what is obtained when no WHIM is included. From the measured WHIM amplitude, we constrain the temperature-density phase diagram of the diffuse gas, and find it to be compatible with numerical simulations. The corresponding baryon fraction in the WHIM varies from 0.43 to 0.47, depending on model parameters. The forthcoming Planck data could set tighter constraints on the temperature-density relation.

  13. Probing Intergalactic Magnetic Fields in the GLAST Era through Pair Echo Emission from TeV Blazars

    E-print Network

    Kohta Murase; Keitaro Takahashi; Susumu Inoue; Kiyomoto Ichiki; Shigehiro Nagataki

    2008-09-04

    More than a dozen blazars are known to be emitters of multi-TeV gamma rays, often with strong and rapid flaring activity. By interacting with photons of the cosmic microwave and infrared backgrounds, these gamma rays inevitably produce electron-positron pairs, which in turn radiate secondary inverse Compton gamma rays in the GeV-TeV range with a characteristic time delay that depends on the properties of the intergalactic magnetic field (IGMF). For sufficiently weak IGMF, such "pair echo" emission may be detectable by the Gamma-ray Large Area Space Telescope (GLAST), providing valuable information on the IGMF. We perform detailed calculations of the time-dependent spectra of pair echos from flaring TeV blazars such as Mrk 501 and PKS 2155-304, taking proper account of the echo geometry and other crucial effects. In some cases, the presence of a weak but non-zero IGMF may enhance the detectability of echos. We discuss the quantitative constraints that can be imposed on the IGMF from GLAST observations, including the case of non-detections.

  14. An interpretation of ring galaxies and the properties of intergalactic gas clouds

    Microsoft Academic Search

    K. C. Freeman; G. de Vaucouleurs

    1974-01-01

    It is proposed that the pairs of peculiar spheroidal galaxies associated with ring-type objects or chaotic multinucleated objects result from encounters of normal spirals with intergalactic H I clouds. Observational constraints restrict the cloud parameters to a small range. A significant fraction of normal lenticular galaxies and of late-type Magellanic irregulars could have been produced by such galaxy-cloud encounters, as

  15. Quantized Redshifts of Galaxies: Stimulated Raman Scattering in Cold Intergalactic Rydberg Matter

    Microsoft Academic Search

    Leif Holmlid

    2004-01-01

    That the redshifts for galaxies in the local supercluster are quantizedwas recently confirmedby Guthrie and Napier(A&Amp;Amp;A310 (1996) 353). These redshifts are here proposed to be due to stimulatedStokes Raman processes in intergalactic matter in the form of Rydberg Matter (RM). Rydberg Matteris an electronically excited material, as demonstrated by its use as laser medium in a thermally excitedultra-broadband tunable IR

  16. Studies of X-ray clusters of galaxies/intergalactic plasmas

    NASA Technical Reports Server (NTRS)

    Scott, J. S.

    1984-01-01

    Intergalactic plasmas were investigated from both an observational and theoretical point of view. A multiobject spectrometer, the MX spectrograph was used to obtain detailed dynamical information on clusters of galaxies; this information was then compared with X ray emission from hot gas in these clusters. Several spectra of galaxies are presented, and data reduction of the spectra was discussed. The existence of quasar winds in Seyfert galaxies and the interaction between such a wind and the interstellar medium also were considered.

  17. A Determination of the Intergalactic Redshift Dependent UV-Optical-NIR Photon Density Using Deep Galaxy Survey Data and the Gamma-ray Opacity of the Universe

    NASA Technical Reports Server (NTRS)

    Stecker, Floyd W.; Malkan, Matthew A.; Scully, Sean T.

    2012-01-01

    We calculate the intensity and photon spectrum of the intergalactic background light (IBL) as a function of redshift using an approach based on observational data obtained in many different wavelength bands from local to deep galaxy surveys. This allows us to obtain an empirical determination of the IBL and to quantify its observationally based uncertainties. Using our results on the IBL, we then place 68% confidence upper and lower limits on the opacity of the universe to gamma-rays, free of the theoretical assumptions that were needed for past calculations. We compare our results with measurements of the extragalactic background light and upper limits obtained from observations made by the Fermi Gamma-ray Space Telescope.

  18. A Determination of the Intergalactic Redshift-dependent Ultraviolet-Optical-NIR Photon Density Using Deep Galaxy Survey Data and the Gamma-Ray Opacity of the Universe

    NASA Astrophysics Data System (ADS)

    Stecker, Floyd W.; Malkan, Matthew A.; Scully, Sean T.

    2012-12-01

    We calculate the intensity and photon spectrum of the intergalactic background light (IBL) as a function of redshift using an approach based on observational data obtained in many different wavelength bands from local to deep galaxy surveys. This allows us to obtain an empirical determination of the IBL and to quantify its observationally based uncertainties. Using our results on the IBL, we then place 68% confidence upper and lower limits on the opacity of the universe to ?-rays, free of the theoretical assumptions that were needed for past calculations. We compare our results with measurements of the extragalactic background light and upper limits obtained from observations made by the Fermi Gamma-ray Space Telescope.

  19. A DETERMINATION OF THE INTERGALACTIC REDSHIFT-DEPENDENT ULTRAVIOLET-OPTICAL-NIR PHOTON DENSITY USING DEEP GALAXY SURVEY DATA AND THE GAMMA-RAY OPACITY OF THE UNIVERSE

    SciTech Connect

    Stecker, Floyd W. [Astrophysics Science Division, NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Malkan, Matthew A. [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095-1547 (United States); Scully, Sean T., E-mail: Floyd.W.Stecker@nasa.gov, E-mail: malkan@astro.ucla.edu, E-mail: scullyst@jmu.edu [Department of Physics, James Madison University, Harrisonburg, VA 22807 (United States)

    2012-12-20

    We calculate the intensity and photon spectrum of the intergalactic background light (IBL) as a function of redshift using an approach based on observational data obtained in many different wavelength bands from local to deep galaxy surveys. This allows us to obtain an empirical determination of the IBL and to quantify its observationally based uncertainties. Using our results on the IBL, we then place 68% confidence upper and lower limits on the opacity of the universe to {gamma}-rays, free of the theoretical assumptions that were needed for past calculations. We compare our results with measurements of the extragalactic background light and upper limits obtained from observations made by the Fermi Gamma-ray Space Telescope.

  20. The Low-redshift Intergalactic Medium as Seen in Archival Legacy HST/STIS and FUSE Data

    NASA Astrophysics Data System (ADS)

    Tilton, Evan M.; Danforth, Charles W.; Shull, J. Michael; Ross, Teresa L.

    2012-11-01

    We present a comprehensive catalog of ultraviolet (HST/STIS and FUSE) absorbers in the low-redshift intergalactic medium (IGM) at z < 0.4. The catalog draws from much of the extensive literature on IGM absorption and reconciles discrepancies among several previous catalogs through a critical evaluation of all reported absorption features in light of new HST/COS data. We report on 746 H I absorbers down to a rest-frame equivalent width of 12 mÅ over a maximum redshift path length ?z = 5.38. We also confirm 111 O VI absorbers, 29 C IV absorbers, and numerous absorption lines due to other metal ions. We characterize the bivariate distribution of absorbers in redshift and column density as a power law, \\left(\\partial ^2 {N}/\\partial z\\partial N\\right) \\propto N^{-\\beta }, where ? = 2.08 ± 0.12 for O VI and ? = 1.68 ± 0.03 for H I. Utilizing a more sophisticated accounting technique than past work, our catalog accounts for ~43% of the baryons: 24% ± 2% in the photoionized Ly? forest and 19% ± 2% in the warm-hot IGM as traced by O VI. We discuss the large systematic effects of various assumed metallicities and ionization states on these calculations, and we implement recent simulation results in our estimates. Based on observations made with the NASA/ESA Hubble Space Telescope, obtained from the data archive at the Space Telescope Science Institute. STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555.

  1. Hot Baryons and the Distribution of Metals in the Intergalactic Medium

    E-print Network

    Jason Tumlinson; Taotao Fang

    2005-01-25

    We use the observed number and column-density distributions of intergalactic O VI absorbers to constrain the distribution of metals in the low-redshift intergalactic medium (IGM). In this simple model the metals in the O VI absorbers are assumed to be produced in and propagated from low-redshift galaxies drawn from a real sample, in this case the Sloan Digital Sky Survey (SDSS). This model can explain the observed dN/dz of metals seen in O VI absorbers if these metals are dispersed out to ~ 200 kpc by galaxies down to L \\~ 0.01 - 0.1 L_r^*. Massive galaxies (L ~ L_r^*) by themselves cannot provide the necessary enrichment unless they can enrich volumes out to $\\gtrsim 0.5 - 1 Mpc. Alternatively, our model allows an estimate of the fraction of O VI absorbers directly caused by galaxies rather than hot IGM. With this assumption we explore the possible connections between the intergalactic O VI absorbers and the known populations of highly-ionized high-velocity clouds (HVCs) surrounding the Milky Way. Our model predicts that more sensitive, complete surveys optimized to uncover weaker O VI absorbers will find the tentative turnover below log N(O VI) ~ 13.5 to be a real effect resulting from the apparently limited volumes over which galaxies can enrich the IGM. If so, it would indicate that metals are not as widespread throughout the low-density IGM as they are assumed to be in cosmological simulations of the WHIM.

  2. Preface: Special Session SpS4 New era for studying interstellar and intergalactic magnetic fields

    NASA Astrophysics Data System (ADS)

    Montmerle, Thierry

    2015-03-01

    Magnetic fields dominate the universal energy balance on a wide variety of spatial scales; preserving life on Earth from extinction by cosmic rays, regulating star formation in giant molecular clouds, regulating the enrichment of the intergalactic medium by galactic winds and possibly regulating the growth of individual galaxies and filaments of galaxies. The structure of magnetic fields is determined by ubiquitous astrophysical turbulence and critically affects transport processes, including propagation and acceleration of cosmic rays and transfer of heat. Turbulent magnetic fields play an important role in magnetic field generation via dynamo processes, and must be understood to separate galactic foregrounds from the Cosmic Microwave Background signal.

  3. The Galactic halo and local intergalactic medium toward PKS 2155-304

    NASA Technical Reports Server (NTRS)

    Bruhweiler, Frederick C.; Boggess, A.; Norman, Dara J.; Grady, C. A.; Urry, C. M.; Kondo, Yoji

    1993-01-01

    Low-resolution UV observations of the bright, low-redshift BL Lac object PKS 2155-304 have been obtained by the HST's high-resolution spectrograph. Attention is here given to results on the number of intergalactic H I Ly-alpha components in the line-of-sight toward this object. The highest-redshift of the observed Ly-alpha systems furnishes a lower limit on the distance of the BL Lac object; this distance is consistent with the approximate redshift deduced from CCD imagery of the probable host galaxy for PKS 2155-304.

  4. Fluctuations in microwave background radiation due to secondary ionization of the intergalactic gas in the universe

    NASA Technical Reports Server (NTRS)

    Sunyayev, R. A.

    1979-01-01

    Secondary heating and ionization of the intergalactic gas at redshifts z approximately 10-30 could lead to the large optical depth of the Universe for Thomson scattering and could smooth the primordial fluctuations formed at z approximately 1500. It is shown that the gas motions connected with the large scale density perturbations at z approximately 10-15 must lead to the generation of secondary fluctuations of microwave background. The contribution of the rich clusters of galaxies and young galaxies to the fluctuations of microwave background is also estimated.

  5. Development of a microcalorimeter array for the Diffuse Intergalactic Oxygen Surveyor (DIOS) mission

    NASA Astrophysics Data System (ADS)

    Ishisaki, Yoshitaka; Ohashi, Takaya; Oshima, Tai; Morita, Umeyo; Shinozaki, Keisuke; Sato, Kosuke; Mitsuda, Kazuhisa; Yamasaki, Noriko Y.; Fujimoto, Ryuichi; Takei, Yoh; Sato, Hirotaka; Takahashi, Noriyuki; Homma, Takayuki; Osaka, Tetsuya

    2004-09-01

    We are developing a superconducting transition-edge sensor (TES) microcalorimeter array for the Diffuse Intergalactic Oxygen Surveyor (DIOS) mission. DIOS is a relatively small Japanese X-ray mission which will study large-scale distribution of the warm-hot intergalactic medium (WHIM) using OVII and OVIII emission lines. The satellite weighs about 400 kg equipped with a four-reflection X-ray telescope (FXT) and a TES microcalorimeter array (XSA). The design goal of the observing system is an effective area larger than 100 cm2 at the oxygen line energy, a field of view about 50 arcmin square, and an energy resolution about 2 eV in the energy range of 0.3-1 keV. The TES microcalorimeter array provides the large field of view and good energy resolution at the same time. We plan to install an array comprising 16 x 16 pixels with an overall size of 1 cm square, which is cooled with a cryogen-free cooler. Pixels are readout by multiplexing signals using a multi-input SQUID amplifier, with each input connected to a TES microcalorimeter which is AC biased with a different frequency. We report the design and present status of the XSA system development.

  6. A uniform metal distribution in the intergalactic medium of the Perseus cluster of galaxies

    NASA Astrophysics Data System (ADS)

    Werner, Norbert; Urban, Ondrej; Simionescu, Aurora; Allen, Steven W.

    2013-10-01

    Most of the metals (elements heavier than helium) produced by stars in the member galaxies of clusters currently reside within the hot, X-ray-emitting intra-cluster gas. Observations of X-ray line emission from this intergalactic medium have suggested a relatively small cluster-to-cluster scatter outside the cluster centres and enrichment with iron out to large radii, leading to the idea that the metal enrichment occurred early in the history of the Universe. Models with early enrichment predict a uniform metal distribution at large radii in clusters, whereas those with late-time enrichment are expected to introduce significant spatial variations of the metallicity. To discriminate clearly between these competing models, it is essential to test for potential inhomogeneities by measuring the abundances out to large radii along multiple directions in clusters, which has not hitherto been done. Here we report a remarkably uniform iron abundance, as a function of radius and azimuth, that is statistically consistent with a constant value of ZFe = 0.306 +/- 0.012 in solar units out to the edge of the nearby Perseus cluster. This homogeneous distribution requires that most of the metal enrichment of the intergalactic medium occurred before the cluster formed, probably more than ten billion years ago, during the period of maximal star formation and black hole activity.

  7. A uniform metal distribution in the intergalactic medium of the Perseus cluster of galaxies.

    PubMed

    Werner, Norbert; Urban, Ondrej; Simionescu, Aurora; Allen, Steven W

    2013-10-31

    Most of the metals (elements heavier than helium) produced by stars in the member galaxies of clusters currently reside within the hot, X-ray-emitting intra-cluster gas. Observations of X-ray line emission from this intergalactic medium have suggested a relatively small cluster-to-cluster scatter outside the cluster centres and enrichment with iron out to large radii, leading to the idea that the metal enrichment occurred early in the history of the Universe. Models with early enrichment predict a uniform metal distribution at large radii in clusters, whereas those with late-time enrichment are expected to introduce significant spatial variations of the metallicity. To discriminate clearly between these competing models, it is essential to test for potential inhomogeneities by measuring the abundances out to large radii along multiple directions in clusters, which has not hitherto been done. Here we report a remarkably uniform iron abundance, as a function of radius and azimuth, that is statistically consistent with a constant value of ZFe = 0.306?±?0.012 in solar units out to the edge of the nearby Perseus cluster. This homogeneous distribution requires that most of the metal enrichment of the intergalactic medium occurred before the cluster formed, probably more than ten billion years ago, during the period of maximal star formation and black hole activity. PMID:24172976

  8. Realistic Multi-ion Absorption Spectra from Simulations of the Intergalactic Medium

    NASA Astrophysics Data System (ADS)

    Kneibel, Jacob; Silvia, Devin; O'Shea, Brian W.

    2015-01-01

    Observational efforts to form a complete baryon census below a redshift of z ~ 3 have proven to be a difficult undertaking. Simulations suggest that much of this baryonic matter may exist between galaxies at low to moderate densities and temperatures of 105 to 107 K, which is best detected by absorption features in the spectra of distant quasars. Due to the challenges of detecting the warm-hot intergalactic medium (WHIM), single ion studies are insufficient in tracing the properties of the WHIM and multi-ion studies are becoming increasingly important. Using cosmological simulations of the IGM, we investigate the ionization structure using multiple ions, including commonly observed species such as OVI, CIV, and NeVIII. To examine the simulation in a manner similar to observations of the IGM, we created a pipeline for producing synthetic absorption spectra from simulated light rays that mimic spectra acquired by observations. Specifically, we add observational noise and convolve the synthetic spectrum with the line spread function of the Cosmic Origins Spectrograph. We then fit the realistic spectra using an automatic process, to determine the properties of the IGM that the light ray intersects. Using the fitted spectra and the inferred physical properties, we help interpret on-going observational studies of the intergalactic medium and aid in forming a complete baryon census.

  9. A Nursery of Young Objects: Intergalactic H II Regions in Stephan's Quintet

    NASA Astrophysics Data System (ADS)

    Mendes de Oliveira, C.; Cypriano, E. S.; Sodré, L., Jr.; Balkowski, C.

    2004-04-01

    We have discovered four intergalactic H II regions in Stephan's quintet, which is more than a 25 kpc projected distance from the center of the nearest group galaxy, with no apparent optical connection to it. They have MB ranging from -11.9 to -12.5 mag, colors B-R=0.7-1.1 mag, radial velocities from 6565 to 6651 km s-1, and they are superposed onto the H I tail east of NGC 7319, with a mean radial velocity of 6610 km s-1. In addition, they have metallicities of the order of 12+log(O/H)=8.58+/-0.25, which suggests that they were formed from preenriched material. We derive a mean age of 4.6+/-0.6 Myr and a mean stellar mass of (2.9+/-1.4)×104 Msolar for the four objects. The masses, ages, colors, velocities, metallicities, and location of the objects suggest that they are H II regions that were formed far away from the galaxies through compression of the intergalactic H I gas by galaxy collisions. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (US), the Particle Physics and Astronomy Research Council (UK), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), CNPq (Brazil), and CONICET (Argentina).

  10. "Marijuana has been compared to walking a foot off the ground as opposed to the intergalactic voyage produced

    E-print Network

    Squire, Larry R.

    to the intergalactic voyage produced by LSD" (source- unknown) Original LSD experience "In afternoon of 16 April, 1943 of Albert Hofmann at Sandoz) when synthesizing LSD-25) #12;2 First LSD Dosing Experiment "After 40 minutes synthesizing LSD-25) Synesthesia "The guide asked me how I felt and I responded `Good'. As I uttered the word

  11. Polarization of Absorption Lines as a Diagnostics of Circumstellar, Interstellar, and Intergalactic Magnetic Fields: Fine-Structure Atoms

    Microsoft Academic Search

    Huirong Yan; A. Lazarian

    2006-01-01

    The relative population of the fine-structure sublevels of an atom's ground state is affected by radiative transitions induced by an anisotropic radiation flux. This causes the alignment of atomic angular momentum. In terms of observational consequences for the interstellar and intergalactic medium, this results in the polarization of the absorption lines. In the paper we consider the conditions necessary for

  12. A census of H? emitters in the intergalactic medium of the NGC 2865 system

    NASA Astrophysics Data System (ADS)

    Urrutia-Viscarra, F.; Arnaboldi, M.; Mendes de Oliveira, C.; Gerhard, O.; Torres-Flores, S.; Carrasco, E. R.; de Mello, D.

    2014-09-01

    Tidal debris, which are rich in HI gas and formed in interacting and merging systems, are suitable laboratories to study star formation outside galaxies. Recently, several such systems were observed, which contained many young star forming regions outside the galaxies. In previous works, we have studied young star forming regions outside galaxies in different systems with optical and/or gaseous tidal debris, in order to understand how often they occur and in which type of environments. In this paper, we searched for star forming regions around the galaxy NGC 2865, a shell galaxy that is circled by a ring of HI with a total mass of 1.2 × 109 M?. Using the multi-slit imaging spectroscopy technique with the Gemini telescope, we detected all H? emitting sources in the surroundings of the galaxy NGC 2865, down to a flux limit of 10-18 erg cm-2 s-1 Å-1. With the spectra information and the near and far-ultraviolet flux, we characterize the star formation rates, masses, ages, and metallicities for these HII regions. In total, we found 26 emission-line sources in a 60 × 60 Kpc field centered over the southeastern tail of the HI gas present around the galaxy NGC 2865. Out of the 26 H? emitters, 19 are in the satellite galaxy FGCE 0745, and seven are intergalactic HII regions scattered over the south tail of the HI gas around NGC 2865. We found that the intergalactic HII regions are young (<200 Myr) with stellar masses in the range 4 × 103 M? to 17 × 106 M?. These are found in a region of low HI gas density, where the probability of forming stars is expected to be low. For one of the intergalactic HII regions, we estimated a solar oxygen abundance of 12 + log(O/H) ~ 8.7. We also were able to estimate the metallicity for the satellite galaxy FGCE 0745 to be 12 + log(O/H) ~ 8.0. Given these physical parameters, the intergalactic HII regions are consistent with young star forming regions (or clusters), which are born in situ outside the NGC 2865 galaxy from a pre-enriched gas removed from the host galaxies in a merger event. The relevance of these observations is discussed. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Science and Technology Facilities Council (United Kingdom), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência e Tecnologia (Brazil) and Ministerio de Ciencia, Tecnología e Innovación Productiva (Argentina) - Observing runs: GS-2008A-Q-35.

  13. Probing the Intergalactic Magnetic Field with the Anisotropy of the Extragalactic Gamma-ray Background

    NASA Technical Reports Server (NTRS)

    Venters, T. M.; Pavlidou, V.

    2013-01-01

    The intergalactic magnetic field (IGMF) may leave an imprint on the angular anisotropy of the extragalactic gamma-ray background through its effect on electromagnetic cascades triggered by interactions between very high energy photons and the extragalactic background light. A strong IGMF will deflect secondary particles produced in these cascades and will thus tend to isotropize lower energy cascade photons, thereby inducing a modulation in the anisotropy energy spectrum of the gamma-ray background. Here we present a simple, proof-of-concept calculation of the magnitude of this effect and demonstrate that current Fermi data already seem to prefer nonnegligible IGMF values. The anisotropy energy spectrum of the Fermi gamma-ray background could thus be used as a probe of the IGMF strength.

  14. Chemical enrichment of the intra-cluster and intergalactic medium in a hierarchical galaxy formation model

    E-print Network

    Gabriella De Lucia; Guinevere Kauffmann; Simon D. M. White

    2004-01-08

    (Abridged) We use a combination of high resolution N-body simulations and semi-analytic techniques to follow the formation, the evolution and the chemical enrichment of cluster galaxies in a Lambda-CDM Universe. We model the transport of metals between the stars, the cold gas in galaxies, the hot gas in dark matter haloes, and the intergalactic gas outside virialized haloes. We have compared three different feedback schemes. The `retention' model assumes that material reheated by supernova explosions is able to leave the galaxy, but not the dark matter halo. The `ejection' model assumes that this material leaves the halo and is then re-incorporated when structure collapses on larger scales. The `wind' model uses prescriptions that are motivated by observations of local starburst galaxies. We require that our models reproduce the cluster LF from the 2dF survey, the relations between stellar mass, gas mass and metallicity inferred from new SDSS data, and the observed amount of metals in the ICM. With suitable adjustment of the free parameters in the model, a reasonable fit to the observational results at redshift zero can be obtained for all three feedback schemes. All three predict that the chemical enrichment of the ICM occurs at high redshift with 60-80 per cent of the metals currently in the ICM ejected at redshifts larger than 1. Massive galaxies are important contributors to the chemical pollution. The observed decline in baryon fraction from rich clusters to galaxy groups is reproduced only in an `extreme' ejection scheme, where material ejected from dark matter haloes is re-incorporated on a timescale comparable to the age of the Universe. We explore how the metal abundance in the intergalactic medium as a function of redshift can constraint how and when galaxies ejected their metals.

  15. Small Scale Structure at High Redshift: III. The Clumpiness of the Intergalactic Medium on Sub-kpc Scales

    Microsoft Academic Search

    Michael Rauch; Wallace L. W. Sargent; Thomas A. Barlow; Robert F. Carswell

    2001-01-01

    Spectra from the Keck HIRES instrument of the Lyman alpha forests in the\\u000alines of sight to the A and C components of the gravitationally lensed QSO\\u000aQ1422+231 were used to investigate the structure of the intergalactic medium at\\u000amean redshift z = 3.3 on sub-kpc scales. We measured the cross-correlation\\u000aamplitude between the two Lyman alpha forests for a

  16. Diagnosing the reionization of the universe - The absorption spectrum of the intergalactic medium and Lyman alpha clouds

    NASA Technical Reports Server (NTRS)

    Giroux, Mark L.; Shapiro, Paul R.

    1991-01-01

    The thermal and ionization evolution of a uniform intergalactic medium composed of H and He and undergoing reionization is studied. The diagnosis of the metagalactic ionizing radiation background at z of about three using metal line ratios for Lyman limit quasar absorption line systems is addressed. The use of the He II Gunn-Peterson effect to diagnose the reionization source and/or nature of the Hy-alpha forest clouds is considered.

  17. Star Formation Feedback and Metal-enrichment History of the Intergalactic Medium

    NASA Astrophysics Data System (ADS)

    Cen, Renyue; Chisari, Nora Elisa

    2011-04-01

    Using the state-of-the-art cosmological hydrodynamic simulations of the standard cold dark matter model with star formation feedback strength normalized to match the observed star formation history of the universe at z= 0-6, we compute the metal-enrichment history of the intergalactic medium (IGM). Overall we show that galactic superwind (GSW) feedback from star formation can transport metals to the IGM and that the properties of simulated metal absorbers match current observations. The distance of influence of GSW from galaxies is typically limited to about <=0.5 Mpc and within regions of overdensity ? >= 10. Most C IV and O VI absorbers are located within shocked regions of elevated temperature (T >= 2 × 104 K), overdensity (? >= 10), and metallicity ([Z/ Z sun] = [ - 2.5, - 0.5]), enclosed by double shocks propagating outward. O VI absorbers have typically higher metallicity, lower density, and higher temperature than C IV absorbers. For O VI absorbers, collisional ionization dominates over the entire redshift range z= 0-6, whereas for C IV absorbers the transition occurs at moderate redshift z ~ 3 from collisionally dominated to photoionization dominated. We find that the observed column density distributions for C IV and O VI in the range log N cm2=12-15 are reasonably reproduced by the simulations. The evolution of mass densities contained in C IV and O VI lines, ?C IV and ?O VI , is also in good agreement with observations, which shows a near constancy at low redshifts and an exponential drop beyond redshift z= 3-4. For both C IV and O VI, most absorbers are transient and the amount of metals probed by C IV and O VI lines of column log N cm2=12-15 is only ~2% of total metal density at any epoch. While gravitational shocks from large-scale structure formation dominate the energy budget (80%-90%) for turning about 50% of the IGM to the warm-hot intergalactic medium (WHIM) by z = 0, GSW feedback shocks are energetically dominant over gravitational shocks at z>=1-2. Most of the so-called missing metals at z= 2-3 are hidden in a warm-hot (T = 104.5-107 K) gaseous phase, heated up by GSW feedback shocks. Their mass distribution is broadly peaked at ?=1-10 in the IGM, outside virialized halos. Approximately 37%, 46%, 10%, and 7% of the total metals at z = 0 are in stars, WHIM, X-ray gas, and cold gas, respectively; the distributions stand at 23%, 57%, 2%, and 18% and 14%, 51%, 4%, and 31% at z = 2 and z = 4, respectively.

  18. The intergalactic medium over the last 10 billion years - I. Ly? absorption and physical conditions

    NASA Astrophysics Data System (ADS)

    Davé, Romeel; Oppenheimer, Benjamin D.; Katz, Neal; Kollmeier, Juna A.; Weinberg, David H.

    2010-11-01

    The intergalactic medium (IGM) is the dominant reservoir of baryons at all cosmic epochs. In this paper, we investigate the evolution of the IGM from z = 2 -> 0 in (48h-1Mpc)3, 110-million particle cosmological hydrodynamic simulations using three prescriptions for galactic outflows. We focus on the evolution of IGM physical properties, and how such properties are traced by Ly? absorption as detectable using Hubble's Cosmic Origins Spectrograph (COS). Our results broadly confirm the canonical picture that most Ly? absorbers arise from highly ionized gas tracing filamentary large-scale structure. Growth of structure causes gas to move from the diffuse photoionized IGM into other cosmic phases, namely stars, cold and hot gas within galaxy haloes, and the unbound and shock-heated warm-hot intergalactic medium (WHIM). By today, baryons are comparably divided between bound phases (35 per cent in our favoured outflow model), the diffuse IGM (41 per cent) and the WHIM (24 per cent). Here we (re)define the WHIM as gas with overdensities lower than that in haloes ( today) and temperatures T > 105 K, to more closely align it with the `missing baryons' that are not easily detectable in emission or Ly? absorption. Strong galactic outflows can have a noticeable impact on the temperature of the IGM, though with our favoured momentum-driven wind scalings they do not. When we (mildly) tune our assumed photoionizing background to match the observed evolution of the Ly? mean flux decrement, we obtain line count evolution statistics that broadly agree with available (pre-COS) observations. We predict a column density distribution slope of for our favoured wind model, in agreement with recent observational estimates, and it becomes shallower with redshift. Winds have a mostly minimal impact, but they do result in a shallower column density slope and more strong lines. With improved statistics, the frequency of strong lines can be a valuable diagnostic of outflows, and the momentum-driven wind model matches existing data significantly better than the two alternatives we consider. The relationship between column density and physical density broadens mildly from z = 2 -> 0, and evolves as for diffuse absorbers, consistent with previous studies. Linewidth distributions are quite sensitive to spectral resolution; COS should yield significantly broader lines than higher resolution data. Thermal contributions to linewidths are typically subdominant, so linewidths only loosely reflect the temperature of the absorbing gas. This will hamper attempts to quantify the WHIM using broad Ly? absorbers, though it may still be possible to do so statistically. Together, COS data and simulations such as these will provide key insights into the physical conditions of the dominant reservoir of baryons over the majority of cosmic time.

  19. Evolution of Structure in the Intergalactic Medium and the Nature of the LY-Alpha Forest

    NASA Technical Reports Server (NTRS)

    Bi, Hongguang; Davidsen, Arthur F.

    1997-01-01

    We have performed a detailed statistical study of the evolution of structure in a photoionized intergalactic medium (IGM) using analytical simulations to extend the calculation into the mildly nonlinear density regime found to prevail at z = 3. Our work is based on a simple fundamental conjecture: that the probability distribution function of the density of baryonic diffuse matter in the universe is described by a lognormal (LN) random field. The LN distribution has several attractive features and follows plausibly from the assumption of initial linear Gaussian density and velocity fluctuations at arbitrarily early times. Starting with a suitably normalized power spectrum of primordial fluctuations in a universe dominated by cold dark matter (CDM), we compute the behavior of the baryonic matter, which moves slowly toward minima in the dark matter potential on scales larger than the Jeans length. We have computed two models that succeed in matching observations. One is a nonstandard CDM model with OMEGA = 1, h = 0.5, and GAMMA = 0.3, and the other is a low-density flat model with a cosmological constant (LCDM), with OMEGA = 0.4, OMEGA(sub LAMBDA) = 0.6, and h = 0.65. In both models, the variance of the density distribution function grows with time, reaching unity at about z = 4, where the simulation yields spectra that closely resemble the Ly-alpha forest absorption seen in the spectra of high-z quasars. The calculations also successfully predict the observed properties of the Ly-alpha forest clouds and their evolution from z = 4 down to at least z = 2, assuming a constant intensity for the metagalactic UV background over this redshift range. However, in our model the forest is not due to discrete clouds, but rather to fluctuations in a continuous intergalactic medium. At z = 3; typical clouds with measured neutral hydrogen column densities N(sub H I) = 10(exp 13.3), 10(exp 13.5), and 10(exp 11.5) /sq cm correspond to fluctuations with mean total densities approximately 10, 1, and 0.1 times the universal mean baryon density. Perhaps surprisingly, fluctuations whose amplitudes are less than or equal to the mean density still appear as "clouds" because in our model more than 70% of the volume of the IGM at z = 3 is filled with gas at densities below the mean value.

  20. Non-parametric 3D map of the intergalactic medium using the Lyman-alpha forest

    NASA Astrophysics Data System (ADS)

    Cisewski, Jessi; Croft, Rupert A. C.; Freeman, Peter E.; Genovese, Christopher R.; Khandai, Nishikanta; Ozbek, Melih; Wasserman, Larry

    2014-05-01

    Visualizing the high-redshift Universe is difficult due to the dearth of available data; however, the Lyman-alpha forest provides a means to map the intergalactic medium at redshifts not accessible to large galaxy surveys. Large-scale structure surveys, such as the Baryon Oscillation Spectroscopic Survey (BOSS), have collected quasar (QSO) spectra that enable the reconstruction of H I density fluctuations. The data fall on a collection of lines defined by the lines of sight (LOS) of the QSO, and a major issue with producing a 3D reconstruction is determining how to model the regions between the LOS. We present a method that produces a 3D map of this relatively uncharted portion of the Universe by employing local polynomial smoothing, a non-parametric methodology. The performance of the method is analysed on simulated data that mimics the varying number of LOS expected in real data, and then is applied to a sample region selected from BOSS. Evaluation of the reconstruction is assessed by considering various features of the predicted 3D maps including visual comparison of slices, probability density functions (PDFs), counts of local minima and maxima, and standardized correlation functions. This 3D reconstruction allows for an initial investigation of the topology of this portion of the Universe using persistent homology.

  1. The Impact of Coupled Dark Energy Cosmologies on the High-Redshift Intergalactic Medium

    E-print Network

    Baldi, Marco

    2010-01-01

    We present an analysis of high-resolution hydrodynamical N-body simulations of coupled dark energy cosmologies which focusses on the statistical properties of the transmitted Lyman-alpha flux in the high-redshift intergalactic medium (IGM). In these models the growth of the diffuse cosmic web differs from the standard LCDM case: the density distribution is skewed towards underdense regions and the matter power spectra are typically larger (in a scale dependent way). These differences are also appreciable in the Lyman-alpha flux and are larger than 5% (10%) at z=2-4 in the flux probability distribution function (pdf) for high transmissivity regions and for values of the coupling parameter \\beta = 0.08 (\\beta = 0.2). The flux power spectrum is also affected at the ~2% (~ 5-10%) level for \\beta = 0.08 (\\beta = 0.2) in a redshift dependent way. We infer the behaviour of flux pdf and flux power for a reasonable range of couplings and present constraints using present high and low resolution data sets. We find an u...

  2. FARADAY ROTATION MEASURE DUE TO THE INTERGALACTIC MAGNETIC FIELD. II. THE COSMOLOGICAL CONTRIBUTION

    SciTech Connect

    Akahori, Takuya [Research Institute of Basic Science, Chungnam National University, Daejeon (Korea, Republic of); Ryu, Dongsu, E-mail: akataku@canopus.cnu.ac.kr, E-mail: ryu@canopus.cnu.ac.kr [Department of Astronomy and Space Science, Chungnam National University, Daejeon (Korea, Republic of)

    2011-09-10

    We investigate the Faraday rotation measure (RM) due to the intergalactic magnetic field (IGMF) through the cosmic web up to cosmological distances, using a model IGMF based on turbulence dynamo in the large-scale structure of the universe. By stacking the IGMF and gas density data up to redshift z = 5 and taking account of the redshift distribution of polarized background radio sources against which the RM is measured, we simulate the sky map of the RM. The contribution from galaxy clusters is subtracted from the map, based on several different criteria of X-ray brightness and temperature. Our findings are as follows. The distribution of RM for radio sources of different redshifts shows that the rms value increases with redshift and saturates for z {approx}> 1. The saturated value is RM{sub rms} {approx} several rad m{sup -2}. The probability distribution function of |RM| follows the lognormal distribution. The power spectrum has a broad plateau over the angular scale of {approx}1{sup 0}-0.{sup 0}1 with a peak around {approx}0.{sup 0}15. The second-order structure function has a flat profile in the angular separation of {approx}> 0.{sup 0}2. Our results could provide useful insights for surveys to explore the IGMF with the Square Kilometer Array (SKA) and upcoming SKA pathfinders.

  3. The Hot Inter-Galactic Medium and the Cosmic Microwave Background

    E-print Network

    Michael Fisher

    2007-05-01

    The physical characteristics of the Lyman-alpha forest cloud systems are combined with observations on the baryonic mass density of the Universe and constraints from primordial nucleosynthesis to set boundary conditions on the Intergalactic Medium (IGM) at the epoch of z=2.5. The Universe is considered a closed system and allowed to expand adiabatically from the epoch when QSOs first ionized the IGM (5 <= z_on <= 20). The average kinetic energy of a gas is calculated in the region where the gas transitions from relativistic to non-relativistic behavior. All of the above measurements are then used to determine the thermal history of the IGM in the redshift range 2.5 <= z <= z_on. The hot IGM is assumed to inverse Compton scatter photons from the Cosmic Microwave Background (CMBR) and consequently distort the CMBR as seen at the present epoch. The temperature of the IGM at z=2.5 and the epoch z_on are adjusted, within the constraints defined above, to give the best overall agreement with published data on the temperature of the IGM. We find that the model of the IGM proposed here does not grossly distort the CMBR, and in fact agrees quite closely with the preliminary results from the Cosmic Background Explorer (COBE) satellite. However, our model of the IGM cannot explain the observed cosmic x ray background. This paper was originally written in 1990. It was never submitted for publication.

  4. Can the intergalactic medium cause a rapid drop in Lyman alpha emission at z>6?

    E-print Network

    Mesinger, Andrei; Vanzella, Eros; Pentericci, Laura; Ferrara, Andrea; Dijkstra, Mark

    2014-01-01

    The large cross-section of the Lyman alpha (Lya) line makes it a sensitive probe of the ionization state of the intergalactic medium (IGM). Here we present the most complete study to date of the IGM Lya opacity, and its application to the redshift evolution of the 'Lya fraction', i.e. the fraction of color-selected galaxies with a detectable Lya emission line. We use a tiered approach, which combines large-scale semi-numeric simulations of reionization with moderate-scale hydrodynamic simulations of the ionized IGM. This allows us to simultaneously account for evolution in both: (i) the opacity from an incomplete (patchy) reionization, parameterized by the filling factor of ionized regions, Q_HII; and (ii) the opacity from self-shielded systems in the ionized IGM, parameterized by the average photo-ionization rate inside HII regions, \\Gamma. In contrast to recent empirical models, attenuation from patchy reionization has a unimodal distribution along different sightlines, while attenuation from self-shielded ...

  5. Measurement of Intergalactic Magnetic and Photon Fields with Secondary Photons and Neutrinos

    NASA Astrophysics Data System (ADS)

    Essey, Warren James

    Active galactic nuclei (AGN) can produce both gamma rays and cosmic rays. The observed high-energy gamma-ray signals from distant blazars may be dominated by secondary gamma rays produced along the line of sight by the interactions of cosmic-ray protons and gamma rays with background photons. This explains the surprisingly low attenuation observed for distant blazars, because the production of secondary gamma rays occurs, on average, much closer to Earth than the distance to the source. Thus the observed spectrum in the TeV range depends on the combination of secondary and primary signals. We apply this hypothesis to a number of sources and, in every case, we obtain an excellent fit, strengthening the interpretation of the observed spectra as being due to secondary gamma rays. We explore the ramifications of this interpretation for limits on the intergalactic magnetics fields, extragalactic background light and AGN properties. We also make predictions for the neutrino signals, which can help probe the acceleration of cosmic rays in AGN.

  6. ANISOTROPIC ACTIVE GALACTIC NUCLEUS OUTFLOWS AND ENRICHMENT OF THE INTERGALACTIC MEDIUM. I. METAL DISTRIBUTION

    SciTech Connect

    Germain, Joel; Barai, Paramita; Martel, Hugo [Departement de physique, de genie physique et d'optique, Universite Laval, Quebec, QC (Canada)

    2009-10-20

    We investigate the cosmological-scale influence of outflows driven by active galactic nuclei (AGNs) on metal enrichment of the intergalactic medium (IGM). AGNs are located in dense cosmological structures which tend to be anisotropic. We designed a semianalytical model for anisotropic AGN outflows which expand away along the direction of least resistance. This model was implemented into a cosmological numerical simulation algorithm for simulating the growth of large-scale structure in the universe. Using this modified algorithm, we perform a series of nine simulations inside cosmological volumes of size (128 h {sup -1} Mpc){sup 3}, in a concordance LAMBDACDM universe, varying the opening angle of the outflows, the lifetimes of the AGNs, their kinetic fractions, and their level of clustering. For each simulation, we compute the volume fraction of the IGM enriched in metals by the outflows. The resulting enriched volume fractions are relatively small at z approx> 2.5, and then grow rapidly afterward up to z = 0. We find that AGN outflows enrich from 65% to 100% of the entire universe at the present epoch, for different values of the model parameters. The enriched volume fraction depends weakly on the opening angle of the outflows. However, increasingly anisotropic outflows preferentially enrich underdense regions, a trend found more prominent at higher redshifts and decreasing at lower redshifts. The enriched volume fraction increases with increasing kinetic fraction and decreasing AGN lifetime, and level of clustering.

  7. PAPER-64 Constraints On Reionization II: The Temperature Of The z=8.4 Intergalactic Medium

    E-print Network

    Pober, Jonathan C; Parsons, Aaron R; McQuinn, Matthew; Aguirre, James E; Bernardi, Gianni; Bradley, Richard F; Carilli, Chris L; Cheng, Carina; DeBoer, David R; Dexter, Matthew R; Furlanetto, Steven R; Grobbelaar, Jasper; Horrell, Jasper; Jacobs, Daniel C; Klima, Patricia J; Kohn, Saul A; Liu, Adrian; MacMahon, David H E; Maree, Matthys; Mesinger, Andrei; Moore, David F; Razavi-Ghods, Nima; Stefan, Irina I; Walbrugh, William P; Walker, Andre; Zheng, Haoxuan

    2015-01-01

    We present constraints on both the kinetic temperature of the intergalactic medium (IGM) at z=8.4, and on models for heating the IGM at high-redshift with X-ray emission from the first collapsed objects. These constraints are derived using a semi-analytic method to explore the new measurements of the 21 cm power spectrum from the Donald C. Backer Precision Array for Probing the Epoch of Reionization (PAPER), which were presented in a companion paper, Ali et al. (2015). Twenty-one cm power spectra with amplitudes of hundreds of mK^2 can be generically produced if the kinetic temperature of the IGM is significantly below the temperature of the Cosmic Microwave Background (CMB); as such, the new results from PAPER place lower limits on the IGM temperature at z=8.4. Allowing for the unknown ionization state of the IGM, our measurements find the IGM temperature to be above ~5 K for neutral fractions between 10% and 85%, above ~7 K for neutral fractions between 15% and 80%, or above ~10 K for neutral fractions betw...

  8. The Volume Fraction of Ionized Intergalactic Gas at Redshift z=6.5

    E-print Network

    Sangeeta Malhotra; James Rhoads

    2005-11-07

    The observed number density of Lyman-alpha sources implies a minimum volume of the inter-galactic medium that must be ionized, in order to allow the Lyman-alpha photons to escape attenuation. We estimate this volume by assigning to each Lyman-alpha emitter the minimum Stromgren sphere that would allow half its Lyman-alpha photons to escape. This implies a lower limit to ionized gas volume fraction of 20-50% at redshift z=6.5. This is a lower limit in two ways: First, we conservatively assume that the Lyman-alpha sources seen (at a relatively bright flux limit) are the only ones present; and second, we assume the smallest Stromgren sphere volume that will allow the photons to escape. This limit is completely independent of what ionizing photon sources produced the bubbles. Deeper Lyman-alpha surveys are possible with present technology, and can strengthen these limits by detecting a higher density of Lyman-alpha galaxies.

  9. Heating and ionization of the primordial intergalactic medium by high-mass X-ray binaries

    NASA Astrophysics Data System (ADS)

    Knevitt, G.; Wynn, G. A.; Power, C.; Bolton, J. S.

    2014-12-01

    We investigate the influence of high-mass X-ray binaries (HMXBs) on their high-redshift environments. Using a one-dimensional radiative transfer code, we predict the ionization and temperature profiles surrounding a coeval stellar population, composed of main-sequence stars and HMXBs, at various times after its formation. We consider both uniform density surroundings, and a cluster embedded in a 108 M? Navarro-Frenk-White (NFW) halo. HMXBs in a constant density environment produce negligible enhanced ionization because of their high-energy spectral energy distributions and short lifetimes. In this case, HMXBs only marginally contribute to the local heating rate. For NFW profiles, radiation from main-sequence stars cannot prevent the initially ionized volume from recombining since it is unable to penetrate the high-density galactic core. However, HMXB photons stall recombinations behind the front, keeping it partially ionized for longer. The increased electron density in these partially ionized regions promotes further cooling, resulting in lower intergalactic medium (IGM) temperatures. In the context of this starburst model, we have shown that HMXBs do not make a major contribution to reionization or IGM heating. However, X-ray escape fractions are high in both density profile cases. Continuous star formation may result in the build up of X-rays over time, reducing the ionization time-scale and potentially leading to low level ionization of the distant IGM.

  10. Fisher analysis on wide-band polarimetry for probing the intergalactic magnetic field

    NASA Astrophysics Data System (ADS)

    Ideguchi, Shinsuke; Takahashi, Keitaro; Akahori, Takuya; Kumazaki, Kohei; Ryu, Dongsu

    2014-02-01

    We investigate the capability of current radio telescopes for probing Faraday rotation measure (RM) due to the intergalactic magnetic field (IGMF) in the large-scale structure of the universe, which is expected to be of order O (1) rad m-2. We consider polarization observations of a compact radio source such as quasars behind a diffuse source such as the Galaxy, and calculate Stokes parameters Q and U assuming a simple model of the Faraday dispersion functions with Gaussian shape. Then, we perform the Fisher analysis to estimate the expected errors in the model parameters from QU-fitting of polarization intensity, accounting for the sensitivities and frequency bands of Australian Square Kilometer Array Pathfinder, Low Frequency Array, and the Giant Meterwave Radio Telescope. Finally, we examine the conditions on the source intensities which are required to detect the IGMF. Our analysis indicates that the QU-fitting is promising for forthcoming wideband polarimetry to explore RM due to the IGMF in filaments of galaxies.

  11. THE SIGNATURE OF THE WARM-HOT INTERGALACTIC MEDIUM IN WMAP AND THE FORTHCOMING PLANCK DATA

    SciTech Connect

    Suarez-Velasquez, I.; Kitaura, F.-S.; Muecket, J. P. [Leibniz-Institut fuer Astrophysik, D-14482 Potsdam (Germany); Atrio-Barandela, F., E-mail: isuarez@aip.de, E-mail: kitaura@aip.de, E-mail: jpmuecket@aip.de, E-mail: atrio@usal.es [Fisica Teorica, Universidad de Salamanca, E-37008 Salamanca (Spain)

    2013-05-20

    We compute the cross-correlation between the Warm-Hot Intergalactic Medium and maps of cosmic microwave background temperature anisotropies using a log-normal probability density function to describe the weakly nonlinear matter density field. We search for this contribution in the data measured by the Wilkinson Microwave Anisotropy Probe. We use a template of projected matter density reconstructed from the Two-Micron All-Sky Redshift Survey as a tracer of the electron distribution. The spatial distribution of filaments is modeled using the recently developed Augmented Lagrangian Perturbation Theory. On the scales considered here, the reconstructed density field is very well described by the assumed log-normal distribution function. We predict that the cross-correlation will have an amplitude of 0.03-0.3 {mu}K. The measured value is close to 1.5 {mu}K, compatible with random alignments between structure in the template and in the temperature anisotropy data. Using the W1 Differencing Assembly to remove this systematic gives a residual correlation dominated by Galactic foregrounds. Planck could detect the Warm-Hot Medium if it is well traced by the density field reconstructed from galaxy surveys. The 217 GHz channel will allow to eliminate spurious contributions and its large frequency coverage can show the sign change from the Rayleigh-Jeans to the Wien part of the spectrum, characteristic of the thermal Sunyaev-Zel'dovich effect.

  12. The evolving intergalactic medium - The uncollapsed baryon fraction in a cold dark matter universe

    NASA Technical Reports Server (NTRS)

    Shapiro, Paul R.; Giroux, Mark L.; Babul, Arif

    1991-01-01

    The time-varying density of the intergalactic medium (IGM) is calculated by coupling detailed numerical calculations of the thermal and ionization balance and radiative transfer in a uniform IGM of H and He to the linearized equations for the growth of density fluctuations in both gases and a dark component in a cold dark matter universe. The IGM density is identified with the collapsed baryon fraction. It is found that even if the IGM is never reheated, a significant fraction of the baryons remain uncollapsed at redshifts of four. If instead the collapsed fraction releases enough ionizing radiation or thermal energy to reionize the IGM by z greater than four as required by the Gunn-Peterson (GP) constraint, the uncollapsed fraction at z of four is even higher. The known quasar distribution is insufficient to supply the ionizing radiation necessary to satisfy the GP constraint in this case and, if stars are instead responsible, a substantial metallicity must have been produced by z of four.

  13. Cosmic gamma-ray background from structure formation in the intergalactic medium

    PubMed

    Loeb; Waxman

    2000-05-11

    The Universe is filled with a diffuse background of gamma-ray radiation, the origin of which remains one of the unsolved puzzles of cosmology. Less than one-quarter of the gamma-ray flux can be attributed to unresolved discrete sources, such as active galactic nuclei; the remainder appears to constitute a truly diffuse background. Here we show that the shock waves induced by gravity in the gas of the intergalactic medium, during the formation of large-scale structures like filaments and sheets of galaxies, produce a population of highly relativistic electrons. These electrons scatter a small fraction of the cosmic microwave background photons in the local Universe up to gamma-ray energies, thereby providing the gamma-ray background. The predicted diffuse flux agrees with the observed background across more than four orders of magnitude in photon energy, and the model predicts that the gamma-ray background, though generated locally, is isotropic to better than five per cent on angular scales larger than a degree. Moreover, the agreement between the predicted and observed background fluxes implies a mean cosmological density of baryons that is consistent with Big Bang nucleosynthesis. PMID:10821264

  14. Intergalactic Magnetic Fields and Gamma-Ray Observations of Extreme TeV Blazars

    NASA Astrophysics Data System (ADS)

    Arlen, Timothy C.; Vassilev, Vladimir V.; Weisgarber, Thomas; Wakely, Scott P.; Yusef Shafi, S.

    2014-11-01

    The intergalactic magnetic field (IGMF) in cosmic voids can be indirectly probed through its effect on electromagnetic cascades initiated by a source of teraelectronvolt (TeV) gamma-rays, such as active galactic nuclei (AGNs). AGNs that are sufficiently luminous at TeV energies, "extreme TeV blazars", can produce detectable levels of secondary radiation from inverse Compton scattering of the electrons in the cascade, provided that the IGMF is not too large. We review recent work in the literature that utilizes this idea to derive constraints on the IGMF for three TeV-detected blazars, 1ES 0229+200, 1ES 1218+304, and RGB J0710+591, and we also investigate four other hard-spectrum TeV blazars in the same framework. Through a recently developed, detailed, three-dimensional particle-tracking Monte Carlo code, incorporating all major effects of QED and cosmological expansion, we research the effects of major uncertainties, such as the spectral properties of the source, uncertainty in the ultraviolet and far-infrared extragalactic background light, undersampled very high energy (energy >=100 GeV) coverage, past history of gamma-ray emission, source versus observer geometry, and the jet AGN Doppler factor. The implications of these effects on the recently reported lower limits of the IGMF are thoroughly examined to conclude that the presently available data are compatible with a zero-IGMF hypothesis.

  15. MAST Interface to Synthetic Telescopes with yt {MISTY}: Observing Simulations of the Intergalactic Medium

    NASA Astrophysics Data System (ADS)

    Peeples, Molly

    2014-10-01

    The COS instrument has shed new light on the metal-rich, massive, multi-phase reservoirs of gas surrounding galaxies. Numerical modeling has greatly enhanced the scientific understanding of the large body of of circumgalactic medium {CGM} and intergalactic medium {IGM} observations taken with COS. These numerical models produce synthetic spectra for direct comparison against COS outputs, a useful data resource for both simulators and observers alike, yet different groups apply different methods and formats, and there is no public archive of this scientific resource. We propose to construct a uniform and public simulation-to-archive pipeline for generating, analyzing, and providing to the community such synthetic spectra. By enabling rigorous and consistent comparisons between COS data and simulations, this project will advance our detailed knowledge of the physical and chemical conditions in CGM/IGM absorbers {density, temperature, metallicity ionization, ionization process}, and of the connection between observed velocity structure and galactic inflows and outflows. The results of our pipeline will be searchable via a MAST interface allowing users to specify subsets of synthetic spectra they wish to download and analyze.

  16. The significance of the Hansen Ideal space frame

    NASA Astrophysics Data System (ADS)

    Jochim, E. F. M.

    2012-10-01

    Known and unknown properties of Hansen Ideal coordinates are summarized. It is shown that the ideal space frame is a general and necessary component of basic celestial mechanics and astrodynamics, as well as of any theory of motion. A typical consequence is the intimate correlation of the Hansen frame with the Lagrange constraint within the method of the variation of the parameters. The use of observations in the ideal frame may allow conclusions on the intergalactic fundamental coordinate system.

  17. STAR FORMATION FEEDBACK AND METAL-ENRICHMENT HISTORY OF THE INTERGALACTIC MEDIUM

    SciTech Connect

    Cen Renyue; Chisari, Nora Elisa, E-mail: cen@astro.princeton.edu, E-mail: nchisari@astro.princeton.edu [Princeton University Observatory, Princeton, NJ 08544 (United States)

    2011-04-10

    Using the state-of-the-art cosmological hydrodynamic simulations of the standard cold dark matter model with star formation feedback strength normalized to match the observed star formation history of the universe at z= 0-6, we compute the metal-enrichment history of the intergalactic medium (IGM). Overall we show that galactic superwind (GSW) feedback from star formation can transport metals to the IGM and that the properties of simulated metal absorbers match current observations. The distance of influence of GSW from galaxies is typically limited to about {<=}0.5 Mpc and within regions of overdensity {delta} {>=} 10. Most C IV and O VI absorbers are located within shocked regions of elevated temperature (T {>=} 2 x 10{sup 4} K), overdensity ({delta} {>=} 10), and metallicity ([Z/Z{sub sun}] = [ - 2.5, - 0.5]), enclosed by double shocks propagating outward. O VI absorbers have typically higher metallicity, lower density, and higher temperature than C IV absorbers. For O VI absorbers, collisional ionization dominates over the entire redshift range z= 0-6, whereas for C IV absorbers the transition occurs at moderate redshift z {approx} 3 from collisionally dominated to photoionization dominated. We find that the observed column density distributions for C IV and O VI in the range log N cm{sup 2}=12-15 are reasonably reproduced by the simulations. The evolution of mass densities contained in C IV and O VI lines, {Omega}{sub CIV} and {Omega}{sub OVI}, is also in good agreement with observations, which shows a near constancy at low redshifts and an exponential drop beyond redshift z= 3-4. For both C IV and O VI, most absorbers are transient and the amount of metals probed by C IV and O VI lines of column log N cm{sup 2}=12-15 is only {approx}2% of total metal density at any epoch. While gravitational shocks from large-scale structure formation dominate the energy budget (80%-90%) for turning about 50% of the IGM to the warm-hot intergalactic medium (WHIM) by z = 0, GSW feedback shocks are energetically dominant over gravitational shocks at z{>=}1-2. Most of the so-called missing metals at z= 2-3 are hidden in a warm-hot (T = 10{sup 4.5}-10{sup 7} K) gaseous phase, heated up by GSW feedback shocks. Their mass distribution is broadly peaked at {delta}=1-10 in the IGM, outside virialized halos. Approximately 37%, 46%, 10%, and 7% of the total metals at z = 0 are in stars, WHIM, X-ray gas, and cold gas, respectively; the distributions stand at 23%, 57%, 2%, and 18% and 14%, 51%, 4%, and 31% at z = 2 and z = 4, respectively.

  18. Far Ultraviolet Spectroscopy of the Intergalactic and Interstellar Absorption Toward 3C 273

    NASA Technical Reports Server (NTRS)

    Sembach, Kenneth R.; Howk, J. Christopher; Savage, Blair D.; Shull, J. Michael; Oegerle, William R.; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    We present Far Ultraviolet Spectroscopic Explorer observations of the molecular, neutral atomic, weakly ionized, and highly ionized components of the interstellar and intergalactic material toward the quasar 3C273. We identify Ly-beta absorption in eight of the known intergalactic Ly-alpha absorbers along the sight line with the rest-frame equivalent widths W(sub r)(Ly-alpha) > 50 micro-angstroms. Refined estimates of the H(I) column densities and Doppler parameters (b) of the clouds are presented. We find a range of b = 16-46 km/s. We detect multiple H(I) lines (Ly-beta - Ly-theta) in the 1590 km/s Virgo absorber and estimate logN(H(I)) = 15.85 +/- 0.10, ten times more H(I) than all of the other absorbers along the sight line combined. The Doppler width of this absorber, b = 16 km/s, implies T < 15,000 K. We detect O(VI) absorption at 1015 km/s at the 2-3(sigma) level that may be associated with hot, X-ray emitting gas in the Virgo Cluster. We detect weak C(III) and O(VI) absorption in the IGM at z=0.12007; this absorber is predominantly ionized and has N(H+)/N(H(I)) > 4000/Z, where Z is the metallicity. Strong Galactic interstellar O(VI) is present between -100 and +100 km/s with an additional high-velocity wing containing about 13% of the total O(VI) between +100 and +240 km/s. The Galactic O(VI), N(V), and C(IV) lines have similar shapes, with roughly constant ratios across the -100 to +100 km/s velocity range. The high velocity O(VI) wing is not detected in other species. Much of the interstellar high ion absorption probably occurs within a highly fragmented medium within the Loop IV remnant or in the outer cavity walls of the remnant. Multiple hot gas production mechanisms are required. The broad O(VI) absorption wing likely traces the expulsion of hot gas out of the Galactic disk into the halo. A flux limit of 5.4 x 10(epx -16) erg/sq cm/s on the amount of diffuse O(VI) emission present = 3.5' off the 3C273 sight line combined with the observed O(VI) column density toward 3C273, logN O(VI) = 14.73 +/- 0.04, implies n(sub e) < 0.02/cubic cm and P/k < 11,500/cubic cm for an assumed temperature of 3 x 10(exp 5) K. The elemental abundances in the neutral and weakly-ionized interstellar clouds are similar to those found for other halo clouds. The warm neutral and warm ionized clouds along the sight line have similar dust-phase abundances, implying that the properties of the dust grains in the two types of clouds are similar. Interstellar H2 absorption is present at positive velocities at a level of logN(H2) = 15.71, but is very weak at the velocities of the main column density concentration along the sight line observed in H(I) 21 cm emission.

  19. The Baryon Census in a Multiphase Intergalactic Medium: 30% of the Baryons May Still be Missing

    NASA Astrophysics Data System (ADS)

    Shull, J. Michael; Smith, Britton D.; Danforth, Charles W.

    2012-11-01

    Although galaxies, groups, and clusters contain ~10% of the baryons, many more reside in the photoionized and shocked-heated intergalactic medium (IGM) and in the circumgalactic medium (CGM). We update the baryon census in the (H I) Ly? forest and warm-hot IGM (WHIM) at 105-6 K traced by O VI ?1032, 1038 absorption. From Enzo cosmological simulations of heating, cooling, and metal transport, we improve the H I and O VI baryon surveys using spatially averaged corrections for metallicity (Z/Z ?) and ionization fractions (f H I , f O VI ). Statistically, the O VI correction product correlates with column density, (Z/Z ?)f O VI ? (0.015)(N O VI /1014 cm-2)0.70, with an N O VI -weighted mean of 0.01, which doubles previous estimates of WHIM baryon content. We also update the Ly? forest contribution to baryon density out to z = 0.4, correcting for the (1 + z)3 increase in absorber density, the (1 + z)4.4 rise in photoionizing background, and cosmological proper length dl/dz. We find substantial baryon fractions in the photoionized Ly? forest (28% ± 11%) and WHIM traced by O VI and broad-Ly? absorbers (25% ± 8%). The collapsed phase (galaxies, groups, clusters, CGM) contains 18% ± 4%, leaving an apparent baryon shortfall of 29% ± 13%. Our simulations suggest that ~15% reside in hotter WHIM (T >= 106 K). Additional baryons could be detected in weaker Ly? and O VI absorbers. Further progress requires higher-precision baryon surveys of weak absorbers, down to minimum column densities N H I >= 1012.0 cm-2, N O VI >= 1012.5 cm-2, N O VII >= 1014.5 cm-2, using high signal-to-noise data from high-resolution UV and X-ray spectrographs.

  20. Absorption in the Cosmic Web: Characterizing the Intergalactic Medium in Cosmological Filaments

    NASA Astrophysics Data System (ADS)

    Tejos, Nicolas

    2014-10-01

    We propose to observe and characterize the IGM associated with cosmological filaments in a statistical manner up to redshift ~0.4. For this purpose, we have used a published cluster catalog (Hao et al. 2010) to identify massive nodes in the cosmic web. We used cluster-pairs separated by < 20 Mpc (transverse) and < 2000 km/s (along the LOS) to identify zones where filaments should reside with high probabilities. We have selected a single QSO whose sightline passess through a total of 9 independent cluster-pairs (8 of which having spectroscopic redshifts) at impact parameters <10 Mpc (7 of which at < 5 Mpc). We propose to observe the QSO with HST/COS using the G130M and G160M gratings to cover the full FUV spectral range at medium resolution (R~20000). We require observations at S/N>10 to ensure a full characterization of HI and OVI lines at column densities N~10^13 cm^-2. This setup will allow us to detect broad and shallow HI and OVI lines (if any) at the redshifts of these filaments, believed to trace portions of the warm-hot intergalactic medium (WHIM). Combining these new observations with those from our pilot study carried out in cycle 20 (ID 12958, PI Tejos), we aim to provide a firm detection of the WHIM in cosmological filaments, at the 95% confidence level. Our findings will test our understanding of galaxy formation and the role of AGN/supernova feedback by comparing them with state-of-the-art hydrodynamical simulations. We will also test the the hypothesis which states that the majority of OVI absorbers at low-z are confined within <300 kpc from galaxies (i.e. circumgalactic medium) thus not related to the WHIM (Prochaska et al. 2011; Tumlinson et al. 2011).

  1. COSMOLOGICAL SIMULATIONS OF INTERGALACTIC MEDIUM EVOLUTION. I. TEST OF THE SUBGRID CHEMICAL ENRICHMENT MODEL

    SciTech Connect

    Côté, Benoit; Martel, Hugo; Drissen, Laurent [Département de physique, de Génie Physique et d'Optique, Université Laval, Québec, QC G1V 0A6 (Canada)

    2013-11-10

    We present a one-zone galactic chemical enrichment model that takes into account the contribution of stellar winds from massive stars under the effect of rotation, Type II supernovae, hypernovae, stellar winds from low- and intermediate-mass stars, and Type Ia supernovae. This enrichment model will be implemented in a galactic model designed to be used as a subgrid treatment for galaxy evolution and outflow generation in large-scale cosmological simulations, in order to study the evolution of the intergalactic medium. We test our enrichment prescription by comparing its predictions with the metallicity distribution function and the abundance patterns of 14 chemical elements observed in the Milky Way stars. To do so, we combine the effect of many stellar populations created from the star formation history of the Galaxy in the solar neighborhood. For each stellar population, we keep track of its specific mass, initial metallicity, and age. We follow the time evolution of every population in order to respect the time delay between the various stellar phases. Our model is able to reproduce the observed abundances of C, O, Na, Mg, Al, S, and Ca. For Si, Cr, Mn, Ni, Cu, and Zn, the fits are still reasonable, but improvements are needed. We marginally reproduce the nitrogen abundance in very low metallicity stars. Overall, our results are consistent with the predicted abundance ratios seen in previous studies of the enrichment history of the Milky Way. We have demonstrated that our semi-analytic one-zone model, which cannot deal with spatial information such as the metallicity gradient, can nevertheless successfully reproduce the global Galactic enrichment evolution obtained by more complex models, at a fraction of the computational cost. This model is therefore suitable for a subgrid treatment of chemical enrichment in large-scale cosmological simulations.

  2. Bringing Simulation and Observation Together to Better Understand the Intergalactic Medium

    NASA Astrophysics Data System (ADS)

    Egan, Hilary; Smith, Britton D.; O'Shea, Brian W.; Shull, J. Michael

    2014-08-01

    The methods by which one characterizes the distribution of matter in cosmological simulations is intrinsically different from how one performs the same task observationally. In this paper, we make substantial steps toward comparing simulations and observations of the intergalactic medium (IGM) in a more sensible way. We present a pipeline that generates and fits synthetic QSO absorption spectra using sight lines cast through a cosmological simulation, and simultaneously identifies structure by directly analyzing the variations in H I and O VI number density. We compare synthetic absorption spectra with a less observationally motivated, but more straightforward density threshold-based method for finding absorbers. Our efforts focus on H I and O VI to better characterize the warm/hot IGM, a subset of the IGM that is challenging to conclusively identify observationally. We find that the two methods trace roughly the same quantities of H I and O VI above observable column density limits, but the synthetic spectra typically identify more substructure in absorbers. We use both methods to characterize H I and O VI absorber properties. We find that both integrated and differential column density distributions from both methods generally agree with observations. The distribution of Doppler parameters between the two methods are similar for Ly? and compare reasonably with observational results, but while the two methods agree with each other with O VI systems, they both are systematically different from observations. We find a strong correlation between O VI baryon fraction and O VI column density. We also discuss a possible bimodality in the temperature distribution of the gas traced by O VI.

  3. Characterizing the cool and warm-hot intergalactic medium in clusters at z < 0.4

    NASA Astrophysics Data System (ADS)

    Tejos, Nicolas

    2014-10-01

    Dedicated surveys with HST/COS and previous UV spectrometers have revealed that present-day galaxies of essentially all mass and spectral-type harbor a substantial reservoir of cool (T~10^4K) and warm (T~10^5-10^6 K) gas in their halos, defining a circumgalactic medium (CGM) around galaxies. At much higher halo mass scales, groups and clusters exhibit a hot (T~10^6-10^7K) tenuous plasma designated the intragroup or intracluster medium (IGrM, ICM). Although these massive structures hosts up to hundreds of individual galaxies, it is unknown whether the IGrM/ICM also contains cool or warm phases. Numerical simulations offer some guidance, predicting that the outer environment is warm (T<10^6K) and recent work on Virgo reveals a cool phase close to its virial radius. Here we venture into this unexplored territory, and propose to use HST/COS spectroscopy of 6 background QSOs to search for the cool (narrow HI Lya) and the warm/highly-ionized gas (broad HI Lya and OVI) at impact parameters of ~0.2 - 3 R_200 from 11 clusters lying in the foreground. We will use both G130M and G160M gratings to cover the full FUV spectral range to simultaneosly survey HI Lya and OVI at the redshifts of the intervening structures. This first systematic study of cool and warm gas in massive, low-z halos will enable us to: (1) quantify the contribution of the warm-hot intergalactic medium (WHIM) within or near massive groups and clusters; (2) explore the signatures of tidal and ram-pressure stripping of group/cluster members; (3) search for evidence of expulsion of baryons via feedback processes; and (4) search for evidence of cold/hot accretion modes in these massive halos.

  4. THE TEMPERATURE-DENSITY RELATION IN THE INTERGALACTIC MEDIUM AT REDSHIFT (z) = 2.4

    SciTech Connect

    Rudie, Gwen C.; Steidel, Charles C. [Cahill Center for Astronomy and Astrophysics, California Institute of Technology, MS 249-17, Pasadena, CA 91125 (United States); Pettini, Max, E-mail: gwen@astro.caltech.edu [Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom)

    2012-10-01

    We present new measurements of the temperature-density (T-{rho}) relation for neutral hydrogen in the 2.0 < z < 2.8 intergalactic medium (IGM) using a sample of {approx}6000 individual H I absorbers fitted with Voigt profiles constrained in all cases by multiple Lyman series transitions. We find model-independent evidence for a positive correlation between the column density of H I (N{sub HI}) and the minimum observed velocity width of absorbers (b{sub min}). With minimal interpretation, this implies that the T-{rho} relation in the IGM is not 'inverted', contrary to many recent studies. Fitting b{sub min} as a function of N{sub HI} results in line-width-column-density dependence of the form b{sub min} = b{sub 0}(N{sub HI}/N{sub HI,0}){sup {Gamma}-1} with a minimum line width at mean density ({rho}/{rho}-bar = 1, N{sub HI,0} = 10{sup 13.6} cm{sup -2}) of b{sub 0} = 17.9 {+-} 0.2 km s{sup -1} and a power-law index of ({Gamma} - 1) = 0.15 {+-} 0.02. Using analytic arguments, these measurements imply an 'equation of state' for the IGM at (z) = 2.4 of the form T=T{sub 0} ({rho}/{rho}-bar){sup {gamma}-1} with a temperature at mean density of T{sub 0} = [1.94 {+-} 0.05] Multiplication-Sign 10{sup 4} K and a power-law index ({gamma} - 1) = 0.46 {+-} 0.05.

  5. TURBULENCE IN THE INTERGALACTIC MEDIUM: SOLENOIDAL AND DILATATIONAL MOTIONS AND THE IMPACT OF NUMERICAL VISCOSITY

    SciTech Connect

    Zhu, Weishan; Gu, Qiusheng [School of Astronomy and Space Science, Nanjing University, Nanjing, 210092 (China); Feng, Long-long [Purple Mountain Observatory, Nanjing, 210008 (China); Xia, Yinhua [School of Mathematical Sciences, University of Science and Technology of China, Hefei, Anhui 230026 (China); Shu, Chi-Wang [Division of Applied Mathematics, Brown University, Providence, RI 02912 (United States); Fang, Li-Zhi [Department of Physics, University of Arizona, Tucson, AZ 85721 (United States)

    2013-11-01

    We use a suite of cosmological hydrodynamical simulations, run by two fixed grid codes, to investigate the properties of solenoidal and dilatational motions of the intergalactic medium (IGM) and the impact of numerical viscosity on turbulence in an ?CDM universe. The codes differ only in the spatial difference discretization. We find that (1) The vortical motion grows rapidly since z = 2 and reaches ?10 km s{sup –1}-90 km s{sup –1} at z = 0. Meanwhile, the small-scale compressive ratio r{sub CS} drops from 0.84 to 0.47, indicating comparable vortical and compressive motions at z = 0. (2) Power spectra of the solenoidal velocity possess two regimes, ?k {sup –0.89} and ?k {sup –2.02}, while the total and dilatational velocity follow the scaling k {sup –1.88} and k {sup –2.20}, respectively, in the turbulent range. The IGM turbulence may contain two distinct phases, the supersonic and post-supersonic phases. (3) The non-thermal pressure support, measured by the vortical kinetic energy, is comparable with the thermal pressure for ?{sub b} ? 10-100, or T < 10{sup 5.5} K at z = 0.0. The deviation of the baryon fraction from the cosmic mean shows a preliminary positive correlation with the turbulence pressure support. (4) A relatively higher numerical viscosity would dissipate both the compressive and vortical motions of the IGM into thermal energy more effectively, resulting in less developed vorticity, remarkably shortened inertial range, and leading to a non-negligible uncertainty in the thermal history of gas accretion. Shocks in regions outside of clusters are significantly suppressed by numerical viscosity since z = 2, which may directly cause the different levels of turbulence between the two codes.

  6. Confirming the Detection of an Intergalactic X-ray Absorber Toward PKS 2155-304

    E-print Network

    Taotao Fang; Claude R. Canizares; Yangsen Yao

    2007-08-14

    We present new observations on PKS 2155-304 with the Chandra Low Energy Transmission Grating Spectrometer (LETG), using the Advanced CCD Imaging Spectrometer (ACIS). We confirm the detection of an absorption line plausibly identified as OVIII Ly-alpha from the warm-hot intergalactic medium associated with a small group of galaxies along the line of sight, as originally reported by Fang et al. 2002 (here after FANG02). Combining the previous observations in FANG02 and five new, long observations on the same target, we increase the total exposure time by a factor of three, and the total counts per resolution element by a factor of five. The measured line equivalent width is smaller than that observed in FANG02, but still consistent at 90% confidence. We also analyze the XMM-Newton observations on the same target, as well as observations using the Chandra LETG and the High Resolution Camera (HRC) combination. These observations have been used to challenge our reported detection. While no line is seen in either the XMM-Newton and the Chandra LETG+HRC data, we find that our result is consistent with the upper limits from both data sets. We attribute the non-detection to (1) higher quality of the Chandra LETG+ACIS spectrum, and (2) the rather extended wings of the line spread functions of both the XMM RGS and the Chandra LETG+HRC. We discuss the implication of our observation on the temperature and density of the absorber. We also confirm the detection of z ~ 0 OVII absorption and, comparing with previous Chandra analysis, we obtain much tighter constraints on the line properties.

  7. Cosmological Simulations of the Intergalactic Medium Evolution. II. Galaxy Model and Feedback

    NASA Astrophysics Data System (ADS)

    Côté, Benoit; Martel, Hugo; Drissen, Laurent

    2015-04-01

    We present a semi-analytical model designed to be included in large-scale cosmological simulations to treat the evolution of galaxies. The goal of this paper is to test our model to make sure that it behaves in a realistic manner. We consider galaxies with current stellar masses between {{10}6.54} and {{10}11.65} {{M}? }. Our model includes radiative cooling, gas inflow, star formation, chemical enrichment, and stellar and AGN feedback. The evolution of each stellar population that forms in our model is individually followed in time by using stellar models found in the literature. Our stellar feedback prescription is based on the production of galactic outflows, which are powered by the mechanical energy (Energy-driven) and the radiative pressure (Momentum-driven). We implemented the physics of bubbles blown by stars to treat the feedback generated by mechanical energy. By keeping track of the energy gained and lost inside bubbles, we can compute the fraction of the stellar mechanical energy that is used to launch an outflow. Our model predicts that E-driven outflows dominate the evolution of low-mass galaxies with current stellar masses below {{10}10} {{M}? }, whereas intermediate-mass galaxies with current stellar masses up to {{10}10.7} {{M}? } are dominated by M-driven outflows. AGN feedback dominates the evolution of the most massive galaxies. With these three sources of feedback, we are able to reproduce the current observed stellar-to-dark-halo mass relation, as well as the current average stellar metallicity of galaxies. Outflows are very efficient in expelling metals out of galaxies, especially with E-driven outflows, which is consistent with the observed trend that metals are ejected more efficiently in low-mass galaxies. At the end of our simulations, a significant fraction of the metals produced by stars is located in the halos of galaxies. Metals can escape efficiently into the intergalactic medium for galaxies with current stellar masses below {{10}8} {{M}? } and above {{10}10.7} {{M}? }. The results presented in this paper are preliminary, since we do not yet consider the full interactions between galaxies and the effect of different types of environment. Nevertheless, since we are able to reproduce characteristics that are consistent with observations, we believe that our model is ready to be implemented in large-scale cosmological simulations to study the interactions between galaxies and their surrounding.

  8. Tracing the re-ionization-epoch intergalactic medium with metal absorption lines

    NASA Astrophysics Data System (ADS)

    Oppenheimer, Benjamin D.; Davé, Romeel; Finlator, Kristian

    2009-06-01

    Intergalactic medium (IGM) metal absorption lines observed in z >~ 6 spectra offer the opportunity to probe early feedback processes, the nature of enriching sources and the topology of re-ionization. We run high-resolution cosmological simulations including galactic outflows to study the observability and physical properties of five ions (CII, CIV, OI, SiII, SiIV) in absorption between z = 8 and 5. We apply three cases for ionization conditions: fully neutral, fully re-ionized and a patchy model based on the flux from the nearest galaxy. We find that our simulations can broadly fit available z ~ 5-6 IGM metal-line data, although all observations cannot be accommodated with a single ionization condition. Variations in OI absorbers among sight lines seen by Becker et al. suggest significant neutral IGM patches down to z ~ 6. Strong CIV absorbers at z ~ 6 may be the result of ionization by the galaxy responsible for that enrichment, although the identification of the neighbouring galaxy will have to wait to confirm this. Our outflows have typical speeds of ~200kms-1 and mass loading factors of ~6. Such high mass loading is critical for enriching the IGM to the observed levels while sufficiently curtailing early star formation to match the observed rest-frame ultraviolet luminosity function. The volume filling factor of metals increases during this epoch, but only reaches ~1per cent for Z > 10-3Zsolar by z = 5. Detectable absorbers generally trace inhomogeneously distributed metals residing outside of galactic haloes. CIV is an ideal tracer of IGM metals at z ~ 5-6, with dropping global ionization fractions to either higher or lower redshifts. This results in a strongly increasing global CIV mass density from z = 8 to 5, in contrast to its relative constancy from z = 5 to 2. Our simulations do not support widespread early IGM enrichment from e.g. Population III stars, as this would overpredict the numbers of weak CIV absorbers in the latest data. High-z absorbers arise from metals mostly on their first outward journey, at distances 5-50 physical kpc, and often exhibit broad profiles (?v > 200kms-1) as a result of outflowing peculiar velocities in the strongest systems. The galaxies responsible for early IGM enrichment have typical stellar masses of 107.0-8.5Msolar, and star formation rates <~1Msolaryr-1. Future facilities will be able to study the high-z galaxy-absorber connection in detail, revealing a wealth of information about feedback processes in the re-ionization epoch.

  9. The scattering of Ly? radiation in the intergalactic medium: numerical methods and solutions

    NASA Astrophysics Data System (ADS)

    Higgins, Jonathan; Meiksin, Avery

    2012-11-01

    Two methods are developed for solving the steady-state spherically symmetric radiative transfer equation for resonance line radiation emitted by a point source in the intergalactic medium, in the context of the Wouthuysen-Field mechanism for coupling the hyperfine structure spin temperature of hydrogen to the gas temperature. One method is based on solving the ray and moment equations using finite differences. The second uses a Monte Carlo approach incorporating methods that greatly improve the accuracy compared with previous approaches in this context. Several applications are presented serving as test problems for both a static medium and an expanding medium, including inhomogeneities in the density and velocity fields. Solutions are obtained in the coherent scattering limit and for Doppler RII redistribution with and without recoils. We find generally that the radiation intensity is linear in the cosine of the azimuthal angle with respect to radius to high accuracy over a broad frequency region across the line centre for both linear and perturbed velocity fields, yielding the Eddington factors f? ? 1/3 and g? ? 3/5. The radiation field produced by a point source divides into three spatial regimes for a uniformly expanding homogeneous medium. The regimes are governed by the fraction of the distance r from the source in terms of the distance r* required for a photon to redshift from line centre to the frequency needed to escape from the expanding gas. For a standard cosmology, before the Universe was reionized r* takes on the universal value independent of redshift of 1.1 Mpc, depending only on the ratio of the baryon to dark matter density. At r/r* < 1, the radiation field is accurately described in the diffusion approximation, with the scattering rate declining with the distance from the source as r-7/3, except at r/r* ? 1 where frequency redistribution nearly doubles the mean intensity around line centre. At r/r* > 1, the diffusion approximation breaks down and the decline of the mean intensity near line centre and the scattering rate approach the geometric dilution scaling 1/r2. The mean intensity and scattering rate are found to be very sensitive to the gradient of the velocity field, growing exponentially with the amplitude of the perturbation as the limit of a vanishing velocity gradient is approached near the source. We expect the 21-cm signal from the epoch of reionization to thus be a sensitive probe of both the density and the peculiar velocity fields. The solutions for the mean intensity are made available in machine-readable format.

  10. ANISOTROPIC ACTIVE GALACTIC NUCLEUS OUTFLOWS AND ENRICHMENT OF THE INTERGALACTIC MEDIUM. II. METALLICITY

    SciTech Connect

    Barai, Paramita [Department of Physics and Astronomy, University of Nevada at Las Vegas, Las Vegas, NV (United States); Martel, Hugo; Germain, Joel [Departement de physique, de genie physique et d'optique, Universite Laval, Quebec, QC (Canada)

    2011-01-20

    We investigate the large-scale influence of outflows from active galactic nuclei (AGNs) in enriching the intergalactic medium (IGM) with metals in a cosmological context. We combine cosmological simulations of large-scale structure formation with a detailed model of metal enrichment, in which outflows expand anisotropically along the direction of least resistance, distributing metals into the IGM. The metals carried by the outflows are generated by two separate stellar populations: stars located near the central AGN, and stars located in the greater galaxy. Using this algorithm, we performed a series of five simulations of the propagation of AGN-driven outflows in a cosmological volume of size (128 h{sup -1} Mpc){sup 3} in a {Lambda}CDM universe, and analyze the resulting metal enrichment of the IGM. We found that the metallicity induced in the IGM is greatly dominated by AGNs having bolometric luminosity L>10{sup 9} L{sub sun}, sources with 10{sup 8} < L/L{sub sun} < 10{sup 9} having a negligible contribution. Our simulations produced an average IGM metallicity of [O/H] = -5 at z = 5.5, which then rises gradually, and remains relatively flat at a value [O/H] = -2.8 between z = 2 and z = 0. The ejection of metals from AGN host galaxies by AGN-driven outflows is found to enrich the IGM to >10%-20% of the observed values, the number dependent on redshift. The enriched IGM volume fractions are small at z>3, then rise rapidly to the following values at z = 0: 6%-10% of the volume enriched to [O/H]> - 2.5, 14%-24% volume to [O/H]> - 3, and 34%-45% volume to [O/H]> - 4. At z {>=} 2, there is a gradient of the induced enrichment, the metallicity decreasing with increasing IGM density, enriching the underdense IGM to higher metallicities, a trend more prominent with increasing anisotropy of the outflows. This can explain observations of the metal-enriched low-density IGM at z {approx} 3-4.

  11. ANISOTROPIC GALACTIC OUTFLOWS AND ENRICHMENT OF THE INTERGALACTIC MEDIUM. II. NUMERICAL SIMULATIONS

    SciTech Connect

    Pinsonneault, Steeve; Martel, Hugo [Departement de physique, de genie physique et d'optique, Universite Laval, Quebec, QC G1K 7P4 (Canada); Pieri, Matthew M. [Department of Astronomy, Ohio State University, Columbus, OH 43210 (United States)

    2010-12-20

    We combine an analytic model for anisotropic outflows and galaxy formation with numerical simulations of large-scale structure and halo formation to study the impact of galactic outflows on the evolution of the intergalactic medium (IGM). Using this algorithm, we have simulated the evolution of a comoving volume of size (15 Mpc){sup 3} in the {Lambda}CDM universe. Using an N-body simulation starting at redshift z = 24, we follow the formation of galaxies and simulate the galactic outflows produced by these galaxies. Outflows are modeled as bipolar cones with opening angle {alpha}, which expand along the direction of least resistance. We consider five opening angles: {alpha} = 60{sup 0}, 90{sup 0}, 120{sup 0}, 150{sup 0}, and 180{sup 0} (isotropic outflows). We also consider the effect of photoionization suppression of galaxy formation by reionization at redshift z = 6. Anisotropic outflows travel preferentially into low-density regions, away from cosmological structures (filaments and pancakes) where galaxies form. These anisotropic outflows are less likely to overlap with one another than isotropic ones. They are also less likely to hit pre-galactic collapsing halos and strip them of their gas, preventing a galaxy from forming. Going from 180{sup 0} to 60{sup 0}, the number of galaxies that actually form doubles, producing twice as many outflows, and these outflows overlap to a lesser extent. As a result, the metal volume filling factor of the IGM goes from 8% for isotropic outflows up to 28% for anisotropic ones. High-density regions are more efficiently enriched than low-density ones ({approx}80% compared to {approx}20% by volume), even though most enriched regions are low densities. Increasing the anisotropy of outflows increases the extent of enrichment at all densities, low and high. This is in part because anisotropic outflows are more numerous. When this effect is factored out, we find that the probability a galaxy will enrich systems at densities up to 10 {rho}-bar is higher for increasingly anisotropic outflows. This is interpreted as an effect of the dynamical evolution of the IGM. Anisotropic outflows expand preferentially into underdense gas, but that gas can later accrete onto overdense structures. The inclusion of photoionization greatly reduces the formation of low-mass galaxies at redshifts z < 3. The result is a decline in the physical extent of galactic outflows after z = 3 as accretion overwhelms the expansion of new outflows and reduces feedback in underdense regions.

  12. Rest-frame ultraviolet line emission from the intergalactic medium at 2 ? z ? 5

    NASA Astrophysics Data System (ADS)

    Bertone, Serena; Schaye, Joop

    2012-01-01

    Rest-frame ultraviolet (UV) emission lines offer the exciting possibility to directly image the gas around high-redshift galaxies with upcoming optical instruments. We use a suite of large, hydrodynamical simulations to predict the nature and detectability of emission lines from the intergalactic medium (IGM) at 2 ? z ? 5. The brightest emission comes from H I Ly? (1216 Å) and the strongest metal line, C III (977), is about an order of magnitude fainter, although H I Ly? may be fainter if the gas is self-shielded to the UV background or if dust is important. The highest surface brightness regions for C IV (1548, 1551), Si III (1207), Si IV (1393, 1403) and O VI (1032, 1038) are fainter than the brightest C III by factors of a few. The N V (1239, 1243) and Ne VIII (770, 780) lines, as well as He II H? (1640), are substantially weaker, but their maximum surface brightnesses still exceed 102 photon s-1 cm-2 sr-1 at z = 2 (for 2-arcsec pixels). Lower ionization lines typically arise in denser and colder gas that produces clumpier emission. The brightest H I Ly? emission arises exclusively in highly overdense gas, but the highest surface brightness emission from high-ionization metal lines traces a much wider range of overdensities. Bright metal-line emission traces gas with temperatures close to the peak of the corresponding emissivity curve. While H I Ly?, He II H?, C III, Si III and Si IV are excellent probes of cold accretion flows and the colder parts of outflows, C IV, N V, O VI and Ne VIII are powerful tracers of the diffuse warm-hot IGM and galactic winds. A comparison of results from simulations with varying physical prescriptions demonstrates that the predictions for the brighter metal-line emission are robust to within factors of a few. Several rest-frame UV emission lines from the high-redshift IGM will become detectable in the near future, possibly starting with the Cosmic Web Imager, which is already operating on Palomar. The Multi Unit Spectroscopic Explorer, which will be commissioned in 2012 on the Very Large Telescope, and the proposed Keck Cosmic Web Imager have the potential to revolutionize studies of the interactions between high-redshift galaxies and their environment.

  13. NEW: a mission to explore the warm-hot intergalactic medium

    NASA Astrophysics Data System (ADS)

    den Herder, Jan-Willem; Kaastra, Jelle S.; Paerels, Frits B. S.; de Korte, Piet A. J.; Kuiper, Lucien; Hoevers, Henk F. C.; Hermsen, Wim; Mèndez, Mariano; Kahn, Steven M.; Rasmussen, Andrew P.

    2006-06-01

    The most recent observations of the cosmic microwave background (e.g., WMAP) show that baryons contribute about 4% to the total density of the Universe. However at redshift less than or equal to 1, about half of these baryons have not yet been observed. Cosmological simulations predict that these "missing" baryons should be distributed in filaments, have temperatures of 10 5 to 10 7 K and overdensities of a few to hundred times the average baryon density, forming the so-called Warm-Hot Intergalactic Medium (WHIM). There is increasing evidence from Chandra and XMM-Newton that the WHIM may indeed exist. However it is clear that to map the morphology of the WHIM and to measure its physical conditions, a completely different class of instruments is required. Measuring the WHIM in emission in the soft X-ray band is a promising option. To detect the relatively weak, extended emission of the WHIM, the instrument should have a large grasp (collecting area times field of view), and an energy resolving power of about 500 at 1 keV is required to separate the emission of these large scale filaments from foreground emission. We discuss a design that includes X-ray mirrors in combination with a large 2D cryogenic detector, which will allow us to map a significant fraction of this gas. Such detector and its read-out based on Frequency Domain Multiplexing, are currently under development at SRON. It seems feasible to build an array of 24 x 24 pixels of TES microcalorimeters with good energy resolution (few eV). This detector will be combined with a mirror design which is based on 2 and 4 reflections and gives a large area (> 500 cm2) over a relatively large field of view. A preliminary study of the mission concept indicates that this can be implemented in a relatively small satellite (total weight 650 kg). While the main goal of this satellite will be to map and study the physical properties of the missing baryons, the instrument's large area and large field of view will also result in major progress in related fields.

  14. PROBING THE INTERGALACTIC MEDIUM/GALAXY CONNECTION. V. ON THE ORIGIN OF Ly? AND O VI ABSORPTION AT z < 0.2

    E-print Network

    Prochaska, J. Xavier

    We analyze the association of galaxies with Ly? and O VI absorption, the most commonly detected transitions of the low-z intergalactic medium (IGM), in the fields of 14 quasars with z[subscript em] = 0.06–0.57. Confirming ...

  15. TURBULENT MOLECULAR GAS AND STAR FORMATION IN THE SHOCKED INTERGALACTIC MEDIUM OF STEPHAN'S QUINTET

    SciTech Connect

    Guillard, P.; Cluver, M. E.; Lisenfeld, U.; Ogle, P. M. [Spitzer Science Center (SSC), California Institute of Technology, MC 220-6, Pasadena, CA 91125 (United States); Boulanger, F.; Pineau des Forets, G. [Institut d'Astrophysique Spatiale (IAS), UMR 8617, CNRS, Universite Paris-Sud 11, Batiment 121, 91405 Orsay Cedex (France); Falgarone, E.; Gusdorf, A. [ENS, LERMA, UMR 8112, CNRS, Observatoire de Paris, 24 rue Lhomond 75005 Paris (France); Appleton, P. N. [NASAHerschel Science Center (NHSC), California Institute of Technology, Mail code 100-22, Pasadena, CA 91125 (United States); Duc, P.-A. [AIM, Unite Mixte de Recherche CEA-CNRS, Universite Paris VII, UMR 7158 (France); Xu, C. K. [Infrared Processing and Analysis Center (IPAC), JPL, Pasadena, CA 91109 (United States)

    2012-04-20

    The Stephan's Quintet (hereafter SQ) is a template source to study the impact of galaxies interaction on the physical state and energetics of their gas. We report on IRAM single-dish CO observations of the SQ compact group of galaxies. These observations follow up the Spitzer discovery of bright mid-IR H{sub 2} rotational line emission (L(H{sub 2}) Almost-Equal-To 10{sup 35} W) from warm (10{sup 2-3} K) molecular gas, associated with a 30 kpc long shock between a galaxy, NGC 7318b, and NGC 7319's tidal arm. We detect CO(1-0), (2-1) and (3-2) line emission in the inter-galactic medium (IGM) with complex profiles, spanning a velocity range of Almost-Equal-To 1000 km s{sup -1}. The spectra exhibit the pre-shock recession velocities of the two colliding gas systems (5700 and 6700 km s{sup -1}), but also intermediate velocities. This shows that much of the molecular gas has formed out of diffuse gas accelerated by the galaxy-tidal arm collision. CO emission is also detected in a bridge feature that connects the shock to the Seyfert member of the group, NGC 7319, and in the northern star forming region, SQ-A, where a new velocity component is identified at 6900 km s{sup -1}, in addition to the two velocity components already known. Assuming a Galactic CO(1-0) emission to H{sub 2} mass conversion factor, a total H{sub 2} mass of Almost-Equal-To 5 Multiplication-Sign 10{sup 9} M{sub Sun} is detected in the shock. The ratio between the warm H{sub 2} mass derived from Spitzer spectroscopy, and the H{sub 2} mass derived from CO fluxes is Almost-Equal-To 0.3 in the IGM of SQ, which is 10--100 times higher than in star-forming galaxies. The molecular gas carries a large fraction of the gas kinetic energy involved in the collision, meaning that this energy has not been thermalized yet. The kinetic energy of the H{sub 2} gas derived from CO observations is comparable to that of the warm H{sub 2} gas from Spitzer spectroscopy, and a factor Almost-Equal-To 5 greater than the thermal energy of the hot plasma heated by the collision. In the shock and bridge regions, the ratio of the PAH-to-CO surface luminosities, commonly used to measure the star formation efficiency of the H{sub 2} gas, is lower (up to a factor 75) than the observed values in star-forming galaxies. We suggest that turbulence fed by the galaxy-tidal arm collision maintains a high heating rate within the H{sub 2} gas. This interpretation implies that the velocity dispersion on the scale of giant molecular clouds in SQ is one order of magnitude larger than the Galactic value. The high amplitude of turbulence may explain why this gas is not forming stars efficiently.

  16. Reionization in a cold dark matter universe: The feedback of galaxy formation on the intergalactic medium

    NASA Technical Reports Server (NTRS)

    Shapiro, Paul R.; Giroux, Mark L.; Babul, Arif

    1994-01-01

    We study the coupled evolution of the intergalactic medium (IGM) and the emerging structure in the universe in the context of the cold dark matter (CDM) model, with a special focus on the consequences of imposing reionization and the Gunn-Peterson constraint as a boundary condition on the model. We have calculated the time-varying density of the IGM by coupling our detailed, numerical calculations of the thermal and ionization balance and radiative transfer in a uniform, spatially averaged IGM of H and He, including the mean opacity of an evolving distribution of gas clumps which correspond to quasar absorption line clouds, to the linearized equations for the growth of density fluctuations in both the gaseous and dark matter components in a CDM universe. We use the linear growth equations to identify the fraction of the gas which must have collapsed out at each epoch, an approach similar in spirit to the so-called Press-Schechter formalism. We identify the IGM density with the uncollapsed baryon fraction. The collapsed fraction is postulated to be a source of energy injection into the IGM, by radiation or bulk hydrodynamical heating (e.g., via shocks) or both, at a rate which is marginally enough to satisfy the Gunn-Peterson constraint at z less than 5. Our results include the following: (1) We find that the IGM in a CDM model must have contained a substantial fraction of the total baryon density of the universe both during and after its reionization epoch. (2) As a result, our previous conclusion that the observed Quasi-Stellar Objects (QSOs) at high redshift are not sufficient to ionize the IGM enough to satisfy the Gunn-Peterson constraint is confirmed. (3) We predict a detectable He II Gunn-Peterson effect at 304(1 + z) A in the spectra of quasars at a range of redshift z greater than or approx. 3, depending on the nature of the sources of IGM reionization. (4) We find, moreover, that a CDM model with high bias parameter b (i.e., b greater than or approx. 2) cannot account for the baryon content of the universe at z approximately 3 observed in quasar absorption line gas unless Omega (sub B) significantly exceeds the maximum value allowed by big bang nucleocynthesis. (5) For a CDM model with bias parameter within the allowed range of (lower) values, the lower limit to Omega(sub B) imposed by big bang nucleosynthesis (Omega(sub B) h(sup 2) greater than or equal to 0.01) combines with our results to yield the minimum IGM density for the CDM fodel. For CDM with b = 1 (Cosmic Background Explorer (COBE) normalization), we find Omega(sub IGM)(sup min) (z approximately 4) approx. equal 0.02-0.03, and Omega(sub IGM)(sup min)(z approximately 0) approx. equal 0.005-0.03, depending upon the nature of the sources of IGM reionization. (6) In general, we find that self-consistent reionization of the IGM by the collapsed baryon fraction has a strong effect on the rate of collapse. (7) As a further example, we show that the feedback effect on the IGM of energy release by the collapsed baryon fraction may explain the slow evolution of the observed comoving QSO number density between z = 5 and z = 2, followed by the sharp decline after z = 2.

  17. Observations of Chemically Enriched QSO Absorbers near z~2.3 Galaxies: Galaxy Formation Feedback Signatures in the Intergalactic Medium

    NASA Astrophysics Data System (ADS)

    Simcoe, Robert A.; Sargent, Wallace L. W.; Rauch, Michael; Becker, George

    2006-02-01

    We present a comparative study of galaxies and intergalactic gas toward the z=2.73 quasar HS 1700+6416, to explore the effects of galaxy formation feedback on the IGM. Our observations and ionization simulations indicate that the volume within 100-200 h-171 physical kpc of high-redshift galaxies is populated by very small (?L<~1 kpc), dense (?/?¯~1000), and metal-rich (Z>~1/10-1/3 Zsolar) absorption-line regions. These systems often contain shock-heated gas seen in O VI and may exhibit [Si/C] abundance enhancements suggestive of preferential enrichment by Type II supernovae. We argue that the absorber geometries resemble thin sheets or bubbles and that their unusual physical properties can be explained using a simple model of radiatively efficient shocks plowing through moderately overdense intergalactic filaments. The high metallicities suggest that these shocks are being expelled from, rather than falling into, star-forming galaxies. There is a drop-off in the intergalactic gas density at galaxy impact parameters of >~300 physical kpc (>~1 comoving Mpc) that may represent boundaries of the gas structures where galaxies reside. The heavy-element enhancement near galaxies covers smaller distances: at galactocentric radii between 100 and 200 h-171 kpc the observed abundances blend into the general metallicity field of the IGM. Our results suggest that either supernova-driven winds or dynamical stripping of interstellar gas alters the IGM near massive galaxies, even at R>~100 kpc. However, only a few percent of the total mass in the Ly? forest is encompassed by this active feedback at z~2.5. The effects could be more widespread if the more numerous metal-poor C IV systems at impact parameters >~200 h-171 kpc are the tepid remnants of very powerful late-time winds. However, based on present observations it is not clear that this scenario is to be favored over one involving preenrichment by smaller galaxies at z>~6. Includes observations made at the W. M. Keck Observatory, which is operated as a scientific partnership between the California Institute of Technology and the University of California; it was made possible by the generous support of the W. M. Keck Foundation.

  18. Keeping the Universe ionised: Photo-heating and the clumping factor of the high-redshift intergalactic medium

    E-print Network

    Andreas H. Pawlik; Joop Schaye; Eveline van Scherpenzeel

    2009-01-10

    The critical star formation rate density required to keep the intergalactic hydrogen ionised depends crucially on the average rate of recombinations in the intergalactic medium (IGM). This rate is proportional to the clumping factor C = / avg(rho_b)^2, where rho_b and avg(rho_b) are the local and cosmic mean baryon density, respectively, and the brackets indicate spatial averaging over the recombining gas in the IGM. We perform a suite of cosmological smoothed particle hydrodynamics simulations that include radiative cooling to calculate the volume-weighted clumping factor of the IGM at redshifts z >= 6. We focus on the effect of photo-ionisation heating by a uniform ultra-violet background and find that photo-heating strongly reduces the clumping factor because the increased pressure support smoothes out small-scale density fluctuations. Photo-ionisation heating is often said to provide a negative feedback on the reionisation of the IGM because it suppresses the cosmic star formation rate by boiling the gas out of low-mass halos. However, because of the reduction of the clumping factor it also makes it easier to keep the IGM ionised. Photo-heating therefore also provides a positive feedback which, while known to exist, has received much less attention. We demonstrate that this positive feedback is in fact very strong. Using conservative assumptions, we find that if the IGM was reheated at z >~ 9, the observed population of star-forming galaxies at z = 6 may be sufficient to keep the IGM ionised, provided that the fraction of ionising photons that escape the star-forming regions to ionise the IGM is larger than 0.2.

  19. Polarization of absorption lines as a diagnostics of circumstellar, interstellar and intergalactic magnetic fields: Fine structure atoms

    E-print Network

    Huirong Yan; A. Lazarian

    2006-11-09

    The relative population of the fine structure sublevels of an atom's ground state is affected by radiative transitions induced by an anisotropic radiation flux. This causes the alignment of atomic angular momentum. In terms of observational consequences for the interstellar and intergalactic medium, this results in the polarization of the absorption lines. In the paper we consider the conditions necessary for this effect and provide calculations of polarization from a few astrophysically important atoms and ions with multiple upper and lower levels for an arbitrary orientation of magnetic fields to the a) source of optical pumping, b) direction of observation, c) absorbed source. We also consider an astrophysically important ``degenerate'' case when the source of optical pumping coincides with the source of the absorbed radiation. We present analytical expressions that relate the degree of linear polarization and the intensity of absorption to the 3D orientation of the magnetic field with respect to the pumping source, the source of the absorbed radiation, and the direction of observations. We discuss how all these parameters can be determined via simultaneous observations of several absorption lines and suggest graphical means that are helpful in practical data interpretation. We prove that studies of absorption line polarization provide a unique tool to study 3D magnetic field topology in various astrophysical conditions.

  20. X-ray Scattering Echoes and Ghost Halos from the Intergalactic Medium: Relation to the nature of AGN variability

    E-print Network

    Corrales, Lia

    2015-01-01

    X-ray bright quasars might be used to trace dust in the circumgalactic and intergalactic medium through the phenomenon of X-ray scattering, which is observed around Galactic objects whose light passes through a sufficient column of interstellar gas and dust. Of particular interest is the abundance of grey dust larger than 0.1 um, which is difficult to detect at other wavelengths. To calculate X-ray scattering from large grains, one must abandon the traditional Rayleigh-Gans approximation. The Mie solution for the X-ray scattering optical depth of the Universe is ~1%. This presents a great difficulty for distinguishing dust scattered photons from the point source image of Chandra, which is currently unsurpassed in imaging resolution. The variable nature of AGN offers a solution to this problem, as scattered light takes a longer path and thus experiences a time delay with respect to non-scattered light. If an AGN dims significantly (> 3 dex) due to a major feedback event, the Chandra point source image will be ...

  1. A Direct Precision Measurement of the Intergalactic Lyman-alpha Opacity at 2

    E-print Network

    C. -A. Faucher-Giguere; J. X. Prochaska; A. Lidz; L. Hernquist; M. Zaldarriaga

    2008-07-25

    We directly measure the evolution of the intergalactic Lya effective optical depth, tau_eff, over the redshift range 2spline fitting are systematically biased low, with the magnitude of the bias increasing with redshift, but that this bias can be accounted for using mock spectra. The mean fractional error is ~3 based on directly fitting the quasar continua in the Lya forest, which have generally neglected this effect, are therefore likely biased low. We provide estimates of the level of absorption arising from metals in the Lya forest based on both direct and statistical metal removal results in the literature, finding that this contribution is ~6-9% at z=3 and decreases monotonically with redshift. The high precision of our measurement, attaining 3% in redshift bins of width Delta z=0.2 around z=3, indicates significant departures from the best-fit power-law redshift evolution (tau_eff=0.0018(1+z)^3.92, when metals are left in), particularly near z=3.2. The observed downward departure is statistically consistent with a similar feature detected in a precision statistical measurement using Sloan Digital Sky Survey spectra by Bernardi and coworkers using an independent approach.

  2. The distribution of dark matter, galaxies, and the intergalactic medium in a cold dark matter dominated universe

    NASA Technical Reports Server (NTRS)

    Ryu, Dongsu; Vishniac, Ethan T.; Chiang, Wei-Hwan

    1988-01-01

    The evolution and distribution of galaxies and the intergalactic medium (IGM) have been studied, along with collisionless dark matter in a Universe dominated by cold dark matter. The Einstein-deSitter universe with omega sub 0 = 1 and h = 0.5 was considered (here h = H sub 0 bar 100/kms/Mpc and H sub 0 is the present value of the Hubble constant). It is assumed that initially dark matter composes 90 pct and baryonic matter composes 10 pct of total mass, and that the primordial baryonic matter is comprised of H and He, with the abundance of He equal to 10 pct of H by number. Galaxies are allowed to form out of the IGM, if the total density and baryonic density satisfy an overdensity criterion. Subsequently, the newly formed galaxies release 10 to the 60th ergs of energy into the IGM over a period of 10 to the 8th years. Calculations have been performed with 32 to the 3rd dark matter particles and 32 to the 3rd cells in a cube with comoving side length L = 9.6/h Mpc. Dark matter particles and galaxies have been followed with an N-body code, while the IGM has been followed with a fluid code.

  3. Eternity in six hours: Intergalactic spreading of intelligent life and sharpening the Fermi paradox

    NASA Astrophysics Data System (ADS)

    Armstrong, Stuart; Sandberg, Anders

    2013-08-01

    The Fermi paradox is the discrepancy between the strong likelihood of alien intelligent life emerging (under a wide variety of assumptions) and the absence of any visible evidence for such emergence. In this paper, we extend the Fermi paradox to not only life in this galaxy, but to other galaxies as well. We do this by demonstrating that travelling between galaxies - indeed even launching a colonisation project for the entire reachable universe - is a relatively simple task for a star-spanning civilisation, requiring modest amounts of energy and resources. We start by demonstrating that humanity itself could likely accomplish such a colonisation project in the foreseeable future, should we want to. Given certain technological assumptions, such as improved automation, the task of constructing Dyson spheres, designing replicating probes, and launching them at distant galaxies, become quite feasible. We extensively analyse the dynamics of such a project, including issues of deceleration and collision with particles in space. Using similar methods, there are millions of galaxies that could have reached us by now. This results in a considerable sharpening of the Fermi paradox.

  4. A Snapshot Survey of AGNS/QSOS for Intergalactic Medium Studies

    NASA Technical Reports Server (NTRS)

    Sonneborn, George (Technical Monitor); Sembach, George

    2005-01-01

    This spectroscopic program with the Far Ultraviolet Spectroscopic Explorer (FUSE) program was designed to identify ultraviolet-bright active galactic nuclei (AGNs) and quasi-stellar objects (QSOs) for follow-up spectroscopy with FUSE and the Hubble Space Telescope (HST). All of the FUSE spectra obtained for this snapshot program (FUSE identifier D808) have been examined for data quality and flux levels. As expected, only a small number of objects observed (4/19) have flux levels suitable for follow-up spectroscopy. A portion of our effort in this program was devoted to comparing the spectra obtained in these snapshot exposures to others to determine if the spectra could be used for detailed scientific analyses. The resulting effort demonstrated that some of the brighter sources are relatively stable (non- variable), as determined through comparisons of the spectra at multiple epochs. For these brighter sources, the exposure times are simply too short to perform meaningful detailed analyses. Comparisons of the absorption lines in these spectra with those of higher signal-to-noise spectra, like those of PG1116+215 and H1821+643, showed that many of the lines of interest could not be characterized adequately at the S/N levels reached in the short snapshot exposures. As a result, the FUSE D808 observations are suitable only for their original purpose - flux determination. Several bright objects identified as part of this program include: HE0153-4520, flux >2x10E-14 erg cm^-2s^-1 at 1000 Angstroms IRASF04250-5718, flux >4x10E-14 erg cm^-2s^-1 A^-1 at 1000 Angstroms RXJ2154.1-4414, flux > 1.6x10E-14 erg cm^-2s^-1 A^-1 at 1000 Angstroms S50716+714, flux >2.5x10E-14 erg cm^-2s^-1 A^-1 at 1000 Angstroms. All of these objects have been incorporated into the primary target lists for the HST Cosmic Origins Spectrograph. Identifying such objects for follow-up observations with HST/COS was the primary goal of this program, so the program wa successful. In addition, some of the objects were included in proposed target lists for future FUSE observations. Given that the state of the FUSE observatory is uncertain at this time, it is unknown whether anyjof htese objects will be re-observed with FUSE. The results of this program have been communicated to the astronomical community via email and by word of mouth since the resuts in and of themselves do not warrant publication in an astronomical journal. However, these lists will be maintained for future observers. The data are archived in the Multi-Mission Archive at the Space Telescioe Science INstitute.

  5. THE NATURE OF THE WARM/HOT INTERGALACTIC MEDIUM. I. NUMERICAL METHODS, CONVERGENCE, AND O VI ABSORPTION

    SciTech Connect

    Smith, Britton D.; Hallman, Eric J.; Shull, J. Michael [Center for Astrophysics and Space Astronomy, Department of Astrophysical and Planetary Sciences, 389 UCB, University of Colorado, Boulder, CO 80309 (United States); O'Shea, Brian W., E-mail: britton.smith@colorado.edu, E-mail: michael.shull@colorado.edu [Department of Physics and Astronomy, Michigan State University, East Lansing, MI 48824 (United States)

    2011-04-10

    We perform a series of cosmological simulations using Enzo, an Eulerian adaptive-mesh refinement, N-body + hydrodynamical code, applied to study the warm/hot intergalactic medium (WHIM). The WHIM may be an important component of the baryons missing observationally at low redshift. We investigate the dependence of the global star formation rate and mass fraction in various baryonic phases on spatial resolution and methods of incorporating stellar feedback. Although both resolution and feedback significantly affect the total mass in the WHIM, all of our simulations find that the WHIM fraction peaks at z {approx} 0.5, declining to 35%-40% at z = 0. We construct samples of synthetic O VI absorption lines from our highest-resolution simulations, using several models of oxygen ionization balance. Models that include both collisional ionization and photoionization provide excellent fits to the observed number density of absorbers per unit redshift over the full range of column densities (10{sup 13} cm{sup -2} {approx}< N{sub OVI} {approx}< 10{sup 15} cm{sup -2}). Models that include only collisional ionization provide better fits for high column density absorbers (N{sub OVI} {approx}> 10{sup 14} cm{sup -2}). The distribution of O VI in density and temperature exhibits two populations: one at T {approx} 10{sup 5.5} K (collisionally ionized, 55% of total O VI) and one at T {approx} 10{sup 4.5} K (photoionized, 37%) with the remainder located in dense gas near galaxies. While not a perfect tracer of hot gas, O VI provides an important tool for a WHIM baryon census.

  6. Tomography of the intergalactic medium with Ly? forests in close QSO pairs

    NASA Astrophysics Data System (ADS)

    D'Odorico, V.; Viel, M.; Saitta, F.; Cristiani, S.; Bianchi, S.; Boyle, B.; Lopez, S.; Maza, J.; Outram, P.

    2006-11-01

    We study the three-dimensional distribution of non-virialized matter at z ~ 2 using high-resolution spectra of quasi-stellar object (QSO) pairs and simulated spectra drawn from cosmological hydrodynamical simulations. We have collected the largest sample of QSO pairs ever observed with Ultraviolet and Visual Echelle Spectrograph (UVES) at the European Southern Observatory-Very Large Telescope (ESO-VLT), with angular separations between ~1 and 14arcmin. The observed correlation functions of the transmitted flux in the HI Lyman ? forest along and transverse to the lines of sight are in good agreement implying that the distortions in redshift space due to peculiar velocities are small. The clustering signal is significant up to velocity separations of ~200kms-1, or about 3h-1 comoving Mpc. The regions at lower overdensity are still clustered but on smaller scales (?v <~ 100kms-1). The observed and simulated correlation functions are compatible at the 3? level. A better concordance is obtained when only the low overdensity regions are selected for the analysis or when the effective optical depth of the simulated spectra is increased artificially, suggesting a deficiency of strong lines in the simulated spectra. We found that also a lower value of the power-law index of the temperature-density relation for the Lyman ? forest gas improves the agreement between observed and simulated results. If confirmed, this would be consistent with other observations favouring a late HeII reionization epoch (at z ~ 3). We remark the detection of a significant clustering signal in the cross-correlation coefficient at a transverse velocity separation ?v? ~ 500kms-1 whose origin needs further investigation. Based on observations collected at the European Southern Observatory Very Large Telescope, Cerro Paranal, Chile - Programs 65.O-0299(A), 68.A-0216(A), 69.A-0204(A), 69.A-0586(A), 70.A-0031(A), 166.A-0106(A). E-mail: dodorico@oats.inaf.it

  7. Detection of an intergalactic meteor particle with the 6-m telescope

    E-print Network

    V. L. Afanasiev; V. V. Kalenichenko; I. D. Karachentsev

    2007-12-10

    On July 28, 2006 the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences recorded the spectrum of a faint meteor. We confidently identify the lines of FeI and MgI, OI, NI and molecular-nitrogen N_2 bands. The entry velocity of the meteor body into the Earth's atmosphere estimated from radial velocity is equal to 300 km/s. The body was several tens of a millimeter in size, like chondrules in carbon chondrites. The radiant of the meteor trajectory coincides with the sky position of the apex of the motion of the Solar system toward the centroid of the Local Group of galaxies. Observations of faint sporadic meteors with FAVOR TV CCD camera confirmed the radiant at a higher than 96% confidence level. We conclude that this meteor particle is likely to be of extragalactic origin. The following important questions remain open: (1) How metal-rich dust particles came to be in the extragalactic space? (2) Why are the sizes of extragalactic particles larger by two orders of magnitude (and their masses greater by six orders of magnitude) than common interstellar dust grains in our Galaxy? (3) If extragalactic dust surrounds galaxies in the form of dust (or gas-and-dust) aureoles, can such formations now be observed using other observational techniques (IR observations aboard Spitzer satellite, etc.)? (4) If inhomogeneous extragalactic dust medium with the parameters mentioned above actually exists, does it show up in the form of irregularities on the cosmic microwave background (WMAP etc.)?

  8. Making Space for Space.

    ERIC Educational Resources Information Center

    Flanagan, Sue

    2001-01-01

    Introduces some ideas for using space in classrooms. Provides a rationale for using space as part of the curriculum and focuses on the concept of a space mission as a vehicle for learning. Includes a list of some space-related web sites. (DDR)

  9. A meeting with the universe: Science discoveries from the space program

    NASA Technical Reports Server (NTRS)

    French, B. M. (editor); Maran, S. P. (editor)

    1981-01-01

    A general history of space exploration is presented. The solar system is discussed. The Sun-Earth relationship is considered, including magnetic fields, solar wind, the magnetosphere, and the Sun-weather relationship. The universe beyond the solar system is discussed. Topics include stellar and galactic evolution, quasars and intergalactic space. The effects of weightlessness and ionizing radiation on human beings are considered. The possibility of extraterrestrial life is discussed. Lunar and planetary exploration, solar-terrestrial physics, astrophysics, biomedical research and exobiology are reviewed. Numerons color illustrations are included.

  10. THE COSMOLOGICAL IMPACT OF LUMINOUS TeV BLAZARS. II. REWRITING THE THERMAL HISTORY OF THE INTERGALACTIC MEDIUM

    SciTech Connect

    Chang, Philip; Broderick, Avery E.; Pfrommer, Christoph, E-mail: aeb@cita.utoronto.ca, E-mail: pchang@cita.utoronto.ca, E-mail: christoph.pfrommer@h-its.org [Canadian Institute for Theoretical Astrophysics, 60 St. George Street, Toronto, ON M5S 3H8 (Canada)

    2012-06-10

    The universe is opaque to extragalactic very high energy gamma rays (VHEGRs, E > 100 GeV) because they annihilate and pair produce on the extragalactic background light. The resulting ultrarelativistic pairs are commonly assumed to lose energy primarily through inverse Compton scattering of cosmic microwave background (CMB) photons, reprocessing the original emission from TeV to GeV energies. In Broderick et al., we argued that this is not the case; powerful plasma instabilities driven by the highly anisotropic nature of the ultrarelativistic pair distribution provide a plausible way to dissipate the kinetic energy of the TeV-generated pairs locally, heating the intergalactic medium (IGM). Here, we explore the effect of this heating on the thermal history of the IGM. We collate the observed extragalactic VHEGR sources to determine a local VHEGR heating rate. Given the pointed nature of VHEGR observations, we estimate the correction for the various selection effects using Fermi observations of high- and intermediate-peaked BL Lac objects. As the extragalactic component of the local VHEGR flux is dominated by TeV blazars, we then estimate the evolution of the TeV blazar luminosity density by tying it to the well-observed quasar luminosity density and producing a VHEGR heating rate as a function of redshift. This heating is relatively homogeneous for z {approx}< 4, but there is greater spatial variation at higher redshift (order unity at z {approx} 6) because of the reduced number of blazars that contribute to local heating. We show that this new heating process dominates photoheating in the low-redshift evolution of the IGM and calculate the effect of this heating in a one-zone model. As a consequence, the inclusion of TeV blazar heating qualitatively and quantitatively changes the structure and history of the IGM. Due to the homogeneous nature of the extragalactic background light, TeV blazars produce a uniform volumetric heating rate. This heating is sufficient to increase the temperature of the mean density IGM by nearly an order of magnitude, and at low densities by substantially more. It also naturally produces the inverted temperature-density relation inferred by recent observations of the high-redshift Ly{alpha} forest, a feature that is difficult to reconcile with standard reionization models. Finally, we close with a discussion on the possibility of detecting this hot low-density IGM suggested by our model either directly or indirectly via the local Ly{alpha} forest, the Comptonized CMB, or free-free emission, but we find that such measurements are currently not feasible.

  11. A New Method to Directly Measure the Jeans Scale of the Intergalactic Medium Using Close Quasar Pairs

    NASA Astrophysics Data System (ADS)

    Rorai, Alberto; Hennawi, Joseph F.; White, Martin

    2013-10-01

    Although the baryons in the intergalactic medium (IGM) trace dark matter fluctuations on megaparsec scales, on smaller scales ~100 kpc, fluctuations are suppressed because the finite temperature gas is pressure supported against gravity, analogous to the classical Jeans argument. This Jeans filtering scale, which quantifies the small-scale structure of the IGM, has fundamental cosmological implications. First, it provides a thermal record of heat injected by ultraviolet photons during cosmic reionization events, and thus constrains the thermal and reionization history of the universe. Second, the Jeans scale determines the clumpiness of the IGM, a critical ingredient in models of cosmic reionization. Third, it sets the minimum mass scale for gravitational collapse from the IGM, and hence plays a pivotal role in galaxy formation. Unfortunately, it is extremely challenging to measure the Jeans scale via the standard technique of analyzing purely longitudinal Ly? forest spectra, because the thermal Doppler broadening of absorption lines along the line-of-sight, is highly degenerate with Jeans smoothing. In this work, we show that the Jeans filtering scale can be directly measured by characterizing the coherence of correlated Ly? forest absorption in close quasar pairs, with separations small enough ~100 kpc to resolve it. We present a novel technique for this purpose, based on the probability density function (PDF) of phase angle differences of homologous longitudinal Fourier modes in close quasar pair spectra. A Bayesian formalism is introduced based on the phase angle PDF, and Markov Chain Monte Carlo techniques are used to characterize the precision of a hypothetical Jeans scale measurement, and explore degeneracies with other thermal parameters governing the IGM. A semi-analytical model of the Ly? forest is used to generate a large grid (500) of thermal models from a dark matter only simulation. Our full parameter study indicates that a realistic sample of only 20 close quasar pair spectra can pinpoint the Jeans scale to ~= 5% precision, independent of the amplitude T 0 and slope ? of the temperature-density relation of the IGM T=T_0(\\rho / {\\bar{\\rho }})^{\\gamma -1}. This exquisite sensitivity arises because even long-wavelength one-dimensional Fourier modes ~10 Mpc, i.e., two orders of magnitude larger than the Jeans scale, are nevertheless dominated by projected small-scale three-dimensional (3D) power. Hence phase angle differences between all modes of quasar pair spectra actually probe the shape of the 3D power spectrum on scales comparable to the pair separation. We show that this new method for measuring the Jeans scale is unbiased and is insensitive to a battery of systematics that typically plague Ly? forest measurements, such as continuum fitting errors, imprecise knowledge of the noise level and/or spectral resolution, and metal-line absorption.

  12. A NEW METHOD TO DIRECTLY MEASURE THE JEANS SCALE OF THE INTERGALACTIC MEDIUM USING CLOSE QUASAR PAIRS

    SciTech Connect

    Rorai, Alberto; Hennawi, Joseph F. [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg (Germany); White, Martin [Department of Astronomy, University of California at Berkeley, 601 Campbell Hall, Berkeley, CA 94720-3411 (United States)

    2013-10-01

    Although the baryons in the intergalactic medium (IGM) trace dark matter fluctuations on megaparsec scales, on smaller scales ?100 kpc, fluctuations are suppressed because the finite temperature gas is pressure supported against gravity, analogous to the classical Jeans argument. This Jeans filtering scale, which quantifies the small-scale structure of the IGM, has fundamental cosmological implications. First, it provides a thermal record of heat injected by ultraviolet photons during cosmic reionization events, and thus constrains the thermal and reionization history of the universe. Second, the Jeans scale determines the clumpiness of the IGM, a critical ingredient in models of cosmic reionization. Third, it sets the minimum mass scale for gravitational collapse from the IGM, and hence plays a pivotal role in galaxy formation. Unfortunately, it is extremely challenging to measure the Jeans scale via the standard technique of analyzing purely longitudinal Ly? forest spectra, because the thermal Doppler broadening of absorption lines along the line-of-sight, is highly degenerate with Jeans smoothing. In this work, we show that the Jeans filtering scale can be directly measured by characterizing the coherence of correlated Ly? forest absorption in close quasar pairs, with separations small enough ?100 kpc to resolve it. We present a novel technique for this purpose, based on the probability density function (PDF) of phase angle differences of homologous longitudinal Fourier modes in close quasar pair spectra. A Bayesian formalism is introduced based on the phase angle PDF, and Markov Chain Monte Carlo techniques are used to characterize the precision of a hypothetical Jeans scale measurement, and explore degeneracies with other thermal parameters governing the IGM. A semi-analytical model of the Ly? forest is used to generate a large grid (500) of thermal models from a dark matter only simulation. Our full parameter study indicates that a realistic sample of only 20 close quasar pair spectra can pinpoint the Jeans scale to ? 5% precision, independent of the amplitude T{sub 0} and slope ? of the temperature-density relation of the IGM T=T{sub 0}(?/ ?-bar ){sup ?-1}. This exquisite sensitivity arises because even long-wavelength one-dimensional Fourier modes ?10 Mpc, i.e., two orders of magnitude larger than the Jeans scale, are nevertheless dominated by projected small-scale three-dimensional (3D) power. Hence phase angle differences between all modes of quasar pair spectra actually probe the shape of the 3D power spectrum on scales comparable to the pair separation. We show that this new method for measuring the Jeans scale is unbiased and is insensitive to a battery of systematics that typically plague Ly? forest measurements, such as continuum fitting errors, imprecise knowledge of the noise level and/or spectral resolution, and metal-line absorption.

  13. Space Tools! Space Tools!

    E-print Network

    - scopes were built. Some used glass lenses to magnify the light from space, while others used large far away. By using telescopes, astronomers have discovered that there are many other things in space of the Universe. Radio telescopes are also used to search for signs of intelligent life on other planets. 13 #12

  14. High Resolution Spectroscopy of X-ray Quasars: Searching for the X-ray Absorption from the Warm-Hot Intergalactic Medium

    NASA Technical Reports Server (NTRS)

    Fang, Taotao; Canizares, Claude R.; Marshall, Herman L.

    2004-01-01

    We present a survey of six low to moderate redshift quasars with Chandra and XMM-Newton. The primary goal is to search for the narrow X-ray absorption lines produced by highly ionized metals in the Warm-Hot Intergalactic Medium. All the X-ray spectra can be well fitted by a power law with neutral hydrogen absorption. Only one feature is detected at above 3-sigma level in all the spectra, which is consistent with statistic fluctuation. We discuss the implications in our understanding of the baryon content of the universe. We also discuss the implication of the non-detection of the local (z approx. 0) X-ray absorption.

  15. A Century of Cosmology: A Direct Precision Measurement of the Intergalactic Lyman-alpha Opacity at 2

    E-print Network

    C. -A. Faucher-Giguere; J. X. Prochaska; A. Lidz; L. Hernquist; M. Zaldarriaga

    2007-10-24

    We directly measure the evolution of the intergalactic Lyman-alpha effective optical depth, tau_eff, over the redshift range 2spline fitting are systematically biased low, but that this bias can be accounted for using mock spectra. The mean fractional error is <1% at z=2, 4% at z=3, and 12% at z=4. We provide estimates of the level of absorption arising from metals in the Ly-alpha forest based on both direct and statistical metal removal results in the literature, finding that this contribution is ~6-9% at z=3 and decreases monotonically with redshift. The high precision of our measurement indicates significant departures from the best-fit power-law redshift evolution, particularly near z=3.2.

  16. Real space (r-space): Fourier space(q-space)

    E-print Network

    Davis, James C.

    0 Å 600 Å 0-|qmax| Real space (r-space): Fourier space(q-space): -2 /a0 +2 /a0 · real space resolution q-space extent 1.2 Å · real space extent q-space resolution 0.6% 1st BZ +|qmax| 0 5 10 15 20 25 30 and measuring the peak in the resulting q-space image. In the past this technique has been used to study metals

  17. LOWER BOUNDS ON MAGNETIC FIELDS IN INTERGALACTIC VOIDS FROM LONG-TERM GeV-TeV LIGHT CURVES OF THE BLAZAR MRK 421

    SciTech Connect

    Takahashi, Keitaro [Department of Physics, Kumamoto University, 2-39-1, Kurokami, Kumamoto 860-8555 (Japan); Mori, Masaki [Department of Physical Sciences, Ritsumeikan University, 1-1-1 Noji Higashi, Kusatsu, Shiga 525-8577 (Japan); Ichiki, Kiyotomo [Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan); Inoue, Susumu [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, D-69117 Heidelberg (Germany); Takami, Hajime, E-mail: keitaro@sci.kumamoto-u.ac.jp [Theory Center, Institute of Particle and Nuclear Studies, KEK, 1-1, Oho, Tsukuba 305-0801 (Japan)

    2013-07-10

    Lower bounds are derived on the amplitude B of intergalactic magnetic fields (IGMFs) in the region between Galaxy and the blazar Mrk 421, from constraints on the delayed GeV pair-echo flux that are emitted by secondary e {sup -} e {sup +} produced in {gamma}{gamma} interactions between primary TeV gamma rays and the cosmic infrared background. The distribution of galaxies mapped by the Sloan Digital Sky Survey shows that this region is dominated by a large intergalactic void. We utilize data from long-term, simultaneous GeV-TeV observations by the Fermi Large Area Telescope and the ARGO-YBJ experiment extending over 850 days. For an assumed value of B, we evaluate the daily GeV pair-echo flux expected from the TeV data, select the dates where this exceeds the Fermi 2{sigma} sensitivity, compute the probability that this flux is excluded by the Fermi data for each date, and then combine the probabilities using the inverse normal method. Consequently, we exclude B < 10{sup -20.5} G for a field coherence length of 1 kpc at {approx}4{sigma} level, as long as plasma instabilities are unimportant for cooling of the pair beam. This is much more significant than the 2{sigma} bounds we obtained previously from observations of Mrk 501, by virtue of more extensive data from the ARGO-YBJ, as well as improved statistical analysis. Compared with most other studies of IGMF bounds, the evidence we present here for a non-zero IGMF is more robust as it does not rely on unproven assumptions on the primary TeV emission during unobserved periods.

  18. Space Listing -Public Spaces Space Formal NameSpace Name

    E-print Network

    Bushman, Frederic

    Space Listing - Public Spaces Space Formal NameSpace Name Fill Ratio Max Capacity Campus Partition Theater Style (Layout E) 250250 16% BRB LOBBY BRB II/III Lobby Break-Out Space Undefined 300250 -- BRB Austrian Lobby Break-Out Space Undefined 200200 -- JMB CLASS 62 JMB Class of 62 Auditorium Theater Style

  19. Space of Spaces

    E-print Network

    Edward Anderson

    2014-11-30

    Wheeler emphasized the study of Superspace - the space of 3-geometries on a spatial manifold of fixed topology. This is a configuration space for GR; knowledge of configuration spaces is useful as regards dynamics and QM.In this Article I consider furthmore generalized configuration spaces to all levels within the conventional `equipped sets' paradigm of mathematical structure used in fundamental Theoretical Physics. This covers A) the more familiar issue of topology change in the sense of topological manifolds (tied to cobordisms), including via pinched manifolds. B) The less familiar issue of not regarding as fixed the yet deeper levels of structure: topological spaces themselves (and their metric space subcase), collections of subsets and sets. Isham has previously presented quantization schemes for a number of these. I consider some classical preliminaries for this program, aside from the most obvious (classical dynamics for each). Rather, I provide I) to all levels Relational and Background Independence criteria, which have Problem of Time facets as consequences. I demonstrate that many of these issues descend all the way down, whilst also documenting at which level the others cease to apply. II) Probability theory on configuration spaces. In fact such a stochastic treatment is how to further mathematize the hitherto fairly formal and sketchy subject of records theory (a type of formultion of quantum gravity). Along these lines I provide a number of further examples of records theories. This is in addition to Kendall's shape statistics being the example corresponding to relational mechanics models. To this example I now add 1) Cech cohomology, 2) Kendall's random sets, 3) the lattice of topologies on a fixed set. I finally consider 4) sheaves, both as a generalization of Cech cohomology and in connection to the study of stratified manifolds such as Superspace itself.

  20. Cognitive Space and Information Space

    E-print Network

    Newby, Gregory B.

    Cognitive Space and Information Space Gregory B. Newby Arctic Region Supercomputing Center newby information spaces (of systems) that are consistent with cognitive spaces (of humans). In such systems, but at the expense of consonance between information spaces and cognitive spaces. These include shortcuts on data

  1. Space Travel

    NSDL National Science Digital Library

    2014-09-18

    Students are introduced to the historical motivation for space exploration. They learn about the International Space Station as an example of space travel innovation and are introduced to new and futuristic ideas that space engineers are currently working on to propel space research far into the future!

  2. THE SIZE AND ORIGIN OF METAL-ENRICHED REGIONS IN THE INTERGALACTIC MEDIUM FROM SPECTRA OF BINARY QUASARS

    SciTech Connect

    Martin, Crystal L.; Fournier, Amanda P. [Department of Physics, University of California, Santa Barbara, CA 93106 (United States); Scannapieco, Evan [School of Earth and Space Exploration, Arizona State University, P.O. Box 871404, Tempe, AZ 85287-1404 (United States); Ellison, Sara L. [Department of Physics and Astronomy, University of Victoria, Victoria, British Columbia, V8P 1A1 (Canada); Hennawi, Joseph F. [Department of Astronomy, 601 Campbell Hall, University of California, Berkeley, CA 94720-3411 (United States); Djorgovski, S. G., E-mail: cmartin@physics.ucsb.ed [Division of Physics, Mathematics, and Astronomy, California Institute of Technology, Pasadena, CA 91125 (United States)

    2010-09-20

    We present tomography of the circum-galactic metal distribution at redshift 1.7-4.5 derived from echellete spectroscopy of binary quasars. We find C IV systems at similar redshifts in paired sightlines more often than expected for sightline-independent redshifts. As the separation of the sightlines increases from 36 kpc to 907 kpc, the amplitude of this clustering decreases. At the largest separations, the C IV systems cluster similar to the Lyman-break galaxies studied by Adelberger et al. in 2005. The C IV systems are significantly less correlated than these galaxies, however, at separations less than R{sub 1} {approx_equal} 0.42 {+-} 0.15 h {sup -1} comoving Mpc. Measured in real space, i.e., transverse to the sightlines, this length scale is significantly smaller than the break scale estimated previously from the line-of-sight correlation function in redshift space by Scannapieco et al. in 2006. Using a simple model, we interpret the new real-space measurement as an indication of the typical physical size of enriched regions. We adopt this size for enriched regions and fit the redshift-space distortion in the line-of-sight correlation function. The fitted velocity kick is consistent with the peculiar velocity of galaxies as determined by the underlying mass distribution and places an upper limit on the average outflow (or inflow) speed of metals. The implied timescale for dispersing metals is larger than the typical stellar ages of Lyman-break galaxies, and we argue that enrichment by galaxies at z {>=} 4.3 played a greater role in dispersing metals. To further constrain the growth of enriched regions, we discuss empirical constraints on the evolution of the C IV correlation function with cosmic time. This study demonstrates the potential of tomography for measuring the metal enrichment history of the circum-galactic medium.

  3. Space Shuttle

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The space shuttle flight system and mission profile are briefly described. Emphasis is placed on the economic and social benefits of the space transportation system. The space shuttle vehicle is described in detail.

  4. Space Carving, Silhouettes Space carving

    E-print Network

    Giger, Christine

    Space Carving, Silhouettes #12;Space carving · So far: depth maps · dense reconstruction in form · discretize 3D object space (rather than 2D ray space) into voxels: small regular volume elements · for each voxel, determine whether it belongs to object or free space · if necessary, convert voxels back

  5. Servicing Mission 4 and the Extraordinary Science of the Hubble Space Telescope

    NASA Technical Reports Server (NTRS)

    Wiseman, Jennifer J.

    2012-01-01

    Just two years ago, NASA astronauts performed a challenging and flawless final Space Shuttle servicing mission to the orbiting Hubble Space Telescope. With science instruments repaired on board and two new ones installed, the observatory. is more powerful now than ever before. I will show the dramatic highlights of the servicing mission and present some of the early scientific results from the refurbished telescope. Its high sensitivity and multi-wavelength capabilities are revealing the highest redshift galaxies ever seen, as well as details of the cosmic web of intergalactic medium, large scale structure formation, solar system bodies, and stellar evolution. Enlightening studies of dark matter, dark energy, and exoplanet atmospheres add to the profound contributions to astrophysics that are being made with Hubble, setting a critical stage for future observatories such as the James Webb Space Telescope.

  6. The Hubble Space Telescope: UV, Visible, and Near-Infrared Pursuits

    NASA Technical Reports Server (NTRS)

    Wiseman, Jennifer

    2010-01-01

    The Hubble Space Telescope continues to push the limits on world-class astrophysics. Cameras including the Advanced Camera for Surveys and the new panchromatic Wide Field Camera 3 which was installed nu last year's successful servicing mission S2N4,o{fer imaging from near-infrared through ultraviolet wavelengths. Spectroscopic studies of sources from black holes to exoplanet atmospheres are making great advances through the versatile use of STIS, the Space Telescope Imaging Spectrograph. The new Cosmic Origins Spectrograph, also installed last year, is the most sensitive UV spectrograph to fly io space and is uniquely suited to address particular scientific questions on galaxy halos, the intergalactic medium, and the cosmic web. With these outstanding capabilities on HST come complex needs for laboratory astrophysics support including atomic and line identification data. I will provide an overview of Hubble's current capabilities and the scientific programs and goals that particularly benefit from the studies of laboratory astrophysics.

  7. LOWER BOUNDS ON INTERGALACTIC MAGNETIC FIELDS FROM SIMULTANEOUSLY OBSERVED GeV-TeV LIGHT CURVES OF THE BLAZAR Mrk 501

    SciTech Connect

    Takahashi, Keitaro [Graduate School of Science and Technology, Kumamoto University, 2-39-1 Kurokami, Kumamoto 860-8555 (Japan); Mori, Masaki [Department of Physical Sciences, Ritsumeikan University, 1-1-1 Noji Higashi, Kusatsu, Shiga 525-8577 (Japan); Ichiki, Kiyotomo [Department of Physics and Astrophysics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan); Inoue, Susumu, E-mail: keitaro@sci.kumamoto-u.ac.jp [Institute for Cosmic Ray Research, University of Tokyo, 5-1-5 Kashiwa-no-Ha, Kashiwa, Chiba 277-8582 (Japan)

    2012-01-15

    We derive lower bounds on intergalactic magnetic fields (IGMFs) from upper limits on the pair echo emission from the blazar Mrk 501, that is, delayed GeV emission from secondary e{sup -}e{sup +} pairs produced via interactions of primary TeV gamma rays with the cosmic infrared background. Utilizing only simultaneous GeV-TeV light curves observed by VERITAS, MAGIC, and the Fermi Large Area Telescope during a multiwavelength campaign in 2009 that included a TeV flare, bounds are deduced on the IGMF strength of B {approx}> 10{sup -20} G at the 90% confidence level for a field coherence length of 1 kpc. Since our analysis is based firmly on the observational data alone and is nearly free of assumptions concerning the primary TeV flux in unobserved periods or spectral bands, our evaluation of the pair echo flux is conservative and the evidence for a non-zero IGMF is more robust compared to previous studies.

  8. Space Weather

    E-print Network

    Shepherd, Simon

    Space Weather :: Printer Friendly Version of Article 2005SW000176 http://www.agu.org/journals/sw/swa/feature/article/print.php?id=2005S... 1 of 5 07/07/2006 12:22 PM Shielding Space Explorers From Cosmic Rays Expert opinions-inducing radiation in space. Eugene N. Parker 18 August 2005 Any space traveler far removed from the protective

  9. Space Power

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Appropriate directions for the applied research and technology programs that will develop space power systems for U.S. future space missions beyond 1995 are explored. Spacecraft power supplies; space stations, space power reactors, solar arrays, thermoelectric generators, energy storage, and communication satellites are among the topics discussed.

  10. Space colonization.

    PubMed

    2002-12-01

    NASA interest in colonization encompasses space tourism; space exploration; space bases in orbit, at L1, on the Moon, or on Mars; in-situ resource utilization; and planetary terraforming. Activities progressed during 2002 in areas such as Mars colonies, hoppers, and biomass; space elevators and construction; and in-situ consumables. PMID:12506926

  11. Themed Space

    ERIC Educational Resources Information Center

    Lynch, Christopher O.

    2010-01-01

    This article presents a classroom activity that introduces students to the concept of themed space. Students learn to think critically about the spaces they encounter on a regular basis by analyzing existing spaces and by working in groups to create their own themed space. This exercise gives students the chance to see the relevance of critical…

  12. Space Day

    NSDL National Science Digital Library

    Space Day '98, to be held on May 21, 1998, celebrates and honors the people who have made space exploration possible. The highlight of the Space Day homepage, maintained by Lockheed Martin Corporation, will be a live interactive webcast all day on May 21. Features of the webcast include experts in the fields of space discussing issues ranging from global collaboration to mysteries that remain. In addition to the webcast, the Space Day '98 home page provides resources for teachers and the curious alike. Mission: Fun allows visitors to test their space knowledge through interactive Shockwave games and quizzes while Teachers' Space provides educators with downloadable lesson plans (Adobe Acrobat [.pdf] format).

  13. Space Missions

    NSDL National Science Digital Library

    Randy Russell

    2004-05-10

    With three levels to choose from on each page - beginner, intermediate or advanced - this site provides in formation on past and current exploration ideas and achievements. The advances science has made in the space exploration area, such as having a permanent space station in space and the hundreds of probes, satellite, and space shuttles that have been launched. Advanced telescopes have given scientists the opportunity to see far beyond we ever imagined, and new explorations are found every day. Also featured are details about the International space station and what kinds of experiments scientists do in outer space.

  14. Innovation Spaces

    E-print Network

    Schneider-Sikorsky, Patrick A

    2014-01-01

    Innovation ecosystems today are the lifeblood or the great hope of many major economies, but at the heart of these ecosystems, there are places and spaces. Silicon Valley is not just a place, but a cluster of spaces where ...

  15. Space basic

    NASA Astrophysics Data System (ADS)

    Herbert, Dexter

    1991-01-01

    In this education video series, 'Liftoff to Learning', astronauts (Bruce Melnick, Thomas Akers, William Shepherd, Robert Cabana, and Richard Richards) describe the historical beginnings of space exploration from the time of Robert H. Goddard (considered the Father of Rocketry), who, in 1929, invented the first propellant rocket, the prototype of modern liquid propellant rockets, up to the modern Space Shuttles. The questions - where is space, what is space, and how do astronauts get to, stay in, and come back from space are answered through historical footage, computer graphics, and animation. The space environment effects, temperature effects, and gravitational effects on the launching, orbiting, and descent of the Shuttles are discussed. Included is historical still photos and film footage of past space programs and space vehicles.

  16. Space Basics

    NASA Technical Reports Server (NTRS)

    Herbert, Dexter (editor)

    1991-01-01

    In this education video series, 'Liftoff to Learning', astronauts (Bruce Melnick, Thomas Akers, William Shepherd, Robert Cabana, and Richard Richards) describe the historical beginnings of space exploration from the time of Robert H. Goddard (considered the Father of Rocketry), who, in 1929, invented the first propellant rocket, the prototype of modern liquid propellant rockets, up to the modern Space Shuttles. The questions - where is space, what is space, and how do astronauts get to, stay in, and come back from space are answered through historical footage, computer graphics, and animation. The space environment effects, temperature effects, and gravitational effects on the launching, orbiting, and descent of the Shuttles are discussed. Included is historical still photos and film footage of past space programs and space vehicles.

  17. Star Formation and the Interstellar Medium in Nearby Tidal Streams (SAINTS): Spitzer Mid-infrared spectroscopy and Imaging of Intergalactic Star-forming Objects

    NASA Astrophysics Data System (ADS)

    Higdon, S. J. U.; Higdon, J. L.; Smith, B. J.; Hancock, M.

    2014-06-01

    A spectroscopic analysis of 10 intergalactic star-forming objects (ISFOs) and a photometric analysis of 67 ISFOs in a sample of 14 interacting systems is presented. The majority of the ISFOs have relative polycyclic aromatic hydrocarbon (PAH) band strengths similar to those of nearby spiral and starburst galaxies. In contrast to what is observed in blue compact dwarfs (BCDs) and local giant H II regions in the Milky Way (NGC 3603) and the Magellanic Clouds (30 Doradus and N 66), the relative PAH band strengths in ISFOs correspond to models with a significant PAH ion fraction (<50%) and bright emission from large PAHs (~100 carbon atoms). The [Ne III]/[Ne II] and [S IV]/[S III] line flux ratios indicate moderate levels of excitation with an interstellar radiation field that is harder than the majority of the Spitzer Infrared Nearby Galaxies Survey and starburst galaxies, but softer than BCDs and local giant H II regions. The ISFO neon line flux ratios are consistent with a burst of star formation lsim6 million years ago. Most of the ISFOs have ~106 M ? of warm H2 with a likely origin in photo-dissociation regions (PDRs). Infrared Array Camera photometry shows the ISFOs to be bright at 8 ?m, with one-third having [4.5] - [8.0] > 3.7, i.e., enhanced non-stellar emission, most likely due to PAHs, relative to normal spirals, dwarf irregulars, and BCD galaxies. The relative strength of the 8 ?m emission compared to that at 3.6 ?m or 24 ?m separates ISFOs from dwarf galaxies in Spitzer two-color diagrams. The infrared power in two-thirds of the ISFOs is dominated by emission from grains in a diffuse interstellar medium. One in six ISFOs have significant emission from PDRs, contributing ~30%-60% of the total power. ISFOs are young knots of intense star formation.

  18. Probing intergalactic neutral hydrogen by the Lyman alpha red damping wing of gamma-ray burst 130606A afterglow spectrum at z = 5.913

    NASA Astrophysics Data System (ADS)

    Totani, Tomonori; Aoki, Kentaro; Hattori, Takashi; Kosugi, George; Niino, Yuu; Hashimoto, Tetsuya; Kawai, Nobuyuki; Ohta, Kouji; Sakamoto, Takanori; Yamada, Toru

    2014-06-01

    The unprecedentedly bright optical afterglow of GRB 130606A located by Swift at a redshift close to the reionization era (z = 5.913) provides a new opportunity to probe the ionization status of the intergalactic medium (IGM). Here we present an analysis of the red Ly? damping wing of the afterglow spectrum taken by Subaru/FOCAS during 10.4-13.2 hr after the burst. We find that the minimal model including only the baseline power-law and H I absorption in the host galaxy does not give a good fit, leaving residuals showing concave curvature in 8400-8900 Å with an amplitude of about 0.6% of the flux. Such a curvature in the short wavelength range cannot be explained either by extinction at the host with standard extinction curves, intrinsic curvature of afterglow spectra, or by the known systematic uncertainties in the observed spectrum. The red damping wing by intervening H I gas outside the host can reduce the residual by about 3 ? statistical significance. We find that a damped Ly? system is not favored as the origin of this intervening H I absorption, from the observed Ly? and metal absorption features. Therefore absorption by diffuse IGM remains as a plausible explanation. A fit by a simple uniform IGM model requires an H I neutral fraction of fH I ˜ 0.1-0.5 depending on the distance to the GRB host, implying high fH I IGM associated with the observed dark Gunn-Peterson (GP) troughs. This gives new evidence that the reionization is not yet complete at z = 6.

  19. The Santa Fe Light Cone Simulation Project. I. Confusion and the Warm-Hot Intergalactic Medium in Upcoming Sunyaev-Zel'dovich Effect Surveys

    NASA Astrophysics Data System (ADS)

    Hallman, Eric J.; O'Shea, Brian W.; Burns, Jack O.; Norman, Michael L.; Harkness, Robert; Wagner, Rick

    2007-12-01

    We present the first results from a new generation of simulated large sky coverage (~100 deg2) Sunyaev-Zel'dovich effect (SZE) cluster surveys using the cosmological adaptive mesh refinement N-body/hydro code Enzo. We have simulated a very large (5123 h-3 Mpc3) volume with unprecedented dynamic range. We have generated simulated light cones to match the resolution and sensitivity of current and future SZE instruments. Unlike many previous studies of this type, our simulation includes unbound gas, where an appreciable fraction of the baryons in the universe reside. We have found that cluster line-of-sight overlap may be a significant issue in upcoming single-dish SZE surveys. Smaller beam surveys (~1') have more than one massive cluster within a beam diameter 5%-10% of the time, and a larger beam experiment like Planck has multiple clusters per beam 60% of the time. We explore the contribution of unresolved halos and unbound gas to the SZE signature at the maximum decrement. We find that there is a contribution from gas outside clusters of ~16% per object, on average, for upcoming surveys. This adds both bias and scatter to the deduced value of the integrated SZE, increasing difficulty in accurately calibrating a cluster Y-M relationship. Finally, we find that in images where objects with M>5×1013 Msolar have had their SZE signatures removed, roughly a third of the total SZE flux remains. This gas exists at least partially in the warm-hot intergalactic medium (WHIM) and will possibly be detectable with the upcoming generation of SZE surveys.

  20. Stochastic Absorption of the Light of Background Sources due to Intergalactic Neutral Hydrogen I. Testing different line-number evolution models via the cosmic flux decrement

    E-print Network

    Thorsten Tepper-Garcia; Uta Fritze

    2007-11-09

    [Abridged] We test the accuracy of different models of the attenuation of light due to resonant scattering by intergalactic neutral hydrogen by comparing their predictions of the evolution of the mean cosmic flux decrement, D_A, to measurements of this quantity based on observations. To this end, we use data available in the literature and our own measurements of the cosmic flux decrement for 25 quasars in the redshift range 2.71 < z < 5.41 taken from the SDSS Data Release 5. In order to perform the measurements of D_A, we fit a power-law to the continuum redward of the Lya emission line, and extrapolate this fit to region blueward of it, where the flux is severely affected by absorption due to intervening HI absorbers. We compute, using numerical simulations, the redshift evolution of D_A accounting for the presence of Lya Forest absorbers and Lyman limit systems randomly distributed along the line-of-sight, and compute its intrinsic scatter at the 1-, 2-, and 3-sigma level due to fluctuations in the absorber properties (column density, Doppler parameter, redshift) along different lines-of-sight. The numerical simulations consist of Monte Carlo realizations of distributions of the absorber properties constrained from observations. The results from the models considered here confirm our theoretical expectation that the distribution of D_A at any given redshift be well described by a lognormal distribution function. This implies that the effective optical depth, usually defined as the negative logarithm of the average flux, 1 - D_A, is very accurately Gaussian distributed, in contrast to previous studies. This result is independent to the form of the input distribution functions, and rather insensitive to the presence of high-column density absorbers, such as the Lyman limit systems.

  1. The Fluctuating Intergalactic Radiation Field at Redshifts z = 2.3-2.9 from He II and H I Absorption towards HE 2347-4342

    E-print Network

    J. Michael Shull; Jason Tumlinson; Mark L. Giroux; Gerard A. Kriss; Dieter Reimers

    2003-09-23

    We provide an in-depth analysis of the He II and H I absorption in the intergalactic medium (IGM) at redshifts z = 2.3-2.9 toward HE 2347-4342, using spectra from the Far Ultraviolet Spectroscopic Explorer (FUSE) and the Ultraviolet-Visual Echelle Spectrograph (UVES) on the VLT telescope. Following up on our earlier study (Kriss et al. 2001, Science, 293, 1112), we focus here on two major topics: (1) small-scale variability (Delta z = 10^-3) in the ratio eta = N(He II)/N(H I); and (2) an observed correlation of high-eta absorbers (soft radiation fields) with voids in the (H I) Ly-alpha distribution. These effects may reflect fluctuations in the ionizing sources on scales of 1 Mpc, together with radiative transfer through a filamentary IGM whose opacity variations control the penetration of 1-5 ryd radiation over 30-40 Mpc distances. Owing to photon statistics and backgrounds, we can measure optical depths over the ranges 0.1 eta = 4 tau(HeII)/tau(HI) over the range 0.1 to 460. Values of eta = 20-200 are consistent with models of photoionization by quasars with observed spectral indices alpha_s = 0-3. Values of eta > 200 may require additional contributions from starburst galaxies, heavily filtered quasar radiation, or density variations. Regions with eta eta is higher in "void" regions, where H I is weak or undetected and 80% of the path length has eta > 100. These voids may be ionized by soft sources (dwarf starbursts) or by QSO radiation softened by escape from the AGN cores or transfer through the "cosmic web". The apparent differences in ionizing spectra may help to explain the 1.45 Gyr lag between the reionization epochs, z(HI) = 6.2 +/-0.2 and z(HeII) = 2.8 +/-0.2.

  2. Space Froggy

    NSDL National Science Digital Library

    2010-01-01

    Help Captain Space Froggy and his family escape from a top secret lab located on the Space Station "Fluffy" above the Earth. To escape they must first cross the busy docking ramp and then traverse deep space landing on one of the transporter pads.

  3. Multipurpose Spaces

    ERIC Educational Resources Information Center

    Gordon, Douglas

    2010-01-01

    The concept of multipurpose spaces in schools is certainly not new. Especially in elementary schools, the combination of cafeteria and auditorium (and sometimes indoor physical activity space as well) is a well-established approach to maximizing the use of school space and a school district's budget. Nonetheless, there continue to be refinements…

  4. Space Law

    NASA Astrophysics Data System (ADS)

    Hermida, Julian

    2006-01-01

    This chapter examines the salient characteristics of Space Law. It analyzes the origins and evolution of Space Law, its main international principles, and some current topics of interest to the scientific community: the delimitation of airspace and outer space, intellectual property, and criminal responsibility.

  5. Space Kimchi

    E-print Network

    Hacker, Randi; Oborny, Jaimie; Tsutsui, William

    2006-07-05

    Broadcast Transcript: In space, no one can hear you scream... but did you know that in space no one can detect your smell either? The smell-taste connection means that food in space is not only weightless but tasteless, too. What's a flavor...

  6. Space Update

    NSDL National Science Digital Library

    2006-01-01

    This DVD includes space science images, movies and activities aligned with national standards. Includes the following sections: Astronomy, Solar System, Sky Tonight, and Space Weather models, which run separately or as a linked system, plus Space Events. It is safe for unattended use and suitable for museums or school libraries. Images can be updated without need of an open web browser.

  7. Space Sciences

    NSDL National Science Digital Library

    Space Sciences contains information on the solar system, the Sun, Moon, and formation of the Earth as well as a wallpaper gallery of astronomical images. There are links to real-time astronomical data, a virtual tour of the International Space Station, star charts, the NASA space launch schedule, maps of the night sky, satellite data, an Earth and Moon viewer, and more.

  8. Space Survey

    NSDL National Science Digital Library

    2012-08-03

    This is a lesson about society and space exploration. Learners will survey the public about their different opinions about space exploration and the use of robotics in space exploration. Then they will represent and analyze the results. This is lesson 5 of 16 in the MarsBots learning module.

  9. A LYMAN BREAK GALAXY IN THE EPOCH OF REIONIZATION FROM HUBBLE SPACE TELESCOPE GRISM SPECTROSCOPY

    SciTech Connect

    Rhoads, James E.; Malhotra, Sangeeta; Cohen, Seth; Zheng Zhenya [School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States); Stern, Daniel [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Dickinson, Mark [National Optical Astronomy Observatory, Tucson, AZ (United States); Pirzkal, Norbert; Grogin, Norman; Koekemoer, Anton; Peth, Michael A. [Space Telescope Science Institute, Baltimore, MD (United States); Spinrad, Hyron [University of California, Berkeley, CA (United States); Reddy, Naveen [University of California, Riverside, CA (United States); Hathi, Nimish [Observatories of the Carnegie Institution of Washington, Pasadena, CA (United States); Budavari, Tamas [Johns Hopkins University, Baltimore, MD (United States); Ferreras, Ignacio [Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT (United Kingdom); Gardner, Jonathan P. [NASA Goddard Space Flight Center, Astrophysics Science Division, Observational Cosmology Laboratory, Code 665, Greenbelt, MD 20771 (United States); Gronwall, Caryl [Department of Astronomy and Astrophysics, and Institute for Gravitation and the Cosmos, The Pennsylvania State University, University Park, PA 16802 (United States); Haiman, Zoltan [Columbia University, New York, NY (United States); Kuemmel, Martin [Universitaets-Sternwarte Muenchen, Scheinerstr. 1, D-81679 Muenchen (Germany); Meurer, Gerhardt, E-mail: James.Rhoads@asu.edu [International Centre for Radio Astronomy Research, University of Western Australia, M468, 35 Stirling Highway, Crawley, WA 6009 (Australia); and others

    2013-08-10

    We present observations of a luminous galaxy at z = 6.573-the end of the reionization epoch-which has been spectroscopically confirmed twice. The first spectroscopic confirmation comes from slitless Hubble Space Telescope Advanced Camera for Surveys grism spectra from the PEARS survey (Probing Evolution And Reionization Spectroscopically), which show a dramatic continuum break in the spectrum at rest frame 1216 A. The second confirmation is done with Keck + DEIMOS. The continuum is not clearly detected with ground-based spectra, but high wavelength resolution enables the Ly{alpha} emission line profile to be determined. We compare the line profile to composite line profiles at z = 4.5. The Ly{alpha} line profile shows no signature of a damping wing attenuation, confirming that the intergalactic gas is ionized at z = 6.57. Spectra of Lyman breaks at yet higher redshifts will be possible using comparably deep observations with IR-sensitive grisms, even at redshifts where Ly{alpha} is too attenuated by the neutral intergalactic medium to be detectable using traditional spectroscopy from the ground.

  10. $?$--Rindler space

    E-print Network

    J. Kowalski-Glikman

    2009-07-18

    In this paper we construct, and investigate some thermal properties of, the non-commutative counterpart of Rindler space, which we call $\\kappa$--Rindler space. This space is obtained by changing variables in the defining commutators of $\\kappa$--Minkowski space. We then re-derive the commutator structure of $\\kappa$--Rindler space with the help of an appropriate star product, obtained from the $\\kappa$--Minkowski one. Using this star product, following the idea of Padmanabhan, we find the leading order, $1/\\kappa$ correction to the Hawking thermal spectrum.

  11. Space Commercialization

    NASA Technical Reports Server (NTRS)

    Martin, Gary L.

    2011-01-01

    A robust and competitive commercial space sector is vital to continued progress in space. The United States is committed to encouraging and facilitating the growth of a U.S. commercial space sector that supports U.S. needs, is globally competitive, and advances U.S. leadership in the generation of new markets and innovation-driven entrepreneurship. Energize competitive domestic industries to participate in global markets and advance the development of: satellite manufacturing; satellite-based services; space launch; terrestrial applications; and increased entrepreneurship. Purchase and use commercial space capabilities and services to the maximum practical extent Actively explore the use of inventive, nontraditional arrangements for acquiring commercial space goods and services to meet United States Government requirements, including measures such as public-private partnerships, . Refrain from conducting United States Government space activities that preclude, discourage, or compete with U.S. commercial space activities. Pursue potential opportunities for transferring routine, operational space functions to the commercial space sector where beneficial and cost-effective.

  12. Space law and space resources

    NASA Technical Reports Server (NTRS)

    Goldman, Nathan C.

    1992-01-01

    Space industrialization is confronting space law with problems that are changing old and shaping new legal principles. The return to the Moon, the next logical step beyond the space station, will establish a permanent human presence there. Science and engineering, manufacturing and mining will involve the astronauts in the settlement of the solar system. These pioneers, from many nations, will need a legal, political, and social framework to structure their lives and interactions. International and even domestic space law are only the beginning of this framework. Dispute resolution and simple experience will be needed in order to develop, over time, a new social system for the new regime of space.

  13. Space America's commercial space program

    NASA Technical Reports Server (NTRS)

    Macleod, N. H.

    1984-01-01

    Space America prepared a private sector land observing space system which includes a sensor system with eight spectral channels configured for stereoscopic data acquisition of four stereo pairs, a spacecraft bus with active three-axis stabilization, a ground station for data acquisition, preprocessing and retransmission. The land observing system is a component of Space America's end-to-end system for Earth resources management, monitoring and exploration. In the context of the Federal Government's program of commercialization of the US land remote sensing program, Space America's space system is characteristic of US industry's use of advanced technology and of commercial, entrepreneurial management. Well before the issuance of the Request for Proposals for Transfer of the United States Land Remote Sensing Program to the Private Sector by the US Department of Commerce, Space Services, Inc., the managing venturer of Space America, used private funds to develop and manage its sub-orbital launch of its Conestoga launch vehicle.

  14. Space Telescopes

    NASA Technical Reports Server (NTRS)

    Clampin, Mark; Flanagan, Kathryn A.

    2012-01-01

    Space telescopes have been a dominant force in astrophysics and astronomy over the last two decades. As Lyman Spitzer predicted in 1946, space telescopes have opened up much of the electromagnetic spectrum to astronomers, and provided the opportunity to exploit the optical performance of telescopes uncompromised by the turbulent atmosphere. This special section of Optical Engineering is devoted to space telescopes. It focuses on the design and implementation of major space observatories from the gamma-ray to far-infrared, and highlights the scientific and technical breakthroughs enabled by these telescopes. The papers accepted for publication include reviews of major space telescopes spanning the last two decades, in-depth discussions of the design considerations for visible and x-ray telescopes, and papers discussing concepts and technical challenges for future space telescopes.

  15. Spaced Out

    NSDL National Science Digital Library

    Integrated Teaching and Learning Program,

    Students are introduced to the space environment, learning about the major differences between the environment on Earth and that of outer space (atmosphere, radiation, microgravity) — and the engineering challenges that arise because of these differences. To prepare students for the upcoming lessons on the human body, they are challenged to think about how their bodies would change and adapt in the unique environment of space.

  16. Probability Spaces

    NSDL National Science Digital Library

    Siegrist, Kyle

    Created by Kyle Siegrist of the University of Alabama-Huntsville, this is an online, interactive lesson on probability spaces. The resource provides examples, exercises, and applets that cover conditional probability, independence, and several modes of convergence that are appropriate for random variables. This section also covers probability space, the paradigm of a random experiment and its mathematical model as well as sample spaces, events, random variables, and probability measures. This is the second of seventeen different statistics lessons provided by Siegrist.

  17. Space suit

    NASA Technical Reports Server (NTRS)

    Shepard, L. F.; Durney, G. P.; Case, M. C.; Kenneway, A. J., III; Wise, R. C.; Rinehart, D.; Bessette, R. J.; Pulling, R. C. (inventors)

    1973-01-01

    A pressure suit for high altitude flights, particularly space missions is reported. The suit is designed for astronauts in the Apollo space program and may be worn both inside and outside a space vehicle, as well as on the lunar surface. It comprises an integrated assembly of inner comfort liner, intermediate pressure garment, and outer thermal protective garment with removable helmet, and gloves. The pressure garment comprises an inner convoluted sealing bladder and outer fabric restraint to which are attached a plurality of cable restraint assemblies. It provides versitility in combination with improved sealing and increased mobility for internal pressures suitable for life support in the near vacuum of outer space.

  18. CHANDRA VIEW OF THE WARM-HOT INTERGALACTIC MEDIUM TOWARD 1ES 1553+113: ABSORPTION-LINE DETECTIONS AND IDENTIFICATIONS. I

    SciTech Connect

    Nicastro, F.; Zappacosta, L. [Osservatorio Astronomico di Roma-INAF, Via di Frascati 33, I-00040 Monte Porzio Catone, RM (Italy); Elvis, M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., MS-04, Cambridge, MA 02138 (United States); Krongold, Y. [Instituto de Astronomia, Universidad Nacional Autonoma de Mexico, Mexico City Mexico (Mexico); Mathur, S.; Gupta, A. [Ohio State University, Columbus, OH (United States); Danforth, C.; Shull, J. M. [CASA, Department of Astrophysical and Planetary Sciences, University of Colorado, 389-UCB, Boulder, CO 80309 (United States); Barcons, X. [Instituto de Fisica de Cantabria (CSIC-UC), E-39005 Santander (Spain); Borgani, S. [Dipartimento di Astronomia dell'Universita di Trieste, Via G.B. Tiepolo 11, I-34131 Trieste (Italy); Branchini, E. [Dipartimento di Fisica ''E. Amaldi'', Universita degli Studi ''Roma Tre'', via della Vasca Navale 84, I-00146 Roma (Italy); Cen, R. [Princeton University Observatory, Princeton, NJ 08544 (United States); Dave, R. [Astronomy Department, University of Arizona, Tucson, AZ 85721 (United States); Kaastra, J. [SRON Netherlands Institute for Space Research, Sorbonnelaan 2, 3584 CA, Utrecht (Netherlands); Paerels, F. [Columbia Astrophysics Laboratory and Department of Astronomy, Columbia University, 550 West 120th Street, New York, NY 10027 (United States); Piro, L. [INAF-IAPS, Via del Fosso del Cavaliere 100, I-00133 Roma (Italy); Takei, Y. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara, Kanagawa 252-5210 (Japan)

    2013-06-01

    We present the first results from our pilot 500 ks Chandra Low Energy Transmission Grating Large Program observation of the soft X-ray brightest source in the z {approx}> 0.4 sky, the blazar 1ES 1553+113, aimed to secure the first uncontroversial detections of the missing baryons in the X-rays. We identify a total of 11 possible absorption lines, with single-line statistical significances between 2.2{sigma} and 4.1{sigma}. Six of these lines are detected at high single-line statistical significance (3.6 {<=} {sigma} {<=} 4.1), while the remaining five are regarded as marginal detections in association with either other X-ray lines detected at higher significance and/or far-ultraviolet (FUV) signposts. Three of these lines are consistent with metal absorption at z {approx_equal} 0, and we identify them with Galactic O I and C II. The remaining eight lines may be imprinted by intervening absorbers and are all consistent with being high-ionization counterparts of FUV H I and/or O VI intergalactic medium signposts. In particular, five of these eight possible intervening absorption lines (single-line statistical significances of 4.1{sigma}, 4.1{sigma}, 3.9{sigma}, 3.8{sigma}, and 2.7{sigma}), are identified as C V and C VI K{alpha} absorbers belonging to three WHIM systems at z{sub X} = 0.312, z{sub X} = 0.237, and (z{sub X} ) = 0.133, which also produce broad H I (and O VI for the z{sub X} = 0.312 system) absorption in the FUV. For two of these systems (z{sub X} = 0.312 and 0.237), the Chandra X-ray data led the a posteriori discovery of physically consistent broad H I associations in the FUV (for the third system the opposite applies), so confirming the power of the X-ray-FUV synergy for WHIM studies. The true statistical significances of these three X-ray absorption systems, after properly accounting for the number of redshift trials, are 5.8{sigma} (z{sub X} = 0.312; 6.3{sigma} if the low-significance O V and C V K{beta} associations are considered), 3.9{sigma} (z{sub X} = 0.237), and 3.8{sigma} ((z{sub X} ) = 0.133), respectively.

  19. Intergalactic Medium Emission Observations with the Cosmic Web Imager. II. Discovery of Extended, Kinematically Linked Emission around SSA22 Ly? Blob 2

    NASA Astrophysics Data System (ADS)

    Martin, D. Christopher; Chang, Daphne; Matuszewski, Matt; Morrissey, Patrick; Rahman, Shahin; Moore, Anna; Steidel, Charles C.; Matsuda, Yuichi

    2014-05-01

    The intergalactic medium (IGM) is the dominant reservoir of baryons, delineates the large-scale structure of the universe at low to moderate overdensities, and provides gas from which galaxies form and evolve. Simulations of a cold-dark-matter- (CDM-) dominated universe predict that the IGM is distributed in a cosmic web of filaments and that galaxies should form along and at the intersections of these filaments. While observations of QSO absorption lines and the large-scale distribution of galaxies have confirmed the CDM paradigm, the cosmic web of IGM has never been confirmed by direct imaging. Here we report our observation of the Ly? blob 2 (LAB2) in SSA22 with the Cosmic Web Imager (CWI). This is an integral field spectrograph optimized for low surface brightness, extended emission. With 22 hr of total on- and off-source exposure, CWI has revealed that LAB2 has extended Ly? emission that is organized into azimuthal zones consistent with filaments. We perform numerous tests with simulations and the data to secure the robustness of this result, which relies on data with modest signal-to-noise ratios. We have developed a smoothing algorithm that permits visualization of data cube slices along image or spectral image planes. With both raw and smoothed data cubes we demonstrate that the filaments are kinematically associated with LAB2 and display double-peaked profiles characteristic of optically thick Ly? emission. The flux is 10-20 times brighter than expected for the average emission from the IGM but is consistent with boosted fluorescence from a buried QSO or gravitation cooling radiation. Using simple emission models, we infer a baryon mass in the filaments of at least 1-4 × 1011 M ?, and the dark halo mass is at least 2 × 1012 M ?. The spatial-kinematic morphology is more consistent with inflow from the cosmic web than outflow from LAB2, although an outflow feature maybe present at one azimuth. LAB2 and the surrounding gas have significant and coaligned angular momentum, strengthening the case for their association.

  20. Amazing Space

    NSDL National Science Digital Library

    This website is part of the Space Telescope Science Institute, and contains a set of interactive, web-based activities and lessons designed for classroom use. Topics include the Hubble Space Telescope, galaxies, comets, black holes, light, and the solar system.

  1. Space Microbiology

    PubMed Central

    Horneck, Gerda; Klaus, David M.; Mancinelli, Rocco L.

    2010-01-01

    Summary: The responses of microorganisms (viruses, bacterial cells, bacterial and fungal spores, and lichens) to selected factors of space (microgravity, galactic cosmic radiation, solar UV radiation, and space vacuum) were determined in space and laboratory simulation experiments. In general, microorganisms tend to thrive in the space flight environment in terms of enhanced growth parameters and a demonstrated ability to proliferate in the presence of normally inhibitory levels of antibiotics. The mechanisms responsible for the observed biological responses, however, are not yet fully understood. A hypothesized interaction of microgravity with radiation-induced DNA repair processes was experimentally refuted. The survival of microorganisms in outer space was investigated to tackle questions on the upper boundary of the biosphere and on the likelihood of interplanetary transport of microorganisms. It was found that extraterrestrial solar UV radiation was the most deleterious factor of space. Among all organisms tested, only lichens (Rhizocarpon geographicum and Xanthoria elegans) maintained full viability after 2 weeks in outer space, whereas all other test systems were inactivated by orders of magnitude. Using optical filters and spores of Bacillus subtilis as a biological UV dosimeter, it was found that the current ozone layer reduces the biological effectiveness of solar UV by 3 orders of magnitude. If shielded against solar UV, spores of B. subtilis were capable of surviving in space for up to 6 years, especially if embedded in clay or meteorite powder (artificial meteorites). The data support the likelihood of interplanetary transfer of microorganisms within meteorites, the so-called lithopanspermia hypothesis. PMID:20197502

  2. Space microbiology.

    PubMed

    Horneck, Gerda; Klaus, David M; Mancinelli, Rocco L

    2010-03-01

    The responses of microorganisms (viruses, bacterial cells, bacterial and fungal spores, and lichens) to selected factors of space (microgravity, galactic cosmic radiation, solar UV radiation, and space vacuum) were determined in space and laboratory simulation experiments. In general, microorganisms tend to thrive in the space flight environment in terms of enhanced growth parameters and a demonstrated ability to proliferate in the presence of normally inhibitory levels of antibiotics. The mechanisms responsible for the observed biological responses, however, are not yet fully understood. A hypothesized interaction of microgravity with radiation-induced DNA repair processes was experimentally refuted. The survival of microorganisms in outer space was investigated to tackle questions on the upper boundary of the biosphere and on the likelihood of interplanetary transport of microorganisms. It was found that extraterrestrial solar UV radiation was the most deleterious factor of space. Among all organisms tested, only lichens (Rhizocarpon geographicum and Xanthoria elegans) maintained full viability after 2 weeks in outer space, whereas all other test systems were inactivated by orders of magnitude. Using optical filters and spores of Bacillus subtilis as a biological UV dosimeter, it was found that the current ozone layer reduces the biological effectiveness of solar UV by 3 orders of magnitude. If shielded against solar UV, spores of B. subtilis were capable of surviving in space for up to 6 years, especially if embedded in clay or meteorite powder (artificial meteorites). The data support the likelihood of interplanetary transfer of microorganisms within meteorites, the so-called lithopanspermia hypothesis. PMID:20197502

  3. Collaborative Spaces

    ERIC Educational Resources Information Center

    Lippman, Peter C.

    2013-01-01

    When architects discuss the educational facilities of the next century and beyond, the conversation turns to collaborative spaces. They envision flexible and fluid spaces that will encourage creative and critical thinking, and free students to communicate clearly about the task at hand. While these are admirable ideals, there are some fundamental…

  4. Space psychology

    NASA Technical Reports Server (NTRS)

    Parin, V. V.; Gorbov, F. D.; Kosmolinskiy, F. P.

    1974-01-01

    Psychological selection of astronauts considers mental responses and adaptation to the following space flight stress factors: (1) confinement in a small space; (2) changes in three dimensional orientation; (3) effects of altered gravity and weightlessness; (4) decrease in afferent nerve pulses; (5) a sensation of novelty and danger; and (6) a sense of separation from earth.

  5. Space Weather

    NSDL National Science Digital Library

    2004-02-06

    With three levels to choose from on each page - beginner, intermediate or advanced - this site provides information on Space Weather and the terms scientists use to describe the everchanging conditions in space. Explosions on the Sun create storms of radiation, fluctuating magnetic fields, and swarms of energetic particles. These phenomena travel outward through the Solar System with the solar wind. Upon arrival at Earth, they interact in complex ways with Earth's magnetic field, creating Earth's radiation belts and the Aurora. Some space weather storms can damage satellites, disable electric power grids, and disrupt cell phone communications systems. This site provides images, activities, and interesting facts about all of these events.

  6. Space Shuttle

    NASA Technical Reports Server (NTRS)

    1975-01-01

    A general description of the space shuttle program is presented, with emphasis on its application to the use of space for commercial, scientific, and defense needs. The following aspects of the program are discussed: description of the flight system (orbiter, external tank, solid rocket boosters) and mission profile, direct benefits related to life on earth (both present and expected), description of the space shuttle vehicle and its associated supporting systems, economic impacts (including indirect benefits such as lower inflation rates), listing of participating organizations.

  7. Built space

    E-print Network

    Dyer, Daniel Joseph

    1984-01-01

    This thesis explores the spatial qualities of built environments through observation and design. Recognition that we move through our environment should be reflected in the space we design. Where applicable, a series of ...

  8. Space Camera

    NASA Technical Reports Server (NTRS)

    1983-01-01

    Nikon's F3 35mm camera was specially modified for use by Space Shuttle astronauts. The modification work produced a spinoff lubricant. Because lubricants in space have a tendency to migrate within the camera, Nikon conducted extensive development to produce nonmigratory lubricants; variations of these lubricants are used in the commercial F3, giving it better performance than conventional lubricants. Another spinoff is the coreless motor which allows the F3 to shoot 140 rolls of film on one set of batteries.

  9. Space education

    NASA Astrophysics Data System (ADS)

    Abiodun, Adigun Ade

    An essential pre-requisite to a successful space technology applications programme is the building of various indigenous capacities, particularly human resources. Efforts to accomplish such a capacity-building must be devoted, at the local level, to the development of necessary high-level knowledge and expertise in space science and technology fields. Such a programme must also focus on long-term in-depth education and research opportunities in the developing countries, where the beneficiaries would gain an in-depth understanding and appreciation of not only the application potentials of a given technology but also an insight into why and how the technology works the way it does. In recognition of such a pre-requisite, it is universally acknowledged that if effective assimilation of space science and appropriate application of space technology are to succeed in the developing countries, and particularly if such a discipline as satellite remote sensing is to transcend its current image of being a technology-driven tool into a user-driven one, efforts must be devoted, at the local level, to the development of necessary high-level knowledge and expertise in requisite space science and technology fields. The justification for such an in-depth education is not far-fetched particularly as one reflects on the myriad of space science and technology activities that are both in progress and are planned. Aspects of these are reflected in this paper.

  10. Space Resources

    NASA Technical Reports Server (NTRS)

    McKay, Mary Fae (Editor); McKay, David S. (Editor); Duke, Michael S. (Editor)

    1992-01-01

    Space resources must be used to support life on the Moon and exploration of Mars. Just as the pioneers applied the tools they brought with them to resources they found along the way rather than trying to haul all their needs over a long supply line, so too must space travelers apply their high technology tools to local resources. The pioneers refilled their water barrels at each river they forded; moonbase inhabitants may use chemical reactors to combine hydrogen brought from Earth with oxygen found in lunar soil to make their water. The pioneers sought temporary shelter under trees or in the lee of a cliff and built sod houses as their first homes on the new land; settlers of the Moon may seek out lava tubes for their shelter or cover space station modules with lunar regolith for radiation protection. The pioneers moved further west from their first settlements, using wagons they had built from local wood and pack animals they had raised; space explorers may use propellant made at a lunar base to take them on to Mars. The concept for this report was developed at a NASA-sponsored summer study in 1984. The program was held on the Scripps campus of the University of California at San Diego (UCSD), under the auspices of the American Society for Engineering Education (ASEE). It was jointly managed under the California Space Inst. and the NASA Johnson Space Center, under the direction of the Office of Aeronautics and Space Technology (OAST) at NASA Headquarters. The study participants (listed in the addendum) included a group of 18 university teachers and researchers (faculty fellows) who were present for the entire 10-week period and a larger group of attendees from universities, Government, and industry who came for a series of four 1-week workshops. The organization of this report follows that of the summer study. Space Resources consists of a brief overview and four detailed technical volumes: (1) Scenarios; (2) Energy, Power, and Transport; (3) Materials; (4) Social Concerns. Although many of the included papers got their impetus from workshop discussions, most have been written since then, thus allowing the authors to base new applications on established information and tested technology. All these papers have been updated to include the authors' current work. This overview, drafted by faculty fellow Jim Burke, describes the findings of the summer study, as participants explored the use of space resources in the development of future space activities and defined the necessary research and development that must precede the practical utilization of these resources. Space resources considered included lunar soil, oxygen derived from lunar soil, material retrieved from near-Earth asteroids, abundant sunlight, low gravity, and high vacuum. The study participants analyzed the direct use of these resources, the potential demand for products from them, the techniques for retrieving and processing space resources, the necessary infrastructure, and the economic tradeoffs. This is certainly not the first report to urge the utilization of space resources in the development of space activities. In fact, Space Resources may be seen as the third of a trilogy of NASA Special Publications reporting such ideas arising from similar studies. It has been preceded by Space Settlements: A Design Study (NASA SP-413) and Space Resources and Space Settlements (NASA SP-428). And other, contemporaneous reports have responded to the same themes. The National Commission on Space, led by Thomas Paine, in Pioneering the Space Frontier, and the NASA task force led by astronaut Sally Ride, in Leadership and America's Future in Space, also emphasize expansion of the space Infrastructure; more detailed exploration of the Moon, Mars, and asteroids; an early start on the development of the technology necessary for using space resources; and systematic development of the skills necessary for long-term human presence in space. Our report does not represent any Government-authorized view or official NASA policy. NASA's official response to these challenging op

  11. Space Rescue

    NASA Technical Reports Server (NTRS)

    Muratore, John F.

    2007-01-01

    Space Rescue has been a topic of speculation for a wide community of people for decades. Astronauts, aerospace engineers, diplomats, medical and rescue professionals, inventors and science fiction writers have all speculated on this problem. Martin Caidin's 1964 novel Marooned dealt with the problems of rescuing a crew stranded in low earth orbit. Legend at the Johnson Space Center says that Caidin's portrayal of a Russian attempt to save the American crew played a pivotal role in convincing the Russians to join the real joint Apollo-Soyuz mission. Space Rescue has been a staple in science fiction television and movies portrayed in programs such as Star Trek, Stargate-SG1 and Space 1999 and movies such as Mission To Mars and Red Planet. As dramatic and as difficult as rescue appears in fictional accounts, in the real world it has even greater drama and greater difficulty. Space rescue is still in its infancy as a discipline and the purpose of this chapter is to describe the issues associated with space rescue and the work done so far in this field. For the purposes of this chapter, the term space rescue will refer to any system which allows for rescue or escape of personnel from situations which endanger human life in a spaceflight operation. This will span the period from crew ingress prior to flight through crew egress postlanding. For the purposes of this chapter, the term primary system will refer to the spacecraft system that a crew is either attempting to escape from or from which an attempt is being made to rescue the crew.

  12. Space.com - Space TV

    NSDL National Science Digital Library

    At this site, users can view and download videos on a variety of space-related topics including exploration, astronomy, the Earth, historic moments in exploration, and the search for extraterrestrial life.

  13. Space Resources and Space Settlements

    NASA Technical Reports Server (NTRS)

    Billingham, J. (editor); Gilbreath, W. P. (editor); Oleary, B. (editor); Gosset, B. (editor)

    1979-01-01

    The technical papers from the five tasks groups that took part in the 1977 Ames Summer Study on Space Settlements and Industrialization Using Nonterrestrial Materials are presented. The papers are presented under the following general topics: (1) research needs for regenerative life-support systems; (2) habitat design; (3) dynamics and design of electromagnetic mass drivers; (4) asteroids as resources for space manufacturing; and (5) processing of nonterrestrial materials.

  14. Space Alive

    NASA Astrophysics Data System (ADS)

    Boucher, M.-P.

    2014-04-01

    This paper looks at earthly architectural applications of scientific research on space orientation in reduced gravity conditions. It asks how unprecedented forms of perception experienced in reduced gravity conditions give rise to unconventional modes of living. Looking at different technical lineages for achieving weightlessness: on the one hand, outer space exploration and its habitats, and on the other, technologies of suspension associated with experimental architecture, it questions the pragmatics of exchangeability between art and science. Instead of insisting on systems of valuation, that is, instead of opposing the functionality of outer space habitats with the aesthetic of experimental architecture, both practices will be approached in their own terms and on their terrain, that is, in the pragmatics of their effectiveness.

  15. An Empirical Determination of the Intergalactic Background Light Using Near-Infrared Deep Galaxy Survey Data Out to 5 Micrometers and the Gamma-Ray Opacity of the Universe

    NASA Technical Reports Server (NTRS)

    Scully, Sean T.; Malkan, Matthew A.; Stecker, Floyd W.

    2014-01-01

    We extend our previous model-independent determination of the intergalactic background light, based purely on galaxy survey data, out to a wavelength of 5 micrometers. Our approach enables us to constrain the range of photon densities, based on the uncertainties from observationally determined luminosity densities and colors. We further determine a 68% confidence upper and lower limit on the opacity of the universe to gamma-rays up to energies of 1.6/(1 + z) terraelectron volts. A comparison of our lower limit redshift-dependent opacity curves to the opacity limits derived from the results of both ground-based air Cerenkov telescope and Fermi-LAT observations of PKS 1424+240 allows us to place a new upper limit on the redshift of this source, independent of IBL modeling.

  16. An Empirical Determination of the Intergalactic Background Light Using Near-infrared Deep Galaxy Survey Data out to 5 ?m and the Gamma-Ray Opacity of the Universe

    NASA Astrophysics Data System (ADS)

    Scully, Sean T.; Malkan, Matthew A.; Stecker, Floyd W.

    2014-04-01

    We extend our previous model-independent determination of the intergalactic background light, based purely on galaxy survey data, out to a wavelength of 5 ?m. Our approach enables us to constrain the range of photon densities, based on the uncertainties from observationally determined luminosity densities and colors. We further determine a 68% confidence upper and lower limit on the opacity of the universe to ?-rays up to energies of 1.6/(1 + z) TeV. A comparison of our lower limit redshift-dependent opacity curves to the opacity limits derived from the results of both ground-based air Cerenkov telescope and Fermi-LAT observations of PKS 1424+240 allows us to place a new upper limit on the redshift of this source, independent of IBL modeling.

  17. Second Symposium on Space Industrialization. [space commercialization

    NASA Technical Reports Server (NTRS)

    Jernigan, C. M. (editor)

    1984-01-01

    The policy, legal, and economic aspects of space industrialization are considered along with satellite communications, material processing, remote sensing, and the role of space carriers and a space station in space industrialization.

  18. Appealing Spaces

    ERIC Educational Resources Information Center

    Dittoe, William; Porter, Nat

    2007-01-01

    For more than a decade, educators and designers have been moving tentatively into uncharted waters. This article reports that administrators, faculty, and planners now recognize that learning spaces should be developed for reasons beyond utilization numbers. With declining retention and graduation rates, education institutions are acknowledging…

  19. Space Gerontology

    NASA Technical Reports Server (NTRS)

    Miquel, J. (editor); Economos, A. C. (editor)

    1982-01-01

    Presentations are given which address the effects of space flght on the older person, the parallels between the physiological responses to weightlessness and the aging process, and experimental possibilities afforded by the weightless environment to fundamental research in gerontology and geriatrics.

  20. Space languages

    NASA Technical Reports Server (NTRS)

    Hays, Dan

    1987-01-01

    Applications of linguistic principles to potential problems of human and machine communication in space settings are discussed. Variations in language among speakers of different backgrounds and change in language forms resulting from new experiences or reduced contact with other groups need to be considered in the design of intelligent machine systems.

  1. Space Weather

    E-print Network

    Shepherd, Simon

    .org/journals/sw/swa/editorial/article/print.php?id=200... 1 of 1 07/06/2006 04:00 PM Active Radiation Shielding in Space? Louis J. Lanzerotti 2 October electrostatic shielding. Professor Eugene Parker of the University of Chicago presented an interesting analysis at the workshop. Professor Parker's conclusions may likely be valid, but continued clever thinking about difficult

  2. Training Spaces

    ERIC Educational Resources Information Center

    Weinstein, Margery

    2010-01-01

    Creating a balanced learning space for employees is about more than trying different types of seating. It is a challenge that an affect how well employees absorb the lessons and whether they will be able to product better results for the company. The possible solutions are as diverse as the learners. This article describes how three companies…

  3. Trading Spaces

    ERIC Educational Resources Information Center

    Cort, Cliff

    2006-01-01

    Education administrators face the dual dilemma of crowded, aging facilities and tightening capital budgets. The challenge is to build the necessary classroom, laboratory and activity space while minimizing the length and expense of the construction process. One solution that offers an affordable alternative is modular construction, a method that…

  4. Friendly Spaces.

    ERIC Educational Resources Information Center

    D'Elia, William

    1996-01-01

    The creation of usable space for gatherings and socializing is an important consideration in any campus planning program. The University of California-San Diego has a large outdoor assembly area. An addition at Cal Poly-San Luis Obispo encompasses an existing pedestrian path. A new building at the University of Alaska, Fairbanks, is designed as a…

  5. Inherit Space

    NASA Technical Reports Server (NTRS)

    Giarratano, Joseph C.; Jenks, K. C.

    1997-01-01

    The objective of the proposed research was to begin development of a unique educational tool targeted at educating and inspiring young people 12-16 years old about NASA and the Space Program. Since these young people are the future engineers, scientists and space pioneers, the nurturing of their enthusiasm and interest is of critical importance to the Nation. This summer the basic infrastructure of the tool was developed in the context of an educational game paradigm. The game paradigm has achieved remarkable success in maintaining the interest of young people in a self-paced, student-directed learning environment. This type of environment encourages student exploration and curiosity which are exactly the traits that future space pioneers need to develop to prepare for the unexpected. The Inherit Space Educational Tool is an open-ended learning environment consisting of a finite-state machine classic adventure game paradigm. As the young person explores this world, different obstacles must be overcome. Rewards will be offered such as using the flight simulator to fly around and explore Titan. This simulator was modeled on conventional Earth flight simulators but has been considerably enhanced to add texture mapping of Titan's atmosphere utilizing the latest information from the NASA Galileo Space Probe. Additional scenery was added to provide color VGA graphics of a futuristic research station on Titan as well as an interesting story to keep the youngster's attention. This summer the game infrastructure has been developed as well as the Titan Flight Simulator. A number of other enhancements are planned.

  6. Space Physics Beyond Space Weather

    NASA Astrophysics Data System (ADS)

    Pulkkinen, T. I.

    2002-12-01

    Dictated by nature, space physics throughout its history has advanced through large observational programs: The International Geophysical Year in 1957-1958 produced the first series of simultaneous auroral pictures from multiple stations. These images led to the definition of the "auroral substorm" and its connection to "the magnetosphericsubstorm". During the International Magnetospheric Study 1976-1979 coordinated space-borne and ground-based measurements guided the way to the conclusion that magnetospheric substorms were powered by magnetic reconnection. Recently, the International Solar Terrestrial Physics Program has completed our picture of the large-scale energy flow from the Sun through the solar wind into the magnetosphere and ionosphere. From the early space age, two still open key questions have been the physics of magnetic reconnection in the fully collisionless plasma environment and the physics of (relativistic) particle acceleration in the magnetosphere. This talk aims at learning from the advances made by the earlier programs, outlining some of the still open issues, and suggesting ways how to entangle them through strong coupling of theory, numerical simulation, ground-based and space-borne observations as well as enhanced collaboration between neighboring fields.

  7. Space Toxicology

    NASA Technical Reports Server (NTRS)

    James, John T.

    2011-01-01

    Safe breathing air for space faring crews is essential whether they are inside an Extravehicular Mobility Suit (EMU), a small capsule such as Soyuz, or the expansive International Space Station (ISS). Sources of air pollution can include entry of propellants, excess offgassing from polymeric materials, leakage of systems compounds, escape of payload compounds, over-use of utility compounds, microbial metabolism, and human metabolism. The toxicological risk posed by a compound is comprised of the probability of escaping to cause air pollution and the magnitude of adverse effects on human health if escape occurs. The risk from highly toxic compounds is controlled by requiring multiple levels of containment to greatly reduce the probability of escape; whereas compounds that are virtually non-toxic may require little or no containment. The potential for toxicity is determined by the inherent toxicity of the compound and the amount that could potentially escape into the breathing air.

  8. America plans for space

    SciTech Connect

    Not Available

    1986-01-01

    Contents include: pursuing a balanced space program; the space defense initiative; warfare in space; the lunar laboratory; the role of space in preserving the peace; living off the land - the use of resources in space for future civilian space operations; the military uses of space; C3I(command control communications and intelligence); aspects of space technology; arms control in space: preserving critical strategic space systems without weapons in space; space and arms control: a skeptical view; options for space arms control; space arms control.

  9. Animated Space

    E-print Network

    Amin, Ash

    2014-01-01

    mingling with the public, and the commercial with the non-commercial; the rub of humans, technologies, buildings, infrastructures, animals and nature; the many human acts of preying, praying, lingering, passing through, watching and listening... ; the amplifications of intersecting bodies, objects, matter, symbols, smells and sounds; the rhythms set by callers, clocks, code, timetables, technologies, and official and unofficial guardians of a public space; and the asynchrony of repetition, emergence...

  10. Space colonization.

    PubMed

    Parrish, Clyde F

    2003-12-01

    A series of workshops were sponsored by the Physical Science Division of NASA's Office of Biological and Physical Research to address operational gravity-compliant in-situ resource utilization and life support techologies. Workshop participants explored a Mars simulation study on Devon Island, Canada; the processing of carbon dioxide in regenerative life support systems; space tourism; rocket technology; plant growth research for closed ecological systems; and propellant extraction of planetary regoliths. PMID:14696587

  11. Sobolev spaces

    Microsoft Academic Search

    Raymond Johnson; V. G. Maz; T. O. Shaposhnikova

    1987-01-01

    i.j=l a~i Oxj Oxi it is clear that Vu c L 2 and u e L 2 are sufficient conditions for the integrals to be well-defined. In addition, when you seek to minimize the functional thus arising (Dirichlet's principle for the Laplacian), they are the natural complete spaces to which the sought after minimizers belong. This allows existence to be

  12. Communication spaces

    PubMed Central

    Coiera, Enrico

    2014-01-01

    Background and objective Annotations to physical workspaces such as signs and notes are ubiquitous. When densely annotated, work areas become communication spaces. This study aims to characterize the types and purpose of such annotations. Methods A qualitative observational study was undertaken in two wards and the radiology department of a 440-bed metropolitan teaching hospital. Images were purposefully sampled; 39 were analyzed after excluding inferior images. Results Annotation functions included signaling identity, location, capability, status, availability, and operation. They encoded data, rules or procedural descriptions. Most aggregated into groups that either created a workflow by referencing each other, supported a common workflow without reference to each other, or were heterogeneous, referring to many workflows. Higher-level assemblies of such groupings were also observed. Discussion Annotations make visible the gap between work done and the capability of a space to support work. Annotations are repairs of an environment, improving fitness for purpose, fixing inadequacy in design, or meeting emergent needs. Annotations thus record the missing information needed to undertake tasks, typically added post-implemented. Measuring annotation levels post-implementation could help assess the fit of technology to task. Physical and digital spaces could meet broader user needs by formally supporting user customization, ‘programming through annotation’. Augmented reality systems could also directly support annotation, addressing existing information gaps, and enhancing work with context sensitive annotation. Conclusions Communication spaces offer a model of how work unfolds. Annotations make visible local adaptation that makes technology fit for purpose post-implementation and suggest an important role for annotatable information systems and digital augmentation of the physical environment. PMID:24005797

  13. Open Spaces

    NSDL National Science Digital Library

    Featuring articles by leading experts on topics from science policy to ecology (such as Bruce Babbitt and Jane Lubchenko), this new publication from Portland, Oregon attempts to incorporate synthetic, broad perspectives with a host of (familiar) environmental topics. A subscription fee is required to access all articles at the Open Spaces Website, but several interesting sample articles are currently posted for free online viewing. Science writers and scientists interested in widening their perspectives will find this an intriguing resource.

  14. Space propulsion

    NASA Astrophysics Data System (ADS)

    Kazaroff, John M.

    1993-02-01

    Lewis Research Center is developing broad-based new technologies for space chemical engines to satisfy long-term needs of ETO launch vehicles and other vehicles operating in and beyond Earth orbit. Specific objectives are focused on high performance LO2/LH2 engines providing moderate thrusts of 7,5-200 klb. This effort encompasses research related to design analysis and manufacturing processes needed to apply advanced materials to subcomponents, components, and subsystems of space-based systems and related ground-support equipment. High-performance space-based chemical engines face a number of technical challenges. Liquid hydrogen turbopump impellers are often so large that they cannot be machined from a single piece, yet high stress at the vane/shroud interface makes bonding extremely difficult. Tolerances on fillets are critical on large impellers. Advanced materials and fabricating techniques are needed to address these and other issues of interest. Turbopump bearings are needed which can provide reliable, long life operation at high speed and high load with low friction losses. Hydrostatic bearings provide good performance, but transients during pump starts and stops may be an issue because no pressurized fluid is available unless a separate bearing pressurization system is included. Durable materials and/or coatings are needed that can demonstrate low wear in the harsh LO2/LH2 environment. Advanced materials are also needed to improve the lifetime, reliability and performance of other propulsion system elements such as seals and chambers.

  15. Space Nutrition

    NASA Technical Reports Server (NTRS)

    Smith, Scott M.

    2009-01-01

    Optimal nutrition will be critical for crew members who embark on space exploration missions. Nutritional assessment provides an opportunity to ensure that crewmembers begin their missions in optimal nutritional status, to document changes during a mission and, if necessary, to provide intervention to maintain that status throughout the mission, and to assesses changes after landing in order to facilitate the return to their normal status as soon as possible after landing. We report here the findings from our nutritional assessment of astronauts who participated in the International Space Station (ISS) missions, along with flight and ground-based research findings. We also present ongoing and planned nutrition research activities. These studies provide evidence that bone loss, compromised vitamin status, and oxidative damage are the critical nutritional concerns for space travelers. Other nutrient issues exist, including concerns about the stability of nutrients in the food system, which are exposed to longterm storage and radiation during flight. Defining nutrient requirements, and being able to provide and maintain those nutrients on exploration missions, will be critical for maintaining crew member health.

  16. An Evolvable Space Telescope for NASA’s Next UVOIR Flagship Mission

    NASA Astrophysics Data System (ADS)

    Lillie, Charles F.; Breckinridge, James B.; MacEwen, Howard A.; Polidan, Ronald S.; Flannery, Martin; Dailey, Dean

    2015-01-01

    NASA has sponsored several studies to develop conceptual designs for the next UVOIR Flagship mission, including an Advanced Technology Large Space Telescope (ATLAST). These studies concluded that a space observatory launched in ~2030 will require a telescope aperture of 8 to 16 meters to address the most compelling astrophysical questions raised by missions such as HST, Kepler, TESS, JWST and WFIRST as well as the large ground based telescopes that will coming on-line in the next decade. This telescope will be designed to search for the bio-signatures of life in the universe as well as to study the physics of star formation and to unravel the complex interactions between dark matter, galaxies and the intergalactic medium.Unfortunately, telescopes with this aperture will have a long development time with peak funding requirements that will absorb most NASA's Astrophysics budget for many years. To minimize this impact on NASA's budget and to drastically shorten the time between program start and 'first light' for this UVOIR space observatory we have been developing conceptual designs for an Evolvable Space Telescope (EST) that would be assembled on-orbit in three stages, beginning with the launch of a 2 mirror 4 x 12 meter telescope with 2 instruments 5 to 7 years after program start, and then adding mirror segments and instruments ay ~ 5 year intervals to obtain a 12-m filled aperture, and then a 20-m filled aperture telescope. We describe our approach in this presentation.

  17. Commercial Space Tourism and Space Weather

    NASA Astrophysics Data System (ADS)

    Turner, Ronald

    2007-08-01

    Space tourism, a concept which even a few years ago was perveived as science fantasy, is now a credible industry. Five individuals have paid up to $25 M to spend more than a week on the International Space Station. Several enterprises are working toward viable suborbital and orbital private space operations. while operational space weather support to human space flight has been the domain of government entities the emergence of space tourism now presents a new opportunity for the commercial space weather community. This article examines the space weather impact on crews and passengers of the future space tourism industry.

  18. SPACE FOR INNOVATION (OR INNOVATION FOR SPACE)

    E-print Network

    Karlsson, Brynjar

    www.hr.is SPACE FOR INNOVATION (OR INNOVATION FOR SPACE) DR. ARI KRISTINN J�NSSON, PRESIDENT RU LECTURE MARATHON #12;www.hr.is Three variations on a theme · Innovation for space ­ Driving innovation at NASA ­ Lessons from Silicon Valley · Space for innovation ­ Opportunities in Iceland · Space

  19. European Space Agency European Space Exploration

    E-print Network

    Crawford, Ian

    European Space Agency Aurora European Space Exploration Programme EXECUTIVE SUMMARY #12;2 Aurora Programme EXECUTIVE SUMMARY 1. What is Aurora? A European Space Exploration Programme based on a road map economically and politically as a leading world power, it cannot leave space exploration to the other space

  20. Space Radiation

    NASA Technical Reports Server (NTRS)

    Wu, Honglu

    2006-01-01

    Astronauts receive the highest occupational radiation exposure. Effective protections are needed to ensure the safety of astronauts on long duration space missions. Increased cancer morbidity or mortality risk in astronauts may be caused by occupational radiation exposure. Acute and late radiation damage to the central nervous system (CNS) may lead to changes in motor function and behavior, or neurological disorders. Radiation exposure may result in degenerative tissue diseases (non-cancer or non-CNS) such as cardiac, circulatory, or digestive diseases, as well as cataracts. Acute radiation syndromes may occur due to occupational radiation exposure.

  1. Space Food

    NASA Technical Reports Server (NTRS)

    1994-01-01

    In planning for the long duration Apollo missions, NASA conducted extensive research into space food. One of the techniques developed was freeze drying. Action Products commercialized this technique, concentrating on snack food including the first freeze-dried ice cream. The foods are cooked, quickly frozen and then slowly heated in a vacuum chamber to remove the ice crystals formed by the freezing process. The final product retains 98 percent of its nutrition and weighs only 20 percent of its original weight. Action snacks are sold at museums, NASA facilities and are exported to a number of foreign countries. Sales run to several million dollars annually.

  2. Space Audio

    NSDL National Science Digital Library

    This site offers the "sounds of space" processed from signals received by University of Iowa instruments on various spacecraft. The collection includes sounds from Saturn collected by the Cassini probe, sounds from the edge of the solar system collected by the Voyager probe, as well as radio bursts from solar flares and sounds created by Earth's magnetosphere. There are also descriptions of several types of sounds (whistlers, choruses, and auroral radio emissions) and sample sounds produced by processed data received from specific spacecraft (Galileo, Polar, Cassini, Cluster, and others).

  3. Cosmic Reionization and Early Star-Forming Galaxies: A Joint Analysis of New Constraints from Planck and Hubble Space Telescope

    E-print Network

    Robertson, Brant E; Furlanetto, Steven R; Dunlop, James S

    2015-01-01

    We discuss new constraints on the epoch of cosmic reionization and test the assumption that most of the ionizing photons responsible arose from high redshift star-forming galaxies. Good progress has been made in charting the end of reionization through spectroscopic studies of z~6-8 QSOs, gamma-ray bursts and galaxies expected to host Lyman-alpha emission. However, the most stringent constraints on its duration have come from the integrated optical depth, tau, of Thomson scattering to the cosmic microwave background. Using the latest data on the abundance and luminosity distribution of distant galaxies from Hubble Space Telescope imaging, we simultaneously match the reduced value tau=0.066 +/- 0.012 recently reported by the Planck collaboration and the evolving neutrality of the intergalactic medium with a reionization history within 6 >10) galaxies. Our analysis strengthens the conclusion that star-forming galaxies dominated the reionization process and has important implications for upcoming 21cm experiment...

  4. Space Policy November, 2011

    E-print Network

    MacMillan, Andrew

    1 Space Policy November, 2011 Approved by FoMD: Dean's Executive Committee ­ February 16, 2011:..................................................................................................................................3 Academic Offices and Administrative Space:..................................................................................................................................................4 Administrative Space Allocation Guidelines

  5. Open Spaces

    NSDL National Science Digital Library

    Recently, the U.S. Fish & Wildlife Service created the "Open Spaces" blog to showcase some of their wildlife refuges and to offer the general public an inside view on the day-to-day operations of the organization. Visitors to the site will find blog posts that profile their work in the Everglades, reflections on September 11th, migratory birds, and the Labrador retrievers that work at the Kenai National Wildlife Refuge in Alaska. Users of the site can search posts by category, and they will find that each entry also contains a selection of links to other materials, such as park management plans and lesson plans. Finally, visitors can also use the social media buttons here to share each post on Twitter and Facebook.

  6. NATIONAL AERONAUTICS AND SPACE ADMINISTRATION Space Infrared

    E-print Network

    Rebull, Luisa M.

    Observatories are the Hubble Space Telescope, Compton Gamma Ray Observatory and Chandra X-ray ObservatoryNATIONAL AERONAUTICS AND SPACE ADMINISTRATION Space Infrared Telescope Facility Launch Press Kit donald.savage@hq.nasa.gov Washington, D.C. Jane Platt Space Infrared Telescope Facility 818/354-0880 Jet

  7. 3741SPACE AUDIT PROCEDURE Space audit

    E-print Network

    Page 1 3741SPACE AUDIT PROCEDURE Space audit identified to be conducted Will audit disrupt or disturb occupants of the space Notify Faculty, School or Business Unit of the audit Is the audit for timetabling purposes Is the audit a physical audit Confirm audit requirements Is the audit for other space

  8. COMMERCIAL SPACE ACCOMPLISHMENTS Commercial Cargo Space Accomplishments

    E-print Network

    Waliser, Duane E.

    11/13/2013 COMMERCIAL SPACE ACCOMPLISHMENTS Commercial Cargo Space Accomplishments The Obama Administration's ambitious commercial space program, which has bipartisan support in Congress, has enabled NASA's successful partnership with two American companies now able to resupply the station - SpaceX and Orbital

  9. UNIVERSITY SPACE POLICY ALLOCATION OF UNIVERSITY SPACE

    E-print Network

    UNIVERSITY COLLEGE DUBLIN UNIVERSITY SPACE POLICY #12;ALLOCATION OF UNIVERSITY SPACE I Purpose To provide a methodology for the allocation of space across the University II Background Due to the university's success in attracting research funding, the need for space and facilities has grown

  10. Space Science in Action: Space Exploration [Videotape].

    ERIC Educational Resources Information Center

    1999

    In this videotape recording, students learn about the human quest to discover what is out in space. Students see the challenges and benefits of space exploration including the development of rocket science, a look back at the space race, and a history of manned space travel. A special section on the Saturn V rocket gives students insight into the…

  11. SPACE DAILY SPACE WAR TERRA DAILY MARS DAILY SPACE MART SPACE TRAVEL World's Smallest Universal Material

    E-print Network

    Espinosa, Horacio D.

    SPACE DAILY SPACE WAR TERRA DAILY MARS DAILY SPACE MART SPACE TRAVEL NANO TECH World's Smallest spaces as required by in situ transmission electron microscopy (TEM), successfully characterized, professor of mechanical Get Our Free Newsletters Via Email Space - War - Earth - Energy - China your email

  12. Space and the Military

    Microsoft Academic Search

    Peter Hays

    This chapter began by providing a foundation to analyze military space issues by discussing three ways to describe spacepower: space activity sectors (civil, commercial, intelligence, and defense); military space mission areas (space support, force enhancement, space control, and force application); and military space doctrines (sanctuary, survivability, control, and high ground). It then briefly described the major organizations that are stakeholders

  13. Equally Spaced?

    NSDL National Science Digital Library

    Beunderman, Joost

    Urbanologists and other types have been interested in the interactions between different groups of people in cities for hundreds of years. There is quite a broad literature on studying different types of communities and public spaces, and this recent paper from the Demos group in the United Kingdom adds to that body of work. This 40-page report was first published in July 2007, and it was authored by Hannah Lownsbrough and Joost Beunderman. As the report's subtitle suggests, it is primarily concerned with presenting a dynamic look at how public places can effectively encourage interaction between diverse communities in urban areas. For this work, the researchers looked at three separate locations in Britain, and this report presents some of their findings on what works well (and not so well) in terms of creating and maintaining high-quality public places. The report is both thoughtful and thorough, and persons with an interest in urban planning, sociology, and related fields will find it quite compelling.

  14. Space habitats. [prognosis for space colonization

    NASA Technical Reports Server (NTRS)

    Johnson, R. D.

    1978-01-01

    Differences between space industrialization and space colonization are outlined along with the physiological, psychological, and esthetic needs of the inhabitants of a space habitat. The detrimental effects of zero gravity on human physiology are reviewed, and the necessity of providing artificial gravity, an acceptable atmosphere, and comfortable relative humidity and temperature in a space habitat is discussed. Consideration is also given to social organization and governance, supply of food and water, and design criteria for space colonies.

  15. National Aeronautics and Space Administration NASAGoddardSpaceFlightCenter

    E-print Network

    Christian, Eric

    National Aeronautics and Space Administration NASAGoddardSpaceFlightCenter http Space Flight Center's IPP Office #12;National Aeronautics and Space Administration NASAGoddardSpace SUA=Software Usage Agreement #12;National Aeronautics and Space Administration NASAGoddardSpace

  16. "Space, the Final Frontier"; Books on Space and Space Exploration.

    ERIC Educational Resources Information Center

    Jordan, Anne Devereaux

    1997-01-01

    Advocates play in a child's life. Describes how science fiction seizes the imaginations of young readers with its tales of the future and of outer space. Talks about various nonfiction books about space. Elaborates a workshop on books about space exploration. Gives 10 questions about stimulating student response. (PA)

  17. Space Transportation: Marshall Space Flight Center

    NSDL National Science Digital Library

    NASA's Marshall Space Flight Center is the location of an ongoing initiative to make access to space easier and more affordable. The center conducts extensive space propulsion research; four focus areas include advanced chemical propulsion, plasma propulsion, high-powered electrical propulsion, and propellantless propulsion. There is also a lot of information about the Integrated Space Transportation System and the Space Launch Initiative, which mainly deal with reusable launch vehicles (RLV). The space shuttle is the first generation RLV; second and third generation RLVs aim to increase safety while dramatically lowering launch costs.

  18. Space on Earth.

    ERIC Educational Resources Information Center

    Leder, Sandra J.

    1992-01-01

    Describes ideas for applying research from space programs to life science instruction including plants in space, exercise and diet on space flights, environmental advantages from space exploration, and the effects of microgravity on health. Discusses space spinoffs used in medicine including digital imaging processing and the Ingestible Thermal…

  19. Space Station propulsion system

    NASA Technical Reports Server (NTRS)

    Henderson, J.

    1990-01-01

    Viewgraphs on space station propulsion systems are presented. Topics covered include: space station propulsion system requirements; space station propulsion system design; space station propulsion system drivers; hydrazine technology development; waste fluid disposal system; space station propulsion system evolution; propellant selection trade study; technology needs to water electrolysis/oxygen-hydrogen propulsion system; and technology needs for bipropellant systems.

  20. CRYSTALLOGRAPHIC POINT AND SPACE

    E-print Network

    California at Santa Cruz, University of

    CRYSTALLOGRAPHIC POINT AND SPACE GROUPS Andy Elvin June 10, 2013 #12;Contents Point and Space no reflection axes #12;Cube and Octahedron are dual Symmetries under Oh #12;Space Groups Subgroups of E(3) Point Group + Translation { R | 0 }{ E | t }a = { R | t }a = Ra + t 230 Space Groups 73 symmorphic space

  1. Definitions Numbered Space

    E-print Network

    Behmer, Spencer T.

    Definitions · Numbered Space ­ a single space marked with a number and reserved for a single permit 24/7 · Unnumbered Space ­ a space which can be used by any customer allowed to park in that lot. High Low Average Question 4: If I buy a staff permit for an UNNUMBERED* space in a non-gated surface

  2. Space Science and Marshall Space Flight Center

    NASA Technical Reports Server (NTRS)

    Spann, James

    2005-01-01

    Space Science a t Marshall Space Flight Center is diverse and very interesting. It ranges from high energy astrophysics to astrobiology, from solar physics to space weather to dusty plasmas. I will present some of the more interesting investigations regarding auroral physics, what it takes to build a space camera, and laboratory investigations of dust. There will be time for questions and answers at the conclusion.

  3. Moving From Problem Space to Solution Space

    Microsoft Academic Search

    Bilal Saeed Raja; M. Ali Iqbal; Imran Ihsan

    Extracting and elaborating software requirements and transforming them into viable software architecture are still an intricate task. This paper defines a solution architecture which is based on the blurred amalgamation of problem space and solution space. The dependencies between domain constraints, requirements and architecture and their importance are described that are to be considered collectively while evolving from problem space

  4. Space history, space policy, and executive leadership

    NASA Technical Reports Server (NTRS)

    Kraemer, Sylvia K.

    1993-01-01

    A lecture that attempts to establish the role of space historians in formulating space policy is presented. The discussion focusses on two adages and their relevance to space policy. The adages are as follows: 'write about what you know;' and 'good managers do things right; good executives do the right things.'

  5. Space Research Centre Space Research Centre

    E-print Network

    Hinton, Jim

    Science missions. Artists impression of James Webb Space Telescope ­ Image courtesy of NASA #12... Astronomy James Webb Space Telescope - Replacement to Hubble Scientists in Leicester are helping to build). It will be a key part of NASA's James Webb Space Telescope (JWST), due for launch in 2018 and the successor

  6. In Outer Space without a Space Suit?

    Microsoft Academic Search

    Alexander Bolonkin

    2008-01-01

    The author proposes and investigates his old idea - a living human in space without the encumbrance of a complex space suit. Only in this condition can biological humanity seriously attempt to colonize space because all planets of Solar system (except the Earth) do not have suitable atmospheres. Aside from the issue of temperature, a suitable partial pressure of oxygen

  7. The partnership: Space shuttle, space science, and space station

    NASA Technical Reports Server (NTRS)

    Culbertson, Philip E.; Freitag, Robert F.

    1989-01-01

    An overview of the NASA Space Station Program functions, design, and planned implementation is presented. The discussed functions for the permanently manned space facility include: (1) development of new technologies and related commercial products; (2) observations of the Earth and the universe; (3) provision of service facilities for resupply, maintenance, upgrade and repair of payloads and spacecraft; (4) provision of a transportation node for stationing, processing and dispatching payloads and vehicles; (5) provision of manufacturing and assembly facilities; (6) provision of a storage depot for parts and payloads; and (7) provision of a staging base for future space endeavors. The fundamental concept for the Space Station, as given, is that it be designed, operated, and evolved in response to a broad variety of scientific, technological, and commercial user interests. The Space Shuttle's role as the principal transportation system for the construction and maintenance of the Space Station and the servicing and support of the station crew is also discussed.

  8. Space Flight Requirements

    E-print Network

    Space Flight Requirements Definition Hardware Ground Testing Hardware Mod Evaluation Hardware Science Glovebox), SpaceDrums (Levitator), EMCS (European Modular Cultivation System), PCDF (Protein Inserts for FSL/MSG/MSL/EMCS/BIOLAB/KUBIK/PCDF SpaceDrums utilization rights

  9. Sculpting space through sound

    E-print Network

    Nakagawa, Junko, 1975-

    2002-01-01

    How does one experience space? What kind of information do humans collect in the process of constructing space in their mind? How does one begin to understand volume, light, texture, material, smell and sense of space? The ...

  10. Space Solar Power Program

    SciTech Connect

    Arif, H.; Barbosa, H.; Bardet, C.; Baroud, M.; Behar, A.; Berrier, K.; Berthe, P.; Bertrand, R.; Bibyk, I.; Bisson, J.; Bloch, L.; Bobadilla, G.; Bourque, D.; Bush, L.; Carandang, R.; Chiku, T.; Crosby, N.; De Seixas, M.; De Vries, J.; Doll, S.; Dufour, F.; Eckart, P.; Fahey, M.; Fenot, F.; Foeckersperger, S.; Fontaine, J.E.; Fowler, R.; Frey, H.; Fujio, H.; Gasa, J.M.; Gleave, J.; Godoe, J.; Green, I.; Haeberli, R.; Hanada, T.; Ha

    1992-08-01

    Information pertaining to the Space Solar Power Program is presented on energy analysis; markets; overall development plan; organizational plan; environmental and safety issues; power systems; space transportation; space manufacturing, construction, operations; design examples; and finance.

  11. Quantum Complex Minkowski Space

    E-print Network

    Grzegorz Jakimowicz; Anatol Odzijewicz

    2005-05-06

    The complex Minkowski phase space has the physical interpretation of the phase space of the scalar massive conformal particle. The aim of the paper is the construction and investigation of the quantum complex Minkowski space.

  12. Space Probe Launch

    NASA Technical Reports Server (NTRS)

    1970-01-01

    Managed by Marshall Space Flight Center, the Space Tug was a reusable multipurpose space vehicle designed to transport payloads to different orbital inclinations. Utilizing mission-specific combinations of its three primary modules (crew, propulsion, and cargo) and a variety of supplementary kits, the Space Tug was capable of numerous space applications. This 1970 artist's concept depicts the Tug's propulsion module launching a space probe into lunar orbit.

  13. The International Space University

    NASA Astrophysics Data System (ADS)

    Elaerts, Roger; Peeters, Walter

    2006-05-01

    The International Space University (ISU) offers, with the support of the world space community and within an international and intercultural environment, interdisciplinary post-graduate programmes in space studies. These graduate programmes prepare professionals from all sectors to meet the challenges of international space cooperation and the restructuring of the space sector. Although it was created as recently as 1987, the ISU is remarkably successful: by 2005 it had around 2400 alumni, forming a strong network in the space community.

  14. Nutrition in space

    NASA Technical Reports Server (NTRS)

    Smith, S. M.; Davis-Street, J.; Rice, B. L.; Lane, H. W.

    1997-01-01

    The authors review studies conducted to define nutritional requirements for astronauts during space flight and to assess nutrition before, during, and after space flight. Topics include space food systems, research and limitations on spacecraft, physiological adaptation to weightlessness, energy requirements, dietary intake during space flight, bone demineralization, gastrointestinal function, blood volume, and nutrition requirements for space flight. Benefits of space-related nutrition research are highlighted.

  15. Studying Galaxy Formation with the Hubble, Spitzer and James Webb Space Telescopes

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.

    2007-01-01

    The deepest optical to infrared observations of the universe include the Hubble Deep Fields, the Great Observatories Origins Deep Survey and the recent Hubble Ultra-Deep Field. Galaxies are seen in these surveys at redshifts z>6, less than 1 Gyr after the Big Bang, at the end of a period when light from the galaxies has reionized Hydrogen in the inter-galactic medium. These observations, combined with theoretical understanding, indicate that the first stars and galaxies formed at z>10, beyond the reach of the Hubble and Spitzer Space Telescopes. To observe the first galaxies, NASA is planning the James Webb Space Telescope (JWST), a large (6.5m), cold (<50K), infrared-optimized observatory to be launched early in the next decade into orbit around the second Earth- Sun Lagrange point. JWST will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. In addition to JWST's ability to study the formation and evolution of galaxies, I will also briefly review its expected contributions to studies of the formation of stars and planetary systems.

  16. Studying Galaxy Formation with the Hubble, Spitzer and James Webb Space Telescopes

    NASA Technical Reports Server (NTRS)

    Gardner, Jonathan P.

    2009-01-01

    The deepest optical to infrared observations of the universe include the Hubble Deep Fields, the Great Observatories Origins Deep Survey and the recent Hubble Ultra-Deep Field. Galaxies are seen in these surveys at redshifts z greater than 6, less than 1 Gyr after the Big Bang, at the end of a period when light from the galaxies has reionized Hydrogen in the inter-galactic medium. These observations, combined with theoretical understanding, indicate that the first stars and galaxies formed at z greater than 10, beyond the reach of the Hubble and Spitzer Space Telescopes. To observe the first galaxies, NASA is planning the James Webb Space Telescope (JWST), a large (6.5m), cold (less than 50K), infrared-optimized observatory to be launched early in the next decade into orbit around the second Earth-Sun Lagrange point. JWST will have four instruments: The Near-Infrared Camera, the Near-Infrared multi-object Spectrograph, and the Tunable Filter Imager will cover the wavelength range 0.6 to 5 microns, while the Mid-Infrared Instrument will do both imaging and spectroscopy from 5 to 28.5 microns. In addition to JWST's ability to study the formation and evolution of galaxies, I will also briefly review its expected contributions to studies of the formation of stars and planetary systems, and discuss recent progress in constructing the observatory.

  17. The International Space Station in Space Exploration

    NASA Technical Reports Server (NTRS)

    Gerstenmaier, William H.; McKay, Meredith M.

    2006-01-01

    The International Space Station (ISS) Program has many lessons to offer for the future of space exploration. Among these lessons of the ISS Program, three stand out as instrumental for the next generation of explorers. These include: 1) resourcefulness and the value of a strong international partnership; 2) flexibility as illustrated by the evolution of the ISS Program and 3) designing with dissimilar redundancy and simplicity of sparing. These lessons graphically demonstrate that the ISS Program can serve as a test bed for future programs. As the ISS Program builds upon the strong foundation of previous space programs, it can provide insight into the prospects for continued growth and cooperation in space exploration. As the capacity for spacefaring increases worldwide and as more nations invest in space exploration and space sector development, the potential for advancement in space exploration is unlimited. By building on its engineering and research achievements and international cooperation, the ISS Program is inspiring tomorrow s explorers today.

  18. National Aeronautics and Space Administration

    E-print Network

    National Aeronautics and Space Administration 2012 NASA's Marshall Space Flight Center anchors Space Flight Center Alabama Economic Impact National Aeronautics and Space Administration Aeronautics and Space Administration George C. Marshall Space Flight Center Huntsville, AL 35812 www

  19. Benefits Stemming from Space Exploration

    E-print Network

    Waliser, Duane E.

    Benefits Stemming from Space Exploration September 2013 International Space from Space Exploration Table of Content Executive Summary .......................................................................................................................................... 3 2. Fundamental Benefits of Space Exploration

  20. Space Glasgow Executive Summary

    E-print Network

    Glasgow, University of

    Space Glasgow #12;Executive Summary The University of Glasgow has been active in space research many different disciplines, primarily across the College of Science and Engineering. The Space Glasgow research activities fall within five key themes: · Enabling technologies for space - hardware · Enabling

  1. Open Space ( 24 30 .)

    E-print Network

    Kaplan, Alexander

    Space» «» / : : -- , . . : -- -- - ; 1 #12. . ? 6 2. « » : 6 3. ( , , ) 4 4. . « » 4 5. "open space". . 6 6 . . « » . « ». . . . « ». « » . « » . . « » . 5 ­ 4 . "OPEN SPACE". . «pen space» - . «Open Spae

  2. SPACE SYSTEMS ENGINEERING

    E-print Network

    Yang, Eui-Hyeok

    0213 SPACE SYSTEMS ENGINEERING In today's space community, change is the only constant. From market and technological changes to policy and budgetary uncertainty, the space industry has been faced with increasing within a modern space-centric enterprise, it is crucial to have both the technical knowledge necessary

  3. Space: The New Frontier.

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Washington, DC.

    This document is designed primarily to describe the U.S. Space Program, its history, its current state of development, and its goals for the future. Chapter headings include: Space and You; The Early History of Space Flight; The Solar System; Space Probes and Satellites; Scientific Satellites and Sounding Rockets; Application Satellites, Unmanned…

  4. Planetary Science Space Physics

    E-print Network

    Mojzsis, Stephen J.

    data to scientists and the public, continuing the cycle of space exploration. Bringing space science#12;Planetary Science Space Physics Solar Influences Atmospheric Science Engineering Mission Operations #12;A message from the Director At the Laboratory for Atmospheric and Space Physics (LASP), we

  5. Humans in space

    Microsoft Academic Search

    Ronald J. White; Maurice Averner

    2001-01-01

    Many successful space missions over the past 40 years have highlighted the advantages and necessity of humans in the exploration of space. But as space travel becomes ever more feasible in the twenty-first century, the health and safety of future space explorers will be paramount. In particular, understanding the risks posed by exposure to radiation and extended weightlessness will be

  6. NEXT GENERATION SPACE TELESCOPE

    E-print Network

    Sirianni, Marco

    the Early Universe: The Dark Ages . . . . . . . . . . . . .1 2 Seeing Beyond the Hubble Space Telescope the feasibility of a large aperture space telescope to follow the Hubble Space Telescope. The scientific goalsTHE NEXT GENERATION SPACE TELESCOPE Visiting a Time When Galaxies Were Young The NGST Study Team

  7. Specification state space memory

    E-print Network

    Hehner, Eric C.R.

    Specification state space memory 1/116 #12;Specification state space memory state memory contents 2/116 #12;Specification state space memory int; (0,..20); char; rat state memory contents 3/116 #12;Specification state space memory int; (0,..20); char; rat state memory contents ­2; 15; "A"; 3.14 4/116 #12

  8. Budgeting Academic Space

    ERIC Educational Resources Information Center

    Harris, Watson

    2011-01-01

    There are many articles about space management, including those that discuss space calculations, metrics, and categories. Fewer articles discuss the space budgeting processes used by administrators to allocate space. The author attempts to fill this void by discussing her administrative experiences with Middle Tennessee State University's (MTSU)…

  9. Demystifying white spaces

    Microsoft Academic Search

    Xuemin Hong; Cheng-Xiang Wang; John Thompson; Yan Zhang

    2008-01-01

    White spaces refer to the unused frequency voids across time or space. The vast existence of white spaces has been validated by many measurements and is widely regarded as an undesirable consequence of the fixed spectrum licensing policy. In this paper, we apply stochastic geometry to study the spatial distribution of white spaces in the presence of a random primary

  10. Space Complexity Algorithms & Complexity

    E-print Network

    Way, Andy

    Space Complexity Algorithms & Complexity Space Complexity Nicolas Stroppa Patrik Lambert - plambert@computing.dcu.ie CA313@Dublin City University. 2008-2009. December 4, 2008 #12;Space Complexity Hierarchy of problems #12;Space Complexity NP-intermediate Languages If P = NP, then are there languages which neither in P

  11. Space Shuttle Program Status

    E-print Network

    Waliser, Duane E.

    1 Space Shuttle Program Status John Casper Associate Manager Space Shuttle Program September 13, 2010 NAC Space Operations Committee #12;2 Operations #12;3 Flown Manifest March 2009 ­ May 2010 #12, 2010 · 132nd Space Shuttle mission · 32nd Flight of Atlantis (120,650,907 statute miles) · 294 Total

  12. National Space Policy and Space Weather

    NASA Astrophysics Data System (ADS)

    Lanzerotti, Louis J.

    2006-12-01

    The new national space policy, authorized by President Bush on 31 August 2006, has been the cause of considerable discussion among space professionals. The policy statement is a broad umbrella that lays out the nation's objectives in space, from science to commercial to national security and intelligence. The policy appears to support numerous national space objectives that were contained in the previous (1996) policy statement, of the Clinton administration. It also articulates in one location many of the pronouncements on space activities that have been promulgated since 2001. Some of the unhappiness expressed in editorial comments would seem to occur because words such as "Mars" and "Moon" do not appear explicitly. At the same time, neither do the words "space weather."

  13. Space Toxicology: Human Health during Space Operations

    NASA Technical Reports Server (NTRS)

    Khan-Mayberry, Noreen; James, John T.; Tyl, ROchelle; Lam, Chiu-Wing

    2010-01-01

    Space Toxicology is a unique and targeted discipline for spaceflight, space habitation and occupation of celestial bodies including planets, moons and asteroids. Astronaut explorers face distinctive health challenges and limited resources for rescue and medical care during space operation. A central goal of space toxicology is to protect the health of the astronaut by assessing potential chemical exposures during spaceflight and setting safe limits that will protect the astronaut against chemical exposures, in a physiologically altered state. In order to maintain sustained occupation in space on the International Space Station (ISS), toxicological risks must be assessed and managed within the context of isolation continuous exposures, reuse of air and water, limited rescue options, and the need to use highly toxic compounds for propulsion. As we begin to explore other celestial bodies in situ toxicological risks, such as inhalation of reactive mineral dusts, must also be managed.

  14. In Outer Space without a Space Suit?

    E-print Network

    Alexander Bolonkin

    2008-06-24

    The author proposes and investigates his old idea - a living human in space without the encumbrance of a complex space suit. Only in this condition can biological humanity seriously attempt to colonize space because all planets of Solar system (except the Earth) do not have suitable atmospheres. Aside from the issue of temperature, a suitable partial pressure of oxygen is lacking. In this case the main problem is how to satiate human blood with oxygen and delete carbonic acid gas (carbon dioxide). The proposed system would enable a person to function in outer space without a space suit and, for a long time, without food. That is useful also in the Earth for sustaining working men in an otherwise deadly atmosphere laden with lethal particulates (in case of nuclear, chemical or biological war), in underground confined spaces without fresh air, under water or a top high mountains above a height that can sustain respiration.

  15. In Outer Space without a Space Suit?

    E-print Network

    Bolonkin, Alexander

    2008-01-01

    The author proposes and investigates his old idea - a living human in space without the encumbrance of a complex space suit. Only in this condition can biological humanity seriously attempt to colonize space because all planets of Solar system (except the Earth) do not have suitable atmospheres. Aside from the issue of temperature, a suitable partial pressure of oxygen is lacking. In this case the main problem is how to satiate human blood with oxygen and delete carbonic acid gas (carbon dioxide). The proposed system would enable a person to function in outer space without a space suit and, for a long time, without food. That is useful also in the Earth for sustaining working men in an otherwise deadly atmosphere laden with lethal particulates (in case of nuclear, chemical or biological war), in underground confined spaces without fresh air, under water or a top high mountains above a height that can sustain respiration.

  16. Space vehicle propulsion systems: Environmental space hazards

    NASA Technical Reports Server (NTRS)

    Disimile, P. J.; Bahr, G. K.

    1990-01-01

    The hazards that exist in geolunar space which may degrade, disrupt, or terminate the performance of space-based LOX/LH2 rocket engines are evaluated. Accordingly, a summary of the open literature pertaining to the geolunar space hazards is provided. Approximately 350 citations and about 200 documents and abstracts were reviewed; the documents selected give current and quantitative detail. The methodology was to categorize the various space hazards in relation to their importance in specified regions of geolunar space. Additionally, the effect of the various space hazards in relation to spacecraft and their systems were investigated. It was found that further investigation of the literature would be required to assess the effects of these hazards on propulsion systems per se; in particular, possible degrading effects on exterior nozzle structure, directional gimbals, and internal combustion chamber integrity and geometry.

  17. Bioprocessing in Space

    NASA Technical Reports Server (NTRS)

    Morrison, D. R. (compiler)

    1977-01-01

    Proceedings are presented of the 1976 NASA Colloquium on bioprocessing in space. The program included general sessions and formal presentations on the following topics: NASA's Space Shuttle, Spacelab, and space-processing programs; the known unusual behavior of materials in space; space-processing experiment results; cell biology, gravity sensors in cells, space electrophoresis of living cells, new approaches to biosynthesis of biologicals from cell culture in space, and zero-g fermentation concepts; and upcoming flight opportunities and industrial application planning studies already underway.

  18. Space Science Curricula

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Johnson High School, Huntsville, Alabama started an international magnet program in 1987. One of the courses in the curriculum was in space science. They appealed to Marshall Space Flight Center (MSFC) when they couldn't find a suitable textbook, nor locate other classes in space science to provide a guideline. MSFC agreed to help and placed the school under an official 'Adopt-A-School' program. MSFC's chief scientist and others at the space center helped prepare a very comprehensive space science program. Examples of the subjects covered include problems of space travel, materials processing in space, technology utilization, robotics, space colonization, etc. MSFC followed up by working with Johnson High to determine if the curriculum is generally usable and workable. If it is, MSFC may make it available to other schools. MSFC not only developed the space science curriculum; they continue to support the program by sponsoring hands- on activities and tours of space research facilities.

  19. Space Physiology and Operational Space Medicine

    NASA Technical Reports Server (NTRS)

    Scheuring, Richard A.

    2009-01-01

    The objectives of this slide presentation are to teach a level of familiarity with: the effects of short and long duration space flight on the human body, the major medical concerns regarding future long duration missions, the environmental issues that have potential medical impact on the crew, the role and capabilities of the Space Medicine Flight Surgeon and the environmental impacts experienced by the Apollo crews. The main physiological effects of space flight on the human body reviewed in this presentation are: space motion sickness (SMS), neurovestibular, cardiovascular, musculoskeletal, immune/hematopoietic system and behavioral/psycho-social. Some countermeasures are discussed to these effects.

  20. Space Today Online

    NSDL National Science Digital Library

    Anthony R. Curtis, Ph.D.

    2006-03-07

    This online magazine is intended to provide accurate information on past, present, and future human activities in and about space, including space science, history, research, space flight, solar system exploration, deep space astronomy, and cosmology. It features news articles on space vehicles, astronauts, coming launches and landings, satellite missions, telescopes, and many other topics. The site also provides image galleries, videos, and resources for teachers such as lesson plans, book reviews, tutorials, and other items.

  1. Space Shuttle Familiarization

    NASA Technical Reports Server (NTRS)

    Mellett, Kevin

    2006-01-01

    This slide presentation visualizes the NASA space center and research facility sites, as well as the geography, launching sites, launching pads, rocket launching, pre-flight activities, and space shuttle ground operations located at NASA Kennedy Space Center. Additionally, highlights the international involvement behind the International Space Station and the space station mobile servicing system. Extraterrestrial landings, surface habitats and habitation systems, outposts, extravehicular activity, and spacecraft rendezvous with the Earth return vehicle are also covered.

  2. National Aeronautics and Space Administration Commercial Space Committee

    E-print Network

    Waliser, Duane E.

    National Aeronautics and Space Administration Commercial Space Committee of the NASA Advisory __________________________________ ________________________________________ John Emond Executive Secretary Commercial Space Committee Bretton Alexander Chair, Commercial Space Michael Lounge Patti Grace Smith John Emond, Executive Secretary 1 #12;NAC Commercial Space Committee

  3. National Aeronautics and Space Administration Commercial Space Committee

    E-print Network

    Waliser, Duane E.

    National Aeronautics and Space Administration Commercial Space Committee of the NASA Advisory space transportation Will Trafton, formerly NASA associate Administrator for space flight, executive Commercial Space Committee, February 16, 2010 4 Committee Direction NASA's Deputy Administrator, Ms Lori

  4. National Aeronautics and Space Administration Commercial Space Committee

    E-print Network

    Waliser, Duane E.

    National Aeronautics and Space Administration Commercial Space Committee of the NASA Advisory ______________________________________________ John Emond, Executive Secretary Commercial Space Committee _____________________________________________ Bretton Alexander, Chair Commercial Space Committee #12;NAC Commercial Space Committee, July 29, 2010

  5. National Aeronautics and Space Administration Space Exploration Vehicle Concept

    E-print Network

    National Aeronautics and Space Administration NASAfacts Space Exploration Vehicle Concept Background NASA is testing concepts for a new generation of space exploration vehicles. These space concept called the common Space Exploration Vehicle (SEV) is currently being developed. The SEV cabin

  6. Man in Space, Space in the Seventies.

    ERIC Educational Resources Information Center

    Froehlich, Walter

    Included is a summary of the Apollo lunar program to date. Projected future NASA programs planned for the 1970's are discussed under the headings Skylab, Space Shuttle, and Space Station. Possibilities for the 1980's are outlined in the final section. (Author/AL)

  7. Space astronomy in the European Space Agency

    Microsoft Academic Search

    F. Macchetto

    1981-01-01

    An overview is presented of past, present, and future astronomical satellites launched by the European Space Agency. Attention is given to the following satellites: Cos-B, TD-1, IUE, Exosat, the Space Telescope, and Hipparcos. The objectives and experiments of the various satellite missions are reviewed, and some results obtained with TD-1 and IUE are summarized. Characteristics of the IUE telescope and

  8. Space Station overview

    NASA Technical Reports Server (NTRS)

    De Sanctis, Carmine E.; Priest, C. C.; Wood, W. V.

    1987-01-01

    This paper presents an overview of the Space Station, including program guidelines, international involvement, current baseline configuration, and utilization for science and application missions. Space Station configuration and capabilities, plus methods of utilizing the Space Station for scientific and engineering investigations, are described. The Space Station is being designed as a multipurpose facility to support a number of functions, such as a laboratory in space, a transportation node, an assembly facility, a staging base, etc. The description includes the baseline configuration, location of the pressurized modules, servicing and assembly facilities, and the work package structure for Space Station management. The Space Station will accommodate a wide variety of user requirements in laboratory modules and as attached payloads. To show the utility of the Space Station, a variety of science and application missions currently being studied for NASA at the Marshall Space Flight Center are discussed.

  9. SpaceTech—Postgraduate space education

    NASA Astrophysics Data System (ADS)

    de Bruijn, Ferdi J.; Ashford, Edward W.; Larson, Wiley J.

    2008-07-01

    SpaceTech is a postgraduate program geared primarily for mid-career space professionals seeking to gain or improve their expertise in space systems engineering and in business engineering. SpaceTech provides a lifelong impact on its participants by broadening their capabilities, encouraging systematic "end-to-end" thinking and preparing them for any technical or business-related engineering challenges they may encounter. This flexible 1-year program offers high competency gain and increased business skills. It is held in attractive locations in a flexible, multi-cultural environment. SpaceTech is a highly effective master's program certified by the esteemed Technical University of Delft (TUD), Netherlands. SpaceTech provides expert instructors who place no barriers between themselves and participants. The program combines innovative and flexible new approaches with time-tested methods to give participants the skills required for future missions and new business, while allowing participants to meet their work commitments at the same time as they study for their master's degree. The SpaceTech program is conducted in separate sessions, generally each of 2-week duration, separated by periods of some 6-8 weeks, during which time participants may return to their normal jobs. It also includes introductory online course material that the participants can study at their leisure. The first session is held at the TUD, with subsequent sessions held at strategic space agency locations. By participating at two or more of these sessions, attendees can earn certificates of satisfactory completion from TU Delft. By participating in all of the sessions, as well as taking part in the companion Central Case Project (CCP), participants earn an accredited and highly respected master's degree in Space Systems Engineering from the TUD. Seven distinct SpaceTech modules are provided during these sessions: Space Mission Analysis and Design, Systems Engineering, Business Engineering, Interpersonal Skills, Telecommunications, Earth Observation and Navigation. A group CCP, a major asset of this unique program, is a focused project, aimed at the formation of a credible virtual commercial space-related business. Participants exercise space systems engineering fundamentals as well as marketing and business engineering tools, with the goal of creating a financially viable business opportunity. They then present the result, in the form of an unsolicited proposal to potential investors, as well as a varied group of engineers, managers and executives from the space community. During the CCP, participants learn the ties between mission and system design and the potential return to investors. They develop an instinct for the technical concepts and which of the parameters to adjust to make their newly conceived business more effective and profitable.

  10. Access to space studies

    NASA Technical Reports Server (NTRS)

    Martin, James A.

    1993-01-01

    The National Aeronautics and Space Administration is currently considering possible directions in Earth-to-orbit vehicle development under a study called 'Access to Space.' This agency-wide study is considering commercial launch vehicles, human transportation, space station logistics, and other space transportation requirements over the next 40 years. Three options are being considered for human transportation: continued use of the Space Shuttle; development of a small personnel carrier (personnel logistics system (PLS)); or development of an advanced vehicle such as a single-stage-to-orbit (SSTO). Several studies related to the overall Access to Space study are reported in this document.

  11. Deep Space Communication

    NASA Technical Reports Server (NTRS)

    Manshadi, Farzin

    2012-01-01

    ITU defines deep space as the volume of Space at distances from the Earth equal to, or greater than, 2 106 km. Deep Space Spacecraft have to travel tens of millions of km from Earth to reach the nearest object in deep space. Spacecraft mass and power are precious. Large ground-based antennas and very high power transmitters are needed to overcome large space loss and spacecraft's small antennas and low power transmitters. Navigation is complex and highly dependent on measurements from the Earth. Every deep space mission is unique and therefore very costly to develop.

  12. Space Station Spartan study

    NASA Technical Reports Server (NTRS)

    Lane, J. H.; Schulman, J. R.; Neupert, W. M.

    1985-01-01

    The required extension, enhancement, and upgrading of the present Spartan concept are described to conduct operations from the space station using the station's unique facilities and operational features. The space station Spartan (3S), the free flyer will be deployed from and returned to the space station and will conduct scientific missions of much longer duration than possible with the current Spartan. The potential benefits of a space station Spartan are enumerated. The objectives of the study are: (1) to develop a credible concept for a space station Spartan; and (2) to determine the associated requirements and interfaces with the space station to help ensure that the 3S can be properly accommodated.

  13. Space Weather FX

    NSDL National Science Digital Library

    Space Weather FX is a vodcast (video podcast) series that explores the science of space weather and how it can impact our every day lives. Episodes include Space Weather and its Effects, Connecting the Sun and Earth, When Space Weather Attacks, Stratospheric Sudden Warming, A Tour of Haystack's Radars, GPS and Space Weather, It Came from the Sun, and The Big Picture. The site also contain links to space weather information and educational materials. The episodes will run on one of four free video players.

  14. Architecting space communication networks

    E-print Network

    Sanchez Net, Marc

    2014-01-01

    Reliable communication and navigation services are critical to robotic and human space missions. NASA currently provides them through three independent and uncoordinated network that consist of both Earth-based and space-based ...

  15. Occupational Space Medicine

    NASA Technical Reports Server (NTRS)

    Tarver, William J.

    2012-01-01

    Learning Objectives are: (1) Understand the unique work environment of astronauts. (2) Understand the effect microgravity has on human physiology (3) Understand how NASA Space Medicine Division is mitigating the health risks of space missions.

  16. Pathfinder: Humans in space

    NASA Technical Reports Server (NTRS)

    Anderson, John L.

    1988-01-01

    Viewgraphs are presented on the Pathfinder program. Information is given on human exploration of the solar system, technical requirements interfaces, program objectives, space suits, human performance, man-machine systems, space habitats, life support systems, and artificial gravity

  17. Basic space science

    SciTech Connect

    Haubold, H.J. [United Nations, New York, NY (USA); Khanna, R.K. [Maryland Univ., College Park, MD (United States). Dept. of Chemistry and Biochemistry] [eds.

    1992-05-01

    This report contains papers on the following topics: basic space science; a challenge and opportunity; solar-terrestrial interaction; solar system science; space astronomy; and astrophysics. The individual paper have been cataloged separately. (LSP)

  18. Basic space science

    SciTech Connect

    Haubold, H.J. (United Nations, New York, NY (USA)); Khanna, R.K. (Maryland Univ., College Park, MD (United States). Dept. of Chemistry and Biochemistry) (eds.)

    1992-01-01

    This report contains papers on the following topics: basic space science; a challenge and opportunity; solar-terrestrial interaction; solar system science; space astronomy; and astrophysics. The individual paper have been cataloged separately. (LSP)

  19. Welding in Space Workshop

    NASA Technical Reports Server (NTRS)

    Workman, Gary L.

    1990-01-01

    The potential was discussed for welding in space, its advantages and disadvantages, and what type of programs can benefit from the capability. Review of the various presentations and comments made in the course of the workshop suggests several routes to obtaining a better understanding of how welding processes can be used in NASA's initiatives in space. They are as follows: (1) development of a document identifying well processes and equipment requirements applicable to space and lunar environments; (2) more demonstrations of welding particular hardware which are to be used in the above environments, especially for space repair operations; (3) increased awareness among contractors responsible for building space equipment as to the potential for welding operations in space and on other planetary bodies; and (4) continuation of space welding research projects is important to maintain awareness within NASA that welding in space is viable and beneficial.

  20. Space spider crane

    NASA Technical Reports Server (NTRS)

    Macconochie, Ian O. (inventor); Mikulas, Martin M., Jr. (inventor); Pennington, Jack E. (inventor); Kinkead, Rebecca L. (inventor); Bryan, Charles F., Jr. (inventor)

    1988-01-01

    A space spider crane for the movement, placement, and or assembly of various components on or in the vicinity of a space structure is described. As permanent space structures are utilized by the space program, a means will be required to transport cargo and perform various repair tasks. A space spider crane comprising a small central body with attached manipulators and legs fulfills this requirement. The manipulators may be equipped with constant pressure gripping end effectors or tools to accomplish various repair tasks. The legs are also equipped with constant pressure gripping end effectors to grip the space structure. Control of the space spider crane may be achieved either by computer software or a remotely situated human operator, who maintains visual contact via television cameras mounted on the space spider crane. One possible walking program consists of a parallel motion walking program whereby the small central body alternatively leans forward and backward relative to end effectors.

  1. The Classroom Space Project.

    ERIC Educational Resources Information Center

    Verbickas, Sarah

    2002-01-01

    Introduces the Classroom Space project aimed at revitalizing science education at Key Stages 3 and 4 by using exciting examples from Space Science and Astronomy to illustrate key science concepts. (Author/YDS)

  2. Target Space Pseudoduality Between Dual Symmetric Spaces

    E-print Network

    Orlando Alvarez

    2000-05-03

    A set of on shell duality equations is proposed that leads to a map between strings moving on symmetric spaces with opposite curvatures. The transformation maps "waves" on a riemannian symmetric space to "waves" on its dual riemannian symmetric space. This transformation preserves the energy momentum tensor though it is not a canonical transformation. The preservation of the energy momentum tensor has a natural geometrical interpretation. The transformation maps "particle-like solutions" into static "soliton-like solutions". The results presented here generalize earlier results of E. Ivanov.

  3. The Tensor Theory Space

    E-print Network

    Vincent Rivasseau

    2014-07-01

    The tensor track is a background-independent discretization of quantum gravity which includes a sum over all topologies. We discuss how to define a functional renormalization group flow and the Wetterich equation in the corresponding theory space. This space is different from the Einsteinian theory space of asymptotic safety. It includes all fixed-rank tensor-invariant interactions, hence generalizes matrix models and the (Moyal) non-commutative field theory space.

  4. Animals in space

    NASA Technical Reports Server (NTRS)

    White, Angela

    1988-01-01

    Animals are indispensable to the space program. Their continued use could have many significant results. Those who are opposed to using animals in space should remember that space animals are treated humanely; they are necessary because results can be obtained from them that would be unobtainable from humans; and results from animal experiments can be applied to human systems. Therefore, NASA should continue to use animals in space research.

  5. Strongly exponential symmetric spaces

    E-print Network

    Yannick Voglaire

    2014-04-06

    We study the exponential map of connected symmetric spaces and characterize, in terms of midpoints and of infinitesimal conditions, when it is a diffeomorphism, generalizing the Dixmier-Saito theorem for solvable Lie groups. We then give a geometric characterization of the (strongly) exponential solvable symmetric spaces as those spaces for which every triangle admits a unique double triangle. This work is motivated by Weinstein's quantization by groupoids program applied to symmetric spaces.

  6. Ice in Space

    NSDL National Science Digital Library

    2012-08-03

    This is a detailed lesson about space and how Earth fits in it. Learners will consider the essential question, "What is space?" Activities include small group miming, speaking, drawing, and/or writing about space and the evidence for ice in space. Included are detailed games and dialogue. Native stories are shared. This is lesson 9 of 12 in the unit, Exploring Ice in the Solar System.

  7. Man's future in space

    NASA Technical Reports Server (NTRS)

    Freitag, R. F.

    1975-01-01

    Studies evaluating potential operational and commercial uses of space are being conducted, taking into account astronomy, astrophysics, manned bases and laboratories in earth orbit, space colonization, terrestrial communications, space processing and manufacturing, interstellar probes, planetary exploration, and the use of space for terrestrial energy supply. The present status in the exploration of the solar system is examined, giving attention to Jupiter, Venus, Mars, and Mercury. A brief outline of the development of human colonies on Mars is presented.

  8. VOIP over Space Networks

    NASA Technical Reports Server (NTRS)

    Okino, C.; Kwong, W.; Pang, Jackson; Gao, Jerry; Clare, L.

    2006-01-01

    This viewgraph presentation reviews Voice over Internet Protocol (VOIP) over a space networking environment. The topics include: 1) Drivers for VOIP in Space; 2) Challenges in the Space Networking Environment: Long Latencies, Path errors, Simplex paths, Asymmetric paths, QoS requirements, Team-based operations, and Overhead concerns; 3) Possible VOIPOSN approaches; 4) Study of BER, code type and voice frame length on PESQ-MOS; 5) Codec Latency Trade Space; and 6) Testbed.

  9. Arizona Space Grant Consortium

    NSDL National Science Digital Library

    The Arizona Space Grant Consortium's mission "is to expand opportunities for Americans to learn about and participate in NASA's aeronautics and space programs by supporting and enhancing science, and engineering education, research, and outreach programs." The website features overviews, explanations of the missions, and the histories of a number of space science projects including Moon Devils and the Students Satellite Program. Students can explore graduate fellowship and undergraduate internship opportunities. Teachers can learn about opportunities to have Space Grant Speakers visit their classrooms.

  10. Canadian 'Handshake in Space'

    NASA Technical Reports Server (NTRS)

    2001-01-01

    A Canadian 'handshake' in space occurred on April 28, 2001, as the Canadian-built space station robotic arm (Canadarm-2) transferred its launch cradle over to Endeavor's robotic arm. Marning the controls from the shuttle's aft flight deck, Canadian Mission Specialist Chris A. Hadfield of the Canadian Space Agency (CSA) was instrumental in the activity. The Spacelab pallet that carried the Canadarm2 robotic arm to the station was developed at the Marshall Space Flight Center (MSFC) in Huntsville, Alabama.

  11. Access to space: The Space Shuttle's evolving rolee

    Microsoft Academic Search

    Steven R. Duttry

    1993-01-01

    Access to space is of extreme importance to our nation and the world. Military, civil, and commercial space activities all depend on reliable space transportation systems for access to space at a reasonable cost. The Space Transportation System or Space Shuttle was originally planned to provide transportation to and from a manned Earth-orbiting space station. To justify the development and

  12. Project space vision

    Microsoft Academic Search

    Pär Edin

    1995-01-01

    This report represents the results of a survey of young space professionals, conducted on the Internet, with a view to giving them an opportunity to influence long-term space policy. The most important goals of space activity were considered to be achieving scientific progress, providing beneficial Earth applications and exploring the universe, but it was felt that these would not come

  13. Space Photography 1977 Index

    NASA Technical Reports Server (NTRS)

    1976-01-01

    An index is provided to representative photographs and transparencies available from NASA. Subjects include spacecraft, astronauts, lunar surface, planets and outer space phenomena, earth observations, and aviation. High altitude aircraft infrared photographs are included along with artists' conceptions of space shuttle and space colonies.

  14. Space processing applications bibliography

    NASA Technical Reports Server (NTRS)

    1978-01-01

    This special bibliography lists 724 articles, papers, and reports which discuss various aspects of the use of the space environment for materials science research or for commercial enterprise. The potentialities of space processing and the improved materials processes that are made possible by the unique aspects of the space environment are emphasized. References identified in April, 1978 are cited.

  15. Space variant image processing

    Microsoft Academic Search

    Richard S. Wallace; Ping-wen Ong; Benjamin B. Bederson; Eric L. Schwartz

    1994-01-01

    This paper describes a graph-based approach to image processing, intended for use with images obtained from sensors having space variant sampling grids. The connectivity graph (CG) is presented as a fundamental framework for posing image operations in any kind of space variant sensor. Partially motivated by the observation that human vision is strongly space variant, a number of research groups

  16. European Space Agency (ESA)

    NSDL National Science Digital Library

    The European Space Agency's homepage provides information on the ESA's telecommunications, navigations, Earth observations, human spaceflight missions, launches, space science, technology, industry, space operations, technical and quality management and television broadcasting. The site also contains a multimedia gallery, press releases, and an educational page for kids.

  17. Hubble Space Telescope

    NSDL National Science Digital Library

    2011-08-12

    This video segment from IdahoPTV's D4K describes the Hubble Space Telescope, shows visualizations of how optical and reflecting telescopes work, and shows original footage of the Hubble in Space. You hear why a telescope in space is valuable as well as see some of the amazing photographs the different cameras on the Hubble have taken.

  18. Radiation effects in space

    SciTech Connect

    Fry, R.J.M.

    1987-07-01

    As more people spend more time in space, and the return to the moon and exploratory missions are considered, the risks require continuing examination. The effects of microgravity and radiation are two potential risks in space. These risks increase with increasing mission duration. This document considers the risk of radiation effects in space workers and explorers. 17 refs., 1 fig., 4 tabs.

  19. Exploring the Design Space

    E-print Network

    Corina Sas; Alan Dix

    This paper explores the topic of exploration (sic) within the design space and discusses how this can support the development of research design. It highlights the relevance of reflecting upon the exploration of the design space and briefly introduces a set of techniques that can be used for this. Author Keywords Design research, design space, idea generation, reflection in action.

  20. Teacher in Space Project.

    ERIC Educational Resources Information Center

    Social Education, 1986

    1986-01-01

    Prepared by NASA, this guide contains lessons dealing with space for use in elementary and secondary social studies classes. Activities are many and varied. For example, students analyze the costs and benefits of space travel, develop their own space station, and explore the decision-making processes involved in the shuttle. (RM)

  1. Deep Space Telecommunications

    NASA Technical Reports Server (NTRS)

    Kuiper, T. B. H.; Resch, G. M.

    2000-01-01

    The increasing load on NASA's deep Space Network, the new capabilities for deep space missions inherent in a next-generation radio telescope, and the potential of new telescope technology for reducing construction and operation costs suggest a natural marriage between radio astronomy and deep space telecommunications in developing advanced radio telescope concepts.

  2. United States Space Policy

    E-print Network

    Colorado at Boulder, University of

    to consider the effects of U.S. export reg- ulations on the country's commercial space industry. Abbey the commercial space industry but also potentially the workforce on which it depended. The national security a long-term balance of commercial, military, and scientific activities in space. The project is producing

  3. SPACEWAR WIRE MILITARY SPACE

    E-print Network

    TERRORWARS SPACEDAILY TERRADAILY MARSDAILY SPACE TRAVEL SPACEMART SPACE DATABASE Endangered Species WeCHANNELS SPACEWAR WIRE MILITARY SPACE UAV NEWS MILITARY COMMS CYBERWARS MISSILE NEWS RAYGUNS project Nepal jails six soldiers for murder, human rights violations Ex-Peruvian spy chief wants CIA

  4. Space travel and gravity

    Microsoft Academic Search

    P. Karmakar; Greeninavin

    2010-01-01

    Space travelling is not possible for human because, by the time, we cross Jupiter, our bones dissolve as there is zero gravity and, by developing a gravity chamber in the space ship itself we will be able to travel in space for generations and explore the universe.

  5. Dr. Massimo Space Telescope

    E-print Network

    Zanibbi, Richard

    to work on the new WFC3 Infrared Camera for the Hubble Space Telescope. Since 2005 he is full scientistDr. Massimo Robberto Space Telescope Science Institute Massimo Robberto received in 1989 his Ph camera for the UKIRT telescope in Mauna Kea, Hawaii. In 1999 he moved to the European Space Agency

  6. Economical space power systems

    NASA Astrophysics Data System (ADS)

    Burkholder, J. H.

    1980-01-01

    A commercial approach to design and fabrication of an economical space power system is investigated. Cost projections are based on a 2 kW space power system conceptual design taking into consideration the capability for serviceability, constraints of operation in space, and commercial production engineering approaches. A breakdown of the system design, documentation, fabrication, and reliability and quality assurance estimated costs are detailed.

  7. Tropical Linear Spaces

    Microsoft Academic Search

    David E. Speyer

    2008-01-01

    We define tropical analogues of the notions of linear space and Plucker coordinate and study their combinatorics. We introduce tropical analogues of intersection and dualization and define a tropical linear space built by repeated dualization and trans- verse intersection to be constructible. Our main result that all constructible tropical linear spaces have the same f-vector and are \\

  8. Space: A new frontier

    Microsoft Academic Search

    Mona Cutolo; Denis M. Miranda

    1986-01-01

    The challenges and the promises of space colonization present an exciting opportunity for exploring and analyzing the values, the institutions and the physical environments we have created on Earth. Here we describe an interdisciplinary course, team-taught, that examines the current state of space exploration and the innovative technologies spawned by space research. The course also explores the possible social, economic,

  9. Space Weather Now

    NSDL National Science Digital Library

    Space Environment Center

    The Space Weather Now page is intended to give the non-technical user a "plain language" look at space weather. It includes information about relevant events and announcements, data from and about different instruments and satellites watching various aspects of space weather, alerts and advisories, daily themes of products and services, and links appropriate for the various groups of users.

  10. Space Jell-O

    NSDL National Science Digital Library

    American Museum of Natural History

    2012-06-26

    Albert Einstein proved that space bends around anything that has mass. This activity uses Jell-O's ability to bend around objects as a model for space bending around planets and stars. The more mass an object has, the more space (and Jell-O) bends around it. Learners can eat their model afterwards.

  11. Dependent Probability Spaces

    ERIC Educational Resources Information Center

    Edwards, William F.; Shiflett, Ray C.; Shultz, Harris

    2008-01-01

    The mathematical model used to describe independence between two events in probability has a non-intuitive consequence called dependent spaces. The paper begins with a very brief history of the development of probability, then defines dependent spaces, and reviews what is known about finite spaces with uniform probability. The study of finite…

  12. My Place, My Space

    ERIC Educational Resources Information Center

    Kostal, Heather

    2011-01-01

    Five- and six-year-olds know a lot about their own homes. Besides school, home is probably where they spend most of their time. But have they ever really thought about their space? Using students' knowledge of their current space will help them design new spaces and think about all the areas that surround them. In this project, students design…

  13. SPACE RESOURCES ROUNDTABLE IX

    E-print Network

    Rathbun, Julie A.

    SPACE RESOURCES ROUNDTABLE IX Colorado School of Mines October 25-27, 2007 http://www.ISRUinfo.com Sponsored by: Colorado School of Mines Lunar and Planetary Institute Space Resources Roundtable, Inc. First Space Michael B. Duke, Colorado School of Mines Leslie Gertsch, University of Missouri-Rolla Alex

  14. The conquest of space

    Microsoft Academic Search

    Harold B. Pepinsky

    1958-01-01

    What do we know about the physical environments in which they [our clients] live? I am surprised that the field theorists, with their central construct of life space, have not shown greater interest in this problem  There are a host of questions that can be asked about the use and effects of architecture as space  On our globe, the spaces

  15. Promoting ASEAN space cooperation

    Microsoft Academic Search

    Chukeat Noichim

    2008-01-01

    In the 21st century space activities are having an ever greater influence on global society, economics, culture and the environment; they are becoming a key tool of sustainable development. However, for many individual developing countries, including those in Southeast Asia, there actually are many obstacles to participating in the space field. Therefore in order to promote sustainable space development and

  16. Space methods in oceanology

    NASA Technical Reports Server (NTRS)

    Bolshakov, A. A.

    1985-01-01

    The study of Earth from space with specialized satellites, and from manned orbiting stations, has become important in the space programs. The broad complex of methods used for probing Earth from space are different methods of the study of ocean, dynamics. The different methods of ocean observation are described.

  17. Autonomous space shuttle

    Microsoft Academic Search

    J. A. Siders; R. H. Smith

    2004-01-01

    The continued assembly and operation of the International Space Station (ISS) is the cornerstone within NASA's overall strategic plan. As indicated in NASA's Integrated Space Transportation Plan (ISTP), the International Space Station requires shuttle to fly through at least the middle of the next decade to complete assembly of the station, provide crew transport, and to provide heavy lift up

  18. Radars in space

    NASA Technical Reports Server (NTRS)

    Delnore, Victor E.

    1990-01-01

    The capabilities of active microwave devices operating from space (typically, radar, scatterometers, interferometers, and altimeters) are discussed. General radar parameters and basic radar principles are explained. Applications of these parameters and principles are also explained. Trends in space radar technology, and where space radars and active microwave sensors in orbit are going are discussed.

  19. Storms in Space

    Microsoft Academic Search

    John W. Freeman

    2001-01-01

    Imagine what an extra-terrestrial Weather Channel would be like, with a professional space weatherman as your forecaster, and you get rather close to the astounding aspects of nature described in John Freeman's Storms in Space. Known only to a handful of space scientists, yet capable of disrupting technical systems as extensive as communication satellites and electric power grids Storms in

  20. Affordable Space Tourism: SpaceStationSim

    NASA Technical Reports Server (NTRS)

    2006-01-01

    For over 5 years, people have been living and working in space on the International Space Station (ISS), a state-of-the-art laboratory complex orbiting high above the Earth. Offering a large, sustained microgravity environment that cannot be duplicated on Earth, the ISS furthers humankind s knowledge of science and how the body functions for extended periods of time in space all of which will prove vital on long-duration missions to Mars. On-orbit construction of the station began in November 1998, with the launch of the Russian Zarya Control Module, which provided battery power and fuel storage. This module was followed by additional components and supplies over the course of several months. In November 2000, the first ISS Expedition crew moved in. Since then, the ISS has continued to change and evolve. The space station is currently 240 feet wide, measured across the solar arrays, and 171 feet long, from the NASA Destiny Laboratory to the Russian Zvezda Habitation Module. It is 90 feet tall, and it weighs approximately 404,000 pounds. Crews inhabit a living space of about 15,000 cubic feet. To date, 90 scientific investigations have been conducted on the space station. New results from space station research, from basic science to exploration research, are being published each month, and more breakthroughs are likely to come. It is not all work on the space station, though. The orbiting home affords many of the comforts one finds on Earth. There is a weightless "weight room" and even a musical keyboard alongside research facilities. Holidays are observed, and with them, traditional foods such as turkey and cobbler are eaten, with lemonade to wash them down

  1. Extragalactic Radio Jets and Intergalactic Medium 2

    NASA Technical Reports Server (NTRS)

    Birkinshaw, Mark

    2000-01-01

    During the mid 1990s, the ROSAT satellite provided the highest resolution X-ray imaging, with useful X-ray spectroscopy, and excellent sensitivity. ROSAT"s PSPC and HRI instruments gave us our first high-quality data on the AGN phenomenon in nearby galaxies - the central theme of this research project. Initially this project concentrated on separating the AGN-related component of the X-ray emission from thermal radiation from the surrounding atmospheres in radio galaxies. There was ample reason to believe that this separation would be possible, although earlier work had taken the view that the X-ray emission from radio galaxies is either wholly AGN-related (and hence of sub-arcsec scale), or wholly from the galaxy and cluster atmospheres (and hence of scales - 10 arcsec or more in the low-redshift radio galaxies that we chose to study). First with the PSPC, and then with the HRI, we proved that a wide range of AGN core X ray emissivities could be found, and that the generic radio galaxy produces both AGN-related and atmosphere-related X-radiation. We demonstrated that there is a close relationship between the core X-ray power and the core radio power, and found instances in which the hot atmospheres of the galaxies must be participating in cooling flows, and other cases where those atmospheres are relatively stable. In some cases, there is a clear active relationship between the extended radio emission and the X-ray atmospheres: thus in NGC 326, we interpret the distorted radio structure as evidence of buoyancy as the radio plasma rises through the cluster atmosphere. In 3C 449, we can see that the radio plasma is displacing the X-ray emitting gas. In a further case (NGC 1265), we hoped that the motion of a radio galaxy through a cluster atmosphere would be apparent though the wake that it might establish - unfortunately, other structure in the atmosphere of the Perseus cluster tends to dominate our X-ray image, and no useful limits could be placed on the strength of the wake. In the light of so-called "unified" models of AGN, it is expected that the low-power radio galaxies studied under these programmes are the unbeamed counterparts of BL Lac objects. Accordingly, we predicted that BL Lac objects, as a class, should show X-ray halos from atmospheres similar to those associated with radio galaxies. The difficulty with studying this is that BL Lac objects tend to be X-ray bright, and the halos then vanish under the wings of the point response function. We found a BL Lac with less of a dynamic range problem, mapped it with the ROSAT HRI, and duly found an atmosphere (Hardcastle et al. 1999). Unfortunately for unification models, this atmosphere is exceptionally dense, so that it must be participating in an intense cooling flow. The implications of this for unification models are far from clear, and further work is under way.

  2. Metal enrichment of the intergalactic medium

    E-print Network

    Nickolay Y. Gnedin

    1997-09-23

    I demonstrate by means of high resolution cosmological simulations, which include modelling of a two-phase interstellar medium, that the dominant mechanism for transporting heavy elements from the proto-galaxies into the IGM is the merger mechanism as discovered by Gnedin & Ostriker. Direct ejection of the interstellar gas by supernovae plays only a minor role in transporting metals into the IGM: for a realistic cosmological scenario only a small fraction of all metals in the IGM is delivered by the supernova-driven winds, while most of all metals in the IGM are transported by the merger mechanism. As the result, the metallicity distribution in the IGM is highly inhomogeneous, in agreement with studies of the QSO metal absorption systems, and the predicted metallicity distribution of Lyman-alpha absorbers as a function of their column density is in excellent agreement with the observational data.

  3. Space Management for Medical Education.

    ERIC Educational Resources Information Center

    Agro, Dino

    1978-01-01

    A reference on current methods and procedures for managing space in academic medical centers is provided. Focus is on elements of space management systems that can enhance the effectiveness of space allocation decisions. These include: space inventory, space standards, evaluation of space utilization, and space allocation. A bibliography is…

  4. TANK SPACE OPTIONS REPORT

    SciTech Connect

    WILLIS WL; AHRENDT MR

    2009-08-11

    Since this report was originally issued in 2001, several options proposed for increasing double-shell tank (DST) storage space were implemented or are in the process of implementation. Changes to the single-shell tank (SST) waste retrieval schedule, completion of DST space saving options, and the DST space saving options in progress have delayed the projected shortfall of DST storage space from the 2007-2011 to the 2018-2025 timeframe (ORP-11242, River Protection Project System Plan). This report reevaluates options from Rev. 0 and includes evaluations of new options for alleviating projected restrictions on SST waste retrieval beginning in 2018 because of the lack of DST storage space.

  5. Madrid space station

    NASA Technical Reports Server (NTRS)

    Fahnestock, R. J.; Renzetti, N. A.

    1975-01-01

    The Madrid space station, operated under bilateral agreements between the governments of the United States and Spain, is described in both Spanish and English. The space station utilizes two tracking and data acquisition networks: the Deep Space Network (DSN) of the National Aeronautics and Space Administration and the Spaceflight Tracking and Data Network (STDN) operated under the direction of the Goddard Space Flight Center. The station, which is staffed by Spanish employees, comprises four facilities: Robledo 1, Cebreros, and Fresnedillas-Navalagamella, all with 26-meter-diameter antennas, and Robledo 2, with a 64-meter antenna.

  6. Storms in Space

    NASA Astrophysics Data System (ADS)

    Freeman, John W.

    2012-11-01

    Introduction; The cast of characters; Vignettes of the storm; 1. Two kinds of weather; 2. The saga of the storm; 3. Weather stations in space; 4. Lights in the night: the signature of the storm; 5. A walking tour of the magnetosphere; 6. The sun: where it all begins; 7. Nowcasting and forecasting storms in space; 8. Technology and the risks from storms in space; 9. A conversation with Joe Allen; 10. Manned exploration and space weather hazards; 11. The present and future of space weather forecasting; Mathematical appendix. A closer look; Glossary; Figure captions.

  7. The Space Science Group

    NSDL National Science Digital Library

    1997-01-01

    The Space Science Group is part of the Division of Mathematics and Sciences at Northwestern State University in Natchitoches, La. The mission of The Space Science Group is to provide activities that encourage participation in math and science, build knowledge of basic concepts, teach basic science skill, and positively influence attitudes. The mission of The Space Science Group is to develop and implement programs which use aspects of the space program to motivate students to study mathematics and science. Many Space Science Group programs are described at the URL below.

  8. Canadian 'Handshake in Space'

    NASA Technical Reports Server (NTRS)

    2001-01-01

    A Canadian 'handshake' in space occurred on April 28, 2001, as the Canadian-built space station robotic arm (Canadarm2) transferred its launch cradle over to Endeavour's robotic arm. Pictured is astronaut James S. Voss, Expedition Two flight engineer, working the controls of the new robotic arm. Marning the controls from the shuttle's aft flight deck, Canadian Mission Specialist Chris A. Hadfield of the Canadian Space Agency (CSA) was instrumental in the activity. The Space lab pallet that carried the Canadarm2 robotic arm to the station was developed at the Marshall Space Flight Center (MSFC) in Huntsville, Alabama.

  9. Overview and Recent Accomplishments of the Advanced Mirror Technology Development (AMTD) for Large Aperture UVOIR Space Telescopes Project

    NASA Technical Reports Server (NTRS)

    Stahl, H. Philip

    2013-01-01

    Per Astro2010, a new, larger UVO telescope is needed to answer fundamental scientific questions, such as: is there life on Earth-like exoplanets; how galaxies assemble stellar populations; how baryonic matter interacts with intergalactic medium; and how solar systems form and evolve. And, present technology is not mature enough to affordably build and launch any potential UVO concept. Advanced Mirror Technology Development (AMTD) is a funded SAT project. Our objective is to mature to TRL-6 the critical technologies needed to produce 4-m or larger flight-qualified UVOIR mirrors by 2018 so that a viable mission can be considered by the 2020 Decadal Review. AMTD uses a science-driven systems engineering approach. We mature technologies required to enable the highest priority science AND result in a high-performance low-cost low-risk system. To provide the science community with options, we are pursuing multiple technology paths. We have assembled an outstanding team from academia, industry, and government with extensive expertise in astrophysics and exoplanet characterization, and in the design/manufacture of monolithic and segmented space telescopes. One of our key accomplishments is that we have derived engineering specifications for advanced normal-incidence monolithic and segmented mirror systems needed to enable both general astrophysics and ultra-high contrast observations of exoplanets missions as a function of potential launch vehicle and its inherent mass and volume constraints. We defined and initiated a program to mature 6 key technologies required to fabricate monolithic and segmented space mirrors.

  10. Space Food Systems Laboratory

    NASA Technical Reports Server (NTRS)

    Perchonok, Michele; Russo, Dane M. (Technical Monitor)

    2001-01-01

    The Space Food Systems Laboratory (SFSL) is a multipurpose laboratory responsible for space food and package research and development. It is located on-site at Johnson Space Center in Building 17. The facility supports the development of flight food, menus, packaging and food related hardware for Shuttle, International Space Station, and Advanced Life Support food systems. All foods used to support NASA ground tests and/or missions must meet the highest standards before they are 'accepted' for use on actual space flights. The foods are evaluated for nutritional content, sensory acceptability, safety, storage and shelf life, and suitability for use in micro-gravity. The food packaging is also tested to determine its functionality and suitability for use in space. Food Scientist, Registered Dieticians, Packaging Engineers, Food Systems Engineers, and Technicians staff the Space Food Systems Laboratory.

  11. SPACE (ROOMS) INVENTORY -CASUARINA CAMPUS Old Space No New Space No Description

    E-print Network

    SPACE (ROOMS) INVENTORY - CASUARINA CAMPUS Old Space No New Space No Description C47. 1.01 1 Yard and Driveway Old Space No New Space No Description ------ 1.01 Tool Store ------ 1.02 Machinery Park ------ 1.03 Toilet - Male ------ 1.04 Toilet - Fem Old Space No New Space No Description ------ 1

  12. Making space law relevant to basic space science in the commercial space age

    Microsoft Academic Search

    Sriram Swaminathan

    2005-01-01

    Space science has been at the heart of humanity's activity in space, a fact reflected in the body of space law set up to regulate such activity. The increase in commercial utilisation of space may threaten the conduct of space science; reform of space law, however, could alleviate this situation. Using the examples of radio and light interference, and space

  13. National Aeronautics and Space Administration Commercial Space Committee

    E-print Network

    Waliser, Duane E.

    __________________________________ ________________________________________ National Aeronautics and Space Administration Commercial Space Committee of the NASA Advisory Council November 26, 2012 NASA Commercial Space Committee Commercial Space Committee Meeting report prepared by Elizabeth Sheley #12;NAC

  14. National Aeronautics and Space Administration Space Life and Physical Sciences

    E-print Network

    Waliser, Duane E.

    National Aeronautics and Space Administration Space Life and Physical Sciences D National Laboratory management organization (CASIS) #12;National Aeronautics and Space Administration #12;National Aeronautics and Space Administration geneLAB Campaign Progress To move forward

  15. National Aeronautics and Space Administration Commercial Space Committee

    E-print Network

    Waliser, Duane E.

    ___________________________________ __________________________________ National Aeronautics and Space Administration Commercial Space Committee of the NASA Advisory Council July 30, 2013 NASA Commercial Space Committee Commercial Space Committee Meeting report prepared by Jill Hacker Zantech IT #12

  16. National Aeronautics and Space Administration Human Space Exploration

    E-print Network

    Waliser, Duane E.

    National Aeronautics and Space Administration Human Space Exploration Framework Summary For Public Release 1 #12;Overview Context and approach for human space exploration Key guiding time. Human Space Exploration Architecture Planning Human spaceflight (HSF) programs

  17. Space Debris and Space Safety - Looking Forward

    NASA Astrophysics Data System (ADS)

    Ailor, W.; Krag, H.

    Man's activities in space are creating a shell of space debris around planet Earth which provides a growing risk of collision with operating satellites and manned systems. Including both the larger tracked objects and the small, untracked debris, more than 98% of the estimated 600,000 objects larger than 1 cm currently in orbit are “space junk”--dead satellites, expended rocket stages, debris from normal operations, fragments from explosions and collisions, and other material. Recognizing the problem, space faring nations have joined together to develop three basic principles for minimizing the growth of the debris population: prevent on-orbit breakups, remove spacecraft and orbital stages that have reached the end of their mission operations from the useful densely populated orbit regions, and limit the objects released during normal operations. This paper provides an overview of what is being done to support these three principles and describes proposals that an active space traffic control service to warn satellite operators of pending collisions with large objects combined with a program to actively remove large objects may reduce the rate of future collisions. The paper notes that cost and cost effectiveness are important considerations that will affect the evolution of such systems.

  18. NATIONAL AERONAUTICS AND SPACE ADMINISTRATION BRITISH NATIONAL SPACE CENTRE

    E-print Network

    Crowther, Paul

    NATIONAL AERONAUTICS AND SPACE ADMINISTRATION­ BRITISH NATIONAL SPACE CENTRE JOINT WORKING GROUP ................................................................................................................ 14 6. UK PPP for NASA Commercial Development

  19. SPACE SHUTTLE PROGRAM Space Shuttle Projects Office (MSFC)

    E-print Network

    Christian, Eric

    SPACE SHUTTLE PROGRAM Space Shuttle Projects Office (MSFC) NASA Marshall Space Flight Center, Huntsville, Alabama January 9, 2003 1 STS-107/ET-93 Flight Readiness Review External Tank Project #12;SPACE SHUTTLE PROGRAM Space Shuttle Projects Office (MSFC) NASA Marshall Space Flight Center, Huntsville

  20. Public choice economics and space policy: realising space tourism

    Microsoft Academic Search

    Patrick Collins

    2001-01-01

    Government space agencies have the statutory responsibility to suport the commercialisation of space activities. NASA's 1998 report “General Public Space Travel and Tourism” concluded that passenger space travel can start using already existing technology, and is likely to grow into the largest commercial activity in space: it is therefore greatly in taxpayers' economic interest that passenger space travel and accommodation

  1. Space Systems Finland 1 Deployment in the Space Sector

    E-print Network

    Southampton, University of

    © Space Systems Finland 1 Deployment in the Space Sector #12;© Space Systems Finland 2 SW Constraints Design Requirements User Requirements SW Requirements #12;© Space Systems Finland 3 The space, but there is no viable alternative · Many requirements are not testable #12;© Space Systems Finland 4 SSF OBJECTIVES

  2. space for science, enterprise and environment Bringing Space Into School

    E-print Network

    space for science, enterprise and environment Bringing Space Into School Science The National Space Education Initiative #12;space for science, enterprise and environment National Space Education Initiative the consultations · Recommendations of the report #12;space for science, enterprise and environment Background

  3. UCL DEPARTMENT OF SPACE & CLIMATE PHYSICS SPACE PLASMA PHYSICS GROUP

    E-print Network

    UCL DEPARTMENT OF SPACE & CLIMATE PHYSICS SPACE PLASMA PHYSICS GROUP 18th September 2012 STFC 2012 #12;UCL DEPARTMENT OF SPACE & CLIMATE PHYSICS SPACE PLASMA PHYSICS GROUP 18th September 2012 STFC · Conclusion #12;UCL DEPARTMENT OF SPACE & CLIMATE PHYSICS SPACE PLASMA PHYSICS GROUP 18th September 2012 STFC

  4. SPACE SHUTTLE PROGRAM Space Shuttle Projects Office (MSFC)

    E-print Network

    Christian, Eric

    SPACE SHUTTLE PROGRAM Space Shuttle Projects Office (MSFC) NASA Marshall Space Flight Center;SPACE SHUTTLE PROGRAM Space Shuttle Projects Office (MSFC) NASA Marshall Space Flight Center, Huntsville, Alabama Presenter Date Page 2September 17, 2002 J. Pilet / LMSSC-ET Overview · Limited Life Component

  5. Space Resources Roundtable 2

    NASA Technical Reports Server (NTRS)

    Ignatiev, A.

    2000-01-01

    Contents include following: Developing Technologies for Space Resource Utilization - Concept for a Planetary Engineering Research Institute. Results of a Conceptual Systems Analysis of Systems for 200 m Deep Sampling of the Martian Subsurface. The Role of Near-Earth Asteroids in Long-Term Platinum Supply. Core Drilling for Extra-Terrestrial Mining. Recommendations by the "LSP and Manufacturing" Group to the NSF-NASA Workshop on Autonomous Construction and Manufacturing for Space Electrical Power Systems. Plasma Processing of Lunar and Planetary Materials. Percussive Force Magnitude in Permafrost. Summary of the Issues Regarding the Martian Subsurface Explorer. A Costing Strategy for Manufacturing in Orbit Using Extraterrestrial Resources. Mine Planning for Asteroid Orebodies. Organic-based Dissolution of Silicates: A New Approach to Element Extraction from LunarRegohth. Historic Frontier Processes Active in Future Space-based Mineral Extraction. The Near-Earth Space Surveillance (NIESS) Mission: Discovery, Tracking, and Characterization of Asteroids, Comets, and Artificial Satellites with a microsatellite. Privatized Space Resource Property Ownership. The Fabrication of Silicon Solar Cells on the Moon Using In-Situ Resources. A New Strategy for Exploration Technology Development: The Human Exploration and Development of Space (HEDS) Exploratiori/Commercialization Technology Initiative. Space Resources for Space Tourism. Recovery of Volatiles from the Moon and Associated Issues. Preliminary Analysis of a Small Robot for Martian Regolith Excavation. The Registration of Space-based Property. Continuous Processing with Mars Gases. Drilling and Logging in Space; An Oil-Well Perspective. LORPEX for Power Surges: Drilling, Rock Crushing. An End-To-End Near-Earth Asteroid Resource Exploitation Plan. An Engineering and Cost Model for Human Space Settlement Architectures: Focus on Space Hotels and Moon/Mars Exploration. The Development and Realization of a Silicon-60-based Economy in CisLunar Space. Our Lunar Destiny: Creating a Lunar Economy. Cost-Effective Approaches to Lunar Passenger Transportation. Lunar Mineral Resources: Extraction and Application. Space Resources Development - The Link Between Human Exploration and the Long-term Commercialization of Space. Toward a More Comprehensive Evaluation of Space Information. Development of Metal Casting Molds by Sol-Gel Technology Using Planetary Resources. A New Concept in Planetary Exploration: ISRU with Power Bursts. Bold Space Ventures Require Fervent Public Support. Hot-pressed Iron from Lunar Soil. The Lunar Dust Problem: A Possible Remedy. Considerations on Use of Lunar Regolith in Lunar Constructions. Experimental Study on Water Production by Hydrogen Reduction of Lunar Soil Simulant in a Fixed Bed Reactor.

  6. National Aeronautics and Space Administration

    E-print Network

    Lüttgen, Gerald

    National Aeronautics and Space Administration Langley Research Center Hampton, Virginia 23681 state space generators 30 . This work was supported by the National Aeronautics and Space Administration State-space Generation Gianfranco Ciardo The College of William & Mary, Williamsburg, Virginia Gerald

  7. Space resources. Overview

    NASA Technical Reports Server (NTRS)

    Mckay, Mary Fae (editor); Mckay, David S. (editor); Duke, Michael B. (editor)

    1992-01-01

    Space resources must be used to support life on the Moon and in the exploration of Mars. Just as the pioneers applied the tools they brought with them to resources they found along the way rather than trying to haul all their needs over a long supply line, so too must space travelers apply their high technology tools to local resources. This overview describes the findings of a study on the use of space resources in the development of future space activities and defines the necessary research and development that must precede the practical utilization of these resources. Space resources considered included lunar soil, oxygen derived from lunar soil, material retrieved from near-Earth asteroids, abundant sunlight, low gravity, and high vacuum. The study participants analyzed the direct use of these resources, the potential demand for products from them, the techniques for retrieving and processing space resources, the necessary infrastructure, and the economic tradeoffs.

  8. The International Space University

    NASA Technical Reports Server (NTRS)

    Davidian, Kenneth J.

    1990-01-01

    The International Space University (ISU) was founded on the premise that any major space program in the future would require international cooperation as a necessary first step toward its successful completion. ISU is devoted to being a leading center for educating future authorities in the world space industry. ISU's background, goals, current form, and future plans are described. The results and benefits of the type of education and experience gained from ISU include technical reports describing the design projects undertaken by the students, an exposure to the many different disciplines which are a part of a large space project, an awareness of the existing activities from around the world in the space community, and an international professional network which spans all aspects of space activities and covers the globe.

  9. Space platforms/stations

    NASA Technical Reports Server (NTRS)

    Priest, C. C.

    1981-01-01

    Platforms in low-earth orbit are examined as simple and cost-effective solutions to the problem of long-duration space flight, providing stability, utilities and access for a variety of Shuttle-tended replaceable payloads over extended periods of time. The requirements for space platforms, which will encompass the advantages of both the free-flying and Shuttle-Spacelab operational modes, are discussed, with consideration given to payloads, operations and platform systems, and the status of the space platform concept, which is expected to begin development in early 1983 following definition studies and design selection, is noted. Possible paths in the evolution of space platform facilities to more advanced concepts are then outlined. Finally, the concept of the Science and Applications Manned Space Platform is examined as the first step toward a permanent manned United States presence in space.

  10. Space biology research development

    NASA Technical Reports Server (NTRS)

    Bonting, Sjoerd L.

    1993-01-01

    The purpose of the Search for Extraterrestrial Intelligence (SETI) Institute is to conduct and promote research related activities regarding the search for extraterrestrial life, particularly intelligent life. Such research encompasses the broad discipline of 'Life in the Universe', including all scientific and technological aspects of astronomy and the planetary sciences, chemical evolution, the origin of life, biological evolution, and cultural evolution. The primary purpose was to provide funding for the Principal Investigator to collaborate with the personnel of the SETI Institute and the NASA-Ames Research center in order to plan and develop space biology research on and in connection with Space Station Freedom; to promote cooperation with the international partners in the space station; to conduct a study on the use of biosensors in space biology research and life support system operation; and to promote space biology research through the initiation of an annual publication 'Advances in Space Biology and Medicine'.

  11. Quantum-Space Attacks

    E-print Network

    Ran Gelles; Tal Mor

    2007-11-25

    Theoretical quantum key distribution (QKD) protocols commonly rely on the use of qubits (quantum bits). In reality, however, due to practical limitations, the legitimate users are forced to employ a larger quantum (Hilbert) space, say a quhexit (quantum six-dimensional) space, or even a much larger quantum Hilbert space. Various specific attacks exploit of these limitations. Although security can still be proved in some very special cases, a general framework that considers such realistic QKD protocols, as well as} attacks on such protocols, is still missing. We describe a general method of attacking realistic QKD protocols, which we call the `quantum-space attack'. The description is based on assessing the enlarged quantum space actually used by a protocol, the `quantum space of the protocol'. We demonstrate these new methods by classifying various (known) recent attacks against several QKD schemes, and by analyzing a novel attack on interferometry-based QKD.

  12. Gymnastics in Phase Space

    SciTech Connect

    Chao, Alexander Wu; /SLAC

    2012-03-01

    As accelerator technology advances, the requirements on accelerator beam quality become increasingly demanding. Facing these new demands, the topic of phase space gymnastics is becoming a new focus of accelerator physics R&D. In a phase space gymnastics, the beam's phase space distribution is manipulated and precision tailored to meet the required beam qualities. On the other hand, all realization of such gymnastics will have to obey accelerator physics principles as well as technological limitations. Recent examples of phase space gymnastics include Emittance exchanges, Phase space exchanges, Emittance partitioning, Seeded FELs and Microbunched beams. The emittance related topics of this list are reviewed in this report. The accelerator physics basis, the optics design principles that provide these phase space manipulations, and the possible applications of these gymnastics, are discussed. This fascinating new field promises to be a powerful tool of the future.

  13. Ultrasound in space

    NASA Technical Reports Server (NTRS)

    Martin, David S.; South, Donna A.; Garcia, Kathleen M.; Arbeille, Philippe

    2003-01-01

    Physiology of the human body in space has been a major concern for space-faring nations since the beginning of the space era. Ultrasound (US) is one of the most cost effective and versatile forms of medical imaging. As such, its use in characterizing microgravity-induced changes in physiology is being realized. In addition to the use of US in related ground-based studies, equipment has also been modified to fly in space. This involves alteration to handle the stresses of launch and different power and cooling requirements. Study protocols also have been altered to accommodate the microgravity environment. Ultrasound studies to date have shown a pattern of adaptation to microgravity that includes changes in cardiac chamber sizes and vertebral spacing. Ultrasound has been and will continue to be an important component in the investigation of physiological and, possibly, pathologic changes occurring in space or as a result of spaceflight.

  14. Presidents and Space Policy

    Microsoft Academic Search

    Linda Krug

    There are more factors, such as partisanship, changing ideology, and pork-barrel politics,84 which have played a role in the failure of Presidents to establish a long-term space exploration program and the corresponding space policy. These other factors are addressed elsewhere in this book primarily in the next chapter on Congress and Space Policy. The five factors discussed in this chapter-level

  15. Aging and space travel

    NASA Technical Reports Server (NTRS)

    Mohler, S. R.

    1982-01-01

    The matter of aging and its relation to space vehicle crewmembers undertaking prolonged space missions is addressed. The capabilities of the older space traveler to recover from bone demineralization and muscle atrophy are discussed. Certain advantages of the older person are noted, for example, a greater tolerance of monotony and repetitious activities. Additional parameters are delineated including the cardiovascular system, the reproductive system, ionizing radiation, performance, and group dynamics.

  16. Space construction data base

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Construction of large systems in space is a technology requiring the development of construction methods to deploy, assemble, and fabricate the elements comprising such systems. A construction method is comprised of all essential functions and operations and related support equipment necessary to accomplish a specific construction task in a particular way. The data base objective is to provide to the designers of large space systems a compendium of the various space construction methods which could have application to their projects.

  17. Whippo Problem Space

    NSDL National Science Digital Library

    Sam Donovan (University of Pittsburgh; Department of Learning and Instruction)

    2005-12-17

    This problem space provides resources for going beyond the discussions of whale evolution presented in biology textbooks to look at how different types of data can be used to resolve this set of phylogenetic puzzles and to explore other related questions. In addition to providing some background on this topic the problem space has: * rich data resources for examining evolutionary relationships * curricular materials focusing on tree reading and interpretation * some suggestions for ways to extend this problem space with related research projects

  18. THz Sources for Space

    NASA Technical Reports Server (NTRS)

    Siegel, Peter H.; Ward, John; Maiwald, Frank; Mehdi, Imran

    2007-01-01

    Terahertz is the primary frequency for line and continuum radiation from cool (5-100K) gas (atoms and molecules) and dust. This viewgraph presentation reviews the reasons for the interest in Terahertz Space Applications; the Terahertz Space Missions: in the past, present and planned for the future, Terahertz source requirements and examples of some JPL instruments; and a case study for a flight deliverable: THz Local Oscillators for ESA s Herschel Space Telescope

  19. Space applications of superconductivity

    NASA Technical Reports Server (NTRS)

    Sullivan, D. B.; Vorreiter, J. W.

    1979-01-01

    Some potential applications of superconductivity in space are summarized, e.g., the use of high field magnets for cosmic ray analysis or energy storage and generation, space applications of digital superconducting devices, such as the Josephson switch and, in the future, a superconducting computer. Other superconducting instrumentation which could be used in space includes: low frequency superconducting sensors, microwave and infrared detectors, instruments for gravitational studies, and high-Q cavities for use as stabilizing elements in clocks and oscillators.

  20. Astronaut Memorial Space Mirror

    NASA Technical Reports Server (NTRS)

    2003-01-01

    A view of the Astronaut Memorial Space Mirror at the Kennedy Space Center Visitor Complex. The memorial is a national tribute to the 17 American astronauts who gave their lives in the quest to explore space. The memorial has received added attention since the loss of the Columbia crew on February 1, 2003, when they perished in an explosion as they were returning to Earth from mission STS-107. For more information on STS-107, please see GRIN Columbia General Explanation

  1. Technology for space station

    NASA Astrophysics Data System (ADS)

    Colladay, R. S.; Carlisle, R. F.

    1984-10-01

    Some of the most significant advances made in the space station discipline technology program are examined. Technological tasks and advances in the areas of systems/operations, environmental control and life support systems, data management, power, thermal considerations, attitude control and stabilization, auxiliary propulsion, human capabilities, communications, and structures, materials, and mechanisms are discussed. An overview of NASA technology planning to support the initial space station and the evolutionary growth of the space station is given.

  2. Diffusion on ?-Minkowski space

    NASA Astrophysics Data System (ADS)

    Arzano, Michele; Trze?niewski, Tomasz

    2014-06-01

    We study the spectral dimension associated with diffusion processes on Euclidean ?-Minkowski space. We start by describing a geometric construction of the "Euclidean" momentum group manifold related to ?-Minkowski space. On such space we identify various candidate Laplacian functions, i.e. deformed Casimir invariants, and calculate the corresponding spectral dimension for each case. The results obtained show a variety of running behaviors for the spectral dimension according to the choice of deformed Laplacian, from dimensional reduction to superdiffusion.

  3. Basics of Space Flight

    NSDL National Science Digital Library

    This training module was designed to help the user identify and grasp basic concepts associated with space travel and deep space missions. Separate sections deal with topics such as the physical environment of space (solar system, gravity, orbital mechanics), flight projects (mission concepts, system requirements, design, onboard systems and instruments), and flight operations (launch, cruise, encounter). Links to related topics are embedded in the text.

  4. news.space

    NSDL National Science Digital Library

    From Science Matters, a company aiming to increase scientific knowledge of every individual, news.space is a gathering of information on current space topics. General knowledge categories include spacecraft, mars, space, and solar; content in each category, most of which consists of hyperlinks to other sites, ranges from news releases to high quality photo images to background information on relevant topics. Chat and Multimedia sections give users the opportunity to visit chat sites, view videos, and listen to recordings.

  5. Space Mechanisms Technology Workshop

    NASA Technical Reports Server (NTRS)

    Oswald, Fred B. (Editor)

    2001-01-01

    The Mechanical Components Branch at NASA Glenn Research Center hosted a workshop to discuss the state of drive systems technology needed for space exploration. The Workshop was held Thursday, November 2, 2000. About 70 space mechanisms experts shared their experiences from working in this field and considered technology development that will be needed to support future space exploration in the next 10 to 30 years.

  6. Space Odyssey Gift Shop

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The Space Odyssey Gift Shop located in StenniSphere at the John C. Stennis Space Center in Hancock County, Miss., offers every visitor the opportunity to go home with 'the right stuff' from his or her StenniSphere visit. The gift shop is located just inside the front doors to StenniSphere and offers a wide range of space-related apparel, memorabilia, toys, books, mission patches and more.

  7. Matter: Space without Time

    E-print Network

    Yousef Ghazi-Tabatabai

    2012-11-19

    While Quantum Gravity remains elusive and Quantum Field Theory retains the interpretational difficulties of Quantum Mechanics, we have introduced an alternate approach to the unification of particles, fields, space and time, suggesting that the concept of matter as space without time provides a framework which unifies matter with spacetime and in which we anticipate the development of complete theories (ideally a single unified theory) describing observed 'particles, charges, fields and forces' solely with the geometry of our matter-space-time universe.

  8. SSC Space Physics Tutorial

    NSDL National Science Digital Library

    Provided by the Space Physics Center of the UCLA Institute of Geophysics and Planetary Physics, the Space Physics Tutorial gives advanced high school and college students an introduction to Space Physics. Topics include the magnetosphere, magnetopause, the Pioneer Venus Mission, planetary magnetospheres, and more. Two downloadable papers are also available in Adobe Acrobat (.pdf) format entitled: Solar Wind and Interplanetary Magnetic Field: A Tutorial and The Solar Wind Interaction with the Earth's Magnetosphere: A Tutorial.

  9. Commercialization of the Space Frontier

    NASA Technical Reports Server (NTRS)

    Piland, William M.

    1997-01-01

    This paper discusses the current outlook for space business, how growing space business will improve the quality of life for all, and identified strategies for better relating international space research, technology, and space system operations to commercial interests in space. By drawing on recent assessments of the future potential for business in space, opportunities will be defined for encouraging the growth of business uses of space and regaining the public's awareness and support for expanding the space frontier.

  10. AB Space Engine

    E-print Network

    Alexander Bolonkin

    2008-03-02

    On 4 January 2007 the author published the article Wireless Transfer of Electricity in Outer Space in http://arxiv.org wherein he offered and researched a new revolutionary method of transferring electric energy in space. In that same article, he offered a new engine which produces a large thrust without throwing away large amounts of reaction mass (unlike the conventional rocket engine). In the current article, the author develops the theory of this kind of impulse engine and computes a sample project which shows the big possibilities opened by this new AB-Space Engine. The AB-Space Engine gets the energy from ground-mounted power; a planet electric station can transfer electricity up to 1000 millions (and more) of kilometers by plasma wires. Author shows that AB-Space Engine can produce thrust of 10 tons (and more). That can accelerate a space ship to some thousands of kilometers/second. AB-Space Engine has a staggering specific impulse owing to the very small mass expended. The AB-Space Engine reacts not by expulsion of its own mass (unlike rocket engine) but against the mass of its planet of origin (located perhaps a thousand of millions of kilometers away) through the magnetic field of its plasma cable. For creating this plasma cable the AB-Space Engine spends only some kg of hydrogen.

  11. Space Weather: Welcome, SEC

    NSDL National Science Digital Library

    COMET

    2005-01-11

    This video presentation welcomes the Space Weather Prediction Center, formerly known as the Space Environment Center or SEC to the National Weather Service (NWS) as an operational entity of the National Centers for Environmental Prediction (NCEP) family. Describing the ways in which space weather affects global communications and power resources, it demonstrates the importance of space weather forecasting as a part of the NWS family of services. With the inclusion of SWPC, the NWS now provides environmental understanding from the sun to the sea.

  12. Kennedy Space Center

    NASA Technical Reports Server (NTRS)

    Griffin, Amanda

    2012-01-01

    Among 2011's many accomplishments, we safely retired the Space Shuttle Program after 30 incredible years; completed the International Space Station and are taking steps to enable it to reach its full potential as a multi-purpose laboratory; and helped to expand scientific knowledge with missions like Aquarius, GRAIL, and the Mars Science Laboratory. Responding to national budget challenges, we are prioritizing critical capabilities and divesting ourselves of assets no longer needed for NASA's future exploration programs. Since these facilities do not have to be maintained or demolished, the government saves money. At the same time, our commercial partners save money because they do not have to build new facilities. It is a win-win for everyone. Moving forward, 2012 will be even more historically significant as we celebrate the 50th Anniversary of Kennedy Space Center. In the coming year, KSC will facilitate commercial transportation to low-Earth orbit and support the evolution of the Space Launch System and Orion crew vehicle as they ready for exploration missions, which will shape how human beings view the universe. While NASA's Vision is to lead scientific and technological advances in aeronautics and space for a Nation on the frontier of discovery KSC's vision is to be the world's preeminent launch complex for government and commercial space access, enabling the world to explore and work in space. KSC's Mission is to safely manage, develop, integrate, and sustain space systems through partnerships that enable innovative, diverse access to space and inspires the Nation's future explorers.

  13. Space construction activities

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The Center for Space Construction at the University of Colorado at Boulder was established in 1988 as a University Space Engineering Research Center. The mission of the Center is to conduct interdisciplinary engineering research which is critical to the construction of future space structures and systems and to educate students who will have the vision and technical skills to successfully lead future space construction activities. The research activities are currently organized around two central projects: Orbital Construction and Lunar Construction. Summaries of the research projects are included.

  14. SpaceRef

    NSDL National Science Digital Library

    This resource is aimed at professionals and informed users with a strong interest in astronomy and astronautics, and the second can be enjoyed by kids of all ages. While the content in some of the multiple categories in SpaceRef's Space Directory is currently a little thin, the site is clearly designed from the ground-up to host a wide array of space resources. In addition to the directory, the site also features breaking news, analysis, full-text briefs from NASA and the European Space Agency (ESA), a calendar of events and launches, and special sections on current missions.

  15. Adventures in Space Medicine

    NASA Technical Reports Server (NTRS)

    Billica, Roger D.

    1999-01-01

    Human space flight experience has demonstrated a variety of hazards and risks to health and performance. In developing ways to help respond to these issues, the field of space medicine has developed a comprehensive program of space flight health risk management that has resulted in positive contributions to medicine and society in general. Examples include accelerated focus on critical health issues such as aging and osteoporosis, and development of new technologies such as non-invasive diagnostic testing for diabetics. The role of health care professionals in human space exploration represents a fulfillment of new adventures and expanding frontiers.

  16. Space station structures development

    NASA Technical Reports Server (NTRS)

    Teller, V. B.

    1986-01-01

    A study of three interrelated tasks focusing on deployable Space Station truss structures is discussed. Task 1, the development of an alternate deployment system for linear truss, resulted in the preliminary design of an in-space reloadable linear motor deployer. Task 2, advanced composites deployable truss development, resulted in the testing and evaluation of composite materials for struts used in a deployable linear truss. Task 3, assembly of structures in space/erectable structures, resulted in the preliminary design of Space Station pressurized module support structures. An independent, redundant support system was developed for the common United States modules.

  17. Space Transportation Propulsion Systems

    NASA Technical Reports Server (NTRS)

    Liou, Meng-Sing; Stewart, Mark E.; Suresh, Ambady; Owen, A. Karl

    2001-01-01

    This report outlines the Space Transportation Propulsion Systems for the NPSS (Numerical Propulsion System Simulation) program. Topics include: 1) a review of Engine/Inlet Coupling Work; 2) Background/Organization of Space Transportation Initiative; 3) Synergy between High Performance Computing and Communications Program (HPCCP) and Advanced Space Transportation Program (ASTP); 4) Status of Space Transportation Effort, including planned deliverables for FY01-FY06, FY00 accomplishments (HPCCP Funded) and FY01 Major Milestones (HPCCP and ASTP); and 5) a review current technical efforts, including a review of the Rocket-Based Combined-Cycle (RBCC), Scope of Work, RBCC Concept Aerodynamic Analysis and RBCC Concept Multidisciplinary Analysis.

  18. The deep space network

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Presented is Deep Space Network (DSN) progress in flight project support, tracking and data acquisition (TDA) research and technology, network engineering, hardware and software implementation, and operations.

  19. Microtechnology in space bioreactors.

    PubMed

    Walther, I; van der Schoot, B; Boillat, M; Muller, O; Cogoli, A

    1999-03-01

    Space biology is a young and rapidly developing discipline comprising basic research and biotechnology. In the next decades it will play a prominent role in the International Space Station (ISS). Therefore, there is an increasing demand for sophisticated instrumentation to satisfy the requirements of the future projects in space biology. Bioreactors will be needed to supply fresh living material (cells and tissues) either to study still obscure basic biological mechanisms or to develop profitable bioprocesses which will take advantage of the peculiar microgravity conditions. Since more than twenty years, the Space Biology Group of the ETHZ is carrying out research projects in space (Space Shuttle/Spacelab, MIR Station, satellites, and sounding rockets) that involve also the development of space-qualified instrumentation. In the last ten years we have developed, in collaboration with Mecanex SA, Nyon, and the Institute of Microtechnology of the University of Neuchatel, a space bioreactor for the continuous culture of yeast cells under controlled conditions. Sensors, pH control, nutrients pump and fluid flowmeter are based on state-of-the-art silicon technology. After two successful space flights, a further improved version is presently prepared for a flight in the year 2000. PMID:11542392

  20. International Space Station: Update

    NSDL National Science Digital Library

    In November 1998, Zarya was launched into space, ushering in the era of the International Space Station (featured in the November 25, 1998 Scout Report for Science & Engineering). This month, the docking of the Zvezda Service Module marks the beginning of yet another phase -- in which Zvezda will serve as living quarters to the first ever resident crew (Expedition One), scheduled to arrive at the International Space Station in early November. This site from NASA provides updated information on the International Space Station, including recent news, planned missions, and a virtual tour of the (yet-to-be-completed) station.

  1. The deep space network

    NASA Technical Reports Server (NTRS)

    1975-01-01

    Summaries are given of Deep Space Network progress in flight project support, tracking and data acquisition research and technology, network engineering, hardware and software implementation, and operations.

  2. National Space Society

    NSDL National Science Digital Library

    2005-02-01

    The National Space Society (NSS) is a nonprofit organization dedicated to the creation of a spacefaring civilization. The NSS web site features information about the organization, its mission and vision, membership information, and a listing of NSS local chapters. The library features links to videos, books, and other publications on space settlements and bases, space policy, and technology. There is also information on the organization's magazine, "Ad Astra," including instructions for authors, publishing and advertising guidelines, and some archived content. Other materials include news articles, event announcements, and information on current space missions.

  3. Growing plant in space

    NASA Technical Reports Server (NTRS)

    Tibbitts, T. W.; Bula, R. J.; Tibbits, T. W.

    1989-01-01

    Space agencies in several countries are planning for the culture of plants in long duration space bases. The challenge of developing crop production procedures suitable for space projects will result in a new approach of problems we may meet today or in the near future in our common production systems. You may keep in mind subjects as: minimizing wastes or pollution problems, saving materials, introductions robotic helps. Discussion between scientists involved with food production for space programmes and protected horticultural cultivation may open new perspectives.

  4. Space Flight Now

    NSDL National Science Digital Library

    Space Flight Now offers the latest space news from around the world. Visitors can discover information on current missions, launch schedules, and mission reports. Along with providing the space news headlines, the web site supplies news archives so people can catch up on the activities of the space science world. Visitors can enjoy video footage from cameras onboard recent rocket launches. While users do have to subscribe to obtain many of the videos and audio recordings, individuals can benefit from the free up-to-date astronomy news stories and a few videos.

  5. Beyond Space-Time

    E-print Network

    A. M. Polyakov

    2006-02-01

    These notes, based on the remarks made at the 23 Solvay Conference, collect several speculative ideas concerning gauge/ strings duality, de Sitter spaces, dimensionality and the cosmological constant.

  6. Space Jell-O

    NSDL National Science Digital Library

    This hands-on OLogy experiment uses Jell-O, fruit, nuts, and candy to demonstrate how space bends around anything that has mass. The activity begins with kid-friendly introductions to the concept of mass and Einstein's theory of bending space. The illustrated, step-by-step directions include notes about how the fruit, nuts, and candy represent stars, planets, and other objects in space. At the end, kids are encouraged to celebrate their new-found knowledge by digging into their edible space.

  7. History of Space Exploration

    NSDL National Science Digital Library

    Users can choose from an extensive selection of links to resources for use in the study of the history of space exploration. The links provide access to historic information and publications, chronologies, and mission summaries for American, Russian, European, and other space missions. For educators, there are links to guides to robotic spacecraft and to observing the space shuttle in orbit. Links are also provided to a variety of spacecraft homepages and to other topics such as a primer on the basics of space flight, the Apollo lunar surface journals, and the NASA historic archives.

  8. Multimegawatt space power reactors

    SciTech Connect

    Dearien, J.A.; Whitbeck, J.F.

    1989-01-01

    In response to the need of the Strategic Defense Initiative (SDI) and long range space exploration and extra-terrestrial basing by the National Air and Space Administration (NASA), concepts for nuclear power systems in the multi-megawatt levels are being designed and evaluated. The requirements for these power systems are being driven primarily by the need to minimize weight and maximize safety and reliability. This paper will discuss the present requirements for space based advanced power systems, technological issues associated with the development of these advanced nuclear power systems, and some of the concepts proposed for generating large amounts of power in space. 31 figs.

  9. Nonuniformly spaced array imaging

    NASA Astrophysics Data System (ADS)

    Li, Hsueh-Jyh; Huang, Gen-Tay; Yen, Shih-Liang

    1993-03-01

    In this paper an image reconstruction algorithm for a randomly spaced array imaging is developed. Based on the fact that the sampled bistatic Fourier space data can occupy almost the same region as that of a rotating object imaging if the angular coverage is suitably defined, the range-Doppler reconstruction method developed in the rotating object imaging can be applied to the uniformly spaced circular array imaging case. When the array elements are randomly spaced, three more steps, a range alignment, a phase compensation, and an interpolation, are required to preprocess the measured signals. Experimental and numerical results have shown the effectiveness of the proposed algorithm.

  10. The space station

    NASA Technical Reports Server (NTRS)

    Munoz, Abraham

    1988-01-01

    Conceived since the beginning of time, living in space is no longer a dream but rather a very near reality. The concept of a Space Station is not a new one, but a redefined one. Many investigations on the kinds of experiments and work assignments the Space Station will need to accommodate have been completed, but NASA specialists are constantly talking with potential users of the Station to learn more about the work they, the users, want to do in space. Present configurations are examined along with possible new ones.

  11. Start of space tourism

    NASA Astrophysics Data System (ADS)

    Nagatomo, Makoto

    1993-03-01

    Space tourism means commercialization of manned space flight. From the early stage of space development, space commercialization is a profound theme in multidisciplinary fields, on the basis of a principle that the outcomes of advanced technique developed by tax should be returned to citizens. In these days, space satellite system in which users pay a fee for utilization has succeeded commercially in business such as communication network or broadcasting, and an attempt has been made to observe the earth from outer space to resolve global problems, such as environmental destruction. There is also an increasing interest in space tourism, however, many obstacles should be overcome for the realization, especially the medical problems such as effect of acceleration, cosmic ray, noise or weightless condition. In addition, the space flight business should be managed on the commercial base so that reasonable cost and large number of passengers are essential. It is necessary to design rockets suitable for tourism. For attractive design, the policy of space tourism should be clarified.

  12. Radiation protection in space.

    PubMed

    Reitz, G; Facius, R; Sandler, H

    1995-01-01

    Radiation environment, basic concepts of radiation protection, and specific aspects of the space radiation field are reviewed. The discussion of physico-chemical and subcellular radiation effects includes mechanisms of radiation action and cellular consequences. The discussion of radiobiological effects includes unique aspects of HZE particle effects, space flight findings, terrestrial findings, analysis of somatic radiation effects and effects on critical organs, and early and delayed effects. Other topics include the impact of the space flight environment, measurement of radiation exposure, establishing radiation protection limits, limitations in establishing space-based radiation exposure limits, radiation protection measures, and recommendations. PMID:11541474

  13. Space Station Freedom Utilization Conference

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The topics addressed in Space Station Freedom Utilization Conference are: (1) space station freedom overview and research capabilities; (2) space station freedom research plans and opportunities; (3) life sciences research on space station freedom; (4) technology research on space station freedom; (5) microgravity research and biotechnology on space station freedom; and (6) closing plenary.

  14. Behaviour modification of space trusses

    Microsoft Academic Search

    Gargari Mousa Tabatabai

    1993-01-01

    A space truss is a three dimensional structural system assembled of linear elements arranged so that forces are transferred in a three dimensional manner. Space trusses are used where large unobstructed spaces are required, such as aircraft hangars. Space trusses have the advantages of light weight, ease of assembly, ability to create multipurpose architectural spaces, and aesthetic appeal. Space trusses

  15. Space Operations in the Eighties.

    ERIC Educational Resources Information Center

    Aviation/Space, 1982

    1982-01-01

    Highlights activities/accomplishments and future endeavors related to space operations. Topics discussed include the Space Shuttle, recovery/refurbishment operations, payload manipulator, upper stages operations, tracking and data relay, spacelab, space power systems, space exposure facility, space construction, and space station. (JN)

  16. National Aeronautics and Space Administration

    E-print Network

    Rathbun, Julie A.

    National Aeronautics and Space Administration Space Launch System A New National Capability Space. The Marshall team is proud to lead development of America's new Space Launch System. National Aeronautics and Space Administration George C. Marshall Space Flight Center Huntsville, AL 35812 www

  17. International Space Station from Space Shuttle Endeavour

    NASA Technical Reports Server (NTRS)

    2007-01-01

    The crew of the Space Shuttle Endeavour took this spectacular image of the International Space Station during the STS118 mission, August 8-21, 2007. The image was acquired by an astronaut through one of the crew cabin windows, looking back over the length of the Shuttle. This oblique (looking at an angle from vertical, rather than straight down towards the Earth) image was acquired almost one hour after late inspection activities had begun. The sensor head of the Orbiter Boom Sensor System is visible at image top left. The entire Space Station is visible at image bottom center, set against the backdrop of the Ionian Sea approximately 330 kilometers below it. Other visible features of the southeastern Mediterranean region include the toe and heel of Italy's 'boot' at image lower left, and the western coastlines of Albania and Greece, which extend across image center. Farther towards the horizon, the Aegean and Black Seas are also visible. Featured astronaut photograph STS118-E-9469 was acquired by the STS-118 crew on August 19, 2007, with a Kodak 760C digital camera using a 28 mm lens, and is provided by the ISS Crew Earth Observations experiment and Image Science and Analysis Laboratory at Johnson Space Center.

  18. Physiologic adaptation to space - Space adaptation syndrome

    NASA Technical Reports Server (NTRS)

    Vanderploeg, J. M.

    1985-01-01

    The adaptive changes of the neurovestibular system to microgravity, which result in space motion sickness (SMS), are studied. A list of symptoms, which range from vomiting to drowsiness, is provided. The two patterns of symptom development, rapid and gradual, and the duration of the symptoms are described. The concept of sensory conflict and rearrangements to explain SMS is being investigated.

  19. 46 CFR 108.205 - Wash spaces; toilet spaces; and shower spaces.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...person occupancy sleeping spaces; and (3) “Public facility” means a toilet...a urinal. (g) Each public toilet space and washing space must...separated. (l) Each public facility that is a toilet space must have at least...

  20. 46 CFR 108.205 - Wash spaces; toilet spaces; and shower spaces.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...person occupancy sleeping spaces; and (3) “Public facility” means a toilet...a urinal. (g) Each public toilet space and washing space must...separated. (l) Each public facility that is a toilet space must have at least...

  1. Cognitive neuroscience in space.

    PubMed

    De la Torre, Gabriel G

    2014-01-01

    Humans are the most adaptable species on this planet, able to live in vastly different environments on Earth. Space represents the ultimate frontier and a true challenge to human adaptive capabilities. As a group, astronauts and cosmonauts are selected for their ability to work in the highly perilous environment of space, giving their best. Terrestrial research has shown that human cognitive and perceptual motor performances deteriorate under stress. We would expect to observe these effects in space, which currently represents an exceptionally stressful environment for humans. Understanding the neurocognitive and neuropsychological parameters influencing space flight is of high relevance to neuroscientists, as well as psychologists. Many of the environmental characteristics specific to space missions, some of which are also present in space flight simulations, may affect neurocognitive performance. Previous work in space has shown that various psychomotor functions degrade during space flight, including central postural functions, the speed and accuracy of aimed movements, internal timekeeping, attentional processes, sensing of limb position and the central management of concurrent tasks. Other factors that might affect neurocognitive performance in space are illness, injury, toxic exposure, decompression accidents, medication side effects and excessive exposure to radiation. Different tools have been developed to assess and counteract these deficits and problems, including computerized tests and physical exercise devices. It is yet unknown how the brain will adapt to long-term space travel to the asteroids, Mars and beyond. This work represents a comprehensive review of the current knowledge and future challenges of cognitive neuroscience in space from simulations and analog missions to low Earth orbit and beyond. PMID:25370373

  2. Chinese Space Program

    NSDL National Science Digital Library

    Leske, Cavin.

    2002-01-01

    China will soon make history by sending the first Chinese man to space. Scheduled for sometime in 2003, it will be the first step toward China's highly ambitious plans for space exploration.The China National Space Administration Web site (1) has a detailed description of the country's space policy. Aerospace China, a journal published online by the administration, has information on space development plans and other issues. The history of China's space program is recounted by the online Encyclopedia Astronautica (2). Several influential scientists and their contributions to Chinese rocketry and satellite technology are highlighted. The China Academy of Launch Vehicle Technology (3) sent the first Chinese satellite into space. Its home page showcases eight launch vehicles and offers an extensive technical description of the LM-3C model. The work of various research groups at the Shanghai Astronomical Observatory (4) deals with topics ranging from satellite dynamics to stellar astronomy. Some of the groups have details of their projects and facilities online. Another observatory studies molecular clouds and star formation (5). A large collection of its research papers are provided on its Web site. A news article from Space.com (6) discusses the forthcoming launch of the Shenzhou IV spacecraft, scheduled for later this year. It is generating considerable interest, since it is said to be identical to China's first manned spacecraft, expected to launch in 2003. Another article (7) considers China's rapidly developing space program. With the tremendous effort and lofty goals for moon bases and Mars missions, the author argues that China could eventually rival the US. Many more news stories about the Chinese space program can be found on the Dragon Space Web site (8).

  3. Access to space: The Space Shuttle's evolving rolee

    NASA Astrophysics Data System (ADS)

    Duttry, Steven R.

    1993-04-01

    Access to space is of extreme importance to our nation and the world. Military, civil, and commercial space activities all depend on reliable space transportation systems for access to space at a reasonable cost. The Space Transportation System or Space Shuttle was originally planned to provide transportation to and from a manned Earth-orbiting space station. To justify the development and operations costs, the Space Shuttle took on other space transportation requirements to include DoD, civil, and a growing commercial launch market. This research paper or case study examines the evolving role of the Space Shuttle as our nation's means of accessing space. The case study includes a review of the events leading to the development of the Space Shuttle, identifies some of the key players in the decision-making process, examines alternatives developed to mitigate the risks associated with sole reliance on the Space Shuttle, and highlights the impacts of this national space policy following the Challenger accident.

  4. Space Resource Roundtable Rationale

    NASA Astrophysics Data System (ADS)

    Duke, Michael

    1999-01-01

    Recent progress in the U.S. Space Program has renewed interest in space resource issues. The Lunar Prospector mission conducted in NASA's Discovery Program has yielded interesting new insights into lunar resource issues, particularly the possibility that water is concentrated in cold traps at the lunar poles. This finding has not yet triggered a new program of lunar exploration or development, however it opens the possibility that new Discovery Missions might be viable. Several asteroid missions are underway or under development and a mission to return samples from the Mars satellite, Phobos, is being developed. These exploration missions are oriented toward scientific analysis, not resource development and utilization, but can provide additional insight into the possibilities for mining asteroids. The Mars Surveyor program now includes experiments on the 2001 lander that are directly applicable to developing propellants from the atmosphere of Mars, and the program has solicited proposals for the 2003/2005 missions in the area of resource utilization. These are aimed at the eventual human exploration of Mars. The beginning of construction of the International Space Station has awakened interest in follow-on programs of human exploration, and NASA is once more studying the human exploration of Moon, Mars and asteroids. Resource utilization will be included as objectives by some of these human exploration programs. At the same time, research and technology development programs in NASA such as the Microgravity Materials Science Program and the Cross-Enterprise Technology Development Program are including resource utilization as a valid area for study. Several major development areas that could utilize space resources, such as space tourism and solar power satellite programs, are actively under study. NASA's interests in space resource development largely are associated with NASA missions rather than the economic development of resources for industrial processes. That is why there is an emphasis in NASA programs on propellant production on Mars - NASA plans missions to Mars, so could make use of those propellants. For other types of applications, however, it will be up to market forces to define the materials and products needed and develop the technologies for extracting them from space resources. Some leading candidates among the potential products from space resources are propellants for other space activities, water from the Moon for use in space, silicon for photovoltaic energy collection in space, and, eventually, He-3 from the Moon for fusion energy production. As the capabilities for manufacturing materials in space are opened up by research aboard the International Space Station, new opportunities for utilization of space resources may emerge. Whereas current research emphasizes increasing knowledge, one program objective should be the development of industrial production techniques for space. These will be based on the development of value-added processing in space, where materials are brought to the space facility, processed there, and returned to Earth. If enough such space processing is developed that the materials transportation requirements are measured in the hundreds of tons a year level, opportunities for substituting lunar materials may develop. The fundamental message is that it is not possible to develop space resources in a vacuum. One must have three things: a recoverable resource, technology to recover it, and a customer. Of these, the customer probably is the most important. All three must be integrated in a space resource program. That is what the Space Resource Roundtable, initiated with this meeting, will bring together.

  5. SPACE (ROOMS) INVENTORY -CASUARINA CAMPUS Old Space No New Space No Description

    E-print Network

    SPACE (ROOMS) INVENTORY - CASUARINA CAMPUS Old Space No New Space No Description ------ 1.01 Foyer 1 ------ 1.S3 Stair 3 at Level 1 ------ 1.S4 Stair 4 at Level 1 Old Space No New Space Precinct 1 of 12 #12;SPACE (ROOMS) INVENTORY - CASUARINA CAMPUS ------ 2.08 Bedroom ------ 2.09 Bedroom

  6. 46 CFR 108.205 - Wash spaces; toilet spaces; and shower spaces.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...2012-10-01 false Wash spaces; toilet spaces; and shower spaces...A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction... § 108.205 Wash spaces; toilet spaces; and shower spaces...Private facility” means a toilet, washing, or shower...

  7. 46 CFR 108.205 - Wash spaces; toilet spaces; and shower spaces.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...2014-10-01 false Wash spaces; toilet spaces; and shower spaces...A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction... § 108.205 Wash spaces; toilet spaces; and shower spaces...Private facility” means a toilet, washing, or shower...

  8. 46 CFR 108.205 - Wash spaces; toilet spaces; and shower spaces.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...2013-10-01 false Wash spaces; toilet spaces; and shower spaces...A-MOBILE OFFSHORE DRILLING UNITS DESIGN AND EQUIPMENT Construction... § 108.205 Wash spaces; toilet spaces; and shower spaces...Private facility” means a toilet, washing, or shower...

  9. Space station dynamics

    NASA Technical Reports Server (NTRS)

    Berka, Reg

    1990-01-01

    Structural dynamic characteristics and responses of the Space Station due to the natural and induced environment are discussed. Problems that are peculiar to the Space Station are also discussed. These factors lead to an overall acceleration environment that users may expect. This acceleration environment can be considered as a loading, as well as a disturbance environment.

  10. The deep space network

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The progress is reported of Deep Space Network (DSN) research in the following areas: (1) flight project support, (2) spacecraft/ground communications, (3) station control and operations technology, (4) network control and processing, and (5) deep space stations. A description of the DSN functions and facilities is included.

  11. Space Shuttle news reference

    NASA Technical Reports Server (NTRS)

    1981-01-01

    A detailed description of the space shuttle vehicle and associated subsystems is given. Space transportation system propulsion, power generation, environmental control and life support system and avionics are among the topics. Also, orbiter crew accommodations and equipment, mission operations and support, and flight crew complement and crew training are addressed.

  12. MEMS for space

    Microsoft Academic Search

    N. F. de Rooij; S. Gautsch; D. Briand; C. Marxer; G. Mileti; W. Noell; H. Shea; U. Staufer; B. van der Schoot

    2009-01-01

    Future space exploration will emphasize on cost effectiveness and highly focused mission objectives. Missions costs are directly proportional to its total weight, thus, the trend will be to replace bulky and heavy components of space carriers, communication and navigation platforms and of scientific payloads. MEMS devices are ideally suited to replace several of these components in the future, first by

  13. Atoms: The Space Between

    NSDL National Science Digital Library

    2002-01-22

    This video segment adapted from A Science Odyssey takes a look at the scale of the atom and the tremendous amount of space between the electrons and the nucleus. If all this empty space exists in matter, how can any substance be solid?

  14. The Deep Space Network

    NASA Technical Reports Server (NTRS)

    1979-01-01

    Deep Space Network progress in flight project support, tracking and data acquisition, research and technology, network engineering, hardware and software implementation, and operations is cited. Topics covered include: tracking and ground based navigation; spacecraft/ground communication; station control and operations technology; ground communications; and deep space stations.

  15. Teenagers and Public Space

    Microsoft Academic Search

    MATS LIEBERG

    1995-01-01

    Teenagers have no obvious right to spaces of their own. They often have nowhere else to go except outdoor public places, where they often come into conflict with other groups. This article explores this dilemma. Based on empirical studies in Sweden, the article describes how teenagers use public spaces in their local environments to create meaning and context in their

  16. Motivations for space exploration

    Microsoft Academic Search

    William Sims Bainbridge

    2009-01-01

    Possibly the greatest barrier to progress in space exploration is the lack of compelling motivations to justify the necessary investments. Spaceflight, a concept that gained currency in the middle of the twentieth century, may not be well adapted to the twenty-first century without significant modification. This article assesses the traditional motivations for space exploration, documented in a Harvard study carried

  17. SPACE TECHNOLOGY Actual Estimate

    E-print Network

    SPACE TECHNOLOGY TECH-1 Actual Estimate Budget Authority (in $ millions) FY 2011 FY 2012 FY 2013 FY.7 247.0 Exploration Technology Development 144.6 189.9 202.0 215.5 215.7 214.5 216.5 Notional SPACE TECHNOLOGY OVERVIEW .............................. TECH- 2 SBIR AND STTR

  18. Commercialization of space

    Microsoft Academic Search

    J. T. Rose; B. A. Stone

    1988-01-01

    Space-commercialization activities are grouped into five categories: private sector development from existing technology for private sector use; pure privatization; private sector development for US government use; private sector development from novel technology for private sector use; and, finally, full commercialization. The authors define the commercialization of space categories and highlight the key issues in each. A description of key NASA

  19. Commercialization of space activities

    Microsoft Academic Search

    Hanneke L. van Traa-Engelman

    1996-01-01

    Commercialization of space activities requires a legal framework for private investors and entrepreneurs in order to promote and develop this sector of industry into a fully-fledged commercial enterprise. Apart from the already existing international public legal framework of space law, rules should be created to provide a level playing field for all interested parties. These rules should point to transparency

  20. Taxonomy of space tessellation

    Microsoft Academic Search

    Y. C. Lee; Z. L. Li; Y. L Li

    2000-01-01

    When we map an area or create a digital database for it, the first task is often to partition the space into smaller units. There are traditionally two methods of partitioning: vector and raster. A vector partition delineates the boundary of features by polylines while a raster partition subdivides the space into a regular matrix of square or rectangular pixels.

  1. Law in Outer Space.

    ERIC Educational Resources Information Center

    Schmidt, William G.

    1997-01-01

    Provides an overview of the current practice and fascinating future of legal issues involved in outer space exploration and colonization. Current space law, by necessity, addresses broad principles rather than specific incidents. Nonetheless, it covers a variety of issues including commercial development, rescue agreements, object registration,…

  2. Arrays for space applications

    NASA Technical Reports Server (NTRS)

    Schuman, Harvey K.; Antonik, Paul; Malagisi, Carmen

    1989-01-01

    Concepts that were studied for application in space based radar (SBR) systems are presented. These antenna systems were for low earth orbit and require large fields of view (FOV). The systems included both space-fed and corporate-fed arrays.

  3. Space Transportation Systems Technologies

    NASA Technical Reports Server (NTRS)

    Laue, Jay H.

    2001-01-01

    This document is the final report by the Science Applications International Corporation (SAIC) on contracted support provided to the National Aeronautics and Space Administration (NASA) under Contract NAS8-99060, 'Space Transportation Systems Technologies'. This contract, initiated by NASA's Marshall Space Flight Center (MSFC) on February 8, 1999, was focused on space systems technologies that directly support NASA's space flight goals. It was awarded as a Cost-Plus-Incentive-Fee (CPIF) contract to SAIC, following a competitive procurement via NASA Research Announcement, NRA 8-21. This NRA was specifically focused on tasks related to Reusable Launch Vehicles (RLVs). Through Task Area 3 (TA-3), "Other Related Technology" of this NRA contract, SAIC extensively supported the Space Transportation Directorate of MSFC in effectively directing, integrating, and setting its mission, operations, and safety priorities for future RLV-focused space flight. Following an initially contracted Base Year (February 8, 1999 through September 30, 1999), two option years were added to the contract. These were Option Year 1 (October 1, 1999 through September 30, 2000) and Option Year 2 (October 1, 2000 through September 30, 2001). This report overviews SAIC's accomplishments for the Base Year, Option Year 1, and Option Year 2, and summarizes the support provided by SAIC to the Space Transportation Directorate, NASA/MSFC.

  4. Fusion for Space Propulsion

    Microsoft Academic Search

    Stephen H. Maslen

    1959-01-01

    The possible role of a controlled thermonuclear reactor in space missions is discussed. Although such a reactor is many years from reality, some of its properties are understood well enough to indicate problems which will appear and which are peculiar to space flight. It appears that it will have to deliver electric power or thrust at a weight of about

  5. International Space Station Assembly

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The International Space Station (ISS) is an unparalleled international scientific and technological cooperative venture that will usher in a new era of human space exploration and research and provide benefits to people on Earth. On-Orbit assembly began on November 20, 1998, with the launch of the first ISS component, Zarya, on a Russian Proton rocket. The Space Shuttle followed on December 4, 1998, carrying the U.S.-built Unity cornecting Module. Sixteen nations are participating in the ISS program: the United States, Canada, Japan, Russia, Brazil, Belgium, Denmark, France, Germany, Italy, the Netherlands, Norway, Spain, Sweden, Switzerland, and the United Kingdom. The ISS will include six laboratories and be four times larger and more capable than any previous space station. The United States provides two laboratories (United States Laboratory and Centrifuge Accommodation Module) and a habitation module. There will be two Russian research modules, one Japanese laboratory, referred to as the Japanese Experiment Module (JEM), and one European Space Agency (ESA) laboratory called the Columbus Orbital Facility (COF). The station's internal volume will be roughly equivalent to the passenger cabin volume of two 747 jets. Over five years, a total of more than 40 space flights by at least three different vehicles - the Space Shuttle, the Russian Proton Rocket, and the Russian Soyuz rocket - will bring together more than 100 different station components and the ISS crew. Astronauts will perform many spacewalks and use new robotics and other technologies to assemble ISS components in space.

  6. Reframing Children's Spaces

    ERIC Educational Resources Information Center

    Duncan, Sandra

    2011-01-01

    Like professional photographers, early childhood teachers can reframe their perspectives to create innovative and inspiring spaces for young children by concentrating on reframing two design elements: color and texture. When thinking about designing spaces for young children, one of the first considerations is the equipment and its arrangement.…

  7. Strange Bedfellows Enchanting Space

    ERIC Educational Resources Information Center

    Thulson, Anne

    2011-01-01

    In this article, the author shares her experience working on a multimedia project with her students. The project creates a context for students to reinterpret space and ethos in an elementary school. It allows students to poetically enter physical spaces and the written word through collaborative observation, contemplation, and remixing.

  8. CH and Ostaszewski spaces

    E-print Network

    Eisworth, Todd; Roitman, Judith A.

    1999-03-08

    another de#12;nition. Definition 4.6. If f is a promise, de#12;ne (4.4) H f = {#11; 6. Ostaszewski spaces are locally countable. Proof. Let X be an Ostaszewski space and suppose x has no countable neighbor...

  9. Conquering enclosed public spaces

    Microsoft Academic Search

    Masserat Amir-Ebrahimi

    2006-01-01

    During the process of modernization, a number of Islamic countries encouraged women to unveil. Among them, only Iran has recently returned to the earlier era of requiring women to veil themselves as the precondition of presence in public spaces. However, this time the difference was that women were already present in almost all public spaces: in universities, administrations, industries, and

  10. NATIONAL AERONAUTICS SPACE ADMINISTRATION

    E-print Network

    Ginzel, Matthew

    NATIONAL AERONAUTICS AND SPACE ADMINISTRATION ********** GUIDEBOOK FOR PROPOSERS RESPONDING. Appendix E.1.2 has been revised as follows: E.1.2 Assurance of Compliance with the National Aeronautics and Space Administration Regulations Pursuant to Nondiscrimination in Federally Assisted Programs "The

  11. Society, planet, space

    Microsoft Academic Search

    A. D. Ursul

    1977-01-01

    The author projects an anthropogeocosmic outlook, derived in part from Tsiolkovskii's views, incorporating an 'optimistic' approach to the further development of human society and conquest of outer space. Cosmoecology is considered, feedback from outer-space ventures beneficial to earthbound society is envisaged, and the immortality of the human species is viewed as guaranteed thanks to the ability to penetrate and colonize

  12. Space Shuttle Overview

    NASA Technical Reports Server (NTRS)

    McNutt, Leslie

    2006-01-01

    Many students are not even aware of the many activities related to the US Space Program. The intent of this presentation is to introduce students to the world of space exploration and encourage them to pursue math, science, and engineering careers. If this is not their particular interest, I want to encourage them to pursue their dream.

  13. What Is Space Weather?

    NSDL National Science Digital Library

    This resource provides a brief overview of the phenomenon known as space weather, which happens when energetic particles emitted by the Sun impact the Earth's magnetosphere. Users can view images, video clips, and animations of auroras and other types of space weather. A set of links to related websites is also provided.

  14. Space Resource Roundtable Rationale

    Microsoft Academic Search

    Michael Duke

    1999-01-01

    Recent progress in the U.S. Space Program has renewed interest in space resource issues. The Lunar Prospector mission conducted in NASA's Discovery Program has yielded interesting new insights into lunar resource issues, particularly the possibility that water is concentrated in cold traps at the lunar poles. This finding has not yet triggered a new program of lunar exploration or development,

  15. Space Base Concept

    NASA Technical Reports Server (NTRS)

    1970-01-01

    This is an illustration of the Space Base concept. In-house work of the Marshall Space Flight Center, as well as a Phase B contract with the McDornel Douglas Astronautics Company, resulted in a preliminary design for a space station in 1969 and l970. The Marshall-McDonnel Douglas approach envisioned the use of two common modules as the core configuration of a 12-man space station. Each common module was 33 feet in diameter and 40 feet in length and provided the building blocks, not only for the space station, but also for a 50-man space base. Coupled together, the two modules would form a four-deck facility: two decks for laboratories and two decks for operations and living quarters. Zero-gravity would be the normal mode of operation, although the station would have an artificial-gravity capability. This general-purpose orbital facility was to provide wide-ranging research capabilities. The design of the facility was driven by the need to accommodate a broad spectrum of activities in support of astronomy, astrophysics, aerospace medicine, biology, materials processing, space physics, and space manufacturing. To serve the needs of Earth observations, the station was to be placed in a 242-nautical-mile orbit at a 55-degree inclination. An Intermediate-21 vehicle (comprised of Saturn S-IC and S-II stages) would have launched the station in 1977.

  16. Plants in Space

    NSDL National Science Digital Library

    2011-12-21

    The BioEd Online website is giving interested parties everywhere the opportunity to learn from plants in space. Created in partnership with the National Space Biomedical Research Institute and BioServe Space Technologies of the University of Colorado, the project brings together plants from the International Space Station and plants grown by young people in their respective classrooms. The videos and teacher's guides here will let students perform their own experiments in the classroom based on data from space. Visitors will find PowerPoint presentations here for use in the classroom, along with videos of the plants in different states of germination. The site is rounded out by detailed information about this type of scientific investigation and the National Science Education Standards.

  17. Plants in Space

    NSDL National Science Digital Library

    The BioEd Online website is giving interested parties everywhere the opportunity to learn from plants in space. Created in partnership with the National Space Biomedical Research Institute and BioServe Space Technologies of the University of Colorado, the project brings together plants from the International Space Station and plants grown by young people in their respective classrooms. The videos and teacher's guides here will let students perform their own experiments in the classroom based on data from space. Visitors will find Power-Point presentations here for use in the classroom, along with videos of the plants in different states of germination. The site is rounded out by detailed information about this type of scientific investigation and the National Science Education Standards.

  18. Lubrication of space systems

    NASA Technical Reports Server (NTRS)

    Fusaro, Robert L.

    1994-01-01

    NASA has many high-technology programs plannned for the future, such as the space station, Mission to Planet Earth (a series of Earth-observing satellites), space telescopes, and planetary orbiters. These missions will involve advanced mechanical moving components, space mechanisms that will need wear protection and lubrication. The tribology practices used in space today are primarily based on a technology that is more than 20 years old. The question is the following: Is this technology base good enough to meet the needs of these future long-duration NASA missions? This paper examines NASA's future space missions, how mechanisms are currently lubricated, some of the mechanism and tribology challenges that may be encountered in future missions, and some potential solutions to these future challenges.

  19. Space and Time

    NSDL National Science Digital Library

    This fun Web site is part of OLogy, where kids can collect virtual trading cards and create projects with them. Here, they are introduced to space and time with six engaging and kid-friendly areas: Welcome to the Fourth Dimension, which looks at how time is needed to describe where you are in the fourth dimension; It's All Relative, an explanation of how time and space are different depending on your frame of reference; Mass Appeal, which uses the example of an elephant on a page of paper to explain how the Sun's mass causes space and time to bend; You Light Up My Life, how Arthur Eddington proved that Einstein's light-bending prediction was right; Everyday Einstein: Black Holes, an overview of these "bottomless dimples in space." and Time Travel Kit, a look at how the faster you move in space, the slower you move in time.

  20. Space Station Food System

    NASA Technical Reports Server (NTRS)

    Thurmond, Beverly A.; Gillan, Douglas J.; Perchonok, Michele G.; Marcus, Beth A.; Bourland, Charles T.

    1986-01-01

    A team of engineers and food scientists from NASA, the aerospace industry, food companies, and academia are defining the Space Station Food System. The team identified the system requirements based on an analysis of past and current space food systems, food systems from isolated environment communities that resemble Space Station, and the projected Space Station parameters. The team is resolving conflicts among requirements through the use of trade-off analyses. The requirements will give rise to a set of specifications which, in turn, will be used to produce concepts. Concept verification will include testing of prototypes, both in 1-g and microgravity. The end-item specification provides an overall guide for assembling a functional food system for Space Station.

  1. Atoms for space

    SciTech Connect

    Buden, D.

    1990-10-01

    Nuclear technology offers many advantages in an expanded solar system space exploration program. These cover a range of possible applications such as power for spacecraft, lunar and planetary surfaces, and electric propulsion; rocket propulsion for lunar and Mars vehicles; space radiation protection; water and sewage treatment; space mining; process heat; medical isotopes; and self-luminous systems. In addition, space offers opportunities to perform scientific research and develop systems that can solve problems here on Earth. These might include fusion and antimatter research, using the Moon as a source of helium-3 fusion fuel, and manufacturing perfect fusion targets. In addition, nuclear technologies can be used to reduce risk and costs of the Space Exploration Initiative. 1 fig.

  2. Radiation Effects In Space

    SciTech Connect

    Tripathi, Ram K. [NASA Langley Research Center, MS - 188 E, Hampton VA 23681 (United States)

    2011-06-01

    Protecting space missions from severe exposures from radiation, in general, and long duration/deep space human missions, in particular, is a critical design driver, and could be a limiting factor. The space radiation environment consists of galactic cosmic rays (GCR), solar particle events (SPE), trapped radiation, and includes ions of all the known elements over a very broad energy range. These ions penetrate spacecraft materials producing nuclear fragments and secondary particles that damage biological tissues and microelectronic devices. One is required to know how every element (and all isotopes of each element) in the periodic table interacts and fragments on every other element in the same table as a function of kinetic energy ranging over many decades. In addition, the accuracy of the input information and database, in general and nuclear data in particular, impacts radiation exposure health assessments and payload penalty. After a brief review of effects of space radiation on materials and electronics, human space missions to Mars is discussed.

  3. Space station data flow

    NASA Technical Reports Server (NTRS)

    1972-01-01

    The results of the space station data flow study are reported. Conceived is a low cost interactive data dissemination system for space station experiment data that includes facility and personnel requirements and locations, phasing requirements and implementation costs. Each of the experiments identified by the operating schedule is analyzed and the support characteristics identified in order to determine data characteristics. Qualitative and quantitative comparison of candidate concepts resulted in a proposed data system configuration baseline concept that includes a data center which combines the responsibility of reprocessing, archiving, and user services according to the various agencies and their responsibility assignments. The primary source of data is the space station complex which provides through the Tracking Data Relay Satellite System (TDRS) and by space shuttle delivery data from experiments in free flying modules and orbiting shuttles as well as from the experiments in the modular space station itself.

  4. Teaching With Space

    NSDL National Science Digital Library

    1969-12-31

    Teaching With Space is intended as a resource for teachers who want to introduce their students to space science and technology. A brief, free registration is required to access the educational modules, of which there are five in all. Among the topics are such elements as aerospace technology, "human exploration and development of space," and methods of teaching with technology. Each of the modules begins with a short quiz to assess the user's familiarity with the subject. One section contains slide presentations about the International Space Station, while others provide educational insights into various space-related concepts. Because of the amount of information presented on this site, anyone, not just teachers, could benefit from the material.

  5. Integrating National Space Visions

    NASA Technical Reports Server (NTRS)

    Sherwood, Brent

    2006-01-01

    This paper examines value proposition assumptions for various models nations may use to justify, shape, and guide their space programs. Nations organize major societal investments like space programs to actualize national visions represented by leaders as investments in the public good. The paper defines nine 'vision drivers' that circumscribe the motivations evidently underpinning national space programs. It then describes 19 fundamental space activity objectives (eight extant and eleven prospective) that nations already do or could in the future use to actualize the visions they select. Finally the paper presents four contrasting models of engagement among nations, and compares these models to assess realistic pounds on the pace of human progress in space over the coming decades. The conclusion is that orthogonal engagement, albeit unlikely because it is unprecedented, would yield the most robust and rapid global progress.

  6. Space Shuttle Drawing

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The Apollo program demonstrated that men could travel into space, perform useful tasks there, and return safely to Earth. But space had to be more accessible. This led to the development of the Space Shuttle. The Shuttle's major components are the orbiter spacecraft; the three main engines, with a combined thrust of more than 1.2 million pounds; the huge external tank (ET) that feeds the liquid hydrogen fuel and liquid oxygen oxidizer to the three main engines; and the two solid rocket boosters (SRBs), with their combined thrust of some 5.8 million pounds, that provide most of the power for the first two minutes of flight. Crucially involved with the Space Shuttle program virtually from its inception, the Marshall Space Flight Center (MSFC) played a leading role in the design, development, testing, and fabrication of many major Shuttle propulsion components.

  7. Space: A new frontier

    NASA Astrophysics Data System (ADS)

    Cutolo, Mona; Miranda, Denis M.

    1986-08-01

    The challenges and the promises of space colonization present an exciting opportunity for exploring and analyzing the values, the institutions and the physical environments we have created on Earth. Here we describe an interdisciplinary course, team-taught, that examines the current state of space exploration and the innovative technologies spawned by space research. The course also explores the possible social, economic, political and international impacts of migration to space of people and industries. A course project is to design a space colony for a community of 10,000 people. Given the technical design parameters and other details, the students are to engineer socially an ideal community, bearing in mind the short lifetimes of utopian communities of the past. The process is intended to help the students gain a fair understanding of the dynamics of human societies and of the technologies we have developed that enable us to change our world and to design new worlds.

  8. Space 2000 Symposium

    NASA Technical Reports Server (NTRS)

    1999-01-01

    The purpose of the Space 2000 Symposium is to present the creativity and achievements of key figures of the 20th century. It offers a retrospective discussion on space exploration. It considers the future of the enterprise, and the legacy that will be left for future generations. The symposium includes panel discussions, smaller session meetings with some panelists, exhibits, and displays. The first session entitled "From Science Fiction to Science Facts" commences after a brief overview of the symposium. The panel discussions include talks on space exploration over many decades, and the missions of the millennium to search for life on Mars. The second session, "Risks and Rewards of Human Space Exploration," focuses on the training and health risks that astronauts face on their exploratory mission to space. Session three, "Messages and Messengers Informing and Inspire Space Exploration and the Public," focuses on the use of TV medium by educators and actors to inform and inspire a wide variety of audiences with adventures of space exploration. Session four, "The Legacy of Carl Sagan," discusses the influences made by Sagan to scientific research and the general public. In session five, "Space Exploration for a new Generation," two student speakers and the NASA Administrator Daniel S. Goldin address the group. Session six, "Destiny or Delusion? -- Humankind's Place in the Cosmos," ends the symposium with issues of space exploration and some thought provoking questions. Some of these issues and questions are: what will be the societal implications if we discover the origin of the universe, stars, or life; what will be the impact if scientists find clear evidence of life outside the domains of the Earth; should there be limits to what humans can or should learn; and what visionary steps should space-faring people take now for future generations.

  9. Space-QUEST: Experiments with quantum entanglement in space

    E-print Network

    Rupert Ursin; Thomas Jennewein; Johannes Kofler; Josep M. Perdigues; Luigi Cacciapuoti; Clovis J. de Matos; Markus Aspelmeyer; Alejandra Valencia; Thomas Scheidl; Alessandro Fedrizzi; Antonio Acin; Cesare Barbieri; Giuseppe Bianco; Caslav Brukner; Jose Capmany; Sergio Cova; Dirk Giggenbach; Walter Leeb; Robert H. Hadfield; Raymond Laflamme; Norbert Lutkenhaus; Gerard Milburn; Momtchil Peev; Timothy Ralph; John Rarity; Renato Renner; Etienne Samain; Nikolaos Solomos; Wolfgang Tittel; Juan P. Torres; Morio Toyoshima; Arturo Ortigosa-Blanch; Valerio Pruneri; Paolo Villoresi; Ian Walmsley; Gregor Weihs; Harald Weinfurter; Marek Zukowski; Anton Zeilinger

    2008-06-05

    The European Space Agency (ESA) has supported a range of studies in the field of quantum physics and quantum information science in space for several years, and consequently we have submitted the mission proposal Space-QUEST (Quantum Entanglement for Space Experiments) to the European Life and Physical Sciences in Space Program. We propose to perform space-to-ground quantum communication tests from the International Space Station (ISS). We present the proposed experiments in space as well as the design of a space based quantum communication payload.

  10. Kennedy Space Center - "America's Gateway to Space"

    NASA Technical Reports Server (NTRS)

    Petro, Janet; Chevalier, Mary Ann; Hurst, Chery

    2011-01-01

    KSC fits into the overall NASA vision and mission by moving forward so that what we do and learn will benefit all here on Earth. In January of last year, KSC revised its Mission and Vision statements to articulate our identity as we align with this new direction the Agency is heading. Currently KSC is endeavoring to form partnerships with industry, , Government, and academia, utilizing institutional assets and technical capabilities to support current and future m!issions. With a goal of safe, low-cost, and readily available access to space, KSC seeks to leverage emerging industries to initiate development of a new space launch system, oversee the development of a multipurpose crew vehicle, and assist with the efficient and timely evolution of commercial crew transportation capabilities. At the same time, KSC is pursuing modernizing the Center's infrastructure and creating a multi-user launch complex with increased onsite processing and integration capabilities.

  11. Space station thermal control surfaces. [space radiators

    NASA Technical Reports Server (NTRS)

    Maag, C. R.; Millard, J. M.; Jeffery, J. A.; Scott, R. R.

    1979-01-01

    Mission planning documents were used to analyze the radiator design and thermal control surface requirements for both space station and 25-kW power module, to analyze the missions, and to determine the thermal control technology needed to satisfy both sets of requirements. Parameters such as thermal control coating degradation, vehicle attitude, self eclipsing, variation in solar constant, albedo, and Earth emission are considered. Four computer programs were developed which provide a preliminary design and evaluation tool for active radiator systems in LEO and GEO. Two programs were developed as general programs for space station analysis. Both types of programs find the radiator-flow solution and evaluate external heat loads in the same way. Fortran listings are included.

  12. The space simulation facilities at IAL SPACE

    NASA Technical Reports Server (NTRS)

    Henrist, M.; Cucchiaro, A.; Domken, I.; Macau, J. P.

    1990-01-01

    The thermal vacuum facilities of IAL SPACE were tailored for testing of the ESA payloads. They were progressively upgraded for cryogenic payloads including 4 K (liquid helium temperature) experiments. A detailed review of the three vacuum chambers, ranging from 1.5 to 5 m diameter, is presented including the corresponding capabilities in the vacuum, thermal, and optical fields. The various aspects of cleanliness, product assurance, and quality control are also presented.

  13. Reversible Space Equals Deterministic Space KlausJorn Lange \\Lambda

    E-print Network

    McKenzie, Pierre

    Reversible Space Equals Deterministic Space Klaus­J¨orn Lange \\Lambda Univ. T¨ubingen Pierre McKenzie reversible were terribly wasteful in terms of space: Lecerf's method [Le63], rediscovered by Bennett [Be73's ``space­ hungry'' method: While we scrupulously preserve space, time becomes exponential in S. We offer

  14. space curves and surfaces 1 Plotting Space Curves

    E-print Network

    Verschelde, Jan

    space curves and surfaces 1 Plotting Space Curves the twisted cubic with matplotlib four subplots 2013 Scientific Software (MCS 507 L-16) space curves and surfaces 2 October 2013 1 / 43 #12;space curves and surfaces 1 Plotting Space Curves the twisted cubic with matplotlib four subplots

  15. UCL DEPARTMENT OF SPACE & CLIMATE PHYSICS SPACE PLASMA PHYSICS GROUP

    E-print Network

    Anand, Mahesh

    Analyser Langmuir probe/ E-field booms Magnetometer LEIA #12;UCL DEPARTMENT OF SPACE & CLIMATE PHYSICSUCL DEPARTMENT OF SPACE & CLIMATE PHYSICS SPACE PLASMA PHYSICS GROUP ESA Lunar Lander ­ L-DEPP C.J. Owen and D.O. Kataria UCL/MSSL #12;UCL DEPARTMENT OF SPACE & CLIMATE PHYSICS SPACE PLASMA PHYSICS GROUP

  16. NATIONAL AERONAUTICS AND SPACE ADMINISTRATION COMMERCIAL SPACE COMMITTEE

    E-print Network

    Waliser, Duane E.

    1 NATIONAL AERONAUTICS AND SPACE ADMINISTRATION COMMERCIAL SPACE COMMITTEE OF THE NASA ADVISORY _____________________________________ ________________________________ John Emond, Executive Secretary Commercial Space Committee Bretton Alexander, Chair Commercial Space Committee #12;2 Commercial Space Committee NASA Headquarters Washington DC 20546 February 8, 2011 MEETING

  17. Space charge measurement techniques and space charge in polyethylene

    Microsoft Academic Search

    T. Mizutani

    1994-01-01

    Recently, several new techniques such as LIPP, PIPS, PEA and TP methods have been developed to measure directly the space charge distributions in insulating polymers. Many papers have been published on space charge in insulating materials. In this paper, the space charge measurement techniques and space charge in polyethylene are reviewed. The space charge distributions in polyethylene depend strongly upon

  18. Skylab, Space Shuttle, Space Benefits Today and Tomorrow.

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Washington, DC.

    The pamphlet "Skylab" describes very generally the kinds of activities to be conducted with the Skylab, America's first manned space station. "Space Shuttle" is a pamphlet which briefly states the benefits of the Space Shuttle, and a concise review of present and future benefits of space activities is presented in the pamphlet "Space Benefits…

  19. Spinorial space-time and privileged space direction (I)

    E-print Network

    Paris-Sud XI, Université de

    Spinorial space-time and privileged space direction (I) Luis Gonzalez-Mestres Abstract Contrary of a privileged space direction are not strange phenomena from the point of view of fundamental space-time geometry. As already emphasized in our previous papers on the subject, the spinorial space-time we

  20. Space Robotic Capabilities David Kortenkamp (NASA Johnson Space Center)

    E-print Network

    Kortenkamp, David

    Johnson Space Center Space Robotic Capabilities David Kortenkamp (NASA Johnson Space Center) Liam) David Wettergreen (Carnegie Mellon University) Dan Clancy (NASA Ames) #12;Johnson Space Center 12/18/2001 Space Robotics State-of-Art 2 ! Motivation Science Objectives Mission Concepts Robots Human