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Sample records for akari nep-deep field

  1. Clustering of the AKARI NEP deep field 24 μm selected galaxies

    NASA Astrophysics Data System (ADS)

    Solarz, A.; Pollo, A.; Takeuchi, T. T.; Małek, K.; Matsuhara, H.; White, G. J.; Pȩpiak, A.; Goto, T.; Wada, T.; Oyabu, S.; Takagi, T.; Ohyama, Y.; Pearson, C. P.; Hanami, H.; Ishigaki, T.; Malkan, M.

    2015-10-01

    Aims: We present a method of selection of 24 μm galaxies from the AKARI north ecliptic pole (NEP) deep field down to 150 μJy and measurements of their two-point correlation function. We aim to associate various 24 μm selected galaxy populations with present day galaxies and to investigate the impact of their environment on the direction of their subsequent evolution. Methods: We discuss using of Support Vector Machines (SVM) algorithm applied to infrared photometric data to perform star-galaxy separation, in which we achieve an accuracy higher than 80%. The photometric redshift information, obtained through the CIGALE code, is used to explore the redshift dependence of the correlation function parameter (r0) as well as the linear bias evolution. This parameter relates galaxy distribution to the one of the underlying dark matter. We connect the investigated sources to their potential local descendants through a simplified model of the clustering evolution without interactions. Results: We observe two different populations of star-forming galaxies, at zmed ~ 0.25, zmed ~ 0.9. Measurements of total infrared luminosities (LTIR) show that the sample at zmed ~ 0.25 is composed mostly of local star-forming galaxies, while the sample at zmed ~ 0.9 is composed of luminous infrared galaxies (LIRGs) with LTIR ~ 1011.62 L⊙. We find that dark halo mass is not necessarily correlated with the LTIR: for subsamples with LTIR = 1011.15 L⊙ at zmed ~ 0.7 we observe a higher clustering length (r0 = 6.21 ± 0.78[ h-1Mpc ]) than for a subsample with mean LTIR = 1011.84 L⊙ at zmed ~ 1.1 (r0 = 5.86 ± 0.69h-1Mpc). We find that galaxies at zmed ~ 0.9 can be ancestors of present day L∗ early type galaxies, which exhibit a very high r0 ~ 8h-1 Mpc.

  2. VizieR Online Data Catalog: AKARI NEP Deep Survey revised catalog (Murata+, 2013)

    NASA Astrophysics Data System (ADS)

    Murata, K.; Matsuhara, H.; Wada, T.; Arimatsu, K.; Oi, N.; Takagi, T.; Oyabu, S.; Goto, T.; Ohyama, Y.; Malkan, M.; Pearson, C.; Malek, K.; Solarz, A.

    2013-09-01

    This is the revised catalogue of the AKARI North Ecliptic Pole Deep survey. The survey was carried out with the InfraRed Camera (IRC) onboard AKARI which has a comprehensive mid-IR wavelength coverage in nine photometric bands at 2-24 micron. For mid-IR source extraction we used a detection image while for near-IR source detection we used optical to near-IR ground-based catalogue which is based on CFHT/MegaCam z', CFHT/WIRCam Ks and Subaru/Scam z' band detection. Here we present an AKARI source with the identification from the ground-based catalogue. For objects with multiple counterparts, all of these were listed in the catalogue with an upper limit for the AKARI flux. The magnitudes are given in the AB system. (1 data file).

  3. OT2_sserje01_2: THE HERSCHEL-AKARI NEP DEEP SURVEY: the cosmological history of stellar mass assembly and black hole accretion

    NASA Astrophysics Data System (ADS)

    Serjeant, S.

    2011-09-01

    We propose a far-IR and submm mapping survey of the premier AKARI deep field in the North Ecliptic Pole, in PACS/SPIRE parallel mode. This is the only major deep infrared field not yet covered by Herschel guaranteed or open time key projects. The outstanding and unparalleled continuous mid-IR photometric coverage from AKARI, far better than equivalent Spitzer surveys, enables a wide range of galaxy evolution diagnostics unachievable in any other survey field (including Herschel HerMES/PEP fields), by spanning the wavelengths of redshifted PAH and silicate features and the peak energy output of AGN dust tori. The investment by AKARI in the NEP represents ~10 percent of the entire pointed observations available throughout the lifetime of AKARI. Our proposal remedies the remarkable omission from Herschel's legacy surveys of the premier extragalactic deep field from another IR space telescope. We will simultaneously identify and find photometric redshifts for the Herschel point source population, make stacking analysis detections of the galaxies which dominate the submm extragalactic background light as a function of redshift, determine the bolometric power outputs of the galaxies that dominate the submm background, compare the UV/optical/mid-IR continuum/PAH/far-IR/submm/radio star formation rate estimator in the most comprehensive IR survey data set to date, and track the coupled stellar mass assembly and black hole accretion throughout most of the history of the Universe. In OT1 the HOTAC concluded "The science output from the proposed survey will be outstanding [...] The panel was convinced that these observations should be done" but it since became clear that priority 2 time is very unlikely to be executed, so we request reclassification to priority 1.

  4. Mid-infrared luminosity function of local star-forming galaxies in the North Ecliptic Pole-Wide survey field of AKARI

    NASA Astrophysics Data System (ADS)

    Kim, Seong Jin; Lee, Hyung Mok; Jeong, Woong-Seob; Goto, Tomotsugu; Matsuhara, Hideo; Im, Myungshin; Shim, Hyunjin; Kim, Min Gyu; Lee, Myung Gyoon

    2015-12-01

    We present mid-infrared (MIR) luminosity functions (LFs) of local (z < 0.3) star-forming (SF) galaxies in the AKARI's North Ecliptic Pole (NEP)-Wide survey field. In order to derive more accurate LF, we used spectroscopic sample only. Based on the NEP-Wide point source catalogue containing a large number of infrared (IR) sources distributed over the wide (5.4 deg2) field, we incorporated the spectroscopic redshift (z) data for ˜1790 selected targets obtained by optical follow-up surveys with MMT/Hectospec and WIYN/Hydra. The AKARI's continuous 2-24 μm wavelength coverage as well as photometric data from optical u* band to near-infrared H band with the spectroscopic redshifts for our sample galaxies enable us to derive accurate spectral energy distributions (SEDs) in the MIR. We carried out SED fit analysis and employed 1/Vmax method to derive the MIR (e.g. 8, 12, and 15 μm rest-frame) LFs. We fit our 8 μm LFs to the double power-law with the power index of α = 1.53 and β = 2.85 at the break luminosity 4.95 × 109 L⊙. We made extensive comparisons with various MIR LFs from several literatures. Our results for local galaxies from the NEP region are generally consistent with other works for different fields over wide luminosity ranges. The comparisons with the results from the NEP-Deep data as well as other LFs imply the luminosity evolution from higher redshifts towards the present epoch.

  5. AKARI Observation of the Sub-degree Scale Fluctuation of the Near-infrared Background

    NASA Astrophysics Data System (ADS)

    Seo, H. J.; Lee, Hyung Mok; Matsumoto, T.; Jeong, W.-S.; Lee, Myung Gyoon; Pyo, J.

    2015-07-01

    We report spatial fluctuation analysis of the sky brightness in the near-infrared from observations toward the north ecliptic pole (NEP) by the AKARI at 2.4 and 3.2 μm. As a follow-up study of our previous work on the Monitor field of AKARI, we used NEP deep survey data, which covered a circular area of about 0.4 square degrees, in order to extend fluctuation analysis at angular scales up to 1000″. We found residual fluctuation over the estimated shot noise at larger angles than the angular scale of the Monitor field. The excess fluctuation of the NEP deep field smoothly connects with that of the Monitor field at angular scales of a few hundred arcseconds and extends without any significant variation to larger angular scales up to 1000″. By comparing excess fluctuations at two wavelengths, we confirm a blue spectral feature similar to the result of the Monitor field. We find that the result of this study is consistent with Spitzer Space Telescope observations at 3.6 μm. The origin of the excess fluctuation in the near-infrared background remains to be determined, but we could exclude zodiacal light, diffuse Galactic light, and unresolved faint galaxies at low redshift based on the comparison with mid- and far-infrared brightness, ground-based near-infrared images.

  6. The first source counts at 18 μm from the AKARI NEP Survey

    NASA Astrophysics Data System (ADS)

    Pearson, Chris P.; Serjeant, S.; Oyabu, S.; Matsuhara, H.; Wada, T.; Goto, T.; Takagi, T.; Lee, H. M.; Im, M.; Ohyama, Y.; Kim, S. J.; Murata, K.

    2014-10-01

    We present the first galaxy counts at 18 μm using the Japanese AKARI satellite's survey at the North Ecliptic Pole (NEP), produced from the images from the NEP-Deep and NEP-Wide surveys covering 0.6 and 5.8 deg2, respectively. We describe a procedure using a point source filtering algorithm to remove background structure and a minimum variance method for our source extraction and photometry that delivers the optimum signal to noise for our extracted sources, confirming this by comparison with standard photometry methods. The final source counts are complete and reliable over three orders of magnitude in flux density, resulting in sensitivities (80 per cent completeness) of 0.15 and 0.3 mJy for the NEP-Deep and NEP-Wide surveys, respectively, a factor of 1.3 deeper than previous catalogues constructed from this field. The differential source counts exhibit a characteristic upturn from Euclidean expectations at around a milliJansky and a corresponding evolutionary bump between 0.2-0.4 mJy consistent with previous mid-infrared surveys with ISO and Spitzer at 15 and 24 μm. We compare our results with galaxy evolution models confirming the striking divergence from the non-evolving scenario. The models and observations are in broad agreement implying that the source counts are consistent with a strongly evolving population of luminous infrared galaxies at redshifts higher than unity. Integrating our source counts down to the limit of the NEP survey at the 150 μJy level we calculate that AKARI has resolved approximately 55 per cent of the 18 μm cosmic infrared background relative to the predictions of contemporary source count models.

  7. J- AND H-BAND IMAGING OF AKARI NORTH ECLIPTIC POLE SURVEY FIELD

    SciTech Connect

    Jeon, Yiseul; Im, Myungshin; Kang, Eugene; Lee, Hyung Mok; Matsuhara, Hideo E-mail: mim@astro.snu.ac.kr

    2014-10-01

    We present the J- and H-band source catalog covering the AKARI North Ecliptic Pole field. Filling the gap between the optical data from other follow-up observations and mid-infrared (MIR) data from AKARI, our near-infrared (NIR) data provides contiguous wavelength coverage from optical to MIR. For the J- and H-band imaging, we used the FLoridA Multi-object Imaging Near-ir Grism Observational Spectrometer on the Kitt Peak National Observatory 2.1m telescope covering a 5.1 deg{sup 2} area down to a 5σ depth of ∼21.6 mag and ∼21.3 mag (AB) for the J and H bands with an astrometric accuracy of 0.''14 and 0.''17 for 1σ in R.A. and decl. directions, respectively. We detected 208,020 sources for the J band and 203,832 sources for the H band. This NIR data is being used for studies including the analysis of the physical properties of infrared sources such as stellar mass and photometric redshifts, and will be a valuable data set for various future missions.

  8. HECTOSPEC AND HYDRA SPECTRA OF INFRARED LUMINOUS SOURCES IN THE AKARI NORTH ECLIPTIC POLE SURVEY FIELD

    SciTech Connect

    Shim, Hyunjin; Im, Myungshin; Jeon, Yiseul; Kim, Seong Jin; Lee, Hyung Mok; Ko, Jongwan; Karouzos, Marios; Papovich, Casey; Willmer, Christopher; Weiner, Benjamin J.

    2013-08-15

    We present spectra of 1796 sources selected in the AKARI North Ecliptic Pole Wide Survey field, obtained with MMT/Hectospec and WIYN/Hydra, for which we measure 1645 redshifts. We complemented the generic flux-limited spectroscopic surveys at 11 {mu}m and 15 {mu}m, with additional sources selected based on the MIR and optical colors. In MMT/Hectospec observations, the redshift identification rates are {approx}80% for objects with R < 21.5 mag. On the other hand, in WIYN/Hydra observations, the redshift identification rates are {approx}80% at R magnitudes brighter than 19 mag. The observed spectra were classified through the visual inspection or from the line diagnostics. We identified 1128 star-forming or absorption-line-dominated galaxies, 198 Type-1 active galactic nuclei (AGNs), 8 Type-2 AGNs, 121 Galactic stars, and 190 spectra in unknown category due to low signal-to-noise ratio. The spectra were flux-calibrated but to an accuracy of 0.1-0.18 dex for most of the targets and worse for the remainder. We derive star formation rates (SFRs) from the mid-infrared fluxes or from the optical emission lines, showing that our sample spans an SFR range of 0.1 to a few hundred M{sub Sun} yr{sup -1}. We find that the extinction inferred from the difference between the IR and optical SFR increases as the IR luminosity increases but with a large scatter.

  9. OPTICAL IMAGES AND SOURCE CATALOG OF AKARI NORTH ECLIPTIC POLE WIDE SURVEY FIELD

    SciTech Connect

    Jeon, Yiseul; Im, Myungshin; Lee, Induk; Ibrahimov, Mansur; Lee, Hyung Mok; Lee, Myung Gyoon E-mail: mim@astro.snu.ac.k

    2010-09-15

    We present the source catalog and the properties of the B-, R-, and I-band images obtained to support the AKARI North Ecliptic Pole Wide (NEP-Wide) survey. The NEP-Wide is an AKARI infrared imaging survey of the north ecliptic pole covering a 5.8 deg{sup 2} area over 2.5-6 {mu}m wavelengths. The optical imaging data were obtained at the Maidanak Observatory in Uzbekistan using the Seoul National University 4k x 4k Camera on the 1.5 m telescope. These images cover 4.9 deg{sup 2} where no deep optical imaging data are available. Our B-, R-, and I-band data reach the depths of {approx}23.4, {approx}23.1, and {approx}22.3 mag (AB) at 5{sigma}, respectively. The source catalog contains 96,460 objects in the R band, and the astrometric accuracy is about 0.''15 at 1{sigma} in each R.A. and decl. direction. These photometric data will be useful for many studies including identification of optical counterparts of the infrared sources detected by AKARI, analysis of their spectral energy distributions from optical through infrared, and the selection of interesting objects to understand the obscured galaxy evolution.

  10. Dust attenuation up to z ≃ 2 in the AKARI North Ecliptic Pole Deep Field

    NASA Astrophysics Data System (ADS)

    Buat, V.; Oi, N.; Heinis, S.; Ciesla, L.; Burgarella, D.; Matsuhara, H.; Malek, K.; Goto, T.; Malkan, M.; Marchetti, L.; Ohyama, Y.; Pearson, C.; Serjeant, S.; Miyaji, T.; Krumpe, M.; Brunner, H.

    2015-05-01

    Aims: We aim to study the evolution of dust attenuation in galaxies selected in the infrared (IR) in the redshift range in which they are known to dominate the star formation activity in the universe. The comparison with other measurements of dust attenuation in samples selected using different criteria will give us a global picture of the attenuation at work in star-forming galaxies and its evolution with redshift. Methods: We selected galaxies in the mid-IR from the deep survey of the North Ecliptic Field performed by the AKARI satellite. Using multiple filters of IRC instrument, we selected more than 4000 galaxies from their rest-frame emission at 8 μm, from z ≃ 0.2 to ~2. We built spectral energy distributions from the rest-frame ultraviolet (UV) to the far-IR by adding ancillary data in the optical-near IR and from GALEX and Herschel surveys. We fit spectral energy distributions with the physically-motivated code CIGALE. We test different templates for active galactic nuclei (AGNs) and recipes for dust attenuation and estimate stellar masses, star formation rates, amount of dust attenuation, and AGN contribution to the total IR luminosity. We discuss the uncertainties affecting these estimates on a subsample of galaxies with spectroscopic redshifts. We also define a subsample of galaxies with an IR luminosity close to the characteristic IR luminosity at each redshift and study the evolution of dust attenuation of this selection representative of the bulk of the IR emission. Results: The AGN contribution to the total IR luminosity is found to be on average approximately 10%, with a slight increase with redshift. The determination of AGN contribution does not depend significantly on the assumed AGN templates except for galaxies detected in X-ray. The choice of attenuation law has a marginal impact on the determination of stellar masses and star formation rates. Dust attenuation in galaxies dominating the IR luminosity function is found to increase from z = 0

  11. Stellar mass - Metallicity Relation for AKARI-FMOS Infrared Luminous Galaxies at z~0.9

    NASA Astrophysics Data System (ADS)

    Oi, Nagisa; Matsuhara, Hideo; Goto, Tomo; Pearson, Chris; Buat, Véronique; Malkan, Matthew A.

    2015-08-01

    Heavy elements are synthesized in stars and returned into the interstellar medium reflecting the result of the past star formation activity in a galaxy. Thus, the gas phase metallicity is a key parameter in understanding the processes of the formation and the evolution of a galaxy. Many investigations of stellar mass (M*) and gas phase metallicity (Z) relation (MZ relation), which is more massive galaxies tend to be more metal-rich, and a fundamental relation (FMR), whereby galaxies define a tight surface in the three-dimensional space of M*, Z, and Star Formation Rate (SFR) have done up to z~3.3. However, this relation only holds to ultraviolet, optical, or near-infrared selected star forming galaxies. Since most of star formation activities in galaxies at high-z universe are hidden by dust, to fully understand the MZ relation and its evolution, it is critical to study dusty galaxies.Here, we investigate the MZ relation and FMR for infrared bright galaxies at z~0.9 discovered by AKARI NEP-Deep survey.We estimated the M* and Z from SED fitting using the AKARI NEP-Deep data with its follow-up multi-wavelength photometric data (from X-ray to FIR) and from Halpha-[NII] emission line ratio taken by Subaru/FMOS, respectively. We found that (1) the infrared bright galaxies at z~0.9 is already chemically evolved to the level of star-forming galaxies in the local universe, and (2) the metallicity of our sample is systematically larger than that of the FMR. The results suggest a possibility that metal was actively created in dusty galaxies up to z~1, then outflow blows out dust and gas, suddenly stopping the chemical evolution and star formation activity, and the galaxies end up being what they are today.

  12. The AKARI Far-Infrared Surveyor young stellar object catalog

    NASA Astrophysics Data System (ADS)

    Tóth, L. Viktor; Marton, Gábor; Zahorecz, Sarolta; Balázs, Lajos G.; Ueno, Munetaka; Tamura, Motohide; Kawamura, Akiko; Kiss, Zoltán T.; Kitamura, Yoshimi

    2014-02-01

    We demonstrate the use of the AKARI all-sky survey photometric data in the study of galactic star formation. Our aim was to select young stellar objects (YSOs) in the AKARI Far-Infrared Surveyor (FIS) Bright Source Catalogue. We used AKARI/FIS and Wide-field Infrared Survey Explorer (WISE) data to derive mid- and far-infrared colors of YSOs. Classification schemes based on quadratic discriminant analysis (QDA) have been given for YSOs and the training catalog for QDA was the whole-sky selection of previously known YSOs (i.e., listed in the SIMBAD database). A new catalog of AKARI FIS YSO candidates including 44001 sources has been prepared; the reliability of the classification is over 90%, as tested in comparison to known YSOs. As much as 76% of our YSO candidates are from previously uncatalogued types. The vast majority of these sources are Class I and II types according to the Lada classification. The distribution of AKARI FIS YSOs is well correlated with that of the galactic ISM; local over-densities were found on infrared loops and towards the cold clumps detected by Planck.

  13. AKARI Infrared Camera Survey of the Large Magellanic Cloud

    NASA Astrophysics Data System (ADS)

    Shimonishi, Takashi; Kato, Daisuke; Ita, Yoshifusa; Onaka, Takashi

    2015-08-01

    The Large Magellanic Cloud (LMC) is one of the closest external galaxies to the Milky Way and has been playing a central role in various fields of modern astronomy and astrophysics. We conducted an unbiased near- to mid-infrared imaging and spectroscopic survey of the LMC with the infrared satellite AKARI. An area of about 10 square degrees of the LMC was observed by five imaging bands (each centered at 3.2, 7, 11, 15, and 24 micron) and the low-resolution slitless prism spectroscopy mode (2--5 micron, R~20) equipped with the Infrared Camera on board AKARI. Based on the data obtained in the survey, we constructed the photometric and spectroscopic catalogues of point sources in the LMC. The photometric catalogue includes about 650,000, 90,000, 49,000, 17,000, 7,000 sources at 3.2, 7, 11, 15, and 24 micron, respectively (Ita et al. 2008, PASJ, 60, 435; Kato et al. 2012, AJ, 144, 179), while the spectroscopic catalogue includes 1,757 sources (Shimonishi et al. 2013, AJ, 145, 32). Both catalogs are publicly released and available through a website (AKARI Observers Page, http://www.ir.isas.ac.jp/AKARI/Observation/). The catalog includes various infrared sources such as young stellar objects, asymptotic giant branch stars, giants/supergiants, and many other cool or dust-enshrouded stars. A large number of near-infrared spectral data, coupled with complementary broadband photometric data, allow us to investigate infrared spectral features of sources by comparison with their spectral energy distributions. Combined use of the present AKARI LMC catalogues with other infrared catalogues such as SAGE and HERITAGE possesses scientific potential that can be applied to various astronomical studies. In this presentation, we report the details of the AKARI photometric and spectroscopic catalogues of the LMC.

  14. AKARI: space infrared cooled telescope

    NASA Astrophysics Data System (ADS)

    Onaka, Takashi; Salama, Alberto

    2009-12-01

    AKARI, formerly known as ASTRO-F, is the second Japanese space mission to perform infrared astronomical observations. AKARI was launched on 21 February 2006 (UT) and brought into a sun-synchronous polar orbit at an altitude of 700 km by a JAXA M-V rocket. AKARI has a telescope with a primary-mirror aperture size of 685 mm together with two focal-plane instruments on board: the Infrared Camera (IRC), which covers the spectral range 2-26 μm and the Far-Infrared Surveyor (FIS), which operates in the range 50-180 μm. The telescope mirrors are made of sandwich-type silicon carbide, specially developed for AKARI. The focal-plane instruments and the telescope are cooled by a unique cryogenic system that kept the telescope at 6K for 550 days with 180 l super-fluid liquid Helium (LHe) with the help of mechanical coolers on board. Despite the small telescope size, the cold environment and the state-of-the-art detectors enable very sensitive observations at infrared wavelengths. To take advantage of the characteristics of the sun-synchronous polar orbit, AKARI performed an all-sky survey during the LHe holding period in four far-infrared bands with FIS and two mid-infrared bands with IRC, which surpasses the IRAS survey made in 1983 in sensitivity, spatial resolution, and spectral coverage. AKARI also made over 5,000 pointing observations at given targets in the sky for approximately 10 min each, for deep imaging and spectroscopy from 2 to 180 μm during the LHe holding period. The LHe ran out on 26 August 2007, since which date the telescope and instrument are still kept around 40K by the mechanical cooler on board, and near-infrared imaging and spectroscopic observations with IRC are now being continued in pointing mode.

  15. Post-AGB Stars in the AKARI Survey

    NASA Astrophysics Data System (ADS)

    Siódmiak, N.; Cox, N.; Szczerba, R.; García-Lario, P.

    2009-12-01

    Obscured by their circumstellar dusty envelopes post-AGB stars emit a large fraction of their energy in the infrared and thus, infrared sky surveys like IRAS were essential for discoveries of post-AGBs in the past. Now, with the AKARI infrared sky survey we can extend our knowledge about the late stages of stellar evolution. The long-term goal of our work is to define new photometric criteria to distinguish new post-AGB candidates from the AKARI data. We have cross-correlated the Toruń catalogue of Galactic post-AGB and related objects with the AKARI/FIS All-Sky Survey Bright Source Catalogue (for simplicity, hereafter AKARI). The scientific and technical aspects of our work are presented here as well as our plans for the future. In particular, we found that only 9 post-AGB sources were detected in all four AKARI bands. The most famous objects like: Red Rectangle, Egg Nebula, Minkowski’s Footprint belong to this group. From the technical point of view we discuss positional accuracy by comparing (mostly) 2MASS coordinates of post-AGB objects with those given by AKARI; flux reliability by comparing IRAS 60 and 100 μm fluxes with those from AKARI -N65 and AKARI -90 bands, respectively; as well as completeness of the sample as a function of the IRAS fluxes.

  16. AKARI-CAS—Online Service for AKARI All-Sky Catalogues

    NASA Astrophysics Data System (ADS)

    Yamauchi, C.; Fujishima, S.; Ikeda, N.; Inada, K.; Katano, M.; Kataza, H.; Makiuti, S.; Matsuzaki, K.; Takita, S.; Yamamoto, Y.; Yamamura, I.; Ishihara, D.; Oyabu, S.

    2011-07-01

    The AKARI All-Sky Catalogues are an important infrared astronomical database for next-generation astronomy that take over the IRAS catalog. We have developed an online service, AKARI Catalogue Archive Server (AKARI-CAS), for astronomers. The service includes useful and attractive search tools and visual tools. One of the new features of AKARI-CAS is cached SIMBAD/NED entries, which can match AKARI catalogs with other catalogs stored in SIMBAD or NED. To allow advanced queries to the databases, direct input of SQL is also supported. In those queries, fast dynamic cross-identification between registered catalogs is a remarkable feature. In addition, multiwavelength quick-look images are displayed in the visualization tools, which will increase the value of the service. In the construction of our service, we considered a wide variety of astronomers' requirements. As a result of our discussion, we concluded that supporting users' SQL submissions is the best solution for the requirements. Therefore, we implemented an RDBMS layer so that it covered important facilities, including the whole processing of tables. We found that PostgreSQL is the best open-source RDBMS products for such purpose, and we wrote codes for both simple and advanced searches into the SQL stored functions. To implement such stored functions for fast radial search and cross-identification with minimum cost, we applied a simple technique that is not based on HTM or HEALPix. In contrast, the online application layer became compact and was written in simple procedural PHP codes. In total, our system realizes cost-effective maintenance and enhancements.

  17. AKARI MLHES Data Set Processing with FAST

    NASA Astrophysics Data System (ADS)

    Tomasino, Rachael; Ueta, Toshiya; Yamamura, Issei

    2012-10-01

    The AKARI MLHES (excavating Mass Loss History in Extended dust shells of Evolved Stars) data set is the largest collection of the most sensitive far-infrared images of the cold extended circumstellar dust shells of evolved stars and it is the key to understanding the dusty mass loss phase of stellar evolution. This data will be processed with a new imaging tool kit FAST (FIS-AKARI Slow-scan Tools). This program allows for an interactive assessment of the data quality and on-the-fly corrections to the time-series data on pixel-by-pixel bases in order to manually correct glitches that would have been missed in the automated process. These corrections include: eliminate bad on-sky calibration sequences, flag out cosmic-rays and their after-effect affected time-series readings from the data stream and remove real sources from local sky-flat frames, among other options. These extra processes result in better-calibrated noise reduced images and would be by far the best detection limit among all existing far-infrared data of extended evolved star dust-shells. Suggestions to improve to the GUI interface and problems with the data visualization were recorded and plan to be implemented in subsequent versions.

  18. Asteroid Catalog Using Akari: AKARI/IRC Mid-Infrared Asteroid Survey

    NASA Astrophysics Data System (ADS)

    Usui, Fumihiko; Kuroda, Daisuke; Müller, Thomas G.; Hasegawa, Sunao; Ishiguro, Masateru; Ootsubo, Takafumi; Ishihara, Daisuke; Kataza, Hirokazu; Takita, Satoshi; Oyabu, Shinki; Ueno, Munetaka; Matsuhara, Hideo; Onaka, Takashi

    2011-10-01

    We present the results of an unbiased asteroid survey in the mid-infrared wavelength region with the Infrared Camera (IRC) on board the Japanese infrared satellite AKARI. About 20% of the point source events recorded in the AKARI All-Sky Survey observations are not used for the IRC Point Source Catalog (IRC-PSC) in its production process because of a lack of multiple detection by position. Asteroids, which are moving objects on the celestial sphere, remain in these ``residual events''. We identify asteroids out of the residual events by matching them with the positions of known asteroids. For the identified asteroids, we calculate the size and albedo based on the Standard Thermal Model. Finally we have a new brand of asteroid catalog, named the Asteroid Catalog Using AKARI (AcuA), which contains 5120 objects, about twice as many as the IRAS asteroid catalog. The catalog objects comprise 4953 main belt asteroids, 58 near-Earth asteroids, and 109 Jovian Trojan asteroids. The catalog is publicly available via the Internet.

  19. A catalogue of AKARI FIS BSC extragalactic objects

    NASA Astrophysics Data System (ADS)

    Marton, Gabor; Toth, L. Viktor; Gyorgy Balazs, Lajos

    2015-08-01

    We combined photometric data of about 70 thousand point sources from the AKARI Far-Infrared Surveyor Bright Source Catalogue with AllWISE catalogue data to identify galaxies. We used Quadratic Discriminant Analysis (QDA) to classify our sources. The classification was based on a 6D parameter space that contained AKARI [F65/F90], [F90/F140], [F140/F160] and WISE W1-W2 colours along with WISE W1 magnitudes and AKARI [F140] flux values. Sources were classified into 3 main objects types: YSO candidates, evolved stars and galaxies. The training samples were SIMBAD entries of the input point sources wherever an associated SIMBAD object was found within a 30 arcsecond search radius. The QDA resulted more than 5000 AKARI galaxy candidate sources. The selection was tested cross-correlating our AKARI extragalactic catalogue with the Revised IRAS-FSC Redshift Catalogue (RIFSCz). A very good match was found. A further classification attempt was also made to differentiate between extragalactic subtypes using Support Vector Machines (SVMs). The results of the various methods showed that we can confidently separate cirrus dominated objects (type 1 of RIFSCz). Some of our “galaxy candidate” sources are associated with 2MASS extended objects, and listed in the NASA Extragalactic Database so far without clear proofs of their extragalactic nature. Examples will be presented in our poster. Finally other AKARI extragalactic catalogues will be also compared to our statistical selection.

  20. Ultraluminous infrared galaxies in the AKARI all-sky survey

    SciTech Connect

    Kilerci Eser, E.; Goto, T.; Doi, Y. E-mail: doi@ea.c.u-tokyo.ac.jp

    2014-12-10

    We present a new catalog of 118 ultraluminous infrared galaxies (ULIRGs) and one hyperluminous infrared galaxy (HLIRG) by cross-matching the AKARI all-sky survey with the Sloan Digital Sky Survey Data Release 10 (SDSS DR10) and the final data release of the Two-Degree Field Galaxy Redshift Survey. Forty of the ULIRGs and one HLIRG are new identifications. We find that ULIRGs are interacting pair galaxies or ongoing or postmergers. This is consistent with the widely accepted view: ULIRGs are major mergers of disk galaxies. We confirm the previously known positive trend between the active galactic nucleus fraction and infrared luminosity. We show that ULIRGs have a large offset from the main sequence up to z ∼ 1; their offset from the z ∼ 2 'main sequence' is relatively smaller. We find a result consistent with the previous studies showing that, compared to local star-forming SDSS galaxies of similar mass, local ULIRGs have lower oxygen abundances. We demonstrate for the first time that ULIRGs follow the fundamental metallicity relation (FMR). The scatter of ULIRGs around the FMR (0.09 dex-0.5 dex) is comparable to the scatter of z ∼ 2-3 galaxies. We provide the largest local (0.050

  1. AKARI Observations of Minor Bodies in the Outer Solar System

    NASA Astrophysics Data System (ADS)

    Sekiguchi, T.; Ootsubo, T.; Hasegawa, S.; Usui, F.; Cruikshank, D. P.; Dalle Ore, C. M.; Müller, T. G.

    2012-05-01

    Akari (Astro-F) is an infrared satellite developed by JAXA. We performed Far-IR photometric observations of 4 centaurs, 12 TNOs with FIS, and Near-IR Spectroscopic observations of a naked cometary nucleus object, P/2006 HR30 in 2-5.5 um with the IRC.

  2. AKARI far-infrared maps of the zodiacal dust bands

    NASA Astrophysics Data System (ADS)

    Ootsubo, Takafumi; Doi, Yasuo; Takita, Satoshi; Nakagawa, Takao; Kawada, Mitsunobu; Kitamura, Yoshimi; Matsuura, Shuji; Usui, Fumihiko; Arimatsu, Ko

    2016-06-01

    Zodiacal emission is thermal emission from interplanetary dust. Its contribution to the sky brightness is non-negligible in the region near the ecliptic plane, even in the far-infrared (far-IR) wavelength regime. We analyze zodiacal emission observed by the AKARI far-IR all-sky survey, which covers 97% of the entire sky at arcminute-scale resolution in four photometric bands, with central wavelengths of 65, 90, 140, and 160 μm. AKARI detected small-scale structures in the zodiacal dust cloud, including the asteroidal dust bands and the circumsolar ring, at far-IR wavelengths. Although the smooth component of the zodiacal emission structure in the far-IR sky can be reproduced well by models based on existing far-IR observations, previous zodiacal emission models have discrepancies in the small-scale structures compared with observations. We investigate the geometry of the small-scale dust-band structures in the AKARI far-IR all-sky maps and construct template maps of the asteroidal dust bands and the circumsolar ring components based on the AKARI far-IR maps. In the maps, ± 1.4°, ± 2.1°, and ± 10° asteroidal dust-band structures are detected in the 65 μm and 90 μm bands. A possible ± 17° band may also have been detected. No evident dust-band structures are identified in either the 140 μm or the 160 μm bands. By subtracting the dust-band templates constructed in this paper, we can achieve a similar level of flux calibration of the AKARI far-IR all-sky maps in the |β| < 40° region to that in the region for |β| > 40°.

  3. AKARI far-infrared maps of the zodiacal dust bands

    NASA Astrophysics Data System (ADS)

    Ootsubo, Takafumi; Doi, Yasuo; Takita, Satoshi; Nakagawa, Takao; Kawada, Mitsunobu; Kitamura, Yoshimi; Matsuura, Shuji; Usui, Fumihiko; Arimatsu, Ko

    2016-04-01

    Zodiacal emission is thermal emission from interplanetary dust. Its contribution to the sky brightness is non-negligible in the region near the ecliptic plane, even in the far-infrared (far-IR) wavelength regime. We analyze zodiacal emission observed by the AKARI far-IR all-sky survey, which covers 97% of the entire sky at arcminute-scale resolution in four photometric bands, with central wavelengths of 65, 90, 140, and 160 μm. AKARI detected small-scale structures in the zodiacal dust cloud, including the asteroidal dust bands and the circumsolar ring, at far-IR wavelengths. Although the smooth component of the zodiacal emission structure in the far-IR sky can be reproduced well by models based on existing far-IR observations, previous zodiacal emission models have discrepancies in the small-scale structures compared with observations. We investigate the geometry of the small-scale dust-band structures in the AKARI far-IR all-sky maps and construct template maps of the asteroidal dust bands and the circumsolar ring components based on the AKARI far-IR maps. In the maps, ± 1.4°, ± 2.1°, and ± 10° asteroidal dust-band structures are detected in the 65 μm and 90 μm bands. A possible ± 17° band may also have been detected. No evident dust-band structures are identified in either the 140 μm or the 160 μm bands. By subtracting the dust-band templates constructed in this paper, we can achieve a similar level of flux calibration of the AKARI far-IR all-sky maps in the |β| < 40° region to that in the region for |β| > 40°.

  4. Radio emission from dusty galaxies observed by AKARI

    NASA Astrophysics Data System (ADS)

    Pepiak, A.; Pollo, A.; Takeuchi, T. T.; Solarz, A.; Jurusik, W.

    2014-10-01

    We probe radio-infrared correlation for two samples of extragalactic sources from the local Universe from the AKARI All-Sky Catalogue. The first, smaller sample (1053 objects) was constructed by the cross-correlation of the AKARI/FIS All-Sky Survey Bright Source Catalogue, the AKARI IRC All-Sky Survey Point Source Catalogue and the NRAO VLA Sky Survey, i.e. it consists of sources detected in the mid- and far-infrared by AKARI, and at the 1.4 GHz radio frequency by NRAO. The second, larger sample (13,324 objects) was constructed by the cross-correlation of only the AKARI/FIS All-Sky Survey Bright Source Catalogue and the NRAO VLA Sky Survey, i.e. it consists of sources detected in the far-infrared and radio, without a condition to be detected in the mid-infrared. Additionally, all objects in both samples were identified as galaxies in the NED and/or SIMBAD databases, and a part of them is known to host active galactic nuclei (AGNs). For the present analysis, we have restricted our samples only to sources with known redshift z. In this paper, we analyse the far-infrared-radio correlation for both of these samples. We compare the ratio of infrared and radio emission from normal star-forming dusty galaxies and AGNs in both samples. For the smaller sample we obtained =2.14 for AGNs and =2.27 for normal galaxies, while for the larger sample =2.15 for AGNs and =2.22 for normal galaxies. An average value of the slope in both samples is ~2.2, which is consistent with the previous measurements from the literature.

  5. Search for Water in Outer Main Belt Based on AKARI Asteroid Catalog

    NASA Astrophysics Data System (ADS)

    Usui, Fumihiko

    2012-06-01

    We propose a program to search water ice on the surface of asteroids in the outer main belt regions, which have high albedo measured with AKARI. The distribution of water in the main belt provides important information to understanding of the formation and evolution of the solar system, because water is a good indicator of temperature in the early solar nebula. The existence of water ice is a hot topic in the solar system studies today. Water ice is recently found in the outer region of the main asteroid belt and some of them are linked to the main belt comets. Brand-new albedo data brought by AKARI opens the possibility of detection of water ice on the C-type asteroids. Here we propose to make the spectroscopic observations with the Subaru telescope in the near-infrared wavelengths to detect water ice on these high-albedo C-type asteroids. Thanks to a large aperture of Subaru telescope and a high altitude of Mauna Kea, it can be only possible to observe a weak signal of the existence of water on the surface of asteroids with a certain S/N. In addition, using the imaging data taken prior to IRCS spectroscopic mode, we intend to seek any comet-like activities by investigating diffuseness of the asteroids, which can be detected by comparing the observed point-spread functions with those of field stars.

  6. AKARI Mapping of an Externally Heated Pre-Stellar Core

    NASA Astrophysics Data System (ADS)

    Nutter, D.; Ward-Thompson, D.; Stamatellos, D.

    2009-12-01

    We present observations of the L1155C pre-stellar core in the Cepheus molecular cloud, taken using the FIS instrument on the AKARI satellite. We compare these data to SCUBA and ISOPHOT data. All of the data show a relation between the position of the emission peak and wavelength, which we interpret as a temperature gradient. We fit modified blackbody curves to the spectral energy distributions at two positions in the core and find that the core is approximately 2 K warmer at one edge than in the centre. We carry out radiative transfer modelling and include the effects from the nearby A6V star BD+67 1263. We generate a good fit to the observed data at all wavelengths, and demonstrate that the appearance of the core at different wavelengths can be explained by the observed temperature gradient, caused by BD+67 1263. Our findings illustrate very clearly that the apparent morphology of a pre-stellar core can be highly dependent on the wavelength of the observation, and that temperature gradients must be taken into account before converting images into column density distributions. This is important to note when interpreting AKARI and Spitzer data and will also be significant for Herschel data.

  7. Cryogenic silicon carbide mirrors for infrared astronomical telescopes: lessons learnt from AKARI for SPICA

    NASA Astrophysics Data System (ADS)

    Onaka, Takashi; Kaneda, Hidehiro; Kawada, Mitsunobu; Enya, Keigo; Nakagawa, Takao

    2013-09-01

    Silicon carbide (SiC) has good thermal conductivity, high stiffness, and a relatively low specific density, all of which are advantageous to the application to telescopes operating at cryogenic temperatures. The first Japanese astronomical infrared space mission AKARI, which was launched in 2006 February and completed the second generation all-sky survey at 6 bands from mid- to far-infrared, employed a 700mm cryogenic telescope made of specially developed SiC. It was a sandwich-type of SiC composed of a lightweight porous core and a dense chemical vapor deposition (CVD) coat to decrease the specific density and facilitate machining for achieving the required surface figure accuracy. Measurements with an interferometer of 160-mm sample mirrors demonstrated that the AKARI mirror SiC had good thermal stability down to cryogenic temperatures (~6K), while the mirror support of the compact design became the primary source of the wave-front errors of the AKARI telescope. Taking the advantage of the heritage of the AKARI telescope development as well as ESA's Herschel telescope, we are planning the next infrared space mission SPICA (Space Infrared Telescope for Cosmology and Astrophysics) of a 3.2m cooled telescope in participation of ESA using SiC-based materials. In this presentation, we summarize the development of AKARI SiC telescope and present the development activities of the SPICA telescope from the point of view of SiC being as the mirror material for cryogenic space infrared telescopes.

  8. AKARI OBSERVATION OF THE FLUCTUATION OF THE NEAR-INFRARED BACKGROUND

    SciTech Connect

    Matsumoto, T.; Seo, H. J.; Lee, H. M.; Jeong, W.-S.; Pyo, J.; Matsuura, S.; Matsuhara, H.; Oyabu, S.; Wada, T.

    2011-12-01

    We report a search for fluctuations of the sky brightness toward the north ecliptic pole with the Japanese infrared astronomical satellite AKARI, at 2.4, 3.2, and 4.1 {mu}m. We obtained circular maps with 10' diameter fields of view, which clearly show a spatial structure on the scale of a few hundred arcseconds. A power spectrum analysis shows that there is a significant excess fluctuation at angular scales larger than 100'' that cannot be explained by zodiacal light, diffuse Galactic light, shot noise of faint galaxies, or clustering of low-redshift galaxies. These results are consistent with observations at 3.6 and 4.5 {mu}m by NASA's Spitzer Space Telescope. The fluctuating component observed at large angular scales has a blue stellar spectrum which is similar to that of the spectrum of the excess isotropic emission observed with the Infrared Telescope in Space. A significant spatial correlation between wavelength bands was found, and the slopes of the linear correlations are consistent with the spectrum of the excess fluctuation. These findings indicate that the detected fluctuation could be attributed to the first stars of the universe, i.e., Population III stars. The observed fluctuation provides an important constraint on the era of the first stars.

  9. AKARI view of star formation in NGC 1313

    NASA Astrophysics Data System (ADS)

    Suzuki, T.; Kaneda, H.; Onaka, T.

    2013-06-01

    Context. In the southwest region of NGC 1313, patchy star-forming regions are found. In the neighborhood, is a giant supershell with a diameter of 3.2 kpc. However, the direct association between star-forming regions and the giant supershell is still unclear. Aims: We investigate the relation between the surface densities of the gas (Σgas) and star formation rate (ΣSFR) within the disk of NGC 1313 to obtain the spatial distribution of the star formation efficiency (SFE). Methods: NGC 1313 was observed with the Infrared Camera (IRC) and Far-Infrared Surveyor (FIS) onboard AKARI in ten bands at 3.2, 4.1, 7, 11, 15, 24, 65, 90, 140, and 160 μm. With these AKARI ten-band images, we spectrally decomposed the stellar and polycyclic aromatic hydrocarbon (PAHs) components in addition to the cold (~20 K) and warm (~60 K) dust emission components. The cold and warm dust components were converted into the gas mass and the SFR. Results: The SFE shows high values in the regions around the giant supershell, with the highest SFE in the galaxy in the southern spiral arm region. A similar trend can be seen in the spatial distribution of the PAH abundance relative to big grains. We find a power-law dependence of the star formation rate per unit area on the column density ΣSFR proportional to ΣgasN. From a region-by-region analysis, the power-law index N for the northern spiral arm is found to be N ≃ 2.0, which is observed on typical spiral arms, whereas those for the southern spiral arm and giant supershell regions have an index of N ~ 1.6. Conclusions: The PAH abundance and the SFE show anomalously high values in regions around the giant supershell. The enhanced PAH abundance can be caused by shattering of big grains through slow shocks (40 km s-1). The power-law index N = 1.62 ± 0.06 obtained in the giant supershell region can be accounted for by the star formation scenario with collect-and-collapse in the expanding giant supershell. These pieces of evidence strongly

  10. Clustering of far-infrared galaxies in the AKARI All-Sky Survey North

    NASA Astrophysics Data System (ADS)

    Pollo, A.; Takeuchi, T. T.; Solarz, A.; Rybka, P.; Suzuki, T. L.; Pȩpiak, A.; Oyabu, S.

    2013-10-01

    We present the measurements of the angular two-point correlation function for AKARI 90-μm point sources, detected outside the Milky Way plane and other regions characterized by high Galactic extinction in the northern Galactic hemisphere, and categorized as extragalactic sources according to our far-infrared-color based criterion. Together with our previous work (Pollo et al., 2013) this is the first measurement of the large-scale angular clustering of galaxies selected in the far-infrared after IRAS. We present the first attempt to estimate the spatial clustering properties of AKARI All-Sky galaxies and we conclude that they are mostly a very nearby ( z ≤ 0.1) population of moderately clustered galaxies. We measure their correlation length r 0 ~ 4.5 h -1 Mpc, which is consistent with the assumption that the FIS AKARI All-Sky surveys observes mostly a nearby star-forming population of galaxies.

  11. Planetary Nebulae from the AKARI Far-IR All-Sky Maps

    NASA Astrophysics Data System (ADS)

    Ueta, T.; Fullard, A.; Tomasino, R. L.

    2015-12-01

    The far-IR all-sky mapping data obtained by the AKARI Astronomical Satellite were released to the public in January 2015. These maps are expected to provide us with further insights into our understanding of the far-IR universe for the first time since IRAS, especially for extended objects. While the AKARI far-IR all-sky maps are calibrated against the diffuse background emission and a flux correction scheme for point sources is provided, it is not necessarily obvious how one flux-corrects extended sources. Here, we briefly summarize a new flux-correction method for extended objects detected in the AKARI far-IR all-sky maps and its application to planetary nebulae.

  12. AKARI NEAR-INFRARED SPECTROSCOPY OF LUMINOUS INFRARED GALAXIES

    SciTech Connect

    Lee, Jong Chul; Lee, Myung Gyoon; Hwang, Ho Seong

    2012-09-01

    We present the AKARI near-infrared (NIR; 2.5-5 {mu}m) spectroscopic study of 36 (ultra)luminous infrared galaxies ((U)LIRGs) at z = 0.01-0.4. We measure the NIR spectral features including the strengths of 3.3 {mu}m polycyclic aromatic hydrocarbon emission and hydrogen recombination lines (Br{alpha} and Br{beta}), optical depths at 3.1 and 3.4 {mu}m, and NIR continuum slope. These spectral features are used to identify optically elusive, buried active galactic nuclei (AGNs). We find that half of the (U)LIRGs optically classified as non-Seyferts show AGN signatures in their NIR spectra. Using a combined sample of (U)LIRGs with NIR spectra in the literature, we measure the contribution of buried AGNs to the infrared luminosity from the spectral energy distribution fitting to the IRAS photometry. The contribution of these buried AGNs to the infrared luminosity is 5%-10%, smaller than the typical AGN contribution of (U)LIRGs including Seyfert galaxies (10%-40%). We show that NIR continuum slopes correlate well with WISE [3.4]-[4.6] colors, which would be useful for identifying a large number of buried AGNs using the WISE data.

  13. AKARI observations of the multiphase intergalactic medium of Stephan's Quintet

    NASA Astrophysics Data System (ADS)

    Suzuki, Toyoaki; Kaneda, Hidehiro; Onaka, Takashi; Kitayama, Tetsu

    2012-08-01

    Stephan's Quintet (SQ, HCG92) is a well studied compact group of galaxies with a disturbed intergalactic medium (IGM). An ``intruder'' galaxy NGC 7318b is currently colliding with the IGM at a relative velocity of 1000 km s-1, causing a large-scale shock front. We observed SQ with the Far-Infrared Surveyor (FIS) aboard AKARI in four far-infrared (far-IR) bands at 65, 90, 140, and 160μm. The 160μm image clearly shows an additional peak of emission overlying structure extending in the North-South direction along the shock ridge seen in the 140μm band, and in H2 and X-ray emission. Whereas most of the far-IR emission in the shocked region is from cold dust (20 K), the [CII]158μm emission - whose luminosity is comparable to that of the warm H2 gas - can significantly contribute to the single peak emission in the 160μm band. We conclude that the [CII] line emission comes from the warm H2 gas in the shock. Our result represents the first detection of shock-excited [CII] line emission.

  14. The AKARI Far-Infrared Surveyor (FIS): all-sky Diffuse Map

    NASA Astrophysics Data System (ADS)

    Komugi, Shinya; Doi, Yasuo; Hattori, Makoto; Kitamura, Yoshimi; Otsubo, Takafumi; Tanaka, Masahiro; Ikeda, Norio; Kato, Daisuke; Nakagawa, Takao

    2011-12-01

    The infrared astronomical satellite AKARI performed an all sky survey at six infrared bands. We report here on the calibration of the all-sky image data, observed in the four long wavelength bands with the FIS instrument (AKARI Far-infrared All Sky Survey : AFASS). The preliminary image attains a calibration uncertainty and sensitivity of better than ~ 30% and ~ 10 MJy str-1, respectively, for all four bands. The point spread function (PSF) is obtained via a stacking technique. The data are shown to be useful for exploring the internal structure and dust spectral energy distributions (SEDs) of nearby galaxies.

  15. AKARI All-Sky Far-Infrared Survey: Where to Look for AGB Stars?

    NASA Astrophysics Data System (ADS)

    Rybka, P.; Pollo, A.; Takeuchi, T. T.

    2011-09-01

    We selected a sample of 5,176 far-infrared sources from the FIS AKARI All-Sky Survey. Searching public databases, we identified their counterparts observed at other wavelengths and derived a method to separate stars from galaxies. The sample of stars is dominated by AGB-related objects.

  16. Albedo distribution of main-belt asteroids based on IRAS, AKARI, and WISE

    NASA Astrophysics Data System (ADS)

    Usui, F.; Hasegawa, S.; Ishiguro, M.; Mueller, T.; Ootsubo, T.

    2014-07-01

    survey of the entire sky. To date, there are two other infrared astronomical satellites dedicated to all-sky survey: the Japanese infrared satellite AKARI [2], and the Wide-field Infrared Survey Explorer (WISE; [3]). Based on the all-sky survey data obtained by IRAS, AKARI, and WISE, the largest asteroid catalogs containing size and albedo data were constructed (e.g., [4--6] and their series of papers). The total number of asteroids with size and albedo measured by these three infrared surveyors is 138,285 (more than 20 % of currently known asteroids), and size and albedo measured by all three surveyors for 1,993 commonly detected asteroids are in good agreement (within ±10 % for diameter and ±22 % for albedo at 1σ deviation level) [7]. In addition, several outstanding works have provided the taxonomic classification of asteroids (e.g., [8--11]), based on ground-based spectroscopic observations in optical and near-infrared wavelengths. Along with these taxonomic classifications, size and albedo data also contribute to our understanding of asteroid compositions. In general, the albedo of C-type asteroids is considered as low and that of S-type asteroids is high (e.g., [12]). The relationship between taxonomic types and albedo is, however, complex and type determinations cannot be made on the basis of albedo values alone. Recently albedos of C- and S-type asteroids are found to vary widely, especially for sizes smaller than several tens of km [13]. In this talk, we present the details of a data compilation including size, albedo, and taxonomy of MBAs, and discuss the compositional distribution in the main belt regions. We found that the heliocentric distribution of the mean albedo of asteroids in each taxonomic type is found to be nearly flat, in spite of albedo transition process like space weathering. In the total distribution, on the other hand, the mean albedo value gradually decreases with increasing the semimajor axis, presumably due to the compositional mixing of

  17. Star formation and dust extinction properties of local galaxies as seen from AKARI and GALEX

    NASA Astrophysics Data System (ADS)

    Sakurai, A.; Takeuchi, T. T.; Yuan, F.-T.; Buat, V.; Burgarella, D.

    2013-03-01

    An accurate estimation of the star formation-related properties of galaxies is crucial for understanding the evolution of galaxies. In galaxies, ultraviolet (UV) light emitted by recently formed massive stars is attenuated by dust, which is also produced by star formation (SF) activity, and is re-emitted at mid- and far- infrared (IR) wavelengths. In this study, we investigate the star formation rate (SFR) and dust extinction using UV and IR data. We selected local galaxies which are detected at AKARI FIS 90 μm and matched the IRAS IIFSC z 60 μm select catalog. We measured FUV and NUV flux densities from GALEX images. We examined the SF and extinction of Local galaxies using four bands of AKARI. Then, we calculated FUV and total IR luminosities, and obtained the SF luminosity, L SF, the total luminosity related to star formation activity, and the SFR. We find that in most galaxies, L SF is dominated by L dust. We also find that galaxies with higher SF activity have a higher fraction of their SF hidden by dust. In fact, the SF of galaxies with SFRs > 20 M⊙ yr-1 is almost completely hidden by dust. Our results boast a significantly higher precision with respect to previously published works, due to the use of much larger object samples from the AKARI and GALEX all sky surveys.

  18. Near to Mid-Infrared Observations of Recent Supernovae with Infrared Camera (IRC) onboard AKARI

    NASA Astrophysics Data System (ADS)

    Sakon, I.; Onaka, T.; Wada, T.; Usui, F.; Kaneda, H.; Ohyama, Y.; Oyabu, S.; Ishihara, D.; Tanabé, T.; Matsuhara, H.; Nakagawa, T.; Murakami, H.; Minezaki, T.; Yoshii, Y.; Nozawa, T.; Nomoto, K.; Tanaka, M.; Tominaga, N.; Kozasa, T.

    2009-12-01

    We present our latest results on near- to mid-infrared observations of supernovae within one year after the explosion with Infrared Camera (IRC) on board AKARI. In this project, we aim to explore the dust formation scenario in the ejecta of core-collapse supernovae. So far, observations of several recent supernovae including SN2006jc and SN2008ax have been carried out as part of the Directors Time of AKARI. At the same time, we have set about the near-infrared slit-less spectroscopic observations of nearby galaxies with high supernovae frequency in preparation for a future supernova in the AKARI Phase-3 Open Time Program “Near-infrared Slit-less Spectroscopy of Nearby Galaxies; Waiting for Supernovae Momentarily (NEWSY)” (P.I. Sakon, I.). The obtained near- to mid-infrared spectral energy distribution (SED) of early-time supernovae is quite valuable and unique to investigate the properties of dust formed around the massive star and will further deepen our knowledge on the origin of dust especially in the early universe.

  19. Modeling of the Zodiacal Emission for the AKARI/IRC Mid-infrared All-sky Diffuse Maps

    NASA Astrophysics Data System (ADS)

    Kondo, Toru; Ishihara, Daisuke; Kaneda, Hidehiro; Nakamichi, Keichiro; Takaba, Sachi; Kobayashi, Hiroshi; Ootsubo, Takafumi; Pyo, Jeonghyun; Onaka, Takashi

    2016-03-01

    The zodiacal emission, which is the thermal infrared (IR) emission from the interplanetary dust (IPD) in our solar system, has been studied for a long time. Nevertheless, accurate modeling of the zodiacal emission has not been successful to reproduce the all-sky spatial distribution of the zodiacal emission, especially in the mid-IR where the zodiacal emission peaks. Therefore, we aim to improve the IPD cloud model based on Kelsall et al., using the AKARI 9 and 18 μm all-sky diffuse maps. By adopting a new fitting method based on the total brightness, we have succeeded in reducing the residual levels after subtraction of the zodiacal emission from the AKARI data and thus in improving the modeling of the zodiacal emission. Comparing the AKARI and the COBE data, we confirm that the changes from the previous model to our new model are mostly due to model improvements, but not temporal variations between the AKARI and the COBE epoch, except for the position of the Earth-trailing blob. Our results suggest that the size of the smooth cloud, a dominant component in the model, is about 10% more compact than previously thought, and that the dust sizes are not large enough to emit blackbody radiation in the mid-IR. Furthermore, we detect a significant isotropically distributed IPD component, owing to an accurate baseline measurement with AKARI.

  20. AKARI NEAR-INFRARED SPECTROSCOPIC OBSERVATIONS OF INTERSTELLAR ICES IN THE EDGE-ON STARBURST GALAXY NGC 253

    SciTech Connect

    Yamagishi, Mitsuyoshi; Kaneda, Hidehiro; Ishihara, Daisuke; Oyabu, Shinki; Onaka, Takashi; Shimonishi, Takashi; Suzuki, Toyoaki

    2011-04-10

    We present the spatially resolved near-infrared (2.5-5.0 {mu}m) spectra of the edge-on starburst galaxy NGC 253 obtained with the Infrared Camera on board AKARI. Near the center of the galaxy, we clearly detect the absorption features of interstellar ices (H{sub 2}O: 3.05 {mu}m, CO{sub 2}: 4.27 {mu}m, and XCN: 4.62 {mu}m) and the emission of polycyclic aromatic hydrocarbons (PAHs) at 3.29 {mu}m and the hydrogen recombination line Br{alpha} at 4.05 {mu}m. We find that the distributions of the ices differ from those of the PAH and gas. We calculate the column densities of the ices and derive the abundance ratios of N(CO{sub 2})/N(H{sub 2}O) = 0.17 {+-} 0.05. They are similar to those obtained around the massive young stellar objects in our Galaxy (0.17 {+-} 0.03), although a much stronger interstellar radiation field and higher dust temperature are expected near the center of NGC 253.

  1. VizieR Online Data Catalog: 20cm survey of the AKARI SEP (ATCA-ADFS) (White+, 2012)

    NASA Astrophysics Data System (ADS)

    White, G. J.; Hatsukade, B.; Pearson, C.; Takagi, T.; Sedgwick, C.; Matsuura, S.; Matsuhara, H.; Serjeant, S.; Nakagawa, T.; Lee, H. M.; Oyabu, S.; Jeong, W.-S.; Shirahata, M.; Kohno, K.; Yamamura, I.; Hanami, H.; Goto, T.; Makiuti, S.; Clements, D. L.; Malek, K.; Khan, S. A.

    2013-08-01

    The AKARI ADF-S survey was primarily made in the far-infrared at wavelengths of 65, 90, 140, 160um over a 12deg2 area with the AKARI Far-Infrared Surveyor (FIS) instrument, with shallower mid-infrared coverage at 9, 18um using the AKARI Infrared Camera (IRC) instrument. In addition to the wide survey, deeper mid-infrared pointed observations, using the IRC, covering ~0.8deg2 and reaching 5σ sensitivities of 16, 16, 74, 132, 280 and 580uJy at 3.2, 4.6, 7, 11, 15, 24um were also carried out. The radio observations were collected over a 13d period in 2007 July using the ATCA operated at 1.344 and 1.432GHz. (1 data file).

  2. AKARI/FIS Mapping of the ISM-Wind Bow Shock around α Orionis

    NASA Astrophysics Data System (ADS)

    Ueta, Toshiya; Izumiura, Hideyuki; Yamamura, Issei; Nakada, Yoshikazu; Matsuura, Mikako; Ita, Yoshifusa; Tanabé, Toshihiko; Fukushi, Hinako; Matsunaga, Noriyuki; Mito, Hiroyuki

    2008-12-01

    We present 10' × 50'scan maps around an M supergiant αOri at 65, 90, 140, and 160μm obtained with the AKARI Infrared Astronomy Satellite. Higher spatial resolution data with the exact analytic solution permit us to fit the de-projected shape of the stellar-wind bow shock around αOri to have a stand-off distance of 4'.8, position angle of 55° and inclination angle of 56°. The shape of the bow shock suggests that the velocity of αOri with respect to the local medium is v* = 40 nH-1/2, where nH is the hydrogen nucleus density at αOri. We found that the local medium is of nH = 1.5 to 1.9 cm-3 and the velocity of the local flow is at 11km s-1 by using the most recent astrometric solutions for αOri under the assumption that the medium local to αOri is moving away from the Orion OB 1 association. AKARI images may also reveal avortex ring due to instabilities on the surface of the bow shock, as demonstrated by numerical models. This research exemplifies the potential of AKARI All-Sky data as well as follow-up observations with Herschel Space Telescope and Stratospheric Observatory for Infrared Astronomy for this avenue of research in revealing the nature of the interaction between the stellar wind and the interstellar medium.

  3. EFFICIENT SELECTION AND CLASSIFICATION OF INFRARED EXCESS EMISSION STARS BASED ON AKARI AND 2MASS DATA

    SciTech Connect

    Huang Yafang; Li Jinzeng; Rector, Travis A.; Mallamaci, Carlos C.

    2013-05-15

    The selection of young stellar objects (YSOs) based on excess emission in the infrared is easily contaminated by post-main-sequence stars and various types of emission line stars with similar properties. We define in this paper stringent criteria for an efficient selection and classification of stellar sources with infrared excess emission based on combined Two Micron All Sky Survey (2MASS) and AKARI colors. First of all, bright dwarfs and giants with known spectral types were selected from the Hipparcos Catalogue and cross-identified with the 2MASS and AKARI Point Source Catalogues to produce the main-sequence and the post-main-sequence tracks, which appear as expected as tight tracks with very small dispersion. However, several of the main-sequence stars indicate excess emission in the color space. Further investigations based on the SIMBAD data help to clarify their nature as classical Be stars, which are found to be located in a well isolated region on each of the color-color (C-C) diagrams. Several kinds of contaminants were then removed based on their distribution in the C-C diagrams. A test sample of Herbig Ae/Be stars and classical T Tauri stars were cross-identified with the 2MASS and AKARI catalogs to define the loci of YSOs with different masses on the C-C diagrams. Well classified Class I and Class II sources were taken as a second test sample to discriminate between various types of YSOs at possibly different evolutionary stages. This helped to define the loci of different types of YSOs and a set of criteria for selecting YSOs based on their colors in the near- and mid-infrared. Candidate YSOs toward IC 1396 indicating excess emission in the near-infrared were employed to verify the validity of the new source selection criteria defined based on C-C diagrams compiled with the 2MASS and AKARI data. Optical spectroscopy and spectral energy distributions of the IC 1396 sample yield a clear identification of the YSOs and further confirm the criteria defined

  4. Efficient Selection and Classification of Infrared Excess Emission Stars Based on AKARI and 2MASS Data

    NASA Astrophysics Data System (ADS)

    Li, Jinzeng; Huang, Yafang

    2015-08-01

    The selection of young stellar objects (YSOs) based on excessive emission in the infrared is easily contaminated by post-main-sequence stars and various types of emission line stars with similar properties. We define here stringent criteria for an efficient selection and classification of stellar sources with infrared excess emission based on combined 2MASS and AKARI colors. First of all, bright dwarfs and giants with known spectral types were selected from the Hipparcos Catalogue and cross-identified with the 2MASS and AKARI Point Source Catalogues to produce the main-sequence and the post-main-sequence tracks, which appear as expected as tight tracks with very small dispersion. However, several of the main-sequence stars indicate excess emission in the color space. Further investigations based on the SIMBAD data help to clarify their nature as classical Be stars, which are found to be located in a well isolated region on each of the color-color (C-C) diagrams. Several kinds of contaminants were then removed based on their distribution on the C-C diagrams. A test sample of Herbig Ae/Be stars and classical T Tauri stars were cross-identified with the 2MASS and AKARI catalogs to define the loci of YSOs with different masses on the C-C diagrams. Well classified Class I and Class II sources were taken as a second test sample to discriminate between various types of YSOs at possibly different evolutionary stages. This helped to define the loci of different types of YSOs and a set of criteria for selecting YSOs based on their colors in the near- and mid-infrared. Candidate YSOs toward IC 1396 indicating excess emission in the near-infrared were employed to verify the validity of the new source selection criteria defined based on C-C diagrams compiled with the 2MASS and AKARI data. Optical spectroscopy and spectral energy distributions of the IC 1396 sample yield a clear identification of the YSOs and further confirm the criteria defined for exploring the nature and

  5. Efficient Selection and Classification of Infrared Excess Emission Stars Based on AKARI and 2MASS Data

    NASA Astrophysics Data System (ADS)

    Huang, Ya Fang; Zeng Li, Jin; Rector, Travis A.; Mallamaci, Carlos C.

    2013-05-01

    The selection of young stellar objects (YSOs) based on excess emission in the infrared is easily contaminated by post-main-sequence stars and various types of emission line stars with similar properties. We define in this paper stringent criteria for an efficient selection and classification of stellar sources with infrared excess emission based on combined Two Micron All Sky Survey (2MASS) and AKARI colors. First of all, bright dwarfs and giants with known spectral types were selected from the Hipparcos Catalogue and cross-identified with the 2MASS and AKARI Point Source Catalogues to produce the main-sequence and the post-main-sequence tracks, which appear as expected as tight tracks with very small dispersion. However, several of the main-sequence stars indicate excess emission in the color space. Further investigations based on the SIMBAD data help to clarify their nature as classical Be stars, which are found to be located in a well isolated region on each of the color-color (C-C) diagrams. Several kinds of contaminants were then removed based on their distribution in the C-C diagrams. A test sample of Herbig Ae/Be stars and classical T Tauri stars were cross-identified with the 2MASS and AKARI catalogs to define the loci of YSOs with different masses on the C-C diagrams. Well classified Class I and Class II sources were taken as a second test sample to discriminate between various types of YSOs at possibly different evolutionary stages. This helped to define the loci of different types of YSOs and a set of criteria for selecting YSOs based on their colors in the near- and mid-infrared. Candidate YSOs toward IC 1396 indicating excess emission in the near-infrared were employed to verify the validity of the new source selection criteria defined based on C-C diagrams compiled with the 2MASS and AKARI data. Optical spectroscopy and spectral energy distributions of the IC 1396 sample yield a clear identification of the YSOs and further confirm the criteria defined

  6. VizieR Online Data Catalog: AKARI Far-Infrared Surveyor YSO catalog (Toth+, 2014)

    NASA Astrophysics Data System (ADS)

    Toth, L. V.; Marton, G.; Zahorecz, S.; Balazs, L. G.; Ueno, M.; Tamura, M.; Kawamura, A.; Kiss, Z. T.; Kitamura, Y.

    2014-01-01

    AKARI FSC BSC data was combined with mid-IR photometric data from the WISE All-Sky Data Release. Classification was made with quadratic discriminant analysis based on the mid- and far-IR colours and brightness values. 44001 sources were classified as young stellar object candidate. For each candidate AKARI FIS ID, celestial position (RA2000, DEC2000), WISE magnitudes measured in passbands centered at 3.4, 4.6, 12 and 22um (W1, W2, W3, W4), their corresponding errors (eW1, eW2, eW3, eW4), FIS flux densities measured in passbands with nominal wavelengths of 65, 90, 140 and 160um (F65, F90, F140, F160) and the corresponding flux qualities (F_QUAL), the probability of being YSO, SIMBAD main type and subtypes, the angular distance between the FIS source and the matching SIMBAD object and the SIMBAD ID of the matching object are listed. (1 data file).

  7. Hunting for Long-lived Protoplanetary Disks Observed with AKARI/FIS

    NASA Astrophysics Data System (ADS)

    Liu, Q.; Liu, Y.

    2015-03-01

    Twenty-one YSOs (Young Stellar Objects) in the solar neighbor have been identified through cross-correlating Hipparcos catalog with AKARI/FIS YSO catalog. The reliability of the match is over 90%. The central objects cover spectral types from B to M. The Hipparcos parallaxes enable us to place the objects in the H-R diagram, which can be used to determine their ages by isochrones. Among these objects, two YSOs have been found whose ages are larger than 10 Myr. The optical to infrared spectral energy distributions (SEDs) of these two YSOs are consistent with those of type II YSOs with protoplanetary disks. Furthermore, from the SED fitting, the ages of these two sources are constrained to (14.1±4.2) Myr and (16.8±4.4) Myr, respectively. Therefore, two YSO candidates with long-lived protoplanetary disks have been detected in AKARI/FIS. The presence of long-lived protoplanetary disks has significant implications for the formation of planets and their host stars.

  8. Hunting for Long-lived Protoplanetary Disks Observed with AKARI/FIS

    NASA Astrophysics Data System (ADS)

    Qiong, LIU; Yao, LIU

    2015-10-01

    Twenty-one YSO (Young Stellar Object) candidates nearby the solar system have been identified through cross-correlating Hipparcos (High Precision Parallax Collecting Satellite) catalog with the AKARI/FIS YSO catalog, and the reliability is over 90%. The central objects cover the spectral types from B to M. The Hipparcos's accurate measurements of trigonometric parallaxes enable us to place these objects in the H-R diagram, which can be used to determine their ages by the isochrones of theoretical evolution trajectories. In this sample, two YSOs have been found to be older than 10 Myr. The spectral energy distributions (SEDs) from optical to infrared show that the two YSOs belong to the type II YSOs with protoplanetary disks. Furthermore, from the SED fitting, the ages of these two sources are constrained to be (14.1±4.2) Myr and (16.8±4.4) Myr, respectively. Therefore, two YSO candidates with long-lived protoplanetary disks have been detected in the AKARI/FIS data. The long-lived protoplanetary disks are closely related with the planet formation, and they are ideal birthplaces of protoplanets.

  9. FAR-INFRARED EMISSION FROM THE INTERGALACTIC MEDIUM IN STEPHAN'S QUINTET REVEALED BY AKARI

    SciTech Connect

    Suzuki, Toyoaki; Kaneda, Hidehiro; Onaka, Takashi; Kitayama, Tetsu

    2011-04-10

    Stephan's Quintet (SQ, HCG92) was observed with the Far-Infrared Surveyor on board AKARI in four far-infrared (IR) bands at 65, 90, 140, and 160 {mu}m. The AKARI four-band images show far-IR emission in the intergalactic medium of SQ. In particular, the 160 {mu}m band image shows single peak emission in addition to the structure extending in the north-south direction along the shock ridge as seen in the 140 {mu}m band, H{sub 2} emission, and X-ray emission. Whereas most of the far-IR emission in the shocked region comes from the cold dust component, shock-powered [C II]158 {mu}m emission can significantly contribute to the emission in the 160 {mu}m band that shows a single peak at the shocked region. In the shocked region, the observed gas-to-dust mass ratio is in agreement with the Galactic one. The color temperature of the cold dust component ({approx}20 K) is lower than that in surrounding galaxies ({approx}30 K). We discuss a possible origin of the intergalactic dust emission.

  10. AKARI observations of dust processing in merger galaxies: NGC2782 and NGC7727

    NASA Astrophysics Data System (ADS)

    Onaka, Takashi; Nakamura, Tomohiko; Sakon, Itsuki; Ohsawa, Ryou; Mori, Tamami; Wu, Ronin; Kaneda, Hidehiro

    2015-08-01

    Dust grains are the major reservoir of heavy elements and play significant roles in the thermal balance and chemistry in the interstellar medium. Where dust grains are formed and how they evolve in the ISM are one of the key issues for the understanding of the material evolution in the Universe. Although theoretical studies have been made, very little is so far known observationally about the lifecycle of dust grains in the ISM and that associated with Galactic scale events. The lifecycle of very small carbonaceous grains that contain polycyclic aromatic hydrocarbons (PAHs) or PAH-like atomic groups are of particular interest because they emit distinct band emission in the near- to mid-infrared region and they are thought to be most vulnerable to environmental conditions. PAHs may be formed in carbon-rich stars, while recent AKARI observations suggest that they may be formed by fragmentation of large carbonaceous grains in shocks in a supernova remnant or a galactic wind (Onaka et al. 2010, A&A, 514, 15; Seok et al. 2012, ApJ, 744, 160).Here we report results of AKARI observations of two mergers. NGC2782 (Arp 215) and NGC7727 (Arp 222). NGC2782 is a merger of 200Myr old. It shows a very long western tail of HI gas by a tidal interaction and the eastern tail that consists mainly of stellar components without an appreciable amount of gas and is thought to be a relic of the colliding low-mass galaxy whose gas component has been stripped off Smith 1994, AJ, 107, 1695. We found significant emission at the 7 μm band of the IRC onboard AKARI, which must come from PAH 6.2 and 7.7 μm bands, in the eastern tail. Based on dust model fitting, we found a low abundance of ~10nm size dust despite of the presence of PAHs, suggesting that PAHs may be formed from fragmentation of ~10nm carbonaceous dust grains. NGC7727 is a 1.2Gyr old merger and shows a SED similar to the NGC2782 tail in the northern tail of the merger event product, suggesting also the formation of PAHs from

  11. The AKARI/IRC mid-infrared all-sky survey

    NASA Astrophysics Data System (ADS)

    Ishihara, D.; Onaka, T.; Kataza, H.; Salama, A.; Alfageme, C.; Cassatella, A.; Cox, N.; García-Lario, P.; Stephenson, C.; Cohen, M.; Fujishiro, N.; Fujiwara, H.; Hasegawa, S.; Ita, Y.; Kim, W.; Matsuhara, H.; Murakami, H.; Müller, T. G.; Nakagawa, T.; Ohyama, Y.; Oyabu, S.; Pyo, J.; Sakon, I.; Shibai, H.; Takita, S.; Tanabé, T.; Uemizu, K.; Ueno, M.; Usui, F.; Wada, T.; Watarai, H.; Yamamura, I.; Yamauchi, C.

    2010-05-01

    Context. AKARI is the first Japanese astronomical satellite dedicated to infrared astronomy. One of the main purposes of AKARI is the all-sky survey performed with six infrared bands between 9 μm and 200 μm during the period from 2006 May 6 to 2007 August 28. In this paper, we present the mid-infrared part (9 μm and 18 μm bands) of the survey carried out with one of the on-board instruments, the infrared camera (IRC). Aims: We present unprecedented observational results of the 9 μm and 18 μm AKARI all-sky survey and detail the operation and data processing leading to the point source detection and measurements. Methods: The raw data are processed to produce small images for every scan, and the point sources candidates are derived above the 5σ noise level per single scan. The celestial coordinates and fluxes of the events are determined statistically and the reliability of their detections is secured through multiple detections of the same source within milli-seconds, hours, and months from each other. Results: The sky coverage is more than 90% for both bands. A total of 877 091 sources (851 189 for 9 μm, 195 893 for 18 μm) are confirmed and included in the current release of the point source catalog. The detection limit for point sources is 50 mJy and 90 mJy for the 9 μm and 18 μm bands, respectively. The position accuracy is estimated to be better than 2''. Uncertainties in the in-flight absolute flux calibration are estimated to be 3% for the 9 μm band and 4% for the 18 μm band. The coordinates and fluxes of detected sources in this survey are also compared with those of the IRAS survey and are found to be statistically consistent. Catalog is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/514/A1

  12. AKARI INFRARED CAMERA SURVEY OF THE LARGE MAGELLANIC CLOUD. II. THE NEAR-INFRARED SPECTROSCOPIC CATALOG

    SciTech Connect

    Shimonishi, Takashi; Onaka, Takashi; Kato, Daisuke; Sakon, Itsuki; Ita, Yoshifusa; Kawamura, Akiko; Kaneda, Hidehiro

    2013-02-01

    We performed a near-infrared spectroscopic survey toward an area of {approx}10 deg{sup 2} of the Large Magellanic Cloud (LMC) with the infrared satellite AKARI. Observations were carried out as part of the AKARI Large-area Survey of the Large Magellanic Cloud (LSLMC). The slitless multi-object spectroscopic capability of the AKARI/IRC enabled us to obtain low-resolution (R {approx} 20) spectra in 2-5 {mu}m for a large number of point sources in the LMC. As a result of the survey, we extracted about 2000 infrared spectra of point sources. The data are organized as a near-infrared spectroscopic catalog. The catalog includes various infrared objects such as young stellar objects (YSOs), asymptotic giant branch (AGB) stars, supergiants, and so on. It is shown that 97% of the catalog sources have corresponding photometric data in the wavelength range from 1.2 to 11 {mu}m, and 67% of the sources also have photometric data up to 24 {mu}m. The catalog allows us to investigate near-infrared spectral features of sources by comparison with their infrared spectral energy distributions. In addition, it is estimated that about 10% of the catalog sources are observed at more than two different epochs. This enables us to study a spectroscopic variability of sources by using the present catalog. Initial results of source classifications for the LSLMC samples are presented. We classified 659 LSLMC spectra based on their near-infrared spectral features by visual inspection. As a result, it is shown that the present catalog includes 7 YSOs, 160 C-rich AGBs, 8 C-rich AGB candidates, 85 O-rich AGBs, 122 blue and yellow supergiants, 150 red super giants, and 128 unclassified sources. Distributions of the classified sources on the color-color and color-magnitude diagrams are discussed in the text. Continuous wavelength coverage and high spectroscopic sensitivity in 2-5 {mu}m can only be achieved by space observations. This is an unprecedented large-scale spectroscopic survey toward the

  13. Extended Dust Shell of the Carbon Star U Hya Revealed by AKARI

    NASA Astrophysics Data System (ADS)

    Ueta, T.; Izumiura, H.; Yamamura, I.; Matsunaga, N.; Ita, Y.; Matsuura, M.; Nakada, Y.; Fukushi, H.; Mito, H.; Tanabé, T.; Hashimoto, O.

    2011-09-01

    We have observed the carbon-rich AGB star U Hya in the far-infrared (FIR) at 65, 90, 140, and 160 μm simultaneously, using the slow-scan observing mode of the Far-Infrared Surveyor (FIS) aboard the Japanese infrared astronomical satellite AKARI. Our aim is to probe the mass-loss history of U Hya in the last ˜104 years by investigating the distribution of cold dust in the extended circumstellar envelope using FIR maps at high spatial resolution. The observed hollow shell and model calculations suggest that the shell was formed as a direct consequence of a thermal pulse, two-wind interactions, a termination shock, or some combination of these processes.

  14. AKARI/AcuA PHYSICAL STUDIES OF THE CYBELE ASTEROID FAMILY

    SciTech Connect

    Kasuga, Toshihiro; Usui, Fumihiko; Hasegawa, Sunao; Kuroda, Daisuke; Ootsubo, Takafumi; Mueller, Thomas G.; Ishiguro, Masateru

    2012-06-15

    We present a study of 107 Cybele asteroids based on the archival database 'Asteroid Catalog Using AKARI (AcuA)' taken by the Infrared Astronomical Satellite. The database provides diameters D > 10 km, geometric albedos, and taxonomic information (75%) of the Cybeles. We find taxonomic diversity (mainly C-, D-, and P-type) in the population of 78 small Cybeles with diameters 10 km 80 km are mostly classified as C- or P-types (90%), with a power-law index of 2.39 {+-} 0.18. The total mass of Cybele asteroids is estimated to be {approx}10{sup -5} M{sub Earth}. We also discuss the origin and formation process of the Cybele asteroid family.

  15. INTERSTELLAR DUST PROPERTIES OF M51 FROM AKARI MID-INFRARED IMAGES

    SciTech Connect

    Egusa, Fumi; Wada, Takehiko; Arimatsu, Ko; Matsuhara, Hideo; Sakon, Itsuki; Onaka, Takashi

    2013-11-20

    Using mid-infrared (MIR) images of four photometric bands of the Infrared Camera on board the AKARI satellite, S7 (7 μm), S11 (11 μm), L15 (15 μm), and L24 (24 μm), we investigate the interstellar dust properties of the nearby pair of galaxies M51 with respect to their spiral arm structure. The arm and interarm regions are defined based on a spatially filtered stellar component model image and we measure the arm/interarm contrast for each band. The contrast is lowest in the S11 image, which we interpret as meaning that among the four AKARI MIR bands, the S11 image best correlates with the spatial distribution of dust grains including colder components. On the other hand, the L24 image, with the highest contrast, traces warmer dust heated by star forming activity. The surface brightness ratio between the bands, i.e., color, is measured over the disk of the main galaxy, M51a, at 300 pc resolution. We find that the distribution of S7/S11 is smooth and traces the global spiral arm pattern well while L15/S11 and L24/S11 peak at individual H II regions. This result indicates that the ionization state of polycyclic aromatic hydrocarbons (PAHs) is related to the spiral structure. Comparison with observational data and dust models also supports the importance of the variation in the PAH ionization state within the M51a disk. However, the mechanism driving this variation is not yet clear from the currently available datasets. Another suggestion from the comparison with the models is that the PAH fraction in the total dust mass is higher than previously estimated.

  16. Widely Extended [O III] 88μm Line Emission around the 30 Doradus Region Revealed with AKARI FIS-FTS

    NASA Astrophysics Data System (ADS)

    Kawada, Mitsunobu; Takahashi, Ai; Yasuda, Akiko; Kiriyama, Yuichi; Mori, Tatsuya; Mouri, Akio; Kaneda, Hidehiro; Okada, Yoko; Takahashi, Hidenori; Murakami, Noriko

    2011-08-01

    We present a distribution map of the far-infrared [O II] 88 μm line emission around the 30 Doradus (30 Dor) region in the Large Magellanic Cloud obtained with the Fourier Transform Spectrometer of the Far-Infrared Surveyor on board AKARI. The map reveals that the [O III] emission is widely distributed by more than 10' around the super star cluster R 136, implying that the 30 Dor region is affluent with interstellar radiation field that is hard enough to ionize O2+. The observed [O III] line intensities are as high as (1-2) × 10-6 W m-2 sr-1 on the peripheral regions 4'-5' away from the center of 30 Dor, which requires gas densities of 60-100 cm-3. However, the observed size of the distribution of the [O III] emission is too large to be explained by massive stars in the 30 Dor region enshrouded by clouds with a constant gas density of 102 cm-3. Therefore, the surrounding structure is likely to be highly clumpy. We also find a global correlation between the [O III] and the far-infrared continuum emission, suggesting that the gas and dust are well mixed in the highly ionized region where the dust survives in clumpy dense clouds shielded from energetic photons.

  17. A SURVEY OF H{sub 2}O, CO{sub 2}, AND CO ICE FEATURES TOWARD BACKGROUND STARS AND LOW-MASS YOUNG STELLAR OBJECTS USING AKARI

    SciTech Connect

    Noble, J. A.; Fraser, H. J.; Aikawa, Y.; Pontoppidan, K. M.; Sakon, I.

    2013-10-01

    We present near-infrared spectroscopic observations of 19 molecular clouds made using the AKARI satellite, and the data reduction pipeline written to analyze those observations. The 2.5-5 μm spectra of 30 objects—22 field stars behind quiescent molecular clouds and 8 low-mass young stellar objects in cores—were successfully extracted using the pipeline. Those spectra are further analyzed to calculate the column densities of key solid phase molecular species, including H{sub 2}O, CO{sub 2}, CO, and OCN{sup –}. The profile of the H{sub 2}O ice band is seen to vary across the objects observed and we suggest that the extended red wing may be an evolutionary indicator of both dust and ice mantle properties. The observation of 22 spectra with fluxes as low as < 5 mJy toward background stars, including 15 where the column densities of H{sub 2}O, CO, and CO{sub 2} were calculated, provides valuable data that could help to benchmark the initial conditions in star-forming regions prior to the onset of star formation.

  18. AKARI INFRARED CAMERA SURVEY OF THE LARGE MAGELLANIC CLOUD. I. POINT-SOURCE CATALOG

    SciTech Connect

    Kato, Daisuke; Onaka, Takashi; Shimonishi, Takashi; Sakon, Itsuki; Ita, Yoshifusa; Tanabe, Toshihiko; Takahashi, Hidenori; Kaneda, Hidehiro; Kawamura, Akiko; Wada, Takehiko; Usui, Fumihiko; Koo, Bon-Chul; Matsuura, Mikako E-mail: onaka@astron.s.u-tokyo.ac.jp

    2012-12-01

    We present a near- to mid-infrared point-source catalog of five photometric bands at 3.2, 7, 11, 15, and 24 {mu}m for a 10 deg{sup 2} area of the Large Magellanic Cloud (LMC) obtained with the Infrared Camera on board the AKARI satellite. To cover the survey area the observations were carried out at three separate seasons from 2006 May to June, 2006 October to December, and 2007 March to July. The 10{sigma} limiting magnitudes of the present survey are 17.9, 13.8, 12.4, 9.9, and 8.6 mag at 3.2, 7, 11, 15, and 24 {mu}m, respectively. The photometric accuracy is estimated to be about 0.1 mag at 3.2 {mu}m and 0.06-0.07 mag in the other bands. The position accuracy is 0.''3 at 3.2, 7, and 11 {mu}m and 1.''0 at 15 and 24 {mu}m. The sensitivities at 3.2, 7, and 24 {mu}m are roughly comparable to those of the Spitzer SAGE LMC point-source catalog, while the AKARI catalog provides the data at 11 and 15 {mu}m, covering the mid-infrared spectral range contiguously. Two types of catalog are provided: a Catalog and an Archive. The Archive contains all the detected sources, while the Catalog only includes the sources that have a counterpart in the Spitzer SAGE point-source catalog. The Archive contains about 650,000, 140,000, 97,000, 43,000, and 52,000 sources at 3.2, 7, 11, 15, and 24 {mu}m, respectively. Based on the catalog, we discuss the luminosity functions at each band, the color-color diagram, and the color-magnitude diagram using the 3.2, 7, and 11 {mu}m band data. Stars without circumstellar envelopes, dusty C-rich and O-rich stars, young stellar objects, and background galaxies are located at distinct regions in the diagrams, suggesting that the present catalog is useful for the classification of objects toward the LMC.

  19. Ice Mapping Observations in Galactic Star-Forming Regions: the AKARI Legacy

    NASA Astrophysics Data System (ADS)

    Fraser, Helen Jane; Suutarinnen, Aleksi; Noble, Jennifer

    2015-08-01

    It is becoming increasingly clear that explaining the small-scale distribution of many gas-phase molecules relies on our interpretation of the complex inter-connectivity between gas- and solid-phase interstellar chemistries. Inputs to proto-stellar astrochemical models are required that exploit ice compositions reflecting the historical physical conditions in pre-stellar environments when the ices first formed. Such data are required to translate the near-universe picture of ice-composition to our understanding of the role of extra-galactic ices in star-formation at higher redshifts.Here we present the first attempts at multi-object ice detections, and the subsequent ice column density mapping. The AKARI space telescope was uniquely capable of observing all the ice features between 2 and 5 microns, thereby detecting H2O, CO and CO2 ices concurrently, through their stretching vibrational features. Our group has successfully extracted an unprecedented volume of ice spectra from AKARI, including sources with not more than 2 mJy flux at 3 microns, showing:(a) H2O CO and CO2 ices on 30 lines of sight towards pre-stellar and star-forming cores, which when combined with laboratory experiments indicate how the chemistries of these three ices are interlinked (Noble et al (2013)),(b) ice maps showing the spatial distribution of water ice across 12 pre-stellar cores, in different molecular clouds (Suutarinnen et al (2015)), and the distribution of ice components within these cores on 1000 AU scales (Noble et al (2015)),(c) over 200 new detections of water ice, mostly on lines of sight towards background sources (> 145), indicating that water ice column density has a minimum value as a function of Av, but on a cloud-by-cloud basis typically correlates with Av, and dust emissivity at 250 microns (Suutarinnen et al (2015)),(d) the first detections of HDO ice towards background stars (Fraser et al (2015)).We discuss whether these results support the picture of a generic chemical

  20. Bright Debris Disk Candidates Detected with the AKARI/Far-infrared Surveyor

    NASA Astrophysics Data System (ADS)

    Liu, Qiong; Wang, Tinggui; Jiang, Peng

    2014-07-01

    We cross-correlate the Hipparcos main-sequence star catalog with the AKARI/FIS catalog and identify 136 stars (at >90% reliability) with far-infrared detections in at least one band. After rejecting 57 stars classified as young stellar objects, Be stars and other type stars with known dust disks or with potential contaminations, and 4 stars without infrared excess emission, we obtain a sample of 75 candidate stars with debris disks. Stars in our sample cover spectral types from B to K with most being early types. This represents a unique sample of luminous debris disks that derived uniformly from an all-sky survey with a spatial resolution factor of four better than the previous such survey by IRAS. Moreover, by collecting the infrared photometric data from other public archives, almost three-quarters of them have infrared excesses in more than one band, allowing an estimate of the dust temperatures. We fit the blackbody model to the broadband spectral energy distribution of these stars to derive the statistical distribution of the disk parameters. Four B stars with excesses in four or more bands require a double blackbody model, with the high one around 100 or 200 K and the low one around 40-50 K.

  1. Point source calibration of the AKARI/FIS all-sky survey maps for stacking analysis

    NASA Astrophysics Data System (ADS)

    Arimatsu, Ko; Doi, Yasuo; Wada, Takehiko; Takita, Satoshi; Kawada, Mitsunobu; Matsuura, Shuji; Ootsubo, Takafumi; Kataza, Hirokazu

    2014-04-01

    Investigations of the point spread functions (PSFs) and flux calibrations for stacking analysis have been performed with the far-infrared (wavelength range of 60 to 140 μm) all-sky maps taken by the Far-Infrared Surveyor (FIS) on board the AKARI satellite. The PSFs are investigated by stacking the maps at the positions of standard stars with their fluxes of 0.02-10 Jy. The derived full widths at the half maximum (FWHMs) of the PSFs are ˜ 60'' at 65 and 90 μm and ˜ 90'' at 140 μm, which are much smaller than those of the previous all-sky maps obtained with the Infrared Astronomical Satellite IRAS (˜ 6'). Any flux dependence in the PSFs is not seen on the investigated flux range. By performing the flux calibrations, we found that absolute photometry for faint sources can be carried out with constant calibration factors, which range from 0.6 to 0.8. After applying the calibration factors, the photometric accuracies for the stacked sources in the 65, 90, and 140 μm bands are 9%, 3%, and 21%, respectively, even below the detection limits of the survey. No systematic dependence between the observed flux and model flux is found. These results indicate that the FIS map is a useful dataset for the stacking analyses of faint sources at far-infrared wavelengths.

  2. WATER MASER SURVEY ON AKARI AND IRAS SOURCES: A SEARCH FOR ''LOW-VELOCITY'' WATER FOUNTAINS

    SciTech Connect

    Yung, Bosco H. K.; Nakashima, Jun-ichi; Kwok, Sun; Imai, Hiroshi; Deguchi, Shuji; Henkel, Christian

    2013-05-20

    We present the results of a 22 GHz H{sub 2}O maser survey toward a new sample of asymptotic giant branch (AGB) and post-AGB star candidates. Most of the objects are selected for the first time based on the AKARI data, which have high flux sensitivity in the mid-infrared ranges. We aim at finding H{sub 2}O maser sources in the transient phase between the AGB and post-AGB stages of evolution, where the envelopes start to develop large deviations from spherical symmetry. The observations were carried out with the Effelsberg 100 m radio telescope. Among 204 observed objects, 63 detections (36 new) were obtained. We found four objects that may be ''water fountain'' sources (IRAS 15193+3132, IRAS 18056-1514, OH 16.3-3.0, and IRAS 18455+0448). They possess an H{sub 2}O maser velocity coverage much smaller than those in other known water fountains. However, the coverage is still larger than that of the 1612 MHz OH maser. It implies that there is an outflow with a higher velocity than the envelope expansion velocity (typically {<=}25 km s{sup -1}), meeting the criterion of the water fountain class. We suggest that these candidates are possibly oxygen-rich late AGB or early post-AGB stars in a stage of evolution immediately after the spherically symmetric AGB mass loss has ceased.

  3. Bright debris disk candidates detected with the AKARI/FAR-infrared surveyor

    SciTech Connect

    Liu, Qiong; Wang, Tinggui; Jiang, Peng E-mail: twang@ustc.edu.cn

    2014-07-01

    We cross-correlate the Hipparcos main-sequence star catalog with the AKARI/FIS catalog and identify 136 stars (at >90% reliability) with far-infrared detections in at least one band. After rejecting 57 stars classified as young stellar objects, Be stars and other type stars with known dust disks or with potential contaminations, and 4 stars without infrared excess emission, we obtain a sample of 75 candidate stars with debris disks. Stars in our sample cover spectral types from B to K with most being early types. This represents a unique sample of luminous debris disks that derived uniformly from an all-sky survey with a spatial resolution factor of four better than the previous such survey by IRAS. Moreover, by collecting the infrared photometric data from other public archives, almost three-quarters of them have infrared excesses in more than one band, allowing an estimate of the dust temperatures. We fit the blackbody model to the broadband spectral energy distribution of these stars to derive the statistical distribution of the disk parameters. Four B stars with excesses in four or more bands require a double blackbody model, with the high one around 100 or 200 K and the low one around 40-50 K.

  4. Calibration of the AKARI far-infrared all-sky survey maps

    NASA Astrophysics Data System (ADS)

    Takita, Satoshi; Doi, Yasuo; Ootsubo, Takafumi; Arimatsu, Ko; Ikeda, Norio; Kawada, Mitsunobu; Kitamura, Yoshimi; Matsuura, Shuji; Nakagawa, Takao; Hattori, Makoto; Morishima, Takahiro; Tanaka, Masahiro; Komugi, Shinya

    2015-06-01

    We present an initial analysis of the properties of an all-sky image obtained by the Far-Infrared Surveyor (FIS) onboard the AKARI satellite, at 65 μm (N60), 90 μm (WIDE-S), 140 μm (WIDE-L), and 160 μm (N160). An absolute flux calibration was determined by comparing the data with COBE/DIRBE data sets; the intensity range was as wide as from a few MJy sr-1 to > 1 GJy sr-1. The uncertainties are considered to be the standard deviations with respect to the DIRBE data, and are less than 10% for intensities above 10, 3, 25, and 26 MJy sr-1 at the N60, WIDE-S, WIDE-L, and N160 bands, respectively. The characteristics of point sources in the image were also determined by stacking maps centred on photometric standard stars. The full width at half maxima of the point spread functions (PSFs) were 63″, 78″, and 88″ at the N60, WIDE-S, and WIDE-L bands, respectively. The PSF at the N160 band was not obtained due to the sensitivity, but it is thought to be the same as that of the WIDE-L one.

  5. AKARI IRC 2.5-5 μm spectroscopy of infrared galaxies over a wide luminosity range

    SciTech Connect

    Ichikawa, Kohei; Ueda, Yoshihiro; Imanishi, Masatoshi; Nakagawa, Takao; Shirahata, Mai; Kaneda, Hidehiro; Oyabu, Shinki

    2014-10-20

    We present the result of a systematic infrared 2.5-5 μm spectroscopic study of 22 nearby infrared galaxies over a wide infrared luminosity range (10{sup 10} L {sub ☉} < L {sub IR} < 10{sup 13} L {sub ☉}) obtained from the AKARI Infrared Camera (IRC). The unique band of the AKARI IRC spectroscopy enables us to access both the 3.3 μm polycyclic aromatic hydrocarbon (PAH) emission feature from star-forming activity and the continuum of torus-dust emission heated by an active galactic nucleus (AGN). Applying our AGN diagnostics to the AKARI spectra, we discover 14 buried AGNs. The large fraction of buried AGNs suggests that AGN activity behind the dust is almost ubiquitous in ultra-/luminous infrared galaxies (U/LIRGs). We also find that both the fraction and energy contribution of buried AGNs increase with infrared luminosity from 10{sup 10} L {sub ☉} to 10{sup 13} L {sub ☉}, including normal infrared galaxies with L {sub IR} < 10{sup 11} L {sub ☉}. The energy contribution from AGNs in the total infrared luminosity is only ∼7% in LIRGs and ∼20% in ULIRGs, suggesting that the majority of the infrared luminosity originates from starburst activity. Using the PAH emission, we investigate the luminosity relation between star formation and AGNs. We find that these infrared galaxies exhibit higher star formation rates than optically selected Seyfert galaxies with the same AGN luminosities, implying that infrared galaxies could be an early evolutionary phase of AGN.

  6. DETECTION OF THE DETACHED DUST SHELL OF U ANTLIAE AT MID-INFRARED WAVELENGTHS WITH AKARI/IRC

    SciTech Connect

    Arimatsu, Ko; Onaka, Takashi; Izumiura, Hideyuki; Ueta, Toshiya; Yamamura, Issei

    2011-03-10

    We report mid-infrared (MIR) imaging observations of the carbon star U Ant made with the Infrared Camera (IRC) on board AKARI. Subtraction of the artifacts and extended point-spread function of the central star reveals the detached dust shell around the carbon star at MIR wavelengths (15 and 24 {mu}m) for the first time. The observed radial brightness profiles of the MIR emission are well explained by two shells at 43'' and 50'' from the central star detected in optical scattered light observations. Combining Herschel/PACS, AKARI/FIS, and AKARI/IRC data, we obtain the infrared spectral energy distribution (SED) of the thermal emission from the detached shell of U Ant in a wide infrared spectral range of 15-160 {mu}m. Thermal emission of amorphous carbon grains with a single temperature cannot account for the observed SED from 15 to 160 {mu}m: it underestimates the emission at 15 {mu}m. Alternatively, the observed SED is fitted by the model in which amorphous carbon grains in the two shells have different temperatures of 60 and 104 K, which allocates most dust mass in the shell at 50''. This supports the previous suggestion that the 43'' shell is gas-rich and the 50'' shell is dust-rich. We suggest a possibility that the segregation of the gas and dust resulting from the drift motion of submicron-sized dust grains relative to the gas and that the hot dust component associated with the gas-rich shell is composed of very small grains that are strongly coupled with the gas.

  7. Detection of the Detached Dust Shell of U Antliae at Mid-infrared Wavelengths with AKARI/IRC

    NASA Astrophysics Data System (ADS)

    Arimatsu, Ko; Izumiura, Hideyuki; Ueta, Toshiya; Yamamura, Issei; Onaka, Takashi

    2011-03-01

    We report mid-infrared (MIR) imaging observations of the carbon star U Ant made with the Infrared Camera (IRC) on board AKARI. Subtraction of the artifacts and extended point-spread function of the central star reveals the detached dust shell around the carbon star at MIR wavelengths (15 and 24 μm) for the first time. The observed radial brightness profiles of the MIR emission are well explained by two shells at 43'' and 50'' from the central star detected in optical scattered light observations. Combining Herschel/PACS, AKARI/FIS, and AKARI/IRC data, we obtain the infrared spectral energy distribution (SED) of the thermal emission from the detached shell of U Ant in a wide infrared spectral range of 15-160 μm. Thermal emission of amorphous carbon grains with a single temperature cannot account for the observed SED from 15 to 160 μm: it underestimates the emission at 15 μm. Alternatively, the observed SED is fitted by the model in which amorphous carbon grains in the two shells have different temperatures of 60 and 104 K, which allocates most dust mass in the shell at 50''. This supports the previous suggestion that the 43'' shell is gas-rich and the 50'' shell is dust-rich. We suggest a possibility that the segregation of the gas and dust resulting from the drift motion of submicron-sized dust grains relative to the gas and that the hot dust component associated with the gas-rich shell is composed of very small grains that are strongly coupled with the gas.

  8. AKARI North Ecliptic Pole Deep Survey. Revision of the catalogue via a new image analysis

    NASA Astrophysics Data System (ADS)

    Murata, K.; Matsuhara, H.; Wada, T.; Arimatsu, K.; Oi, N.; Takagi, T.; Oyabu, S.; Goto, T.; Ohyama, Y.; Malkan, M.; Pearson, C.; Małek, K.; Solarz, A.

    2013-11-01

    Context. We present the revised near- to mid-infrared catalogue of the AKARI North Ecliptic Pole deep survey. The survey has the unique advantage of continuous filter coverage from 2 to 24 μm over nine photometric bands, but the initial version of the survey catalogue leaves room for improvement in the image analysis stage; the original images are strongly contaminated by the behaviour of the detector and the optical system. Aims: The purpose of this study is to devise new image analysis methods and to improve the detection limit and reliability of the source extraction. Methods: We removed the scattered light and stray light from the Earth limb, and corrected for artificial patterns in the images by creating appropriate templates. We also removed any artificial sources due to bright sources by using their properties or masked them out visually. In addition, for the mid-infrared source extraction, we created detection images by stacking all six bands. This reduced the sky noise and enabled us to detect fainter sources more reliably. For the near-infrared source catalogue, we considered only objects with counterparts from ground-based catalogues to avoid fake sources. For our ground-based catalogues, we used catalogues based on the CFHT/MegaCam z' band, CFHT/WIRCam Ks band and Subaru/Scam z' band. Objects with multiple counterparts were all listed in the catalogue with a merged flag for the AKARI flux. Results: The detection limits of all mid-infrared bands were improved by ~20%, and the total number of detected objects was increased by ~2000 compared with the previous version of the catalogue; it now has 9560 objects. The 5σ detection limits in our catalogue are 11, 9, 10, 30, 34, 57, 87, 93, and 256 μJy in the N2, N3, N4, S7, S9W, S11, L15, L18W, and L24 bands, respectively. The astrometric accuracies of these band detections are 0.48, 0.52, 0.55, 0.99, 0.95, 1.1, 1.2, 1.3, and 1.6 arcsec, respectively. The false-detection rate of all nine bands was decreased

  9. AKARI NEAR-INFRARED SPECTROSCOPIC SURVEY FOR CO{sub 2} IN 18 COMETS

    SciTech Connect

    Ootsubo, Takafumi; Kawakita, Hideyo; Hamada, Saki; Kobayashi, Hitomi; Yamaguchi, Mitsuru; Usui, Fumihiko; Nakagawa, Takao; Ueno, Munetaka; Ishiguro, Masateru; Sekiguchi, Tomohiko; Watanabe, Jun-ichi; Sakon, Itsuki; Shimonishi, Takashi; Onaka, Takashi

    2012-06-10

    We conducted a spectroscopic survey of cometary volatiles with the Infrared Camera on board the Japanese infrared satellite AKARI in the wavelength range from 2.5 to 5 {mu}m. In our survey, 18 comets, including both the Oort cloud comets and the Jupiter-family comets, were observed in the period from 2008 June to 2010 January, most of which were observed at least twice. The prominent emission bands in the observed spectra are the fundamental vibrational bands of water (H{sub 2}O) at 2.7 {mu}m and carbon dioxide (CO{sub 2}) at 4.3 {mu}m. The fundamental vibrational band of carbon monoxide (CO) around 4.7 {mu}m and the broad emission feature, probably related to carbon-hydrogen-bearing molecules, can also be recognized around the 3.3-3.5-{mu}m region in some of the comets. With respect to H{sub 2}O, gas production rate ratios of CO{sub 2} have been derived in 17 comets, except for the comet 29P/Schwassmann-Wachmann 1. Our data set provides the largest homogeneous database of CO{sub 2}/H{sub 2}O production rate ratios in comets obtained so far. The CO{sub 2}/H{sub 2}O production rate ratios are considered to reflect the composition of cometary ice when a comet is observed at a heliocentric distance within {approx}2.5 AU, since H{sub 2}O ice fully sublimates there. The CO{sub 2}/H{sub 2}O ratio in cometary ice spans from several to {approx}30% among the comets observed at <2.5 AU (13 out of the 17 comets). Alternatively, the ratio of CO/CO{sub 2} in the comets seems to be smaller than unity based on our observations, although we only obtain upper limits for CO in most of the comets.

  10. Revised wavelength and spectral response calibrations for AKARI near-infrared grism spectroscopy: Cryogenic phase

    NASA Astrophysics Data System (ADS)

    Baba, Shunsuke; Nakagawa, Takao; Shirahata, Mai; Isobe, Naoki; Usui, Fumihiko; Ohyama, Youichi; Onaka, Takashi; Yano, Kenichi; Kochi, Chihiro

    2016-04-01

    We perform revised spectral calibrations for the AKARI near-infrared grism to correct quantitatively for the effect of the wavelength-dependent refractive index. The near-infrared grism covering the wavelength range of 2.5-5.0 μm, with a spectral resolving power of 120 at 3.6 μm, is found to be contaminated by second-order light at wavelengths longer than 4.9 μm, which is especially serious for red objects. First, we present the wavelength calibration considering the refractive index of the grism as a function of the wavelength for the first time. We find that the previous solution is positively shifted by up to 0.01 μm compared with the revised wavelengths at 2.5-5.0 μm. In addition, we demonstrate that second-order contamination occurs even with a perfect order-sorting filter owing to the wavelength dependence of the refractive index. Secondly, the spectral responses of the system from the first- and second-order light are simultaneously obtained from two types of standard objects with different colors. The response from the second-order light suggests leakage of the order-sorting filter below 2.5 μm. The relations between the output of the detector and the intensities of the first- and second-order light are formalized by a matrix equation that combines the two orders. The removal of the contaminating second-order light can be achieved by solving the matrix equation. The new calibration extends the available spectral coverage of the grism mode from 4.9 μm up to 5.0 μm. The revision can be used to study spectral features falling in these extended wavelengths, e.g., the carbon monoxide fundamental ro-vibrational absorption within nearby active galactic nuclei.

  11. Spectral energy distributions of an AKARI-SDSS-GALEX sample of galaxies

    NASA Astrophysics Data System (ADS)

    Buat, V.; Giovannoli, E.; Takeuchi, T. T.; Heinis, S.; Yuan, F.-T.; Burgarella, D.; Noll, S.; Iglesias-Páramo, J.

    2011-05-01

    Context. The nearby universe remains the best laboratory to understand the physical properties of galaxies and is a reference for any comparison with high redshift observations. The all sky (or very large) surveys that have been performed from the ultraviolet (UV) to the far-infrared (far-IR) provide us with large datasets of very large wavelength coverage to perform a reference study. Aims: We investigate the dust attenuation characteristics, as well as the star formation rate (SFR) calibrations of a sample of nearby galaxies observed over 13 bands from 0.15 to 160 μm. Methods: A sample of 363 galaxies is built from the AKARI /FIS all sky survey cross-correlated with the SDSS and GALEX surveys. Broad-band spectral energy distributions are fitted with the CIGALE code optimized to analyse variations in the dust attenuation curves and SFR measurements and based on an energetic budget between the stellar and dust emission. Results: Our galaxy sample is primarily selected in far-IR and mostly constituted of massive, actively star-forming galaxies. There is some evidence for a dust attenuation law that is slightly steeper than that used for starburst galaxies but we are unable to constrain the presence or not of a bump at 220 nm. We confirm that a time-dependent dust attenuation is necessary to perform the best fits. Various calibrations of the dust attenuation in the UV as a function of UV-optical colours are discussed. A calibration of the current SFR combining UV and total IR emissions is proposed with an accurate estimate of dust heating by old stars. For the whole sample, 17% of the total dust luminosity is unrelated to the recent star formation.

  12. A New Sample of Obscured AGNs Selected from the XMM-Newton and AKARI Surveys

    NASA Astrophysics Data System (ADS)

    Terashima, Yuichi; Hirata, Yoshitaka; Awaki, Hisamitsu; Oyabu, Shinki; Gandhi, Poshak; Toba, Yoshiki; Matsuhara, Hideo

    2015-11-01

    We report a new sample of obscured active galactic nuclei (AGNs) selected from the XMM-Newton serendipitous source and AKARI point-source catalogs. We match X-ray sources with infrared (18 and 90 μm) sources located at | b| \\gt 10^\\circ to create a sample consisting of 173 objects. Their optical classifications and absorption column densities measured by X-ray spectra are compiled and study efficient selection criteria to find obscured AGNs. We apply the criteria (1) X-ray hardness ratio defined by using the 2-4.5 keV and 4.5-12 keV bands > -0.1 and (2) EPIC-PN count rate (CR) in the 0.2-12 keV to infrared flux ratio CR/{F}90\\lt 0.1 or CR/{F}18\\lt 1, where F18 and F90 are infrared fluxes at 18 and 90 μm in Jy, respectively, to search for obscured AGNs. X-ray spectra of 48 candidates, for which no X-ray results have been published, are analyzed and X-ray evidence for the presence of obscured AGNs such as a convex shape X-ray spectrum indicative of absorption of {N}{{H}} ˜ 1022-24 cm-2, a very flat continuum, or a strong Fe-K emission line with an equivalent width of \\gt 700 {{eV}} is found in 26 objects. Six of them are classified as Compton-thick AGNs, and four are represented by either Compton-thin or Compton-thick spectral models. The success rate of finding obscured AGNs combining our analysis and the literature is 92% if the 18 μm condition is used. Of the 26 objects, 4 are optically classified as an H ii nucleus and are new “elusive AGNs” in which star formation activity likely overwhelms AGN emission in the optical and infrared bands.

  13. AKARI observations of ice absorption bands towards edge-on YSOs

    NASA Astrophysics Data System (ADS)

    Aikawa, Y.; Kamuro, D.; Sakon, I.; Itoh, Y.; Noble, J. A.; Pontoppidan, K. M., Fraser, H. J.; Terada, H.; Tamura, M.; Kandori, R.; Kawamura, A.; Ueno, M.

    2011-05-01

    Circumstellar disks and envelopes of low-mass YSOs contain significant amounts of ice. Such icy material will evolve to volatile components of planetary systems, such as comets in our solar system. In order to investigate the composition and evolution of circumstellar ice around low-mass YSOs, we have observed ice absorption bands towards eight YSOs ranging from class 0 to class II, among which seven are associated with edge-on disks. Slit-less spectroscopic observations are performed using the grism mode of Infrared Camera (IRC) on board AKARI, which enables us to obtain full NIR spectra from 2.5 μm to 5 μm, including the CO_2 band and the blue wing of the H_2O band, which are not accessible from the ground. We developed procedures to reduce the spectra of targets with nebulosity. The spectra are fitted with polynomial baselines to derive the absorption spectra. Then we fit the molecular absorption bands with the laboratory spectra from the database, considering the instrumental line profile and the spectral resolution of the dispersion element. Towards the Class 0-I sources, absorption bands of H_2O, CO_2, CO and XCN (OCN^-) are clearly detected. Weak features of 13CO_2, HDO, the C-H band, and gaseous CO are detected as well. OCS ice absorption is tentatively detected towards IRC-L1041-2. The detected features would mostly originate in the cold envelope, while CO gas and OCN^- could originate in the region close to the protostar. Towards class II stars, H_2O ice band is detected. We also detected H_2O ice, CO_2 ice and tentative CO gas features of the foreground component of class II stars.

  14. Dust Thermal Emission in a Suspected H2-Forming, Perseus-Arm Cloud via AKARI, IRAS, and SST

    NASA Astrophysics Data System (ADS)

    Bell, Aaron C.; Gibson, S. J.; Onaka, T.; Sakon, I.; Ohsawa, R.; Noriega-Crespo, A.; Reach, W. T.; Carey, S. J.; Miville-Deschenes, M.; Boulanger, F.; Brunt, C.; Taylor, A. R.; Martin, P. G.; Douglas, K. A.

    2013-01-01

    Formation of new stars requires the condensation of ambient neutral atomic hydrogen into the molecular phase. It is well known that stars form from molecular hydrogen clouds; less understood is how molecular clouds themselves begin to form. We use AKARI (MIR and FIS), HIRES (IRAS) and Spitzer (IRAC and MIPS) imaging photometry to probe thermal dust emission in a target cloud in the Perseus spiral arm, where the H1 to H2 transition appears to be underway. H2 formation in this region is indicated by strong HI self-absorption, variable CO emission, and significant ``excess'' infrared emission. We have sampled the dust spectral energy distribution (SED) at many positions on and off this cloud using AKARI, IRAS, and SST data. We present these SED plots with fits generated by the DustEM modeling program to provide some insight as to the nature of the dust composition, size distribution, and dominant heating mechanisms within this target and possibly other H2 forming regions.

  15. AKARI observations of ice absorption bands towards edge-on young stellar objects

    NASA Astrophysics Data System (ADS)

    Aikawa, Y.; Kamuro, D.; Sakon, I.; Itoh, Y.; Terada, H.; Noble, J. A.; Pontoppidan, K. M.; Fraser, H. J.; Tamura, M.; Kandori, R.; Kawamura, A.; Ueno, M.

    2012-02-01

    Context. Circumstellar disks and envelopes of low-mass young stellar objects (YSOs) contain significant amounts of ice. Such icy material will evolve to become volatile components of planetary systems, such as comets in our solar system. Aims: To investigate the composition and evolution of circumstellar ice around low-mass young stellar objects (YSOs), we observed ice absorption bands in the near infrared (NIR) towards eight YSOs ranging from class 0 to class II, among which seven are associated with edge-on disks. Methods: We performed slit-less spectroscopic observations using the grism mode of the InfraRed Camera (IRC) on board AKARI, which enables us to obtain full NIR spectra from 2.5 μm to 5 μm, including the CO2 band and the blue wing of the H2O band, which are inaccessible from the ground. We developed procedures to carefully process the spectra of targets with nebulosity. The spectra were fitted with polynomial baselines to derive the absorption spectra. The molecular absorption bands were then fitted with the laboratory database of ice absorption bands, considering the instrumental line profile and the spectral resolution of the grism dispersion element. Results: Towards the class 0-I sources (L1527, IRC-L1041-2, and IRAS 04302), absorption bands of H2O, CO2, CO, and XCN are clearly detected. Column density ratios of CO2 ice and CO ice relative to H2O ice are 21-28% and 13-46%, respectively. If XCN is OCN-, its column density is as high as 2-6% relative to H2O ice. The HDO ice feature at 4.1 μm is tentatively detected towards the class 0-I sources and HV Tau. Non-detections of the CH-stretching mode features around 3.5 μm provide upper limits to the CH3OH abundance of 26% (L1527) and 42% (IRAS 04302) relative to H2O. We tentatively detect OCS ice absorption towards IRC-L1041-2. Towards class 0-I sources, the detected features should mostly originate in the cold envelope, while CO gas and OCN- could originate in the region close to the protostar

  16. The initial conditions of isolated star formation - IX. Akari mapping of an externally heated pre-stellar core

    NASA Astrophysics Data System (ADS)

    Nutter, D.; Stamatellos, D.; Ward-Thompson, D.

    2009-07-01

    We present observations of L1155 and L1148 in the Cepheus molecular cloud, taken using the Far Infrared Surveyor (FIS) instrument on the Akari satellite. We compare these data to submillimetre data taken using the Submillimetre Common-User Bolometer Array (SCUBA) camera on the James Clerk Maxwell Telescope, and far-infrared data taken with the imaging photo-polarimeter (ISOPHOT) camera on board the Infrared Space Observatory (ISO) satellite. The Akari data cover a similar spectral window and are consistent with the ISO data. All of the data show a relation between the position of the peak of emission and the wavelength for the core of L1155. We interpret this as a temperature gradient. We fit modified blackbody curves to the spectral energy distributions at two positions in the core and see that the central core in L1155 (L1155C) is approximately 2° warmer at one edge than it is in the centre. We consider a number of possible heating sources and conclude that the A6V star BD+67 1263 is the most likely candidate. This star is at a distance of 0.7pc from the front of L1155C in the plane of the sky. We carry out radiative transfer modelling of the L1155C core including the effects from the nearby star. We find that we can generate a good fit to the observed data at all wavelengths, and demonstrate that the different morphologies of the core at different wavelengths can be explained by the observed 2° temperature gradient. The L1148 core exhibits a similar morphology to that of L1155C, and the data are also consistent with a temperature gradient across the core. In this case, the most likely heating source is the star BD197053. Our findings illustrate very clearly that the apparent observed morphology of a pre-stellar core can be highly dependent on the wavelength of the observation, and that temperature gradients must be taken into account before converting images into column density distributions. This is important to note when interpreting Akari and Spitzer data

  17. AKARI All-Sky Survey: Contribution from AGB Stars to the Far Infrared Flux of the Milky Way

    NASA Astrophysics Data System (ADS)

    Pollo, A.; Rybka, P.; Takeuchi, T. T.

    2011-09-01

    Using the data from the AKARI FIS All-Sky Survey, we estimate the contribution from AGB stars to the far-infrared (FIR) flux from the Milky Way. We check the positions of different types of AGB stars in FIR color-color diagrams. Our conclusion is a large contribution from AGB stars, and particularly post-AGB stars, to the FIR flux in the outer regions of the Milky Way, and possibly other similar galaxies. FIR colors of different types of AGB stars are similar, with a large scatter, but post-AGB stars seem to be significantly redder and, as a result, contribute more to the total Galaxy flux at longer FIR wavelengths.

  18. Llaki and ñakary: idioms of distress and suffering among the highland Quechua in the Peruvian Andes.

    PubMed

    Pedersen, Duncan; Kienzler, Hanna; Gamarra, Jeffrey

    2010-06-01

    This article examines some of the long-term health outcomes of extreme adversities and the ways in which social inequalities and idioms of distress are historically and socially produced in the Peruvian context. We describe how the highland Quechua of northern Ayacucho construct and experience expressions of distress and suffering such as pinsamientuwan (worrying thoughts, worries), ñakary (suffering) and llaki (sorrow, sadness), in a context of persistent social inequalities, social exclusion and a recent history of political violence. It is concluded that the multiple expressions of distress and suffering are closely related to past and current events, shaped by beliefs, core values and cultural norms and, in this process, transformed, recreated and invested with new meanings and attributions. PMID:20405314

  19. Revised calibration for near- and mid-infrared images from ˜4000 pointed observations with AKARI/IRC

    NASA Astrophysics Data System (ADS)

    Egusa, Fumi; Usui, Fumihiko; Murata, Kazumi; Yamashita, Takuji; Yamamura, Issei; Onaka, Takashi

    2016-04-01

    The Japanese infrared astronomical satellite AKARI performed ˜4000 pointed observations for 16 months until the end of August 2007, when the telescope and instruments were cooled by liquid helium. Observation targets include solar system objects, Galactic objects, local galaxies, and galaxies at cosmological distances. We describe recent updates on calibration processes of near- and mid-infrared images taken by the Infrared Camera (IRC), which has nine photometric filters covering 2-27 μm continuously. Using the latest data reduction toolkit, we created calibrated and stacked images from each pointed observation. About 90% of the stacked images have a position accuracy better than 1{^''.}5. Uncertainties in aperture photometry estimated from a typical standard sky deviation of stacked images are a factor of ˜2-4 smaller than those of AllWISE at similar wavelengths. The processed images, together with documents such as process logs, as well as the latest toolkit are available online.

  20. Properties of Newly Formed Dust by SN 2006JC Based on Near- to Mid-Infrared Observation With AKARI

    NASA Astrophysics Data System (ADS)

    Sakon, I.; Onaka, T.; Wada, T.; Ohyama, Y.; Kaneda, H.; Ishihara, D.; Tanabé, T.; Minezaki, T.; Yoshii, Y.; Tominaga, N.; Nomoto, K.; Nozawa, T.; Kozasa, T.; Tanaka, M.; Suzuki, T.; Umeda, H.; Ohyabu, S.; Usui, F.; Matsuhara, H.; Nakagawa, T.; Murakami, H.

    2009-02-01

    We present our latest results on near- to mid-infrared (MIR) observation of supernova (SN) 2006jc at 200 days after the discovery using the Infrared Camera (IRC) on board AKARI. The near-infrared (2-5 μm) spectrum of SN 2006jc is obtained for the first time and is found to be well interpreted in terms of the thermal emission from amorphous carbon of 800 ± 10 K with the mass of 6.9 ± 0.5 × 10-5 M sun that was formed in the SN ejecta. This dust mass newly formed in the ejecta of SN 2006jc is in a range similar to those obtained for other several dust-forming core-collapse supernovae based on recent observations (i.e., 10-3-10-5 M sun). MIR photometric data with AKARI/IRC MIR-S/S7, S9W, and S11 bands have shown excess emission over the thermal emission by hot amorphous carbon of 800 K. This MIR excess emission is likely to be accounted for by the emission from warm amorphous carbon dust of 320 ± 10 K with the mass of 2.7+0.7 -0.5 × 10-3 M sun rather than by the band emission of astronomical silicate and/or silica grains. This warm amorphous carbon dust is expected to have been formed in the mass-loss wind associated with the Wolf-Rayet stellar activity before the SN explosion. Our result suggests that a significant amount of dust is condensed in the mass-loss wind prior to the SN explosion.

  1. AKARI IRC INFRARED 2.5-5 {mu}m SPECTROSCOPY OF A LARGE SAMPLE OF LUMINOUS INFRARED GALAXIES

    SciTech Connect

    Imanishi, Masatoshi; Nakagawa, Takao; Shirahata, Mai; Ohyama, Yoichi; Onaka, Takashi

    2010-10-01

    We present the results of our systematic infrared 2.5-5 {mu}m spectroscopy of 60 luminous infrared galaxies (LIRGs) with infrared luminosities L{sub IR} = 10{sup 11}-10{sup 12} L{sub sun} and 54 ultraluminous infrared galaxies (ULIRGs) with L{sub IR} {>=} 10{sup 12} L{sub sun}, using the AKARI Infrared Camera (IRC). AKARI IRC slit-less spectroscopy allows us to probe the full range of emission from these galaxies, including spatially extended components. The 3.3 {mu}m polycyclic aromatic hydrocarbon (PAH) emission features, hydrogen recombination emission lines, and various absorption features are detected and used to investigate the properties of these galaxies. Because of the relatively small effect of dust extinction in the infrared range, quantitative discussion of these dusty galaxy populations is possible. For sources with clearly detectable Br{beta} (2.63 {mu}m) and Br{alpha} (4.05 {mu}m) emission lines, the flux ratios are found to be similar to those predicted by case B theory. Starburst luminosities are estimated from both 3.3 {mu}m PAH and Br{alpha} emission, which roughly agree with each other. In addition to the detected starburst activity, a significant fraction of the observed sources display signatures of obscured active galactic nuclei (AGNs), such as low PAH equivalent widths, large optical depths of dust absorption features, and red continuum emission. The energetic importance of optically elusive buried AGNs in optically non-Seyfert galaxies tends to increase with increasing galaxy infrared luminosity, from LIRGs to ULIRGs.

  2. BRIGHTNESS AND FLUCTUATION OF THE MID-INFRARED SKY FROM AKARI OBSERVATIONS TOWARD THE NORTH ECLIPTIC POLE

    SciTech Connect

    Pyo, Jeonghyun; Jeong, Woong-Seob; Matsumoto, Toshio; Matsuura, Shuji

    2012-12-01

    We present the smoothness of the mid-infrared sky from observations by the Japanese infrared astronomical satellite AKARI. AKARI monitored the north ecliptic pole (NEP) during its cold phase with nine wave bands covering from 2.4 to 24 {mu}m, out of which six mid-infrared bands were used in this study. We applied power-spectrum analysis to the images in order to search for the fluctuation of the sky brightness. Observed fluctuation is explained by fluctuation of photon noise, shot noise of faint sources, and Galactic cirrus. The fluctuations at a few arcminutes scales at short mid-infrared wavelengths (7, 9, and 11 {mu}m) are largely caused by the diffuse Galactic light of the interstellar dust cirrus. At long mid-infrared wavelengths (15, 18, and 24 {mu}m), photon noise is the dominant source of fluctuation over the scale from arcseconds to a few arcminutes. The residual fluctuation amplitude at 200'' after removing these contributions is at most 1.04 {+-} 0.23 nW m{sup -2} sr{sup -1} or 0.05% of the brightness at 24 {mu}m and at least 0.47 {+-} 0.14 nW m{sup -2} sr{sup -1} or 0.02% at 18 {mu}m. We conclude that the upper limit of the fluctuation in the zodiacal light toward the NEP is 0.03% of the sky brightness, taking 2{sigma} error into account.

  3. Effects of High-Energy Ionizing Particles on the Si:As Mid-Infrared Detector Array on Board the AKARI Satellite

    NASA Astrophysics Data System (ADS)

    Mouri, A.; Kaneda, H.; Ishihara, D.; Oyabu, S.; Yamagishi, M.; Mori, T.; Onaka, T.; Wada, T.; Kataza, H.

    2011-05-01

    We evaluate the effects of high-energy ionizing particles on the Si:As impurity band conduction (IBC) mid-infrared detector on board AKARI, the Japanese infrared astronomical satellite. IBC-type detectors are known to be little influenced by ionizing radiation. However, we find that the detector is significantly affected by in-orbit ionizing radiation even after spikes induced by ionizing particles are removed. The effects are described as changes mostly in the offset of detector output, but not in the gain. We conclude that the changes in the offset are caused mainly by increase in dark current. We establish a method to correct these ionizing radiation effects. The method is essential to improve the quality and to increase the sky coverage of the AKARI mid-infrared all-sky-survey map.

  4. ALBEDO PROPERTIES OF MAIN BELT ASTEROIDS BASED ON THE ALL-SKY SURVEY OF THE INFRARED ASTRONOMICAL SATELLITE AKARI

    SciTech Connect

    Usui, Fumihiko; Hasegawa, Sunao; Matsuhara, Hideo; Kasuga, Toshihiro; Ishiguro, Masateru; Kuroda, Daisuke; Mueller, Thomas G.; Ootsubo, Takafumi

    2013-01-01

    We present an analysis of the albedo properties of main belt asteroids (MBAs) detected by the All-Sky Survey of the infrared astronomical satellite AKARI. The characteristics of 5120 asteroids detected by the survey, including their sizes and albedos, were cataloged in the Asteroid Catalog Using AKARI (AcuA). Size and albedo measurements were based on the standard thermal model, using inputs of infrared fluxes and absolute magnitudes measured at optical wavelengths. MBAs, which account for 4722 of the 5120 AcuA asteroids, have semimajor axes of 2.06-3.27 AU, except for the near-Earth asteroids. AcuA provides a complete data set of all MBAs brighter than the absolute magnitude of H < 10.3, which corresponds to the diameter of d > 20 km. We confirmed that the albedo distribution of the MBAs is strongly bimodal as was already known from the past observations, and that the bimodal distribution occurs not only in the total population, but also within inner, middle, and outer regions of the main belt. The bimodal distribution in each group consists of low-albedo components in C-type asteroids and high-albedo components in S-type asteroids. We found that the small asteroids have much more variety in albedo than the large asteroids. In spite of the albedo transition process like space weathering, the heliocentric distribution of the mean albedo of asteroids in each taxonomic type is nearly flat. The mean albedo of the total, on the other hand, gradually decreases with an increase in semimajor axis. This can be explained by the compositional ratio of taxonomic types; that is, the proportion of dark asteroids such as C- and D-types increases, while that of bright asteroids such as S-type decreases, with increasing heliocentric distance. The heliocentric distributions of X-subclasses: E-, M-, and P-types, which can be divided based on albedo values, are also examined. P-types, which are the major component in X-types, are distributed throughout the main belt regions, and the

  5. Mid- and Far-Infrared Photometry of Galactic Planetary Nebulae with the AKARI All-Sky Survey

    NASA Astrophysics Data System (ADS)

    Phillips, J. P.; Márquez-Lugo, R. A.

    2011-04-01

    We provide mid- and far-infrared photometry of 857 Galactic planetary nebulae (PNe) using data derived from the AKARI All-Sky Survey. These include fluxes at 9 and 18 μm obtained with the Infrared Camera (IRC), and at 65, 90, 140 and 160 μm using the far-Infrared Surveyor (FIS). It is noted that the IR luminosities of the youngest PNe are comparable to the total luminosities of the central stars, and subsequently decline to 5×102 L⊙ where D > 0.08 pc. This is consistent with an evolution of PNe dust opacities, and appreciable absorption in young and proto-PNe. We also note that there is little evidence for the evolution in IR/radio flux ratios suggested by previous authors. The fall-off of dust temperatures with increasing nebular diameter is similar to that determined in previous studies, whilst levels of Lyα heating are <0.5 of the total energy budget of the grains. There appears to be an evolution in the infrared excess (IRE) as nebulae expand, with the largest values occurring in the most compact PNe.

  6. Searching for the Culprit of Anomalous Microwave Emission: An AKARI PAHrange Analysis of Probable Electric Dipole Emitting Regions

    NASA Astrophysics Data System (ADS)

    Bell, A. C.; Onaka, T.; Sakon, I.; Ishihara, D.; Kaneda, H.; Lee, H. G.; Itoh, M.; Ohsawa, R.; Hammonds, M.

    In the march forward of interstellar medium inquiry, many new species of interstellar dust have been modelled and discovered. The modes by which these species interact and evolve are beginning to be understood, but in recent years a peculiar new feature has appeared in microwave surveys. Anomalous microwave emission (AME), appearing between 10 and 90Ghz, has been correlated with thermal dust emission, leading to the popular suggestion that this anomaly is electric dipole emission from spinning dust [2]. The observed frequencies suggest that spinning grains should be on the order of 10nm in size, hinting at poly-cyclic aromatic hydrocarbon molecules. We present data from AKARI/Infrared Camera [1], due to the effective PAH/Unidentified Infrared Band (UIR) coverage of its 9um survey to investigate their role within a few regions showing strong AME in the Planck low frequency data. We include the well studied Perseus and ρOphiuchi clouds . We use the IRAS/IRIS 100µm data to account for the overall dust temperature. We present our results as abundance maps for dust emitting around 9µm, and 100µm. Part of the AME in these regions may actually be attributed to thermal dust emission, or the star forming nature of these targets is masking the vibrational modes of PAHs which should be present there, suggesting further investigation for various galactic environments.

  7. Mid- and far-infrared properties of Spitzer Galactic bubbles revealed by the AKARI all-sky surveys

    NASA Astrophysics Data System (ADS)

    Hattori, Yasuki; Kaneda, Hidehiro; Ishihara, Daisuke; Fukui, Yasuo; Torii, Kazufumi; Hanaoka, Misaki; Kokusho, Takuma; Kondo, Akino; Shichi, Kazuyuki; Ukai, Sota; Yamagishi, Mitsuyoshi; Yamaguchi, Yuta

    2016-06-01

    We have carried out a statistical study on the mid- and far-infrared (IR) properties of Galactic IR bubbles observed by Spitzer. Using the Spitzer 8 μm images, we estimated the radii and covering fractions of their shells, and categorized them into closed, broken, and unclassified bubbles with our data analysis method. Then, using the AKARI all-sky images at wavelengths of 9, 18, 65, 90, 140, and 160 μm, we obtained the spatial distributions and the luminosities of polycyclic aromatic hydrocarbon (PAH), warm, and cold dust components by decomposing six-band spectral energy distributions with model fitting. As a result, 180 sample bubbles show a wide range of total IR luminosities corresponding to the bolometric luminosities of a single B-type star to many O-type stars. For all the bubbles, we investigated relationships between the radius, luminosities, and luminosity ratios, and found that there are overall similarities in the IR properties among the bubbles regardless of their morphological types. In particular, they follow a power-law relation with an index of ˜3 between the total IR luminosity and radius, as expected from the conventional picture of the Strömgren sphere. The exceptions are large broken bubbles; they indicate higher total IR luminosities, lower fractional luminosities of the PAH emission, and dust heating sources located nearer to the shells. We discuss the implications of those differences for a massive star-formation scenario.

  8. Mid- and far-infrared properties of Spitzer Galactic bubbles revealed by the AKARI all-sky surveys

    NASA Astrophysics Data System (ADS)

    Hattori, Yasuki; Kaneda, Hidehiro; Ishihara, Daisuke; Fukui, Yasuo; Torii, Kazufumi; Hanaoka, Misaki; Kokusho, Takuma; Kondo, Akino; Shichi, Kazuyuki; Ukai, Sota; Yamagishi, Mitsuyoshi; Yamaguchi, Yuta

    2016-04-01

    We have carried out a statistical study on the mid- and far-infrared (IR) properties of Galactic IR bubbles observed by Spitzer. Using the Spitzer 8 μm images, we estimated the radii and covering fractions of their shells, and categorized them into closed, broken, and unclassified bubbles with our data analysis method. Then, using the AKARI all-sky images at wavelengths of 9, 18, 65, 90, 140, and 160 μm, we obtained the spatial distributions and the luminosities of polycyclic aromatic hydrocarbon (PAH), warm, and cold dust components by decomposing six-band spectral energy distributions with model fitting. As a result, 180 sample bubbles show a wide range of total IR luminosities corresponding to the bolometric luminosities of a single B-type star to many O-type stars. For all the bubbles, we investigated relationships between the radius, luminosities, and luminosity ratios, and found that there are overall similarities in the IR properties among the bubbles regardless of their morphological types. In particular, they follow a power-law relation with an index of ˜3 between the total IR luminosity and radius, as expected from the conventional picture of the Strömgren sphere. The exceptions are large broken bubbles; they indicate higher total IR luminosities, lower fractional luminosities of the PAH emission, and dust heating sources located nearer to the shells. We discuss the implications of those differences for a massive star-formation scenario.

  9. Infrared and hard X-ray diagnostics of AGN identifications from the Swift/BAT and AKARI all sky surveys.

    NASA Astrophysics Data System (ADS)

    Matsuta, Keiko

    2011-11-01

    It is known that there is a good correlation between the mid-infrared and the intrinsic soft X-ray luminosities (<10 keV) of local active galactic nuclei (AGN). We now combine two complete all sky surveys in order to study the connection between the infrared and very hard X-ray (>10 keV) luminosities in AGN. We selected sources from the 22-month Swift/BAT hard X-ray survey catalogue which were also detected by Infrared Camera (IRC, 9 and 18 micron) and Far-Infrared Surveyor (FIS, 90 micron) on AKARI. The large sample allows us to include not only Seyfert 1 and 2 galaxies but also quasars, low luminosity AGN and radio-loud objects. We found a strong linear correlation for most of the AGN between the logarithms of the observed infrared and hard X-ray powers over four decades in luminosity, L(IR) vs. L(HX). Many Compton-thick sources show a large deviation from the correlation, probably because of the relatively low observed L(HX) due to the high column density. The observed luminosity correlation indicates that the various types of AGN may be occupying distinct regions of parameter space in the diagram. Color-color plots such as "L(90um)/L(9um) vs. L(HX)/L(9um)" are found to be useful redshift independent indicators for isolating Compton-thick AGN. Interestingly, starburst galaxies are also separated in this plane. This correlation can be a new and important tool for AGN classification, which may be useful for large upcoming surveys.

  10. OBSERVATIONS OF THE OPTICAL TRANSIENT IN NGC 300 WITH AKARI/IRC: POSSIBILITIES OF ASYMMETRIC DUST FORMATION

    SciTech Connect

    Ohsawa, R.; Sakon, I.; Onaka, T.; Tanaka, M.; Moriya, T.; Nozawa, T.; Maeda, K.; Nomoto, K.; Tominaga, N.; Usui, F.; Matsuhara, H.; Nakagawa, T.; Murakami, H.

    2010-08-01

    We present the results of near-infrared (NIR) multi-epoch observations of the optical transient in the nearby galaxy NGC 300 (NGC 300-OT) at 398 and 582 days after the discovery with the Infrared Camera (IRC) on board AKARI. NIR spectra (2-5 {mu}m) of NGC 300-OT were obtained for the first time. They show no prominent emission nor absorption features, but are dominated by continuum thermal emission from the dust around NGC 300-OT. NIR images were taken in the 2.4, 3.2, and 4.1 {mu}m bands. The spectral energy distributions (SEDs) of NGC 300-OT indicate the dust temperature of 810 {+-} 14 K at 398 days and 670 {+-} 12 K at 582 days. We attribute the observed NIR emission to the thermal emission from dust grains formed in the ejecta of NGC 300-OT. The multi-epoch observations enable us to estimate the dust optical depth as {approx}>12 at 398 days and {approx}>6 at 582 days at 2.4 {mu}m by assuming an isothermal dust cloud. The observed NIR emission must be optically thick, unless the amount of dust grains increases with time. Little extinction at visible wavelengths reported in earlier observations suggests that the dust cloud around NGC 300-OT should be distributed inhomogeneously so as to not screen the radiation from the ejecta gas and the central star. The present results suggest the dust grains are not formed in a spherically symmetric geometry, but rather in a torus, a bipolar outflow, or clumpy cloudlets.

  11. FAR-INFRARED IMAGING OF POST-ASYMPTOTIC GIANT BRANCH STARS AND (PROTO)-PLANETARY NEBULAE WITH THE AKARI FAR-INFRARED SURVEYOR

    SciTech Connect

    Cox, N. L. J.; Garcia-Hernandez, D. A.; Manchado, A.

    2011-04-15

    By tracing the distribution of cool dust in the extended envelopes of post-asymptotic giant branch stars and (proto)-planetary nebulae ((P)PNe), we aim to recover, or constrain, the mass-loss history experienced by these stars in their recent past. The Far-Infrared Surveyor (FIS) instrument on board the AKARI satellite was used to obtain far-infrared maps for a selected sample of post-AGB stars and (P)PNe. We derived flux densities (aperture photometry) for 13 post-AGB stars and (P)PNe at four far-infrared wavelengths (65, 90, 140, and 160 {mu}m). Radial (azimuthally averaged) profiles are used to investigate the presence of extended emission from cool dust. No (detached) extended emission is detected for any target in our sample at levels significant with respect to background and cirrus emission. Only IRAS 21046+4739 reveals tentative excess emission between 30'' and 130''. Estimates of the total dust and gas mass from the obtained maps indicate that the envelope masses of these stars should be large in order to be detected with the AKARI FIS. Imaging with higher sensitivity and higher spatial resolution is needed to detect and resolve, if present, any cool compact or extended emission associated with these evolved stars.

  12. DIFFERENCE IN THE SPATIAL DISTRIBUTION BETWEEN H{sub 2}O AND CO{sub 2} ICES IN M 82 FOUND WITH AKARI

    SciTech Connect

    Yamagishi, Mitsuyoshi; Kaneda, Hidehiro; Ishihara, Daisuke; Oyabu, Shinki; Onaka, Takashi; Shimonishi, Takashi; Suzuki, Toyoaki; Minh, Young Chol

    2013-08-20

    With AKARI, we obtain the spatially resolved near-infrared (NIR) (2.5-5.0 {mu}m) spectra for the nearby starburst galaxy M 82. These spectra clearly show absorption features due to interstellar ices. Based on the spectra, we created the column density maps of H{sub 2}O and CO{sub 2} ices. As a result, we find that the spatial distribution of H{sub 2}O ice is significantly different from that of CO{sub 2} ice; H{sub 2}O ice is widely distributed, while CO{sub 2} ice is concentrated near the galactic center. Our result reveals for the first time variations in CO{sub 2}/H{sub 2}O ice abundance ratio on a galactic scale, suggesting that an ice-forming interstellar environment changes within a galaxy. We discuss the cause of the spatial variations in the ice abundance ratio, utilizing spectral information on the hydrogen recombination Br{alpha} and Br{beta} lines and the polycyclic aromatic hydrocarbon 3.3 {mu}m emission appearing in the AKARI NIR spectra.

  13. The AKARI 2.5-5.0 μm Spectral Atlas of Type-1 Active Galactic Nuclei: Black Hole Mass Estimator, Line Ratio, and Hot Dust Temperature

    NASA Astrophysics Data System (ADS)

    Kim, Dohyeong; Im, Myungshin; Kim, Ji Hoon; Jun, Hyunsung David; Woo, Jong-Hak; Lee, Hyung Mok; Lee, Myung Gyoon; Nakagawa, Takao; Matsuhara, Hideo; Wada, Takehiko; Oyabu, Shinki; Takagi, Toshinobu; Ohyama, Youichi; Lee, Seong-Kook

    2015-01-01

    We present 2.5-5.0 μm spectra of 83 nearby (0.002 < z < 0.48) and bright (K < 14 mag) type-1 active galactic nuclei (AGNs) taken with the Infrared Camera on board AKARI. The 2.5-5.0 μm spectral region contains emission lines such as Brβ (2.63 μm), Brα (4.05 μm), and polycyclic aromatic hydrocarbons (3.3 μm), which can be used for studying the black hole (BH) masses and star formation activity in the host galaxies of AGNs. The spectral region also suffers less dust extinction than in the ultra violet (UV) or optical wavelengths, which may provide an unobscured view of dusty AGNs. Our sample is selected from bright quasar surveys of Palomar-Green and SNUQSO, and AGNs with reverberation-mapped BH masses from Peterson et al. Using 11 AGNs with reliable detection of Brackett lines, we derive the Brackett-line-based BH mass estimators. We also find that the observed Brackett line ratios can be explained with the commonly adopted physical conditions of the broad line region. Moreover, we fit the hot and warm dust components of the dust torus by adding photometric data of SDSS, 2MASS, WISE, and ISO to the AKARI spectra, finding hot and warm dust temperatures of ~1100 K and ~220 K, respectively, rather than the commonly cited hot dust temperature of 1500 K.

  14. Deep 15μm AKARI Observations in the CDFS: Estimating Dust Luminosities for a MIR-Selected Sample and for Lyman Break Galaxies and the Evolution of Ldust/LUV with the Redshift

    NASA Astrophysics Data System (ADS)

    Burgarella, Denis; Buat, Véronique; Takeuchi, Tsutomu T.; Wada, Takehiko; Pearson, Chris

    2009-02-01

    Deep observations of the Chandra Deep Field South have been secured at 15μm with AKARI/IRC infrared space telescope. From these observations, we define a sample of mid infrared-selected galaxies at 15μm and we also obtain 15μm flux densities for a sample of Lyman Break Galaxies at z ˜ 1 already observed at 24μm with Spitzer/MIPS. Number counts for the mid infrared-selected sample show a bump around a 15μm flux density of 0.2mJy that can be attributed to galaxies at z > 0.4 and at z > 0.8 for the fainter part of the bump. This bump seems to be shifted as compared to other works and a possible origin can be the Cosmic variance. On the two above samples at z ˜ 1 we have tested the validity of the conversions from luminosities ν.fν at 8νm to total dust luminosities by comparing with luminosities estimated from 12νm data used as a reference. Some calibrations seem better when compared to evaluated from longer wavelength luminosities. We also find that the rest-frame 8μm luminosities provide good estimates of Ldust. By comparing our data to several libraries of spectral energy distributions, we find that models can explain the diversity of the observed f24/f15 ratio quite reasonably. However, when we analyse the luminosity dependence of this ratio, we find important discrepancies. Finally, we revisit the evolution of Ldust/LUV ratio with the redshift z by re-calibrating previous Ldust at z ˜ 2 based on our results and added new data points at higher redshifts. The decreasing trend is amplified as compared to the previous estimate.

  15. AKARI All Sky Survey: contribution from AGB stars to the far infrared flux from the Milky Way related to point sources outside the Galactic plane

    NASA Astrophysics Data System (ADS)

    Pollo, A.; Takeuchi, T. T.; Rybka, P.

    2011-10-01

    Using data from the FIS AKARI All-Sky Survey, we make a first step towards the estimation of the contribution from Asymptotic Giant Branch (AGB) stars to the far-infrared (FIR) flux from the Milky Way. We estimate the contribution from the AGB, and post-AGB, stars to the total flux generated by point sources outside the Galactic plane. Additionally, we present the positions of different types of AGB, and post-AGB, stars in the FIR color-color diagrams. Our main conclusion is that there is a high contribution from AGB stars, and particularly post-AGB stars, to the FIR flux coming from point sources in the outer parts of the Milky Way and possibly other Milky Way-type galaxies. FIR colors of different types of AGB stars remain similar but post-AGB stars are redder in the FIR and, as a result, contribute more to the total Galaxy flux density at longer FIR wavelengths.

  16. INFRARED AND HARD X-RAY DIAGNOSTICS OF ACTIVE GALACTIC NUCLEUS IDENTIFICATION FROM THE SWIFT/BAT AND AKARI ALL-SKY SURVEYS

    SciTech Connect

    Matsuta, K.; Dotani, T.; Yamamura, I.; Gandhi, P.; Nakagawa, T.; Isobe, N.; Stawarz, L.; Ueda, Y.; Ichikawa, K.; Terashima, Y.; Oyabu, S.

    2012-07-10

    We combine data from two all-sky surveys in order to study the connection between the infrared and hard X-ray (>10 keV) properties for local active galactic nuclei (AGNs). The Swift Burst Alert Telescope all-sky survey provides an unbiased, flux-limited selection of hard X-ray-detected AGNs. Cross-correlating the 22 month hard X-ray survey with the AKARI all-sky survey, we studied 158 AGNs detected by the AKARI instruments. We find a strong correlation for most AGNs between the infrared (9, 18, and 90 {mu}m) and hard X-ray (14-195 keV) luminosities, and quantify the correlation for various subsamples of AGNs. Partial correlation analysis confirms the intrinsic correlation after removing the redshift contribution. The correlation for radio galaxies has a slope and normalization identical to that for Seyfert 1 galaxies, implying similar hard X-ray/infrared emission processes in both. In contrast, Compton-thick (CT) sources show a large deficit in the hard X-ray band, because high gas column densities diminish even their hard X-ray luminosities. We propose two photometric diagnostics for source classification: one is an X-ray luminosity versus infrared color diagram, in which type 1 radio-loud AGNs are well isolated from the others in the sample. The other uses the X-ray versus infrared color as a useful redshift-independent indicator for identifying CT AGNs. Importantly, CT AGNs and starburst galaxies in composite systems can also be differentiated in this plane based upon their hard X-ray fluxes and dust temperatures. This diagram may be useful as a new indicator to classify objects in new and upcoming surveys such as WISE and NuSTAR.

  17. AKARI observations of brown dwarfs. IV. Effect of elemental abundances on near-infrared spectra between 1.0 and 5.0 μm

    SciTech Connect

    Sorahana, S.; Yamamura, I.

    2014-09-20

    The detection of the CO{sub 2} absorption band at 4.2 μm in brown dwarf spectra by AKARI has made it possible to discuss CO{sub 2} molecular abundance in brown dwarf atmospheres. In our previous studies, we found an excess in the 4.2 μm CO{sub 2} absorption band of three brown dwarf spectra, and suggested that these deviations were caused by high C and O elemental abundances in their atmospheres. To validate this hypothesis, we have constructed a set of models of brown dwarf atmospheres with various elemental abundance patterns, and we investigate the variations of the molecular composition and the thermal structure, and how they affect the near-infrared spectra between 1.0 and 5.0 μm. The 4.2 μm CO{sub 2} absorption band in some late-L and T dwarfs taken by AKARI is stronger or weaker than predicted by corresponding models with solar abundance. By comparing the CO{sub 2} band in the model spectra to the observed near-infrared spectra, we confirm possible elemental abundance variations among brown dwarfs. We find that the band strength is especially sensitive to O abundance, but C is also needed to reproduce the entire near-infrared spectra. This result indicates that both the C and O abundances should increase and decrease simultaneously for brown dwarfs. We find that a weaker CO{sub 2} absorption band in a spectrum can also be explained by a model with lower 'C and O' abundances.

  18. THE AKARI 2.5-5.0 μm SPECTRAL ATLAS OF TYPE-1 ACTIVE GALACTIC NUCLEI: BLACK HOLE MASS ESTIMATOR, LINE RATIO, AND HOT DUST TEMPERATURE

    SciTech Connect

    Kim, Dohyeong; Im, Myungshin; Kim, Ji Hoon; Jun, Hyunsung David; Lee, Seong-Kook; Woo, Jong-Hak; Lee, Hyung Mok; Lee, Myung Gyoon; Nakagawa, Takao; Matsuhara, Hideo; Wada, Takehiko; Takagi, Toshinobu; Oyabu, Shinki; Ohyama, Youichi E-mail: mim@astro.snu.ac.kr

    2015-01-01

    We present 2.5-5.0 μm spectra of 83 nearby (0.002 < z < 0.48) and bright (K < 14 mag) type-1 active galactic nuclei (AGNs) taken with the Infrared Camera on board AKARI. The 2.5-5.0 μm spectral region contains emission lines such as Brβ (2.63 μm), Brα (4.05 μm), and polycyclic aromatic hydrocarbons (3.3 μm), which can be used for studying the black hole (BH) masses and star formation activity in the host galaxies of AGNs. The spectral region also suffers less dust extinction than in the ultra violet (UV) or optical wavelengths, which may provide an unobscured view of dusty AGNs. Our sample is selected from bright quasar surveys of Palomar-Green and SNUQSO, and AGNs with reverberation-mapped BH masses from Peterson et al. Using 11 AGNs with reliable detection of Brackett lines, we derive the Brackett-line-based BH mass estimators. We also find that the observed Brackett line ratios can be explained with the commonly adopted physical conditions of the broad line region. Moreover, we fit the hot and warm dust components of the dust torus by adding photometric data of SDSS, 2MASS, WISE, and ISO to the AKARI spectra, finding hot and warm dust temperatures of ∼1100 K and ∼220 K, respectively, rather than the commonly cited hot dust temperature of 1500 K.

  19. VizieR Online Data Catalog: IR sources spectroscopy in the AKARI NEP (Shim+, 2013)

    NASA Astrophysics Data System (ADS)

    Shim, H.; Im, M.; Ko, J.; Jeon, Y.; Karouzos, M.; Kim, S. J.; Lee, H. M.; Papovich, C.; Willmer, C.; Weiner, B. J.

    2013-09-01

    Most of the targets for the spectroscopic observation were selected from the optical to mid-infrared band-merged photometry catalog over the NEP-Wide field (Kim et al. 2012, Cat. J/A+A/548/A29). The observations, with the MMT/Hectospec spectrograph, were executed in queue mode: a total of five configurations were observed between 2008 May and November, with each configuration covering an area within a 1deg diameter circle. The observations used the 270 line/mm grating covering ~3700Å to ~8500Å, with a spectral resolution of about 6.2Å. We obtained optical spectra using the Hydra multi-object spectrograph on WIYN, the 3.5m telescope at the Kitt Peak National Observatory, on the nights of 2008 June 27-30. The covered wavelength range is 4500-9000Å, yet the spectrum quality is very poor beyond 8000Å. We used 98 red fibers feeding the bench spectrograph with a 316 lines/mm grating, yielding a spectral resolution of 5.7Å. (2 data files).

  20. AKARI OBSERVATION OF THE NORTH ECLIPTIC POLE (NEP) SUPERCLUSTER AT z = 0.087: MID-INFRARED VIEW OF TRANSITION GALAXIES

    SciTech Connect

    Ko, Jongwan; Im, Myungshin; Lee, Hyung Mok; Lee, Myung Gyoon; Kim, Seong Jin; Jeon, Yiseul; Shim, Hyunjin; Hwang, Ho Seong; Willmer, Christopher N. A.; Weiner, Benjamin J.; Malkan, Matthew A.; Papovich, Casey; Matsuhara, Hideo; Takagi, Toshinobu; Oyabu, Shinki

    2012-02-01

    We present the mid-infrared (MIR) properties of galaxies within a supercluster in the north ecliptic pole region at z {approx} 0.087 observed with the AKARI satellite. We use data from the AKARI NEP-Wide (5.4 deg{sup 2}) IR survey and the CLusters of galaxies EVoLution studies (CLEVL) mission program. We show that near-IR (3 {mu}m)-mid-IR (11 {mu}m) color can be used as an indicator of the specific star formation rate and the presence of intermediate-age stellar populations. From the MIR observations, we find that red-sequence galaxies consist not only of passively evolving red early-type galaxies, but also of (1) 'weak-SFGs' (disk-dominated star-forming galaxies that have star formation rates lower by {approx}4 Multiplication-Sign than blue-cloud galaxies) and (2) 'intermediate-MXGs' (bulge-dominated galaxies showing stronger MIR dust emission than normal red early-type galaxies). These two populations can be a set of transition galaxies from blue, star-forming, late-type galaxies evolving into red, quiescent, early-type ones. We find that the weak-SFGs are predominant at intermediate masses (10{sup 10} M{sub Sun} < M{sub *} < 10{sup 10.5} M{sub Sun }) and are typically found in local densities similar to the outskirts of galaxy clusters. As much as 40% of the supercluster member galaxies in this mass range can be classified as weak-SFGs, but their proportion decreases to <10% at larger masses (M{sub *} > 10{sup 10.5} M{sub Sun }) at any galaxy density. The fraction of the intermediate-MXG among red-sequence galaxies at 10{sup 10} M{sub Sun} < M{sub *} < 10{sup 11} M{sub Sun} also decreases as the density and mass increase. In particular, {approx}42% of the red-sequence galaxies with early-type morphologies are classified as intermediate-MXGs at intermediate densities. These results suggest that the star formation activity is strongly dependent on the stellar mass, but that the morphological transformation is mainly controlled by the environment.

  1. Image stacking analysis of SDSS galaxies with AKARI Far-Infrared Surveyor maps at 65 μm, 90 μm, and 140 μm

    NASA Astrophysics Data System (ADS)

    Okabe, Taizo; Kashiwagi, Toshiya; Suto, Yasushi; Matsuura, Shuji; Doi, Yasuo; Takita, Satoshi; Ootsubo, Takafumi

    2016-04-01

    We perform image stacking analysis of Sloan Digital Sky Survey (SDSS) photometric galaxies over the AKARI Far-Infrared Surveyor maps at 65 μm, 90 μm, and 140 μm. The resulting image profiles are decomposed into the central galaxy component (single term) and the nearby galaxy component (clustering term), as a function of the r-band magnitude, mr, of the central galaxy. We find that the mean far-infrared (FIR) flux of a galaxy with magnitude mr is well fitted with f^s_{90μ m}=13× 10^{0.306(18-m_{ r})} [mJy]. The FIR amplitude of the clustering term is consistent with that expected from the angular-correlation function of the SDSS galaxies, but galaxy morphology dependence needs to be taken into account for a more quantitative conclusion. We also fit the spectral energy distribution of stacked galaxies at 65 μm, 90 μm, and 140 μm, and derive a mean dust temperature of ˜30 K. This is consistent with the typical dust temperature of galaxies that are FIR luminous and individually detected.

  2. Low-Resolution Spectrum of the Diffuse Galactic Light and 3.3 μm PAH Emission with the AKARI InfraRed Camera

    NASA Astrophysics Data System (ADS)

    Tsumura, Kohji; Matsumoto, Toshio; Matsuura, Shuji; Sakon, Itsuki; Tanaka, Masahiro; Wada, Takehiko

    2013-12-01

    We first obtained the spectrum of the diffuse Galactic light (DGL) at general interstellar space in the 1.8-5.3μm wavelength region with the low-resolution prism spectroscopy mode of the AKARI Infra-Red Camera (IRC) NIR channel. The 3.3μm m PAH band is detected in the DGL spectrum at Galactic latitude |b| < 15˚, and its correlations with the Galactic dust and gas are confirmed. The correlation between the 3.3μm PAH band and the thermal emission from the Galactic dust is expressed not by a simple linear correlation, but by a relation with extinction. Using this correlation, the spectral shape of DGL at an optically thin region (5˚ < |b| < 15˚) was derived as a template spectrum. Assuming that the spectral shape of this template spectrum is uniform at any position, the DGL spectrum can be estimated by scaling this template spectrum using the correlation between the 3.3μm PAH band and the thermal emission from the Galactic dust.

  3. DETECTION OF PARENT H{sub 2}O AND CO{sub 2} MOLECULES IN THE 2.5-5 {mu}m SPECTRUM OF COMET C/2007 N3 (LULIN) OBSERVED WITH AKARI

    SciTech Connect

    Ootsubo, Takafumi; Usui, Fumihiko; Hasegawa, Sunao; Ueno, Munetaka; Wada, Takehiko; Matsuhara, Hideo; Nakagawa, Takao; Murakami, Hiroshi; Kawakita, Hideyo; Ishiguro, Masateru; Furusho, Reiko; Watanabe, Jun-ichi; Sekiguchi, Tomohiko; Ohyama, Youichi; Oyabu, Shinki; Onaka, Takashi

    2010-07-01

    Comet C/2007 N3 (Lulin) was observed with the Japanese infrared satellite AKARI in the near-infrared at a post-perihelion heliocentric distance of 1.7 AU. Observations were performed with the spectroscopic (2.5-5.0 {mu}m) and imaging (2.4, 3.2, and 4.1 {mu}m) modes on 2009 March 30 and 31 UT, respectively. AKARI images of the comet exhibit a sunward crescent-like shape coma and a dust tail extended toward the anti-solar direction. The 4.1 {mu}m image (CO/CO{sub 2} and dust grains) shows a distribution different from the 2.4 and 3.2 {mu}m images (H{sub 2}O and dust grains). The observed spectrum shows distinct bands at 2.66 and 4.26 {mu}m, attributed to H{sub 2}O and CO{sub 2}, respectively. This is the fifth comet in which CO{sub 2} has been directly detected in the near-infrared spectrum. In addition, CO at 4.67 {mu}m and a broad 3.2-3.6 {mu}m emission band from C-H bearing molecules were detected in the AKARI spectrum. The relative abundance ratios CO{sub 2}/H{sub 2}O and CO/H{sub 2}O derived from the molecular production rates are {approx}4%-5% and <2%, respectively. Comet Lulin belongs to the group that has relatively low abundances of CO and CO{sub 2} among all observed comets.

  4. Star formation and dust extinction properties of local galaxies from the AKARI-GALEX all-sky surveys . First results from the most secure multiband sample from the far-ultraviolet to the far-infrared

    NASA Astrophysics Data System (ADS)

    Takeuchi, T. T.; Buat, V.; Heinis, S.; Giovannoli, E.; Yuan, F.-T.; Iglesias-Páramo, J.; Murata, K. L.; Burgarella, D.

    2010-05-01

    Aims: We explore spectral energy distributions (SEDs), star formation (SF), and dust extinction properties of galaxies in the Local Universe. Methods: The AKARI all-sky survey provided the first bright point source catalog detected at 90 μm. Beginning with this catalog, we selected galaxies by matching the AKARI sources with those in the IRAS point source catalog redshift survey. We measured the total GALEX FUV and NUV flux densities with a photometry software we specifically developed for this purpose. In a further step we matched this sample with the Sloan digital sky survey (SDSS) and 2 micron all sky survey (2MASS) galaxies. With this procedure we obtained a basic sample which consists of 776 galaxies. After removing objects whose photometry was contaminated by foreground sources (mainly in the SDSS), we defined the “secure sample” which contains 607 galaxies. Results: The sample galaxies have redshifts of ⪉0.15, and their 90-μm luminosities range from 106 to 1012 L_⊙, with a peak at 1010 L_⊙. The SEDs display a large variety, especially more than four orders of magnitude at the mid-far-infrared (M-FIR), but if we sort the sample with respect to 90 μm, the average SED shows a coherent trend: the more luminous an SED at 90 μm, the redder the global SED becomes. The Mr - NUV - r color-magnitude relation of our sample does not show bimodality, and the distribution is centered on the green valley. We established formulae to convert the FIR luminosity from the AKARI bands to the total IR (TIR) luminosity LTIR. The luminosity related to the SF activity (LSF) is dominated by LTIR even if we take into account the FIR emission from dust heated by old stars. At a high SF rate (SFR) (>20 M_⊙ yr-1), the fraction of the directly visible SFR, SFRFUV, decreases. We also estimated the FUV attenuation AFUV from the FUV-to-TIR luminosity ratio. We examined the LTIR/LFUV-UV slope (FUV - NUV) relation. The majority of the sample has LTIR/LFUV ratios five to ten

  5. The Spitzer-IRAC/MIPS Extragalactic Survey (SIMES) in the South Ecliptic Pole Field

    NASA Astrophysics Data System (ADS)

    Baronchelli, I.; Scarlata, C.; Rodighiero, G.; Franceschini, A.; Capak, P. L.; Mei, S.; Vaccari, M.; Marchetti, L.; Hibon, P.; Sedgwick, C.; Pearson, C.; Serjeant, S.; Menéndez-Delmestre, K.; Salvato, M.; Malkan, M.; Teplitz, H. I.; Hayes, M.; Colbert, J.; Papovich, C.; Devlin, M.; Kovacs, A.; Scott, K. S.; Surace, J.; Kirkpatrick, J. D.; Atek, H.; Urrutia, T.; Scoville, N. Z.; Takeuchi, T. T.

    2016-03-01

    We present the Spitzer-IRAC/MIPS Extragalactic survey (SIMES) in the South Ecliptic Pole field. The large area covered (7.7 deg2), together with one of the lowest Galactic cirrus emissions in the entire sky and a very extensive coverage by Spitzer, Herschel, Akari, and GALEX, make the SIMES field ideal for extragalactic studies. The elongated geometry of the SIMES area (≈4:1), allowing for significant cosmic variance reduction, further improves the quality of statistical studies in this field. Here we present the reduction and photometric measurements of the Spitzer/IRAC data. The survey reaches depths of 1.93 and 1.75 μJy (1σ) at 3.6 and 4.5 μm, respectively. We discuss the multiwavelength IRAC-based catalog, completed with optical, mid-, and far-IR observations. We detect 341,000 sources with {F}3.6μ {{m}}≥slant 3σ . Of these, 10% have an associated 24 μm counterpart, while 2.7% have an associated SPIRE source. We release the catalog through the NASA/IPAC Infrared Science Archive. Two scientific applications of these IRAC data are presented in this paper. First, we compute integral number counts at 3.6 μm. Second, we use the [3.6]-[4.5] color index to identify galaxy clusters at z > 1.3. We select 27 clusters in the full area, a result consistent with previous studies at similar depth.

  6. THE COSMIC INFRARED BACKGROUND EXPERIMENT (CIBER): THE WIDE-FIELD IMAGERS

    SciTech Connect

    Bock, J.; Battle, J.; Sullivan, I.; Arai, T.; Matsumoto, T.; Matsuura, S.; Tsumura, K.; Cooray, A.; Mitchell-Wynne, K.; Smidt, J.; Hristov, V.; Lam, A. C.; Levenson, L. R.; Mason, P.; Keating, B.; Renbarger, T.; Kim, M. G.; Lee, D. H.; Nam, U. W.; Suzuki, K.; and others

    2013-08-15

    We have developed and characterized an imaging instrument to measure the spatial properties of the diffuse near-infrared extragalactic background light (EBL) in a search for fluctuations from z > 6 galaxies during the epoch of reionization. The instrument is part of the Cosmic Infrared Background Experiment (CIBER), designed to observe the EBL above Earth's atmosphere during a suborbital sounding rocket flight. The imaging instrument incorporates a 2 Degree-Sign Multiplication-Sign 2 Degree-Sign field of view to measure fluctuations over the predicted peak of the spatial power spectrum at 10 arcmin, and 7'' Multiplication-Sign 7'' pixels, to remove lower redshift galaxies to a depth sufficient to reduce the low-redshift galaxy clustering foreground below instrumental sensitivity. The imaging instrument employs two cameras with {Delta}{lambda}/{lambda} {approx} 0.5 bandpasses centered at 1.1 {mu}m and 1.6 {mu}m to spectrally discriminate reionization extragalactic background fluctuations from local foreground fluctuations. CIBER operates at wavelengths where the electromagnetic spectrum of the reionization extragalactic background is thought to peak, and complements fluctuation measurements by AKARI and Spitzer at longer wavelengths. We have characterized the instrument in the laboratory, including measurements of the sensitivity, flat-field response, stray light performance, and noise properties. Several modifications were made to the instrument following a first flight in 2009 February. The instrument performed to specifications in three subsequent flights, and the scientific data are now being analyzed.

  7. Visual field

    MedlinePlus

    Perimetry; Tangent screen exam; Automated perimetry exam; Goldmann visual field exam; Humphrey visual field exam ... Confrontation visual field exam : This is a quick and basic check of the visual field. The health care provider sits directly in front ...

  8. Visual field

    MedlinePlus

    Perimetry; Tangent screen exam; Automated perimetry exam; Goldmann visual field exam; Humphrey visual field exam ... Confrontation visual field exam : This is a quick and basic check of the visual field. The health care provider ...

  9. Probing Ancient Mass Loss with AKARI's Extended Dust Emission Objects

    NASA Astrophysics Data System (ADS)

    Tomasino, R.; Ueta, T.; Yamamura, I.; Izumiura, H.

    2014-04-01

    We present the results from the calibration and analysis of 166 far-IR extended thermal dust emission objects that were observed with AKARI’s FIS detector. The primary goal is to map the circumstellar shells of evolved stars in detail to excavate the ancient history of dusty mass loss. After establishing an extended aperture photometry method, we characterized the flux dependent slow transient response correction factors for each of the four wavelength bands. Using the new correction factors for extended (far-IR) emission, we present the photometric values that were calculated for the entire data set and also report our work on morphology characterization of the extended dust shells.

  10. Multivalued Fields

    SciTech Connect

    Kleinert, Hagen

    2008-01-03

    The lecture gives a short introduction to the theory of multivalued fields which are important for understanding the behavior and phase transitions of many physical systems, such as superfluids, superconductors, crystals, and confined charges.

  11. Overview of North Ecliptic Pole Deep Multi-wavelength Survey as a Probe of the Cosmic Noon Era

    NASA Astrophysics Data System (ADS)

    Matsuhara, Hideo; Oi, Nagisa

    2015-08-01

    An overview of the North Ecliptic Pole deep (0.5 deg2, NEP-Deep) multi-wavelength survey covering from X-ray to radio-wave is presented. The NEP-Deep provides us with several thousands of 15 μm or 18 μm selected sample of galaxies, which is the largest sample ever made at these wavelengths. A continuous filter coverage in the mid-infrared wavelength (7, 9, 11, 15, 18, and 24 μm) is unique and vital to diagnose the contributions from starbursts and AGNs in the galaxies out to z=2. The goal of the project is to resolve the nature of the cosmic star formation history at the cosmic noon era (e.g. z=1--2), and to find a clue to understand its decline from z=1 to present universe by utilizing the unique power of the multiwavelength survey. To achieve the goal we use a few diagnostic physical parameters unique to the NEP dataset: specific star-formation rate, dust attenuation, and obscured AGN fraction, etc.It is also noteworthy that the NEP is the legacy field thanks to its high visibility by the space observatories, such as eROSITA, Euclid, JWST, and SPICA. SPICA, the next generation large cooled space telescope is extremely powerful to study the rise and fall of the cosmic star-formation history in the universe.

  12. Arun field

    SciTech Connect

    Jordan, C.F. Jr.; Abdullah, M.

    1988-01-01

    The Arun field is a giant gas-condensate field operated by Mobil and Pertamina with over 20,000 acres of closure at the top of the Arun reservoir. A middle-shelf patch reef complex of early to middle Miocene age is the producing facies at the Arun field. About 1,100 ft of porous limestones, encased in shales, create a stratigraphic trap for overpressure hydrocarbons. Three main carbonate lithologies were encountered during the examination of over 4,300 ft of core; (1) a reef facies consisting of vuggy, coral encrusting, red-algal boundstones, (2) a near-reef facies consisting of foraminiferal, mixed-skeletal packstones with gravel-size coral fragments, and (3) an interreef lagoonal facies consisting of benthonic-foram packstones. Twenty-two species of corals have been identified from Arun reef facies; major reef-forming coals, listed in order of decreasing abundance, are Porites cf P. Lutes, Cyphastrea microphthalma, Astreopora myriophthalma, Styloconiella gunetheri, Porites solida, and Acropora ssp. The Arun reef is comprised of limestones (with minor amounts of dolomite). No shale beds occur in the sequence, and all carbonate facies are in communication. A pervasive microporosity, occurring throughout the Arun Limestone, results from meteoric alteration of original carbonate mud to form a microrhombic porosity that accounts for about three-fourths of the field's total porosity.

  13. Gauge fields

    SciTech Connect

    Mills, R.

    1989-06-01

    This article is a survey of the history and ideas of gauge theory. Described here are the gradual emergence of symmetry as a driving force in the shaping of physical theory; the elevation of Noether's theorem, relating symmetries to conservation laws, to a fundamental principle of nature; and the force of the idea (''the gauge principle'') that the symmetries of nature, like the interactions themselves, should be local in character. The fundamental role of gauge fields in mediating the interactions of physics springs from Noether's theorem and the gauge principle in a remarkably clean and elegant way, leaving, however, some tantalizing loose ends that might prove to be the clue to a future deeper level of understanding. The example of the electromagnetic field as the prototype gauge theory is discussed in some detail and serves as the basis for examining the similarities and differences that emerge in generalizing to non-Abelian gauge theories. The article concludes with a brief examination of the dream of total unification: all the forces of nature in a single unified gauge theory, with the differences among the forces due to the specific way in which the fundamental symmetries are broken in the local environment.

  14. Beyond Field Education: Leadership of Field Directors

    ERIC Educational Resources Information Center

    Wertheimer, Mindy R.; Sodhi, Mimi

    2014-01-01

    This article presents a conceptual model of the field director's role outside of field education, specifically in the following 3 areas of leadership: (1) curricular, (2) programmatic, and (3) institutional. A survey was conducted to explore the field director's input targeted in these areas beyond prescribed field education tasks. The…

  15. Internal split field generator

    SciTech Connect

    Thundat; Thomas George; Van Neste, Charles W.; Vass, Arpad Alexander

    2012-01-03

    A generator includes a coil of conductive material. A stationary magnetic field source applies a stationary magnetic field to the coil. An internal magnetic field source is disposed within a cavity of the coil to apply a moving magnetic field to the coil. The stationary magnetic field interacts with the moving magnetic field to generate an electrical energy in the coil.

  16. Transverse Schwarzschild field

    SciTech Connect

    Belinfante, F.J.

    1982-06-15

    For Schwarzschild's static spherically symmetric external field, a coordinate system is determined in which the metric field is the transverse field satisfying the coordinate conditions of Arnowitt, Deser, and Misner.

  17. Electrostatic Field Invisibility Cloak.

    PubMed

    Lan, Chuwen; Yang, Yuping; Geng, Zhaoxin; Li, Bo; Zhou, Ji

    2015-01-01

    The invisibility cloak has been drawing much attention due to its new concept for manipulating many physical fields, from oscillating wave fields (electromagnetic, acoustic and elastic) to static magnetic fields, dc electric fields, and diffusive fields. Here, an electrostatic field invisibility cloak has been theoretically investigated and experimentally demonstrated to perfectly hide two dimensional objects without disturbing their external electrostatic fields. The desired cloaking effect has been achieved via both cancelling technology and transformation optics (TO). This study demonstrates a novel way for manipulating electrostatic fields, which shows promise for a wide range of potential applications. PMID:26552343

  18. Fractal vector optical fields.

    PubMed

    Pan, Yue; Gao, Xu-Zhen; Cai, Meng-Qiang; Zhang, Guan-Lin; Li, Yongnan; Tu, Chenghou; Wang, Hui-Tian

    2016-07-15

    We introduce the concept of a fractal, which provides an alternative approach for flexibly engineering the optical fields and their focal fields. We propose, design, and create a new family of optical fields-fractal vector optical fields, which build a bridge between the fractal and vector optical fields. The fractal vector optical fields have polarization states exhibiting fractal geometry, and may also involve the phase and/or amplitude simultaneously. The results reveal that the focal fields exhibit self-similarity, and the hierarchy of the fractal has the "weeding" role. The fractal can be used to engineer the focal field. PMID:27420485

  19. Electrostatic Field Invisibility Cloak

    PubMed Central

    Lan, Chuwen; Yang, Yuping; Geng, Zhaoxin; Li, Bo; Zhou, Ji

    2015-01-01

    The invisibility cloak has been drawing much attention due to its new concept for manipulating many physical fields, from oscillating wave fields (electromagnetic, acoustic and elastic) to static magnetic fields, dc electric fields, and diffusive fields. Here, an electrostatic field invisibility cloak has been theoretically investigated and experimentally demonstrated to perfectly hide two dimensional objects without disturbing their external electrostatic fields. The desired cloaking effect has been achieved via both cancelling technology and transformation optics (TO). This study demonstrates a novel way for manipulating electrostatic fields, which shows promise for a wide range of potential applications. PMID:26552343

  20. Electrostatic Field Invisibility Cloak

    NASA Astrophysics Data System (ADS)

    Lan, Chuwen; Yang, Yuping; Geng, Zhaoxin; Li, Bo; Zhou, Ji

    2015-11-01

    The invisibility cloak has been drawing much attention due to its new concept for manipulating many physical fields, from oscillating wave fields (electromagnetic, acoustic and elastic) to static magnetic fields, dc electric fields, and diffusive fields. Here, an electrostatic field invisibility cloak has been theoretically investigated and experimentally demonstrated to perfectly hide two dimensional objects without disturbing their external electrostatic fields. The desired cloaking effect has been achieved via both cancelling technology and transformation optics (TO). This study demonstrates a novel way for manipulating electrostatic fields, which shows promise for a wide range of potential applications.

  1. External split field generator

    SciTech Connect

    Thundat, Thomas George; Van Neste, Charles W.; Vass, Arpad Alexander

    2012-02-21

    A generator includes a coil disposed about a core. A first stationary magnetic field source may be disposed on a first end portion of the core and a second stationary magnetic field source may be disposed on a second end portion of core. The first and second stationary magnetic field sources apply a stationary magnetic field to the coil. An external magnetic field source may be disposed outside the coil to apply a moving magnetic field to the coil. Electrical energy is generated in response to an interaction between the coil, the moving magnetic field, and the stationary magnetic field.

  2. Wake fields and wake field acceleration

    SciTech Connect

    Bane, K.L.F.; Wilson, P.B.; Weiland, T.

    1984-12-01

    In this lecture we introduce the concepts of wake fields and wake potentials, examine some basic properties of these functions, show how they can be calculated, and look briefly at a few important applications. One such application is wake field acceleration. The wake field accelerator is capable of producing the high gradients required for future very high energy e/sup +/e/sup -/ linear colliders. The principles of wake field acceleration, and a brief description of experiments in progress in this area, are presented in the concluding section. 40 references, 27 figures.

  3. Field Trips. Beginnings Workshop.

    ERIC Educational Resources Information Center

    Cartwright, Sally; Aronson, Susan S.; Stacey, Susan; Winbush, Olga

    2001-01-01

    Five articles highlight benefits and organization of field trips: (1) "Field Trips Promote Child Learning at Its Best"; (2) "Planning for Maximum Benefit, Minimum Risk"; (3) "Coaching Community Hosts"; (4) "The Story of a Field Trip: Trash and Its Place within Children's Learning and Community"; and (5) "Field Trip Stories and Perspectives" (from…

  4. Field Campaign Guidelines

    SciTech Connect

    Voyles, J. W.; Chapman, L. A.

    2015-12-01

    This document establishes a common set of guidelines for the Atmospheric Radiation Measurement (ARM) Climate Research Facility for planning, executing, and closing out field campaigns. The steps that guide individual field campaigns are described in the Field Campaign Tracking System and are specifically tailored to meet the scope of each field campaign.

  5. PREPROCESSING MAGNETIC FIELDS WITH CHROMOSPHERIC LONGITUDINAL FIELDS

    SciTech Connect

    Yamamoto, Tetsuya T.; Kusano, K.

    2012-06-20

    Nonlinear force-free field (NLFFF) extrapolation is a powerful tool for the modeling of the magnetic field in the solar corona. However, since the photospheric magnetic field does not in general satisfy the force-free condition, some kind of processing is required to assimilate data into the model. In this paper, we report the results of new preprocessing for the NLFFF extrapolation. Through this preprocessing, we expect to obtain magnetic field data similar to those in the chromosphere. In our preprocessing, we add a new term concerning chromospheric longitudinal fields into the optimization function proposed by Wiegelmann et al. We perform a parameter survey of six free parameters to find minimum force- and torque-freeness with the simulated-annealing method. Analyzed data are a photospheric vector magnetogram of AR 10953 observed with the Hinode spectropolarimeter and a chromospheric longitudinal magnetogram observed with SOLIS spectropolarimeter. It is found that some preprocessed fields show the smallest force- and torque-freeness and are very similar to the chromospheric longitudinal fields. On the other hand, other preprocessed fields show noisy maps, although the force- and torque-freeness are of the same order. By analyzing preprocessed noisy maps in the wave number space, we found that small and large wave number components balance out on the force-free index. We also discuss our iteration limit of the simulated-annealing method and magnetic structure broadening in the chromosphere.

  6. What Are Electromagnetic Fields?

    MedlinePlus

    ... with distance from it. Conductors such as metal shield them very effectively. Other materials, such as building ... with distance from the source. Most building materials shield electric fields to some extent. Magnetic fields arise ...

  7. Dissipative Field Theory

    SciTech Connect

    Kheirandish, F.; Amooshahi, M.

    2008-11-18

    Quantum field theory of a damped vibrating string as the simplest dissipative scalar field theory is investigated by introducing a minimal coupling method. The rate of energy flowing between the system and its environment is obtained.

  8. Understanding Vector Fields.

    ERIC Educational Resources Information Center

    Curjel, C. R.

    1990-01-01

    Presented are activities that help students understand the idea of a vector field. Included are definitions, flow lines, tangential and normal components along curves, flux and work, field conservation, and differential equations. (KR)

  9. Nonperturbative Quantum Field Evolution

    NASA Astrophysics Data System (ADS)

    Zhao, Xingbo; Ilderton, Anton; Maris, Pieter; Vary, James P.

    2014-06-01

    We introduce a nonperturbative, first-principles approach to time-dependent problems in quantum field theory. In this approach, the time-evolution of quantum field configurations is calculated in real time and at the amplitude level. This method is particularly suitable for treating systems interacting with a time-dependent background field. As a test problem, we apply this approach to QED and study electron acceleration and the associated photon emission in a time- and space-dependent electromagnetic background field.

  10. Electric Field Imaging Project

    NASA Technical Reports Server (NTRS)

    Wilcutt, Terrence; Hughitt, Brian; Burke, Eric; Generazio, Edward

    2016-01-01

    NDE historically has focused technology development in propagating wave phenomena with little attention to the field of electrostatics and emanating electric fields. This work is intended to bring electrostatic imaging to the forefront of new inspection technologies, and new technologies in general. The specific goals are to specify the electric potential and electric field including the electric field spatial components emanating from, to, and throughout volumes containing objects or in free space.

  11. Solar Wind Magnetic Fields

    NASA Technical Reports Server (NTRS)

    Smith, E. J.

    1995-01-01

    The magnetic fields originate as coronal fields that are converted into space by the supersonic, infinitely conducting, solar wind. On average, the sun's rotation causes the field to wind up and form an Archimedes Spiral. However, the field direction changes almost continuously on a variety of scales and the irregular nature of these changes is often interpreted as evidence that the solar wind flow is turbulent.

  12. Magnetic field sensor

    NASA Astrophysics Data System (ADS)

    Silva, Nicolas

    2012-09-01

    Earlier papers1-3 in this journal have described experiments on measuring the magnetic fields of current-carrying wires and permanent magnets using magnetic field probes of various kinds. This paper explains how to use an iPad and the free app MagnetMeter-3D Vector Magnetometer and Accelerometer4 (compass HD) to measure the magnetic fields.

  13. Far field acceleration

    SciTech Connect

    Fernow, R.C.

    1995-07-01

    Far fields are propagating electromagnetic waves far from their source, boundary surfaces, and free charges. The general principles governing the acceleration of charged particles by far fields are reviewed. A survey of proposed field configurations is given. The two most important schemes, Inverse Cerenkov acceleration and Inverse free electron laser acceleration, are discussed in detail.

  14. Introducing Electromagnetic Field Momentum

    ERIC Educational Resources Information Center

    Hu, Ben Yu-Kuang

    2012-01-01

    I describe an elementary way of introducing electromagnetic field momentum. By considering a system of a long solenoid and line charge, the dependence of the field momentum on the electric and magnetic fields can be deduced. I obtain the electromagnetic angular momentum for a point charge and magnetic monopole pair partially through dimensional…

  15. Politics of aviation fields

    NASA Technical Reports Server (NTRS)

    Vivent, Jacques

    1922-01-01

    In short, the "politics of aviation" lies in a few propositions: the need of having as large a number of fields as possible and of sufficient area; the utilization of the larger part of the existing military fields; the selection of uncultivated or unproductive fields, whenever technical conditions permit; ability to disregard (save in exceptional cases) objections of an agricultural nature.

  16. String field theory and tachyon field

    NASA Astrophysics Data System (ADS)

    Yang, Yi

    In this thesis, we study Sen's conjecture on tachyon condensation by using string field theories, i.e. boundary string field theory (BSFT) and cubic string field theory (CSFT). In the BSFT side, the first explicit calculation of effective tachyon action for the bosonic string was given by Witten ten years ago and by many other authors in the last two years. It was extended to the superstring case shortly after. In our work, we give an explicit calculation of Green functions for the fermionic fields and compute the effective tachyon action for the superstring. The results we obtain agree with earlier results. We then generalize the BSFT method to one loop level. The tachyon condensation at one loop level is systematically studied, and many interesting results are obtained which verify Sen's conjecture. We also apply this method to the non-orientable theory at one loop level, where the expected divergence cancellation is reproduced and the similar effective tachyon action is obtained. By using the boundary state formalism, we verify the duality between open and closed strings. In the CSFT side, since there is no known solution to this theory, tachyon condensation can only be studied by numerical methods, i.e. level truncation. However, at the tachyon vacuum, CSFT is simplified to vacuum string field theory (VSFT) which has a solution - sliver state. By adding a tachyon vertex to the boundary of the sliver state, we have calculated the effective action.

  17. Artificial gravity field

    NASA Astrophysics Data System (ADS)

    Markley, Larry C.; Lindner, John F.

    Using computer algebra to run Einstein's equations "backward", from field to source rather than from source to field, we design an artificial gravity field for a space station or spaceship. Everywhere inside astronauts experience normal Earth gravity, while outside they float freely. The stress-energy that generates the field contains exotic matter of negative energy density but also relies importantly on pressures and shears, which we describe. The same techniques can be readily used to design other interesting spacetimes and thereby elucidate the connection between the source and field in general relativity.

  18. Magnetic field generator

    DOEpatents

    Krienin, Frank

    1990-01-01

    A magnetic field generating device provides a useful magnetic field within a specific retgion, while keeping nearby surrounding regions virtually field free. By placing an appropriate current density along a flux line of the source, the stray field effects of the generator may be contained. One current carrying structure may support a truncated cosine distribution, and it may be surrounded by a current structure which follows a flux line that would occur in a full coaxial double cosine distribution. Strong magnetic fields may be generated and contained using superconducting cables to approximate required current surfaces.

  19. Probing Ancient Mass Loss with AKARI's Extended Thermal Dust Emission Objects

    NASA Astrophysics Data System (ADS)

    Tomasino, Rachael L.; Ueta, Toshiya; Yamamura, Issei; Izumiura, Hideyuki

    We present the method for the calibration and analysis of 166 far-IR extended thermal dust emission objects that were observed with AKARI’s FIS detector. The primary goal of the analysis of this data set is to map the circumstellar shells of evolved stars in detail to understand the ancient history of dusty mass loss. After establishing an extended aperture photometry method, we re-characterize the flux dependent slow transient response correction factors for each of the four wavelength bands and propose a new flux calibration method for extended sources. Using these new correction factors, the photometric measurements are made using a extended aperture which is defined by a background + 3σ threshold. With photometry measurements for each of the four FIS bands, an SED of a modified blackbody was fit to produce the emissivity beta, effective temperature, and color correction factor.

  20. AKARI/IRC Near-infrared Spectral Atlas of Galactic Planetary Nebulae

    NASA Astrophysics Data System (ADS)

    Ohsawa, Ryou; Onaka, Takashi; Sakon, Itsuki; Matsuura, Mikako; Kaneda, Hidehiro

    2016-04-01

    Near-infrared (2.5-5.0 μm) low-resolution (λ/Δλ ˜ 100) spectra of 72 Galactic planetary nebulae (PNe) were obtained with the Infrared Camera (IRC) in the post-helium phase. The IRC, equipped with a 1‧ × 1‧ window for spectroscopy of a point source, was capable of obtaining near-infrared spectra in a slit-less mode without any flux loss due to a slit. The spectra show emission features including hydrogen recombination lines and the 3.3-3.5 μm hydrocarbon features. The intensity and equivalent width of the emission features were measured by spectral fitting. We made a catalog providing unique information on the investigation of the near-infrared emission of PNe. In this paper, details of the observations and characteristics of the catalog are described.

  1. 3D field harmonics

    SciTech Connect

    Caspi, S.; Helm, M.; Laslett, L.J.

    1991-03-30

    We have developed an harmonic representation for the three dimensional field components within the windings of accelerator magnets. The form by which the field is presented is suitable for interfacing with other codes that make use of the 3D field components (particle tracking and stability). The field components can be calculated with high precision and reduced cup time at any location (r,{theta},z) inside the magnet bore. The same conductor geometry which is used to simulate line currents is also used in CAD with modifications more readily available. It is our hope that the format used here for magnetic fields can be used not only as a means of delivering fields but also as a way by which beam dynamics can suggest correction to the conductor geometry. 5 refs., 70 figs.

  2. Gauge fields in spintronics

    NASA Astrophysics Data System (ADS)

    Fujita, T.; Jalil, M. B. A.; Tan, S. G.; Murakami, S.

    2011-12-01

    We present an overview of gauge fields in spintronics, focusing on their origin and physical consequences. Important topics, such as the Berry gauge field associated with adiabatic quantum evolution as well as gauge fields arising from other non-adiabatic considerations, are discussed. We examine the appearance and effects of gauge fields across three spaces, namely real-space, momentum-space, and time, taking on a largely semiclassical approach. We seize the opportunity to study other "spin-like" systems, including graphene, topological insulators, magnonics, and photonics, which emphasize the ubiquity and importance of gauge fields. We aim to provide an intuitive and pedagogical insight into the role played by gauge fields in spin transport.

  3. Simulated workplace neutron fields

    NASA Astrophysics Data System (ADS)

    Lacoste, V.; Taylor, G.; Röttger, S.

    2011-12-01

    The use of simulated workplace neutron fields, which aim at replicating radiation fields at practical workplaces, is an alternative solution for the calibration of neutron dosemeters. They offer more appropriate calibration coefficients when the mean fluence-to-dose equivalent conversion coefficients of the simulated and practical fields are comparable. Intensive Monte Carlo modelling work has become quite indispensable for the design and/or the characterization of the produced mixed neutron/photon fields, and the use of Bonner sphere systems and proton recoil spectrometers is also mandatory for a reliable experimental determination of the neutron fluence energy distribution over the whole energy range. The establishment of a calibration capability with a simulated workplace neutron field is not an easy task; to date only few facilities are available as standard calibration fields.

  4. Quaternion gauge fields. Pseudocolor

    SciTech Connect

    Govorkov, A.B.

    1987-03-01

    A simplified Guenaydin-Guersey model, in which a Majorana field constructed using quaternions combines a lepton and a color quark, is considered. Formulation of the gauge principle directly in the quaternions leads to the appearance of two vector quaternion gauge fields, these corresponding to the decomposition SO(4) approx. SO(3) x SO(3) of the invariance group. The diagonal subgroup SO(3) of automorphisms of the quarternions appears as a pseudocolor symmetry of the quarks, and the gauge field corresponding to it as the field of three color gluons. The other gauge field corresponds to lepton-quark transitions and in the presence of spontaneous breaking of the SO(4) gauge symmetry by the scalar quaternion field acquires a (large) finite mass.

  5. Wake field accelerators

    SciTech Connect

    Wilson, P.B.

    1986-02-01

    In a wake field accelerator a high current driving bunch injected into a structure or plasma produces intense induced fields, which are in turn used to accelerate a trailing charge or bunch. The basic concepts of wake field acceleration are described. Wake potentials for closed cavities and periodic structures are derived, as are wake potentials on a collinear path with a charge distribution. Cylindrically symmetric structures excited by a beam in the form of a ring are considered. (LEW)

  6. Field emission electron source

    DOEpatents

    Zettl, Alexander Karlwalter; Cohen, Marvin Lou

    2000-01-01

    A novel field emitter material, field emission electron source, and commercially feasible fabrication method is described. The inventive field emission electron source produces reliable electron currents of up to 400 mA/cm.sup.2 at 200 volts. The emitter is robust and the current it produces is not sensitive to variability of vacuum or the distance between the emitter tip and the cathode. The novel emitter has a sharp turn-on near 100 volts.

  7. Field emission electron source

    SciTech Connect

    Zettl, A.K.; Cohen, M.L.

    2000-05-02

    A novel field emitter material, field emission electron source, and commercially feasible fabrication method is described. The inventive field emission electron source produces reliable electron currents of up to 400 mA/cm{sup 2} at 200 volts. The emitter is robust and the current it produces is not sensitive to variability of vacuum or the distance between the emitter tip and the cathode. The novel emitter has a sharp turn-on near 100 volts.

  8. Field emission chemical sensor

    DOEpatents

    Panitz, J.A.

    1983-11-22

    A field emission chemical sensor for specific detection of a chemical entity in a sample includes a closed chamber enclosing two field emission electrode sets, each field emission electrode set comprising (a) an electron emitter electrode from which field emission electrons can be emitted when an effective voltage is connected to the electrode set; and (b) a collector electrode which will capture said electrons emitted from said emitter electrode. One of the electrode sets is passive to the chemical entity and the other is active thereto and has an active emitter electrode which will bind the chemical entity when contacted therewith.

  9. Magnetic Fields in Galaxies

    NASA Astrophysics Data System (ADS)

    Beck, Rainer

    Magnetic fields are a major agent in the interstellar medium. They contribute significantly to the total pressure which balances the gas disk against gravitation. They affect the gas flows in spiral arms (Gómez and Cox, 2002). The effective sound speed of the gas is increased by the presence of strong fields which reduce the shock strength. The interstellar fields are closely connected to gas clouds. They affect the dynamics of the gas clouds (Elmegreen, 1981; de Avillez and Breitschwerdt, 2004). The stability and evolution of gas clouds are also influenced by magnetic fields, but it is not understood how (Crutcher, 1999; see Chap. 7). Magnetic fields are essential for the onset of star formation as they enable the removal of angular momentum from the protostellar cloud during its collapse (magnetic braking, Mouschovias, 1990). Strong fields may shift the stellar mass spectrum towards the more massive stars (Mestel, 1990). MHD turbulence distributes energy from supernova explosions within the ISM (Subramanian, 1998) and regenerates the field via the dynamo process (Wielebinski, R., Krause, 1993, Beck et al., 1996; Sect. 6). Magnetic reconnection is a possible heating source for the ISM and halo gas (Birk et al., 1998). Magnetic fields also control the density and distribution of cosmic rays in the ISM. A realistic model for any process in the ISM needs basic information about the magnetic field which has to be provided by observations.

  10. Abandoned Texas oil fields

    SciTech Connect

    Not Available

    1980-12-01

    Data for Texas abandoned oil fields were primarily derived from two sources: (1) Texas Railroad Commission (TRRC), and (2) Dwight's ENERGYDATA. For purposes of this report, abandoned oil fields are defined as those fields that had no production during 1977. The TRRC OILMASTER computer tapes were used to identify these abandoned oil fields. The tapes also provided data on formation depth, gravity of oil production, location (both district and county), discovery date, and the cumulative production of the field since its discovery. In all, the computer tapes identified 9211 abandoned fields, most of which had less than 250,000 barrel cumulative production. This report focuses on the 676 abandoned onshore Texas oil fields that had cumulative production of over 250,000 barrels. The Dwight's ENERGYDATA computer tapes provided production histories for approximately two-thirds of the larger fields abandoned in 1966 and thereafter. Fields which ceased production prior to 1966 will show no production history nor abandonment date in this report. The Department of Energy hopes the general availability of these data will catalyze the private sector recovery of this unproduced resource.

  11. Photospheric magnetic fields

    NASA Technical Reports Server (NTRS)

    Howard, R.

    1972-01-01

    Knowledge on the nature of magnetic fields on the solar surface is reviewed. At least a large part of the magnetic flux in the solar surface is confined to small bundles of lines of force within which the field strength is of the order of 500 gauss. Magnetic fields are closely associated with all types of solar activity. Magnetic flux appears at the surface at the clearly defined birth or regeneration of activity of an active region. As the region ages, the magnetic flux migrates to form large-scale patterns and the polar fields. Some manifestations of the large-scale distribution are discussed.

  12. Modeling Saturn's Magnetospheric Field

    NASA Astrophysics Data System (ADS)

    Khurana, K. K.; Leinweber, H. K.; Russell, C. T.; Dougherty, M. K.

    2015-12-01

    The Cassini spacecraft has now provided an excellent coverage of radial distances, local times and latitudes in Saturn's magnetosphere. The magnetic field observations from Cassini continue to provide deep insights on the structure and dynamics of Saturn's magnetosphere. Two of the unexpected findings from Saturn's magnetosphere are that the current sheet of Saturn assumes a shallow saucer like shape from the forcing of the solar wind on the magnetosphere and that rotational diurnal periodicities are ubiquitous in a magnetosphere formed by an axisymmetric internal field from Saturn. We have used the comprehensive magnetic field data from Cassini to construct a versatile new model of Saturn's magnetospheric field for use in current and future data analysis. Our model consists of fully shielded modules that specify the internal spherical harmonic field of Saturn, the ring current and the magnetotail current systems and the interconnection magnetic field from the solar wind IMF. The tilt and hinging of the current sheet is introduced by using the general deformation technique [Tsyganenko, 1998]. In the new model, Saturn's current sheet field is based on Tsyganenko and Peredo [1994] formalism for disk-shaped current sheets. The shielding field from the magnetopause for the equatorial current sheet and the internal field is specified by Cartesian and cylindrical harmonics, respectively. To derive the shielding fields we use a model of the magnetopause constructed from magnetopause crossings observed by both Cassini and Voyager (Arridge et al. 2006). The model uses observations from Pioneer, Voyager and Cassini. A comparison of model field with the observations will be presented. Finally, we discuss both the applications of the new model and its further generalization using data from the proximal orbit phase of Cassini.

  13. Electromagnetic Field Penetration Studies

    NASA Technical Reports Server (NTRS)

    Deshpande, M.D.

    2000-01-01

    A numerical method is presented to determine electromagnetic shielding effectiveness of rectangular enclosure with apertures on its wall used for input and output connections, control panels, visual-access windows, ventilation panels, etc. Expressing EM fields in terms of cavity Green's function inside the enclosure and the free space Green's function outside the enclosure, integral equations with aperture tangential electric fields as unknown variables are obtained by enforcing the continuity of tangential electric and magnetic fields across the apertures. Using the Method of Moments, the integral equations are solved for unknown aperture fields. From these aperture fields, the EM field inside a rectangular enclosure due to external electromagnetic sources are determined. Numerical results on electric field shielding of a rectangular cavity with a thin rectangular slot obtained using the present method are compared with the results obtained using simple transmission line technique for code validation. The present technique is applied to determine field penetration inside a Boeing-757 by approximating its passenger cabin as a rectangular cavity filled with a homogeneous medium and its passenger windows by rectangular apertures. Preliminary results for, two windows, one on each side of fuselage were considered. Numerical results for Boeing-757 at frequencies 26 MHz, 171-175 MHz, and 428-432 MHz are presented.

  14. Field Trip Fundamentals

    ERIC Educational Resources Information Center

    Wilson, Margaret

    2011-01-01

    In this article, the author discusses how to prepare for and conduct a safe and worry-free educational experience. She shares a few tips that will ensure field trips will be fun, safe, engaging, and productive. She stresses that with proper planning, field trips can be unique ways to explore the world with students.

  15. Octonic Massive Field Equations

    NASA Astrophysics Data System (ADS)

    Demir, Süleyman; Kekeç, Seray

    2016-07-01

    In the present paper we propose the octonic form of massive field equations based on the analogy with electromagnetism and linear gravity. Using the advantages of octon algebra the Maxwell-Dirac-Proca equations have been reformulated in compact and elegant way. The energy-momentum relations for massive field are discussed.

  16. Pulsed electric fields

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The concept of pulsed electric fields (PEF) was first proposed in 1967 to change the behavior or microorganisms. The electric field phenomenon was identified as membrane rupture theory in the 1980s. Increasing the membrane permeability led to the application of PEF assisted extraction of cellular co...

  17. Undulator Field Integral Measurements

    SciTech Connect

    Wolf, Zachary

    2010-12-07

    The LCLS undulator field integrals must be very small so that the beam trajectory slope and offset stay within tolerance. In order to make accurate measurements of the small field integrals, a long coil will be used. This note describes the design of the coil measurement system.

  18. Track and Field Facilities.

    ERIC Educational Resources Information Center

    Wood, Tony

    2001-01-01

    Discusses planning and design tips that help ensure track and field facilities are successful and well-suited to both school and community use. Examines approaches to determining the best track surface and ways to maximize track and field flexibility with limited space. (GR)

  19. Octonic Massive Field Equations

    NASA Astrophysics Data System (ADS)

    Demir, Süleyman; Kekeç, Seray

    2016-03-01

    In the present paper we propose the octonic form of massive field equations based on the analogy with electromagnetism and linear gravity. Using the advantages of octon algebra the Maxwell-Dirac-Proca equations have been reformulated in compact and elegant way. The energy-momentum relations for massive field are discussed.

  20. Forrest or Field?

    ERIC Educational Resources Information Center

    Mangiante, Elaine Silva

    2009-01-01

    An open field--with its wildflowers, grasses, and vole tunnels--became an instant classroom. Students' senses were awakened there, and upon entering a nearby forest, they immediately detected a difference: less light and cooler air. "Why are there no grasses in the forest? Why aren't there ferns in the field?" These and other questions emerged as…

  1. Diamond fiber field emitters

    DOEpatents

    Blanchet-Fincher, Graciela B.; Coates, Don M.; Devlin, David J.; Eaton, David F.; Silzars, Aris K.; Valone, Steven M.

    1996-01-01

    A field emission electron emitter comprising an electrode formed of at least one diamond, diamond-like carbon or glassy carbon composite fiber, said composite fiber having a non-diamond core and a diamond, diamond-like carbon or glassy carbon coating on said non-diamond core, and electronic devices employing such a field emission electron emitter.

  2. Virtual Field Trips.

    ERIC Educational Resources Information Center

    Cooper, Gail; Cooper, Garry

    The Internet field trips in this directory allow teachers to take students almost anywhere--without the usual ordeals associated with field trips. Organized by subject and cross-referenced for quick and easy access, this book leads educators and students to the most exciting, educational, and innovative Web sites on the Internet. Chapters cover…

  3. A Biomes Field Trip.

    ERIC Educational Resources Information Center

    Leonard, William H.; And Others

    1983-01-01

    Describes a field trip designed to give students opportunities to experience relevant data leading to concepts in biogeography. Suggests that teachers (including college instructors) adapt the areas studied and procedures used to their own locations. Includes a suggested field trip handout. (JN)

  4. Tips from the Field

    ERIC Educational Resources Information Center

    Connolly, Rachel; Groome, Meghan; Sheppard, Keith; Stroud, Nick

    2006-01-01

    Field trips are opportunities to experience science in settings beyond the classroom. Much educational research has focused on effective ways of designing and planning field trips for optimal impact on the classroom and science curriculum. However, teachers are sometimes at a loss on how to design a trip that will enhance students' analytical…

  5. OMSI's Hancock Field Program.

    ERIC Educational Resources Information Center

    Jones, Connie Hofferber

    1990-01-01

    The Hancock field station (Oregon), owned by the Oregon Museum of Science and Industry, offers programs for children (age 6-13) which stress development of scientific observation and investigation skills, through field work in such areas as fossil hunting with professional paleontologists as well as other outdoor activities. (DB)

  6. Teaching in the Field.

    ERIC Educational Resources Information Center

    Donaldson, Lou; Donaldson, George

    Beginning with a field-trip justification, this guide illuminates the problems and procedural considerations of taking school classes outside of school grounds. Major divisions of treatment are Motivating Field Work, Preparing Yourself (the teacher), Determining Purposes, Preparing for the Mechanics of the Trip, Getting Permission, Planning for…

  7. Quaternion scalar field

    SciTech Connect

    De Leo, S. ); Rotelli, P. )

    1992-01-15

    We discuss the extension of a version of {ital quaternion} quantum mechanics to field theory and in particular to the simplest example, the free scalar field. A previous difficulty with the conservation of four-momentum for the anomalous'' bosonic particles is resolved.

  8. Dual double field theory

    NASA Astrophysics Data System (ADS)

    Bergshoeff, Eric A.; Hohm, Olaf; Penas, Victor A.; Riccioni, Fabio

    2016-06-01

    We present the dual formulation of double field theory at the linearized level. This is a classically equivalent theory describing the duals of the dilaton, the Kalb-Ramond field and the graviton in a T-duality or O( D, D) covariant way. In agreement with previous proposals, the resulting theory encodes fields in mixed Young-tableau representations, combining them into an antisymmetric 4-tensor under O( D, D). In contrast to previous proposals, the theory also requires an antisymmetric 2-tensor and a singlet, which are not all pure gauge. The need for these additional fields is analogous to a similar phenomenon for "exotic" dualizations, and we clarify this by comparing with the dualizations of the component fields. We close with some speculative remarks on the significance of these observations for the full non-linear theory yet to be constructed.

  9. Open field lines instabilities

    SciTech Connect

    Pozzoli, R. |

    1995-09-01

    The results of some recent theoretical papers dealing with flute-like instabilities in the scrape-off layer of a tokamak with limiter configuration, where the magnetic field intersects conducting walls, are briefly recalled. Attention is then paid to the instability driven by the electron temperature gradient across the field in conjunction with the formation of the Debye sheath at the boundary, and to the effects due to the inclination of the end walls with respect to the magnetic field. When a divertor configuration is considered, important modifications are found owing to the strong deformations of the flux tubes passing near the {ital x}-point, which contrast the onset of flute-like perturbations, and to the stochasticity of field lines that can be excited by magnetic field perturbations. {copyright} {ital 1995 American Institute of Physics.}

  10. The Coriolis field

    NASA Astrophysics Data System (ADS)

    Costa, L. Filipe; Natário, José

    2016-05-01

    We present a pedagogical discussion of the Coriolis field, emphasizing its not-so-well-understood aspects. We show that this field satisfies the field equations of the so-called Newton-Cartan theory, a generalization of Newtonian gravity that is covariant under changes of arbitrarily rotating and accelerated frames. Examples of solutions of this theory are given, including the Newtonian analogue of the Gödel universe. We discuss how to detect the Coriolis field by its effect on gyroscopes, of which the gyrocompass is an example. Finally, using a similar framework, we discuss the Coriolis field generated by mass currents in general relativity, and its measurement by the gravity probe B and LAGEOS/LARES experiments.

  11. Field-Dependence/Field-Independence. Educational Implications for Bilingual Education.

    ERIC Educational Resources Information Center

    Holtzman, Elsa Hernandez; And Others

    An overview of cognitve styles and research in the field of field dependence/field independence within the context of the special needs of Hispanic students is presented. Various studies by Witkin et al. on the dimension of field dependence/field independence required the subject to perceive an item independently of the field or context that…

  12. Gauge fields and inflation

    NASA Astrophysics Data System (ADS)

    Maleknejad, A.; Sheikh-Jabbari, M. M.; Soda, J.

    2013-07-01

    The isotropy and homogeneity of the cosmic microwave background (CMB) favors “scalar driven” early Universe inflationary models. However, gauge fields and other non-scalar fields are far more common at all energy scales, in particular at high energies seemingly relevant to inflation models. Hence, in this review we consider the role and consequences, theoretical and observational, that gauge fields can have during the inflationary era. Gauge fields may be turned on in the background during inflation, or may become relevant at the level of cosmic perturbations. There have been two main classes of models with gauge fields in the background, models which show violation of the cosmic no-hair theorem and those which lead to isotropic FLRW cosmology, respecting the cosmic no-hair theorem. Models in which gauge fields are only turned on at the cosmic perturbation level, may source primordial magnetic fields. We also review specific observational features of these models on the CMB and/or the primordial cosmic magnetic fields. Our discussions will be mainly focused on the inflation period, with only a brief discussion on the post inflationary (p)reheating era. Large field models: The initial value of the inflaton field is large, generically super-Planckian, and it rolls slowly down toward the potential minimum at smaller φ values. For instance, chaotic inflation is one of the representative models of this class. The typical potential of large-field models has a monomial form as V(φ)=V0φn. A simple analysis using the dynamical equations reveals that for number of e-folds Ne larger than 60, we require super-Planckian initial field values,5φ0>3M. For these models typically ɛ˜η˜Ne-1. Small field models: Inflaton field is initially small and slowly evolves toward the potential minimum at larger φ values. The small field models are characterized by the following potential V(φ)=V0(1-(), which corresponds to a Taylor expansion about the origin, but more realistic

  13. Introducing electromagnetic field momentum

    NASA Astrophysics Data System (ADS)

    Yu-Kuang Hu, Ben

    2012-07-01

    I describe an elementary way of introducing electromagnetic field momentum. By considering a system of a long solenoid and line charge, the dependence of the field momentum on the electric and magnetic fields can be deduced. I obtain the electromagnetic angular momentum for a point charge and magnetic monopole pair partially through dimensional analysis and without using vector calculus identities or the need to evaluate integrals. I use this result to show that linear and angular momenta are conserved for a charge in the presence of a magnetic dipole when the dipole strength is changed.

  14. Remnant field detector

    DOEpatents

    Visser, Age T.

    1988-01-01

    A method apparatus for qualitatively detecting remnant magnetic fields in matched pairs of magnet cores. Equal magnitude and oppositely oriented magnetic flux is induced in the magnet cores by oppositely wound primary windings and current source. Identically wound secondary windings generate output voltages in response to the induced flux. The output voltages generated should be of equal magnitude and opposite polarity if there is no remnant field in the cores. The output voltages will be unequal which is detected if either core has a remnant field.

  15. Introducing electric fields

    NASA Astrophysics Data System (ADS)

    Roche, John

    2016-09-01

    The clear introduction of basic concepts and definitions is crucial for teaching any topic in physics. I have always found it difficult to teach fields. While searching for better explanations I hit on an approach of reading foundational texts and electromagnetic textbooks in ten year lots, ranging from 1840 to the present. By combining this with modern techniques of textual interpretation I attempt to clarify three introductory concepts: how the field is defined; the principle of superposition and the role of the electrostatic field in a circuit.

  16. Octonic massless field equations

    NASA Astrophysics Data System (ADS)

    Demir, Süleyman; Tanişli, Murat; Kansu, Mustafa Emre

    2015-05-01

    In this paper, it is proven that the associative octons including scalar, pseudoscalar, pseudovector and vector values are convenient and capable tools to generalize the Maxwell-Dirac like field equations of electromagnetism and linear gravity in a compact and simple way. Although an attempt to describe the massless field equations of electromagnetism and linear gravity needs the sixteen real component mathematical structures, it is proved that these equations can be formulated in terms of eight components of octons. Furthermore, the generalized wave equation in terms of potentials is derived in the presence of electromagnetic and gravitational charges (masses). Finally, conservation of energy concept has also been investigated for massless fields.

  17. Magnetic Field Measurement System

    SciTech Connect

    Kulesza, Joe; Johnson, Eric; Lyndaker, Aaron; Deyhim, Alex; Waterman, Dave; Blomqvist, K. Ingvar; Dunn, Jonathan Hunter

    2007-01-19

    A magnetic field measurement system was designed, built and installed at MAX Lab, Sweden for the purpose of characterizing the magnetic field produced by Insertion Devices (see Figure 1). The measurement system consists of a large granite beam roughly 2 feet square and 14 feet long that has been polished beyond laboratory grade for flatness and straightness. The granite precision coupled with the design of the carriage yielded minimum position deviations as measured at the probe tip. The Hall probe data collection and compensation technique allows exceptional resolution and range while taking data on the fly to programmable sample spacing. Additional flip coil provides field integral data.

  18. Gauge fields and inflation

    NASA Astrophysics Data System (ADS)

    Maleknejad, A.; Sheikh-Jabbari, M. M.; Soda, J.

    2013-07-01

    The isotropy and homogeneity of the cosmic microwave background (CMB) favors “scalar driven” early Universe inflationary models. However, gauge fields and other non-scalar fields are far more common at all energy scales, in particular at high energies seemingly relevant to inflation models. Hence, in this review we consider the role and consequences, theoretical and observational, that gauge fields can have during the inflationary era. Gauge fields may be turned on in the background during inflation, or may become relevant at the level of cosmic perturbations. There have been two main classes of models with gauge fields in the background, models which show violation of the cosmic no-hair theorem and those which lead to isotropic FLRW cosmology, respecting the cosmic no-hair theorem. Models in which gauge fields are only turned on at the cosmic perturbation level, may source primordial magnetic fields. We also review specific observational features of these models on the CMB and/or the primordial cosmic magnetic fields. Our discussions will be mainly focused on the inflation period, with only a brief discussion on the post inflationary (p)reheating era. Large field models: The initial value of the inflaton field is large, generically super-Planckian, and it rolls slowly down toward the potential minimum at smaller φ values. For instance, chaotic inflation is one of the representative models of this class. The typical potential of large-field models has a monomial form as V(φ)=V0φn. A simple analysis using the dynamical equations reveals that for number of e-folds Ne larger than 60, we require super-Planckian initial field values,5φ0>3M. For these models typically ɛ˜η˜Ne-1. Small field models: Inflaton field is initially small and slowly evolves toward the potential minimum at larger φ values. The small field models are characterized by the following potential V(φ)=V0(1-(), which corresponds to a Taylor expansion about the origin, but more realistic

  19. Remnant field detector

    DOEpatents

    Visser, Age T.

    1988-05-03

    A method apparatus for qualitatively detecting remnant magnetic fields in matched pairs of magnet cores. Equal magnitude and oppositely oriented magnetic flux is induced in the magnet cores by oppositely wound primary windings and current source. Identically wound secondary windings generate output voltages in response to the induced flux. The output voltages generated should be of equal magnitude and opposite polarity if there is no remnant field in the cores. The output voltages will be unequal which is detected if either core has a remnant field.

  20. Field resonance propulsion concept

    NASA Technical Reports Server (NTRS)

    Holt, A. C.

    1979-01-01

    A propulsion concept was developed based on a proposed resonance between coherent, pulsed electromagnetic wave forms, and gravitational wave forms (or space-time metrics). Using this concept a spacecraft propulsion system potentially capable of galactic and intergalactic travel without prohibitive travel times was designed. The propulsion system utilizes recent research associated with magnetic field line merging, hydromagnetic wave effects, free-electron lasers, laser generation of megagauss fields, and special structural and containment metals. The research required to determine potential, field resonance characteristics and to evaluate various aspects of the spacecraft propulsion design is described.

  1. Crystal Field Handbook

    NASA Astrophysics Data System (ADS)

    Newman, D. J.; Ng, Betty

    2007-09-01

    List of contributors; Preface; Introduction; 1. Crystal field splitting mechanisms D. J. Newman and Betty Ng; 2. Empirical crystal fields D. J. Newman and Betty Ng; 3. Fitting crystal field parameters D. J. Newman and Betty Ng; 4. Lanthanide and actinide optical spectra G. K. Liu; 5. Superposition model D. J. Newman and Betty Ng; 6. Effects of electron correlation on crystal field splitting M. F. Reid and D. J. Newman; 7. Ground state splittings in S-state ions D. J. Newman and Betty Ng; 8. Invariants and moments Y. Y. Yeung; 9. Semiclassical model K. S. Chan; 10. Transition intensities M. F. Reid; Appendix 1. Point symmetry D. J. Newman and Betty Ng; Appendix 2. QBASIC programs D. J. Newman and Betty Ng; Appendix 3. Accessible program packages Y. Y. Yeung, M. F. Reid and D. J. Newman; Appendix 4. Computer package CST Cz. Rudowicz; Bibliography; Index.

  2. Algebraic Mean Field Theory

    NASA Astrophysics Data System (ADS)

    Dankova, T. S.; Rosensteel, G.

    1998-10-01

    Mean field theory has an unexpected group theoretic mathematical foundation. Instead of representation theory which applies to most group theoretic quantum models, Hartree-Fock and Hartree-Fock-Bogoliubov have been formulated in terms of coadjoint orbits for the groups U(n) and O(2n). The general theory of mean fields is formulated for an arbitrary Lie algebra L of fermion operators. The moment map provides the correspondence between the Hilbert space of microscopic wave functions and the dual space L^* of densities. The coadjoint orbits of the group in the dual space are phase spaces on which time-dependent mean field theory is equivalent to a classical Hamiltonian dynamical system. Indeed it forms a finite-dimensional Lax system. The mean field theories for the Elliott SU(3) and symplectic Sp(3,R) algebras are constructed explicitly in the coadjoint orbit framework.

  3. On Cosmic Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Florido, E.; Battaner, E.

    2010-12-01

    Magnetic fields are present in all astrophysical media. However, many models and interpretations of observations often ignore them, because magnetic fields are difficult to handle and because they produce complicated morphological features. Here we will comment on the basic intuitive properties, which even if not completely true, provide a first guiding insight on the physics of a particular astrophysical problem. These magnetic properties are not mathematically demonstrated here. How magnetic fields evolve and how they introduce dynamical effects are considered, also including a short comment on General Relativity Magnetohydrodynamics. In a second part we consider some audacious and speculative matters. They are answers to three questions: a) How draw a cube without lifting the pencil from the paper so that when the pen passes through the same side do in the same direction? B) Are MILAGRO anisotropies miraculous? C) Do cosmic magnetic lenses exist?. The last two questions deal with issues related with the interplay between magnetic fields and cosmic ray propagation.

  4. Field Geology/Processes

    NASA Technical Reports Server (NTRS)

    Allen, Carlton; Jakes, Petr; Jaumann, Ralf; Marshall, John; Moses, Stewart; Ryder, Graham; Saunders, Stephen; Singer, Robert

    1996-01-01

    The field geology/process group examined the basic operations of a terrestrial field geologist and the manner in which these operations could be transferred to a planetary lander. Four basic requirements for robotic field geology were determined: geologic content; surface vision; mobility; and manipulation. Geologic content requires a combination of orbital and descent imaging. Surface vision requirements include range, resolution, stereo, and multispectral imaging. The minimum mobility for useful field geology depends on the scale of orbital imagery. Manipulation requirements include exposing unweathered surfaces, screening samples, and bringing samples in contact with analytical instruments. To support these requirements, several advanced capabilities for future development are recommended. Capabilities include near-infrared reflectance spectroscopy, hyper-spectral imaging, multispectral microscopy, artificial intelligence in support of imaging, x ray diffraction, x ray fluorescence, and rock chipping.

  5. Kepler Field of View

    NASA Video Gallery

    The Kepler mission will be looking continuously at over 100,000 stars in one region of the sky, in the Cygnus and Lyra constellations. The field of view is extremely large for an astronomical teles...

  6. Electric Field Lines

    NASA Astrophysics Data System (ADS)

    Arribas, E.; Gallardo, C.; Molina, M.; Sanjosé, V.

    We present the computer program called LINES which is able to calculate and visualize the electric field lines due to seven different discrete configurations of electric point charges. Also we show two examples of the graphic screens generated by LINES.

  7. MISR Field Campaign Imagery

    Atmospheric Science Data Center

    2014-07-23

      MISR Support of Field Campaigns Aerosol Arctic Research of the Composition of the ... Daily ARCTAS Aerosol Polar Imagery ​Gulf of Mexico Atmospheric Composition and Climate Study ( GoMACCS ) ​July - ...

  8. Hyperspectral light field imaging

    NASA Astrophysics Data System (ADS)

    Leitner, Raimund; Kenda, Andreas; Tortschanoff, Andreas

    2015-05-01

    A light field camera acquires the intensity and direction of rays from a scene providing a 4D representation L(x,y,u,v) called the light field. The acquired light field allows to virtually change view point and selectively re-focus regions algorithmically, an important feature for many applications in imaging and microscopy. The combination with hyperspectral imaging provides the additional advantage that small objects (beads, cells, nuclei) can be categorised using their spectroscopic signatures. Using an inverse fluorescence microscope, a LCTF tuneable filter and a light field setup as a test-bed, fluorescence-marked beads have been imaged and reconstructed into a 4D hyper-spectral image cube LHSI(x,y,z,λ). The results demonstrate the advantages of the approach for fluorescence microscopy providing extended depth of focus (DoF) and the fidelity of hyper-spectral imaging.

  9. Magnetic field dosimeter development

    SciTech Connect

    Lemon, D.K.; Skorpik, J.R.; Eick, J.L.

    1980-09-01

    In recent years there has been increased concern over potential health hazards related to exposure of personnel to magnetic fields. If exposure standards are to be established, then a means for measuring magnetic field dose must be available. To meet this need, the Department of Energy has funded development of prototype dosimeters at the Battelle Pacific Northwest Laboratory. This manual reviews the principle of operation of the dosimeter and also contains step-by-step instructions for its operation.

  10. Collective field accelerator

    DOEpatents

    Luce, John S.

    1978-01-01

    A collective field accelerator which operates with a vacuum diode and utilizes a grooved cathode and a dielectric anode that operates with a relativistic electron beam with a .nu./.gamma. of .about. 1, and a plurality of dielectric lenses having an axial magnetic field thereabout to focus the collectively accelerated electrons and ions which are ejected from the anode. The anode and lenses operate as unoptimized r-f cavities which modulate and focus the beam.

  11. Introduction to Geomagnetic Fields

    NASA Astrophysics Data System (ADS)

    Hinze, William J.

    Coincidentally, as I sat down in late October 2003 to read and review the second edition of Wallace H. Campbell's text, Introduction to Geomagnetic Fields, we received warnings from the news media of a massive solar flare and its possible effect on power supply systems and satellite communications. News programs briefly explained the source of Sun-Earth interactions. If you are interested in learning more about the physics of the connection between sun spots and power supply systems and their impact on orbiting satellites, I urge you to become acquainted with Campbell's book. It presents an interesting and informative explanation of the geomagnetic field and its applications to a wide variety of topics, including oil exploration, climate change, and fraudulent claims of the utility of magnetic fields for alleviating human pain. Geomagnetism, the study of the nature and processes of the Earth's magnetic fields and its application to the investigation of the Earth, its processes, and history, is a mature science with a well-developed theoretical foundation and a vast array of observations. It is discussed in varied detail in Earth physics books and most entry-level geoscience texts. The latter treatments largely are driven by the need to discuss paleomagnetism as an essential tool in studying plate tectonics. A more thorough explanation of geomagnetism is needed by many interested scientists in related fields and by laypersons. This is the objective of Campbell's book. It is particularly germane in view of a broad range of geomagnetic topics that are at the forefront of today's science, including environmental magnetism, so-called ``jerks'' observed in the Earth's magnetic field, the perplexing magnetic field of Mars, improved satellite magnetic field observations, and the increasing availability of high-quality continental magnetic anomaly maps, to name only a few.

  12. Radial Field Piezoelectric Diaphragms

    NASA Technical Reports Server (NTRS)

    Bryant, R. G.; Effinger, R. T., IV; Copeland, B. M., Jr.

    2002-01-01

    A series of active piezoelectric diaphragms were fabricated and patterned with several geometrically defined Inter-Circulating Electrodes "ICE" and Interdigitated Ring Electrodes "ICE". When a voltage potential is applied to the electrodes, the result is a radially distributed electric field that mechanically strains the piezoceramic along the Z-axis (perpendicular to the applied electric field). Unlike other piezoelectric bender actuators, these Radial Field Diaphragms (RFDs) strain concentrically yet afford high displacements (several times that of the equivalent Unimorph) while maintaining a constant circumference. One of the more intriguing aspects is that the radial strain field reverses itself along the radius of the RFD while the tangential strain remains relatively constant. The result is a Z-deflection that has a conical profile. This paper covers the fabrication and characterization of the 5 cm. (2 in.) diaphragms as a function of poling field strength, ceramic thickness, electrode type and line spacing, as well as the surface topography, the resulting strain field and displacement as a function of applied voltage at low frequencies. The unique features of these RFDs include the ability to be clamped about their perimeter with little or no change in displacement, the environmentally insulated packaging, and a highly repeatable fabrication process that uses commodity materials.

  13. Distillation under electric fields

    SciTech Connect

    Shah, V.M.; Blankenship, K.D.; Tsouris, C.

    1997-11-01

    Distillation Is the most common separation process used in the chemical and petroleum industry. Major limitations in the applicability and efficiency of distillation come from thermodynamic equilibria, that is, vapor-liquid equilibria (VLE), and heat and mass transfer rates. In this work, electric fields are used to manipulate the VLE of mixtures. VLE experiments are performed for various binary mixtures in the presence of electric fields on the order of a few kilovolts per centimeter. The results show that the VLE is changed by electric fields, with changes in the separation factor as high as 10% being observed. Batch distillation experiments are also carried out for binary mixtures of 2-propanol and water with and without an applied electric field. Results show enhanced distillation rates and separation efficiency in the presence of an electric field but decreased separation enhancement when the electric current is increased. The latter phenomenon is caused by the formation at the surface of the liquid mixture of microdroplets that are entrained by the vapor. These observations suggest that there should be an electric field strength for each system for which the separation enhancement is maximum.

  14. The Gorgon gas field

    SciTech Connect

    Clegg, L.J.; Sayers, M.J.; Tait, A.M. )

    1990-09-01

    The Gorgon gas field was discovered by West Australian Petroleum Pty Limited (WAPET) in 1980 with the 1 Gorgon well, and appraised by 1 North Gorgon in 1982 and 1 Central Gorgon in 1983. The gas field is situated on the North West Shelf of Western Australia, 65 km northwest of WAPET's Barrow Island oil field, itself 65 km offshore. The Gorgon gas field is at the southwestern end of the Rankin Platform, which contains several giant gas fields. Water depth at the Gorgon gas field is around 250 m. The top of the Triassic Mungaroo Formation reservoir sequence is at approximately 3,500 m subsea. Individual meander-belt sandstones are up to 50 m thick and occur either interbedded with interchannel claystones or stacked to form sand bodies up to 220 m thick. The Triassic sediments form a tilted horst sealed by Cretaceous Barrow Group shales. Gross gas columns and net gas pays in the 1 Gorgon, 1 Central Gorgon, and 1 North Gorgon wells are 409 and 106 m, 441 and 45 m, and 761 and 136 m, respectively. The field is 5 km wide and at least 30 km long. Gas reserves are estimated at 232 {times} 10{sup 9} m{sup 3}, of which around 17% is carbon dioxide and nitrogen. The reservoir sandstones have porosities of 15 to 20% and permeabilities from tens to thousands of millidarcys. Individual zones have flowed gas at rates of up to 1.06 million m{sup 3}/day through a 31.75 mm choke.

  15. Field error lottery

    SciTech Connect

    Elliott, C.J.; McVey, B. ); Quimby, D.C. )

    1990-01-01

    The level of field errors in an FEL is an important determinant of its performance. We have computed 3D performance of a large laser subsystem subjected to field errors of various types. These calculations have been guided by simple models such as SWOOP. The technique of choice is utilization of the FELEX free electron laser code that now possesses extensive engineering capabilities. Modeling includes the ability to establish tolerances of various types: fast and slow scale field bowing, field error level, beam position monitor error level, gap errors, defocusing errors, energy slew, displacement and pointing errors. Many effects of these errors on relative gain and relative power extraction are displayed and are the essential elements of determining an error budget. The random errors also depend on the particular random number seed used in the calculation. The simultaneous display of the performance versus error level of cases with multiple seeds illustrates the variations attributable to stochasticity of this model. All these errors are evaluated numerically for comprehensive engineering of the system. In particular, gap errors are found to place requirements beyond mechanical tolerances of {plus minus}25{mu}m, and amelioration of these may occur by a procedure utilizing direct measurement of the magnetic fields at assembly time. 4 refs., 12 figs.

  16. Spiking the Geomagnetic Field

    NASA Astrophysics Data System (ADS)

    Constable, C.; Davies, C. J.

    2015-12-01

    Geomagnetic field intensities corresponding to virtual axial dipole moments of up to 200 ZAm2, more than twice the modern value, have been inferred from archeomagnetic measurements on artifacts dated at or shortly after 1000 BC. Anomalously high values occur in the Levant and Georgia, but not in Bulgaria. The origin of this spike is believed to lie in Earth's core: however, its spatio-temporal characteristics and the geomagnetic processes responsible for such a feature remain a mystery. We show that a localized spike in the radial magnetic field at the core-mantle boundary (CMB) must necessarily contribute to the largest scale changes in Earth's surface field, namely the dipole. Even the limiting spike of a delta function at the CMB produces a minimum surface cap size of 60 degrees for a factor of two increase in paleointensity. Combined evidence from modern satellite and millennial scale field modeling suggests that the Levantine Spike is intimately associated with a strong increase in dipole moment prior to 1000 BC and likely the product of north-westward motion of concentrated near equatorial Asian flux patches like those seen in the modern field. New archeomagnetic studies are needed to confirm this interpretation. Minimum estimates of the power dissipated by the spike are comparable to independent estimates of the dissipation associated with the entire steady state geodynamo. This suggests that geomagnetic spikes are either associated with rapid changes in magnetic energy or strong Lorentz forces.

  17. Frontier Field RXCJ2248

    NASA Astrophysics Data System (ADS)

    Soifer, Tom; Capak, Peter

    2014-08-01

    After considering valuable advice from the astronomical community and broad range of open questions in galaxy evolution an advisory committee unanimously recommended HST undertake a program of six deep fields centered on strong lensing galaxy clusters in p arallel with six deep "blank fields". The key science goals of these twelve new frontier fields are: 1) to reveal hitherto inaccessible populations of z = 5 - 10 galaxies that are 10 - 50 times fainter intrinsically than any presently known. 2) to solidify our understanding of the stellar masses and star formation histories of sub-L* galaxies at the earliest times 3) to provide the first statistically meaningful morphological characterization of star forming galaxies at z > 5 4) to find z > 8 galaxies stretched out enough by cluster lensing to discern internal structure and/or magnified enough by cluster lensing for spectroscopic follow-up. Spitzer data are essential to meeting these goals because it enables mass and physical parameter estimates for the high redshift sources and differentiates between low and high redshift galaxies. As a result Spitzer has committed to observing these fields as a major DDT program. The first 4 galaxies clusters and the first 4 deep "blank fields" will be observed by Spitzer over cycles 9 and 10.

  18. Frontier Field Abell 370

    NASA Astrophysics Data System (ADS)

    Soifer, Tom; Capak, Peter

    2014-08-01

    After considering valuable advice from the astronomical community and broad range of open questions in galaxy evolution an advisory committee unanimously recommended HST undertake a program of six deep fields centered on strong lensing galaxy clusters in p arallel with six deep blank fields". The key science goals of these twelve new frontier fields are: 1) to reveal hitherto inaccessible populations of z = 5 - 10 galaxies thatare 10 - 50 times fainter intrinsically than any presently known. 2) to solidify our understanding of the stellar masses and star formation histories of sub-L* galaxies at the earliest times 3) to provide the first statistically meaningful morphological characterization of star forming galaxies at z > 5 4) to find z > 8 galaxies stretched out enough by cluster lensing to discern internal structure and/or magnified enough by cluster lensing for spectroscopic follow-up. Spitzer data are essential to meeting these goals because it enables mass and physical parameter estimates for the high redshift sources and differentiates between low and high redshift galaxies. As a result Spitzer has committed to observing these fields as a major DDT program. The first 4 galaxies clusters and the first 4 deep "blank fields" will be observed by Spitzer over cycles 9 and 10.

  19. Field reversed ion rings

    SciTech Connect

    Sudan, R.N.; Omelchenko, Y.A.

    1995-09-01

    In typical field-reversed ion ring experiments, an intense annular ion beam is injected across a plasma-filled magnetic cusp region into a neutral gas immersed in a ramped solenoidal magnetic field. Assuming the characteristic ionization time is much shorter than the long ({ital t}{approx_gt}2{pi}/{Omega}{sub {ital i}}) beam evolution time scale, we investigate the formation of an ion ring in the background plasma followed by field reversal, using a 21/2-D hybrid, PIC code FIRE, in which the beam and background ions are treated as particles and the electrons as a massless fluid. We show that beam bunching and trapping occurs downstream in a ramped magnetic field for an appropriate set of experimental parameters. We find that a compact ion ring is formed and a large field reversal {zeta}={delta}{ital B}/{ital B}{approx_gt}1 on axis develops. We also observe significant deceleration of the ring on reflection due to the transfer of its axial momentum to the background ions, which creates favorable trapping conditions. {copyright} {ital 1995 American Institute of Physics.}

  20. Coronal Magnetic Field Models

    NASA Astrophysics Data System (ADS)

    Wiegelmann, Thomas; Petrie, Gordon J. D.; Riley, Pete

    2015-07-01

    Coronal magnetic field models use photospheric field measurements as boundary condition to model the solar corona. We review in this paper the most common model assumptions, starting from MHD-models, magnetohydrostatics, force-free and finally potential field models. Each model in this list is somewhat less complex than the previous one and makes more restrictive assumptions by neglecting physical effects. The magnetohydrostatic approach neglects time-dependent phenomena and plasma flows, the force-free approach neglects additionally the gradient of the plasma pressure and the gravity force. This leads to the assumption of a vanishing Lorentz force and electric currents are parallel (or anti-parallel) to the magnetic field lines. Finally, the potential field approach neglects also these currents. We outline the main assumptions, benefits and limitations of these models both from a theoretical (how realistic are the models?) and a practical viewpoint (which computer resources to we need?). Finally we address the important problem of noisy and inconsistent photospheric boundary conditions and the possibility of using chromospheric and coronal observations to improve the models.

  1. Cubesat Gravity Field Mission

    NASA Astrophysics Data System (ADS)

    Burla, Santoshkumar; Mueller, Vitali; Flury, Jakob; Jovanovic, Nemanja

    2016-04-01

    CHAMP, GRACE and GOCE missions have been successful in the field of satellite geodesy (especially to improve Earth's gravity field models) and have established the necessity towards the next generation gravity field missions. Especially, GRACE has shown its capabilities beyond any other gravity field missions. GRACE Follow-On mission is going to continue GRACE's legacy which is almost identical to GRACE mission with addition of laser interferometry. But these missions are not only quite expensive but also takes quite an effort to plan and to execute. Still there are few drawbacks such as under-sampling and incapability of exploring new ideas within a single mission (ex: to perform different orbit configurations with multi satellite mission(s) at different altitudes). The budget is the major limiting factor to build multi satellite mission(s). Here, we offer a solution to overcome these drawbacks using cubesat/ nanosatellite mission. Cubesats are widely used in research because they are cheaper, smaller in size and building them is easy and faster than bigger satellites. Here, we design a 3D model of GRACE like mission with available sensors and explain how the Attitude and Orbit Control System (AOCS) works. The expected accuracies on final results of gravity field are also explained here.

  2. Canonical field theory

    NASA Astrophysics Data System (ADS)

    You, Setthivoine

    2015-11-01

    A new canonical field theory has been developed to help interpret the interaction between plasma flows and magnetic fields. The theory augments the Lagrangian of general dynamical systems to rigourously demonstrate that canonical helicity transport is valid across single particle, kinetic and fluid regimes, on scales ranging from classical to general relativistic. The Lagrangian is augmented with two extra terms that represent the interaction between the motion of matter and electromagnetic fields. The dynamical equations can then be re-formulated as a canonical form of Maxwell's equations or a canonical form of Ohm's law valid across all non-quantum regimes. The field theory rigourously shows that helicity can be preserved in kinetic regimes and not only fluid regimes, that helicity transfer between species governs the formation of flows or magnetic fields, and that helicity changes little compared to total energy only if density gradients are shallow. The theory suggests a possible interpretation of particle energization partitioning during magnetic reconnection as canonical wave interactions. This work is supported by US DOE Grant DE-SC0010340.

  3. Pulsed hybrid field emitter

    DOEpatents

    Sampayan, Stephen E.

    1998-01-01

    A hybrid emitter exploits the electric field created by a rapidly depoled ferroelectric material. Combining the emission properties of a planar thin film diamond emitter with a ferroelectric alleviates the present technological problems associated with both types of emitters and provides a robust, extremely long life, high current density cathode of the type required by emerging microwave power generation, accelerator technology and display applications. This new hybrid emitter is easy to fabricate and not susceptible to the same failures which plague microstructure field emitter technology. Local electrode geometries and electric field are determined independently from those for optimum transport and brightness preservation. Due to the large amount of surface charge created on the ferroelectric, the emitted electrons have significant energy, thus eliminating the requirement for specialized phosphors in emissive flat-panel displays.

  4. Pulsed hybrid field emitter

    DOEpatents

    Sampayan, S.E.

    1998-03-03

    A hybrid emitter exploits the electric field created by a rapidly depoled ferroelectric material. Combining the emission properties of a planar thin film diamond emitter with a ferroelectric alleviates the present technological problems associated with both types of emitters and provides a robust, extremely long life, high current density cathode of the type required by emerging microwave power generation, accelerator technology and display applications. This new hybrid emitter is easy to fabricate and not susceptible to the same failures which plague microstructure field emitter technology. Local electrode geometries and electric field are determined independently from those for optimum transport and brightness preservation. Due to the large amount of surface charge created on the ferroelectric, the emitted electrons have significant energy, thus eliminating the requirement for specialized phosphors in emissive flat-panel displays. 11 figs.

  5. Carbohydrate force fields

    PubMed Central

    Foley, B. Lachele; Tessier, Matthew B.; Woods, Robert J.

    2014-01-01

    Carbohydrates present a special set of challenges to the generation of force fields. First, the tertiary structures of monosaccharides are complex merely by virtue of their exceptionally high number of chiral centers. In addition, their electronic characteristics lead to molecular geometries and electrostatic landscapes that can be challenging to predict and model. The monosaccharide units can also interconnect in many ways, resulting in a large number of possible oligosaccharides and polysaccharides, both linear and branched. These larger structures contain a number of rotatable bonds, meaning they potentially sample an enormous conformational space. This article briefly reviews the history of carbohydrate force fields, examining and comparing their challenges, forms, philosophies, and development strategies. Then it presents a survey of recent uses of these force fields, noting trends, strengths, deficiencies, and possible directions for future expansion. PMID:25530813

  6. Orsted Initial Field Model

    NASA Technical Reports Server (NTRS)

    Olsen, N.; Holme, R.; Hulot, G.; Sabaka, T.; Neubert, T.; Toffner-Clausen, L.; Primdahl, F.; Jorgensen, J.; Leger, J.-M.; Barraclough, D.; Smith, David E. (Technical Monitor)

    2000-01-01

    Magnetic measurements taken by the Orsted satellite during geomagnetic quiet conditions around January 1, 2000 have been used to derive a spherical harmonic model of the Earth's magnetic field for epoch 2000.0. The maximum degree and order of the model is 19 for internal, and 2 for external, source fields; however, coefficients above degree 14 may not be robust. Such detailed models exist for only one previous epoch, 1980. Achieved rms misfit is 2 nT for the scalar intensity and 4 nT for the vector components perpendicular to the magnetic field. This model is of higher detail than the IGRF 2000, which for scientific purposes related to the Orsted mission it supersedes.

  7. Electric and magnetic fields

    NASA Technical Reports Server (NTRS)

    Kaufman, H. R.; Robinson, R. S.; Etters, R. D.

    1982-01-01

    A number of energy momentum anomalies are described that result from the use of Abraham-Lorentz electromagnetic theory. These anomalies have in common the motion of charged bodies or current carrying conductors relative to the observer. The anomalies can be avoided by using the nonflow approach, based on internal energy of the electromagnetic field. The anomalies can also be avoided by using the flow approach, if all contributions to flow work are included. The general objective of this research is a fundamental physical understanding of electric and magnetic fields which, in turn, might promote the development of new concepts in electric space propulsion. The approach taken is to investigate quantum representations of these fields.

  8. Microbial field pilot study

    SciTech Connect

    Knapp, R.M.; McInerney, M.J.; Menzie, D.E.; Coates, J.D.; Chisholm, J.L.

    1993-05-01

    A multi-well microbially enhanced oil recovery field pilot has been performed in the Southeast Vassar Vertz Sand Unit in Payne County, Oklahoma. The primary emphasis of the experiment was preferential plugging of high permeability zones for the purpose of improving waterflood sweep efficiency. Studies were performed to determine reservoir chemistry, ecology, and indigenous bacteria populations. Growth experiments were used to select a nutrient system compatible with the reservoir that encouraged growth of a group of indigenous nitrate-using bacteria and inhibit growth of sulfate-reducing bacteria. A specific field pilot area behind an active line drive waterflood was selected. Surface facilities were designed and installed. Injection protocols of bulk nutrient materials were prepared to facilitate uniform distribution of nutrients within the pilot area. By the end of December, 1991, 82.5 tons (75.0 tonnes) of nutrients had been injected in the field. A tracer test identified significant heterogeneity in the SEVVSU and made it necessary to monitor additional production wells in the field. The tracer tests and changes in production behavior indicate the additional production wells monitored during the field trial were also affected. Eighty two and one half barrels (13.1 m[sup 3]) of tertiary oil have been recovered. Microbial activity has increased CO[sub 2] content as indicated by increased alkalinity. A temporary rise in sulfide concentration was experienced. These indicate an active microbial community was generated in the field by the nutrient injection. Pilot area interwell pressure interference test results showed that significant permeability reduction occurred. The interwell permeabilities in the pilot area between the injector and the three pilot production wells were made more uniform which indicates a successful preferential plugging enhanced oil recovery project.

  9. LSA field test

    NASA Technical Reports Server (NTRS)

    Jaffe, P.

    1979-01-01

    Degradation tests indicate that electrical degradation is not a slow monotonically increasing phenomenon as originally thought but occurs abruptly as the result of some traumatic event. This finding has led to a change in the test philosophy. A discussion of this change is presented along with a summary of degradation and failure data from all the sites and results from a variety of special tests. New instrumentation for in-field measurements are described. Field testing activity was expanded by the addition of twelve remote sites located as far away as Alaska and the Canal Zone. Descriptions of the new sites are included.

  10. Octonic Gravitational Field Equations

    NASA Astrophysics Data System (ADS)

    Demir, Süleyman; Tanişli, Murat; Tolan, Tülay

    2013-08-01

    Generalized field equations of linear gravity are formulated on the basis of octons. When compared to the other eight-component noncommutative hypercomplex number systems, it is demonstrated that associative octons with scalar, pseudoscalar, pseudovector and vector values present a convenient and capable tool to describe the Maxwell-Proca-like field equations of gravitoelectromagnetism in a compact and simple way. Introducing massive graviton and gravitomagnetic monopole terms, the generalized gravitational wave equation and Klein-Gordon equation for linear gravity are also developed.

  11. Field of Dreams.

    ERIC Educational Resources Information Center

    Webb, Richard

    2003-01-01

    When planning summer work, school athletic facility managers must address the maintenance and renovation of natural grass and synthetic fields, tennis courts, and running tracks. This article presents a guide to the simple, effective, and relatively inexpensive summer maintenance of athletic facilities in order to help extend the life of a schools…

  12. Lessons from the Field

    ERIC Educational Resources Information Center

    Billett, Paulina

    2012-01-01

    Social capital is an exciting and growing field in academic circles. However, its research has often been criticised by youth theorists for its lack of relevance to youth life and experience--the portrayal of young people as consumers rather than producers of social capital--and a failure to acknowledge the complexity of youth life. Many of these…

  13. Managing Field Evacuations.

    ERIC Educational Resources Information Center

    Satz, Jay A.; McEvoy, David; Merrill, Kurt

    In the event of a debilitating injury or illness, outdoor leaders should consider four critical phases in successfully managing backcountry field evaluations. The first phase, managing the immediate scene, involves assuring scene safety, medical care of the patient, instituting the emergency response plan, and providing for the needs of uninjured…

  14. Assessment of Field Placement.

    ERIC Educational Resources Information Center

    Marshood, Nabil

    While field placement in human services programs is an extremely important practical phase of training, it has generally not been standardized, and thus can be difficult to assess. A model program and assessment format developed by Hudson County Community College (HCCC), in Jersey City, New Jersey, however, provides a possible framework for…

  15. Warp Field Mechanics 101

    NASA Astrophysics Data System (ADS)

    White, H.

    This paper will begin with a short review of the Alcubierre warp drive metric and describes how the phenomenon might work based on the original paper. The canonical form of the metric was developed and published in [6] which provided key insight into the field potential and boost for the field which remedied a critical paradox in the original Alcubierre concept of operations. A modified concept of operations based on the canonical form of the metric that remedies the paradox is presented and discussed. The idea of a warp drive in higher dimensional space-time (manifold) will then be briefly considered by comparing the null-like geodesics of the Alcubierre metric to the Chung-Freese metric to illustrate the mathematical role of hyperspace coordinates. The net effect of using a warp drive "technology" coupled with conventional propulsion systems on an exploration mission will be discussed using the nomenclature of early mission planning. Finally, an overview of the warp field interferometer test bed being implemented in the Advanced Propulsion Physics Laboratory: Eagleworks (APPL:E) at the Johnson Space Center will be detailed. While warp field mechanics has not had a "Chicago Pile" moment, the tools necessary to detect a modest instance of the phenomenon are near at hand.

  16. [Field Learning Activities].

    ERIC Educational Resources Information Center

    Nolde Forest Environmental Education Center, Reading, PA.

    Seventy field activities, pertinent to outdoor, environmental studies, are described in this compilation. Designed for elementary and junior high school students, the activities cover many discipline areas--science, social studies, language arts, health, history, mathematics, and art--and many are multidisciplinary in use. Topics range from soil…

  17. Quantum field tomography

    NASA Astrophysics Data System (ADS)

    Steffens, A.; Riofrío, C. A.; Hübener, R.; Eisert, J.

    2014-12-01

    We introduce the concept of quantum field tomography, the efficient and reliable reconstruction of unknown quantum fields based on data of correlation functions. At the basis of the analysis is the concept of continuous matrix product states (cMPS), a complete set of variational states grasping states in one-dimensional quantum field theory. We innovate a practical method, making use of and developing tools in estimation theory used in the context of compressed sensing such as Prony methods and matrix pencils, allowing us to faithfully reconstruct quantum field states based on low-order correlation functions. In the absence of a phase reference, we highlight how specific higher order correlation functions can still be predicted. We exemplify the functioning of the approach by reconstructing randomized cMPS from their correlation data and study the robustness of the reconstruction for different noise models. Furthermore, we apply the method to data generated by simulations based on cMPS and using the time-dependent variational principle. The presented approach is expected to open up a new window into experimentally studying continuous quantum systems, such as those encountered in experiments with ultra-cold atoms on top of atom chips. By virtue of the analogy with the input-output formalism in quantum optics, it also allows for studying open quantum systems.

  18. Field-Flow Fractionation.

    ERIC Educational Resources Information Center

    Caldwell, Karin D.

    1988-01-01

    Describes a technique for separating samples that range over 15 orders of magnitude in molecular weight. Discusses theory, apparatus, and sample preparation techniques. Lists several types of field-flow fractionation (FFF) and their uses: sedimentation FFF, thermal FFF, flow FFF, electrical FFF, and steric FFF. (ML)

  19. Virtual Field Trips.

    ERIC Educational Resources Information Center

    Walter, Virginia A.

    1997-01-01

    Virtual field trips can provide experiences beyond the reach of average K-12 students. Describes multimedia products for school use: Africa Trail, Dinosaur Hunter, Louvre Museum, Magic School Bus Explores the Rainforest, and Up to the Himalayas: Kingdoms in the Clouds and provides book and Internet connections for additional learning, highlighting…

  20. Extended conformal field theories

    NASA Astrophysics Data System (ADS)

    Taormina, Anne

    1990-08-01

    Some extended conformal field theories are briefly reviewed. They illustrate how non minimal models of the Virasoro algebra (c≥1) can become minimal with respect to a larger algebra. The accent is put on N-extended superconformal algebras, which are relevant in superstring compactification.

  1. Warp Field Mechanics 101

    NASA Technical Reports Server (NTRS)

    White, Harold

    2011-01-01

    This paper will begin with a short review of the Alcubierre warp drive metric and describes how the phenomenon might work based on the original paper. The canonical form of the metric was developed and published in [6] which provided key insight into the field potential and boost for the field which remedied a critical paradox in the original Alcubierre concept of operations. A modified concept of operations based on the canonical form of the metric that remedies the paradox is presented and discussed. The idea of a warp drive in higher dimensional space-time (manifold) will then be briefly considered by comparing the null-like geodesics of the Alcubierre metric to the Chung-Freese metric to illustrate the mathematical role of hyperspace coordinates. The net effect of using a warp drive technology coupled with conventional propulsion systems on an exploration mission will be discussed using the nomenclature of early mission planning. Finally, an overview of the warp field interferometer test bed being implemented in the Advanced Propulsion Physics Laboratory: Eagleworks (APPL:E) at the Johnson Space Center will be detailed. While warp field mechanics has not had a Chicago Pile moment, the tools necessary to detect a modest instance of the phenomenon are near at hand.

  2. Magnetic fields at neptune.

    PubMed

    Ness, N F; Acuña, M H; Burlaga, L F; Connerney, J E; Lepping, R P; Neubauer, F M

    1989-12-15

    The National Aeronautics and Space Administration Goddard Space Flight Center-University of Delaware Bartol Research Institute magnetic field experiment on the Voyager 2 spacecraft discovered a strong and complex intrinsic magnetic field of Neptune and an associated magnetosphere and magnetic tail. The detached bow shock wave in the supersonic solar wind flow was detected upstream at 34.9 Neptune radii (R(N)), and the magnetopause boundary was tentatively identified at 26.5 R(N) near the planet-sun line (1 R(N) = 24,765 kilometers). A maximum magnetic field of nearly 10,000 nanoteslas (1 nanotesla = 10(-5) gauss) was observed near closest approach, at a distance of 1.18 R(N). The planetary magnetic field between 4 and 15 R(N) can be well represented by an offset tilted magnetic dipole (OTD), displaced from the center of Neptune by the surprisingly large amount of 0.55 R(N) and inclined by 47 degrees with respect to the rotation axis. The OTD dipole moment is 0.133 gauss-R(N)(3). Within 4 R(N), the magnetic field representation must include localized sources or higher order magnetic multipoles, or both, which are not yet well determined. The obliquity of Neptune and the phase of its rotation at encounter combined serendipitously so that the spacecraft entered the magnetosphere at a time when the polar cusp region was directed almost precisely sunward. As the spacecraft exited the magnetosphere, the magnetic tail appeared to be monopolar, and no crossings of an imbedded magnetic field reversal or plasma neutral sheet were observed. The auroral zones are most likely located far from the rotation poles and may have a complicated geometry. The rings and all the known moons of Neptune are imbedded deep inside the magnetosphere, except for Nereid, which is outside when sunward of the planet. The radiation belts will have a complex structure owing to the absorption of energetic particles by the moons and rings of Neptune and losses associated with the significant changes

  3. Magnetic fields in spiral galaxies

    NASA Astrophysics Data System (ADS)

    Chiba, Masashi

    The magnetic-field characteristics in spiral galaxies are investigated, with emphasis on the Milky Way. The dynamo theory is considered, and axisymmetric spiral (ASS) and bisymmetric spiral (BSS) magnetic fields are analyzed. Toroidal and poloidal magnetic fields are discussed.

  4. Holden Crater Dune Field

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Our topic for the weeks of April 4 and April 11 is dunes on Mars. We will look at the north polar sand sea and at isolated dune fields at lower latitudes. Sand seas on Earth are often called 'ergs,' an Arabic name for dune field. A sand sea differs from a dune field in two ways: 1) a sand sea has a large regional extent, and 2) the individual dunes are large in size and complex in form.

    A common location for dune fields on Mars is in the basin of large craters. This dune field is located in Holden Crater at 25 degrees South atitude.

    Image information: VIS instrument. Latitude -25.5, Longitude 326.8 East (33.2 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  5. NPOESS Field Terminal Updates

    NASA Astrophysics Data System (ADS)

    Heckmann, G.; Route, G.

    2009-12-01

    The National Oceanic and Atmospheric Administration (NOAA), Department of Defense (DoD), and National Aeronautics and Space Administration (NASA) are jointly acquiring the next-generation weather and environmental satellite system; the National Polar-orbiting Operational Environmental Satellite System (NPOESS). NPOESS replaces the current Polar-orbiting Operational Environmental Satellites (POES) managed by NOAA and the Defense Meteorological Satellite Program (DMSP) managed by the DoD. The NPOESS satellites carry a suite of sensors that collect meteorological, oceanographic, climatological, and solar-geophysical observations of the earth, atmosphere, and space. The ground data processing segment for NPOESS is the Interface Data Processing Segment (IDPS), developed by Raytheon Intelligence and Information Systems. The IDPS processes NPOESS satellite data to provide environmental data products (aka, Environmental Data Records or EDRs) to NOAA and DoD processing centers operated by the United States government. The IDPS will process EDRs beginning with the NPOESS Preparatory Project (NPP) and continuing through the lifetime of the NPOESS system. IDPS also provides the software and requirements for the Field Terminal Segment (FTS). NPOESS provides support to deployed field terminals by providing mission data in the Low Rate and High Rate downlinks (LRD/HRD), mission support data needed to generate EDRs and decryption keys needed to decrypt mission data during Selective data Encryption (SDE). Mission support data consists of globally relevant data, geographically constrained data, and two line element sets. NPOESS provides these mission support data via the Internet accessible Mission Support Data Server and HRD/LRD downlinks. This presentation will illustrate and describe the NPOESS capabilities in support of Field Terminal users. This discussion will include the mission support data available to Field Terminal users, content of the direct broadcast HRD and LRD

  6. Methane Hydrate Field Program

    SciTech Connect

    2013-12-31

    This final report document summarizes the activities undertaken and the output from three primary deliverables generated during this project. This fifteen month effort comprised numerous key steps including the creation of an international methane hydrate science team, determining and reporting the current state of marine methane hydrate research, convening an international workshop to collect the ideas needed to write a comprehensive Marine Methane Hydrate Field Research Plan and the development and publication of that plan. The following documents represent the primary deliverables of this project and are discussed in summary level detail in this final report. • Historical Methane Hydrate Project Review Report • Methane Hydrate Workshop Report • Topical Report: Marine Methane Hydrate Field Research Plan • Final Scientific/Technical Report

  7. Field site selection

    NASA Technical Reports Server (NTRS)

    Schwarz, D. E.; Ellefsen, R. E.

    1981-01-01

    Several general guidelines should be kept in mind when considering the selection of field sites for teaching remote sensing fundamentals. Proximity and vantage point are two very practical considerations. Only through viewing a broad enough area to place the site in context can one make efficient use of a site. The effects of inclement weather when selecting sites should be considered. If field work is to be an effective tool to illustrate remote sensing principles, the following criteria are critical: (1) the site must represent the range of class interest; (2) the site must have a theme or add something no other site offers; (3) there should be intrasite variation within the theme; (4) ground resolution and spectral signature distinction should be illustrated; and (5) the sites should not be ordered sequentially.

  8. Segmented field OFFGEL® electrophoresis.

    PubMed

    Tobolkina, Elena; Cortés-Salazar, Fernando; Momotenko, Dmitry; Maillard, Julien; Girault, Hubert H

    2012-11-01

    A multielectrode setup for protein OFFGEL electrophoresis that significantly improves protein separation efficiency has been developed. Here, the electric field is applied by segments between seven electrodes connected in series to six independent power supplies. The aim of this strategy is to distribute evenly the electric field along the multiwell system, and as a consequence to enhance electrophoresis in terms of separation time, resolution, and protein collection efficiency, while minimizing the overall potential difference and therefore the Joule heating. The performances were compared to a standard two-electrode setup for OFFGEL fractionation of a protein mixture, using UV-Vis spectroscopy for quantification and MALDI-MS for identification. The electrophoretic separation process was simulated, and optimized by solving the time-dependent Nernst-Planck differential equation. PMID:23086720

  9. Graphene field emission devices

    SciTech Connect

    Kumar, S. Raghavan, S.; Duesberg, G. S.; Pratap, R.

    2014-09-08

    Graphene field emission devices are fabricated using a scalable process. The field enhancement factors, determined from the Fowler-Nordheim plots, are within few hundreds and match the theoretical predictions. The devices show high emission current density of ∼10 nA μm{sup −1} at modest voltages of tens of volts. The emission is stable with time and repeatable over long term, whereas the noise in the emission current is comparable to that from individual carbon nanotubes emitting under similar conditions. We demonstrate a power law dependence of emission current on pressure which can be utilized for sensing. The excellent characteristics and relative ease of making the devices promise their great potential for sensing and electronic applications.

  10. The interplanetary magnetic field

    NASA Technical Reports Server (NTRS)

    Davis, L., Jr.

    1972-01-01

    Large-scale properties of the interplanetary magnetic field as determined by the solar wind velocity structure are examined. The various ways in which magnetic fields affect phenomena in the solar wind are summarized. The dominant role of high and low velocity solar wind streams that persist, with fluctuations and evolution, for weeks or months is emphasized. It is suggested that for most purposes the sector structure is better identified with the stream structure than with the magnetic polarity and that the polarity does not necessarily change from one velocity sector to the next. Several mechanisms that might produce the stream structure are considered. The interaction of the high and low velocity streams is analyzed in a model that is steady state when viewed in a frame that corotates with the sun.

  11. Classical higgs fields

    NASA Astrophysics Data System (ADS)

    Sardanashvily, G. A.

    2014-12-01

    We consider a classical gauge theory on a principal fiber bundle P → X in the case where its structure group G is reduced to a subgroup H in the presence of classical Higgs fields described by global sections of the quotient fiber bundle P/H → X. We show that matter fields with the exact symmetry group H in such a theory are described by sections of the composition fiber bundle Y → P/H → X, where Y → P/H is the fiber bundle with the structure group H, and the Lagrangian of these sections is factored by virtue of the vertical covariant differential determined by a connection on the fiber bundle Y → P/H.

  12. Bigfoot Field Manual

    NASA Astrophysics Data System (ADS)

    Campbell, J. L.; Burrows, S.; Gower, S. T.; Cohen, W. B.

    1999-09-01

    The BigFoot Project is funded by the Earth Science Enterprise to collect and organize data to be used in the EOS Validation Program. The data collected by the BigFoot Project are unique in being ground-based observations coincident with satellite overpasses. In addition to collecting data, the BigFoot project will develop and test new algorithms for scaling point measurements to the same spatial scales as the EOS satellite products. This BigFoot Field Manual Mill be used to achieve completeness and consistency of data collected at four initial BigFoot sites and at future sites that may collect similar validation data. Therefore, validation datasets submitted to the ORNL DAAC that have been compiled in a manner consistent with the field manual will be especially valuable in the validation program.

  13. Microbial Field Pilot Study

    SciTech Connect

    Knapp, R.M.; McInerney, M.J.; Menzie, D.E.; Chisholm, J.L.

    1990-11-01

    This report covers progress made during the first year of the Microbial Field Pilot Study project. Information on reservoir ecology and characterization, facility and treatment design, core experiments, bacterial mobility, and mathematical modeling are addressed. To facilitate an understanding of the ecology of the target reservoir analyses of the fluids which support bacteriological growth and the microbiology of the reservoir were performed. A preliminary design of facilities for the operation of the field pilot test was prepared. In addition, procedures for facilities installation and for injection treatments are described. The Southeast Vassar Vertz Sand Unit (SEVVSU), the site of the proposed field pilot study, is described physically, historically, and geologically. The fields current status is presented and the ongoing reservoir simulation is discussed. Core flood experiments conducted during the last year were used to help define possible mechanisms involved in microbial enhanced oil recovery. Two possible mechanisms, relative permeability effects and changes in the capillary number, are discussed and related to four Berea core experiments' results. The experiments were conducted at reservoir temperature using SEVVSU oil, brine, and bacteria. The movement and activity of bacteria in porous media were investigated by monitoring the growth of bacteria in sandpack cores under no flow conditions. The rate of bacteria advancement through the cores was determined. A mathematical model of the MEOR process has been developed. The model is a three phase, seven species, one dimensional model. Finite difference methods are used for solution. Advection terms in balance equations are represented with a third- order upwind differencing scheme to reduce numerical dispersion and oscillations. The model is applied to a batch fermentation example. 52 refs., 26 figs., 21 tabs.

  14. Conformal scalar field wormholes

    NASA Technical Reports Server (NTRS)

    Halliwell, Jonathan J.; Laflamme, Raymond

    1989-01-01

    The Euclidian Einstein equations with a cosmological constant and a conformally coupled scalar field are solved, taking the metric to be of the Robertson-Walker type. In the case Lambda = 0, solutions are found which represent a wormhole connecting two asymptotically flat Euclidian regions. In the case Lambda greater than 0, the solutions represent tunneling from a small Tolman-like universe to a large Robertson-Walker universe.

  15. Phase Field Fracture Mechanics.

    SciTech Connect

    Robertson, Brett Anthony

    2015-11-01

    For this assignment, a newer technique of fracture mechanics using a phase field approach, will be examined and compared with experimental data for a bend test and a tension test. The software being used is Sierra Solid Mechanics, an implicit/explicit finite element code developed at Sandia National Labs in Albuquerque, New Mexico. The bend test experimental data was also obtained at Sandia Labs while the tension test data was found in a report online from Purdue University.

  16. Nili Patera Dune Field

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Our topic for the weeks of April 4 and April 11 is dunes on Mars. We will look at the north polar sand sea and at isolated dune fields at lower latitudes. Sand seas on Earth are often called 'ergs,' an Arabic name for dune field. A sand sea differs from a dune field in two ways: 1) a sand sea has a large regional extent, and 2) the individual dunes are large in size and complex in form.

    This VIS image shows a dune field within Nili Patera, the northern caldera of a large volcanic complex in Syrtis Major.

    Image information: VIS instrument. Latitude 9, Longitude 67 East (293 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  17. Crater Floor Dune Field

    NASA Technical Reports Server (NTRS)

    2005-01-01

    [figure removed for brevity, see original site]

    Our topic for the weeks of April 4 and April 11 is dunes on Mars. We will look at the north polar sand sea and at isolated dune fields at lower latitudes. Sand seas on Earth are often called 'ergs,' an Arabic name for dune field. A sand sea differs from a dune field in two ways: 1) a sand sea has a large regional extent, and 2) the individual dunes are large in size and complex in form.

    Our final dune image shows a small dune field inside an unnamed crater south of Nili Fossae.

    Image information: VIS instrument. Latitude 20.6, Longitude 79 East (281 West). 19 meter/pixel resolution.

    Note: this THEMIS visual image has not been radiometrically nor geometrically calibrated for this preliminary release. An empirical correction has been performed to remove instrumental effects. A linear shift has been applied in the cross-track and down-track direction to approximate spacecraft and planetary motion. Fully calibrated and geometrically projected images will be released through the Planetary Data System in accordance with Project policies at a later time.

    NASA's Jet Propulsion Laboratory manages the 2001 Mars Odyssey mission for NASA's Office of Space Science, Washington, D.C. The Thermal Emission Imaging System (THEMIS) was developed by Arizona State University, Tempe, in collaboration with Raytheon Santa Barbara Remote Sensing. The THEMIS investigation is led by Dr. Philip Christensen at Arizona State University. Lockheed Martin Astronautics, Denver, is the prime contractor for the Odyssey project, and developed and built the orbiter. Mission operations are conducted jointly from Lockheed Martin and from JPL, a division of the California Institute of Technology in Pasadena.

  18. Proca and electromagnetic fields

    SciTech Connect

    Hillion, P.; Quinnerz, S.

    1986-07-01

    In the framework of the proper orthochronous Lorentz group, the old connection is revived between the electromagnetic field characterized by a self-dual tensor and a traceless second-rank spinor obeying the Proca equation. The relationship between this spinor and the Hertz potential also considered as a self-dual tensor is emphasized. The extension of this formalism to meet the covariance under the full Lorentz group is also discussed.

  19. Fields, Flares, And Forecasts

    NASA Astrophysics Data System (ADS)

    Boucheron, L.; Al-Ghraibah, Amani; McAteer, J.; Cao, H.; Jackiewicz, J.; McNamara, B.; Voelz, D.; Calabro, B.; DeGrave, K.; Kirk, M.; Madadi, A.; Petsov, A.; Taylor, G.

    2011-05-01

    Solar active regions are the source of many energetic and geo-effective events such as solar flares and coronal mass ejections (CMEs). Understanding how these complex source regions evolve and produce these events is of fundamental importance, not only to solar physics, but also to the demands of space weather forecasting. We propose to investigate the physical properties of active region magnetic fields using fractal-, gradient-, neutral line-, emerging flux-, wavelet- and general image-based techniques, and to correlate them to solar activity. The combination of these projects with solarmonitor.org and the international Max Millenium Campaign presents an opportunity for accurate and timely flare predictions for the first time. Many studies have attempted to relate solar flares to their concomitant magnetic field distributions. However, a consistent, causal relationship between the magnetic field on the photosphere and the production of solar flares is unknown. Often the local properties of the active region magnetic field - critical in many theories of activity - are lost in the global definition of their diagnostics, in effect smoothing out variations that occur on small spatial scales. Mindful of this, our overall goal is to create measures that are sensitive to both the global and the small-scale nature of energy storage and release in the solar atmosphere in order to study solar flare prediction. This set of active region characteristics will be automatically explored for discriminating features through the use of feature selection methods. Such methods search a feature space while optimizing a criterion - the prediction of a flare in this case. The large size of the datasets used in this project make it well suited for an exploration of a large feature space. This work is funded through a New Mexico State University Interdisciplinary Research Grant.

  20. Heavy rain field measurements

    NASA Technical Reports Server (NTRS)

    Melson, ED

    1991-01-01

    A weight-measuring rain gauge was developed to collect rain data and configured to operate at a high sample rate (one sample pre second). Instead of averaging the rain rate in minutes, hours, and sometime days as normally performed, the rain data collected are examined in seconds. The results of six field sites are compiled. Rain rate levels, duration of downpours, and frequency of heavy rainfall events are presented.

  1. Microbial field pilot study

    SciTech Connect

    Knapp, R.M.; McInerney, M.J.; Menzie, D.E.; Chisholm, J.L.

    1992-03-01

    The objective of this project is to perform a microbial enhanced oil recovery field pilot in the Southeast Vassar Vertz Sand Unit (SEVVSU) in Payne County, Oklahoma. Indigenous, anaerobic, nitrate reducing bacteria will be stimulated to selectively plug flow paths which have been referentially swept by a prior waterflood. This will force future flood water to invade bypassed regions of the reservoir and increase sweep efficiency. This report covers progress made during the second year, January 1, 1990 to December 31, 1990, of the Microbial Field Pilot Study project. Information on reservoir ecology, surface facilities design, operation of the unit, core experiments, modeling of microbial processes, and reservoir characterization and simulation are presented in the report. To better understand the ecology of the target reservoir, additional analyses of the fluids which support bacteriological growth and the microbiology of the reservoir were performed. The results of the produced and injected water analysis show increasing sulfide concentrations with respect to time. In March of 1990 Mesa Limited Partnership sold their interest in the SEVVSU to Sullivan and Company. In April, Sullivan and Company assumed operation of the field. The facilities for the field operation of the pilot were refined and implementation was begun. Core flood experiments conducted during the last year were used to help define possible mechanisms involved in microbial enhanced oil recovery. The experiments were performed at SEVVSU temperature using fluids and inoculum from the unit. The model described in last year's report was further validated using results from a core flood experiment. The model was able to simulate the results of one of the core flood experiments with good quality.

  2. Microbial field pilot study

    SciTech Connect

    Knapp, R.M.; McInerney, M.J.; Menzie, D.E.; Chisholm, J.L.

    1992-03-01

    The objective of this project is to perform a microbial enhanced oil recovery field pilot in the Southeast Vassar Vertz Sand Unit (SEVVSU) in Payne County, Oklahoma. Indigenous, anaerobic, nitrate reducing bacteria will be stimulated to selectively plug flow paths which have been referentially swept by a prior waterflood. This will force future flood water to invade bypassed regions of the reservoir and increase sweep efficiency. This report covers progress made during the second year, January 1, 1990 to December 31, 1990, of the Microbial Field Pilot Study project. Information on reservoir ecology, surface facilities design, operation of the unit, core experiments, modeling of microbial processes, and reservoir characterization and simulation are presented in the report. To better understand the ecology of the target reservoir, additional analyses of the fluids which support bacteriological growth and the microbiology of the reservoir were performed. The results of the produced and injected water analysis show increasing sulfide concentrations with respect to time. In March of 1990 Mesa Limited Partnership sold their interest in the SEVVSU to Sullivan and Company. In April, Sullivan and Company assumed operation of the field. The facilities for the field operation of the pilot were refined and implementation was begun. Core flood experiments conducted during the last year were used to help define possible mechanisms involved in microbial enhanced oil recovery. The experiments were performed at SEVVSU temperature using fluids and inoculum from the unit. The model described in last year`s report was further validated using results from a core flood experiment. The model was able to simulate the results of one of the core flood experiments with good quality.

  3. Mobile Field Goniospectrometry

    NASA Astrophysics Data System (ADS)

    Peltoniemi, J. I.; Kaasalainen, S.; Näränen, J.

    2004-05-01

    Multiangle remote sensing needs multiangle models and multiangle ground reference data. The ground data can be measured using goniometers. Many targets are in difficult terrains and hard to bring into laboratory, which makes the ground data collection more complicated We have developed several field goniometers to measure the directional and spectral reflection signatures of various targets. The heaviest of the instruments is fully manual and very robust for field work. It can be transported using a light trailer and mounted in an hour. The new very light goniometer measures the BRDF automatically in few minutes. It can be carried by two persons even large distances to difficult places. Both of these instruments use the ASD Field Spec PRO FR spectrometer with a 4m light fibre allowing optics to be mounted up and the heavy parts down. The dimensions --- arm length about 2m --- and optics (1--8 degree view angles) limit the useful spot diameter to about 3, 10 or 30cm, making the system useful for small vegetation and soil. These two wide angle goniometers are complemented by a narrow angle backscattering goniometer utilising beamsplitters to measure up to exact backscattering direction and about 15 degree around. We present BRDF and spectra for undergrowth (lichen, moss, peat, twigs) from a field campaign in August 2003, and various grasses dry and wet. We recognise significant differences in the directional pattern between different species (factors of 2-10) and varying structural properties, making the use of directional signal for remote sensing very attractive. We are working with scattering models of snow and soil, and will continue with vegetation soon.

  4. COS NUV Flat Fields

    NASA Astrophysics Data System (ADS)

    Mason, Elena

    2011-10-01

    This program aims at obtaining COS NUV-MAMA flat-field observations for monitoring purpose only.The program uses the internal deuterium lamp and the MR grism G185M {at the central wavelengths 1835, 1850 and 1864 A}, as during thermal vacuum testing and SMOV4. The estimated SNR reached at the end of the program {13 hr integration during 10 orbits} is 20-25 per 3x3 pixel.

  5. Magnetic Field Solver

    NASA Technical Reports Server (NTRS)

    Ilin, Andrew V.

    2006-01-01

    The Magnetic Field Solver computer program calculates the magnetic field generated by a group of collinear, cylindrical axisymmetric electromagnet coils. Given the current flowing in, and the number of turns, axial position, and axial and radial dimensions of each coil, the program calculates matrix coefficients for a finite-difference system of equations that approximates a two-dimensional partial differential equation for the magnetic potential contributed by the coil. The program iteratively solves these finite-difference equations by use of the modified incomplete Cholesky preconditioned-conjugate-gradient method. The total magnetic potential as a function of axial (z) and radial (r) position is then calculated as a sum of the magnetic potentials of the individual coils, using a high-accuracy interpolation scheme. Then the r and z components of the magnetic field as functions of r and z are calculated from the total magnetic potential by use of a high-accuracy finite-difference scheme. Notably, for the finite-difference calculations, the program generates nonuniform two-dimensional computational meshes from nonuniform one-dimensional meshes. Each mesh is generated in such a way as to minimize the numerical error for a benchmark one-dimensional magnetostatic problem.

  6. Warped conformal field theory

    NASA Astrophysics Data System (ADS)

    Detournay, Stéphane; Hartman, Thomas; Hofman, Diego M.

    2012-12-01

    We study field theories in two spacetime dimensions invariant under a chiral scaling symmetry that acts only on right-movers. The local symmetries include one copy of the Virasoro algebra and a U(1) current algebra. This differs from the two-dimensional conformal group but in some respects is equally powerful in constraining the theory. In particular, the symmetries on a torus lead to modular covariance of the partition function, which is used to derive a universal formula for the asymptotic density of states. For an application we turn to the holographic description of black holes in quantum gravity, motivated by the fact that the symmetries in the near-horizon geometry of any extremal black hole are identical to those of a two-dimensional field theory with chiral scaling. We consider two examples: black holes in warped AdS3 in topologically massive gravity and in string theory. In both cases, the density of states in the two-dimensional field theory reproduces the Bekenstein-Hawking entropy of black holes in the gravity theory.

  7. Polymer parametrized field theory

    SciTech Connect

    Laddha, Alok; Varadarajan, Madhavan

    2008-08-15

    Free scalar field theory on 2-dimensional flat spacetime, cast in diffeomorphism invariant guise by treating the inertial coordinates of the spacetime as dynamical variables, is quantized using loop quantum gravity (LQG) type 'polymer' representations for the matter field and the inertial variables. The quantum constraints are solved via group averaging techniques and, analogous to the case of spatial geometry in LQG, the smooth (flat) spacetime geometry is replaced by a discrete quantum structure. An overcomplete set of Dirac observables, consisting of (a) (exponentials of) the standard free scalar field creation-annihilation modes and (b) canonical transformations corresponding to conformal isometries, are represented as operators on the physical Hilbert space. None of these constructions suffer from any of the 'triangulation'-dependent choices which arise in treatments of LQG. In contrast to the standard Fock quantization, the non-Fock nature of the representation ensures that the group of conformal isometries as well as that of the gauge transformations generated by the constraints are represented in an anomaly free manner. Semiclassical states can be analyzed at the gauge invariant level. It is shown that 'physical weaves' necessarily underlie such states and that such states display semiclassicality with respect to, at most, a countable subset of the (uncountably large) set of observables of type (a). The model thus offers a fertile testing ground for proposed definitions of quantum dynamics as well as semiclassical states in LQG.

  8. Bright field illumination system

    NASA Technical Reports Server (NTRS)

    Huber, Edward D. (Inventor)

    1998-01-01

    A Bright Field Illumination system for inspecting a range of characteristically different kinds of defects, depressions, and ridges in a selected material surface. The system has an illumination source placed near a first focus of an elliptical reflector. In addition, a camera facing the inspected area is placed near the illumination source and the first focus. The second focus of the elliptical reflector is located at a distance approximately twice the elliptical reflector's distance above the inspected surface. The elliptical reflector directs the light from the source onto the inspected surface. Due to the shape of the elliptical reflector, light that is specularly reflected from the inspected surface is directed into the camera is which located at the position of the reflected second focus of the ellipse. This system creates a brightly lighted background field against which damage sites appear as high contrast dark objects which can be easily detected by a person or an automated inspection system. In addition, the Bright Field Illumination system and method can be used in combination with a vision inspection system providing for multiplexed illumination and data handling of multiple kinds of surface characteristics including abrupt and gradual surface variations and differences between measured characteristics of different kinds and prior instruments.

  9. Field Trips: Tradition in Jeopardy

    ERIC Educational Resources Information Center

    Wheeler, Ginger

    2011-01-01

    The school field trip: something fun, different, exciting, exhausting--a break from the school day grind. But the field trip has ramifications beyond just getting out of school for the day. For students, the field trip is to the classroom what the big game is to athletes. For museums and other attractions, the field trip is a way to cultivate…

  10. Unbalanced field RF electron gun

    DOEpatents

    Hofler, Alicia

    2013-11-12

    A design for an RF electron gun having a gun cavity utilizing an unbalanced electric field arrangement. Essentially, the electric field in the first (partial) cell has higher field strength than the electric field in the second (full) cell of the electron gun. The accompanying method discloses the use of the unbalanced field arrangement in the operation of an RF electron gun in order to accelerate an electron beam.