2,137 research outputs found

    Use NASA GES DISC Data in ArcGIS

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    This presentation describes GIS relevant data at NASA Goddard Earth Sciences Data and Information Services Center (GES DISC), GES DISC Services and Support for GIS Users, and use cases of GES DISC data in ArcGIS

    HST/STIS Spectroscopy of the Intermediate Polar EX Hydrae

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    We present the results of our analysis of six orbits of HST/STIS time-tagged spectroscopy of the intermediate polar, EX Hydrae. The high time and wavelength resolution of the HST/STIS spectra provided an excellent opportunity to study the UV properties of EX Hya. Measurements of the continuum and emission line fluxes corroborate earlier studies that show that the emission line fluxes are modulated more strongly than the continuum flux and originate from the accretion curtains, while the continuum flux originates from the white dwarf photosphere. The measured K amplitude of the narrow emission line radial velocity curve is used to calculate a white dwarf mass of 0.91+/-0.05 M_sun. Synthetic white dwarf photosphere and accretion disk spectral models are used to further refine the white dwarf and accretion disk properties. Using the spectral models, it is determined that EX Hya has a white dwarf of mass 0.9 M_sun, T=23000 K, an accretion disk truncated at 2.5 R_WD, and is at a distance of 60 pc.Comment: Accepted to ApJ, 28 pages including 12 figure

    Nova-like Cataclysmic Variables in the Infrared

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    Novalike cataclysmic variables have persistently high mass transfer rates and prominent steady state accretion disks. We present an analysis of infrared observations of twelve novalikes obtained from the Two Micron All Sky Survey, the Spitzer Space Telescope, and the Wide-field Infrared Survey Explorer All Sky Survey. The presence of an infrared excess at >3-5 microns over the expectation of a theoretical steady state accretion disk is ubiquitous in our sample. The strength of the infrared excess is not correlated with orbital period, but shows a statistically significant correlation (but shallow trend) with system inclination that might be partially (but not completely) linked to the increasing view of the cooler outer accretion disk and disk rim at higher inclinations. We discuss the possible origin of the infrared excess in terms of emission from bremsstrahlung or circumbinary dust, with either mechanism facilitated by the mass outflows (e.g., disk wind/corona, accretion stream overflow, and so on) present in novalikes. Our comparison of the relative advantages and disadvantages of either mechanism for explaining the observations suggests that the situation is rather ambiguous, largely circumstantial, and in need of stricter observational constraints.Peer reviewe

    The Vehicle, Fall 1983

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    Vol. 25, No. 1 Table of Contents Amish BoyDevon Flesorpage 3 SyllogismJ. Maura Davispage 3 Ten SecondsD.L. Lewispage 4 The Cedar ChestBridget M. Howepage 4 A Christmas With CarolSteve Longpage 5 TeethMichelle Mitchellpage 7 An I-Love-You PoemD.L. Lewispage 8 The Dragon SlayerSusan Gradypage 8 A DefinitionAmy J. Eadespage 9 FingernailsSuzanne Hornpage 10 The Liar\u27s TableBrook Wilsonpage 10 Fifi\u27s Last PartySteve Longpage 12 Absence/PresenceSuzanne Hornpage 13 From the Rantings of a Mad Astronomy StudentAmy J. Eadespage 13 In the Name of the Father, the Son, and MachiavelliF. Link Rapierpage 15 Errant LoverBecky Lawsonpage 16 DaddyKevin Lylespage 16 GhostsGary Ervinpage 17 TangoF. Link Rapierpage 17 Grandma\u27s SlippersBecky Lawsonpage 18 EdgesAmy J. Eadespage 19 Having ChildrenDevon Flesorpage 20 Young Black GirlKevin Lylespage 21 CatSuzanne Hornpage 22 Breakfast for OneMichelle Mitchellpage 22 A Modest ProposalBrooke Sanfordpage 23 Post MortemF. Link Rapierpage 26 Who Said I Forgot?Lynne Krausepage 27 The Corner Booth at StuckeysMaggie Kennedypage 28 The First DayDavis Brydenpage 29 DownLynne Krausepage 30 Fairie RingDevon Flesorpage 31 The LaundrymatKathy Fordpage 32 Sunday in OctoberBridget M. Howepage 32 The Kitchen WindowMaggie Kennedypage 33 UntitledChristina Maire Vitekpage 34 8th Grade Field Trip to SpringfieldMichelle Mitchellpage 34 Children of the FortiesF. Link Rapierpage 35 one winter and i was eightGary Ervinpage 35 Don\u27t we all know?Thomas B. Waltrippage 36 The TravelerMaggie Kennedypage 36 The VisitKathy Fordpage 40 CubismMaggie Kennedypage 40https://thekeep.eiu.edu/vehicle/1042/thumbnail.jp

    The Vehicle, Fall 1983

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    Vol. 25, No. 1 Table of Contents Amish BoyDevon Flesorpage 3 SyllogismJ. Maura Davispage 3 Ten SecondsD.L. Lewispage 4 The Cedar ChestBridget M. Howepage 4 A Christmas With CarolSteve Longpage 5 TeethMichelle Mitchellpage 7 An I-Love-You PoemD.L. Lewispage 8 The Dragon SlayerSusan Gradypage 8 A DefinitionAmy J. Eadespage 9 FingernailsSuzanne Hornpage 10 The Liar\u27s TableBrook Wilsonpage 10 Fifi\u27s Last PartySteve Longpage 12 Absence/PresenceSuzanne Hornpage 13 From the Rantings of a Mad Astronomy StudentAmy J. Eadespage 13 In the Name of the Father, the Son, and MachiavelliF. Link Rapierpage 15 Errant LoverBecky Lawsonpage 16 DaddyKevin Lylespage 16 GhostsGary Ervinpage 17 TangoF. Link Rapierpage 17 Grandma\u27s SlippersBecky Lawsonpage 18 EdgesAmy J. Eadespage 19 Having ChildrenDevon Flesorpage 20 Young Black GirlKevin Lylespage 21 CatSuzanne Hornpage 22 Breakfast for OneMichelle Mitchellpage 22 A Modest ProposalBrooke Sanfordpage 23 Post MortemF. Link Rapierpage 26 Who Said I Forgot?Lynne Krausepage 27 The Corner Booth at StuckeysMaggie Kennedypage 28 The First DayDavis Brydenpage 29 DownLynne Krausepage 30 Fairie RingDevon Flesorpage 31 The LaundrymatKathy Fordpage 32 Sunday in OctoberBridget M. Howepage 32 The Kitchen WindowMaggie Kennedypage 33 UntitledChristina Maire Vitekpage 34 8th Grade Field Trip to SpringfieldMichelle Mitchellpage 34 Children of the FortiesF. Link Rapierpage 35 one winter and i was eightGary Ervinpage 35 Don\u27t we all know?Thomas B. Waltrippage 36 The TravelerMaggie Kennedypage 36 The VisitKathy Fordpage 40 CubismMaggie Kennedypage 40https://thekeep.eiu.edu/vehicle/1042/thumbnail.jp

    The First Hour of Extra-galactic Data of the Sloan Digital Sky Survey Spectroscopic Commissioning: The Coma Cluster

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    On 26 May 1999, one of the Sloan Digital Sky Survey (SDSS) fiber-fed spectrographs saw astronomical first light. This was followed by the first spectroscopic commissioning run during the dark period of June 1999. We present here the first hour of extra-galactic spectroscopy taken during these early commissioning stages: an observation of the Coma cluster of galaxies. Our data samples the Southern part of this cluster, out to a radius of 1.5degrees and thus fully covers the NGC 4839 group. We outline in this paper the main characteristics of the SDSS spectroscopic systems and provide redshifts and spectral classifications for 196 Coma galaxies, of which 45 redshifts are new. For the 151 galaxies in common with the literature, we find excellent agreement between our redshift determinations and the published values. As part of our analysis, we have investigated four different spectral classification algorithms: spectral line strengths, a principal component decomposition, a wavelet analysis and the fitting of spectral synthesis models to the data. We find that a significant fraction (25%) of our observed Coma galaxies show signs of recent star-formation activity and that the velocity dispersion of these active galaxies (emission-line and post-starburst galaxies) is 30% larger than the absorption-line galaxies. We also find no active galaxies within the central (projected) 200 h-1 Kpc of the cluster. The spatial distribution of our Coma active galaxies is consistent with that found at higher redshift for the CNOC1 cluster survey. Beyond the core region, the fraction of bright active galaxies appears to rise slowly out to the virial radius and are randomly distributed within the cluster with no apparent correlation with the potential merger of the NGC 4839 group. [ABRIDGED]Comment: Accepted in AJ, 65 pages, 20 figures, 5 table

    Infrared Spectroscopic Observations of the Secondary Stars of Short Period Sub-Gap Cataclysmic Variables

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    We present K-band spectroscopy of short period, "sub-gap" cataclysmic variable (CV) systems obtained using ISAAC on the VLT. We show the infrared spectra (IR) for nine systems below the 2-3 hour period gap: V2051 Oph, V436 Cen, EX Hya, VW Hyi, Z Cha, WX Hyi, V893 Sco, RZ Leo, and TY PsA. We are able to clearly detect the secondary star in all but WX Hyi, V893 Sco, and TY PsA. We present the first direct detection of the secondary stars of V2051 Oph, V436 Cen, and determine new spectral classifications for EX Hya, VW Hyi, Z Cha, and RZ Leo. We find that the CO band strengths of all but Z Cha appear normal for their spectral types, in contrast to their longer period cousins above the period gap. This brings the total number of CVs and pre-CVs with moderate resolution (R >~ 1500) IR spectroscopy to sixty-one systems: nineteen pre-CVs, thirty-one non-magnetic systems, and eleven magnetic or partially magnetic systems. We discuss the trends seen in the IR abundance patterns thus far, and highlight a potential link between anomalous abundances seen in the IR with the C IV/N V anomaly seen in the ultraviolet. We present a compilation of all systems with sufficient resolution IR observations to assess the CO band strengths, and, by proxy, obtain an estimate on the C abundance on the secondary star.Comment: 44 pages, 8 figures, 4 tables. Accepted for publication to Ap

    LSST: from Science Drivers to Reference Design and Anticipated Data Products

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    (Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg2^2 field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5σ\sigma point-source depth in a single visit in rr will be 24.5\sim 24.5 (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg2^2 with δ<+34.5\delta<+34.5^\circ, and will be imaged multiple times in six bands, ugrizyugrizy, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg2^2 region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to r27.5r\sim27.5. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie

    The state of the Martian climate

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    60°N was +2.0°C, relative to the 1981–2010 average value (Fig. 5.1). This marks a new high for the record. The average annual surface air temperature (SAT) anomaly for 2016 for land stations north of starting in 1900, and is a significant increase over the previous highest value of +1.2°C, which was observed in 2007, 2011, and 2015. Average global annual temperatures also showed record values in 2015 and 2016. Currently, the Arctic is warming at more than twice the rate of lower latitudes
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