54 research outputs found

    Spitzer IRS Pipelines for General Users

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    An effort is underway to make the Spitzer InfraRed Spectrograph (IRS) data-processing pipelines available for use by astronomers worldwide. This will allow users to reprocess raw data downloaded from the Spitzer archive with customized calibration files, updated operational parameters, and/or a modified list of processing steps. The pipelines will create all standard BCD (basic calibrated data) and post-BCD products, plus additional intermediate products. The pipelines will be made up of newly developed Perl and C-shell ``executive'' scripts, plus the binary-executable modules currently used in operations (the modules' source code will not be distributed, however). The scripts are being designed for ease of use and will facilitate user-customization. The operating systems targeted for support are Mac OS X, Linux, Solaris, and possibly Windows

    A SURVEY OF NEARBY MAIN-SEQUENCE STARS FOR SUBMILLIMETER EMISSION

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    We searched for submillimeter emission around 10 Vega-type stars and one Herbig Ae star with the four-color bolometer at 1300 μm and the 19 channel bolometer array at 870 μm using the Heinrich Hertz Telescope at the Submillimeter Telescope Observatory. All of our sources were undetected at 870 μm. In the case of HD 131156, we have a 3 σ detection at 1300 μm. We report a flux of 6.25 ± 1.88 mJy for the HD 131156 disk and a corresponding dust mass of 2.4 ± 0.7 lunar masses. However, we did not detect HD 131156 at 870 μm, so we are cautious about the 1300 μm detection. We performed follow-up infrared observations of HD 131156 using MIRLIN at the Palomar 200 inch telescope, which resolved both components of the binary. The data are photospheric, implying that the system does not have a hot, inner dust component. We report submillimeter upper limits on fluxes for the remaining systems

    Wide-Field Infrared Survey Explorer Observations of Young Stellar Objects in the Lynds 1509 Dark Cloud in Auriga

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    The Wide-Field Infrared Survey Explorer (WISE) has uncovered a striking cluster of young stellar object (YSO) candidates associated with the L1509 dark cloud in Auriga. The WISE observations, at 3.4 μm, 4.6 μm, 12 μm, and 22 μm, show a number of objects with colors consistent with YSOs, and their spectral energy distributions suggest the presence of circumstellar dust emission, including numerous Class I, flat spectrum, and Class II objects. In general, the YSOs in L1509 are much more tightly clustered than YSOs in other dark clouds in the Taurus-Auriga star forming region, with Class I and flat spectrum objects confined to the densest aggregates, and Class II objects more sparsely distributed. We estimate a most probable distance of 485-700 pc, and possibly as far as the previously estimated distance of 2 kpc

    Cirugía ambulatoria en afecciones nodulares del tiroides. Ambulatory surgery in thyroid-nodular conditions

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    Se realizó un estudio comparativo, transversal y prospectivo de 104 pacientes afectados por patologías quirúrgicas del tiroides en el periodo comprendido de enero de 2001 hasta diciembre de 2002, los cuales fueron intervenidos quirúrgicamente 50 pacientes por el método de Cirugía Mayor no Ambulatoria en el Hospital Universitario "Abel Santamaría Cuadrado" de Pinar del Río. En la serie predominaron las patologías nodulares con respecto a los difusos, ya que estas últimas fueron excluidas de nuestro trabajo, intervenidos en su totalidad con anestesia general con intubación endotraqueal. Las enfermedades asociadas no constituyen limitaciones en la muestra escogida, en tanto la estadía hospitalaria en los pacientes con patologías nodulares benignas fue inferior a 24 horas postoperatorio, los cuales evolucionaron satisfactoriamente. Se demostró que las operaciones de nódulo de tiroides por cirugía ambulatoria son seguras y factibles para el paciente por el bajo número de complicaciones lo que reduce significativamente el costo hospitalario, ya que la mayoría de los pacientes fueron egresados entre 12 y 24 horas después. Se obtuvieron evidentes ventajas económicas con respecto al ahorro del recurso cama y la del costo hospitalario, así como un elevado grado de satisfacción por parte de los operados, lo que justifica que se recomiende incrementar la aplicación de este proceder y extenderlo al mayor número posible de afecciones quirúrgicas. DeCS: BOCIO NODULAR, CIRUGIA, CIRUGIA AMBULATORIA, COSTOS DIRECTOS DE SERVICIOS, TIROIDECTOMIA. ABSTRACT A comparative, cross-sectional and prospective study was carried out in 104 patients affected by surgical thyroid pathologies from January 2001 to December 2002. 50 patients underwent surgery through non ambulatory major surgery method and other 54 patients through ambulatory major surgery at Abel Santamaría Cuadrado Hospital in Pinar del Rio. In the sample nodose pathologies prevailed as for diffuses. Since the latter were excluded from our work, assisted totally with general anesthesia and endotraqueal intubations. Associated diseases constitute limitations in the chosen sample, as long as hospital stay in patients with nodose benign pathologies was lower than 24 hours post-operatively, whose progress was satisfactory. The study showed that surgeries of thyroid nodes with ambulatory surgery are safe and feasible for the patients because of low amounts of complications, which significantly reduces hospitalary cost, since most patients were discharged 12 and 24 hours later. Evident economical advantages were known as to saving bed resource and hospitalary cost, as well as a high degree of satisfaction by those patients undergoing surgery, which justifies the fact of recommending the increase of the application of this procedure and the spread of it to as many surgical diseases as possible. DeCS: AMBULATORY SURGERY, DIRECT SERVICE COSTS, GOITER NODULAR, SURGERY, THYROIDECTOMY

    Visual Orbits & Alignments of Planet Hosting Binary Systems

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    Roughly half of Solar-type planet hosts have stellar companions, so understanding how these binary companions affect the formation and evolution of planets is an important component to understanding planetary systems overall. Measuring the dynamical properties of planet host binaries enables a valuable test of planet formation in multi-star systems and requires knowledge of the binary orbital parameters. Using high resolution imaging, we have measured the relative astrometry and visual orbits of 13 binary systems where one of the stars is known to host a transiting exoplanet. Our results indicate that the mutual inclination between the orbits of the binary hosts and the transiting planets are well aligned. Our results for close binary systems (a<100 AU) complement past work for wide planet host binaries from Gaia.Comment: Accepted for publication in A

    Radii of 88 M subdwarfs and updated radius relations for low-metallicity M-dwarf stars

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    M subdwarfs are low-metallicity M dwarfs that typically inhabit the halo population of the Galaxy. Metallicity controls the opacity of stellar atmospheres; in metal-poor stars, hydrostatic equilibrium is reached at a smaller radius, leading to smaller radii for a given effective temperature. We compile a sample of 88 stars that span spectral classes K7 to M6 and include stars with metallicity classes from solar-metallicity dwarf stars to the lowest metallicity ultra subdwarfs to test how metallicity changes the stellar radius. We fit models to Palomar Double Spectrograph (DBSP) optical spectra to derive effective temperatures (T_ eff) and we measure bolometric luminosities (L_ bol) by combining broad wavelength-coverage photometry with Gaia parallaxes. Radii are then computed by combining the T_ eff and L_ bol using the Stefan–Boltzman law. We find that for a given temperature, ultra subdwarfs can be as much as five times smaller than their solar-metallicity counterparts. We present color-radius and color-surface brightness relations that extend down to [Fe/H] of −2.0 dex, in order to aid the radius determination of M subdwarfs, which will be especially important for the WFIRST exoplanetary microlensing survey.Published versio

    NEOWISE-R Observation of the Coolest Known Brown Dwarf

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    The Wide-field Infrared Survey Explorer (WISE) spacecraft has been reactivated as NEOWISE-R to characterize and search for Near Earth Objects. The brown dwarf WISE J085510.83-071442.5 has now been reobserved by NEOWISE-R, and we confirm the results of Luhman (2014b), who found a very low effective temperature (≈250\approx 250 K), a very high proper motion (8.1 +/- 0.1 arcsec/yr) , and a large parallax (454 +/- 45 mas). The large proper motion has separated the brown dwarf from the background sources that influenced the 2010 WISE data, allowing a measurement of a very red WISE color of W1-W2 >3.9> 3.9 mag. A re-analysis of the 2010 WISE astrometry using only the W2 band, combined with the new NEOWISE-R 2014 position, gives an improved parallax of 448 +/- 33 mas and proper motion of 8.08 +/- 0.05\; arcsec/yr. These are all consistent with Luhman (2014b).Comment: 6 pages, AJ accepte

    Discovery of the Young L Dwarf WISE J174102.78–464225.5

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    We report the discovery of the L dwarf WISE J174102.78–464225.5, which was discovered as part of a search for nearby L dwarfs using the Wide-field Infrared Survey Explorer (WISE). The distinct triangular peak of the H-band portion of its near-infrared spectrum and its red near-infrared colors (J – K_S = 2.35 ± 0.08 mag) are indicative of a young age. Via comparison to spectral standards and other red L dwarfs, we estimate a near-infrared spectral type of L7 ± 2 (pec). From a comparison to spectral and low-mass evolutionary models, we determine self-consistent effective temperature, log g, age, and mass values of 1450 ± 100 K, 4.0 ± 0.25 (cm s^(–2)), 10-100 Myr, and 4-21 M_(Jup), respectively. With an estimated distance of 10-30 pc, we explore the possibility that WISE J174102.78–464225.5 belongs to one of the young nearby moving groups via a kinematic analysis and we find potential membership in the β Pictoris or AB Doradus associations. A trigonometric parallax measurement and a precise radial velocity can help to secure its membership in either of these groups

    Discovery of a Possible Cool White Dwarf Companion from the AllWISE Motion Survey

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    We present optical and near-infrared spectroscopy of WISEA J061543.91−124726.8, which we rediscovered as a high motion object in the AllWISE survey. The spectra of this object are unusual; while the red optical (λ > 7000 Å) and near-infrared spectra exhibit characteristic TiO, VO, and H_2O bands of a late-M dwarf, the blue portion of its optical spectrum shows a significant excess of emission relative to late-M-type templates. The excess emission is relatively featureless, with the exception of a prominent and very broad Na I D doublet. We find that no single, ordinary star can reproduce these spectral characteristics. The most likely explanation is an unresolved binary system of an M7 dwarf and a cool white dwarf. The flux of a cool white dwarf drops in the optical red and near-infrared, due to collision-induced absorption, thus allowing the flux of a late-M dwarf to show through. This scenario, however, does not explain the Na D feature, which is unlike that of any known white dwarf, but which could perhaps be explained via unusual abundance or pressure conditions
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