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EVIDENCE FOR THE DIRECT DETECTION OF THE THERMAL SPECTRUM OF THE NON-TRANSITING HOT GAS GIANT HD 88133 bPiskorz, Danielle, Benneke, Björn, Crockett, Nathan R., Lockwood, Alexandra C., Blake, Geoffrey A., Barman, Travis S., Bender, Chad F., Bryan, Marta L., Carr, John S., Fischer, Debra A., Howard, Andrew W., Isaacson, Howard, Johnson, John A. 23 November 2016 (has links)
We target the thermal emission spectrum of the non-transiting gas giant HD 88133 b with high-resolution near-infrared spectroscopy, by treating the planet and its host star as a spectroscopic binary. For sufficiently deep summed flux observations of the star and planet across multiple epochs, it is possible to resolve the signal of the hot gas giant's atmosphere compared to the brighter stellar spectrum, at a level consistent with the aggregate shot noise of the full data set. To do this, we first perform a principal component analysis to remove the contribution of the Earth's atmosphere to the observed spectra. Then, we use a cross-correlation analysis to tease out the spectra of the host star and HD 88133 b to determine its orbit and identify key sources of atmospheric opacity. In total, six epochs of Keck NIRSPEC L-band observations and three epochs of Keck NIRSPEC K-band observations of the HD 88133 system were obtained. Based on an analysis of the maximum likelihood curves calculated from the multi-epoch cross-correlation of the full data set with two atmospheric models, we report the direct detection of the emission spectrum of the non-transiting exoplanet HD 88133 b and measure a radial projection of the Keplerian orbital velocity of 40 +/- 15 km s(-1), a true mass of 1.02(-0.28)(+0.61) M-J, a nearly face-on orbital inclination of 15(-5)(+60), and an atmosphere opacity structure at high dispersion dominated by water vapor. This, combined with 11 years of radial velocity measurements of the system, provides the most up-to-date ephemeris for HD 88133.
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HI4PI: a full-sky H i survey based on EBHIS and GASSBen Bekhti, N., Flöer, L., Keller, R., Kerp, J., Lenz, D., Winkel, B., Bailin, J., Calabretta, M. R., Dedes, L., Ford, H. A., Gibson, B. K., Haud, U., Janowiecki, S., Kalberla, P. M. W., Lockman, F. J., McClure-Griffiths, N. M., Murphy, T., Nakanishi, H., Pisano, D. J., Staveley-Smith, L. 20 October 2016 (has links)
Context. Measurement of the Galactic neutral atomic hydrogen (H I) column density, NH I, and brightness temperatures, T-B, is of high scientific value for a broad range of astrophysical disciplines. In the past two decades, one of the most-used legacy H I datasets has been the Leiden/Argentine/Bonn Survey (LAB). Aims. We release the H I 4 pi survey (HI4PI), an all-sky database of Galactic H I, which supersedes the LAB survey. Methods. The HI4PI survey is based on data from the recently completed first coverage of the Effelsberg-Bonn H I Survey (EBHIS) and from the third revision of the Galactic All-Sky Survey (GASS). EBHIS and GASS share similar angular resolution and match well in sensitivity. Combined, they are ideally suited to be a successor to LAB. Results. The new HI4PI survey outperforms the LAB in angular resolution (theta(FWHM) = 16'.2) and sensitivity (sigma(rms) = 43 mK). Moreover, it has full spatial sampling and thus overcomes a major drawback of LAB, which severely undersamples the sky. We publish all-sky column density maps of the neutral atomic hydrogen in the Milky Way, along with full spectroscopic data, in several map projections including HEALPix.
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FIGS—Faint Infrared Grism Survey: Description and Data ReductionPirzkal, Norbert, Malhotra, Sangeeta, Ryan, Russell E., Rothberg, Barry, Grogin, Norman, Finkelstein, Steven L., Koekemoer, Anton M., Rhoads, James, Larson, Rebecca L., Christensen, Lise, Cimatti, Andrea, Ferreras, Ignacio, Gardner, Jonathan P., Gronwall, Caryl, Hathi, Nimish P., Hibon, Pascale, Joshi, Bhavin, Kuntschner, Harald, Meurer, Gerhardt R., O’Connell, Robert W., Oestlin, Goeran, Pasquali, Anna, Pharo, John, Straughn, Amber N., Walsh, Jeremy R., Watson, Darach, Windhorst, Rogier A., Zakamska, Nadia L, Zirm, Andrew 01 September 2017 (has links)
The Faint Infrared Grism Survey (FIGS) is a deep Hubble Space Telescope (HST) WFC3/IR (Wide Field Camera 3 Infrared) slitless spectroscopic survey of four deep fields. Two fields are located in the Great Observatories Origins Deep Survey-North (GOODS-N) area and two fields are located in the Great Observatories Origins Deep Survey-South (GOODS-S) area. One of the southern fields selected is the Hubble Ultra Deep Field. Each of these four fields were observed using the WFC3/G102 grism (0.8 mu m-1.15 mu m continuous coverage) with a total exposure time of 40 orbits (approximate to 100 kilo-seconds) per field. This reaches a 3 sigma continuum depth of approximate to 26 AB magnitudes and probes emission lines to similar to 10(-17) erg s(-1) cm(-2). This paper details the four FIGS fields and the overall observational strategy of the project. A detailed description of the Simulation Based Extraction (SBE) method used to extract and combine over 10,000 spectra of over 2000 distinct sources brighter than m(F105W) = 26.5 mag is provided. High fidelity simulations of the observations is shown to significantly improve the background subtraction process, the spectral contamination estimates, and the final flux calibration. This allows for the combination of multiple spectra to produce a final high quality, deep, 1D spectra for each object in the survey.
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Detection of Water Vapor in the Thermal Spectrum of the Non-transiting Hot Jupiter Upsilon Andromedae bPiskorz, Danielle, Benneke, Björn, Crockett, Nathan R., Lockwood, Alexandra C., Blake, Geoffrey A., Barman, Travis S., Bender, Chad F., Carr, John S., Johnson, John A. 01 August 2017 (has links)
The Upsilon Andromedae system was the first multi-planet system discovered orbiting a main-sequence star. We describe the detection of water vapor in the atmosphere of the innermost non-transiting gas giant ups. And. b by treating the star-planet system as a spectroscopic binary with high-resolution, ground-based spectroscopy. We resolve the signal of the planet's motion and break the mass-inclination degeneracy for this non-transiting planet via deep combined flux observations of the star and the planet. In total, seven epochs of Keck NIRSPEC L band observations, three epochs of Keck NIRSPEC short-wavelength K band observations, and three epochs of Keck NIRSPEC long wavelength K band observations of the ups. And. system were obtained. We perform a multi-epoch cross-correlation of the full data set with an atmospheric model. We measure the radial projection of the Keplerian velocity (K-P = 55 +/- 9 km s(-1)), true mass (M-b = 1.7(-0.24)(+0.33)M(J)), and orbital inclination (i(b) 24 degrees +/- 4 degrees), and determine that the planet's opacity structure is dominated by water vapor at the probed wavelengths. Dynamical simulations of the planets in the ups. And. system with these orbital elements for ups. And. b show that stable, long-term (100 Myr) orbital configurations exist. These measurements will inform future studies of the stability and evolution of the ups. And. system, as well as the atmospheric structure and composition of the hot Jupiter.
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Phase-Dependent Spectroscopy of Mira Variable StarsCastelaz, Michael W., Luttermoser, Donald G., Caton, Daniel B., Piontek, Robert A. 01 January 2000 (has links)
Spectroscopic measurements of Mira variable stars as a function of phase probe the stellar atmospheres and underlying pulsation mechanisms. For example, measuring variations in TiO, VO, and ZrO with phase can be used to help determine whether these molecular species are produced in an extended region above the layers where Balmer line emission occurs or below this shocked region. Using the same methods, the Balmer line increment, where the strongest Balmer line at phase zero is Hδ and not Hα, can be measured and explanations tested, along with another peculiarity, the absence of the H∈ line in the spectra of Mira variables when the other Balmer lines are strong. We present new spectra covering the spectral range from 6200 to 9000 Å of 20 Mira variables. A relationship between variations in the Ca II IR triplet and Hα as a function of phase support the hypothesis that H∈'s observational characteristics result from an interaction of H∈ photons with the Ca II H line. New periods and epochs of variability are also presented for each star.
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Parallaxes and infrared photometry of three Y0 dwarfsSmart, R. L., Apai, D'aniel, Kirkpatrick, J. Davy, Leggett, S. K., Marocco, F., Morrison, Jane E., Jones, H. R. A., Pinfield, D., Tremblin, P., Amundsen, D. S. 07 1900 (has links)
We have followed up the three Y0 dwarfs WISEPA J041022.71+150248.5, WISEPA J173835.53+273258.9 and WISEPC J205628.90+145953.3 using the United Kingdom Infrared Telescope Wide Field Camera. We find parallaxes that are more consistent and accurate than previously published values. We estimate absolute magnitudes in photometric passbands from Y to W3 and find them to be consistent between the three Y0 dwarfs indicating that the inherent cosmic absolute magnitude spread of these objects is small. We examine the Mauna Kea Observatory system J magnitudes over the 4 yr time line and find small but significant monotonic variations. Finally, we estimate physical parameters from a comparison of spectra and parallax to equilibrium and non-equilibrium models finding values consistent with solar metallicity, an effective temperature of 450-475 K and log g of 4.0-4.5.
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A VERSATILE TECHNIQUE TO ENABLE SUB-MILLI-KELVIN INSTRUMENT STABILITY FOR PRECISE RADIAL VELOCITY MEASUREMENTS: TESTS WITH THE HABITABLE-ZONE PLANET FINDERStefansson, Gudmundur, Hearty, Frederick, Robertson, Paul, Mahadevan, Suvrath, Anderson, Tyler, Levi, Eric, Bender, Chad, Nelson, Matthew, Monson, Andrew, Blank, Basil, Halverson, Samuel, Henderson, Chuck, Ramsey, Lawrence, Roy, Arpita, Schwab, Christian, Terrien, Ryan 16 December 2016 (has links)
Insufficient instrument thermomechanical stability is one of the many roadblocks for achieving 10 cm s(-1) Doppler radial velocity precision, the precision needed to detect Earth-twins orbiting solar-type stars. Highly temperature and pressure stabilized spectrographs allow us to better calibrate out instrumental drifts, thereby helping in distinguishing instrumental noise from astrophysical stellar signals. We present the design and performance of the Environmental Control System (ECS) for the Habitable-zone Planet Finder (HPF), a high-resolution (R = 50,000) fiber-fed near-infrared (NIR) spectrograph for the 10 m Hobby-Eberly Telescope at McDonald Observatory. HPF will operate at 180 K, driven by the choice of an H2RG NIR detector array with a 1.7 mu m cutoff. This ECS has demonstrated 0.6 mK rms stability over 15 days at both 180 and 300 K, and maintained high-quality vacuum (< 10 (7) Torr) over months, during long-term stability tests conducted without a planned passive thermal enclosure surrounding the vacuum chamber. This control scheme is versatile and can be applied as a blueprint to stabilize future NIR and optical high-precision Doppler instruments over a wide temperature range from similar to 77 K to elevated room temperatures. A similar ECS is being implemented to stabilize NEID, the NASA/NSF NN-EXPLORE spectrograph for the 3.5 m WIYN telescope at Kitt Peak, operating at 300 K. A [full SolidWorks 3D-CAD model] and a comprehensive parts list of the HPF ECS are included with this manuscript to facilitate the adaptation of this versatile environmental control scheme in the broader astronomical community.
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DETECTION OF ROTATIONAL SPECTRAL VARIATION ON THE M-TYPE ASTEROID (16) PSYCHESanchez, Juan A., Reddy, Vishnu, Shepard, Michael K., Thomas, Cristina, Cloutis, Edward A., Takir, Driss, Conrad, Albert, Kiddell, Cain, Applin, Daniel 28 December 2016 (has links)
The asteroid (16) Psyche is of scientific interest because it contains similar to 1% of the total mass of the asteroid belt and is thought to be the remnant metallic core of a protoplanet. Radar observations have indicated the significant presence of metal on the surface with a small percentage of silicates. Prior ground-based observations showed rotational variations in the near-infrared (NIR) spectra and radar albedo of this asteroid. However, no comprehensive study that combines multi-wavelength data has been conducted so far. Here we present rotationally resolved NIR spectra (0.7-2.5 mu m) of (16) Psyche obtained with the NASA Infrared Telescope Facility. These data have been combined with shape models of the asteroid for each rotation phase. Spectral band parameters extracted from the NIR spectra show that the pyroxene band center varies from similar to 0.92 to 0.94 mu m. Band center values were used to calculate the pyroxene chemistry of the asteroid, whose average value was found to be Fs(30)En(65)Wo(5). Variations in the band depth (BD) were also observed, with values ranging from 1.0% to 1.5%. Using a new laboratory spectral calibration method, we estimated an average orthopyroxene content of 6% +/- 1%. The mass-deficit region of Psyche, which exhibits the highest radar albedo, also shows the highest value for the spectral slope and the minimum BD. The spectral characteristics of Psyche suggest that its parent body did not have the typical structure expected for a differentiated body or that the sequence of events that led to its current state was more complex than previously thought.
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HST PanCET Program: A Cloudy Atmosphere for the Promising JWST Target WASP-101bWakeford, H. R., Stevenson, K. B., Lewis, N. K., Sing, D. K., López-Morales, M., Marley, M., Kataria, T., Mandell, A., Ballester, G. E., Barstow, J., Ben-Jaffel, L., Bourrier, V., Buchhave, L. A., Ehrenreich, D., Evans, T., García Muñoz, A., Henry, G., Knutson, H., Lavvas, P., Lecavelier des Etangs, A., Nikolov, N., Sanz-Forcada, J. 20 January 2017 (has links)
We present results from the first observations of the Hubble Space Telescope (HST) Panchromatic Comparative Exoplanet Treasury program for WASP-101b, a highly inflated hot Jupiter and one of the community targets proposed for the James Webb Space Telescope (JWST) Early Release Science (ERS) program. From a single HST Wide Field Camera 3 observation, we find that the near-infrared transmission spectrum of WASP-101b contains no significant H2O absorption features and we rule out a clear atmosphere at 13 sigma. Therefore, WASP-101b is not an optimum target for a JWST ERS program aimed at observing strong molecular transmission features. We compare WASP-101b to the well-studied and nearly identical hot Jupiter WASP-31b. These twin planets show similar temperature-pressure profiles and atmospheric features in the near-infrared. We suggest exoplanets in the same parameter space as WASP-101b and WASP-31b will also exhibit cloudy transmission spectral features. For future HST exoplanet studies, our analysis also suggests that a lower count limit needs to be exceeded per pixel on the detector in order to avoid unwanted instrumental systematics.
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PHYSICAL CHARACTERIZATION OF ∼2 m DIAMETER NEAR-EARTH ASTEROID 2015 TC25: A POSSIBLE BOULDER FROM E-TYPE ASTEROID (44) NYSAReddy, Vishnu, Sanchez, Juan A., Bottke, William F., Thirouin, Audrey, Rivera-Valentin, Edgard G., Kelley, Michael S., Ryan, William, Cloutis, Edward A., Tegler, Stephen C., Ryan, Eileen V., Taylor, Patrick A., Richardson, James E., Moskovitz, Nicholas, Le Corre, Lucille 14 November 2016 (has links)
Small near-Earth asteroids (NEAs) (< 20 m) are interesting, because they are progenitors for meteorites in our terrestrial collection. The physical characteristics of these small NEAs are crucial to our understanding of the effectiveness of our atmosphere in filtering low-strength impactors. In the past, the characterization of small NEAs has been a challenge, because of the difficulty in detecting them prior to close Earth flyby. In this study, we physically characterized the 2 m diameter NEA 2015 TC25 using ground-based optical, near-infrared and radar assets during a close flyby of the Earth (distance 128,000 km) in 2015 October 12. Our observations suggest that its surface composition is similar to aubrites, a rare class of high-albedo differentiated meteorites. Aubrites make up only 0.14% of all known meteorites in our terrestrial meteorite collection. 2015 TC25 is also a very fast rotator with a period of 133 +/- 6 s. We combined the spectral and dynamical properties of 2015 TC25 and found the best candidate source body in the inner main belt to be the 70 km diameter E-type asteroid (44) Nysa. We attribute the difference in spectral slope between the two objects to the lack of regolith on the surface of 2015 TC25. Using the albedo of E-type asteroids (50%-60%) we refine the diameter of 2015 TC25 to 2 m, making it one of the smallest NEAs ever to be characterized.
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