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Item The 69 μm forsterite band in spectra of protoplanetary disks. Results from the Herschel DIGIT programme(2013-05) Sturm, B.; Bouwman, J.; Henning, T.; Evans, N. J.; Waters, Lbfm; van Dishoeck, E. F.; Green, J. D.; Olofsson, J.; Meeus, G.; Maaskant, K.; Dominik, C.; Augereau, J. C.; Mulders, G. D.; Acke, B.; Merin, B.; Herczeg, G. J.; Digit Team; Evans, Neal J.; Green, J. D.Context. We have analysed far-infrared spectra of 32 circumstellar disks around Herbig Ae/Be and T Tauri stars obtained within the Herschel key programme Dust, Ice and Gas in Time (DIGIT). The spectra were taken with the Photodetector Array Camera and Spectrometer (PACS) on board the Herschel Space Observatory. In this paper we focus on the detection and analysis of the 69 mu m emission band of the crystalline silicate forsterite. Aims. This work aims at providing an overview of the 69 mu m forsterite bands present in the DIGIT sample. We use characteristics of the emission band (peak position and FWHM) to derive the dust temperature and to constrain the iron content of the crystalline silicates. With this information, constraints can be placed on the spatial distribution of the forsterite in the disk and the formation history of the crystalline grains. Methods. The 69 mu m forsterite emission feature is analysed in terms of position and shape to derive the temperature and composition of the dust by comparison to laboratory spectra of that band. The PACS spectra are combined with existing Spitzer IRS spectra and we compare the presence and strength of the 69 mu m band to the forsterite bands at shorter wavelengths. Results. A total of 32 disk sources have been observed. Out of these 32, 8 sources show a 69 mu m emission feature that can be attributed to forsterite. With the exception of the T Tauri star AS 205, all of the detections are for disks associated with Herbig Ae/Be stars. Most of the forsterite grains that give rise to the 69 mu m bands are found to be warm (similar to 100-200 K) and iron-poor (less than similar to 2% iron). AB Aur is the only source where the emission cannot be fitted with iron-free forsterite requiring approximately 3-4% of iron. Conclusions. Our findings support the hypothesis that the forsterite grains form through an equilibrium condensation process at high temperatures. The large width of the emission band in some sources may indicate the presence of forsterite reservoirs at different temperatures. The connection between the strength of the 69 and 33 mu m bands shows that at least part of the emission in these two bands originates fom the same dust grains. We further find that any model that can explain the PACS and the Spitzer IRS observations must take the effects of a wavelength dependent optical depth into account. We find weak indications of a correlation of the detection rate of the 69 mu m band with the spectral type of the host stars in our sample. However, the sample size is too small to obtain a definitive result.Item Almost All Of Kepler's Multiple-Planet Candidates Are Planets(2012-05) Lissauer, Jack J.; Marcy, Geoffrey W.; Rowe, Jason F.; Bryson, Stephen T.; Adams, Elisabeth; Buchhave, Lars A.; Ciardi, David R.; Cochran, William D.; Fabrycky, D. C.; Ford, Eric B.; Fressin, Francois; Geary, John; Gilliland, Ronald L.; Holman, Matthew J.; Howell, Steve B.; Jenkins, Jon M.; Kinemuchi, Karen; Koch, David G.; Morehead, Robert C.; Ragozzine, Darin; Seader, Shawn E.; Tanenbaum, Peter G.; Torres, Guillermo; Twicken, Joseph D.; Cochran, William D.We present a statistical analysis that demonstrates that the overwhelming majority of Kepler candidate multiple transiting systems (multis) indeed represent true, physically associated transiting planets. Binary stars provide the primary source of false positives among Kepler planet candidates, implying that false positives should be nearly randomly distributed among Kepler targets. In contrast, true transiting planets would appear clustered around a smaller number of Kepler targets if detectable planets tend to come in systems and/or if the orbital planes of planets encircling the same star are correlated. There are more than one hundred times as many Kepler planet candidates in multi-candidate systems as would be predicted from a random distribution of candidates, implying that the vast majority are true planets. Most of these multis are multiple-planet systems orbiting the Kepler target star, but there are likely cases where (1) the planetary system orbits a fainter star, and the planets are thus significantly larger than has been estimated, or (2) the planets orbit different stars within a binary/multiple star system. We use the low overall false-positive rate among Kepler multis, together with analysis of Kepler spacecraft and ground-based data, to validate the closely packed Kepler-33 planetary system, which orbits a star that has evolved somewhat off of the main sequence. Kepler-33 hosts five transiting planets, with periods ranging from 5.67 to 41 days.Item c2d Spitzer-IRS Spectra Of Disks Around T Tauri Stars IV. Crystalline Silicates(2009-11) Olofsson, J.; Augereau, J. C.; van Dishoeck, E. F.; Merin, B.; Lahuis, F.; Kessler-Silacci, J.; Dullemond, C. P.; Oliveira, I.; Blake, G. A.; Boogert, A. C. A.; Brown, J. M.; Evans, Neal J.; Geers, V.; Knez, C.; Monin, J. L.; Pontoppidan, K.; Kessler-Silacci, J.; Evans, N. J.Aims. Dust grains in the planet-forming regions around young stars are expected to be heavily processed due to coagulation, fragmentation, and crystallization. This paper focuses on the crystalline silicate dust grains in protoplanetary disks for a statistically significant number of TTauri stars (96). Methods. As part of the cores to disks (c2d) legacy program, we obtained more than a hundred Spitzer/IRS spectra of TTauri stars, over a spectral range of 5-35 mu m where many silicate amorphous and crystalline solid-state features are present. At these wavelengths, observations probe the upper layers of accretion disks up to distances of a dozen AU from the central object. Results. More than 3/4 of our objects show at least one crystalline silicate emission feature that can be essentially attributed to Mg-rich silicates. The Fe-rich crystalline silicates are largely absent in the c2d IRS spectra. The strength and detection frequency of the crystalline features seen at lambda > 20 mu m correlate with each other, while they are largely uncorrelated with the observational properties of the amorphous silicate 10 mu m feature. This supports the idea that the IRS spectra essentially probe two independent disk regions: a warm zone (<= 1 AU) emitting at mu similar to 10 mu m and a much colder region emitting at lambda > 20 mu m (<= 10 AU). We identify a crystallinity paradox, as the long-wavelength (lambda > 20 mu m) crystalline silicate features are detected 3.5 times more frequently (similar to 55% vs. similar to 15%) than the crystalline features arising from much warmer disk regions (lambda similar to 10 mu m). This suggests that the disk has an inhomogeneous dust composition within similar to 10 AU. The analysis of the shape and strength of both the amorphous 10 mu m feature and the crystalline feature around 23 mu m provides evidence for the prevalence of mu m-sized (amorphous and crystalline) grains in upper layers of disks. Conclusions. The abundant crystalline silicates found far from their presumed formation regions suggest efficient outward radial transport mechanisms in the disks around TTauri stars. The presence of mu m-sized grains in disk atmospheres, despite the short timescales for settling to the midplane, suggests efficient (turbulent) vertical diffusion, probably accompanied by grain-grain fragmentation to balance the expected efficient growth. In this scenario, the depletion of submicron-sized grains in the upper layers of the disks points toward removal mechanisms such as stellar winds or radiation pressure.Item c2d Spitzer-IRS Spectra Of Disks Around T Tauri Stars IV. Crystalline Silicates(2009-11) Olofsson, J.; Augereau, J. C.; van Dishoeck, E. F.; Merin, B.; Lahuis, F.; Kessler-Silacci, J.; Dullemond, C. P.; Oliveira, I.; Blake, G. A.; Boogert, A. C. A.; Brown, J. M.; Evans, Neal J.; Geers, V.; Knez, C.; Monin, J. L.; Pontoppidan, K.; Kessler-Silacci, J.; Evans, N. J.Aims. Dust grains in the planet-forming regions around young stars are expected to be heavily processed due to coagulation, fragmentation, and crystallization. This paper focuses on the crystalline silicate dust grains in protoplanetary disks for a statistically significant number of TTauri stars (96). Methods. As part of the cores to disks (c2d) legacy program, we obtained more than a hundred Spitzer/IRS spectra of TTauri stars, over a spectral range of 5-35 mu m where many silicate amorphous and crystalline solid-state features are present. At these wavelengths, observations probe the upper layers of accretion disks up to distances of a dozen AU from the central object. Results. More than 3/4 of our objects show at least one crystalline silicate emission feature that can be essentially attributed to Mg-rich silicates. The Fe-rich crystalline silicates are largely absent in the c2d IRS spectra. The strength and detection frequency of the crystalline features seen at lambda > 20 mu m correlate with each other, while they are largely uncorrelated with the observational properties of the amorphous silicate 10 mu m feature. This supports the idea that the IRS spectra essentially probe two independent disk regions: a warm zone (<= 1 AU) emitting at mu similar to 10 mu m and a much colder region emitting at lambda > 20 mu m (<= 10 AU). We identify a crystallinity paradox, as the long-wavelength (lambda > 20 mu m) crystalline silicate features are detected 3.5 times more frequently (similar to 55% vs. similar to 15%) than the crystalline features arising from much warmer disk regions (lambda similar to 10 mu m). This suggests that the disk has an inhomogeneous dust composition within similar to 10 AU. The analysis of the shape and strength of both the amorphous 10 mu m feature and the crystalline feature around 23 mu m provides evidence for the prevalence of mu m-sized (amorphous and crystalline) grains in upper layers of disks. Conclusions. The abundant crystalline silicates found far from their presumed formation regions suggest efficient outward radial transport mechanisms in the disks around TTauri stars. The presence of mu m-sized grains in disk atmospheres, despite the short timescales for settling to the midplane, suggests efficient (turbulent) vertical diffusion, probably accompanied by grain-grain fragmentation to balance the expected efficient growth. In this scenario, the depletion of submicron-sized grains in the upper layers of the disks points toward removal mechanisms such as stellar winds or radiation pressure.Item Central Rotations of Milky Way Globular Clusters(2014-06) Fabricius, Maximilian H.; Noyola, Eva; Rukdee, Surangkhana; Saglia, Roberto P.; Bender, Ralf; Hopp, Ulrich; Thomas, Jens; Opitsch, Michael; Williams, Michael J.; Noyola, EvaMost Milky Way globular clusters (GCs) exhibit measurable flattening, even if on a very low level. Both cluster rotation and tidal fields are thought to cause this flattening. Nevertheless, rotation has only been confirmed in a handful of GCs, based mostly on individual radial velocities at large radii. We are conducting a survey of the central kinematics of Galactic GCs using the new Integral Field Unit instrument VIRUS-W. We detect rotation in all 11 GCs that we have observed so far, rendering it likely that a large majority of the Milky Way GCs rotate. We use published catalogs of GCs to derive central ellipticities and position angles. We show that in all cases where the central ellipticity permits an accurate measurement of the position angle, those angles are in excellent agreement with the kinematic position angles that we derive from the VIRUS-W velocity fields. We find an unexpected tight correlation between central rotation and outer ellipticity, indicating that rotation drives flattening for the objects in our sample. We also find a tight correlation between central rotation and published values for the central velocity dispersion, most likely due to rotation impacting the old dispersion measurements.Item Correcting For Telluric Absorption: Methods, Case Studies, And Release Of The TelFit Code(2014-09) Gullikson, Kevin; Dodson-Robinson, Sarah; Kraus, Adam; Gullikson, Kevin; Kraus, AdamGround-based astronomical spectra are contaminated by the Earth's atmosphere to varying degrees in all spectral regions. We present a Python code that can accurately fit a model to the telluric absorption spectrum present in astronomical data, with residuals of similar to 3%-5% of the continuum for moderately strong lines. We demonstrate the quality of the correction by fitting the telluric spectrum in a nearly featureless A0V star, HIP 20264, as well as to a series of dwarf M star spectra near the 819 nm sodium doublet. We directly compare the results to an empirical telluric correction of HIP 20264 and find that our model-fitting procedure is at least as good and sometimes more accurate. The telluric correction code, which we make freely available to the astronomical community, can be used as a replacement for telluric standard star observations for many purposes.Item The Early Asymmetries Of Supernova 2008D/XRF 080109(2009-11) Maund, Justyn R.; Wheeler, J. Craig; Baade, Dietrich; Patat, Ferdinando; Hoflich, Patat; Wang, Lifan F.; Clocchiatti, Alejandro; Wheeler, J. CraigSpectropolarimetry of the Type Ib SN 2008D, associated with the X-ray Flash (XRF) 080109, at two separate epochs, is presented. The epochs of these observations correspond to V-band light curve maximum and 15 days after light curve maximum (or 21 and 36 days after the XRF). We find SN 2008D to be significantly polarized, although the largest contribution is due to the interstellar polarization component of Q(ISP) = 0% +/- 0.1% and U(ISP) = -1.2% +/- 0.1%. At the two epochs, the spectropolarimetry of SN 2008D is classified as being D1+L(He I)+L(Ca II). The intrinsic polarization of continuum wavelength regions is < 0.4%, at both epochs, implying an asymmetry of the photosphere of < 10%. Similar to other Type Ibc SNe, such as 2005bf, 2006aj, and 2007gr, we observed significant polarization corresponding to the spectral features of Ca II, He I, Mg I, Fe II and, possibly, O I lambda 7774, about a close-to-spherically symmetric photosphere. We introduce a new plot showing the chemically distinct line-forming regions in the ejecta and comment on the apparent ubiquity of highly polarized high-velocity Ca II features in Type Ibc SNe. The polarization angle of Ca II IR triplet was significantly different, at both epochs, to those of the other species, suggesting high-velocity Ca II forms in a separate part of the ejecta. The apparent structure in the outer layers of SN 2008D has implications for the interpretation of the early-time X-ray emission associated with shock breakout. We present two scenarios, within the jet-torus paradigm, which explain the lack of an apparent geometry discontinuity between the two observations: (1) a jet which punched a hole straight through the progenitor and deposited Ni outside the ejecta and (2) a jet which stalled inside the radius of the photosphere as observed at the second epoch. The lack of a peculiar polarization signature, suggesting strongly asymmetric excitation of the ejecta, and the reported properties of the shock-breakout favor the second scenario.Item H Alpha Activity Of Old M Dwarfs: Stellar Cycles And Mean Activity Levels For 93 Low-Mass Stars In The Solar Neighborhood(2013-02) Robertson, Paul; Endl, Michael; Cochran, William D.; Dodson-Robinson, Sarah E.; Robertson, Paul; Endl, Michael; Cochran, William D.; Dodson-Robinson, Sarah E.Through the McDonald Observatory M Dwarf Planet Search, we have acquired nearly 3000 high-resolution spectra of 93 late-type (K5-M5) stars over more than a decade using the High Resolution Spectrograph on the Hobby-Eberly Telescope. This sample provides a unique opportunity to investigate the occurrence of long-term stellar activity cycles for low-mass stars. In this paper, we examine the stellar activity of our targets as reflected in the H alpha feature. We have identified periodic signals for six stars, with periods ranging from days to more than 10 years, and find long-term trends for seven others. Stellar cycles with P >= 1 year are present for at least 5% of our targets. Additionally, we present an analysis of the time-averaged activity levels of our sample, and search for correlations with other stellar properties. In particular, we find that more massive, earlier type (M0-M2) stars tend to be more active than later type dwarfs. Furthermore, high-metallicity stars tend to be more active at a given stellar mass. We also evaluate H alpha variability as a tracer of activity-induced radial velocity (RV) variation. For the M dwarf GJ 1170, H alpha variation reveals stellar activity patterns matching those seen in the RVs, mimicking the signal of a giant planet, and we find evidence that the previously identified stellar activity cycle of GJ 581 may be responsible for the recently retracted planet f in that system. In general, though, we find that H alpha is not frequently correlated with RV at the precision (typically 6-7 m s(-1)) of our measurements.Item The Infrared Colors Of The Sun(2012-12) Casagrande, L.; Ramirez, Ivan; Melendez, Jorge; Asplund, Martin; Ramirez, IvanSolar infrared colors provide powerful constraints on the stellar effective temperature scale, but they must be measured with both accuracy and precision in order to do so. We fulfill this requirement by using line-depth ratios to derive in a model-independent way the infrared colors of the Sun, and we use the latter to test the zero point of the Casagrande et al. effective temperature scale, confirming its accuracy. Solar colors in the widely used Two Micron All Sky Survey (2MASS) JHK(s) and WISE W1-4 systems are provided: (V - J)(circle dot) = 1.198, (V - H)(circle dot) = 1.484, (V - K-s)(circle dot) = 1.560, (J - H)(circle dot) = 0.286, (J - K-s)(circle dot) = 0.362, (H - K-s)(circle dot) = 0.076, (V - W1)(circle dot) = 1.608, (V - W2)(circle dot) = 1.563, (V - W3)(circle dot) = 1.552, and (V - W4)(circle dot) = 1.604. A cross-check of the effective temperatures derived implementing 2MASS or WISE magnitudes in the infrared flux method confirms that the absolute calibration of the two systems agrees within the errors, possibly suggesting a 1% offset between the two, thus validating extant near-and mid-infrared absolute calibrations. While 2MASS magnitudes are usually well suited to derive T-eff, we find that a number of bright, solar-like stars exhibit anomalous WISE colors. In most cases, this effect is spurious and can be attributed to lower-quality measurements, although for a couple of objects (3%+/- 2% of the total sample) it might be real, and may hint at the presence of warm/hot debris disks.Item Kepler Mission Design, Realized Photometric Performance, and Early Science(2010-04) Koch, David G.; Borucki, William J.; Basri, Gibor; Batalha, Natalie M.; Brown, Timothy M.; Caldwell, Douglas; Christensen-Dalsgaard, Jorgen; Cochran, William D.; DeVore, Edna; Dunham, Edward W.; Gautier, Thomas N., III; Geary, John C.; Gilliland, Ronald L.; Gould, Alan; Jenkins, Jon; Kondo, Yoji; Latham, David W.; Lissauer, Jack J.; Marcy, Geoffrey; Monet, David; Sasselov, Dimitar; Boss, Alan; Brownlee, Donald; Caldwell, John; Dupree, Andrea K.; Howell, Steve B.; Kjeldsen, Hans; Meibom, Soren; Morrison, David; Owen, Tobias; Reitsema, Harold; Tarter, Jill; Bryson, Stephen T.; Dotson, Jessie L.; Gazis, Paul; Haas, Michael R.; Kolodziejczak, Jeffrey; Rowe, Jason F.; Van Cleve, Jeffrey E.; Allen, Christopher; Chandrasekaran, Hema; Clarke, Bruce D.; Li, Jie; Quintana, Elisa V.; Tenenbaum, Peter; Twicken, Joseph D.; Wu, Hayley; Cochran, William D.The Kepler Mission, launched on 2009 March 6, was designed with the explicit capability to detect Earth-size planets in the habitable zone of solar-like stars using the transit photometry method. Results from just 43 days of data along with ground-based follow-up observations have identified five new transiting planets with measurements of their masses, radii, and orbital periods. Many aspects of stellar astrophysics also benefit from the unique, precise, extended, and nearly continuous data set for a large number and variety of stars. Early results for classical variables and eclipsing stars show great promise. To fully understand the methodology, processes, and eventually the results from the mission, we present the underlying rationale that ultimately led to the flight and ground system designs used to achieve the exquisite photometric performance. As an example of the initial photometric results, we present variability measurements that can be used to distinguish dwarf stars from red giants.Item Kepler-15B: A Hot Jupiter Enriched in Heavy Elements and the First Kepler Mission Planet Confirmed With the Hobby-Eberly Telescope(2011-11) Endl, Michael; MacQueen, Phillip J.; Cochran, William D.; Brugamyer, Erik J.; Buchhave, Lars A.; Rowe, Jason; Lucas, Phillip; Isaacson, Howard; Bryson, Steve; Howell, Steve B.; Fortney, Jonathan J.; Hansen, Terese; Borucki, William J.; Caldwell, Douglas; Christiansen, Jessie L.; Ciardi, David R.; Demory, Brice-Olivier; Everett, Mark; Ford, Eric B.; Haas, Michael R.; Holman, Matthew J.; Horch, Elliott; Jenkins, Jon M.; Koch, David J.; Lissauer, Jack J.; Machalek, Pavel; Still, Martin; Welsh, William F.; Sanderfer, Dwight T.; Seader, Shawn E.; Smith, Jeffrey C.; Thompson, Susan E.; Twicken, Joseph D.; Endl, Michael; MacQueen, Phillip J.; Cochran, William D.; Brugamyer, Erik J.We report the discovery of Kepler-15b (KOI-128), a new transiting exoplanet detected by NASA's Kepler mission. The transit signal with a period of 4.94 days was detected in the quarter 1 (Q1) Kepler photometry. For the first time, we have used the High Resolution Spectrograph (HRS) at the Hobby-Eberly Telescope (HET) to determine the mass of a Kepler planet via precise radial velocity (RV) measurements. The 24 HET/HRS RVs and 6 additional measurements from the Fibre-fed Echelle Spectrograph spectrograph at the Nordic Optical Telescope reveal a Doppler signal with the same period and phase as the transit ephemeris. We used one HET/HRS spectrum of Kepler-15 taken without the iodine cell to determine accurate stellar parameters. The host star is a metal-rich ([Fe/H] = 0.36 +/- 0.07) G-type main-sequence star with T-eff = 5515 +/- 124 K. The semi-amplitude K of the RV orbit is 78.7(-9.5)(+ 8.5) m s(-1), which yields a planet mass of 0.66 +/- 0.1 M-Jup. The planet has a radius of 0.96 +/- 0.06 R-Jup and a mean bulk density of 0.9 +/- 0.2 g cm(-3). The radius of Kepler-15b is smaller than the majority of transiting planets with similar mass and irradiation level. This suggests that the planet is more enriched in heavy elements than most other transiting giant planets. For Kepler-15b we estimate a heavy element mass of 30-40 M-circle plus.Item Laboratory Measurements Of White Dwarf Photospheric Spectral Lines: H Beta(2015-06) Falcon, Ross E.; Rochau, G. A.; Bailey, J. E.; Gomez, Thomas A.; Montgomery, Michael H.; Winget, D. E.; Nagayama, T.; Falcon, Ross E.; Gomez, Thomas A.; Montgomery, Michael H.; Winget, D. E.We spectroscopically measure multiple hydrogen Balmer line profiles from laboratory plasmas to investigate the theoretical line profiles used in white dwarf (WD) atmosphere models. X-ray radiation produced at the Z Pulsed Power Facility at Sandia National Laboratories initiates plasma formation in a hydrogen-filled gas cell, replicating WD photospheric conditions. Here we present time-resolved measurements of H beta and fit this line using different theoretical line profiles to diagnose electron density, n(e), and n = 2 level population, n2. Aided by synthetic tests, we characterize the validity of our diagnostic method for this experimental platform. During a single experiment, we infer a continuous range of electron densities increasing from n(e) similar to 4 to similar to 30 x 10(16) cm(-3) throughout a 120-ns evolution of our plasma. Also, we observe n(2) to be initially elevated with respect to local thermodynamic equilibrium (LTE); it then equilibrates within similar to 55 ns to become consistent with LTE. This supports our electrontemperature determination of T-e similar to 1.3 eV (similar to 15,000 K) after this time. At n(e) greater than or similar to 10(17) cm(-3), we find that computer-simulation-based line-profile calculations provide better fits (lower reduced chi(2)) than the line profiles currently used in the WD astronomy community. The inferred conditions, however, are in good quantitative agreement. This work establishes an experimental foundation for the future investigation of relative shapes and strengths between different hydrogen Balmer lines.Item The Lick AGN Monitoring Project 2011: Spectroscopic Campaign and Emission-Line Light Curves(2015-04) Barth, Aaron J.; Bennert, Vardha N.; Canalizo, Gabriela; Filippenko, Alexei V.; Gates, Elinor L.; Greene, Jenny E.; Li, Weidong; Malkan, Matthew A.; Pancoast, Anna; Sand, David J.; Stern, Daniel; Treu, Tommaso; Woo, Jong-Hak; Assef, Roberto J.; Bae, Hyun-Jin; Brewer, Brendon J.; Cenko, S. Bradley; Clubb, Kelsey I.; Cooper, Michael C.; Diamond-Stanic, Aleksandar M.; Hiner, Kyle D.; Hoenig, Sebastian F.; Hsiao, Eric; Kandrashoff, Michael T.; Lazarova, Mariana S.; Nierenberg, A. M.; Rex, Jacob; Silverman, Jeffrey M.; Tollerud, Erik J.; Walsh, Jonelle L.; Silverman, Jeffrey M.In the Spring of 2011 we carried out a 2.5 month reverberation mapping campaign using the 3 m Shane telescope at Lick Observatory, monitoring 15 low-redshift Seyfert 1 galaxies. This paper describes the observations, reductions and measurements, and data products from the spectroscopic campaign. The reduced spectra were fitted with a multicomponent model in order to isolate the contributions of various continuum and emission-line components. We present light curves of broad emission lines and the active galactic nucleus (AGN) continuum, and measurements of the broad H beta line widths in mean and rms spectra. For the most highly variable AGNs we also measured broad Ha line widths and velocity centroids from the nightly spectra. In four AGNs exhibiting the highest variability amplitudes, we detect anticorrelations between broad H beta width and luminosity, demonstrating that the broad-line region "breathes" on short timescales of days to weeks in response to continuum variations. We also find that broad Ha velocity centroids can undergo substantial changes in response to continuum variations; in NGC 4593, the broad H beta velocity shifted by similar to 250 km s(-1) over a 1 month period. This reverberation-induced velocity shift effect is likely to contribute a significant source of confusion noise to binary black hole searches that use multi-epoch quasar spectroscopy to detect binary orbital motion. We also present results from simulations that examine biases that can occur in measurement of broad-line widths from rms spectra due to the contributions of continuum variations and photon-counting noise.Item The MaNGA Integral Field Unit Fiber Feed System For The Sloan 2.5 M Telescope(2015-02) Drory, N.; MacDonald, N.; Bershady, M. A.; Bundy, K.; Gunn, J.; Law, D. R.; Smith, M.; Stoll, R.; Tremonti, C. A.; Wake, D. A.; Yan, R.; Weijmans, A. M.; Byler, N.; Cherinka, B.; Cope, F.; Eigenbrot, A.; Harding, P.; Holder, D.; Huehnerhoff, J.; Jaehnig, K.; Jansen, T. C.; Klaene, M.; Paat, A. M.; Percival, J.; Sayres, C.; Drory, N.We describe the design, manufacture, and performance of bare-fiber integral field units (IFUs) for the SDSS-IV survey Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) on the the Sloan 2.5 m telescope at Apache Point Observatory. MaNGA is a luminosity-selected integral-field spectroscopic survey of 10(4) local galaxies covering 360-1030 nm at R similar to 2200. The IFUs have hexagonal dense packing of fibers with packing regularity of 3 mu m (rms), and throughput of 96 +/- 0.5% from 350 nm to 1 mu m in the lab. Their sizes range from 19 to 127 fibers (3-7 hexagonal layers) using Polymicro FBP 120: 132: 150 mu m core: clad: buffer fibers to reach a fill fraction of 56%. High throughput (and low focal-ratio degradation (FRD)) is achieved by maintaining the fiber cladding and buffer intact, ensuring excellent surface polish, and applying a multi-layer anti-reflection (AR) coating of the input and output surfaces. In operations on-sky, the IFUs show only an additional 2.3% FRD-related variability in throughput despite repeated mechanical stressing during plate plugging (however other losses are present). The IFUs achieve on-sky throughput 5% above the single-fiber feeds used in SDSS-III/BOSS, attributable to equivalent performance compared to single fibers and additional gains from the AR coating. The manufacturing process is geared toward mass-production of high-multiplex systems. The low-stress process involves a precision ferrule with a hexagonal inner shape designed to lead inserted fibers to settle in a dense hexagonal pattern. The ferrule ID is tapered at progressively shallower angles toward its tip and the final 2 mm are straight and only a few microns larger than necessary to hold the desired number of fibers. Our IFU manufacturing process scales easily to accommodate other fiber sizes and can produce IFUs with substantially larger fiber counts. To assure quality, automated testing in a simple and inexpensive system enables complete characterization of throughput and fiber metrology. Future applications include larger IFUs, higher fill factors with stripped buffer, decladding, and lenslet coupling.Item The Mass Of Hd 38529c From Hubble Space Telescope Astrometry And High-Precision Radial Velocities(2010-05) Benedict, G. Fritz; McArthur, Barbara E.; Bean, Jacob L.; Barnes, Rory; Harrison, Thomas E.; Hatzes, Artie; Martioli, Eder; Nelan, Edmund P.; Benedict, G. Fritz; McArthur, Barbara E.Hubble Space Telescope Fine Guidance Sensor astrometric observations of the G4 IV star HD 38529 are combined with the results of the analysis of extensive ground-based radial velocity (RV) data to determine the mass of the outermost of two previously known companions. Our new RVs obtained with the Hobby-Eberly Telescope and velocities from the Carnegie-California group now span over 11 yr. With these data we obtain improved RV orbital elements for both the inner companion, HD 38529b, and the outer companion, HD 38529c. We identify a rotational period of HD 38529 (P(rot) = 31.65 +/- 0(d).17) with Fine Guidance Sensor photometry. The inferred star spot fraction is consistent with the remaining scatter in velocities being caused by spot-related stellar activity. We then model the combined astrometric and RV measurements to obtain the parallax, proper motion, perturbation period, perturbation inclination, and perturbation size due to HD 38529c. For HD 38529c we find P = 2136.1 +/- 0.3 d, perturbation semimajor axis alpha = 1.05 +/- 0.06 mas, and inclination i = 48 degrees.3 +/- 3 degrees.7. Assuming a primary mass M(*) = 1.48 M(circle dot), we obtain a companion mass M(c) = 17.6(1.2)(+1.5) M(Jup), 3 sigma above a 13 M(Jup) deuterium burning, brown dwarf lower limit. Dynamical simulations incorporating this accurate mass for HD 38529c indicate that a near-Saturn mass planet could exist between the two known companions. We find weak evidence of an additional low amplitude signal that can be modeled as a planetary-mass (similar to 0.17 M(Jup)) companion at P similar to 194 days. Including this component in our modeling lowers the error of the mass determined for HD 38529c. Additional observations (RVs and/or Gaia astrometry) are required to validate an interpretation of HD 38529d as a planetary-mass companion. If confirmed, the resulting HD 38529 planetary system may be an example of a >Packed Planetary System.>Item Modification Of The MOOG Spectral Synthesis Codes To Account For Zeeman Broadening Of Spectral Lines(2013-09) Deen, Casey P.; Deen, Casey P.In an attempt to widen access to the study of magnetic fields in stellar astronomy, I present MOOGStokes, a version of the MOOG one-dimensional local thermodynamic equilibrium radiative transfer code, overhauled to incorporate a Stokes vector treatment of polarized radiation through a magnetic medium. MOOGStokes is a suite of three complementary programs, which together can synthesize the disk-averaged emergent spectrum of a star with a magnetic field. The first element (a pre-processing script called CounterPoint) calculates for a given magnetic field strength, wavelength shifts, and polarizations for the components of Zeeman-sensitive lines. The second element (a MOOG driver called SynStokes derived from the existing MOOG driver Synth) uses the list of Zeeman-shifted absorption lines together with the existing machinery of MOOG to synthesize the emergent spectrum at numerous locations across the stellar disk, accounting for stellar and magnetic field geometry. The third and final element (a post-processing script called DiskoBall) calculates the disk-averaged spectrum by weighting the individual emergent spectra by limb darkening and projected area, and applying the effects of Doppler broadening. All together, the MOOGStokes package allows users to synthesize emergent spectra of stars with magnetic fields in a familiar computational framework. MOOGStokes produces disk-averaged spectra for all Stokes vectors (I, Q, U, V), normalized by the continuum. MOOGStokes agrees well with the predictions of INVERS10 a polarized radiative transfer code with a long history of use in the study of stellar magnetic fields. In the non-magnetic limit, MOOGStokes also agrees with the predictions of the scalar version of MOOG.Item News From The Gamma Cephei Planetary System(2011-01) Endl, M.; Cochran, W. D.; Hatzes, A. P.; Wittenmyer, R. A.; Endl, Michael; Cochran, William D.The gamma Cephei planetary system is one of the most interesting systems due to several reasons: I.) it is the first planet candidate detected by precise radial velocity (RV) measurements that was discussed in the literature (Campbell et al. 1988); 2.) it is a tight binary system with a approximate to 20 AU; and 3.) the planet host star is an evolved K-type star. In Hatzcs et al. (2003) we confirmed the presence of the planetary companion with a minimum mass of 1.7 M-Jup at 2 AU. In this paper we present additional eight years of precise RV data from the Harlan J. Smith 2.7 m Telescope and its Tull Coude spectrograph at McDonald Observatory. The 900 d signal, that is interpreted as the presence of the giant planetary companion, is strongly confirmed by adding the new data. We present an updated orbital solution for the planet, which shows that the planet is slightly more massive and the orbit more circular than previous results have suggested. An intensive high-cadence week of RV observations in 2007 revealed that gamma Cep A is a multi-periodic pulsator. We discuss this issue within the context of searching for additional planets in this system.Item Planetary Candidates Observed by Kepler. III. Analysis of the First 16 Months of Data(2013-02) Batalha, Natalie M.; Rowe, Jason F.; Bryson, Stephen T.; Barclay, Thomas; Burke, Christopher J.; Caldwell, Douglas A.; Christiansen, Jessie L.; Mullally, Fergal; Thompson, Susan E.; Brown, Timothy M.; Dupree, Andrea K.; Fabrycky, Daniel C.; Ford, Eric B.; Fortney, Jonathan J.; Gilliland, Ronald L.; Isaacson, Howard; Latham, David W.; Marcy, Geoffrey W.; Quinn, Samuel N.; Ragozzine, Darin; Shporer, Avi; Borucki, William J.; Ciardi, David R.; Gautier, Thomas N., III; Haas, Michael R.; Jenkins, Jon M.; Koch, David G.; Lissauer, Jack J.; Rapin, William; Basri, Gibor S.; Boss, Alan P.; Buchhave, Lars A.; Carter, Joshua A.; Charbonneau, David; Christensen-Dalsgaard, Joergen; Clarke, Bruce D.; Cochran, William D.; Demory, Brice-Olivier; Desert, Jean-Michel; Devore, Edna; Doyle, Laurance R.; Esquerdo, Gilbert A.; Everett, Mark; Fressin, Francois; Geary, John C.; Girouard, Forrest R.; Gould, Alan; Hall, Jennifer R.; Holman, Matthew J.; Howard, Andrew W.; Howell, Steve B.; Ibrahim, Khadeejah A.; Kinemuchi, Karen; Kjeldsen, Hans; Klaus, Todd C.; Li, Jie; Lucas, Philip W.; Meibom, Soren; Morris, Robert L.; Prsa, Andrej; Quintana, Elisa; Sanderfer, Dwight T.; Sasselov, Dimitar; Seader, Shawn E.; Smith, Jeffrey C.; Steffen, Jason H.; Still, Martin; Stumpe, Martin C.; Tarter, Jill C.; Tenenbaum, Peter; Torres, Guillermo; Twicken, Joseph D.; Uddin, Kamal; Van Cleve, Jeffrey; Walkowicz, Lucianne; Welsh, William F.; Cochran, William D.New transiting planet candidates are identified in 16 months (2009 May-2010 September) of data from the Kepler spacecraft. Nearly 5000 periodic transit-like signals are vetted against astrophysical and instrumental false positives yielding 1108 viable new planet candidates, bringing the total count up to over 2300. Improved vetting metrics are employed, contributing to higher catalog reliability. Most notable is the noise-weighted robust averaging of multiquarter photo-center offsets derived from difference image analysis that identifies likely background eclipsing binaries. Twenty-two months of photometry are used for the purpose of characterizing each of the candidates. Ephemerides (transit epoch, T-0, and orbital period, P) are tabulated as well as the products of light curve modeling: reduced radius (R-P / R-star), reduced semimajor axis (d / R-star), and impact parameter (b). The largest fractional increases are seen for the smallest planet candidates (201% for candidates smaller than 2R(circle plus). compared to 53% for candidates larger than 2R.) and those at longer orbital periods (124% for candidates outside of 50 day orbits versus 86% for candidates inside of 50 day orbits). The gains are larger than expected from increasing the observing window from 13 months (Quarters 1-5) to 16 months (Quarters 1-6) even in regions of parameter space where one would have expected the previous catalogs to be complete. Analyses of planet frequencies based on previous catalogs will be affected by such incompleteness. The fraction of all planet candidate host stars with multiple candidates has grown from 17% to 20%, and the paucity of short-period giant planets in multiple systems is still evident. The progression toward smaller planets at longer orbital periods with each new catalog release suggests that Earth-size planets in the habitable zone are forthcoming if, indeed, such planets are abundant.Item SDSS J074511.56+194926.5: Discovery Of A Metal-Rich And Tidally Distorted Extremely Low Mass White Dwarf(2014-02) Gianninas, A.; Hermes, J. J.; Brown, Warren R.; Dufour, Patrick; Barber, S. D.; Kilic, Mukremin; Kenyon, S. J.; Harrold, Samuel T.; Hermes, J. J.; Harrold, S. T.We present the discovery of an unusual, tidally distorted extremely low mass white dwarf (WD) with nearly solar metallicity. Radial velocity measurements confirm that this is a compact binary with an orbital period of 2.6975 hr and a velocity semi-amplitude of K = 108.7 km s(-1). Analysis of the hydrogen Balmer lines yields an effective temperature of T-eff = 8380 K and a surface gravity of log g = 6.21 that in turn indicate a mass of M = 0.16 M-circle dot and a cooling age of 4.2 Gyr. In addition, a detailed analysis of the observed metal lines yields abundances of log (Mg/H) = -3.90, log(Ca/H) = -5.80, log(Ti/ H) = -6.10, log(Cr/H) = -5.60, and log(Fe/H) = -4.50, similar to the sun. We see no evidence of a debris disk from which these metals would be accreted, though the possibility cannot entirely be ruled out. Other potential mechanisms to explain the presence of heavy elements are discussed. Finally, we expect this system to ultimately undergo unstable mass transfer and merge to form a similar to 0.3-0.6 M-circle dot WD in a few Gyr.Item A Search For Giant Planet Companions To T Tauri Stars(2012-12) Crockett, Christopher J.; Mahmud, Naved I.; Prato, L.; Johns-Krull, Christopher M.; Jaffe, Daniel T.; Hartigan, Patrick M.; Beichman, Charles A.; Jaffe, Daniel T.We present results from an ongoing multiwavelength radial velocity (RV) survey of the Taurus-Auriga star-forming region as part of our effort to identify pre-main-sequence giant planet hosts. These 1-3 Myr old T Tauri stars present significant challenges to traditional RV surveys. The presence of strong magnetic fields gives rise to large, cool star spots. These spots introduce significant RV jitter which can mimic the velocity modulation from a planet-mass companion. To distinguish between spot-induced and planet-induced RV modulation, we conduct observations at similar to 6700 angstrom and similar to 2.3 mu m and measure the wavelength dependence (if any) in the RV amplitude. CSHELL observations of the known exoplanet host Gl 86 demonstrate our ability to detect not only hot Jupiters in the near-infrared but also secular trends from more distant companions. Observations of nine very young stars reveal a typical reduction in RV amplitude at the longer wavelengths by a factor of similar to 2-3. While we cannot confirm the presence of planets in this sample, three targets show different periodicities in the two wavelength regions. This suggests different physical mechanisms underlying the optical and the K-band variability.