Now showing items 21-40 of 70908

    • Does feedback matter for job search self‐regulation? It depends on feedback quality

      Chawla, Nitya; Gabriel, Allison S.; da Motta Veiga, Serge P.; Slaughter, Jerel E.; Univ Arizona, Dept Management & Org, Eller Coll Management (WILEY, 2019-02-20)
      Job search represents a dynamic process through which job seekers must consistently engage in effective self‐regulation. Although scholars have increasingly begun to theorize and conceptualize the job search in this manner, little is known about what fosters effective self‐regulation week‐to‐week. In light of this theoretical gap, we integrate self‐regulation theory with the feedback literature to examine how feedback quality influences affective, cognitive, and behavioral regulatory processes in job search. Furthermore, we examine feedback self‐efficacy (i.e., how efficacious a job seeker feels with respect to processing and implementing feedback received during the job search) as a stable, person‐level moderator of these within‐person relationships. In a sample of job seekers surveyed once a week for seven weeks, results indicate that receiving high‐quality feedback has a direct influence on positive and negative affective reactions tied to the job search, influencing subsequent positive (i.e., metacognitive strategies) and negative (i.e., affective rumination) cognitive processes. Metacognitive strategies, in turn, impact both the number of résumés sent and hours spent job seeking each week. Moreover, lower feedback self‐efficacy amplifies the relationship between feedback quality and negative affective reactions. Our results highlight the importance of high‐quality feedback in helping job seekers effectively regulate week‐to‐week.
    • The Effects of Telluric Contamination in Iodine-calibrated Precise Radial Velocities

      Wang, Sharon Xuesong; Wright, Jason T.; Bender, Chad; Howard, Andrew W.; Isaacson, Howard; Veyette, Mark; Muirhead, Philip S.; Univ Arizona, Steward Observ (IOP PUBLISHING LTD, 2019-11-01)
      We characterized the effects of telluric absorption lines on the radial velocity (RV) precision of stellar spectra taken through an iodine cell. To isolate the effects induced by telluric contamination from other stellar, instrumental, or numerical systematic RV noise, we extracted RVs from simulated iodine-calibrated spectra of three RV standard stars regularly observed by Keck/HIRES. We add in water absorption lines according to measured precipitable water vapor (PWV) contents over a one-year period. We conclude that telluric contamination introduces additional RV noise and spurious periodic signals at the level of 10–20 cm s−1, consistent with similar previous studies. Our findings show that forward modeling the telluric lines effectively recovers the RV precision and accuracy, with no prior knowledge of the PWV needed. Such a recovery is less effective when the water absorption lines are relatively deep in the stellar template used in the forward modeling. Overall, telluric contamination plays an insignificant role in typical iodine-calibrated RV programs aiming at ~1–2 m s−1, but we recommend adding modeling of telluric lines and taking stellar template observations on nights with low humidity for programs aiming to achieve a precision of better than 1 m s–1.
    • Compositional Constraints for Lucy Mission Trojan Asteroids via Near-infrared Spectroscopy

      Sharkey, Benjamin N. L.; Reddy, Vishnu; Sanchez, Juan A.; Izawa, Matthew R. M.; Emery, Joshua P.; Univ Arizona, Lunar & Planetary Lab (IOP PUBLISHING LTD, 2019-10-25)
      We report near-infrared (0.7–2.5 μm) reflectance spectra for each of the six target asteroids of the forthcoming NASA Discovery-class mission Lucy. Five Jupiter Trojans (the binary (617) Patroclus system, (3548) Eurybates, (21900) Orus, (11351) Leucus, and (15094) Polymele) are well characterized, with measurable spectral differences. We also report a survey-quality spectrum for main-belt asteroid (52246) Donaldjohanson. We measured a continuum of spectral slopes including "red" (Orus, Leucus), "less red" (Eurybates, Patroclus-Menoetius), and intermediate (Polymele), indicating a range of compositional end-members or geological histories. We perform radiative transfer modeling of several possible surface compositions. We find that the mild-sloped spectra and low albedo of Patroclus and Eurybates imply similar compositions. Eurybates (~7 wt.% water ice) and Patroclus (~4 wt.% water ice) are consistent with a hydrated surface. Models for Orus and Leucus are consistent with each other and require a significantly more reddening agent (e.g., iron-rich silicates or tholin-like organics). Polymele has a linear spectrum like Patroclus, but a higher albedo more closely aligned with Orus/Leucus, defying simple grouping. Solar system formation models generally predict that the Jovian Trojans accreted in the outer solar system. Our observations and analysis are generally consistently with this expectation, although not uniquely so.
    • Radial Velocity Measurements of HR 8799 b and c with Medium Resolution Spectroscopy

      Ruffio, Jean-Baptiste; Macintosh, Bruce; Konopacky, Quinn M.; Barman, Travis; De Rosa, Robert J.; Wang, Jason J.; Wilcomb, Kielan K.; Czekala, Ian; Marois, Christian; Univ Arizona, Lunar & Planetary Lab (IOP PUBLISHING LTD, 2019-10-24)
      High-contrast medium resolution spectroscopy has been used to detect molecules such as water and carbon monoxide in the atmospheres of gas giant exoplanets. In this work, we show how it can be used to derive radial velocity (RV) measurements of directly imaged exoplanets. Improving upon the traditional cross-correlation technique, we develop a new likelihood based on joint forward modeling of the planetary signal and the starlight background (i.e., speckles). After marginalizing over the starlight model, we infer the barycentric RV of HR 8799 b and c in 2010 yielding ?9.20.5 km s(?1) and ?11.60.5 km s(?1), respectively. These RV measurements help to constrain the 3D orientation of the orbit of the planet by resolving the degeneracy in the longitude of an ascending node. Assuming coplanar orbits for HR 8799 b and c, but not including d and e, we estimate Omega = 89 degrees(27)(-17+) and i = 20 degrees.8(-3.7)(+4.5).
    • Search for the H Chondrite Parent Body among the Three Largest S-type Asteroids: (3) Juno, (7) Iris, and (25) Phocaea

      Noonan, John W.; Reddy, Vishnu; Harris, Walter M.; Bottke, William F.; Sanchez, Juan A.; Furfaro, Roberto; Brown, Zarah; Fernandes, Rachel; Kareta, Theodore; Lejoly, Cassandra; et al. (IOP PUBLISHING LTD, 2019-11-01)
      Linking meteorites to source regions in the main asteroid belt is important for understanding the conditions under which their parent bodies formed. Ordinary chondrites are the most abundant class of meteorites on Earth, totaling 86% of all collected samples. Some S-type asteroids/families have been proposed as sources for the three different (H, L, and LL) types of ordinary chondrites with Hebe, Agnia, Merxia, and Koronis families being the source for H chondrites, Gefion for H/L chondrites, and Flora family for LL chondrites. However, the composition and meteorite affinity of several large S-type main belt asteroids remains unconstrained leaving the possibility of additional source regions for ordinary chondrite meteorites. Here we investigate the surface composition of three large S-type asteroids, (3) Juno, (7) Iris, and (25) Phocaea, using their near-infrared spectra (0.7–2.55 μm) to identify the parent body of the H chondrites. We use a Bayesian inference model to confirm the meteorite analogs of the three asteroids. Based on our Bayes classifier we find the following analogs and probabilities: Juno is likely H chondrite (89%), Iris is likely LL chondrite (97.5%), and Phocaea is likely H chondrite (98.6%). While Phocaea has the highest probability of being an H chondrite, it is dynamically unlikely to deliver material to near-Earth space. While Juno has spectral properties similar to H chondrites, its family is unlikely to produce sizeable H-chondrite-type near-Earth objects (NEOs). If Juno is the primary source of H chondrite meteorites, it suggests that an additional source is needed to explain the H-chondrite-type NEOs.
    • Exploring the Correlation Between Multiple Latent Variables and Covariates in Hierarchical Data Based on the Multilevel Multidimensional IRT Model

      Zhang, Jiwei; Lu, Jing; Chen, Feng; Tao, Jian; Univ Arizona, Dept East Asian Studies (FRONTIERS MEDIA SA, 2019-10-25)
      In many large-scale tests, it is very common that students are nested within classes or schools and that the test designers try to measure their multidimensional latent traits (e.g., logical reasoning ability and computational ability in the mathematics test). It is particularly important to explore the influences of covariates on multiple abilities for development and improvement of educational quality monitoring mechanism. In this study, motivated by a real dataset of a large-scale English achievement test, we will address how to construct an appropriate multilevel structural models to fit the data in many of multilevel models, and what are the effects of gender and socioeconomic-status differences on English multidimensional abilities at the individual level, and how does the teachers' satisfaction and school climate affect students' English abilities at the school level. A full Gibbs sampling algorithm within the Markov chain Monte Carlo (MCMC) framework is used for model estimation. Moreover, a unique form of the deviance information criterion (DIC) is used as a model comparison index. In order to verify the accuracy of the algorithm estimation, two simulations are considered in this paper. Simulation studies show that the Gibbs sampling algorithm works well in estimating all model parameters across a broad spectrum of scenarios, which can be used to guide the real data analysis. A brief discussion and suggestions for further research are shown in the concluding remarks.
    • A simple knowledge-based tool for stereotactic radiosurgery pre-planning

      Goldbaum, Daniel S; Hurley, Justin D; Hamilton, Russell J; Univ Arizona, Dept Radiat Oncol (WILEY, 2019-11-19)
      We studied the dosimetry of single-isocenter treatment plans generated to treat a solitary intracranial lesion using linac-based stereotactic radiosurgery (SRS). A common metric for evaluating SRS plan quality is the volume of normal brain tissue irradiated by a dose of at least 12 Gy (V12), which is important because multiple studies have shown a strong correlation between V12 and incidence of radiation necrosis. Unrealistic expectations for values of V12 can lead to wasted planning time. We present a model that estimates V12 without having to construct a full treatment plan. This model was derived by retrospectively analyzing 50 SRS treatment plans, each clinically approved for delivery using circular collimator cone arc therapy (CAT). Each case was re-planned for delivery via dynamic conformal arc therapy (DCAT), and then scaling arguments were used to extend dosimetric data to account for different prescription dose (PD) values (15, 18, 21, or 24 Gy). We determined a phenomenological expression for the total volume receiving at least 12 Gy (TV12) as a function of both planning target volume (PTV) and PD: T V 12 / 1 c c = n ∗ P D / 1 G y + d ∗ P T V / 1 c c a ∗ P D / 1 G y c , where a , c , n , d are fit parameters, and a separate set of values is determined for each plan type. In addition, we generated a sequence of plots to clarify how the relationship between conformity index (CI) and TV12 depends on plan type (CAT vs DCAT), PTV, and PD. These results can be used to suggest realistic plan parameters and planning goals before the start of treatment planning. In the absence of access to more sophisticated pre-planning tools, this model can be locally generated and implemented at relatively low cost with respect to time, money, and expertise.
    • Extracellular acidosis differentiates pancreatitis and pancreatic cancer in mouse models using acidoCEST MRI

      High, Rachel A; Randtke, Edward A; Jones, Kyle M; Lindeman, Leila R; Ma, Jacqueline C; Zhang, Shu; LeRoux, Lucia G; Pagel, Mark D; Univ Arizona, Canc Biol Interdisciplinary Program; Univ Arizona, Dept Med Imaging; et al. (ELSEVIER SCIENCE INC, 2019-11-01)
      Differentiating pancreatitis from pancreatic cancer would improve diagnostic specificity, and prognosticating pancreatitis that progresses to pancreatic cancer would also improve diagnoses of pancreas pathology. The high glycolytic metabolism of pancreatic cancer can cause tumor acidosis, and different levels of pancreatitis may also have different levels of acidosis, so that extracellular acidosis may be a diagnostic biomarker for these pathologies. AcidoCEST MRI can noninvasively measure extracellular pH (pHe) in the pancreas and pancreatic tissue. We used acidoCEST MRI to measure pHe in a KC model treated with caerulein, which causes pancreatitis followed by development of pancreatic cancer. We also evaluated the KC model treated with PBS, and wild-type mice treated with caerulein or PBS as controls. The caerulein-treated KC cohort had lower pHe of 6.85–6.92 before and during the first 48 h after initiating treatment, relative to a pHe of 6.92 to 7.05 pHe units for the other cohorts. The pHe of the caerulein-treated KC cohort decreased to 6.79 units at 5 weeks when pancreatic tumors were detected with anatomical MRI, and sustained a pHe of 6.75 units at the 8-week time point. Histopathology was used to evaluate and validate the presence of tumors and inflammation in each cohort. These results showed that acidoCEST MRI can differentiate pancreatic cancer from pancreatitis in this mouse model, but does not appear to differentiate pancreatitis that progresses to pancreatic cancer vs. pancreatitis that does not progress to cancer.
    • A transient reporter for editing enrichment (TREE) in human cells

      Standage-Beier, Kylie; Tekel, Stefan J; Brookhouser, Nicholas; Schwarz, Grace; Nguyen, Toan; Wang, Xiao; Brafman, David A; Univ Arizona, Coll Med Phoenix, Grad Program Clin Translat Sci (OXFORD UNIV PRESS, 2019-11-20)
      Current approaches to identify cell populations that have been modified with deaminase base editing technologies are inefficient and rely on downstream sequencing techniques. In this study, we utilized a blue fluorescent protein (BFP) that converts to green fluorescent protein (GFP) upon a C-to-T substitution as an assay to report directly on base editing activity within a cell. Using this assay, we optimize various base editing transfection parameters and delivery strategies. Moreover, we utilize this assay in conjunction with flow cytometry to develop a transient reporter for editing enrichment (TREE) to efficiently purify base-edited cell populations. Compared to conventional cell enrichment strategies that employ reporters of transfection (RoT), TREE significantly improved the editing efficiency at multiple independent loci, with efficiencies approaching 80%. We also employed the BFP-to-GFP conversion assay to optimize base editor vector design in human pluripotent stem cells (hPSCs), a cell type that is resistant to genome editing and in which modification via base editors has not been previously reported. At last, using these optimized vectors in the context of TREE allowed for the highly efficient editing of hPSCs. We envision TREE as a readily adoptable method to facilitate base editing applications in synthetic biology, disease modeling, and regenerative medicine.
    • Thermotectonic History of the Kluane Ranges and Evolution of the Eastern Denali Fault Zone in Southwestern Yukon, Canada

      McDermott, Robert G.; Ault, Alexis K.; Caine, Jonathan Saul; Thomson, Stuart N.; Univ Arizona, Dept Geosci (AMER GEOPHYSICAL UNION, 2019-08-15)
      Exhumation and landscape evolution along strike-slip fault systems reflect tectonic processes that accommodate and partition deformation in orogenic settings. We present 17 new apatite (U-Th)/He (He), zircon He, apatite fission-track (FT), and zircon FT dates from the eastern Denali fault zone (EDFZ) that bounds the Kluane Ranges in Yukon, Canada. The dates elucidate patterns of deformation along the EDFZ. Mean apatite He, apatite FT, zircon He, and zircon FT sample dates range within similar to 26-4, similar to 110-12, similar to 94-28, and similar to 137-83 Ma, respectively. A new zircon U-Pb date of 113.9 +/- 1.7 Ma (2 sigma) complements existing geochronology and aids in interpretation of low-temperature thermochronometry data patterns. Samples <= 2 km southwest of the EDFZ trace yield the youngest thermochronometry dates. Multimethod thermochronometry, zircon He date-effective U patterns, and thermal history modeling reveal rapid cooling similar to 95-75 Ma, slow cooling similar to 75-30 Ma, and renewed rapid cooling similar to 30 Ma to present. The magnitude of net surface uplift constrained by published paleobotanical data, exhumation, and total surface uplift from similar to 30 Ma to present are similar to 1, similar to 2-6, and similar to 1-7 km, respectively. Exhumation is highest closest to the EDFZ trace but substantially lower than reported for the central Denali fault zone. We infer exhumation and elevation changes associated with similar to 95-75 Ma terrane accretion and EDFZ activity, relief degradation from similar to 75-30 Ma, and similar to 30 Ma to present exhumation and surface uplift as a response to flat-slab subduction and transpressional deformation. Integrated results reveal new constraints on landscape evolution within the Kluane Ranges directly tied to the EDFZ during the last similar to 100 Myr.
    • The Third Data Release of the Beijing–Arizona Sky Survey

      Zou, Hu; Zhou, Xu; Fan, Xiaohui; Zhang, Tianmeng; Zhou, Zhimin; Peng, Xiyan; Nie, Jundan; Jiang, Linhua; McGreer, Ian; Cai, Zheng; et al. (IOP PUBLISHING LTD, 2019-10-30)
      The Beijing–Arizona Sky Survey (BASS) is a wide and deep imaging survey that covers a 5400 deg2 area in the northern Galactic cap with the 2.3 m Bok telescope using two filters (g and r bands). The Mosaic z-band Legacy Survey (MzLS) covers the same area in the z band with the 4 m Mayall telescope. These two surveys will be used for spectroscopic targeting by the Dark Energy Spectroscopic Instrument (DESI) in the northernmost portion of the DESI footprint. This paper describes the third data release (DR3) of BASS, which contains the photometric data from all BASS and MzLS observations from 2015 January until the completion of BASS in 2019 March. The median astrometric precision relative to Gaia positions is about 17 mas and the median photometric offset relative to the Pan-STARRS1 photometry is within 5 mmag. The median 5σ AB magnitude depths for point sources are 24.2, 23.6, and 23.0 mag for the g, r, and z bands, respectively. The photometric depth within the survey area is highly homogeneous, and the difference between the 20% and 80% depth is less than 0.3 mag. The DR3 data, including raw data, calibrated single-epoch images, single-epoch photometric catalogs, stacked images, and co-added photometric catalogs, are publicly accessible at http://batc.bao.ac.cn/BASS/doku.php?id=datarelease:home.
    • Probe misalignment calibration in fiber point-diffraction interferometer

      Wang, Daodang; Xie, Zhongmin; Wang, Chao; Liang, Jian; Wu, Heng; Kong, Ming; Univ Arizona, James C Wyant Coll Opt Sci (OPTICAL SOC AMER, 2019-11-07)
      The measuring probe integrated with multiple fiber point-diffraction sources can be applied to measure both the three-dimensional coordinates and highly accurate point-diffraction wavefront. The probe determines the achievable measurement accuracy of fiber point-diffraction interferometer (PDI), in which the fiber exit end plane is required to be parallel with the detector plane. The probe misalignment due to fabrication error could introduce significant measurement error. A high-precision method is proposed to calibrate the probe misalignment in fiber PDI, including the central positioning based on phase difference and tilt adjustment based on Zernike polynomials fitting. Both numerical simulation and experiments have been carried out to demonstrate the feasibility and accuracy of the proposed probe misalignment calibration method. The proposed method provides a feasible way to address the processing uncertainty on measuring probe in fiber PDI, and enables high-precision geometry alignment and misalignment calibration in the interferometric testing systems with case of no imaging lens.
    • Distinct stores and the routing of water in the deep critical zone of a snow-dominated volcanic catchment

      White, Alissa; Moravec, Bryan; McIntosh, Jennifer; Olshansky, Yaniv; Paras, Ben; Sanchez, R. Andres; Ferré, Ty P. A.; Meixner, Thomas; Chorover, Jon; Univ Arizona, Dept Soil Water & Environm Sci; et al. (COPERNICUS GESELLSCHAFT MBH, 2019-11-18)
      This study combines major ion and isotope chemistry, age tracers, fracture density characterizations, and physical hydrology measurements to understand how the structure of the critical zone (CZ) influences its function, including water routing, storage, mean water residence times, and hydrologic response. In a high elevation rhyolitic tuff catchment in the Jemez River Basin Critical Zone Observatory (JRB-CZO) within the Valles Caldera National Preserve (VCNP) of northern New Mexico, a periodic precipitation pattern creates different hydrologic flow regimes during spring snowmelt, summer monsoon rain, and fall storms. Hydrometric, geochemical, and isotopic analyses of surface water and groundwater from distinct stores, most notably shallow groundwater that is likely a perched aquifer in consolidated collapse breccia and deeper groundwater in a fractured tuff aquifer system, enabled us to untangle the interactions of these groundwater stores and their contribution to streamflow across 1 complete water year (WY). Despite seasonal differences in groundwater response due to water partitioning, major ion chemistry indicates that deep groundwater from the highly fractured site is more representative of groundwater contributing to streamflow across the entire water year. Additionally, the comparison of streamflow and groundwater hydrographs indicates a hydraulic connection between the fractured welded tuff aquifer system and streamflow, while the shallow aquifer within the collapse breccia deposit does not show this same connection. Furthermore, analysis of age tracers and oxygen (δ18O) and stable hydrogen (δ2H) isotopes of water indicates that groundwater is a mix of modern and older waters recharged from snowmelt, and downhole neutron probe surveys suggest that water moves through the vadose zone both by vertical infiltration and subsurface lateral flow, depending on the lithology. We find that in complex geologic terrain like that of the JRB-CZO, differences in the CZ architecture of two hillslopes within a headwater catchment control water stores and routing through the subsurface and suggest that shallow groundwater does not contribute significantly to streams, while deep fractured aquifer systems contribute most to streamflow.
    • GATA2 controls lymphatic endothelial cell junctional integrity and lymphovenous valve morphogenesis through

      Mahamud, Md Riaj; Geng, Xin; Ho, Yen-Chun; Cha, Boksik; Kim, Yuenhee; Ma, Jing; Chen, Lijuan; Myers, Greggory; Camper, Sally; Mustacich, Debbie; et al. (COMPANY BIOLOGISTS LTD, 2019-11-05)
      Mutations in the transcription factor GATA2 cause lymphedema. GATA2 is necessary for the development of lymphatic valves and lymphovenous valves, and for the patterning of lymphatic vessels. Here, we report that GATA2 is not necessary for valvular endothelial cell (VEC) differentiation. Instead, GATA2 is required for VEC maintenance and morphogenesis. GATA2 is also necessary for the expression of the cell junction molecules VE-cadherin and claudin 5 in lymphatic vessels. We identified miR-126 as a target of GATA2, and miR-126-/- embryos recapitulate the phenotypes of mice lacking GATA2. Primary human lymphatic endothelial cells (HLECs) lacking GATA2 (HLECΔGATA2) have altered expression of claudin 5 and VE-cadherin, and blocking miR-126 activity in HLECs phenocopies these changes in expression. Importantly, overexpression of miR-126 in HLECΔGATA2 significantly rescues the cell junction defects. Thus, our work defines a new mechanism of GATA2 activity and uncovers miR-126 as a novel regulator of mammalian lymphatic vascular development.
    • Niraparib Maintenance Therapy in Patients With Recurrent Ovarian Cancer After a Partial Response to the Last Platinum-Based Chemotherapy in the ENGOT-OV16/NOVA Trial

      Del Campo, Josep M; Matulonis, Ursula A; Malander, Susanne; Provencher, Diane; Mahner, Sven; Follana, Philippe; Waters, Justin; Berek, Jonathan S; Woie, Kathrine; Oza, Amit M; et al. (AMER SOC CLINICAL ONCOLOGY, 2019-06-07)
      A total of 553 patients were enrolled in the trial. Of 203 patients with a germline BRCA mutation (gBRCAmut), 99 had a PR and 104 had a CR to their last platinum-based therapy; of 350 patients without a confirmed gBRCAmut (non-gBRCAmut), 173 had a PR and 177 had a CR. Post hoc analyses were carried out to evaluate safety and the risk of progression in these patients according to gBRCAmut status and response to their last platinum-based therapy. Ovarian cancer-specific symptoms and quality of life were assessed using the Functional Assessment of Cancer Therapy-Ovarian Symptom Index.
    • Quantifying the thermal Sunyaev–Zel’dovich effect and excess millimetre emission in quasar environments

      Hall, Kirsten R; Zakamska, Nadia L; Addison, Graeme E; Battaglia, Nicholas; Crichton, Devin; Devlin, Mark; Dunkley, Joanna; Gralla, Megan; Hill, J Colin; Hilton, Matt; et al. (OXFORD UNIV PRESS, 2019-10-03)
      In this paper, we probe the hot, post-shock gas component of quasar-driven winds through the thermal SunyaevZeldovich (tSZ) effect. Combining data sets from the Atacama Cosmology Telescope, the Herschel Space Observatory, and the Very Large Array, we measure average spectral energy distributions of 109 829 optically selected, radio quiet quasars from 1.4 to 3000 GHz in six redshift bins between 0.3 < z < 3.5. We model the emission components in the radio and far-infrared, plus a spectral distortion from the tSZ effect. At z > 1.91, we measure the tSZ effect at 3.8 sigma significance with an amplitude corresponding to a total thermal energy of 3.1 x 10(60) erg. If this energy is due to virialized gas, then our measurement implies quasar host halo masses are similar to 6 x 10(12) h(-1) M-circle dot. Alternatively, if the host dark matter halo masses are similar to 2 x 10(12) h(-1) M-circle dot as some measurements suggest, then we measure a >90 per?cent excess in the thermal energy over that expected due to virialization. If the measured SZ effect is primarily due to hot bubbles from quasar-driven winds, we find that (5(-1.3)(+1.2)) per?cent of the quasar bolometric luminosity couples to the intergalactic medium over a fiducial quasar lifetime of 100 Myr. An additional source of tSZ may be correlated structure, and further work is required to separate the contributions. At z <= 1.91, we detect emission at 95 and 148 GHz that is in excess of thermal dust and optically thin synchrotron emission. We investigate potential sources of this excess emission, finding that CO line emission and an additional optically thick synchrotron component are the most viable candidates.
    • A Triple AGN in a Mid-infrared Selected Late-stage Galaxy Merger

      Pfeifle, Ryan W.; Satyapal, Shobita; Manzano-King, Christina; Cann, Jenna; Sexton, Remington O.; Rothberg, Barry; Canalizo, Gabriela; Ricci, Claudio; Blecha, Laura; Ellison, Sara L.; et al. (IOP PUBLISHING LTD, 2019-10-01)
      The coevolution of galaxies and the supermassive black holes (SMBHs) at their centers via hierarchical galaxy mergers is a key prediction of Lambda CDM cosmology. As gas and dust are funneled to the SMBHs during the merger, the SMBHs light up as active galactic nuclei (AGNs). In some cases, a merger of two galaxies can encounter a third galaxy, leading to a triple merger, which would manifest as a triple AGN if all three SMBHs are simultaneously accreting. Using high spatial resolution X-ray, near-IR, and optical spectroscopic diagnostics, we report here a compelling case of an AGN triplet with mutual separations <10 kpc in the advanced merger SDSS J084905.51+111447.2 at z = 0.077. The system exhibits three nuclear X-ray sources, optical spectroscopic line ratios consistent with AGN in each nucleus, a high excitation near-IR coronal line in one nucleus, and broad Pa alpha detections in two nuclei. Hard X-ray spectral fitting reveals a high column density along the line of sight, consistent with the picture of late-stage mergers hosting heavily absorbed AGNs. Our multiwavelength diagnostics support a triple AGN scenario, and we rule out alternative explanations such as star formation activity, shock-driven emission, and emission from fewer than three AGN. The dynamics of gravitationally bound triple SMBH systems can dramatically reduce binary SMBH inspiral timescales, providing a possible means to surmount the "Final Parsec Problem." AGN triplets in advanced mergers are the only observational forerunner to bound triple SMBH systems and thus offer a glimpse of the accretion activity and environments of the AGNs prior to the gravitationally bound triple phase.
    • Cloud Atlas: Variability in and out of the Water Band in the Planetary-mass HD 203030B Points to Cloud Sedimentation in Low-gravity L Dwarfs

      Miles-Páez, Paulo A.; Metchev, Stanimir; Apai, Dániel; Zhou, Yifan; Manjavacas, Elena; Karalidi, Theodora; Lew, Ben W. P.; Burgasser, Adam J.; Bedin, Luigi R.; Cowan, Nicolas; et al. (IOP PUBLISHING LTD, 2019-10-03)
      We use the Wide Field Camera 3 on the Hubble Space Telescope to spectrophotometrically monitor the young L7.5 companion HD 203030B. Our time series reveal photometric variability at 1.27 and 1.39 mu m on timescales compatible with rotation. We find a rotation period of 7.5(0.5)(+0.6) hr: comparable to those observed in other brown dwarfs and planetary-mass companions younger than 300 Myr. We measure variability amplitudes of 1.1% +/- 0.3% (1.27 mu m) and 1.7% +/- 0.4% (1.39 mu m), and a phase lag of 56 degrees +/- 28 degrees between the two light curves. We attribute the difference in photometric amplitudes and phases to a patchy cloud layer that is sinking below the level where water vapor becomes opaque. HD 203030B and the few other known variable young late-L dwarfs are unlike warmer (earlier-type and/or older) L dwarfs, for which variability is much less wavelength-dependent across the 1.1-1.7 mu m region. We further suggest that a sinking of the top-most cloud deck below the level where water or carbon monoxide gas become opaque may also explain the often enhanced variability amplitudes of even earlier-type low-gravity L dwarfs. Because these condensate and gas opacity levels are already well-differentiated in T dwarfs, we do not expect the same variability amplitude enhancement in young versus old T dwarfs.
    • Formulating an Elasticity Approach to Quantify the Effects of Climate Variability and Ecological Restoration on Sediment Discharge Change in the Loess Plateau, China

      Zhang, Jianjun; Gao, Guangyao; Fu, Bojie; Gupta, Hoshin V.; Univ Arizona, Dept Hydrol & Atmospher Sci (AMER GEOPHYSICAL UNION, 2019-11-11)
      Suspended sediment yields (SSY) respond strongly to ecological restoration (ER) efforts, and significant improvements in SSY control have been achieved in the Loess Plateau of China. However, it remains challenging to quantify the net impacts of ER on SSY. Here, we formulate the notion of elasticity of sediment discharge, by associating SSY change to climate variability and ER over the period 1950s to 2014. All ten of the subcatchments studied experienced significant decreases in annual SSY, streamflow, and suspended sediment concentration. Our results strongly support the hypothesis that changes to both streamflow volumes and to the suspended sediment concentration versus water discharge (C-Q) relationships result in reduced SSY, so that streamflow is reduced but runs clearer. We find that two of the ER strategies resulted in weaker relative impacts of climate variability, largely by reducing streamflow (by 55% to 75%). Meanwhile, ER predominantly decreased SSY (by 63% to 81%). Regarding ER practices, (i) the predominant measure acting to reduce SSY changed, over time, from engineering to reforestation; (ii) check dams preferentially act to regulate the C-Q relationships, whereas reforestation preferentially acts to moderate streamflow. Overall, our results suggest that a combination of engineering and vegetation measures is critical to achieving high-efficiency ER. While change to the ER strategy increased the efficiency of streamflow for SSY control, the lost water discharge per unit SSY reduction increased from 5.2 to 6.4 m(3)t(-1). Conflicting demands for water necessitate that further ER should target precision management by revegetation of targeted areas in the Loess Plateau.
    • Dynamical masses and mass-to-light ratios of resolved massive star clusters – I. NGC 419 and NGC 1846

      Song, Ying-Yi; Mateo, Mario; Mackey, A D; Olszewski, Edward W; Roederer, Ian U; Walker, Matthew G; Bailey, John I; Univ Arizona, Steward Observ (OXFORD UNIV PRESS, 2019-09-07)
      As an introduction of a kinematic survey of Magellanic Cloud (MC) star clusters, we report on the dynamical masses and mass-to-light ratios (M/L) of NGC 419 (Small Magellanic Cloud) and NGC 1846 (Large Magellanic Cloud). We have obtained more than one hundred high-resolution stellar spectra in and around each cluster using the multi-object spectrograph M2FS on the Magellan/Clay Telescope. Line-of-sight velocities and positions of the stars observed in each cluster were used as input to an expectation-maximization algorithm used to estimate cluster membership probabilities, resulting in samples of 46 and 52 likely members (P-M >= 50 per cent) in NGC 419 and NGC 1846, respectively. This process employed single-mass King models constrained by the structural parameters of the clusters and provided self-consistent dynamical mass estimates for both clusters. Our best-fitting results show that NGC 419 has a projected central velocity dispersion of 2.44(-0.21)(+0.37) km s(-1), corresponding to a total mass of 7.6(-1.3)(+2.5) x 10(4) M-circle dot and V-band M/L ratio of 0.22(-0.05)(+0.08) in solar units. For NGC 1846, the corresponding results are 2.04(-0.24)(+0.28) km s(-1), 5.4(-1.4)(+1.5) x 10(4) M-circle dot, and 0.32(-0.11)(+0.11). The mean metallicities of NGC 419 and NGC 1846 are found to be [Fe/H] =-0.84 +/- 0.19 and -0.70 +/- 0.08, respectively, based on the spectra of likely cluster members. We find marginal statistical evidence of rotation in both clusters, though in neither cluster does rotation alter our mass estimates significantly. We critically compare our findings with those of previous kinematic studies of these two clusters in order to evaluate the consistency of our observational results and analytic tools.