Science.gov

Sample records for aged mcs outflow

  1. The Non-coding Mammary Carcinoma Susceptibility Locus, Mcs5c, Regulates Pappa Expression via Age-Specific Chromatin Folding and Allele-Dependent DNA Methylation

    PubMed Central

    Henning, Amanda N.; Haag, Jill D.; Smits, Bart M. G.; Gould, Michael N.

    2016-01-01

    In understanding the etiology of breast cancer, the contributions of both genetic and environmental risk factors are further complicated by the impact of breast developmental stage. Specifically, the time period ranging from childhood to young adulthood represents a critical developmental window in a woman’s life when she is more susceptible to environmental hazards that may affect future breast cancer risk. Although the effects of environmental exposures during particular developmental Windows of Susceptibility (WOS) are well documented, the genetic mechanisms governing these interactions are largely unknown. Functional characterization of the Mammary Carcinoma Susceptibility 5c, Mcs5c, congenic rat model of breast cancer at various stages of mammary gland development was conducted to gain insight into the interplay between genetic risk factors and WOS. Using quantitative real-time PCR, chromosome conformation capture, and bisulfite pyrosequencing we have found that Mcs5c acts within the mammary gland to regulate expression of the neighboring gene Pappa during a critical mammary developmental time period in the rat, corresponding to the human young adult WOS. Pappa has been shown to positively regulate the IGF signaling pathway, which is required for proper mammary gland/breast development and is of increasing interest in breast cancer pathogenesis. Mcs5c-mediated regulation of Pappa appears to occur through age-dependent and mammary gland-specific chromatin looping, as well as genotype-dependent CpG island shore methylation. This represents, to our knowledge, the first insight into cellular mechanisms underlying the WOS phenomenon and demonstrates the influence developmental stage can have on risk locus functionality. Additionally, this work represents a novel model for further investigation into how environmental factors, together with genetic factors, modulate breast cancer risk in the context of breast developmental stage. PMID:27537370

  2. The Non-coding Mammary Carcinoma Susceptibility Locus, Mcs5c, Regulates Pappa Expression via Age-Specific Chromatin Folding and Allele-Dependent DNA Methylation.

    PubMed

    Henning, Amanda N; Haag, Jill D; Smits, Bart M G; Gould, Michael N

    2016-08-01

    In understanding the etiology of breast cancer, the contributions of both genetic and environmental risk factors are further complicated by the impact of breast developmental stage. Specifically, the time period ranging from childhood to young adulthood represents a critical developmental window in a woman's life when she is more susceptible to environmental hazards that may affect future breast cancer risk. Although the effects of environmental exposures during particular developmental Windows of Susceptibility (WOS) are well documented, the genetic mechanisms governing these interactions are largely unknown. Functional characterization of the Mammary Carcinoma Susceptibility 5c, Mcs5c, congenic rat model of breast cancer at various stages of mammary gland development was conducted to gain insight into the interplay between genetic risk factors and WOS. Using quantitative real-time PCR, chromosome conformation capture, and bisulfite pyrosequencing we have found that Mcs5c acts within the mammary gland to regulate expression of the neighboring gene Pappa during a critical mammary developmental time period in the rat, corresponding to the human young adult WOS. Pappa has been shown to positively regulate the IGF signaling pathway, which is required for proper mammary gland/breast development and is of increasing interest in breast cancer pathogenesis. Mcs5c-mediated regulation of Pappa appears to occur through age-dependent and mammary gland-specific chromatin looping, as well as genotype-dependent CpG island shore methylation. This represents, to our knowledge, the first insight into cellular mechanisms underlying the WOS phenomenon and demonstrates the influence developmental stage can have on risk locus functionality. Additionally, this work represents a novel model for further investigation into how environmental factors, together with genetic factors, modulate breast cancer risk in the context of breast developmental stage. PMID:27537370

  3. Cohort profile: UK Millennium Cohort Study (MCS).

    PubMed

    Connelly, Roxanne; Platt, Lucinda

    2014-12-01

    The UK Millennium Cohort Study (MCS) is an observational, multidisciplinary cohort study that was set up to follow the lives of children born at the turn of the new century. The MCS is nationally representative and 18 552 families (18 827 children) were recruited to the cohort in the first sweep. There have currently been five main sweeps of data collection, at ages 9 months and 3, 5, 7 and 11 years. A further sweep of data collection is planned for age 14 years. A range of health-related data have been collected as well as measures concerning child development, cognitive ability and educational attainment. The data also include a wealth of information describing the social, economic and demographic characteristics of the cohort members and their families. In addition, the MCS data have been linked to administrative data resources including health records. The MCS provides a unique and valuable resource for the analysis of health outcomes and health inequalities. The MCS data are freely available to bona fide researchers under standard access conditions via the UK Data Service (http://ukdataservice.ac.uk) and the MCS website provides detailed information on the study (http://www.cls.ioe.ac.uk/mcs). PMID:24550246

  4. Toward an improved understanding of MCS propagation

    NASA Astrophysics Data System (ADS)

    Peters, J. M.

    2015-12-01

    Processes that drive the propagation of elevated mesoscale convective systems (MCSs) have been the topic of a growing body of recent research. Elevated MCSs are responsible for a large percentage of warm season rainfall in the continental United States, and produce flash floods more frequently than other modes of convection. A comprehensive understanding of the dynamics of MCS propagation is important, since propagation sometimes opposes other environmental forces that influence MCS motion. This leads to nearly stationary MCSs that produce prolific local rainfall totals. The ingredients-based Propagation index (IPI) is introduced in this research. IPI is defined as the normalized product of horizontal warm thermal advection (a proxy for lifting), convective available potential energy (CAPE), and relative humidity. Horizontal plots of IPI are useful in identifying regions of probable convective initiation, including the intersections between potentially unstable flow and outflow boundaries, regions of mesoscale lift along the nose of the low-level jet, convectively induced gravity waves, and frontogenesis. Effective inflow-layer shear vectors are also introduced, and found to be useful for scenarios where IPI does yield predictive insight, such as the traditional "RKW" scenario where the forward propagation of an MCS is driven by thunderstorm outflow. It is argued that horizontal maps of IPI and EILS vectors will contribute significantly to short-term (e.g. 1-2 hr) predictions of the movement of MCSs, and to the subsequent assessment of their potential for flash flood production.

  5. Microscopic Characterization of Carbonaceous Aerosol Particle Aging in the Outflow from Mexico City

    SciTech Connect

    Moffet, R. C.; Henn, T. R.; Tivanski, A. V.; Hopkins, R. J.; Desyaterik, Y.; Kilcoyne, A. L. D.; Tyliszczak, T.; Fast, J.; Barnard, J.; Shutthanandan, V.; Cliff, S.S.; Perry, K. D.; Laskin, A.; Gilles, M. K.

    2009-09-16

    This study was part of the Megacities Initiative: Local and Global Research Observations (MILAGRO) field campaign conducted in Mexico City Metropolitan Area during spring 2006. The physical and chemical transformations of particles aged in the outflow from Mexico City were investigated for the transport event of 22 March 2006. A detailed chemical analysis of individual particles was performed using a combination of complementary microscopy and micro-spectroscopy techniques. The applied techniques included scanning transmission X-ray microscopy (STXM) coupled with near edge X-ray absorption fine structure spectroscopy (NEXAFS) and computer controlled scanning electron microscopy with an energy dispersive X-ray analyzer (CCSEM/EDX). As the aerosol plume evolves from the city center, the organic mass per particle increases and the fraction of carbon-carbon double bonds (associated with elemental carbon) decreases. Organic functional groups enhanced with particle age include: carboxylic acids, alkyl groups, and oxygen bonded alkyl groups. At the city center (T0) the most prevalent aerosol type contained inorganic species (composed of sulfur, nitrogen, oxygen, and potassium) coated with organic material. At the T1 and T2 sites, located northeast of T0 (~;;29 km and ~;;65 km, respectively), the fraction of homogenously mixed organic particles increased in both size and number. These observations illustrate the evolution of the physical mixing state and organic bonding in individual particles in a photochemically active environment.

  6. Dust Science with SPICA/MCS

    NASA Astrophysics Data System (ADS)

    Sakon, I.; Onaka, T.; Kataza, H.; Wada, T.; Sarugaku, Y.; Matsuhara, H.; Nakagawa, T.; Kobayashi, N.; Kemper, C.; Ohyama, Y.; Matsumoto, T.; Seok, J. Y.

    Mid-Infrared Camera and Spectrometers (MCS) is one of the Focal-Plane Instruments proposed for the SPICA mission in the pre-project phase. SPICA MCS is equipped with two spectrometers with different spectral resolution powers (R=λ /δ λ ); medium-resolution spectrometer (MRS) which covers 12-38µ m with R≃1100-3000, and high-resolution spectrometer (HRS) which covers either 12-18µ m with R≃30000. MCS is also equipped with Wide Field Camera (WFC), which is capable of performing multi-objects grism spectroscopy in addition to the imaging observation. A small slit aperture for low-resolution slit spectroscopy is planned to be placed just next to the field of view (FOV) aperture for imaging and slit-less spectroscopic observation. MCS covers an important part of the core spectral range of SPICA and, complementary with SAFARI (SpicA FAR-infrared Instrument), can do crucial observations for a number of key science cases to revolutionize our understanding of the lifecycle of dust in the universe. In this article, the latest design specification and the expected performance of the SPICA/MCS are introduced. Key science cases that should be targetted by SPICA/MCS have been discussed by the MCS science working group. Among such science cases, some of those related to dust science are briefly introduced.

  7. Relating the Hadamard Variance to MCS Kalman Filter Clock Estimation

    NASA Technical Reports Server (NTRS)

    Hutsell, Steven T.

    1996-01-01

    The Global Positioning System (GPS) Master Control Station (MCS) currently makes significant use of the Allan Variance. This two-sample variance equation has proven excellent as a handy, understandable tool, both for time domain analysis of GPS cesium frequency standards, and for fine tuning the MCS's state estimation of these atomic clocks. The Allan Variance does not explicitly converge for the nose types of alpha less than or equal to minus 3 and can be greatly affected by frequency drift. Because GPS rubidium frequency standards exhibit non-trivial aging and aging noise characteristics, the basic Allan Variance analysis must be augmented in order to (a) compensate for a dynamic frequency drift, and (b) characterize two additional noise types, specifically alpha = minus 3, and alpha = minus 4. As the GPS program progresses, we will utilize a larger percentage of rubidium frequency standards than ever before. Hence, GPS rubidium clock characterization will require more attention than ever before. The three sample variance, commonly referred to as a renormalized Hadamard Variance, is unaffected by linear frequency drift, converges for alpha is greater than minus 5, and thus has utility for modeling noise in GPS rubidium frequency standards. This paper demonstrates the potential of Hadamard Variance analysis in GPS operations, and presents an equation that relates the Hadamard Variance to the MCS's Kalman filter process noises.

  8. Raman Lidar Observations of a MCS in the frame of the Convective and Orographically-induced Precipitation Study

    NASA Astrophysics Data System (ADS)

    Di Girolamo, Paolo; Bhawar, Rohini; Summa, Donato; Di Iorio, Tatiana; Demoz, Belay B.

    2009-03-01

    The Raman lidar system BASIL was deployed in Achern (Supersite R, Lat: 48.64° N, Long: 8.06° E, Elev.: 140 m) in the frame of the Convective and Orographically-induced Precipitation Study. On 20 July 2007 a frontal zone passed over the COPS region, with a Mesoscale Convective System (MCS) imbedded in it. BASIL was operated continuously during this day, providing measurements of temperature, water vapour, particle backscattering coefficient at 355, 532 and 1064 nm, particle extinction coefficient at 355 and 532 nm and particle depolarization at 355 and 532 nm. The thunderstorm approaching determined the lowering of the anvil clouds, which is clearly visible in the lidar data. A cloud deck is present at 2 km, which represents a mid-level outflow from the thunderstorm/MCS. The mid-level outflow spits out hydrometeor-debris (mostly virga) and it is recycled back into it. The MCS modified the environment at 1.6-2.5 km levels directly (outflow) and the lower levels through the virga/precipitation. Wave structures were observed in the particle backscatter data. The wave activity seems to be a reflection of the shear that is produced by the MCS and the inflow environmental wind. Measurements in terms of particle backscatter and water vapour mixing ratio are discussed to illustrate the above phenomena.

  9. S1 guideline: microscopically controlled surgery (MCS).

    PubMed

    Löser, Christoph R; Rompel, Rainer; Möhrle, Matthias; Häfner, Hans-Martin; Kunte, Christian; Hassel, Jessica; Hohenleutner, Ulrich; Podda, Maurizio; Sebastian, Günther; Hafner, Jürg; Kaufmann, Roland; Breuninger, Helmut

    2015-09-01

    When using procedures that enable complete examination of surgical margins (3D histology), microscopically controlled surgery (MCS) represents a safe and proven method to confirm R0 resection of infiltrating tumors, especially at problematic sites, while preserving the adjacent tissue. This allows for excellent or good aesthetic results that are superior (cryosurgery, short-range irradiation) or equivalent (PDT) to nonsurgical and less safe procedures (PDT). PMID:26882393

  10. Response of mesoscale convective system (MCS) and cold pool formation to dust-radiative effects

    NASA Astrophysics Data System (ADS)

    Waylonis, M. T.; Chen, S. H.

    2014-12-01

    This study examines the role of dust in the development of a mesoscale convective system (MCS) over the central-west Sahara, and how cold pools from the MCS feedback to dust emissions. Few studies have simulated the direct-radiative effects of dust on cloud development. Moderate Resolution Imaging Spectrometer (MODIS) and Multi-angle Imaging Spectrometer (MISR) Retrieved aerosol optical depth and Meteosat Second Generation dust enhancement product were used to examine a dust outbreak that occurred between 13 and 15 August 2005 and revealed that an moist intrusion into the Sahara caused a MCS to form and resulted in dust emission due to cold pool outflow from the MCS. A dust model based on the Weather Research and Forecasting model was developed to include dust emissions, transport, dry and moist deposition, and radiation interactions and was used to simulate the case. Dust-radiation interactions were found to enhance convective strength through low-level heating, which increased convective available potential energy and low-level convergence. The increased intensity of the convection led to stronger and more widespread cold pool formation, which in turn emitted more dust into the atmosphere.

  11. Multiple Chemical Sensitivity (MCS) - Scientific and Public-Health Aspects

    PubMed Central

    Schwenk, Michael

    2004-01-01

    Multiple Chemical Sensitivity (MCS) is a phenomenon which the ENT-doctor should be familiar with. It has its roots in the description of a syndrome in 1987. A worker spilled chemicals at his workplace and from then on he reacted highly sensitive to chemicals. Today, there are many people who explain their complaints with self-suspected MCS. Various pathopysiological models have been proposed, including toxicological, immunological or behaviorial models. But no-one could be proved so far. Since controlled provocation tests have also provided unclear results, an increasing number of doctors assumes today, that MCS reflects a psychic condition. In 1996, an expert team of the WHO has suggested the renaming of MCS to "idiopathic environmental illness" (IEI). However, other doctors still assume a chemical cause. Since there are neither straightforward diagnostic methods to proof MCS, nor reliable therapeutic concepts, treatment of MCS-patients is usually difficult. The MCS-debate (somatic vs psychic causes) seems to reflect the dilemma of the medical profession today, that somatic disorders of known origin can be well treated, whereas the increasing number of psychosomatic/ somatoform disorders is often resistant to medical help. The ENT-doctor should pay attention to changes of the nasal mucous membrane, nasal resistance and the sense of smell. Moreover he should know about the peculiarities of MCS-patients. The manuscript describes the present knowledge and state of discussion with special regard to the situation in Germany. PMID:22073047

  12. Testing the MCS Deconvolution Algorithm on Infrared Data

    NASA Astrophysics Data System (ADS)

    Egan, M.

    Magain, Courbin and Sohy (MCS 1998, AJ, 494, 472) proposed a two-channel (separable point source and extended background) method for astronomical image deconvolution. Unlike the two-channel Richardson-Lucy algorithm, the MCS method does not require prior knowledge of the point source amplitudes and positions. MCS have claimed that their method produces accurate astrometry and photometry in crowded fields and in the presence of variable backgrounds. This paper compares MSX 8 micron Galactic plane images deconvolved via the MCS method with Spitzer Space Telescope IRAC 8 micron images of the same regions. The improved sampling and final image PSF for the deconvolved MSX image is chosen to match the Spitzer observation. In the parlance of MCS, this determines the light distribution for an 85 cm telescope (Spitzer) by deconvolving data taken with a 33 cm space telescope (MSX). Deconvolution of both the Spitzer and MSX data are also presented that reconstruct the image at resolution consistent with that expected from the 6.5 meter aperture James Webb Space Telescope. I will present results for varying degrees of background complexity and examine the limitations of the MCS method for use on infrared data in regions of high source density and bright, complex backgrounds.

  13. Deformation of ICMEs/MCs along their path

    NASA Astrophysics Data System (ADS)

    Lynnyk, A.; Šafránková, J.; Němeček, Z.; Richardson, J. D.

    2011-07-01

    Interplanetary coronal mass ejections (ICMEs) and their subset, magnetic clouds (MCs), are important manifestations of solar activity which have substantial impact on the geomagnetic field. We re-analyze events already identified in Wind and Voyager 2 data and estimate changes of their geometry along the path from the Sun. The analysis is based on the thickness of the sheath between a shock and a particular ICME or MC which is proportional to the apparent curvature radius of ICMEs/MCs. We have found that this apparent radius of curvature increases with the Mach number and this effect is attributed to the larger deformation of the fast ICME/MC. Further, the relative sheath thickness that is proportional to the flux rope oblateness decreases with the magnetic field intensity inside the ICME/MC and increases with the heliospheric distance.

  14. Fine tuning GPS clock estimation in the MCS

    NASA Technical Reports Server (NTRS)

    Hutsell, Steven T.

    1995-01-01

    With the completion of a 24 operational satellite constellation, GPS is fast approaching the critical milestone, Full Operational Capability (FOC). Although GPS is well capable of providing the timing accuracy and stability figures required by system specifications, the GPS community will continue to strive for further improvements in performance. The GPS Master Control Station (MCS) recently demonstrated that timing improvements are always composite Clock, and hence, Kalman Filter state estimation, providing a small improvement to user accuracy.

  15. MCS precipitation and downburst intensity response to increased aerosol concentrations

    NASA Astrophysics Data System (ADS)

    Clavner, M.; Cotton, W. R.; van den Heever, S. C.

    2015-12-01

    Mesoscale convective systems (MCSs) are important contributors to rainfall in the High Plains of the United States as well as producers of severe weather such as hail, tornados and straight-line wind events known as derechos. Past studies have shown that changes in aerosol concentrations serving as cloud condensation nuclei (CCN) alter the MCS hydrometeor characteristics which in turn modify precipitation yield, downdraft velocity, cold-pool strength, storm propagation and the potential for severe weather to occur. In this study, the sensitivity of MCS precipitation characteristics and convective downburst velocities associated with a derecho to changes in CCN concentrations were examined by simulating a case study using the Regional Atmospheric Modeling System (RAMS). The case study of the 8 May 2009 "Super-Derecho" MCS was chosen since it produced a swath of widespread wind damage in association with an embedded large-scale bow echo, over a broad region from the High Plains of western Kansas to the foothills of the Appalachians. The sensitivity of the storm to changes in CCN concentrations was examined by conducting a set of three simulations which differed in the initial aerosol concentration based on output from the 3D chemical transport model, GEOS-Chem. Results from this study indicate that while increasing CCN concentrations led to an increase in precipitation rates, the changes to the derecho strength were not linear. A moderate increase in aerosol concentration reduced the derecho strength, while the simulation with the highest aerosol concentrations increased the derecho intensity. These changes are attributed to the impact of enhanced CCN concentration on the production of convective downbursts. An analysis of aerosol loading impacts on these MCS features will be presented.

  16. Clinical consequences of the EI/MCS "diagnosis": two paths.

    PubMed

    Staudenmayer, H

    1996-08-01

    There are two distinct paths down which patients "diagnosed" with environmental illness/multiple chemical sensitivities (EI/MCS) can travel. Along the first path, beliefs about low-level, multiple chemical sensitivities as the cause of physical and psychological symptoms are instilled and reinforced by a host of factors including toxicogenic speculation, iatrogenic influence mediated by unsubstantiated diagnostic and treatment practices, patient support/advocacy networks, and social contagion. Intrapsychic factors also reinforce this path through the motivational mechanism of factitious malingering, or unconscious primary and secondary gain, mediated through psychological defenses, particularly projection of cause of illness onto the physical environment. The second path involves restructuring distorted beliefs about chemical sensitivities. Explanations of the placebo effect, the physiology of the stress response, and the symptoms of anxiety and panic facilitate the direction of EI/MCS patients onto this path. A decision model is presented to discriminate among toxicogenic and psychogenic explanations of the EI/MCS phenomenon, based on appraisal of reaction and physiologic and cognitive responses during provocation chamber challenges under double-blind, placebo-controlled conditions. These studies have been helpful therapeutically for some patients in selecting the path that leads to wellness. This paper suggests how various therapeutic techniques can be employed with difficult patients. Often, supportive psychotherapy establishes a therapeutic alliance which facilitates cognitive therapy to restructure distorted beliefs. In the process of finding alternative explanations to chemical sensitivities, the etiology of symptoms is related to stressful life events, including childhood experiences which may have disrupted normal personality development and coping capacity. Furthermore, biological and physiological sequelae stemming from early, chronic trauma have been

  17. Pulsatile-flow mechanical circulatory support (MCS) as a bridge to transplantation or recovery. Single-centre experience with the POLCAS system in 2014

    PubMed Central

    Kuśmierczyk, Mariusz; Szymański, Jarosław; Juraszek, Andrzej; Kołsut, Piotr; Kuśmierski, Krzysztof; Zieliński, Tomasz; Sobieszczańska-Małek, Małgorzata; Sitkowska-Rysiak, Ewa

    2015-01-01

    Introduction Mechanical circulatory support (MCS) is a recognised method of treatment for patients with end-stage chronic or acute heart failure. The POLCAS pulsatile-flow system has been used in our institution for 15 years. Currently, it is being widely replaced by continuous-flow mechanical circulatory support equipment of the second and third generations (HeartMateII, HeartWare). The MCS presented in this study is associated with a significant risk of complications and its use is increasingly considered controversial. The aim of the study was an evaluation of the results of treatment utilising the POLCAS MCS system at our institution in 2014. Material and methods The POLCAS system was implanted in 12 patients aged 16-63 years (42 ± 17 years) during a period of 12 months (from January to December, 2014). Full-blown cardiogenic shock was observed in all patients before MCS implantation. Four of the analysed patients (33%) required prior circulatory support with other devices: IABP (n = 2) or ECMO (n = 2). Episodes of cardiac arrest were reported in three patients; three other patients experienced serious arrhythmias, which accelerated the decision to implant MCS. The presented data was retrospectively obtained from the CliniNET system of the Institute of Cardiology. OpenOffice Calc spreadsheet was used for data analysis. Results Average MCS time was 41 days ± 25 (from 15 to 91 days). Survival until transplantation or explantation was 91.67%. The most frequent complications following the therapy were: cardiac tamponade or bleeding requiring an intervention – 25% (n = 3), renal failure requiring dialysis – 25% (n = 3), ischaemic stroke associated with the MCS – 16.6% (n = 2), bacteraemia – 16.6% (n = 2), and wound infection – 8% (n = 1). No malfunctions of the MCS system were reported. Early survival in patients who completed the MCS therapy, defined as discharge, amounted to 63.6% (n = 7). Conclusions The POLCAS heart assist system is an effective

  18. Cirrus outflow dynamics

    NASA Technical Reports Server (NTRS)

    Lilly, Douglas K.

    1988-01-01

    In the present analyses of cirrus clouds' deep-convection outflow plumes as dynamically and thermodynamically active systems, the initial outflow is considered as an analog to wake collapse: after a neutrally-buoyant flow intrusion is flattened and stretched by its stratified environment, the initially isotropic turbulence within it is converted to other forms. Dugan et al.'s (1976) analytic and numerical calculations are used to predict the early spread of the outflow. Strong radiative heat flux curvature then leads to maintenance or regeneration of buoyant turbulence in the collapsed outflow plume. The rise of narrow plumes is sufficiently rapid that their mean temperature does not significantly differ from that of their environment.

  19. Structure and activity of the imbricated wedge of the Gulf of Cadiz from MCS images

    NASA Astrophysics Data System (ADS)

    Calahorrano Betancourt, Alcinoe; Ranero, César R.; Gràcia, Eulàlia

    2015-04-01

    In this work we present new results on the structure and activity of the imbricated wedge of the Gulf of Cadiz based on ˜ 3000 km of multichannel (MCS) profiles acquired off NW Moroccan margin. Seismic images indicates that the imbricated wedge is bounded between the Gulf of Cadiz margin at the north, the Kenitra margin at the south and the Rharb margin at the east. It is imaged as a sedimentary body with variable seismic amplitude, and structured by imbricated thrust sheets similar to an accretionary prism. Its maximum thickness is located at the east region of the gulf. It gradually thins toward the center and south of the gulf, where it is buried by ˜0.3 twts of sedimentary deposits, indicating that the imbricated wedge is actually not growing. It probably stops it s activity at ˜5-6 Ma. The imbricated wedge is overlaid by sedimentary sequences whose oldest unit is uppermost Tortonian. No evidences of gravitational (olistostrom) origin were founded. Active deformation related to plate convergence corresponds mainly to strike-slip faulting and minor thrusting. Mud diapirism is imaged intruding both the imbricated wedge and the overlaying sediments. At the south, the seismic images show normal faulting probably related with an extended continental crust or a continent-ocean transition crust. The age of this extension is probably Triassic-Jurassic, and we propose it as the conjugated margin of the Gulf of Cadiz. Toward the east, MCS profiles image high-amplitude continent-verging reflections corresponding to pervasive normal faulting. These deformation related to a extended terrain, named Rharb margin, seems to act as the backstop of the imbricated wedge, and it is over-thrusted by Prebetic/Flysh sequences off the Strait of Gibraltar.

  20. Cdc2 and the Regulation of Mitosis: Six Interacting Mcs Genes

    PubMed Central

    Molz, L.; Booher, R.; Young, P.; Beach, D.

    1989-01-01

    A cdc2-3w weel-50 double mutant of fission yeast displays a temperature-sensitive lethal phenotype that is associated with gross abnormalities of chromosome segregation and has been termed mitotic catastrophe. In order to identify new genetic elements that might interact with the cdc2 protein kinase in the regulation of mitosis, we have isolated revertants of the lethal double mutant. The suppressor mutations define six mcs genes (mcs: mitotic catastrophe suppressor) that are not allelic to any of the following mitotic control genes: cdc2, wee1, cdc13, cdc25, suc1 or nim1. Each mcs mutation is recessive with respect to wild-type in its ability to suppress mitotic catastrophe. None confer a lethal phenotype as a single mutant but few of the mutants are expected to be nulls. A diverse range of genetic interactions between the mcs mutants and other mitotic regulators were uncovered, including the following examples. First, mcs2 cdc2w or mcs6 cdc2w double mutants display a cell cycle defect dependent on the specific wee allele of cdc2. Second, both mcs1 cdc25-22 or mcs4 cdc25-22 double mutants are nonconditionally lethal, even at a temperature normally permissive for cdc25-22. Finally, the characteristic suppression of the cdc25 phenotype by a loss-of-function wee1 mutation is reversed in a mcs3 mutant background. The mcs genes define new mitotic elements that might be activators or substrates of the cdc2 protein kinase. PMID:2474475

  1. Outflow Propagation in Collapsars: Collimated Jets And Expanding Outflows

    SciTech Connect

    Mizuta, A.; Yamasaki, T.; Nagataki, S.; Mineshige, S.; /Kyoto U., Yukawa Inst., Kyoto /KIPAC, Menlo Park

    2007-06-08

    We investigate the outflow propagation in the collapsar in the context of gamma-ray bursts (GRBs) with 2D relativistic hydrodynamic simulations. We vary the specific internal energy and bulk Lorentz factor of the injected outflow from non-relativistic regime to relativistic one, fixing the power of the outflow to be 10{sup 51}erg s{sup -1}. We observed the collimated outflow, when the Lorentz factor of the injected outflow is roughly greater than 2. To the contrary, when the velocity of the injected outflow is slower, the expanding outflow is observed. The transition from collimated jet to expanding outflow continuously occurs by decreasing the injected velocity. Different features of the dynamics of the outflows would cause the difference between the GRBs and similar phenomena, such as, X-ray flashes.

  2. Galaxy Outflows Without Supernovae

    NASA Astrophysics Data System (ADS)

    Sur, Sharanya; Scannapieco, Evan; Ostriker, Eve C.

    2016-02-01

    High surface density, rapidly star-forming galaxies are observed to have ≈50-100 km s-1 line of sight velocity dispersions, which are much higher than expected from supernova driving alone, but may arise from large-scale gravitational instabilities. Using three-dimensional simulations of local regions of the interstellar medium, we explore the impact of high velocity dispersions that arise from these disk instabilities. Parametrizing disks by their surface densities and epicyclic frequencies, we conduct a series of simulations that probe a broad range of conditions. Turbulence is driven purely horizontally and on large scales, neglecting any energy input from supernovae. We find that such motions lead to strong global outflows in the highly compact disks that were common at high redshifts, but weak or negligible mass loss in the more diffuse disks that are prevalent today. Substantial outflows are generated if the one-dimensional horizontal velocity dispersion exceeds ≈35 km s-1, as occurs in the dense disks that have star-formation rate (SFR) densities above ≈0.1 M⊙ yr-1 kpc-2. These outflows are triggered by a thermal runaway, arising from the inefficient cooling of hot material coupled with successive heating from turbulent driving. Thus, even in the absence of stellar feedback, a critical value of the SFR density for outflow generation can arise due to a turbulent heating instability. This suggests that in strongly self-gravitating disks, outflows may be enhanced by, but need not caused by, energy input from supernovae.

  3. Studies of Quasar Outflows

    NASA Technical Reports Server (NTRS)

    Arav, Nahum

    2002-01-01

    The main aim of this research program is to determine the ionization equilibrium and abundances in quasar outflows. Especially in the broad absorption line QSO PG 0946+301. We find that the outflow's metalicity is consistent with being solar, while the abundance ratio of phosphorus to other metals is at least ten times solar. These findings are based on diagnostics that are not sensitive to saturation and partial covering effects in the BALs (Broad Adsorption Lines), which considerably weakened previous claims for enhanced metalicity. Ample evidence for these effects is seen in the spectrum.

  4. Quantifying the Age Spectra of Particulate Organic Carbon in the Lower Mississippi River and Atchafalaya Outflow during the Great Flood of 2011 - How Does a High-Flow Event Effect Carbon Transport?

    NASA Astrophysics Data System (ADS)

    Rosenheim, B. E.; Roberts, B. J.; Allison, M. A.

    2011-12-01

    Biogeochemically, the role of rivers in transporting carbon to long-term sedimentary reservoirs is important to regulating atmospheric CO2 on several geologic time scales. Physically, sediment transport processes link carbon transport and depositional potential at different flow regimes. In the deltaic depositional setting, both types of processes dictate what carbon is stored, what is transported through the system, and what is reconverted to atmospheric CO2. To constrain first order relationships between sediment processes, biogeochemistry, and age spectra of transported carbon, we employ ramped pyrolysis radiocarbon analysis to samples taken in conjunction with bedload and suspended sediment surveys in the Mississippi River and with bioavailability data from the Atchafalaya River. Samples of particulate organic carbon (POC) were filtered from the Mississippi River and Atchafalaya outflow during the rising limb, crest, and falling limb of the 2011 Great Flood event. These samples were analyzed by ramped pyrolysis radiocarbon determination, whereby different temperature intervals of the bulk POC are pyrolyzed, collected, and measured for radiocarbon content. Past sampling of different flow regimes have shown older carbon being transported by both rivers during higher flow events, as well as increasing age of POC toward both river outflows. Deltaic deposits are constructed largely from high flow events, thus previous data indicate an attenuation of young carbon storage in such deposits with progressively larger flow events. Data from these samples will be compared to past sampled flow regimes to further assess the relationship between flow regime and age spectrum of POC. Ramped pyrolysis data from the Mississippi River will be compared to bedload and suspended sediment transport, and data from the Atchafalaya will be compared to bioavailability data from both the water column and the underlying sediments. These approaches will provide information about the

  5. Multi-scale evolution of a derecho-producing MCS

    NASA Astrophysics Data System (ADS)

    Bernardet, Ligia Ribeiro

    1997-12-01

    In this dissertation we address one type of severe weather: strong straight-line winds. In particular, we focus on derechos, a type of wind storm caused by a convective system and characterized by its long duration and by the large area it covers. One interesting characteristic of these storms is that they develop at night, on the cold side of a thermal boundary. This region is not characterized by large convective instability. In fact, surface parcels are generally stable with respect to vertical displacements. To gain understanding of the physical processes involved in these storms, we focused on the case of a MCS that developed in eastern Colorado on 12-13 May, 1985. The system formed in the afternoon, was active until early morning, and caused strong winds during the night. A multi-scale full physics simulation of this case was performed using a non-hydrostatic mesoscale model. Four telescopically nested grids covering from the synoptic scale down to cloud scale circulations were used. A Lagrangian model was used to follow trajectories of parcels that took part in the updraft and in the downdraft, and balance of forces were computed along the trajectories. Our results show that the synoptic and mesoscale environment of the storm largely influences convective organization and cloud-scale circulations. During the day, when the boundary layer is well mixed, the source of air for the clouds is located within the boundary layer. At night, when the boundary layer becomes stable, the source of air shifts to the top of the boundary layer. It is composed of warm, moist air that is brought by the nocturnal low-level jet. The downdraft structure also changes from day to night. During the day, parcels acquire negative buoyancy because of cooling due to evaporation and melting. As they sink, they remain colder than the environment, and end up at the surface constituting the cold pool. During the night, downdrafts are stronger, generating the strong surface winds. The most

  6. Metallicity and Quasar Outflows

    NASA Astrophysics Data System (ADS)

    Wang, Huiyuan; Zhou, Hongyan; Yuan, Weimin; Wang, Tinggui

    2012-06-01

    Correlations of the outflow strength of quasars, as measured by the blueshift and asymmetry index (BAI) of the C IV line, with intensities and ratios of broad emission lines, based on composite quasar spectra built from the Sloan Digital Sky Survey, are investigated. We find that most of the line ratios of other ions to C IV increase prominently with BAI. These behaviors can be well understood in the context of increasing metallicity with BAI. The strength of the dominant coolant, C IV line, decreases, and weak collisionally excited lines increase with gas metallicity as a result of the competition between different line coolants. Using Si IV+O IV]/C IV as an indicator of gas metallicity, we present, for the first time, a strong correlation between the metallicity and the outflow strength of quasars over a wide range of 1.7-6.9 times solar abundance. Our result implies that metallicity plays an important role in the formation of quasar outflows, likely by affecting outflow acceleration. This effect may have a profound impact on galaxy evolution via momentum feedback and chemical enrichment.

  7. METALLICITY AND QUASAR OUTFLOWS

    SciTech Connect

    Wang, Huiyuan; Zhou, Hongyan; Wang, Tinggui; Yuan, Weimin

    2012-06-01

    Correlations of the outflow strength of quasars, as measured by the blueshift and asymmetry index (BAI) of the C IV line, with intensities and ratios of broad emission lines, based on composite quasar spectra built from the Sloan Digital Sky Survey, are investigated. We find that most of the line ratios of other ions to C IV increase prominently with BAI. These behaviors can be well understood in the context of increasing metallicity with BAI. The strength of the dominant coolant, C IV line, decreases, and weak collisionally excited lines increase with gas metallicity as a result of the competition between different line coolants. Using Si IV+O IV]/C IV as an indicator of gas metallicity, we present, for the first time, a strong correlation between the metallicity and the outflow strength of quasars over a wide range of 1.7-6.9 times solar abundance. Our result implies that metallicity plays an important role in the formation of quasar outflows, likely by affecting outflow acceleration. This effect may have a profound impact on galaxy evolution via momentum feedback and chemical enrichment.

  8. Outflows and Shock Chemistry

    NASA Astrophysics Data System (ADS)

    Tafalla, M.

    2016-05-01

    Bipolar outflows result from the supersonic ejection of material by a protostar, and constitute one of the most characteristic signposts of stellar birth. They also provide ideal targets to test chemical models, and can serve as templates for more complex systems of galactic and extragalactic astronomy where supersonic interactions between gas components take place.

  9. Northwestern Tharsis Latent Outflow Activity Mars

    NASA Technical Reports Server (NTRS)

    Dohm, J. M.; Anderson, R. C.; Baker, V. R.; Ferris, J. C.; Hare, T. M.; Strom, R. G.; Rudd, L.; Rice, J. W., Jr.; Scott, D. H.

    2000-01-01

    Previously defined outflow channels, which are indicated by relict landforms similar to those observed on Earth, signify ancient catastrophic flood events on Mars. These conspicuous geomorphic features are some of the most remarkable yet profound discoveries made by geologists to date. These outflow channels, which debouched tremendous volumes of water into topographic lows such as Chryse, Utopia, Elysium, and Hellas Planitiae, may represent the beginning of warmer and wetter climatic periods unlike the present-day cold and dry Mars. In addition to the previously identified outflow channels, observations permitted by the newly acquired Mars Orbiter Laser Altimeter (MOLA) data have revealed a system of gigantic valleys, referred to as the northwestern slope valleys (NSV), that are located to the northwest of a huge shield volcano, Arsia Mons, western hemisphere of Mars. These features generally correspond spatially to gravity lows similar to the easternmost, circum-Chryse outflow channel systems. Geologic investigations of the Tharsis region suggest that the large valley system pre-dates the construction of Arsia Mons and its extensive associated lava flows of mainly Late Hesperian and Amazonian age and coincides stratigraphically with the early development of the circum-Chryse outflow channel systems that debouch into Chryse Planitia. This newly identified system, the NSV, potentially signifies the largest flood event(s) ever recorded for the solar system. Additional information is contained in original extended abstract.

  10. Investigation on stress distribution of multilayered composite structure (MCS) using infrared thermographic technique

    NASA Astrophysics Data System (ADS)

    Liu, Junyan; Gong, Jinlong; Liu, Liqiang; Qin, Lei; Wang, Yang

    2013-11-01

    In this paper, the thermoelastic stress analysis (TSA) on a multilayered composite structure (MCS) was investigated by means of lock-in thermographic image technique (LITI). The application of thermoelastic stress analysis on MCS becomes particularly complicated due to consisting of different material components, which determines the different thermoelastic coupling response depended on material thermal-physical property. The thermoelastic coupling constants (TCC) of GFRP, medium-carbon steel and foam were obtained through thermomechanical calibration experiments, respectively. An artificial neural network was proposed to determine the component of MCS. Comparisons between finite element analysis (FEA) and LITI measurement are reported. It is found that the stress distribution of MCS can be evaluated with good accuracies using LITI measurement.

  11. Schizosaccharomyces pombe Mop1-Mcs2 is related to mammalian CAK.

    PubMed Central

    Damagnez, V; Mäkelä, T P; Cottarel, G

    1995-01-01

    The cyclin-dependent kinase (CDK)-activating kinase, CAK, from mammals and amphibians consists of MO15/CDK7 and cyclin H, a complex which has been identified also as a RNA polymerase II C-terminal domain (CTD) kinase. While the Schizosaccharomyces pombe cdc2 gene product also requires an activating phosphorylation, the enzyme responsible has not been identified. We have isolated an essential S.pombe gene, mop1, whose product is closely related to MO15 and to Saccharomyces cerevisiae Kin28. The functional similarity of Mop1 and MO15 is reflected in the ability of MO15 to rescue a mop1 null allele. This suggests that Mop1 would be a CDK, and indeed Mop1 associates with a previously characterized cyclin H-related cyclin Mcs2 of S.pombe. Also, Mop1 and Mcs2 can associate with the heterologous partners human cyclin H and MO15, respectively. Moreover, the rescue of a temperature-sensitive mcs2 strain by expression of mop1+ demonstrates a genetic interaction between mop1 and mcs2. In a functional assay, immunoprecipitated Mop1-Mcs2 acts both as an RNA polymerase II CTD kinase and as a CAK. The CAK activity of Mop1-Mcs2 distinguishes it from the related CDK-cyclin pair Kin28-Ccl1 from S.cerevisiae, and supports the notion that Mop1-Mcs2 may represent a homolog of MO15-cyclin H in S.pombe with apparent dual roles as a RNA polymerase CTD kinase and as a CAK. Images PMID:8557036

  12. A SPECTACULAR OUTFLOW IN AN OBSCURED QUASAR

    SciTech Connect

    Greene, Jenny E.; Zakamska, Nadia L.; Smith, Paul S.

    2012-02-10

    SDSS J1356+1026 is a pair of interacting galaxies at redshift z = 0.123 that hosts a luminous obscured quasar in its northern nucleus. Here we present two long-slit Magellan LDSS-3 spectra that reveal a pair of symmetric {approx}10 kpc size outflows emerging from this nucleus, with observed expansion velocities of {approx}250 km s{sup -1} in projection. We present a kinematic model of these outflows and argue that the deprojected physical velocities of expansion are likely {approx}1000 km s{sup -1} and that the kinetic energy of the expanding shells is likely 10{sup 44-45} erg s{sup -1}, with an absolute minimum of >10{sup 42} erg s{sup -1}. Although a radio counterpart is detected at 1.4 GHz, it is faint enough that the quasar is considered to be radio quiet by all standard criteria, and there is no evidence of extended emission due to radio lobes, whether aged or continuously powered by an ongoing jet. We argue that the likely level of star formation is insufficient to power the observed energetic outflow and that SDSS J1356+1026 is a good case for radio-quiet quasar feedback. In further support of this hypothesis, polarimetric observations show that the direction of quasar illumination is coincident with the direction of the outflow.

  13. Luminescent, mesoporous, and bioactive europium-doped calcium silicate (MCS: Eu3+) as a drug carrier.

    PubMed

    Fan, Yong; Huang, Shanshan; Jiang, Jinhua; Li, Guogang; Yang, Piaoping; Lian, Hongzhou; Cheng, Ziyong; Lin, Jun

    2011-05-15

    Luminescent, mesoporous, and bioactive europium-doped calcium silicate (MCS: Eu) was successfully synthesized. The obtained MCS: Eu(3+) was performed as a drug delivery carrier to investigate the drug storage/release properties using ibuprofen (IBU) as the model drug. The structural, morphological, textural, and optical properties were well characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), N(2) adsorption/desorption, and photoluminescence (PL) spectra, respectively. The results reveal that the MCS: Eu exhibits the typical ordered characteristics of the mesostructure. This composite shows a sustained release profile with IBU as the model drug. The IBU-loaded samples still present red luminescence of Eu(3+) ((5)D(0)-(7)F(1,2)) under UV irradiation. The emission intensities of Eu(3+) in the drug carrier system vary with the amount of released IBU, making the drug release easily tracked and monitored. The system demonstrates a great potential for drug delivery and disease therapy. PMID:21376337

  14. Sequence and batch language programs and alarm related C Programs for the 242-A MCS

    SciTech Connect

    Berger, J.F.

    1996-04-15

    A Distributive Process Control system was purchased by Project B-534, 242-A Evaporator/Crystallizer Upgrades. This control system, called the Monitor and Control system (MCS), was installed in the 242-A evaporator located in the 200 East Area. The purpose of the MCS is to monitor and control the Evaporator and monitor a number of alarms and other signals from various Tank Farm facilities. Applications software for the MCS was developed by the Waste Treatment Systems Engineering (WTSE) group of Westinghouse. The standard displays and alarm scheme provide for control and monitoring, but do not directly indicate the signal location or depict the overall process. To do this, WTSE developed a second alarm scheme.

  15. Acoustic imaging of the Mediterranean water outflowing through the Strait of Gibraltar

    NASA Astrophysics Data System (ADS)

    Biescas Gorriz, Berta; Carniel, Sandro; Sallarès, Valentí; Rodriguez Ranero, Cesar

    2016-04-01

    Acoustic imaging of the Mediterranean water outflowing through the Strait of Gibraltar Berta Biescas (1), Sandro Carniel (2) , Valentí Sallarès (3) and Cesar R. Ranero(3) (1) Istituto di Scienze Marine, CNR, Bologna, Italy (2) Istituto di Scienze Marine, CNR, Venice, Italy (3) Institut de Ciències del Mar, CSIC, Barcelona, Spain Acoustic reflectivity acquired with multichannel seismic reflection (MCS) systems allow to detect and explore the thermohaline structure in the ocean with vertical and lateral resolutions in the order of 10 m, covering hundreds of kilometers in the lateral dimension and the full-depth water column. In this work we present a MCS 2D profile that crosses the Strait of Gibraltar, from the Alboran Sea to the internal Gulf of Cadiz (NE Atlantic Ocean). The MCS data was acquired during the Topomed-Gassis Cruise (European Science Foundation TopoEurope), which was carried out on board of the Spanish R/V Sarmiento de Gamboa in October 2011. The strong thermohaline contrast between the Mediterranean water and the Atlantic water, characterizes this area and allows to visualize, with unprecedented resolution, the acoustic reflectivity associated to the dense flow of the Mediterranean water outflowing through the prominent slope of the Strait of Gibraltar. During the first kilometers, the dense flow drops attached to the continental slope until it reaches the buoyancy depth at 700 m. Then, it detaches from the sea floor and continues flowing towards the Atlantic Ocean, occupying the layer at 700-1500 m deep and developing clear staircase layers. The reflectivity images display near seabed reflections that could well correspond to turbidity layers. The XBT data acquired coincident in time and space with the MCS data will help us in the interpretation and analysis of the acoustic data.

  16. High Velocity Outflows in Quasars

    NASA Astrophysics Data System (ADS)

    Hamann, Fred; Rodriguez Hidalgo, Paola; Nestor, Daniel

    2006-02-01

    High velocity (HV) outflows are important components of SMBH growth and evolution. The ability of SMBHs to accrete matter and light up as AGN probably requires that outflows are present to carry away angular momentum. Outflows during the luminous AGN phase might also play a critical role in ``unveiling" young dust-enshrouded AGN and in ``polluting" the intergalactic medium with metals at high redshifts. Nonetheless, AGN outflows remain poorly understood. We have begun a program to study a nearly unexplored realm of AGN outflow parameter space: HV winds with v> 10,000 km/s up to v~ 0.2c but small velocity dispersions (narrow absorption lines), such that v/(Delta) v ≫ 1. These extreme outflows have been detected so far in just a few quasars, but they might be ubiquitous if, as expected, the flows subtend a small solid angle as seen from the central engine. Narrow-line HV flows merit specific attention because they pose unique challenges for theoretical models of the wind acceleration, mass loss rates, launch radii, etc. They might also comprise a significant fraction of absorbers previously attributed to unrelated (interveinng) gas or galaxies. We have compiled a list of bright quasars with candidate HV outflow lines (CIV 1550 A) in existing SDSS spectra. We now propose to observe ~50 of these candidates with the 2.1m GoldCam to i) identify/confirm some of the true outflow systems (based on line variability), ii) place a firm lower limit on the fraction of quasars with narrow-line HV outflows, iii) compile a short list of confirmed HV outflow sources for future study, and iv) use the combined SDSS and GoldCam data to measure or constrain basic outflow properties, such as the kinematics, locations, and physical conditions.

  17. Evolution of Mass Outflow in Protostars

    NASA Astrophysics Data System (ADS)

    Watson, Dan M.; Calvet, Nuria P.; Fischer, William J.; Forrest, W. J.; Manoj, P.; Megeath, S. Thomas; Melnick, Gary J.; Najita, Joan; Neufeld, David A.; Sheehan, Patrick D.; Stutz, Amelia M.; Tobin, John J.

    2016-09-01

    We have surveyed 84 Class 0, Class I, and flat-spectrum protostars in mid-infrared [Si ii], [Fe ii], and [S i] line emission, and 11 of these in far-infrared [O i] emission. We use the results to derive their mass outflow rates, {\\dot{M}}w. Thereby we observe a strong correlation of {\\dot{M}}w with bolometric luminosity, and with the inferred mass accretion rates of the central objects, {\\dot{M}}a, which continues through the Class 0 range the trend observed in Class II young stellar objects. Along this trend from large to small mass flow rates, the different classes of young stellar objects lie in the sequence Class 0–Class I/flat-spectrum–Class II, indicating that the trend is an evolutionary sequence in which {\\dot{M}}a and {\\dot{M}}w decrease together with increasing age, while maintaining rough proportionality. The survey results include two that are key tests of magnetocentrifugal outflow-acceleration mechanisms: the distribution of the outflow/accretion branching ratio b={\\dot{M}}w/{\\dot{M}}a, and limits on the distribution of outflow speeds. Neither rules out any of the three leading outflow-acceleration, angular-momentum-ejection mechanisms, but they provide some evidence that disk winds and accretion-powered stellar winds (APSWs) operate in many protostars. An upper edge observed in the branching-ratio distribution is consistent with the upper bound of b = 0.6 found in models of APSWs, and a large fraction (31%) of the sample have a branching ratio sufficiently small that only disk winds, launched on scales as large as several au, have been demonstrated to account for them.

  18. Particle Acceleration in Relativistic Outflows

    NASA Technical Reports Server (NTRS)

    Bykov, Andrei; Gehrels, Neil; Krawczynski, Henric; Lemoine, Martin; Pelletier, Guy; Pohl, Martin

    2012-01-01

    In this review we confront the current theoretical understanding of particle acceleration at relativistic outflows with recent observational results on various source classes thought to involve such outflows, e.g. gamma-ray bursts, active galactic nuclei, and pulsar wind nebulae. We highlight the possible contributions of these sources to ultra-high-energy cosmic rays.

  19. Zephyria Outflow Features

    NASA Technical Reports Server (NTRS)

    2004-01-01

    1 October 2004 This Mars Global Surveyor (MGS) Mars Orbiter Camera (MOC) image shows streamlined islands and a small cataract in an outflow channel system in the Zephyria region of Mars, south of Cerberus. The fluids responsible for creating these landforms flowed from the lower left (southwest) toward upper right (northeast). The fluids may have been water and mud or, some Mars scientists have argued, extremely fluid lava. The presence of a small cataract probably argues more strongly for a water and mud origin. This image is located near 3.8oN, 204.7oW. The picture covers an area about 3 km (1.9 mi) wide and is illuminated by sunlight from upper left.

  20. Driving Mechanisms for Molecular Outflows

    NASA Astrophysics Data System (ADS)

    Downes, Turlough P.

    Molecular outflows are observed to be closely associated with star formation. The cumulative momentum and the momentum injection rate in these outflows are important parameters in theories of star formation. The cumulative momentum in an outflow is a measure of the feed-back from star formation on molecular cloud turbulence. The level of turbulence in a cloud also effects the formation of further stars and, indeed, the survival of the cloud itself (e.g. [15]). In addition the rate of injection of momentum is an important constraint for theoretical models of outflows from young stars [10, 18]. Hence, while these outflows are interesting in themselves, it is also critical to understand their origin and behaviour as part of the general study of how stars themselves form.

  1. Clinical characteristics of chemical sensitivity: an illustrative case history of asthma and MCS.

    PubMed

    Ross, G H

    1997-03-01

    A case history of the induction of asthma and chemical sensitivity in a 42-year-old registered nurse illustrates several of the characteristic features of multiple chemical sensitivity (MCS). This patient's problems started shortly after moving into a new home under construction, with associated chemical exposures. Other MCS patients report the onset of the condition with other chemical exposures such as those encountered at their places of work or use of pesticides at their residences. Patients often describe a spreading phenomenon of increasing intolerance to commonly encountered chemicals at concentrations well tolerated by other people. Symptoms usually wax and wane with exposures, and are more likely to occur in patients or families with preexisting histories of migraine or with classical allergies. Idiosyncratic medication reactions (especially to preservative chemicals) are common in MCS patients, as are dysautonomia symptoms (such as vascular instability) and poor temperature regulation. Myalgia and joint pains and food intolerance are common features as well. Contamination with xenobiotic chemicals is frequently found in these patients when they are tested. Reactive airways dysfunction syndrome is a recently identified condition that exhibits features of both asthma and chemical sensitivity. MCS patients frequently have patterns of neurotoxic brain metabolism that can be confirmed on single photo emission computed tomography imaging. PMID:9167976

  2. Clinical characteristics of chemical sensitivity: an illustrative case history of asthma and MCS.

    PubMed Central

    Ross, G H

    1997-01-01

    A case history of the induction of asthma and chemical sensitivity in a 42-year-old registered nurse illustrates several of the characteristic features of multiple chemical sensitivity (MCS). This patient's problems started shortly after moving into a new home under construction, with associated chemical exposures. Other MCS patients report the onset of the condition with other chemical exposures such as those encountered at their places of work or use of pesticides at their residences. Patients often describe a spreading phenomenon of increasing intolerance to commonly encountered chemicals at concentrations well tolerated by other people. Symptoms usually wax and wane with exposures, and are more likely to occur in patients or families with preexisting histories of migraine or with classical allergies. Idiosyncratic medication reactions (especially to preservative chemicals) are common in MCS patients, as are dysautonomia symptoms (such as vascular instability) and poor temperature regulation. Myalgia and joint pains and food intolerance are common features as well. Contamination with xenobiotic chemicals is frequently found in these patients when they are tested. Reactive airways dysfunction syndrome is a recently identified condition that exhibits features of both asthma and chemical sensitivity. MCS patients frequently have patterns of neurotoxic brain metabolism that can be confirmed on single photo emission computed tomography imaging. PMID:9167976

  3. The trabecular meshwork outflow pathways: structural and functional aspects.

    PubMed

    Tamm, Ernst R

    2009-04-01

    The major drainage structures for aqueous humor (AH) are the conventional or trabecular outflow pathways, which are comprised of the trabecular meshwork (made up by the uveal and corneoscleral meshworks), the juxtacanalicular connective tissue (JCT), the endothelial lining of Schlemm's canal (SC), the collecting channels and the aqueous veins. The trabecular meshwork (TM) outflow pathways are critical in providing resistance to AH outflow and in generating intraocular pressure (IOP). Outflow resistance in the TM outflow pathways increases with age and primary open-angle glaucoma. Uveal and corneoscleral meshworks form connective tissue lamellae or beams that are covered by flat TM cells which rest on a basal lamina. TM cells in the JCT are surrounded by fibrillar elements of the extracellular matrix (ECM) to form a loose connective tissue. In contrast to the other parts of the TM, JCT cells and ECM fibrils do not form lamellae, but are arranged more irregularly. SC inner wall endothelial cells form giant vacuoles in response to AH flow, as well as intracellular and paracellular pores. In addition, minipores that are covered with a diaphragm are observed. There is considerable evidence that normal AH outflow resistance resides in the inner wall region of SC, which is formed by the JCT and SC inner wall endothelium. Modulation of TM cell tone by the action of their actomyosin system affects TM outflow resistance. In addition, the architecture of the TM outflow pathways and consequently outflow resistance appear to be modulated by contraction of ciliary muscle and scleral spur cells. The scleral spur contains axons that innervate scleral spur cells or that have the ultrastructural characteristics of mechanosensory nerve endings. PMID:19239914

  4. Auroral arcs and ion outflow

    NASA Astrophysics Data System (ADS)

    Maggiolo, Romain

    2016-04-01

    This presentation provides an overwiew of the chapter "Auroral Arcs and Ion Outflow" from the AGU book "Auroral Dynamics and Space Weather" (eds Y. Zhang and L. J. Paxton). This topic covers a wide range of domains, from auroral acceleration processes, auroral arc morphology and dynamics to global magnetosphere-ionosphere coupling and atmospheric erosion. This presentation mainly focuses on the observational properties of auroral ion outflow. Recent observations about their large-scale spatial distribution and link with auroral forms will be presented. Auroral ion outflow statistical dependence on solar and geomagnetic activity and its modulation by auroral dynamics at the timescale of substorms will also be discussed.

  5. DisoMCS: Accurately Predicting Protein Intrinsically Disordered Regions Using a Multi-Class Conservative Score Approach

    PubMed Central

    Wang, Zhiheng; Yang, Qianqian; Li, Tonghua; Cong, Peisheng

    2015-01-01

    The precise prediction of protein intrinsically disordered regions, which play a crucial role in biological procedures, is a necessary prerequisite to further the understanding of the principles and mechanisms of protein function. Here, we propose a novel predictor, DisoMCS, which is a more accurate predictor of protein intrinsically disordered regions. The DisoMCS bases on an original multi-class conservative score (MCS) obtained by sequence-order/disorder alignment. Initially, near-disorder regions are defined on fragments located at both the terminus of an ordered region connecting a disordered region. Then the multi-class conservative score is generated by sequence alignment against a known structure database and represented as order, near-disorder and disorder conservative scores. The MCS of each amino acid has three elements: order, near-disorder and disorder profiles. Finally, the MCS is exploited as features to identify disordered regions in sequences. DisoMCS utilizes a non-redundant data set as the training set, MCS and predicted secondary structure as features, and a conditional random field as the classification algorithm. In predicted near-disorder regions a residue is determined as an order or a disorder according to the optimized decision threshold. DisoMCS was evaluated by cross-validation, large-scale prediction, independent tests and CASP (Critical Assessment of Techniques for Protein Structure Prediction) tests. All results confirmed that DisoMCS was very competitive in terms of accuracy of prediction when compared with well-established publicly available disordered region predictors. It also indicated our approach was more accurate when a query has higher homologous with the knowledge database. Availability The DisoMCS is available at http://cal.tongji.edu.cn/disorder/. PMID:26090958

  6. Shining a light on galactic outflows: photoionized outflows

    NASA Astrophysics Data System (ADS)

    Chisholm, John; Tremonti, Christy A.; Leitherer, Claus; Chen, Yanmei; Wofford, Aida

    2016-04-01

    We study the ionization structure of galactic outflows in 37 nearby, star-forming galaxies with the Cosmic Origins Spectrograph on the Hubble Space Telescope. We use the O I, Si II, Si III, and Si IV ultraviolet absorption lines to characterize the different ionization states of outflowing gas. We measure the equivalent widths, line widths, and outflow velocities of the four transitions, and find shallow scaling relations between them and galactic stellar mass and star formation rate. Regardless of the ionization potential, lines of similar strength have similar velocities and line widths, indicating that the four transitions can be modelled as a comoving phase. The Si equivalent width ratios (e.g. Si IV/Si II) have low dispersion, and little variation with stellar mass; while ratios with O I and Si vary by a factor of 2 for a given stellar mass. Photoionization models reproduce these equivalent width ratios, while shock models under predict the relative amount of high ionization gas. The photoionization models constrain the ionization parameter (U) between -2.25 < log (U) < -1.5, and require that the outflow metallicities are greater than 0.5 Z⊙. We derive ionization fractions for the transitions, and show that the range of ionization parameters and stellar metallicities leads to a factor of 1.15-10 variation in the ionization fractions. Historically, mass outflow rates are calculated by converting a column density measurement from a single metal ion into a total hydrogen column density using an ionization fraction, thus mass outflow rates are sensitive to the assumed ionization structure of the outflow.

  7. Chandra Observations of Outflows from PSR J1509–5850

    NASA Astrophysics Data System (ADS)

    Klingler, Noel; Kargaltsev, Oleg; Rangelov, Blagoy; Pavlov, George G.; Posselt, Bettina; Ng, C.-Y.

    2016-09-01

    PSR J1509–5850 is a middle-aged pulsar with a period of P ≈ 89 ms and spin-down power of \\dot{E}=5.1× {10}35 erg s‑1, at a distance of about 3.8 kpc. We report on deep Chandra X-ray Observatory observations of this pulsar and its pulsar wind nebula (PWN). In addition to the previously detected tail extending up to 7‧ southwest from the pulsar (the southern outflow), the deep images reveal similarly long, faint, diffuse emission stretched toward the north (the northern outflow) and the fine structure of the compact nebula (CN) in the pulsar vicinity. The CN is resolved into two lateral tails and one axial tail pointing southwest (a morphology remarkably similar to that of the Geminga PWN), which supports the assumption that the pulsar moves toward the northeast. The luminosities of the southern and northern outflows are about 1× {10}33 and 4× {10}32 erg s‑1, respectively. The spectra extracted from four regions of the southern outflow do not show any softening with increasing distance from the pulsar. The lack of synchrotron cooling suggests a high flow speed or in situ acceleration of particles. The spectra extracted from two regions of the northern outflow show a hint of softening with distance from the pulsar, which may indicate slower particle propagation. We speculate that the northern outflow is associated with particle leakage from the bow-shock apex into the ISM, while the southern outflow represents the tail of the shocked pulsar wind behind the moving pulsar. We estimate the physical parameters of the observed outflows and compare the J1509–5850 PWN with PWNe of other supersonically moving pulsars.

  8. Vertical Profiles of Aerosol Particle Sizes using MGS/TES and MRO/MCS

    NASA Astrophysics Data System (ADS)

    Wolff, M. J.; Clancy, R. T.; Smith, M. D.; Benson, J. L.; McConnochie, T. H.; Pankine, A.

    2012-12-01

    Vertical variations in aerosol particle sizes often have a dramatic impact on the state and evolution of the Martian atmosphere. Recent analyses of data from the Spectroscopy for the Investigation of the Characteristics of the Atmosphere of Mars (SPICAM), the Thermal Emission Spectrometer (TES), and the Mars Climate Sounder (MCS) instruments offer some long overdue progress in constraining this aspect of aerosols. However, significantly more work remains to be done along these lines in order to better constrain and inform modern dynamical simulations of the Martian atmosphere. Thus, the primary goal of our work is to perform retrievals of particle size as a function of altitude for both dust and water ice aerosols. The choice of the TES and MCS dataset, with pole-to-pole coverage over a period of nearly eight martian years, provides the crucial systematic temporal and spatial sampling. Our presentation will include: 1) A summary of our limb radiative transfer algorithms and retrieval schemes; 2) The initial results of the application of our particle size retrieval scheme to the 2001 TES and 2007 MCS observations of those planet encircling dust events; 3) Near-term plans for for additional retrievals (aphelion cloud season, lower optical depth locations and seasons, etc.); 4) Location of the archive to be used for the distribution of the derived profiles and associated retrieval metadata.

  9. Molecular Outflows in Massive Star Forming Regions

    NASA Astrophysics Data System (ADS)

    Cunningham, Nichol

    2015-11-01

    This thesis presents millimetre continuum and molecular line observations exploring the properties of molecular outflows towards massive star forming regions. Massive stars produce some of the most energetic phenomena in the Galaxy, yet we still do not have a comprehensive understanding of how they actually form. Outflows are known to play a key role in this formation process and their properties, particularly how they change depending on the mass, luminosity and evolution of the driving source can shed light on how massive stars actually form. This thesis presents observations at both high (SMA 3 arcsecond) and low (JCMT 15 arcsecond) spatial resolution of the known jet/outflow tracers, SiO and 12CO, towards a sample massive star forming region drawn from the RMS survey. Furthermore, the presence of infall signatures is explored through observations of HCO+ and H13CO+, and the hot core nature of the regions is probed using tracers such as CH3CN, HC3N and CH3OH. SiO is detected towards approximately 50% of the massive young stellar objects and HII regions in the JCMT sample. The detection of SiO appears to be linked to the age of the RMS source, with the likely younger sources showing a stronger dependence with SiO. The presence of SiO also appears to be linked to the CO velocity, with SiO more efficiently tracing sources with higher velocity dispersions. In the MOPRA observations towards a sample of 33 RMS sources, CH3CN is detected towards 66% of the sources, with the redder likely younger sources having the largest rotational temperatures. This thesis presents the first interferometric SiO (5-4) and 12CO (2-1) observations, taken with the SMA, towards the massive star forming region G203.3166/NGC 2264-C. In this intermediate/massive star forming cluster, SiO is again tracing the youngest sources. Both the SiO and 12CO emission trace two bipolar, high velocity outflows towards the mm brightest, IR-dark, likely youngest sources in this reg! ion. In contrast the IR

  10. Origin of outflows and winds

    NASA Technical Reports Server (NTRS)

    Koenigl, Arieh; Ruden, Steven P.

    1993-01-01

    Recent developments concerning the accretion-outflow connection and the role of magnetic fields are examined. It is argued that the weakly ionized wind most likely represents an MHD outflow driven centrifugally from the disk surfaces or from the boundary between the disk and the star. Specific wind models for each of these alternatives are presented, and it is contended that both provide a natural explanation of the observed correlation between accretion and outflow. The kinematic, thermal, and chemical wind properties predicted by these models are described and their observational implications are considered. It is suggested that the wind characteristics may be reflected in the observed forbidden line and IR continuum emission of T Tauri stars and in the measured abundances of various molecular species.

  11. Mediterranean Outflow Mixing and Dynamics

    NASA Astrophysics Data System (ADS)

    Price, James F.; O'Neil Baringer, Molly; Lueck, Rolf G.; Johnson, Gregory C.; Ambar, Isabel; Parrilla, Gregorio; Cantos, Alain; Kennelly, Maureen A.; Sanford, Thomas B.

    1993-02-01

    The Mediterranean Sea produces a salty, dense outflow that is strongly modified by entrainment as it first begins to descend the continental slope in the eastern Gulf of Cadiz. The current accelerates to 1.3 meters per second, which raises the internal Froude number above 1, and is intensely turbulent through its full thickness. The outflow loses about half of its density anomaly and roughly doubles its volume transport as it entrains less saline North Atlantic Central water. Within 100 kilometers downstream, the current is turned by the Coriolis force until it flows nearly parallel to topography in a damped geostrophic balance. The mixed Mediterranean outflow continues westward, slowly descending the continental slope until it becomes neutrally buoyant in the thermocline where it becomes an important water mass.

  12. Mediterranean outflow mixing and dynamics.

    PubMed

    Price, J F; Baringer, M O; Lueck, R G; Johnson, G C; Ambar, I; Parrilla, G; Cantos, A; Kennelly, M A; Sanford, T B

    1993-02-26

    The Mediterranean Sea produces a salty, dense outflow that is strongly modified by entrainment as it first begins to descend the continental slope in the eastern Gulf of Cadiz. The current accelerates to 1.3 meters per second, which raises the internal Froude number above 1, and is intensely turbulent through its full thickness. The outflow loses about half of its density anomaly and roughly doubles its volume transport as it entrains less saline North Atlantic Central water. Within 100 kilometers downstream, the current is turned by the Coriolis force until it flows nearly parallel to topography in a damped geostrophic balance. The mixed Mediterranean outflow continues westward, slowly descending the continental slope until it becomes neutrally buoyant in the thermocline where it becomes an important water mass. PMID:17732247

  13. A Look at Dust Storms on Mars (2007 To 2009) Using MCS and THEMIS Observations

    NASA Astrophysics Data System (ADS)

    Flynn, William; Bowles, N. E.; Teanby, N. A.; Montabone, L.; Calcutt, S. B.; Read, P. L.; Kass, D. M.; Hale, A. S.

    2009-09-01

    Martian dust storms may be small, localised and short lived or can be large and intense and expand to enshroud most, if not all, of the planet within a few days. The martian dusty season occurs near the time of perihelion (closest approach to the sun) during Mars' southern hemisphere spring and summer. During this period (+/- 90 degrees Ls of perihelion) local and regional dust storms are more frequent and there is a higher probability of a major and possible planet-encircling dust storm occuring. Despite this there is still a lot of interannual variability and uncertainty regarding the occurence of both major and regional dust storms. The Mars Climate Sounder (MCS) instrument onboard NASA's Mars Reconnaissance Orbiter (MRO) is a two telescope 9 channel filter IR radiometer (0.3 to 45 microns), with each channel consisting of a linear array of 21 detectors. Each pixel sounds a 5km thick region of the Martian atmosphere in a limb viewing/scanning mode. We present a comparison of dust storm activity on Mars for 2007 to 2009 using MCS limb observations of changes in dust opacity. These measurements are also compared with observations and atmospheric opacity maps generated by the Thermal Emission Imaging System (THEMIS) multi-wavelength instrument onboard the Mars Odyssey spacecraft and Mars weather maps from MRO's Mars Color Imager (MARCI) for this period. Model predictions from the Mars Climate Database and simulations from the UK Mars General Circulation Model (GCM) are also used. This comparison gives us an empirical method for using MCS data directly to identify dust storm activity during this period.

  14. Cascade filtration (CF) with the Haemonetics MCS+: a new technical adaptation.

    PubMed

    Valbonesi, M; Bo, A; De Luigi, M C; Bruni, R; Stura, P; Sanfilippo, B; Varinelli, I

    2001-03-01

    CF was introduced in clinical medicine in 1980. Up to now, exclusively two-vein procedures have been carried out with some limitations to expansion of this technique. In this report we describe the very first application of single-needle CF carried out with Haemonetics MCS + apparatus. Twenty procedures were completed without any untoward effect in patients suffering from TTP, post-hepatitic cryoblobulinemia, familial hypercholesterolemia and acute Guillan-Barrè Syndrome. From 1 to 4 sessions were carried out per patient with the expected laboratory and clinical results. The only limit is the procedure time that averages 231 +/- 48 min., approximately 40% longer than two needle procedures. PMID:11314811

  15. Functional Anatomy of the Outflow Facilities

    PubMed Central

    Pizzirani, Stefano; Gong, Haiyan

    2016-01-01

    The aqueous humor (AH) is the fluid that fills the anterior and posterior chambers of the eye. Its main roles are to provide nourishment and metabolic waste removal to active metabolic ocular structures that are avascular and to contribute maintaining a normal intraocular pressure (IOP) without altering the refractive status of the eye. Its composition and the fluid dynamics associated with its flow are voluble and undergo changes associated with age and disease. Of particular importance is that the resistance to the outflow of AH from the anterior chamber is influenced by morphologic, physiologic, and biochemical dynamic factors.1 Beside aqueous nutritional importance, its solutes also participate in establishing the anterior chamber associate immune deviation, and carry and distribute the different proteins and molecules that promote and direct tissue remodeling and changes in the anterior segment that are associated with both age and disease. PMID:26337760

  16. Molecular outflows in starburst nuclei

    NASA Astrophysics Data System (ADS)

    Roy, Arpita; Nath, Biman B.; Sharma, Prateek; Shchekinov, Yuri

    2016-08-01

    Recent observations have detected molecular outflows in a few nearby starburst nuclei. We discuss the physical processes at work in such an environment in order to outline a scenario that can explain the observed parameters of the phenomenon, such as the molecular mass, speed and size of the outflows. We show that outflows triggered by OB associations, with NOB ≥ 105 (corresponding to a star formation rate (SFR)≥1 M⊙ yr-1 in the nuclear region), in a stratified disk with mid-plane density n0 ˜ 200-1000 cm-3 and scale height z0 ≥ 200(n0/102 cm-3)-3/5 pc, can form molecules in a cool dense and expanding shell. The associated molecular mass is ≥107 M⊙ at a distance of a few hundred pc, with a speed of several tens of km s-1. We show that a SFR surface density of 10 ≤ ΣSFR ≤ 50 M⊙ yr-1 kpc-2 favours the production of molecular outflows, consistent with observed values.

  17. The Geometry of Quasar Outflows

    NASA Astrophysics Data System (ADS)

    Ganguly, Rajib

    2012-10-01

    Quasar outflows are important for understanding the accretion and growth processes of the central black hole, but also potentially play a role in feedback to the galaxy, halting star formation and infall of gas. A big uncertainty lies in the geometry and density of these outflows, especially as a function of ionization and velocity. We aim to tackle this using the archival COS M grating spectra of 266 quasars. We separate the geometry of outflows into two parts: the solid angle subtended around the black hole, and the distance of the outflow from the central engine. Large numbers of quasars with high resolution spectra are required for each aspect of this statistical investigation. First, we will determine which/how many absorption-line systems are intrinsic through both partial covering methods and statistical assessments. Second, we will consider the incidence of intrinsic absorbers as a function of quasar property {e.g., radio-loudness, SED shape, black hole mass, bolometric luminosity}. This will reveal what determines the solid angle. This can only be done at moderate redshifts where quasars with a larger range of properties are observable, and hence requires HST/COS. Third, we will use the wide range of diagnostic lines to constrain the physical conditions of the absorbers. We will target the CIII*1175 complex and apply photoionization models to constrain the densities and ionization parameters. This will provide the largest set yet of intrinsic absorbers with systematic distance constraints. In tandem with the solid angles, this work will inform models regarding the geometry of quasar outflows.

  18. Hot outflows in galaxy clusters

    NASA Astrophysics Data System (ADS)

    Kirkpatrick, C. C.; McNamara, B. R.

    2015-10-01

    The gas-phase metallicity distribution has been analysed for the hot atmospheres of 29 galaxy clusters using Chandra X-ray Observatory observations. All host brightest cluster galaxies (BCGs) with X-ray cavity systems produced by radio AGN. We find high elemental abundances projected preferentially along the cavities of 16 clusters. The metal-rich plasma was apparently lifted out of the BCGs with the rising X-ray cavities (bubbles) to altitudes between twenty and several hundred kiloparsecs. A relationship between the maximum projected altitude of the uplifted gas (the `iron radius') and jet power is found with the form R_Fe ∝ P_jet^{0.45}. The estimated outflow rates are typically tens of solar masses per year but exceed 100 M⊙ yr- 1 in the most powerful AGN. The outflow rates are 10-20 per cent of the cooling rates, and thus alone are unable to offset a cooling inflow. Nevertheless, hot outflows effectively redistribute the cooling gas and may play a significant role at regulating star formation and AGN activity in BCGs and presumably in giant elliptical galaxies. The metallicity distribution overall can be complex, perhaps due to metal-rich gas returning in circulation flows or being blown around in the hot atmospheres. Roughly 15 per cent of the work done by the cavities is expended lifting the metal-enriched gas, implying their nuclear black holes have increased in mass by at least ˜107-109 M⊙. Finally, we show that hot outflows can account for the broad, gas-phase metallicity distribution compared to the stellar light profiles of BCGs, and we consider a possible connection between hot outflows and cold molecular gas flows discovered in recent Atacama Large Millimeter Array observations.

  19. Effectiveness of the haemonetics MCS cell separator in the collection of apheresis platelets.

    PubMed

    Keklik, Muzaffer; Keklik, Ertugrul; Korkmaz, Serdal; Aygun, Bilal; Arik, Ferhat; Kilic, Ozcan; Sarikoc, Murat

    2015-12-01

    Platelet (PLT) transfusions play an important role in patients with thrombocytopenia or severely impaired platelet function. Platelet concentrates are prepared from whole-blood donations or by plateletpheresis. In recent years, different instruments have been developed to perform plateletpheresis. We evaluated an apheresis instrument, the Haemonetics MCS(®) + with regard to PLT yield, collection efficiency (CE), and collection rate (CR) in a retrospective, randomized study in 526 donors. In this system, we used leukoreduction filters post collection to obtain leukoreduced products. The Haemonetics MCS(®) + cell separator efficiently collected apheresis platelets with median PLT yields of 3.7 × 10(11), mean CE of 66.69 ± 13.73% and mean CR of 0.063 ± 0.013 × 10(11)/min. The median blood volume processed was 3290 (2420-4370) ml, and the median volume of acid citrate dextrose-A (ACD-A) used in collections on the device was 385 (196-517) ml. Also, this device allowed the collection of white blood cell (WBC) reduced plateletpheresis with mean 0.07 ± 0.15 × 10(6) WBC content. No serious donor or recipient reactions occurred. PMID:26283175

  20. A Combined MCS and Refraction Study of the Convergent Nicaraguan Margin

    NASA Astrophysics Data System (ADS)

    Berhorst, A.; Flueh, E. R.; McIntosh, K.; Ranero, C. R.; Walther, C. H.; Dole, J.

    2001-12-01

    The presented seismic profile is part of an extensive MCS and wide-angle survey. The seismic measurements were carried out using a 6 km long streamer, 14 ocean bottom hydrophones (OBH) and 12 landstations recording marine airgun shots. One important objective of this study is the imaging of the subduction zone from the trench to the coast and the determination of the margin P-wave velocity structure. The image of the upper seismogenic plate boundary zone beneath the shelf should improve the knowledge of the seismogenic character and the evolution of this convergent margin. The profile was acquired during a cruise with the R/V Maurice Ewing as part of the MARGINS program. The purpose of this seismic investigation was to improve the scarce knowledge about the structure of the Nicaraguan margin, which is located between the intensively studied margins of Guatemala to the north and Costa Rica to the south.

  1. Using observational retrievals to expose precipitation and convective dynamics biases in simulations of a tropical MCS

    NASA Astrophysics Data System (ADS)

    Varble, A.; Zipser, E. J.

    2013-12-01

    Realistically simulating convective and stratiform structures of mesoscale convective systems (MCSs) requires proper representation of the large-scale environment and adequate representation of convective dynamics and parameterized microphysics in the simulation. The partitioning and areal coverage of such structures determine the heating distribution of any given system, thus affecting the large-scale dynamic response to the system. This issue is becoming evermore relevant with increasing computing power that will allow numerical weather prediction and global climate models to approach 1-10 km horizontal grid spacing in the coming decades. To test whether mesoscale simulations using 1-km grid spacing properly simulate a large tropical monsoonal MCS, several cloud-resolving model (CRM) and limited area model (LAM) simulations of a Tropical Warm Pool-International Cloud Experiment (TWP-ICE) MCS are compared with several observational retrievals. These comparisons expose a high bias in convective radar reflectivity aloft and a low bias in stratiform rainfall. Combined with errors due to large-scale environmental biases, model setup, and bulk microphysics parameterization assumptions, these biases appear related to overly intense deep convection in the simulations based on comparisons with dual-Doppler retrieved vertical velocity. The difference between simulated and dual-Doppler retrieved vertical velocity is especially large in the upper troposphere. This upper tropospheric difference is partially due to lofting and freezing of large rain water contents in simulations, which leads to large increases in buoyancy through latent heating. Possible reasons for overly intense simulated convective updrafts with large condensate loadings at mid and upper levels are explored.

  2. How well does CO emission measure the H2 mass of MCs?

    NASA Astrophysics Data System (ADS)

    Szűcs, László; Glover, Simon C. O.; Klessen, Ralf S.

    2016-07-01

    We present numerical simulations of molecular clouds (MCs) with self-consistent CO gas-phase and isotope chemistry in various environments. The simulations are post-processed with a line radiative transfer code to obtain 12CO and 13CO emission maps for the J = 1 → 0 rotational transition. The emission maps are analysed with commonly used observational methods, i.e. the 13CO column density measurement, the virial mass estimate and the so-called XCO (also CO-to-H2) conversion factor, and then the inferred quantities (i.e. mass and column density) are compared to the physical values. We generally find that most methods examined here recover the CO-emitting H2 gas mass of MCs within a factor of 2 uncertainty if the metallicity is not too low. The exception is the 13CO column density method. It is affected by chemical and optical depth issues, and it measures both the true H2 column density distribution and the molecular mass poorly. The virial mass estimate seems to work the best in the considered metallicity and radiation field strength range, even when the overall virial parameter of the cloud is above the equilibrium value. This is explained by a systematically lower virial parameter (i.e. closer to equilibrium) in the CO-emitting regions; in CO emission, clouds might seem (sub-)virial, even when, in fact, they are expanding or being dispersed. A single CO-to-H2 conversion factor appears to be a robust choice over relatively wide ranges of cloud conditions, unless the metallicity is low. The methods which try to take the metallicity dependence of the conversion factor into account tend to systematically overestimate the true cloud masses.

  3. Quasi-Stationary Shear-parallel MCS in a Near-saturated Environment

    NASA Astrophysics Data System (ADS)

    Liu, Changhai; Moncrieff, Mitchell

    2016-04-01

    Idealized simulations are performed to investigate a poorly-understood category of Mesoscale Convective Systems (MCSs) - quasi-stationary convective lines with upstream-building and downstream stratiform observed in very moist environments. A specific feature in the experimental design is the inclusion of a highly idealized moisture front, mimicking the water vapor variations across the large-scale quasi-stationary (Mei-Yu) front during the Asian summer monsoon, where this regime of convective organization has been frequently observed. The numerical experiment with a wind profile of significant low-level vertical shear, plus a moist thermodynamic sounding with low convective inhibition, generates a long-lasting convective system which is down-shear tilted with a morphology resembling the documented MCSs with back-building or parallel stratiform in East Asia and North America. This is the first successful simulations of the carrot-like MCS morphology, where cells initiate near the upstream edge in either back-building or forward-building form depending on the system propagation direction. A major disparity from most types of MCSs, especially the well-studied squall line, is the weak and shallow cold pool and its negligible effect on system sustenance and propagation. Instead of the cold-pool-shear interaction, it is found that convectively-excited gravity waves are responsible for the intermittent upstream initiation of convective elements. Sensitivity tests show that both the moisture front and shear are critical for this MCS category. Our study suggests that the background spatial moisture variability affects the selection of the modes of organization, and that a systematic investigation of its role in convective organization in various wind shear conditions should be explored.

  4. Co-Occurrence of Health Conditions during Childhood: Longitudinal Findings from the UK Millennium Cohort Study (MCS)

    PubMed Central

    Law, Catherine; Bedford, Helen; Hope, Steven

    2016-01-01

    Aims To identify patterns of stability and change in co-occurrence in children between 5–11 years, and to assess if they vary by socio-demographic factors. Methods Data from 9548 singleton children from the UK Millennium Cohort Study (MCS) were assessed for co-occurrence of five common adverse conditions: wheeze; longstanding illness; unfavorable weight; injury; and socio-emotional difficulties. We summed adverse conditions (0–5) for each child at ages 5, 7, and 11 and identified co-occurrence (≥2 conditions). Using multinomial regression, we explored associations between co-occurrence trajectories and child’s sex and ethnicity, maternal education, and income quintile. Results 45.6% of children experienced co-occurrence between 5–11 years (7% experienced constant co-occurrence). More children moved into co-occurrence than moved out (16.9 vs. 11.9%). Mutually-adjusted relative risk ratios (aRRR) showed a gradient by maternal education: compared to children with no co-occurrence whose mothers had a higher/degree, children whose mothers had no qualifications were more likely to move into (aRRR = 1.32(95%CI:1.02,1.70)), out of (1.74(1.34,2.26)), have fluctuating (1.52(1.09,2.10)) or constant co-occurrence (2.58(1.76,3.80)). The same gradient (high vs. low) was evident for income quintiles. Girls were less likely to experience co-occurrence. Conclusions Co-occurrence of adverse conditions is common during childhood, and trajectories are socially patterned. Child-focused care for lower-income children and boys early in life may prevent and reduce co-occurrence in later childhood. PMID:27281228

  5. The ionospheric outflow feedback loop

    NASA Astrophysics Data System (ADS)

    Moore, T. E.; Fok, M.-C.; Garcia-Sage, K.

    2014-08-01

    Following a long period of observation and investigation beginning in the early 1970s, it has been firmly established that Earth's magnetosphere is defined as much by the geogenic plasma within it as by the geomagnetic field. This plasma is not confined to the ionosphere proper, defined as the region within a few density scale heights of the F-region plasma density peak. Rather, it fills the flux tubes on which it is created, and circulates throughout the magnetosphere in a pattern driven by solar wind plasma that becomes magnetically connected to the ionosphere by reconnection through the dayside magnetopause. Under certain solar wind conditions, plasma and field energy is stored in the magnetotail rather than being smoothly recirculated back to the dayside. Its release into the downstream solar wind is produced by magnetotail disconnection of stored plasma and fields both continuously and in the form of discrete plasmoids, with associated generation of energetic Earthward-moving bursty bulk flows and injection fronts. A new generation of global circulation models is showing us that outflowing ionospheric plasmas, especially O+, load the system in a different way than the resistive F-region load of currents dissipating energy in the plasma and atmospheric neutral gas. The extended ionospheric load is reactive to the primary dissipation, forming a time-delayed feedback loop within the system. That sets up or intensifies bursty transient behaviors that would be weaker or absent if the ionosphere did not “strike back” when stimulated. Understanding this response appears to be a necessary, if not sufficient, condition for us to gain accurate predictive capability for space weather. However, full predictive understanding of outflow and incorporation into global simulations requires a clear observational and theoretical identification of the causal mechanisms of the outflows. This remains elusive and requires a dedicated mission effort.

  6. Analysis of hysteresis effect on the vibration motion of a bimodal non-uniform micro-cantilever using MCS theory

    NASA Astrophysics Data System (ADS)

    Korayem, M. H.; Korayem, A. H.; Hosseini Hashemi, Sh.

    2016-02-01

    Nowadays, to enhance the performance of atomic force microscopy (AFM) micro-cantilevers (MCs) during imaging, reduce costs and increase the surface topography precision, advanced MCs equipped with piezoelectric layers are utilized. Using the modified couple stress (MCS) theory not only makes the modeling more exhaustive, but also increases the accuracy of prediction of the vibration behavior of the system. In this paper, Hamilton's principle by consideration of the MCS theory has been used to extract the equations. In addition, to discretize the equations, differential quadrature method has been adopted. Analysis of the hysteresis effect on the vibration behavior of the AFM MC is of significant importance. Thus, to model the hysteresis effect, Bouc-Wen method, which is solved simultaneously with the vibration equations of non-uniform Timoshenko beam, has been utilized. Furthermore, a bimodal excitation of the MC has been considered. The results reveal that the hysteresis effect appears as a phase difference in the time response. Finally, the effect of the geometric parameters on the vibration frequency of the system which is excited by combination of the first two vibration modes of the non-uniform piezoelectric MC has been examined. The results indicate the considerable effect of the MC length in comparison with other geometric parameters such as the MC width and thickness.

  7. Outflows in Sodium Excess Objects

    NASA Astrophysics Data System (ADS)

    Park, Jongwon; Jeong, Hyunjin; Yi, Sukyoung K.

    2015-08-01

    Van Dokkum and Conroy revisited the unexpectedly strong Na i lines at 8200 Å found in some giant elliptical galaxies and interpreted them as evidence for an unusually bottom-heavy initial mass function. Jeong et al. later found a large population of galaxies showing equally extraordinary Na D doublet absorption lines at 5900 Å (Na D excess objects: NEOs) and showed that their origins can be different for different types of galaxies. While a Na D excess seems to be related to the interstellar medium (ISM) in late-type galaxies, smooth-looking early-type NEOs show little or no dust extinction and hence no compelling signs of ISM contributions. To further test this finding, we measured the Doppler components in the Na D lines. We hypothesized that the ISM would have a better (albeit not definite) chance of showing a blueshift Doppler departure from the bulk of the stellar population due to outflow caused by either star formation or AGN activities. Many of the late-type NEOs clearly show blueshift in their Na D lines, which is consistent with the former interpretation that the Na D excess found in them is related to gas outflow caused by star formation. On the contrary, smooth-looking early-type NEOs do not show any notable Doppler components, which is also consistent with the interpretation of Jeong et al. that the Na D excess in early-type NEOs is likely not related to ISM activities but is purely stellar in origin.

  8. Secretory prostate apoptosis response (Par)-4 sensitizes multicellular spheroids (MCS) of glioblastoma multiforme cells to tamoxifen-induced cell death

    PubMed Central

    Jagtap, Jayashree C.; Parveen, D.; Shah, Reecha D.; Desai, Aarti; Bhosale, Dipali; Chugh, Ashish; Ranade, Deepak; Karnik, Swapnil; Khedkar, Bhushan; Mathur, Aaishwarya; Natesh, Kumar; Chandrika, Goparaju; Shastry, Padma

    2014-01-01

    Glioblastoma multiforme (GBM) is the most malignant form of brain tumor and is associated with resistance to conventional therapy and poor patient survival. Prostate apoptosis response (Par)-4, a tumor suppressor, is expressed as both an intracellular and secretory/extracellular protein. Though secretory Par-4 induces apoptosis in cancer cells, its potential in drug-resistant tumors remains to be fully explored. Multicellular spheroids (MCS) of cancer cells often acquire multi-drug resistance and serve as ideal experimental models. We investigated the role of Par-4 in Tamoxifen (TAM)-induced cell death in MCS of human cell lines and primary cultures of GBM tumors. TCGA and REMBRANT data analysis revealed that low levels of Par-4 correlated with low survival period (21.85 ± 19.30 days) in GBM but not in astrocytomas (59.13 ± 47.26 days) and oligodendrogliomas (58.04 ± 59.80 days) suggesting low PAWR expression as a predictive risk factor in GBM. Consistently, MCS of human cell lines and primary cultures displayed low Par-4 expression, high level of chemo-resistance genes and were resistant to TAM-induced cytotoxicity. In monolayer cells, TAM-induced cytotoxicity was associated with enhanced expression of Par-4 and was alleviated by silencing of Par-4 using specific siRNA. TAM effectively induced secretory Par-4 in conditioned medium (CM) of cells cultured as monolayer but not in MCS. Moreover, MCS were rendered sensitive to TAM-induced cell death by exposure to conditioned medium (CM)-containing Par-4 (derived from TAM-treated monolayer cells). Also TAM reduced the expression of Akt and PKCζ in GBM cells cultured as monolayer but not in MCS. Importantly, combination of TAM with inhibitors to PI3K inhibitor (LY294002) or PKCζ resulted in secretion of Par-4 and cell death in MCS. Since membrane GRP78 is overexpressed in most cancer cells but not normal cells, and secretory Par-4 induces apoptosis by binding to membrane GRP78, secretory Par-4 is an

  9. Mars Energy Spectrum studies from Assimilated MCS data using the UK MGCM

    NASA Astrophysics Data System (ADS)

    Valeanu, Alexandru; Read, Peter; Wang, Yixiong; Lewis, Stephen; Montabone, Luca; Tabataba-Vakili, Fachreddin

    2015-04-01

    Introduction The energy spectrum (ES) analysis is a renowned tool for understanding the driving mechanisms behind atmospheric turbulence (Lindborg, 1998). We aim to investigate whether energy and enstrophy inertial ranges exist in the kinetic energy spectrum (KES), and to quantify the corresponding cascades (with their ranges), and relationship with the atmospheric forcing and energy dissipation scales. The calculation of the ES from observational data is known to be highly non-trivial due to the lack of global coverage in space and time. Gage and Nastrom (1984) were the first to overcome this problem for Earth but this has not so far been attempted for Mars. Our approach is to take the sparse observational data and assimilate it using a global numerical model. We present preliminary results using the Mars Climate Sounder (MCS) retrievals and the LMD-UK Mars GCM (MGCM). This was pioneered by Lewis and Read (1999). Methodology The equations we used to calculate the Eddy and Zonal Mean kinetic energies are derived from total KES formula presented in Lindborg and Augier (2013). Hence, adding the two spectra together, we obtain the full KES spectrum as presented in their paper. For the Available Potential Energy Spectrum (APES), we have used a preliminary simplified version of the approach presented in Lindborg and Augier (2013). The Energy Spectra To date we have assimilated the MCS data at the resolution of T31 (triangular truncation), hence the ES only spans up to total wavenumber 31. This encompasses a portion of the energy inertial range, which might be expected to manifest the -3 exponential law by analogy with the Earth (Gage & Nastrom, 1984). Features: - velocities and corresponding KEs are higher with increasing height compared to Earth, - "-3" slope is restricted to ~30 km altitude, suggesting an early departure from the enstrophy inertial range, - boundary layer velocities are similar to Earth References 1. Gage and Nastrom, A Climatology of Atmospheric

  10. A young bipolar outflow from IRAS15398-3359

    NASA Astrophysics Data System (ADS)

    Bjerkeli, Per; Jørgensen, Jes K.

    2015-08-01

    The Class 0 protostar IRAS 15398-3359 is located in the Lupus I cloud at a distance of 155 pc. The source is known to harbour a molecular outflow, but the region has not attracted much interest until recently. IRAS 15398 is known to show interesting chemical signatures and being one of the very nearby, young outflow sources makes it an excellent target for detailed studies of the gas kinematics of different species.We present observations of several molecular species, carried out with the Submillimeter Array and ALMA, towards the IRAS 15398 outflow. The analysis of CO emission show obvious signs of episodic mass ejections, with a dynamical time scale between the knots in the jet, of the order 100 years. This is consistent with recent ALMA results where luminosity outbursts are estimated to occur on similar time-scales. The physical properties of the outflow, such as mass, momentum, momentum rate, mechanical luminosity, kinetic energy and mass-loss rate are estimated at relatively low values. We argue that this source is of a very young age, possibly younger than ~1000 years. This is consistent with recent studies of the kinematics of the inner envelope/disk. The observed line profiles were compared to full 3D radiative transfer models of the source, constructed with the Line Modelling Engine (LIME). The observed line shapes can only be understood when considering several distinctly different physical components, viz. the outflow cavity, the infalling envelope and the surrounding cloud material. This allows us to put quantitative constraints on the kinematics of the material close to the central source.

  11. Multiwavelength Spectroscopy of the Bipolar Outflow from Cepheus E

    NASA Astrophysics Data System (ADS)

    Smith, Michael D.; Froebrich, Dirk; Eislöffel, Jochen

    2003-07-01

    Cepheus E is the site of an exceptional example of a protostellar outflow with a very young dynamical age and extremely high near-infrared luminosity. We combine molecular spectroscopic data from the submillimeter to the near-infrared in order to interpret the rotational excitation of CO and the rovibrational excitation of H2. We conclude that C-type shocks with a paraboloidal bow shock geometry can simultaneously explain all the molecular excitations. Extinction accounts for the deviation of the column densities from local thermodynamic equilibrium. A difference in the extinction between the red- and blueshifted outflow lobes may account for the measured flux difference. The outflow is deeply embedded in a clump of density 105 cm-3, yet a good fraction of atomic hydrogen, about 40%, is required to explain the excitation and statistical equilibrium. We propose that this atomic component arises, self-consistently, from the dissociated gas at the apex of the leading bow shocks and the relatively long molecule reformation time. At least 20 bow shocks are required in each lobe, although these may be subdivided into smaller bows and turbulent shocked regions. The total outflow mechanical power and cooling amounts to over 30 Lsolar, almost half the source's bolometric luminosity. Nevertheless, only about 6% of the clump mass has been set in outward motion by the outflow, allowing a collapse to continue. Based on observations with ISO, an ESA project with instruments funded by ESA Member States (especially the PI countries: France, Germany, the Netherlands and the United Kingdom) and with the participation of ISAS and NASA.

  12. Starburst outflows from nearby galaxies

    NASA Technical Reports Server (NTRS)

    Waller, William H.

    1990-01-01

    Starburst outflows from NGC 5461, 1569 and M82 are discussed. The Sc I galaxy, M101, is reknowned for the kpc-size superassociations of star clusters and HII regions that dominate its spiral arms. NGC 5461 is one of the brightest of these superassociations, rivaling the Large Magellanic Cloud in H alpha luminosity. The NGC 5461 superassociation is dominated by a single unresolved HII region of outstanding luminosity (approx. 1000 Orion nebulae). Detailed examination of corresponding continuum images indicates that only the southern plume has any sort of stellar counterpart. The other plumes are clearly diffuse with no underlying hot stars. An image of NGC 1569 is discussed. Besides showing the peculiar arm noted by Zwicky (1971) and the filamentary extensions to the North and South (as noted by Hodge 1974), this image also reveals two arc-like features of diffuse ionized gas to the South. Both arcs are concentric with the bright center of the galaxy - where the super star clusters, A and B are located. The inner arc (Arc 1) appears to follow the same curve as the SW arm thus suggesting that the two features represent limb-brightened fragments of vast superbubble that was blown out by a central starburst sometime in the past. As the classic starburst galaxy, M82 displays all the luminous hallmarks of intense high-mass star formation and outflow activity. The diffuse H alpha and x ray emitting gas along the minor axis provides especially good evidence for a bipolar outflow of hot gas which is shock heating the swept-up interstellar medium (ISM) to temperatures of approx. 10(exp 4) K. An image shows the H alpha emission within the disk and along the minor axis. Another image shows the same field in the light of near-infrared. Both figures are based on charge coupled device images taken with the McGraw-Hill 1.3 m telescope (Waller 1989). The longer wavelength emission clearly shows a more extended morphology along the major axis. The morphological discrepancy is most

  13. Geological structure of the offshore Sumatra forearc region estimated from high-resolution MCS reflection survey

    NASA Astrophysics Data System (ADS)

    Misawa, Ayanori; Hirata, Kenji; Seeber, Leonard; Arai, Kohsaku; Nakamura, Yasuyuki; Rahardiawan, Riza; Udrekh; Fujiwara, Toshiya; Kinoshita, Masataka; Baba, Hisatoshi; Kameo, Katsura; Adachi, Keita; Sarukawa, Hiroshi; Tokuyama, Hidekazu; Permana, Haryadi; Djajadihardja, Yusuf S.; Ashi, Juichiro

    2014-01-01

    To investigate detailed fault distributions and shallow geological structure offshore northwestern Sumatra, we obtained high-resolution Multi-Channel Seismic (MCS) reflection data around the Sunda Trench, trench slope, and forearc high regions offshore northwestern Sumatra. In general, trench-parallel anticlinal ridges are distributed from trench slope region to forearc high region. Two kinds of different vergence systems are characterized in the Sumatra forearc region; landward vergence is dominant in the lower trench slope region, and seaward vergence is dominant in the forearc high region. Moreover, piggyback or slope basins are recognized between anticlinal ridges. Deformation in the uppermost part of these basins, that is referred to ‘recent’ deformation in this paper, can be identified not only along major thrusts but also between major thrusts and the lower trench slope, suggesting these are related to recently active faulting. Several but the largest number of such deformation are distributed along a major thrust located in the middle of the forearc high region, whereas few are done along other major thrusts.

  14. Bright crater outflows: Possible emplacement mechanisms

    NASA Technical Reports Server (NTRS)

    Chadwick, D. John; Schaber, Gerald G.; Strom, Robert G.; Duval, Darla M.

    1992-01-01

    Lobate features with a strong backscatter are associated with 43 percent of the impact craters cataloged in Magellan's cycle 1. Their apparent thinness and great lengths are consistent with a low-viscosity material. The longest outflow yet identified is about 600 km in length and flows from the 90-km-diameter crater Addams. There is strong evidence that the outflows are largely composed of impact melt, although the mechanisms of their emplacement are not clearly understood. High temperatures and pressures of target rocks on Venus allow for more melt to be produced than on other terrestrial planets because lower shock pressures are required for melting. The percentage of impact craters with outflows increases with increasing crater diameter. The mean diameter of craters without outflows is 14.4 km, compared with 27.8 km for craters with outflows. No craters smaller than 3 km, 43 percent of craters in the 10- to 30-km-diameter range, and 90 percent in the 80- to 100-km-diameter range have associated bright outflows. More melt is produced in the more energetic impact events that produce larger craters. However, three of the four largest craters have no outflows. We present four possible mechanisms for the emplacement of bright outflows. We believe this 'shotgun' approach is justified because all four mechanisms may indeed have operated to some degree.

  15. MULTIPLE FAST MOLECULAR OUTFLOWS IN THE PRE-PLANETARY NEBULA CRL 618

    SciTech Connect

    Lee, Chin-Fei; Huang, Po-Sheng; Sahai, Raghvendra; Sánchez Contreras, Carmen; Tay, Jeremy Jian Hao

    2013-11-01

    CRL 618 is a well-studied pre-planetary nebula. It has multiple highly collimated optical lobes, fast molecular outflows along the optical lobes, and an extended molecular envelope that consists of a dense torus in the equator and a tenuous round halo. Here we present our observations of this source in CO J = 3-2 and HCN J = 4-3 obtained with the Submillimeter Array at up to ∼0.''3 resolutions. We spatially resolve the fast molecular outflow region previously detected in CO near the central star and find it to be composed of multiple outflows that have similar dynamical ages and are oriented along the different optical lobes. We also detect fast molecular outflows further away from the central star near the tips of the extended optical lobes and a pair of equatorial outflows inside the dense torus. We find that two episodes of bullet ejections in different directions are needed, one producing the fast molecular outflows near the central star and one producing the fast molecular outflows near the tips of the extended optical lobes. One possibility to launch these bullets is a magneto-rotational explosion of the stellar envelope.

  16. Outflow Driven Turbulence in Star Forming Clouds

    NASA Astrophysics Data System (ADS)

    Frank, Adam

    Setting young stellar object jets and outflows in their broadest context requires an understanding of outflows as “feedback” in the development of molecular cloud turbulence and the determination of star formation efficiencies. In this contribution I review our group’s recent studies exploring relationships between protostellar outflows and turbulence in molecular clouds. We first present studies of turbulence and fossil cavities driven by YSO outflows using numerical simulations which track the evolution of single transient jets driven into a turbulent medium. Our simulations show both the effect of turbulence on outflow structures and, conversely, the effect of outflows on the ambient turbulence. These studies demonstrate that individual transient outflows have the capacity to re-energize decaying turbulence. Next we present simulations of multiple interacting jets. We show that turbulence can readily be sustained by these interactions and show that it is possible to broadly characterize an effective driving scale of the outflows. Comparing the velocity spectrum obtained in our studies to that of an isotropically forced control we show that in outflow driven turbulence a power law of the form E(k) ∝ k - β is indeed achieved. However we find a steeper spectrum β ˜ 3 is obtained in outflow driven turbulence models than in isotropically forced simulations β ˜ 2. 0. Taken together both studies provide broad support for the conclusion that fossil cavities driven by decaying jets can provide a source of turbulence and feedback which mediate star formation processes in molecular clouds. Whether this does obtain in real clouds remains a point which must be demonstrated

  17. Cirrus clouds in convective outflow during the HIBISCUS campaign

    NASA Astrophysics Data System (ADS)

    Fierli, F.; di Donfrancesco, G.; Cairo, F.; Zampieri, M.; Orlandi, E.

    2007-05-01

    Light-weight microlidar measurements were taken on-board a stratospheric balloon during the HIBISCUS 2004 campaign, held in Bauru, Brazil (22 S, 49 W). Tropical cirrus observations showed high mesoscale variability in optical and microphysical properties. The cirrus clouds were observed throughout the flight between 12 and 15 km height. It was found that the clouds were composed of different layers, characterized by a marked variability in height, thickness and optical properties. Trajectory analysis and mesoscale transport simulations clearly revealed that the clouds had formed in the outflow of a large and persistent convective region, while the observed optical properties and cloud structure variability could be linked to different residence times of convective-processed air in the upper troposphere. Mesoscale simulations were able to reproduce the supersaturation due to recent outflow, while it was necessary to consider the presence of other formation processes than convective hydration for cirrus forming in aged detrained anvils.

  18. Examination of physical processes of convective cell evolved from a MCS - using a different model initialization

    NASA Astrophysics Data System (ADS)

    Spiridonov, Vlado; Ćurić, Mladjen

    2016-06-01

    The present study is focused on examination of the physical processes of convective cell evolved from a MCS occurred on 4 November 2011 over Genoa, Italy. The Quantitative Precipitation Forecasts (QPF) have been performed using WRF v3.6 model under different configurations and cloud permitting simulations. The results indicate underestimation of the amount of precipitation and spatial displacement of the area with a peak 24-h accumulated rainfall in (mm). Our main objective in the research is to test the cloud model ability and performance in simulation of this particular case. For that purpose a set of sensitivity experiments under different model initializations and initial data have been conducted. The results also indicate that the merging process apparently alters the physical processes through low- and middle-level forcing, increasing cloud depth, and enhancing convection. The examination of the microphysical process simulated by the model indicates that dominant production terms are the accretion of rain by graupel and snow, probabilistic freezing of rain to form graupel and dry and wet growth of graupel. Experiment under WRF v3.6 model initialization has shown some advantage in simulation of the physical processes responsible for production and initiation of heavy rainfall compared to other model runs. Most of the precipitation came from ice-phase particles-via accretion processes and the graupel melting at temperature T0 ≥ 0°C. The rainfall intensity and accumulated rainfall calculated by the model closely reflect the amount of rainfall recorded. Thus, the main benefit is to better resolve convective showers or storms which, in extreme cases, can give rise to major flooding events. In such a way, this model may become major contributor to improvements in weather analysis and small-scale atmospheric predictions and early warnings of such subscale processes.

  19. The resolved outflow from 3C 48

    SciTech Connect

    Shih, Hsin-Yi; Stockton, Alan E-mail: stockton@ifa.hawaii.edu

    2014-10-20

    We investigate the properties of the high-velocity outflow driven by the young radio jet of 3C 48, a compact-steep-spectrum source. We use the Space Telescope Imaging Spectrograph on board the Hubble Space Telecope to obtain (1) low-resolution UV and optical spectra and (2) multi-slit medium-resolution spectra of the ionized outflow. With supporting data from ground-based spectrographs, we are able to accurately measure the ratios of diagnostic emission lines such as [O III] λ5007, [O III] λ3727, [N II] λ6548, Hα, Hβ, [Ne V] λ3425, and [Ne III] λ3869. We fit the observed emission-line ratios using a range of ionization models, powered by active galactic nucleus (AGN) radiation and shocks, produced by the MAPPINGS code. We have determined that AGN radiation is likely the dominant ionization source. The outflow's density is estimated to be in the range n = 10{sup 3}-10{sup 4} cm{sup –3}, the mass is ∼6 × 10{sup 6} M {sub ☉}, and the metallicity is likely equal to or higher than solar. Compared with the typical outflows associated with more evolved radio jets, this young outflow is denser, less massive, and more metal rich. Multi-slit observations allow us to construct a two-dimensional velocity map of the outflow that shows a wide range of velocities with distinct velocity components, suggesting a wide-angle clumpy outflow.

  20. Comparative studies of MCs(+)-SIMS and e(-)-beam SNMS for quantitative analysis of bulk materials and layered structures.

    PubMed

    Breuer, U; Holzbrecher, H; Gastel, M; Becker, J S; Dietze, H J

    1995-10-01

    For the quantification of heterostructure depth profiles the knowledge of relative sensitivity factors (RSF) and the influence of matrix effects on the measured profiles is necessary. Matrix dependencies of the measured ion intensities have been investigated for sputtered neutral mass spectrometry (SNMS) and MCs(+)-SIMS. The use of Cs as primary ions for SNMS is advantageous compared to Ar because the depth resolution is improved without changing RSFs determined under Ar bombardment. No significant amount of molecules has been found in the SNMS spectra under Cs bombardment. Using MCs(+)-SIMS the RSFs are matrix dependent. An improvement of depth resolution can be achieved by biasing the sample against the primary ion beam for SNMS due to a reduction of the net energy of the primary ions and a resulting more gracing impact angle. PMID:15048502

  1. Sequence and batch language programs and alarm-related ``C`` programs for the 242-A MCS. Revision 2

    SciTech Connect

    Berger, J.F.

    1995-03-01

    A Distributive Process Control system was purchased by Project B-534, ``242-A Evaporator/Crystallizer Upgrades``. This control system, called the Monitor and Control System (MCS), was installed in the 242-A Evaporator located in the 200 East Area. The purpose of the MCS is to monitor and control the Evaporator and monitor a number of alarms and other signals from various Tank Farm facilities. Applications software for the MCS was developed by the Waste Treatment Systems Engineering (WTSE) group of Westinghouse. The standard displays and alarm scheme provide for control and monitoring, but do not directly indicate the signal location or depict the overall process. To do this, WTSE developed a second alarm scheme which uses special programs, annunciator keys, and process graphics. The special programs are written in two languages; Sequence and Batch Language (SABL), and ``C`` language. The WTSE-developed alarm scheme works as described below: SABL relates signals and alarms to the annunciator keys, called SKID keys. When an alarm occurs, a SABL program causes a SKID key to flash, and if the alarm is of yellow or white priority then a ``C`` program turns on an audible horn (the D/3 system uses a different audible horn for the red priority alarms). The horn and flashing key draws the attention of the operator.

  2. Outflows in Sodium Excess Objects

    NASA Astrophysics Data System (ADS)

    Park, Jongwon; Jeong, Hyunjin; Yi, Sukyoung

    2016-01-01

    van Dokkum and Conroy reported that some giant elliptical galaxies show extraordinarily strong Na I absorption lines and suggested that this is the evidence of unusually bottom-heavy initial mass function. Jeong et al. later studied galaxies with unexpectedly strong Na D absorption lines (Na D excess objects: NEOs) and showed that the origins of NEOs are different for different types of galaxies. According to their study, the origin of Na D excess seems to be related to interstellar medium (ISM) in late-type galaxies, but there seems to be no contributions from ISM in smooth-looking early-type galaxies. In order to test this finding, we measured the Doppler components in Na D lines of NEOs. We hypothesized that if Na D absorption line is related to ISM, the absorption line is more likely to be blueshifted in the spectrum by the motion of ISM caused by outflow. Many of late-type NEOs show blueshifted Na D absorption lines, so their origin seems related to ISM. On the other hand, smooth-looking early-type NEOs do not show Doppler departure and Na D excess in early-type NEOs is likely not related to ISM, which is consistent with the finding of Jeong et al.

  3. Magnetosphere sawtooth oscillations induced by ionospheric outflow.

    PubMed

    Brambles, O J; Lotko, W; Zhang, B; Wiltberger, M; Lyon, J; Strangeway, R J

    2011-06-01

    The sawtooth mode of convection of Earth's magnetosphere is a 2- to 4-hour planetary-scale oscillation powered by the solar wind-magnetosphere-ionosphere (SW-M-I) interaction. Using global simulations of geospace, we have shown that ionospheric O(+) outflows can generate sawtooth oscillations. As the outflowing ions fill the inner magnetosphere, their pressure distends the nightside magnetic field. When the outflow fluence exceeds a threshold, magnetic field tension cannot confine the accumulating fluid; an O(+)-rich plasmoid is ejected, and the field dipolarizes. Below the threshold, the magnetosphere undergoes quasi-steady convection. Repetition and the sawtooth period are controlled by the strength of the SW-M-I interaction, which regulates the outflow fluence. PMID:21636770

  4. Low-fold, ultra-deep MCS Profiling of the Mariana Arc

    NASA Astrophysics Data System (ADS)

    Tidwell, T.; Klemperer, S. L.; Kerr, B. C.; Goodliffe, A. M.

    2002-12-01

    We collected 2600 km of 12- and 15-fold MCS profiles in April 2002, using the R/V Ewing 6-km 240-channel streamer and a tuned 20-airgun array (10,810 cu. in.). The unusually low fold resulted because our primary focus was OBS wide-angle recording (Kerr et al., this session), so airguns were fired at a shot-interval of 90 to 110 s (shot-spacing of 200 m or 250 m) to allow water-column noise to decay between shots. As a positive aspect we recorded 60 s record lengths (the Syntrak-480 recording system could not record longer traces), so potentially imaging structure to over 200-km depth. We acquired 4 arc-parallel profiles: along the back-arc margin of the Mariana arc 30 km west of the main arc; along the volcanic line from 14°30'N (near Rota) to 18°00'N (latitude of Pagan), 30 km east of the arc along the uplifted forearc high; and along the forearc 80 km east of the arc but 140 km west of the trench. We also shot 6 arc-perpendicular lines to link the arc-parallel lines. All profiles were processed through post-stack migration during the cruise, but to only 20 s travel-time. Despite the low fold, the data provide excellent images of shallow basins between the volcanoes that shed light on the volumes and relative timings of eruptions along the arc, and of normal faults particularly along our eastern fore-arc line. Large and rapid topographic variations along the volcanic arc and uplifted forearc cause significant problems of sideswipe (Gunther et al., this session); and strong water-bottom multiples make recognition of deep structure almost impossible on the preliminarily processed data. However, beneath the shallowest, smoothest bathymetry (the guyot extending north of Farallon de Mendenilla in the uplifted forearc high) clear reflections are seen to 6 s (c. 15 km). In principle our low-frequency high-power source should penetrate deep into the mantle, and our streamer was towed at 12-m depth to minimize swell noise and enhance low-frequency signals. Currently we

  5. Powerful Molecular Outflows in Nearby Active Galaxies

    NASA Astrophysics Data System (ADS)

    Veilleux, Sylvain; Meléndez, Marcio

    2014-07-01

    We report the results from a systematic search for molecular (OH 119 μm) outflows with Herschel-PACS† in a sample of 43 nearby (z < 0.3) galaxy mergers, mostly ultraluminous infrared galaxies (ULIRGs) and QSOs. We find that the character of the OH feature (strength of the absorption relative to the emission) correlates with that of the 9.7-μm silicate feature, a measure of obscuration in ULIRGs. Unambiguous evidence for molecular outflows, based on the detection of OH absorption profiles with median velocities more blueshifted than -50 km s-1, is seen in 26 (70%) of the 37 OH-detected targets, suggesting a wide-angle (~ 145°) outflow geometry. Conversely, unambiguous evidence for molecular inflows, based on the detection of OH absorption profiles with median velocities more redshifted than +50 km s-1, is seen in only 4 objects, suggesting a planar or filamentary geometry for the inflowing gas. Terminal outflow velocities of ~ -1000 km s-1 are measured in several objects, but median outflow velocities are typically ~ -200 km s-1. While the outflow velocities show no statistically significant dependence on the star formation rate, they are distinctly more blueshifted among systems with large AGN fractions and luminosities [log (L AGN/L ⊙) >= 11.8 +/- 0.3]. The quasars in these systems play a dominant role in driving the molecular outflows. In contrast, the most AGN dominated systems, where OH is seen purely in emission, show relatively modest OH line widths, despite their large AGN luminosities, perhaps indicating that molecular outflows subside once the quasar has cleared a path through the obscuring material.

  6. An interferometric study of the HH 288 molecular outflow

    NASA Astrophysics Data System (ADS)

    Gueth, F.; Schilke, P.; McCaughrean, M. J.

    2001-09-01

    We present an interferometric study of the CO line emission in the HH 288 molecular outflow. The IRAM Plateau de Bure interferometer was used to obtain an 11-field mosaic covering the whole flow ( ~ 2 pc) with an angular resolution of about 3.5'' (7000 AU at a distance of 2 kpc). The data were complemented with short-spacings derived from IRAM 30-m observations. The exciting source of HH 288, IRAS 00342+6347, is a young (dynamical age of the outflow =~ a few 104 years) intermediate-mass (bolometric luminosity =~ 500lsun , envelope mass =~ 6 to 30msun ) embedded protostar. This source is likely to be an intermediate-mass counterpart of a classical Class 0 low-mass protostar. HH 288 is actually a quadrupolar outflow, and the angular resolution provided by the interferometric observations allows us to rule out models involving limb-brightened walls of a wide-angle single flow to explain such a morphology. The presence of two protostars in the central condensation is the most appealing explanation to account for the presence of the two flows. While the small East-West flow has a quite simple morphology and kinematics, the large North-South flow includes several overlapping structures, created by successive ejection events. Large collimated limb-brightened cavities are observed, with high-velocity material located along or near the flow axis. The internal structure of HH 288, including morphological coincidence between the CO and H2 emission, supports prompt entrainment at the head of large bow-shocks as the main formation process of molecular outflows from intermediate-mass protostars. Based on observations carried out with the IRAM Plateau de Bure Interferometer. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).

  7. Can an Alternative Outflow Strategy be Utilized for High-Risk Bridged Patients with Previous Cardiac Surgery?

    PubMed

    Danish, Timothy F; Davis, Mary E; Xu, Meng; Djunaidi, Monica; Danter, Matthew R; Kushwaha, Sudhir S; Stulak, John M; Haglund, Nicholas A; Maltais, Simon

    2016-01-01

    The HeartWare ventricular assist device (HVAD) is an implantable continuous-flow centrifugal pump that has allowed the development of sternal-sparing techniques, with the use of alternative outflow strategies. We compared early outcomes for patients bridged with the conventional versus alternative outflow graft strategy. From January 2013 to October 2014, 89 patients with HVAD implantation were identified. Survival was analyzed with Kaplan-Meier methods, and a log-rank test was used to compare outcomes between groups. Thirty patients (34%) had ≥1 previous sternotomy before HVAD implantation. Eight patients (27%) were approached using an alternative outflow graft technique with outflow graft connection to the descending aorta (n = 4, 50%) or left subclavian artery (n = 4, 50%), whereas 22 (73%) were implanted via a conventional sternotomy approach with the outflow graft to the ascending aorta. Preoperative characteristics (age, Interagency Registry for Mechanically Assisted Circulatory Support [INTERMACS], and Lietz-Miller score) were comparable between groups (all p > 0.05). Median follow-up was 4.7 (2.8-9.3) months of support. Outcomes were comparable between conventional and alternative outflow groups; survival at 6 months was 74% for the conventional group and 83% in the alternative outflow group. An alternative outflow graft strategy can be utilized to support bridged patients with a history of prior sternotomy. PMID:27111737

  8. Aging.

    PubMed

    Park, Dong Choon; Yeo, Seung Geun

    2013-09-01

    Aging is initiated based on genetic and environmental factors that operate from the time of birth of organisms. Aging induces physiological phenomena such as reduction of cell counts, deterioration of tissue proteins, tissue atrophy, a decrease of the metabolic rate, reduction of body fluids, and calcium metabolism abnormalities, with final progression onto pathological aging. Despite the efforts from many researchers, the progression and the mechanisms of aging are not clearly understood yet. Therefore, the authors would like to introduce several theories which have gained attentions among the published theories up to date; genetic program theory, wear-and-tear theory, telomere theory, endocrine theory, DNA damage hypothesis, error catastrophe theory, the rate of living theory, mitochondrial theory, and free radical theory. Although there have been many studies that have tried to prevent aging and prolong life, here we introduce a couple of theories which have been proven more or less; food, exercise, and diet restriction. PMID:24653904

  9. Aging

    PubMed Central

    Park, Dong Choon

    2013-01-01

    Aging is initiated based on genetic and environmental factors that operate from the time of birth of organisms. Aging induces physiological phenomena such as reduction of cell counts, deterioration of tissue proteins, tissue atrophy, a decrease of the metabolic rate, reduction of body fluids, and calcium metabolism abnormalities, with final progression onto pathological aging. Despite the efforts from many researchers, the progression and the mechanisms of aging are not clearly understood yet. Therefore, the authors would like to introduce several theories which have gained attentions among the published theories up to date; genetic program theory, wear-and-tear theory, telomere theory, endocrine theory, DNA damage hypothesis, error catastrophe theory, the rate of living theory, mitochondrial theory, and free radical theory. Although there have been many studies that have tried to prevent aging and prolong life, here we introduce a couple of theories which have been proven more or less; food, exercise, and diet restriction. PMID:24653904

  10. A Robust Measurement of the Mass Outflow Rate of the Galactic Outflow from NGC 6090

    NASA Astrophysics Data System (ADS)

    Chisholm, John; Tremonti, Christy A.; Leitherer, Claus; Chen, Yanmei

    2016-08-01

    To evaluate the impact of stellar feedback, it is critical to estimate the mass outflow rates of galaxies. Past estimates have been plagued by uncertain assumptions about the outflow geometry, metallicity, and ionization fraction. Here we use Hubble Space Telescope ultraviolet spectroscopic observations of the nearby starburst NGC 6090 to demonstrate that many of these quantities can be constrained by the data. We use the Si IV absorption lines to calculate the scaling of velocity (v), covering fraction (Cf), and density with distance from the starburst (r), assuming the Sobolev optical depth and a velocity law of the form: v~∝(1 - Ri/r)β (where Ri is the inner outflow radius). We find that the velocity (β=0.43) is consistent with an outflow driven by an r-2 force with the outflow radially accelerated, while the scaling of the covering fraction (Cf∝r-0.82) suggests that cool clouds in the outflow are in pressure equilibrium with an adiabatically expanding medium. We use the column densities of four weak metal lines and CLOUDY photoionization models to determine the outflow metallicity, the ionization correction, and the initial density of the outflow. Combining these values with the profile fitting, we find Ri = 63 pc, with most of the mass within 300 pc of the starburst. Finally, we find that the maximum mass outflow rate is 2.3 M⊙ yr-1 and the mass loading factor (outflow divided by the star formation rate) is 0.09, a factor of 10 lower than the value calculated using common assumptions for the geometry, metallicity and ionization structure of the outflow.

  11. Rotating molecular outflows: the young T Tauri star in CB 26

    NASA Astrophysics Data System (ADS)

    Launhardt, R.; Pavlyuchenkov, Ya.; Gueth, F.; Chen, X.; Dutrey, A.; Guilloteau, S.; Henning, Th.; Piétu, V.; Schreyer, K.; Semenov, D.

    2009-01-01

    Context: The disk-outflow connection is thought to play a key role in extracting excess angular momentum from a forming proto-star. Although jet rotation has been observed in a few objects, no rotation of molecular outflows has been unambiguously reported so far. Aims: We report new millimeter-interferometric observations of the edge-on T Tauri star - disk system in the isolated Bok globule CB 26. The aim of these observations was to study the disk-outflow relation in this 1 Myr old low-mass young stellar object. Methods: The IRAM PdBI array was used to observe 12CO(2-1) at 1.3 mm in two configurations, resulting in spectral line maps with 1.5´´ resolution. We use an empirical parameterized steady-state outflow model combined with 2-D line radiative transfer calculations and χ^2-minimization in parameter space to derive a best-fit model and constrain parameters of the outflow. Results: The data reveal a previously undiscovered collimated bipolar molecular outflow of total length ≈2000 AU, escaping perpendicular to the plane of the disk. We find peculiar kinematic signatures that suggest that the outflow is rotating with the same orientation as the disk. However, we could not ultimately exclude jet precession or two misaligned flows as possible origins of the observed peculiar velocity field. There is indirect indication that the embedded driving source is a binary system, which, together with the youth of the source, could provide a clue to the observed kinematic features of the outflow. Conclusions: CB 26 is so far the most promising source in which to study the rotation of a molecular outflow. Assuming that the outflow is rotating, we compute and compare masses, mass flux, angular momenta, and angular momentum flux of the disk and outflow and derive disk dispersal timescales of 0.5 ldots 1 Myr, comparable to the age of the system. Based on observations carried out with the IRAM Plateau de Bure Interferometer. IRAM is supported by INSU/CNRS (France), MPG

  12. Characterizing Quasar Outflows I: Sample, Spectral Measurements

    NASA Astrophysics Data System (ADS)

    Ganguly, Rajib; Christenson, D. H.; Richmond, J. M.; Derseweh, J. A.; Robbins, J. M.; Townsend, S. L.; Stark, M. A.

    2012-05-01

    Galaxy evolution models have shown that quasars are a crucial ingredient in the evolution of massive galaxies. Outflows play a key role in the story of quasars and their host galaxies, by helping regulate the accretion process, the star-formation rate and mass of the host galaxy (i.e., feedback). The prescription for modeling outflows as a contributor to feedback requires knowledge of the outflow velocity, geometry, and column density. In particular, we need to understand how these depend on physical parameters and how much is determined stochastically (and with what distribution). For this purpose, we are examining a sample of 11000 z=1.7-2.0 quasars from the Sloan Digital Sky Survey. This redshift range permits the following from the SDSS spectra: (1) separation of objects that do and do not exhibit outflows; (2) classification/measurement of outflow properties (ionization, velocity, velocity width); and (3) measurements of UV emission line and continuum parameters. In this poster, we subjectively divide these quasars into four categories: broad absorption-line quasars (2700 objects), associated absorption-line quasars (1700 objects), reddened quasars (160 objects), and unabsorbed/unreddened quasars (6300 objects). We present measurements of the absorption (velocities, velocity widths, equivalent widths), composite spectral profiles of outflows as a function of velocity, as well as measurements of the continuum and CIV, MgII, and FeII emission-line properties. In accompanying posters, we add photometry from the rest-frame X-ray (ROSAT and Chandra), EUV (GALEX), optical (2MASS), and infrared (WISE) bands to complete the SED. The continuum and emission-line measurements from the SDSS spectra and accompanying photometry provides estimates on the black hole masses, bolometric luminsosities, and SED. We consider empirically how these affect the outflow properties. This material is based upon work supported by the National Aeronautics and Space Administration under

  13. Quality of packed red blood cells and platelet concentrates collected by multicomponent collection using the MCS plus device.

    PubMed

    Leitner, G C; Jilma-Stohlawetz, P; Stiegler, G; Weigel, G; Horvath, M; Tanzmann, A; Höcker, P; Fischer, M B

    2003-01-01

    The demand for blood components is constantly increasing, while the exclusion criteria for donors are strengthened in order to reach maximal safety for donors and patients. To counterbalance reduced availability of volunteers, multicomponent collections (MCC) is an attractive approach to produce more than one component during a single apheresis procedure from one donor, such as packed red blood cells (PRBCs) and platelet concentrates (PCs). Further, the exposures of patients to a limited number of donors reduces the possibility of alloimmunization and transfusion-related diseases. We measured the quality of PRBCs and PCs obtained by MCC, using the MCS+ device with the LDPRBC program, Revision B, and compared them with the quality of manually collected PRBCs and PCs collected with the Revision C2 of the MCS+. We found higher pH levels and lower hemolysis assessed by means of fHb and K+ in the supernatant of PRBCs over the whole storage period of 42 days in MCC-derived PRBCs. The functional metabolism assessed by intracellular ATP was higher in PRBCs collected by MCC than in manually collected units. Furthermore, PCs obtained during MCC showed an increase in p-selectin expression on day 5 of storage compared to PCs collected with the Revision C2 of the MCS+. The p-selectin expression on MCC platelets was within the range of p-selectin expression found in PCs obtained by other apheresis devices. These results indicate less storage lesion in MCC-derived PRBCs compared to manually collected units and no compromise in the quality of MCC PCs obtained in the same apheresis procedure. PMID:12717789

  14. Impacts of pure shocks in the BHR71 bipolar outflow

    NASA Astrophysics Data System (ADS)

    Gusdorf, A.; Riquelme, D.; Anderl, S.; Eislöffel, J.; Codella, C.; Gómez-Ruiz, A. I.; Graf, U. U.; Kristensen, L. E.; Leurini, S.; Parise, B.; Requena-Torres, M. A.; Ricken, O.; Güsten, R.

    2015-03-01

    Context. During the formation of a star, material is ejected along powerful jets that impact the ambient material. This outflow regulates star formation by e.g. inducing turbulence and heating the surrounding gas. Understanding the associated shocks is therefore essential to the study of star formation. Aims: We present comparisons of shock models with CO, H2, and SiO observations in a "pure" shock position in the BHR71 bipolar outflow. These comparisons provide an insight into the shock and pre-shock characteristics, and allow us to understand the energetic and chemical feedback of star formation on Galactic scales. Methods: New CO (Jup = 16, 11, 7, 6, 4, 3) observations from the shocked regions with the SOFIA and APEX telescopes are presented and combined with earlier H2 and SiO data (from the Spitzer and APEX telescopes). The integrated intensities are compared to a grid of models that were obtained from a magneto-hydrodynamical shock code, which calculates the dynamical and chemical structure of these regions combined with a radiative transfer module based on the "large velocity gradient" approximation. Results: The CO emission leads us to update the conclusions of our previous shock analysis: pre-shock densities of 104 cm-3 and shock velocities around 20-25 km s-1 are still constrained, but older ages are inferred (~4000 years). Conclusions: We evaluate the contribution of shocks to the excitation of CO around forming stars. The SiO observations are compatible with a scenario where less than 4% of the pre-shock SiO belongs to the grain mantles. We infer outflow parameters: a mass of 1.8 × 10-2 M⊙ was measured in our beam, in which a momentum of 0.4 M⊙ km s-1 is dissipated, corresponding to an energy of 4.2 × 1043 erg. We analyse the energetics of the outflow species by species. Comparing our results with previous studies highlights their dependence on the method: H2 observations only are not sufficient to evaluate the mass of outflows.

  15. Galaxy ecosystems: gas contents, inflows and outflows

    NASA Astrophysics Data System (ADS)

    Lu, Zhankui; Mo, H. J.; Lu, Yu

    2015-06-01

    We use a set of observational data for galaxy cold gas mass fraction and gas phase metallicity to constrain the content, inflow and outflow of gas in central galaxies hosted by haloes with masses between 1011 and 1012 M⊙. The gas contents in high-redshift galaxies are obtained by combining the empirical star formation histories and star formation models that relate star formation rate with the cold gas mass in galaxies. We find that the total baryon mass in low-mass galaxies is always much less than the universal baryon mass fraction since z = 2, regardless of star formation model adopted. The data for the evolution of the gas phase metallicity require net metal outflow at z ≲ 2, and the metal loading factor is constrained to be about 0.01, or about 60 per cent of the metal yield. Based on the assumption that galactic outflow is more enriched in metal than both the interstellar medium and the material ejected at earlier epochs, we are able to put stringent constraints on the upper limits for both the net accretion rate and the net mass outflow rate. The upper limits strongly suggest that the evolution of the gas phase metallicity and gas mass fraction for low-mass galaxies at z < 2 is not compatible with strong outflow. We speculate that the low star formation efficiency of low-mass galaxies is owing to some preventative processes that prevent gas from accreting into galaxies in the first place.

  16. Example of Reduced Turbulence during Thunderstorm Outflow.

    NASA Astrophysics Data System (ADS)

    Bowen, Brent M.

    1996-06-01

    The vertical structures of turbulence, winds, and temperatures are analyzed from a 92-m instrumented tower and a collocated acoustic sodar during an outflow episode from a weak thunderstorm over sloping terrain in northern New Mexico. Prior to the onset of the outflow, strong insolation and light winds caused unstable conditions during the middle part of a June day, as evidenced by the large values of horizontal and vertical turbulence coefficients ( and , respectively) extending from the surface up to at 1east 750 m above ground level (AGL). There was a dramatic change in wind direction and speed as the gust front passed during the early afternoon. The outflow was a well-defined jet, with its core reaching a maximum average of 16 m S1 at 120 m AGL. The and values decreased sharply throughout the outflow region, especially near the height of the wind speed maximum (120 m AGL), where reached a value of only 2°. Consequently, horizontal and vertical dispersion of a hypothetical pollutant could each decrease by about 55% at 12 m AGL to 87% at 120 m AGL up to several kilometers downwind. In turn, this could increase plume centerline concentrations by factors of 1.5 and 14 for releases at 12 and 120 m AOL, respectively. As a result of intensified winds and reduced turbulence in the outflow layer, elevated pollutant concentrations would rapidly be transported downwind before fumigation could lead to elevated pollutant levels at ground level.

  17. Observations of Protostellar Outflow Feedback in Clustered Star Formation

    NASA Astrophysics Data System (ADS)

    Nakamura, F.

    2016-05-01

    We discuss the role of protostellar outflow feedback in clustered star formation using the observational data of recent molecular outflow surveys toward nearby cluster-forming clumps. We found that for almost all clumps, the outflow momentum injection rate is significantly larger than the turbulence dissipation rate. Therefore, the outflow feedback is likely to maintain supersonic turbulence in the clumps. For less massive clumps such as B59, L1551, and L1641N, the outflow kinetic energy is comparable to the clump gravitational energy. In such clumps, the outflow feedback probably affects significantly the clump dynamics. On the other hand, for clumps with masses larger than about 200 M⊙, the outflow kinetic energy is significantly smaller than the clump gravitational energy. Since the majority of stars form in such clumps, we conclude that outflow feedback cannot destroy the whole parent clump. These characteristics of the outflow feedback support the scenario of slow star formation.

  18. Zooplankton in the Arctic outflow

    NASA Astrophysics Data System (ADS)

    Soloviev, K. A.; Dritz, A. V.; Nikishina, A. B.

    2009-04-01

    Climate changes in the Arctic cause the changes in the current system that may have cascading effect on the structure of plankton community and consequently on the interlinked and delicately balanced food web. Zooplankton species are by definition incapable to perform horizontal moving. Their transport is connected with flowing water. There are zooplankton species specific for the definite water masses and they can be used as markers for the different currents. That allows us to consider zooplankton community composition as a result of water mixing in the studied area. Little is known however about the mechanisms by which spatial and temporal variability in advection affect dynamics of local populations. Ice conditions are also very important in the function of pelagic communities. Melting time is the trigger to all "plankton blooming" processes, and the duration of ice-free conditions determines the food web development in the future. Fram Strait is one of the key regions for the Arctic: the cold water outflow comes through it with the East Greenland Current and meets warm Atlantic water, the West Spitsbergen Current, producing complicated hydrological situation. During 2007 and 2008 we investigated the structure functional characteristics of zooplankton community in the Fram Strait region onboard KV "Svalbard" (April 2007, April and May 2008) and RV "Jan Mayen" (May 2007, August 2008). This study was conducted in frame of iAOOS Norway project "Closing the loop", which, in turn, was a part of IPY. During this cruises multidisciplinary investigations were performed, including sea-ice observations, CTD and ADCP profiling, carbon flux, nutrients and primary production measurements, phytoplankton sampling. Zooplankton was collected with the Hydro-Bios WP2 net and MultiNet Zooplankton Sampler, (mouth area 0.25 m2, mesh size 180 um).Samples were taken from the depth strata of 2000-1500, 1500-1000, 1000-500,500-200, 200-100, 100-60, 60-30, 30-0 m. Gut fluorescence

  19. Spitzer IRAC Detection of Protostellar Outflows

    NASA Astrophysics Data System (ADS)

    Ybarra, Jason E.; Lada, E. A.; Balog, Z.

    2009-01-01

    We will discuss a method for detecting shocked H2 emission in IRAC band images and distinguishing H2 knots from stellar sources. Using this method we will present Spitzer IRAC imaging of a recently discovered parsec scale protostellar outflow. This outflow was detected in all four IRAC bands. The proposed source of the outflow is an embedded Class 0 object detected in the MIPS images. This work is based in part on archival data obtained with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by an award issued by JPL/Caltech and also a NASA LTSA Grant NNG05GD66G

  20. Wind influence on a coastal buoyant outflow

    NASA Astrophysics Data System (ADS)

    Whitney, Michael M.; Garvine, Richard W.

    2005-03-01

    This paper investigates the interplay between river discharge and winds in forcing coastal buoyant outflows. During light winds a plume influenced by the Earth's rotation will flow down shelf (in the direction of Kelvin wave propagation) as a slender buoyancy-driven coastal current. Downwelling favorable winds augment this down-shelf flow, narrow the plume, and mix the water column. Upwelling favorable winds drive currents that counter the buoyancy-driven flow, spread plume waters offshore, and rapidly mix buoyant waters. Two criteria are developed to assess the wind influence on a buoyant outflow. The wind strength index (Ws) determines whether a plume's along-shelf flow is in a wind-driven or buoyancy-driven state. Ws is the ratio of the wind-driven and buoyancy-driven along-shelf velocities. Wind influence on across-shelf plume structure is rated with a timescale (ttilt) for the isopycnal tilting caused by wind-driven Ekman circulation. These criteria are used to characterize wind influence on the Delaware Coastal Current and can be applied to other coastal buoyant outflows. The Delaware buoyant outflow is simulated for springtime high-river discharge conditions. Simulation results and Ws values reveal that the coastal current is buoyancy-driven most of the time (∣Ws∣ < 1 on average). Wind events, however, overwhelm the buoyancy-driven flow (∣Ws∣ > 1) several times during the high-discharge period. Strong upwelling events reverse the buoyant outflow; they constitute an important mechanism for transporting fresh water up shelf. Across-shelf plume structure is more sensitive to wind influence than the along-shelf flow. Values of ttilt indicate that moderate or strong winds persisting throughout a day can modify plume width significantly. Plume widening during upwelling events is accompanied by mixing that can erase the buoyant outflow.

  1. Explosive Outflows from Forming Massive Stars

    NASA Astrophysics Data System (ADS)

    Bally, J.; Ginsburg, A.; Kasliwal, M. M.

    2016-05-01

    AO imaging of the near IR [Fe ii] and H2 lines and ALMA CO J = 2 - 1 data confirms the explosive nature of the BN/KL outflow in Orion. N-body interactions in compact groups may be responsible for the production of powerful, explosive protostellar outflows and luminous infrared flares. The Orion event may have been triggered by a protostellar merger. First results of a search for Orion-like events in 200 nearby galaxies with the SPitzer InfraRed Intensive Transients Survey (SPIRITS) are briefly discussed.

  2. Episodic outflows from high-mass protostars

    SciTech Connect

    Mitchell, G.F.; Maillard, J.P.; Hasegawa, T.I. Canada-France-Hawaii Telescope Corp., Waimea, HI CNRS, Institut d'Astrophysique, Paris Duke University, Durham, NC )

    1991-04-01

    This paper examines the kinematics and physical properties of the outflowing gas from seven luminous deeply embedded young stellar objects or protostars: M8E-IR, GL 490, GL 2591, W3 IRS 5, NGC 7538 IRS 1, NGC 7538 IRS 9, and S140 IRS 1. The outflows are seen as blueshifted absorption features in lines of the fundamental band of CO. The CO lines seen in absorption are compared with CO lines seen in emission at mm wavelengths. New CO J = 2-1 emission-line data are presented for the first five of the sources. 60 refs.

  3. Episodic High-velocity Outflows from V899 Mon: A Constraint On The Outflow Mechanisms

    NASA Astrophysics Data System (ADS)

    Ninan, J. P.; Ojha, D. K.; Philip, N. S.

    2016-07-01

    We report the detection of large variations in the outflow wind velocity from a young eruptive star, V899 Mon, during its ongoing high accretion outburst phase. Such large variations in the outflow velocity (from ‑722 to ‑425 km s‑1) have never been reported previously in this family of objects. Our continuous monitoring of this source shows that the multi-component, clumpy, and episodic high velocity outflows are stable in the timescale of a few days, and vary over the timescale of a few weeks to months. We detect significant decoupling in the instantaneous outflow strength to accretion rate. From the comparison of various possible outflow mechanisms in magnetospheric accretion of young stellar objects, we conclude magnetically driven polar winds to be the most consistent mechanism for the outflows seen in V899 Mon. The large scale fluctuations in outflow over the short period makes V899 Mon the most ideal source to constrain various magnetohydrodynamics simulations of magnetospheric accretion. Based on observations made with the Southern African Large Telescope (SALT).

  4. Secondary chaotic terrain formation in the higher outflow channels of southern circum-Chryse, Mars

    NASA Astrophysics Data System (ADS)

    Rodríguez, J. Alexis P.; Kargel, Jeffrey S.; Tanaka, Kenneth L.; Crown, David A.; Berman, Daniel C.; Fairén, Alberto G.; Baker, Victor R.; Furfaro, Roberto; Candelaria, Pat; Sasaki, Sho

    2011-05-01

    relatively warm upper crustal materials in volcanic settings, or within highly saline crustal materials where cryopegs developed, lenses of volatiles in liquid form within the cryolithosphere could have formed, and/or remained stable. In addition, our numerical simulations suggest that low thermal conductivity, dry fine-grained porous geologic materials just a few tens of meters in thickness (e.g., dunes, sand sheets, some types of regolith materials), could have produced high thermal anomalies resulting in subsurface melting. The existence of a global layer of dry geologic materials overlying the cryolithosphere would suggest that widespread lenses of fluids existed (and may still exist) at shallow depths wherever these materials are fine-grained and porous. The surface ages of the investigated outflow channels and chaotic terrains span a full 500 to 700 Myr. Chaotic terrains similar in dimensions and morphology to secondary chaotic terrains are not observed conspicuously throughout the surface of Mars, suggesting that intra-cryolithospheric fluid lenses may form relatively stable systems. The existence of widespread groundwater lenses at shallow depths of burial has tremendous implications for exobiological studies and future human exploration. We find that the clear geomorphologic anomaly that the chaotic terrains and outflow channels of southern Chryse form within the Martian landscape could have been a consequence of large-scale resurfacing resulting from anomalously extensive subsurface melt in this region of the planet produced by high concentrations of salts within the regional upper crust. Crater count statistics reveal that secondary chaotic terrains and the outflow channels within which they occur have overlapping ages, suggesting that the instabilities leading to their formation rapidly dissipated, perhaps as the thickness of the cryolithosphere was reset following the disruption of the upper crustal thermal structure produced during outflow channel excavation.

  5. The formation and dust lifting processes associated with a large Saharan meso-scale convective system (MCS)

    NASA Astrophysics Data System (ADS)

    Roberts, Alex; Knippertz, Peter

    2013-04-01

    This work focusses on the meteorology that produced a large Mesoscale Convective System (MCS) and the dynamics of its associated cold pool. The case occurred between 8th-10th June 2010 and was initiated over the Hoggar and Aïr Mountains in southern Algeria and northern Niger respectively. The dust plume created covered parts of Algeria, Mali and Mauritania and was later deformed the by background flow and transported over the Atlantic and Mediterranean. This study is based on: standard surface observations (where available), ERA-Interim reanalysis, Meteosat imagery, MODIS imagery, Tropical Rainfall Measuring Mission (TRMM) rainfall estimates, Cloud Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO), CloudSat and a high resolution (3.3km) limited area simulation using the Weather Research and Forecasting (WRF) model. A variety of different processes appear to be important for the generation of this MCS and the spreading of the associated dusty cold pool. These include: the presence of a trough on the subtropical jet, the production of a tropical cloud plume, disruption to the structure of the Saharan heat low and the production of a Libyan high. These features produced moistening of the boundary layer and a convergence zone over the region of MCS initiation. Another important factor appears to have been the production of a smaller MCS and cold pool on the evening of the 7th June. This elevated low-level moisture and encouraged convective initiation the following day. Once triggered on the 8th June some cells grew and merged into a single large system that propagated south westward and produced a large cold pool that emanated from its northern edge. The cells on the northern edge of the system over the Hoggar grew and collapsed producing a haboob that spread over a large area. Cells further south continued to develop into the MCS and actively produce a cold pool over the system's lifetime. This undercut the dusty air from the earlier cold pool and

  6. Did the martian outflow channels mostly form during the Amazonian Period?

    NASA Astrophysics Data System (ADS)

    Rodriguez, J. Alexis P.; Platz, Thomas; Gulick, Virginia; Baker, Victor R.; Fairén, Alberto G.; Kargel, Jeffrey; Yan, Jianguo; Miyamoto, Hideaki; Glines, Natalie

    2015-09-01

    Simud, Tiu, and Ares Valles comprise some of the largest outflow channels on Mars. Their excavation has been attributed variously to (or a combination of) erosion by catastrophic floods, glaciers, and debris flows. Numerous investigations indicate that they formed largely during the Late Hesperian (3.61-3.37 Ga). However, these studies mostly equate the ages of the outflow channel floors to those of the flows that generated mesoscale (several hundred meters to a few kilometers) bedforms within them. To improve the statistical accuracy in the age determinations of these flow events, we have used recently acquired high-resolution image and topographic data to map and date portions of Simud, Tiu and Ares Valles, which are extensively marked by these bedforms. Our results, which remove the statistical effects of older and younger outflow channel floor surfaces on the generation of modeled ages, reveal evidence for major outflow channel discharges occurring during the Early (3.37-1.23 Ga) and Middle (1.23-0.328 Ga) Amazonian, with activity significantly peaking during the Middle Amazonian stages. We also find that during the documented stages of Middle Amazonian discharges, the floor of Tiu Valles underwent widespread collapse, resulting in chaotic terrain formation. In addition, we present evidence showing that following the outflow channel discharges, collapse within northern Simud Valles generated another chaotic terrain. This younger chaos region likely represents the latest stage of large-scale outflow channel resurfacing within the study area. Our findings imply that in southern circum-Chryse the martian hydrosphere experienced large-scale drainage during the Amazonian, which likely led to periodic inundation and sedimentation within the northern plains.

  7. Protostellar Outflow Evolution in Turbulent Environments

    SciTech Connect

    Cunningham, A; Frank, A; Carroll, J; Blackman, E; Quillen, A

    2008-04-11

    The link between turbulence in star formatting environments and protostellar jets remains controversial. To explore issues of turbulence and fossil cavities driven by young stellar outflows we present a series of numerical simulations tracking the evolution of transient protostellar jets driven into a turbulent medium. Our simulations show both the effect of turbulence on outflow structures and, conversely, the effect of outflows on the ambient turbulence. We demonstrate how turbulence will lead to strong modifications in jet morphology. More importantly, we demonstrate that individual transient outflows have the capacity to re-energize decaying turbulence. Our simulations support a scenario in which the directed energy/momentum associated with cavities is randomized as the cavities are disrupted by dynamical instabilities seeded by the ambient turbulence. Consideration of the energy power spectra of the simulations reveals that the disruption of the cavities powers an energy cascade consistent with Burgers-type turbulence and produces a driving scale-length associated with the cavity propagation length. We conclude that fossil cavities interacting either with a turbulent medium or with other cavities have the capacity to sustain or create turbulent flows in star forming environments. In the last section we contrast our work and its conclusions with previous studies which claim that jets can not be the source of turbulence.

  8. A Well-Defined Bipolar Outflow Shell

    NASA Astrophysics Data System (ADS)

    Xie, Taoling; Goldsmith, Paul F.; Patel, Nimesh

    1992-12-01

    A well-defined "eggplant-shaped" thin shell is revealed in the Mon R2 central core region by CO and (13) CO J=1-0 maps obtained with QUARRY. This thin shell outlines the extended blue lobe of the massive bipolar outflow. The projected length and width of the shell are about 5.7 pc and 2.5 pc respectively, and the averaged projected thickness of the shell is ~ 0.3 pc. The shape of this shell can be satisfactorily accounted for quantitatively in terms of limb-brightening within the framework of the Shu et al shell model with radially directed wind, although the model seems to be oversimplified with respect to the complexity that our data reveal. The outflow shell's symmetry axis is estimated to be inclined by ~ 70(deg) with respect to the line of sight. We suggest that the coincident blue- and red-shifted emission and the bending of the red-shifted lobe are the result of the red-shifted shell being compressed, rather than having a second bipolar outflow aligned roughly perpendicular to the axis of the first bipolar outflow.

  9. The cellular basis of aqueous outflow regulation.

    PubMed

    Francis, B A; Alvarado, J

    1997-04-01

    This review begins with an introduction to the concept of the cellular regulation of aqueous outflow, current methods used for its study, and the cell types that are known to participate in this process. Current research in the field is divided into work on cell properties, cell products and extracellular matrix, cytoskeletal and structural changes, and drug interactions. PMID:10168352

  10. Protostellar Outflow Evolution in Turbulent Environments

    NASA Astrophysics Data System (ADS)

    Cunningham, Andrew J.; Frank, Adam; Carroll, Jonathan; Blackman, Eric G.; Quillen, Alice C.

    2009-02-01

    The link between turbulence in star-forming environments and protostellar jets remains controversial. To explore issues of turbulence and fossil cavities driven by young stellar outflows, we present a series of numerical simulations tracking the evolution of transient protostellar jets driven into a turbulent medium. Our simulations show both the effect of turbulence on outflow structures and, conversely, the effect of outflows on the ambient turbulence. We demonstrate how turbulence will lead to strong modifications in jet morphology. More importantly, we demonstrate that individual transient outflows have the capacity to re-energize decaying turbulence. Our simulations support a scenario in which the directed energy/momentum associated with cavities is randomized as the cavities are disrupted by dynamical instabilities seeded by the ambient turbulence. Consideration of the energy power spectra of the simulations reveals that the disruption of the cavities powers an energy cascade consistent with Burgers'-type turbulence and produces a driving scale length associated with the cavity propagation length. We conclude that fossil cavities interacting either with a turbulent medium or with other cavities have the capacity to sustain or create turbulent flows in star-forming environments. In the last section, we contrast our work and its conclusions with previous studies which claim that jets cannot be the source of turbulence.

  11. The Resolved Outflow from 3C 48

    NASA Astrophysics Data System (ADS)

    Shih, Hsin-Yi; Stockton, Alan

    2014-10-01

    We investigate the properties of the high-velocity outflow driven by the young radio jet of 3C 48, a compact-steep-spectrum source. We use the Space Telescope Imaging Spectrograph on board the Hubble Space Telecope to obtain (1) low-resolution UV and optical spectra and (2) multi-slit medium-resolution spectra of the ionized outflow. With supporting data from ground-based spectrographs, we are able to accurately measure the ratios of diagnostic emission lines such as [O III] λ5007, [O III] λ3727, [N II] λ6548, Hα, Hβ, [Ne V] λ3425, and [Ne III] λ3869. We fit the observed emission-line ratios using a range of ionization models, powered by active galactic nucleus (AGN) radiation and shocks, produced by the MAPPINGS code. We have determined that AGN radiation is likely the dominant ionization source. The outflow's density is estimated to be in the range n = 103-104 cm-3, the mass is ~6 × 106 M ⊙, and the metallicity is likely equal to or higher than solar. Compared with the typical outflows associated with more evolved radio jets, this young outflow is denser, less massive, and more metal rich. Multi-slit observations allow us to construct a two-dimensional velocity map of the outflow that shows a wide range of velocities with distinct velocity components, suggesting a wide-angle clumpy outflow. Based in part on observations made with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555. These observations are associated with program GO-11574. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. Some of the

  12. OUTFLOWS FROM EVOLVED STARS: THE RAPIDLY CHANGING FINGERS OF CRL 618

    SciTech Connect

    Balick, Bruce; Huarte-Espinosa, Martin; Frank, Adam; Gomez, Thomas; Alcolea, Javier; Corradi, Romano L. M.; Vinkovic, Dejan E-mail: martinHE@pas.rochester.edu E-mail: gomezt@astro.as.utexas.edu E-mail: rcorradi@iac.es

    2013-07-20

    Our ultimate goal is to probe the nature of the collimator of the outflows in the pre-planetary nebula CRL 618. CRL 618 is uniquely suited for this purpose owing to its multiple, bright, and carefully studied finger-shaped outflows east and west of its nucleus. We compare new Hubble Space Telescope images to images in the same filters observed as much as 11 yr ago to uncover large proper motions and surface brightness changes in its multiple finger-shaped outflows. The expansion age of the ensemble of fingers is close to 100 yr. We find strong brightness variations at the fingertips during the past decade. Deep IR images reveal a multiple ring-like structure of the surrounding medium into which the outflows propagate and interact. Tightly constrained three-dimensional hydrodynamic models link the properties of the fingers to their possible formation histories. We incorporate previously published complementary information to discern whether each of the fingers of CRL 618 are the results of steady, collimated outflows or a brief ejection event that launched a set of bullets about a century ago. Finally, we argue on various physical grounds that fingers of CRL 618 are likely to be the result of a spray of clumps ejected at the nucleus of CRL 618 since any mechanism that form a sustained set of unaligned jets is unprecedented.

  13. HOT ELECTROMAGNETIC OUTFLOWS. I. ACCELERATION AND SPECTRA

    SciTech Connect

    Russo, Matthew; Thompson, Christopher

    2013-04-20

    The theory of cold, relativistic, magnetohydrodynamic outflows is generalized by the inclusion of an intense radiation source. In some contexts, such as the breakout of a gamma-ray burst (GRB) jet from a star, the outflow is heated to a high temperature at a large optical depth. Eventually it becomes transparent and is pushed to a higher Lorentz factor by a combination of the Lorentz force and radiation pressure. We obtain its profile, both inside and outside the fast magnetosonic critical point, when the poloidal magnetic field is radial and monopolar. Most of the energy flux is carried by the radiation field and the toroidal magnetic field that is wound up close to the rapidly rotating engine. Although the entrained matter carries little energy, it couples the radiation field to the magnetic field. Then the fast critical point is pulled inward from infinity and, above a critical radiation intensity, the outflow is accelerated mainly by radiation pressure. We identify a distinct observational signature of this hybrid outflow: a hardening of the radiation spectrum above the peak of the seed photon distribution, driven by bulk Compton scattering. The non-thermal spectrum-obtained by a Monte Carlo method-is most extended when the Lorentz force dominates the acceleration, and the seed photon beam is wider than the Lorentz cone of the MHD fluid. This effect is a generic feature of hot, magnetized outflows interacting with slower relativistic material. It may explain why some GRB spectra appear to peak at photon energies above the original Amati et al. scaling. A companion paper addresses the case of jet breakout, where diverging magnetic flux surfaces yield strong MHD acceleration over a wider range of Lorentz factor.

  14. Hot Electromagnetic Outflows. I. Acceleration and Spectra

    NASA Astrophysics Data System (ADS)

    Russo, Matthew; Thompson, Christopher

    2013-04-01

    The theory of cold, relativistic, magnetohydrodynamic outflows is generalized by the inclusion of an intense radiation source. In some contexts, such as the breakout of a gamma-ray burst (GRB) jet from a star, the outflow is heated to a high temperature at a large optical depth. Eventually it becomes transparent and is pushed to a higher Lorentz factor by a combination of the Lorentz force and radiation pressure. We obtain its profile, both inside and outside the fast magnetosonic critical point, when the poloidal magnetic field is radial and monopolar. Most of the energy flux is carried by the radiation field and the toroidal magnetic field that is wound up close to the rapidly rotating engine. Although the entrained matter carries little energy, it couples the radiation field to the magnetic field. Then the fast critical point is pulled inward from infinity and, above a critical radiation intensity, the outflow is accelerated mainly by radiation pressure. We identify a distinct observational signature of this hybrid outflow: a hardening of the radiation spectrum above the peak of the seed photon distribution, driven by bulk Compton scattering. The non-thermal spectrum—obtained by a Monte Carlo method—is most extended when the Lorentz force dominates the acceleration, and the seed photon beam is wider than the Lorentz cone of the MHD fluid. This effect is a generic feature of hot, magnetized outflows interacting with slower relativistic material. It may explain why some GRB spectra appear to peak at photon energies above the original Amati et al. scaling. A companion paper addresses the case of jet breakout, where diverging magnetic flux surfaces yield strong MHD acceleration over a wider range of Lorentz factor.

  15. Cloud resolving modelling of the life cycle of a MCS: Sensitivity to soil conditions over West Africa

    NASA Astrophysics Data System (ADS)

    Gantner, L.; Kalthoff, N.

    2009-09-01

    In the African Sahelian (12°N-18°N) and Sudanian climate zone (9°N-11°N) convective systems contribute about 80-90% and about 50%, respectively, to the annual rainfall. Thus, they play a key role in the water cycle of West Africa. Their rainfall, however, is highly variable in space as well as in time. The initiation and modification of rain-producing convective systems in West Africa are still not well understood. In addition to mid- and upper-tropospheric forcing, the influence of surface and convective boundary layer (CBL) processes on the initiation of convection is often emphasised. Major factors are the spatial distribution and temporal development of water vapour in the CBL. Besides advective processes, water vapour is made available in the atmosphere locally through evapotranspiration from soil and vegetation; the latter is an important component of the earth's surface energy balance. Soil moisture affects the energy balance via the albedo and emissivity of the surface, the conduction of heat in the soil and the stomata resistance of vegetation. Research findings show that the soil moisture exerts greater influence on the CBL than vegetation. Cloud resolving real-case simulations initialized with ECMWF analysis data were performed to investigate the sensitivity of a mesoscale convective system (MCS) to soil properties. Several scenarios with different content of soil moisture and distribution of soil conditions were investigated. Initiation of convection was observed in all experiments. The initiation area was characterised by very low convective inhibition (CIN) and high convective available potential energy. The simulations showed some evidence that convection was initiated in the vicinity of orography and along soil moisture inhomogeneities. In a moist case precipitating cells were weak and disappeared when entering a region with higher CIN. In the other experiments MCSs developed. In the control run a weakening of the system was observed when

  16. THE CIRCUMBINARY OUTFLOW: A PROTOSTELLAR OUTFLOW DRIVEN BY A CIRCUMBINARY DISK

    SciTech Connect

    Machida, Masahiro N.; Inutsuka, Shu-ichiro; Matsumoto, Tomoaki E-mail: inutsuka@nagoya-u.j

    2009-10-10

    Protostellar outflow is a star's first cry at the moment of birth. The outflows have an indispensable role in the formation of single stars because they carry off the excess angular momentum from the center of the shrinking gas cloud, and permit further collapse to form a star. On the other hand, a significant fraction of stars is supposedly born as binaries with circumbinary disks that are frequently observed. Here, we investigate the evolution of a magnetized rotating cloud using a three-dimensional resistive MHD nested-grid code, and show that the outflow is driven by the circumbinary disk and has an important role even in the binary formation. After the adiabatic core formation in the collapsing cloud core, the magnetic flux is significantly removed from the center of the cloud by the Ohmic dissipation. Since this removal makes the magnetic braking ineffective, the adiabatic core continuously acquires the angular momentum to induce fragmentation and subsequent binary formation. The magnetic field accumulates in the circumbinary disk where the removal and accretion of magnetic field are balanced, and finally drives the circumbinary outflow. This result explains the spectacular morphology of some specific young stellar objects such as L1551 IRS5. We can infer that most of the bipolar molecular outflows observed by low density tracers (i.e., CO) would correspond to circumbinary or circum-multiple outflows found in this Letter, since most of the young stellar objects are supposed to be binaries or multiples.

  17. Atmospheric pollutant outflow from southern Asia: a review

    NASA Astrophysics Data System (ADS)

    Lawrence, M. G.; Lelieveld, J.

    2010-11-01

    is provided as a guideline for future research, pointing out particularly critical issues such as: resolving discrepancies between top down and bottom up emissions estimates; assessing the processing and aging of the pollutant outflow; developing a better understanding of the observed elevated pollutant layers and their relationship to local sea breeze and large scale monsoon circulations; and determining the impacts of the pollutant outflow on the Asian monsoon meteorology and the regional hydrological cycle, in particular the mountain cryospheric reservoirs and the fresh water supply, which in turn directly impact the lives of over a billion inhabitants of southern Asia.

  18. Tectonic Inversion of the Algerian Continental Margin off Great Kabylia (North Algeria) - Insights from new MCS data (SPIRAL cruise)

    NASA Astrophysics Data System (ADS)

    Aidi, Chafik; Beslier, Marie-Odile; Yelles-Chaouche, Karim; Ribodetti, Alessandra; Bracene, Rabah; Schenini, Laure; Djellit, Hamou; Sage, Françoise; Déverchère, Jacques; Medaouri, Mourad; Klingelhoefer, Frauke; Abtout, Abdeslam; Charvis, Philippe; Bounif, Abdallah

    2014-05-01

    Sub-marine active faulting threatens the coastline of Algeria, as shown by the major Mw 6.9 May 21, 2003 earthquake that occurred in Great Kabylia close to Boumerdes. We present here the structures associated to the Plio-Quaternary (P-Q) tectonic inversion of the central part of the Algerian margin offshore Great Kabylia using new deep multichannel seismic (MCS) lines. Five MCS lines were acquired in the study area during the Algerian-French SPIRAL cruise (September 2009, R/V Atalante). Four lines were acquired using a 3040 cu. in. air-gun array and a 4.5 km 360 channel digital streamer and a 8350 cu. in. source favoring deep penetration was used for one coincident WAS profile and the fifth MCS line. All profiles are pre-stack time migrated and additional pre-stack depth migration was performed in key areas. The MCS lines crosscut the margin from the upper slope to the deep Algero-Provençal Basin either in a N-S direction sub-perpendicular to the structural trend of the margin, or in a NW-SE direction parallel to the actual convergence between Africa and Eurasia plates. Tectonic inversion is expressed on all profiles at the deep margin. The eastern line displays a flat-ramp compressive system in the deep sedimentary series, which emerges at the foot of the continental slope and marks the seaward limit of a P-Q basin perched at mid-slope. The south-dipping ramps are neo-formed structures, whereas the flats use inherited lithologic discontinuities (base of the Messinian evaporitic series, top of the acoustic basement). Westward in the Boumerdes area, the compressive deformation is expressed deeper in the acoustic basement where a southward dipping reflector is interpreted as a blind thrust on top of which all the sedimentary series (Miocene to P-Q) are bent in an antiform that uplifts the base of the Messinian series. A second antiform prolongates this uplift 20 km northward although no clear reverse structure is imaged underneath. These antiforms delimit two

  19. Tectonic Inversion of the Algerian Continental Margin off Great Kabylia (North Algeria) - Insights from new MCS data (SPIRAL cruise)

    NASA Astrophysics Data System (ADS)

    Beslier, M.; Aidi, C.; Yelles-Chaouche, A.; Ribodetti, A.; Bracene, R.; Schenini, L.; Djellit, H.; Sage, F.; Deverchere, J.; Medaouri, M.; Klingelhoefer, F.; Abtout, A.; Charvis, P.; Bounif, A.

    2013-12-01

    Sub-marine active faulting threatens the coastline of Algeria, as shown by the major Mw 6.9 May 21, 2003 earthquake that occurred in Great Kabylia close to Boumerdes. We present here the structures associated to the Plio-Quaternary (P-Q) tectonic inversion of the central part of the Algerian margin offshore Great Kabylia using new deep multichannel seismic (MCS) lines. The large-scale structure of the margin deduced from wide-angle seismic (WAS) data modeling is presented in a companion abstract. Five MCS lines were acquired in the study area during the Algerian-French SPIRAL cruise (September 2009, R/V Atalante). Four lines were acquired using a 3040 cu. in. air-gun array and a 4.5 km 360 channel digital streamer and a 8350 cu. in. source favoring deep penetration was used for one coincident WAS profile and the fifth MCS line. All profiles are pre-stack time migrated and additional pre-stack depth migration was performed in key areas. The MCS lines crosscut the margin from the upper slope to the deep Algero-Provençal Basin either in a N-S direction sub-perpendicular to the structural trend of the margin, or in a NW-SE direction parallel to the actual convergence between Africa and Eurasia plates. Tectonic inversion is expressed on all profiles at the deep margin. The eastern line displays a flat-ramp compressive system in the deep sedimentary series, which emerges at the foot of the continental slope and marks the seaward limit of a P-Q basin perched at mid-slope. The south-dipping ramps are neo-formed structures, whereas the flats use inherited lithologic discontinuities (base of the Messinian evaporitic series, top of the acoustic basement). Westward in the Boumerdes area, the compressive deformation is expressed deeper in the acoustic basement where a southward dipping reflector is interpreted as a blind thrust on top of which all the sedimentary series (Miocene to P-Q) are bent in an antiform that uplifts the base of the Messinian series. A second antiform

  20. Tracing outflows in the AGN forbidden region with SINFONI

    NASA Astrophysics Data System (ADS)

    Kakkad, D.; Mainieri, V.; Padovani, P.; Cresci, G.; Husemann, B.; Carniani, S.; Brusa, M.; Lamastra, A.; Lanzuisi, G.; Piconcelli, E.; Schramm, M.

    2016-08-01

    Context. Active galactic nucleus (AGN) driven outflows are invoked in numerical simulations to reproduce several observed properties of local galaxies. The z > 1 epoch is of particular interest as it was during this time that the volume averaged star formation and the accretion rate of black holes were at their maximum. Radiatively driven outflows are therefore believed to be common during this epoch. Aims: We aim to trace and characterize outflows in AGN hosts with high mass accretion rates at z > 1 using integral field spectroscopy. We obtain spatially resolved kinematics of the [O iii] λ5007 line in two targets which reveal the morphology and spatial extension of the outflows. Methods: We present SINFONI observations in the J band and the H + K band of five AGNs at 1.2 < z < 2.2. To maximize the chance of observing radiatively driven outflows, our sample was pre-selected based on peculiar values of the Eddington ratio and the hydrogen column density of the surrounding interstellar medium. We observe high velocity (~600-1900 km s-1) and kiloparsec scale extended ionized outflows in at least three of our targets, using [O iii] λ5007 line kinematics tracing the AGN narrow line region. We estimate the total mass of the outflow, the mass outflow rate, and the kinetic power of the outflows based on theoretical models and report on the uncertainties associated with them. Results: We find mass outflow rates of ~1-10 M⊙/yr for the sample presented in this paper. Based on the high star formation rates of the host galaxies, the observed outflow kinetic power, and the expected power due to the AGN, we infer that both star formation and AGN radiation could be the dominant source for the outflows. The outflow models suffer from large uncertainties, hence we call for further detailed observations for an accurate determination of the outflow properties to confirm the exact source of these outflows.

  1. Accretion, winds and outflows in young stars

    NASA Astrophysics Data System (ADS)

    Günther, H. M.

    2013-02-01

    Young stars and planetary systems form in molecular clouds. After the initial radial infall an accretion disk develops. For classical T Tauri stars (CTTS, F-K type precursors) the accretion disk does not reach down to the central star, but it is truncated near the co-rotation radius by the stellar magnetic field. The inner edge of the disk is ionized by the stellar radiation, so that the accretion stream is funneled along the magnetic field lines. On the stellar surface an accretion shock develops, which is observed over a wide wavelength range as X-ray emission, UV excess, optical veiling and optical and IR emission lines. Some of the accretion tracers, e.g. Hα, can be calibrated to measure the accretion rate. This accretion process is variable on time scales of hours to years due to changing accretion rates, stellar rotation and reconfiguration of the magnetic field. Furthermore, many (if not all) accreting systems also drive strong outflows which are ultimately powered by accretion. However, the exact driving mechanism is still unclear. Several components could contribute to the outflows: slow, wide-angle disk winds, X-winds launched close to the inner disk rim, and thermally driven stellar winds. In any case, the outflows contain material of very different temperatures and speeds. The disk wind is cool and can have a molecular component with just a few tens of km s-1, while the central component of the outflow can reach a few 100 km s-1. In some cases the inner part of the outflow is collimated to a small-angle jet. These jets have an onion-like structure, where the inner components are consecutively hotter and faster. The jets can contain working surfaces, which show up as Herbig-Haro knots. Accretion and outflows in the CTTS phase do not only determine stellar parameters like the rotation rate on the main-sequence, they also can have a profound impact on the environment of young stars. This review concentrates on CTTS in near-by star forming regions where

  2. Crustal thickness from 3D MCS data collected over the fast-spreading East Pacific Rise at 9°50'N

    NASA Astrophysics Data System (ADS)

    Aghaei, O.; Nedimović, M. R.; Canales, J.; Carton, H. D.; Carbotte, S. M.; Mutter, J. C.

    2011-12-01

    We compute, analyze and present crustal thickness variations for a section of the fast-spreading East Pacific Rise (EPR). The area of 3D coverage is between 9°38'N and 9°58' N (~1000 km2), where the documented eruptions of 1990-91 and 2005-06 occurred. The crustal thickness is computed by depth converting the two-way reflection travel times from the seafloor to the Moho. The seafloor and Moho reflections are picked on the migrated stack volume produced from the 3D multichannel seismic (MCS) data collected on R/V Marcus G. Langseth in summer of 2008 during cruise MGL0812. The crustal velocities used for depth conversion were computed by Canales et al. (2003; 2011) by simultaneous inversion of seismic refractions and wide-angle Moho reflection traveltimes from four ridge-parallel and one ridge-perpendicular ocean bottom seismometer (OBS) profile for which data were collected during the 1998 UNDERSHOOT experiment. The MCS data analysis included 1D and 2D filtering, offset-dependent spherical divergence correction, surface-consistent amplitude correction, common midpoint (CMP) sort with flex binning, velocity analysis, normal moveout, and CMP stretch mute. The poststack processing includes seafloor multiple mute and 3D Kirchhoff poststack time migration. Here we use the crustal thickness and Moho seismic signature variations to detail their relationship with ridge segmentation, crustal age, bathymetry, and on- and off-axis magmatism. On the western flank (Pacific plate) from 9°41' to 9°48', the Moho reflection is strong. From 9°48' to 9°52', the Moho reflection varies from moderate to weak and disappears from ~3 km to ~9 km from the ridge axis. On the eastern flank (Cocos plate) from 9°41' to 9°51', the Moho reflection varies from strong to moderate. From 9°51' to 9°54' the Moho reflection varies from moderate to weak and disappears beneath a region ~3 km to ~9 km from the axis. On the Cocos plate, across-axis crustal thickness variations (5.5-6.2 km) show a

  3. Electron-positron outflow from black holes.

    PubMed

    van Putten, M H

    2000-04-24

    Cosmological gamma-ray bursts (GRBs) appear as the brightest transient phenomena in the Universe. The nature of their central engine is a missing link in the theory of fireballs to stellar mass progenitors, and may be associated with low mass black holes. In contact with an external magnetic field B, black hole spin produces a gravitational potential on the wave function of charged particles. We show that a rapidly rotating black hole of mass M produces outflow from initially electrostatic equilibrium with normalized isotropic emission approximately 10(48)(B/B(c))(2)(M/7M)(2)sin (2) theta erg/s, where B(c) = 4.4x10(13) G. The half-opening angle satisfies theta >or = square root[B(c)/3B]. The outflow proposed as input to GRB fireball models. PMID:11019197

  4. Molecular emission in chemically active protostellar outflows

    NASA Astrophysics Data System (ADS)

    Lefloch, B.

    2011-12-01

    Protostellar outflows play an important role in the dynamical and chemical evolution of cloud through shocks. The Herschel Space Observatory (HSO) brings new insight both on the molecular content and the physical conditions in protostellar shocks through high spectral and angular resolution studies of the emission of major gas cooling agents and hydrides. The Herschel/CHESS key-program is carrying out an in depth study of the prototypical shock region L1157-B1. Analysis of the line profiles detected allows to constrain the formation/destruction route of various molecular species, in relation with the predictions of MHD shock models. The Herschel/WISH key-program investigates the properties and origin of water emission in a broad sample of protostellar outflows and envelopes. Implications of the first results for future studies on mass-loss phenomena are discussed.

  5. Hepatic venous outflow obstruction: Three similar syndromes

    PubMed Central

    Bayraktar, Ulas Darda; Seren, Soley; Bayraktar, Yusuf

    2007-01-01

    Our goal is to provide a detailed review of veno-occlusive disease (VOD), Budd-Chiari syndrome (BCS), and congestive hepatopathy (CH), all of which results in hepatic venous outflow obstruction. This is the first article in which all three syndromes have been reviewed, enabling the reader to compare the characteristics of these disorders. The histological findings in VOD, BCS, and CH are almost identical: sinusoidal congestion and cell necrosis mostly in perivenular areas of hepatic acini which eventually leads to bridging fibrosis between adjacent central veins. Tender hepatomegaly with jaundice and ascites is common to all three conditions. However, the clinical presentation depends mostly on the extent and rapidity of the outflow obstruction. Although the etiology and treatment are completely different in VOD, BCS, and CH; the similarities in clinical manifestations and liver histology may suggest a common mechanism of hepatic injury and adaptation in response to increased sinusoidal pressure. PMID:17461490

  6. Example of reduced turbulence during thunderstorm outflow

    SciTech Connect

    Bowen, B.M.

    1996-06-01

    This research note describes the effects of a gust front passage resulting from a thunderstorm outflow on wind, turbulence, and other basic meteorological variables in northern Mew Mexico. The purpose of this note is to explain how a thunderstorm outflow can greatly reduce horizontal and vertical turbulence and produce strong winds, thereby promoting the rapid transport of elevated pollutant concentrations. Another goal is to demonstrate the usefulness of a sodar in combination with a tower to provide data for dispersion and transport calculations during an emergency response. Hopefully, this note will motivate other researchers to analyze and document the effects of thunderstorms on turbulence and dispersion by routine monitoring or by experimentation. 12 refs., 3 figs., 1 tab.

  7. THE OUTFLOWING WIND OF V1057 CYGNI

    SciTech Connect

    Herbig, G. H.

    2009-08-15

    In 1970-1971, V1057 Cyg rose from about m {sub pg} {approx} 16 to a peak near 10.5 mag. It has subsequently faded to about B = 15, and although it appeared to be a T Tauri star (TTS) before the outburst, it now resembles a rather peculiar rapidly rotating G-type supergiant. Before the outburst, it showed unmistakable evidence of high-velocity outflow (by the suppression of emission Ca II {lambda}3968 by the P Cyg absorption component of H{epsilon} {lambda}3970). Such outflow absorptions are currently found at many strong lines (H{alpha}, Na I D{sub 1,2}, K I {lambda}{lambda}7664, 7698, Ca II {lambda}{lambda}8498, 8662, ...). The same phenomenon has since been observed in a number of other FUors near maximum light, suggesting that it is a FUor characteristic that clearly differs from the outflows found in TTSs. The Li I resonance line at 6707 A is relatively weak, and on high-resolution spectra obtained between 1997 and 2008 showed variable absorption structure on its shortward side that probably represents wind structure that is lost in the stronger lines. In addition, a narrow emission line at 6707 A persists throughout the series and is the counterpart of the sharp emission lines that occur near the centers of many of the broad stellar absorption lines (v sin i = 55 km s{sup -1}) and that were responsible for the line-splitting phenomenon formerly regarded as evidence of a Keplerian disk. Given the evidence of a quasi-permanent outflow at V1057 Cyg, the hypothesis is advanced that a FUor outburst may be the result of a rapidly rotating TTS having contracted to a point of rotational instability, at which time it sheds enough material and angular momentum to resume contraction, until the next such event.

  8. Temperatures and aerosol opacities of the Mars atmosphere at aphelion: Validation and inter-comparison of limb sounding profiles from MRO/MCS and MGS/TES

    NASA Astrophysics Data System (ADS)

    Shirley, James H.; McConnochie, Timothy H.; Kass, David M.; Kleinböhl, Armin; Schofield, John T.; Heavens, Nicholas G.; McCleese, Daniel J.; Benson, Jennifer; Hinson, David P.; Bandfield, Joshua L.

    2015-05-01

    We exploit the relative stability and repeatability of the Mars atmosphere at aphelion for an inter-comparison of Mars Global Surveyor/Thermal Emission Spectrometer (MGS/TES) and Mars Reconnaissance Orbiter/Mars Climate Sounder (MRO/MCS) nighttime temperature profiles and aerosol opacity profiles in Mars years 25, 26, 29, 30, and 31. Cross-calibration of these datasets is important, as they together provide an extended climatology for this planetary atmosphere. As a standard of comparison we employ temperature profiles obtained by radio occultation methods during the MGS mission in Mars years 24, 25, and 26. We first compare both zonal mean TES limb sounding profiles and zonal mean MCS limb sounding profiles with zonal means of radio occultation temperature profiles for the same season (Ls = 70-80°) and latitudes (55-70°N). We employ a statistical z test for quantifying the degree of agreement of temperature profiles by pressure level. For pressures less than 610 Pa (altitudes > 3 km), the ensemble mean temperature difference between the radio occultation and TES limb sounding profiles found in these comparisons was 1.7 ± 0.7 K. The ensemble mean temperature difference between radio occultation and MCS profiles was 1.4 ± 1.0 K. These differences fall within the formal error estimates for both TES and MCS, validating the accuracy of the instruments and their respective retrieval algorithms. In the second phase of our investigation, we compare aphelion season zonal mean TES limb sounding temperature, water ice opacity, and dust opacity profiles with those obtained at the same latitudes in different years by MCS. The ensemble mean temperature difference found for three comparisons between TES and MCS zonal mean temperature profiles was 2.8 ± 2.1 K. MCS and TES temperatures between 610 Pa and 5 Pa from 55 to 70°N are largely in agreement (with differences < 2 K) when water ice aerosol opacities are comparable. Temperature differences increase when the opacities

  9. Differentiability and retrievability of CO2 and H2O clouds on Mars from MRO/MCS measurements: A radiative-transfer study

    NASA Astrophysics Data System (ADS)

    Hurley, J.; Teanby, N. A.; Irwin, P. G. J.; Calcutt, S. B.; Sefton-Nash, E.

    2014-07-01

    Since the 1970s, it has been predicted that both CO2 and H2O clouds can form in the Martian atmosphere, and many remote-sounding instruments have directly observed layers of extinction asserted to be clouds composed of either CO2 or H2O ice on Mars. The Mars Climate Sounder, onboard the Mars Reconnaissance Orbiter (MRO/MCS), entered orbit around Mars in 2006, and has been providing near-continuous coverage of the full planet since, at wavelengths from visible through to the mid-infrared, primarily in limb-viewing geometry, making it a suitable candidate to study the parameters of these clouds. In this work, the multiple scattering radiative-transfer tool NemesisMCS has been used to create a large dataset of simulations of CO2 and H2O clouds on Mars as would be measured by MRO/MCS, using a range of atmospheric conditions as well as cloud parameters derived from literature suitable for upper atmospheric clouds, and building specifically on the work of Sefton-Nash et al. (2013). This ensemble of simulations has been used to characterise the spectral signature of plausible CO2 and H2O clouds, as well as to assess the suitability of MRO/MCS to observe, to differentiate between, and to derive properties of such clouds. It has been found, given the noise levels expected for MRO/MCS and the range of atmospheric and cloud parameters sampled in this study, that radiance signals introduced by upper atmospheric clouds having nadir optical depths greater than about 10-5 should be distinguishable, with S/N≥1. This corresponds to specific concentrations greater than about 105 particles/g, particle radii greater than around 0.5 μm, and cloud depths greater than about 2 km. MRO/MCS measurements should be able to be used with confidence to differentiate between upper atmospheric cloud and dust in the lower atmosphere, and clear conditions, with high success (≈100%). Lower reliability classification is accomplished for CO2 clouds, with only 60% being correctly identified as CO2

  10. Shaping the outflows of evolved stars

    NASA Astrophysics Data System (ADS)

    Mohamed, Shazrene

    2015-08-01

    Both hot and cool evolved stars, e.g., red (super)giants and Wolf-Rayet stars, lose copious amounts of mass, momentum and mechanical energy through powerful, dense stellar winds. The interaction of these outflows with their surroundings results in highly structured and complex circumstellar environments, often featuring knots, arcs, shells and spirals. Recent improvements in computational power and techniques have led to the development of detailed, multi-dimensional simulations that have given new insight into the origin of these structures, and better understanding of the physical mechanisms driving their formation. In this talk, I will discuss three of the main mechanisms that shape the outflows of evolved stars:- interaction with the interstellar medium (ISM), i.e., wind-ISM interactions- interaction with a stellar wind, either from a previous phase of evolution or the wind from a companion star, i.e., wind-wind interactions- and interaction with a companion star that has a weak or insignicant outflow (e.g., a compact companion such as a neutron star or black hole), i.e., wind-companion interactions.I will also highlight the broader implications and impact of these stellar wind interactions for other phenomena, e.g, for symbiotic and X-ray binaries, supernovae and Gamma-ray bursts.

  11. Magnetohydrodynamic simulations of outflows from accretion disks

    NASA Technical Reports Server (NTRS)

    Ustyugova, G. V.; Koldoba, A. V.; Romanova, M. M.; Chechetkin, V. M.; Lovelace, R. V. E.

    1995-01-01

    Magnetohydrodynamic simulations have been made of the formation of outflows from a Keplerian disk threaded by a magnetic field. The disk is treated as a boundary condition, where matter is ejected with Keplerian azimuthal speed and poloidal speed less than the slow magnetosonic velocity, and where boundary conditions on the magnetic field correspond to a highly conducting disk. Initially, the space above the disk, the corona, is filled with high specific entropy plasma in thermal equilibrium in the gravitational potential of the central object. The initial magnetic field is poloidal and is represented by a superposition of monopoles located below the plane of the disk. The rotation of the disk twists the initial poloidal magnetic field, and this twist propagates into the corona pushing and collimating matter into jetlike outflow in a cylindrical region. Matter outflowing from the disk flows and accelerates in the z-direction owing to both the magnetic and pressure gradient forces. The flow accelerates through the slow magnetosonic and Alfven surfaces and at larger distances through the fast magnetosonic surface. The flow velocity of the jet is approximately parallel to the z-axis, and the collimation results from the pinching force of the toroidal magnetic field. For a nonrotating disk no collimation is observed.

  12. Outflows of stars due to quasar feedback

    NASA Astrophysics Data System (ADS)

    Zubovas, Kastytis; Nayakshin, Sergei; Sazonov, Sergey; Sunyaev, Rashid

    2013-05-01

    Quasar feedback outflows are commonly invoked to drive gas out of galaxies in the early gas-rich epoch to terminate growth of galaxies. Here we present simulations that show that AGN feedback may drive not only gas but also stars out of their host galaxies under certain conditions. The mechanics of this process is as follows: (1) AGN-driven outflows accelerate and compress gas filling the host galaxy; (2) the accelerated dense shells become gravitationally unstable and form stars on radial trajectories. For the spherically symmetric initial conditions explored here, the black hole needs to exceed the host's Mσ mass by a factor of a few to accelerate the shells and the new stars to escape velocities. We discuss potential implications of these effects for the host galaxies: (i) radial mixing of bulge stars with the rest of the host; (ii) contribution of quasar outflows to galactic fountains as sources of high-velocity clouds; (iii) wholesale ejection of hypervelocity stars out of their hosts, giving rise to Type II supernovae on galactic outskirts, and contributing to reionization and metal enrichment of the Universe; (iv) bulge erosion and even complete destruction in extreme cases resulting in overweight or bulgeless SMBHs.

  13. CARMA OBSERVATIONS OF PROTOSTELLAR OUTFLOWS IN NGC 1333

    SciTech Connect

    Plunkett, Adele L.; Arce, Hector G.; Corder, Stuartt A.; Mardones, Diego; Sargent, Anneila I.; Schnee, Scott L.

    2013-09-01

    We present observations of outflows in the star-forming region NGC 1333 using the Combined Array for Research in Millimeter-Wave Astronomy (CARMA). We combined the {sup 12}CO and {sup 13}CO (1-0) CARMA mosaics with data from the 14 m Five College Radio Astronomy Observatory to probe the central, most dense, and active region of this protostellar cluster at scales from 5'' to 7' (or 1000 AU to 0.5 pc at a distance of 235 pc). We map and identify {sup 12}CO outflows, and along with {sup 13}CO data we estimate their mass, momentum, and energy. Within the 7' Multiplication-Sign 7' map, the 5'' resolution allows for a detailed study of morphology and kinematics of outflows and outflow candidates, some of which were previously confused with other outflow emission in the region. In total, we identify 22 outflow lobes, as well as 9 dense circumstellar envelopes marked by continuum emission, of which 6 drive outflows. We calculate a total outflow mass, momentum, and energy within the mapped region of 6 M{sub Sun }, 19 M{sub Sun} km s{sup -1}, and 7 Multiplication-Sign 10{sup 44} erg, respectively. Within this same region, we compare outflow kinematics with turbulence and gravitational energy, and we suggest that outflows are likely important agents for the maintenance of turbulence in this region. In the earliest stages of star formation, outflows do not yet contribute enough energy to totally disrupt the clustered region where most star formation is happening, but have the potential to do so as the protostellar sources evolve. Our results can be used to constrain outflow properties, such as outflow strength, in numerical simulations of outflow-driven turbulence in clusters.

  14. Stratigraphy and multi-phase tectonic history of the Chukchi Borderland from MCS data

    NASA Astrophysics Data System (ADS)

    Ilhan, I.; Coakley, B.

    2012-12-01

    The Chukchi Edges project was designed to establish the relationship between the Chukchi Shelf and Borderland and indirectly test theories of opening for the Canada Basin. During this cruise, ~5300 km of 2D multi-channel seismic profiles and other geophysical measurements (swath bathymetry, gravity, magnetics, sonobuoy refraction seismic) were collected from the RV Marcus G. Langseth across the transition between the Chukchi Shelf and Chukchi Borderland. These profiles reveal extended basins separated by faulted high-standing blocks. Basin stratigraphy can be subdivided on the basis of gross stratal geometry, reflection terminations and inferred unconformities. The wedge-shaped synrift sequences terminate against the basement highs and/or major faults, burying the basement topography. The inferred postrift seismic units are more nearly tabular, but thicken locally due to compaction of underlying synrift sediments. Reflection character is dominated by alternating high and low amplitude continuous reflectors which may be consistent with pelagic or turbidite sediments. Chaotic units are also observed, which may indicate mass-flow deposits. The truncated sediments over the basement highs of the Chukchi Shelf, Chukchi Plateau and Northwind Ridge suggest major erosion due both to glacial planation and earlier erosional events perhaps associated with basement uplift prior to or during rifting and extension. It is believed that the bulk of the synrift sediments are Mesozoic in age. Certainly Cenozoic sediments are also preserved in these basins, but the position of the boundary is uncertain. Locally, continuous reflectors are observed underlying the rift basin fill. These older units, of very uncertain age, would, if sampled, provide constraint on the history and affinities of the Chukchi Borderland. In addition to the extensional basins, a number of small symmetric basins are observed on the flanks of the Chukchi Plateau. These basins may be transtensional and argue for a

  15. BAL OUTFLOW CONTRIBUTION TO AGN FEEDBACK: FREQUENCY OF S IV OUTFLOWS IN THE SDSS

    SciTech Connect

    Dunn, Jay P.; Arav, Nahum; Laughlin, Courtney; Edmonds, Doug; Aoki, Kentaro; Wilkins, Ashlee; Bautista, Manuel E-mail: arav@vt.edu E-mail: kentaro.aoki@hawaiiantel.net E-mail: manuel.bautista@wmich.edu

    2012-05-10

    We present a study of broad absorption line (BAL) quasar outflows that show S IV {lambda}1063 and S IV* {lambda}1073 troughs. The fractional abundances of S IV and C IV peak at similar value of the ionization parameter, implying that they arise from the same physical component of the outflow. Detection of the S IV* troughs will allow us to determine the distance to this gas with higher resolution and higher signal-to-noise spectra, therefore providing the distance and energetics of the ubiquitous C IV BAL outflows. In our bright sample of 156 SDSS quasars, 14% show C IV and 1.9% S IV troughs, which are consistent with a fainter magnitude sample with twice as many objects. One object in the fainter sample shows evidence of a broad S IV trough without any significant trough present from the excited state line, which implies that this outflow could be at a distance of several kpc. Given the fractions of C IV and S IV, we establish firm limits on the global covering factor on S IV that ranges from 2.8% to 21% (allowing for the k-correction). Comparison of the expected optical depth for these ions with their detected percentage suggests that these species arise from common outflows with a covering factor closer to the latter.

  16. The Launch Region of the SVS 13 Outflow and Jet

    NASA Astrophysics Data System (ADS)

    Hodapp, Klaus W.; Chini, Rolf

    2014-10-01

    We present the results of Keck telescope laser adaptive-optics integral field spectroscopy with OSIRIS of the innermost regions of the NGC 1333 SVS 13 outflow that forms the system of Herbig-Haro objects 7-11. We find a bright 0.''2 long microjet traced by the emission of shock-excited [Fe II]. Beyond the extent of this jet, we find a series of bubbles and fragments of bubbles that are traced in the lower excitation H2 1-0 S(1) line. While the most recent outflow activity is directed almost precisely (P.A. ≈ 145°) to the southeast of SVS 13, there is clear indication that prior bubble ejections were pointed in different directions. Within these variations, a clear connection between the newly observed bubble ejection events and the well-known, poorly collimated HH 7-11 system of Herbig-Haro objects is established. The astrometry of the youngest of the expanding shock fronts at three epochs, covering a timespan of over 2 yr, gives kinematic ages for two of these bubbles. The kinematic age of the youngest bubble is slightly older than the historically observed last photometric outburst of SVS 13 in 1990, consistent with that event, launching the bubble and some deceleration of its expansion. A re-evaluation of historic infrared photometry and new data show that SVS 13 has not yet returned to its brightness before that outburst and thus reveal behavior similar to FUor outbursts, albeit with a smaller amplitude. We postulate that the creation of a series of bubbles and the changes in outflow direction are indicative of a precessing disk and accretion events triggered by a repetitive phenomenon possibly linked to the orbit of a close binary companion. However, our high-resolution images in the H and K bands do not directly detect any companion object. We have tried, but failed, to detect the kinematic rotation signature of the microjet in the [Fe II] emission line at 1.644 μm.

  17. The launch region of the SVS 13 outflow and jet

    SciTech Connect

    Hodapp, Klaus W.; Chini, Rolf E-mail: rolf.chini@astro.ruhr-uni-bochum.de

    2014-10-20

    We present the results of Keck telescope laser adaptive-optics integral field spectroscopy with OSIRIS of the innermost regions of the NGC 1333 SVS 13 outflow that forms the system of Herbig-Haro objects 7-11. We find a bright 0.''2 long microjet traced by the emission of shock-excited [Fe II]. Beyond the extent of this jet, we find a series of bubbles and fragments of bubbles that are traced in the lower excitation H{sub 2} 1-0 S(1) line. While the most recent outflow activity is directed almost precisely (P.A. ≈ 145°) to the southeast of SVS 13, there is clear indication that prior bubble ejections were pointed in different directions. Within these variations, a clear connection between the newly observed bubble ejection events and the well-known, poorly collimated HH 7-11 system of Herbig-Haro objects is established. The astrometry of the youngest of the expanding shock fronts at three epochs, covering a timespan of over 2 yr, gives kinematic ages for two of these bubbles. The kinematic age of the youngest bubble is slightly older than the historically observed last photometric outburst of SVS 13 in 1990, consistent with that event, launching the bubble and some deceleration of its expansion. A re-evaluation of historic infrared photometry and new data show that SVS 13 has not yet returned to its brightness before that outburst and thus reveal behavior similar to FUor outbursts, albeit with a smaller amplitude. We postulate that the creation of a series of bubbles and the changes in outflow direction are indicative of a precessing disk and accretion events triggered by a repetitive phenomenon possibly linked to the orbit of a close binary companion. However, our high-resolution images in the H and K bands do not directly detect any companion object. We have tried, but failed, to detect the kinematic rotation signature of the microjet in the [Fe II] emission line at 1.644 μm.

  18. Quasar feedback revealed by giant molecular outflows

    NASA Astrophysics Data System (ADS)

    Feruglio, C.; Maiolino, R.; Piconcelli, E.; Menci, N.; Aussel, H.; Lamastra, A.; Fiore, F.

    2010-07-01

    In the standard scenario for galaxy evolution young star-forming galaxies transform into red bulge-dominated spheroids, where star formation has been quenched. To explain this transformation, a strong negative feedback generated by accretion onto a central super-massive black hole is often invoked. The depletion of gas resulting from quasar-driven outflows should eventually stop star-formation across the host galaxy and lead the black hole to “suicide” by starvation. Direct observational evidence for a major quasar feedback onto the host galaxy is still missing, because outflows previously observed in quasars are generally associated with the ionized component of the gas, which only accounts for a minor fraction of the total gas content, and typically occurrs in the central regions. We used the IRAM PdB Interferometer to observe the CO(1-0) transition in Mrk 231, the closest quasar known. Thanks to the wide band we detected broad wings of the CO line, with velocities of up to 750 km s-1 and spatially resolved on the kpc scale. These broad CO wings trace a giant molecular outflow of about 700 M_⊙/year, far larger than the ongoing star-formation rate (~200 M_⊙/year) observed in the host galaxy. This wind will totally expel the cold gas reservoir in Mrk 231 in about 107 yrs, therefore halting the star-formation activity on the same timescale. The inferred kinetic energy in the molecular outflow is ~1.2 × 1044 erg/s, corresponding to a few percent of the AGN bolometric luminosity, which is very close to the fraction expected by models ascribing quasar feedback to highly supersonic shocks generated by radiatively accelerated nuclear winds. Instead, the contribution by the SNe associated with the starburst fall short by several orders of magnitude to account for the kinetic energy observed in the outflow. The direct observational evidence for quasar feedback reported here provides solid support to the scenarios ascribing the observed properties of local massive

  19. HiRes deconvolved Spitzer images of 89 protostellar jets and outflows: New data on the evolution of the outflow morphology

    SciTech Connect

    Velusamy, T.; Langer, W. D.; Thompson, T. E-mail: William.D.Langer@jpl.nasa.gov

    2014-03-01

    To study the role of protosellar jets and outflows in the time evolution of the parent cores and the protostars, the astronomical community needs a large enough database of infrared images of protostars at the highest spatial resolution possible to reveal the details of their morphology. Spitzer provides unprecedented sensitivity in the infrared to study both the jet and outflow features, however, its spatial resolution is limited by its 0.85 m mirror. Here, we use a high-resolution deconvolution algorithm, 'HiRes,' to improve the visualization of spatial morphology by enhancing resolution (to subarcsecond levels in the IRAC bands) and removing the contaminating side lobes from bright sources in a sample of 89 protostellar objects. These reprocessed images are useful for detecting (1) wide-angle outflows seen in scattered light, (2) morphological details of H{sub 2} emission in jets and bow shocks, and (3) compact features in MIPS 24 μm images as protostar/disk and atomic/ionic line emission associated with the jets. The HiRes FITS image data of such a large homogeneous sample presented here will be useful to the community in studying these protostellar objects. To illustrate the utility of this HiRes sample, we show how the opening angle of the wide-angle outflows in 31 sources, all observed in the HiRes-processed Spitzer images, correlates with age. Our data suggest a power-law fit to opening angle versus age with an exponent of ∼0.32 and 0.02, respectively, for ages ≤8000 yr and ≥8000 yr.

  20. SPITZER OBSERVATIONS OF BOW SHOCKS AND OUTFLOWS IN RCW 38

    SciTech Connect

    Winston, E.; Wolk, S. J.; Bourke, T. L.; Spitzbart, B.; Megeath, S. T.; Gutermuth, R.

    2012-01-10

    We report Spitzer observations of five newly identified bow shocks in the massive star-forming region RCW 38. Four are visible at Infrared Array Camera (IRAC) wavelengths, the fifth is only visible at 24 {mu}m. Chandra X-ray emission indicates that winds from the central O5.5 binary, IRS 2, have caused an outflow to the northeast and southwest of the central subcluster. The southern lobe of hot ionized gas is detected in X-rays; shocked gas and heated dust from the shock front are detected with Spitzer at 4.5 and 24 {mu}m. The northern outflow may have initiated the present generation of star formation, based on the filamentary distribution of the protostars in the central subcluster. Further, the bow-shock driving star, YSO 129, is photo-evaporating a pillar of gas and dust. No point sources are identified within this pillar at near- to mid-IR wavelengths. We also report on IRAC 3.6 and 5.8 {mu}m observations of the cluster DBS2003-124, northeast of RCW 38, where 33 candidate young stellar objects (YSOs) are identified. One star associated with the cluster drives a parsec-scale jet. Two Herbig-Haro objects associated with the jet are visible at IRAC and Multiband Imaging Photometer for Spitzer (MIPS) wavelengths. The jet extends over a distance of {approx}3 pc. Assuming a velocity of 100 km s{sup -1} for the jet material gives an age of 3 Multiplication-Sign 10{sup 4} yr, indicating that the star (and cluster) are likely to be very young, with a similar or possibly younger age than RCW 38, and that star formation is ongoing in the extended RCW 38 region.

  1. The Prevalence of Gas Outflows in Type 2 AGNs. II. 3D Biconical Outflow Models

    NASA Astrophysics Data System (ADS)

    Bae, Hyun-Jin; Woo, Jong-Hak

    2016-09-01

    We present 3D models of biconical outflows combined with a thin dust plane for investigating the physical properties of the ionized gas outflows and their effect on the observed gas kinematics in type 2 active galactic nuclei (AGNs). Using a set of input parameters, we construct a number of models in 3D and calculate the spatially integrated velocity and velocity dispersion for each model. We find that three primary parameters, i.e., intrinsic velocity, bicone inclination, and the amount of dust extinction, mainly determine the simulated velocity and velocity dispersion. Velocity dispersion increases as the intrinsic velocity or the bicone inclination increases, while velocity (i.e., velocity shifts with respect to systemic velocity) increases as the amount of dust extinction increases. Simulated emission-line profiles well reproduce the observed [O iii] line profiles, e.g., narrow core and broad wing components. By comparing model grids and Monte Carlo simulations with the observed [O iii] velocity–velocity dispersion distribution of ∼39,000 type 2 AGNs, we constrain the intrinsic velocity of gas outflows ranging from ∼500 to ∼1000 km s‑1 for the majority of AGNs, and up to ∼1500–2000 km s‑1 for extreme cases. The Monte Carlo simulations show that the number ratio of AGNs with negative [O iii] velocity to AGNs with positive [O iii] velocity correlates with the outflow opening angle, suggesting that outflows with higher intrinsic velocity tend to have wider opening angles. These results demonstrate the potential of our 3D models for studying the physical properties of gas outflows, applicable to various observations, including spatially integrated and resolved gas kinematics.

  2. SU-E-T-325: The New Evaluation Method of the VMAT Plan Delivery Using Varian DynaLog Files and Modulation Complexity Score (MCS)

    SciTech Connect

    Tateoka, K; Fujimomo, K; Hareyama, M; Saitou, Y; Nakazawa, T; Abe, T; Nakata, A; Yano, M

    2014-06-01

    Purpose: The aim of the study is to evaluate the use of Varian DynaLog files to verify VMAT plans delivery and modulation complexity score (MCS) of VMAT. Methods: Delivery accuracy of machine performance was quantified by multileaf collimator (MLC) position errors, gantry angle errors and fluence delivery accuracy for volumetric modulated arc therapy (VMAT). The relationship between machine performance and plan complexity were also investigated using the modulation complexity score (MCS). Plan and Actual MLC positions, gantry angles and delivered fraction of monitor units were extracted from Varian DynaLog files. These factors were taken from the record and verify system of MLC control file. Planned and delivered beam data were compared to determine leaf position errors and gantry angle errors. Analysis was also performed on planned and actual fluence maps reconstructed from those of the DynaLog files. This analysis was performed for all treatment fractions of 5 prostate VMAT plans. The analysis of DynaLog files have been carried out by in-house programming in Visual C++. Results: The root mean square of leaf position and gantry angle errors were about 0.12 and 0.15, respectively. The Gamma of planned and actual fluence maps at 3%/3 mm criterion was about 99.21. The gamma of the leaf position errors were not directly related to plan complexity as determined by the MCS. Therefore, the gamma of the gantry angle errors were directly related to plan complexity as determined by the MCS. Conclusion: This study shows Varian dynalog files for VMAT plan can be diagnosed delivery errors not possible with phantom based quality assurance. Furthermore, the MCS of VMAT plan can evaluate delivery accuracy for patients receiving of VMAT. Machine performance was found to be directly related to plan complexity but this is not the dominant determinant of delivery accuracy.

  3. On the origin of pronounced O3 gradients in the thunderstorm outflow region during DC3

    NASA Astrophysics Data System (ADS)

    Huntrieser, H.; Lichtenstern, M.; Scheibe, M.; Aufmhoff, H.; Schlager, H.; Pucik, T.; Minikin, A.; Weinzierl, B.; Heimerl, K.; Fütterer, D.; Rappenglück, B.; Ackermann, L.; Pickering, K. E.; Cummings, K. A.; Biggerstaff, M. I.; Betten, D. P.; Honomichl, S.; Barth, M. C.

    2016-06-01

    Unique in situ measurements of CO, O3, SO2, CH4, NO, NOx, NOy, VOC, CN, and rBC were carried out with the German Deutsches Zentrum für Luft- und Raumfahrt (DLR)-Falcon aircraft in the central U.S. thunderstorms during the Deep Convective Clouds and Chemistry experiment in summer 2012. Fresh and aged anvil outflow (9-12 km) from supercells, mesoscale convective systems, mesoscale convective complexes, and squall lines were probed over Oklahoma, Texas, Colorado, and Kansas. For three case studies (30 May and 8 and 12 June) a combination of trace species, radar, lightning, and satellite information, as well as model results, were used to analyze and design schematics of major trace gas transport pathways within and in the vicinity of the probed thunderstorms. The impact of thunderstorms on the O3 composition in the upper troposphere/lower stratosphere (LS) region was analyzed. Overshooting cloud tops injected high amounts of biomass burning and lightning-produced NOx emissions into the LS, in addition to low O3 mixing ratios from the lower troposphere. As a dynamical response, O3-rich air from the LS was transported downward into the anvil and also surrounded the outflow. The ΔO3/ΔCO ratio was determined in the anvil outflow region. A pronounced in-mixing of O3-rich stratospheric air masses was observed in the outflow indicated by highly positive or even negative ΔO3/ΔCO ratios (+1.4 down to -3.9). Photochemical O3 production (ΔO3/ΔCO = +0.1) was found to be minor in the recently lofted pollution plumes. O3 mixing ratios within the aged anvil outflow were mainly enhanced due to dynamical processes.

  4. Evidence for Collimated Outflow from Sgr A*?

    NASA Astrophysics Data System (ADS)

    Yusef-Zadeh, Farhad; Arendt, R.; Bushouse, H.; Cotton, W.; Haggard, D.; Heinke, C.; Roberts, D. A.; Royster, M.; Wardle, M.

    2012-05-01

    The compact radio source Sgr A* is considered to be coincident with a 4 million solar mass black hole at the dynamical center of the Galaxy. There has been a considerable debate as to whether the jet or the accretion flow model can explain the broad band spectrum of the emission. Here, we present high resolution radio, X-ray continuum and FeII line images showing new structural details within the inner arcminute (2.4pc) of Sgr A*. On a small scale, we find a chain of radio blobs which appear to be emanating from Sgr A*. These blobs are detected beyond the inner 1" of Sgr A* and are distributed along a continuous linear feature that is tilted by 28 degrees with respect to the Galactic plane. In linear polarization images at 3.6cm, three blobs of emission have been detected symmetrically about 1' from Sgr A*. The morphology and polarization of the linear feature suggest a jet outflow from Sgr A*, punching through the orbiting ionized gas and producing X-ray emission as well as a hot bubble of FeIII/FeII line emission. On a scale of about 15pc, we also note a collection of large-scale radio and X-ray "streamers" in the direction perpendicular to the Galactic plane. This complex structure consists of nonthermal and thermal continuum features as well as molecular clouds traced at infrared wavelengths. The base of the outflowing gas appears to be confined by the 2-pc molecular ring, within which a cluster of massive stars lie. These features suggest star-burst driven outflow may be responsible for this energetic activity.

  5. Characterization of the submesoscale energy cascade in the Alboran Sea thermocline from spectral analysis of high-resolution MCS data

    NASA Astrophysics Data System (ADS)

    Sallares, Valenti; Mojica, Jhon F.; Biescas, Berta; Klaeschen, Dirk; Gràcia, Eulàlia

    2016-06-01

    Part of the kinetic energy that maintains ocean circulation cascades down to small scales until it is dissipated through mixing. While most steps of this downward energy cascade are well understood, an observational gap exists at horizontal scales of 103-101 m that prevents characterizing a key step in the chain: the transition from anisotropic internal wave motions to isotropic turbulence. Here we show that this observational gap can be covered using high-resolution multichannel seismic (HR-MCS) data. Spectral analysis of acoustic reflectors imaged in the Alboran Sea thermocline shows that this transition is likely caused by shear instabilities. In particular, we show that the averaged horizontal wave number spectra of the reflectors vertical displacements display three subranges that reproduce theoretical spectral slopes of internal waves (λx > 100 m), Kelvin-Helmholtz-type shear instabilities (100 m > λx > 33 m), and turbulence (λx < 33 m), indicating that the whole chain of events is occurring continuously and simultaneously in the surveyed area.

  6. Requirements for theoretical models of outflows

    NASA Technical Reports Server (NTRS)

    Linsky, Jeffrey L.

    1988-01-01

    Recent observational and theoretical investigations of astrophysical mass outflows are reviewed, with a focus on the basic physical principles. Specific limitations on the observational data and their interpretation are listed and discussed. Modeling problems considered include the role of the critical point in determining the mass-loss rate and terminal velocity, the physical processes controlling density at the critical point, the possible coexistence of multiple mass-loss mechanisms, time scales, instabilities and phase changes, multiphase atmospheres and winds, the definition of geometries, the role of the environment, explosive transient events, stochastic phenomena, mode-mode coupling and damping processes, departures from ionization equilibrium, and nonthermal phenomena.

  7. Shock Waves in Outflows from Young Stars

    NASA Astrophysics Data System (ADS)

    Hartigan, Patrick

    This review focuses on physics of the cooling zones behind radiative shocks and the emission line diagnostics that can be used to infer physical conditions and mass loss rates in jets from young stars. Spatial separations of the cooling zones from the shock fronts, now resolvable with HST, and recent evidence for C-shocks have greatly increased our understanding of how shocks in outflows interact with the surrounding medium and with other material within the flow. By combining multiple epoch HST images, one can create `movies' of flows like those produced from numerical codes, and learn what kinds of instabilities develop within these systems.

  8. Valles Marineris and Chryse Outflow Channels

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A color image of Valles Marineris, the great canyon and the south Chryse basin-Valles Marineris outflow channels of Mars; north toward top. The scene shows the entire Valles Marineris canyon system, over 3,000 km long and averaging 8 km deep, extending from Noctis Labyrinthus, the arcuate system of graben to the west, to the chaotic terrain to the east and related outflow canyons that drain toward the Chryse basin. Eos and Capri Chasmata (south to north) are two canyons connected to Valles Marineris. Ganges Chasma lies directly north. The chaos in the southeast part of the image gives rise to several outflow channels, Shalbatana, Simud, Tiu, and Ares Valles (left to right), that drained north into the Chryse basin. The mouth of Ares Valles is the site of the Mars Pathfinder lander.

    This image is a composite of Viking medium-resolution images in black and white and low-resolution images in color; Mercator projection. The image roughly extends from latitude 20 degrees S. to 20 degrees N. and from longitude 15 degrees to 102.5 degrees.

    The connected chasma or valleys of Valles Marineris may have formed from a combination of erosional collapse and structural activity. Layers of material in the eastern canyons might consist of carbonates deposited in ancient lakes, eolian deposits, or volcanic materials. Huge ancient river channels began from Valles Marineris and from adjacent canyons and ran north. Many of the channels flowed north into Chryse Basin.

    The south Chryse outflow channels are cut an average of 1 km into the cratered highland terrain. This terrain is about 9 km above datum near Valles Marineris and steadily decreases in elevation to 1 km below datum in the Chryse basin. Shalbatana is relatively narrow (10 km wide) but can reach 3 km in depth. The channel begins at a 2- to 3-km-deep circular depression within a large impact crater, whose floor is partly covered by chaotic material, and ends in Simud Valles. Tiu and Simud Valles consist of a

  9. ATOMIC HYDROGEN IN A GALACTIC CENTER OUTFLOW

    SciTech Connect

    McClure-Griffiths, N. M.; Green, J. A.; Hill, A. S.; Lockman, F. J.; Dickey, J. M.; Gaensler, B. M.; Green, A. J.

    2013-06-10

    We describe a population of small, high-velocity, atomic hydrogen clouds, loops, and filaments found above and below the disk near the Galactic center. The objects have a mean radius of 15 pc, velocity widths of {approx}14 km s{sup -1}, and are observed at |z| heights up to 700 pc. The velocity distribution of the clouds shows no signature of Galactic rotation. We propose a scenario where the clouds are associated with an outflow from a central star-forming region at the Galactic center. We discuss the clouds as entrained material traveling at {approx}200 km s{sup -1} in a Galactic wind.

  10. GGD 37: AN EXTREME PROTOSTELLAR OUTFLOW

    SciTech Connect

    Green, J. D.; Watson, D. M.; Forrest, W. J.; Kim, K. H.; Bergin, E.; Maret, S.; Melnick, G.; Tolls, V.; Sonnentrucker, P.; Sargent, B. A.; Raines, S. N.

    2011-01-01

    We present the first Spitzer-IRS spectral maps of the Herbig-Haro flow GGD 37 detected in lines of [Ne III], [O IV], [Ar III], and [Ne V]. The detection of extended [O IV] (55 eV) and some extended emission in [Ne V] (97 eV) indicates a shock temperature in excess of 100,000 K, in agreement with X-ray observations, and a shock speed in excess of 200 km s{sup -1}. The presence of an extended photoionization or collisional ionization region indicates that GGD 37 is a highly unusual protostellar outflow.

  11. METAL-ENRICHED OUTFLOWS IN THE ULTRALUMINOUS INFRARED QUASAR Q1321+058

    SciTech Connect

    Wang Tinggui; Zhou Hongyan; Lu HongLin; Dong Xiaobo; Yuan Weimin; Shan Hongguang

    2009-09-10

    Quasar outflows may play important role in the evolution of its host galaxy and central black hole, and are most often studied in absorption lines. In this paper, we present a detailed study of multiple outflows in the obscured ultraluminous infrared quasar Q1321+058. The outflows reveal themselves in the complex optical and ultraviolet (UV) emission-line spectrum, with a broad component blueshifted by 1650 km s{sup -1} and a narrow component by 360 km s{sup -1}, respectively. The higher velocity component shows ever strong N III] (N III]/C III] = 3.8 {+-} 0.3 and N III]/C IV = 0.53) and strong Si III] (Si III]/C III] {approx_equal} 1), in addition to strong [O III]{lambda}5007 and [Ne III]{lambda}3869 emission. A comparison of these line ratios with photoionization models suggests an overabundance of N and Si relative to C. The abundance pattern is consistent with a fast chemical enriching process associated with a recent starburst, triggered by a recent galaxy merger. The outflow extends to several tens to hundred parsecs from the quasar, and covers only a very small sky. We find that the outflow with line emitting gas is energetically insufficient to remove the interstellar medium of the host galaxy, but total kinetic energy may be much larger than suggested by the emission lines. The velocity range and the column density suggest that the outflow might be part of the low-ionization broad absorption line region as seen in a small class of quasars. The optical and UV continuum is starlight dominated and can be modeled with a young-aged (1 Myr) plus an intermediate-aged ({approx}0.5-1 Gyr) stellar populations, suggesting a fast building of the stellar mass in the host galaxy, consistent with the starburst-type metal abundances inferred from the high-velocity outflow spectrum. The broadband spectral energy distribution shows that it is an obscured quasar with its bulk emission in the middle infrared. The star formation rate, independently estimated from UV, far

  12. A BIPOLAR OUTFLOW FROM THE MASSIVE PROTOSTELLAR CORE W51e2-E

    SciTech Connect

    Shi Hui; Han, J. L.; Zhao Junhui E-mail: hil@nao.cas.c

    2010-08-01

    We present high-resolution images of the bipolar outflow from W51e2, which are produced from the Submillimeter Array archival data observed for CO(3-2) and HCN(4-3) lines with angular resolutions of 0.''8 x 0.''6 and 0.''3 x 0.''2, respectively. The images show that the powerful outflow originates from the protostellar core W51e2-E rather than from the ultracompact H II region W51e2-W. The kinematic timescale of the outflow from W51e2-E is about 1000 yr, younger than the age ({approx}5000 yr) of the ultracompact H II region W51e2-W. A large mass-loss rate of {approx}1 x 10{sup -3} M{sub sun} yr{sup -1} and a high mechanical power of 120 L{sub sun} are inferred, suggesting that an O star or a cluster of B stars are forming in W51e2-E. The observed outflow activity along with the inferred large accretion rate indicates that at present W51e2-E is in a rapid phase of star formation.

  13. Studying the outflow-core interaction with ALMA Cycle 1 observations of the HH 46/47 molecular outflow

    NASA Astrophysics Data System (ADS)

    Zhang, Yichen; Arce, Hector G.; Mardones, Diego; Dunham, Michael; Garay, Guido; Noriega-Crespo, Alberto; Corder, Stuartt; Offner, Stella; Cabrit, Sylvie

    2016-01-01

    We present ALMA Cycle 1 observations of the HH 46/47 molecular outflow which is driven by a low-mass Class 0/I protostar. Previous ALMA Cycle 0 12CO observation showed outflow cavities produced by the entrainment of ambient gas by the protostellar jet and wide-angle wind. Here we present analysis of observation of 12CO, 13CO, C18O and other species using combined 12m array and ACA observations. The improved angular resolution and sensitivity allow us to detect details of the outflow structure. Specially, we see that the outflow cavity wall is composed of two or more layers of outflowing gas, which separately connect to different shocked regions along the outflow axis inside the cavity, suggesting the outflow cavity wall is composed of multiple shells entrained by a series of jet bow-shock events. The new 13CO and C18O data also allow us to trace relatively denser and slower outflow material than that traced by the 12CO. These species are only detected within about 1 to 2 km/s from the cloud velocity, tracing the outflow to lower velocities than what is possible using only the 12CO emission. Interestingly, the cavity wall of the red lobe appears at very low outflow velocities (as low as ~0.2 km/s). In addition, 13CO and C18O allow us to correct for the CO optical depth, allowing us to obtain more accurate estimates of the outflow mass, momentum and kinetic energy. Applying the optical depth correction significantly increases the previous mass estimate by a factor of 14. The outflow kinetic energy distribution shows that even though the red lobe is mainly entrained by jet bow-shocks, most of the outflow energy is being deposited into the cloud at the base of the outflow cavity rather than around the heads of the bow shocks. The estimated total mass, momentum, and energy of the outflow indicate that the outflow has the ability to disperse the parent core. We found possible evidence for a slowly moving rotating outflow in CS. Our 13CO and C18O observations also trace a

  14. Suppression of galactic outflows by cosmological infall and circumgalactic medium

    NASA Astrophysics Data System (ADS)

    Singh, Priyanka; Rana, Sandeep; Bagla, Jasjeet S.; Nath, Biman B.

    2016-06-01

    We investigate the relative importance of two galactic outflow suppression mechanisms: (a) cosmological infall of the intergalactic gas on to the galaxy, and (b) the existence of a hot circumgalactic medium (CGM). Considering only radial motion, the infall reduces the speed of outflowing gas and even halts the outflow, depending on the mass and redshift of the galaxy. For star-forming galaxies, there exists an upper mass limit beyond which outflows are suppressed by the gravitational field of the galaxy. We find that infall can reduce this upper mass limit approximately by a factor of 2 (independent of the redshift). Massive galaxies (≳1012 M⊙) host large reservoir of hot, diffuse CGM around the central part of the galaxy. The CGM acts as a barrier between the infalling and outflowing gas and provides an additional source of outflow suppression. We find that at low redshifts (z ≲ 3.5), the CGM is more effective than the infall in suppressing the outflows. Together, these two processes give a mass range in which galaxies are unable to have effective outflows. We also discuss the impact of outflow suppression on the enrichment history of the galaxy and its environment.

  15. Endogenous Bioactive Lipids and the Regulation of Conventional Outflow Facility

    PubMed Central

    Wan, Zhou; Woodward, David F.; Stamer, W. Daniel

    2009-01-01

    Summary Perturbation of paracrine signaling within the human conventional outflow pathway influences tissue homeostasis and outflow function. For example, exogenous introduction of the bioactive lipids, sphingosine-1-phosphate, anandamide or prostaglandin F2α, to conventional outflow tissues alters the rate of drainage of aqueous humor through the trabecular meshwork, and into Schlemm’s canal. This review summarizes recent data that characterizes endogenous bioactive lipids, their receptors and associated signaling partners in the conventional outflow tract. We also discuss the potential of targeting such signaling pathways as a strategy for the development of therapeutics to treat ocular hypertension and glaucoma. PMID:19381354

  16. TRACING THE BIPOLAR OUTFLOW FROM ORION SOURCE I

    SciTech Connect

    Plambeck, R. L.; Wright, M. C. H.; Friedel, D. N.; Widicus Weaver, S. L.; Bolatto, A. D.; Pound, M. W.; Woody, D. P.; Lamb, J. W.; Scott, S. L.

    2009-10-10

    Using CARMA, we imaged the 87 GHz SiO v = 0 J = 2-1 line toward Orion-KL with 0.''45 angular resolution. The maps indicate that radio source I drives a bipolar outflow into the surrounding molecular cloud along a NE-SW axis, in agreement with the model of Greenhill et al. The extended high-velocity outflow from Orion-KL appears to be a continuation of this compact outflow. High-velocity gas extends farthest along a NW-SE axis, suggesting that the outflow direction changes on timescales of a few hundred years.

  17. Discovery of Relativistic Outflow in the Seyfert Galaxy Ark 564

    NASA Astrophysics Data System (ADS)

    Gupta, A.; Mathur, S.; Krongold, Y.; Nicastro, F.

    2013-07-01

    We present Chandra High Energy Transmission Grating Spectra of the narrow-line Seyfert-1 galaxy Ark 564. The spectrum shows numerous absorption lines which are well modeled with low-velocity outflow components usually observed in Seyfert galaxies. There are, however, some residual absorption lines which are not accounted for by low-velocity outflows. Here, we present identifications of the strongest lines as Kα transitions of O VII (two lines) and O VI at outflow velocities of ~0.1c. These lines are detected at 6.9σ, 6.2σ, and 4.7σ, respectively, and cannot be due to chance statistical fluctuations. Photoionization models with ultra-high velocity components improve the spectral fit significantly, providing further support for the presence of relativistic outflow in this source. Without knowing the location of the absorber, its mass and energy outflow rates cannot be well constrained; we find \\dot{E}(outflow)/L_{bol} lower limit of >=0.006% assuming a bi-conical wind geometry. This is the first time that absorption lines with ultra-high velocities are unambiguously detected in the soft X-ray band. The presence of outflows with relativistic velocities in active galactic nuclei (AGNs) with Seyfert-type luminosities is hard to understand and provides valuable constraints to models of AGN outflows. Radiation pressure is unlikely to be the driving mechanism for such outflows and magnetohydrodynamic may be involved.

  18. Shining a light on star formation driven outflows: the physical conditions within galactic outflows

    NASA Astrophysics Data System (ADS)

    Chisholm, John P.; Tremonti, Christina A.; Leitherer, Claus; Wofford, Aida; Chen, Yanmei

    2016-01-01

    Stellar feedback drives energy and momentum into the surrounding gas, which drives gas and metals out of galaxies through a galactic outflow. Unfortunately, galactic outflows are difficult to observe and characterize because they are extremely diffuse, and contain gas at many different temperatures. Here we present results from a sample of 37 nearby (z < 0.27) star forming galaxies observed in the ultraviolet with the Cosmic Origins Spectrograph on the Hubble Space Telescope. The sample covers over three decades in stellar mass and star formation rate, probing different morphologies such as dwarf irregulars and high-mass merging systems. Using four different UV absorption lines (O I, Si II, Si III and Si IV) that trace a wide range of temperatures (ionization potentials between 13.6 eV and 45 eV), we find shallow correlations between the outflow velocity or the equivalent width of absorption lines with stellar mass or star formation rate. Absorption lines probing different temperature phases have similar centroid velocities and line widths, indicating that they are comoving. Using the equivalent width ratios of the four different transitions, we find the ratios to be consistent with photo-ionized outflows, with moderately strong ionization parameters. By constraining the ionization mechanism we model the ionization fractions for each transition, but find the ionization fractions depend crucially on input model parameters. The shallow velocity scalings imply that low-mass galaxies launch outflows capable of escaping their galactic potential, while higher mass galaxies retain all of their gas, unless they undergo a merger.

  19. Characterizing Quasar Outflows II: The Incidence of the Highest Velocity Outflows

    NASA Astrophysics Data System (ADS)

    Stark, Michele A.; Ganguly, R.; Christenson, D. H.; Richmond, J. M.; Derseweh, J. A.; Robbins, J. M.; Townsend, S. L.

    2012-05-01

    Galaxy evolution models have shown that quasars are a crucial ingredient in the evolution of massive galaxies. Outflows play a key role in the story of quasars and their host galaxies, by helping regulate the accretion process, the star-formation rate and mass of the host galaxy (i.e., feedback). The prescription for modeling outflows as a contributor to feedback requires knowledge of the outflow velocity, geometry, and column density. In particular, we need to understand how these depend on physical parameters and how much is determined stochastically (and with what distribution). For this purpose, we are examining a sample of 11000 z=1.7-2.0 quasars from the Sloan Digital Sky Survey. This redshift range permits the following from the SDSS spectra: (1) separation of objects that do and do not exhibit outflows; (2) classification/measurement of outflow properties (ionization, velocity, velocity width); and (3) measurements of UV emission line and continuum parameters. In an accompanying poster, we subjectively divide these quasars into four categories (broad absorption-line quasars, associated absorption-line quasars, reddened quasars, and unabsorbed/unreddened quasars). This subjective scheme is limited with regard to classifying narrow absorption-line systems (NALs). With single epoch, low dispersion SDSS spectra, we cannot distinguish between cosmologically intervening NALs, and intrinsic NALs that appear at large velocity offsets. In this poster, we tackle this uncertainty statistically by considering the incidence of both CIV and MgII NALs as a function of velocity, and how this distribution changes with quasar properties. We expect that absorption by intervening structures should not vary with quasar property. Other accompanying posters add photometry from rest-frame X-ray through the infrared (WISE) to complete the SED, which we utilize in these efforts. This material is based upon work supported by the National Aeronautics and Space Administration under

  20. Disks and Outflows Around Young Stars

    NASA Astrophysics Data System (ADS)

    Beckwith, Steven; Staude, Jakob; Quetz, Axel; Natta, Antonella

    The subject of the book, the ubiquitous circumstellar disks around very young stars and the corresponding jets of outflowing matter, has recently become one of the hottest areas in astrophysics. The disks are thought to be precursors to planetary systems, and the outflows are thought to be a necessary phase in the formation of a young star, helping the star to get rid of angular momentum and energy as it makes its way onto the main sequence. The possible connections to planetary systems and stellar astrophysics makes these topics especially broad, appealing to generalists and specialists alike. The CD not only contains papers that could not be printed in the book but allows the authors to include a fair amount of data, often displayed as color images. The CD-ROM contains all the contributions printed in the corresponding book (Lecture Notes in Physics Vol. 465) and, in addition, those presented exclusively in digital form. Each contribution consists of a file in portable document format (PDF). The electronic version allows full-text searching within each file using Adobe's Acrobat Reader providing instructions for installation on Unix (Sun), PC and Macintosh computers, respectively. All contributions can be printed out; the color diagrams and color frames, which are printed in black and white in the book, can be viewed in color on screen.

  1. Simulating galactic outflows with kinetic supernova feedback

    NASA Astrophysics Data System (ADS)

    Dalla Vecchia, Claudio; Schaye, Joop

    2008-07-01

    Feedback from star formation is thought to play a key role in the formation and evolution of galaxies, but its implementation in cosmological simulations is currently hampered by a lack of numerical resolution. We present and test a subgrid recipe to model feedback from massive stars in cosmological smoothed particle hydrodynamics simulations. The energy is distributed in kinetic form among the gas particles surrounding recently formed stars. The impact of the feedback is studied using a suite of high-resolution simulations of isolated disc galaxies embedded in dark haloes with total mass 1010 and 1012h-1Msolar. We focus, in particular, on the effect of pressure forces on wind particles within the disc, which we turn off temporarily in some of our runs to mimic a recipe that has been widely used in the literature. We find that this popular recipe gives dramatically different results because (ram) pressure forces on expanding superbubbles determine both the structure of the disc and the development of large-scale outflows. Pressure forces exerted by expanding superbubbles puff up the disc, giving the dwarf galaxy an irregular morphology and creating a galactic fountain in the massive galaxy. Hydrodynamic drag within the disc results in a strong increase in the effective mass loading of the wind for the dwarf galaxy, but quenches much of the outflow in the case of the high-mass galaxy.

  2. IONIZED OUTFLOWS FROM COMPACT STEEP SPECTRUM SOURCES

    SciTech Connect

    Shih, Hsin-Yi; Stockton, Alan; Kewley, Lisa E-mail: stockton@ifa.hawaii.edu

    2013-08-01

    Massive outflows are known to exist, in the form of extended emission-line regions (EELRs), around about one-third of powerful FR II radio sources. We investigate the origin of these EELRs by studying the emission-line regions around compact-steep-spectrum (CSS) radio galaxies that are younger (10{sup 3}-10{sup 5} yr old) versions of the FR II radio galaxies. We have searched for and analyzed the emission-line regions around 11 CSS sources by taking integral field spectra using Gemini Multi-Object Spectrograph on Gemini North. We fit the [O III] {lambda}5007 line and present the velocity maps for each detected emission-line region. We find, in most cases, that the emission-line regions have multi-component velocity structures with different velocity dispersions and/or flux distributions for each component. The velocity gradients of the emission-line gas are mostly well aligned with the radio axis, suggesting a direct causal link between the outflowing gas and the radio jets. The complex velocity structure may be a result of different driving mechanisms related to the onset of the radio jets. We also present the results from the line-ratio diagnostics we used to analyze the ionization mechanism of the extended gas, which supports the scenario where the emission-line regions are ionized by a combination of active galactic nucleus radiation and shock excitation.

  3. Transparency parameters from relativistically expanding outflows

    SciTech Connect

    Bégué, D.; Iyyani, S.

    2014-09-01

    In many gamma-ray bursts a distinct blackbody spectral component is present, which is attributed to the emission from the photosphere of a relativistically expanding plasma. The properties of this component (temperature and flux) can be linked to the properties of the outflow and have been presented in the case where there is no sub-photospheric dissipation and the photosphere is in coasting phase. First, we present the derivation of the properties of the outflow for finite winds, including when the photosphere is in the accelerating phase. Second, we study the effect of localized sub-photospheric dissipation on the estimation of the parameters. Finally, we apply our results to GRB 090902B. We find that during the first epoch of this burst the photosphere is most likely to be in the accelerating phase, leading to smaller values of the Lorentz factor than the ones previously estimated. For the second epoch, we find that the photosphere is likely to be in the coasting phase.

  4. Magnetospheric and Thermospheric Influence on Ionospheric Outflow

    NASA Astrophysics Data System (ADS)

    Garcia-Sage, K.; Moore, T. E.; Mitchell, E. J.; Olson, D. K.

    2013-12-01

    The Fast Auroral SnapshoT (FAST) small explorer has been used extensively to study ionospheric outflow. Past research has used particle and field data to examine the contemporaneous transfer of electromagnetic energy and particle flow downward from the magnetosphere and upward from the ionosphere. Single event studies published by Strangeway et al. [2005] and Brambles et al. [2011, Supporting Online Material] showed that downward electromagnetic energy and particle flow into the ionosphere are correlated with the upward flow of ions out of the ionosphere. It is expected, however, that this correlation will be affected by circumstances that are unique to each specific event, including but not limited to the outflow location (cusp or nightside), preconditioning due to prior geomagnetic activity, and thermospheric neutral densities. Although knowledge of the thermospheric neutral density is usually unavailable, data from the CHAllenging Minisatellite Payload (CHAMP) is able to provide insight into thermospheric populations at altitudes of about 400 km for a few select events. We expand on the previously-mentioned studies by looking at FAST particle and field data for additional events, and we further examine the influence of thermospheric neutral populations, based on CHAMP data.

  5. Accretion Disk Outflows from Compact Object Mergers

    NASA Astrophysics Data System (ADS)

    Metzger, Brian

    Nuclear reactions play a key role in the accretion disks and outflows associated with the merger of binary compact objects and the central engines of gamma-ray bursts and supernovae. The proposed research program will investigate the impact of nucleosynthesis on these events and their observable signatures by means of analytic calculations and numerical simulations. One focus of this research is rapid accretion following the tidal disruption of a white dwarf (WD) by a neutron star (NS) or black hole (BH) binary companion. Tidal disruption shreds the WD into a massive torus composed of C, O, and/or He, which undergoes nuclear reactions and burns to increasingly heavier elements as it flows to smaller radii towards the central compact object. The nuclear energy so released is comparable to that released gravitationally, suggesting that burning could drastically alter the structure and stability of the accretion flow. Axisymmetric hydrodynamic simulations of the evolution of the torus including nuclear burning will be performed to explore issues such as the mass budget of the flow (accretion vs. outflows) and its thermal stability (steady burning and accretion vs. runaway explosion). The mass, velocity, and composition of outflows from the disk will be used in separate radiative transfer calculations to predict the lightcurves and spectra of the 56Ni-decay powered optical transients from WD-NS/WD-BH mergers. The possible connection of such events to recently discovered classes of sub-luminous Type I supernovae will be assessed. The coalescence of NS-NS/NS-BH binaries also results in the formation of a massive torus surrounding a central compact object. Three-dimensional magnetohydrodynamic simulations of the long-term evolution of such accretion disks will be performed, which for the first time follow the effects of weak interactions and the nuclear energy released by Helium recombination. The nucleosynthetic yield of disk outflows will be calculated using a detailed

  6. MCS Systems Administration Toolkit

    2001-09-30

    This package contains a number of systems administration utilities to assist a team of system administrators in managing a computer environment by automating routine tasks and centralizing information. Included are utilities to help install software on a network of computers and programs to make an image of a disk drive, to manage and distribute configuration files for a number of systems, and to run self-testss on systems, as well as an example of using amore » database to manage host information and various utilities.« less

  7. Ionised outflows in z ~ 2.4 quasar host galaxies

    NASA Astrophysics Data System (ADS)

    Carniani, S.; Marconi, A.; Maiolino, R.; Balmaverde, B.; Brusa, M.; Cano-Díaz, M.; Cicone, C.; Comastri, A.; Cresci, G.; Fiore, F.; Feruglio, C.; La Franca, F.; Mainieri, V.; Mannucci, F.; Nagao, T.; Netzer, H.; Piconcelli, E.; Risaliti, G.; Schneider, R.; Shemmer, O.

    2015-08-01

    Aims: Outflows driven by active galactic nuclei (AGN) are invoked by galaxy evolutionary models to quench star formation and to explain the origin of the relations observed locally between super-massive black holes and their host galaxies. We here aim to detect extended ionised outflows in luminous quasars, where we expect the highest activity both in star formation and in black-hole accretion. Currently, there are only a few studies based on spatially resolved observations of outflows at high redshift, z > 2. Methods: We analysed a sample of six luminous (L > 1047 erg/s) quasars at z ~ 2.4, observed in H-band using the near-IR integral field spectrometer SINFONI at the VLT. We performed a kinematic analysis of the [Oiii] emission line at λ = 5007 Å. Results: We detect fast, spatially extended outflows in five out of six targets. [Oiii]λ5007 has a complex gas kinematic, with blue-shifted velocities of a few hundreds of km s-1 and line widths up to 1500 km s-1. Using the spectroastrometric method, we infer a size of the ionised outflows of up to ~2 kpc. The properties of the ionised outflows, mass outflow rate, momentum rate, and kinetic power, are correlated with the AGN luminosity. The increase in outflow rate with increasing AGN luminosity is consistent with the idea that a luminous AGN pushes away the surrounding gas through fast outflows that are driven by radiation pressure, which depends on the emitted luminosity. Conclusions: We derive mass outflow rates of about 6-700 M⊙ yr-1 for our sample, which are lower than those observed in molecular outflows. The physical properties of ionised outflows show dependences on AGN luminosity that are similar to those of molecular outflows, but indicate that the mass of ionised gas is lower than that of molecular outflows. Alternatively, this discrepancy between ionised and molecular outflows could be explained with different acceleration mechanisms. Based on Observations collected at the European Organisation for

  8. Measurement of Outflow Facility Using iPerfusion

    PubMed Central

    Sherwood, Joseph M.; Reina-Torres, Ester; Bertrand, Jacques A.; Rowe, Barnaby; Overby, Darryl R.

    2016-01-01

    Elevated intraocular pressure (IOP) is the predominant risk factor for glaucoma, and reducing IOP is the only successful strategy to prevent further glaucomatous vision loss. IOP is determined by the balance between the rates of aqueous humour secretion and outflow, and a pathological reduction in the hydraulic conductance of outflow, known as outflow facility, is responsible for IOP elevation in glaucoma. Mouse models are often used to investigate the mechanisms controlling outflow facility, but the diminutive size of the mouse eye makes measurement of outflow technically challenging. In this study, we present a new approach to measure and analyse outflow facility using iPerfusion™, which incorporates an actuated pressure reservoir, thermal flow sensor, differential pressure measurement and an automated computerised interface. In enucleated eyes from C57BL/6J mice, the flow-pressure relationship is highly non-linear and is well represented by an empirical power law model that describes the pressure dependence of outflow facility. At zero pressure, the measured flow is indistinguishable from zero, confirming the absence of any significant pressure independent flow in enucleated eyes. Comparison with the commonly used 2-parameter linear outflow model reveals that inappropriate application of a linear fit to a non-linear flow-pressure relationship introduces considerable errors in the estimation of outflow facility and leads to the false impression of pressure-independent outflow. Data from a population of enucleated eyes from C57BL/6J mice show that outflow facility is best described by a lognormal distribution, with 6-fold variability between individuals, but with relatively tight correlation of facility between fellow eyes. iPerfusion represents a platform technology to accurately and robustly characterise the flow-pressure relationship in enucleated mouse eyes for the purpose of glaucoma research and with minor modifications, may be applied in vivo to mice, as

  9. Examination of physical processes of convective cell evolved from a MCS — Using a different model initialization

    NASA Astrophysics Data System (ADS)

    Spiridonov, Vlado; Ćurić, Mladjen

    2016-06-01

    The present study is focused on examination of the physical processes of convective cell evolved from a MCS occurred on 4 November 2011 over Genoa, Italy. The Quantitative Precipitation Forecasts (QPF) have been performed using WRF v3.6 model under different configurations and cloud permitting simulations. The results indicate underestimation of the amount of precipitation and spatial displacement of the area with a peak 24-h accumulated rainfall in (mm). Our main objective in the research is to test the cloud model ability and performance in simulation of this particular case. For that purpose a set of sensitivity experiments under different model initializations and initial data have been conducted. The results also indicate that the merging process apparently alters the physical processes through low- and middle-level forcing, increasing cloud depth, and enhancing convection. The examination of the microphysical process simulated by the model indicates that dominant production terms are the accretion of rain by graupel and snow, probabilistic freezing of rain to form graupel and dry and wet growth of graupel. Experiment under WRF v3.6 model initialization has shown some advantage in simulation of the physical processes responsible for production and initiation of heavy rainfall compared to other model runs. Most of the precipitation came from ice-phase particles-via accretion processes and the graupel melting at temperature T0 ≥ 0°C. The rainfall intensity and accumulated rainfall calculated by the model closely reflect the amount of rainfall recorded. Thus, the main benefit is to better resolve convective showers or storms which, in extreme cases, can give rise to major flooding events. In such a way, this model may become major contributor to improvements in weather analysis and small-scale atmospheric predictions and early warnings of such subscale processes.

  10. Characterizing Quasar Outflows IV: Regulating Outflows Through X-ray and EUV Absorption

    NASA Astrophysics Data System (ADS)

    Derseweh, Jeffrey; Ganguly, R.; Richmond, J. M.; Stark, M. A.; Christenson, D. H.; Robbins, J. M.; Townsend, S. L.

    2012-05-01

    Galaxy evolution models have shown that quasars are a crucial ingredient in the evolution of massive galaxies. Outflows play a key role in the story of quasars and their host galaxies, by helping regulate the accretion process, the star-formation rate and mass of the host galaxy (i.e., feedback). The prescription for modeling outflows as a contributor to feedback requires knowledge of the outflow velocity, geometry, and column density. In particular, we need to understand how these depend on physical parameters and how much is determined stochastically (and with what distribution). For this purpose, we are examining a sample of 11000 z=1.7-2.0 quasars from the Sloan Digital Sky Survey. This redshift range permits the following from the SDSS spectra: (1) separation of objects that do and do not exhibit outflows; (2) classification/measurement of outflow properties (ionization, velocity, velocity width); and (3) measurements of UV emission line and continuum parameters. In this poster, we add photometry from the GALEX All-sky imaging survey, as well as the Chandra and ROSAT archives. These provide coverage of the rest-frame extreme ultraviolet, and soft X-ray bands. In an accompanying poster, we have subjectively divided these quasars into four categories: broad absorption-line quasars (2700 objects), associated absorption-line quasars (1700 objects), reddened quasars (160 objects), and unabsorbed/unreddened quasars (6300 objects). We are interested in testing the radiative-driving hypothesis that requires a suppression of X-ray flux in order to transfer momentum efficiently to the UV-absorbing gas. Hence, we explore how absorption in both the extreme ultraviolet and the soft X-ray bands correlate with properties of the UV outflows, quasar property, and changes in SED shape. This material is based upon work supported by the National Aeronautics and Space Administration under Grant No. 09-ADP09-0016 issued through the Astrophysics Data Analysis Program and by Chandra

  11. HiRes Deconvolution of Outflow Cavities Imaged by Spitzer

    NASA Astrophysics Data System (ADS)

    Velusamy, Thangasamy; Langer, W. D.; Marsh, K. A.

    2007-05-01

    Circumstellar outflows are believed to play a central role in the dispersal of the envelope and the ejection of angular momentum from protostars and their associated disks. The opening angle of the outflow is an important indicator of the time evolution of the outflow and its effects on infall and accretion. The scattered light emission escaping out the outflow cavities can be observed in the deep Spitzer images in the IRAC bands. We present examples of HiRes deconvolved Spitzer IRAC images of outflow cavities. HiRes achieves sub-arcsec resolution (< 0.8") for IRAC channels at 3.6 and 4.5 microns and 1" at 5.8 and 8 microns. Furthermore, HiRes deconvolution removes all the diffraction lobes producing cleaner looking narrow image of the protostar and nearby bright stars. Thus HiRes analysis improves our ability to trace the outflow cavities. We also present geometric models of the outflow (inclination and deprojected opening angles) derived by fitting SEDs and images of the outflow cavities. This work was performed by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration

  12. Confronting the outflow-regulated cluster formation model with observations

    SciTech Connect

    Nakamura, Fumitaka; Li, Zhi-Yun E-mail: zl4h@virginia.edu

    2014-03-10

    Protostellar outflows have been shown theoretically to be capable of maintaining supersonic turbulence in cluster-forming clumps and keeping the star formation rate per free-fall time as low as a few percent. We aim to test two basic predictions of this outflow-regulated cluster formation model, namely, (1) the clump should be close to virial equilibrium and (2) the turbulence dissipation rate should be balanced by the outflow momentum injection rate, using recent outflow surveys toward eight nearby cluster-forming clumps (B59, L1551, L1641N, Serpens Main Cloud, Serpens South, ρ Oph, IC 348, and NGC 1333). We find, for almost all sources, that the clumps are close to virial equilibrium and the outflow momentum injection rate exceeds the turbulence momentum dissipation rate. In addition, the outflow kinetic energy is significantly smaller than the clump gravitational energy for intermediate and massive clumps with M {sub cl} ≳ a few × 10{sup 2} M {sub ☉}, suggesting that the outflow feedback is not enough to disperse the clump as a whole. The number of observed protostars also indicates that the star formation rate per free-fall time is as small as a few percent for all clumps. These observationally based results strengthen the case for outflow-regulated cluster formation.

  13. Collective outflow from a small multiple stellar system

    SciTech Connect

    Peters, Thomas; Klaassen, Pamela D.; Mac Low, Mordecai-Mark; Schrön, Martin; Klessen, Ralf S.; Federrath, Christoph; Smith, Michael D.

    2014-06-10

    The formation of high-mass stars is usually accompanied by powerful protostellar outflows. Such high-mass outflows are not simply scaled-up versions of their lower-mass counterparts, since observations suggest that the collimation degree degrades with stellar mass. Theoretically, the origins of massive outflows remain open to question because radiative feedback and fragmentation of the accretion flow around the most massive stars, with M > 15 M {sub ☉}, may impede the driving of magnetic disk winds. We here present a three-dimensional simulation of the early stages of core fragmentation and massive star formation that includes a subgrid-scale model for protostellar outflows. We find that stars that form in a common accretion flow tend to have aligned outflow axes, so that the individual jets of multiple stars can combine to form a collective outflow. We compare our simulation to observations with synthetic H{sub 2} and CO observations and find that the morphology and kinematics of such a collective outflow resembles some observed massive outflows, such as Cepheus A and DR 21. We finally compare physical quantities derived from simulated observations of our models to the actual values in the models to examine the reliability of standard methods for deriving physical quantities, demonstrating that those methods indeed recover the actual values to within a factor of two to three.

  14. EXPLOSIVE OUTFLOWS POWERED BY THE DECAY OF NON-HIERARCHICAL MULTIPLE SYSTEMS OF MASSIVE STARS: ORION BN/KL

    SciTech Connect

    Bally, John; Cunningham, Nathaniel J.; Moeckel, Nickolas; Burton, Michael G.; Smith, Nathan; Frank, Adam; Nordlund, Ake E-mail: ncunningham2@unl.edu E-mail: mgb@phys.unsw.edu.au E-mail: afrank@pas.rochester.edu

    2011-02-01

    The explosive Becklin-Neugebauer (BN)/Kleinman-Low (KL) outflow emerging from OMC1 behind the Orion Nebula may have been powered by the dynamical decay of a non-hierarchical multiple system {approx}500 years ago that ejected the massive stars I, BN, and source n, with velocities of about 10-30 km s{sup -1}. New proper-motion measurements of H{sub 2} features show that within the errors of measurement, the outflow originated from the site of stellar ejection. Combined with published data, these measurements indicate an outflow age of {approx}500 years, similar to the time since stellar ejection. The total kinetic energy of the ejected stars and the outflow is about 2 to 6 x 10{sup 47} erg. It is proposed that the gravitational potential energy released by the formation of a short-period binary, most likely source I, resulted in stellar ejection and powered the outflow. A scenario is presented for the formation of a compact, non-hierarchical multiple star system, its decay into an ejected binary and two high-velocity stars, and launch of the outflow. Three mechanisms may have contributed to the explosion in the gas: (1) unbinding of the circumcluster envelope following stellar ejection, (2) disruption of circumstellar disks and high-speed expulsion of the resulting debris during the final stellar encounter, and (3) the release of stored magnetic energy. Plausible protostellar disk end envelope properties can produce the observed outflow mass, velocity, and kinetic energy distributions. The ejected stars may have acquired new disks by fall-back or Bondi-Hoyle accretion with axes roughly orthogonal to their velocities. The expulsion of gas and stars from OMC1 may have been driven by stellar interactions.

  15. Simulation of Breach Outflow for Earthfill Dam

    NASA Astrophysics Data System (ADS)

    Razad, Azwin Zailti Abdul; Sabri Muda, Rahsidi; Mohd Sidek, Lariyah; Azia, Intan Shafilah Abdul; Hanum Mansor, Faezah; Yalit, Ruzaimei

    2013-06-01

    Dams have been built for many reasons such as irrigation, hydropower, flood mitigation, and water supply to support development for the benefit of human. However, the huge amount of water stored behind the dam can seriously pose adverse impacts to the downstream community should it be released due to unwanted dam break event. To minimise the potential loss of lives and property damages, a workable Emergency Response Plan is required to be developed. As part of a responsible dam owner and operator, TNB initiated a study on dam breach modelling for Cameron Highlands Hydroelectric Scheme to simulate the potential dam breach for Jor Dam. Prediction of dam breach parameters using the empirical equations of Froehlich and Macdonal-Langridge-Monopolis formed the basis of the modelling, coupled with MIKE 11 software to obtain the breach outflow due to Probable Maximum Flood (PMF). This paper will therefore discuss the model setup, simulation procedure and comparison of the prediction with existing equations.

  16. 'What controls aqueous humour outflow resistance?'.

    PubMed

    Johnson, Mark

    2006-04-01

    The bulk of aqueous humour outflow resistance is generated in or near the inner wall endothelium of Schlemm's canal in normal eyes, and probably also in glaucomatous eyes. Fluid flow through this region is controlled by the location of the giant vacuoles and pores found in cells of the endothelium of Schlemm's canal, but the flow resistance itself is more likely generated either in the extracellular matrix of the juxtacanalicular connective tissue or the basement membrane of Schlemm's canal. Future studies utilizing in vitro perfusion studies of inner wall endothelial cells may give insights into the process by which vacuoles and pores form in this unique endothelium and why inner wall pore density is greatly reduced in glaucoma. PMID:16386733

  17. FIRE simulations: galactic outflows and their consequences

    NASA Astrophysics Data System (ADS)

    Keres, Dusan; FIRE team

    2016-06-01

    We study gaseous outflows and their consequences in high-resolution galaxy formation simulations with explicit stellar feedback from the Feedback in Realistic Environments project. Collective, galaxy scale, effect of stellar feedback results in episodic ejections of large amount of gas and heavy elements into the circum-galactic medium. Gas ejection episodes follow strong bursts of star formation. Properties of galactic star formation and ejection episodes depend on galaxy mass and redshift and, together with gas infall and recycling, shape the evolution of the circum-galactic medium and galaxies. As a consequence, our simulated galaxies have masses, star formation histories and heavy element content in good agreement with the observed population of galaxies.

  18. Ice sculpture in the Martian outflow channels

    NASA Technical Reports Server (NTRS)

    Lucchitta, B. K.

    1982-01-01

    Viking Orbiter and terrestrial satellite images are examined at similar resolution to compare features of the Martian outflow channels with features produced by the movement of ice on earth, and many resemblances are found. These include the anastomoses, sinuosities, and U-shaped cross profiles of valleys; hanging valleys; linear scour marks on valley walls; grooves and ridges on valley floors; and the streamlining of bedrock highs. Attention is given to the question whether ice could have moved in the Martian environment. It is envisaged that springs or small catastrophic outbursts discharged fluids from structural outlets or chaotic terrains. These fluids built icings that may have grown into substantial masses and eventually flowed like glaciers down preexisting valleys. An alternative is that the fluids formed rivers or floods that in turn formed ice jams and consolidated into icy masses in places where obstacles blocked their flow.

  19. Magnetic field and spatial structure of bipolar outflow sources

    NASA Technical Reports Server (NTRS)

    Hodapp, Klaus-Werner

    1990-01-01

    Deep K band images of three bipolar outflow sources (Cep A, GL 490, and R Mon) are presented. The polarization of background or embedded stars close to these star-forming regions has been measured in the I band to determine the local projected magnetic field direction. For Cep A the outflow direction and the magnetic field are almost parallel as is the case for most bipolar outflow sources. This alignment is poorer in the case of R Mon while GL 490 is a peculiar case with the outflow direction almost perpendicular to the local magnetic field. No indication was found for a distortion of the magnetic field close to the collimating disks of the outflows.

  20. Searching for molecular outflows in hyperluminous infrared galaxies

    NASA Astrophysics Data System (ADS)

    Calderón, D.; Bauer, F. E.; Veilleux, S.; Graciá-Carpio, J.; Sturm, E.; Lira, P.; Schulze, S.; Kim, S.

    2016-08-01

    We present constraints on the molecular outflows in a sample of five hyperluminous infrared galaxies using Herschel observations of the OH doublet at 119 μm. We have detected the OH doublet in three cases: one purely in emission and two purely in absorption. The observed emission profile has a significant blueshifted wing suggesting the possibility of tracing an outflow. Out of the two absorption profiles, one seems to be consistent with the systemic velocity while the other clearly indicates the presence of a molecular outflow whose maximum velocity is about ˜1500 km s-1. Our analysis shows that this system is in general agreement with previous results on ultraluminous infrared galaxies and QSOs, whose outflow velocities do not seem to correlate with stellar masses or starburst luminosities (star formation rates). Instead, the galaxy outflow likely arises from an embedded active galactic nuclei.

  1. Detection and validation of a small broad-host-range plasmid pBBR1MCS-2 for use in genetic manipulation of the extremely acidophilic Acidithiobacillus sp.

    PubMed

    Hao, Likai; Liu, Xiangmei; Wang, Huiyan; Lin, Jianqun; Pang, Xin; Lin, Jianqiang

    2012-09-01

    An efficient genetic system for introducing genes into biomining microorganisms is essential not only to experimentally determine the functions of genes predicted based on bioinformatic analysis, but also for their genetic breeding. In this study, a small broad-host-range vector named pBBR1MCS-2, which does not belong to the IncQ, IncW, or IncP groups, was studied for the feasibility of its use in conjugative gene transfer into extremely acidophilic strains of Acidithiobacillus. To do this, a recombinant plasmid pBBR-tac-Sm, a derivative of pBBR1MCS-2, was constructed and the streptomycin resistant gene (Sm(r)) was used as the reporter gene. Using conjugation, pBBR-tac-Sm was successfully transferred into three tested strains of Acidithiobacillus. Then we measured its transfer frequency, its stability in Acidithiobacillus cells, and the level of resistance to streptomycin of the transconjugants and compared this with the IncQ plasmid pJRD215 control. Our results indicate that pBBR1MCS-2 provides a new and useful tool in the genetic manipulation of Acidithiobacillus strains. PMID:22705922

  2. Optically thick outflows in ultraluminous supersoft sources

    NASA Astrophysics Data System (ADS)

    Urquhart, R.; Soria, R.

    2016-02-01

    Ultraluminous supersoft sources (ULSs) are defined by a thermal spectrum with colour temperatures ˜0.1 keV, bolometric luminosities ˜ a few 1039 erg s-1, and almost no emission above 1 keV. It has never been clear how they fit into the general scheme of accreting compact objects. To address this problem, we studied a sample of seven ULSs with extensive Chandra and XMM-Newton coverage. We find an anticorrelation between fitted temperatures and radii of the thermal emitter, and no correlation between bolometric luminosity and radius or temperature. We compare the physical parameters of ULSs with those of classical supersoft sources, thought to be surface-nuclear-burning white dwarfs, and of ultraluminous X-ray sources (ULXs), thought to be super-Eddington stellar-mass black holes. We argue that ULSs are the sub-class of ULXs seen through the densest wind, perhaps an extension of the soft-ultraluminous regime. We suggest that in ULSs, the massive disc outflow becomes effectively optically thick and forms a large photosphere, shrouding the inner regions from our view. Our model predicts that when the photosphere expands to ≳ 105 km and the temperature decreases below ≈50 eV, ULSs become brighter in the far-UV but undetectable in X-rays. Conversely, we find that harder emission components begin to appear in ULSs when the fitted size of the thermal emitter is smallest (interpreted as a shrinking of the photosphere). The observed short-term variability and absorption edges are also consistent with clumpy outflows. We suggest that the transition between ULXs (with a harder tail) and ULSs (with only a soft thermal component) occurs at blackbody temperatures of ≈150 eV.

  3. Myocardialization of the cardiac outflow tract

    NASA Technical Reports Server (NTRS)

    van den Hoff, M. J.; Moorman, A. F.; Ruijter, J. M.; Lamers, W. H.; Bennington, R. W.; Markwald, R. R.; Wessels, A.

    1999-01-01

    During development, the single-circuited cardiac tube transforms into a double-circuited four-chambered heart by a complex process of remodeling, differential growth, and septation. In this process the endocardial cushion tissues of the atrioventricular junction and outflow tract (OFT) play a crucial role as they contribute to the mesenchymal components of the developing septa and valves in the developing heart. After fusion, the endocardial ridges in the proximal portion of the OFT initially form a mesenchymal outlet septum. In the adult heart, however, this outlet septum is basically a muscular structure. Hence, the mesenchyme of the proximal outlet septum has to be replaced by cardiomyocytes. We have dubbed this process "myocardialization." Our immunohistochemical analysis of staged chicken hearts demonstrates that myocardialization takes place by ingrowth of existing myocardium into the mesenchymal outlet septum. Compared to other events in cardiac septation, it is a relatively late process, being initialized around stage H/H28 and being basically completed around stage H/H38. To unravel the molecular mechanisms that are responsible for the induction and regulation of myocardialization, an in vitro culture system in which myocardialization could be mimicked and manipulated was developed. Using this in vitro myocardialization assay it was observed that under the standard culture conditions (i) whole OFT explants from stage H/H20 and younger did not spontaneously myocardialize the collagen matrix, (ii) explants from stage H/H21 and older spontaneously formed extensive myocardial networks, (iii) the myocardium of the OFT could be induced to myocardialize and was therefore "myocardialization-competent" at all stages tested (H/H16-30), (iv) myocardialization was induced by factors produced by, most likely, the nonmyocardial component of the outflow tract, (v) at none of the embryonic stages analyzed was ventricular myocardium myocardialization-competent, and finally

  4. The structure of the Cepheus E protostellar outflow: The jet, the bowshock, and the cavity

    NASA Astrophysics Data System (ADS)

    Lefloch, B.; Gusdorf, A.; Codella, C.; Eislöffel, J.; Neri, R.; Gómez-Ruiz, A. I.; Güsten, R.; Leurini, S.; Risacher, C.; Benedettini, M.

    2015-09-01

    component. In the terminal bowshock HH377, we detect gas of moderate excitation, with a temperature in the range Tkin ≈ 400-500 K, density n(H2) ≃ (1 -2) × 106 cm-3 and column density N(CO) = 1017 cm-2. The amounts of momentum carried away in the jet and in the entrained ambient medium are similar. Comparison with time-dependent shock models shows that the hot gas emission in the jet is well accounted for by a magnetized shock with an age of 220-740 yr propagating at 20-30 km s-1 in a medium of density n(H2) = (0.5-1) × 105 cm-3, consistent with that of the bulk material. Conclusions: The Cep E protostellar outflow appears to be a convincing case of jet bowshock driven outflow. Our observations trace the recent impact of the protostellar jet into the ambient cloud, produing a non-stationary magnetized shock, which drives the formation of an outflow cavity. Appendices are available in electronic form at http://www.aanda.org

  5. Development and Morphology of the Ventricular Outflow Tracts.

    PubMed

    Anderson, Robert H; Mori, Shumpei; Spicer, Diane E; Brown, Nigel A; Mohun, Timothy J

    2016-09-01

    It is customary, at the current time, to consider many, if not most, of the lesions involving the ventricular outflow tract in terms of conotruncal malformations. This reflects the introduction, in the early 1940s, of the terms conus and truncus to describe the components of the developing outflow tract. The definitive outflow tracts in the postnatal heart, however, possess three, rather than two, components. These are the intrapericardial arterial trunks, the arterial roots, and the subvalvar ventricular outflow tracts. Congenital lesions afflicting the arterial roots, however, are not currently considered to be conotruncal malformations. This suggests a lack of logic in the description of cardiac development and its use as a means of categorizing congenital malformations. It is our belief that the developing outflow tract, like the postnatal outflow tracts, can readily be described in tripartite fashion, with its distal, intermediate, and proximal components forming the primordiums of the postnatal parts. In this review, we present evidence obtained from developing mice and human hearts to substantiate this notion. We show that the outflow tract, initially with a common lumen, is divided into its aortic and pulmonary components by a combination of an aortopulmonary septum derived from the dorsal wall of the aortic sac and outflow tract cushions that spiral through its intermediate and proximal components. These embryonic septal structures, however, subsequently lose their septal functions as the outflow tracts develop their own discrete walls. We then compare the developmental findings with the anatomic arrangements seen postnatally in the normal human heart. We show how correlations with the embryologic findings permit logical analysis of the congenital lesions involving the outflow tracts. PMID:27587491

  6. A distance-limited sample of massive molecular outflows

    NASA Astrophysics Data System (ADS)

    Maud, L. T.; Moore, T. J. T.; Lumsden, S. L.; Mottram, J. C.; Urquhart, J. S.; Hoare, M. G.

    2015-10-01

    We have observed 99 mid-infrared-bright, massive young stellar objects and compact H II regions drawn from the Red MSX source survey in the J = 3-2 transition of 12CO and 13CO, using the James Clerk Maxwell Telescope. 89 targets are within 6 kpc of the Sun, covering a representative range of luminosities and core masses. These constitute a relatively unbiased sample of bipolar molecular outflows associated with massive star formation. Of these, 59, 17 and 13 sources (66, 19 and 15 per cent) are found to have outflows, show some evidence of outflow, and have no evidence of outflow, respectively. The time-dependent parameters of the high-velocity molecular flows are calculated using a spatially variable dynamic time-scale. The canonical correlations between the outflow parameters and source luminosity are recovered and shown to scale with those of low-mass sources. For coeval star formation, we find the scaling is consistent with all the protostars in an embedded cluster providing the outflow force, with massive stars up to ˜30 M⊙ generating outflows. Taken at face value, the results support the model of a scaled-up version of the accretion-related outflow-generation mechanism associated with discs and jets in low-mass objects with time-averaged accretion rates of ˜10-3 M⊙ yr-1 on to the cores. However, we also suggest an alternative model, in which the molecular outflow dynamics are dominated by the entrained mass and are unrelated to the details of the acceleration mechanism. We find no evidence that outflows contribute significantly to the turbulent kinetic energy of the surrounding dense cores.

  7. Development and Morphology of the Ventricular Outflow Tracts

    PubMed Central

    Mori, Shumpei; Spicer, Diane E.; Brown, Nigel A.; Mohun, Timothy J.

    2016-01-01

    It is customary, at the current time, to consider many, if not most, of the lesions involving the ventricular outflow tract in terms of conotruncal malformations. This reflects the introduction, in the early 1940s, of the terms conus and truncus to describe the components of the developing outflow tract. The definitive outflow tracts in the postnatal heart, however, possess three, rather than two, components. These are the intrapericardial arterial trunks, the arterial roots, and the subvalvar ventricular outflow tracts. Congenital lesions afflicting the arterial roots, however, are not currently considered to be conotruncal malformations. This suggests a lack of logic in the description of cardiac development and its use as a means of categorizing congenital malformations. It is our belief that the developing outflow tract, like the postnatal outflow tracts, can readily be described in tripartite fashion, with its distal, intermediate, and proximal components forming the primordiums of the postnatal parts. In this review, we present evidence obtained from developing mice and human hearts to substantiate this notion. We show that the outflow tract, initially with a common lumen, is divided into its aortic and pulmonary components by a combination of an aortopulmonary septum derived from the dorsal wall of the aortic sac and outflow tract cushions that spiral through its intermediate and proximal components. These embryonic septal structures, however, subsequently lose their septal functions as the outflow tracts develop their own discrete walls. We then compare the developmental findings with the anatomic arrangements seen postnatally in the normal human heart. We show how correlations with the embryologic findings permit logical analysis of the congenital lesions involving the outflow tracts. PMID:27587491

  8. Modeling the Causal Regulation of Transversely Accelerated Ion (TAI) Outflows

    NASA Astrophysics Data System (ADS)

    Varney, R. H.; Wiltberger, M. J.; Zhang, B.; Schmitt, P.; Lotko, W.

    2013-12-01

    TAIs are generated by wave particle interactions driven by waves at temporal and spatial scales which are inaccessible in global coupled geospace models. So far attempts to include TAI outflows in global models have focused on the use of empirical correlations between observed outflow fluxes and various inputs such as DC Poynting flux, Alfvénic Poynting flux, and electron precipitation fluxes. These treatments ignore feedbacks between the outflow and the state of the ionosphere and assume the spatial and temporal distributions of the outflows are identical to those of their drivers. This work presents an alternative approach which can overcome these deficiencies while still being sufficiently computationally efficient to couple into a global modeling framework. TAIs are incorporated into a 3-D fluid model of the ionosphere and polar wind by modeling them as a separate fluid which obeys transport equations appropriate for monoenergetic conic distributions. The characteristics of the TAI outflow produced depend on the assumed transverse heating rates and the 'promotion rate' which connects the TAI fluid to the thermal O+ fluid. Using drivers extracted from runs of the Coupled Magnetosphere Ionosphere Thermosphere (CMIT) model, different strategies for causally regulating these free parameters are explored. The model can reproduce many of the observed features of TAI outflows but also exhibits physical attributes that empirical relationships alone miss. These characteristics include flux limiting of the outflow from below when intense outflow creates high-altitude cavities, time delays between the onset of transverse heating and the appearance of outflow, and spatial distributions of outflow which are different from the spatial distributions of the applied transverse heating and which depend on the ionospheric convection pattern.

  9. Seasonal variability of organic matter composition in an Alaskan glacier outflow: insights into glacier carbon sources

    NASA Astrophysics Data System (ADS)

    Spencer, Robert G. M.; Vermilyea, Andrew; Fellman, Jason; Raymond, Peter; Stubbins, Aron; Scott, Durelle; Hood, Eran

    2014-05-01

    Glacier ecosystems are a significant source of bioavailable, yet ancient dissolved organic carbon (DOC). Characterizing DOC in Mendenhall Glacier outflow (southeast Alaska) we document a seasonal persistence to the radiocarbon-depleted signature of DOC, highlighting ancient DOC as a ubiquitous feature of glacier outflow. We observed no systematic depletion in Δ 14C-DOC with increasing discharge during the melt season that would suggest mobilization of an aged subglacial carbon store. However, DOC concentration, δ 13C-DOC, Δ 14C-DOC and fluorescence signatures appear to have been influenced by runoff from vegetated hillslopes above the glacier during onset and senescence of melt. In the peak glacier melt period, the Δ 14C-DOC of stream samples at the outflow (-181.7 to -355.3‰) was comparable to the Δ 14C-DOC for snow samples from the accumulation zone (-207.2 to -390.9‰), suggesting that ancient DOC from the glacier surface is exported in glacier runoff. The pre-aged DOC in glacier snow and runoff is consistent with contributions from fossil fuel combustion sources similar to those documented previously in ice cores and thus provides evidence for anthropogenic perturbation of the carbon cycle. Overall, our results emphasize the need to further characterize DOC inputs to glacier ecosystems, particularly in light of predicted changes in glacier mass and runoff in the coming century.

  10. Recent Developments in Understanding the Role of Aqueous Humor Outflow in Normal and Primary Open Angle Glaucoma

    PubMed Central

    Hann, Cheryl R.; Fautsch, Michael P.

    2015-01-01

    Primary open angle glaucoma (POAG) is the second leading cause of blindness in the world's rapidly aging population. POAG is characterized by progressive degeneration of neural structures in the posterior segment, often associated with a concomitant elevation of intraocular pressure. Changes in IOP are believed to be caused by a disruption in the normal outflow of aqueous humor. This article reviews recent research associated with normal and POAG aqueous humor outflow. Novel findings elucidating biochemical and pathological changes in the ocular tissues affected in POAG are presented. Stem cell research, identification of lymphatic markers, and increased use of mouse models give researchers exciting new tools to understand aqueous humor outflow, changes associated with POAG and identify underlying causes of the disease. PMID:26236568

  11. Emission line diagnostics for accretion and outflows in young very low-mass stars and brown dwarfs

    NASA Astrophysics Data System (ADS)

    Stelzer, B.; Alcalá, J. M.; Whelan, E.; Scholz, A.

    2014-01-01

    We discuss accretion and outflow properties of three very low-mass young stellar objects based on broad-band mid-resolution X-Shooter/VLT spectra. Our targets (FU Tau A, 2M1207-39, and Par-Lup3-4) have spectral types between M5 and M8, ages between 1Myr and ~ 10Myr, and are known to be accreting from previous studies. The final objective of our project is the determination of mass outflow to accretion rate for objects near or within the substellar regime as a probe for the T Tauri phase of brown dwarfs and the investigation of variability in the accretion and outflow processes.

  12. Increased choroidal mast cells and their degranulation in age-related macular degeneration

    PubMed Central

    Bhutto, Imran A; McLeod, D Scott; Jing, Tian; Sunness, Janet S.; Seddon, Johanna M.; Lutty, Gerard A

    2016-01-01

    Background/Aims Inflammation has been implicated in age-related macular degeneration (AMD). This study investigates the association of mast cells (MCs), a resident choroidal inflammatory cell, with pathological changes in AMD. Methods Human donor eyes included aged controls (n=10), clinically diagnosed with early AMD (n=8), geographic atrophy (GA, n=4), and exudative AMD (n=11). The choroids were excised and incubated alkaline phosphatase (APase; blood vessels) and nonspecific esterase activities (MCs). Degranulated (DG) and nondegranulated (NDG) MCs in four areas of posterior choroid (nasal, nonmacular, paramacular, and submacular) were counted in flat mounts (4∼6 fields/area). Choroids were subsequently embedded in JB-4 and sectioned for histological analyses. Results The number of MCs was significantly increased in all choroidal areas in early AMD (p=0.0006) and in paramacular area in exudative AMD (139.44±55.3 cells/mm2; p=0.0091) and GA (199.08±82.0 cells/mm2; p=0.0019) compared to the aged controls. DG MCs was also increased in paramacular (p=0.001) and submacula choroid (p=0.02) in all forms of AMD. Areas with the greatest numbers of DG MC had loss of choriocapillaris (CC). Sections revealed that the MCs were widely distributed in Sattler's and Haller's layer in the choroidal stroma in aged controls, whereas MCs were frequently found in close proximity to CC in GA and exudative AMD and in choroidal neovascularization (CNV). Conclusion Increased MC numbers and degranulation were observed in all AMD choroids. These results suggest that MC degranulation may contribute to the pathogenesis of AMD: death of CC and RPE and CNV formation. The proteolytic enzymes released from MC granules may result in thinning of AMD choroid. PMID:26931413

  13. Latent outflow activity for western Tharsis, Mars: Significant flood record exposed

    USGS Publications Warehouse

    Dohm, J.M.; Anderson, R.C.; Baker, V.R.; Ferris, J.C.; Rudd, L.P.; Hare, T.M.; Rice, J. W., Jr.; Casavant, R.R.; Strom, R.G.; Zimbelman, J.R.; Scott, D.H.

    2001-01-01

    Observations permitted by the newly acquired Mars Observer Laser Altimeter data have revealed a system of gigantic valleys northwest of the huge Martian shield volcano, Arsia Mons, in the western hemisphere of Mars (northwestern slope valleys (NSVs)). These features, which generally correspond spatially to gravity lows, are obscured by veneers of materials including volcanic lava flows, air fall deposits, and eolian materials. Geologic investigations of the Tharsis region suggest that the system of gigantic valleys predates the construction of Arsia Mons and its extensive associated lava flows of mainly late Hesperian and Amazonian age and coincides stratigraphically with the early development of the outflow channels that debouch into Chryse Planitia. Similar to the previously identified outflow channels, which issued tremendous volumes of water into topographic lows such as Chryse Planitia, the NSVs potentially represent flooding of immense magnitude and, as such, a source of water for a northern plains ocean.

  14. High resolution observations of the L1551 bipolar outflow

    NASA Technical Reports Server (NTRS)

    Snell, R.; Moriarty-Schieven, G.; Strom, S.; Schloerb, P.; Strom, K.; Grasdalen, G.

    1986-01-01

    The nearby dark cloud Lynds 1551 contains one of the closest examples of a well-collimated bipolar molecular outflow. This source has the largest angular size of any known outflow and was the first bipolar outflow to be detected. The outflow originates from a low-luminosity young stellar object, IRS-5. Optical and radio continuum observations show the presence of a highly collimated, ionized stellar wind orginating from close to IRS-5 and aligned with the molecular outflow. However, we have little information on the actual mechanism that generates the stellar wind and collimates it into opposed jets. The Very Large Array (VLA) observations indicate that the winds originate within 10(15) cm of IRS-5, unfortunately at a size scale difficult to resolve. For these reasons, observations of the structure and dynamics of the hypersonic molecular gas may provide valuable information on the origin and evolution of these outflows. In addition, the study of the impact of the outflowing gas on the surrounding molecular material is essential to understand the consequence these outflows have on the evolution and star formation history of the entire cloud. Moriarty-Schieven et al. (1986) obtained a oversampled map of the CO emission of a portion of both the blueshifted and redshifted outflows in LI551 using Five College Radio Astronomy Observatory 14 m telescope. The oversampled maps have been reconstructed to an effective angular resolution of 20 arcsec using a maximum entropy algorithm. A continuation of the study of Moriarty-Schieven et al. is presented. The entire L1551 outflow has now been mapped at 12 arcsec sampling requiring roughly 4000 spectra. This data has been constructed to 20 arcsec resolution to provide the first high resolution picture of the entire L1551 outflow. This new data has shown that the blueshifted lobe is more extended than previously thought and has expanded downstream sufficiently to break out of the dense molecular cloud, but the redshifted outflow

  15. Numerical and Observational Investigations of Long-Lived Mcs-Induced Severe Surface Wind Events: the Derecho

    NASA Astrophysics Data System (ADS)

    Schmidt, Jerome Michael

    This study addresses the production of sustained, straight-line, severe surface winds associated with mesoscale convective systems (MCSs) of extratropical origin otherwise known as derechos. The physical processes which govern the observed derecho characteristics are identified and their possible forcing mechanisms are determined. Detailed observations of two derechos are presented along with simulations using the Colorado State University Regional Atmospheric Modeling System (CSU-RAMS). The observations revealed a derecho environment characterized by strong vertical wind shear through the depth of the troposphere and large values of convective available potential energy (CAPE). The thermodynamic environment of the troposphere in each case had a distinct three-layer structure consisting of: (i) a surface-based stable layer of 1-to-2 km in depth, (ii) an elevated well -mixed layer of 2-4 km in depth, and (iii) an upper tropospheric layer of intermediate stability that extended to the tropopause. Two primary sets of simulations were performed to assess the impact of the observed environmental profiles on the derecho structure, propagation, and longevity. The first set consisted of nested-grid regional-scale simulations initialized from the standard NMC analyses on a domain having relatively coarse horizontal resolution (75 km). The second set of simulations consisted of two and three-dimensional experiments initialized in a horizontally homogeneous environment having a relatively fine horizontal resolution (2 km) and explicit microphysics. The results from these experiments indicate the importance of convectively -induced gravity waves on the MCS structure, propagation, longevity, and severe surface wind development. The sensitivity of the simulated convection and gravity waves to variations in the vertical wind shear and moisture profiles are described. Detailed Doppler radar analyses and 3-D simulations of a severe, bow echo squall line are presented which reveal

  16. The implications of non-linear biological oscillations on human electrophysiology for electrohypersensitivity (EHS) and multiple chemical sensitivity (MCS).

    PubMed

    Sage, Cindy

    2015-01-01

    maintenance; and resilience can be compromised. Electrohypersensitivity can be caused by successive assaults on human bioelectrochemical dynamics from exogenous electromagnetic fields (EMF) and RFR or a single acute exposure. Once sensitized, further exposures are widely reported to cause reactivity to lower and lower intensities of EMF/RFR, at which point thousand-fold lower levels can cause adverse health impacts to the electrosensitive person. Electrohypersensitivity (EHS) can be a precursor to, or linked with, multiple chemical sensitivity (MCS) based on reports of individuals who first develop one condition, then rapidly develop the other. Similarity of chemical biomarkers is seen in both conditions [histamines, markers of oxidative stress, auto-antibodies, heat shock protein (HSP), melatonin markers and leakage of the blood-brain barrier]. Low intensity pulsed microwave activation of voltage-gated calcium channels (VGCCs) is postulated as a mechanism of action for non-thermal health effects. PMID:26368042

  17. The contribution of quasar outflows to cosmological structure formation

    NASA Astrophysics Data System (ADS)

    Arav, Nahum

    2011-10-01

    A vast new discovery space is opened up by the high sensitivity of COS in the far UV. These new capabilities are ushering a revolution in the study of AGN outflows. We now have the ability to obtain high quality data on objects up to a redshift of about 1, providing access to ten times more {and better} diagnostic absorption lines than was possible with STIS {which could only observe outflows at z<0.05 with sufficient S/N}. These diagnostics will allow us to quantify how much do quasar outflow contribute to AGN feedback. On the way to this lofty goal, we'll be able to resolve important questions in the study of these outflows: Where are they situated within the host galaxy? What is their ionization equilibrium and chemical abundances? Unlike ground-based observations, COS data can yield the answers to all these questions for the most ubiquitous outflows, and therefore connect them to our developing understanding of cosmological structure formation.Our analysis of recent archived COS observations gives a concrete example for the above claims; including the first determination of the distance from the central source for a high-ionization outflow. Here we propose an archive program to look through the 520 COS G130M and G160M orbits of AGN archive observations, identify quasar outflows and publish the analyses of the best cases.

  18. PROTOSTELLAR OUTFLOWS AND RADIATIVE FEEDBACK FROM MASSIVE STARS

    SciTech Connect

    Kuiper, Rolf; Yorke, Harold W.; Turner, Neal J. E-mail: Harold.W.Yorke@jpl.nasa.gov

    2015-02-20

    We carry out radiation hydrodynamical simulations of the formation of massive stars in the super-Eddington regime including both their radiative feedback and protostellar outflows. The calculations start from a prestellar core of dusty gas and continue until the star stops growing. The accretion ends when the remnants of the core are ejected, mostly by the force of the direct stellar radiation in the polar direction and elsewhere by the reradiated thermal infrared radiation. How long the accretion persists depends on whether the protostellar outflows are present. We set the mass outflow rate to 1% of the stellar sink particle's accretion rate. The outflows open a bipolar cavity extending to the core's outer edge, through which the thermal radiation readily escapes. The radiative flux is funneled into the polar directions while the core's collapse proceeds near the equator. The outflow thus extends the ''flashlight effect'', or anisotropic radiation field, found in previous studies from the few hundred AU scale of the circumstellar disk up to the 0.1 parsec scale of the core. The core's flashlight effect allows core gas to accrete on the disk for longer, in the same way that the disk's flashlight effect allows disk gas to accrete on the star for longer. Thus although the protostellar outflows remove material near the core's poles, causing slower stellar growth over the first few free-fall times, they also enable accretion to go on longer in our calculations. The outflows ultimately lead to stars of somewhat higher mass.

  19. Simulation of California's Major Reservoirs Outflow Using Data Mining Technique

    NASA Astrophysics Data System (ADS)

    Yang, T.; Gao, X.; Sorooshian, S.

    2014-12-01

    The reservoir's outflow is controlled by reservoir operators, which is different from the upstream inflow. The outflow is more important than the reservoir's inflow for the downstream water users. In order to simulate the complicated reservoir operation and extract the outflow decision making patterns for California's 12 major reservoirs, we build a data-driven, computer-based ("artificial intelligent") reservoir decision making tool, using decision regression and classification tree approach. This is a well-developed statistical and graphical modeling methodology in the field of data mining. A shuffled cross validation approach is also employed to extract the outflow decision making patterns and rules based on the selected decision variables (inflow amount, precipitation, timing, water type year etc.). To show the accuracy of the model, a verification study is carried out comparing the model-generated outflow decisions ("artificial intelligent" decisions) with that made by reservoir operators (human decisions). The simulation results show that the machine-generated outflow decisions are very similar to the real reservoir operators' decisions. This conclusion is based on statistical evaluations using the Nash-Sutcliffe test. The proposed model is able to detect the most influential variables and their weights when the reservoir operators make an outflow decision. While the proposed approach was firstly applied and tested on California's 12 major reservoirs, the method is universally adaptable to other reservoir systems.

  20. Outflow and hot dust emission in broad absorption line quasars

    SciTech Connect

    Zhang, Shaohua; Zhou, Hongyan; Wang, Huiyuan; Wang, Tinggui; Xing, Feijun; Jiang, Peng; Zhang, Kai E-mail: whywang@mail.ustc.edu.cn

    2014-05-01

    We have investigated a sample of 2099 broad absorption line (BAL) quasars with z = 1.7-2.2 built from the Sloan Digital Sky Survey Data Release Seven and the Wide-field Infrared Survey. This sample is collected from two BAL quasar samples in the literature and is refined by our new algorithm. Correlations of outflow velocity and strength with a hot dust indicator (β{sub NIR}) and other quasar physical parameters—such as an Eddington ratio, luminosity, and a UV continuum slope—are explored in order to figure out which parameters drive outflows. Here β{sub NIR} is the near-infrared continuum slope, which is a good indicator of the amount of hot dust emission relative to the accretion disk emission. We confirm previous findings that outflow properties moderately or weakly depend on the Eddington ratio, UV slope, and luminosity. For the first time, we report moderate and significant correlations of outflow strength and velocity with β{sub NIR} in BAL quasars. It is consistent with the behavior of blueshifted broad emission lines in non-BAL quasars. The statistical analysis and composite spectra study both reveal that outflow strength and velocity are more strongly correlated with β{sub NIR} than the Eddington ratio, luminosity, and UV slope. In particular, the composites show that the entire C IV absorption profile shifts blueward and broadens as β{sub NIR} increases, while the Eddington ratio and UV slope only affect the high and low velocity part of outflows, respectively. We discuss several potential processes and suggest that the dusty outflow scenario, i.e., that dust is intrinsic to outflows and may contribute to the outflow acceleration, is most likely.

  1. Contribution of alluvial groundwater to the outflow of mountainous catchments

    NASA Astrophysics Data System (ADS)

    Käser, Daniel; Hunkeler, Daniel

    2016-02-01

    Alluvial aquifers in mountainous regions cover typically a limited area. Their contribution to catchment storage and outflow is rarely isolated; alluvial groundwater discharge under gauging stations is generally assumed negligible; and hydrological models tend to lump alluvial storage with other units. The role of alluvial aquifers remains therefore unclear: can they contribute significantly to outflow when they cover a few percent of catchment area? Should they be considered a dynamic storage unit or merely a transmission zone? We address these issues based on the continuous monitoring of groundwater discharge, river discharge (one year), and aquifer storage (6 months) in the 6 km2 alluvial system of a 194 km2 catchment. River and groundwater outflow were measured jointly through "coupled gauging stations." The contribution of alluvial groundwater to outflow was highest at the outlet of a subcatchment (52 km2), where subsurface discharge amounted to 15% of mean annual outflow, and 85% of outflow during the last week of a drought. In this period, alluvial-aquifer depletion supported 75% of the subcatchment outflow and 35% of catchment outflow—thus 3% of the entire catchment supported a third of the outflow. Storage fluctuations occurred predominantly in the aquifer's upstream part, where heads varied over 6 m. Not only does this section act as a significant water source, but storage recovers also rapidly at the onset of precipitation. Storage dynamics were best conceptualized along the valley axis, rather than across the more conventional riparian-channel transect. Overall the contribution of alluvial aquifers to catchment outflow deserves more attention.

  2. A Study of PG Quasar-Driven Outflows with COS

    NASA Astrophysics Data System (ADS)

    Hamann, Frederick

    2013-10-01

    Quasar outflows are an important part of the quasar phenomenon, but many questions remain about their energetics, physical properties and the role they might play in providing feedback to host galaxy evolution. We searched our own COS far-UV observations from the QUEST survey and other large COS programs to find a sample of 6 bright PG quasars with broad {FWHM > 400 km/s} high velocity {v > 1000 km/s} absorption lines that clearly form in quasar-driven winds. These quasars can fill an important gap in our understanding between local Seyferts with low-speed winds and high-redshift quasars with extreme BAL outflows. They are also well-studied at other wavelengths, with some evidence for the quasars driving galaxy-scale blowouts and shutting down star formation. But almost nothing is known about the quasar outflows themselves. We propose a detailed study of these 6 outflow quasars using new COS FUV observations to 1} expand the existing wavelength coverage across critical lines that are diagnostic of the outflow physical conditions, kinetic energies, and metallicities, and 2} check for line variability as an indicator of the outflow structure and locations. This quasar sample includes unusual cases with many low-abundance {PV 1118,1128 and SIV 1063} and excited-state lines {SIV 1073*, CIII* 1175, CII* 1335} that will provide unprecedented constraints on the outflow properties, plus the first known OVI-only mini-BAL outflow {no lower ions detected} for which we will cover NeVIII 770,780 to probe the highest ionization gas. The high FUV sensitivity of COS is uniquely able to measure this wide range of outflow lines in low-redshift quasars with no Lya forest contamination.

  3. A Doppler dimming determination of coronal outflow velocity

    NASA Technical Reports Server (NTRS)

    Strachan, Leonard; Kohl, John L.; Weiser, Heinz; Withbroe, George L.; Munro, Richard H.

    1993-01-01

    Outflow velocities in a polar coronal hole are derived from observations made during a 1982 sounding rocket flight. The velocity results are derived from a Doppler dimming analysis of resonantly scattered H I Ly-alpha. This analysis indicates radial outflow velocities of 217 km/s at 2 solar radii from sun-center with an uncertainty range of 153 to 251 km/s at a confidence level of 67 percent. These results are best characterized as strong evidence for supersonic outflow within 2 solar radii of sun-center in a polar coronal hole. Several means for obtaining improved accuracy in future observations are discussed.

  4. Magnified Views of Relativistic Outflows in Gravitationally Lensed Quasars

    NASA Astrophysics Data System (ADS)

    Chartas, G.; Cappi, M.; Hamann, F.; Eracleous, M.; Strickland, S.; Vignali, C.; Dadina, M.; Giustini, M.; Saez, C.; Misawa, T.

    2016-06-01

    We presents results from X-ray observations of relativistic outflows in lensed quasars. The lensing magnification of the observed objects provides high signal-to-noise X-ray spectra of quasars showing the absorption signatures of relativistic outflows at redshifts near a crucial phase of black hole growth and the peak of cosmic AGN activity. We summarise the properties of the wide-angle relativistic outflow of the z = 1.51 NAL quasar HS 0810 detected in recent deep XMM-Newton and Chandra observations of this object. We also present preliminary results from a mini-survey of gravitationally lensed mini-BAL quasars performed with XMM-Newton.

  5. Accretion driven outflows across the black hole mass scale

    NASA Astrophysics Data System (ADS)

    King, Ashley L.

    2016-04-01

    Pumping highly relativistic particles and radiation into their environment, accreting black holes co-evolve with their surroundings through their powerful outflows. These outflows are divided into highly collimated, relativistic jets and wide-angle winds, and are primarily associated with a particular accretion states. Understanding just how these outflows couple to the accretion flow will enable us to assess the amount of energy and feedback that is injected into the vicinity of a black hole. During this talk, I will discuss our studies of both stellar-mass and supermassive black hole outlfows, and how the similarities of these flows across the mass scale may point to common driving mechanisms.

  6. The Outflow Pathway: A Tissue With Morphological and Functional Unity.

    PubMed

    Saccà, Sergio Claudio; Gandolfi, Stefano; Bagnis, Alessandro; Manni, Gianluca; Damonte, Gianluca; Traverso, Carlo Enrico; Izzotti, Alberto

    2016-09-01

    The trabecular meshwork (TM) plays an important role in high-tension glaucomas. Indeed, the TM is a true organ, through which the aqueous humor flows from the anterior chamber to Schlemm's canal (SC). Until recently, the TM, which is constituted by endothelial-like cells, was described as a kind of passive filter. In reality, it is much more. The cells delineating the structures of the collagen framework of the TM are endowed with a cytoskeleton, and are thus able to change their shape. These cells also have the ability to secrete the extracellular matrix, which expresses proteins and cytokines, and are capable of phagocytosis and autophagy. The cytoskeleton is attached to the nuclear membrane and can, in millionths of a second, send signals to the nucleus in order to alter the expression of genes in an attempt to adapt to biomechanical insult. Oxidative stress, as happens in aging, has a deleterious effect on the TM, leading eventually to cell decay, tissue malfunction, subclinical inflammation, changes in the extracellular matrix and cytoskeleton, altered motility, reduced outflow facility, and (ultimately) increased IOP. TM failure is the most relevant factor in the cascade of events triggering apoptosis in the inner retinal layers, including ganglion cells. J. Cell. Physiol. 231: 1876-1893, 2016. © 2016 Wiley Periodicals, Inc. PMID:26754581

  7. HOT ELECTROMAGNETIC OUTFLOWS. II. JET BREAKOUT

    SciTech Connect

    Russo, Matthew; Thompson, Christopher

    2013-08-20

    We consider the interaction between radiation, matter, and a magnetic field in a compact, relativistic jet. The entrained matter accelerates outward as the jet breaks out of a star or other confining medium. In some circumstances, such as gamma-ray bursts (GRBs), the magnetization of the jet is greatly reduced by an advected radiation field while the jet is optically thick to scattering. Where magnetic flux surfaces diverge rapidly, a strong outward Lorentz force develops and radiation and matter begin to decouple. The increase in magnetization is coupled to a rapid growth in Lorentz factor. We take two approaches to this problem. The first examines the flow outside the fast magnetosonic critical surface, and calculates the flow speed and the angular distribution of the radiation field over a range of scattering depths. The second considers the flow structure on both sides of the critical surface in the optically thin regime, using a relaxation method. In both approaches, we find how the terminal Lorentz factor and radial profile of the outflow depend on the radiation intensity and optical depth at breakout. The effect of bulk Compton scattering on the radiation spectrum is calculated by a Monte Carlo method, while neglecting the effects of internal dissipation. The peak of the scattered spectrum sits near the seed peak if radiation pressure dominates the acceleration, but is pushed to a higher frequency if the Lorentz force dominates. The unscattered seed radiation can form a distinct, low-frequency component of the spectrum, especially if the magnetic Poynting flux dominates.

  8. Hydrothermal outflow plume of Valles caldera, New Mexico, and a comparison with other outflow plumes

    SciTech Connect

    Goff, F.; Shevenell, L.; Gardner, J.N.; Vuataz, F.; Grigsby, C.O.

    1988-06-10

    Stratigraphic, temperature gradient, hydrogeochemical, and hydrologic data have been integrated with geologic data from previous studies to show the structural configuration of the Valles caldera hydrothermal outflow plume. Hydrologic data suggest that 25--50% of the discharge of the Valles outflow is confined to the Jemez fault zone, which predates caldera formation. Thermal gradient data from bores penetrating the plume show that shallow gradients are highest in the vicinity of the Jemez fault zone (up to 190 /sup 0/C/km). Shallow heat flow above the hydrothermal plume is as high as 500 mW m/sup -2/ near core hole VC-1 (Jemez fault zone) to 200 mW m/sup -2/ at Fenton Hill (Jemez Plateau). Chemical and isotopic data indicate that two source reservoirs within the caldera (Redondo Creek and Sulphur Springs reservoirs) are parents to mixed fluids flowing in the hydrothermal plume. However, isotopic data, borehole data, basic geology, and inverse relations between temperature and chloride content at major hot springs indicate that no single reservoir fluid and no single diluting fluid are involved in mixing. The Valles caldera hydrothermal plume is structurally dominated by lateral flow through a belt of vertical conduits (Jemez fault zone) that strike away from the source reservoir. Stratigraphically confined flow is present but dispersed over a wide area in relatively impermeable rocks. The Valles configuration is contrasted with the configuration of the hydrothermal plume at Roosevelt Hot Springs, which is dominated by lateral flow through a near-surface, widespread, permeable aquifer. Data from 12 other representative geothermal systems show that outflow plumes occur in a variety of magmatic and tectonic settings, have varying reservoir compositions, and have different flow characteristics.

  9. Indirect measurement of Delta outflow using ultrasonic velocity meters and comparison with mass-balance calculated outflow

    USGS Publications Warehouse

    Oltmann, Richard N.

    1998-01-01

    A measurement of the quantity of water flowing from the Sacramento-San Joaquin Delta into Suisun Bay (Delta outflow) has been desired by those studying and managing the San Francisco Bay/Delta estuary since the 1920s.  Historically, Delta outflow has been estimated using a mass-balance calculation that uses measured Delta inflows and exports, and imprecise estimates of consumptive use for the approximately 2,000 small agricultural diversions with the Delta.  The DWR has estimated Delta outflow for 1929 to present using the computer program DAYFLOW.

  10. OBSERVATIONS OF MOLECULAR OUTFLOW IN CAR 291.6-01.9

    SciTech Connect

    Saul, M.; Saul, L. E-mail: luke.saul@space.unibe.ch

    2012-01-20

    We report the first observations of a dense molecular gas nebula and bipolar outflow in Car 291.6-01.9, showing characteristics of an embedded young stellar object (YSO). Using the Mopra radio telescope near Coonabarabaran, Australia, we image the kinematic structure of several emission features to examine physical properties within a molecular clump of mass {approx}3.2 {+-} 0.6 Multiplication-Sign 10{sup 3} M{sub Sun} in which a stellar cluster may be forming. Motivated by acquiring a more thorough understanding of star formation we ask what may have initiated collapse in the clump; observed outflow alignment is suggestive of {approx}1.0 pc distant massive star HD 308280 radiative-driven compression as a formation trigger for the dense core. An outflow derived age of <10{sup 6} years, together with significant C{sup 18}O and SO core depletion, support the case for the core as the host of an extremely YSO cluster.

  11. Constraining Engine Paradigms of Pre-Planetary Nebulae Using Kinematic Properties of their Outflows

    NASA Astrophysics Data System (ADS)

    Blackman, E.

    2014-04-01

    Binary interactions and accretion plausibly conspire to produce the ubiquitous collimated outflows from planetary nebulae (PN) and their presumed pre-planetary nebulae (PPN) progenitors. But which accretion engines are viable? The difficulty in observationally resolving the engines warrants indirect constraints. I discuss how momentum outflow data for PPN can be used to determine the minimum required accretion rate for presumed main sequence (MS) or white dwarf (WD) accretors by comparing to several example accretion rates inferred from published models. While the main goal is to show the method in anticipation of more data and better theoretical constraints, taking the present results at face value already rule out modes of accretion: Bondi-Hoyle Lyttleton (BHL) wind accretion and wind Roche lobe overflow (M-WRLOF, based on Mira parameters) are too feeble for all 19/19 objects for a MS accretor. For a WD accretor, BHL is ruled out for 18/19 objects and M-WRLOF for 15/19 objects. Roche lobe overflow from the primary can accommodate 7/19 objects but only common envelope evolution accretion modes seem to be able to accommodate all 19 objects. Sub-Eddington rates for a MS accretor are acceptable but 8/19 would require super-Eddington rates for a WD. I also briefly discuss a possible anti-correlation between age and maximum observed outflow speed, and the role of magnetic fields.

  12. Detection of an Extended Outflow in NGC 4102

    NASA Astrophysics Data System (ADS)

    Trent Braun, Timothy; van Zee, Liese; Richards, Emily E.; McQuinn, Kristen B.; Skillman, Evan D.; Edges

    2015-01-01

    We report the detection of an extended galactic outflow in narrowband H alpha imaging of NGC 4102, a nearby spiral galaxy that hosts a low ionization nuclear emission region (LINER) and a circumnuclear H II region. NGC 4102 is a moderate luminosity galaxy, M_B = -19.3, in the Ursa Major Cluster. The outflow protrudes out to 60' (5 kpc at an adopted distance of 17.4 Mpc) to the northwest of the galactic center and may extend as much as 75' (6.3 kpc.) Follow-up integral field spectroscopic observations reveal split line profiles over the outflow region, indicative of both blue and red shifted emission-line components. Based on [N II] / H alpha and [S II] flux ratios of this region, the line emission appears to be nonthermal. We discuss possible origins of the outflow, including both nuclear and/or starburst activity.

  13. Morphology of Fresh Outflow Channel Deposits on Mars

    NASA Astrophysics Data System (ADS)

    Rice, J. W., Jr.; Parker, T. J.; Russell, A. J.; Knudsen, O.

    2002-03-01

    We interpret the channel surface of Athabasca and Marte Valles to be fresh former ice-rich fluvial (hyperconcentrated) deposits rather than volcanic flows. Simply stated, this is what a fresh outflow channel deposit would look like.

  14. 56. LOOKING WEST AT CONCRETE TUNNEL DIVERING LOG POND OUTFLOW ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    56. LOOKING WEST AT CONCRETE TUNNEL DIVERING LOG POND OUTFLOW AWAY FROM SAWMILL SUPPORTS. PHOTOGRAPHER: UNKNOWN. DATE: 1954. COURTESY OF RALPH HULL. - Hull-Oakes Lumber Company, 23837 Dawson Road, Monroe, Benton County, OR

  15. MISALIGNMENT OF MAGNETIC FIELDS AND OUTFLOWS IN PROTOSTELLAR CORES

    SciTech Connect

    Hull, Charles L. H.; Plambeck, Richard L.; Bower, Geoffrey C.; Heiles, Carl; Meredith Hughes, A.; Bolatto, Alberto D.; Jameson, Katherine; Mundy, Lee; Pound, Marc W.; Carpenter, John M.; Lamb, James W.; Pillai, Thushara; Crutcher, Richard M.; Hakobian, Nicholas S.; Kwon, Woojin; Looney, Leslie W.; Fiege, Jason D.; Franzmann, Erica; Houde, Martin; Matthews, Brenda C.; and others

    2013-05-10

    We present results of {lambda}1.3 mm dust-polarization observations toward 16 nearby, low-mass protostars, mapped with {approx}2.''5 resolution at CARMA. The results show that magnetic fields in protostellar cores on scales of {approx}1000 AU are not tightly aligned with outflows from the protostars. Rather, the data are consistent with scenarios where outflows and magnetic fields are preferentially misaligned (perpendicular), or where they are randomly aligned. If one assumes that outflows emerge along the rotation axes of circumstellar disks, and that the outflows have not disrupted the fields in the surrounding material, then our results imply that the disks are not aligned with the fields in the cores from which they formed.

  16. Mechanism, diagnosis, and treatment of outflow tract tachycardia.

    PubMed

    Lerman, Bruce B

    2015-10-01

    Idiopathic ventricular arrhythmia is a generic term for a spectrum of arrhythmias that occur in the absence of structural heart disease or ion channelopathy. These arrhythmias include monomorphic premature ventricular contractions (PVCs), nonsustained monomorphic ventricular tachycardia (VT), and sustained VT. Most idiopathic ventricular arrhythmias originate from the right and left ventricular outflow tracts and include sites accessed from the aortic sinuses of Valsalva. Outflow tract arrhythmia is identified by an electrocardiographic pattern consistent with a left bundle branch block inferior axis morphology. Characteristically, outflow tract VT is caused by cAMP-mediated triggered activity, and is terminated by administration of adenosine. Outflow tract arrhythmias are focal and, therefore, are readily amenable to definitive treatment with catheter-based radiofrequency ablation. Although arrhythmia might be associated with reversible PVC-mediated cardiomyopathy, and infrequently with PVC-induced polymorphic VT or ventricular fibrillation, prognosis is generally favourable. PMID:26283265

  17. Stormtime Ionospheric Outflow Effects in Global Multi-Fluid MHD

    NASA Astrophysics Data System (ADS)

    Garcia-Sage, K.; Moore, T. E.; Eccles, V.; Merkin, V. G.; Welling, D. T.; Schunk, R. W.; Barakat, A. R.

    2015-12-01

    We present work detailing the effects of ionospheric outflow in the magnetosphere during the Sept 27- Oct 4, 2002 and Oct 22- Oct 29, 2002 GEM storms. The Multi-Fluid LFM global MHD code is driven by OMNI solar wind and IMF data and by outflow from the Generalized Polar Wind (GPW) model. The GPW input results in a realistic and dynamic, although not self-consistent, outflow of O+, H+, and He+ from the ionosphere. The validity of this outflow and its entry into the magnetosphere is tested through comparisons to Cluster and geosynchronous spacecraft observations. We show the access of these various populations to the magnetosphere, and we examine their effects on plasma sheet structure and storm time dynamics.

  18. RECONNECTION OUTFLOW GENERATED TURBULENCE IN THE SOLAR WIND

    SciTech Connect

    Vörös, Z.; Sasunov, Y. L.; Zaqarashvili, T. V.; Khodachenko, M.; Semenov, V. S.; Bruno, R.

    2014-12-10

    Petschek-type time-dependent reconnection (TDR) and quasi-stationary reconnection (QSR) models are considered to understand reconnection outflow structures and the generation of local turbulence in the solar wind. Comparing TDR/QSR model predictions of the outflow structures with actual measurements shows that both models can explain the data equally well. It is demonstrated that the outflows can often generate more or less spatially extended turbulent boundary layers. The structure of a unique extended reconnection outflow is investigated in detail. The analysis of spectral scalings and spectral break locations shows that reconnection can change the local field and plasma conditions which may support different local turbulent dissipation mechanisms at their characteristic wavenumbers.

  19. HH 666: different kinematics from H α and [Fe II] emission provide a missing link between jets and outflows

    NASA Astrophysics Data System (ADS)

    Reiter, Megan; Smith, Nathan; Kiminki, Megan M.; Bally, John

    2015-06-01

    HH 666 is an externally irradiated protostellar outflow in the Carina nebula for which we present new near-IR [Fe II] spectra obtained with the Folded-Port Infrared Echellette spectrograph at Magellan Observatory. Earlier H α and near-IR [Fe II] imaging revealed that the two emission lines trace substantially different morphologies in the inner ˜40 arcsec of the outflow. H α traces a broad cocoon that surrounds the collimated [Fe II] jet that extends throughout the parent dust pillar. New spectra show that this discrepancy extends to their kinematics. Near-IR [Fe II] emission traces steady, fast velocities of ±200 km s-1 from the eastern and western limbs of the jet. We compare this to a previously published H α spectrum that reveals a Hubble-flow velocity structure near the jet-driving source. New, second-epoch Hubble Space Telescope (HST)/Advanced Camera for Surveys (ACS) H α images reveal the lateral spreading of the H α outflow lobe away from the jet axis. H α proper motions also indicate a sudden increase in the mass-loss rate ˜1000 yr ago, while steady [Fe II] emission throughout the inner jet suggest that the burst is ongoing. An accretion burst sustained for ˜1000 yr is an order of magnitude longer than expected for FU Orionis outbursts, but represents only a small fraction of the total age of the HH 666 outflow. Altogether, available data suggests that [Fe II] traces the highly collimated protostellar jet while H α traces the entrained and irradiated outflow. HH 666 appears to be a missing link between bare jets seen in H II regions and entrained molecular outflows seen from embedded protostars in more quiescent regions.

  20. Toward a Prescription for Feedback from Quasar Outflows

    NASA Astrophysics Data System (ADS)

    Ganguly, Rajib; Bourjaily, M.; Munsell, J.; Brotherton, M. S.; Bhattacharjee, A.; Runnoe, J.; Charlton, J. C.; Eracleous, M.

    2011-01-01

    Models have shown that quasars are a crucial ingredient in the evolution of massive galaxies. Outflows play a key role in the story of quasars and their host galaxies, by helping regulate the accretion process, the star-formation rate and mass of the host galaxy (i.e., feedback). The prescription for modeling outflows as a contributor to feedback requires knowledge of the outflow velocity, distance, geometry, and column density. In particular, we need to understand how these depend on physical parameters and how much is determined stochastically (and with what distribution). For this purpose, we are examining a sample of 14000 z=1.7-2.0 quasars from the Sloan Digital Sky Survey. This redshift range permits the following from the SDSS spectra: (1) separation of objects that do and do not exhibit outflows; (2) classification/measurement of outflow properties (ionization, velocity, velocity width); and (3) estimates of the quasar black hole mass. To this, we are adding photometry from GALEX, 2MASS, and ROSAT in an effort to characterize more fully the quasar SEDs. ROSAT photometry provides estimates of the level of soft X-ray absorption, which helps regulate the velocity of outflows. GALEX photometry samples the extreme ultraviolet range where several high ionization species, that may be present in the outflows, absorb light. 2MASS photometry samples the rest-frame optical, where the effects of absorption and dust reddening are minimal, yield better estimates of the bolometric luminosity (hence, Eddington ratio). In this poster, we will present preliminary measurements of the amount of absorption in the soft X-ray and extreme ultraviolet bands as a function of both outflow properties and quasar physical properties. This material is based upon work supported by the National Aeronautics and Space Administration under Grant No. 09-ADP09-0016 issued through the Astrophysics Data Analysis Program.

  1. Identifying the Main Driver of Active Region Outflows

    NASA Astrophysics Data System (ADS)

    Baker, D.; van Driel-Gesztelyi, L.; Mandrini, C. H.; Démoulin, P.; Murray, M. J.

    2012-08-01

    Hinode's EUV Imaging Spectrometer (EIS) has discovered ubiquitous outflows of a few to 50 km s-1 from active regions (ARs). The characteristics of these outflows are very curious in that they are most prominent at the AR boundary and appear over monopolar magnetic areas. They are linked to strong non-thermal line broadening and are stronger in hotter EUV lines. The outflows persist for at least several days. Whereas red-shifted down flows observed in AR closed loops are well understood, to date there is no general consensus for the mechanism(s) driving blue-shifted AR-related outflows. We use Hinode EIS and X-Ray Telescope observations of AR 10942 coupled with magnetic modeling to demonstrate for the first time that the outflows originate from specific locations of the magnetic topology where field lines display strong gradients of magnetic connectivity, namely quasi-separatrix layers (QSLs), or in the limit of infinitely thin QSLs, separatrices. The strongest AR outflows were found to be in the vicinity of QSL sections located over areas of strong magnetic field. We argue that magnetic reconnection at QSLs, separating closed field lines of the AR and either large-scale externally connected or ‘open’ field lines, is a viable mechanism for driving AR outflows which are potentially sources of the slow solar wind. In fact, magnetic reconnection along QSLs (including separatricies) is the first theory to explain the most puzzling characteristics of the outflows, namely their occurrence over monopolar areas at the periphery of ARs and their longevity.

  2. Physical Factors Affecting Outflow Facility Measurements in Mice

    PubMed Central

    Boussommier-Calleja, Alexandra; Li, Guorong; Wilson, Amanda; Ziskind, Tal; Scinteie, Oana Elena; Ashpole, Nicole E.; Sherwood, Joseph M.; Farsiu, Sina; Challa, Pratap; Gonzalez, Pedro; Downs, J. Crawford; Ethier, C. Ross; Stamer, W. Daniel; Overby, Darryl R.

    2015-01-01

    Purpose Mice are commonly used to study conventional outflow physiology. This study examined how physical factors (hydration, temperature, and anterior chamber [AC] deepening) influence ocular perfusion measurements in mice. Methods Outflow facility (C) and pressure-independent outflow (Fu) were assessed by multilevel constant pressure perfusion of enucleated eyes from C57BL/6 mice. To examine the effect of hydration, seven eyes were perfused at room temperature, either immersed to the limbus in saline and covered with wet tissue paper or exposed to room air. Temperature effects were examined in 12 eyes immersed in saline at 20°C or 35°C. Anterior chamber deepening was examined in 10 eyes with the cannula tip placed in the anterior versus posterior chamber (PC). Posterior bowing of the iris (AC deepening) was visualized by three-dimensional histology in perfusion-fixed C57BL/6 eyes and by spectral-domain optical coherence tomography in living CD1 mice. Results Exposure to room air did not significantly affect C, but led to a nonzero Fu that was significantly reduced upon immersion in saline. Increasing temperature from 20°C to 35°C increased C by 2.5-fold, more than could be explained by viscosity changes alone (1.4-fold). Perfusion via the AC, but not the PC, led to posterior iris bowing and increased outflow. Conclusions Insufficient hydration contributes to the appearance of pressure-independent outflow in enucleated mouse eyes. Despite the large lens, AC deepening may artifactually increase outflow in mice. Temperature-dependent metabolic processes appear to influence conventional outflow regulation. Physical factors should be carefully controlled in any outflow studies involving mice. PMID:26720486

  3. Ultra-fast outflows (aka UFOs) from AGNs and QSOs

    NASA Astrophysics Data System (ADS)

    Cappi, M.; Tombesi, F.; Giustini, M.

    During the last decade, strong observational evidence has been accumulated for the existence of massive, high velocity winds/outflows (aka Ultra Fast Outflows, UFOs) in nearby AGNs and in more distant quasars. Here we briefly review some of the most recent developments in this field and discuss the relevance of UFOs for both understanding the physics of accretion disk winds in AGNs, and for quantifying the global amount of AGN feedback on the surrounding medium.

  4. Characterization of Molecular Outflows in the Substellar Domain

    NASA Astrophysics Data System (ADS)

    Phan-Bao, Ngoc; Lee, Chin-Fei; Ho, Paul T. P.; Dang-Duc, Cuong; Li, Di

    2014-11-01

    We report here our latest search for molecular outflows from young brown dwarfs and very low-mass stars in nearby star-forming regions. We have observed three sources in Taurus with the Submillimeter Array and the Combined Array for Research in Millimeter-wave Astronomy at 230 GHz frequency to search for CO J = 2 → 1 outflows. We obtain a tentative detection of a redshifted and extended gas lobe at about 10 arcsec from the source GM Tau, a young brown dwarf in Taurus with an estimated mass of 73 M J , which is right below the hydrogen-burning limit. No blueshifted emission around the brown dwarf position is detected. The redshifted gas lobe that is elongated in the northeast direction suggests a possible bipolar outflow from the source with a position angle of about 36°. Assuming that the redshifted emission is outflow emission from GM Tau, we then estimate a molecular outflow mass in the range from 1.9 × 10-6 M ⊙ to 2.9 × 10-5 M ⊙ and an outflow mass-loss rate from 2.7 × 10-9 M ⊙ yr-1 to 4.1 × 10-8 M ⊙ yr-1. These values are comparable to those we have observed in the young brown dwarf ISO-Oph 102 of 60 M J in ρ Ophiuchi and the very low-mass star MHO 5 of 90 M J in Taurus. Our results suggest that the outflow process in very low-mass objects is episodic with a duration of a few thousand years and the outflow rate of active episodes does not significantly change for different stages of the formation process of very low-mass objects. This may provide us with important implications that clarify the formation process of brown dwarfs.

  5. Characterization of molecular outflows in the substellar domain

    SciTech Connect

    Phan-Bao, Ngoc; Dang-Duc, Cuong; Lee, Chin-Fei; Ho, Paul T. P.; Li, Di E-mail: pbngoc@asiaa.sinica.edu.tw

    2014-11-01

    We report here our latest search for molecular outflows from young brown dwarfs and very low-mass stars in nearby star-forming regions. We have observed three sources in Taurus with the Submillimeter Array and the Combined Array for Research in Millimeter-wave Astronomy at 230 GHz frequency to search for CO J = 2 → 1 outflows. We obtain a tentative detection of a redshifted and extended gas lobe at about 10 arcsec from the source GM Tau, a young brown dwarf in Taurus with an estimated mass of 73 M {sub J}, which is right below the hydrogen-burning limit. No blueshifted emission around the brown dwarf position is detected. The redshifted gas lobe that is elongated in the northeast direction suggests a possible bipolar outflow from the source with a position angle of about 36°. Assuming that the redshifted emission is outflow emission from GM Tau, we then estimate a molecular outflow mass in the range from 1.9 × 10{sup –6} M {sub ☉} to 2.9 × 10{sup –5} M {sub ☉} and an outflow mass-loss rate from 2.7 × 10{sup –9} M {sub ☉} yr{sup –1} to 4.1 × 10{sup –8} M {sub ☉} yr{sup –1}. These values are comparable to those we have observed in the young brown dwarf ISO-Oph 102 of 60 M {sub J} in ρ Ophiuchi and the very low-mass star MHO 5 of 90 M {sub J} in Taurus. Our results suggest that the outflow process in very low-mass objects is episodic with a duration of a few thousand years and the outflow rate of active episodes does not significantly change for different stages of the formation process of very low-mass objects. This may provide us with important implications that clarify the formation process of brown dwarfs.

  6. Prospective randomised comparison of the COBE spectra version 6 and haemonetics MCS(+) cell separators for hematopoietic progenitor cells leucapheresis in patients with multiple myeloma.

    PubMed

    Abdelkefi, A; Maamar, M; Torjman, L; Ladeb, S; Lakhal, A; Ben Othman, T; Slama, H; Jenhani, F; Mojaat, N; Ben Hamed, L; Bouhoula, S; Hsairi, M; Boukef, K; Ben Abdeladhim, A

    2006-07-01

    A randomised crossover trial of two separators was undertaken to compare the mononuclear cell, CD34(+) cell and CFU-GM yield, in patients (<61 years) with previously untreated symptomatic multiple myeloma. After first-line therapy, all patients received mobilising chemotherapy (cyclophosphamide 4 g/m(2)) and daily G-CSF. The first leucapheresis was performed on the first day the peripheral blood absolute CD34(+) cell count was > 20 cells/microl. All patients underwent 2 leucaphereses on consecutive days. The patients were randomised to undergo either the first or second leucapheresis using the COBE Spectra. The target duration of the procedure on the COBE Spectra was 2 total blood volumes, and for the Haemonetics MCS(+) it was 20 cycles with four recirculations. Between September 2003 and March 2005, 60 patients were entered in the study. COBE Spectra version 6 processed significantly larger volumes of blood than the Haemonetics MCS(+) (8,845 and 5,680 ml, respectively, P < 0.01). The absolute yield of mononuclear cells (2.1 vs. 1.5 x 10(8)/kg, P = 0.04), CFU-GM (11 vs. 3 x 10(4)/kg, P = 0.01) and CD34(+) cells (3 vs. 1.7 x 10(6)/kg, P = 0.02) were all significantly higher with the COBE Spectra version 6, as were the yields per unit volume of blood processed. In conclusion, our study shows that COBE Spectra Version 6 is faster and has a better yield than the Haemonetics MCS(+), in patients with multiple myeloma. PMID:16395725

  7. Crustal Thickness and Moho Character of the Fast-Spreading East Pacific Rise Between 9º37.5'N and 9º57'N From Poststack and Prestack Time Migrated 3D MCS data

    NASA Astrophysics Data System (ADS)

    Nedimovic, M. R.; Aghaei, O.; Carbotte, S. M.; Carton, H. D.; Canales, J. P.

    2014-12-01

    We measured crustal thickness and mapped Moho transition zone (MTZ) character over an 880 km2 section of the fast-spreading East Pacific Rise (EPR) using the first full 3D multichannel seismic (MCS) dataset collected across a mid-ocean ridge (MOR). The 9°42'-9°57'N area was initially investigated using 3D poststack time migration, which was followed by application of 3D prestack time migration (PSTM) to the whole dataset. This first attempt at applying 3D PSTM to MCS data from a MOR environment resulted in the most detailed reflection images of a spreading center to date. MTZ reflections are for the first time imaged below the ridge axis away from axial discontinuities indicating that Moho is formed at zero age at least at some sections of the MOR system. The average crustal thickness and crustal velocity derived from PSTM are 5920±320 m and 6320±290 m/s, respectively. The average crustal thickness varies little from Pacific to Cocos plate suggesting mostly uniform crustal production in the last ~180 Ka. However, the crust thins by ~400 m from south to north. The MTZ reflections were imaged within ~92% of the study area, with ~66% of the total characterized by impulsive reflections interpreted to originate from a thin MTZ and 26% characterized by diffusive reflections interpreted to originate from a thick MTZ. The MTZ is dominantly diffusive at the southern (9°37.5'-9°40'N) and northern (9°51'-9°57'N) ends of the study area, and it is impulsive in the central region (9°42'-9°51'N). No data were collected between 9°40'N and 9°42'N. More efficient mantle melt extraction is inferred within the central region with greater proportion of the lower crust accreted from the axial magma lens than within the northern and southern sections. This along-axis variation in the crustal accretion style may be caused by interaction between the melt sources for the ridge and the local seamounts, which are present within the northern and southern survey sections. Third

  8. What Fraction of Active Galaxies Actually Show Outflows?

    NASA Astrophysics Data System (ADS)

    Ganguly, Rajib; Brotherton, M. S.

    2007-12-01

    Outflows from active galactic nuclei (AGNs) seem to be common and are thought to be important from a variety of perspectives: as an agent of chemical enhancement of the interstellar and intergalactic media, as an agent of angular momentum removal from the accreting central engine, and as an agent limiting star formation in starbursting systems by blowing out gas and dust from the host galaxy. To understand these processes, we must determine what fraction of AGNs feature outflows and understand what forms they take. We examine recent surveys of outflows detected in ultraviolet absorption over the entire range of velocities and velocity widths (i.e., broad absorption lines, associated absorption lines, and high-velocity narrow absorption lines). While the fraction of specific forms of outflows depends on AGN properties, the overall fraction displaying outflows is fairly constant, approximately 60%, over many orders of magnitude in luminosity. We discuss implications of this result and ways to refine our understanding of outflows. We acknowledge support from the US National Science Foundation through grant AST 05-07781.

  9. The Implications of Extreme Outflows from Extreme Starbursts

    NASA Astrophysics Data System (ADS)

    Heckman, Timothy M.; Borthakur, Sanchayeeta

    2016-05-01

    Interstellar ultraviolet absorption lines provide crucial information about the properties of galactic outflows. In this paper, we augment our previous analysis of the systematic properties of starburst-driven galactic outflows by expanding our sample to include a rare population of starbursts with exceptionally high outflow velocities. In principle, these could be a qualitatively different phenomenon from more typical outflows. However, we find that instead these starbursts lie on, or along the extrapolation of, the trends defined by the more typical systems studied previously by us. We exploit the wide dynamic range provided by this new sample to determine scaling relations of outflow velocity with galaxy stellar mass (M *), circular velocity, star formation rate (SFR), SFR/M *, and SFR/area. We argue that these results can be accommodated within the general interpretational framework we previously advocated, in which a population of ambient interstellar or circumgalactic clouds is accelerated by the combined forces of gravity and the momentum flux from the starburst. We show that this simple physical picture is consistent with both the strong cosmological evolution of galactic outflows in typical star-forming galaxies and the paucity of such galaxies with spectra showing inflows. We also present simple parameterizations of these results that can be implemented in theoretical models and numerical simulations of galaxy evolution.

  10. Spectroscopy of Reconnection Inflow and Outflow in Solar Flares

    NASA Astrophysics Data System (ADS)

    Hara, Hirohisa

    We report reconnection inflow and outflow structures in a type of solar flares that were observed by spectroscopic observations with the Hinode EUV Imaging Spectrometer. A dark outflow has been found by EIS raster scan observations in hot emission lines like Fe XXIII and Fe XXIV as a structure extended from a site above a bright flare loop. The outflow structure is heated to ~10 MK, and the electron density of the outflow is enhanced by about a factor of 2 from the surrounding corona. The hot emission lines in the outflow structure show a large excess width, which may imply the presence of an internal flow structure or the plasma in a turbulent state. A high-density blob structure that appears above the loop-top region where the reconnection outflow collides shows the Doppler motion toward the low-altitude direction. The reconnection rate is estimated to be 0.01-0.1 in combination with the signature of reconnection inflow from the Doppler velocity measurement.

  11. On the physical origin of AGN outflow driving mechanisms

    NASA Astrophysics Data System (ADS)

    Ishibashi, Wako

    2016-07-01

    Super-massive black holes in active galactic nuclei (AGN) respond to the accretion process by feeding back energy and momentum into the surrounding environment. Galaxy-scale outflows are thought to provide the physical link connecting the small scales of the central black hole to the large scales of the host galaxy. Such powerful outflows are now starting to be commonly observed, and have been considered as a proof of AGN feedback in action. However, the physical origin of the mechanism driving the observed outflows is still unclear, and whether it is due to energy-driving or radiation-driving is a source of much debate in the literature. We consider AGN feedback driven by radiation pressure on dust, and show that AGN radiative feedback is capable of driving powerful outflows on galactic scales. In particular, we can obtain outflowing shells with high velocity and large momentum flux, by properly taking into account the effects of radiation trapping. Alternatively, the observed outflow characteristics may be significantly biased by AGN variability. I will discuss the resulting implications in the global context of black hole accretion-AGN feedback coupling.

  12. RADIATION TRANSPORT FOR EXPLOSIVE OUTFLOWS: OPACITY REGROUPING

    SciTech Connect

    Wollaeger, Ryan T.; Van Rossum, Daniel R. E-mail: daan@flash.uchicago.edu

    2014-10-01

    Implicit Monte Carlo (IMC) and Discrete Diffusion Monte Carlo (DDMC) are methods used to stochastically solve the radiative transport and diffusion equations, respectively. These methods combine into a hybrid transport-diffusion method we refer to as IMC-DDMC. We explore a multigroup IMC-DDMC scheme that in DDMC, combines frequency groups with sufficient optical thickness. We term this procedure ''opacity regrouping''. Opacity regrouping has previously been applied to IMC-DDMC calculations for problems in which the dependence of the opacity on frequency is monotonic. We generalize opacity regrouping to non-contiguous groups and implement this in SuperNu, a code designed to do radiation transport in high-velocity outflows with non-monotonic opacities. We find that regrouping of non-contiguous opacity groups generally improves the speed of IMC-DDMC radiation transport. We present an asymptotic analysis that informs the nature of the Doppler shift in DDMC groups and summarize the derivation of the Gentile-Fleck factor for modified IMC-DDMC. We test SuperNu using numerical experiments including a quasi-manufactured analytic solution, a simple 10 group problem, and the W7 problem for Type Ia supernovae. We find that opacity regrouping is necessary to make our IMC-DDMC implementation feasible for the W7 problem and possibly Type Ia supernova simulations in general. We compare the bolometric light curves and spectra produced by the SuperNu and PHOENIX radiation transport codes for the W7 problem. The overall shape of the bolometric light curves are in good agreement, as are the spectra and their evolution with time. However, for the numerical specifications we considered, we find that the peak luminosity of the light curve calculated using SuperNu is ∼10% less than that calculated using PHOENIX.

  13. Radiation Transport for Explosive Outflows: Opacity Regrouping

    NASA Astrophysics Data System (ADS)

    Wollaeger, Ryan T.; van Rossum, Daniel R.

    2014-10-01

    Implicit Monte Carlo (IMC) and Discrete Diffusion Monte Carlo (DDMC) are methods used to stochastically solve the radiative transport and diffusion equations, respectively. These methods combine into a hybrid transport-diffusion method we refer to as IMC-DDMC. We explore a multigroup IMC-DDMC scheme that in DDMC, combines frequency groups with sufficient optical thickness. We term this procedure "opacity regrouping." Opacity regrouping has previously been applied to IMC-DDMC calculations for problems in which the dependence of the opacity on frequency is monotonic. We generalize opacity regrouping to non-contiguous groups and implement this in SuperNu, a code designed to do radiation transport in high-velocity outflows with non-monotonic opacities. We find that regrouping of non-contiguous opacity groups generally improves the speed of IMC-DDMC radiation transport. We present an asymptotic analysis that informs the nature of the Doppler shift in DDMC groups and summarize the derivation of the Gentile-Fleck factor for modified IMC-DDMC. We test SuperNu using numerical experiments including a quasi-manufactured analytic solution, a simple 10 group problem, and the W7 problem for Type Ia supernovae. We find that opacity regrouping is necessary to make our IMC-DDMC implementation feasible for the W7 problem and possibly Type Ia supernova simulations in general. We compare the bolometric light curves and spectra produced by the SuperNu and PHOENIX radiation transport codes for the W7 problem. The overall shape of the bolometric light curves are in good agreement, as are the spectra and their evolution with time. However, for the numerical specifications we considered, we find that the peak luminosity of the light curve calculated using SuperNu is ~10% less than that calculated using PHOENIX.

  14. XMM Observations of Two Quadrupolar Outflows

    NASA Astrophysics Data System (ADS)

    Simon, Theodore

    2009-03-01

    X-ray images of two small dark clouds, L1455 and L723, have been obtained with the EPIC cameras on board the XMM-Newton telescope. Both regions contain multiple independent but overlapping bipolar flows in high-velocity CO, a collection of Herbig-Haro objects, and a number of filaments and knots of H2 emission. The field of view in each cloud was centered on the confluence of the nearly orthogonal CO flows. More than three dozen compact X-ray sources were detected. However, the Class 0/I protostars thought to be the driving sources of the flows in both clouds were not detected. Strong emission was observed from RNO 15, an optically visible, nebulous T Tauri star in the dense core of L1455. A thermal plasma model for the X-ray spectrum of RNO 15 gave a luminosity of L X ~ 1031.2 erg s-1. The heavily reddened Class II star L1455 IRS 5 in the same region was detected as a weak X-ray source. No emission was detected from IRS 1 or IRS 4, which have been suggested as the launch sites for separate outflows in L1455. X-ray emission was observed from IRAS 19156+1906 in L723. The thermal radio source VLA 2, which is offset ~10'' east of the IRAS position and is considered the most likely energy source for the strong east-west flow in L723, was not detected. The source of the more narrowly collimated north-south flow in L723 is unknown but may be an embedded infrared object at the X-ray and IRAS position.

  15. Studying the Outflow-Core Interaction with ALMA Cycle 1 Observations of the HH46/47 Molecular Outflow

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Arce, H. G.; Mardones, D.; Dunham, M. M.; Garay, G.; Noriega-Crespo, A.; Corder, S.; Offner, S.

    2015-12-01

    We present preliminary analysis of ALMA cycle 1 12m array 12CO /13CO /C18O data of the HH 46/47 molecular outflow. 13CO and C18O trace relatively denser outflow material than 12CO and allow us to trace the outflow to lower velocities than what it possible using only the 12CO emission. Interestingly, the cavity wall of the red lobe can be seen at velocity as low as 0.2 km/s. Using C18O, we are now able to estimate the optical depth of 13CO, and then use the corrected 13CO emission to further and better correct the 12CO emission and estimate the mass, momentum, and kinetic energy of the outflow. Moreover, C18O reveals a flattened rotational structure at the center, likely to be a rotational envelope infalling onto an inner Keplerian disk.

  16. Kiloparsec-scale outflows are prevalent among luminous AGN: outflows and feedback in the context of the overall AGN population

    NASA Astrophysics Data System (ADS)

    Harrison, C. M.; Alexander, D. M.; Mullaney, J. R.; Swinbank, A. M.

    2014-07-01

    We present integral field unit observations covering the [O III]λλ4959, 5007 and Hβ emission lines of 16 z < 0.2 type 2 active galactic nuclei (AGN). Our targets are selected from a well-constrained parent sample of ≈24 000 AGN so that we can place our observations into the context of the overall AGN population. Our targets are radio quiet with star formation rates (SFRs; ≲[10-100] M⊙ yr-1) that are consistent with normal star-forming galaxies. We decouple the kinematics of galaxy dynamics and mergers from outflows. We find high-velocity ionized gas (velocity widths ≈600-1500 km s-1; maximum velocities ≤1700 km s-1) with observed spatial extents of ≳(6-16) kpc in all targets and observe signatures of spherical outflows and bi-polar superbubbles. We show that our targets are representative of z < 0.2, luminous (i.e. L[O III] > 1041.7 erg s-1) type 2 AGN and that ionized outflows are not only common but also in ≥70 per cent (3σ confidence) of cases, they are extended over kiloparsec scales. Our study demonstrates that galaxy-wide energetic outflows are not confined to the most extreme star-forming galaxies or radio-luminous AGN; however, there may be a higher incidence of the most extreme outflow velocities in quasars hosted in ultraluminous infrared galaxies. Both star formation and AGN activity appear to be energetically viable to drive the outflows and we find no definitive evidence that favours one process over the other. Although highly uncertain, we derive mass outflow rates (typically ≈10 times the SFRs), kinetic energies (≈0.5-10 per cent of LAGN) and momentum rates (typically ≳10-20 × LAGN/c) consistent with theoretical models that predict AGN-driven outflows play a significant role in shaping the evolution of galaxies.

  17. Quasars Outflows As A Function of SED - An Empirical Approach

    NASA Astrophysics Data System (ADS)

    Richmond, Joseph M.; Ganguly, Rajib

    2015-08-01

    Feedback from quasars (jets, outflows, and luminosity) is now recognized as a vital phase in describing galaxy evolution, growth, and star formation efficiency. Regarding outflows, roughly 60% are observed to have outflowing gas appearing at large velocities and with a variety of velocity dispersions. The most extreme observed form of these outflows appears in the ultraviolet spectrum of 15-20% of objects. Understanding the physics of these outflows is important for both astrophysical and cosmological reasons. Establishing empirical relationships to test the theoretical models of how these outflows are driven (and hence, how they impact their surroundings) is currently plagued by having too few objects, where other parameters like the black hole mass or accretion rate, may add to the scatter. We aim to fix this by using a systematic study of a large sample of objects. As a follow up to a previous study, we have identified a sample of nearly 11000 z=1.7-2 quasars using archived data from the Sloan Digital Sky Survey (Data Release 7), of which roughly 4400 appear to show outflows according to the visual inspection. The specific redshift range is chosen to feature both the Mg II 2800 emission line as well as wavelengths extending to nearly 20,000 km/s blueward of the C IV 1549 emission line. Our goals for this study are: (1) To temper our visual inspection schemes with a more automated, computer-driven scheme; (2) To measure the properties of the outflows (velocity, velocity dispersion, equivalent width, ionization); (3) To supplement the SDSS spectra with photometric measurements from GALEX, 2MASS, and WISE to further characterize the spectral energy distributions (SEDs) and dust content; (4) To form spectral composites to investigate possible SED changes with outflow properties; and (5) To use published estimates of the quasar physical properties (black hole mass, accretion rate, etc.) to fully establish in an empirical way the complex dependencies between the

  18. Evidence for a chemically differentiated outflow in Mrk 231

    NASA Astrophysics Data System (ADS)

    Lindberg, J. E.; Aalto, S.; Muller, S.; Martí-Vidal, I.; Falstad, N.; Costagliola, F.; Henkel, C.; van der Werf, P.; García-Burillo, S.; González-Alfonso, E.

    2016-03-01

    Aims: Our goal is to study the chemical composition of the outflows of active galactic nuclei and starburst galaxies. Methods: We obtained high-resolution interferometric observations of HCN and HCO+J = 1 → 0 and J = 2 → 1 of the ultra-luminous infrared galaxy Mrk 231 with the IRAM Plateau de Bure Interferometer. We also use previously published observations of HCN and HCO+J = 1 → 0 and J = 3 → 2, and HNC J = 1 → 0 in the same source. Results: In the line wings of the HCN, HCO+, and HNC emission, we find that these three molecular species exhibit features at distinct velocities which differ between the species. The features are not consistent with emission lines of other molecular species. Through radiative transfer modelling of the HCN and HCO+ outflow emission we find an average abundance ratio X(HCN) /X(HCO+) ≳ 1000. Assuming a clumpy outflow, modelling of the HCN and HCO+ emission produces strongly inconsistent outflow masses. Conclusions: Both the anti-correlated outflow features of HCN and HCO+ and the different outflow masses calculated from the radiative transfer models of the HCN and HCO+ emission suggest that the outflow is chemically differentiated. The separation between HCN and HCO+ could be an indicator of shock fronts present in the outflow, since the HCN/HCO+ ratio is expected to be elevated in shocked regions. Our result shows that studies of the chemistry in large-scale galactic outflows can be used to better understand the physical properties of these outflows and their effects on the interstellar medium in the galaxy. Based on observations with the IRAM Plateau de Bure Interferometer. IRAM is supported by INSU/CNRS (France), MPG (Germany), and IGN (Spain).Reduced datacubes as FITS files are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/587/A15

  19. Outflow Physiology of the Mouse Eye: Pressure Dependence and Washout

    PubMed Central

    Lei, Yuan; Overby, Darryl R.; Boussommier-Calleja, Alexandra; Stamer, W. Daniel

    2011-01-01

    Purpose. Mice are commonly used in glaucoma research, but relatively little is known about aqueous outflow dynamics in the species. To facilitate future use of the mouse as a model of aqueous humor outflow, several fundamental physiological parameters were measured in the mouse eye. Methods. Eyes from adult mice of either sex (C57BL/6 background) were enucleated, cannulated with a 33-gauge needle, and perfused at constant pressure while inflow was continuously measured. Results. At 8 mm Hg, total outflow facility (Ctotal) was 0.022 ± 0.005 μL/min/mm Hg (all values mean ± SD; n = 21). The flow–pressure relationship was linear up to 35 mm Hg. The conventional outflow facility (Cconv) was 0.0066 ± 0.0009 μL/min/mm Hg, and the unconventional outflow (Fu) was 0.114 ± 0.019 μL/min, both measured at room temperature. At 8 mm Hg, 66% of the outflow was via the unconventional pathway. In a more than 2-hour-long perfusion at 8 mm Hg, the rate of facility change was 2.4% ± 5.4% (n = 11) of starting facility per hour. The ocular compliance (0.086 ± 0.017 μL/mm Hg; n = 5) was comparable to the compliance of the perfusion system (0.100 ± 0.004 μL/mm Hg). Conclusions. Mouse eyes are similar to human eyes, in that they have no detectable washout rate and a linear pressure–flow relationship over a broad range of intraocular pressures. Because of the absence of washout and the apparent presence of a true Schlemm's canal, the mouse is a useful model for studying the physiology of the inner wall of Schlemm's canal and the conventional outflow tissues. PMID:21169533

  20. Modeling jet and outflow feedback during star cluster formation

    SciTech Connect

    Federrath, Christoph; Schrön, Martin; Banerjee, Robi; Klessen, Ralf S.

    2014-08-01

    Powerful jets and outflows are launched from the protostellar disks around newborn stars. These outflows carry enough mass and momentum to transform the structure of their parent molecular cloud and to potentially control star formation itself. Despite their importance, we have not been able to fully quantify the impact of jets and outflows during the formation of a star cluster. The main problem lies in limited computing power. We would have to resolve the magnetic jet-launching mechanism close to the protostar and at the same time follow the evolution of a parsec-size cloud for a million years. Current computer power and codes fall orders of magnitude short of achieving this. In order to overcome this problem, we implement a subgrid-scale (SGS) model for launching jets and outflows, which demonstrably converges and reproduces the mass, linear and angular momentum transfer, and the speed of real jets, with ∼1000 times lower resolution than would be required without the SGS model. We apply the new SGS model to turbulent, magnetized star cluster formation and show that jets and outflows (1) eject about one-fourth of their parent molecular clump in high-speed jets, quickly reaching distances of more than a parsec, (2) reduce the star formation rate by about a factor of two, and (3) lead to the formation of ∼1.5 times as many stars compared to the no-outflow case. Most importantly, we find that jets and outflows reduce the average star mass by a factor of ∼ three and may thus be essential for understanding the characteristic mass of the stellar initial mass function.

  1. OUTFLOW AND HOT DUST EMISSION IN HIGH-REDSHIFT QUASARS

    SciTech Connect

    Wang, Huiyuan; Xing, Feijun; Wang, Tinggui; Zhou, Hongyan; Zhang, Kai; Zhang, Shaohua

    2013-10-10

    Correlations of hot dust emission with outflow properties are investigated, based on a large z ∼ 2 non-broad absorption line quasar sample built from the Wide-field Infrared Survey and the Sloan Digital Sky Survey data releases. We use the near-infrared slope and the infrared to UV luminosity ratio to indicate the hot dust emission relative to the emission from the accretion disk. In our luminous quasars, these hot dust emission indicators are almost independent of the fundamental parameters, such as luminosity, Eddington ratio and black hole mass, but moderately dependent on the blueshift and asymmetry index (BAI) and FWHM of C IV lines. Interestingly, the latter two correlations dramatically strengthen with increasing Eddington ratio. We suggest that, in high Eddington ratio quasars, C IV regions are dominated by outflows so the BAI and FWHM (C IV) can reliably reflect the general properties and velocity of outflows, respectively. In low Eddington ratio quasars, on the other hand, C IV lines are primarily emitted by virialized gas so the BAI and FWHM (C IV) become less sensitive to outflows. Therefore, the correlations for the highest Eddington ratio quasars are more likely to represent the true dependence of hot dust emission on outflows and the correlations for the entire sample are significantly diluted by the low Eddington ratio quasars. Our results show that an outflow with a large BAI or velocity can double the hot dust emission on average. We suggest that outflows either contain hot dust in themselves or interact with the dusty interstellar medium or torus.

  2. Tracing inflows and outflows with absorption lines in circumgalactic gas

    NASA Astrophysics Data System (ADS)

    Ford, Amanda Brady; Davé, Romeel; Oppenheimer, Benjamin D.; Katz, Neal; Kollmeier, Juna A.; Thompson, Robert; Weinberg, David H.

    2014-10-01

    We examine how H I and metal absorption lines within low-redshift galaxy haloes trace the dynamical state of circumgalactic gas, using cosmological hydrodynamic simulations that include a well-vetted heuristic model for galactic outflows. We categorize inflowing, outflowing, and ambient gas based on its history and fate as tracked in our simulation. Following our earlier work, showing that the ionization level of absorbers was a primary factor in determining the physical conditions of absorbing gas, we show here that it is also a governing factor for its dynamical state. Low-ionization metal absorbers (e.g. Mg II) tend to arise in gas that will fall on to galaxies within several Gyr, while high-ionization metal absorbers (e.g. O VI) generally trace material that was deposited by outflows many Gyr ago. Inflowing gas is dominated by enriched material that was previously ejected in an outflow; hence, accretion at low redshifts is typically substantially enriched. Recycling wind material is preferentially found closer to galaxies, and is more dominant in lower mass haloes since high-mass haloes have more hot gas that is able to support itself against infall. Low-mass haloes also tend to re-eject more of their accreted material, owing to our outflow prescription that employs higher mass loading factors for lower mass galaxies. Typical H I absorbers trace unenriched ambient material that is not participating in the baryon cycle, but stronger H I absorbers arise in cool, enriched inflowing gas. Instantaneous radial velocity measures of absorbers are generally poor at distinguishing between inflowing and outflowing gas, except in the case of very recent outflows. These results suggest that probing halo gas using a range of absorbers can provide detailed information about the amount and physical conditions of material that is participating in the baryon cycle.

  3. Constraints on the Aleutian Subduction Zone from the Shumagin Gap to Kodiak Asperity from New MCS and OBS Data of the ALEUT Project

    NASA Astrophysics Data System (ADS)

    Shillington, D. J.; Nedimović, M. R.; Webb, S. C.; Bécel, A.; Delescluse, M.; Li, J.; Kuehn, H.; Biescas, B.; Wessbecher, A.; Farkas, A.; Eddy, C.; Hostetler, K.; Perls, H.; Zietman, J.; Keranen, K. M.; Louden, K. E.

    2011-12-01

    In July-August 2011, the Alaska Langseth Experiment to Understand the megaThrust (ALEUT) program acquired deep penetration multichannel seismic (MCS) reflection and ocean bottom seismometer (OBS) data along a part of the Aleutian subduction zone that exhibits the full spectrum of coupling, from locked to freely slipping. The goal of this program is to characterize variations in the geometry and properties of the megathrust, over-riding and downgoing plates and other structures and relate them to downdip and along-strike changes in slip behavior and seismogenesis. Our study encompassed 1) the freely slipping Shumagin Gap; 2) the locked Semidi segment, which last ruptured in 1938, and 3) the locked western Kodiak asperity, the western extent of the 1964 M9.2 rupture. We acquired 3700 km of MCS data with the R/V Langseth along a series of strike and dip profiles that span the entire locked zone on the megathrust (as indicated by GPS data and estimated rupture zones of past earthquakes), its updip and downdip transitions to stable sliding, bending of the downgoing plate, and preexisting structures in the oceanic crust. Data were acquired with a 6600 cu. in. air gun array and two 8-km-long streamers. The source and one of the streamers were towed at a depth of 12 m to maximize low frequencies (and deep imaging) while the second streamer was towed at 9 m for better imaging of the sediments and upper crust. Refraction data were acquired using the same source and short period OBS spaced at ~15 km along two ~400-km profiles coincident with MCS data across the Shumagin Gap and Semidi segment. Eight seismometers were also deployed onshore in the summer of 2011 that recorded the entire offshore experiment plus local and regional seismicity. Here we present initial results from MCS and OBS data regarding the megathrust and the hydration of the downgoing plate. Initial images reveal deep reflections from the megathrust from both the locked region and the estimated downdip

  4. Absorption-line measurements of AGN outflows

    NASA Astrophysics Data System (ADS)

    Fields, Dale L.

    Investigations into the elemental abundances in two nearby active galaxies, the narrow-line Seyfert 1 Markarian 1044 and the Seyfert 1 Markarian 279, are reported. Spectra from three space-based observatories HST, FUSE, and CHANDRA, are used to measure absorption lines in material outflowing from the nucleus. I make multi-wavelength comparisons to better convert the ionic column densities into elemental column densities which can then be used to determine abundances (metallicities). Narrow-line Seyfert 1 galaxies are known to have extreme values of a number of properties compared to active galactic nuclei (AGNs) as a class. In particular, emission-line studies have suggested that NLS1s are unusually metal-rich compared to broad-line AGNs of comparable luminosity. To test these suggestions I perform absorption-line studies on the NLS1 Markarian 1044, a nearby and bright AGN. I use lines of H I, C IV, N V, and O VI to properly make the photoionization correction through the software Cloudy and determine abundances of Carbon, Nitrogen and Oxygen. I find two results. The first is that Markarian 1044 has a bulk metallicity greater than five times solar. The second is that the N/C ratio in Markarian 1044 is consistent with a solar mixture. This is in direct contradiction of extrapolations from local H II regions which state N/ C should scale with bulk metallicity. This implies a different enrichment history in Markarian 1044 than in the Galactic disk. I also report discovery of three new low-redshift Lya forest lines with log N HI >= 12:77 in the spectrum of Markarian 1044. This number is consistent with the 2.6 expected Lya forest lines in the path length to Markarian 1044. I also investigate the CHANDRA X-ray spectrum of Markarian 279, a broad-line Seyfert 1. I use a new code, PHASE, to self-consistently model the entire absorption spectrum simultaneously. Using solely the X-ray spectrum I am able to determine the physical parameters of this absorber to a degree only

  5. Supernovae and AGN Driven Galactic Outflows

    NASA Astrophysics Data System (ADS)

    Sharma, Mahavir; Nath, Biman B.

    2013-01-01

    mass scale (Mh ~ 1012-1012.5 M ⊙) that signifies the crossover of AGN domination in outflow properties from starburst activity at lower masses. We find that stellar mass for massive galaxies scales as M sstarfvpropM 0.26 h , and for low-mass galaxies, M sstarfvpropM 5/3 h .

  6. Stellar Populations And Galactic Outflows At z ˜ 3

    NASA Astrophysics Data System (ADS)

    McLinden, Emily; Rhoads, J. E.; Malhotra, S.; Finkelstein, S. L.; Hibon, P.; Richardson, M. L. A.

    2012-01-01

    We have measured a velocity offset between the Lyman-α emission line and the [OIII] nebular emission line in three spectroscopically confirmed z 3.1 Lyman-α emitting galaxies (LAEs). Such velocity offsets indicate the presence of powerful outflows in these galaxies. We made these measurements by combining near-infrared spectroscopy of the [OIII] line (from LBT/LUCIFER) with optical spectroscopy of the Lyman-α line (from MMT/Hectospec). We contend that tracing the kinematics of these galaxies is crucial for understanding how the prominent Ly-α emission from these galaxies is produced and how it escapes. LAEs are an exciting tool for studying the early universe, as Lyman-α emission is a prominent sign of young star forming galaxies at high redshift. It can be used to identify galaxy samples with characteristic continuum luminosities and stellar masses well below those typically obtained from Lyman break selection or other high-redshift galaxy search methods. To further understand what these young, low-mass objects tell us about galaxy formation, assembly, and evolution we have used our NIR spectroscopic data to demonstrate how the [OIII] emission line in the Ks filter alters SED fitting results of our z 3.1 LAEs. This information allows us to produce more accurate SED fits of those LAEs with NIR data, and predict [OIII] line fluxes in those LAEs that have yet to be observed in the NIR. Our SED fitting sample of 30 confirmed z 3.1 LAEs is one of the largest produced to date and provides a powerful look at accurate ages, masses, metallicities, dust characteristics and star formation histories of these early galaxies.

  7. The collimated outflows of the planetary nebula Hu 1-2: proper motion and radial velocity measurements

    NASA Astrophysics Data System (ADS)

    Miranda, L. F.; Blanco, M.; Guerrero, M. A.; Riera, A.

    2012-04-01

    Hu 1-2 is a planetary nebula that contains an isolated knot located north-west of the main nebula, which could be related to a collimated outflow. We present a subarcsecond Hα+[N II] image and a high-resolution, long-slit spectrum of Hu 1-2 that allow us to identify the south-eastern counterpart of the north-western knot and to establish their high-velocity (>340 km s-1), collimated bipolar outflow nature. The detection of the north-western knot in Palomar Observatory Sky Atlas (POSS) red plates allows us to carry out a proper motion analysis by combining three POSS red plates and two narrow-band Hα+[N II] CCD images, with a time baseline of ≃57 yr. A proper motion of 20 ± 6 mas yr-1 along position angle 312°± 15° and a dynamical age of 1375? yr are obtained for the bipolar outflow. The measured proper motion and the spatio-kinematical properties of the bipolar outflow yield a lower limit of 2.7 kpc for the distance to Hu 1-2. The Andalucia Faint Object Spectrograph and Camera (ALFOSC) is provided by the Instituto de Astrofísica de Andalucía (IAA) under a joint agreement with the University of Copenhagen and NOTSA. The IACUB uncrossed echelle spectrograph was built in a collaboration between the IAC and the Queen's University of Belfast.

  8. PROBING THE FERMI BUBBLES IN ULTRAVIOLET ABSORPTION: A SPECTROSCOPIC SIGNATURE OF THE MILKY WAY'S BICONICAL NUCLEAR OUTFLOW

    SciTech Connect

    Fox, Andrew J.; Bordoloi, Rongmon; Hernandez, Svea; Tumlinson, Jason; Savage, Blair D.; Wakker, Bart P.; Lockman, Felix J.; Bland-Hawthorn, Joss; Kim, Tae-Sun; Benjamin, Robert A.

    2015-01-20

    Giant lobes of plasma extend ≈55° above and below the Galactic center, glowing in emission from gamma rays (the Fermi Bubbles) to microwaves and polarized radio waves. We use ultraviolet absorption-line spectra from the Hubble Space Telescope to constrain the velocity of the outflowing gas within these regions, targeting the quasar PDS 456 (ℓ, b = 10.°4, +11.°2). This sightline passes through a clear biconical structure seen in hard X-ray and gamma-ray emission near the base of the northern Fermi Bubble. We report two high-velocity metal absorption components, at v {sub LSR} = –235 and +250 km s{sup –1}, which cannot be explained by co-rotating gas in the Galactic disk or halo. Their velocities are suggestive of an origin on the front and back side of an expanding biconical outflow emanating from the Galactic center. We develop simple kinematic biconical outflow models that can explain the observed profiles with an outflow velocity of ≳900 km s{sup –1} and a full opening angle of ≈110° (matching the X-ray bicone). This indicates Galactic center activity over the last ≈2.5-4.0 Myr, in line with age estimates of the Fermi Bubbles. The observations illustrate the use of UV spectroscopy to probe the properties of swept-up gas venting into the Fermi Bubbles.

  9. Estimation of cold plasma outflow during geomagnetic storms

    NASA Astrophysics Data System (ADS)

    Haaland, S.; Eriksson, A. I.; Andre, M.; Maes, L.; Baddeley, L. J.; Barakat, A. R.; Chappell, C. R.; Eccles, V.; Johnsen, C.; Lybekk, B.; Li, K.; Pedersen, A.; Schunk, R. W.; Welling, D. T.

    2015-12-01

    Low energy ions of ionospheric origin provide a significant contributon to the magnetospheric plasmapopulation. Measuring cold ions is difficult though. Observations have to be done at sufficiently high altitudes and typically in regions of space where spacecraft attain a positive charge due to solar illumination. Cold ions are therefore shielded from the satellite particle detectors. Furthermore, spacecraft can only cover key regions of ion outflow during segments of their orbit, so additional complications arise arise if continuous longtime observations such as the during a geomagnetic storms are needed. In this paper we suggest a new approach, based on a combination of synoptic observations and a novel technique to estimate the flux and total outflow during the various phases of geomagnetic storms. Our results indicate large variations in both outflow rates and transport throughout the storm. Prior to the storm main phase, outflow rates are moderate, and the cold ions are mainly emanating from moderately sized polar cap regions. Throughout the main phase of the storm, outflow rates increase and the polar cap source regions expand. Furthermore, faster transport, resulting from enhanced convection, leads to a much larger supply of cold ions to the near Earth region during gemagnetic storms.

  10. Estimation of cold plasma outflow during geomagnetic storms

    NASA Astrophysics Data System (ADS)

    Haaland, S.; Eriksson, A.; André, M.; Maes, L.; Baddeley, L.; Barakat, A.; Chappell, R.; Eccles, V.; Johnsen, C.; Lybekk, B.; Li, K.; Pedersen, A.; Schunk, R.; Welling, D.

    2015-12-01

    Low-energy ions of ionospheric origin constitute a significant contributor to the magnetospheric plasma population. Measuring cold ions is difficult though. Observations have to be done at sufficiently high altitudes and typically in regions of space where spacecraft attain a positive charge due to solar illumination. Cold ions are therefore shielded from the satellite particle detectors. Furthermore, spacecraft can only cover key regions of ion outflow during segments of their orbit, so additional complications arise if continuous longtime observations, such as during a geomagnetic storm, are needed. In this paper we suggest a new approach, based on a combination of synoptic observations and a novel technique to estimate the flux and total outflow during the various phases of geomagnetic storms. Our results indicate large variations in both outflow rates and transport throughout the storm. Prior to the storm main phase, outflow rates are moderate, and the cold ions are mainly emanating from moderately sized polar cap regions. Throughout the main phase of the storm, outflow rates increase and the polar cap source regions expand. Furthermore, faster transport, resulting from enhanced convection, leads to a much larger supply of cold ions to the near-Earth region during geomagnetic storms.

  11. Cluster Formation in Protostellar Outflow-driven Turbulence

    NASA Astrophysics Data System (ADS)

    Li, Zhi-Yun; Nakamura, Fumitaka

    2006-04-01

    Most, perhaps all, stars go through a phase of vigorous outflow during formation. We examine, through three-dimensional MHD simulation, the effects of protostellar outflows on cluster formation. We find that the initial turbulence in the cluster-forming region is quickly replaced by motions generated by outflows. The protostellar outflow-driven turbulence (``protostellar turbulence'' for short) can keep the region close to a virial equilibrium long after the initial turbulence has decayed away. We argue that there exist two types of turbulence in star-forming clouds: a primordial (or ``interstellar'') turbulence and a protostellar turbulence, with the former transformed into the latter mostly in embedded clusters such as NGC 1333. Since the majority of stars are thought to form in clusters, an implication is that the stellar initial mass function is determined to a large extent by the stars themselves, through outflows that individually limit the mass accretion onto forming stars and collectively shape the environments (density structure and velocity field) in which most cluster members form. We speculate that massive cluster-forming clumps supported by protostellar turbulence gradually evolve toward a highly centrally condensed ``pivotal'' state, culminating in rapid formation of massive stars in the densest part through accretion.

  12. Quasar Outflow Constraints using Broad Absorption Line Variability Studies

    NASA Astrophysics Data System (ADS)

    McGraw, Sean; Shields, Joseph C.; Hamann, Fred; Capellupo, Daniel M.; Gallagher, Sarah; Brandt, W. Niel; Herbst, Hanna

    2016-01-01

    Quasar outflows are plausible candidates for AGN feedback processes influencing the host galaxy and may explain the established correlations between the supermassive black hole (SMBH) and the surrounding bulge. In order to better understand feedback and the physical conditions of the outflowing gas, observational constraints on absorber kinematics and energetics are needed. We are utilizing multiple epoch, rest frame UV quasar spectra to establish limits on outflow locations and total column densities for the purpose of estimating wind kinetic energies and momenta. We are also investigating the variability patterns of broad absorption lines (BALs) and mini-BALs across a range of ionization states to probe underlying connections between the various classes of absorbers. This work employs observations from the Sloan Digital Sky Survey, Hobby Eberly Telescope, and MDM observatory. We detect BAL variability in 3 out of 12 FeLoBAL quasars over multiple year timescales and conclude that the variable absorbers lie within tens of parsecs of the SMBH based on interpretations of the Fe II and Mg II BALS. We also measure significant BAL changes across daily to yearly timescales in a sample of 71 quasars with plausible detections of the P V 1117,1128 BAL. Detecting phosphorus in absorption is notable because it traces high column density outflows and is therefore relevant for studying AGN feedback. Constraints on outflow energetics and other selected results will be presented.

  13. Studying AGN Feedback with Galactic Outflows in Luminous Obscured Quasar

    NASA Astrophysics Data System (ADS)

    Sun, Ai-Lei

    2016-01-01

    Feedback from Active galactic nuclei (AGN) has been proposed as an important quenching mechanism to suppress star formation in massive galaxies. We investigate the most direct form of AGN feedback - galactic outflows - in the most luminous obscured AGN (L>10^45 erg/s) from the SDSS sample in the nearby universe (z<0.2). Using ALMA and Magellan observations to target molecular and ionized outflows, we find that luminous AGN can impact the dynamics and phase of the galactic medium, and confirm the complex multi-phase and multi-scaled nature of the feedback phenomenon. In particular, we found that most of these luminous AGN hosts ionized outflows. The outflow size, velocity, and energetics correlate with the AGN luminosity, and can be very extended (r > 10 kpc) and fast (v > 1000 km/s) for the most luminous ones. I end with presenting a new technique to find extended ionized outflows using broadband imaging surveys, and to characterize their occurrence rate, morphology, size distribution, and their dependence on the AGN luminosity. This technique will open a new window for feedback studies in the era of large-scale optical imaging surveys, e.g., HSC and then LSST.

  14. Star Formation Ecology: YSO Outflow Feedback in Young Clusters

    NASA Astrophysics Data System (ADS)

    Frank, Adam; Bally, John; Blackman, Eric; Gutermuth, Robert; Pipher, Judy; Quillen, Alice

    2007-05-01

    Energetic outflows associated with young stellar objects exert a strong effect on their parent molecular clouds. The dynamics of this interaction is yet to be well understood. In particular the role of jets and outflows in powering cloud turbulence, modifying the star formation efficiency (SFE) and/or disrupting the parent clouds remains unclear. Spitzer images of young clusters have provided new views of jet-cloud interactions that can help resolve these critical issues. In this proposal we seek to continue a highly successful (cycle 2) theory program to explore theoretical issues of jet-cloud interactions, turbulence and cloud disruption. Our research relies on 3-D Adaptive Mesh Refinement hydrodynamic and MHD simulations developed in house, in concert with Spitzer databases and other complementary observations. The team we have assembled includes computational and analytic theorists (Frank, Blackman) as well as observers who have worked closely with existing Spitzer Datasets (Bally, Quillen, Pipher, Gutermuth) The work funded through the previous TR program revealed fundamentally new aspects of YSO outflow feedback on parent cloud cores including the importance of the temporal evolution of outflow power. In this proposal we seek to extend the understanding gained in those studies to address specific questions on the nature and efficacy of outflow feedback in real systems.

  15. Envelope structure on 700 AU scales and the molecular outflows of low-mass young stellar objects

    NASA Technical Reports Server (NTRS)

    Hogerheijde, M. R.; van Dishoeck, E. F.; Blake, G. A.; van Langevelde, H. J.

    1998-01-01

    IRS 5 outflow, which extends over 10' (0.4 pc), seven of the remaining eight sources are found to drive 12CO 3-2 outflows over < or = 1' (0.04 pc); only L1527 IRS has a well-developed outflow of some 3'(0.12 pc). Estimates are obtained for the outflow kinetic luminosity, Lkin, and the flow momentum rate, FCO, applying corrections for line opacity and source inclination. The flow force FCO correlates with the envelope mass and with the 2.7 mm flux of the circumstellar disk. Only a weak correlation is seen with Lbol, while none is found with the relative age of the object as measured by integral Tmb(HCO+ 3-2)dV/Lbol. These trends support the hypothesis that outflows are driven by accretion through a disk, with a global mass infall rate determined by the mass and density of the envelope. The association of compact HCO+ emission with the walls of the outflow cavities indicates that outflows in turn influence the appearance of the envelopes. It is not yet clear, however, whether they are actively involved in sweeping up envelope material, or merely provide a low-opacity pathway for heating radiation to reach into the envelope.

  16. SUPERNOVAE AND AGN DRIVEN GALACTIC OUTFLOWS

    SciTech Connect

    Sharma, Mahavir; Nath, Biman B. E-mail: biman@rri.res.in

    2013-01-20

    an appropriate relation between M {sub .} and M{sub h} and an appropriate opacity of dust grains in infrared (K band), this ratio has the attractive property of being minimum at a certain halo mass scale (M{sub h} {approx} 10{sup 12}-10{sup 12.5} M {sub Sun }) that signifies the crossover of AGN domination in outflow properties from starburst activity at lower masses. We find that stellar mass for massive galaxies scales as M {sub *}{proportional_to}M {sup 0.26} {sub h}, and for low-mass galaxies, M {sub *}{proportional_to}M {sup 5/3} {sub h}.

  17. Mapping Large-Scale Gaseous Outflows in Ultraluminous Infrared Galaxies with Keck II ESI Spectra: Spatial Extent of the Outflow

    NASA Astrophysics Data System (ADS)

    Martin, Crystal L.

    2006-08-01

    The kinematics of neutral gas and warm ionized gas have been mapped across ultraluminous starburst galaxies using the Na I λλ5890, 5896 absorption-line and Hα emission-line profiles, respectively, in Keck II ESI spectra. Blueshifted, interstellar absorption is found over extended regions, exceeding 15 kpc in several systems. An outflow diverging from the nuclear starburst would have to reach large heights to cover this area in projection. The scale height of the absorbing material could be lower, however, if the outflow emanates from a larger region of the galaxy. The large velocity gradient discovered across several outflows is inconsistent with a flow diverging from the nuclear starburst. Widespread star formation, triggered by the merger, probably drives these extended outflows via mechanical feedback from supernovae, although shocks generated by the galaxy-galaxy merger may also contribute to the formation of a hot wind. In a typical ULIG, the mass carried by the cool phase of the outflow is ~108 Msolar i.e., a few percent of the dynamical mass in the starburst region. Assuming the starburst activity has persisted for 10 Myr, the kinetic energy of the cool outflows is a few percent of the supernova energy. The cool wind is expected to be accelerated by momentum deposition, possibly from radiation pressure as well as the ram pressure of the hot, supernova-induced wind. The turnaround radii of the cool outflows are at least ~30-90 kpc, which presents a significant Na I absorption cross section. If most L>0.1L* galaxies pass through a luminous starburst phase, then relics of cool outflows will create a significant redshift-path density. Galaxy formation models should include this cool phase of the outflow in addition to a hot wind in feedback models. Data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California, and the National

  18. Bipolar Molecular Outflows from High-Mass Protostars

    NASA Astrophysics Data System (ADS)

    Su, Yu-Nung; Zhang, Qizhou; Lim, Jeremy

    2004-03-01

    We report observations of the bipolar molecular outflows associated with the luminous (~2×104 Lsolar) far-IR sources IRAS 21519+5613 and IRAS 22506+5944, as well the dust and molecular gas condensations on which these outflows appear to be centered. The observations were made in 12CO, 13CO, C18O, and continuum at 3 mm with the BIMA array and in 12CO and 13CO with the NRAO 12 m telescope to recover extended emission filtered out by the interferometric array. We find that the outflow associated with each IRAS source shows a clear bipolar morphology in 12CO, with properties (i.e., total mass of order 10-100 Msolar, mass-outflow rate >~10-3 Msolar, dynamical timescale 104-105 yr, and energetics) comparable with those of other massive outflows associated with luminous young stellar objects. Each outflow appears to be centered on a dust and gas condensation with a mass of 200-300 Msolar, likely marking the location of the driving source. The outflow lobes of both sources are fully resolved along their major but not minor axes, and they have collimation factors that may be comparable with young low-mass stars. The mass-velocity diagrams of both outflows change in slope at a velocity of ~10 km s-1, suggesting that the high-velocity component (HVC) may drive the low-velocity component (LVC). Although the HVC of IRAS 21519+5613 shows evidence for deceleration, no such signature is seen in the HVC of IRAS 22506+5944. Neither HVC has a momentum supply rate sufficient to drive their corresponding LVCs, although it is possible that the HVC is more highly excited and hence its thrust underestimated. Like for other molecular outflows the primary driving agent cannot be ionized gas, leaving atomic gas as the other remaining candidate. Neither IRAS 21519+5613 nor IRAS 22506+5944 exhibits detectable free-free emission, which together with the observed properties of their molecular outflows and surrounding condensations make them credible candidates for high-mass protostars. The mass

  19. Triggered star formation: Rotation, magnetic fields and outflows

    NASA Astrophysics Data System (ADS)

    Frank, A.; Li, S.; Blackman, E. G.

    2015-12-01

    Star formation can be triggered by compression from wind or supernova driven shock waves that sweep over molecular clouds. In a previous work we used Adaptive Mesh Refinement (AMR) simulation methods, including sink particles, to simulate the full collapse of a stable Bonnor-Ebert sphere subjected to a passing shock. We tracked the flow of cloud material after a star (a sink particle) had formed. For rotating clouds we observed the formation of disks which then interact with the post-shock flow. In this paper we take the next step forward in complexity, presenting first results of simulations that include a magnetized cloud. Our results show that after a disk is formed a collimated magneto-centrifugal outflow is launched. The outflow is bipolar but asymmetric, due to interactions with the shocked flow. We explore the influence of the outflows on the post-triggering collapse dynamics.

  20. Plasma Outflows: Known Knowns, Known Unknowns, and The Unknown

    NASA Technical Reports Server (NTRS)

    Moore, T. E.

    2012-01-01

    A brief summary is given of i) what we know from observing ionospheric outflows and ii) how outflow parameterizations are being used in global simulations to evaluate their effects on magnetospheric dynamics. Then, a list of unanswered questions and issues to be resolved is given, followed by a description of the known future mission plans expressed in the Heliophysics Roadmap, such as Origin of Near-Earth Plasmas (ONEP), and Ion-Neutral Coupling in the Atmosphere (INCA). Finally, a set of requirements for definitive plasma outflow observations are identified, along with possible methods for fulfilling them in future missions. Since results of the current Heliophysics Decadal Survey are expected soon, it is hoped that future plans can be summarized and discussed without speculation at the GEM 2012 meeting.

  1. Dominant Nuclear Outflow Driving Mechanisms in Powerful Radio Galaxies

    NASA Astrophysics Data System (ADS)

    Batcheldor, Dan; Tadhunter, Clive; Holt, Joanna; Morganti, Raffaella; O'Dea, Christopher P.; Axon, David J.; Koekemoer, Anton

    2007-05-01

    In order to identify the dominant nuclear outflow mechanisms in active galactic nuclei, we have undertaken deep, high-resolution observations of two compact radio sources (PKS 1549-79 and PKS 1345+12) with the Advanced Camera for Surveys (ACS) aboard the Hubble Space Telescope. Not only are these targets known to have powerful emission-line outflows, but they also contain all the potential drivers for the outflows: relativistic jets, quasar nuclei, and starbursts. ACS allows the compact nature (<0.15") of these radio sources to be optically resolved for the first time. Through comparison with existing radio maps, we have seen consistency in the nuclear position angles of both the optical emission-line and radio data. There is no evidence for biconical emission-line features on the large scale, and there is a divergence in the relative position angles of the optical and radio structure. This enables us to exclude starburst-driven outflows. However, we are unable to clearly distinguish between radiative AGN wind-driven outflows and outflows powered by relativistic radio jets. The small-scale biconical features, indicative of such mechanisms, could be below the resolution limit of ACS, especially if aligned close to the line of sight. In addition, there may be offsets between the radio and optical nuclei induced by heavy dust obscuration, nebular continuum, or scattered light from the AGN. Based on observations made with the NASA/ESA Hubble Space Telescope obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc. under NASA contract NAS 5-26555. These observations are associated with program 10206.

  2. Empirical outflow velocities in an equatorial coronal streamer

    NASA Astrophysics Data System (ADS)

    Strachan, L.; Suleiman, R.; Panasyuk, A.; Biesecker, D.; Kohl, J.

    We use combined Ultraviolet Coronagraph Spectrometer (UVCS) and Large Angle Spectroscopic Coronagraph (LASCO) data to determine the O5+ outflow velocities as a function of height along the axis of an equatorial streamer at solar minimum and as a function of latitude (at 2.3 solar radii from sun center). The results show that outflow increases rather abruptly in the region between 3.6 and 4.1 solar radii near the streamer cusp, and gradually increases to 90 km/s at about 5 solar radii in the streamer stalk beyond the cusp. The latitudinal variation at 2.3 solar radii shows that there is no outflow (within the measurement uncertainties) in the center of the streamer called the core, and that a steep increase in outflow occurs just beyond the streamer legs, where the O VI 1032 intensity relative to H I 1216 (Ly) is higher than in the core. Velocity variations in both height and latitude show that the transitions from no measurable outflow to positive outflow are relatively sharp and thus can be used to infer the location of the transition from closed to open field lines in streamer magnetic field topologies. Such information, including the densities and kinetic temperatures derived from the observations, provides hard constraints for realistic theoretical models of streamers and the source regions of the slow solar wind. This work is supported by NASA Grant NAG5-11420 to the Smithsonian Astrophysical Observatory, by the Italian Space Agency, and by the ESA PRODEX program (Swiss contribution).

  3. Mass Outflows from Dissipative Shocks in Hot Accretion Flows

    NASA Astrophysics Data System (ADS)

    Fukumura, Keigo; Kazanas, Demosthenes

    2007-11-01

    We consider stationary, axisymmetric hydrodynamic accretion flows in Kerr geometry. As a plausible means of efficiently separating a small population of nonthermal particles from the bulk accretion flows, we investigate the formation of standing dissipative shocks, i.e., shocks at which fraction of the energy, angular momentum, and mass fluxes do not participate in the shock transition of the flow that accretes onto the compact object but are lost into collimated (jets) or uncollimated (winds) outflows. The mass-loss fraction (at a shock front) is found to vary over a wide range (0%-95%), depending on flow's angular momentum and energy. On the other hand, the associated energy-loss fraction appears to be relatively low (<~1%) for a flow onto a nonrotating black hole case, whereas the fraction could be an order of magnitude higher (<~10%) for a flow onto a rapidly rotating black hole. By estimating the escape velocity of the outflowing particles with a mass-accretion rate relevant for typical active galactic nuclei, we find that nearly 10% of the accreting mass could escape to form an outflow in a disk around a nonrotating black hole, while as much as 50% of the matter may contribute to outflows in a disk around a rapidly rotating black hole. In the context of disk-jet paradigm, our model suggests that shock-driven outflows from accretion can occur in regions not too far from a central engine. Our results imply that a shock front under some conditions could serve as a plausible site where (nonthermal) seed particles of the outflows (jets/winds) are efficiently decoupled from bulk accretion.

  4. Mass Outflows from Dissipative Shocks in Hot Accretion Flows

    NASA Astrophysics Data System (ADS)

    Fukumura, Keigo; Kazanas, D.

    2007-05-01

    We consider stationary, axisymmetric hydrodynamic accretion flows in Kerr geometry. As a plausible means of efficiently separating small population of nonthermal particles from the bulk accretion flows, we investigate the formation of dissipative standing shocks where energy, angular momentum and mass are partially lost into collimated (jets) or uncollimated (winds) outflows subsequently. Mass loss fraction (at a shock front) is found to vary over a wide range (0% - 95%) depending on flow's angular momentum and energy. On the other hand, energy loss fraction appears to be relatively low (<1%) for a non-rotating black hole case, whereas the fraction could be an order of magnitude higher (<10%) for a rapidly-rotating black hole case. By estimating the escape velocity of the outflowing particles, we find that nearly 10% of the accreting mass (decoupled from the bulk accretion flows) could participate in forming the outflows around a non-rotating black hole, while as much as 50% of the matter may contribute to the outflows around a rapidly-rotating black hole. In the context of disk-jet paradigm, our model suggests that shock-driven outflows from accretion can occur in regions not too far from a central engine (within 2-40 gravitational radii), as observed in some active galaxies (e.g., M87 and 3C120). Slope of radial density profile for upstream flows is found to be -3/2 as in advection-dominated accretion flow (ADAF) solution while that for downstream flows is as steep as -5/2. Our results imply that a shock front under some conditions could serve as a plausible site where seed particles of the outflows (jets/winds) are efficiently decoupled from bulk accretion.

  5. High resolution imaging of the outflow channels on Mars

    NASA Astrophysics Data System (ADS)

    Davatzes, A. K.; Gulick, V. C.

    2008-12-01

    We report observations of the outflow channels on Mars from HiRISE images in MRO's first Martian year. Several hundred images of the outflow channels on Mars have been collected to date from HiRISE, as well as coordinated images with CTX and CRISM. Depositional features, such as slackwater deposits and small bedforms that are expected to be visible at the resolution of HiRISE have not yet been observed, largely due to post-fluvial modification of the channels. Many of the channels have been subsequently covered by a thin layer of lava, ash, dust, or lineated valley fill. Although altered slightly by later aeolian modification, Ares Valles and Kasei Valles preserve much of the original fluvial erosional forms, particularly cataracts and longitudinal grooves that can be used to infer the mechanics of the flow. Cataracts, steep knickpoints in the large outflow channels, were once large waterfalls on the Martian surface. These have been observed in all of the larger outflow systems, including Kasai, Athabasca, Mangala, and Reull Valles. High resolution imaging shows that all of the cataract systems have multiple generations of erosion, with smaller subchannels within the cataract system. Based on the length of the recession and the morphological evidence most of the large channels experienced multiple flooding events or pulses. The tectonically sourced outflow channels, such as Athabasca and Mangala Valles, show sourcing at regions of complex fault geometries, specifically at fault relays. In terrestrial systems, relays tend to be regions of concentrated stress that can produce dilation manifested as high joint density, as well as point sources for hydrothermal outflow on Earth. Athabasca and Mangala Valles, sourced proximal to large volcanic centers, may have been regions of major hydrothermal activity in the past.

  6. A cluster of outflows in the Vulpecula Rift

    NASA Astrophysics Data System (ADS)

    Mottram, J. C.; Brunt, C. M.

    2012-02-01

    We present 12CO, 13CO and C18O (J=3-2) observations of a new cluster of outflows in the Vulpecula Rift with HARP on the James Clerk Maxwell Telescope (JCMT). The mass associated with the outflows, measured using the 12CO HARP observations and assuming a distance to the region of 2.3 kpc, is 129 M⊙, while the mass associated with the dense gas from C18O observations is 458 M⊙ and the associated sub-millimeter (sub-mm) core has a mass of 327 ± 112 M⊙ independently determined from Bolocam 1.1-mm data. The outflow-to-core mass ratio is therefore ˜0.4, making this region one of the most efficient observed thus far with more than an order of magnitude more mass in the outflow than would be expected based on previous results. The kinetic energy associated with the flows, 94 × 1045 erg, is enough to drive the turbulence in the local clump, and potentially unbind the local region altogether. The detection of SiO (J=8-7) emission towards the outflows indicates that the flow is still active, and not simply a fossil flow. We also model the spectral energy distributions (SEDs) of the four young stellar objects (YSOs) associated with the molecular material, finding them all to be of mid to early B spectral type. The energetic nature of the outflows and significant reservoir of cold dust detected in the sub-mm suggest that these intermediate mass YSOs will continue to accrete and become massive, rather than reach the main sequence at their current mass.

  7. SCATTERED EMISSION FROM z {approx} 1 GALACTIC OUTFLOWS

    SciTech Connect

    Martin, Crystal L.; Pancoast, Anna; Shapley, Alice E.; Kornei, Katherine A.; Coil, Alison L.; Murray, Norman

    2013-06-10

    Mapping Mg II resonance emission scattered by galactic winds offers a means to determine the spatial extent and density of the warm outflow. Using Keck/LRIS spectroscopy, we have resolved scattered Mg II emission to the east of 32016857, a star-forming galaxy at z = 0.9392 with an outflow. The Mg II emission from this galaxy exhibits a P-Cygni profile, extends further than both the continuum and [O II] emission along the eastern side of the slit, and has a constant Doppler shift along the slit which does not follow the velocity gradient of the nebular [O II] emission. Using the Sobolev approximation, we derive the density of Mg{sup +} ions at a radius of 12-18 kpc in the outflow. We model the ionization correction and find that much of the outflowing Mg is in Mg{sup ++}. We estimate that the total mass flux could be as large as 330-500 M{sub Sun} yr{sup -1}, with the largest uncertainties coming from the depletion of Mg onto grains and the clumpiness of the warm outflow. We show that confining the warm clouds with a hot wind reduces the estimated mass flux of the warm outflow and indicates a mass-loading factor near unity in the warm phase alone. Based on the high blue luminosities that distinguish 32016857 and TKRS 4389, described by Rubin et al., from other galaxies with P-Cygni emission, we suggest that, as sensitivity to diffuse emission improves, scattering halos may prove to be a generic property of star-forming galaxies at intermediate redshifts.

  8. Formation of Hydrocarbons in the Outflows from Red Giants

    NASA Technical Reports Server (NTRS)

    Roberge, Wayne; Kress, Monika; Tielens, Alexander G.

    1995-01-01

    The formation of hydrocarbons in the oxygen-rich outflows from red giants was studied. The existence of organic molecules in such outflows has been known for several years; however, their surprisingly high abundances has been a mystery since all of the carbon had been thought to be irretrievably locked up in CO, the most strongly bound molecule. CO is the first molecule to form from the atoms present in the star's extended atmosphere, and as strong stellar winds drive a cooling outflow, dust grains condense out. In oxygen-rich outflows, the dust is thought to be composed mainly of silicates and other metal oxides. Perhaps the noble metals can condense out in metallic form, in particular the relatively abundant transition metals iron and nickel. We proposed that perhaps the carbon reservoir held as CO can be accessed through a catalytic process involving the chemisorption of CO and H2 onto grains rich in metallic iron. CO and H2 are the two most abundant molecules in circumstellar outflows, and they both are known to dissociate on transition metal surfaces at elevated temperatures, freeing carbon to form organic molecules such as methane. We believe methane is a precursor molecule to the organics observed in oxygen-rich red giants. We have developed a nonequilibrium numerical model of a surface chemical (catalytic) process. Based on this model, we believe that methane can be formed under the conditions present in circumstellar outflows. Although the methane formation rates are exceptionally low under these conditions, over dynamical timescales, a significant amount of CO can be converted to methane and driven further out in the envelope, explaining the presence of organics there.

  9. Left Ventricular Outflow Tract Pseudoaneurysm after Aortic Valve Replacement

    PubMed Central

    Shariff, Masood A.; Martingano, Daniel; Khan, Usman; Goyal, Nikhil; Sharma, Raman; Rizvi, Syed B.; Motivala, Apurva; Asgarian, Kourosh T.; Nabagiez, John P.

    2015-01-01

    Left ventricular outflow tract pseudoaneurysm is an uncommon complication following aortic valve replacement (AVR), occurring most frequently secondary to endocarditis. We present a case of a 47-year-old female with a history of intravenous drug abuse and a past surgical history of two AVRs (2001 and 2009 with aortic root replacement for endocarditis) who presented with symptoms of lower extremity weakness. Subsequent radiologic imaging revealed the presence of a left ventricular outflow tract pseudoaneurysm, which was surgically managed with a homologous conduit. PMID:27175367

  10. The Anatomy of the Young Protostellar Outflow HH 211

    NASA Astrophysics Data System (ADS)

    Tappe, A.; Forbrich, J.; Martín, S.; Yuan, Y.; Lada, C. J.

    2012-05-01

    We present Spitzer Space Telescope 5-36 μm mapping observations toward the southeastern lobe of the young protostellar outflow HH 211. The southeastern terminal shock of the outflow shows a rich mid-infrared spectrum including molecular emission lines from OH, H2O, HCO+, CO2, H2, and HD. The spectrum also shows a rising infrared continuum toward 5 μm, which we interpret as unresolved emission lines from highly excited rotational levels of the CO v = 1-0 fundamental band. This interpretation is supported by a strong excess flux observed in the Spitzer/IRAC 4-5 μm channel 2 image compared to the other IRAC channels. The extremely high critical densities of the CO v = 1-0 ro-vibrational lines and a comparison to H2 and CO excitation models suggest jet densities larger than 106 cm-3 in the terminal shock. We also observed the southeastern terminal outflow shock with the Submillimeter Array and detected pure rotational emission from CO 2-1, HCO+ 3-2, and HCN 3-2. The rotationally excited CO traces the collimated outflow backbone as well as the terminal shock. HCN traces individual dense knots along the outflow and in the terminal shock, whereas HCO+ solely appears in the terminal shock. The unique combination of our mid-infrared and submillimeter observations with previously published near-infrared observations allow us to study the interaction of one of the youngest known protostellar outflows with its surrounding molecular cloud. Our results help us to understand the nature of some of the so-called green fuzzies (Extended Green Objects), and elucidate the physical conditions that cause high OH excitation and affect the chemical OH/H2O balance in protostellar outflows and young stellar objects. In an appendix to this paper, we summarize our Spitzer follow-up survey of protostellar outflow shocks to find further examples of highly excited OH occurring together with H2O and H2.

  11. THE ANATOMY OF THE YOUNG PROTOSTELLAR OUTFLOW HH 211

    SciTech Connect

    Tappe, A.; Forbrich, J.; Lada, C. J.; Martin, S.; Yuan, Y.

    2012-05-20

    We present Spitzer Space Telescope 5-36 {mu}m mapping observations toward the southeastern lobe of the young protostellar outflow HH 211. The southeastern terminal shock of the outflow shows a rich mid-infrared spectrum including molecular emission lines from OH, H{sub 2}O, HCO{sup +}, CO{sub 2}, H{sub 2}, and HD. The spectrum also shows a rising infrared continuum toward 5 {mu}m, which we interpret as unresolved emission lines from highly excited rotational levels of the CO v = 1-0 fundamental band. This interpretation is supported by a strong excess flux observed in the Spitzer/IRAC 4-5 {mu}m channel 2 image compared to the other IRAC channels. The extremely high critical densities of the CO v = 1-0 ro-vibrational lines and a comparison to H{sub 2} and CO excitation models suggest jet densities larger than 10{sup 6} cm{sup -3} in the terminal shock. We also observed the southeastern terminal outflow shock with the Submillimeter Array and detected pure rotational emission from CO 2-1, HCO{sup +} 3-2, and HCN 3-2. The rotationally excited CO traces the collimated outflow backbone as well as the terminal shock. HCN traces individual dense knots along the outflow and in the terminal shock, whereas HCO{sup +} solely appears in the terminal shock. The unique combination of our mid-infrared and submillimeter observations with previously published near-infrared observations allow us to study the interaction of one of the youngest known protostellar outflows with its surrounding molecular cloud. Our results help us to understand the nature of some of the so-called green fuzzies (Extended Green Objects), and elucidate the physical conditions that cause high OH excitation and affect the chemical OH/H{sub 2}O balance in protostellar outflows and young stellar objects. In an appendix to this paper, we summarize our Spitzer follow-up survey of protostellar outflow shocks to find further examples of highly excited OH occurring together with H{sub 2}O and H{sub 2}.

  12. A Model for Infall-Outflow Interactions in Protostellar Disks

    NASA Technical Reports Server (NTRS)

    Velusamy, W. Langer T.

    1997-01-01

    Recently we have shown(sup 1,2) from (sup 12)CO and C(sup 18)O OVRO-MMA observations evidence of infall-outflow interactions in the Young Stellar Object IRS1 in B5. We present new data obtained with the OVRO-MMA in (sup 13)CO(2-1) and (1-0) to trace the full extent of this infall-outflow interaction region.

  13. Super Star Clusters: the Engines of Galactic Outflows

    NASA Astrophysics Data System (ADS)

    Lockhart, Kelly; Lu, Jessica R.; Kewley, Lisa; Kudritzki, Rolf; Barnes, Joshua Edward

    2015-08-01

    Winds in starburst galaxies are ubiquitous; however, we still do not understand how winds from individual star clusters unite into a large-scale galactic outflow. Recent work suggests that radiation pressure from young (<7 Myr) massive super star clusters (SSCs) may be a necessary first step in launching global starburst winds. We have begun a program using integral field spectroscopy with Keck/OSIRIS to investigate the winds from these very young clusters, and how energy is transferred from the stellar population to the surrounding medium to launch galactic-scale outflows. We present preliminary work on a sample of young massive clusters from the Antennae.

  14. River Outflow of the Conterminous United States, 1939-1988.

    NASA Astrophysics Data System (ADS)

    Guetter, Alexandre K.; Georgakakos, Konstantine P.

    1993-10-01

    A record of 50 years of daily outflows through the boundaries of the continental United States has been assembled based on observations recorded by U.S. Geological Survey streamflow stations. Only stations with continuous records from 1939 through 1988 were included. These stations (197 total) are near the outlets of rivers located at the vicinity of the Canadian, Mexican, Atlantic (including the Gulf of Mexico), and Pacific borders of the continental United States. The drainage area of the selected stations covers 77% of the conterminous United States, whereas the existing network of gauging stations covers 83% of the conterminous U.S. area. Station daily data were aggregated over the entire boundary of the United States and were integrated in monthly and annual totals. The 50-year average annual streamflow divergence normalized by the aggregated drainage area is 210.2 mm yr1, reaching a peak in April with 27.3 mm month1 and a minimum in September with 8.7 mm month1. The Mississippi-Missouri Basin comprises 50% of the gauged area and dominates the absolute value of the outflow discharge. Spectral analysis of the monthly outflow anomalies shows an 11-year dominant cycle. The 1939-1988 period contains four notable droughts. Two droughts are partially registered in the limits of the records characterized by the negative anomalies extending from 1939 to 1941 and by the 1987-1988 anomalies for the late 1980s drought. The middle 1950s and early 1960s droughts are fully included in the dataset. Periods of high outflows were registered in the middle 1940s, early 1970s, and early 1980s. Analysis of the spatial coherence of the annual anomalies shows large-scale features, whereas analysis of the monthly anomalies yields the frequency and persistence patterns of floods and droughts. An estimate of the climatological land-surface water budget for the continental United States was done based on recorded precipitation, panevaporation, and outflow. Eigenvector analysis of the

  15. Fast outflows and star formation quenching in quasar host galaxies

    NASA Astrophysics Data System (ADS)

    Carniani, S.; Marconi, A.; Maiolino, R.; Balmaverde, B.; Brusa, M.; Cano-Díaz, M.; Cicone, C.; Comastri, A.; Cresci, G.; Fiore, F.; Feruglio, C.; La Franca, F.; Mainieri, V.; Mannucci, F.; Nagao, T.; Netzer, H.; Piconcelli, E.; Risaliti, G.; Schneider, R.; Shemmer, O.

    2016-06-01

    Negative feedback from active galactic nuclei (AGN) is considered a key mechanism in shaping galaxy evolution. Fast, extended outflows are frequently detected in the AGN host galaxies at all redshifts and luminosities, both in ionised and molecular gas. However, these outflows are only potentially able to quench star formation, and we are still lacking decisive evidence of negative feedback in action. Here we present observations obtained with the Spectrograph for INtegral Field Observations in the Near Infrared (SINFONI) H- and K-band integral-field of two quasars at z ~ 2.4 that are characterised by fast, extended outflows detected through the [Oiii]λ5007 line. The high signal-to-noise ratio of our observations allows us to identify faint narrow (FWHM< 500 km s-1) and spatially extended components in [Oiii]λ5007 and Hα emission associated with star formation in the host galaxy. This star formation powered emission is spatially anti-correlated with the fast outflows. The ionised outflows therefore appear to be able to suppress star formation in the region where the outflow is expanding. However, the detection of narrow spatially extended Hα emission indicates star formation rates of at least ~50-90 M⊙ yr-1, suggesting either that AGN feedback does not affect the whole galaxy or that many feedback episodes are required before star formation is completely quenched. On the other hand, the narrow Hα emission extending along the edges of the outflow cone may also lead also to a positive feedback interpretation. Our results highlight the possible double role of galaxy-wide outflows in host galaxy evolution. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, P.ID: 086.B-0579(A) and 091.A-0261(A).The reduced data cubes are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (http://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/591/A28

  16. The multi-phase winds of Markarian 231: from the hot, nuclear, ultra-fast wind to the galaxy-scale, molecular outflow

    NASA Astrophysics Data System (ADS)

    Feruglio, C.; Fiore, F.; Carniani, S.; Piconcelli, E.; Zappacosta, L.; Bongiorno, A.; Cicone, C.; Maiolino, R.; Marconi, A.; Menci, N.; Puccetti, S.; Veilleux, S.

    2015-11-01

    Mrk 231 is a nearby ultra-luminous IR galaxy exhibiting a kpc-scale, multi-phase AGN-driven outflow. This galaxy represents the best target to investigate in detail the morphology and energetics of powerful outflows, as well as their still poorly-understood expansion mechanism and impact on the host galaxy. In this work, we present the best sensitivity and angular resolution maps of the molecular disk and outflow of Mrk 231, as traced by CO(2-1) and (3-2) observations obtained with the IRAM/PdBI. In addition, we analyze archival deep Chandra and NuSTAR X-ray observations. We use this unprecedented combination of multi-wavelength data sets to constrain the physical properties of both the molecular disk and outflow, the presence of a highly-ionized ultra-fast nuclear wind, and their connection. The molecular CO(2-1) outflow has a size of 1 kpc, and extends in all directions around the nucleus, being more prominent along the south-west to north-east direction, suggesting a wide-angle biconical geometry. The maximum projected velocity of the outflow is nearly constant out to 1 kpc, thus implying that the density of the outflowing material must decrease from the nucleus outwards as r-2. This suggests that either a large part of the gas leaves the flow during its expansion or that the bulk of the outflow has not yet reached out to 1 kpc, thus implying a limit on its age of 1 Myr. Mapping the mass and energy rates of the molecular outflow yields dot {M} OF = [500-1000] M⊙ yr-1 and Ėkin,OF = [7-10] × 1043 erg s-1. The total kinetic energy of the outflow is Ekin,OF is of the same order of the total energy of the molecular disk, Edisk. Remarkably, our analysis of the X-ray data reveals a nuclear ultra-fast outflow (UFO) with velocity -20 000 km s-1, dot {M}UFO = [0.3-2.1] M⊙ yr-1, and momentum load dot {P}UFO/ dot {P}rad = [0.2-1.6]. We find Ėkin,UFO Ėkin,OF as predicted for outflows undergoing an energy conserving expansion. This suggests that most of the UFO

  17. Deciphering the mechanics of an imaged fault system in the over-riding plate at the Shumagin Seismic Gap, Alaska subduction zone using MCS waveform tomography

    NASA Astrophysics Data System (ADS)

    Michaelson, C. A.; Delescluse, M.; Becel, A.; Nedimovic, M. R.; Shillington, D. J.; Louden, K. E.; Webb, S. C.

    2013-12-01

    The 2011 ALEUT program acquired 3500 km of multichannel seismic (MCS) data along a part of the western Alaska subduction zone, from the freely slipping Shumagin Seismic Gap to the locked regions in the Semidi segment and the western Kodiak asperity. The MCS profiles were acquired on the R/V Langseth using two 8-km-long streamers and span the entire locked zone on the megathrust, including the updip and downdip transitions to stable sliding. The primary goal was to characterize variations in the geometry and properties of the megathrust and the downgoing plate and relate them to downdip and along-strike changes in slip behavior and seismogenesis. The images capture the targeted megathrust reflectivity and its spatial variation. Notably, the two westernmost profiles show reflections arising from a major fault in the overriding plate within the Shumagin Seismic Gap located 75 km from the trench, which can be followed from the seafloor to the megathrust. The imaged normal fault bounds the seaward end of the Sanak forearc Cenozoic basin, formed after the Early Eocene reorganization of the Alaska subduction zone. The new reflection images also show that the seaward pair of the previously interpreted growth faults, thought to indicate deposition contemporaneous with basin subsidence, is a part of the imaged fault system. The unexpected imaging of this major fault system in the over-riding plate raises important questions: Has this fault been active during the most recent nearby megathrust earthquakes, such as the 1946 and 1948 earthquakes? Was the Sanak basin formed as a result of slip on the imaged normal fault system or is it a result of growth faulting that predates the formation of this fault? The timing and style of deformation on this fault has significant implications for both coupling on the megathrust seaward and landward of where the normal fault roots and tsunamigenesis. To complement constraints on the geometry and reflection characteristics of this structure

  18. Strong composition-dependent variation of MCs + calibration factors in TiO x and GeO x ( x ≤ 2) films

    NASA Astrophysics Data System (ADS)

    Gnaser, Hubert; Le, Yongkang; Su, Weifeng

    2006-07-01

    The emission of MCs + secondary ions (M designates the analyte species) from TiO x (0.2 ≤ x ≤ 2) and GeO x (0.001 ≤ x ≤ 0.8) films under Cs + bombardment was examined. The relative calibration factors of OCs +/TiCs + and OCs +/GeCs + were determined and were found to depend pronouncedly on the O/Ti and O/Ge atomic concentration ratios. Specifically, with increasing oxygen content OCs + ions form much more efficiently (as compared to TiCs + or GeCs + ions), an enhancement amounting to more than a factor of 10 for the highest oxygen concentrations. Concurrently, the formation of TiOCs + or GeOCs + ions increases drastically. For both oxide systems, an empirical relation for the oxygen-concentration dependence of the relative calibration factors could be established.

  19. (abstract) A Test of the Theoretical Models of Bipolar Outflows: The Bipolar Outflow in Mon R2

    NASA Technical Reports Server (NTRS)

    Xie, Taoling; Goldsmith, Paul; Patel, Nimesh

    1993-01-01

    We report some results of a study of the massive bipolar outflow in the central region of the relatively nearby giant molecular cloud Monoceros R2. We make a quantative comparison of our results with the Shu et al. outflow model which incorporates a radially directed wind sweeping up the ambient material into a shell. We find that this simple model naturally explains the shape of this thin shell. Although Shu's model in its simplest form predicts with reasonable parameters too much mass at very small polar angles, as previously pointed out by Masson and Chernin, it provides a reasonable good fit to the mass distribution at larger polar angles. It is possible that this discrepancy is due to inhomogeneities of the ambient molecular gas which is not considered by the model. We also discuss the constraints imposed by these results on recent jet-driven outflow models.

  20. Aged Organic Aerosol in the Upper Troposphere: Aging of boundary layer aerosol during and after convective transport and in-situ SOA formation during DC3. (Invited)

    NASA Astrophysics Data System (ADS)

    Campuzano Jost, P.; Palm, B. B.; Day, D. A.; Ortega, A. M.; Hayes, P. L.; Jimenez, J. L.; Hodzic, A.; Bela, M. M.; Barth, M. C.; Olson, J. R.; Crawford, J. H.; Brune, W. H.; Pollack, I. B.; Ryerson, T. B.; Blake, D. R.; Wisthaler, A.; Mikoviny, T.

    2013-12-01

    While aerosol scavenging in deep convection is efficient (comparable to soluble species like formaldehyde), significant transport of submicron aerosol was observed repeatedly during storms targeted in the course of the DC3 (Deep Convective Clouds and Chemistry ) campaign. The lofted aerosol was mostly organic, and even in fresh outflow was significantly more oxidized than the aerosol sampled in the source region of the convection. Organic aerosol (OA) sampled in both day-old outflow as well as in the background continental UT was in general significantly more oxidized than OA observed both in the fresh outflow, and in most lower tropospheric aerosol. This suggests either fast oxidative chemistry, and/or long residence times in the UT. Some of the potential factors contributing to this fast oxidation will be explored in this talk. A second source of UT OA was observed during several flights where gas-phase organics in the presence of NOx lead to the formation of secondary OA (SOA), including particulate organic nitrate. Most observations of this UT SOA during DC3 were made in fresh outflow. However, a unique opportunity to study the chemistry of this SOA formation in more detail with a box model presented itself in the flight on July 21st, 2012; here an initially near-particle-free UT airmass originating in the wake of a dissolving nighttime mesoscale convective system (MCS) was observed over several hours until new particle growth dominated by OA and particulate nitrate was measured.

  1. Morphology of Fresh Outflow Channel Deposits on Mars

    NASA Technical Reports Server (NTRS)

    Rice, J. W., Jr.; Parker, T. J.; Russell, A. J.; Knudsen, O.

    2002-01-01

    We interpret the channel surface of Athabasca and Marte Valles to be fresh former ice-rich fluvial (hyperconcentrated) deposits rather than volcanic flows. Simply stated, this is what a fresh outflow channel deposit would look like. Additional information is contained in the original extended abstract.

  2. Far-Infrared Water Line Emissions from Circumstellar Outflows

    NASA Technical Reports Server (NTRS)

    Chen, Wesley; Neufeld, David A.

    1995-01-01

    We have modeled the far-infrared water line emission expected from circumstellar outflows from oxygen-rich late-type stars, as a function of the mass-loss rate and the terminal outflow velocity. For each mass-loss rate and terminal outflow velocity considered, we computed self-consistently the gas density, temperature, outflow velocity, and water abundance as a function of distance from the star. We then used an escape probability method to solve for the equilibrium level populations of 80 rotational states of water and thereby obtained predictions for the luminosity of a large number of far-infrared rotational transitions of water. In common with previous models, our model predicts that water will be copiously produced in the warm circumstellar gas and that water rotational emission will dominate the radiative cooling. However, our use of a realistic radiative cooling function for water leads to a lower gas temperature than that predicted in previous models. Our predictions for the far-infrared water line luminosities are consequently significantly smaller than those obtained in previous studies. Observations to be carried out by the Infrared Space Observatory will provide a crucial test of the models presented here.

  3. Atmospheric transport and outflow of polycyclic aromatic hydrocarbons from China.

    PubMed

    Lang, Chang; Tao, Shu; Liu, Wenxin; Zhang, Yanxu; Simonich, Staci

    2008-07-15

    A potential receptor influence function (PRIF) model, based on air mass forward trajectory calculations, was applied to simulate the atmospheric transport and outflow of polycyclic aromatic hydrocarbons (PAHs) emitted from China. With a 10 day atmospheric transport time, most neighboring countries and regions, as well as remote regions, were influenced by PAH emissions from China. Of the total annual PAH emission of 114 Gg, 92.7% remained within the boundary of mainland China. The geographic distribution of PRIFs within China was similar to the geographic distribution of the source regions, with high values in the North China Plain, Sichuan Basin, Shanxi, and Guizhou province. The Tarim basin and Sichuan basin had unfavorable meteorological conditions for PAH outflow. Of the PAH outflow from China (8092 tons or 7.1% of the total annual PAH emission), approximately 69.9% (5655 tons) reached no further than the offshore environment of mainland China and the South China Sea. Approximate 227, 71, 746, and 131 tons PAHs reached North Korea, South Korea, Russia-Mongolia region, and Japan, respectively, 2-4 days after the emission. Only 1.4 tons PAHs reached North America after more than 9 days. Interannual variation in the eastward PAH outflow was positively correlated to cold episodes of El Niño/Southern Oscillation. However, trans-Pacific atmospheric transport of PAHs from China was correlated to Pacific North America index (PNA) which is associated with the strength and position of westerly winds. PMID:18754369

  4. PROTOSTELLAR OUTFLOW HEATING IN A GROWING MASSIVE PROTOCLUSTER

    SciTech Connect

    Wang Ke; Wu Yuefang; Zhang Huawei; Zhang Qizhou; Li Huabai

    2012-02-15

    The dense molecular clump P1 in the infrared dark cloud complex G28.34+0.06 harbors a massive protostellar cluster at its extreme youth. Our previous Submillimeter Array observations revealed several jet-like CO outflows emanating from the protostars, indicative of intense accretion and potential interaction with ambient natal materials. Here, we present the Expanded Very Large Array spectral line observations toward P1 in the NH{sub 3} (J,K) = (1,1), (2,2), (3,3) lines, as well as H{sub 2}O and class I CH{sub 3}OH masers. Multiple NH{sub 3} transitions reveal the heated gas widely spread in the 1 pc clump. The temperature distribution is highly structured; the heated gas is offset from the protostars, and morphologically matches the outflows very well. Hot spots of spatially compact, spectrally broad NH{sub 3} (3,3) emission features are also found coincident with the outflows. A weak NH{sub 3} (3,3) maser is discovered at the interface between an outflow jet and the ambient gas. These findings suggest that protostellar heating may not be effective in suppressing fragmentation during the formation of massive cores.

  5. Simulated O VI Doppler dimming measurements of coronal outflow velocities

    NASA Technical Reports Server (NTRS)

    Strachan, Leonard; Gardner, L. D.; Kohl, John L.

    1992-01-01

    The possibility of determining O(5+) outflow velocities by using a Doppler dimming analysis of the resonantly scattered intensities of O VI lambda 1031.9 and lambda 1037.6 is addressed. The technique is sensitive to outflow velocities, W, in the range W greater than 30 and less than 250 km/s and can be used for probing regions of the inner solar corona, where significant coronal heating and solar wind acceleration may be occurring. These velocity measurements, when combined with measurements of other plasma parameters (temperatures and densities of ions and electrons) can be used to estimate the energy and mass flux of O(5+). In particular, it may be possible to locate where the flow changes from subsonic to supersonic and to identify source regions for the high and low speed solar wind. The velocity diagnostic technique is discussed with emphasis placed on the requirements needed for accurate outflow velocity determinations. Model determinations of outflow velocities based on simulated Doppler observations are presented.

  6. Estimation of the mass outflow rates around rotating black holes

    NASA Astrophysics Data System (ADS)

    Aktar, Ramiz; Das, Santabrata

    We consider steady, advective, rotating, inviscid accretion disc around the spinning black holes to compute the mass outflow rate (R_{dot{m}}) defined as the ratio of mass flux of outflowing to the inflowing matter. Due to centrifugal barrier, accreting matter suffers discontinuous shock transition and because of shock compression, the post-shock matter becomes hot and denser than the pre-shock matter. We call the post-shock disc as Post Shock Corona (PSC). During accretion, a part of the inflowing matter deflects as bipolar outflows due to the presence of excess thermal gradient force at PSC. We find that R_{dot{m}}is directly correlated with the spin of the black hole (a_{k}) for the same set of inflow parameter, namely specific energy (E) and specific angular momentum (λ). We observe that the maximum outflow rate(R_{dot{m}}^{max}) weakly depends on spin (a_{k}) that lies in the range˜ 17% - 18% of the inflow rate.

  7. Effects of stellar outflows on interstellar sulfur oxide chemistry

    NASA Technical Reports Server (NTRS)

    Welch, W. J.; Vogel, S.; Terebey, S.; Dreher, J.; Jackson, J.; Carlstrom, J.

    1986-01-01

    Interferometer Maps with 2" to 6" resolution of a number of regions with active star formation (Orion A, W49, W51, SGRB2) show that the distribution of the molecule SO is very compact around stellar outflow sources. Both SO and SO2 were studied near three outflows, OrionA/IRc2 and two sources in W49. The two molecules have similar distributions and abundances. More than 95% of the emission comes from regions whose extents are only .05 to .2 pc., being larger around the more energetic sources. Their spectra are broad, 30 km/sec or more, suggesting that the oxide production is associated with the flows. The outflows are identified by water masers and by extended bipolar flows in SiO. Maps in other molecules, such as HCO+ and CS, which have similar collisional excitation requirements, have much greater spatial extent. Thus it appears that the SO and SO2 abundances are truly compact and are closely associated with the outflows.

  8. Atmospheric transport and outflow of polycyclic aromatic hydrocarbons from China

    SciTech Connect

    Chang Lang; Shu Tao; Wenxin Liu; Yanxu Zhang; Staci Simonich

    2008-07-15

    A potential receptor influence function (PRIF) model, based on air mass forward trajectory calculations, was applied to simulate the atmospheric transport and outflow of polycyclic aromatic hydrocarbons (PAHs) emitted from China. With a 10 day atmospheric transport time, most neighboring countries and regions, as well as remote regions, were influenced by PAH emissions from China. Of the total annual PAH emission of 114 Gg, 92.7% remained within the boundary of mainland China. The geographic distribution of PRIFs within China was similar to the geographic distribution of the source regions, with high values in the North China Plain, Sichuan Basin, Shanxi, and Guizhou province. The Tarim basin and Sichuan basin had unfavorable meteorological conditions for PAH outflow. Of the PAH outflow from China (8092 tons or 7.1% of the total annual PAH emission), approximately 69.9% (5655 tons) reached no further than the offshore environment of mainland China and the South China Sea. Approximate 227, 71, 746, and 131 tons PAHs reached North Korea, South Korea, Russia-Mongolia region, and Japan, respectively, 2-4 days after the emission. Only 1.4 tons PAHs reached North America after more than 9 days. Interannual variation in the eastward PAH outflow was positively correlated to cold episodes of El Nino/Southern Oscillation. However, trans-Pacific atmospheric transport of PAHs from China was correlated to Pacific North America index (PNA) which is associated with the strength and position of westerly winds. 38 refs., 4 figs.

  9. Star formation and the nature of bipolar outflows

    NASA Technical Reports Server (NTRS)

    Shu, Frank H.; Ruden, Steven P.; Lada, Charles J.; Lizano, Susana

    1991-01-01

    This paper presents a simple physical model for the bipolar molecular outflows that frequently accompany star formation. The model forges an intrinsic link between the bipolar flow phenomenon and the process of star formation, and it helps to explain many of the systematics known for existing sources.

  10. ARE MOLECULAR OUTFLOWS AROUND HIGH-MASS STARS DRIVEN BY IONIZATION FEEDBACK?

    SciTech Connect

    Peters, Thomas; Klessen, Ralf S.; Klaassen, Pamela D.; Mac Low, Mordecai-Mark; Banerjee, Robi

    2012-11-20

    The formation of massive stars exceeding 10 M {sub Sun} usually results in large-scale molecular outflows. Numerical simulations, including ionization, of the formation of such stars show evidence for ionization-driven molecular outflows. Here we examine whether the outflows seen in these models reproduce the observations. We compute synthetic ALMA and CARMA maps of CO emission lines of the outflows, and compare their signatures to existing single-dish and interferometric data. We find that the ionization-driven models can only reproduce weak outflows around high-mass star-forming regions. We argue that expanding H II regions probably do not represent the dominant mechanism for driving observed outflows. We suggest instead that observed outflows are driven by the collective action of the outflows from the many lower-mass stars that inevitably form around young massive stars in a cluster.

  11. Effects of induction and inhibition of matrix cross-linking on remodeling of the aqueous outflow resistance by ocular trabecular meshwork cells

    PubMed Central

    Yang, Yong-Feng; Sun, Ying Ying; Acott, Ted S.; Keller, Kate E.

    2016-01-01

    The trabecular meshwork (TM) tissue controls drainage of aqueous humor from the anterior chamber of the eye primarily by regulating extracellular matrix (ECM) remodeling by matrix metalloproteinases (MMPs). Glaucomatous TM tissue is stiffer than age-matched controls, which may be due to alterations in ECM cross-linking. In this study, we used genipin or beta-aminopropionitrile (BAPN) agents to induce or inhibit matrix cross-linking, respectively, to investigate the effects on outflow resistance and ECM remodeling. Treatment with BAPN increased outflow rates in perfused human and porcine anterior segments, whereas genipin reduced outflow. Using a fluorogenic peptide assay, MMP activity was increased with BAPN treatment, but reduced with genipin treatment. In genipin-treated TM cells, Western immunoblotting showed a reduction of active MMP2 and MMP14 species and the presence of TIMP2-MMP14 higher molecular weight complexes. BAPN treatment increased collagen type I mRNA and protein levels, but genipin reduced the levels of collagen type I, tenascin C, elastin and versican. CD44 and fibronectin levels were unaffected by either treatment. Collectively, our results show that matrix cross-linking has profound effects on outflow resistance and ECM composition and are consistent with the emerging paradigm that the stiffer the ECM, the lower the aqueous outflow facility through the TM. PMID:27465745

  12. Storm time heavy ion outflow at mid-latitudes

    SciTech Connect

    Yeh, H.C.; Foster, J.C. )

    1990-06-01

    Local ionospheric observations with the Millstone Hill incoherent scatterradar reveal an upward ion bulk velocity in excess of 3 km s{sup {minus} 1} at 1,000 km altitude during the very large magnetic storm on February 8, 1986. The upward flux of O{sup +} ions exceeded 3 {times} 10{sup 9} cm{sup {minus}2} s{sup {minus}1} at 42{degree} geodetic latitude (55{degree} {Lambda}) for a 3-hour period around 18 MLT during the event. Frictinal ion heating with ion temperatures in excess of 4,000 K at 500 km altitude was observed by the radar in the vicinity of the ion outflow event. Satellite observations place the ion outflow event within a region of intense ion and electron precipitation on field lines associated with the storm-perturbed ring current. For a one-dimensional analysis of the observed plasma profiles, continuity considerations indicate a region of intense O{sup +} production (200 cm{sup {minus}3} s{sup {minus}1}) as well as significant upward acceleration (5-10 m s{sup {minus}2}) in the region between 600 km and 800 km altitude where the outflow approaches supersonic speed. Ionizing collisions involving fast backsplash neutral O atoms (Torr et al., 1974) produced by ring current heavy ion precipitation can provide sufficient upward momentum to account for the acceleration in the observed outflowing thermal O{sup +} fluxes. Alternatively, the outflow event can be explained in terms of a time-dependent diffusion process triggered by a sudden change in the frictional heating rate in the collision-dominated F region (St.-Maurice, 1989). The concurrence of rapid ion convection and energetic ring current precipitation is unique at mid-latitudes during intense magnetic storms. Under these conditions, the observations indicate that the mid-latitude ionosphere constitutes a significant source of upflowing thermal O{sup +} fluxes to the overlying magnetosphere.

  13. Generation of shockwave and vortex structures at the outflow of a boiling water jet

    NASA Astrophysics Data System (ADS)

    Alekseev, M. V.; Lezhnin, S. I.; Pribaturin, N. A.; Sorokin, A. L.

    2014-12-01

    Results of numerical simulation for shock waves and generation of vortex structures during unsteady outflow of boiling liquid jet are presented. The features of evolution of shock waves and vortex structures formation during unsteady outflow of boiling water are compared with corresponding structures during unsteady gas outflow.

  14. Late renal failure due to prostatic outflow obstruction: a preventable disease.

    PubMed

    Sacks, S H; Aparicio, S A; Bevan, A; Oliver, D O; Will, E J; Davison, A M

    1989-01-21

    Nineteen patients presenting with late renal failure due to prostatic outflow obstruction (mean age 68.7 years; mean serum creatinine concentration 1158 mumol/l) were identified from the admission records of two renal units. As late renal failure secondary to prostatic enlargement is preventable case records were analysed retrospectively in an attempt to identify aspects of management in which preventive efforts might be of value. Delays in referral were common, with a mean of 2.8 years between the onset of prostatic symptoms and time of referral, six patients being referred who had had symptoms for more than three years. Four of five patients who had had a prostatectomy were known to be in renal failure at the time of operation but were not referred until 2-13 years later, when prostatic symptoms had recurred and there was evidence of progressive nephropathy with dilatation of the upper urinary tract. Two patients died on admission and eight (47% of survivors) required long term dialysis, most patients (80%) requiring some dialysis support during the initial period. These findings suggest that progressive nephropathy caused by prostatic outflow obstruction might, in part, be averted by more adequate screening of renal function in men with untreated prostatism and closer follow up of patients with uraemia at the time of prostatectomy. PMID:2466506

  15. STIS Observations of the Disk and Outflow of the Herbig Ae Star HD163296

    NASA Technical Reports Server (NTRS)

    Kimble, Randy; Fisher, Richard R. (Technical Monitor)

    2001-01-01

    Coronagraphic imaging with the Space Telescope Imaging Spectrograph on board the Hubble Space Telescope reveals a approx. 450 AU radius circumstellar disk around the Herbig Ae star HDI63296. The disk includes an annulus of reduced scattering at 325 AU and exhibits a flat trend of surface brightness in to 180-222 AU, consistent with a cleared central zone. The disk is accompanied by a chain of nebulosities ("knots") oriented roughly perpendicular to the disk. Followup spectroscopy in the visible and the far ultraviolet confirms the Herbig-Haro nature of the observed knots. The FUV data in particular reveal the presence of a collimated, bipolar outflow, with a blue-shifted Lyman alpha jet that can be traced to within 0.06 arcseconds (7.3 AU) of HD163296 and a red-shifted Lyman alpha component that may be due to infall or to a poorly collimated wind. If the estimated age of this system is correct, these data indicate that protostellar outflows may last up to 10 times longer than previously believed.

  16. Temporal changes in the geographic distribution, elevation, and potential origin of the Martian outflow channels

    NASA Technical Reports Server (NTRS)

    Tribe, S.; Clifford, S. M.

    1993-01-01

    Observational evidence of outflow channel activity on Mars suggests that water was abundant in the planet's early crust. However, with the decline in the planet's internal heat flow, a freezing front developed within the regolith that propagated downward with time and acted as a thermodynamic sink for crustal H2O. One result of this thermal evolution is that, if the initial inventory of water on Mars was small, the cryosphere may have grown to the point where all the available water was taken up as ground ice. Alternatively, if the inventory of H2O exceeds the current pore volume of the cryosphere, then Mars has always possessed extensive bodies of subpermafrost groundwater. We have investigated the relative age, geographic distribution, elevation, and geologic setting of the outflow channels in an effort to accomplish the following: (1) identify possible modes of origin and evolutionary trends in their formation; (2) gain evidence regarding the duration and spatial distribution of groundwater in the crust; and (3) better constraint estimates of the planetary inventory of H2O.

  17. Fast outflows in broad absorption line quasars and their connection with CSS/GPS sources

    NASA Astrophysics Data System (ADS)

    Bruni , G.; Mack, K.-H.; Montenegro-Montes, F. M.; Brienza, M.; González-Serrano, J. I.

    2016-02-01

    Broad absorption line quasars are among the objects presenting the fastest outflows. The launching mechanism itself is not completely understood. Models in which they could be launched from the accretion disk, and then curved and accelerated by the effect of the radiation pressure, have been presented. We conducted an extensive observational campaign, from radio to optical band, to collect information about their nature and test the models present in the literature, the main dichotomy being between a young scenario and an orientation one. We found a variety of possible orientations, morphologies, and radio ages, not converging to a particular explanation for the BAL phenomenon. From our latest observations in the m- and mm-band, we obtained an indication of a lower dust abundance with respect to normal quasars, thus suggesting a possible feedback process on the host galaxy. Also, in the low-frequency regime we confirmed the presence of CSS components, sometime in conjunction with a GPS one already detected at higher frequencies. Following this, about 70 % of our sample turns out to be in a GPS or CSS+GPS phase. We conclude that fast outflows, responsible for the BAL features, can be more easily present among objects going through a restarting or just-started radio phase, where radiation pressure can substantially contribute to their acceleration.

  18. Characterizing Quasar Outflows III: SEDs, and Bolometric Luminosity Estimates

    NASA Astrophysics Data System (ADS)

    Richmond, Joseph; Robbins, J. M.; Ganguly, R.; Stark, M. A.; Christenson, D. H.; Derseweh, J. A.; Townsend, S. L.

    2012-05-01

    Galaxy evolution models have shown that quasars are a crucial ingredient in the evolution of massive galaxies. Outflows play a key role in the story of quasars and their host galaxies, by helping regulate the accretion process, the star-formation rate and mass of the host galaxy (i.e., feedback). The prescription for modeling outflows as a contributor to feedback requires knowledge of the outflow velocity, geometry, and column density. In particular, we need to understand how these depend on physical parameters and how much is determined stochastically (and with what distribution). For this purpose, we are examining a sample of 11000 z=1.7-2.0 quasars from the Sloan Digital Sky Survey. This redshift range permits the following from the SDSS spectra: (1) separation of objects that do and do not exhibit outflows; (2) classification/measurement of outflow properties (ionization, velocity, velocity width); and (3) measurements of UV emission line and continuum parameters. In this poster, we add photometry from both the Two Micron All-Sky Survey (2MASS) and from the Wide-Field Infrared Survey Explorer (WISE). 2MASS photometry covers the rest-frame optical regime of these qusars, while the WISE W1, W2, and W3 bands cover the rest-frame wavelength ranges 0.9-1.27 micron, 1.35-1.75 micron, and 2.52-5.51 micron, respectively. The preliminary release of WISE data cover 3800 of our quasars. In an accompnying poster, we have subjectively divided these quasars into four categories: broad absorption-line quasars (2700 objects), associated absorption-line quasars (1700 objects), reddened quasars (160 objects), and unabsorbed/unreddened quasars (6300 objects). Here, we present average SEDs for these subsamples, estimates of bolometric luminosity, and explore changes in SED based on both outflow properties and quasar physical properties. This material is based upon work supported by the National Aeronautics and Space Administration under Grant No. 09-ADP09-0016 issued through the

  19. Grain formation around carbon stars. 1: Stationary outflow models

    NASA Technical Reports Server (NTRS)

    Egan, Michael P.; Leung, Chun Ming

    1995-01-01

    Asymptotic giant branch (AGB) stars are known to be sites of dust formation and undergo significant mass loss. The outflow is believed to be driven by radiation pressure on grains and momentum coupling between the grains and gas. While the physics of shell dynamics and grain formation are closely coupled, most previous models of circumstellar shells have treated the problem separately. Studies of shell dynamics typically assume the existence of grains needed to drive the outflow, while most grain formation models assume a constant veolcity wind in which grains form. Furthermore, models of grain formation have relied primarily on classical nucleation theory instead of using a more realistic approach based on chemical kinetics. To model grain formation in carbon-rich AGB stars, we have coupled the kinetic equations governing small cluster growth to moment equations which determine the growth of large particles. Phenomenological models assuming stationary outflow are presented to demonstrate the differences between the classical nucleation approach and the kinetic equation method. It is found that classical nucleation theory predicts nucleation at a lower supersaturation ratio than is predicted by the kinetic equations, resulting in significant differences in grain properties. Coagulation of clusters larger than monomers is unimportant for grain formation in high mass-loss models but becomes more important to grain growth in low mass-loss situations. The properties of the dust grains are altered considerably if differential drift velocities are ignored in modeling grain formation. The effect of stellar temperature, stellar luminosity, and different outflow velocities are investigated. The models indicate that changing the stellar temperature while keeping the stellar luminosity constant has little effect on the physical parameters of the dust shell formed. Increasing the stellar luminosity while keeping the stellar temperature constant results in large differences in

  20. Hydrodynamic Simulations of Jet- and Wind-driven Protostellar Outflows

    NASA Astrophysics Data System (ADS)

    Lee, Chin-Fei; Stone, James M.; Ostriker, Eve C.; Mundy, Lee G.

    2001-08-01

    We present two-dimensional hydrodynamic simulations of both jet- and wind-driven models for protostellar outflows in order to make detailed comparisons to the kinematics of observed molecular outflows. The simulations are performed with the ZEUS-2D hydrodynamic code using a simplified equation of state, simplified cooling and no external heating, and no self-gravity. In simulations of steady jets, swept-up ambient gas forms a thin shell that can be identified as a molecular outflow. We find a simple ballistic bow shock model is able to reproduce the structure and transverse velocity of the shell. Position-velocity (PV) diagrams for the shell cut along the outflow axis show a convex spur structure with the highest velocity at the bow tip and low-velocity red and blue components at any viewing angle. The power-law index of the mass-velocity (MV) relationship ranges from 1.5 to 3.5, depending strongly on the inclination. If the jet is time-variable, the PV diagrams show multiple convex spur structures, and the power-law index becomes smaller than the steady jet simulation. In simulations of isothermal steady wide-angle winds, swept-up ambient gas forms a thin shell that at early stages has a similar shape to the shell in the jet-driven model; it becomes broader at later times. We find the structure and kinematics of the shell is well described by a momentum-conserving model similar to that of Shu et al. (1991). In contrast to the results from jet simulations, the PV diagrams for the shell cut along the outflow axis show a lobe structure tilted with source inclination, with components that are primarily either red or blue unless the inclination is nearly in the plane of sky. The power-law index of the MV relationship ranges from 1.3 to 1.8. If the wind is time-variable, the PV diagrams also show multiple structures, and the power-law index becomes smaller than the steady wind simulation. Comparing the different simulations with observations, we find that some outflows

  1. A young bipolar outflow from IRAS 15398-3359

    NASA Astrophysics Data System (ADS)

    Bjerkeli, P.; Jørgensen, J. K.; Brinch, C.

    2016-03-01

    Context. Changing physical conditions in the vicinity of protostars allow for a rich and interesting chemistry to occur. Heating and cooling of the gas allows molecules to be released from and frozen out on dust grains. These changes in physics, traced by chemistry as well as the kinematical information, allows us to distinguish between different scenarios describing the infall of matter and the launching of molecular outflows and jets. Aims: We aim to determine the spatial distribution of different species that are of different chemical origin. This is to examine the physical processes in play in the observed region. From the kinematical information of the emission lines we aim to determine the nature of the infalling and outflowing gas in the system. We also aim to determine the physical properties of the outflow. Methods: Maps from the Submillimeter Array (SMA) reveal the spatial distribution of the gaseous emission towards IRAS 15398-3359. The line radiative transfer code LIME is used to construct a full 3D model of the system taking all relevant components and scales into account. Results: CO, HCO+, and N2H+ are detected and shown to trace the motions of the outflow. For CO, the circumstellar envelope and the surrounding cloud also have a profound impact on the observed line profiles. N2H+ is detected in the outflow, but is suppressed towards the central region, perhaps because of the competing reaction between CO and H3+ in the densest regions as well as the destruction of N2H+ by CO. N2D+ is detected in a ridge south-west of the protostellar condensation and is not associated with the outflow. The morphology and kinematics of the CO emission suggests that the source is younger than ~1000 years. The mass, momentum, momentum rate, mechanical luminosity, kinetic energy, and mass-loss rate are also all estimated to be low. A full 3D radiative transfer model of the system can explain all the kinematical and morphological features in the system.

  2. Effects of Prostaglandin Analogues on Aqueous Humor Outflow Pathways

    PubMed Central

    Winkler, Nelson S.

    2014-01-01

    Abstract Elevated intraocular pressure (IOP) is the most prevalent risk factor for glaucoma. All treatments, whether surgical or pharmaceutical, are aimed at lowering IOP. Prostaglandin analogues are a first line therapy for glaucoma due to their ability to reduce IOP, once-daily dosing, efficacy, and minimal side-effect profile. Whereas prostaglandin analogues have been known to alter aqueous humor outflow through the unconventional (uveoscleral) pathway, more recent evidence suggests their action also occurs through the conventional (trabecular) pathway. Understanding how prostaglandin analogues successfully lower IOP is important, as this information may lead to the discovery of new molecular targets for future therapeutic intervention. This review explores the current understanding of prostaglandin analogue biology as it pertains to IOP reduction and improved aqueous humor outflow facility. PMID:24359106

  3. The Influence of Outflow in Supercritical Accretion Flows

    NASA Astrophysics Data System (ADS)

    Zahra Zeraatgari, Fatemeh; Abbassi, Shahram; Mosallanezhad, Amin

    2016-06-01

    We solve the radiation-hydrodynamic equations of supercritical accretion flows in the presence of radiation force and outflow by using self-similar solutions. Similar to the pioneering works, in this paper we consider a power-law function for mass inflow rate as \\dot{M}\\propto {r}s. We found that s = 1 when the radiative cooling term is included in the energy equation. Correspondingly, the effective temperature profile with respect to the radius was obtained as {T}{eff}\\propto {r}-1/2. In addition, we investigated the influence of the outflow on the dynamics of the accretion flow. We also calculated the continuum spectrum emitted from the disk surface as well as the bolometric luminosity of the accretion flow. Furthermore, our results show that the advection parameter, f, depends strongly on mass inflow rate.

  4. Modeling the interaction between convection and nonthermal ion outflows

    NASA Astrophysics Data System (ADS)

    Varney, R. H.; Wiltberger, M.; Lotko, W.

    2015-03-01

    Initial demonstrations of an ionosphere/polar wind model including a phenomenological treatment of transverse heating by wave particle interactions (WPIs) are presented. Tests with fixed WPI parameters in a designated heating region on the dayside with time-varying convection show that the parameters of the resulting nonthermal ion outflow are strongly coupled to the convection. The hemispheric outflow rate is positively correlated with the convection speed with a time delay related to the travel time to the upper boundary. Increases in convection increase the thermal plasma access to the heating region, both by increasing the upflow associated with frictional heating and by increasing the horizontal transport. The average parallel velocities and energies of the escaping nonthermal ions are anticorrelated with the convection speed due to the finite dwell time in the heating region. The computationally efficient model can be readily coupled into global geospace modeling frameworks in the future.

  5. Experimental demonstration of an inertial collimation mechanism in nested outflows.

    PubMed

    Yurchak, R; Ravasio, A; Pelka, A; Pikuz, S; Falize, E; Vinci, T; Koenig, M; Loupias, B; Benuzzi-Mounaix, A; Fatenejad, M; Tzeferacos, P; Lamb, D Q; Blackman, E G

    2014-04-18

    Interaction between a central outflow and a surrounding wind is common in astrophysical sources powered by accretion. Understanding how the interaction might help to collimate the inner central outflow is of interest for assessing astrophysical jet formation paradigms. In this context, we studied the interaction between two nested supersonic plasma flows generated by focusing a long-pulse high-energy laser beam onto a solid target. A nested geometry was created by shaping the energy distribution at the focal spot with a dedicated phase plate. Optical and x-ray diagnostics were used to study the interacting flows. Experimental results and numerical hydrodynamic simulations indeed show the formation of strongly collimated jets. Our work experimentally confirms the "shock-focused inertial confinement" mechanism proposed in previous theoretical astrophysics investigations. PMID:24785042

  6. Incidence of galactic outflows: EAGLE simulations vs SAMI observations

    NASA Astrophysics Data System (ADS)

    Tescari, E.

    2016-06-01

    I presented the results of the joint SAMI-EAGLE project on outflows I lead at the University of Melbourne. We use the highest resolution EAGLE cosmological simulations to study the incidence of supernova driven winds ejected from galaxies on the main sequence. We produce synthetic SAMI observations of outflows that we compare directly with real data. While winds are observed in only a fraction of SAMI galaxies, they appear ubiquitous among simulated star forming objects. Moreover, the velocity dispersion distribution is only weakly dependent on stellar mass (M*) and sSFR (SFR/M*). I presented additional analyses and discuss the implications of these results and how they provide important constraints to ongoing and future IFS surveys.

  7. Younger Dryas interval and outflow from the Laurentide ice sheet

    USGS Publications Warehouse

    Moore, T.C., Jr.; Walker, J.C.G.; Rea, David K.; Lewis, C.F.M.; Shane, L.C.K.; Smith, A.J.

    2000-01-01

    A boxmodel of the Great Lakes is used to estimate meltwater flow into the North Atlantic between 8000 and 14,000 calendar years B.P. Controls on the model include the oxygen isotopic composition of meltwaters and lake waters as measured in the shells of ostracodes. Outflow rates are highest when oxygen isotopic values of the lake waters are most negative, denoting a maximum glacial meltwater component. Flow rates reach maximum values before the onset of the Younger Dryas and after it ends. These maxima appear to be correlative with the major meltwater pulses MWP 1A and 1B. Although the resumption of North Atlantic Deep Water formation may be tied to the reduction in ice sheet melting, neither the onset nor the end of the Younger Dryas, as recorded in the Greenland Ice Sheet Project (GISP2) records, appear tied to maxima in meltwater outflow from the Laurentide ice sheet. Copyright 2000 by the American Geophysical Union.

  8. Experimental Demonstration of an Inertial Collimation Mechanism in Nested Outflows

    NASA Astrophysics Data System (ADS)

    Yurchak, R.; Ravasio, A.; Pelka, A.; Pikuz, S.; Falize, E.; Vinci, T.; Koenig, M.; Loupias, B.; Benuzzi-Mounaix, A.; Fatenejad, M.; Tzeferacos, P.; Lamb, D. Q.; Blackman, E. G.

    2014-04-01

    Interaction between a central outflow and a surrounding wind is common in astrophysical sources powered by accretion. Understanding how the interaction might help to collimate the inner central outflow is of interest for assessing astrophysical jet formation paradigms. In this context, we studied the interaction between two nested supersonic plasma flows generated by focusing a long-pulse high-energy laser beam onto a solid target. A nested geometry was created by shaping the energy distribution at the focal spot with a dedicated phase plate. Optical and x-ray diagnostics were used to study the interacting flows. Experimental results and numerical hydrodynamic simulations indeed show the formation of strongly collimated jets. Our work experimentally confirms the "shock-focused inertial confinement" mechanism proposed in previous theoretical astrophysics investigations.

  9. On the Thermal Line Emission from the Outflows in Ultraluminous X-Ray Sources

    NASA Astrophysics Data System (ADS)

    Xu, Ya-Di; Cao, Xinwu

    2016-08-01

    The atomic features in the X-ray spectra of ultraluminous X-ray sources (ULXs) may be associated with the outflow, which may provide a way to explore the physics of the ULXs. We construct a conical outflow model and calculate the thermal X-ray Fe emission lines from the outflows. Our results show that thermal line luminosity decreases with increasing outflow velocity and/or opening angle of the outflow for a fixed kinetic power of the outflows. Assuming the kinetic power of the outflows to be comparable with the accretion power in the ULXs, we find that the equivalent width can be several eV for the thermal X-ray Fe emission line from the outflows in the ULXs with stellar-mass black holes. The thermal line luminosity is proportional to 1/M bh (M bh is the black hole mass of the ULX). The equivalent width decreases with the black hole mass, which implies that the Fe line emission from the outflows can hardly be detected if the ULXs contain intermediate-mass black holes. Our results suggest that the thermal X-ray Fe line emission should be preferentially be detected in the ULXs with high kinetic power slowly moving outflows from the accretion disks surrounding stellar-mass black holes/neutron stars. The recently observed X-ray atomic features of the outflows in a ULX may imply that it contains a stellar-mass black hole.

  10. The JCMT Gould Belt Survey: Understanding the influence of outflows on Gould Belt clouds

    NASA Astrophysics Data System (ADS)

    Drabek-Maunder, E.; Hatchell, J.; Buckle, J. V.; Di Francesco, J.; Richer, J.

    2016-03-01

    Using James Clerk Maxwell Telescope (JCMT) Gould Belt Survey data from CO J = 3 → 2 isotopologues, we present a meta-analysis of the outflows and energetics of star-forming regions in several Gould Belt clouds. The majority of the regions are strongly gravitationally bound. There is evidence that molecular outflows transport large quantities of momentum and energy. Outflow energies are at least 20 per cent of the total turbulent kinetic energies in all of the regions studied and greater than the turbulent energy in half of the regions. However, we find no evidence that outflows increase levels of turbulence, and there is no correlation between the outflow and turbulent energies. Even though outflows in some regions contribute significantly to maintaining turbulence levels against dissipation, this relies on outflows efficiently coupling to bulk motions. Other mechanisms (e.g. supernovae) must be the main drivers of turbulence in most if not all of these regions.

  11. A spectacular molecular outflow in the Monoceros OB1 molecular cloud

    NASA Technical Reports Server (NTRS)

    Margulis, Michael; Lada, Charles J.; Hasegawa, Tetsuo; Hayashi, Saeko S.; Hayashi, Masihiko

    1990-01-01

    Detailed observations of CO, CS, IR continuum, and H2 emission from a large, highly collimated, bipolar outflow in the Monoceros OB1 molecular cloud are presented. The CO observations suggest that molecular gas in the outflow is contained in a shell with higher velocity material situated interior to lower velocity material. The velocities of outflow emission are found to increase with increasing distance from the center of the outflow. Additional detections include shock-excited molecular hydrogen emission from the blueshifted lobe of the outflow and six 2-micron sources in the direction of the outflow. Near-IR and IRAS observations suggest that the driving source for the outflow must have a bolometric luminosity below about 4.5 solar luminosities. It is concluded that the flow is probably not driven by stellar radiation from a central source.

  12. Testing the Radiative-Driving Hypothesis of Quasar Outflows

    NASA Astrophysics Data System (ADS)

    Stark, Michele A.; Ganguly, R.; Gallagher, S. C.; Gibson, R.; Brotherton, M. S.

    2011-01-01

    Outflows are seen prominently in the UV spectra of Broad Absorption Line (BAL) QSOs. Models of radiatively-driven outflows predict that the velocity should scale with UV luminosity. Observations show that the UV luminosity only provides a cap to the velocity. One explanation is that the X-ray absorbing gas in an individual quasar provides a shield that improves its radiative-driving efficiency. That is, quasars with thick shields can accelerate gas to higher velocity. X-ray observations of BALQSOs support this in the sense that BALQSOs with more soft X-ray absorption tend to have higher velocity outflows. But there is much scatter in this trend, making the underlying physics difficult to extract. To combat this, we conducted an experiment using exploratory Chandra-ACIS observations of 12 carefully-selected z=1.7-2.0 BALQSOs. These BALQSOs were chosen to have very narrow ranges in (1) UV luminosity, (2) UV spectral shape, and (3) absorption velocity width. Within this otherwise uniform sample, the outflow velocities range from 4500km/s to 18000km/s, a factor of four. All objects are detected in the full band (0.5-8keV), with count rates in the range (0.5-5)e-3 cps, and have hardness ratios in the range -0.6 to 0.3. We compare the X-ray brightnesses and spectral shapes of our sample with those of more diverse samples of BALQSOs. We gratefully acknowledge support through Chandra grant GO9-0120X.

  13. Thermospheric Wind Impacts on Ionospheric Upflow and Outflow

    NASA Astrophysics Data System (ADS)

    Burleigh, M.; Zettergren, M. D.

    2014-12-01

    Significant amounts of thermal ionospheric plasma can be transported to high altitudes in response to magnetospheric and atmospheric forcing. Soft electron precipitation serves as a heat source for the ambient F-region ionospheric electrons, which enhances the ambipolar electric field and induces upflowing ions. Frictional heating of ions from fast convection through the neutral atmosphere creates pressure-driven ion upflows. Finally, large neutral winds along the geomagnetic field may effectively lift or lower the F-region density peak. At regions above where ion upflows are typically initiated, transverse ion acceleration is thought to give upflowing ions sufficient energy to escape to the magnetosphere. This study examines how low-altitude upflow processes affect ion outflow, focusing particularly on the impacts of neutral winds. A new multi-fluid ionospheric model, which solves conservation equations for mass, momentum, and parallel and perpendicular energy is developed for this study. These fluid equations are solved for all species relevant to the E, F, and topside ionospheric regions and the system is closed through an electrostatic treatment of the auroral currents. This model is driven by the specification of field-aligned currents and a resonant transverse heating term. The model therefore encapsulates the basic ionospheric upflow processes and provides a simple way to approximate the effects of transverse heating and ion outflow. Using this model, individual species responses to electron precipitation, frictional heating, neutral winds, and transverse heating are examined to determine the effects of these low-altitude upflow processes on ion outflow. Results suggest that upflows, including those induced by neutral winds, can have a significant impact on the types and amounts of outflowing ions.

  14. A numerical study of the Nordic Sea circulation and outflows

    NASA Astrophysics Data System (ADS)

    Yang, J.; Pratt, L. J.

    2010-12-01

    The Nordic Seas outflow over the Greenland-Iceland-Scotland Ridge is investigated by using a two-layer numerical model with both idealized and realistic topography. The study focuses on physical processes and topographic effects that influence the pathways of the Nordic Seas source water that feeds the overflow through the Denmark Strait and Faroe Bank Channel. The potential vorticity balance and integral constraints will be used to explain the sensitivity of the overflows to the upstream (Nordic Seas) circulation and forcing.

  15. Fluid outflows from Venus impact craters - Analysis from Magellan data

    NASA Technical Reports Server (NTRS)

    Asimow, Paul D.; Wood, John A.

    1992-01-01

    Many impact craters on Venus have unusual outflow features originating in or under the continuous ejecta blankets and continuing downhill into the surrounding terrain. These features clearly resulted from flow of low-viscosity fluids, but the identity of those fluids is not clear. In particular, it should not be assumed a priori that the fluid is an impact melt. A number of candidate processes by which impact events might generate the observed features are considered, and predictions are made concerning the rheological character of flows produce by each mechanism. A sample of outflows was analyzed using Magellan images and a model of unconstrained Bingham plastic flow on inclined planes, leading to estimates of viscosity and yield strength for the flow materials. It is argued that at least two different mechanisms have produced outflows on Venus: an erosive, channel-forming process and a depositional process. The erosive fluid is probably an impact melt, but the depositional fluid may consist of fluidized solid debris, vaporized material, and/or melt.

  16. Observations of fresh, anticyclonic eddies in the Hudson Strait outflow

    NASA Astrophysics Data System (ADS)

    Sutherland, David A.; Straneo, Fiammetta; Lentz, Steven J.; Saint-Laurent, Pierre

    2011-12-01

    The waters that flow out through Hudson Strait, a coastal system that connects Hudson Bay with the Labrador Sea, constitute the third largest freshwater contribution to the northern North Atlantic. Recent studies have documented the mean structure and transport of the outflow, as well as highlighting significant variability on synoptic scales (days-week). This study examines the outflow's variability on these synoptic scales through the use of observations collected by a mooring array from 2005 to 2006. We focus on the mechanisms that cause the freshwater export to be concentrated in a series of discrete pulses during the fall/winter season. We find that the pulses occur once every 4.4 days on average and are associated with anticyclonic, surface-trapped eddies propagated through the strait by the mean outflow. Their occurrence is related to the passage of storms across Hudson Bay, although local instability processes also play a role in their formation. The eddies are responsible for approximately 40% of the mean volume transport and 50% of the mean freshwater transport out of the strait. We discuss the implications of this freshwater release mechanism on the delivery of nutrient-rich and highly stratified waters to the Labrador shelf, a productive region south of Hudson Strait.

  17. Analysis of in situ measurements of cirrus anvil outflow dynamics

    NASA Astrophysics Data System (ADS)

    Lederman, J. I.; Whiteway, J. A.

    2012-12-01

    The airborne campaign, EMERALD 2 (Egrett Microphysics Experiment with Radiation, Lidar, and Dynamics,) was conducted out of Darwin, Australia in 2002. Objectives included characterization of the dynamics in the cirrus anvil outflow from tropical deep convection. Two aircraft, the Egrett and King Air, were flown in tandem in the upper troposphere (7 km - 15 km) to collect in situ measurements in the anvil outflow from a storm named "Hector" that occurs on a regular basis over the Tiwi Islands north of Darwin during November and December. Turbulence probes mounted on the wings of the Egrett aircraft were used to measure the wind fluctuations across the anvil and along its length with a spatial resolution of 2 meters. The in situ measurements from the Egrett were coincident with lidar measurements of the cloud structure from the King Air aircraft flying directly below. The presentation will show results of the analysis of the measurements with an emphasis on the turbulence, gravity waves, and coherent structures that are particular to the cirrus anvil outflow environment. Emphasis is placed on the dynamics associated with the generation of mammatus formations at the base of the anvil clouds.

  18. Physical Processes for Driving Ionospheric Outflows in Global Simulations

    NASA Technical Reports Server (NTRS)

    Moore, Thomas Earle; Strangeway, Robert J.

    2009-01-01

    We review and assess the importance of processes thought to drive ionospheric outflows, linking them as appropriate to the solar wind and interplanetary magnetic field, and to the spatial and temporal distribution of their magnetospheric internal responses. These begin with the diffuse effects of photoionization and thermal equilibrium of the ionospheric topside, enhancing Jeans' escape, with ambipolar diffusion and acceleration. Auroral outflows begin with dayside reconnexion and resultant field-aligned currents and driven convection. These produce plasmaspheric plumes, collisional heating and wave-particle interactions, centrifugal acceleration, and auroral acceleration by parallel electric fields, including enhanced ambipolar fields from electron heating by precipitating particles. Observations and simulations show that solar wind energy dissipation into the atmosphere is concentrated by the geomagnetic field into auroral regions with an amplification factor of 10-100, enhancing heavy species plasma and gas escape from gravity, and providing more current carrying capacity. Internal plasmas thus enable electromagnetic driving via coupling to the plasma, neutral gas and by extension, the entire body " We assess the Importance of each of these processes in terms of local escape flux production as well as global outflow, and suggest methods for their implementation within multispecies global simulation codes. We complete 'he survey with an assessment of outstanding obstacles to this objective.

  19. CASSIOPE Enhanced Polar Outflow Probe (e-POP) Mission Overview

    NASA Astrophysics Data System (ADS)

    Yau, A. W.; James, H. G.

    2015-06-01

    The Enhanced Polar Outflow Probe (e-POP) on the polar-orbiting CASSIOPE small satellite (325×1500 km, 80° inclination) is a suite of 8 plasma instruments, including imaging plasma and neutral particle sensors, magnetometers, dual-frequency Global Positioning System (GPS) receivers, charge coupled-device (CCD) cameras, a radio wave receiver and a beacon transmitter. The scientific objective of e-POP is to make observations of mesoscale and microscale plasma processes in the topside high-latitude ionosphere at the highest-possible resolution, specifically to study the microscale characteristics of plasma outflow and related acceleration processes, the occurrence morphology of neutral escape, and the effects of auroral currents on plasma outflow and those of plasma microstructures on radio propagation: the strategy is to use the large data storage and high-speed telemetry downlink capacity of a companion, experimental communications payload on board CASSIOPE to support the high-resolution observations of particle distributions, waves and magnetic fields to 10-ms time scale (˜100 m spatial scale) and the imaging of the aurora on 100-ms time scale, as well as imaging studies of the ionosphere in conjunction with ground-based transmitters and ground receiving stations on comparable (10-100 ms) time scales.

  20. Spin properties of supermassive black holes with powerful outflows

    NASA Astrophysics Data System (ADS)

    Daly, Ruth. A.

    2016-05-01

    Relationships between beam power and accretion disc luminosity are studied for a sample of 55 high excitation radio galaxies (HERG), 13 low excitation radio galaxies (LERG), and 29 radio loud quasars (RLQ) with powerful outflows. The ratio of beam power to disc luminosity tends to be high for LERG, low for RLQ, and spans the full range of values for HERG. Writing general expressions for the disc luminosity and beam power and applying the empirically determined relationships allows a function that parametrizes the spins of the holes to be estimated. Interestingly, one of the solutions that is consistent with the data has a functional form that is remarkably similar to that expected in the generalized Blandford-Znajek model with a magnetic field that is similar in form to that expected in magnetically arrested disk (MAD) and advection-dominated accretion flow (ADAF) models. Values of the spin function, obtained independent of specific outflow models, suggest that spin and active galactic nucleus type are not related for these types of sources. The spin function can be used to solve for black hole spin in the context of particular outflow models, and one example is provided.

  1. The Launch Region of the SVS13 Outflow

    NASA Astrophysics Data System (ADS)

    Hodapp, Klaus

    2013-07-01

    We present the results of Keck Telescope laser adaptive optics integral field spectroscopy with OSIRIS of the innermost regions of the NGC1333 SVS13 jet that drives the system of Herbig-Haro objects 7-11. We find a 0.4" long micro-jet traced by the emission of shock-excited [FeII]. Beyond the extent of this jet, we find a series of near-spherical bubbles traced in the lower excitation H 2 1-0 S(1) line. While this most recent outflow activity is directed almost precisely (PA 170°) to the south of SVS13, the older bubbles show a different direction of motion and orientation more towards the south-east, connecting the recent outflow activity to the well-known, poorly collimated HH 7-11 system of Herbig-Haro objects. We postulate that the creation of a series of bubbles and the changes in outflow direction are indicative of a precessing disk. Our velocity-resolved observations of the microjet in the [FeII] emission line at 1.644μm, as well as the HI12-4 and 13-4 (Brackett series) emission lines originating from the accretion disk or jet launch region clearly show the kinematic signature of disk and jet rotation.

  2. Hot Jupiter breezes: time-dependent outflows from extrasolar planets

    NASA Astrophysics Data System (ADS)

    Owen, James E.; Adams, Fred C.

    2016-03-01

    We explore the dynamics of magnetically controlled outflows from hot Jupiters, where these flows are driven by UV heating from the central star. In these systems, some of the open field lines do not allow the flow to pass smoothly through the sonic point, so that steady-state solutions do not exist in general. This paper focuses on this type of magnetic field configuration, where the resulting flow becomes manifestly time-dependent. We consider the case of both steady heating and time-variable heating, and find the time-scales for the corresponding time variations of the outflow. Because the flow cannot pass through the sonic transition, it remains subsonic and leads to so-called breeze solutions. One manifestation of the time variability is that the flow samples a collection of different breeze solutions over time, and the mass outflow rate varies in quasi-periodic fashion. Because the flow is subsonic, information can propagate inwards from the outer boundary, which determines, in part, the time-scale of the flow variability. This work finds the relationship between the outer boundary scale and the time-scale of flow variations. In practice, the location of the outer boundary is set by the extent of the sphere of influence of the planet. The measured time variability can be used, in principle, to constrain the parameters of the system (e.g. the strengths of the surface magnetic fields).

  3. Massive Star Formation: Characterising Infall and Outflow in dense cores.

    NASA Astrophysics Data System (ADS)

    Akhter, Shaila; Cunningham, Maria; Harvey-Smith, Lisa; Jones, Paul Andrew; Purcell, Cormac; Walsh, Andrew John

    2015-08-01

    Massive stars are some of the most important objects in the Universe, shaping the evolution of galaxies, creating chemical elements, and hence shaping the evolution of the Universe. However, the processes by which they form, and how they shape their environment during their birth processes, are not well understood. We are using NH3 data from the "The H2O Southern Galactic Plane Survey" (HOPS) to define the positions of dense cores/clumps of gas in the southern Galactic plane that are likely to form stars. Due to its effective critical density, NH3 can detect massive star forming regions effectively compared to other tracers. We did a comparative study with different methods for finding clumps and found Fellwalker as the best. We found ~ 10% of the star forming clumps with multiple components and ~ 90% clumps with single component along the line of sight. Then, using data from the "The Millimetre Astronomy Legacy Team 90 GHz" (MALT90) survey, we search for the presence of infall and outflow associated with these cores. We will subsequently use the "3D Molecular Line Radiative Transfer Code" (MOLLIE) to constrain properties of the infall and outflow, such as velocity and mass flow. The aim of the project is to determine how common infall and outflow are in star forming cores, hence providing valuable constraints on the timescales and physical process involved in massive star formation.

  4. The role of superthermal electrons in high latitude ionospheric outflows

    NASA Astrophysics Data System (ADS)

    Glocer, A.; Khazanov, G. V.; Liemohn, M. W.; Toth, G.; Gombosi, T. I.

    2014-12-01

    It is well accepted that the ionosphere is a critical source of plasma for the magnetosphere, providing O+, H+, and He+ which can have wide ranging consequences for the space environment system. Changing ion composition affects magnetic reconnection in the magnetosphere, the ring current, and the wave environment which is important for high energy radiation belt electrons. Of the myriad of mechanisms that are important in determining the ionospheric outflow solution at high latitudes, we focus on the role of superthermal electron populations. It has been demonstrated in multiple studies that even small concentrations of superthermal electrons can have a dramatic effect on the outflow solution. In this presentation, we present simulation results using our Polar Wind Outflow Model (PWOM) and our SuperThermal Electron Transport (STET) code. We describe recent results on superthermal electrons role in defining the quiet time solar wind solution with comparisons to observations. We also discuss preliminary results that combine the PWOM and STET codes for a more comprehensive treatment of the impact of superthermal electrons.

  5. On-line Java Tools for Analyzing AGN Outflows

    NASA Astrophysics Data System (ADS)

    Chamberlain, Carter

    2011-10-01

    We present six interactive programs created to aid in the analysis of outflows from Active Galactic Nuclei. 1. An interactive plot showing the ionic fraction versus the ionization parameter, for each ion of several elements and for different SEDs. 2. An interactive plot showing the excitation ratio versus electron number density for several elements. 3. A tool for finding the ionization parameter solution from the measured column densities. The user provides the measured ionic column densities and chooses an SED. Then the program displays the locus of possible models in a plot of Hydrogen column density versus ionization parameter. The program also calculates and overlays a chi-squared map for one- or two-ionization parameter solutions. 4. A spectral identification tool displays a spectrum, and allows the user to interactively identify the absorption features. This will give the redshift of each outflow and intervening system along the line of sight to the quasar. 5. Two calculators a) Calculate the velocity of an outflow given the systemic redshift and the absorber redshift. b) Convert GALEX flux to units of 10-15ergs/s/cm^2/å.

  6. ON THE STRUCTURE OF ACCRETION DISKS WITH OUTFLOWS

    SciTech Connect

    Jiao Chengliang; Wu Xuebing E-mail: wuxb@pku.edu.cn

    2011-06-01

    To study the outflows from accretion disks, we solve the set of hydrodynamic equations for accretion disks in spherical coordinates (r{theta}{phi}) to obtain the explicit structure along the {theta}-direction. Using self-similar assumptions in the radial direction, we change the equations to a set of ordinary differential equations about the {theta}-coordinate, which are then solved with symmetrical boundary conditions in the equatorial plane; the velocity field is then obtained. The {alpha} viscosity prescription is applied and an advective factor f is used to simplify the energy equation. The results display thinner, quasi-Keplerian disks for Shakura-Sunyaev disks; thicker, sub-Keplerian disks for advection-dominated accretion flows; and slim disks which are consistent with previous popular analytical models. However, an inflow region and an outflow region always exist, except when the viscosity parameter {alpha} is too large, which supports the results of some recent numerical simulation works. Our results indicate that the outflows should be common in various accretion disks and may be stronger in slim disks, where both advection and radiation pressure are dominant. We also present the structure's dependence on the input parameters and discuss their physical meanings. The caveats of this work and possible improvements for the future are discussed.

  7. BOLIVAR and GULFREX MCS Data Constrain Closure of the Grenada Backarc Basin During Oblique Collision Between the Lesser Antilles Arc System and Northern South America

    NASA Astrophysics Data System (ADS)

    Aitken, T. J.; Mann, P.; Christeson, G.

    2004-12-01

    The Lesser Antilles evolved from the mid-Cretaceous as an extensional arc system formed above a steeply dipping slab of Atlantic oceanic crust. The arc became extensional during the Paleocene - early Eocene along normal faults at the eastern edge of the basin as the present-day Lesser Antilles chain rifted away from the Aves Ridge. Backarc rifting ceased during the early Eocene, leaving the 140 km wide 3 km deep Grenada backarc basin. Sediment accumulation reached nearly 8 km during the Paleogene with another 1.5 km of sediments accumulating during the Neogene. In this presentation, we combine newly acquired MCS lines from the BOLIVAR study with existing GULFREX data collected in 1975 to document the structural and stratigraphic effects of closure of the Grenada backarc basin because of the progressive, oblique collision between the Lesser Antilles arc system and northern South America. The southern end of the Grenada basin has been narrowed from an undeformed width of approximately 100 km to a deformed width of 30 km, and rotated nearly 90 degrees to the west as the arc system obliquely collides with the South American margin. Shortening of the colliding backarc basin is mainly accommodated by inversion of Paleogene normal faults on the eastern edge of the basin, folding, low-angle thrust faults, and possibly shale diapirism. We propose that this closure in the area is a backthrusting response during Oligocene - late Miocene closure along the leading edge of the oblique arc-continent collision in the Eastern Venezuelan basin.

  8. Estimating shallow water sound power levels and mitigation radii for the R/V Marcus G. Langseth using an 8 km long MCS streamer

    NASA Astrophysics Data System (ADS)

    Crone, Timothy J.; Tolstoy, Maya; Carton, Helene

    2014-10-01

    seismic surveys in shallow-water environments, the complexity of local geology and seafloor topography can make it difficult to accurately predict associated sound levels and establish appropriate mitigation radii required to ensure the safety of local marine protected species. This is primarily because necessary detailed information regarding the local seafloor topography and subseafloor geology is often unavailable before a survey begins. One potential solution to this problem is to measure received levels using the ship's multichannel seismic (MCS) streamer, which could allow for the dynamic real-time determination of sound levels and mitigation radii while a survey is underway. We analyze R/V Langseth streamer data collected on the shelf and slope near the Washington coast during the Cascadia Open-Access Seismic Transects (COAST) and Ridge2Trench projects to measure received levels up to a distance of approximately 8 km from the sound source array. We establish methods to filter, clean, and process streamer data to accurately determine received power levels and confidently establish mitigation radii. We show that in shallow water measured power levels can fluctuate due to the influence of seafloor topographic features, but that the use of the streamer for the establishment of dynamic mitigation radii is feasible and should be further pursued. The establishment of mitigation radii based on local conditions may help to maximize the safety of marine protected species while also maximizing the ability of researchers to conduct seismic studies.

  9. Probing the Fermi Bubbles in Ultraviolet Absorption: A Spectroscopic Signature of the Milky Way's Biconical Nuclear Outflow

    NASA Astrophysics Data System (ADS)

    Fox, Andrew J.; Bordoloi, Rongmon; Savage, Blair D.; Lockman, Felix J.; Jenkins, Edward B.; Wakker, Bart P.; Bland-Hawthorn, Joss; Hernandez, Svea; Kim, Tae-Sun; Benjamin, Robert A.; Bowen, David V.; Tumlinson, Jason

    2015-01-01

    Giant lobes of plasma extend ≈55° above and below the Galactic center, glowing in emission from gamma rays (the Fermi Bubbles) to microwaves and polarized radio waves. We use ultraviolet absorption-line spectra from the Hubble Space Telescope to constrain the velocity of the outflowing gas within these regions, targeting the quasar PDS 456 (l, b = 10.°4, +11.°2). This sightline passes through a clear biconical structure seen in hard X-ray and gamma-ray emission near the base of the northern Fermi Bubble. We report two high-velocity metal absorption components, at v LSR = -235 and +250 km s-1, which cannot be explained by co-rotating gas in the Galactic disk or halo. Their velocities are suggestive of an origin on the front and back side of an expanding biconical outflow emanating from the Galactic center. We develop simple kinematic biconical outflow models that can explain the observed profiles with an outflow velocity of gsim900 km s-1 and a full opening angle of ≈110° (matching the X-ray bicone). This indicates Galactic center activity over the last ≈2.5-4.0 Myr, in line with age estimates of the Fermi Bubbles. The observations illustrate the use of UV spectroscopy to probe the properties of swept-up gas venting into the Fermi Bubbles. Based on observations taken under program 13448 of the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS 5-26555, and under program 14B-299 of the NRAO Green Bank Telescope, which is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

  10. Infrared and optical imaging of IRAS sources with CO outflow - A snapshot of early star formation

    NASA Technical Reports Server (NTRS)

    Chen, H.; Tokunaga, A. T.; Strom, K. M.; Hodapp, K.-W.

    1993-01-01

    We present multiband imaging of three IRAS sources associated with CO molecular outflows. We find stellar density enhancements around all three IRAS sources. Optical and near-IR photometry indicates that at least 60 percent of the near-IR sources in the vicinity of the IRAS sources are pre-main-sequence stars. Using the photometric data at nbL and M, we are able to identify candidates for the near-IR counterparts of the IRAS sources. We also find that (1) the spectral energy distribution of the deeply embedded sources could be complicated by source confusion and scattered light from the young stellar objects; (2) star formation in the vicinity of the IRAS sources is a continuous process with an age span of 0.5-3 Myr; and (3) stellar density enhancement is probably a phenomenon found at the earliest stage of star formation.

  11. [Accessory mitral tissue responsible for left ventricular outflow obstruction. Reports of 7 cases].

    PubMed

    Arnaud-Crozat, E; Nottin, R; Chambran, P; Serraf, A; Verrier, J F; Detroux, M; Lacour-Gayet, F; Planche, C; Langlois, J; Binet, J P

    1990-09-01

    The authors report the medico-surgical experience of Marie Lannelongue hospital of a rare condition: accessory mitral valve tissue. Seven patients aged 2 to 28 years (average: 8.7 years) had left ventricular outflow obstruction due to accessory mitral valve tissue. The diagnostic was not obvious clinically and was based on the association of echocardiographic and angiographic data. This condition was associated with another intra-cardiac malformation in 6 of the 7 patients. Surgical treatment included resection of the accessory mitral valve tissue by an aortic or combined aorto-left atrial approach, together with correction of the associated intracardiac abnormality. The postoperative results were excellent with the regression of the ventriculo-aortic pressure gradient and the physiological integrity of the mitral valve. PMID:2122834

  12. Developing the Next Generation of Tools for Simulating Galaxy Outflows

    NASA Astrophysics Data System (ADS)

    Scannapieco, Evan

    Outflows are observed in starbursting galaxies of all masses and at all cosmological epochs. They play a key role throughout the history of the Universe: shaping the galaxy mass-metallicity relation, drastically affecting the content and number density of dwarf galaxies, and transforming the chemical composition of the intergalactic medium. Yet, a complete model of galaxy out ows has proven to be elusive, as it requires both a better understanding of the evolution of the turbulent, multiphase gas in and around starbursting galaxies, and better tools to reproduce this evolution in galaxy-scale simulations. Here we propose to conduct a detailed series of numerical simulations designed to help develop such next-generation tools for the simulation of galaxy outflows. The program will consist of three types of direct numerical simulations, each of which will be targeted to allow galaxy-scale simulations to more accurately model key microphysical processes and their observational consequences. Our first set of simulations will be targeted at better modeling the starbursting interstellar medium (ISM) from which galaxy outflows are driven. The surface densities in starbursting galaxies are much larger than those in the Milky Way, resulting in larger gravitational accelerations and random velocities exceeding 30 or even 100 km/s. Under these conditions, the thermal stability of the ISM is changed dramatically, due to the sharp peak in gas cooling efficiency at H 200,000 K. Our simulations will carefully quantify the key ways in which this medium differs from the local ISM, and the consequences of these differences for when, where, and how outflows are driven. A second set of simulations will be targeted at better modeling the observed properties of rapidly cooling, highly turbulent gas. Because gas cooling in and around starbursts is extremely efficient, turbulent motions are often supersonic, which leads to a distribution of ionization states that is vastly different than

  13. The Second Digital Divide and Its Effect on African-American (K-12) School-Age Children

    ERIC Educational Resources Information Center

    Barrett, Christopher A.

    2010-01-01

    The qualitative phenomenological study explored the perceptions of educators and parents of African-American (K-12) school-age children on how the children were using technology. The study was conducted in the Memphis City Public School System (MCS) and was limited to three schools in a school district. Common themes emerged from the analysis of…

  14. Long-range pollution transport during the MILAGRO-2006 campaign: a case study of a major Mexico City outflow event using free-floating altitude-controlled balloons

    NASA Astrophysics Data System (ADS)

    Voss, P. B.; Zaveri, R. A.; Flocke, F. M.; Mao, H.; Hartley, T. P.; Deamicis, P.; Deonandan, I.; Contreras-Jiménez, G.; Martínez-Antonio, O.; Figueroa Estrada, M.; Greenberg, D.; Campos, T. L.; Weinheimer, A. J.; Knapp, D. J.; Montzka, D. D.; Crounse, J. D.; Wennberg, P. O.; Apel, E.; Madronich, S.; de Foy, B.

    2010-08-01

    One of the major objectives of the Megacities Initiative: Local And Global Research Observations (MILAGRO-2006) campaign was to investigate the long-range transport of polluted Mexico City Metropolitan Area (MCMA) outflow and determine its downwind impacts on air quality and climate. Six research aircraft, including the National Center for Atmospheric Research (NCAR) C-130, made extensive chemical, aerosol, and radiation measurements above MCMA and more than 1000 km downwind in order to characterize the evolution of the outflow as it aged and dispersed over the Mesa Alta, Sierra Madre Oriental, Coastal Plain, and Gulf of Mexico. As part of this effort, free-floating Controlled-Meteorological (CMET) balloons, commanded to change altitude via satellite, made repeated profile measurements of winds and state variables within the advecting outflow. In this paper, we present an analysis of the data from two CMET balloons that were launched near Mexico City on the afternoon of 18 March 2006 and floated downwind with the MCMA pollution for nearly 30 h. The repeating profile measurements show the evolving structure of the outflow in considerable detail: its stability and stratification, interaction with other air masses, mixing episodes, and dispersion into the regional background. Air parcel trajectories, computed directly from the balloon wind profiles, show three transport pathways on 18-19 March: (a) high-altitude advection of the top of the MCMA mixed layer, (b) mid-level outflow over the Sierra Madre Oriental followed by decoupling and isolated transport over the Gulf of Mexico, and (c) low-level outflow with entrainment into a cleaner northwesterly jet above the Coastal Plain. The C-130 aircraft intercepted the balloon-based trajectories three times on 19 March, once along each of these pathways; in all three cases, peaks in urban tracer concentrations and LIDAR backscatter are consistent with MCMA pollution. In comparison with the transport models used in the

  15. Extensive MRO CRISM Observations of 1.27 micron O2 Airglow in Mars Polar Night and Their Comparison to MRO MCS Temperature Profiles and LMD GCM Simulations

    NASA Technical Reports Server (NTRS)

    Clancy, R. Todd; Sandor, Brad J.; Wolff, Michael J.; Smith, Michael Doyle; Lefevre, Franck; Madeleine, Jean-Baptiste; Forget, Francois; Murchie, Scott L.; Seelos, Frank P.; Seelos, Kim D.; Nair, Hari A.; Toigo, Anthony D.; Humm, David; Kass, David M.; Kleinbahl, Armin; Heavens, Nicholas

    2012-01-01

    The Martian polar night distribution of 1.27 micron (0-0) band emission from O2 singlet delta [O2(1Delta(sub g))] is determined from an extensive set of Mars Reconnaissance Orbiter (MRO) Compact Reconnaissance Imaging Spectral Mapping (CRISM) limb scans observed over a wide range of Mars seasons, high latitudes, local times, and longitudes between 2009 and 2011. This polar nightglow reflects meridional transport and winter polar descent of atomic oxygen produced from CO2 photodissociation. A distinct peak in 1.27 micron nightglow appears prominently over 70-90NS latitudes at 40-60 km altitudes, as retrieved for over 100 vertical profiles of O2(1Delta(sub g)) 1.27 micron volume emission rates (VER). We also present the first detection of much (x80+/-20) weaker 1.58 micron (0-1) band emission from Mars O2(1Delta(sub g)). Co-located polar night CRISM O2(1Delta(sub g)) and Mars Climate Sounder (MCS) (McCleese et al., 2008) temperature profiles are compared to the same profiles as simulated by the Laboratoire de Météorologie Dynamique (LMD) general circulation/photochemical model (e.g., Lefèvre et al., 2004). Both standard and interactive aerosol LMD simulations (Madeleine et al., 2011a) underproduce CRISM O2(1Delta(sub g)) total emission rates by 40%, due to inadequate transport of atomic oxygen to the winter polar emission regions. Incorporation of interactive cloud radiative forcing on the global circulation leads to distinct but insufficient improvements in modeled polar O2(1Delta(sub g)) and temperatures. The observed and modeled anti-correlations between temperatures and 1.27 mm band VER reflect the temperature dependence of the rate coefficient for O2(1Delta(sub g)) formation, as provided in Roble (1995).

  16. Chemical Characteristics of Continental Outflow Over the Tropical South Atlantic Ocean from Brazil and Africa

    NASA Technical Reports Server (NTRS)

    Talbot, R. W.; Bradshaw, J. D.; Sandholm, S. T.; Smyth, S.; Blake, D. R.; Blake, N. R.; Sachse, G. W.; Collins, J. E.; Heikes, B. G.; Anderson, B. E.; Gregory, G. L.; Singh, H. B.; Lefer, B. L.; Bachmeier, A. S.

    1996-01-01

    The chemical characteristics of air parcels over the tropical South Atlantic during September - October 1992 are summarized by analysis of aged marine and continental outflow classifications. Positive correlations between CO and CH3CL and minimal enhancements of C2CL40, and various ChloroFluoroCarbon (CFC) species in air parcels recently advected over the South Atlantic basin strongly suggest an impact on tropospheric chemistry from biomass burning on adjacent continental areas of Brazil and Africa. Comparison of the composition of aged Pacific air with aged marine air over the South Atlantic basin from 0.3 to 12.5 km altitude indicates potential accumulation of long-lived species during the local dry season. This may amount to enhancements of up to two-fold for C2H6, 30% for CO, and 10% for CH3Cl. Nitric oxide and NO(x) were significantly enhanced (up to approx. 1 part per billion by volume (ppbv)) above 10 km altitude and poorly correlated with CO and CH3Cl. In addition, median mixing ratios of NO and NO(x) were essentially identical in aged marine and continental outflow air masses. It appears that in addition to biomass burning, lightning or recycled reactive nitrogen may be an important source of NO(x) to the upper troposphere. Methane exhibited a monotonic increase with altitude from approx. 1690 to 1720 ppbv in both aged marine and continental outflow air masses. The largest mixing ratios in the upper troposphere were often anticorrelated with CO, CH3Cl, and CO2, suggesting CH, contributions from natural sources. We also argue, based on CH4/CO ratios and relationships with various hydrocarbon and CFC species, that inputs from biomass burning and the northern hemisphere are unlikely to be the dominant sources of CO, CH4 and C2H6 in aged marine air. Emissions from urban areas would seem to be necessary to account for the distribution of at least CH4 and C2H6. Over the African and South American continents an efficient mechanism of convective vertical transport

  17. Modeling water outflow from tile-drained agricultural fields.

    PubMed

    Kuzmanovski, Vladimir; Trajanov, Aneta; Leprince, Florence; Džeroski, Sašo; Debeljak, Marko

    2015-02-01

    The estimation of the pollution risk of surface and ground water with plant protection products applied on fields depends highly on the reliable prediction of the water outflows over (surface runoff) and through (discharge through sub-surface drainage systems) the soil. In previous studies, water movement through the soil has been simulated mainly using physically-based models. The most frequently used models for predicting soil water movement are MACRO, HYDRUS-1D/2D and Root Zone Water Quality Model. However, these models are difficult to apply to a small portion of land due to the information required about the soil and climate, which are difficult to obtain for each plot separately. In this paper, we focus on improving the performance and applicability of water outflow modeling by using a modeling approach based on machine learning techniques. It allows us to overcome the major drawbacks of physically-based models e.g., the complexity and difficulty of obtaining the information necessary for the calibration and the validation, by learning models from data collected from experimental fields that are representative for a wider area (region). We evaluate the proposed approach on data obtained from the La Jaillière experimental site, located in Western France. This experimental site represents one of the ten scenarios contained in the MACRO system. Our study focuses on two types of water outflows: discharge through sub-surface drainage systems and surface runoff. The results show that the proposed modeling approach successfully extracts knowledge from the collected data, avoiding the need to provide the information for calibration and validation of physically-based models. In addition, we compare the overall performance of the learned models with the performance of existing models MACRO and RZWQM. The comparison shows overall improvement in the prediction of discharge through sub-surface drainage systems, and partial improvement in the prediction of the surface

  18. Solar Jets as Sources of Outflows, Heating and Waves

    NASA Astrophysics Data System (ADS)

    Nishizuka, N.

    2013-05-01

    Recent space solar observations of the Sun, such as Hinode and SDO, have revealed that magnetic reconnection is ubiquitous in the solar atmosphere, ranging from small scale reconnection (observed as nanoflares) to large scale one (observed as long duration flares or giant arcades). Especially recent Hinode observations has found various types of tiny chromospheric jets, such as chromospheric anemone jets, penumbral microjets and light bridge jets from sunspot umbra. It was also found that the corona is full of tiny X-ray jets. Often they are seen as helical spinning jets with Alfvenic waves in the corona. Sometimes they are seen as chromospheric jets with slow-mode magnetoacoustic waves and sometimes as unresolved jet-like events at the footpoint of recurrent outflows and waves at the edge of the active region. There is increasing evidence of magnetic reconnection in these tiny jets and its association with waves. The origin of outflows and waves is one of the issues concerning coronal heating and solar wind acceleration. To answer this question, we had a challenge to reproduce solar jets with laboratory plasma experiment and directly measured outflows and waves. As a result, we could find a propagating wave excited by magnetic reconnection, whose energy flux is 10% of the released magnetic energy. That is enough for solar wind acceleration and locally enough for coronal heating, consistent with numerical MHD simulations of solar jets. Here we would discuss recent observations with Hinode, theories and experimental results related to jets and waves by magnetic reconnection, and discuss possible implication to reconnection physics, coronal heating and solar wind acceleration.

  19. A Two-temperature Model of Magnetized Protostellar Outflows

    NASA Astrophysics Data System (ADS)

    Wang, Liang-Yao; Shang, Hsien; Krasnopolsky, Ruben; Chiang, Tzu-Yang

    2015-12-01

    We explore kinematics and morphologies of molecular outflows driven by young protostars using magnetohydrodynamic simulations in the context of the unified wind model of Shang et al. The model explains the observed high-velocity jet and low-velocity shell features. In this work we investigate how these characteristics are affected by the underlying temperature and magnetic field strength. We study the problem of a warm wind running into a cold ambient toroid by using a tracer field that keeps track of the wind material. While an isothermal equation of state is adopted, the effective temperature is determined locally based on the wind mass fraction. In the unified wind model, the density of the wind is cylindrically stratified and highly concentrated toward the outflow axis. Our simulations show that for a sufficiently magnetized wind, the jet identity can be well maintained even at high temperatures. However, for a high temperature wind with low magnetization, the thermal pressure of the wind gas can drive material away from the axis, making the jet less collimated as it propagates. We also study the role of the poloidal magnetic field of the toroid. It is shown that the wind-ambient interface becomes more resistant to corrugation when the poloidal field is present, and the poloidal field that bunches up within the toroid prevents the swept-up material from being compressed into a thin layer. This suggests that the ambient poloidal field may play a role in producing a smoother and thicker swept-up shell structure in the molecular outflow.

  20. Cellular Basis for Bimatoprost Effects on Human Conventional Outflow

    PubMed Central

    Piwnica, David; Jolas, Thierry; Carling, Robert W.; Cornell, Clive L.; Fliri, Hans; Martos, Jose; Pettit, Simon N.; Wang, Jenny W.; Woodward, David F.

    2010-01-01

    Purpose. Bimatoprost is a widely used ocular hypotensive agent to treat glaucoma. It lowers intraocular pressure in humans by increasing both pressure-independent (uveoscleral) and pressure-dependent (conventional) aqueous humor outflow. The present study specifically examines bimatoprost effects on the cells that populate human outflow tissues. Methods. The authors tested for prostamide receptor activation in primary cultures of human trabecular meshwork (TM), Schlemm's canal (SC), and ciliary smooth muscle (CSM) cells using cellular dielectric spectroscopy (CDS). Results. The authors observed that bimatoprost produced an immediate and concentration-dependent increase in cell monolayer impedance for TM, SC, and CSM cells with EC50 values of 4.3, 1.2, and 1.7 nM, respectively; corresponding to decreased cell contractility. Notably, in TM, SC, and CSM cells, bimatoprost was approximately equipotent to the selective FP receptor agonists fluprostenol and 17-phenyl PGF2α. Bimatoprost effects were insensitive to cholera toxin and pertussis toxin but were abolished by phorbol 12-myristate 13-acetate pretreatment, suggesting Gq-involvement in cell signaling. The effects of bimatoprost on TM and SC cells were inhibited by the prostamide receptor antagonist AGN211334, with IC50 values of 1.2 and 3.3 μM, respectively. Interestingly, AGN211334 behaved as an apparent inverse agonist in CDS assays involving TM cells but as a neutral prostamide antagonist with SC cells. Conclusions. Taken together, results suggest that bimatoprost specifically activates receptors in both cell types of the human conventional outflow pathway to modify intraocular pressure. However, only TM cell monolayers appear to have autocrine, or agonist-independent, receptor signaling that is sensitive to a prostamide receptor antagonist. PMID:20435598

  1. Multiple Outflows in the Giant Eruption of a Massive Star

    NASA Astrophysics Data System (ADS)

    Humphreys, Roberta M.; Martin, John C.; Gordon, Michael S.; Jones, Terry J.

    2016-08-01

    The supernova impostor PSN J09132750+7627410 in NGC 2748 reached a maximum luminosity of ≈‑14 mag. It was quickly realized that it was not a true supernova, but another example of a nonterminal giant eruption. PSN J09132750+7627410 is distinguished by multiple P Cygni absorption minima in the Balmer emission lines that correspond to outflow velocities of ‑400, ‑1100, and ‑1600 km s‑1. Multiple outflows have been observed in only a few other objects. In this paper we describe the evolution of the spectrum and the P Cygni profiles for 3 months past maximum, the post-maximum formation of a cool, dense wind, and the identification of a possible progenitor. One of the possible progenitors is an infrared source. Its pre-eruption spectral energy distribution suggests a bolometric luminosity of ‑8.3 mag and a dust temperature of 780 K. If it is the progenitor, it is above the AGB limit, unlike the intermediate-luminosity red transients. The three P Cygni profiles could be due to ejecta from the current eruption, the wind of the progenitor, or previous mass-loss events. We suggest that they were all formed as part of the same high-mass-loss event and are due to material ejected at different velocities or energies. We also suggest that multiple outflows during giant eruptions may be more common than reported. Based on observations obtained with the Large Binocular Telescope (LBT), an international collaboration among institutions in the United States, Italy, and Germany. LBT Corporation partners are the University of Arizona on behalf of the Arizona university system; Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft, Germany, representing the Max-Planck Society, the Astrophysical Institute Potsdam, and Heidelberg University; The Ohio State University and The Research Corporation, on behalf of the University of Notre Dame, University of Minnesota, and University of Virginia.

  2. Bipolar Nuclear Outflow from the Seyfert 1 Galaxy NGC 5548

    NASA Astrophysics Data System (ADS)

    Wrobel, J. M.

    1994-12-01

    The S0/Sa galaxy NGC 5548 hosts a Seyfert 1 nucleus. Echo mapping of its broad optical-line-emitting region yields a radial extent R <~ 20 light days = (1)/(60) pc, or 70 h microarcseonds for H_0 = 100 h km s(-1) Mpc(-1) (Peterson 1993). Using data from larger radii, what boundary conditions can be imposed on the geometry and velocity field of the broad line region? R <~ 1400 h(-1) pc: Bipolar radio continuum lobes straddle a central radio component in NGC 5548. These lobes, which emit optically-thin synchrotron radiation with a 4-cm power of 10(21) h(-2) W Hz(-1) , trace bipolar outflow from the nucleus (Wilson & Ulvestad 1982; Wrobel 1994). R <~ 720 h(-1) pc: The radio lobes of NGC 5548 share the elongation position angle of the [OIII] narrow-line gas, with the broadest known line widths occuring NW of the nucleus at these radii (Wilson et al. 1989). This hints that some narrow-line gas receives additional mechanical energy from the bipolar outflow feeding the radio lobes, a situation analogous to the narrow-line superbubble in NGC 3079 (Veilleux et al. 1994). R <~ 10 h(-1) pc: Blueshifted absorption in the broad CIV lines proves that some gas is flowing out of the nucleus of NGC 5548, with observed speeds of 1200 km s(-1) relative to systemic (Shull & Sachs 1993). This absorption line outflow may have, or be able to achieve, a bipolar shape via the disk-focusing scheme proposed for NGC 3079 (Duric & Seaquist 1988; Veilleux et al. 1994).

  3. Friction and Mixing In The Faroe Bank Channel Outflow

    NASA Astrophysics Data System (ADS)

    Duncan, L. M.; Bryden, H. L.; Cunningham, S. A.

    Three hydrographic sections made during DISCOVERY cruise 242, from 07 Septem- ber 1999 - 06 October 1999, are used to study the Faroe Bank Channel overflow. Each section, made perpendicular to the plume direction, comprised of 10 - 14 sta- tions measuring the outflow properties and velocity. The overflow defined as water with potential temperatures below 3 degrees has densities greater than 28.1 kgm-3. Salinities range between 34.9 and 35.1, with velocities reaching as high as 80 cms-1 approximately 20 km downstream from the sill. We use these data to describe the characteristics of the outflow and to estimate the amount of friction and mixing as the plume travels along the continental slope into the Iceland Basin. From LADCP measurements we estimate stress in the bottom Ekman layer. Our stress results are best related to the overflow velocity with a drag coefficient of 0.5x10-3 and to the height of the bottom Ekman layer with a von Karman constant of 0.75. Below a potential temperature of 8 degrees, the isotherms sink with distance downstream. Calculating transport below different isotherms, we make an estimate for the amount of entrainment. In the region downstream of the sill, entrainment is initially maxi- mum near the zero degree isotherm just above the cold dense outflow and turbulent diffusivities reach as high as 500 cm2s-1. 50 km downstream of the sill the depth of maximum entrainment has moved upwards to the 2 degrees isotherm and turbulent diffusivity has decreased to 50 cm2s-1. Froude numbers are found to exceed one in the centre of the overflow on all sections.

  4. Inflow and outflow signatures in flowing wellbore electrical conductivity logs

    SciTech Connect

    Doughty, Christine; Tsang, Chin-Fu

    2002-08-28

    Flowing wellbore electrical-conductivity logging provides a means to determine hydrologic properties of fractures, fracture zones, or other permeable layers intersecting a borehole in saturated rock. The method involves analyzing the time-evolution of fluid electrical-conductivity logs obtained while the well is being pumped and yields information on the location, hydraulic transmissivity, and salinity of permeable layers, as well as their initial (or ambient) pressure head. Earlier analysis methods were restricted to the case in which flows from the permeable layers or fractures were directed into the borehole. More recently, a numerical model for simulating flowing-conductivity logging was adapted to permit treatment of both inflow and outflow, including analysis of natural regional flow in the permeable layer. However, determining the fracture properties with the numerical model by optimizing the match to the conductivity logs is a laborious trial-and-error procedure. In this paper, we identify the signatures of various inflow and outflow features in the conductivity logs to expedite this procedure and to provide physical insight for the analysis of these logs. Generally, inflow points are found to produce a distinctive signature on the conductivity logs themselves, enabling the determination of location, inflow rate, and ion concentration in a straightforward manner. Identifying outflow locations and flow rates, on the other hand, can be done with a more complicated integral method. Running a set of several conductivity logs with different pumping rates (e.g., half and double the original pumping rate) provides further information on the nature of the feed points. In addition to enabling the estimation of flow parameters from conductivity logs, an understanding of the conductivity log signatures can aid in the design of follow-up logging activities.

  5. Dense Clumps and Candidates for Molecular Outflows in W40

    NASA Astrophysics Data System (ADS)

    Shimoikura, Tomomi; Dobashi, Kazuhito; Nakamura, Fumitaka; Hara, Chihomi; Tanaka, Tomohiro; Shimajiri, Yoshito; Sugitani, Kouji; Kawabe, Ryohei

    2015-06-01

    We report the results of the 12CO (J = 3-2) and HCO+ (J = 4-3) observations of the W40 H ii region with the Atacama Submillimeter Telescope Experiment (ASTE) 10 m telescope (HPBW ≃ 22″) to search for molecular outflows and dense clumps. We found that the velocity field in the region is highly complex, consisting of at least four distinct velocity components at VLSR ≃ 3, 5, 7, and 10 km s-1. The ˜7 km s-1 component represents the systemic velocity of cold gas surrounding the entire region, and causes heavy absorption in the 12CO spectra over the velocity range 6 ≲ VLSR ≲ 9 km s-1. The ˜5 and ˜10 km s-1 components exhibit high 12CO temperature (≳40 K) and are found mostly around the H ii region, suggesting that these components are likely to be tracing dense gas interacting with the expanding shell around the H ii region. Based on the 12CO data, we identified 13 regions of high velocity gas, which we interpret as candidate outflow lobes. Using the HCO+ data, we also identified six clumps and estimated their physical parameters. On the basis of the ASTE data and near-infrared images from 2MASS, we present an updated three-dimensional model of this region. In order to investigate molecular outflows in W40, the SiO (J = 1-0, v = 0) emission line and some other emission lines at 40 GHz were also observed with the 45 m telescope at the Nobeyama Radio Observatory, but they were not detected at the present sensitivity.

  6. Shocked Outflows and Gas Disks in Local Merging Galaxies

    NASA Astrophysics Data System (ADS)

    Soto, Kurt; Martin, C. L.; Prescott, M. K. M.; Armus, L.

    2012-01-01

    We have mapped the kinematic and physical properties of gas emitting optical emission lines across 39 gas-rich mergers, which were previously shown to host tidally-induced gas inflows, with deep ESI spectroscopy. In our unique analysis of these longslit spectra, we fitted multiple kinematic components to forbidden lines and recombination lines simultaneously, enabling an examination of the excitation mechanism in different kinematic components. We identify many rotating gas disks in systems whose stellar component is no longer a disk due to the merger. Many of these disks present gas excited by hot stars, but some of the disks present shock-like ratios of diagnostic emission lines, an observation we attribute to the collision of the two galaxies. In another subset of galaxies, we find very broad (sigma > 150 km/s) emission components that also present shock-like emission-line ratios. The large spatial extent of this emission favors shocks over the narrow-line region of a hidden AGN as the excitation mechanism. The high star formation rate, high dust content, and blueshift of the broad emission further suggest an origin in a galactic outflow. If this interpretation is correct, then our study of these nearby galaxies provides important insight for interpreting the broad emission lines associated with giant star-forming clumps in z 2 galaxies. It also shows that galactic outflows can be recognized via resolved emission lines, in addition to absorption lines, even in integrated spectra; and this technique could prove very powerful for studying galactic outflows in infrared spectra of high-redshift galaxies in the future. This work was supported by the National Science Foundation under contract 0808161.

  7. ALMA OBSERVATIONS OF THE MASSIVE MOLECULAR OUTFLOW G331.512-0.103

    SciTech Connect

    Merello, Manuel; Bronfman, Leonardo; Garay, Guido; Lo, Nadia; Evans, Neal J. II; Nyman, Lars-Ake; Cortes, Juan R.; Cunningham, Maria R.

    2013-09-01

    The object of this study is one of the most energetic and luminous molecular outflows known in the Galaxy, G331.512-0.103. Observations with ALMA Band 7 (350 GHz; 0.86 mm) reveal a very compact, extremely young bipolar outflow and a more symmetric outflowing shocked shell surrounding a very small region of ionized gas. The velocities of the bipolar outflow are about 70 km s{sup -1} on either side of the systemic velocity. The expansion velocity of the shocked shell is {approx}24 km s{sup -1}, implying a crossing time of about 2000 yr. Along the symmetry axis of the outflow, there is a velocity feature, which could be a molecular ''bullet'' of high-velocity dense material. The source is one of the youngest examples of massive molecular outflow found associated with a high-mass star.

  8. The Turbulent Origin of Outflow and Spin Misalignment in Multiple Star Systems

    NASA Astrophysics Data System (ADS)

    Offner, Stella S. R.; Dunham, Michael M.; Lee, Katherine I.; Arce, Héctor G.; Fielding, Drummond B.

    2016-08-01

    The protostellar outflows of wide-separation forming binaries frequently appear misaligned. We use magneto-hydrodynamic simulations to investigate the alignment of protostellar spin and molecular outflows for forming binary pairs. We show that the protostellar pairs, which form from turbulent fragmentation within a single parent core, have randomly oriented angular momentum. Although the pairs migrate to closer separations, their spins remain partially misaligned. We produce 12CO(2-1) synthetic observations of the simulations and characterize the outflow orientation in the emission maps. The CO-identified outflows exhibit a similar random distribution and are also statistically consistent with the observed distribution of molecular outflows. We conclude that the observed misalignment provides a clear signature of binary formation via turbulent fragmentation. The persistence of misaligned outflows and stellar spins following dynamical evolution may provide a signature of binary origins for more evolved multiple star systems.

  9. A Micro-Molecular Bipolar Outflow from HL Tauri

    NASA Astrophysics Data System (ADS)

    Takami, Michihiro; Beck, Tracy L.; Pyo, Tae-Soo; McGregor, Peter; Davis, Christopher

    2007-11-01

    We present detailed geometry and kinematics of the inner outflow toward HL Tau observed using Near Infrared Integral Field Spectrograph (NIFS) at the Gemini-North 8 m Observatory. We analyzed H2 2.122 μm emission and [Fe II] 1.644 μm line emission as well as the adjacent continuum observed at a <0.2" resolution. The H2 emission shows (1) a bubble-like geometry to the northeast of the star, as briefly reported in the previous paper, and (2) faint emission in the southwest counterflow, which has been revealed through careful analysis. The emission on both sides of the star shows an arc 1.0" away from the star, exhibiting a bipolar symmetry. Different brightnesses and morphologies in the northeast and southwest flows are attributed to absorption and obscuration of the latter by a flattened envelope and a circumstellar disk. The H2 emission shows a remarkably different morphology from the collimated jet seen in [Fe II] emission. The positions of some features coincide with scattering continuum, indicating that these are associated with cavities in the dusty envelope. Such properties are similar to millimeter CO outflows, although the spatial scale of the H2 outflow in our image (~150 AU) is strikingly smaller than the millimeter outflows, which often extend over 1000-10000 AU scales. The position-velocity diagrams of the H2 and [Fe II] emission do not show any evidence for kinematic interaction between these flows. All results described above support the scenario that the jet is surrounded by an unseen wide-angled wind, which interacts with the ambient gas and produces the bipolar cavity and shocked H2 emission. Based on observations obtained at the Gemini Observatory, which is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science Foundation (United States), the Particle Physics and Astronomy Research Council (United Kingdom), the National

  10. Shocked molecular hydrogen in the bipolar outflow NGC 2071

    NASA Technical Reports Server (NTRS)

    Burton, Michael G.; Geballe, T. R.; Brand, P. W. J. L.

    1989-01-01

    Maps of the emission from the v = 1-0 S(1) line of molecular hydrogen in the bipolar outflow of NGC 2071 are presented. The line emission is shown to peak at six positions distributed irregularly along two lobes which are parallel to, but offset about 20 arcsec from, the lobes of the high-velocity CO-line emission. The energetics and composition of the high-velocity gas support a model in which the driving agent is a bipolar atomic wind which arises from the vicinity of the central IR sources and shocks the surrounding molecular cloud, evacuating a cavity within it.

  11. Spitzer spectral line mapping of the HH211 outflow

    NASA Astrophysics Data System (ADS)

    Dionatos, O.; Nisini, B.; Cabrit, S.; Kristensen, L.; Pineau Des Forêts, G.

    2010-10-01

    Context. Jets from the youngest protostars are often detected only at mm wavelengths, by means of line emission of CO and SiO. However, it is not yet clear whether these jets are mostly molecular or atomic, nor whether they trace ejected gas or an entrained layer around an embedded atomic jet. Aims: We investigate the warm gas content of the HH211 protostellar outflow to assess the jet mass-flux in the form of H2 and investigate the existence of an embedded atomic jet. Methods: We employ archival Spitzer slit-scan observations of the HH211 outflow over 5.2-37 μm obtained with the low resolution IRS modules. Detected molecular and atomic lines are interpreted by means of emission line diagnostics and an existing grid of molecular shock models. The physical properties of the warm gas are compared with those of other molecular jet tracers and to the results of a similar study towards the L1448-C outflow. Results: We detected and mapped the v = 0-0 S(0)-S(7) H2 lines as well as fine-structure lines of S, Fe+, and Si+. The H2 is detected to 5" from the source and is characterized by a “cool” T ~ 300 K and a “warm” T ~ 1000 ± 300 K component, with an extinction AV ~ 8 mag. The amount of cool H2 towards the jet agrees with that estimated from CO assuming fully molecular gas. The warm component is well fitted by C-type shocks with a low beam filling factor ~0.01-0.04 and a mass-flux similar to the cool H2. The fine-structure line emission arises from dense gas with ionization fraction ~0.5-5 × 10-3, and is indicative of dissociative shocks. Line ratios with respect to sulfur indicate that iron and silicon are depleted relative to solar abundances by a factor ~10-50. Conclusions: Spitzer spectral mapping observations reveal for the first time a cool H2 component towards the CO jet of HH211 consistent with the CO material being fully molecular and warm at ≃300 K. These maps detect also for the first time an embedded atomic jet in the HH211 outflow that can be

  12. Antarctic ice streams and outflow channels on Mars

    USGS Publications Warehouse

    Lucchitta, B.K.

    2001-01-01

    New sonar images of the Antarctic sea floor reveal mega-scale glacial lineations that are strikingly similar to longitudinal flutes in martian outflow channels. The analogs suggest that ice moved through the martian channels in places and carved the flutes. The ice in martian channels may have moved like Antarctic ice streams on deformable debris saturated with water under high pore pressure. On Mars, water at the base of ice-filled channels may have come from residual water or melt water liberated during past warmer climates or higher heat flows.

  13. Variable outflow in the O6ef star Lambda Cephei

    NASA Technical Reports Server (NTRS)

    Leep, E. M.; Conti, P. S.

    1979-01-01

    The paper analyzes spectroscopic data from the UV region using the Copernicus satellite on six consecutive days in September, 1975. It is found that the P Cygni lines of C III at 1175 A and of N V at 1238 and 1242 A show little or no variation in their profiles. The results indicate that the changes in the 4686-A H II and H-alpha can be interpreted as a variable outflow near the surface of the star, either due to random density inhomogeneities propagating outward, or the effects of rotation of a nonspherical star, or both. Insufficient data exist at present to distinguish between periodic and random fluctuations.

  14. Summary of Clinical Experience of Modified Double Root Translocation in the Management of Complete Transposition of Great Arteries With Left Ventricular Outflow Tract Obstruction.

    PubMed

    Yang, Bin; Xu, Jing; Zhou, Zhiming; Wang, Ke; Chen, Jianchao; Chen, Hongling; Wen, Meng; Liang, Qiaoru

    2016-07-27

    To summarize the therapeutic effects of modified double root translocation (MDRT) in the management of congenital heart disease-transposition of great arteries (TGA) with ventricular septum defect (VSD) and left ventricular outflow tract obstruction (LVOTO). From May 2013 to March 2015, we treated 6 patients (4 males, 2 females, aged from 1 year and 8 months old to 5 years old) with complete transposition of great arteries with left ventricular outflow tract obstruction, SaO2 54 ± 7.3%; the outflow velocity of the left ventricular or pulmonary valve measured by Doppler was 4.46 ± 0.15 m/s, and the Nakata index was 217 ± 32 cm(2)/m(2). We carried out a double root translocation operation on these 6 patients.One patient developed low cardiac output syndrome 4 hours after the operation. Extracorporeal membrane oxygenation (ECMO) was performed, but the patient died of multiple organ failure. The other 5 patients all recovered and were discharged from the hospital. During the 3-month to 2-year follow-up period, these 5 patients all demonstrated NYHA Class I or NYHA Class II LVEF (65 ± 2.7) %; 4 had mild pulmonary regurgitation, 1 moderate pulmonary regurgitation; 3 no aortic regurgitation, and 2 micro aortic regurgitation, SaO2 99 ± 0.4%.Modified double root translocation is an effective treatment method in the management of complete transposition of great arteries with left ventricular outflow tract obstruction. PMID:27396558

  15. Contained Rupture in HeartMate II Outflow Graft Bend Relief Disconnection.

    PubMed

    Chua, Kim Chai; Tan, Teing Ee; Lim, Chong Hee; Kerk, Ka Lee; Sivathasan, Cumaraswamy

    2016-03-01

    Thoratec recalled their HeartMate II ventricular assist device in March 2012 after some problems related to disconnection of the bend relief. Abrasion on the pump outflow graft caused by a disconnected bend relief is rare. We report the case of a 49-year-old man in whom a disconnected bend relief caused a puncture in the outflow graft, resulting in a contained hematoma, requiring outflow graft replacement. PMID:25348159

  16. Discovery of Relativistic Outflows in the Seyfert Galaxies Ark 564 and Mrk 590

    NASA Astrophysics Data System (ADS)

    Gupta, A.; Mathur, S.

    2014-07-01

    Outflows are ubiquitous in AGNs, manifested by blueshifted absorption lines in the soft X-ray and UV bands and have outflow velocities of 100-1000 km s^{-1}. The discovery of ultra-fast outflows (0.1 c) exhibited by blueshifted absorption lines in the hard X-ray band has added an intriguing aspect to the rich field of AGN outflows. The significance of these absorption line detections is often questioned and with only a few lines observed, accurate parametrization of the photoionized plasma becomes difficult. We recently discovered relativistic outflows in the soft X-ray band in two Seyfert galaxies; these detections are robust and alleviate earlier concerns about statistical significance of the lines in the hard X-ray band. I will discuss the our recent results on the discovery of high velocity outflows in the narrow line Seyfert 1 galaxies Ark 564 and Mrk 590. These absorbers are identified through multiple absorption lines at blueshift of 0.1c-0.17c detected in the Chandra HETG-MEG spectra. These high-velocity outflows have ionization parameter and column density typical of low-velocity outflows, but much higher velocity, probing a distinct region in the velocity versus ionization/column parameter space. The presence of such relativistic outflows in Seyfert galaxies poses a challenge to theoretical models of AGN winds. I will briefly discuss existing models and future prospects.

  17. Discovery of Relativistic Outflows in the Seyfert Galaxies Ark 564 and Mrk 590

    NASA Astrophysics Data System (ADS)

    Gupta, Anjali; mathur, Smita

    2015-08-01

    Outflows are ubiquitous in AGNs, manifested by blueshifted absorption lines in the soft X-ray and UV bands and have outflow velocities of 100-1000 km s-1. The discovery of ultra-fast outflows (0.1 c) exhibited by blueshifted absorption lines in the hard X-ray band has added an intriguing aspect to the rich field of AGN outflows. The significance of these absorption line detections is often questioned and with only a few lines observed, accurate parametrization of the photoionized plasma becomes difficult. We recently discovered relativistic outflows in the soft X-ray band in two Seyfert galaxies; these detections are robust and alleviate earlier concerns about statistical significance of the lines in the hard X-ray band. I will discuss the our recent results on the discovery of high velocity outflows in the narrow line Seyfert 1 galaxies Ark 564 and Mrk 590. These absorbers are identified through multiple absorption lines at blueshift of 0.1c-0.17c detected in the Chandra HETG-MEG spectra. These high-velocity outflows have ionization parameter and column density typical of low-velocity outflows, but much higher velocity, probing a distinct region in the velocity versus ionization/column parameter space. The presence of such relativistic outflows in Seyfert galaxies poses a challenge to theoretical models of AGN winds. I will briefly discuss existing models and future prospects.

  18. Equivalent lenses of supersonic seeker's outflow refractive index field obtained by simulation and experiment

    NASA Astrophysics Data System (ADS)

    Wei, Qun; Jia, Hongguang; Xuan, Ming

    2008-12-01

    In order to decrease the aerodynamic drag of supersonic image guide missile and design a non-spherical dome, the outflow field of the missile's dome is simulated using FLUENT. Based on the simulated results, the accurate density field of the outflow field at all kinds of flight conditions is obtained, and then the refractive index field of the outflow field is gotten according to the Gladstone-Dale law. The results show that the shock wave induces the heterogeneity of the refractive index field and the turbulent causes distortion. The outflow field is divided into several zones which are taken as equivalent lenses for aberration analysis.

  19. Searching for Outflows from the central kpc of nearby ULIRGs with OSIRIS

    NASA Astrophysics Data System (ADS)

    Rudy, Alexander R.; Max, Claire E.; Srinath, Srikar

    2016-01-01

    We present integral field spectroscopy of the central kiloparsec of 4 nearby ultra-luminous infrared-galaxies which are known to have high velocity (v≤100 km/s) molecular outflows. These observations were performed with the OH-Suppressing Infra-red Imaging Spectrograph (OSIRIS) assisted by the Keck I and II Adaptive Optics systems, which enables spatial resolutions of a few 10s of parsecs. We present the preliminary results of a survey designed to explore the relationship between AGN luminosity fraction (αAGN) and outflow properties among lower-redshift (z≤0.15) systems that we know host high velocity outflows. Our data allow us to examine the opening angle and launching point of the outflow, excitation and temperature of outflowing components (through H2 lines and high-excitation lines such as [SiIV] and [AlIX]), and molecular outflow mass in these systems. This work provides a nearby, spatially resolved analogue to higher-redshift outflows, allowing us to study the physical processes which launch outflows on their smallest scales, and relate that to the outflows which must govern the evolution of the most massive galaxies.

  20. The Detection of [C i] in Molecular Outflows Associated with Young Stellar Objects

    NASA Astrophysics Data System (ADS)

    Walker, Christopher K.; Narayanan, Gopal; Buettgenbach, Thomas H.; Carlstrom, John E.; Keene, Jocelyn; Phillips, T. G.

    1993-10-01

    The first observations of atomic carbon in molecular outflows are presented. Most of the outflow regions show similar [C I] and 13CO line profiles suggesting the [C I] emission from outflow sources traces the same volume of gas as the CO emission, as previous studies have suggested for molecular clouds in general. The [C I] and CO column densities for the 11 sources surveyed are computed over wing and line center velocities. If the [C I] column densities derived from line center velocities are probing conditions in the ambient cloud in the vicinity of the infrared source, then a comparison of these values indicates the carbon abundance in the low-velocity component of the outflows is essentially the same as in the ambient cloud; there is no evidence for shock enhancement of [C 1] in the swept-up material. A map of the [C I] emission from the central arcminute of the luminous DR 21 outflow is presented. The [C I] emission is detected from the two CO outflow lobes; [C I] emission from the southwest lobe appears as a limb-brightened, conical shell. Outflow parameters derived from [C I] are consistent with those derived from CO, suggesting the [C I] emission arises from ambient cloud material swept-up by the outflow. The presence of carbon in the swept-up component of the outflows indicates that gas phase carbon is present deep within molecular clouds and is not confined solely to surface layers.

  1. Photochemical Evolution of Continental Outflow to the N. Atlantic Lower Free Troposphere During Spring and Summer

    NASA Astrophysics Data System (ADS)

    Honrath, R. E.; Owen, R. C.; Val Martin, M.; Helmig, D.; Parrish, D. D.; Li, Q.; Tanner, D.; Fialho, P.

    2006-12-01

    Measurements at the 2.2 km PICO-NARE observatory indicate significant impacts of N. American pollution outflow upon ozone and ozone precursors in the lower free troposphere (FT) of the Azores region, ~5--7 days downwind of N. America, with a summertime d[O3]/d[CO] slope near 1.0. We use a combination of PICO-NARE observations of lower FT composition, FLEXPART-based transport analyses, and GEOS-Chem simulations to investigate the ways that export, photochemical ozone formation, and photochemical destruction of ozone and CO combine to produce the observed enhancements. The FLEXPART particle dispersion model is used to characterize the transport events that carry anthropogenic emissions to the central N. Atlantic lower FT, with a focus on N. American pollution outflow events during spring and summer. The observed enhancements of ozone, non-methane hydrocarbons (NMHC), nitrogen oxides (NOx and NOy) and CO during these events will be described. Photochemical processing during (or prior to) transport is investigated using photochemical ages indicated by measured NMHC-NMHC ratios and through analysis of GEOS-Chem simulation results at the upwind locations indicated by FLEXPART{}. This analysis will be used to provide an initial assessment of the relative contributions of pollution transport events and regional photochemistry (outside of such events) to the observed O3-CO relationship. The degree to which the in-situ measurements are consistent with satellite observations and GEOS-Chem simulations of trans-Atlantic O3 transport will be discussed.

  2. Outflow patterns of pollutants from East Asia to the North Pacific in the winter monsoon

    NASA Astrophysics Data System (ADS)

    Kaneyasu, Naoki; Takeuchi, Koji; Hayashi, Masayasu; Fujita, Shin-Ichi; Uno, Itsushi; Sasaki, Hidetaka

    2000-07-01

    Outflow patterns of air pollutants, and mechanisms associated with a "monsoon" condition that is peculiar to the East Asian region in winter, have been studied. To capture the continental outflow, airborne and shipboard measurements of aerosols and trace gases were conducted over the northern part of the East China Sea and the western part of the Sea of Japan on January 17-26, 1991 (airborne), January 28-29, 1992 (airborne), January 22-31, 1993 (shipboard), and January 29-30, 1993 (airborne). At least two types of highly polluted air masses were found at different times of the monsoon. Type 1 polluted air mass, which contained more than 10 μg m-3 of non-sea-salt SO42- and more than 5 μgC m-3 of black carbon aerosols, typically appeared over the East China Sea at the beginning of the monsoon period. Chemical and microphysical characteristics suggest that the type 1 polluted air mass is chemically aged. Type 2 air mass appeared in the later half of the monsoon period and had characteristics of freshly emitted pollutants. It consisted of several high concentrations of SO2 (>10 ppbv) confined in narrow horizontal width (10 to 30 km wide). Analyses using an Eulerian chemical transport model and detailed backward trajectories indicate that the type 1 polluted air mass was subcontinental in extent and its formation and the transport were dominated by a synoptic-scale weather cycle; it was formed over the Asian continent under anticyclonic conditions that persisted for 3-4 days, and transported intermittently to the east over the Pacific Ocean by the passage and the development of traveling cyclones. This study suggests that aerosols that flow out from East Asia are enriched with carbonaceous materials and consequently have low single-scattering albedo, which may affect the direct radiative forcing by aerosols over the North Pacific.

  3. Chemical and Aerosol Characteristics of Asian Outflow as Observed during INTEX-B and TRACE-P

    NASA Astrophysics Data System (ADS)

    Thornhill, L.; Anderson, B. E.; Winstead, E. L.; Chen, G.; Clarke, A.; Dibb, J.; Scheuer, E.; Sachse, G.; Blake, D.; Fuelberg, H.

    2007-12-01

    The NASA Intercontinental Transport and Chemistry Experiment, phase B (INTEX-B) was conducted in the spring of 2006 to investigate the transport and transformation of gases and aerosols on transcontinental/intercontinental scales and to assess the impacts of the aged pollutants on air quality and climate. To accomplish these goals, the instrumented, North Dakota DC-8 aircraft was deployed during two separate phases to study vastly different pollution and transport phenomena. During the first 3 weeks of March, the aircraft was based in Houston and flew sorties over Mexico City and the western Gulf to examine the composition, outflow pathways, and evolution of pollution from Mexico City. The second phase took place between April 17 and May 15, and involved basing the aircraft at first Hickam AFB, Hawaii, then Anchorage, AK to examine the outflow of pollution from Asia at different points along the transport pathway. In this presentation, we analyze data from the second phase of INTEX-B to characterize the composition of Asian outflow as a function of age (e.g. C2H2/CO ratio) and vertical location (0-2, 2-4, 4-6, 6-8, and >8 km). We use airmass trajectories to identify the primary Asian continental source regions that influence atmospheric composition within the Northeast Pacific region and characterize those source regions using aerosol and gas phase tracers. In addition, we compare INTEX-B vertical profiles of trace gas and aerosol species with similar measurements recorded aboard the DC-8 just off the Asian coast during the 2001 NASA Transport and Chemistry near the Equator - Pacific (TRACE-P) experiment to evaluate changes in species concentrations/characteristics during the approximately 10-day transport period between the two regions.

  4. Warm molecular hydrogen in outflows from ultraluminous infrared Galaxies

    NASA Astrophysics Data System (ADS)

    Hill, Matthew J.; Zakamska, Nadia L.

    2014-04-01

    Ultraluminous infrared galaxies (ULIRGs) show on average three times more emission in the rotational transitions of molecular hydrogen than expected based on their star formation rates. Using Spitzer archival data, we investigate the origin of excess warm H2 emission in 115 ULIRGs of the IRAS 1 Jy sample. We find a strong correlation between H2 and [Fe II] line luminosities, suggesting that excess H2 is produced in shocks propagating within neutral or partially ionized medium. This view is supported by the correlations between H2 and optical line ratios diagnostic of such shocks. The galaxies powered by star formation and those powered by active nuclei follow the same relationship between H2 and [Fe II], with emission line width being the major difference between these classes (˜500 and ˜1000 km s-1, respectively). We conclude that excess H2 emission is produced as the supernovae and active nuclei drive outflows into the neutral interstellar medium of the ULIRGs. A weak positive correlation between H2 and the length of the tidal tails indicates that these outflows are more likely to be encountered in more advanced mergers, but there is no evidence for excess H2 produced as a result of the collision shocks during the final coalescence.

  5. Disc outflows and high-luminosity true type 2 AGN

    NASA Astrophysics Data System (ADS)

    Elitzur, Moshe; Netzer, Hagai

    2016-06-01

    The absence of intrinsic broad-line emission has been reported in a number of active galactic nuclei (AGN), including some with high Eddington ratios. Such `true type 2 AGN' are inherent to the disc-wind scenario for the broad-line region: broad-line emission requires a minimal column density, implying a minimal outflow rate and thus a minimal accretion rate. Here we perform a detailed analysis of the consequences of mass conservation in the process of accretion through a central disc. The resulting constraints on luminosity are consistent with all the cases where claimed detections of true type 2 AGN pass stringent criteria, and predict that intrinsic broad-line emission can disappear at luminosities as high as ˜4 × 1046 erg s-1 and any Eddington ratio, though more detections can be expected at Eddington ratios below ˜1 per cent. Our results are applicable to every disc outflow model, whatever its details and whether clumpy or smooth, irrespective of the wind structure and its underlying dynamics. While other factors, such as changes in spectral energy distribution or covering factor, can affect the intensities of broad emission lines, within this scenario they can only produce true type 2 AGN of higher luminosity then those prescribed by mass conservation.

  6. Glider observations of the Dotson Ice Shelf outflow

    NASA Astrophysics Data System (ADS)

    Miles, Travis; Lee, Sang Hoon; Wåhlin, Anna; Ha, Ho Kyung; Kim, Tae Wan; Assmann, Karen M.; Schofield, Oscar

    2016-01-01

    The Amundsen Sea is one of the most productive polynyas in the Antarctic per unit area and is undergoing rapid changes including a reduction in sea ice duration, thinning ice sheets, retreat of glaciers and the potential collapse of the Thwaites Glacier in Pine Island Bay. A growing body of research has indicated that these changes are altering the water mass properties and associated biogeochemistry within the polynya. Unfortunately difficulties in accessing the remote location have greatly limited the amount of in situ data that has been collected. In this study data from a Teledyne-Webb Slocum glider was used to supplement ship-based sampling along the Dotson Ice Shelf (DIS). This autonomous underwater vehicle revealed a detailed view of a meltwater laden outflow from below the western flank of the DIS. Circumpolar Deep Water intruding onto the shelf drives glacial melt and the supply of macronutrients that, along with ample light, supports the large phytoplankton blooms in the Amundsen Sea Polynya. Less well understood is the source of micronutrients, such as iron, necessary to support this bloom to the central polynya where chlorophyll concentrations are highest. This outflow region showed decreasing optical backscatter with proximity to the bed indicating that particulate matter was sourced from the overlying glacier rather than resuspended sediment. This result suggests that particulate iron, and potentially phytoplankton primary productivity, is intrinsically linked to the magnitude and duration of sub-glacial melt from Circumpolar Deep Water intrusions onto the shelf.

  7. Discovery of a fast, broad, transient outflow in NGC 985

    NASA Astrophysics Data System (ADS)

    Ebrero, J.; Kriss, G. A.; Kaastra, J. S.; Ely, J. C.

    2016-02-01

    Aims: We observed the Seyfert 1 galaxy NGC 985 on several occasions to search for variability in its UV and X-ray absorption features to establish their location and physical properties. Methods: We used XMM-Newton to obtain X-ray spectra using the EPIC-pn camera, and the Cosmic Origins Spectrograph (COS) on the Hubble Space Telescope (HST) to obtain UV spectra. Our observations were simultaneous and span timescales of days to years. Results: We find that the soft X-ray obscuration that absorbed the low energy continuum of NGC 985 in August 2013 diminished greatly by January 2015. The total X-ray column density decreased from 2.1 × 1022 cm-2 to ~6 × 1021 cm-2. We also detect broad, fast UV absorption lines in COS spectra obtained during the 2013 obscuration event. Lines of C iii*, Lyα, Si iv, and C iv with outflow velocities of -5970 km s-1 and a full-width at half-maximum of 1420 km s-1 are prominent in the 2013 spectrum, but have disappeared in all but Lyα in the 2015 spectra. The ionization state and the column density of the UV absorbing gas is compatible with arising in the same gas as that causing the X-ray obscuration. The high velocity of the UV-absorbing gas suggests that the X-ray obscurer and the associated UV outflow are manifestations of an accretion disk wind.

  8. Dynamic accessibility of inflow and outflow reconnective solutions

    SciTech Connect

    Tassi, E.; Titov, V. S.; Hornig, G.

    2005-11-15

    An analysis of the accessibility properties of exact stationary solutions of the resistive magnetohydrodynamics equations is presented. The issue is raised of whether such solutions, which describe a particular type of magnetic reconnection, can be obtained as the final state of a time-dependent evolution of the magnetic- and velocity-field disturbances superimposed onto background fields possessing a null point. Numerical experiments indicate that, whereas for the solutions of inflow type with super-Alfvenic background flow the imposed boundary conditions are sufficient to determine the accessed steady-state solution, in the case of outflow solutions with sub-Alfvenic background flow the final steady-state turns out to depend on the initial disturbance as well. It is found that the directions of the characteristic curves of the evolution equations and an implicit condition on the vorticity at the stagnation point are responsible for this behavior. Implications for the maximum current density attained in the final state are discussed. An argument to explain the appearance of damped oscillations in the evolution of the disturbance fields for the outflow case, as opposed to the flux pileup characterizing the inflow case, is also provided.

  9. Ultrafast Outflows: Galaxy-scale Active Galactic Nucleus Feedback

    NASA Astrophysics Data System (ADS)

    Wagner, A. Y.; Umemura, M.; Bicknell, G. V.

    2013-01-01

    We show, using global three-dimensional grid-based hydrodynamical simulations, that ultrafast outflows (UFOs) from active galactic nuclei (AGNs) result in considerable feedback of energy and momentum into the interstellar medium (ISM) of the host galaxy. The AGN wind interacts strongly with the inhomogeneous, two-phase ISM consisting of dense clouds embedded in a tenuous, hot, hydrostatic medium. The outflow floods through the intercloud channels, sweeps up the hot ISM, and ablates and disperses the dense clouds. The momentum of the UFO is primarily transferred to the dense clouds via the ram pressure in the channel flow, and the wind-blown bubble evolves in the energy-driven regime. Any dependence on UFO opening angle disappears after the first interaction with obstructing clouds. On kpc scales, therefore, feedback by UFOs operates similarly to feedback by relativistic AGN jets. Negative feedback is significantly stronger if clouds are distributed spherically rather than in a disk. In the latter case, the turbulent backflow of the wind drives mass inflow toward the central black hole. Considering the common occurrence of UFOs in AGNs, they are likely to be important in the cosmological feedback cycles of galaxy formation.

  10. ULTRAFAST OUTFLOWS: GALAXY-SCALE ACTIVE GALACTIC NUCLEUS FEEDBACK

    SciTech Connect

    Wagner, A. Y.; Umemura, M.; Bicknell, G. V.

    2013-01-20

    We show, using global three-dimensional grid-based hydrodynamical simulations, that ultrafast outflows (UFOs) from active galactic nuclei (AGNs) result in considerable feedback of energy and momentum into the interstellar medium (ISM) of the host galaxy. The AGN wind interacts strongly with the inhomogeneous, two-phase ISM consisting of dense clouds embedded in a tenuous, hot, hydrostatic medium. The outflow floods through the intercloud channels, sweeps up the hot ISM, and ablates and disperses the dense clouds. The momentum of the UFO is primarily transferred to the dense clouds via the ram pressure in the channel flow, and the wind-blown bubble evolves in the energy-driven regime. Any dependence on UFO opening angle disappears after the first interaction with obstructing clouds. On kpc scales, therefore, feedback by UFOs operates similarly to feedback by relativistic AGN jets. Negative feedback is significantly stronger if clouds are distributed spherically rather than in a disk. In the latter case, the turbulent backflow of the wind drives mass inflow toward the central black hole. Considering the common occurrence of UFOs in AGNs, they are likely to be important in the cosmological feedback cycles of galaxy formation.

  11. Stellar Feedback: A Multiphase Interstellar Medium and Galactic Outflows

    NASA Astrophysics Data System (ADS)

    Ceverino, D.

    2009-12-01

    I am presenting new results in our ongoing effort of improving the theory of galaxy formation in a ΛCDM Universe. I pay a special attention to the role of supernova explosions and stellar winds in the galaxy assembly. These processes happen at very small scales, they affect the interstellar medium (ISM) at galactic scales and regulate the formation of a whole galaxy. Previous attempts of mimicking these effects in simulations of galaxy formation use very simplified assumptions. I develop a much more realistic prescription for modeling the feedback, which minimizes any ad hoc sub-grid physics. I start with developing high resolution models of the ISM and formulate the conditions required for its realistic functionality: formation of multi-phase medium with hot chimneys, super-bubbles, cold molecular phase, and very slow consumption of gas. Once these effects are resolved in cosmological simulations, galaxy formation proceeds more realistically. For example, I do not have the overcooling problem. The angular momentum problem (resulting in a too massive bulge) is also reduced substantially: the rotation curves are nearly flat. The galaxy formation also becomes more violent. At high redshift, I routinely find substantial gas outflows from star-forming galaxies. I describe several scaling relations between outflow properties and galaxy properties: maximum velocity, mass and kinetic energy versus stellar mass and SFR. The simulations reproduce this picture only if the resolution is very high: better than 70 pc.

  12. Giant magnetized outflows from the centre of the Milky Way.

    PubMed

    Carretti, Ettore; Crocker, Roland M; Staveley-Smith, Lister; Haverkorn, Marijke; Purcell, Cormac; Gaensler, B M; Bernardi, Gianni; Kesteven, Michael J; Poppi, Sergio

    2013-01-01

    The nucleus of the Milky Way is known to harbour regions of intense star formation activity as well as a supermassive black hole. Recent observations have revealed regions of γ-ray emission reaching far above and below the Galactic Centre (relative to the Galactic plane), the so-called 'Fermi bubbles'. It is uncertain whether these were generated by nuclear star formation or by quasar-like outbursts of the central black hole and no information on the structures' magnetic field has been reported. Here we report observations of two giant, linearly polarized radio lobes, containing three ridge-like substructures, emanating from the Galactic Centre. The lobes each extend about 60 degrees in the Galactic bulge, closely corresponding to the Fermi bubbles, and are permeated by strong magnetic fields of up to 15 microgauss. We conclude that the radio lobes originate in a biconical, star-formation-driven (rather than black-hole-driven) outflow from the Galaxy's central 200 parsecs that transports a huge amount of magnetic energy, about 10(55) ergs, into the Galactic halo. The ridges wind around this outflow and, we suggest, constitute a 'phonographic' record of nuclear star formation activity over at least ten million years. PMID:23282363

  13. Indirect detection of subsurface outflow from a rift valley lake

    NASA Astrophysics Data System (ADS)

    Darling, W. G.; Allen, D. J.; Armannsson, H.

    1990-02-01

    Naivasha, highest of the Kenya (Gregory) Rift Valley lakes, has no surface outlet. However, unlike other Rift lakes it has not become saline despite high potential evaporation rates, which indicates that there must be some subsurface drainage. The fate of this outflow has been the subject of speculation for many years, especially during the general decline in lake water level during the 1980's. Particularly to the south of the lake, there are few opportunities to obtain information from direct groundwater sampling. However, the stable isotopic composition of fumarole steam from late Quaternary volcanic centres in the area has been used to infer groundwater composition. Using a simple mixing model between Rift-flank groundwater and highly-evaporated lakewater, this has enabled subsurface water flow to be contoured by its lakewater content. By this method, outflow can still be detected some 30 km to the south of the lake. Stable isotope data also confirm that much of the steam used by the local Olkaria geothermal power station is derived from lakewater, though simple balance considerations show that steam use cannot alone be responsible for the fall in lake level observed during the 1980's.

  14. The response of large outflows to wind forcing

    NASA Astrophysics Data System (ADS)

    Pimenta, Felipe M.; Kirwan, A. D., Jr.

    2014-10-01

    A numerical model is used to gauge the impact of winds on the evolution of coastal plumes generated by a variety of inlet outflows. The analysis is summarized by a conceptual model that accounts for the formation of surface and bottom mixed layers and tilting of the plume front. It also provides the basis for a two parameter classification of upwelling. The first parameter indicates when a wind event is capable of fully exporting plume waters offshore. The second determines when winds can overcome the plume buoyancy-driven flow. These indices help to explain why larger outflows tend to be less susceptible to upwelling. During an upwelling event, large plumes tend to maintain their structure, while smaller systems are commonly detached and dispersed offshore. The onset of downwelling events often reorganizes large plumes, thus promoting their net downshelf displacement. In contrast smaller systems frequently restart their formation, consequently limiting their downshelf penetration. The addition of long-term fluctuations, superimposed to the synoptic wind forcing, suggests a mechanism for typical seasonal to interannual variability commonly observed for large discharges.

  15. Flood routing of the Maja outflow across Xanthe Terra

    NASA Technical Reports Server (NTRS)

    Dehon, R. A.

    1991-01-01

    The object is to trace a single flood crest through the Maja outflow system and to evaluate the effects of topography on ponding and multiple channel routing. Maja Valles provides a good model because it has a single source and a well defined channel system. The 1500 km long Maja Valles originates in Juventae Chasma. The outflow system stretches 1100 km northward along the Lunae Planum/Xanthe Terra boundary, then eastward across the Xanthe Terra highlands. It descends to Chryse Planitia where it extends northeastward toward the middle of the basin. It is concluded that flood routing through multiple channels and retardation in local impoundments are responsible for breakup of the initial flood crest and the formation of multiple flood crests. Recombined flow near the mouths of these canyons results in an extended flow regime and multiple flood surges. As a result of ponding along the flood course, depositional sites are localized and renewed erosion downstream (from ponded sites) results in sediment source areas not greatly removed from depositional sites.

  16. Screen channel liquid acquisition device outflow tests in liquid hydrogen

    NASA Astrophysics Data System (ADS)

    Hartwig, J. W.; Chato, D. J.; McQuillen, J. B.; Vera, J.; Kudlac, M. T.; Quinn, F. D.

    2014-11-01

    This paper presents experimental design and test results of the recently concluded 1-g inverted vertical outflow testing of two 325 × 2300 full scale liquid acquisition device (LAD) channels in liquid hydrogen (LH2). One of the channels had a perforated plate and internal cooling from a thermodynamic vent system (TVS) to enhance performance. The LADs were mounted in a tank to simulate 1-g outflow over a wide range of LH2 temperatures (20.3-24.2 K), pressures (100-350 kPa), and flow rates (0.010-0.055 kg/s). Results indicate that the breakdown point is dominated by liquid temperature, with a second order dependence on mass flow rate through the LAD. The best performance is always achieved in the coldest liquid states for both channels, consistent with bubble point theory. Higher flow rates cause the standard channel to break down relatively earlier than the TVS cooled channel. Both the internal TVS heat exchanger and subcooling the liquid in the propellant tank are shown to significantly improve LAD performance.

  17. Screen Channel Liquid Acquisition Device Outflow Tests in Liquid Hydrogen

    NASA Technical Reports Server (NTRS)

    Hartwig, Jason W.; Chato, David J.; McQuillen, J. B.; Vera, J.; Kudlac, M. T.; Quinn, F. D.

    2013-01-01

    This paper presents experimental design and test results of the recently concluded 1-g inverted vertical outflow testing of two 325x2300 full scale liquid acquisition device (LAD) channels in liquid hydrogen (LH2). One of the channels had a perforated plate and internal cooling from a thermodynamic vent system (TVS) to enhance performance. The LADs were mounted in a tank to simulate 1-g outflow over a wide range of LH2 temperatures (20.3 - 24.2 K), pressures (100 - 350 kPa), and flow rates (0.010 - 0.055 kg/s). Results indicate that the breakdown point is dominated by liquid temperature, with a second order dependence on mass flow rate through the LAD. The best performance is always achieved in the coldest liquid states for both channels, consistent with bubble point theory. Higher flow rates cause the standard channel to break down relatively earlier than the TVS cooled channel. Both the internal TVS heat exchanger and subcooling the liquid in the propellant tank are shown to significantly improve LAD performance.

  18. The Shaping of Circumstellar Envelopes by Outflow and Infall Motions

    NASA Astrophysics Data System (ADS)

    Arce, H. G.; Calvet, N.; Sargent, A.

    2004-12-01

    In this study, we combine the complementary information obtained from Owens Valley Radio Observatory (OVRO) millimeter array observations of molecular gas around protostars and HST (WFPC2 and NICMOS) archival images of reflection nebulae to obtain the best information available on the physical and dynamical properties of infalling circumstellar envelopes and the outflow-envelope interaction. The HST images of protostellar nebulae probe the dust component of the envelope, and are the best tracers of the geometry of the cavities in the envelope down to regions very close to the central source. The interferometric molecular line observations from OVRO probe the gas component, which constitutes most of the mass, and provide kinematic information that directly reflects the energetics and directions of the outflows, and the distribution of the infalling gas. We plan to analyze the information provided by these two sets of data using scattered light models of protostellar envelopes of different geometries in which cavities due to infall and/or winds with different morphologies and strength have been carved. Preliminary results show that the cavities traced by nebular emission are most likely produced by the interaction of wide-angle protostellar winds and the stellar envelope, rather than by infall of the envelope material onto the forming star. Support for this study is provided in part by an STScI HST Archival grant (HST-AR-09909.01-A). HGA is supported by an NSF Astronomy and Astrophysics Postdoctoral Fellowship under award AST-0401568.

  19. [A new separation protocol (DRBCP-F) for automated blood component donation with the MCS 3p cell separator for collection of leukocyte depleted erythrocyte concentrates and plasma].

    PubMed

    Zeiler, T; Kretschmer, V

    1997-01-01

    Previously published studies on automated blood component donation with the MCS 3p cell separator proved fairly good quality of the collected red blood cells (RBC) and fresh frozen plasma (FFP), with the disadvantage of a low hematocrit of the filtered RBC and a high platelet contamination of the FFP (RBCP-F protocol.) The DRBCP-F protocol was designed to eliminate the above-mentioned disadvantages and to provide 1 unit of leuko-depleted (filtered) RBC, 2 units of FFP, and additionally 1 platelet concentrate (PC) from the buffy coat. Twenty automated blood component collections (2 cycles, Latham bowl at 5,500 rpm, 230 ml isotonic saline for volume balance, PAGGS-M as additive solution) were performed. The RBC were filtered in a closed system after storage at 4 degrees C for 24 h. Blood cell counts and biochemical parameters of the RBC were determined initially and after 49 days. PC were separated from buffy coat after a soft spin. The volume of the RBC amounted to 293 +/- 12 ml (mean +/- SD) with a hematocrit of 0.61 +/- 0.05 l/l. Residual leukocytes after filtration were found to be 0.04 x 10(6) +/- 0.06 per unit. After storage, the following data were obtained: hemolysis 0.38%, ATP 2.1 +/- 0.4 mumol/g Hb, 2,3-diphosphoglycerate (2,3-DPG) 1.4 +/- 0.3 mumol/g Hb, ph 6.3 +/- 0.1, potassium 6.4 mmol per unit, and LDH in the supernatant was 219 U/l. None of the RBC showed bacterial growth after 49 days. The volume of the collected FFP was 398 +/- 32 ml, with 3.4 +/- 3.5 x 10(3) residual platelets and 5 +/- 12 leukocytes per microliter. Platelet concentrates contained 90.2 +/- 32 x 10(9) platelets in 88 +/- 14 ml plasma. Automated blood donation with the DRBCP-F protocol provided RBC with very low residual leukocyte counts, adequate hematocrit and good metabolic status up to 49 days, and FFP with low platelet contamination. The platelet concentrates were even superior to those prepared from whole blood using the buffy coat method. The storable leuko-depleted RBC are

  20. Sea Level History in 3D: Early results of an ultra-high resolution MCS survey across IODP Expedition 313 drillsites

    NASA Astrophysics Data System (ADS)

    Mountain, G. S.; Kucuk, H. M.; Nedimovic, M. R.; Austin, J. A., Jr.; Fulthorpe, C.; Newton, A.; Baldwin, K.; Johnson, C.; Stanley, J. N.; Bhatnagar, T.

    2015-12-01

    Although globally averaged sea level is rising at roughly 3 mm/yr (and is accelerating), rates of local sea-level change measured at coastlines may differ from this number by a factor of two or more; at some locations, sea level may even be falling. This is due to local processes that can match or even reverse the global trend, making it clear that reliable predictions of future impacts of sea-level rise require a firm understanding of processes at the local level. The history of local sea-level change and shoreline response is contained in the geologic record of shallow-water sediments. We report on a continuing study of sea-level history in sediments at the New Jersey continental margin, where compaction and glacial isostatic adjustment are currently adding 2 mm/yr to the globally averaged rise. We collected 570 sq km of ultra-high resolution 3D MCS data aboard the R/V Langseth in June-July 2015; innovative recording and preliminary results are described by Nedimovic et al. in this same session. The goal was to provide regional context to coring and logging at IODP Exp 313 sites 27-29 that were drilled 750 m into the New Jersey shelf in 2009. These sites recovered a nearly continuous record of post-Eocene sediments from non-marine soils, estuaries, shoreface, delta front, pro-delta and open marine settings. Existing seismic data are good but are 2D high-resolution profiles at line spacings too wide to enable mapping of key nearshore features. The Langseth 3D survey used shallow towing of a tuned air gun array to preserve high frequencies, and twenty-four 50-m PCables each 12.5 apart provided 6.25 x 3.125 m common-midpoint bins along seventy-seven 50-km sail lines. With this especially dense spatial resolution of a pre-stack time migrated volume we expect to map rivers, incised valleys, barrier islands, inlets and bays, pro-delta clinoforms, tidal deltas, sequence boundaries, debris flow aprons, and more. Seismic attributes linked to sedimentary facies and

  1. Martian groundwater outflow processes and morphology; reconstruction of paleohydrology using landscape evolution experiments

    NASA Astrophysics Data System (ADS)

    Marra, Wouter A.; Kleinhans, Maarten G.; de Jong, Steven M.; Hauber, Ernst

    2015-04-01

    Groundwater played an important role in the aqueous history of Mars but how, how long, and with what intensity remains unclear. Two types of fluvial landforms related to groundwater emergence are the giant outflow channels and the disputed sapping valleys. Understanding of the relation between subsurface and surface processes is slim, which limits inferences of climate implications from the observable morphology. We aim to increase this understanding and to apply this knowledge to Martian cases to reconstruct former hydrological conditions. Using a series of sandbox experiments, we investigated formative processes of valleys formed by groundwater. These experiments showed the morphology and processes of groundwater sapping and pressurized groundwater outflow (see Marra et al, 2014, Icarus doi:10.1016/j.icarus.2013.12.026) and further focused on landscape characteristics of groundwater sapping sourced locally or distally, and identified various processes linked to pressurized groundwater outbursts including the formation and eruption of subsurface reservoirs that can explain the high reconstructed discharges of large outflow valleys (see Marra et al, 2014, JGR doi:10.1002/2014JE004701). Based on the experiments, we identified novel morphological indicators for groundwater outflow in the outflow channel region of Lunae and Ophir Plana. These, in combination with the classic outflow features, show a clear trend of increasing outflow magnitude with decreasing elevation to the northeast, indicating a head from a common aquifer. The putative aquifer we identified was likely recharged by infiltration over the Tharsis region. Outflow channel activity peaked in the Hesperian, but continued in the Amazonian at a lower magnitude. Our results agree well with groundwater recharge in the Noachian and Early Hesperian, corresponding to a climate that sustained an active hydrological cycle. Furthermore, the large outflow events require a confining layer to build up enough pressure

  2. A statistical study of plasmaspheric plumes and ionospheric outflows observed at the dayside magnetopause

    NASA Astrophysics Data System (ADS)

    Lee, S. H.; Zhang, H.; Zong, Q.-G.; Otto, A.; Rème, H.; Liebert, E.

    2016-01-01

    We present a statistical study of plasmaspheric plumes and ionospheric outflows observed by the Cluster spacecraft near the dayside magnetopause. Plasmaspheric plumes are identified when the low-energy ions (<1 keV) with ˜90° pitch angle distributions are observed by the Cluster Ion Spectrometer/Hot Ion Analyzer instrument. The ionospheric outflows are characterized by unidirectional or bidirectional field-aligned pitch angle distributions of low-energy ions observed in the dayside magnetosphere. Forty-three (10%) plasmaspheric plume events and 32 (7%) ionospheric outflow events were detected out of the 442 times that C3 crossed the dayside magnetopause between 2007 and 2009. The occurrence rate of plumes at duskside is significantly higher than that at dawnside. The occurrence rate of outflows shows a weak dawn-dusk asymmetry. We investigate the dependence of the occurrence rates of plumes and ionospheric outflows on geomagnetic activity and on solar wind/interplanetary magnetic field (IMF) conditions. The plume events tend to occur during southward IMF (duskward solar wind electric field) and moderate geomagnetic activity (Kp = 3,-30≤Dst <- 10 nT). However, the ionospheric outflow events tend to occur during northward IMF (dawnward solar wind electric field). The ionospheric outflows do not occur when Kp = 0, and the occurrence rate of the ionospheric outflows does not have a clear Dst dependence. Seventy-five percent (46%) of the outflows are observed in the duskside for negative (positive) IMF By. Conversely, 54% (25%) of the outflows are observed in the dawnside for positive (negative) IMF By. Finally, the occurrence rates of both plumes and outflows increase with solar wind dynamic pressure.

  3. The physics and the structure of the quasar-driven outflow in Mrk 231

    NASA Astrophysics Data System (ADS)

    Cicone, C.; Feruglio, C.; Maiolino, R.; Fiore, F.; Piconcelli, E.; Menci, N.; Aussel, H.; Sturm, E.

    2012-07-01

    Massive AGN-driven outflows are invoked by AGN-galaxy co-evolutionary models to suppress both star formation and black hole accretion. Massive molecular outflows have been discovered in some AGN hosts. However, the physical properties and structures of these AGN-driven molecular outflows are still poorly constrained. Here we present new IRAM PdBI observations of Mrk 231, the closest quasar known, targeting both the CO(1-0) and CO(2-1) transitions. We detect broad wings in both transitions, which trace a massive molecular outflow moving with velocities of up to 800 km s-1. The wings are spatially resolved at high significance levels (5-11σ), indicating that the molecular outflow extends to the kpc scale. The CO(2-1)/CO(1-0) ratio of the red broad wings is consistent with the ratio observed in the narrow core, while the blue broad wing is less excited than the core. The latter result suggests that quasar-driven outflow models invoking shocks (which would predict higher gas excitation) are inappropriate for describing the bulk of the outflow in Mrk 231. However, we note that within the central 700 pc the CO(2-1)/CO(1-0) ratio of the red wing is slightly, but significantly, higher than in the line core, suggesting that shocks may play a role in the central region. We also find that the average size of the outflow anticorrelates with the critical density of the transition used as a wind tracer. This indicates that, although diffuse and dense clumps coexist in the outflowing gas, dense outflowing clouds have shorter lifetimes and that they evaporate into the diffuse component along the outflow or, more simply, that diffuse clouds are more efficiently accelerated to larger distances by radiation pressure.

  4. [Fe II] 1.64 μm FEATURES OF JETS AND OUTFLOWS FROM YOUNG STELLAR OBJECTS IN THE CARINA NEBULA

    SciTech Connect

    Shinn, Jong-Ho; Lee, Jae-Joon; Chun, Moo-Young; Lyo, A.-Ran; Moon, Dae-Sik; Kyeong, Jaemann; Park, Byeong-Gon; Pyo, Tae-Soo; Lee, Ho-Gyu; Kim, Hyun-Jeong; Koo, Bon-Chul; Lee, Yong-Hyun; Sung, Hwankyung; Hur, Hyeonoh

    2013-11-01

    We present [Fe II] 1.64 μm imaging observations for jets and outflows from young stellar objects (YSOs) over the northern part (∼24' × 45') of the Carina Nebula, a massive star-forming region. The observations were performed with IRIS2 of the Anglo-Australian Telescope and the seeing was ∼1.''5 ± 0.''5. Eleven jet and outflow features are detected at eight different regions and are termed ionized Fe objects (IFOs). One Herbig-Haro candidate that was missed in Hubble Space Telescope Hα observations is newly identified as HHc-16, referring to our [Fe II] images. IFOs have knotty or longish shapes, and the detection rate of IFOs against previously identified YSOs is 1.4%, which should be treated as a lower limit. Four IFOs show anti-correlated peak intensities in [Fe II] and Hα, where the ratio I([Fe II])/I(Hα) is higher for longish IFOs than for knotty IFOs. We estimate the outflow mass loss rate from the [Fe II] flux using two different methods. The jet-driving objects are identified for three IFOs (IFO-2, -4, and -7) for which we study the relations between the outflow mass loss rate and the YSO physical parameters from the radiative transfer model fitting. The ratios of the outflow mass loss rate over the disk accretion rate for IFO-4 and -7 are consistent with the previously reported values (10{sup –2}-10{sup +1}), while the ratio is higher for IFO-2. This excess may result from underestimating the disk accretion rate. The jet-driving objects are likely to be low- or intermediate-mass stars. Other YSO physical parameters, such as luminosity and age, show reasonable relations or trends.

  5. Long-range pollution transport during the MILAGRO-2006 campaign: a case study of a major Mexico City outflow event using free-floating altitude-controlled balloons

    NASA Astrophysics Data System (ADS)

    Voss, P. B.; Zaveri, R. A.; Flocke, F. M.; Mao, H.; Hartley, T. P.; Deamicis, P.; Deonandan, I.; Contreras-Jiménez, G.; Martínez-Antonio, O.; Figueroa Estrada, M.; Greenberg, D.; Campos, T. L.; Weinheimer, A. J.; Knapp, D. J.; Montzka, D. D.; Crounse, J. D.; Wennberg, P. O.; Apel, E.; Madronich, S.; de Foy, B.

    2010-02-01

    One of the major objectives of the Megacities Initiative: Local And Global Research Observations (MILAGRO-2006) campaign was to investigate the long-range transport of polluted Mexico City Metropolitan Area (MCMA) outflow and determine its downwind impacts on air quality and climate. Six research aircraft, including the National Center for Atmospheric Research (NCAR) C-130, made extensive chemical, aerosol, and radiation measurements above MCMA and more than 1000 km downwind in order to characterize the evolution of the outflow as it aged and dispersed over the Mesa Alta and Gulf of Mexico. As part of this effort, free-floating Controlled-Meteorological (CMET) balloons, commanded to change altitude via satellite, made repeated profile measurements of winds and state variables within the advecting outflow. In this paper, we present an analysis based on the data from two CMET balloons that were launched near Mexico City on the afternoon of 18 March 2006 and floated downwind with the MCMA pollution for nearly 30 h. The repeating profile measurements show the evolving structure of the outflow in considerable detail: its stability and stratification, interaction with other air masses, mixing episodes, and dispersion into the regional background. Air parcel trajectories, computed directly from the balloon wind profiles, show three different transport pathways on 18-19 March: (a) high-altitude advection of the top of the MCMA mixed layer, (b) mid-level outflow over the Sierra Madre Oriental followed by decoupling and isolated transport over the Gulf, and (c) low-altitude outflow with entrainment into a cleaner westerly jet below the plateau. The C-130 aircraft intercepted the balloon-based trajectories three times on 19 March, once along each of these pathways. In all three cases, distinct peaks in the urban tracer signatures and LIDAR backscatter imagery were consistent with MCMA pollution. The coherence of the high-altitude outflow was well preserved after one day

  6. The baryonic Tully-Fisher relation and galactic outflows

    NASA Astrophysics Data System (ADS)

    Dutton, Aaron A.

    2012-08-01

    Most of the baryons in the Universe are not in the form of stars and cold gas in galaxies. Galactic outflows driven by supernovae/stellar winds are the leading mechanisms for explaining this fact. The scaling relation between galaxy mass and outer rotation velocity (also known as the baryonic Tully-Fisher relation, BTF) has recently been used as evidence against this viewpoint. We use a Λ cold dark matter (ΛCDM)-based semi-analytic disc galaxy formation model to investigate these claims. In our model, galaxies with less efficient star formation and higher gas fractions are more efficient at ejecting gas from galaxies. This somewhat counter intuitive result is due to the (observational) fact that galaxies with less efficient star formation and higher gas fractions tend to live in dark matter haloes with lower circular velocities, from which less energy is required to escape the potential well. In our model the intrinsic scatter in the BTF is ≃0.15 dex, and mostly reflects scatter in dark halo concentration. The scatter is largely independent of galaxy structure because of the large radius within which galaxy rotation velocities are measured. The observed scatter, equal to ≃0.24 dex, is dominated by measurement errors. The best estimate for the intrinsic scatter is that it is less than 0.15 dex, and thus our ΛCDM-based model (which does not include all possible sources of scatter) is only just consistent with this. Future observations of the BTF scatter could be made with a more stringent measurement of the intrinsic scatter, and thus provide a strong constraint to galaxy formation models. In our model, gas-rich galaxies, at fixed virial velocity (Vvir), with lower stellar masses have lower baryonic masses. This is consistent with the expectation that galaxies with lower stellar masses have had less energy available to drive an outflow. However, when the outer rotation velocity (Vflat) is used the correlation has the opposite sign, with a slope in agreement

  7. Modified technique for heterotopic implantation of a right ventricular outflow tract conduit.

    PubMed

    Dave, Hitendu; Dodge-Khatami, Ali; Kadner, Alexander; Prêtre, René

    2006-06-01

    This article describes a modified technique of side-to-side proximal connection of a conduit during heterotopic implantation in the right ventricular outflow tract. It results in a better geometry of the right ventricular outflow and avoids distortion of the valve annulus, especially when the newer generation of straight xenografts are used. PMID:16731190

  8. ISOTROPICALLY DRIVEN VERSUS OUTFLOW DRIVEN TURBULENCE: OBSERVATIONAL CONSEQUENCES FOR MOLECULAR CLOUDS

    SciTech Connect

    Carroll, Jonathan J.; Frank, Adam; Blackman, Eric G.

    2010-10-10

    Feedback from protostellar outflows can influence the nature of turbulence in star-forming regions even if they are not the primary source of velocity dispersion for all scales of molecular clouds. For the rate and power expected in star-forming regions, we previously (Carroll et al.) demonstrated that outflows could drive supersonic turbulence at levels consistent with the scaling relations from Matzner although with a steeper velocity power spectrum than expected for an isotropically driven supersonic turbulent cascade. Here, we perform higher resolution simulations and combine simulations of outflow driven turbulence with those of isotropically forced turbulence. We find that the presence of outflows within an ambient isotropically driven turbulent environment produces a knee in the velocity power spectrum at the outflow scale and a steeper slope at sub-outflow scales than for a purely isotropically forced case. We also find that the presence of outflows flattens the density spectrum at large scales effectively reducing the formation of large-scale turbulent density structures. These effects are qualitatively independent of resolution. We have also carried out Principal Component Analysis (PCA) for synthetic data from our simulations. We find that PCA as a tool for identifying the driving scale of turbulence has a misleading bias toward low amplitude large-scale velocity structures even when they are not necessarily the dominant energy containing scales. This bias is absent for isotropically forced turbulence but manifests strongly for collimated outflow driven turbulence.

  9. DETECTION OF HIGH VELOCITY OUTFLOWS IN THE SEYFERT 1 GALAXY Mrk 590

    SciTech Connect

    Gupta, A.; Mathur, S.; Krongold, Y.

    2015-01-01

    We report on the detection of ultra-fast outflows in the Seyfert 1 galaxy Mrk 590. These outflows are identified through highly blueshifted absorption lines of O VIII and Ne IX in the medium energy grating spectrum and Si XIV and Mg XII in the high energy grating spectrum on board the Chandra X-ray observatory. Our best-fit photoionization model requires two absorber components at outflow velocities of 0.176c and 0.0738c and a third tentative component at 0.0867c. The components at 0.0738c and 0.0867c have high ionization parameters and high column densities, similar to other ultra-fast outflows detected at low resolution by Tombesi et al. We also found suggestive evidence for super-solar silicon in these components. These outflows carry sufficient mass and energy to provide effective feedback proposed by theoretical models. The component at 0.176c, on the other hand, has a low ionization parameter and low column density, similar to those detected by Gupta et al. in Ark 564. These absorbers occupy a different locus on the velocity versus ionization parameter plane and have opened up a new parameter space of active galactic nucleus (AGN) outflows. The presence of ultra-fast outflows in moderate luminosity AGNs poses a challenge to models of AGN outflows.

  10. MASSIVE MOLECULAR OUTFLOWS AND NEGATIVE FEEDBACK IN ULIRGs OBSERVED BY HERSCHEL-PACS

    SciTech Connect

    Sturm, E.; Gracia-Carpio, J.; Hailey-Dunsheath, S.; Contursi, A.; Poglitsch, A.; Davies, R.; Genzel, R.; Lutz, D.; Tacconi, L.; De Jong, J. A.; Gonzalez-Alfonso, E.; Veilleux, S.; Fischer, J.; Sternberg, A.; Verma, A.; Maiolino, R.

    2011-05-20

    Mass outflows driven by stars and active galactic nuclei (AGNs) are a key element in many current models of galaxy evolution. They may produce the observed black-hole-galaxy mass relation and regulate and quench both star formation in the host galaxy and black hole accretion. However, observational evidence of such feedback processes through outflows of the bulk of the star-forming molecular gas is still scarce. Here we report the detection of massive molecular outflows, traced by the hydroxyl molecule (OH), in far-infrared spectra of ULIRGs obtained with Herschel-PACS as part of the SHINING key project. In some of these objects the (terminal) outflow velocities exceed 1000 km s{sup -1}, and their outflow rates (up to {approx}1200 M{sub sun} yr{sup -1}) are several times larger than their star formation rates. We compare the outflow signatures in different types of ULIRGs and in starburst galaxies to address the issue of the energy source (AGN or starburst) of these outflows. We report preliminary evidence that ULIRGs with a higher AGN luminosity (and higher AGN contribution to L{sub IR}) have higher terminal velocities and shorter gas depletion timescales. The outflows in the observed ULIRGs are able to expel the cold gas reservoirs from the centers of these objects within {approx}10{sup 6}-10{sup 8} years.

  11. [Functional morphology of the outflow pathways of aqueous humor and their changes in open angle glaucoma].

    PubMed

    Tamm, E R

    2013-11-01

    Aqueous humor exits the eye through the trabecular and uveoscleral outflow pathways. Under normal conditions intraocular pressure is maintained in the trabecular outflow pathways in which aqueous humor passes through the trabecular meshwork into Schlemm's canal. Intraocular pressure is generated through an outflow resistance in the juxtacanalicular region which consists of juxtacanalicular tissue and the inner wall endothelium of Schlemm's canal. The resistance of this region is under the influence of two contractile systems, the anterior longitudinal portion of the ciliary muscle and the contractile myofibroblast-like cells in the trabecular outflow pathways. Resistance is lowered through contraction of the ciliary muscle or relaxation of the contractile cells in the trabecular outflow pathways. In primary open angle glaucoma, resistance in the juxtacanalicular region is abnormally high. The cause of the increase is related to an increased activity in transforming growth factor beta and connective tissue growth factor signaling. The cells of the trabecular meshwork outflow pathways are stimulated to form a stronger contractile phenotype involving both an increase in the actin cytoskeleton and the surrounding fibrillar extracellular matrix. As a result there is an increase in cellular tone in the trabecular outflow pathways leading to an increase in rigidity and outflow resistance. PMID:24231909

  12. Asymptotic distribution of the maximum deficit with correlated, partially regulated outflows.

    USGS Publications Warehouse

    Troutman, B.M.

    1983-01-01

    The asymptotic distribution of the maximum accumulated deficit with partially regulated, Markov-dependent net outflows having a Bernoulli distribution is derived, and the distribution for independent, continuous outflows is presented. Under partial regulation the maximum deficit behaves as log n, where n is the length of the series.-from Author

  13. Financial Crisis, Capital Outflows, and Policy Responses: Examples from East Asia

    ERIC Educational Resources Information Center

    Rajan, Ramkishen S.

    2007-01-01

    Financial crises seem to have become the norm rather than the exception since 1992. The author examines the impact of a crisis of confidence and resultant capital outflows from a small and open economy and the possible policy options in response to such outflows, using simple tools and definitions that will be familiar to any money and banking or…

  14. Supernova blast wave within a stellar cluster outflow

    NASA Astrophysics Data System (ADS)

    Rodríguez-Ramírez, J. C.; Raga, A. C.; Velázquez, P. F.; Rodríguez-González, A.; Toledo-Roy, J. C.

    2014-11-01

    In this paper, we develop a semi-analytic model of a supernova which goes off in the centre of a stellar cluster. The supernova remnant interacts with a stratified, pre-existent outflow produced by the winds of the cluster stars. We compare our semi-analytic model with numerical simulations using the spherically symmetric Euler equations with appropriate mass and energy source terms. We find good agreement between these two approaches, and we find that for typical parameters the blast wave is likely to reach the Taylor-Sedov regime outside the cluster radius. We also calculate the predicted X-ray luminosity of the flow as a function of time, and we obtain its dependence on the outer radius and the number of stars of the cluster.

  15. Jets and Outflows in Radio Galaxies: Implications for AGN Feedback

    NASA Astrophysics Data System (ADS)

    Torresi, Eleonora; Grandi, Paola; Costantini, Elisa; Palumbo, Giorgio G. C.

    One of the main debated astrophysical problems is the role of the AGN feedback in galaxy formation. It is known that massive black holes have a profound effect on the formation and evolution of galaxies, but how black holes and galaxies communicate is still an unsolved problem. For Radio Galaxies, feedback studies have mainly focused on jet/cavity systems in the most massive and X-ray luminous galaxy clusters. The recent high-resolution detection of warm absorbers in some Broad Line Radio Galaxies allow us to investigate the interplay between the nuclear engine and the surrounding medium from a different perspective. We report on the detection of warm absorbers in two Broad Line Radio Galaxies, 3C 382 and 3C 390.3, and discuss the physical and energetic properties of the absorbing gas. Finally, we attempt a comparison between radio-loud and radio-quiet outflows.

  16. Chasma Australe Mars: Structural Framework for a Catastrophic Outflow Origin

    NASA Technical Reports Server (NTRS)

    Anguita, F.; Babin, R.; Benito, G.; Collado, A.; Gomez, D.; Rice, J. W.

    1998-01-01

    Chasma Australe is the most remarkable of the martian south pole erosional reentrants carved in the polar layered deposits. Ms chasma originates near the south pole and runs across the polar troughs over a distance of about 500 km. Its width varies between 20 and 80 km and, with a depth up to 1000 m, it reaches the bedrock. Following an idea put forward originally for Chasma Boreale, we propose for the genesis of Chasma Australe a mechanism of catastrophic outflow preceded by a tectonically induced powerful sapping process. A detailed geomorphological analysis of Chasma Australe shows erosional and depositional features that can be interpreted as produced by the motion of a fluid. Like other polar reentrants, Chasma Australe is clearly assymetric, with a steep eastern margin where basal and lateral erosion prevailed, and a gentler western side, where the stepped topography and bedrock spurs favored deposition.

  17. Outflows, Jets and Shocks in the Orion Nebula

    NASA Technical Reports Server (NTRS)

    ODell, C. R.; Bally, John

    2000-01-01

    The rich young cluster of stars associated with the Orion Nebula provides a unique laboratory for the study of plasma phenomena. We see five types of flows and shocks. Photoablation outflow from the proplyds nearest theta (exp 1) Ori C form nearly stationary shocks with the high velocity wind from that star. Microjets, with scales of less than 10 (exp 4) AU, are seen around some 20 low mass stars. Isolated jets, with high velocities and scales of about, 104 AU, are less numerous but common. One also sees the shocks formed when these jets impinge on the ionized nebular gas and the neutral gas in the foreground lid. The final type of object is the stationary shock formed by the interaction from the stellar wind that arises during disk formation with the ambient, gas flowing away from the main body of the nebula.

  18. Bipolar Outflow Offset from the Nucleus of M33

    NASA Astrophysics Data System (ADS)

    Roming, P. W. A.; Moody, J. W.; Hintz, M. L.; Wu, K.; Soria, R.

    2002-12-01

    Using long-slit spectra centered in wavelength about Hα , we have produced a velocity map of a 0.5' x 2' hourglass shaped object centered 38" southeast of the optical center of M33. The velocity resolution is 1.1 km/s. We have also produced electron temperature, electron density, and shock heating maps of the same region using the [NII](λ 6548), [NII](λ 6583), Hα , [SII](λ 6717), and [SII](λ 6731) lines. The data reveal that the gas is flowing away from the center of this hourglass shaped object and that the electron temperature and density of the region is relatively low. The shock heating maps indicate that very little of the gas in the region is shock heated. Using this new data and previously published UV, IR, and radio data we investigate possible scenarios that could explain this large scale, low velocity outflow.

  19. Doubling of Ion Up-flow for Ion Outflow Calculations

    NASA Astrophysics Data System (ADS)

    Carlson, H. C.; Moen, J. I.; Oksavik, K.; Aruliah, A. L.; Skjaeveland, A.

    2013-12-01

    Estimates of O+ ion escape fluxes from the ionosphere to the magnetosphere, involve the combination of ionospheric O+ up-flow to adequate altitudes for intermediate altitude acceleration processes to boost them into storage in the magnetosphere. Calculations of ambiploar up-flow based on measured ion and electron gas temperatures lead to ion up-flows order 100 m/s in the vicinity of 400 km, but are found to be only order half ion up-flow velocities observed. It has been speculated that this calculated shortfall can be explained by magnetic reconnection, leading to plasma flow jets, in turn leading to frictional drag heating of the thermosphere and consequent upwelling of the neutral rest frame within which ambipolar up-flow occurs. We report here the first direct observations confirming this mechanism for order doubling the ion up-flow speeds. This new perspective needs to be added to thinking within the heavy ion outflow community.

  20. Paleoceanography. Onset of Mediterranean outflow into the North Atlantic.

    PubMed

    Hernández-Molina, F Javier; Stow, Dorrik A V; Alvarez-Zarikian, Carlos A; Acton, Gary; Bahr, André; Balestra, Barbara; Ducassou, Emmanuelle; Flood, Roger; Flores, José-Abel; Furota, Satoshi; Grunert, Patrick; Hodell, David; Jimenez-Espejo, Francisco; Kim, Jin Kyoung; Krissek, Lawrence; Kuroda, Junichiro; Li, Baohua; Llave, Estefania; Lofi, Johanna; Lourens, Lucas; Miller, Madeline; Nanayama, Futoshi; Nishida, Naohisa; Richter, Carl; Roque, Cristina; Pereira, Hélder; Sanchez Goñi, Maria Fernanda; Sierro, Francisco J; Singh, Arun Deo; Sloss, Craig; Takashimizu, Yasuhiro; Tzanova, Alexandrina; Voelker, Antje; Williams, Trevor; Xuan, Chuang

    2014-06-13

    Sediments cored along the southwestern Iberian margin during Integrated Ocean Drilling Program Expedition 339 provide constraints on Mediterranean Outflow Water (MOW) circulation patterns from the Pliocene epoch to the present day. After the Strait of Gibraltar opened (5.33 million years ago), a limited volume of MOW entered the Atlantic. Depositional hiatuses indicate erosion by bottom currents related to higher volumes of MOW circulating into the North Atlantic, beginning in the late Pliocene. The hiatuses coincide with regional tectonic events and changes in global thermohaline circulation (THC). This suggests that MOW influenced Atlantic Meridional Overturning Circulation (AMOC), THC, and climatic shifts by contributing a component of warm, saline water to northern latitudes while in turn being influenced by plate tectonics. PMID:24926012

  1. Irrelevance of information outflow in opinion dynamics models

    NASA Astrophysics Data System (ADS)

    Castellano, Claudio; Pastor-Satorras, Romualdo

    2011-01-01

    The Sznajd model for opinion dynamics has attracted a large interest as a simple realization of the psychological principle of social validation. As its most salient feature, it has been claimed that the Sznajd model is qualitatively different from other ordering processes because it is the only one featuring outflow of information as opposed to inflow. We show that this claim is unfounded by presenting a generalized zero-temperature Glauber type of dynamics, which yields results indistinguishable from those of the Sznajd model. In one dimension, we also derive an exact expression for the exit probability of the Sznajd model, which turns out to coincide with the result of an analytical approach based on the Kirkwood approximation. This observation raises interesting questions about the applicability and limitations of this approach.

  2. The bipolar outflow from the rotating carbon star, V Hydrae

    NASA Technical Reports Server (NTRS)

    Kahane, C.; Maizels, C.; Jura, M.

    1988-01-01

    A high-resolution optical spectrum of the mass-losing red giant carbon star, V Hya, has been obtained, and the (C-12)O (J = 1-0) millimeter emission in the circumstellar envelope around this star has been mapped. It is found that the CO emission is extended, clearly anisotropic and can be interpreted as the superposition of an isotropic emission with that of a bipolar flow. The optical spectrum of the photosphere suggests that this star is rotating with v sin i between 10 and 20 km/s. These data are interpreted, together, to suggest that the bipolar nature of the outflow results from the flattening of the star induced by its rapid rotation.

  3. Antioxidant response and related gene expression in aged oat seed

    PubMed Central

    Kong, Lingqi; Huo, Heqiang; Mao, Peisheng

    2015-01-01

    To evaluate deterioration of oat seeds during storage, we analyzed oxygen radicals, antioxidant enzyme activity, proline content, and gene transcript levels in oat seeds with different moisture contents (MCs; 4, 16, and 28% w/w) during storage for 0, 6, and 12 months (CK, LT-6, and LT-12 treatments, respectively) at 4°C. The germination percentage decreased significantly with higher seed MCs and longer storage duration. The concentrations of superoxide radical and hydrogen peroxide increased with seed MC increasing. The activities of catalase (CAT), ascorbate peroxidase (APX), and superoxide dismutase (SOD) may have had a complementary or interacting role to scavenge reactive oxygen species. As the storage duration extended, the proline content decreased in seeds with 4 and 16% MC and increased in 28%. These findings suggest that proline played the main role in adaptation to oxidative stress in seeds with higher MC (28%), while antioxidant enzymes played the main role in seeds with lower MCs (4%, 16%). In the gene transcript analyses, SOD1 transcript levels were not consistent with total SOD activity. The transcript levels of APX1 and CAT1 showed similar trends to those of APX and CAT activity. The transcript levels of P5CS1, which encodes a proline biosynthetic enzyme, increased with seed MC increasing in CK. Compared with changing of proline content in seeds stored 12 months, PDH1 transcript levels showed the opposite trend and maintained the lower levels in seeds of 16 and 28% MCs. The transcript level of P5CS1 was significantly affected by MC, and PDH1 could improve stress resistance for seed aging and maintain seed vigor during long-term storage. PMID:25852711

  4. Quantitation of uveoscleral outflow in normotensive and glaucomatous Beagles by /sup 3/H-labeled dextran

    SciTech Connect

    Barrie, K.P.; Gum, G.G.; Samuelson, D.A.; Gelatt, K.N.

    1985-01-01

    In uveoscleral outflow, aqueous humor leaves the anterior chamber and passes caudally through the trabecular meshwork and the sclerociliary cleft to enter the supraciliary and suprachoroidal spaces. The fluid is then absorbed by choroidal and scleral circulations. Using /sup 3/H-labeled dextran, uveoscleral outflow was quantitated in normotensive and glaucomatous Beagles under general anesthesia. The intrascleral plexus was isolated and /sup 3/H-labeled dextran was injected into the anterior chamber. Intrascleral plexus contents were sampled every 5 minutes over a 30- to 60-minute period. The eyes were enucleated, sectioned, and prepared for scintillation counting. Uveoscleral outflow accounted for 15% and 3% of the total aqueous humor outflow in the normotensive dogs and in the advanced glaucomatous dogs, respectively. In the advanced glaucomatous Beagle, conventional and uveoscleral outflow pathways were reduced and contributed to the etiopathogenesis of glaucoma.

  5. Dynamic left ventricular outflow tract obstruction: underestimated cause of hypotension and hemodynamic instability

    PubMed Central

    2014-01-01

    Left ventricular outflow tract obstruction, which is typically associated with hypertrophic cardiomyopathy, is the third most frequent cause of unexplained hypotension. This underestimated problem may temporarily accompany various diseases (it is found in even <1% of patients with no tangible cardiac disease) and clinical situations (hypovolemia, general anesthesia). It is currently assumed that left ventricular outflow tract obstruction is a dynamic phenomenon, the occurrence of which requires the coexistence of predisposing anatomic factors and a physiological condition that induces it. The diagnosis of left ventricular outflow tract obstruction should entail immediate implementation of the therapy to eliminate the factors that can potentially intensify the obstruction. Echocardiography is the basic modality in the diagnosis and treatment of left ventricular outflow tract obstruction. This paper presents four patients in whom the immediate implementation of bedside echocardiography enabled a rapid diagnosis of left ventricular outflow tract obstruction and implementation of proper treatment. PMID:26674265

  6. An Unbiased Search for Molecular Hydrogen Outflows in the Orion B Star Forming Region

    NASA Astrophysics Data System (ADS)

    Froebrich, D.; Ziener, R.; Eislöffel, J.

    The formation of stars is often accompanied by molecular outflows. One possible tracer of these outflows is the shocked emission of molecular hydrogen in the near-infrared. We conducted an unbiased survey for molecular outflows in the Orion B region with MAGIC at the 1.23 m telescope on Calar Alto in the 1-0 S(1) line of molecular hydrogen at 2.212μm and in the K' bandpass (continuum). The observed field was about 2.7 square degrees, including the known outflows of NGC2071, HH19, HH24, HH25, HH26, HH27, HH37, HH67, HH91, HH92, HH93, HH94, HH212, HH247, HH248, HH249 and HH260. In addition to these known H2 flows, we find ten new groups of H2 emission features, and discuss their morphology and possible outflow sources.

  7. Jets and outflows from pre main sequence stars

    NASA Astrophysics Data System (ADS)

    Wassell, Edward Joseph, III

    2009-09-01

    Extensive research has been done on the evolution of young low mass T Tauri stars (TTS), and a paradigm has been developed that successfully explains how the star grows by the accretion of matter from a circumstellar disk. It is currently a matter of debate whether or not the same paradigm can be applied to the higher mass counterpart Herbig Ae stars. In this dissertation, I propose to address this issue. By investigating a wide range of phenomena using ground- based and satellite observing platforms, I will construct detailed observational pictures of the two prototypical Herbig Ae stars, HD163296 and AB Aur. Then, I will test whether or not this model can explain all the phenomena associated with these two stars. First, my research characterized the bipolar collimated outflow from HD163296. Using narrowband coronagraphic imagery with the Goddard Fabry-Perot, I discovered a chain of six previously unreported Herbig-Haro (HH) knots along the redshifted counterjet spanning greater than 27 arcseconds, and three HH knots along the blueshifted jet. Combining Hubble Space Telescope imagery and spectroscopy, I found a striking asymmetry in velocity, momentum and ionization between the two lobes of the outflow. Such asymmetries have been found in TTS, and can readily be explained through the same paradigm of magnetospheric accretion successfully applied to TTS. Next, by piecing together a wide range of data for AB Aur, I found evidence for magnetospheric accretion with the detection of excess continuum emission and semi-forbidden line emission in the ultraviolet. Reviewing archival spectra from the International Ultraviolet Explorer for AB Aur and five other Herbig Ae stars known to be powering microjets, I found a correlation between the Magnesium II wind absorption profile and inclination, which correlation strongly suggests that AB Aur is also powering a microjet, although currently, high resolution imagers have failed to detect jet signatures.

  8. Regionally Discrete Aqueous Humor Outflow Quantification Using Fluorescein Canalograms

    PubMed Central

    Roy, Pritha; Schuman, Joel S.; Sigal, Ian A.; Loewen, Nils A.

    2016-01-01

    Purpose To visualize and quantify conventional outflow directly in its anatomic location. Methods We obtained fluorescein canalograms in six porcine whole eyes and six porcine anterior segment cultures. Eyes were perfused with a constant pressure of 15 mmHg using media containing 0.017 mg/ml fluorescein. Flow patterns were visualized using a stereo dissecting microscope equipped for fluorescent imaging. Images were captured every 30 seconds for 20 minutes for time lapse analysis. Anterior chamber cultures were imaged again on day three of culture. Canalograms were first analyzed for filling time per quadrant. We then wrote a program to automatically compute focal flow fits for each macropixel and to detect convergent perilimbal flow patterns with macropixels grouped into 3 equal-radial width rings around the cornea. A generalized additive model was used to determine fluorescence changes of individual macropixels. Results The resulting imaging algorithm deployed 1024 macropixels that were fit to determine maximum intensity and time to fill. These individual fits highlighted the focal flow function. In whole eyes, significantly faster flow was seen in the inferonasal (IN) and superonasal (SN) quadrants compared to the superotemporal (ST) and inferotemporal (IT) ones (p<0.05). In anterior chamber cultures, reduced flow on day 1 increased in all quadrants on day 3 except in IT (p<0.05). Perilimbal ring analysis uncovered convergent perilimbal flow. Conclusions An algorithm was developed that analyzes regional and circumferential outflow patterns. This algorithm found flow patterns that changed over time and differ in whole eyes and anterior segment cultures. PMID:26998833

  9. Inverse modelling of multiple infiltration-outflow experiments

    NASA Astrophysics Data System (ADS)

    Sobotková, M.; Snehota, M.; Dohnal, M.; Cislerova, M.

    2009-04-01

    Changes of (quasi)steady state water flow rates were observed in laboratory infiltration experiments done on columns of compacted sand and on two undisturbed soil columns of sandy loam and loamy sand cambisol soil. Infiltration-outflow experiments consisted of series of ponded infiltration runs with seepage face boundary condition at the lower end of columns. The initial water contents were different for each run. The results of the experiment done on an undisturbed soil column showed that the flux rates and water contents measured during quasi-steady state differ between infiltration runs. This finding contradicts the standard theory. The fluctuations of the water content during the steady state flow can be ascribed to the variations in volume of the entrapped air. The same behaviour was not observed in the sample of homogeneous sand. Computer tomography was used to characterize the structure of the undisturbed soil sample with focus on potential preferential flow pathways. In order to asses the changes between runs quantitatively, hydraulic characteristics were estimated for each infiltration run separately by inverse modelling. Experimental outflow data and tensiometric pressure head data were used as an input for inverse modelling. Numerical code based on dual permeability approach was coupled with parameter estimator. Result of the inverse modelling for each column is specific set of hydraulic properties for each infiltration run of particular soil column. Since we hypothesise that the steady state flow is affected by soil water content at the beginning of the infiltration run, we will study the relationships between initial moistures and hydraulic parameters values. Furthermore we will test if the above phenomena can be ascribed to hysteresis of hydraulic functions.

  10. The density structure of the L1157 molecular outflow

    NASA Astrophysics Data System (ADS)

    Gómez-Ruiz, A. I.; Codella, C.; Lefloch, B.; Benedettini, M.; Busquet, G.; Ceccarelli, C.; Nisini, B.; Podio, L.; Viti, S.

    2015-02-01

    We present a multiline CS survey towards the brightest bow-shock B1 in the prototypical chemically active protostellar outflow L1157. We made use of (sub-)mm data obtained in the framework of the Chemical HErschel Surveys of Star forming regions and Astrochemical Surveys at IRAM (ASAI) key science programs. We detected 12C32S, 12C34S, 13C32S, and 12C33S emissions, for a total of 18 transitions, with Eu up to ˜180 K. The unprecedented sensitivity of the survey allows us to carefully analyse the line profiles, revealing high-velocity emission, up to 20 km s-1 with respect to the systemic. The profiles can be well fitted by a combination of two exponential laws that are remarkably similar to what previously found using CO. These components have been related to the cavity walls produced by the ˜2000 yr B1 shock and the older (˜4000 yr) B2 shock, respectively. The combination of low- and high-excitation CS emission was used to properly sample the different physical components expected in a shocked region. Our CS observations show that this molecule is highlighting the dense, nH2 = 1-5 × 105 cm-3, cavity walls produced by the episodic outflow in L1157. In addition, the highest excitation (Eu ≥ 130 K) CS lines provide us with the signature of denser (1-5 × 106 cm-3) gas, associated with a molecular reformation zone of a dissociative J-type shock, which is expected to arise where the precessing jet impacting the molecular cavities. The CS fractional abundance increases up to ˜10-7 in all the kinematical components. This value is consistent with what previously found for prototypical protostars and it is in agreement with the prediction of the abundances obtained via the chemical code Astrochem.

  11. Shocks in nova outflows. II. Synchrotron radio emission

    NASA Astrophysics Data System (ADS)

    Vlasov, Andrey; Vurm, Indrek; Metzger, Brian D.

    2016-08-01

    The discovery of GeV gamma-rays from classical novae indicates that shocks and relativistic particle acceleration are energetically key in these events. Further evidence for shocks comes from thermal keV X-ray emission and an early peak in the radio light curve on a timescale of months with a brightness temperature which is too high to result from freely expanding photo-ionized gas. Paper I developed a one dimensional model for the thermal emission from nova shocks. This work concluded that the shock-powered radio peak cannot be thermal if line cooling operates in the post-shock gas at the rate determined by collisional ionization equilibrium. Here we extend this calculation to include non-thermal synchrotron emission. Applying our model to three classical novae, we constrain the amplification of the magnetic field ɛB and the efficiency ɛe of accelerating relativistic electrons of characteristic Lorentz factor γ ˜ 100. If the shocks are radiative (low velocity v_sh ≲ 1000 km s-1) and cover a large solid angle of the nova outflow, as likely characterize those producing gamma-rays, then values of ɛe ˜ 0.01 - 0.1 are required to achieve the peak radio brightness for ɛB = 10-2. Such high efficiencies exclude secondary pairs from pion decay as the source of the radio-emitting particles, instead favoring the direct acceleration of electrons at the shock. If the radio-emitting shocks are instead adiabatic (high velocity), as likely characterize those responsible for the thermal X-rays, then much higher brightness temperatures are possible, allowing the radio-emitting shocks to cover a smaller outflow solid angle.

  12. UNDERSTANDING GALAXY OUTFLOWS AS THE PRODUCT OF UNSTABLE TURBULENT SUPPORT

    SciTech Connect

    Scannapieco, Evan

    2013-02-01

    The interstellar medium is a multiphase gas in which turbulent support is as important as thermal pressure. Sustaining this configuration requires both continuous turbulent stirring and continuous radiative cooling to match the decay of turbulent energy. While this equilibrium can persist for small turbulent velocities, if the one-dimensional velocity dispersion is larger than Almost-Equal-To 35 km s{sup -1}, the gas moves into an unstable regime that leads to rapid heating. I study the implications of this turbulent runaway, showing that it causes a hot gas outflow to form in all galaxies with a gas surface density above Almost-Equal-To 50 M{sub Sun} pc{sup -2}, corresponding to a star formation rate per unit area of Almost-Equal-To 0.1 M{sub Sun} yr{sup -1} kpc{sup -2}. For galaxies with v{sub esc} {approx}> 200 km s{sup -1}, the sonic point of this hot outflow should lie interior to the region containing cold gas and stars, while for galaxies with smaller escape velocities, the sonic point should lie outside this region. This leads to efficient cold cloud acceleration in higher mass galaxies, while in lower mass galaxies, clouds may be ejected by random turbulent motions rather than accelerated by the wind. Finally, I show that energy balance cannot be achieved at all for turbulent media above a surface density of Almost-Equal-To 10{sup 5} M{sub Sun} pc{sup -2}.

  13. Cooling and Freshening of the Weddell Sea Outflow

    NASA Astrophysics Data System (ADS)

    Heywood, K. J.; Thompson, A. F.; Fahrbach, E.; Mackensen, A.; Aoki, S.

    2009-04-01

    The Weddell Sea is the primary source of the coldest, densest water invading most of the world ocean, known as Antarctic Bottom Water. The formation process involves brine rejection during sea ice formation, which salinifies the relatively fresh waters on the Antarctic continental shelf. Mixing with meltwater from the floating Antarctic ice shelves is believed to contribute also. When it becomes sufficiently dense, the shelf waters can spill down the continental slope as a deep outflow plume, mixing as it descends with the warmer and saltier Warm Deep Water above. By the time the plume reaches the western Weddell Sea, it is a narrow ribbon of cold, dense water hugging the continental slope. Here we will show that this outflow is now colder and fresher than in any of the observations since 1989. This freshening is comparable in magnitude to that seen in bottom water off Adelie Land which implies that the freshening is circumpolar, contrary to some recent analyses. This is likely associated with freshening of source waters on the continental shelf of Antarctica caused by an accelerated hydrological cycle and/or additional melting of the Antarctic ice sheet. Such melting may in turn be caused by a strengthening of the circumpolar winds associated with the Southern Annular Mode, leading to a southward ocean transport of heat towards the Antarctic. The Weddell Sea freshening may have been exacerbated by the break-up of the Larsen Ice Shelf on the eastern Antarctic Peninsula in the late 1990s, leaving a large expanse of continental shelf able to host the formation of sea ice and hence form dense bottom water.

  14. Ultrafast outflows in radio-loud active galactic nuclei

    NASA Astrophysics Data System (ADS)

    Tombesi, F.; Tazaki, F.; Mushotzky, R. F.; Ueda, Y.; Cappi, M.; Gofford, J.; Reeves, J. N.; Guainazzi, M.

    2014-09-01

    Recent X-ray observations show absorbing winds with velocities up to mildly relativistic values of the order of ˜0.1c in a limited sample of six broad-line radio galaxies. They are observed as blueshifted Fe XXV-XXVI K-shell absorption lines, similarly to the ultrafast outflows (UFOs) reported in Seyferts and quasars. In this work we extend the search for such Fe K absorption lines to a larger sample of 26 radio-loud active galactic nuclei (AGN) observed with XMM-Newton and Suzaku. The sample is drawn from the Swift Burst Alert Telescope 58-month catalogue and blazars are excluded. X-ray bright Fanaroff-Riley Class II radio galaxies constitute the majority of the sources. Combining the results of this analysis with those in the literature we find that UFOs are detected in >27 per cent of the sources. However, correcting for the number of spectra with insufficient signal-to-noise ratio, we can estimate that the incidence of UFOs is this sample of radio-loud AGN is likely in the range f ≃ (50 ± 20) per cent. A photoionization modelling of the absorption lines with XSTAR allows us to estimate the distribution of their main parameters. The observed outflow velocities are broadly distributed between vout ≲ 1000 km s-1 and vout ≃ 0.4c, with mean and median values of vout ≃ 0.133c and vout ≃ 0.117c, respectively. The material is highly ionized, with an average ionization parameter of logξ ≃ 4.5 erg s-1 cm, and the column densities are larger than NH > 1022 cm-2. Overall, these characteristics are consistent with the presence of complex accretion disc winds in a significant fraction of radio-loud AGN and demonstrate that the presence of relativistic jets does not preclude the existence of winds, in accordance with several theoretical models.

  15. The application of pulmonary valve biorifice for reconstruction of right ventricular outflow tract in tetralogy of Fallot

    PubMed Central

    2013-01-01

    Background To introduce a new technique to create a pulmonary valve biorifice for the reconstruction of the right ventricular outflow tract in tetralogy of Fallot (TOF), and to summarize the initial clinical experiment. Methods The new technique of reconstructing the right ventricular outflow tract with pulmonary valve biorifice was used in 53 cases of TOF (the observation group). While the conventional technique for reconstructing the right ventricular outflow tract was used in other 50 cases of TOF (the control group). The clinical Data of all cases was reviewed retrospectively. Results The ages, weights, cardiopulmonary bypass time, cardiac arrest time, as well as the post operation ventilation support time were not different significantly between groups. Unlike patients in the control group, patients from the observation group had shorter duration of ICU stay. Post- operation, in the observation group, only 2 cases had a large amount of pleural effusion, 1 case had mid-level effusion and 8 cases had a small amount of pleural effusion. While in the control group, there was 1 case of a large amount of effusion, 5 cases of mid-level effusion and 17 cases of a small amount of pleural effusion. 1 week after the operation, all patients were rechecked by echocardiography and no evidence of pulmonary valve stenosis was found. In the observation group, moderate pulmonary valve regurgitation was found in 8 cases, and mild regurgitation was observed in 15 cases. In the control group, severe regurgitation was observed in 3 cases, moderate regurgitation in 17 cases, and mild regurgitation in 16 cases. 33 cases from the observation group were rechecked six months, post-operation, and moderate-mild pulmonary regurgitation was found in 3 cases. As a follow up, 18 cases from the observation group were rechecked 1 year later, and no pulmonary regurgitation was found. Conclusion The new technique to create pulmonary valve biorifice can reduce the pulmonary valve regurgitation

  16. The Retrograde Transvenous Push-Through Method: A Novel Treatment of Peripheral Arteriovenous Malformations with Dominant Venous Outflow

    SciTech Connect

    Wohlgemuth, Walter A. Müller-Wille, René Teusch, Veronika I.; Dudeck, Oliver; Cahill, Anne M.; Alomari, Ahmad I.; Uller, Wibke

    2015-06-15

    PurposeTo evaluate the efficacy and safety of a novel retrograde transvenous embolization technique of peripheral arteriovenous malformations (AVMs) using Onyx.Materials and MethodsWe conducted a retrospective analysis of all patients who underwent transvenous retrograde Onyx embolization of peripheral AVMs with dominant venous outflow over a 29-month period. The embolization is aimed at retrograde filling of the nidus after building a solid plug in the dominant venous outflow (push-through). Classification, clinical signs, technical aspects, clinical and technical success rates, and complications were recorded. Short-term outcome was assessed.Results11 Symptomatic patients (8 female; mean age 31.4 years) were treated at our Vascular Anomalies Center with this method between January 2012 and May 2014. The AVMs were located on the upper extremity (n = 3), pelvis (n = 2), buttock (n = 2), and lower extremity (n = 4). Retrograde embolization was successfully carried out after preparatory transarterial-flow reduction in eight cases (73 %) and venous-flow reduction with Amplatzer Vascular Plugs in four cases (36 %). Complete devascularization (n = 10; 91 %) or 95 % devascularization (n = 1; 9 %) led to complete resolution (n = 8; 73 %) or improvement of clinical symptoms (n = 3; 27 %). One minor complication occurred (pain and swelling). During a mean follow-up time of 8 months, one clinically asymptomatic recurrence of AVM was detected.ConclusionInitial results suggest that retrograde transvenous Onyx embolization of peripheral AVMs with dominant venous outflow is a safe and effective novel technique with a low complication rate.

  17. JCMT HARP CO 3-2 observations of molecular outflows in W5

    NASA Astrophysics Data System (ADS)

    Ginsburg, Adam; Bally, John; Williams, Jonathan P.

    2011-12-01

    New James Clerk Maxwell Telescope (JCMT) HARP CO 3-2 observations of the W5 star forming complex are presented, totalling an area of ˜12 000 arcmin2 with sensitivity better than 0.1 K per 0.4 km s-1 channel. We discovered 55 CO outflow candidates, of which 40 are associated with W5 and 15 are more distant than the Perseus arm. Most of the outflows are located on the periphery of the W5 H II region. However, two outflow clusters are >5 pc from the ionization fronts, indicating that their driving protostars formed without directly being triggered by the O-stars in W5. We compare the derived outflow properties to those in Perseus and find that the total W5 outflow mass is surprisingly low given the cloud masses. The outflow mass deficiency in the more massive W5 cloud [M(H2) ˜ 5 × 104 M⊙] can be explained if ionizing radiation dissociates molecules as they break out of their host cloud cores. Although CO J = 3-2 is a good outflow tracer, it is likely to be a poor mass tracer because of sub-thermal line excitation and high opacity, which may also contribute to the outflow mass discrepancy. It is unlikely that outflows could provide the observed turbulent energy in the W5 molecular clouds even accounting for undetected outflow material. Many cometary globules have been observed with velocity gradients from head to tail, displaying strong interaction with the W5 H II region and exhibiting signs of triggered or revealed star formation in their heads. Because it is observed face-on, W5 is an excellent region to study feedback effects, both positive and negative, of massive stars on star formation.

  18. NUCLEOSYNTHESIS IN THE OUTFLOWS ASSOCIATED WITH ACCRETION DISKS OF TYPE II COLLAPSARS

    SciTech Connect

    Banerjee, Indrani; Mukhopadhyay, Banibrata E-mail: bm@physics.iisc.ernet.in

    2013-11-20

    We investigate nucleosynthesis inside the outflows from gamma-ray burst (GRB) accretion disks formed by the Type II collapsars. In these collapsars, massive stars undergo core collapse to form a proto-neutron star initially, and a mild supernova (SN) explosion is driven. The SN ejecta lack momentum, and subsequently this newly formed neutron star gets transformed to a stellar mass black hole via massive fallback. The hydrodynamics and the nucleosynthesis in these accretion disks have been studied extensively in the past. Several heavy elements are synthesized in the disk, and much of these heavy elements are ejected from the disk via winds and outflows. We study nucleosynthesis in the outflows launched from these disks by using an adiabatic, spherically expanding outflow model, to understand which of these elements thus synthesized in the disk survive in the outflow. While studying this, we find that many new elements like isotopes of titanium, copper, zinc, etc., are present in the outflows. {sup 56}Ni is abundantly synthesized in most of the cases in the outflow, which implies that the outflows from these disks in a majority of cases will lead to an observable SN explosion. It is mainly present when outflow is considered from the He-rich, {sup 56}Ni/{sup 54}Fe-rich zones of the disks. However, outflow from the Si-rich zone of the disk remains rich in silicon. Although emission lines of many of these heavy elements have been observed in the X-ray afterglows of several GRBs by Chandra, BeppoSAX, XMM-Newton, etc., Swift seems to have not yet detected these lines.

  19. Outflow activity near Hadriaca Patera, Mars: Fluid-tectonic interaction investigated with High Resolution Stereo Camera stereo data and finite element modeling

    NASA Astrophysics Data System (ADS)

    Musiol, S.; Cailleau, B.; Platz, T.; Kneissl, T.; Dumke, A.; Neukum, G.

    2011-08-01

    We investigate the formation of the outflow channels Dao and Niger Valles near the eastern rim of the Hellas impact basin, Mars. Methods used include image and topography analysis, surface age determination, and finite element modeling. Observations show that deep depressions, source regions for Dao and Niger Valles, are located in an area of shallow subsidence to the south and east of the volcano Hadriaca Patera. Cratering model ages allow for fluvial processes triggered by volcanic loading. Based on the observations, we develop a numerical model of volcanic loading on top of a poroelastic plate leading to flexure and fracturing of the lithosphere. Modeling results show that fracturing may occur up to a depth of about 6 km within an area of shallow subsidence, i.e., the moat surrounding the volcano. Depending on initial aquifer pressurization, groundwater could have reached the surface. Model discharges and channel morphometry suggest that the Dao Vallis channel never reached bankfull flow and that the wetted channel perimeter may have formed during multiple outflow events. The following scenario is proposed: (1) emplacement of a volcanic load on top of a confined, overpressurized aquifer in the early Hesperian, (2) fracturing around the load, possibly reactivated during various stages of volcanic activity, (3) channeling of groundwater to the surface along fractures and outflow channel formation during several events in the Hesperian, and (4) collapse, mass wasting and modification of depressions in the Amazonian.

  20. Sea level history in 3D: Data acquisition and processing for an ultra-high resolution MCS survey across IODP Expedition 313 drillsite

    NASA Astrophysics Data System (ADS)

    Nedimovic, M. R.; Mountain, G. S.; Austin, J. A., Jr.; Fulthorpe, C.; Aali, M.; Baldwin, K.; Bhatnagar, T.; Johnson, C.; Küçük, H. M.; Newton, A.; Stanley, J.

    2015-12-01

    In June-July 2015, we acquired the first 3D/2D hybrid (short/long streamer) multichannel seismic (MCS) reflection dataset. These data were collected simultaneously across IODP Exp. 313 drillsites, off New Jersey, using R/V Langsethand cover ~95% of the planned 12x50 km box. Despite the large survey area, the lateral and vertical resolution for the 3D dataset is almost a magnitude of order higher than for data gathered for standard petroleum exploration. Such high-resolution was made possible by collection of common midpoint (CMP) lines whose combined length is ~3 times the Earth's circumference (~120,000 profile km) and a source rich in high-frequencies. We present details on the data acquisition, ongoing data analysis, and preliminary results. The science driving this project is presented by Mountain et al. The 3D component of this innovative survey used an athwartship cross cable, extended laterally by 2 barovanes roughly 357.5 m apart and trailed by 24 50-m P-Cables spaced ~12.5 m with near-trace offset of 53 m. Each P-Cable had 8 single hydrophone groups spaced at 6.25 m for a total of 192 channels. Record length was 4 s and sample rate 0.5 ms, with no low cut and an 824 Hz high cut filter. We ran 77 sail lines spaced ~150 m. Receiver locations were determined using 2 GPS receivers mounted on floats and 2 compasses and depth sensors per streamer. Streamer depths varied from 2.1 to 3.7 m. The 2D component used a single 3 km streamer, with 240 9-hydrophone groups spaced at 12.5 m, towed astern with near-trace offset of 229 m. The record length was 4 s and sample rate 0.5 ms, with low cut filter at 2 Hz and high cut at 412 Hz. Receiver locations were recorded using GPS at the head float and tail buoy, combined with 12 bird compasses spaced ~300 m. Nominal streamer depth was 4.5 m. The source for both systems was a 700 in3 linear array of 4 Bolt air guns suspended at 4.5 m towing depth, 271.5 m behind the ship's stern. Shot spacing was 12.5 m. Data analysis to

  1. Formation and spreading of Red Sea Outflow Water in the Red Sea

    NASA Astrophysics Data System (ADS)

    Zhai, Ping; Bower, Amy S.; Smethie, William M.; Pratt, Larry J.

    2015-09-01

    Hydrographic data, chlorofluorocarbon-12 (CFC-12) and sulfur hexafluoride (SF6) measurements collected in March 2010 and September-October 2011 in the Red Sea, as well as an idealized numerical experiment are used to study the formation and spreading of Red Sea Outflow Water (RSOW) in the Red Sea. Analysis of inert tracers, potential vorticity distributions, and model results confirm that RSOW is formed through mixed-layer deepening caused by sea surface buoyancy loss in winter in the northern Red Sea and reveal more details on RSOW spreading rates, pathways, and vertical structure. The southward spreading of RSOW after its formation is identified as a layer with minimum potential vorticity and maximum CFC-12 and SF6. Ventilation ages of seawater within the RSOW layer, calculated from the partial pressure of SF6 (pSF6), range from 2 years in the northern Red Sea to 15 years at 17°N. The distribution of the tracer ages is in agreement with the model circulation field which shows a rapid transport of RSOW from its formation region to the southern Red Sea where there are longer circulation pathways and hence longer residence time due to basin wide eddies. The mean residence time of RSOW within the Red Sea estimated from the pSF6 age is 4.7 years. This time scale is very close to the mean transit time (4.8 years) for particles from the RSOW formation region to reach the exit at the Strait of Bab el Mandeb in the numerical experiment.

  2. Initial experience using the Palmaz Corinthian stent for right ventricular outflow obstruction in infants and small children.

    PubMed

    Turner, D R; Rodriguez-Cruz, E; Ross, R D; Forbes, T J

    2000-12-01

    The original Palmaz balloon expandable stent has been used extensively for the treatment of vascular stenoses in older children and young adults. Placement of the Palmaz stent in infants and small children, however, is limited by stent inflexibility, large delivery sheath size, and concerns about creating fixed obstructions after the placement of small diameter stents in growing patients. New Palmaz Corinthian stents were placed through 6 French sheaths in four high-risk patients with postoperative right ventricular outflow obstruction. Patients were not considered candidates for surgical repair. Median patient age and weight were 17 months (range 5-32 months) and 7.7 kg (range 4.6-11.1 kg), respectively. Median fluoroscopy time was 58.2 min (range 55.2-172 min). No complications were encountered. In each case, successful stent placement was achieved, and surgery with cardiopulmonary bypass was avoided. Palmaz Corinthian stents are more flexible, require a smaller delivery sheath, have equal or increased radial strength, and can be maximally expanded to a greater cross sectional area when compared to the original Palmaz stent. These characteristics make the Palmaz Corinthian stent a reasonable alternative for use in a select group of infants and small children who are not candidates for surgical repair of postoperative right ventricular outflow obstruction. PMID:11108677

  3. Sources and light absorption of water-soluble organic carbon aerosols in the outflow from northern China

    NASA Astrophysics Data System (ADS)

    Kirillova, E. N.; Andersson, A.; Han, J.; Lee, M.; Gustafsson, Ö.

    2014-02-01

    High loadings of anthropogenic carbonaceous aerosols in Chinese air influence the air quality for over one billion people and impact the regional climate. A large fraction (17-80%) of this aerosol carbon is water-soluble, promoting cloud formation and thus climate cooling. Recent findings, however, suggest that water-soluble carbonaceous aerosols also absorb sunlight, bringing additional direct and indirect climate warming effects, yet the extent and nature of light absorption by this water-soluble "brown carbon" and its relation to sources is poorly understood. Here, we combine source estimates constrained by dual carbon isotopes with light-absorption measurements of water-soluble organic carbon (WSOC) for a March 2011 campaign at the Korea Climate Observatory at Gosan (KCOG), a receptor station in SE Yellow Sea for the outflow from northern China. The mass absorption cross section at 365 nm (MAC365) of WSOC for air masses from N. China were in general higher (0.8-1.1 m2 g-1), than from other source regions (0.3-0.8 m2 g-1). However, this effect corresponds to only 2-10% of the radiative forcing caused by light absorption by elemental carbon. Radiocarbon constraints show that the WSOC in Chinese outflow had significantly higher fraction fossil sources (30-50%) compared to previous findings in S. Asia, N. America and Europe. Stable carbon (δ13C) measurements were consistent with aging during long-range air mass transport for this large fraction of carbonaceous aerosols.

  4. The Orion Fingers: Near-IR Spectral Imaging of an Explosive Outflow

    NASA Astrophysics Data System (ADS)

    Youngblood, Allison; Ginsburg, Adam; Bally, John

    2016-06-01

    We present near-IR (1.1–2.4 μm) position–position–velocity cubes of the 500 year old Orion BN/KL explosive outflow with spatial resolution 1″ and spectral resolution 86 km s‑1. We construct integrated intensity maps free of continuum sources of 15 H2 and [Fe ii] lines while preserving kinematic information of individual outflow features. Included in the detected H2 lines are the 1-0 S(1) and 1-0 Q(3) transitions, allowing extinction measurements across the outflow. Additionally, we present dereddened flux ratios for over two dozen outflow features to allow for the characterization of the true excitation conditions of the BN/KL outflow. All of the ratios show the dominance of the shock excitation of the H2 emission, although some features exhibit signs of fluorescent excitation from stellar radiation or J-type shocks. We also detect tracers of the PDR/ionization front north of the Trapezium stars in [O i] and [Fe ii] and analyze other observed outflows not associated with the BN/KL outflow.

  5. Endogenous 5-HT outflow from chicken aorta by 5-HT uptake inhibitors and amphetamine derivatives

    PubMed Central

    DELGERMURUN, Dugar; ITO, Shigeo; OHTA, Toshio; YAMAGUCHI, Soichiro; OTSUGURO, Ken-ichi

    2015-01-01

    Chemoreceptor cells aggregating in clusters in the chicken thoracic aorta contain 5-hydroxytryptamine (5-HT) and have voltage-dependent ion channels and nicotinic acetylcholine receptors, which are characteristics typically associated with neurons. The aim of the present study was to investigate the effects of 5-HT uptake inhibitors, fluvoxamine, fluoxetine and clomipramine (CLM), and amphetamine derivatives, p-chloroamphetamine (PCA) and methamphetamine (MET), on endogenous 5-HT outflow from the isolated chick thoracic aorta in vitro. 5-HT was measured by using a HPLC system with electrochemical detection. The amphetamine derivatives and 5-HT uptake inhibitors caused concentration-dependent increases in endogenous 5-HT outflow. PCA was about ten times more effective in eliciting 5-HT outflow than MET. The 5-HT uptake inhibitors examined had similar potency for 5-HT outflow. PCA and CLM increased 5-HT outflow in a temperature-dependent manner. The outflow of 5-HT induced by PCA or 5-HT uptake inhibitors was independent of extracellular Ca2+ concentration. The 5-HT outflow induced by CLM, but not that by PCA, was dependent on the extracellular NaCl concentration. These results suggest that the 5-HT uptake system of 5-HT-containing chemoreceptor cells in the chicken thoracic aorta has characteristics similar to those of 5-HT-containing neurons in the mammalian central nervous system (CNS). PMID:26321443

  6. Integral Field Spectroscopy of AGN Absorption Outflows: Mrk 509 and IRAS F04250-5718

    NASA Astrophysics Data System (ADS)

    Liu, Guilin; Arav, Nahum; Rupke, David S. N.

    2015-11-01

    Ultraviolet (UV) absorption lines provide abundant spectroscopic information enabling the probe of the physical conditions in active galactic nucleus (AGN) outflows, but the outflow radii (and the energetics consequently) can only be determined indirectly. We present the first direct test of these determinations using integral field unit (IFU) spectroscopy. We have conducted Gemini IFU mapping of the ionized gas nebulae surrounding two AGNs, whose outflow radii have been constrained by UV absorption line analyses. In Mrk 509, we find a quasi-spherical outflow with a radius of 1.2 kpc and a velocity of ˜290 km s-1, while IRAS F04250-5718 is driving a biconical outflow extending out to 2.9 kpc, with a velocity of ˜580 km s-1 and an opening angle of ˜70°. The derived mass flow rate ˜5 and >1 M⊙ yr-1, respectively, and the kinetic luminosity ≳1 × 1041 erg s-1 for both. Adopting the outflow radii and geometric parameters measured from IFU, absorption line analyses would yield mass flow rates and kinetic luminosities in agreement with the above results within a factor of ˜2. We conclude that the spatial locations, kinematics, and energetics revealed by this IFU emission-line study are consistent with pre-existing UV absorption line analyses, providing a long-awaited direct confirmation of the latter as an effective approach for characterizing outflow properties.

  7. Paradoxical inhibitory effect of cromakalim on sup 86 Rb outflow from pancreatic islet cells

    SciTech Connect

    Lebrun, P.; Antoine, M.H.; Devreux, V.; Hermann, M.; Herchuelz, A. )

    1990-12-01

    Cromakalim appears to be the most potent pharmacologic agent belonging to the new class of smooth muscle relaxants: the K+ channel openers. The present study aimed at characterizing the effects of cromakalim on 86Rb outflow, 45Ca outflow and insulin release from prelabeled and perifused rat pancreatic islets. Cromakalim provoked a concentration-dependent reduction in 86Rb outflow. This inhibitory effect was attenuated in islets exposed throughout to glibenclamide or to a Ca+(+)-free medium. In islets exposed to glucose and extracellular Ca++, cromakalim induced a dose-dependent reduction in 45Ca outflow. The drug also inhibited the increase in 45Ca outflow mediated by K+ depolarization. Lastly, cromakalim elicited a concentration-dependent inhibition of insulin release from islets perifused in the presence of glucose and extracellular Ca++. The present data suggest that the paradoxical inhibitory effect of cromakalim on 86Rb outflow probably reflects the capacity of the drug to reduce the activity of the ATP-sensitive K+ channels and to indirectly inhibit the Ca+(+)-activated K+ channels. Furthermore, the cromakalim-induced changes in 45Ca outflow are compatible with an inhibitory effect of the drug on the voltage-dependent Ca++ channels.

  8. Endogenous 5-HT outflow from chicken aorta by 5-HT uptake inhibitors and amphetamine derivatives.

    PubMed

    Delgermurun, Dugar; Ito, Shigeo; Ohta, Toshio; Yamaguchi, Soichiro; Otsuguro, Ken-ichi

    2016-01-01

    Chemoreceptor cells aggregating in clusters in the chicken thoracic aorta contain 5-hydroxytryptamine (5-HT) and have voltage-dependent ion channels and nicotinic acetylcholine receptors, which are characteristics typically associated with neurons. The aim of the present study was to investigate the effects of 5-HT uptake inhibitors, fluvoxamine, fluoxetine and clomipramine (CLM), and amphetamine derivatives, p-chloroamphetamine (PCA) and methamphetamine (MET), on endogenous 5-HT outflow from the isolated chick thoracic aorta in vitro. 5-HT was measured by using a HPLC system with electrochemical detection. The amphetamine derivatives and 5-HT uptake inhibitors caused concentration-dependent increases in endogenous 5-HT outflow. PCA was about ten times more effective in eliciting 5-HT outflow than MET. The 5-HT uptake inhibitors examined had similar potency for 5-HT outflow. PCA and CLM increased 5-HT outflow in a temperature-dependent manner. The outflow of 5-HT induced by PCA or 5-HT uptake inhibitors was independent of extracellular Ca(2+) concentration. The 5-HT outflow induced by CLM, but not that by PCA, was dependent on the extracellular NaCl concentration. These results suggest that the 5-HT uptake system of 5-HT-containing chemoreceptor cells in the chicken thoracic aorta has characteristics similar to those of 5-HT-containing neurons in the mammalian central nervous system (CNS). PMID:26321443

  9. The Role of Cosmic-Ray Pressure in Accelerating Galactic Outflows

    NASA Astrophysics Data System (ADS)

    Simpson, Christine M.; Pakmor, Rüdiger; Marinacci, Federico; Pfrommer, Christoph; Springel, Volker; Glover, Simon C. O.; Clark, Paul C.; Smith, Rowan J.

    2016-08-01

    We study the formation of galactic outflows from supernova (SN) explosions with the moving-mesh code AREPO in a stratified column of gas with a surface density similar to the Milky Way disk at the solar circle. We compare different simulation models for SN placement and energy feedback, including cosmic rays (CRs), and find that models that place SNe in dense gas and account for CR diffusion are able to drive outflows with similar mass loading as obtained from a random placement of SNe with no CRs. Despite this similarity, CR-driven outflows differ in several other key properties including their overall clumpiness and velocity. Moreover, the forces driving these outflows originate in different sources of pressure, with the CR diffusion model relying on non-thermal pressure gradients to create an outflow driven by internal pressure and the random-placement model depending on kinetic pressure gradients to propel a ballistic outflow. CRs therefore appear to be non-negligible physics in the formation of outflows from the interstellar medium.

  10. DIRECT EVIDENCE FOR TERMINATION OF OBSCURED STAR FORMATION BY RADIATIVELY DRIVEN OUTFLOWS IN REDDENED QSOs

    SciTech Connect

    Farrah, Duncan; Urrutia, Tanya; Lacy, Mark; Lonsdale, Carol; Efstathiou, Andreas; Afonso, Jose; Coppin, Kristen; Hall, Patrick B.; Jarrett, Tom; Borys, Colin; Bridge, Carrie; Petty, Sara

    2012-02-01

    We present optical to far-infrared photometry of 31 reddened QSOs that show evidence for radiatively driven outflows originating from active galactic nuclei (AGNs) in their rest-frame UV spectra. We use these data to study the relationships between the AGN-driven outflows, and the AGN and starburst infrared luminosities. We find that FeLoBAL QSOs are invariably IR-luminous, with IR luminosities exceeding 10{sup 12} L{sub Sun} in all cases. The AGN supplies 76% of the total IR emission, on average, but with a range from 20% to 100%. We find no evidence that the absolute luminosity of obscured star formation is affected by the AGN-driven outflows. Conversely, we find an anticorrelation between the strength of AGN-driven outflows, as measured from the range of outflow velocities over which absorption exceeds a minimal threshold, and the contribution from star formation to the total IR luminosity, with a much higher chance of seeing a starburst contribution in excess of 25% in systems with weak outflows than in systems with strong outflows. Moreover, we find no convincing evidence that this effect is driven by the IR luminosity of the AGN. We conclude that radiatively driven outflows from AGNs can have a dramatic, negative impact on luminous star formation in their host galaxies. We find that such outflows act to curtail star formation such that star formation contributes less than {approx}25% of the total IR luminosity. We also propose that the degree to which termination of star formation takes place is not deducible from the IR luminosity of the AGN.

  11. The triggering mechanism and properties of ionized outflows in the nearest obscured quasars

    NASA Astrophysics Data System (ADS)

    Villar Martín, M.; Emonts, B.; Humphrey, A.; Cabrera Lavers, A.; Binette, L.

    2014-06-01

    We have identified ionized outflows in the narrow-line region of all but one Sloan Digital Sky Survey type 2 quasars (QSO2) at z≲0.1 (20/21, detection rate 95 per cent), implying that this is a ubiquitous phenomenon in this object class also at the lowest z. The outflowing gas has high densities (ne≳1000 cm-3) and covers a region the size of a few kpc. This implies ionized outflow masses Moutf ˜ (0.3-2.4) × 106 M⊙ and mass outflow rates Ṁ< few M⊙ yr-1. The triggering mechanism of the outflows is related to the nuclear activity. The QSO2 can be classified into two groups according to the behaviour and properties of the outflowing gas. QSO2 in Group 1 (5/20 objects) show the most extreme turbulence; they have on average higher radio luminosities and higher excess of radio emission. QSO2 in Group 2 (15/20 objects) show less extreme turbulence; they have lower radio luminosities and, on average, lower or no radio excess. We propose that two competing outflow mechanisms are at work: radio jets and accretion disc winds. Radio jet induced outflows are dominant in Group 1, while disc winds dominate in Group 2. We find that the radio jet mode is capable of producing more extreme outflows. To test this interpretation, we predict that (1) high resolution radio imaging will reveal the presence of jets in Group 1 QSO2; (2) the morphology of their extended ionized nebulae must be more highly collimated and kinematically perturbed.

  12. Interactions between gravity waves and cold air outflows in a stably stratified uniform flow

    NASA Technical Reports Server (NTRS)

    Lin, Yuh-Lang; Wang, Ting-An; Weglarz, Ronald P.

    1993-01-01

    Interactions between gravity waves and cold air outflows in a stably stratified uniform flow forced by various combinations of prescribed heat sinks and sources are studied using a hydrostatic two-dimensional nonlinear numerical model. The formation time for the development of a stagnation point or reversed flow at the surface is not always directly proportional to the Froude number when wave reflections exist from upper levels. A density current is able to form by the wave-otuflow interaction, even though the Froude number is greater than a critical value. This is the result of the wave-outflow interaction shifting the flow response to a different location in the characteristic parameter space. A density current is able to form or be destroyed due to the wave-outflow interaction between a traveling gravity wave and cold air outflow. This is proved by performing experiments with a steady-state heat sink and an additional transient heat source. In a quiescent fluid, a region of cold air, convergence, and upward motion is formed after the collision between two outflows produced by two prescribed heat sinks. After the collision, the individual cold air outflows lose their own identity and merge into a single, stationary, cold air outflow region. Gravity waves tend to suppress this new stationary cold air outflow after the collision. The region of upward motion associated with the collision is confined to a very shallow layer. In a moving airstream, a density current produced by a heat sink may be suppressed or enhanced nonlinearly by an adjacent heat sink due to the wave-outflow interaction.

  13. Interactions between gravity waves and cold air outflows in a stably stratified uniform flow

    NASA Astrophysics Data System (ADS)

    Lin, Yuh-Lang; Wang, Ting-An; Weglarz, Ronald P.

    1993-11-01

    Interactions between gravity waves and cold air outflows in a stably stratified uniform flow forced by various combinations of prescribed heat sinks and sources are studied using a hydrostatic two-dimensional nonlinear numerical model. The formation time for the development of a stagnation point or reversed flow at the surface is not always directly proportional to the Froude number when wave reflections exist from upper levels. A density current is able to form by the wave-otuflow interaction, even though the Froude number is greater than a critical value. This is the result of the wave-outflow interaction shifting the flow response to a different location in the characteristic parameter space. A density current is able to form or be destroyed due to the wave-outflow interaction between a traveling gravity wave and cold air outflow. This is proved by performing experiments with a steady-state heat sink and an additional transient heat source. In a quiescent fluid, a region of cold air, convergence, and upward motion is formed after the collision between two outflows produced by two prescribed heat sinks. After the collision, the individual cold air outflows lose their own identity and merge into a single, stationary, cold air outflow region. Gravity waves tend to suppress this new stationary cold air outflow after the collision. The region of upward motion associated with the collision is confined to a very shallow layer. In a moving airstream, a density current produced by a heat sink may be suppressed or enhanced nonlinearly by an adjacent heat sink due to the wave-outflow interaction.

  14. Episodic molecular outflow in the very young protostellar cluster Serpens South.

    PubMed

    Plunkett, Adele L; Arce, Héctor G; Mardones, Diego; van Dokkum, Pieter; Dunham, Michael M; Fernández-López, Manuel; Gallardo, José; Corder, Stuartt A

    2015-11-01

    The loss of mass from protostars, in the form of a jet or outflow, is a necessary counterpart to protostellar mass accretion. Outflow ejection events probably vary in their velocity and/or in the rate of mass loss. Such 'episodic' ejection events have been observed during the class 0 protostellar phase (the early accretion stage), and continue during the subsequent class I phase that marks the first one million years of star formation. Previously observed episodic-ejection sources were relatively isolated; however, the most common sites of star formation are clusters. Outflows link protostars with their environment and provide a viable source of the turbulence that is necessary for regulating star formation in clusters, but it is not known how an accretion-driven jet or outflow in a clustered environment manifests itself in its earliest stage. This early stage is important in establishing the initial conditions for momentum and energy transfer to the environment as the protostar and cluster evolve. Here we report that an outflow from a young, class 0 protostar, at the hub of the very active and filamentary Serpens South protostellar cluster, shows unambiguous episodic events. The (12)C(16)O (J = 2-1) emission from the protostar reveals 22 distinct features of outflow ejecta, the most recent having the highest velocity. The outflow forms bipolar lobes--one of the first detectable signs of star formation--which originate from the peak of 1-mm continuum emission. Emission from the surrounding C(18)O envelope shows kinematics consistent with rotation and an infall of material onto the protostar. The data suggest that episodic, accretion-driven outflow begins in the earliest phase of protostellar evolution, and that the outflow remains intact in a very clustered environment, probably providing efficient momentum transfer for driving turbulence. PMID:26536957

  15. Radiation-Hydrodynamic Simulations of Massive Star Formation with Protostellar Outflows

    SciTech Connect

    Cunningham, A J; Klein, R I; Krumholz, M R; McKee, C F

    2011-03-02

    We report the results of a series of AMR radiation-hydrodynamic simulations of the collapse of massive star forming clouds using the ORION code. These simulations are the first to include the feedback effects protostellar outflows, as well as protostellar radiative heating and radiation pressure exerted on the infalling, dusty gas. We find that that outflows evacuate polar cavities of reduced optical depth through the ambient core. These enhance the radiative flux in the poleward direction so that it is 1.7 to 15 times larger than that in the midplane. As a result the radiative heating and outward radiation force exerted on the protostellar disk and infalling cloud gas in the equatorial direction are greatly diminished. The simultaneously reduces the Eddington radiation pressure barrier to high-mass star formation and increases the minimum threshold surface density for radiative heating to suppress fragmentation compared to models that do not include outflows. The strength of both these effects depends on the initial core surface density. Lower surface density cores have longer free-fall times and thus massive stars formed within them undergo more Kelvin contraction as the core collapses, leading to more powerful outflows. Furthermore, in lower surface density clouds the ratio of the time required for the outflow to break out of the core to the core free-fall time is smaller, so that these clouds are consequently influenced by outflows at earlier stages of collapse. As a result, outflow effects are strongest in low surface density cores and weakest in high surface density one. We also find that radiation focusing in the direction of outflow cavities is sufficient to prevent the formation of radiation pressure-supported circumstellar gas bubbles, in contrast to models which neglect protostellar outflow feedback.

  16. Transport Pathways for Asian Pollution Outflow Over the Pacific: Interannual and Seasonal Variations

    NASA Technical Reports Server (NTRS)

    Liu, Hong-Yu; Jacob, Daniel J.; Bey, Isabelle; Yantosca, Robert M.; Duncan, Bryan N.; Sachse, Glen W.

    2003-01-01

    The meteorological pathways contributing to Asian pollution outflow over the Pacific are examined with a global three-dimensional model analysis of CO observations from the Transport and Chemical Evolution over the Pacific (TRACE-P) aircraft mission (February-April 2001). The model is used also to place the TRACE-P observations in an interannual (1994-2001) and seasonal context. The major process driving Asian pollution outflow in spring is frontal lifting ahead of southeastward-moving cold fronts (the leading edge of cold surges) and transport in the boundary layer behind the cold fronts. Orographic lifting over central and eastern China combines with the cold fronts to promote the transport of Chinese pollution to the free troposphere. Outflow of seasonal biomass burning in Southeast Asia during spring takes place mostly by deep convection but also by northeastward transport and frontal lifting, mixing with the anthropogenic outflow. Boundary layer outflow over the western Pacific is largely devoid of biomass burning influence. European and African (biomass burning) plumes in Asian outflow during TRACE-P were weak (less than 60 ppbv and 20 ppbv CO, respectively) and were not detectable in the observations because of superposition of the much larger Asian pollution signal. Spring 2001 (La Nina) was characterized by unusually frequent cold surge events in the Asian Pacific rim and strong convection in Southeast Asia, leading to unusually strong boundary layer outflow of anthropogenic emissions and convective outflow of biomass burning emissions in the upper troposphere. The Asian outflow flux of CO to the Pacific is found to vary seasonally by a factor of 3-4 (maximum in March and minimum in summer). The March maximum results from frequent cold surge events and seasonal biomass burning emissions.

  17. Radiation-hydrodynamic Simulations of Massive Star Formation with Protostellar Outflows

    NASA Astrophysics Data System (ADS)

    Cunningham, Andrew J.; Klein, Richard I.; Krumholz, Mark R.; McKee, Christopher F.

    2011-10-01

    We report the results of a series of adaptive mesh refinement radiation-hydrodynamic simulations of the collapse of massive star-forming clouds using the ORION code. These simulations are the first to include the feedback effects protostellar outflows, as well as protostellar radiative heating and radiation pressure exerted on the infalling, dusty gas. We find that outflows evacuate polar cavities of reduced optical depth through the ambient core. These enhance the radiative flux in the poleward direction so that it is 1.7-15 times larger than that in the midplane. As a result the radiative heating and outward radiation force exerted on the protostellar disk and infalling cloud gas in the equatorial direction are greatly diminished. This simultaneously reduces the Eddington radiation pressure barrier to high-mass star formation and increases the minimum threshold surface density for radiative heating to suppress fragmentation compared to models that do not include outflows. The strength of both these effects depends on the initial core surface density. Lower surface density cores have longer free-fall times and thus massive stars formed within them undergo more Kelvin contraction as the core collapses, leading to more powerful outflows. Furthermore, in lower surface density clouds the ratio of the time required for the outflow to break out of the core to the core free-fall time is smaller, so that these clouds are consequently influenced by outflows at earlier stages of the collapse. As a result, outflow effects are strongest in low surface density cores and weakest in high surface density ones. We also find that radiation focusing in the direction of outflow cavities is sufficient to prevent the formation of radiation pressure-supported circumstellar gas bubbles, in contrast to models which neglect protostellar outflow feedback.

  18. Massive Stellar Outflows From the Combined Action of Multiple Stellar Jets

    NASA Astrophysics Data System (ADS)

    Mac Low, Mordecai-Mark; Peters, T.; Klaassen, P.; Schrön, M.; Klessen, R.

    2014-01-01

    The formation of high-mass stars is usually accompanied by powerful protostellar outflows. Such high-mass outflows are not simply scaled-up versions of their lower-mass counterparts, since observations seem to suggest that the collimation degree degrades with stellar mass. Theoretically, the origins of massive outflows are not well understood because radiative feedback and gravitational fragmentation of the accretion flow around the high-mass star impede the driving of magnetic disk winds. We here present the first 3D simulation of massive star formation that simultaneously includes feedback by non-ionizing and ionizing radiation as well as a subgrid-scale model for protostellar outflows. We ran this model with the Flash adaptive mesh refinement hydrocode. We find that stars that form in a common accretion flow have aligned outflow axes, so that the individual jets of lower-mass companion stars combine to form a collective outflow. We compare our simulation to observations with synthetic H2 and CO observations and find that the morphology and kinematics of this collective outflow is very similar to observed massive outflows, such as Cepheus A and DR 21. The properties of high-mass outflows are therefore generally consistent with the formation of massive stars in gravitationally unstable accretion flows. We acknowledge support from SNF grant 200020 137896, U. Zurich grant FK-13-112, NSF grant AST11-09395, and DFG grant KL 1358/14-1, as well as SBB 811, and computing time at the LRZ (project h1343), the CSCS (Project 364), and the Juelich Supercomputing Center (project HHD14).

  19. Episodic molecular outflow in the very young protostellar cluster Serpens South

    NASA Astrophysics Data System (ADS)

    Plunkett, Adele L.; Arce, Héctor G.; Mardones, Diego; van Dokkum, Pieter; Dunham, Michael M.; Fernández-López, Manuel; Gallardo, José; Corder, Stuartt A.

    2015-11-01

    The loss of mass from protostars, in the form of a jet or outflow, is a necessary counterpart to protostellar mass accretion. Outflow ejection events probably vary in their velocity and/or in the rate of mass loss. Such `episodic' ejection events have been observed during the Class 0 protostellar phase (the early accretion stage), and continue during the subsequent class I phase that marks the first one million years of star formation. Previously observed episodic-ejection sources were relatively isolated; however, the most common sites of star formation are clusters. Outflows link protostars with their environment and provide a viable source of turbulence that is necessary for regulating star formation in clusters, but it is not known how an accretion-driven jet or outflow in a clustered environment manifests itself in its earliest stage. This early stage is important in establishing the initial conditions for momentum and energy transfer to the environment as the protostar and cluster evolve. Here we report that an outflow from a very young class 0 protostar, at the hub of the very active and filamentary Serpens South protostellar cluster, shows unambiguous episodic events. The 12CO (J=2-1) emission from the protostar reveals 22 distinct features of outflow ejecta, the most recent having the highest velocity. The outflow forms bipolar lobes --- one of the first detectable signs of star formation --- which originate from the peak of 1-mm continuum emission. Emission from the surrounding C18O envelope shows kinematics consistent with rotation and an infall of material onto the protostar. The data suggest that episodic accretion-driven outflow begins in the earliest phase of protostellar evolution, and that the outflow remains intact in a very clustered environment, probably providing efficient momentum transfer for driving turbulence.

  20. Changes in the Composition of the Fram Strait Freshwater Outflow

    NASA Astrophysics Data System (ADS)

    Dodd, Paul; Granskog, Mats; Fransson, Agneta; Chierici, Melissa; Stedmon, Colin

    2016-04-01

    Fram Strait is the largest gateway and only deep connection between the Arctic Ocean and the subpolar oceans. Monitoring the exchanges through Fram Strait allows us to detect and understand current changes occurring in the Arctic Ocean and to predict the effects of those changes on the Arctic and Subarctic climate and ecosystems. Polar water, recirculating Atlantic Water and deeper water masses exported from the Arctic Ocean through western Fram Strait are monitored year-round by an array of moored instruments along 78°50'N, continuously maintained by the Norwegian Polar Institute since the 1990s. Complimentary annual hydrographic sections have been repeated along the same latitude every September. This presentation will focus on biogeochemical tracer measurements collected along repeated sections from 1997-2015, which can be used to identify freshwater from different sources and reveal the causes of variations in total volume of freshwater exported e. g.: pulses of freshwater from the Pacific. Repeated tracer sections across Fram Strait reveal significant changes in the composition of the outflow in recent years, with recent sections showing positive fractions of sea ice meltwater at the surface near the core of the EGC, suggesting that more sea ice melts back into the surface than previously. The 1997-2015 time series of measurements reveals a strong anti-correlation between run-off and net sea ice meltwater inventories, suggesting that run-off and brine may be delivered to Fram Strait together from a common source. While the freshwater outflow at Fram Strait typically exhibits a similar run-off to net sea ice meltwater ratio to the central Arctic Ocean and Siberian shelves, we find that the ratio of run-off to sea ice meltwater at Fram Strait is decreasing with time, suggesting an increased surface input of sea ice meltwater in recent years. In 2014 and 2015 measurements of salinity, δ18O and total alkalinity were collected from sea ice cores as well as the

  1. Dispersion of Outflow from Small Rivers and Coastal Lagoons

    NASA Astrophysics Data System (ADS)

    Largier, J. L.; Basdurak, N. B.

    2013-05-01

    Along many tropical and subtropical coasts, waters enter the ocean via small streams or lagoons. These outflow plumes are known to be important to coastal productivity, but as pollutant loading increases they are also seen as an increasing source of coastal pollution. Physical processes in these small plumes interact in ways that are different to larger plumes, e.g., flow rate varies on short time scales, and the coriolis term is typically unimportant. After a brief review of dominant terms, attention will be given to observed plume patterns with a focus on the presence of low-salinity and outflow-related constituents nearshore. Data from studies off California and elsewhere will be used to suggest that there are common transport and mixing patterns at this scale. While the ultimate aim is to understand and model physical processes controlling dispersion of land-derived pollutants, at the very least one can recognize a spatial pattern of probability that can be characterized by primary physical parameters. Due to limited data on physical processes at the requisite resolution, numerical modeling is used to better understand processes and phenomena including inertial jets, buoyant plumes, alongshore flow, mixing and surface stresses. Ultimately, one can expect that a reasonable estimate of a probabilistic "zone of impact" can be obtained from knowledge of fundamental physical parameters that control transport and mixing. This link between physical forcing and response needs both a dynamical explanation and statistical support - yielding a general model that can be used for countless small inflows along many coasts. These features may be small but they are very common, and it is argued that their importance for coastal pollution and ecology is disproportionately big. The benefit of recognizing a transport-based zone of impact is that this pattern is the basis of distribution patterns for a variety of constituents, including dissolved and particulate contaminants

  2. Outflow Tract Premature Ventricular Contractions and Ventricular Tachycardia: The Typical and the Challenging.

    PubMed

    John, Roy M; Stevenson, William G

    2016-09-01

    The ventricular outflow tracts are the most common sites of origin for ventricular arrhythmias that occur in the absence of structural heart disease. Drug therapy with β-blockers and calcium blockers has limited efficacy for control. In the presence of marked symptoms or frequent arrhythmia causing left ventricular (LV) dysfunction, catheter ablation is a consideration. The right ventricular outflow tract, aortic root, LV outflow endocardium, and epicardium are potential sites for ablation for these arrhythmias. In intractable cases of highly symptomatic ventricular arrhythmias originating from the LV summit, surgical ablation is an option. PMID:27521088

  3. Massive molecular outflows and evidence for AGN feedback from CO observations

    NASA Astrophysics Data System (ADS)

    Cicone, C.; Maiolino, R.; Sturm, E.; Graciá-Carpio, J.; Feruglio, C.; Neri, R.; Aalto, S.; Davies, R.; Fiore, F.; Fischer, J.; García-Burillo, S.; González-Alfonso, E.; Hailey-Dunsheath, S.; Piconcelli, E.; Veilleux, S.

    2014-02-01

    We study the properties of massive, galactic-scale outflows of molecular gas and investigate their impact on galaxy evolution. We present new IRAM PdBI CO(1-0) observations of local ultra-luminous infrared galaxies (ULIRGs) and quasar-hosts: a clear signature of massive and energetic molecular outflows, extending on kpc scales, is found in the CO(1-0) kinematics of four out of seven sources, with measured outflow rates of several 100 M⊙ yr-1. We combine these new observations with data from the literature, and explore the nature and origin of massive molecular outflows within an extended sample of 19 local galaxies. We find that starburst-dominated galaxies have an outflow rate comparable to their star formation rate (SFR), or even higher by a factor of ~2-4, implying that starbursts can indeed be effective in removing cold gas from galaxies. Nevertheless, our results suggest that the presence of an active galactic nucleus (AGN) can boost the outflow rate by a large factor, which is found to increase with the LAGN/Lbol ratio. The gas depletion time scales due to molecular outflows are anti-correlated with the presence and luminosity of an AGN in these galaxies, and range from a few hundred million years in starburst galaxies down to just a few million years in galaxies hosting powerful AGNs. In quasar hosts, the depletion time scales due to the outflow are much shorter than the depletion time scales due to star formation. We estimate the outflow kinetic power and find that, for galaxies hosting powerful AGNs, it corresponds to about 5% of the AGN luminosity, as expected by models of AGN feedback. Moreover, we find that momentum rates of about 20 LAGN/c are common among the AGN-dominated sources in our sample. For "pure" starburst galaxies, our data tentatively support models in which outflows are mostly momentum-driven by the radiation pressure from young stars onto dusty clouds. Overall, our results indicate that, although starbursts are effective in powering

  4. Elemental abundances associated with gamma-ray bursts: nucleosynthesis in outflows

    NASA Astrophysics Data System (ADS)

    Hu, Tao

    2015-06-01

    Aims: Outflows from accretion disks have been suggested to be suitable sites for producing heavy elements. The objective of this work is to investigate nucleosynthesis in the outflows launched from the inner accretion disks of collapsars that are associated with gamma-ray bursts (GRBs). Methods: By using a collapsar model of advection-dominated accretion and an adiabatic expanding outflow model, we simulated chemical yields inside the outflows associated with GRBs. As a result of the extremely high temperature (above 1010 K), the dominated species existing in the inner region of the disk are proton, neutron, 2H, and 4He, which are photodisintegrated from heavy nuclei. Assuming that an explosive nucleosynthesis could operate in outflows from collapsar accretions associated with GRBs, heavier species including the iron-group will be synthesized significantly. Although various outflow models have been investigated carefully in the past, the uncertainties in predicting the outflow birthplace (ejected-radius rj) in the accretion disk are still quite large. Unlike recent researches on this topic that located the production of heavy elements in GRBs in the outer parts of the disk, in this study we focus our attention mainly on the outflows triggered from the inner region of collapsar accretion. Results: We find 56Ni can be abundantly produced in all the outflow cases considered here from the inner collapsar disk. The highest 56Ni's mass fraction in the outflows reaches 0.463, which can imply that the 56Ni-rich outflows will lead to an observable violent explosion of a GRB event. The mass fractions of 57Ni, 59Cu (decays to 59Ni), and 60Zn (decays to 60Ni) could be 10-2, and the abundance of 58Ni reaches 10-3. Our simulations support that the effective production of heavy elements can occur in the outflows from the inner regions of the collapsar accretion disks. Our results also show that the amount of heavy species produced in outflows depends on the eject-radius rj of the

  5. Chemical Characteristics of Continental Outflow from Asia to the Troposphere over the Western Pacific Ocean during September - October 1991: Results from PEM-West A

    NASA Technical Reports Server (NTRS)

    Talbot, R. W.; Dibb, J. E.; Klemm, K. I.; Bradshaw, J. D.; Sandholm, S. T.; Blake, D. R.; Sachse, G. W.; Collins, J.; Heikes, B. G.; Gregory, G. L.; Anderson, B. E.; Singh, H. B.; Thornton, D. C.; Merrill J. T.

    1996-01-01

    An important objective of the Pacific Exploratory Mission-West A (PEM-West A) was the chemical characterization of the outflow of tropospheric trace gases and aerosol particles from the Asian continent over the western Pacific Ocean. This paper summarizes the chemistry of this outflow during the period September - October 1991. The vertical distributions of CO, C2H6, and NO(x), showed regions of outflow at altitudes below 2 km and from 8 to 12 km. Mixing ratios of CO were approx. equals 130 parts per billion by volume (ppbv), approx. equals 1OOO parts per trillion by volume (pptv) for C2H6, and approx. equals 100 pptv for NO(x) in both of these regions. Direct outflow of Asian industrial materials was clearly evident at altitudes below 2 km, where halocarbon tracer compounds such as CH3CCl3 and C2Cl4 were enhanced about threefold compared to aged Pacific air. The source attribution of species outflowing from Asia to the Pacific at 8-12 km altitude was not straightforward. Above 10 km altitude there were substantial enhancements of NO(y), O3, CO, CH4, SO2, C2H6, C3H8, C2H2, and aerosol Pb-210 but not halocarbon industrial tracers. These air masses were rich in nitrogen relative to sulfur and contained ratios of C2H2/CO and C3H8/C2H6 (approx. equals l.5 and 0.1 respectively) indicative of several- day-old combustion emissions. It is unclear if these emissions were of Asian origin, or if they were rapidly transported to this region from Europe by the high wind speeds in this tropospheric region (60 - 70 m/s). The significant cyclonic activity over Asia at this time could have transported to the upper troposphere emissions from biomass burning in Southeast Asia or emissions from the extensive use of various biomass materials for cooking and space heating. Apparently, the emissions in the upper troposphere were brought there by wet convective systems since water-soluble gases and aerosols were depleted in these air masses. Near 9 km altitude there was a distinct

  6. Long-range pollution transport during the MILAGRO-2006 campaign: a case study of a major Mexico City outflow event using free-floating altitude-controlled balloons

    SciTech Connect

    Voss, Paul B.; Zaveri, Rahul A.; Flocke, Frank M.; Mao, Huitimg; Hartley, Tom; DeAmicis, Pam; Deonandan, Indira; Contrerars-Jimenez, G.; Martinez-Antonio, O.; Figueroa Estrada, M.; Greenberg, David; Campos, Teresa; Weinheimer, Andrew J.; Knapp, David; Montzka, DeeDee; Crounse, J. D.; Wennberg, P. O.; Apel, Eric; Madronich, Sasha; de Foy, B.

    2010-08-04

    One of the major objectives of the Megacities Initiative: Local And Global Research 3 Observations (MILAGRO 2006) campaign was to investigate the long-range transport of 4 Mexico City Metropolitan Area (MCMA) pollution outflow and its downwind impacts on air 5 quality and climate. Four aircraft (DOE G-1, NSF/NCAR C-130, NASA-J31, and NASA 6 DC-8) made extensive chemical, aerosol, and radiation measurements above MCMA and over 7 1000 km downwind in order to characterize the evolution of MCMA pollution as it aged and 8 dispersed over the central Mexican plateau and the Gulf of Mexico. As part of this effort, 9 free-floating Controlled-Meteorological (CMET) balloons, capable of changing altitude on 10 command via satellite, characterized the MCMA outflow by performing repeated soundings 11 during the transit. In this paper, we present an analysis based on the data from two CMET 12 balloons that were launched near Mexico City on the afternoon of 18 March 2006 and floated 13 downwind with the outflow for nearly 30 hours. Continuous profile measurements made by 14 the balloons show the evolving structure of the MCMA outflow in considerable detail: its 15 stability and stratification, interaction with other air masses, mixing episodes, and dispersion 16 into the regional background. Air parcel trajectories, computed directly from the balloon 17 wind profiles, show three different transport pathways for Mexico City outflow on 18-19 18 March: (a) high-altitude advection of the top of the MCMA mixed layer, (b) low-altitude flow 19 over the Sierra Madre Oriental followed by decoupling and isolated transport over the Gulf, 20 and (c) the same decoupling scenario with entrainment into a cleaner westerly jet below the 21 plateau. The C-130 intercepted the balloon-based trajectories three times on 19 March, once 22 along each transport pathway. In all three cases, distinct peaks in the urban tracer signature 23 and LIDAR backscatter imagery provided evidence for Mexico City air

  7. Modeling the Quiet Time Outflow Solution in the Polar Cap

    NASA Technical Reports Server (NTRS)

    Glocer, Alex

    2011-01-01

    We use the Polar Wind Outflow Model (PWOM) to study the geomagnetically quiet conditions in the polar cap during solar maximum, The PWOM solves the gyrotropic transport equations for O(+), H(+), and He(+) along several magnetic field lines in the polar region in order to reconstruct the full 3D solution. We directly compare our simulation results to the data based empirical model of Kitamura et al. [2011] of electron density, which is based on 63 months of Akebono satellite observations. The modeled ion and electron temperatures are also compared with a statistical compilation of quiet time data obtained by the EISCAT Svalbard Radar (ESR) and Intercosmos Satellites (Kitamura et al. [2011]). The data and model agree reasonably well. This study shows that photoelectrons play an important role in explaining the differences between sunlit and dark results, ion composition, as well as ion and electron temperatures of the quiet time polar wind solution. Moreover, these results provide validation of the PWOM's ability to model the quiet time ((background" solution.

  8. Estimation of future outflows of e-waste in India

    SciTech Connect

    Dwivedy, Maheshwar; Mittal, R.K.

    2010-03-15

    The purpose of this study is to construct an approach and a methodology to estimate the future outflows of electronic waste (e-waste) in India. Consequently, the study utilizes a time-series multiple lifespan end-of-life model proposed by Peralta and Fontanos for estimating the current and future quantities of e-waste in India. The model estimates future e-waste generation quantities by modeling their usage and disposal. The present work considers two scenarios for the approximation of e-waste generation based on user preferences to store or to recycle the e-waste. This model will help formal recyclers in India to make strategic decisions in planning for appropriate recycling infrastructure and institutional capacity building. Also an extension of the model proposed by Peralta and Fontanos is developed with the objective of helping decision makers to conduct WEEE estimates under a variety of assumptions to suit their region of study. During 2007-2011, the total WEEE estimates will be around 2.5 million metric tons which include waste from personal computers (PC), television, refrigerators and washing machines. During the said period, the waste from PC will account for 30% of total units of WEEE generated.

  9. Inverted Outflow Ground Testing of Cryogenic Propellant Liquid Acquisition Devices

    NASA Technical Reports Server (NTRS)

    Chato, David J.; Hartwig, Jason W.; Rame, Enrique; McQuillen, John B.

    2014-01-01

    NASA is currently developing propulsion system concepts for human exploration. These propulsion concepts will require the vapor free acquisition and delivery of the cryogenic propellants stored in the propulsion tanks during periods of microgravity to the exploration vehicles engines. Propellant management devices (PMD's), such as screen channel capillary liquid acquisition devices (LAD's), vanes and sponges have been used for earth storable propellants in the Space Shuttle Orbiter and other spacecraft propulsion systems, but only very limited propellant management capability currently exists for cryogenic propellants. NASA is developing PMD technology as a part of their cryogenic fluid management (CFM) project. System concept studies have looked at the key factors that dictate the size and shape of PMD devices and established screen channel LADs as an important component of PMD design. Modeling validated by normal gravity experiments is examining the behavior of the flow in the LAD channel assemblies (as opposed to only prior testing of screen samples) at the flow rates representative of actual engine service (similar in size to current launch vehicle upper stage engines). Recently testing of rectangular LAD channels has included inverted outflow in liquid oxygen and liquid hydrogen. This paper will report the results of liquid oxygen testing compare and contrast them with the recently published hydrogen results; and identify the sensitivity of these results to flow rate and tank internal pressure.

  10. Inverted Outflow Ground Testing of Cryogenic Propellant Liquid Acquisition Devices

    NASA Technical Reports Server (NTRS)

    Chato, David J.; Hartwig, Jason W.; Rame, Enrique; McQuillen, John B.

    2014-01-01

    NASA is currently developing propulsion system concepts for human exploration. These propulsion concepts will require the vapor free acquisition and delivery of the cryogenic propellants stored in the propulsion tanks during periods of microgravity to the exploration vehicles engines. Propellant management devices (PMDs), such as screen channel capillary liquid acquisition devices (LADs), vanes and sponges have been used for earth storable propellants in the Space Shuttle Orbiter and other spacecraft propulsion systems, but only very limited propellant management capability currently exists for cryogenic propellants. NASA is developing PMD technology as a part of their cryogenic fluid management (CFM) project. System concept studies have looked at the key factors that dictate the size and shape of PMD devices and established screen channel LADs as an important component of PMD design. Modeling validated by normal gravity experiments is examining the behavior of the flow in the LAD channel assemblies (as opposed to only prior testing of screen samples) at the flow rates representative of actual engine service (similar in size to current launch vehicle upper stage engines). Recently testing of rectangular LAD channels has included inverted outflow in liquid oxygen and liquid hydrogen. This paper will report the results of liquid oxygen testing compare and contrast them with the recently published hydrogen results; and identify the sensitivity these results to flow rate and tank internal pressure.

  11. Binary star formation and mass outflows: MHD nested grid simulation

    NASA Astrophysics Data System (ADS)

    Machida, M. N.; Tomisaka, K.; Matsumoto, T.

    2004-08-01

    We study the binary star formation process from a rotating magnetized molecular cloud. We assume an isothermal cylindrical cloud in hydrostatic balance whose rotation axis and the direction of global magnetic field lines are both identical, and parallel to the cylinder axis. We added axisymmetric and non-axisymmetric density perturbations to the initial state and followed the subsequent evolutions. The evolution is characterized by three parameters: the amplitude of the non-axisymmetric perturbations, the rotation speed, and the magnetic field strength. As a result, it is found that non-axisymmetry hardly evolves in the early phase, but begins to grow after the gas contracts and forms a thin disk. There are two types of fragmentation: fragmentation from a ring and that from a bar. Thin adiabatic cores fragments if a thickness is smaller than 1/4 of the radius. For the fragments to survive, they should be formed in a heavily elongated barred core or a flat round disk. In the models showing fragmentation, outflows from respective fragments are found as well as those driven by the rotating bar or the disk.

  12. GRB 011121: A Collimated Outflow into Wind-Blown Surroundings

    NASA Technical Reports Server (NTRS)

    Greiner, J.; Klose, S.; Salvato, M.; Zeh, A.; Schwarz, R.; Hartmann, D. H.; Masetti, N.; Stecklum, B.; Lamer, G.; Lodieu, N.; Burud, I.; Rhoads, J.; Fruchter, A.

    2003-01-01

    We report optical and near-infrared follow-up observations of GRB 011121 collected predominantly at ESO telescopes in Chile. We discover a break in the afterglow light curve after 1.3 days, which implies an initial jet opening angle of about 9 deg. The jet origin of this break is supported by the fact that the spectral energy distribution is achromatic during the first four days. During later phases, GRB 011121 shows significant excess emission above the flux predicted by a power law, which we interpret as additional light from an underlying supernova. In particular, the spectral energy distribution of the optical transient approximately 2 weeks after the burst is clearly not of power-law type, but can be presented by a black body with a temperature of approx. 6000 K. The deduced parameters for the decay slope as well as the spectral index favor a wind scenario, i.e. an outflow into a circum-burst environment shaped by the stellar wind of a massive GRB progenitor. Due to its low redshift of z=0.36, GRB 011121 has been the best example for the GRB-supernova connection until GRB 030329, and provides compelling evidence for a circum-burster wind region expected to exist if the progenitor was a massive star.

  13. Ultrafast Outflows from Black Hole Mergers with a Minidisk

    NASA Astrophysics Data System (ADS)

    Murase, Kohta; Kashiyama, Kazumi; Mészáros, Peter; Shoemaker, Ian; Senno, Nicholas

    2016-05-01

    Recently, the direct detection of gravitational waves from black hole (BH) mergers was announced by the Advanced LIGO Collaboration. Multi-messenger counterparts of stellar-mass BH mergers are of interest, and it had been suggested that a small disk or celestial body may be involved in the binary of two BHs. To test such possibilities, we consider the fate of a wind powered by an active minidisk in a relatively short, super-Eddington accretion episode onto a BH with ∼10–100 solar masses. We show that its thermal emission could be seen as a fast optical transient with the duration from hours to days. We also find that the coasting outflow forms external shocks due to interaction with the interstellar medium, whose synchrotron emission might be expected in the radio band on a timescale of years. Finally, we also discuss a possible jet component and the associated high-energy neutrino emission as well as ultra-high-energy cosmic-ray acceleration.

  14. The Conical Outflow of NGC 7026, a Multipolar Planetary Nebula

    NASA Astrophysics Data System (ADS)

    Clark, David M.; López, J.; Steffen, W.; Richer, M. G.

    2013-01-01

    We use the 3-dimensional visualization and kinematic program, Shape, together with high-resolution spectra and detailed HST images to study the complex planetary nebula (PN) NGC 7026. The spectra were acquired using the Manchester Echelle Spectrometer at San Pedro Martir Observatory in Baja California, Mexico. This PN displays remarkable symmetry consisting of three pairs of lobes and four sets of knots, all symmetrical about the nucleus and exhibiting a conical outflow. We also investigate the relationship between the 3-D structure and extended X-ray emission using recently acquired XMM-Newton observations from the literature. The X-ray emission is predominantly confined to the closed, northern lobes of this PN and also shows an abrupt termination in the middle of the SE lobe, which our long slit data shows to be open. Here is where the shocked, fast wind appears to be escaping the interior of the nebula and the X-ray emission cools rapidly in this region.

  15. Surgical therapy for benign prostatic hypertrophy/bladder outflow obstruction

    PubMed Central

    Thiruchelvam, Nikesh

    2014-01-01

    Monopolar transurethral resection of the prostate (TURP) with endoscopic electrocautery remains the gold standard surgical technique for benign prostatic hypertrophy (BPH) by which all new procedures are compared. We reviewed the current literature, and international urological guidelines and consensus opinion on various surgical options for BPH and present a brief overview of alternative techniques including bipolar TURP, transurethral incision of the prostate, transurethral vaporization of the prostate, laser prostatectomy (with holmium, thulium and potassium titanyl phosphate greenlight lasers) and open prostatectomy (with mention of new techniques including laparoscopic and robotic prostatectomy). Emerging, experimental and less established techniques are also described including endoscopic heat generation (transurethral microwave thermotherapy, radiofrequency transurethral needle ablation of the prostate, high intensity focused ultrasound, hot water induced thermotherapy, pulsed electromagnetic radiofrequency), injection therapy (transurethral ethanol ablation and botulinum toxin) and mechanical devices (intraprostatic stents and urethral lift devices). Despite a plethora of surgical options, none have realistically improved outcomes in the long-term compared with TURP. Improvements have been made on improving surgical morbidity and time in hospital. Questions remain in this area, including what specific elements of bladder outflow obstruction (BOO) result in damage to the urinary tract, how does BPH contribute to BOO and how much prostate volume reduction is necessary to relieve BOO or lower urinary tract symptoms. Given these unanswered questions and the multitude of procedures available, it is clear that appropriate counselling is necessary in all men who undergo BPH surgery. PMID:24744521

  16. Anatomy of the Vestibulo-automatic Outflow to the Gut

    NASA Technical Reports Server (NTRS)

    Torigoe, Y.

    1985-01-01

    Motion sickness can be induced by vestibular effects on the sympathetic portion of the autonomic nervous system. However, the pathways linking the vestibular and autonomic pathways are unknown. As a first step in this analysis, the locations of preganglionic sympathetic neurons (PSN) and dorsal root afferent ganglionic neurons (DRG) which supply sympathetic innervation to major portions of the gastrointestinal tract in rabbits were identified. The objective of a second series of experiments is to determine which of the brainstem nuclei project to the autonomic regions of the spinal cord that control gastrointestinal motility. To achieve this goal, a trans-synaptic retrograde tracer (3H-tetanus toxoid) is applied to the greater splanchnic nerve. This method allows the labeling of neurons within the brainstem that project only to the preganglionic synpathetic neurons. One structure that has been strongly implicated in mediating vestibulo-autonomic control is the cerebellum (i.e., nodulus and uvula). The outflow of these lobules to the autonomic regions of the brainstem is mediated by the fastigial nucleus. To determine the precise projections of the fastigial nucleus to the brainstem nuclei involved in emesis, anterograde tracer (3H-leucine) was injected into the fastigial nucleus in a third series of experiments.

  17. LOW-IONIZATION OUTFLOWS IN HIGH EDDINGTON RATIO QUASARS

    SciTech Connect

    Marziani, Paola; Sulentic, Jack W.; Plauchu-Frayn, Ilse; Del Olmo, Ascension

    2013-02-20

    The broad Mg II {lambda}2800 doublet has been frequently studied in connection with its potentially important role as a virial estimator of black hole mass in high-redshift quasars. An important task, therefore, is the identification of any line components that are likely related to broadening by non-virial motions. High signal-to-noise median composite spectra (binned in the {sup f}our-dimensional eigenvector 1'' context of Sulentic et al.) were constructed for the brightest 680 Sloan Digital Sky Survey Data Release 7 quasars in the 0.4 {<=} z {<=} 0.75 range where both Mg II {lambda}2800 and H{beta} are recorded in the same spectra. Composite spectra representing 90% of the quasars confirm previous findings that FWHM(Mg II {lambda}2800) is about 20% narrower than FWHM(H{beta}). The situation is clearly different for the most extreme (Population A) sources, which are the highest Eddington radiators in the sample. In the median spectra of these sources, FWHM Mg II {lambda}2800 is equal to or greater than FWHM(H{beta}) and shows a significant blueshift relative to H{beta}. We interpret the Mg II {lambda}2800 blueshift as the signature of a radiation-driven wind or outflow in the highest accreting quasars. In this interpretation, the Mg II {lambda}2800 line width-affected by blueshifted emission-is unsuitable for virial mass estimation in Almost-Equal-To 10% of quasars.

  18. Human sinus arrhythmia as an index of vagal cardiac outflow

    NASA Technical Reports Server (NTRS)

    Eckberg, D. L.

    1983-01-01

    The human central vagal mechanisms were investigated by measuring the intervals between heartbeats during controlled breathing (at breathing intervals of 2.5-10 s and nominal tidal volumes of 1000 and 1500 ml) in six young men and women. It was found that as the breathing interval increased, the longest heart periods became longer, the shortest heart periods became shorter, and the peak-valley P-P intervals increased asymptotically. Peak-valley intervals also increased in proportion to tidal volume, although this influence was small. The phase angles between heart period changes and respiration were found to vary as linear functions of breathing interval. Heart period shortening began in inspiration at short breathing intervals and in expiration at long breathing intervals, while heart period lengthening began in early expiration at all breathing intervals studied. It is concluded that a close relationship exists between variations of respiratory depth and interval and the quantity, periodicity, and timing of vagal cardiac outflow in conscious humans. The results indicate that at usual breathing rates, phasic respiration-related changes of vagal motoneuron activity begin in expiration, progress slowly, and are incompletely expressed at fast breathing ratges.

  19. Atmospheric Outflows from Hot Jupiters: 2D MHD Simulations

    NASA Astrophysics Data System (ADS)

    Uribe, A.; Matsakos, T.; Konigl, A.

    2015-01-01

    Recent observations of stellar hydrogen Ly-α line absorption during transits of some hot Jupiter exoplanets suggest the presence of a dense, fast wind that is blowing from planetary atmosphere tep{2003Natur.422..143V,2007ApJ...671L..61B}. Modeling efforts include 1D hydrodynamic models tep{2009ApJ...693...23M,2004Icar..170..167Y,2007P&SS...55.1426G} and 2D isothermal magnetized wind models tep{2014arXiv1404.5817T}, among others. In this work, we model the 2D structure of the irradiated upper atmosphere of a hot Jupiter planet and its interaction with the planetary magnetic field. We calculate self consistently the heating by stellar UV radiation and the cooling of the atmosphere by Ly-α emission. We solve for the ionization structure assuming a 100% hydrogen atmosphere, accounting for the radiative ionization, recombination and advection of the gas. We show the effect of stellar tides and planetary magnetic field on the planet outflow and calculate the Ly-α transmission spectra of the resulting atmosphere.

  20. Optical and Near Infrared Study of the Cepheus E Outflow, a Very Low Excitation Object

    NASA Technical Reports Server (NTRS)

    Noreiga-Crespo, A.; Ayala, S.; Garnavich, P.; Curiel, S.; Raga, A.; Bohm, K.; Raymond, J.

    2000-01-01

    In this study, we explore the link between the physical properties of the outflow as determined from optical imaging and spectroscopy, and compare these results with those obtained from observations in the near infrared.

  1. An Iron K Component to the Ultrafast Outflow in NGC 1313 X-1

    NASA Astrophysics Data System (ADS)

    Walton, D. J.; Middleton, M. J.; Pinto, C.; Fabian, A. C.; Bachetti, M.; Barret, D.; Brightman, M.; Fuerst, F.; Harrison, F. A.; Miller, J. M.; Stern, D.

    2016-08-01

    We present the detection of an absorption feature at E={8.77}-0.06+0.05 keV in the combined X-ray spectrum of the ultraluminous X-ray source NGC 1313 X-1 observed with XMM-Newton and NuSTAR, significant at the 3σ level. If associated with blueshifted ionized iron, the implied outflow velocity is ˜0.2c for Fe xxvi, or ˜0.25c for Fe xxv. These velocities are similar to the ultrafast outflow seen in absorption recently discovered in this source at lower energies by XMM-Newton, and we therefore conclude that this is an iron component to the same outflow. Photoionization modeling marginally prefers the Fe xxv solution, but in either case the outflow properties appear to be extreme, potentially supporting a super-Eddington hypothesis for NGC 1313 X-1.

  2. Misalignment of Outflow Axes in the Proto-multiple Systems in Perseus

    NASA Astrophysics Data System (ADS)

    Lee, Katherine I.; Dunham, Michael M.; Myers, Philip C.; Arce, Héctor G.; Bourke, Tyler L.; Goodman, Alyssa A.; Jørgensen, Jes K.; Kristensen, Lars E.; Offner, Stella S. R.; Pineda, Jaime E.; Tobin, John J.; Vorobyov, Eduard I.

    2016-03-01

    We investigate the alignment between outflow axes in nine of the youngest binary/multiple systems in the Perseus Molecular Cloud. These systems have typical member spacing larger than 1000 au. For outflow identification, we use 12CO(2-1) and 12CO(3-2) data from a large survey with the Submillimeter Array: Mass Assembly of Stellar Systems and their Evolution with the SMA. The distribution of outflow orientations in the binary pairs is consistent with random or preferentially anti-aligned distributions, demonstrating that these outflows are misaligned. This result suggests that these systems are possibly formed in environments where the distribution of angular momentum is complex and disordered, and these systems do not come from the same co-rotating structures or from an initial cloud with aligned vectors of angular momentum.

  3. Factors Controlling Water Volumes and Release Rates in Martian Outflow Channels

    NASA Technical Reports Server (NTRS)

    Wilson, L.; Head, J. W.; Leask, H. J.; Ghatan, G.; Mitchell, K. L.

    2004-01-01

    We discuss estimates of water fluxes on Mars and suggest that many are overestimates. Even so, we can only explain very high martian outflow rates by either unusually permeable aquifer systems or sudden release of shallow concentrations of water.

  4. Large-scale outflow in quasar LBQS J1206+1052: HST/COS observations

    NASA Astrophysics Data System (ADS)

    Chamberlain, Carter; Arav, Nahum

    2015-11-01

    Using two orbits of HST/COS archival observations, we measure the location and energetics of a quasar outflow from LBQS J1206+1052. From separate collisional excitation models of observed N III/N III* and S III/S III* troughs, we measure the electron number density n_e of the outflow. Both independent determinations are in full agreement and yield n_e =10^{3.0} cm^{-3}. Combining this value of n_e with photoionization simulations, we determine that the outflow is located 840 pc from the central source. The outflow has a velocity of 1400 km s-1, a mass flux of 9 M⊙ yr-1 and a kinetic luminosity of 1042.8 erg s-1. The distance finding is much larger than predicted from radiative acceleration models, but is consistent with recent empirical distance determinations.

  5. Dysregulated endocardial TGFβ signaling and mesenchymal transformation result in heart outflow tract septation failure.

    PubMed

    Ma, Man C; Li, Peng; Shen, Hua; Estrada, Kristine D; Xu, Jian; Kumar, S Ram; Sucov, Henry M

    2016-01-01

    Heart outflow tract septation in mouse embryos carrying mutations in retinoic acid receptor genes fails with complete penetrance. In this mutant background, ectopic TGFβ signaling in the distal outflow tract is responsible for septation failure, but it was uncertain what tissue was responsive to ectopic TGFβ and why this response interfered with septation. By combining RAR gene mutation with tissue-specific Cre drivers and a conditional type II TGFβ receptor (Tgfbr2) allele, we determined that ectopic activation of TGFβ signaling in the endocardium is responsible for septation defects. Ectopic TGFβ signaling results in ectopic mesenchymal transformation of the endocardium and thereby in improperly constituted distal OFT cushions. Our analysis highlights the interactions between myocardium, endocardium, and neural crest cells in outflow tract morphogenesis, and demonstrates the requirement for proper TGFβ signaling in outflow tract cushion organization and septation. PMID:26522286

  6. Heart fossilization is possible and informs the evolution of cardiac outflow tract in vertebrates.

    PubMed

    Maldanis, Lara; Carvalho, Murilo; Almeida, Mariana Ramos; Freitas, Francisco Idalécio; de Andrade, José Artur Ferreira Gomes; Nunes, Rafael Silva; Rochitte, Carlos Eduardo; Poppi, Ronei Jesus; Freitas, Raul Oliveira; Rodrigues, Fábio; Siljeström, Sandra; Lima, Frederico Alves; Galante, Douglas; Carvalho, Ismar S; Perez, Carlos Alberto; de Carvalho, Marcelo Rodrigues; Bettini, Jefferson; Fernandez, Vincent; Xavier-Neto, José

    2016-01-01

    Elucidating cardiac evolution has been frustrated by lack of fossils. One celebrated enigma in cardiac evolution involves the transition from a cardiac outflow tract dominated by a multi-valved conus arteriosus in basal actinopterygians, to an outflow tract commanded by the non-valved, elastic, bulbus arteriosus in higher actinopterygians. We demonstrate that cardiac preservation is possible in the extinct fish Rhacolepis buccalis from the Brazilian Cretaceous. Using X-ray synchrotron microtomography, we show that Rhacolepis fossils display hearts with a conus arteriosus containing at least five valve rows. This represents a transitional morphology between the primitive, multivalvar, conal condition and the derived, monovalvar, bulbar state of the outflow tract in modern actinopterygians. Our data rescue a long-lost cardiac phenotype (119-113 Ma) and suggest that outflow tract simplification in actinopterygians is compatible with a gradual, rather than a drastic saltation event. Overall, our results demonstrate the feasibility of studying cardiac evolution in fossils. PMID:27090087

  7. Submarine fresh water outflow detection with a dual-frequency microwave and an infrared radiometer system

    NASA Technical Reports Server (NTRS)

    Blume, H.-J. C.; Kendall, B. M.; Fedors, J. C.

    1981-01-01

    Since infrared measurements are only very slightly affected by whitecap and banking angle influences, the combined multifrequency radiometric signatures of the L-band, the S-band, and an infrared radiometer are used in identifying freshwater outflows (submerged and superficial). To separate the river and lagoon outflows from the submarine outflows, geographical maps with a scale of 1:100,000 are used. In all, 44 submarine freshwater springs are identified. This is seen as indicating that the submarine freshwater outflow locations are more numerous around the island than had earlier been estimated. Most of the submarine springs are located at the northwest and southeast portion of the Puerto Rican coastline; the success in detecting the submarine springs during both missions at the northwest portion of the island is 39%. Salinity and temperature distribution plots along the flight path in longitude and latitude coordinates reveal that runoff direction can be determined.

  8. Time-dependent modelling of the molecular line emission from shock waves in outflow sources

    NASA Astrophysics Data System (ADS)

    Flower, D. R.; Pineau des Forêts, G.

    2012-04-01

    We have developed further the technique of time-dependent modelling of magnetohydrodynamic shock waves, with a view to interpreting the molecular line emission from outflow sources. The extensively observed source L1157 B1 was chosen as an exemplar of the application of this technique. The dynamical age of the shock wave model was varied in the range 500 ≤t≤ 5000 yr, with the best fit to the observed line intensities being obtained for t= 1000 yr; this is of the same order as the dynamical age derived by Gueth, Guilloteau & Bachiller from their observations of L1157 B1. The emission line spectra of H2, CO, SiO, ortho- and para-H2O, ortho- and para-NH3, and A- and E-type CH3OH were calculated in parallel with the dynamical and chemical parameters of the model, using the 'large velocity gradient' (LVG) approximation to the line transfer problem. We compared the predictions of the models with the observed intensities of emission lines of H2, CO, SiO, ortho-H2O, ortho-NH3 and CH3OH, which include recent Herschel satellite measurements. In the case of SiO, we show (in Appendix A) that extrapolations of the collisional rate coefficients beyond the range of kinetic temperature for which they were originally calculated lead to spurious rotational line intensities and profiles. The computed emission-line spectra of SiO, NH3 and CH3OH are shown to depend on the assumed initial composition of the grain mantles, from whence they are released, by sputtering in the shock wave, into the gas phase. The dependence of the model predictions on the adopted form of the grain-size distribution is investigated in Appendix B; the corresponding integral line intensities are given in tabular form, for a range of C-type shock speeds, in the online Supporting Information.

  9. Nature or Nurture: the peculiar HH 900 jet and outflow system in the Carina nebula

    NASA Astrophysics Data System (ADS)

    Reiter, Megan; Smith, Nathan; Kiminki, Megan M.; Bally, John

    2015-01-01

    We present new optical and IR spectroscopy and Hubble Space Telescope imaging of HH 900, a peculiar protostellar outflow in the Carina nebula. Previous Hα imaging from HST revealed an unusually broad, bipolar outflow emerging from a small, tadpole-shaped globule that is illuminated by the many O-type stars in nearby Trumpler 16. Near-IR narrowband [Fe II] images reveal a symmetric, collimated jet that bisects the broad outflow traced by Hα. In a giant H II region like Carina, [Fe II] emission traces dense gas that is self-shielded from Lyman continuum photons from nearby O-type stars, but is excited by non-ionizing FUV photons that penetrate the ionization front within the jet. New Gemini AO images of near-IR H2 emission show that molecules survive in the outflow, and follow the Hα morphology. Position-velocity diagrams of the three lines also reveal very different kinematics. [Fe II] traces steady, jet-like velocities that are faster than those observed in H2 emission. Most strikingly, Hα velocities resemble the Hubble wedges seen in the position-velocity diagrams of some molecular outflows, but few other protostellar jets. We propose that [Fe II] emission traces the protostellar jet itself while H2 emission reveals the molecules that (briefly) survive in the outflow, and Hα traces the ionized skin of the outflow sheath entrained by the jet. The high estimated mass-loss rate of the jet requires a high accretion rate, implying that the unseen driving source is an intermediate-mass (~2-8 Msun) protostar. We propose that HH 900 provides a bridge between molecular outflows driven by deeply embedded sources, and jets from unobscured low-mass protostars because external irradiation from nearby O-type stars illuminates both the collimated atomic jet core and the material it sweeps up.

  10. The SINS/zC-SINF Survey of z ~ 2 Galaxy Kinematics: Outflow Properties

    NASA Astrophysics Data System (ADS)

    Newman, Sarah F.; Genzel, Reinhard; Förster-Schreiber, Natascha M.; Shapiro Griffin, Kristen; Mancini, Chiara; Lilly, Simon J.; Renzini, Alvio; Bouché, Nicolas; Burkert, Andreas; Buschkamp, Peter; Carollo, C. Marcella; Cresci, Giovanni; Davies, Ric; Eisenhauer, Frank; Genel, Shy; Hicks, Erin K. S.; Kurk, Jaron; Lutz, Dieter; Naab, Thorsten; Peng, Yingjie; Sternberg, Amiel; Tacconi, Linda J.; Vergani, Daniela; Wuyts, Stijn; Zamorani, Gianni

    2012-12-01

    Using SINFONI Hα, [N II], and [S II] AO data of 27 z ~ 2 star-forming galaxies (SFGs) from the SINS and zC-SINF surveys, we explore the dependence of outflow strength (via the broad flux fraction) on various galaxy parameters. For galaxies that have evidence for strong outflows, we find that the broad emission is spatially extended to at least the half-light radius (~a few kpc). Decomposition of the [S II] doublet into broad and narrow components suggests that this outflowing gas probably has a density of ~10-100 cm-3, less than that of the star-forming gas (600 cm-3). There is a strong correlation of the Hα broad flux fraction with the star formation surface density of the galaxy, with an apparent threshold for strong outflows occurring at 1 M ⊙ yr-1 kpc-2. Above this threshold, we find that SFGs with log m * > 10 have similar or perhaps greater wind mass-loading factors (η = \\dot{M}_out/SFR) and faster outflow velocities than lower mass SFGs, suggesting that the majority of outflowing gas at z ~ 2 may derive from high-mass SFGs. The mass-loading factor is also correlated with the star formation rate (SFR), galaxy size, and inclination, such that smaller, more star-forming, and face-on galaxies launch more powerful outflows. We propose that the observed threshold for strong outflows and the observed mass loading of these winds can be explained by a simple model wherein break-out of winds is governed by pressure balance in the disk. Based on observations at the Very Large Telescope (VLT) of the European Southern Observatory (ESO), Paranal, Chile (ESO program IDs 076.A-0527, 079.A-0341, 080.A-0330, 080.A-0339, 080.A-0635, and 183.A-0781).

  11. Exploring the engines of molecular outflows. Radio continuum and H_2_O maser observations.

    NASA Astrophysics Data System (ADS)

    Tofani, G.; Felli, M.; Taylor, G. B.; Hunter, T. R.

    1995-09-01

    We present A-configuration VLA observations of the 22GHz H_2_O maser line and 8.4GHz continuum emission of 22 selected CO bipolar outflows associated with water masers. These observations allow us to study the region within 10^4^AU of the engine powering the outflow. The positions of the maser spots are compared with those of ultra-compact (UC) continuum sources found in our observations, with IRAS data and with data from the literature on the molecular outflows. Weak unresolved continuum sources are found in several cases associated with the maser. Most probably they represent the ionized envelope surrounding the young stellar object (YSO) which powers the maser and the outflow. These weak radio continuum sources are not necessarily associated with the IRAS sources, which are more representative of the global emission from the star forming region. A comparison of the velocity pattern of the CO outflow with those of the maser spots detected with the VLA is also made. Asymmetries in the H_2_O velocities are found on opposite sides of the YSO, suggesting that the outflow acceleration begins from the YSO itself. In a few cases we find evidence for two outflows in different evolutionary stages. The H_2_O masers in these sources are always found at the centre of the younger outflow. The degree of variability of each maser is derived from single dish observations obtained with the Medicina radiotelescope before and after the VLA observations. Velocity drifts of some features are interpreted as acceleration of the maser.

  12. FAST MOLECULAR OUTFLOWS IN LUMINOUS GALAXY MERGERS: EVIDENCE FOR QUASAR FEEDBACK FROM HERSCHEL

    SciTech Connect

    Veilleux, S.; Meléndez, M.; Sturm, E.; Gracia-Carpio, J.; Contursi, A.; Lutz, D.; Poglitsch, A.; Davies, R.; Genzel, R.; Tacconi, L.; De Jong, J. A.; Fischer, J.; González-Alfonso, E.; Sternberg, A.; Netzer, H.; Hailey-Dunsheath, S.; Verma, A.; Rupke, D. S. N.; Maiolino, R.; Teng, S. H. E-mail: marcio@astro.umd.edu; and others

    2013-10-10

    We report the results from a systematic search for molecular (OH 119 μm) outflows with Herschel/PACS in a sample of 43 nearby (z < 0.3) galaxy mergers, mostly ultraluminous infrared galaxies (ULIRGs) and QSOs. We find that the character of the OH feature (strength of the absorption relative to the emission) correlates with that of the 9.7 μm silicate feature, a measure of obscuration in ULIRGs. Unambiguous evidence for molecular outflows, based on the detection of OH absorption profiles with median velocities more blueshifted than –50 km s{sup –1}, is seen in 26 (70%) of the 37 OH-detected targets, suggesting a wide-angle (∼145°) outflow geometry. Conversely, unambiguous evidence for molecular inflows, based on the detection of OH absorption profiles with median velocities more redshifted than +50 km s{sup –1}, is seen in only four objects, suggesting a planar or filamentary geometry for the inflowing gas. Terminal outflow velocities of ∼–1000 km s{sup –1} are measured in several objects, but median outflow velocities are typically ∼–200 km s{sup –1}. While the outflow velocities show no statistically significant dependence on the star formation rate, they are distinctly more blueshifted among systems with large active galactic nucleus (AGN) fractions and luminosities [log (L{sub AGN}/L{sub ☉}) ≥ 11.8 ± 0.3]. The quasars in these systems play a dominant role in driving the molecular outflows. However, the most AGN dominated systems, where OH is seen purely in emission, show relatively modest OH line widths, despite their large AGN luminosities, perhaps indicating that molecular outflows subside once the quasar has cleared a path through the obscuring material.

  13. Fast Molecular Outflows in Luminous Galaxy Mergers: Evidence for Quasar Feedback from Herschel

    NASA Technical Reports Server (NTRS)

    Veilleux, S.; Melendez, M.; Sturm, E.; Garcia-Carpio, J.; Fischer, J.; Gonzalez-Alfonso, E.; Contursi, A.; Lutz, D.; Poglitsch, A.; Davies, R.; Genzel, R.; Tacconi, L.; deJong, J. A.; Sternberg, A.; Netzer, H.; Hailey-Dunsheath, S.; Verma, A.; Rupke, D. S. N.; Maiolino, R.; Teng, S. H.; Polisensky, E.

    2013-01-01

    We report the results from a systematic search for molecular (OH 119 micron) outflows with Herschel/PACS in a sample of 43 nearby (z < 0.3) galaxy mergers, mostly ultraluminous infrared galaxies (ULIRGs) and QSOs. We find that the character of the OH feature (strength of the absorption relative to the emission) correlates with that of the 9.7 micron silicate feature, a measure of obscuration in ULIRGs. Unambiguous evidence for molecular outflows, based on the detection of OH absorption profiles with median velocities more blueshifted than-50 km/s, is seen in 26 (70%) of the 37 OH-detected targets, suggesting a wide-angle (approx. 145 deg.) outflow geometry. Conversely, unambiguous evidence for molecular inflows, based on the detection of OH absorption profiles with median velocities more redshifted than +50 km/s is seen in only four objects, suggesting a planar or filamentary geometry for the inflowing gas. Terminal outflow velocities of approx. -1000 km/s are measured in several objects, but median outflow velocities are typically approx.-200 km/s-1. While the outflow velocities show no statistically significant dependence on the star formation rate, they are distinctly more blueshifted among systems with large active galactic nucleus (AGN) fractions and luminosities [log (L(sub AGN)/L(sub solar)) => 11.8 +/- 0.3]. The quasars in these systems play a dominant role in driving the molecular outflows. However, the most AGN dominated systems, where OH is seen purely in emission, show relatively modest OH line widths, despite their large AGN luminosities, perhaps indicating that molecular outflows subside once the quasar has cleared a path through the obscuring material.

  14. NEUTRAL GAS OUTFLOWS AND INFLOWS IN INFRARED-FAINT SEYFERT GALAXIES

    SciTech Connect

    Krug, Hannah B.; Veilleux, Sylvain; Rupke, David S. N. E-mail: veilleux@astro.umd.ed

    2010-01-10

    Previous studies of the Na I D interstellar absorption line doublet have shown that galactic winds occur in most galaxies with high infrared luminosities. However, in infrared-bright composite systems where a starburst coexists with an active galactic nucleus (AGN), it is unclear whether the starburst, the AGN, or both are driving the outflows. The present paper describes the results from a search for outflows in 35 infrared-faint Seyferts with 10{sup 9.9}< L{sub IR}/L{sub sun} < 10{sup 11}, or, equivalently, star formation rates (SFRs) of approx0.4-9 M{sub sun} yr{sup -1}, to attempt to isolate the source of the outflow. We find that the outflow detection rates for the infrared-faint Seyfert 1s (6%) and Seyfert 2s (18%) are lower than previously reported for infrared-luminous Seyfert 1s (50%) and Seyfert 2s (45%). The outflow kinematics of infrared-faint and infrared-bright Seyfert 2 galaxies resemble those of starburst galaxies, while the outflow velocities in Seyfert 1 galaxies are significantly larger. Taken together, these results suggest that the AGN does not play a significant role in driving the outflows in most infrared-faint and infrared-bright systems, except the high-velocity outflows seen in Seyfert 1 galaxies. Another striking result of this study is the high rate of detection of inflows in infrared-faint galaxies (39% of Seyfert 1s, 35% of Seyfert 2s), significantly larger than in infrared-luminous Seyferts (15%). This inflow may be contributing to the feeding of the AGN in these galaxies, and potentially provides more than enough material to power the observed nuclear activity over typical AGN lifetimes.

  15. Helical Magnetic Fields in the NGC 1333 IRAS 4A Protostellar Outflows

    NASA Astrophysics Data System (ADS)

    Ching, Tao-Chung; Lai, Shih-Ping; Zhang, Qizhou; Yang, Louis; Girart, Josep M.; Rao, Ramprasad

    2016-03-01

    We present Submillimeter Array polarization observations of the CO J = 3-2 line toward NGC 1333 IRAS 4A. The CO Stokes I maps at an angular resolution of ˜1″ reveal two bipolar outflows from the binary sources of NGC 1333 IRAS 4A. The kinematic features of the CO emission can be modeled by wind-driven outflows at ˜20° inclined from the plane of the sky. Close to the protostars the CO polarization, at an angular resolution of ˜2.″3, has a position angle approximately parallel to the magnetic field direction inferred from the dust polarizations. The CO polarization direction appears to vary smoothly from an hourglass field around the core to an arc-like morphology wrapping around the outflow, suggesting a helical structure of magnetic fields that inherits the poloidal fields at the launching point and consists of toroidal fields at a farther distance of outflow. The helical magnetic field is consistent with the theoretical expectations for launching and collimating outflows from a magnetized rotating disk. Considering that the CO polarized emission is mainly contributed from the low-velocity and low-resolution data, the helical magnetic field is likely a product of the wind-envelope interaction in the wind-driven outflows. The CO data reveal a PA of ˜30° deflection in the outflows. The variation in the CO polarization angle seems to correlate with the deflections. We speculate that the helical magnetic field contributes to ˜10° deflection of the outflows by means of Lorentz force.