Characterizing Intermediate-Mass, Pre-Main-Sequence Stars via X-Ray Emision

NASA Astrophysics Data System (ADS)

Haze Nunez, Evan; Povich, Matthew Samuel; Binder, Breanna Arlene; Broos, Patrick; Townsley, Leisa K.

2018-01-01

The X-ray emission from intermediate-mass, pre-main-sequence stars (IMPS) can provide useful constraints on the ages of very young (${<}5$~Myr) massive star forming regions. IMPS have masses between 2 and 8 $M_{\\odot}$ and are getting power from the gravitational contraction of the star. Main-sequence late-B and A-type stars are not expected to be strong X-ray emitters, because they lack the both strong winds of more massive stars and the magneto-coronal activity of lower-mass stars. There is, however, mounting evidence that IMPS are powerful intrinsic x-ray emitters during their convection-dominated early evolution, before the development and rapid growth of a radiation zone. We present our prime candidates for intrinsic, coronal X-ray emission from IMPS identified in the Chandra Carina Complex Project. The Carina massive star-forming complex is of special interest due to the wide variation of star formation stages within the region. Candidate IMPS were identified using infrared spectral energy distribution (SED) models. X-ray properties, including thermal plasma temperatures and absorption-corrected fluxes, were derived from XSPEC fits performed using absorption ($N_{H}$) constrained by the extinction values returned by the infrared SED fits. We find that IMPS have systematically higher X-ray luminosities compared to their lower-mass cousins, the TTauri stars.This work is supported by the National Science Foundation under grant CAREER-1454334 and by NASA through Chandra Award 18200040.

Utility of blind forceps biopsy of the main carina and upper-lobe carina in patients with non-small cell lung cancer.

PubMed

Gunen, H; Kizkin, O; Tahaoglu, C; Aktas, O

2001-02-01

Preoperative detection of non-small cell lung cancer (NSCLC) metastasis to the main carina and upper-lobe carina can alter the operative approach, preclude further staging procedures, and save many patients from thoracotomy. This study assessed whether bronchoscopic forceps biopsy of the normal-appearing main carina and upper-lobe carina (blind biopsy) ipsilateral to the primary NSCLC lesion improved the accuracy of cancer staging and helped guide the management of these patients. A prospective study of 52 patients was carried out at the SSK Süreyyapasa Center for Chest Disease and Cardiothoracic Surgery. Over a 6-month period, we bronchoscopically evaluated 52 consecutive NSCLC patients who were radiologically classified as operable. At least five blind forceps biopsy specimens were obtained from the main carina and/or upper-lobe carina during each patient's initial fiberoptic bronchoscopic examination. Biopsy specimens were collected from the main carina and upper-lobe carina in 51 and 17 patients, respectively. Initially, all patients were staged and evaluated for operability in standard fashion, without histologic assessment of the blind biopsy specimens. We then restaged the disease and reassessed the patients' operability in light of the biopsy findings. Metastasis was histologically diagnosed in seven patients (13.7%) who underwent main carina biopsy and in four patients (23.5%) who underwent upper-lobe carina biopsy. Cancer-positive blind biopsy results changed the status of 25% (6 of 24) of patients from operable to inoperable, and changed the surgical approach in 11.1% (2 of 18) of patients who ultimately did undergo surgery. We found no statistical relationship between metastasis to either carina and tumor type, stage of disease, visibility of the tumor on fiberoptic bronchoscopy, primary tumor location, T status, or N status (p > 0.05). A blind forceps biopsy of the main carina and upper-lobe carina ipsilateral to the lesion site should be done routinely at initial bronchoscopic examination of all radiologically operable patients with suspected lung cancer. This type of screening can save a significant number of NSCLC patients from inappropriate or unnecessary thoracotomy and further staging procedures with their associated morbidity and risk.

Carina Nebula Detail

NASA Image and Video Library

2017-12-08

Carina Nebula Details: Great Clouds Credit for Hubble Image: NASA, ESA, N. Smith (University of California, Berkeley), and The Hubble Heritage Team (STScI/AURA) Credit for CTIO Image: N. Smith (University of California, Berkeley) and NOAO/AURA/NSF The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute conducts Hubble science operations. Goddard is responsible for HST project management, including mission and science operations, servicing missions, and all associated development activities. To learn more about the Hubble Space Telescope go here: www.nasa.gov/mission_pages/hubble/main/index.html NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe. Follow us on Twitter Join us on Facebook

Large-Scale Structure of the Carina Nebula.

PubMed

Smith; Egan; Carey; Price; Morse; Price

2000-04-01

Observations obtained with the Midcourse Space Experiment (MSX) satellite reveal for the first time the complex mid-infrared morphology of the entire Carina Nebula (NGC 3372). On the largest size scale of approximately 100 pc, the thermal infrared emission from the giant H ii region delineates one coherent structure: a (somewhat distorted) bipolar nebula with the major axis perpendicular to the Galactic plane. The Carina Nebula is usually described as an evolved H ii region that is no longer actively forming stars, clearing away the last vestiges of its natal molecular cloud. However, the MSX observations presented here reveal numerous embedded infrared sources that are good candidates for sites of current star formation. Several compact infrared sources are located at the heads of dust pillars or in dark globules behind ionization fronts. Because their morphology suggests a strong interaction with the peculiar collection of massive stars in the nebula, we speculate that these new infrared sources may be sites of triggered star formation in NGC 3372.

CARINA TCO2 data in the Atlantic Ocean

NASA Astrophysics Data System (ADS)

Pierrot, D.; Brown, P.; van Heuven, S.; Tanhua, T.; Schuster, U.; Wanninkhof, R.; Key, R. M.

2010-01-01

Water column data of carbon and carbon-relevant hydrographic and hydrochemical parameters from 188 cruises in the Arctic, Atlantic and Southern Ocean have been retrieved and merged in a new data base: the CARINA (CARbon IN the Atlantic) Project. These data have gone through rigorous quality control (QC) procedures to assure the highest possible quality and consistency. Secondary quality control, which involved objective study of data in order to quantify systematic differences in the reported values, was performed for the pertinent parameters in the CARINA data base. Systematic biases in the data have been corrected in the data products. The products are three merged data files with measured, adjusted and interpolated data of all cruises for each of the three CARINA regions (Arctic, Atlantic and Southern Ocean). Ninety-eight cruises were conducted in the "Atlantic" defined as the region south of the Greenland-Iceland-Scotland Ridge and north of about 30° S. Here we report the details of the secondary QC which was done on the total dissolved inorganic carbon (TCO2) data and the adjustments that were applied to yield the final data product in the Atlantic. Procedures of quality control - including crossover analysis between stations and inversion analysis of all crossover data - are briefly described. Adjustments were applied to TCO2 measurements for 17 of the cruises in the Atlantic Ocean region. With these adjustments, the CARINA data base is consistent both internally as well as with GLODAP data, an oceanographic data set based on the WOCE Hydrographic Program in the 1990s, and is now suitable for accurate assessments of, for example, regional oceanic carbon inventories, uptake rates and model validation.

Volumetric Image Guidance Using Carina vs Spine as Registration Landmarks for Conventionally Fractionated Lung Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lavoie, Caroline; Higgins, Jane; Bissonnette, Jean-Pierre

2012-12-01

Purpose: To compare the relative accuracy of 2 image guided radiation therapy methods using carina vs spine as landmarks and then to identify which landmark is superior relative to tumor coverage. Methods and Materials: For 98 lung patients, 2596 daily image-guidance cone-beam computed tomography scans were analyzed. Tattoos were used for initial patient alignment; then, spine and carina registrations were performed independently. A separate analysis assessed the adequacy of gross tumor volume, internal target volume, and planning target volume coverage on cone-beam computed tomography using the initial, middle, and final fractions of radiation therapy. Coverage was recorded for primary tumormore » (T), nodes (N), and combined target (T+N). Three scenarios were compared: tattoos alignment, spine registration, and carina registration. Results: Spine and carina registrations identified setup errors {>=}5 mm in 35% and 46% of fractions, respectively. The mean vector difference between spine and carina matching had a magnitude of 3.3 mm. Spine and carina improved combined target coverage, compared with tattoos, in 50% and 34% (spine) to 54% and 46% (carina) of the first and final fractions, respectively. Carina matching showed greater combined target coverage in 17% and 23% of fractions for the first and final fractions, respectively; with spine matching, this was only observed in 4% (first) and 6% (final) of fractions. Carina matching provided superior nodes coverage at the end of radiation compared with spine matching (P=.0006), without compromising primary tumor coverage. Conclusion: Frequent patient setup errors occur in locally advanced lung cancer patients. Spine and carina registrations improved combined target coverage throughout the treatment course, but carina matching provided superior combined target coverage.« less

Eta Carinae: Orientation of The Orbital Plane

NASA Technical Reports Server (NTRS)

Gull, T. R.; Nielsen, K. E.; Ivarsson, S.; Corcoran, M. F.; Verner, E.; Hillier, J. D.

2006-01-01

Evidence continues to build that Eta Carinae is a massive binary system with a hidden hot companion in a highly elliptical orbit. We present imaging and spectroscopic evidence that provide clues to the orientation of the orbital plane. The circumstellar ejecta, known as the Homunculus and Little Homunculus, are hourglass-shaped structures, one encapsulated within the other, tilted at about 45 degrees from the sky plane. A disk region lies between the bipolar lobes. Based upon their velocities and proper motions, Weigelt blobs B, C and D, very bright emission clumps 0.1 to 0.3" Northwest from Eta Carinae, lie in the disk. UV flux from the hot companion, Eta Car B, photoexcites the Weigelt blobs. Other clumps form a complete chain around the star, but are not significantly photoexcited. The strontium filament, a 'neutral' emission structure, lies in the same general direction as the Weigelt blobs and exhibits peculiar properties indicative that much mid-UV, but no hydrogen-ionizing radiation impinges on this structure. It is shielded by singly-ionized iron. P Cygni absorptions in Fe I I lines, seen directly in line of sight from Eta Carinae, are absent in the stellar light scattered by the Weigelt blobs. Rather than a strong absorption extending to -600 km/s, a low velocity absorption feature extends from -40 to -150 km/s. No absorbing Fe II exists between Eta Carinae and Weigelt D, but the outer reaches of the wind are intercepted in line of sight from Weigelt D to the observer. This indicates that the UV radiation is constrained by the dominating wind of Eta Car A to a small cavity carved out by the weaker wind of Eta Car B. Since the high excitation nebular lines are seen in the Weigelt blobs at most phases, the cavity, and hence the major axis of the highly elliptical orbit, must lie in the general direction of the Weigelt blobs. The evidence is compelling that the orbital major axis of Eta Carinae is projected at -45 degrees position angle on the sky. Moreover the milliarcsecond-scale extended structure of Eta Carinae, recently detected by VLTI, may be evidence of the binary companion in the disk plane, not necessarily of a single star as a prolate spheroid extending along the ejecta polar axis.

The environment of the wind-wind collision region of η Carinae

NASA Astrophysics Data System (ADS)

Panagiotou, C.; Walter, R.

2018-02-01

Context. η Carinae is a colliding wind binary hosting two of the most massive stars and featuring the strongest wind collision mechanical luminosity. The wind collision region of this system is detected in X-rays and γ-rays and offers a unique laboratory for the study of particle acceleration and wind magneto-hydrodynamics. Aim. Our main goal is to use X-ray observations of η Carinae around periastron to constrain the wind collision zone geometry and understand the reasons for its variability. Methods: We analysed 10 Nuclear Spectroscopic Telescope Array (NuSTAR) observations, which were obtained around the 2014 periastron. The NuSTAR array monitored the source from 3 to 30 keV, which allowed us to grasp the continuum and absorption parameters with very good accuracy. We were able to identify several physical components and probe their variability. Results: The X-ray flux varied in a similar way as observed during previous periastrons and largely as expected if generated in the wind collision region. The flux detected within 10 days of periastron is lower than expected, suggesting a partial disruption of the central region of the wind collision zone. The Fe Kα line is likely broadened by the electrons heated along the complex shock fronts. The variability of its equivalent width indicates that the fluorescence region has a complex geometry and that the source obscuration varies quickly with the line of sight.

Kinematics of [CII] Emission in Trumpler 14 & Carina I Probed with Stratospheric Terahertz Observatory

NASA Astrophysics Data System (ADS)

Seo, Youngmin; Goldsmith, Paul; Walker, Christopher; Kulesa, Craig; STO2 Team

2018-01-01

We present observations of the Trumpler 14 / Carina I regions carried out with the Stratospheric Terahertz Observatory 2 (STO2). The Trumpler 14 / Carina I region is in the west part of the Carina Nebula, which is one of the most active star-forming regions in the Milky Way. The Trumpler 14 / Carina I region is a promising place to study multiple, interacting phases of the ISM, including photon-dominated regions, HII regions, and dense molecular clouds. We observed Trumpler 14 / Carina I in the 158 μm transition of [CII] with a spatial resolution of 48 arcseconds and a velocity resolution of 0.17 km/s. The observations cover a 0.25°by 0.28°area with the center position at l= 297.33° b= -0.60°. We found that the [CII] emission is extended covering roughly 80% of the observed area with >5 K intensity. The peak intensity of [CII] is located four arcminutes southwest of Trumpler 14 and one arcminute east of the CO peak intensity of Carina I. The kinematics show that [CII] structures are spatially and spectrally correlated with the surfaces of CO clumps illuminated by Eta Carinae and Trumpler 14. The [CII] emission also shows a good correlation with dust continuum emission at 160 μm, which is typically originating from heated dust grains to ~20 K. Our results show layered structures of photon-dominated regions in the Trumpler 14 / Carina I region.

New dedicated bifurcated silicone stent placement for stenosis around the primary right carina.

PubMed

Oki, Masahide; Saka, Hideo

2013-08-01

Silicone stenting has been widely used to palliate respiratory symptoms in patients suffering from airway stenosis. Although many types and shapes of stents have been developed, there is no ideal stent for stenosis around the carina between the bronchus to the right upper lobe and the bronchus intermedius (primary right carina). The purpose of this study was to evaluate the feasibility, efficacy, and safety of a new silicone stent designed for treating airway stenosis around the primary right carina. We recruited 16 patients with suspected stenosis around the primary right carina. Ten of the patients met the inclusion criteria for inserting the study stent. All stenting procedures were performed with a rigid and flexible bronchoscope under general anesthesia. The study stent could be mounted successfully on the primary right carina in all 10 patients. Five patients underwent stenting using only the new stent, and the other five underwent stenting with it on the primary right carina and a silicone Y stent on the main carina. The dyspnea index improved in eight of the 10 patients, including one who was mechanically ventilated. Early complications developed in three patients (temporary pneumonia in two and retention of secretions in one), and late complications occurred in two patients (granuloma formation in one and hemoptysis in one). Stent placement with the new silicone stent designed to fit on the primary right carina is feasible, effective, and acceptably safe. UMIN-Clinical Trials Registry; No.: UMIN000001776; URL: www.umin.ac.jp/ctr.

Discovery of two neighbouring satellites in the Carina constellation with MagLiteS

NASA Astrophysics Data System (ADS)

Torrealba, G.; Belokurov, V.; Koposov, S. E.; Bechtol, K.; Drlica-Wagner, A.; Olsen, K. A. G.; Vivas, A. K.; Yanny, B.; Jethwa, P.; Walker, A. R.; Li, T. S.; Allam, S.; Conn, B. C.; Gallart, C.; Gruendl, R. A.; James, D. J.; Johnson, M. D.; Kuehn, K.; Kuropatkin, N.; Martin, N. F.; Martinez-Delgado, D.; Nidever, D. L.; Noël, N. E. D.; Simon, J. D.; Stringfellow, G. S.; Tucker, D. L.

2018-04-01

We report the discovery of two ultra-faint satellites in the vicinity of the Large Magellanic Cloud (LMC) in data from the Magellanic Satellites Survey (MagLiteS ). Situated 18 deg (˜20 kpc) from the LMC and separated from each other by only 18 arcmin, Carina II and III form an intriguing pair. By simultaneously modelling the spatial and the colour-magnitude stellar distributions, we find that both Carina II and Carina III are likely dwarf galaxies, although this is less clear for Carina III. There are in fact several obvious differences between the two satellites. While both are well described by an old and metal poor population, Carina II is located at ˜36 kpc from the Sun, with MV ˜ -4.5 and rh ˜ 90 pc, and it is further confirmed by the discovery of 3 RR Lyrae at the right distance. In contrast, Carina III is much more elongated, measured to be fainter (MV ˜ -2.4), significantly more compact (rh ˜ 30 pc), and closer to the Sun, at ˜28 kpc, placing it only 8 kpc away from Car II. Together with several other systems detected by the Dark Energy Camera, Carina II and III form a strongly anisotropic cloud of satellites in the vicinity of the Magellanic Clouds.

Recurrent X-ray Emission Variations of Eta Carinae and the Binary Hypothesis

NASA Technical Reports Server (NTRS)

Ishibashi, K.; Corcoran, M. F.; Davidson, K.; Swank, J. H.; Petre, R.; Drake, S. A.; Damineki, A.; White, S.

1998-01-01

Recent studies suggest that, the super-massive star eta Carinae may have a massive stellar companion (Damineli, Conti, and Lopes 1997), although the dense ejecta surrounding the star make this claim hard to test using conventional methods. Settling this question is critical for determining the current evolutionary state and future evolution of the star. We address this problem by an unconventional method: If eta Carinae is a binary, X-ray emission should be produced in shock waves generated by wind-wind collisions in the region between eta Carinae and its companion. Detailed X-ray monitoring of eta Carinae for more that) 2 years shows that the observed emission generally resembles colliding-wind X-ray emission, but with some significant discrepancies. Furthermore, periodic X-ray "flaring" may provide an additional clue to determine the presence of a companion star and for atmospheric pulsation in eta Carinae.

Comparison of carina-based versus bony anatomy-based registration for setup verification in esophageal cancer radiotherapy.

PubMed

Machiels, Mélanie; Jin, Peng; van Gurp, Christianne H; van Hooft, Jeanin E; Alderliesten, Tanja; Hulshof, Maarten C C M

2018-03-21

To investigate the feasibility and geometric accuracy of carina-based registration for CBCT-guided setup verification in esophageal cancer IGRT, compared with current practice bony anatomy-based registration. Included were 24 esophageal cancer patients with 65 implanted fiducial markers, visible on planning CTs and follow-up CBCTs. All available CBCT scans (n = 236) were rigidly registered to the planning CT with respect to the bony anatomy and the carina. Target coverage was visually inspected and marker position variation was quantified relative to both registration approaches; the variation of systematic (Σ) and random errors (σ) was estimated. Automatic carina-based registration was feasible in 94.9% of the CBCT scans, with an adequate target coverage in 91.1% compared to 100% after bony anatomy-based registration. Overall, Σ (σ) in the LR/CC/AP direction was 2.9(2.4)/4.1(2.4)/2.2(1.8) mm using the bony anatomy registration compared to 3.3(3.0)/3.6(2.6)/3.9(3.1) mm for the carina. Mid-thoracic placed markers showed a non-significant but smaller Σ in CC and AP direction when using the carina-based registration. Compared with a bony anatomy-based registration, carina-based registration for esophageal cancer IGRT results in inadequate target coverage in 8.9% of cases. Furthermore, large Σ and σ, requiring larger anisotropic margins, were seen after carina-based registration. Only for tumors entirely confined to the mid-thoracic region the carina-based registration might be slightly favorable.

Hubble Captures Cosmic Ice Sculptures

NASA Image and Video Library

2017-12-08

NASA image release September 16, 2010 Enjoying a frozen treat on a hot summer day can leave a sticky mess as it melts in the Sun and deforms. In the cold vacuum of space, there is no edible ice cream, but there is radiation from massive stars that is carving away at cold molecular clouds, creating bizarre, fantasy-like structures. These one-light-year-tall pillars of cold hydrogen and dust, imaged by the Hubble Space Telescope, are located in the Carina Nebula. Violent stellar winds and powerful radiation from massive stars are sculpting the surrounding nebula. Inside the dense structures, new stars may be born. This image of dust pillars in the Carina Nebula is a composite of 2005 observations taken of the region in hydrogen light (light emitted by hydrogen atoms) along with 2010 observations taken in oxygen light (light emitted by oxygen atoms), both times with Hubble's Advanced Camera for Surveys. The immense Carina Nebula is an estimated 7,500 light-years away in the southern constellation Carina. The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI) conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc. in Washington, D.C. NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe. Follow us on Twitter Join us on Facebook

3D printing meets computational astrophysics: deciphering the structure of η Carinae's inner colliding winds

NASA Astrophysics Data System (ADS)

Madura, T. I.; Clementel, N.; Gull, T. R.; Kruip, C. J. H.; Paardekooper, J.-P.

2015-06-01

We present the first 3D prints of output from a supercomputer simulation of a complex astrophysical system, the colliding stellar winds in the massive (≳120 M⊙), highly eccentric (e ˜ 0.9) binary star system η Carinae. We demonstrate the methodology used to incorporate 3D interactive figures into a PDF (Portable Document Format) journal publication and the benefits of using 3D visualization and 3D printing as tools to analyse data from multidimensional numerical simulations. Using a consumer-grade 3D printer (MakerBot Replicator 2X), we successfully printed 3D smoothed particle hydrodynamics simulations of η Carinae's inner (r ˜ 110 au) wind-wind collision interface at multiple orbital phases. The 3D prints and visualizations reveal important, previously unknown `finger-like' structures at orbital phases shortly after periastron (φ ˜ 1.045) that protrude radially outwards from the spiral wind-wind collision region. We speculate that these fingers are related to instabilities (e.g. thin-shell, Rayleigh-Taylor) that arise at the interface between the radiatively cooled layer of dense post-shock primary-star wind and the fast (3000 km s-1), adiabatic post-shock companion-star wind. The success of our work and easy identification of previously unrecognized physical features highlight the important role 3D printing and interactive graphics can play in the visualization and understanding of complex 3D time-dependent numerical simulations of astrophysical phenomena.

Discovery of two neighbouring satellites in the Carina constellation with MagLiteS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Torrealba, G.; Belokurov, V.; Koposov, S. E.

Here, we report the discovery of two ultra-faint satellites in the vicinity of the Large Magellanic Cloud (LMC) in data from the Magellanic Satellites Survey (MagLiteS). Situated 18more » $$^{\\circ}$$ ($$\\sim 20$$ kpc) from the LMC and separated from each other by only $$18^\\prime$$, Carina~II and III form an intriguing pair. By simultaneously modeling the spatial and the color-magnitude stellar distributions, we find that both Carina~II and Carina~III are likely dwarf galaxies, although this is less clear for Carina~III. There are in fact several obvious differences between the two satellites. While both are well described by an old and metal poor population, Carina~II is located at $$\\sim 36$$ kpc from the Sun, with $$M_V\\sim-4.5$$ and $$r_h\\sim 90$$ pc, and it is further confirmed by the discovery of 3 RR Lyrae at the right distance. In contrast, Carina~III is much more elongated, measured to be fainter ($$M_V\\sim-2.4$$), significantly more compact ($$r_h\\sim30$$ pc), and closer to the Sun, at $$\\sim 28$$ kpc, placing it only 8 kpc away from Car~II. Together with several other systems detected by the Dark Energy Camera, Carina~II and III form a strongly anisotropic cloud of satellites in the vicinity of the Magellanic Clouds.« less

Vocal cords-carina distance in anaesthetised Caucasian adults and its clinical implications for tracheal intubation.

PubMed

Pang, G; Edwards, M J; Greenland, K B

2010-11-01

Previous work has assessed vocal cords-carina distance in Chinese patients and compared it to commonly used tracheal tubes. In addition, an attempt was made to identify surface anatomy measurements with short tracheas. We have examined the length of tracheas in Caucasian patients and compared it with currently used tracheal tubes. We have investigated a wider range of surface anatomy measurements in an attempt to correlate measurements with vocal cords-carina distance and identifying patients who may be at risk of endobronchial intubation. In this study, the vocal cords-carina distance was measured in 150 anaesthetised Caucasian patients with a fibreoptic bronchoscope. We also attempted to correlate height and various surface anatomy measurements on the patients' chest, neck and limb regions to predict those patients at risk of endobronchial intubation. The mean vocal cords-carina distance was 12.7 cm (standard deviation 1.6 cm). The best predictors in our study of vocal cords-carina distance less than 11.3 cm were a height of < or = 182 cm, an ulnar length of < or = 31.2 cm or a thyroid to xiphisternum distance of < or = 31.8 cm. This correlation is poor however and prediction of vocal cords-carina distance remains difficult clinically. It was therefore concluded that surface anatomy measurements are a poor predictor of vocal cords-carina distance.

Discovery of two neighbouring satellites in the Carina constellation with MagLiteS

DOE PAGES

Torrealba, G.; Belokurov, V.; Koposov, S. E.; ...

2018-01-23

Here, we report the discovery of two ultra-faint satellites in the vicinity of the Large Magellanic Cloud (LMC) in data from the Magellanic Satellites Survey (MagLiteS). Situated 18more » $$^{\\circ}$$ ($$\\sim 20$$ kpc) from the LMC and separated from each other by only $$18^\\prime$$, Carina~II and III form an intriguing pair. By simultaneously modeling the spatial and the color-magnitude stellar distributions, we find that both Carina~II and Carina~III are likely dwarf galaxies, although this is less clear for Carina~III. There are in fact several obvious differences between the two satellites. While both are well described by an old and metal poor population, Carina~II is located at $$\\sim 36$$ kpc from the Sun, with $$M_V\\sim-4.5$$ and $$r_h\\sim 90$$ pc, and it is further confirmed by the discovery of 3 RR Lyrae at the right distance. In contrast, Carina~III is much more elongated, measured to be fainter ($$M_V\\sim-2.4$$), significantly more compact ($$r_h\\sim30$$ pc), and closer to the Sun, at $$\\sim 28$$ kpc, placing it only 8 kpc away from Car~II. Together with several other systems detected by the Dark Energy Camera, Carina~II and III form a strongly anisotropic cloud of satellites in the vicinity of the Magellanic Clouds.« less

Analysis of Carina Position as Surrogate Marker for Delivering Phase-Gated Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weide, Lineke van der; Soernsen de Koste, John R. van; Lagerwaard, Frank J.

2008-07-15

Purpose: Respiratory gating can mitigate the effect of tumor mobility in radiotherapy (RT) for lung cancer. Because the tumor is generally not visualized, external surrogates of tumor position are used to trigger respiration-gated RT. We evaluated the suitability of the carina position as a surrogate in respiration-gated RT. Methods and Materials: A total of 30 four-dimensional (4D) computed tomography (CT) scans from 14 patients with lung cancer were retrospectively analyzed. Both uncoached (free breathing) and audio-coached 4D-CT scans were acquired from 9 patients, and 12 uncoached 4D-CT scans were acquired from 5 other patients during a 2-4-week period of stereotacticmore » RT. The repeat scans were co-registered. The carina position was identified on the coronal cut planes in all 4D-CT phases. The correlation between the carina position and the total lung volume for each phase was determined, and the reproducibility of the carina position was studied in the 5 patients with repeat uncoached 4D-CT scans. Results: The mean extent of carina motion in 21 uncoached scans was 5.3 {+-} 1.6 mm in the craniocaudal (CC), 2.3 {+-} 1.4 mm in the anteroposterior, and 1.5 {+-} 0.7 mm in the mediolateral direction. Audio coaching resulted in a twofold increase in carina mobility in all directions. The CC carina position correlated with changes in the total lung volume (R = 0.89 {+-} 0.14), but the correlation was better for the audio-coached than for the uncoached 4D-CT scans (R = 0.93 {+-} 0.08 vs. R = 0.85 {+-} 0.17; paired t test, p = 0.034). Preliminary data from the 5 patients indicated that the CC carina motion correlated better with tumor motion than did the motion of the diaphragm. Conclusions: The CC position of the carina correlated well with the total lung volume, indicating that the carina is a good surrogate for verifying the total lung volume during respiration-gated RT.« less

WFPC2 Image of the Variable Star Eta Carinae

NASA Image and Video Library

2016-01-06

The discovery of likely Eta Carinae twins in other galaxies will help scientists better understand this brief phase in the life of a massive star with images such as this from NASA Hubble Space Telescope. Astronomers cannot yet explain what caused the titanic eruption of star Eta Carinae in the 1840s. The discovery of likely Eta Carinae "twins" in other galaxies will help scientists better understand this brief phase in the life of a massive star. http://photojournal.jpl.nasa.gov/catalog/PIA20294

CARINA alkalinity data in the Atlantic Ocean

NASA Astrophysics Data System (ADS)

Velo, A.; Perez, F. F.; Brown, P.; Tanhua, T.; Schuster, U.; Key, R. M.

2009-08-01

Data on carbon and carbon-relevant hydrographic and hydrochemical parameters from previously non-publicly available cruise data sets in the Arctic, Atlantic and Southern Ocean have been retrieved and merged to a new database: CARINA (CARbon IN the Atlantic). These data have gone through rigorous quality control (QC) procedures to assure the highest possible quality and consistency. The data for most of the measured parameters in the CARINA data base were objectively examined in order to quantify systematic differences in the reported values, i.e. secondary quality control. Systematic biases found in the data have been corrected in the data products, i.e. three merged data files with measured, calculated and interpolated data for each of the three CARINA regions; Arctic, Atlantic and Southern Ocean. Out of a total of 188 cruise entries in the CARINA database, 98 were conducted in the Atlantic Ocean and of these, 75 cruises report alkalinity values. Here we present details of the secondary QC on alkalinity for the Atlantic Ocean part of CARINA. Procedures of quality control, including crossover analysis between cruises and inversion analysis of all crossover data are briefly described. Adjustments were applied to the alkalinity values for 16 of the cruises in the Atlantic Ocean region. With these adjustments the CARINA database is consistent both internally as well as with GLODAP data, an oceanographic data set based on the World Hydrographic Program in the 1990s. Based on our analysis we estimate the internal accuracy of the CARINA-ATL alkalinity data to be 3.3 μmol kg-1. The CARINA data are now suitable for accurate assessments of, for example, oceanic carbon inventories and uptake rates and for model validation.

CARINA: nutrient data in the Atlantic Ocean

NASA Astrophysics Data System (ADS)

Tanhua, T.; Brown, P. J.; Key, R. M.

2009-11-01

Data on carbon and carbon-relevant hydrographic and hydrochemical parameters from previously non-publicly available cruise data sets in the Arctic, Atlantic and Southern Ocean have been retrieved and merged to a new database: CARINA (CARbon IN the Atlantic). These data have gone through rigorous quality control (QC) procedures to assure the highest possible quality and consistency. The data for most of the measured parameters in the CARINA data base were objectively examined in order to quantify systematic differences in the reported values, i.e. secondary quality control. Systematic biases found in the data have been corrected in the data products, i.e. three merged data files with measured, calculated and interpolated data for each of the three CARINA regions; Arctic Mediterranean Seas, Atlantic and Southern Ocean. Out of a total of 188 cruise entries in the CARINA database, 98 were conducted in the Atlantic Ocean and of these 84 cruises report nitrate values, 79 silicate, and 78 phosphate. Here we present details of the secondary QC for nutrients for the Atlantic Ocean part of CARINA. Procedures of quality control, including crossover analysis between cruises and inversion analysis of all crossover data are briefly described. Adjustments were applied to the nutrient values for 43 of the cruises in the Atlantic Ocean region. With these adjustments the CARINA database is consistent both internally as well as with GLODAP data, an oceanographic data set based on the World Hydrographic Program in the 1990s (Key et al., 2004). Based on our analysis we estimate the internal accuracy of the CARINA-ATL nutrient data to be: nitrate 1.5%; phosphate 2.6%; silicate 3.1%. The CARINA data are now suitable for accurate assessments of, for example, oceanic carbon inventories and uptake rates and for model validation.

CARINA: nutrient data in the Atlantic Ocean

NASA Astrophysics Data System (ADS)

Tanhua, T.; Brown, P. J.; Key, R. M.

2009-07-01

Data on carbon and carbon-relevant hydrographic and hydrochemical parameters from previously non-publicly available cruise data sets in the Arctic, Atlantic and Southern Ocean have been retrieved and merged to a new database: CARINA (CARbon IN the Atlantic). These data have gone through rigorous quality control (QC) procedures to assure the highest possible quality and consistency. The data for most of the measured parameters in the CARINA data base were objectively examined in order to quantify systematic differences in the reported values, i.e. secondary quality control. Systematic biases found in the data have been corrected in the data products, i.e. three merged data files with measured, calculated and interpolated data for each of the three CARINA regions; Arctic, Atlantic and Southern Ocean. Out of a total of 188 cruise entries in the CARINA database, 98 were conducted in the Atlantic Ocean and of these 84 cruises report nitrate values, 79 silicate, and 78 phosphate. Here we present details of the secondary QC for nutrients for the Atlantic Ocean part of CARINA. Procedures of quality control, including crossover analysis between cruises and inversion analysis of all crossover data are briefly described. Adjustments were applied to the nutrient values for 43 of the cruises in the Atlantic Ocean region. With these adjustments the CARINA database is consistent both internally as well as with GLODAP data, an oceanographic data set based on the World Hydrographic Program in the 1990s (Key et al., 2004). Based on our analysis we estimate the internal accuracy of the CARINA-ATL nutrient data to be: nitrate 1.5%; phosphate 2.6%; silicate 3.1%. The CARINA data are now suitable for accurate assessments of, for example, oceanic carbon inventories and uptake rates and for model validation.

CARINA alkalinity data in the Atlantic Ocean

NASA Astrophysics Data System (ADS)

Velo, A.; Perez, F. F.; Brown, P.; Tanhua, T.; Schuster, U.; Key, R. M.

2009-11-01

Data on carbon and carbon-relevant hydrographic and hydrochemical parameters from previously non-publicly available cruise data sets in the Arctic, Atlantic and Southern Ocean have been retrieved and merged to a new database: CARINA (CARbon IN the Atlantic). These data have gone through rigorous quality control (QC) procedures to assure the highest possible quality and consistency. The data for most of the measured parameters in the CARINA data base were objectively examined in order to quantify systematic differences in the reported values, i.e. secondary quality control. Systematic biases found in the data have been corrected in the data products, i.e. three merged data files with measured, calculated and interpolated data for each of the three CARINA regions; Arctic, Atlantic and Southern Ocean. Out of a total of 188 cruise entries in the CARINA database, 98 were conducted in the Atlantic Ocean and of these, 75 cruises report alkalinity values. Here we present details of the secondary QC on alkalinity for the Atlantic Ocean part of CARINA. Procedures of quality control, including crossover analysis between cruises and inversion analysis of all crossover data are briefly described. Adjustments were applied to the alkalinity values for 16 of the cruises in the Atlantic Ocean region. With these adjustments the CARINA database is consistent both internally as well as with GLODAP data, an oceanographic data set based on the World Hydrographic Program in the 1990s. Based on our analysis we estimate the internal accuracy of the CARINA-ATL alkalinity data to be 3.3 μmol kg-1. The CARINA data are now suitable for accurate assessments of, for example, oceanic carbon inventories and uptake rates and for model validation.

Radio observations of globulettes in the Carina nebula

NASA Astrophysics Data System (ADS)

Haikala, L. K.; Gahm, G. F.; Grenman, T.; Mäkelä, M. M.; Persson, C. M.

2017-06-01

Context. The Carina nebula hosts a large number of globulettes. An optical study of these tiny molecular clouds shows that the majority are of planetary mass, but there are also those with masses of several tens up to a few hundred Jupiter masses. Aims: We seek to search for, and hopefully detect, molecular line emission from some of the more massive objects; in case of successful detection we aim to map their motion in the Carina nebula complex and derive certain physical properties. Methods: We carried out radio observations of molecular line emission in 12CO and 13CO (2-1) and (3-2) of 12 globulettes in addition to positions in adjacent shell structures using APEX. Results: All selected objects were detected with radial velocities shifted relative to the emission from related shell structures and background molecular clouds. Globulettes along the western part of an extended dust shell show a small spread in velocity with small velocity shifts relative to the shell. This system of globulettes and shell structures in the foreground of the bright nebulosity surrounding the cluster Trumpler 14 is expanding with a few km s-1 relative to the cluster. A couple of isolated globulettes in the area move at similar speed. Compared to similar studies of the molecular line emission from globulettes in the Rosette nebula, we find that the integrated line intensity ratios and line widths are very different. The results show that the Carina objects have a different density/temperature structure than those in the Rosette nebula. In comparison the apparent size of the Carina globulettes is smaller, owing to the larger distance, and the corresponding beam filling factors are small. For this reason we were unable to carry out a more detailed modelling of the structure of the Carina objects in the way as performed for the Rosette objects. Conclusions: The Carina globulettes observed are compact and denser than objects of similar mass in the Rosette nebula. The distribution and velocities of these globulettes suggest that they have originated from eroding shells and elephant trunks. Some globulettes in the Trumpler 14 region are quite isolated and located far from any shell structures. These objects move at a similar speed as the globulettes along the shell, suggesting that they once formed from cloud fragments related to the same foreground shell. Based on observations collected with the Atacama Pathfinder Experiment (APEX), Llano Chajnantor, Chile (O-091.F-9316A and O-094.F-9312A).The final reduced radio data (FITS format) are 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/602/A61

The Character and Variability of the Eta Carinae Wind Lines

NASA Technical Reports Server (NTRS)

Nielsen, K. E.; Corcoran, M. F.; Gull, T. R.; Ivarsson, S.; Hillier, J. D.

2006-01-01

The binarity of Eta Carinae has been debated for a long time. We have searched for more evidence for a companion star in a spectroscopic investigation of the Eta Carinae stellar wind lines, using moderate spectral and high angular resolution HST/STIS data. Over Eta Carinae's 5.54 year spectroscopic period many of the observable wind lines in the NUV/Optical spectral region exhibit peculiar line profiles with unusual velocity shifts relative to the system velocity. Some of the lines are exclusively blue-shifted over the entire cycle. Their ionization/excitation imply formation not in the stellar wind but rather in the interface between the two massive stars. We have analyzed velocity and intensity variations over the spectroscopic period and interpreted what the variations tell us about the geometry of the nebular structure close to Eta Carinae.

A Smoking Gun in the Carina Nebula

NASA Technical Reports Server (NTRS)

Hamaguchi, Kenji; Corcoran, Michael F.; Ezoe, Yuichiro; Townsley, Leisa; Broos, Patrick; Gruendl, Robert; Vaidya, Kaushar; White, Stephen M.; Petre, Rob; Chu, You-Hua

2009-01-01

The Carina Nebula is one of thc youngest, most active sites of massive star formation in our Galaxy. In this nebula, we have discovered a bright X-ray source that has persisted for approx.30 years. The soft X-ray spectrum. consistent with kT approx.130 eV blackbody radiation with mild extinction, and no counterpart in the near- and mid-infrared wavelengths indicate that it is a, approx. 10(exp 6)-year-old neutron star housed in the Carina Nebula. Current star formation theory does not suggest that the progenitor of the neutron star and massive stars in the Carina Nebula, in particular (eta)Car, are coeval. This result demonstrates that the Carina Nebula experienced at least two major episodes of massive star formation. The neutron star would be responsible for remnants of high energy activity seen in multiple wavelengths.

Eta Carinae: Enigmatic Eta Carinae

NASA Astrophysics Data System (ADS)

Pittard, J. M.

2003-02-01

Eta Carinae is perhaps the most massive and luminous star in our galaxy, and is also one of the most enigmatic. Despite over a century and a half of study since an enormous eruption which expelled several solar masses of material into interstellar space, and which guaranteed its infamy, astronomers have struggled to understand its true nature. With a key event in the cycle of this star expected during the summer of 2003, an unprecedented programme of observations has been organized by astronomers around the world. Eta Carinae may at last be about to reveal some of its most fundamental secrets.

A CATALOG OF NEW SPECTROSCOPICALLY CONFIRMED MASSIVE OB STARS IN CARINA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alexander, Michael J.; Hanes, Richard J.; McSwain, M. Virginia

2016-12-01

The Carina star-forming region is one of the largest in the Galaxy, and its massive star population is still being unveiled. The large number of stars combined with high, and highly variable, interstellar extinction makes it inherently difficult to find OB stars in this type of young region. We present the results of a spectroscopic campaign to study the massive star population of the Carina Nebula, with the primary goal to confirm or reject previously identified Carina OB star candidates. A total of 141 known O- and B-type stars and 94 candidates were observed, of which 73 candidates had highmore » enough signal-to-noise ratio to classify. We find 23 new OB stars within the Carina Nebula, a 32% confirmation rate. One of the new OB stars has blended spectra and is suspected to be a double-lined spectroscopic binary (SB2). We also reclassify the spectral types of the known OB stars and discover nine new SB2s among this population. Finally, we discuss the spatial distribution of these new OB stars relative to known structures in the Carina Nebula.« less

A Tactile Carina Nebula

NASA Astrophysics Data System (ADS)

Grice, Noreen A.; Mutchler, M.

2010-01-01

Astronomy was once considered a science restricted to fully sighted participants. But in the past two decades, accessible books with large print/Braille and touchable pictures have brought astronomy and space science to the hands and mind's eye of students, regardless of their visual ability. A new universally-designed tactile image featuring the Hubble mosaic of the Carina Nebula is being presented at this conference. The original dataset was obtained with Hubble's Advanced Camera for Surveys (ACS) hydrogen-alpha filter in 2005. It became an instant icon after being infused with additional color information from ground-based CTIO data, and released as Hubble's 17th anniversary image. Our tactile Carina Nebula promotes multi-mode learning about the entire life-cycle of stars, which is dramatically illustrated in this Hubble mosaic. When combined with descriptive text in print and Braille, the visual and tactile components seamlessly reach both sighted and blind populations. Specific touchable features of the tactile image identify the shapes and orientations of objects in the Carina Nebula that include star-forming regions, jets, pillars, dark and light globules, star clusters, shocks/bubbles, the Keyhole Nebula, and stellar death (Eta Carinae). Visit our poster paper to touch the Carina Nebula!

Proper Motions of Dwarf Spheroidal Galaxies from Hubble Space Telescope Imaging. II. Measurement for Carina

NASA Astrophysics Data System (ADS)

Piatek, Slawomir; Pryor, Carlton; Olszewski, Edward W.; Harris, Hugh C.; Mateo, Mario; Minniti, Dante; Tinney, Christopher G.

2003-11-01

This article presents and discusses a measurement of the proper motion for the Carina dwarf spheroidal galaxy (dSph) from images in two distinct fields in the direction of Carina taken with the Hubble Space Telescope, at three epochs. Each field contains a confirmed quasi-stellar object that is the reference point for measuring the proper motion of the dSph. The consecutive epochs are 1-2 yr apart. The components of the measured proper motion for Carina, expressed in the equatorial coordinate system, are μα=22+/-9 mas century-1 and μδ=15+/-9 mas century-1. The quoted proper motion is a weighted mean of two independent measurements and has not been corrected for the motions of the Sun and of the local standard of rest. Given the proper motion and its uncertainty, integrating the family of possible orbits of Carina in a realistic gravitational potential for the Milky Way indicates that Carina is bound gravitationally to the Milky Way and is close to apogalacticon. The best estimate of, and the 95% confidence interval for, the apogalacticon of the orbit is 102 kpc and (102,113) kpc, for the perigalacticon is 20 kpc and (3.0,63) kpc, and for the orbital period is 1.4 Gyr and (1.3,2.0) Gyr. Carina does not seem to be on a polar orbit. The best estimate of the inclination of the orbit with respect to the Galactic plane is 39°, but the 95% confidence interval is so wide, (23°,102°), that it includes a polar orbit. We are unable to confirm or to rule out the membership of Carina in a ``stream'' of galaxies in the Galactic halo because the difference between the observed and predicted directions of the proper motion is 1.6 times the uncertainty of the difference. Carina must contain dark matter to have survived the tidal interaction with the Milky Way until the present. The triggering of star formation by perigalacticon passages and crossings of the Galactic disk do not explain the history of star formation in Carina. Based on observations with 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.

Strong Winds over the Keel

NASA Astrophysics Data System (ADS)

2009-02-01

The latest ESO image reveals amazing detail in the intricate structures of one of the largest and brightest nebulae in the sky, the Carina Nebula (NGC 3372), where strong winds and powerful radiation from an armada of massive stars are creating havoc in the large cloud of dust and gas from which the stars were born. ESO PR Photo 05a/09 The Carina Nebula ESO PR Video 05a/09 Pan over the Carina Nebula ESO PR Video 05b/09 Carina Nebula Zoom-in The large and beautiful image displays the full variety of this impressive skyscape, spattered with clusters of young stars, large nebulae of dust and gas, dust pillars, globules, and adorned by one of the Universe's most impressive binary stars. It was produced by combining exposures through six different filters from the Wide Field Imager (WFI), attached to the 2.2 m ESO/MPG telescope at ESO's La Silla Observatory, in Chile. The Carina Nebula is located about 7500 light-years away in the constellation of the same name (Carina; the Keel). Spanning about 100 light-years, it is four times larger than the famous Orion Nebula and far brighter. It is an intensive star-forming region with dark lanes of cool dust splitting up the glowing nebula gas that surrounds its many clusters of stars. The glow of the Carina Nebula comes mainly from hot hydrogen basking in the strong radiation of monster baby stars. The interaction between the hydrogen and the ultraviolet light results in its characteristic red and purple colour. The immense nebula contains over a dozen stars with at least 50 to 100 times the mass of our Sun. Such stars have a very short lifespan, a few million years at most, the blink of an eye compared with the Sun's expected lifetime of ten billion years. One of the Universe's most impressive stars, Eta Carinae, is found in the nebula. It is one of the most massive stars in our Milky Way, over 100 times the mass of the Sun and about four million times brighter, making it the most luminous star known. Eta Carinae is highly unstable, and prone to violent outbursts, most notably the false supernova event in 1842. For just a few years, Eta Carinae became the second brightest star in the night sky and produced almost as much visible light as a supernova explosion (the usual death throes of a massive star), but it survived. Eta Carinae is also thought to have a hot companion that orbits around it in 5.54 years, in an elliptical orbit. Both stars have strong winds, which collide, leading to interesting phenomena. In mid-January 2009, the companion was at its closest distance to Eta Carinae. This event, which may provide a unique insight into the wind structure of the massive stars, has been followed by a flotilla of instruments on several of ESO's telescopes.

Water masers and ammonia (1, 1) and (2, 2) towards six regions in the Carina Nebula

NASA Astrophysics Data System (ADS)

Breen, S. L.; Green, C.-E.; Cunningham, M. R.; Voronkov, M. A.; Horiuchi, S.; Green, J. A.

2018-01-01

We present water maser and ammonia (1, 1) and (2, 2) observations, towards six regions in the Carina Nebula, conducted with the Australia Telescope Compact Array. In total five water masers were detected within two of the target fields, and we provide their accurate positions and characteristics. These five water masers constitute all of the known masers detected towards star formation regions in the Carina Nebula and we argue, that given the evidence for active star formation, and the presence of many high-mass stars, the Carina Nebula is uncharacteristically devoid of masers. Our results are consistent with the Carina Nebula having a lack of young high-mass stars, despite the presence of older high-mass stars. Ammonia (1, 1) and (2, 2) emission was detected towards all but one of the target fields and we find that their linewidths and derived temperatures are consistent with the presence of young star formation regions.

Atlantic Ocean CARINA data: overview and salinity adjustments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tanhua, T.; Steinfeldt, R.; Key, Robert

2010-01-01

Water column data of carbon and carbon-relevant hydrographic and hydrochemical parameters from 188 previously non-publicly available cruise data sets in the Arctic Mediterranean Seas, Atlantic and Southern Ocean have been retrieved and merged into a new database: CARINA (CARbon dioxide IN the Atlantic Ocean). The data have gone through rigorous quality control procedures to assure the highest possible quality and consistency. The data for the pertinent parameters in the CARINA database were objectively examined in order to quantify systematic differences in the reported values, i.e. secondary quality control. Systematic biases found in the data have been corrected in the threemore » data products: merged data files with measured, calculated and interpolated data for each of the three CARINA regions, i.e. the Arctic Mediterranean Seas, the Atlantic and the Southern Ocean. These products have been corrected to be internally consistent. Ninety-eight of the cruises in the CARINA database were conducted in the Atlantic Ocean, defined here as the region south of the Greenland-Iceland-Scotland Ridge and north of about 30 S. Here we present an overview of the Atlantic Ocean synthesis of the CARINA data and the adjustments that were applied to the data product. We also report the details of the secondary QC (Quality Control) for salinity for this data set. Procedures of quality control including crossover analysis between stations and inversion analysis of all crossover data are briefly described. Adjustments to salinity measurements were applied to the data from 10 cruises in the Atlantic Ocean region. Based on our analysis we estimate the internal consistency of the CARINA-ATL salinity data to be 4.1 ppm. With these adjustments the CARINA data products are consistent both internally was well as with GLODAP data, an oceanographic data set based on the World Hydrographic Program in the 1990s, and is now suitable for accurate assessments of, for example, oceanic carbon inventories and uptake rates and for model validation.« less

Speech perception comparisons using an implanted and an external microphone in existing cochlear implant users.

PubMed

Jenkins, Herman A; Uhler, Kristin

2012-01-01

To compare the speech understanding abilities of cochlear implant listeners using 2 microphone technologies, the Otologics fully implantable Carina and the Cochlear Freedom microphones. Feasibility study using direct comparison of the 2 microphones, nonrandomized and nonblinded within case studies. Tertiary referral center hospital outpatient clinic. Four subjects with greater than 1 year of unilateral listening experience with the Freedom Cochlear Implant and a CNC word score higher than 40%. A Carina microphone coupled to a percutaneous plug was implanted on the ipsilateral side of the cochlear implant. Two months were allowed for healing before connecting to the Carina microphone. The percutaneous plug was connected to a body worn external processor with output leads inserted into the auxiliary port of the Freedom processor. Subjects were instructed to use each of the 2 microphones for half of their daily implant use. Aided pure tone thresholds, consonant-nucleus-consonant (CNC), Bamford-Kowel-Bench Speech in Noise test (BKN-SIN), and Abbreviated Profile of Hearing Aid Benefit. All subjects had sound perceptions using both microphones. The loudness and quality of the sound was judged to be poorer with the Carina in the first 2 subjects. The latter 2 demonstrated essential equivalence in the second two listeners, with the exception of the Abbreviated Profile of Hearing Aid Benefit reporting greater percentage of problems for the Carina in the background noise situation for subject 0011-003PP. CNC word scores were better with the Freedom than the Carina in all 4 subjects. The latter 2 showed improved speech perception abilities with the Carina, compared with the first 2. The BKB-SIN showed consistently better results with the Freedom in noise. Early observations indicate that it is potentially feasible to use the fully implanted Carina microphone with the Freedom Cochlear Implant. The authors would anticipate that outcomes would improve as more knowledge is gained in signal processing and with the fabrication of an integrated device.

Atlantic Ocean CARINA data: overview and salinity adjustments

NASA Astrophysics Data System (ADS)

Tanhua, T.; Steinfeldt, R.; Key, R. M.; Brown, P.; Gruber, N.; Wanninkhof, R.; Perez, F.; Körtzinger, A.; Velo, A.; Schuster, U.; van Heuven, S.; Bullister, J. L.; Stendardo, I.; Hoppema, M.; Olsen, A.; Kozyr, A.; Pierrot, D.; Schirnick, C.; Wallace, D. W. R.

2009-08-01

Water column data of carbon and carbon-relevant hydrographic and hydrochemical parameters from 188 previously non-publicly available cruise data sets in the Arctic, Atlantic and Southern Ocean have been retrieved and merged into a new database: CARINA (CARbon IN the Atlantic). The data have gone through rigorous quality control procedures to assure the highest possible quality and consistency. The data for the pertinent parameters in the CARINA database were objectively examined in order to quantify systematic differences in the reported values, i.e. secondary quality control. Systematic biases found in the data have been corrected in the data products, i.e. three merged data files with measured, calculated and interpolated data for each of the three CARINA regions, i.e. Arctic, Atlantic and Southern Ocean. Ninety-eight of the cruises in the CARINA database were conducted in the Atlantic Ocean, defined here as the region south of the Greenland-Iceland-Scotland Ridge and north of about 30° S. Here we present an overview of the Atlantic Ocean synthesis of the CARINA data and the adjustments that were applied to the data product. We also report details of the secondary QC for salinity for this data set. Procedures of quality control - including crossover analysis between stations and inversion analysis of all crossover data - are briefly described. Adjustments to salinity measurements were applied to the data from 10 cruises in the Atlantic Ocean region. Based on our analysis we estimate the internal accuracy of the CARINA-ATL salinity data to be 4.1 ppm. With these adjustments the CARINA database is consistent both internally as well as with GLODAP data, an oceanographic data set based on the World Hydrographic Program in the 1990s (Key et al., 2004), and is now suitable for accurate assessments of, for example, oceanic carbon inventories and uptake rates and for model validation.

Atlantic Ocean CARINA data: overview and salinity adjustments

NASA Astrophysics Data System (ADS)

Tanhua, T.; Steinfeldt, R.; Key, R. M.; Brown, P.; Gruber, N.; Wanninkhof, R.; Perez, F.; Körtzinger, A.; Velo, A.; Schuster, U.; van Heuven, S.; Bullister, J. L.; Stendardo, I.; Hoppema, M.; Olsen, A.; Kozyr, A.; Pierrot, D.; Schirnick, C.; Wallace, D. W. R.

2010-02-01

Water column data of carbon and carbon-relevant hydrographic and hydrochemical parameters from 188 previously non-publicly available cruise data sets in the Arctic Mediterranean Seas, Atlantic and Southern Ocean have been retrieved and merged into a new database: CARINA (CARbon dioxide IN the Atlantic Ocean). The data have gone through rigorous quality control procedures to assure the highest possible quality and consistency. The data for the pertinent parameters in the CARINA database were objectively examined in order to quantify systematic differences in the reported values, i.e. secondary quality control. Systematic biases found in the data have been corrected in the three data products: merged data files with measured, calculated and interpolated data for each of the three CARINA regions, i.e. the Arctic Mediterranean Seas, the Atlantic and the Southern Ocean. These products have been corrected to be internally consistent. Ninety-eight of the cruises in the CARINA database were conducted in the Atlantic Ocean, defined here as the region south of the Greenland-Iceland-Scotland Ridge and north of about 30° S. Here we present an overview of the Atlantic Ocean synthesis of the CARINA data and the adjustments that were applied to the data product. We also report the details of the secondary QC (Quality Control) for salinity for this data set. Procedures of quality control - including crossover analysis between stations and inversion analysis of all crossover data - are briefly described. Adjustments to salinity measurements were applied to the data from 10 cruises in the Atlantic Ocean region. Based on our analysis we estimate the internal consistency of the CARINA-ATL salinity data to be 4.1 ppm. With these adjustments the CARINA data products are consistent both internally as well as with GLODAP data, an oceanographic data set based on the World Hydrographic Program in the 1990s, and is now suitable for accurate assessments of, for example, oceanic carbon inventories and uptake rates and for model validation.

A Full Panel of Twins

NASA Image and Video Library

2016-01-06

Researchers found likely twins of the giant, erupting star Eta Carinae by comparing infrared images from NASA Spitzer Space Telescope (top) and NASA Hubble Space Telescope (bottom). Astronomers cannot yet explain what caused the titanic eruption of star Eta Carinae in the 1840s. The discovery of likely Eta Carinae "twins" in other galaxies will help scientists better understand this brief phase in the life of a massive star. http://photojournal.jpl.nasa.gov/catalog/PIA20018

An investigation of the Carina Nebula

NASA Astrophysics Data System (ADS)

Brooks, Kate J.

2000-10-01

It is well known that the radiation fields and stellar winds of massive stars can drastically affect the physical conditions, structure and chemistry of the giant molecular cloud (GMC) from which they formed. It is also thought that massive stars are at least partly responsible for triggering further star formation within a GMC. The details of this interaction, however, are not well understood and additional detailed study of massive star-forming regions is needed. This study has focused on a multi-wavelength investigation of the Carina Nebula. This is a spectacular massive star-forming region that contains two of the most massive star clusters in our galaxy, Trumpler 14 and Trumpler 16, and one of the most massive stars known -- η Car. The goal of this study has been to obtain information on the molecular gas, ionized gas and photodissociation regions (PDRs) from a collection of instruments which have the highest angular resolution and sensitivity available to date. The Mopra Telescope and the Swedish-ESO Submillimeter Telescope (SEST) were used to obtain a series of molecular line observations of the GMC between 150 and 230 GHz. Observations of H110α recombination-line emission at 4.874 GHz and the related continuum emission were obtained with the Australia Telescope Compact Array and used to study the ionized gas associated with the two HII regions, Car I and Car II. H2 1--0 S(1) (2.12 microns) and Brγ (2.16 microns) observations using the University of New South Wales Infrared Fabry-Perot (UNSWIRF) and 3.29 micron narrow-band observations obtained with the SPIREX/Abu thermal infrared camera were used to study the PDRs on the surface of molecular clumps in the Keyhole region, a dark optical feature in the vicinity of η Car. The results of these observations provide detailed information on the excitation conditions, kinematics and morphology of regions within the HII region/molecular cloud complex of the Carina Nebula. In addition, the results confirm that the Carina Nebula is one of the most extreme and complex cases of massive stars interacting with their environment and show that there is still a wealth of information to be gained from future studies of this region. %% If you have your thesis on the web, please provide the web address here Copies currently available at: http://www.atnf.csiro.au/people/kbrooks/html/publications.html

An Evaluation of Two Internal Surrogates for Determining the Three-Dimensional Position of Peripheral Lung Tumors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Spoelstra, Femke; Soernsen de Koste, John R. van; Vincent, Andrew

2009-06-01

Purpose: Both carina and diaphragm positions have been used as surrogates during respiratory-gated radiotherapy. We studied the correlation of both surrogates with three-dimensional (3D) tumor position. Methods and Materials: A total of 59 repeat artifact-free four-dimensional (4D) computed tomography (CT) scans, acquired during uncoached breathing, were identified in 23 patients with Stage I lung cancer. Repeat scans were co-registered to the initial 4D CT scan, and tumor, carina, and ipsilateral diaphragm were manually contoured in all phases of each 4D CT data set. Correlation between positions of carina and diaphragm with 3D tumor position was studied by use of log-likelihoodmore » ratio statistics. Models to predict 3D tumor position from internal surrogates at end inspiration (EI) and end expiration (EE) were developed, and model accuracy was tested by calculating SDs of differences between predicted and actual tumor positions. Results: Motion of both the carina and diaphragm significantly correlated with tumor motion, but log-likelihood ratios indicated that the carina was more predictive for tumor position. When craniocaudal tumor position was predicted by use of craniocaudal carina positions, the SDs of the differences between the predicted and observed positions were 2.2 mm and 2.4 mm at EI and EE, respectively. The corresponding SDs derived with the diaphragm positions were 3.7 mm and 3.9 mm at EI and EE, respectively. Prediction errors in the other directions were comparable. Prediction accuracy was similar at EI and EE. Conclusions: The carina is a better surrogate of 3D tumor position than diaphragm position. Because residual prediction errors were observed in this analysis, additional studies will be performed using audio-coached scans.« less

Interfraction Displacement of Primary Tumor and Involved Lymph Nodes Relative to Anatomic Landmarks in Image Guided Radiation Therapy of Locally Advanced Lung Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jan, Nuzhat; Balik, Salim; Hugo, Geoffrey D.

Purpose: To analyze primary tumor (PT) and lymph node (LN) position changes relative to each other and relative to anatomic landmarks during conventionally fractionated radiation therapy for patients with locally advanced lung cancer. Methods and Materials: In 12 patients with locally advanced non-small cell lung cancer PT, LN, carina, and 1 thoracic vertebra were manually contoured on weekly 4-dimensional fan-beam CT scans. Systematic and random interfraction displacements of all contoured structures were identified in the 3 cardinal directions, and resulting setup margins were calculated. Time trends and the effect of volume changes on displacements were analyzed. Results: Three-dimensional displacement vectorsmore » and systematic/random interfraction displacements were smaller for carina than for vertebra both for PT and LN. For PT, mean (SD) 3-dimensional displacement vectors with carina-based alignment were 7 (4) mm versus 9 (5) mm with bony anatomy (P<.0001). For LN, smaller displacements were found with carina- (5 [3] mm, P<.0001) and vertebra-based (6 [3] mm, P=.002) alignment compared with using PT for setup (8 [5] mm). Primary tumor and LN displacements relative to bone and carina were independent (P>.05). Displacements between PT and bone (P=.04) and between PT and LN (P=.01) were significantly correlated with PT volume regression. Displacements between LN and carina were correlated with LN volume change (P=.03). Conclusions: Carina-based setup results in a more reproducible PT and LN alignment than bony anatomy setup. Considering the independence of PT and LN displacement and the impact of volume regression on displacements over time, repeated CT imaging even with PT-based alignment is recommended in locally advanced disease.« less

Stellar populations in the Carina region. The Galactic plane at l = 291°

NASA Astrophysics Data System (ADS)

Molina-Lera, J. A.; Baume, G.; Gamen, R.; Costa, E.; Carraro, G.

2016-08-01

Context. Previous studies of the Carina region have revealed its complexity and richness as well as a significant number of early-type stars. However, in many cases, these studies only concentrated on the central region (Trumpler 14/16) or were not homogeneous. This latter aspect, in particular, is crucial because very different ages and distances for key clusters have been claimed in recent years. Aims: The aim of this work is to study in detail an area of the Galactic plane in Carina, eastward η Carina. We analyze the properties of different stellar populations and focus on a sample of open clusters and their population of young stellar objects and highly reddened early stars. We also studied the stellar mass distribution in these clusters and the possible scenario of their formation. Finally, we outline the Galactic spiral structure in this direction. Methods: We obtained deep and homogeneous photometric data (UBVIKC) for six young open clusters: NGC 3752, Trumpler 18, NGC 3590, Hogg 10, 11, and 12, located in Carina at l ~ 291°, and their adjacent stellar fields, which we complemented with spectroscopic observations of a few selected targets. We also culled additional information from the literature, which includes stellar spectral classifications and near-infrared photometry from 2MASS. We finally developed a numerical code that allowed us to perform a homogeneous and systematic analysis of the data. Our results provide more reliable estimates of distances, color excesses, masses, and ages of the stellar populations in this direction. Results: We estimate the basic parameters of the studied clusters and find that they identify two overdensities of young stellar populations located at about 1.8 kpc and 2.8 kpc, with EB - V ~ 0.1 - 0.6. We find evidence of pre-main-sequence populations inside them, with an apparent coeval stellar formation in the most conspicuous clusters. We also discuss apparent age and distance gradients in the direction NW-SE. We study the mass distributions of the covered clusters and several others in the region (which we took form the literature). They consistently show a canonical IMF slope (the Salpeter one). We discover and characterise an abnormally reddened massive stellar population, scattered between 6.6 and 11 kpc. Spectroscopic observations of ten stars of this latter population show that all selected targets were massive OB stars. Their location is consistent with the position of the Carina-Sagittarius spiral arm. The catalogue is 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/592/A149

All Pillars Point to Eta

NASA Technical Reports Server (NTRS)

2005-01-01

[figure removed for brevity, see original site] [figure removed for brevity, see original site] Eta Carinae Starforming RegionSimulated Infrared View of Comet Tempel 1 (artist's concept)

These false-color image taken by NASA's Spitzer Space Telescope shows the 'South Pillar' region of the star-forming region called the Carina Nebula. Like cracking open a watermelon and finding its seeds, the infrared telescope 'busted open' this murky cloud to reveal star embryos (yellow or white) tucked inside finger-like pillars of thick dust (pink). Hot gases are green and foreground stars are blue. Not all of the newfound star embryos can be easily spotted.

Though the nebula's most famous and massive star, Eta Carinae, is too bright to be observed by infrared telescopes, the downward-streaming rays hint at its presence above the picture frame. Ultraviolet radiation and stellar winds from Eta Carinae and its siblings have shredded the cloud to pieces, leaving a mess of tendrils and pillars. This shredding process triggered the birth of the new stars uncovered by Spitzer.

The inset visible-light picture (figure 2) of the Carina Nebula shows quite a different view. Dust pillars are fewer and appear dark because the dust is soaking up visible light. Spitzer's infrared detectors cut through this dust, allowing it to see the heat from warm, embedded star embryos, as well as deeper, more buried pillars. The visible-light picture is from the National Optical Astronomy Observatory.

Eta Carina is a behemoth of a star, with more than 100 times the mass of our Sun. It is so massive that it can barely hold itself together. Over the years, it has brightened and faded as material has shot away from its surface. Some astronomers think Eta Carinae might die in a supernova blast within our lifetime.

Eta Carina's home, the Carina Nebula, is located in the southern portion of our Milky Way galaxy, 10,000 light-years from Earth. This colossal cloud of gas and dust stretches across 200 light-years of space. Though it is dominated by Eta Carinae, it also houses the star's slightly less massive siblings, in addition to the younger generations of stars.

This image was taken by the infrared array camera on Spitzer. It is a three-color composite of invisible light, showing emissions from wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange), and 8.0 microns (red).

The movie begins with a visible-light picture of the southern region of our Milky Way galaxy then slowly zooms into the area imaged by Spitzer.

CARINA Satellite Mission to Investigate the Upper Atmosphere below the F-Layer Ionosphere

NASA Astrophysics Data System (ADS)

Siefring, C. L.; Bernhardt, P. A.; Briczinski, S. J., Jr.; Huba, J.; Montgomery, J. A., Jr.

2017-12-01

A new satellite design permits broad science measurements from the ocean to the ionosphere by flying below the F-Layer. The satellite called CARINA for Coastal-Ocean, Assimilation, Radio, Ionosphere, Neutral-Drag, and Atmospherics. The unique system capabilities are long duration orbits below the ionosphere and a HF receiver to measure broadband signals. The CARINA science products include recording the ocean surface properties, data for assimilation into global ionosphere models, radio wave propagation measurements, in-situ observations of ionospheric structures, validating neutral drag models and theory, and broadband atmospheric lightning characterization. CARINA will also measure nonlinear wave-generation using ionospheric modification sites in Alaska, Norway, Puerto Rico, and Russia and collaborate with geophysics HF radars (such as Super-DARN) for system calibration. CARINA is a linear 6-U CubeSat with a long antenna extended in the wake direction. The CARINA science mission is supported by three instruments. First, the Electric Field Instrument (EFI) is a radio receiver covering the 2 to 18 MHz range. The receiver can capture both narrow and wide bandwidths for up to 10 minutes. EFI is designed to provide HF signal strength and phase, radar Doppler shift and group delay, and electron plasma density from photoelectron excited plasma waves. Second a Ram Langmuir Probe (RLP) measures high-resolution ion currents at a 10 kHz rate. These measurements yield electron and ion density at the spacecraft. Finally, the Orbiting GPS Receiver (OGR) provides dual frequency GPS position with ionosphere correction. OGR also measures total electron content above the spacecraft and L-Band scintillations. CARINA will be the lowest satellite in orbit at 250 km altitude, <0.01 eccentricity, and up to 4-month lifetime. The design supports unique capabilities with broad applications to the geosciences. Remote sensing of the ocean will sample the HF signals scattered from the rough sea surface to measure the wave height spectrum over large areas. CARINA will provide an enhanced understanding of HF system limiting phenomena such as travelling ionospheric disturbances, field aligned irregularities, sporadic-E and bottomside ionosphere structures.This work supported by the Naval Research Laboratory Base Program.

X-ray superbubbles

NASA Technical Reports Server (NTRS)

Cash, W.

1983-01-01

Four regions of the galaxy, the Cygnus Superbubble, the Eta Carina complex, the Orion/Eridanus complex, and the Gum Nebula, are discussed as examples of collective effects in the interstellar medium. All four regions share certain features, indicating a common structure. The selection effects which determine the observable X-ray properties of the superbubbles are discussed, and it is demonstrated that only a very few more in our Galaxy can be detected in X rays. X-ray observation of extragalactic superbubbles is shown to be possible but requires the capabilities of a large, high quality, AXAF class observatory.

Is the Ejecta of ETA Carinae Overabundant or Overexcited

NASA Technical Reports Server (NTRS)

Gull, Theodore; Davidson, Kris; Johansson, Sveneric; Damineli, Augusto; Ishibashi, Kaxunori; Corcoran, Michael; Hartman, Henrick; Viera, Gladys; Nielsen, Krister

2003-01-01

The ejecta of Eta Carinae, revealed by HST/STIS, are in a large range of physical conditions. As Eta Carinae undergoes a 5.52 period, changes occur in nebular emission and nebular absorption. "Warm" neutral regions, partially ionized regions, and fully ionized regions undergo significant changes. Over 2000 emission lines, most of Fe-like elements, have been indentified in the Weigelt blobs B and D. Over 500 emission lines have been indentified in the Strontium Filament. An ionized Little Homunculus is nestled within the neutral-shelled Homunculus. In line of sight, over 500 nebular absorption lines have been identified with up to twenty velocity components. STIS is following changes in many nebular emission and absorption lines as Eta Carinae approaches the minimum, predicted to be in June/July 2003, during the General Assembly. Coordinated observations with HST, CHANDRA, RXTE, FUSE, UVES/VLT, Gemini and other observatories are following this minimum.

Massive stars near Eta Carinae - The stellar content of TR 14 and TR 16

NASA Astrophysics Data System (ADS)

Massey, Philip; Johnson, Jennifer

1993-03-01

The stellar content of the region around the star Eta Carinae, including the two Galactic OB clusters Tr 14 and Tr 16, are investigated using CCD photometry and spectroscopy. A physical H-R diagram is constructed which shows that several stars are located above the 85-solar mass track, as well as that the location of Eta Carinae is consistent with the interpretation that it is a very massive star undergoing a normal evolutionary stage. The W-R star which is present in this region is lower in luminosity than expected. The initial mass function derived, which is similar to two other young Galactic clusters studied, has a slope flatter than some regions in the Magellanic Clouds that are also rich in massive stars. The most luminous and massive stars near Eta Carinae are not significantly more than the most luminous and massive stars found in the Magellanic Clouds.

Brightness Variations in the Central Star of Eta Carinae From 1998 to the Present

NASA Technical Reports Server (NTRS)

Martin, J. C.; Koppelman, M. D.

2004-01-01

Recently, Eta Carinae has varied suprisingly in brightness combining a long term brightening trend with a 5.5-year cycle and unpredictable sporadic jumps. Only the Hubble Space Telescope had been able to provide reliable photometry of the central star resolved separately from its bright ejecta. We present data from the Hubble Space Telescope Space Telescope Imaging Spectrograph (STIS) and the Advanced Camera for Surveys High Resolution Camera (ACS/HRC) which chronicle the dramatic brightening of the central star of Eta Carinae from the 1998 "event" through 2000 and show that is has continued to slowly brighten. More frequent photometry during its recent "event" and a continued rise afterward. These data are compared to the more long term data compiled by the American Association of Variable Star Observers (AAVSO) which also shows substantial brightening between events and other intervening fluctuations in the brightness of Eta Carinae at visual wavelengths.

Eta Carinae: Viewed from Multiple Vantage Points

NASA Technical Reports Server (NTRS)

Gull, Theodore

2007-01-01

The central source of Eta Carinae and its ejecta is a massive binary system buried within a massive interacting wind structure which envelops the two stars. However the hot, less massive companion blows a small cavity in the very massive primary wind, plus ionizes a portion of the massive wind just beyond the wind-wind boundary. We gain insight on this complex structure by examining the spatially-resolved Space Telescope Imaging Spectrograph (STIS) spectra of the central source (0.1") with the wind structure which extends out to nearly an arcsecond (2300AU) and the wind-blown boundaries, plus the ejecta of the Little Homunculus. Moreover, the spatially resolved Very Large Telescope/UltraViolet Echelle Spectrograph (VLT/UVES) stellar spectrum (one arcsecond) and spatially sampled spectra across the foreground lobe of the Homunculus provide us vantage points from different angles relative to line of sight. Examples of wind line profiles of Fe II, and the.highly excited [Fe III], [Ne III], [Ar III] and [S III)], plus other lines will be presented.

Complexity on Small Scales. III. Iron and α Element Abundances in the Carina Dwarf Spheroidal Galaxy

NASA Astrophysics Data System (ADS)

Koch, Andreas; Grebel, Eva K.; Gilmore, Gerard F.; Wyse, Rosemary F. G.; Kleyna, Jan T.; Harbeck, Daniel R.; Wilkinson, Mark I.; Wyn Evans, N.

2008-04-01

We have obtained high-resolution spectroscopy of ten red giants in the Carina dwarf spheroidal (dSph) galaxy with the ultraviolet and visual echelle spectrograph at the European Southern Observatory Very Large Telescope in order to study the detailed chemical evolution of this Galactic satellite. Here we present the abundances of O, Na, Mg, Si, Ca, Ti, and Fe. By comparison of the derived iron abundances [Fe/H] with metallicities based on the well-established calcium triplet (CaT) calibration, [Fe/H]CaT, we show that the empirical CaT technique yields good agreement with the high-resolution data for [Fe/H] gsim 2 dex, but tends to deviate from these data at lower metallicities. With [Fe/H] ~ 1.7 dex the mean iron abundance of our targets is fully consistent with the peak metallicity of Carina as derived from medium-resolution spectroscopy and previous photometric studies, all calibrated onto iron via Galactic globular cluster scales. We identify two metal-poor stars with iron abundances of 2.72 and 2.50 dex. These stars are found to have enhanced [α/Fe] ratios similar to the elemental ratios of stars in the Milky Way halo. In this context, it is conceivable that the moderately metal-poor halo stars may originate from an early dSph accretion event. The bulk of the Carina red giants exhibit a depletion in the [α/Fe] abundance ratios with respect to the Galactic halo at a given metallicity. One of our targets with a moderately low [Fe/H] of 1.5 dex is considerably depleted in almost all of the α-elements by ~0.5 dex compared to the solar values. Such low values of the ratio of α-elements to iron can be produced by stochastical fluctuations in terms of an incomplete mixing of single type Ia and type II supernova (SN) events into the interstellar medium. Moreover, the system's slow star-formation (SF) rate grants sufficient time for SNe I to occur. Our derived chemical element ratios are consistent with the episodic and extended SF in Carina previously derived from analyses of its color-magnitude diagram. We find a considerable star-to-star scatter in the abundance ratios. This suggests that Carina's SF history varies with position within the galaxy, with incomplete mixing. In addition, or alternatively, the SF rate is so low that the high-mass stellar initial mass function is sparsely populated, as expected on statistical grounds in low-mass star clusters, leading to true scatter in the resultant mass-integrated yields. Both ideas are consistent with slow stochastic SF in dissolving associations or star clusters, so that one may not speak prima facie of a single "SF history" at a detailed level. Based on observations collected at the European Southern Observatory at Paranal, Chile; Large Programme proposal 171.B-0520(A).

An Aboriginal Australian Record of the Great Eruption of Eta Carinae

NASA Astrophysics Data System (ADS)

Hamacher, Duane W.; Frew, David J.

2010-11-01

We present evidence that the Boorong Aboriginal people of northwestern Victoria observed the Great Eruption of Eta Carinae in the nineteenth century and incorporated this event into their oral traditions. We identify this star, as well as others not specifically identified by name, using descriptive material presented in the 1858 paper by William Edward Stanbridge in conjunction with early southern star catalogues. This identification of a transient astronomical event supports the assertion that Aboriginal oral traditions are dynamic and evolving, and not static. This is the only definitive indigenous record of Eta Carinae's outburst identified in the literature to date.

The ``Ghost Shell'': Discovery of the Forward Shock from Colliding Winds about Eta Carinae

NASA Astrophysics Data System (ADS)

Dorland, B. N.; Currie, D. G.; Kaufer, A.; Bacciotti, F.

2003-01-01

We report on the newly discovered ``Ghost Shell'' around eta Carinae. We have detected a high-velocity ( ~ - 850 km /s), spatially extended, narrow emission feature lying in front of the southeast lobe of eta Carinae's homunculus. This feature has the speed of a high-velocity shock but the spectrum of a low-velocity shock. We propose that the Ghost Shell is the forward shock between the fast stellar wind of the great eruption of 1842 and the older, slow, massive wind. This discovery is described in more detail in Currie, Dorland, & Kaufer (2002).

IR Variability During a Shell Ejection of Eta Carinae

NASA Astrophysics Data System (ADS)

Smith, Nathan

2006-02-01

Every 5.5 years, η Carinae experiences a dramatic ``spectroscopic event'' when high-excitation lines in its UV, optical, and IR spectrum disappear, and its hard X-ray and radio continuum flux crash. This periodicity has been attributed to a very eccentric binary system with a shell ejection occurring at periastron. Mid-IR images and spectra with T-ReCS are needed to measure changes in the current bolometric luminosity and to trace dust formation episodes. This will provide a direct estimate of the mass ejected. Near-IR emission lines trace related changes in the post-event wind and ionization changes in the circumstellar environment needed to test specific models for the cause of η Car's variability as it recovers from its recent ``event''. High resolution near-IR spectra with GNIRS will continue the important work of HST/STIS, investigating changes in the direct and reflected spectrum of the stellar wind, and ionization changes in the nebula. The complex kinematic structure of η Car's ejecta also holds important clues to its mass ejection history, and is essential for interpreting other data. Phoenix can provide a unique kinematic map of the complex density and time-variable ionization structure of η Car's nebula, which is our best example of the pre-explosion environment of very massive stars.

A low pre-infall mass for the Carina dwarf galaxy from disequilibrium modelling

PubMed Central

Ural, Uğur; Wilkinson, Mark I.; Read, Justin I.; Walker, Matthew G.

2015-01-01

Dark matter-only simulations of galaxy formation predict many more subhalos around a Milky Way-like galaxy than the number of observed satellites. Proposed solutions require the satellites to inhabit dark matter halos with masses 109–1010 Msun at the time they fell into the Milky Way. Here we use a modelling approach, independent of cosmological simulations, to obtain a pre-infall mass of Msun for one of the Milky Way's satellites: Carina. This determination of a low halo mass for Carina can be accommodated within the standard model only if galaxy formation becomes stochastic in halos below ∼1010 Msun. Otherwise Carina, the eighth most luminous Milky Way dwarf, would be expected to inhabit a significantly more massive halo. The implication of this is that a population of ‘dark dwarfs' should orbit the Milky Way: halos devoid of stars and yet more massive than many of their visible counterparts. PMID:26133650

A low pre-infall mass for the Carina dwarf galaxy from disequilibrium modelling.

PubMed

Ural, Uğur; Wilkinson, Mark I; Read, Justin I; Walker, Matthew G

2015-07-02

Dark matter-only simulations of galaxy formation predict many more subhalos around a Milky Way-like galaxy than the number of observed satellites. Proposed solutions require the satellites to inhabit dark matter halos with masses 10(9)-10(10 )Msun at the time they fell into the Milky Way. Here we use a modelling approach, independent of cosmological simulations, to obtain a pre-infall mass of 3.6(-2.3)(+3.8) × 10(8) Msun for one of the Milky Way's satellites: Carina. This determination of a low halo mass for Carina can be accommodated within the standard model only if galaxy formation becomes stochastic in halos below ∼10(10 )Msun. Otherwise Carina, the eighth most luminous Milky Way dwarf, would be expected to inhabit a significantly more massive halo. The implication of this is that a population of 'dark dwarfs' should orbit the Milky Way: halos devoid of stars and yet more massive than many of their visible counterparts.

Characterising the Structure of Molecular Clouds

NASA Astrophysics Data System (ADS)

Wong, Graeme Francis

The Interstellar Medium contains the building blocks of matter in our Galaxy and plays a vital role in the evolution of low mass star formation. The poorly studied molecular clouds of Lupus and Chamaeleon contain ongoing low mass star formation, and are in close proximity to our Solar System. While on the other hand the Carina molecular cloud, poorly observed in radio wavelength, is an active region of star formation and host some of the brightest stars known within our Galaxy. Using tracers like carbon monoxide, atomic neutral carbon, and ammonia, we are able to measure the temperature and density of the gas cloud. This information allows us to understand the initial conditions of the formation of low mass stars. Observations conducted with the 22-m Mopra radio telescope (located at the edge of the Warrumbungle Mountains near Coonabarabran), in the Carbon monoxide (CO) isotopologues 12 CO, 13 CO, C17O, and C18O (1-0) transitions, have mapped the Chamaeleon II cloud, an intermediate mass cloud within the Chamaeleon. Through the sub-arcminute maps, comparisons have been made to previous low resolution (2.5') maps which have been to resolve some of the dense clumps previously identified. Optical depth, column density, and excitation temperature derived from the CO maps, are consistent with previous results. A detailed comparison between identified C18O clumps have shown the different conditions occurring within the clumps, some of which contain or are located near a population of young stellar objects. The Northern region of the Carina Nebular Complex, was observed with NANTEN2, a 4-m radio telescope (located in the Chilean Atacama desert), in the 12CO (4-3) and [C I] 3P1-3P0 emission lines. Previous observations towards this region has either been at poor resolution or had limited coverage. The presented observations, strike a balance between the two; observing in sub-arcmin resolution (0.6') and with an area of 0.9° X 0.5° mapped. Excitation temperature of the 12CO (4-3) and column density of [C I] 3P1-3P0 have been derived. Discussions have been made of the complex morphology of the Northern Carina Nebular Complex region, compared to optical features, and supported the assertion of the HII region (Car I) expanding into the molecular cloud. The selected areas within the Lupus molecular clouds (regions I, III and IV) were observed with the DSS43 (also known as Tid-70m), the largest steerable single dish radio telescope (70-m) in the Southern Hemisphere located at Canberra Deep Space Communication Complex (CDSCC) near Canberra, in the ammonia transitions (1,1) and (2,2). Due to the observation modes and limited amount of time available for the Astronomical community, the targeted areas were mapped in a series of position-switching strips. Column density, kinetic and rotation temperatures were derived, which were compared and analysed to low-resolution maps towards the dense clumps. As Tid-70m had limited observing capabilities, this project has been able to improve the observation capabilities by implementing on-the-fly (OTF) mapping. With its size and unique capabilities, implementing OTF mapping will increase the efficiency of observations. Test observations were carried out towards the well known sources of Orion A, and Sagittarius A through the newly implemented OTF observing mode. Analysis and comparison of Orion A and Sagittarius A, shows consistency with the new maps produced.

A MegaCam Survey of Outer Halo Satellites. VI. The Spatially Resolved Star-formation History of the Carina Dwarf Spheroidal Galaxy

NASA Astrophysics Data System (ADS)

Santana, Felipe A.; Muñoz, Ricardo R.; de Boer, T. J. L.; Simon, Joshua D.; Geha, Marla; Côté, Patrick; Guzmán, Andrés E.; Stetson, Peter; Djorgovski, S. G.

2016-10-01

We present the spatially resolved star-formation history (SFH) of the Carina dwarf spheroidal galaxy, obtained from deep, wide-field g and r imaging and a metallicity distribution from the literature. Our photometry covers ˜2 deg2, reaching up to ˜10 times the half-light radius of Carina with a completeness higher than 50% at g ˜ 24.5, more than one magnitude fainter than the oldest turnoff. This is the first time a combination of depth and coverage of this quality has been used to derive the SFH of Carina, enabling us to trace its different populations with unprecedented accuracy. We find that Carina’s SFH consists of two episodes well separated by a star-formation temporal gap. These episodes occurred at old (\\gt 10 Gyr) and intermediate (2-8 Gyr) ages. Our measurements show that the old episode comprises the majority of the population, accounting for 54 ± 5% of the stellar mass within 1.3 times the King tidal radius, while the total stellar mass derived for Carina is 1.60+/- 0.09× {10}6 {M}⊙ , and the stellar mass-to-light ratio is 1.8 ± 0.2. The SFH derived is consistent with no recent star formation, which hints that the observed blue plume is due to blue stragglers. We conclude that the SFH of Carina evolved independently of the tidal field of the Milky Way, since the frequency and duration of its star-formation events do not correlate with its orbital parameters. This result is supported by the age-metallicity relation observed in Carina and the gradients calculated indicating that outer regions are older and more metal-poor. Based on observations obtained with the MegaCam imager on the Magellan II-Clay telescope at Las Campanas Observatory in the Atacama Region, Chile. This telescope is operated by a consortium consisting of the Carnegie Institution of Washington, Harvard University, MIT, the University of Michigan, and the University of Arizona.

hs-2007-16-e-full_jpg

NASA Image and Video Library

2010-03-01

Carina Nebula Details: The Caterpillar Credit for Hubble Image: NASA, ESA, N. Smith (University of California, Berkeley), and The Hubble Heritage Team (STScI/AURA) Credit for CTIO Image: N. Smith (University of California, Berkeley) and NOAO/AURA/NSF The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute conducts Hubble science operations. Goddard is responsible for HST project management, including mission and science operations, servicing missions, and all associated development activities. To learn more about the Hubble Space Telescope go here: www.nasa.gov/mission_pages/hubble/main/index.html

Forming Planets in the Hostile Carina Nebula

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2016-07-01

Can protoplanetary disks form and be maintained around low-mass stars in the harsh environment of a highly active, star-forming nebula? A recent study examines the Carina nebula to answer this question.Crowded ClustersStars are often born in clusters that contain both massive and low-mass stars. The most massive stars in these clusters emit far-ultraviolet and extreme-ultraviolet light that irradiates the region around them, turning the surrounding area into a hostile environment for potential planet formation.Planet formation from protoplanetary disks typically requires timescales of at least 12 million years. Could the harsh radiation from massive stars destroy the protoplanetary disks around low-mass stars by photoevaporation before planets even have a chance to form?Artists impression of a protoplanetary disk. Such disks can be photoevaporated by harsh ultraviolet light from nearby massive stars, causing the disk to be destroyed before planets have a chance to form within them. [ESO/L. Calada]Turning ALMA Toward CarinaA perfect case study for exploring hostile environments is the Carina nebula, located about 7500 lightyears away and home to nearly 100 O-type stars as well as tens of thousands of lower-mass young stars. The Carina population is ~14 Myr old: old enough to form planets within protoplanetary disks, but also old enough that photoevaporation could already have wreaked havoc on those disks.Due to the dense stellar populations in Carinas clusters, this is a difficult region to explore, but the Atacama Large Millimeter-submillimeter Array (ALMA) is up to the task. In a recent study, a team of scientists led by Adal Mesa-Delgado (Pontifical Catholic University of Chile) made use of ALMAs high spatial resolution to image four regions spaced throughout Carina, searching for protoplanetary disks.Detections and Non-DetectionsTwo evaporating gas globules in the Carina nebula, 104-593 and 105-600, that each contain a protoplanetary disk. The top panels are Hubble images of the globules; the bottom panels are ALMA images of the disks detected within them. [Mesa-Delgado et al. 2016]In searching regions outside of the densest, most luminous clusters, the team succeeded in detecting two protoplanetary disks. This region in Carina now marks the most distant massive cluster in which disks have ever been imaged! The discovered disks have radii of roughly 60 AU and masses of 30 and 50 Jupiter masses and given their ages, its entirely plausible that planets are actively forming in these disks.Equally important: Mesa-Delgado and collaborators failed to detect any indication of disks in the core of Trumpler 14, a cluster in Carina that is home to some of the most massive and luminous stars in the Galaxy. This non-detection suggests that the particularly harsh environment of Trumpler 14 is too brutal for disks within it to survive.These observations provide new clues as to where we should be looking to study planet formation: less dense regions in star-forming nebulae seem to be locations that can support giant-planet-forming disks, whereas the harsh radiation fields of especially dense subclusters seem to cause the rapid destruction of such disks.CitationA. Mesa-Delgado et al 2016 ApJ 825 L16. doi:10.3847/2041-8205/825/1/L16

Reconstructing the past outburst history of Eta Carinae from WFPC2 proper motions

NASA Astrophysics Data System (ADS)

Smith, Nathan

2016-10-01

The HST archive contains multiple epochs of WFPC2 images of the nebula around Eta Carinae taken over a 15-year timespan, although only the earliest few years of data have been analyzed and published. The fact that all these images were taken with the same instrument, with the same pixel sampling and field distortion, makes them an invaluable resource for accurately measuring the expanding ejecta. The goal of a previously accepted AR proposal was to analyze the full set of appropriate continuum-filter HST images to place precise constraints on the avereage ejection date of the Homunculus Nebula; this analysis is now complete (Smith et al 2016) and the nebula appears to have been ejected in the second half of 1847. Here we propose to continue this project by constraining the motion of the more extended and much older Outer Ejecta around Eta Carinae. Older material outside the main bipolar nebula traces previous major outbursts of the star with no recorded historical observations. We propose an ambitious reduction and analysis of the complete WFPC2 imaging dataset of Eta Car. These data can reconstruct its violent mass-loss history over the past thousand years. We have already started this by analyzing two epochs of ACS F658N images, and astonishingly, these data suggested two previous eruptions in the 13th and 15th centuries assuming ballistic motion. WFPC2 images will extend the baseline by 10 yr, and critically, more than 2 epochs allow us to measure any deceleration in the ejecta. We will also analyze Doppler shifts in ground-based spectra in order to reconstruct the 3D geometry of past mass ejection. This AR proposal will fund the final year of a PhD thesis.

Modeling the Structure and Dynamics of Dwarf Spheroidal Galaxies with Dark Matter and Tides

NASA Astrophysics Data System (ADS)

Muñoz, Ricardo R.; Majewski, Steven R.; Johnston, Kathryn V.

2008-05-01

We report the results of N-body simulations of disrupting satellites aimed at exploring whether the observed features of dSphs can be accounted for with simple, mass-follows-light (MFL) models including tidal disruption. As a test case, we focus on the Carina dwarf spheroidal (dSph), which presently is the dSph system with the most extensive data at large radius. We find that previous N-body, MFL simulations of dSphs did not sufficiently explore the parameter space of satellite mass, density, and orbital shape to find adequate matches to Galactic dSph systems, whereas with a systematic survey of parameter space we are able to find tidally disrupting, MFL satellite models that rather faithfully reproduce Carina's velocity profile, velocity dispersion profile, and projected density distribution over its entire sampled radius. The successful MFL model satellites have very eccentric orbits, currently favored by CDM models, and central velocity dispersions that still yield an accurate representation of the bound mass and observed central M/L ~ 40 of Carina, despite inflation of the velocity dispersion outside the dSph core by unbound debris. Our survey of parameter space also allows us to address a number of commonly held misperceptions of tidal disruption and its observable effects on dSph structure and dynamics. The simulations suggest that even modest tidal disruption can have a profound effect on the observed dynamics of dSph stars at large radii. Satellites that are well described by tidally disrupting MFL models could still be fully compatible with ΛCDM if, for example, they represent a later stage in the evolution of luminous subhalos.

VizieR Online Data Catalog: The populations of Carina. II. Abundances (Norris+, 2017)

NASA Astrophysics Data System (ADS)

Norris, J. E.; Yong, D.; Venn, K. A.; Gilmore, G.; Casagrande, L.; Dotter, A.

2017-08-01

Our selection of objects is based on unpublished CCD V, I observations that we have made of the Carina galaxy. High-resolution, moderate-S/N spectra were obtained of 39 Carina red giants, during 2007 November-2008 March, with the FLAMES system at the 8.2m Kueyen (VLT/UT2) telescope at Cerro Paranal. The spectra cover the wavelength ranges 4800-5750Å and 5840-6800Å. The resolving power was R=47000. Photometry has been obtained from several sources: P. B. Stetson provided us with homogenized BVI, M. J. Irwin furnished JHK from ESO VISTA survey photometry, and M. Gullieuszik supplied BVIJHKs. (12 data files).

Peculiar macrophagous adaptations in a new Cretaceous pliosaurid

PubMed Central

Arkhangelsky, Maxim S.; Stenshin, Ilya M.; Uspensky, Gleb N.; Zverkov, Nikolay G.

2015-01-01

During the Middle and Late Jurassic, pliosaurid plesiosaurs evolved gigantic body size and a series of craniodental adaptations that have been linked to the occupation of an apex predator niche. Cretaceous pliosaurids (i.e. Brachaucheninae) depart from this morphology, being slightly smaller and lacking the macrophagous adaptations seen in earlier forms. However, the fossil record of Early Cretaceous pliosaurids is poor, concealing the evolution and ecological diversity of the group. Here, we report a new pliosaurid from the Late Hauterivian (Early Cretaceous) of Russia. Phylogenetic analyses using reduced consensus methods recover it as the basalmost brachauchenine. This pliosaurid is smaller than other derived pliosaurids, has tooth alveoli clustered in pairs and possesses trihedral teeth with complex serrated carinae. Maximum-likelihood ancestral state reconstruction suggests early brachauchenines retained trihedral teeth from their ancestors, but modified this feature in a unique way, convergent with macrophagous archosaurs or sphenacodontoids. Our findings indicate that Early Cretaceous marine reptile teeth with serrated carinae cannot be unequivocally assigned to metriorhynchoid crocodylomorphs. Furthermore, they extend the known diversity of dental adaptations seen in Sauropterygia, the longest lived clade of marine tetrapods. PMID:27019740

Signs of η Carinae Outburst in Artifacts of Ancient Bolivia

NASA Astrophysics Data System (ADS)

Teames, Sallie

Recent HST and X-ray photos of η Carinae reveal the bipolar gaseous lobes--the Homunculus Nebula--created by the star's "Great Eruption of 1843." From debris gases on the outskirts beyond the two gaseous lobes, astrophysicists surmise an earlier outburst. The 1999 Chandra X-ray photo of the horseshoe-shaped outer nebula surrounding the bipolar lobes indicates an earlier outburst occurring over a thousand years ago. Because η Carinae is so far south, it is entirely possible that the outburst would not have been seen by the Chinese and other observers in the northern hemisphere. Researchers are looking for possible recordings by early southern hemisphere observers. Pre-Incan artifacts excavated in Bolivia may provide an answer. In the script and artwork carvings on a monolith stone statue, an artifact of the Tiahuanacan culture, are signs possibly depicting the earlier outburst of η Carinae--the recordings of a star that suddenly brightened in their night sky. Two small stones from the same era and also found on the south shore of Lake Titicaca may also show depictions related to this brightening.

Biggest Star in Our Galaxy Sits within a Rugby-Ball Shaped Cocoon

NASA Astrophysics Data System (ADS)

2003-11-01

VLT Interferometer Gives Insight Into the Shape of Eta Carinae Summary Ever since 1841, when the until then inconspicuous southern star Eta Carinae underwent a spectacular outburst, astronomers have wondered what exactly is going on in this unstable giant star. However, due to its considerable distance - 7,500 light-years - details of the star itself were beyond observation. This star is known to be surrounded by the Homunculus Nebula , two mushroom-shaped clouds ejected by the star, each of which is hundreds of times larger than our solar system. Now, for the first time, infrared interferometry with the VINCI instrument on ESO's Very Large Telescope Interferometer (VLTI) enabled an international team of astronomers [1] to zoom-in on the inner part of its stellar wind. For Roy van Boekel , leader of the team, these results indicate that " the wind of Eta Carinae turns out to be extremely elongated and the star itself is highly unstable because of its fast rotation." PR Photo 32a/03 : The Immediate Surroundings of Eta Carinae (NAOS-CONICA/YEPUN). PR Photo 32b/03 : The Highly Unstable Star Eta Carinae (Artist's Impression) A monster in the southern sky ESO PR Photo 32a/03 ESO PR Photo 32a/03 [Preview - JPEG: 549 x 400 pix - 60k [Normal - JPEG: 1098 x 800 pix - 566k] Caption : The image to the left in PR Photo 32a/03 shows the mushroom-shaped clouds, known as the Homunculus Nebula , that surround the massive star Eta Carinae (Credit: NASA/ESA HST). To the right is an image obtained with the VLT NACO adaptive-optics camera that reveals the structure of the star's immediate surroundings. The central region displays a complex morphology of luminous objects. Eta Carinae , the most luminous star known in our Galaxy, is by all standards a real monster: it is 100 times more massive than our Sun and 5 million times as luminous. This star has now entered the final stage of its life and is highly unstable. It undergoes giant outbursts from time to time; one of the most recent happened in 1841 and created the beautiful bipolar nebula known as the Homunculus Nebula (see ESO PR Photo 32a/03 ). At that time, and despite the comparatively large distance - 7,500 light-years - Eta Carinae briefly became the second brightest star in the night sky, surpassed only by Sirius. Eta Carinae is so big that, if placed in our solar system, it would extend beyond the orbit of Jupiter. This large size, though, is somewhat arbitrary. Its outer layers are continually being blown into space by radiation pressure - the impact of photons on atoms of gas. Many stars, including our Sun, lose mass because of such "stellar winds", but in the case of Eta Carinae , the resulting mass loss is enormous (about 500 Earth-masses a year) and it is difficult to define the border between the outer layers of the star and the surrounding stellar wind region. Now, VINCI and NAOS-CONICA, two infrared-sensitive instuments on ESO's Very Large Telescope (VLT) at the Paranal Observatory (Chile), have probed the shape of the stellar wind region for the first time. Looking down into the stellar wind as far as possible, the astronomers could infer some of the structure of this enigmatic object. The astronomer team [1] first used the NAOS-CONICA adaptive optics camera [2], attached to the 8.2-m VLT YEPUN telescope, to image the hazy surroundings of Eta Carinae , with a spatial resolution comparable to the size of the solar system, cf. PR Photo 32a/03 . This image shows that the central region of the Homunculus nebula is dominated by an object that is seen as a point-like light source with many luminous "blobs" in the immediate vicinity. Towards the limit In order to obtain an even sharper view, the astronomers then turned to interferometry. This technique combines two or more telescopes to achieve an angular resolution [3] equal to that of a telescope as large as the separation of the individual telescopes (cf. ESO PR 06/01 and ESO PR 23/01 ). For the study of the rather bright star Eta Carinae the full power of the 8.2-m VLT telescopes is not required. The astronomers thus used VINCI, the VLT INterferometer Commissioning Instrument [4], together with two 35-cm siderostat test telescopes that served to obtain "First Light" with the VLT Interferometer in March 2001 (see ESO PR 06/01 ). The siderostats were placed at selected positions on the VLT Observing Platform at the top of Paranal to provide different configurations and a maximum baseline of 62 meters. During several nights, the two small telescopes were pointed towards Eta Carinae and the two light beams were directed towards a common focus in the VINCI test instrument in the centrally located VLT Interferometric Laboratory. It was then possible to measure the angular size of the star (as seen in the sky) in different directions. Pushing the spatial resolution of this configuration to the limit, the astronomers succeeded in resolving the shape of the outer layer of Eta Carinae . They were able to provide spatial information on a scale of 0.005 arcsec, that is about 11 AU (1650 million km) at the distance of Eta Carinae , corresponding to the full size of the orbit of Jupiter. Scaled down to terrestial dimensions, this achievement compares to making the distinction between an egg and a billiard ball at a distance of 2,000 kilometers. A most unusual shape ESO PR Photo 32b/03 ESO PR Photo 32b/03 [Preview - JPEG: 400 x 500 pix - 28k [Normal - JPEG: 800 x 999 pix - 302k] Caption : PR Photo 32b/03 is an artist's impression of the unstable star Eta Carinae , based on the new knowledge gained from measurements with the VLT Interferometer (VLTI). The inner elongated shape is the central star, as it would be visible in the absence of the stellar wind. The larger rugby-ball shape indicates the region where the strong stellar wind becomes opaque to VINCI. The longer axis of the system is found to coincide with the direction of the bipolar outflow, both on large and small scales. The VLTI observations brought the astronomers a surprise. They indicate that the wind around Eta Carinae is amazingly elongated: one axis is one-and-a-half times longer than the other! Moreover, the longer axis is found to be aligned with the direction in which the much larger mushroom-shaped clouds (seen on less sharp images) were ejected. Spanning a scale from 10 to 20-30,000 AU, the star itself and the Homunculus Nebula are thus closely aligned in space . VINCI was able to detect the boundary where the stellar wind from Eta Carinae becomes so dense that it is no longer transparent. Apparently, this stellar wind is much stronger in the direction of the long axis than of the short axis. According to mainstream theories, stars lose most mass around their equator. This is because this is where the stellar wind gets "lifting" assistance from the centrifugal force caused by the star's rotation. However, if this were so in the case of Eta Carinae , the axis of rotation (through the star's poles) would then be perpendicular to both mushroom-shaped clouds. But it is virtually impossible that the mushroom clouds are positioned like spokes in a wheel, relative to the rotating star. The matter ejected in 1841 would then have been stretched into a ring or torus. For Roy van Boekel , " the current overall picture only makes sense if the stellar wind of Eta Carinae is elongated in the direction of its poles . This is a surprising reversal of the usual situation, where stars (and planets) are flattened at the poles due to the centrifugal force . The next supernova? Such an exotic shape for Eta Carinae-type stars was predicted by theoreticians. The main assumption is that the star itself, which is located deep inside its stellar wind, is flattened at the poles for the usual reason. However, as the polar areas of this central zone are then closer to the centre where nuclear fusion processes take place, they will be hotter. Consequently, the radiation pressure in the polar directions will be higher and the outer layers above the polar regions of the central zone will get more "puffed up" than the outer layers at the equator. Assuming this model is correct, the rotation of Eta Carinae can be calculated. It turns out that it should spin at over 90 percent of the maximum speed possible (before break-up). Eta Carinae has experienced large outbursts other than the one in 1841, most recently around 1890. Whether another outburst will happen again in the near future is unknown, but it is certain that this unstable giant star will not settle down. At the present, it is losing so much mass so rapidly that nothing will be left of it after less than 100,000 years. More likely, though, Eta Carinae will destroy itself long before that in a supernova blast that could possibly become visible in the daytime sky with the naked eye. This may happen "soon" on the astronomical time-scale, perhaps already within the next 10-20,000 years. More information The research presented in this Press Release was published as a Letter to the Editor in the European astronomy journal Astronomy and Astrophysics ("Direct measurement of the size and shape of the present-day stellar wind of Eta Carinae", by Roy van Boekel et al. , A&A 410, L37-L40). Notes [1]: The team is composed of Roy van Boekel (ESO and the University of Amsterdam, The Netherlands), Pierre Kervella, Francesco Paresce and Markus Schöller (ESO), Wolfgang Brandner , Tom Herbst and Rainer Lenzen (MPI for Astronomy, Heidelberg, Germany), Alex de Koter and Rens Waters (University of Amsterdam, The Netherlands), John Hillier (University of Pittsburgh, USA), and Anne-Marie Lagrange (Observatoire de Grenoble, France). [2]: The Nasmyth Adaptive Optics System (NAOS) has been developed by a French Consortium including the Office National d'Etudes et de Recherches Aérospatiales (ONERA), the Laboratoire d'Astrophysique de Grenoble (LAOG) and Observatoire de Paris (DESPA and DASGAL), in collaboration with ESO. The CONICA Near-Infrared CAmera has been developed by the Max-Planck-Institut für Astronomie (MPIA, Heidelberg) and the Max-Planck-Institut für Extraterrestrische Physik (MPE, Garching), with an extensive ESO collaboration. See ESO PR 25/01. [3]: The achievable angular resolution is inversely proportional to the aperture of a telescope for single telescope observation, and to the length of the "baseline" between two telescopes for an interferometric observation. However, interferometric observations with two telescopes will improve the resolution only in the direction parallel to this baseline, while the resolution in the perpendicular direction will remain that of a single telescope. Nevertheless, the use of other telescope pairs with different baseline orientations "adds" resolution in other directions. [4]: The VINCI instrument was built under ESO contract at the Observatoire de Paris (France) and the camera in this instrument was delivered by the Max-Planck-Institute für Extraterrestrische Physik (Garching, Germany). The IR detector and the IRACE detector electronics were supplied by ESO.

NASA Explores the Carina Nebula by Touch

NASA Image and Video Library

2017-12-08

Release Date March 30, 2010 The raised arcs, lines, dots, and other markings in this 17-by-11-inch Hubble Space Telescope image of the Carina Nebula highlight important features in the giant gas cloud, allowing visually impaired people to feel what they cannot see and form a picture of the nebula in their minds. To read more abou this image go to: www.nasa.gov/mission_pages/hubble/science/carina-touch.html Credit: NASA, ESA, and M. Mutchler (STScI/AURA) and N. Grice (You Can Do Astronomy LLC) NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Reference Values for Central Airway Dimensions on CT Images of Children and Adolescents.

PubMed

Kuo, Wieying; Ciet, Pierluigi; Andrinopoulou, Eleni-Rosalina; Chen, Yong; Pullens, Bas; Garcia-Peña, Pilar; Fleck, Robert J; Paoletti, Matteo; McCartin, Michael; Vermeulen, Francois; Morana, Giovanni; Lee, Edward Y; Tiddens, Harm A W M

2018-02-01

The purpose of this study was to acquire normative data on central airway dimensions on chest CT scans in the pediatric population. Chest CT findings reported as normal by a radiologist were collected retrospectively at 10 international centers. An experienced and independent thoracic radiologist reevaluated all CT scans for image quality and for normal findings. Semiautomated image analysis was performed to measure dimensions of the trachea and right and left main bronchi at inspiration. Intrathoracic tracheal length was measured from carina to thorax inlet. Cross-sectional area and short and long axes were measured perpendicular to the longitudinal airway axis starting from the carina every centimeter upward for the trachea and every 0.5 cm downward for the main bronchi. The effects on airway diameters of age, sex, intrathoracic tracheal length, and distance from the carina were investigated by use of mixed-effects models analysis. Among 1160 CT scans collected, 388 were evaluated as normal by the independent radiologist with sufficient image quality and adequate inspiratory volume level. Central airways were successfully semiautomatically analyzed in 294 of 388 CT studies. Age, sex, intrathoracic tracheal length, and distance from carina were all significant predictors in the models for tracheal and right and left main bronchial diameters (p < 0.001). The central airway dimensions increased with age up to 20 years, and dimensions were larger in male than in female adolescents. Normative data were determined for the central airways of children and adolescents. Central airway dimensions depended on distance from the carina and on intrathoracic tracheal length.

Discovery of Penicillidmus in the Bismarck Archipelago, Papua New Guinea, with description of a new species from Lavongai (New Hanover) Island (Coleoptera, Staphylinidae, Scydmaeninae).

PubMed

Jałoszyński, Paweł

2017-04-18

Penicillidmus Jałoszyński, 2014 was established to accommodate two Australian species of Glandulariini. Penicillidmus masseyensis Jałoszyński, 2014 and P. unicolor Jałoszyński, 2014 are known to occur in Cape York, northern Queensland. With the adult body length ranging from 0.83 to 0.86 mm, these species are among the smallest Australian scydmaenines. Another, yet undescribed species represented by a female, is also known to occur within the same area (Jałoszyński 2014). Penicillidmus resembles similarly small adults of Microscydmus Saulcy & Croissandeau, 1893, but can be easily distinguished on the basis of remarkable cephalic and prothoracic structures. Unlike any other Glandulariini, species of Penicillidmus have a unique system of carinae on the flattened ventral surface of the head, located posterior and lateral to the mouthparts. The submental carina runs along the anterior margin of the submentum and extends laterally along cardinal bases; the longitudinal lateral carina runs at each side of mouthparts and extends from the anterior margin of the head capsule to the 'neck' region; and the transverse carina connects each longitudinal lateral carina with the mesoventral margin of the compound eye. Additionally, the apex of the terminal maxillary palpomere is thickened, and the pronotum bears a thick posterolateral brush of several long setae. The latter character is most easily observable; under a stereomicroscope the brush appears as a solid rod-like structure, individual setae can be recognized in transparent mounts under a compound microscope.

4-D Imaging and Modeling of Eta Carinae's Inner Fossil Wind Structures

NASA Astrophysics Data System (ADS)

Madura, Thomas I.; Gull, Theodore; Teodoro, Mairan; Clementel, Nicola; Corcoran, Michael; Damineli, Augusto; Groh, Jose; Hamaguchi, Kenji; Hillier, D. John; Moffat, Anthony; Richardson, Noel; Weigelt, Gerd; Lindler, Don; Feggans, Keith

2017-11-01

Eta Carinae is the most massive active binary within 10,000 light-years and is famous for the largest non-terminal stellar explosion ever recorded. Observations reveal that the supermassive (~120 M⊙) binary, consisting of an LBV and either a WR or extreme O star, undergoes dramatic changes every 5.54 years due to the stars' very eccentric orbits (e ~ 0.9). Many of these changes are caused by a dynamic wind-wind collision region (WWCR) between the stars, plus expanding fossil WWCRs formed one, two, and three 5.54-year cycles ago. The fossil WWCRs can be spatially and spectrally resolved by the Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS). Starting in June 2009, we used the HST/STIS to spatially map Eta Carinae's fossil WWCRs across one full orbit, following temporal changes in several forbidden emission lines (e.g. [Feiii] 4659 Å, [Feii] 4815 Å), creating detailed data cubes at multiple epochs. Multiple wind structures were imaged, revealing details about the binary's orbital motion, photoionization properties, and recent (~5 - 15 year) mass-loss history. These observations allow us to test 3-D hydrodynamical and radiative-transfer models of the interacting winds. Our observations and models strongly suggest that the wind and photoionization properties of Eta Carinae's binary have not changed substantially over the past several orbital cycles. They also provide a baseline for following future changes in Eta Carinae, essential for understanding the late-stage evolution of this nearby supernova progenitor. For more details, see Gull et al. (2016) and references therein.

Overview of the Nordic Seas CARINA data and salinity measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olsen, Are; Key, Robert; Jeansson, Emil

2009-01-01

Water column data of carbon and carbon relevant hydrographic and hydrochemical parameters from 188 previously non-publicly available cruises in the Arctic, Atlantic, and Southern Ocean have been retrieved and merged into a new database: CARINA (CARbon IN the Atlantic). The data have been subject to rigorous quality control (QC) in order to ensure highest possible quality and consistency. The data for most of the parameters included were examined in order to quantify systematic biases in the reported values, i.e. secondary quality control. Significant biases have been corrected for in the data products, i.e. the three merged files with measured, calculatedmore » and interpolated values for each of the three CARINA regions; the Arctic Mediterranean Seas (AMS), the Atlantic (ATL) and the Southern Ocean (SO).With the adjustments the CARINA database is consistent both internally as well as with GLODAP (Key et al., 2004) and is suitable for accurate assessments of, for example, oceanic carbon inventories and uptake rates and for model validation. The Arctic Mediterranean Seas include the Arctic Ocean and the Nordic Seas, and the quality control was carried out separately in these two areas. This contribution provides an overview of the CARINA data from the Nordic Seas and summaries the findings of the QC of the salinity data. One cruise had salinity data that were of questionable quality, and these have been removed from the data product. An evaluation of the consistency of the quality controlled salinity data suggests that they are consistent to at least 0.005.« less

A COMPREHENSIVE, WIDE-FIELD STUDY OF PULSATING STARS IN THE CARINA DWARF SPHEROIDAL GALAXY

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vivas, A. Katherina; Mateo, Mario, E-mail: akvivas@cida.ve, E-mail: mmateo@umich.edu

2013-12-01

We report the detection of 388 pulsating variable stars (and some additional miscellaneous variables) in the Carina dwarf spheroidal galaxy over an area covering the full visible extent of the galaxy and extending a few times beyond its photometric (King) tidal radius along the direction of its major axis. Included in this total are 340 newly discovered dwarf Cepheids (DCs), which are mostly located ∼2.5 mag below the horizontal branch and have very short periods (<0.1 days), typical of their class and consistent with their location on the upper part of the extended main sequence of the younger populations ofmore » the galaxy. Several extra-tidal DCs were found in our survey up to a distance of ∼1° from the center of Carina. Our sample also includes RR Lyrae stars and anomalous Cepheids, some of which were found outside the galaxy's tidal radius as well. This supports past works that suggest that Carina is undergoing tidal disruption. We use the period-luminosity relationship for DCs to estimate a distance modulus of μ{sub 0} = 20.17 ± 0.10 mag, in very good agreement with the estimate from RR Lyrae stars. We find some important differences in the properties of the DCs of Carina and those in Fornax and the LMC, the only extragalactic samples of DCs currently known. These differences may reflect a metallicity spread, depth along the line of sight, and/or different evolutionary paths of the DC stars.« less

Developing a Curriculum for Remote Research Mentoring of Virginia High School Students

NASA Astrophysics Data System (ADS)

Dirienzo, William J.; Corby, J.; Beaton, R.; Barcos-Munoz, L. D.; Jones, K. M.; Pennucci, T.

2014-01-01

Graduate students at the University of Virginia (UVa) are volunteering as research advisors on astronomy projects for Virginia's science and technology high schools. Over five years, we have worked with more than a dozen students through a research class at Central Virginia Governor's School for Science and Technology in Lynchburg and two students last year at Roanoke Valley Governor's School in Roanoke to develop an astronomy research curriculum that teaches background concepts and terminology, guides students in data analysis, and prepares them to present material in poster and oral forums. Because both schools are far from UVa in Charlottesville, the program operates remotely; graduate advisors and high school students interact through "virtual" means, establishing a successful framework for meaningful remote mentoring. In the current year, four students will complete projects on astrophysical topics including megamasers and astrochemistry using data taken by the Robert C. Byrd Green Bank Telescope (GBT). Previous topics also include pulsar searches, extended green object (EGO) searches, and the X-ray properties of YSOs in the Carina complex. All four students this year will receive hands-on experience in handling GBT data. The current projects are components of larger research efforts by graduate student and professional level researchers, so that the projects contribute to high-level projects only possible with the GBT. This stands as a rare outreach program that uses the principle of “deliberative practice” to train high school students in the development of skills that are crucial to success in science. Furthermore, it provides graduate students with an opportunity to plan and advise research projects, developing a skill set that is required in more advanced academic positions. Our poster discusses the implementation of our online curriculum in two distinct class settings and highlights the students' research contributions.

Detection of the Compressed Primary Stellar Wind in eta Carinae

NASA Technical Reports Server (NTRS)

Teodoro, Mairan Macedo; Madura, Thomas I.; Gull, Theodore R.; Corcoran, Michael F.; Hamaguchi, K.

2014-01-01

A series of three HST/STIS spectroscopic mappings, spaced approximately one year apart, reveal three partial arcs in [Fe II] and [Ni II] emissions moving outward from eta Carinae. We identify these arcs with the shell-like structures, seen in the 3D hydrodynamical simulations, formed by compression of the primary wind by the secondary wind during periastron passages.

The Abundance of Iron-Peak Elements and the Dust Composition in eta Carinae: Manganese

NASA Technical Reports Server (NTRS)

Bautista, M. A.; Melendez, M.; Hartman, H.; Gull, T. R.; Lodders, K.

2010-01-01

We study the chemical abundances of the Strontium Filament found in the ejecta of (eta) Carinae. In particular, we derive the abundances of iron-peak elements front spectra of their singly ionized ions present in the optical/IR spectra. In this paper we analyze the spectrum of Mn II using a new non-LTE model for this system. In constructing this models we carried out theoretical calculations of radiative transition rates and electron impact excitation rate coefficients. We find that relative to Ni the gas phase abundance ratio of Mn is roughly solar, similar to the Cr abundance but in contrast to the large enhancements in the abundances of Sc and Ti. NVe interpret this result as an indication of non-equilibrium condensation in the ejecta of (eta) Carinae.

How anomalous is the interstellar extinction in NGC 3372, the Carina Nebula?

NASA Astrophysics Data System (ADS)

Tapia, M.; Roth, M.; Marraco, H.; Ruiz, M. T.

Near-infrared JHKL photometry of more than 200 stars in the open clusters Tr 14, Tr 15, Tr 16, Cr 228, and Cr 232 in the Carina Nebula is presented. By comparing these results with the available visual photometry and spectroscopy, it is found that the intracluster reddening is characterized, except in Tr 15, by a 'normal' extinction law for lambda greater than 0.5 micron, but is highly anomalous and variable in the U and B bands. Provisional two-color visual polarimetry suggests that the wavelength of maximum polarization is similar to that in the general interstellar medium. This behavior may be explained by the presence of intracluster interstellar grains 'processed' by the passage of shock waves, presumably associated with the violent history of Eta Carinae.

Molecular clouds in the Carina arm

NASA Technical Reports Server (NTRS)

Grabelsky, D. A.

1986-01-01

Results from the first large-scale survey in the CO(J = 1 to 0) line of the Vela-Carina-Centaurus region of the Southern Milky Way are reported. The observations, made with the Columbia University 1.2 m millimeter-wave telescope at Cerro Tololo, were spaced every beamwidth (0.125 deg) in the range 270 deg is less than or = l is less than or = 300 deg and -1 deg less than or = b less then or = 1 deg, with latitude extensions to cover all Carina arm emission beyond absolute b = 1 deg. In a concurrent survey made with the same telescope, every half-degree in latitude and longitude was sampled. Both surveys had a spectral coverage of 330 km/s with a resolution of 1.3 km/s. The Carina arm is the dominant feature in the data. Its abrupt tangent at l is approx. = 280 deg and characteristic loop in the l,v diagram are unmistakable evidence for CO spiral structure. When the emission is integrated over velocity and latitude, the height of the step seen in the tangent direction suggests that the arm-interarm contrast is at least 13:1. Comparison of the CO and H I data shows close agreement between these two species in a segment of the arm lying outside the solar circle. The distribution of the molecular layer about the galactic plane in the outer Galaxy is determined. Between R = 10.5 and 12.5 kpc, the average CO midplane dips from z = -48 to -167 pc below the b = 0 deg plane, following a similar well-known warping of the H I layer. In the same range of radii the half-thickness of the CO layer increases from 112 to 182 pc. Between l = 270 deg and 300 deg, 27 molecular clouds are identified and cataloged along with heliocentric distances and masses. An additional 16 clouds beyond 300 deg are cataloged from an adjoining CO survey made with the same telescope. The average mass for the Carina arm clouds is 1.4x 10(6)M (solar), and the average intercloud spacing along the arm is 700 pc. Comparison of the distribution of the Carina arm clouds with that of similarly massive molecular clouds in the first and second quadrants strongly suggests that the Carina and Sagittarius arms form a single spiral arm approx. 40 kpc long wrapping two-thirds of the way around the Galaxy.

A census of the Carina Nebula - II. Energy budget and global properties of the nebulosity

NASA Astrophysics Data System (ADS)

Smith, Nathan; Brooks, Kate J.

2007-08-01

The first paper in this series took a direct census of energy input from the known OB stars in the Carina Nebula, and in this paper we study the global properties of the surrounding nebulosity. This detailed comparison may prove useful for interpreting observations of extragalactic giant HII regions and ultraluminous infrared (IR) galaxies. We find that the total IR luminosity of Carina is about 1.2 × 107Lsolar, accounting for only about 50-60 per cent of the known stellar luminosity from Paper I. Similarly, the ionizing photon luminosity derived from the integrated radio continuum is about 7 × 1050 s-1, accounting for ~75 per cent of the expected Lyman continuum from known OB stars. The total kinetic energy of the nebula is about 8 × 1051 erg, or ~30 per cent of the mechanical energy from stellar winds over the lifetime of the nebula, so there is no need to invoke a supernova (SN) explosion based on energetics. Warm dust grains residing in the HII region interior dominate emission at 10-30μm, but cooler grains at 30-40K dominate the IR luminosity and indicate a likely gas mass of ~106Msolar. We find an excellent correlation between the radio continuum and 20-25μm emission, consistent with the idea that the ~80-K grain population is heated by trapped Lyα photons. Similarly, we find a near perfect correlation between the far-IR optical depth map of cool grains and 8.6-μm hydrocarbon emission, indicating that most of the nebular mass resides as atomic gas in photodissociation regions and not in dense molecular clouds. Synchronized star formation around the periphery of Carina provides a strong case that star formation here was indeed triggered by stellar winds and ultraviolet radiation. This second generation appears to involve a cascade toward preferentially intermediate- and low-mass stars, but this may soon change when ηCarinae and its siblings explode. If the current reservoir of atomic and molecular gas can be tapped at that time, massive star formation may be rejuvenated around the periphery of Carina much as if it were a young version of Gould's Belt. Furthermore, when these multiple SNe occur, the triggered second generation will be pelted repeatedly with SN ejecta bearing short-lived radioactive nuclides. Carina may therefore represent the most observable analogue to the cradle of our own Solar system.

Detection of the Compressed Primary Stellar Wind in eta Carinae*

NASA Technical Reports Server (NTRS)

Teodoro, M.; Madura, T. I.; Gull, T. R.; Corcoran, M. F.; Hamaguchi, K.

2013-01-01

A series of three Hubble Space Telescope Space Telescope Imaging Spectrograph (HST/STIS) spectroscopic mappings, spaced approximately one year apart, reveal three partial arcs in [Fe II] and [Ni II] emissions moving outward from ? Carinae. We identify these arcs with the shell-like structures, seen in the 3D hydrodynamical simulations, formed by compression of the primary wind by the secondary wind during periastron passages.

Eta Carinae and Other Luminous Blue Variables

NASA Technical Reports Server (NTRS)

Corcoran, M. F.

2006-01-01

Luminous Blue Variables (LBVs) are believed to be evolved, extremely massive stars close to the Eddington Limit and hence prone to bouts of large-scale, unstable mass loss. I discuss current understanding of the evolutionary state of these objects, the role duplicity may play and known physical characteristics of these stars using the X-ray luminous LBVs Eta Carinae and HD 5980 as test cases.

The X-Ray Lightcurve of Eta Carinae: Refinement of the Orbit and Evidence for Phase Dependent Mass Loss

NASA Technical Reports Server (NTRS)

Corcoran, M. F.; Ishibashi, K.; Swank, J. H.; Petre, R.; White, Nicholas E. (Technical Monitor)

2000-01-01

We solve the RXTE X-ray lightcurve of the extremely luminous and massive star eta Carinae with a colliding wind emission model to refine the ground-based orbital elements. The sharp decline to X-ray minimum at the end of 1997 fixes the date of the last periastron passage at 1997.95 +/- 0.05, not 1998.13 as derived from ground-based radial velocities. This helps resolve a discrepancy between the ground-based radial velocities and spatially-resolved velocity measures obtained by STIS. The X-ray data are consistent with a mass function f(M) approx. = 1.5, lower than the value f(M) approx. = 7.5 previously reported, so that the masses of eta Carinae and the companion are M(sub eta) greater than or = 80 solar mass and M(sub c) approx. 30 solar mass respectively. In addition the X-ray data suggest that the mass loss rate from eta Carinae is generally less than 3 x 10(exp -4) solar mass/yr, about a factor of 5 lower than that derived from some observations in other wavebands. We could not match the duration of the X-ray minimum with any standard colliding wind model in which the wind is spherically symmetric and the mass loss rate is constant. However we show that we can match the variations around X-ray minimum if we include an increase of a factor of approx. 20 in the mass loss rate from eta Carinae for approximately 80 days following periastron. If real, this excess in M would be the first evidence of enhanced mass flow off the primary when the two stars are close (presumably driven by tidal interactions). Our interpretation of the X-ray data suggest that the ASCA and RXTE X-ray spectra near the X-ray minimum are significantly contaminated by unresolved hard emission (E greater than or = 2 keV) from sonic other nearby source, probably associated with scattering of tile colliding wind emission by circumstellar dust. Based on the X-ray fluxes the distance to n Carinae is 2300 pc with formal uncertainties of only approx. 10%.

The CHANDRA HETGS X-ray Grating Spectrum of Eta Carinae

NASA Technical Reports Server (NTRS)

Corcoran, M. F.; Swank, J. H.; Petre, R.; Ishibashi, K.; Davidson, K.; Townsley, L.; Smith, R.; White, S.; Viotti, R.; Damineli, A.;

A 205 {mu}m [N II] MAP OF THE CARINA NEBULA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oberst, T. E.; Parshley, S. C.; Nikola, T.

We present the results of a {approx}250 arcmin{sup 2} mapping of the 205 {mu}m [N II] fine-structure emission over the northern Carina Nebula, including the Car I and Car II H II regions. Spectra were obtained using the South Pole Imaging Fabry-Perot Interferometer (SPIFI) at the Antarctic Submillimeter Telescope and Remote Observatory (AST/RO) at the South Pole. We supplement the 205 {mu}m data with new reductions of far-IR fine-structure spectra from the Infrared Space Observatory (ISO) Long Wavelength Spectrometer (LWS) in 63 {mu}m [O I], 122 {mu}m [N II], 146 {mu}m [O I], and 158 {mu}m [C II]; the 146more » {mu}m [O I] data include 90 raster positions which have not been previously published. Morphological comparisons are made with optical, radio continuum, and CO maps. The 122/205 line ratio is used to probe the density of the low-ionization gas, and the 158/205 line ratio is used to probe the fraction of C{sup +} arising from photodissociation regions (PDRs). The [O I] and [C II] lines are used to construct a PDR model of Carina. When the PDR properties are compared with other sources, Carina is found to be more akin to 30 Doradus than galactic star-forming regions such as Orion, M17, or W49; this is consistent with the view of Carina as a more evolved region, where much of the parent molecular cloud has been ionized or swept away. These data constitute the first ground-based detection of the 205 {mu}m [N II] line, and the third detection overall since those of COBE FIRAS and the Kuiper Airborne Observatory in the early 1990s.« less

Was the nineteenth century giant eruption of Eta Carinae a merger event in a triple system?

NASA Astrophysics Data System (ADS)

Portegies Zwart, S. F.; van den Heuvel, E. P. J.

2016-03-01

We discuss the events that led to the giant eruption of Eta Carinae, and find that the mid-nineteenth century (in 1838-1843) giant mass-loss outburst has the characteristics of being produced by the merger event of a massive close binary, triggered by the gravitational interaction with a massive third companion star, which is the current binary companion in the Eta Carinae system. We come to this conclusion by a combination of theoretical arguments supported by computer simulations using the Astrophysical Multipurpose Software Environment. According to this model the ˜90 M⊙ present primary star of the highly eccentric Eta Carinae binary system is the product of this merger, and its ˜30 M⊙ companion originally was the third star in the system. In our model, the Homunculus nebula was produced by an extremely enhanced stellar wind, energized by tidal energy dissipation prior to the merger, which enormously boosted the radiation-driven wind mass-loss. The current orbital plane is then aligned with the equatorial plane of the Homunculus, and the symmetric lobes are roughly aligned with the argument of periastron of the current Eta Carina binary. The merger itself then occurred in 1838, which resulted in a massive asymmetric outflow in the equatorial plane of the Homunculus. The 1843 outburst can in our model be attributed to the subsequent encounter when the companion star (once the outermost star in the triple system) plunges through the bloated envelope of the merger product, once when it passed periastron again. We predict that the system has an excess space velocity of order 50 km s-1 in the equatorial plane of the Homunculus. Our triple model gives a viable explanation for the high runaway velocities typically observed in LBVs.

Eta Carina: What was the Great Eruption in the 19th Century?

NASA Astrophysics Data System (ADS)

Gull, Theodore; Eta Carina Bunch

2018-01-01

In the 1840’s, Eta Carina brightened to rival Sirius in apparent magnitude only to fade to naked-eye visibility for 5 decades, brightened somewhat in the 1890s and faded again until the 1940’s when it began a progressive brightening that continues. Today Eta Carina is a massive binary (100 Mo and 30 Mo) with a 5.54-year period, immersed in a massive (>40Mo) dusty, bipolar nebula. The radiation and kinetic energy of the 1840s event rivals that of a supernova, but the binary survived. While Eta Carina is suggested to be a supernova imposter, most imposters, seen in nearby galaxies, lead to actual supernova events months to years afterwards, yet the binary, Eta Carina, is still with us 170 years after the outburst.With modern observatories we are gaining much insight on the massive binary--followed by many ground-based telescopes, the fossil wind structures--mapped with HST/STIS, the Little Homunculus--discovered with HST/STIS and Homunculus--now being studied with ALMA. 3D models are able to explain much of the structures, but potentially much material remains hidden in the form of molecules on the far side of the Homunculus in the equatorial skirt region, where Herschel observations indicate the bulk of dust-emitting continuum resides.Was there a third star that became a supernova? Did one of the two stars go through a near supernova experience?This poster will summarize observations and modeling of the current system in hopes that theorists will become interested in providing scenarios and models that led to the ejecta and binary we observe today.

Macroscopic barotrauma caused by stiff and soft-tipped airway exchange catheters: an in vitro case series.

PubMed

Axe, Robert; Middleditch, Alex; Kelly, Fiona E; Batchelor, Tim J; Cook, Tim M

2015-02-01

Many airway management guidelines include the use of airway exchange catheters (AECs). There are reports, however, of harm from their use, from both malpositioning and in particular from the administration of oxygen via an AEC leading to barotrauma. We used an in vitro pig lung model to investigate the safety of administering oxygen at 4 different flow rates from a high-pressure source via 2 different AECs: a standard catheter and a soft-tipped catheter. Experiments were performed with the catheters positioned either above the carina or below it at the first point of resistance to advancement (hold-up). The experiments were then repeated to produce a series of 32 cases. With an AEC positioned above the carina, we did not observe macroscopic lung damage after the administration of oxygen. The administration of oxygen through an AEC positioned below the carina resulted in macroscopic barotrauma regardless of the rate of oxygen delivery. Increasing speed of oxygen flow led to faster and more extensive damage. Use of an "injector" at 2.5 or 4 bar led to instantaneous macroscopic lung damage and advancement of the AEC through the lung tissue. Our observations were the same when both types of AECs were used. Our results are consistent with reports of harm during the use of AECs and demonstrate the risk of administering oxygen through these devices when they are positioned below the carina. An indicator, ideally made on an AEC at the time of manufacture and designed to lie at the same level as the teeth, may be useful in preventing the insertion of that AEC beyond the level of the carina and improve the safety of using such devices.

Brilliant Star in a Colourful Neighbourhood

NASA Astrophysics Data System (ADS)

2010-07-01

A spectacular new image from ESO's Wide Field Imager at the La Silla Observatory in Chile shows the brilliant and unusual star WR 22 and its colourful surroundings. WR 22 is a very hot and bright star that is shedding its atmosphere into space at a rate many millions of times faster than the Sun. It lies in the outer part of the dramatic Carina Nebula from which it formed. Very massive stars live fast and die young. Some of these stellar beacons have such intense radiation passing through their thick atmospheres late in their lives that they shed material into space many millions of times more quickly than relatively sedate stars such as the Sun. These rare, very hot and massive objects are known as Wolf-Rayet stars [1], after the two French astronomers who first identified them in the mid-nineteenth century, and one of the most massive ones yet measured is known as WR 22. It appears at the centre of this picture, which was created from images taken through red, green and blue filters with the Wide Field Imager on the MPG/ESO 2.2-metre telescope at ESO's La Silla Observatory in Chile. WR 22 is a member of a double star system and has been measured to have a mass at least 70 times that of the Sun. WR 22 lies in the southern constellation of Carina, the keel of Jason's ship Argo in Greek mythology. Although the star lies over 5000 light-years from the Earth it is so bright that it can just be faintly seen with the unaided eye under good conditions. WR 22 is one of many exceptionally brilliant stars associated with the beautiful Carina Nebula (also known as NGC 3372) and the outer part of this huge region of star formation in the southern Milky Way forms the colourful backdrop to this image. The subtle colours of the rich background tapestry are a result of the interactions between the intense ultraviolet radiation coming from hot massive stars, including WR 22, and the vast gas clouds, mostly hydrogen, from which they formed. The central part of this enormous complex of gas and dust lies off the left side of this picture as can be seen in image eso1031b. This area includes the remarkable star Eta Carinae and was featured in an earlier press release (eso0905). Notes [1] More information about Wolf-Rayet stars More information ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory and VISTA, the world's largest survey telescope. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

An Investigation of the Ionization Structure of the Carina Spiral Arm with WHAM

NASA Astrophysics Data System (ADS)

Benjamin, Robert A.; Krishnarao, Dhanesh; Haffner, L. Matthew

2018-01-01

Recent investigations of the Sagittarius-Carina spiral arm with the Wisconsin H-alpha Mapper (Krishnarao et al 2017) show the presence of ionized gas stretching up to three kiloparsecs above and below the Carina section of this spiral arm. This arm segment, which wraps outside the solar circle in the fourth quadrant of the Galactic disk, seems to be unusual when compared to the other Milky Way spiral arms measured with WHAM. We review the status of what is known about the vertical ionization structure of the spiral arms of the Milky Way Galaxy and relate the properties of this spiral arm section to recent investigations of midplane HII regions and star formation in the Milky Way disk. We discuss potential implications of this star formation and ionization for our understanding of Milky Way Galactic structure.

VizieR Online Data Catalog: UBVI CCD photometry of Carina region stars (Molina-Lera+, 2016)

NASA Astrophysics Data System (ADS)

Molina-Lera, J. A.; Baume, G.; Gamen, R.; Costa, E.; Carraro, G.

2016-08-01

Photometric parameters for 62730 stars in the carina region covering 6 stellar clusters (NGC 3752, Trumpler 18, NGC 3590, Hogg 10, 11 and 12) and the surrounding field. The photometry was secured in March 2006 and March 2009 with the Y4KCAM camera attached to the Cerro Tololo Inter American Observatory (CTIO, Chile) 1.0-m telescope. (1 data file).

Apparent migration of implantable port devices: normal variations in consideration of BMI.

PubMed

Wyschkon, Sebastian; Löschmann, Jan-Phillip; Scheurig-Münkler, Christian; Nagel, Sebastian; Hamm, Bernd; Elgeti, Thomas

2016-01-01

To evaluate the extent of normal variation in implantable port devices between supine fluoroscopy and upright chest x-ray in relation to body mass index (BMI) based on three different measurement methods. Retrospectively, 80 patients with implanted central venous access port systems from 2012-01-01 until 2013-12-31 were analyzed. Three parameters (two quantitative and one semi-quantitative) were determined to assess port positions: projection of port capsule to anterior ribs (PCP) and intercostal spaces, ratio of extra- and intravascular catheter portions (EX/IV), normalized distance of catheter tip to carina (nCTCD). Changes were analyzed for males and females and normal-weight and overweight patients using analysis of variance with Bonferroni-corrected pairwise comparison. PCP revealed significantly greater changes in chest x-rays in overweight women than in the other groups (p<0.001, F-test). EX/IV showed a significantly higher increase in overweight women than normal-weight women and men and overweight men (p<0.001). nCTCD showed a significantly greater increase in overweight women than overweight men (p = 0.0130). There were no significant differences between the other groups. Inter- and intra-observer reproducibility was high (Cronbach alpha of 0.923-1.0) and best for EX/IV. Central venous port systems show wide normal variations in the projection of catheter tip and port capsule. In overweight women apparent catheter migration is significantly greater compared with normal-weight women and with men. The measurement of EX/IV and PCP are straightforward methods, quick to perform, and show higher reproducibility than measurement of catheter tip-to-carina distance.

Eta Carinae: Linelist for the Emission Spectrum of the Weigelt Blobs in the 1700-10400Angstrom Wavelength Region

NASA Technical Reports Server (NTRS)

Zethson, T.; Johansson, S.; Hartman, H.; Gull, T. R.

2011-01-01

Aims. We present line identifications in the 1700 to 10400A region for the Weigelt Blobs B and D, located 0.1 to 0.3" NNW of Eta Carinae. The aim of this work is to characterize the behavior of these luminous, dense gas condensations in response to the broad maximum and short minimum states of Eta Carinae during its 5.54-year spectroscopic period. Methods. The observations were carried out during March 1998, the minimum spectrum, and in February 1999, early maximum spectrum, with the Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) from 1640 to 10400A using the 52"x0.1" aperture centered on Eta Carinae at position angle -28 degrees. Extractions of the reduced spectrum centered on Weigelt B and D, 0.28: in length along the slit, were used to identify the narrow, nebular emission lines, measure their wavelengths and estimate their fluxes. Results. A linelist of 1500 lines is presented for the maximum and minimum states of combined Weigelt blobs B and D. The spectra are dominated by emission lines from the iron-group elements, but include lines from lighter elements. They include parity permitted and forbidden lines. A number of lines are fluorescent lines pumped by H Ly alpha. Other lines show anomalous excitation.

ARE LARGE, COMETARY-SHAPED PROPLYDS REALLY (FREE-FLOATING) EVAPORATING GAS GLOBULES?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sahai, R.; Guesten, R.; Morris, M. R., E-mail: raghvendra.sahai@jpl.nasa.gov

2012-12-20

We report the detection of strong and compact molecular line emission (in the CO J = 3-2, 4-3, 6-5, 7-6, {sup 13}CO J = 3-2, HCN, and HCO{sup +} J = 4-3 transitions) from a cometary-shaped object (Carina-frEGG1) in the Carina star-forming region (SFR) previously classified as a photoevaporating protoplanetary disk (proplyd). We derive a molecular mass of 0.35 M{sub Sun} for Carina-frEGG1, which shows that it is not a proplyd, but belongs to a class of free-floating evaporating gas globules (frEGGs) recently found in the Cygnus SFR by Sahai et al. Archival adaptive optics near-IR (Ks) images show amore » central hourglass-shaped nebula. The derived source luminosity (about 8-18 L{sub Sun }), the hourglass morphology, and the presence of collimated jets seen in Hubble Space Telescope images imply the presence of a jet-driving, young, low-mass star deeply embedded in the dust inside Carina-frEGG1. Our results suggest that the true nature of many or most such cometary-shaped objects seen in massive SFRs and previously labeled as proplyds has been misunderstood, and that these are really frEGGs.« less

Double Y-stenting for tracheobronchial stenosis.

PubMed

Oki, Masahide; Saka, Hideo

2012-12-01

The purpose of the present study was to evaluate the feasibility, efficacy and safety of the double Y-stenting technique, by which silicone Y-stents are placed on both the main carina and another peripheral carina, for patients with tracheobronchial stenosis. Under general anaesthesia, using rigid and flexible bronchoscopes, a Dumon™ Y-stent (Novatech, La Ciotat, France) was first placed on the primary right or secondary left carina followed by another Y-stent on the main carina so as to insert the bronchial limb of the stent into the first Y-stent. Patients who underwent double Y-stent placement during 3 yrs and 1 month in a single centre were retrospectively reviewed. In the study period, 93 patients underwent silicone stent placement and 12 (13%) underwent double Y-stent placement (11 for right and one for left bronchus). A combination of Y-stents, 14 × 10 × 10 mm and 16 × 13 × 13 mm in outer diameter, were most frequently used. Dyspnoea was relieved in all patients. Six out of seven patients with supplemental oxygen before stent placement could be discharged without supplemental oxygen. Median survival after stenting was 94.5 days. One pneumothorax and one granuloma formation occurred. Double Y-stent placement for patients with tracheobronchial stenosis was technically feasible, effective and acceptably safe.

The Carina project. VII. Toward the breaking of the age-metallicity degeneracy of red giant branch stars using the C {sub U,} {sub B,} {sub I} index

DOE Office of Scientific and Technical Information (OSTI.GOV)

Monelli, M.; Milone, A. P.; Gallart, C.

2014-12-01

We present an analysis of photometric and spectroscopic data of the Carina dSph galaxy, testing a new approach similar to that used to disentangle multiple populations in Galactic globular clusters (GCs). We show that a proper color combination is able to separate a significant fraction of the red giant branch (RGB) of the two main Carina populations (the old one, ∼12 Gyr, and the intermediate-age one, 4-8 Gyr). In particular, the c {sub U,} {sub B,} {sub I} = (U – B) – (B – I) pseudo-color allows us to follow the RGB of both populations along a relevant portionmore » of the RGB. We find that the oldest stars have a more negative c {sub U,} {sub B,} {sub I} pseudo-color than intermediate-age ones. We correlate the pseudo-color of RGB stars with their chemical properties, finding a significant trend between the iron content and the c {sub U,} {sub B,} {sub I}. Stars belonging to the old population are systematically more metal-poor ([Fe/H] =–2.32 ± 0.08 dex) than the intermediate-age ones ([Fe/H] =–1.82 ± 0.03 dex). This gives solid evidence of the chemical evolution history of this galaxy, and we have a new diagnostic that can allow us to break the age-metallicity degeneracy of H-burning advanced evolutionary phases. We compared the distribution of stars in the c {sub U,} {sub B,} {sub I} plane with theoretical isochrones, finding that no satisfactory agreement can be reached with models developed in a theoretical framework based on standard heavy element distributions. Finally, we discuss possible systematic differences when compared with multiple populations in GCs.« less

Radio Observations of Nova Muscae 2018 and Nova Carinae 2018 (ASASSN-18fv)

NASA Astrophysics Data System (ADS)

Ryder, S. D.; Kool, E. C.; Chomiuk, L.

2018-04-01

The two optically-bright Galactic novae in Musca (CBET #4473, ATel #11183, #11201, #11212, #11296) and in Carina (ATel #11454, #11456, #11457, #11460, #11468) were observed at radio wavelengths using the Australia Telescope Compact Array (ATCA) on 2018 Apr 3.3 UT. Nova Muscae 2018 has faded by a factor of 3 at 9.0 and 5.5 GHz since peaking at > 30 mJy/bm in mid-March.

HUBBLE SHOWS EXPANSION OF ETA CARINAE DEBRIS

NASA Technical Reports Server (NTRS)

2002-01-01

The furious expansion of a huge, billowing pair of gas and dust clouds are captured in this NASA Hubble Space Telescope comparison image of the supermassive star Eta Carinae. To create the picture, astronomers aligned and subtracted two images of Eta Carinae taken 17 months apart (April 1994, September 1995). Black represents where the material was located in the older image, and white represents the more recent location. (The light and dark streaks that make an 'X' pattern are instrumental artifacts caused by the extreme brightness of the central star. The bright white region at the center of the image results from the star and its immediate surroundings being 'saturated' in one of the images.)Photo Credit: Jon Morse (University of Colorado), Kris Davidson (University of Minnesota), and NASA Image files in GIF and JPEG format and captions may be accessed on Internet via anonymous ftp from oposite.stsci.edu in /pubinfo.

Global X-ray Spectral Variation of Eta Carinae through the 2003 X-ray Minimum

NASA Technical Reports Server (NTRS)

Hamaguchi, K.; Corcoran, M. F.; White, N. E.; Gull, T.; Damineli, A.; Davidson, K.

2006-01-01

We report on the results of the X-ray observing campaign of the massive, evolved star Eta Carinae in 2003 around its recent X-ray Minimum, mainly using data from the XMM-Newton observatory. These imaging observations show that the hard X-ray source associated with the Eta Carinae system does not completely disappear in any of the observations during the Minimum. The variation of the spectral shape revealed two emission components. One newly discovered component did not exhibit any variation on kilo-second to year-long timescales, in a combined analysis with earlier ASCA and ROSAT data, and might represent the collision of a high speed outflow from Eta Carinae with ambient gas clouds. The other emission component was strongly variable in flux but the temperature of the hottest plasma did not vary significantly at any orbital phase. Absorption to the hard emission, was about a factor of three larger than the absorption determined from the cutoff of the soft emission, and reached a maximum of approx.4 x 10(exp 23)/sq cm before the Minimum. The thermal Fe\\rm XXV emission line showed significant excesses on both the red and blue sides of the line outside the Minimum and exhibited a large redward excess during the Minimum. This variation in the line profile probably requires an abrupt change in ionization balance in the shocked gas.

Carina® and Esteem®: a systematic review of fully implantable hearing devices.

PubMed

Pulcherio, Janaina Oliveira Bentivi; Bittencourt, Aline Gomes; Burke, Patrick Rademaker; Monsanto, Rafael da Costa; de Brito, Rubens; Tsuji, Robinson Koji; Bento, Ricardo Ferreira

2014-01-01

To review the outcomes of the fully implantable middle ear devices Carina and Esteem regarding the treatment of hearing loss. PubMed, Embase, Scielo, and Cochrane Library databases were searched. Abstracts of 77 citations were screened, and 43 articles were selected for full review. From those, 22 studies and two literature reviews in English directly demonstrating the results of Carina and Esteem were included. There were a total of 244 patients ranging from 18 to 88 years. One hundred and 10 patients were implanted with Carina and with 134 Esteem. There were registered 92 males and 67 females. Five studies provided no information about patients' age or gender. From the data available, the follow-up ranged from 2 to 29.4 months. The comparison of the results about word recognition is difficult as there was no standardization of measurement. The results were obtained from various sound intensities and different frequencies. The outcomes comparing to conventional HAs were conflicting. Nevertheless, all results comparing to unaided condition showed improvement and showed a subjective improvement of quality of life. There are still some problems to be solved, mainly related to device functioning and price. Due to the relatively few publications available and small sample sizes, we must be careful in extrapolating these results to a broader population. Additionally, none of all these studies represented level high levels of evidence (i.e. randomized controlled trials).

Chandra X-Ray Observatory Image of Eta Carinae

NASA Technical Reports Server (NTRS)

1999-01-01

This Chandra X-Ray Observatory image of the mysterious superstar Eta Carinae reveals a surprising hot irner core, creating more questions than answers for astronomers. The image shows three distinct structures: An outer, horseshoe shaped ring about 2 light-years in diameter, a hot inner core about 3 light-months in diameter, and a hot central source less than a light-month in diameter which may contain the superstar. In 1 month, light travels a distance of approximately 489 billion miles (about 788 billion kilometers). All three structures are thought to represent shock waves produced by matter rushing away from the superstar at supersonic speeds. The temperature of the shock-heated gas ranges from 60 million degrees Kelvin in the central regions to 7 million degrees Kelvin on the outer structure. Eta Carinae is one of the most enigmatic and intriguing objects in our galaxy. Between 1837 and 1856, it increased dramatically in brightness to become the most prominent star in the sky except for Sirius, even through it is 7,500 light-years away, more than 80 times the distance to Sirius. This 'Great Eruption,' as it is called, had an energy comparable to a supernova, yet did not destroy the star, which faded to become a dim star, invisible to the naked eye. Since 1940, Eta Carinae has begun to brighten again, becoming visible to the naked eye. Photo credit: NASA/CXC/SAO

Stellar properties of dwarf galaxies and their connections with the Milky Way halo

NASA Astrophysics Data System (ADS)

Revaz, Yves; Pascale Jablonka

2018-06-01

In this talk, relying on recent chemo-dynamical simulations, I will describe the stellar properties and in particular the abundances ratios of dwarf galaxies emerging from a LCDM framework. Faint systems quenched by the UV-background as well as luminous ones exhibiting an extended star formation history nicely reproduce observations, without necessary requiring a strong interaction with the Milky Way. However, dwarf galaxies with complex star formation histories like Carina and Fornax are much more difficult to reproduce. Those systems are often believed to result from an interaction with the Milky Way. I will show that when such interaction is taken into account in our high resolution simulations through ram pressure stripping, a much more complex reality appears.

Sub-Ionospheric Measurements of the Ocean, Atmosphere, and Ionosphere from the CARINA Satellites

NASA Astrophysics Data System (ADS)

Bernhardt, P. A.; Montgomery, J. A., Jr.; Siefring, C. L.; Gatling, G.

2016-12-01

New satellites designed to fly between 150 and 250 km has been constructed to study a wide range of geophysical topics extending from the ocean to the topside ionosphere. The key features of the CARINA satellites are (1) the ability of sustain long duration (60 day) orbits below the F-Layer ionosphere, (2) download large quantities of data (10 GBytes) per pass over a ground station, and (3) a heritage instrument payload comprised of an Electric Field Instrument (EFI) with full range measurements from 3 to 13 MHz, a Ram Langmuir Probe (RLP) the measures ion density from 102 to 106 cm-3 with 10 kHz sample rate, an Orbiting GPS Receiver (OGR) providing overhead total electron content and satellite position and the Wake Retro Reflectors (WRR) that use laser ranging for precise orbit determination. Each letter in "CARINA" represents one of the science objectives. "Coastal" ocean wave remote sensing of the sea surface wave height spectrum derived from HF surface wave scatter to the satellite. Assimilation ionospheric models are supported by Global measurements of GPS total electron count (TEC) and in situ plasma density for updating data driven ionospheric models (GAIM, IDA3D, etc.). Radio wave propagation and interactions determine the impact of the bottomside ionosphere on HF ray trajectories, the effects of ionospheric irregularities that yield UHF/L-band scintillations and ionospheric modifications by high power HF waves. Ionospheric structures such are sporadic-E and intermediate layers, traveling ionospheric disturbances (TID's) and large scale bottomside fluctuations in the F-layer are directly measured by CARINA sensors. Neutral drag is studied along the orbit through reentry modeling of drag coefficients and neutral density model updates. Finally, Atmospherics and lightning knowledge is acquired through studies of lightning EM pulses and their impact on ionosphere. Two CARINA satellites separated by 2000 km flying above 50 degree inclination represents the baseline mission.

CTIO Image of Carina Nebula

NASA Image and Video Library

2017-12-08

NASA image release April 22, 2010 Object Names: Carina Nebula, NGC 3372 Image Type: Astronomical Credit: NASA/N. Smith (University of California, Berkeley) and NOAO/AURA/NSF To read learn more about this image go to: www.nasa.gov/mission_pages/hubble/science/hubble20th-img.... NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Constraining the Absolute Orientation of eta Carinae's Binary Orbit: A 3-D Dynamical Model for the Broad [Fe III] Emission

NASA Technical Reports Server (NTRS)

Madura, T. I.; Gull, T. R.; Owocki, S. P.; Groh, J. H.; Okazaki, A. T.; Russell, C. M. P.

2011-01-01

We present a three-dimensional (3-D) dynamical model for the broad [Fe III] emission observed in Eta Carinae using the Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS). This model is based on full 3-D Smoothed Particle Hydrodynamics (SPH) simulations of Eta Car's binary colliding winds. Radiative transfer codes are used to generate synthetic spectro-images of [Fe III] emission line structures at various observed orbital phases and STIS slit position angles (PAs). Through a parameter study that varies the orbital inclination i, the PA(theta) that the orbital plane projection of the line-of-sight makes with the apastron side of the semi-major axis, and the PA on the sky of the orbital axis, we are able, for the first time, to tightly constrain the absolute 3-D orientation of the binary orbit. To simultaneously reproduce the blue-shifted emission arcs observed at orbital phase 0.976, STIS slit PA = +38deg, and the temporal variations in emission seen at negative slit PAs, the binary needs to have an i approx. = 130deg to 145deg, Theta approx. = -15deg to +30deg, and an orbital axis projected on the sky at a P A approx. = 302deg to 327deg east of north. This represents a system with an orbital axis that is closely aligned with the inferred polar axis of the Homunculus nebula, in 3-D. The companion star, Eta(sub B), thus orbits clockwise on the sky and is on the observer's side of the system at apastron. This orientation has important implications for theories for the formation of the Homunculus and helps lay the groundwork for orbital modeling to determine the stellar masses.

Eclipse and Collapse of the Colliding Wind X-ray Emission from Eta Carinae

NASA Technical Reports Server (NTRS)

Hamaguchi, Kenji; Corcoran, Michael F.

2012-01-01

X-ray emission from the massive stellar binary system, Eta Carinae, drops strongly around periastron passage; the event is called the X-ray minimum. We launched a focused observing campaign in early 2009 to understand the mechanism of causing the X-ray minimum. During the campaign, hard X-ray emission (<10 keV) from Eta Carinae declined as in the previous minimum, though it recovered a month earlier. Extremely hard X-ray emission between 15-25 keV, closely monitored for the first time with the Suzaku HXD/PIN, decreased similarly to the hard X-rays, but it reached minimum only after hard X-ray emission from the star had already began to recover. This indicates that the X-ray minimum is produced by two composite mechanisms: the thick primary wind first obscured the hard, 2-10 keV thermal X-ray emission from the wind-wind collision (WWC) plasma; the WWC activity then decays as the two stars reach periastron.

Searching for Radial Velocity Variations in eta Carinae

NASA Technical Reports Server (NTRS)

Iping, R. C.; Sonneborn, G.; Gull, T. R.; Ivarsson, S.; Nielsen, K.

2006-01-01

A hot companion of eta Carinae has been detected using high resolution spectra (905 - 1180 A) obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite (see poster by Sonneborn et al.). Analysis of the far-UV spectrum shows that eta Car B is a luminous hot star. The N II 1084-86 emission feature indicates that the star may be nitrogen rich. The FUV continuum and the S IV 1073 P-Cygni wind line suggest that the effective temperature of eta Car B is at least 25,000 K. FUV spectra of eta Carinae were obtained with the FUSE satellite at 9 epochs between 2000 February and 2005 July. The data consists of 12 observations taken with the LWRS aperture (30x30 arcsec), three with the HIRS aperture (1.25x20 arcsec), and one MRDS aperture (4x20 arcsec). In this paper we discuss the analysis of these spectra to search for radial velocity variations associated with the 5.54-year binary orbit of Eta Car AB.

Front teeth-to-carina distance in children undergoing cardiac catheterization.

PubMed

Hunyady, Agnes I; Pieters, Benjamin; Johnston, Troy A; Jonmarker, Christer

2008-06-01

Knowledge of normal front teeth-to-carina distance (FT-C) might prevent accidental bronchial intubation. The aim of the current study was to measure FT-C and to examine whether the Morgan formula for oral intubation depth, i.e., endotracheal tube (ETT) position at front teeth (cm) = 0.10 x height (cm) + 5, gives appropriate guidance when intubating children of different ages. FT-C was measured in 170 infants and children, aged 1 day to 19 yr, undergoing cardiac catheterization. FT-C was obtained as the sum of the ETT length at the upper front teeth/dental ridge and the distance from the ETT tip to the carina. The latter measure was taken from an anterior-posterior chest x-ray. There was close linear correlation between FT-C and height: FT-C (cm) = 0.12 x height (cm) + 5.2, R = 0.98. The linear correlation coefficients (R) for FT-C versus weight and age were 0.78 and 0.91, respectively. If the Morgan formula had been used for intubation, the ETT tip would have been at 90 +/- 4% of FT-C. No patient would have been bronchially intubated, but the ETT tip would have been less than 0.5 cm from the carina in 13 infants. FT-C can be well predicted from the height/length of the child. The Morgan formula provides good guidance for intubation in children but can result in a distal ETT tip position in small infants. Careful auscultation is necessary to ensure correct tube position.

Carina® and Esteem®: A Systematic Review of Fully Implantable Hearing Devices

PubMed Central

Pulcherio, Janaina Oliveira Bentivi; Bittencourt, Aline Gomes; Burke, Patrick Rademaker; Monsanto, Rafael da Costa; de Brito, Rubens; Tsuji, Robinson Koji; Bento, Ricardo Ferreira

2014-01-01

Objective To review the outcomes of the fully implantable middle ear devices Carina and Esteem regarding the treatment of hearing loss. Data Sources PubMed, Embase, Scielo, and Cochrane Library databases were searched. Study Selection Abstracts of 77 citations were screened, and 43 articles were selected for full review. From those, 22 studies and two literature reviews in English directly demonstrating the results of Carina and Esteem were included. Data Extraction There were a total of 244 patients ranging from 18 to 88 years. One hundred and 10 patients were implanted with Carina and with 134 Esteem. There were registered 92 males and 67 females. Five studies provided no information about patients’ age or gender. From the data available, the follow-up ranged from 2 to 29.4 months. Data Synthesis The comparison of the results about word recognition is difficult as there was no standardization of measurement. The results were obtained from various sound intensities and different frequencies. The outcomes comparing to conventional HAs were conflicting. Nevertheless, all results comparing to unaided condition showed improvement and showed a subjective improvement of quality of life. Conclusion There are still some problems to be solved, mainly related to device functioning and price. Due to the relatively few publications available and small sample sizes, we must be careful in extrapolating these results to a broader population. Additionally, none of all these studies represented level high levels of evidence (i.e. randomized controlled trials). PMID:25329463

Fermi Large Area Telescope Observation Of A Gamma-Ray Source At The Position Of Eta Carinae

DOE PAGES

Abdo, A. A,

2010-10-13

The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope detected a γ-ray source that is spatially consistent with the location of Eta Carinae. This source has been persistently bright since the beginning of the LAT survey observations (from 2008 August to 2009 July, the time interval considered here). The γ-ray signal is detected significantly throughout the LAT energy band (i.e., up to ~100 GeV). The 0.1-100 GeV energy spectrum is well represented by a combination of a cutoff power-law model (<10 GeV) and a hard power-law component (>10 GeV). The total flux (>100 MeV) is 3.7 +0.3more » –0.1 × 10 –7 photons s –1 cm –2, with additional systematic uncertainties of 10%, and consistent with the average flux measured by AGILE. The light curve obtained by Fermi is consistent with steady emission. Our observations do not confirm the presence of a γ-ray flare in 2008 October, as reported by Tavani et al., although we cannot exclude that a flare lasting only a few hours escaped detection by the Fermi LAT. We also do not find any evidence for γ-ray variability that correlates with the large X-ray variability of Eta Carinae observed during 2008 December and 2009 January. We are thus not able to establish an unambiguous identification of the LAT source with Eta Carinae.« less

A visual stethoscope to detect the position of the tracheal tube.

PubMed

Kato, Hiromi; Suzuki, Akira; Nakajima, Yoshiki; Makino, Hiroshi; Sanjo, Yoshimitsu; Nakai, Takayoshi; Shiraishi, Yoshito; Katoh, Takasumi; Sato, Shigehito

2009-12-01

Advancing a tracheal tube into the bronchus produces unilateral breath sounds. We created a Visual Stethoscope that allows real-time fast Fourier transformation of the sound signal and 3-dimensional (frequency-amplitude-time) color rendering of the results on a personal computer with simultaneous processing of 2 individual sound signals. The aim of this study was to evaluate whether the Visual Stethoscope can detect bronchial intubation in comparison with auscultation. After induction of general anesthesia, the trachea was intubated with a tracheal tube. The distance from the incisors to the carina was measured using a fiberoptic bronchoscope. While the anesthesiologist advanced the tracheal tube from the trachea to the bronchus, another anesthesiologist auscultated breath sounds to detect changes of the breath sounds and/or disappearance of bilateral breath sounds for every 1 cm that the tracheal tube was advanced. Two precordial stethoscopes placed at the left and right sides of the chest were used to record breath sounds simultaneously. Subsequently, at a later date, we randomly entered the recorded breath sounds into the Visual Stethoscope. The same anesthesiologist observed the visualized breath sounds on the personal computer screen processed by the Visual Stethoscope to examine changes of breath sounds and/or disappearance of bilateral breath sound. We compared the decision made based on auscultation with that made based on the results of the visualized breath sounds using the Visual Stethoscope. Thirty patients were enrolled in the study. When irregular breath sounds were auscultated, the tip of the tracheal tube was located at 0.6 +/- 1.2 cm on the bronchial side of the carina. Using the Visual Stethoscope, when there were any changes of the shape of the visualized breath sound, the tube was located at 0.4 +/- 0.8 cm on the tracheal side of the carina (P < 0.01). When unilateral breath sounds were auscultated, the tube was located at 2.6 +/- 1.2 cm on the bronchial side of the carina. The tube was also located at 2.3 +/- 1.0 cm on the bronchial side of the carina when a unilateral shape of visualized breath sounds was obtained using the Visual Stethoscope (not significant). During advancement of the tracheal tube, alterations of the shape of the visualized breath sounds using the Visual Stethoscope appeared before the changes of the breath sounds were detected by auscultation. Bilateral breath sounds disappeared when the tip of the tracheal tube was advanced beyond the carina in both groups.

A New M Dwarf Debris Disk Candidate in a Young Moving Group Discovered with Disk Detective

NASA Technical Reports Server (NTRS)

Silverberg, Steven M.; Kuchner, Marc J.; Wisniewski, John P.; Gagne, Jonathan; Bans, Alissa S.; Bhattacharjee, Shambo; Currie, Thayne R.; Debes, John R.; Biggs, Joseph R; Bosch, Milton

2016-01-01

We used the Disk Detective citizen science project and the BANYAN II Bayesian analysis tool to identify a new candidate member of a nearby young association with infrared excess. WISE J080822.18-644357.3, an M5.5-type debris disk system with significant excess at both 12 and 22 microns, is a likely member (approx.90% BANYAN II probability) of the approx.45 Myr old Carina association. Since this would be the oldest M dwarf debris disk detected in a moving group, this discovery could be an important constraint on our understanding of M dwarf debris disk evolution.

Eta Carinae, the Integral Nebula and the Homunculus Observations

NASA Astrophysics Data System (ADS)

Gull, Theodore

2000-07-01

In the past two years, observations of Eta Carina have revealed much new and very exciting information. Augusto Damineli noted a 5.5 year period in the visible and near infrared spectroscopy. Michael Corcoran and Bish Ishibashi noticed modulation of the x-ray fluxes with various periodicities around 90 days before and after the xray and radio minimum in December 1997. Observations, done in March 1998 under proposal 7302 {Davidson et al} from 1640A to 10400A using STIS in GXXXM mode and the 50x0.1 arcsecond slit, revealed much new information in the immediate regions of Eta Carina. The slit orientation was slightly off the major axis of the Homunculus, but passed through Weigelt components B and D. Bish Ishibashi and Ted Gull have reduced the data and provided it to various team members. Torgil Zethson has identified well over 90 percent of the emission lines in the March 1998 spectrum and finds most to be FeII emission lines. Based upon the past ground-based history of Eta Carina, we expected that FeIII and other high ionization states would return within the year. STIS GTO observations {Ted Gull, PI program 8036} characterized a bright internal emission nebula by turning the slit 90 degrees for visit 1 and studying the changes in spectrum as the FeIII lines appear by using visit 2 with the identical slit orientation from March 19, 1998. Data from the four visits of STIS to Eta Carinae between December 1997 and February 1999 demonstrate that the star has brightened by a factor of two during that interval and that the immediate nebulosity has tripled in surface brightness. Moreover a small circular nebular shell, seen in multiple [Fe II] lines has disappeared and the opacity in the 2000 to 3000A region obscuring the star has lifted considerable as the Fe II is converting to Fe III. Given the strong changes in the spectrum, we have chosen to use the six orbits in two visits. Visit 1 will be a precise repeat of the March 1998 and February 1999 observations, adjusted for the increasing brightness and compacted into two orbits of CVZ time. Visit 2 is designed to map the integral nebula in Hbeta and [FeII] lines at a fully sampled spacing of 0.1" with the 52x0.1 slit. The Homunculus will be mapped in H alpha and FeII lines at 0.2" spacing. Our primary objective is to get a three-dimensional snapshot of the nebulosities around Eta Carinae at one epoch as we are finding considerable changes even in times only a few months apart. At the end of these observations, a series of exposures are designed with Eta Carinae behind the F2 fiducial by a POS TARG maneuver. THIS IS NOT 52X0.2F1 We will not have complete information on the inner 0.8" region as the four orbits CVZ do not accomodate. An additional two orbits would be necessary as the dynamic range requires a number of very specific observations.

Abundance analysis of a CEMP-no star in the Carina dwarf spheroidal galaxy

NASA Astrophysics Data System (ADS)

Susmitha, A.; Koch, A.; Sivarani, T.

2017-10-01

Carbon-enhanced metal-poor (CEMP) stars bear important imprints of the early chemical enrichment of any stellar system. While these stars are known to exist in copious amounts in the Milky Way halo, detailed chemical abundance data from the faint dwarf spheroidal (dSph) satellites are still sparse, although the relative fraction of these stars increases with decreasing metallicity. Here, we report the abundance analysis of a metal-poor ([ Fe / H ] = - 2.5 dex), carbon-rich ([C/Fe] = 1.4 dex) star, ALW-8, in the Carina dSph using high-resolution spectroscopy obtained with the ESO/UVES instrument. Its spectrum does not indicate any over-enhancements of neutron capture elements. Thus classified as a CEMP-no star, this is the first detection of this kind of star in Carina. Another of our sample stars, ALW-1, is shown to be a CEMP-s star, but its immediate binarity prompted us to discard it from a detailed analysis. The majority of the 18 chemical elements we measured are typical of Carina's field star population and also agree with CEMP stars in other dSph galaxies. Similar to the only known CEMP-no star in the Sculptor dSph and the weak-r-process star HD 122563, the lack of any strong barium-enhancement is accompanied by a moderate overabundance in yttrium, indicating a weak r-process activity. The overall abundance pattern confirms that, also in Carina, the formation site for CEMP-no stars has been affected by both faint supernovae and by standard core collapse supernovae. Whichever process was responsible for the heavy element production in ALW-8 must be a ubiquitous source to pollute the CEMP-no stars, acting independently of the environment such as in the Galactic halo or in dSphs. Based on observations collected at the European Southern Observatory at Paranal, Chile; Large Programme proposal 171.B- 0520.Table A.1 is also 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/606/A112

Proper motions of five OB stars with candidate dusty bow shocks in the Carina Nebula

NASA Astrophysics Data System (ADS)

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

2017-06-01

We constrain the proper motions of five OB stars associated with candidate stellar wind bow shocks in the Carina Nebula using Hubble Space Telescope ACS imaging over 9-10 yr baselines. These proper motions allow us to directly compare each star's motion to the orientation of its candidate bow shock. Although these stars are saturated in our imaging, we assess their motion by the shifts required to minimize residuals in their airy rings. The results limit the direction of each star's motion to sectors less than 90° wide. None of the five stars are moving away from the Carina Nebula's central clusters as runaway stars would be, confirming that a candidate bow shock is not necessarily indicative of a runaway star. Two of the five stars are moving tangentially relative to the orientation of their candidate bow shocks, both of which point at the OB cluster Trumpler 14. In these cases, the large-scale flow of the interstellar medium, powered by feedback from the cluster, appears to dominate over the motion of the star in producing the observed candidate bow shock. The remaining three stars all have some component of motion towards the central clusters, meaning that we cannot distinguish whether their candidate bow shocks are indicators of stellar motion, of the flow of ambient gas or of density gradients in their surroundings. In addition, these stars' lack of outward motion hints that the distributed massive-star population in Carina's South Pillars region formed in place, rather than migrating out from the association's central clusters.

HUBBLE DISCOVERS POWERFUL LASER BEAMED FROM CHAOTIC STAR

NASA Technical Reports Server (NTRS)

2002-01-01

This is an artist's concept of a gas cloud (left) that acts as a natural ultraviolet laser, near the huge, unstable star Eta Carinae (right) -- one of most massive and energetic stars in our Milky Way Galaxy. The super-laser was identified by a team led by Kris Davidson of the University of Minnesota, and including nine other collaborators in the U.S. and Sweden during spectroscpic observations made with the Goddard High Resolution spectrograph aboard NASA's Hubble Space Telescope. Since it's unlikely that a single beam from the cloud would happen to be precisely aimed in earth's driection, the astronomers conclude that numerous beams must be radiating from the cloud in all directions - beams from a dance hall mirror-ball. The interstellar laser may result from Eta Carinae's violently chaotic eruptions, illustrated here as a reddish (due to light scattering by dust) outflow from the bright star. A laser, (an acronym for Light Amplification by Stimulated Emission of Radiation) creates an intense coherent beam of light when atoms or molecules in a gas, liquid or solid medium, force an incoming mix of wavelengths (or colors) of light to work in phase, or, at the same wavelength. Though a natural infrared laser was identified in space in 1995, lasers are very rare in space and nothing like the UV laser has ever been seen before. Eta Carinae is several million times brighter than the Sun, and one hundred times as massive. The superstar, located 8,000 light-years away in the souther constellation Carina, underwent a colossal outburst 150 years ago. Illustration courtesy James Gitlin/STScI

The first full orbit of η Carinae seen by Fermi

DOE PAGES

Reitberger, Klaus; Reimer, A.; Reimer, O.; ...

2015-05-08

The binary system η Carinae has completed its first 5.54 y orbit since the beginning of science operation of the Fermi Large Area Telescope (LAT). We are now able to investigate the high-energy γ-ray source at the position of η Carinae over its full orbital period. By this, we can address and confirm earlier predictions for temporal and spectral variability. Here, newer versions of the LAT datasets, instrument response functions and background models allow for a more accurate analysis. Therefore it is important to re-evaluate the previously analyzed time period along with the new data to further constrain location, spectralmore » shape, and flux time history of the γ-ray source. As a result, we confirm earlier predictions of increasing flux values above 10 GeV toward the next periastron passage. For the most recent part of the data sample, flux values as high as those before the first periastron passage in 2008 are recorded. A comparison of spectral energy distributions around periastron and apastron passages reveals strong variation in the high-energy band. This is due to a second spectral component that is present only around periastron. In conclusion, improved spatial consistency with the γ-ray source at the position of η Carinae along with the confirmation of temporal variability above 10 GeV in conjunction with the orbital period strengthens the argument for unambiguous source identification. Spectral variability provides additional constraints for future modeling of the particle acceleration and γ-ray emission in colliding-wind binary systems.« less

The carina angle-new geometrical parameter associated with periprocedural side branch compromise and the long-term results in coronary bifurcation lesions with main vessel stenting only.

PubMed

Gil, Robert J; Vassilev, Dobrin; Formuszewicz, Radoslaw; Rusicka-Piekarz, Teresa; Doganov, Alexander

2009-12-01

The two main problems unresolved in coronary bifurcation stenting are periprocedural side branch compromise and higher restenosis at long term. The purpose of this study is to reveal the link between periprocedural side branch compromise and long-term results after main vessel stenting only in coronary bifurcations. Eighty-four patients formed the study population. The inclusion criteria were good-quality angiograms, with maximal between-branch angle opening, no overlap, permitting accurate angiographic analysis. Carina angle (alpha)-the distal angle between main vessel (MV) before bifurcation and side branch (SB)-was measured pre- and poststenting. Clinical follow-up 9-12 months was obtained with coronary angiography if needed. The patient population was high-risk with 33% diabetics and 84% two- and three-vessel disease. Ninety-five stents were implanted in 92 lesions, with three T-stenting cases. Drug-eluting stents were implanted in 54%. Kissing-balloon (KBI) or sequential inflation was performed in 35%. SB functional closure occurred in 17.4%, with independent predictors alpha < 40 degrees and diameter ratio MB/SB >1.22. After 12+/-4 months there were five myocardial infarctions (6%) and 13 (15%) target lesion revascularization procedures. Independent predictors of major cardiovascular events were carina angle <40 degrees , MB lesion length >8 mm, negative change of between-branch angle, DES usage, and KBI. Smaller carina angle with straightening of MV-main branch from stent implantation in coronary bifurcations predicted higher SB compromise, restenosis, and MACE rates during follow-up of 1 year.

Exploring the multifaceted circumstellar environment of the luminous blue variable HR Carinae

NASA Astrophysics Data System (ADS)

Buemi, C. S.; Trigilio, C.; Leto, P.; Umana, G.; Ingallinera, A.; Cavallaro, F.; Cerrigone, L.; Agliozzo, C.; Bufano, F.; Riggi, S.; Molinari, S.; Schillirò, F.

2017-03-01

We present a multiwavelength study of the Galactic luminous blue variable HR Carinae, based on new high-resolution mid-infrared (IR) and radio images obtained with the Very Large Telescope (VLT) and the Australia Telescope Compact Array (ATCA), which have been complemented by far-infrared Herschel-Photodetector Array Camera and Spectrometer (PACS) observations and ATCA archive data. The Herschel images reveal the large-scale distribution of the dusty emitting nebula, which extends mainly to the north-east direction, up to 70 arcsec from the central star, and is oriented along the direction of the space motion of the star. In the mid-infrared images, the brightness distribution is characterized by two arc-shaped structures, tracing an inner envelope surrounding the central star more closely. At radio wavelengths, the ionized gas emission lies on the opposite side of the cold dust with respect to the position of the star, as if the ionized front were confined by the surrounding medium in the north-south direction. Comparison with previous data indicates significant changes in the radio nebula morphology and in the mass-loss rate from the central star, which has increased from 6.1 × 10-6 M⊙ yr-1 in 1994-1995 to 1.17 × 10-5 M⊙ yr-1 in 2014. We investigate possible scenarios that could have generated the complex circumstellar environment revealed by our multiwavelength data.

Eta Carinae: A Box of Puzzles...Some Solved, Others Await

NASA Technical Reports Server (NTRS)

Gull, Theodore

2010-01-01

In the l840's, Eta Carinae brightened to rival Sirius, then faded. Today we see a marginally naked-eye binary with an expanding, very dusty bipolar Homunculus. The energetics of the ejected mass (>l2 to 40 solar masses at 500-700 km/s plus outer bullets/strings up to 3000 km/s} approach that of a supernova. Extragalactic SN surveys detect near-supernovae thought to be like the Great Eruption of the 1840's. Eta Carinae presents an abundance of puzzles: rich in N, but 1/100th the solar C and O abundances; Ti, V, Sr, Sc persist in atomic states.... yet an abundance of molecules and dust exists in the Homunculus. How did molecules and dust form with low C and O? A near supernova occurred in the l840m, yet both binary companions, with total mass > 120 solar masses, survive in a very eccentric orbit. What is the near future of this system: a GRB? a SN? or just two WR stars that ultimately become two SNs? These and other puzzles will be presented

Estudio de la población estelar de varios cúmulos en Carina

NASA Astrophysics Data System (ADS)

Molina-Lera, J. A.; Baume, G. L.; Carraro, G.; Costa, E.

2015-08-01

Based on deep photometric data in the bands, complemented with infrared 2MASS data, we conducted an analysis of the fundamental parameters of six open clusters located in the Carina region. To perform a systematic study we developed a specialized code. In particular, we investigated the behavior of the respective lower main sequences. Our analysis indicated the presence of a significant population of pre-sequence stars in several of the clusters. We therefore obtained estimated values of contraction ages. Furthermore, we have determined the slopes of the initial mass functions of the studied clusters.

A Search for EGRET/Radio Pulsars in the ETA Carina Region

NASA Technical Reports Server (NTRS)

2002-01-01

Our analysis of EGRET data for the radio pulsar PSR B1046-58, which lies it the Eta Carina region of the Galaxy, was highly successful, resulting in the discovery of strong evidence for gamma-ray pulsations from this source. This work was published in the Astrophysical Journal. Additional support for the association was published in a companion paper in which an analysis of the X-ray counterpart to PSR B1046-58 was done, and we showed that it was the only possible counterpart to the gamma ray source within the EGRET error box.

The Changing Nature of QU Carinae: SN Ia Progenitor or a Hoax?

NASA Astrophysics Data System (ADS)

Kafka, Stella

2013-01-01

The race to the elusive Type Ia supernovae (SNe Ia) progenitors is at its zenith, with numerous clues from SNe Ia ejecta and a dearth of observational candidates. Still, the single degenerate channel is a viable route of mass accumulation onto a white dwarf to the Chandrasekhar limit. I present long-term high resolution spectroscopy of QU Carinae, one of the most promising single degenerate SNe Ia progenitors. I discuss its highly variable nature and compare it to current scenarios for mass accumulation onto high-mass white dwarfs, eventually leading to WD detonation and to a supernova explosion.

The Invisible Universe: A Tactile and Braille Exhibit of Astronomical Images

NASA Astrophysics Data System (ADS)

Arcand, Kimberly; Lestition, K.; Watzke, M.; Steel, S.

2010-01-01

As part of the "From Earth to the Universe" (FETTU) project, a NASA-funded tactile exhibit for the visually impaired community was launched in July 2009 at the Martin Luther King Library in D.C. The exhibit is part of the global FETTU exhibit, a project of the International Year of Astronomy 2009. The science content of the exhibit includes explanations of our Sun, Eta Carinae, Crab Nebula, Whirlpool Galaxy, and the electromagnetic spectrum, and was adapted from the NASA-funded Braille/tactile book Touch the Invisible Sky. Multiple geographic locations and venue types have been targeted for the displays. The FETTU-tactile exhibit opens a wider door to experiencing and understanding astronomy, bridging a gap in learning. This exhibit is based upon work supported by the National Aeronautics and Space Administration under proposal 08-EPO08-0068 issued through the Science Mission Directorate.

Exploring the Invisible Universe: A Tactile and Braille Exhibit of Astronomical Images

NASA Astrophysics Data System (ADS)

Arcand, K. K.; Watzke, M.; de Pree, C.

2010-06-01

A tactile/Braille exhibit for the visually impaired community in the USA was launched in July 2009. The exhibit is part of the global From Earth to the Universe (FETTU) project, a Cornerstone of the International Year of Astronomy 2009. The science content of the travelling tactile/Braille exhibit includes explanations of our Sun, Eta Carinae, the Crab Nebula, the Whirlpool Galaxy and the electromagnetic spectrum, and was adapted from the tactile/Braille book Touch the Invisible Sky. We present some of the early observations and findings on the tactile/Braille FETTU exhibit. The new exhibit opens a wider door to experiencing and understanding astronomy for the underserved visually impaired population.

Eta Carinae: An Astrophysical Laboratory to Study Conditions During the Transition Between a Pseudo-Supernova and a Supernova

NASA Astrophysics Data System (ADS)

McKinnon, Darren; Gull, T. R.; Madura, T.

2014-01-01

A major puzzle in the studies of supernovae is the pseudo-supernova, or the near-supernovae state. It has been found to precede, in timespans ranging from months to years, a number of recently-detected distant supernovae. One explanation of these systems is that a member of a massive binary underwent a near-supernova event shortly before the actual supernova phenomenon. Luckily, we have a nearby massive binary, Eta Carinae, that provides an astrophysical laboratory of a near-analog. The massive, highly-eccentric, colliding-wind binary star system survived a non-terminal stellar explosion in the 1800's, leaving behind the incredible bipolar, 10"x20" Homunculus nebula. Today, the interaction of the binary stellar winds 1") is resolvable by the Space Telescope Imaging Spectrograph (STIS) aboard the Hubble Space Telescope (HST). Using HST/STIS, several three-dimensional (3D) data cubes (2D spatial, 1D velocity) have been obtained at selected phases during Eta Carinae's 5.54-year orbital cycle. The data cubes were collected by mapping the central 1-2" at 0.05" intervals with a 52"x0.1" aperture. Selected forbidden lines, that form in the colliding wind regions, provide information on electron density of the shocked regions, the ionization by the hot secondary companion of the primary wind and how these regions change with orbital phase. By applying various analysis techniques to these data cubes, we can compare and measure temporal changes due to the interactions between the two massive winds. The observations, when compared to current 3D hydrodynamic models, provide insight on Eta Carinae's recent mass-loss history, important for determining the current and future states of this likely nearby supernova progenitor.

[Changes in the distance between carina and orotracheal tube during open or videolaparoscopic bariatric surgery].

PubMed

de Figueiredo Locks, Giovani; Simões de Almeida, Maria Cristina; Sperotto Ceccon, Maurício; Campos Pastório, Karen Adriana

2015-01-01

To examine whether there are changes in the distance between the orotracheal tubeand carina induced by orthostatic retractor placement or by pneumoperitoneum insufflation in obese patients undergoing gastroplasty. 60 patients undergoing bariatric surgery by two techniques: open (G1) or videola-paroscopic (G2) gastroplasty were studied. After tracheal intubation, adequate ventilation of both hemitoraxes was confirmed by lung auscultation. The distance orotracheal tube-carina was estimated with the use of a fiber bronchoscope before and after installation of orthostatic retractors in G1 or before and after insufflation of pneumoperitoneum in patients in G2. G1 was composed of 22 and G2 of 38 patients. No cases of endobronchial intubationwere detected in either group. The mean orotracheal tube-carina distance variation was estimated in -0.03 cm (95% CI 0.06 to -0.13) in the group of patients undergoing open gastroplastyand in -0.42 cm (95% CI -0.56 to -1.4) in the group of patients undergoing videolaparoscopic gastroplasty. The extremes of variation in each group were: 0.5 cm to -1.6 cm in patients under-going open surgery and 0.1 cm to -2.2 cm in patients undergoing videolaparoscopic surgery. There was no significant change in orotracheal tube-CA distance after placementof orthostatic retractors in patients undergoing open gastroplasty. There was a reduction inorotracheal tube-CA distance after insufflation of pneumoperitoneum in patients undergoing videolaparoscopic gastroplasty. We recommend attention to lung auscultation and to signals of ventilation monitoring and reevaluation of orotracheal tube placement after peritoneal insufflation. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Publicado por Elsevier Editora Ltda. All rights reserved.

Changes in the distance between carina and orotracheal tube during open or videolaparoscopic bariatric surgery.

PubMed

de Figueiredo Locks, Giovani; Simões de Almeida, Maria Cristina; Sperotto Ceccon, Maurício; Campos Pastório, Karen Adriana

2015-01-01

To examine whether there are changes in the distance between the orotracheal tube and carina induced by orthostatic retractor placement or by pneumoperitoneum insufflation in obese patients undergoing gastroplasty. 60 patients undergoing bariatric surgery by two techniques: open (G1) or videolaparoscopic (G2) gastroplasty were studied. After tracheal intubation, adequate ventilation of both hemitoraxes was confirmed by lung auscultation. The distance orotracheal tube-carina was estimated with the use of a fiber bronchoscope before and after installation of orthostatic retractors in G1 or before and after insufflation of pneumoperitoneum in patients in G2. G1 was composed of 22 and G2 of 38 patients. No cases of endobronchial intubation were detected in either group. The mean orotracheal tube-carina distance variation was estimated in -0.03cm (95% CI 0.06 to -0.13) in the group of patients undergoing open gastroplasty and in -0.42cm (95% CI -0.56 to -1.4) in the group of patients undergoing videolaparoscopic gastroplasty. The extremes of variation in each group were: 0.5cm to -1.6cm in patients undergoing open surgery and 0.1cm to -2.2cm in patients undergoing videolaparoscopic surgery. There was no significant change in orotracheal tube-CA distance after placement of orthostatic retractors in patients undergoing open gastroplasty. There was a reduction in orotracheal tube-CA distance after insufflation of pneumoperitoneum in patients undergoing videolaparoscopic gastroplasty. We recommend attention to lung auscultation and to signals of ventilation monitoring and reevaluation of orotracheal tube placement after peritoneal insufflation. Copyright © 2014 Sociedade Brasileira de Anestesiologia. Published by Elsevier Editora Ltda. All rights reserved.

The X-ray Spectral Evolution of eta Carinae as Seen by ASCA

NASA Technical Reports Server (NTRS)

Corcoran, M. F.; Fredericks, A. C.; Petre, R.; Swank, J. H.; Drake, S. A.; White, Nicholas E. (Technical Monitor)

2000-01-01

Using data from the ASCA X-ray observatory, we examine the variations in the X-ray spectrum of the supermassive star nu Carinae with an unprecedented combination of spatial and spectral resolution. We include data taken during the recent X-ray eclipse in 1997-1998, after recovery from the eclipse, and during and after an X-ray flare. We show that the eclipse variation in the X-ray spectrum is apparently confined to a decrease in the emission measure of the source. We compare our results with a simple colliding wind binary model and find that the observed spectral variations are only consistent, with the binary model if there is significant high-temperature emission far from the star and/or a substantial change in the temperature distribution of the hot plasma. If contamination in the 2-10 keV band is important, the observed eclipse spectrum requires an absorbing column in excess of 10(exp 24)/sq cm for consistency with the binary model, which may indicate an increase in the first derivative of M from nu Carinae near the time of periastron passage. The flare spectra are consistent with the variability seen in nearly simultaneous RXTE observations and thus confirm that nu Carinae itself is the source of the flare emission. The variation in the spectrum during the flare seems confined to a change in the source emission measure. By comparing 2 observations obtained at the same phase in different X-ray cycles, we find that the current, X-ray brightness of the source is slightly higher than the brightness of the source during the last cycle perhaps indicative of a long-term increase in the first derivative of M, not associated with the X-ray cycle.

Constraining the Properties of the Eta Carinae System via 3-D SPH Models of Space-Based Observations: The Absolute Orientation of the Binary Orbit

NASA Technical Reports Server (NTRS)

Madura, Thomas I.; Gull, Theodore R.; Owocki, Stanley P.; Okazaki, Atsuo T.; Russell, Christopher M. P.

2010-01-01

The extremely massive (> 90 Solar Mass) and luminous (= 5 x 10(exp 6) Solar Luminosity) star Eta Carinae, with its spectacular bipolar "Homunculus" nebula, comprises one of the most remarkable and intensely observed stellar systems in the galaxy. However, many of its underlying physical parameters remain a mystery. Multiwavelength variations observed to occur every 5.54 years are interpreted as being due to the collision of a massive wind from the primary star with the fast, less dense wind of a hot companion star in a highly elliptical (e approx. 0.9) orbit. Using three-dimensional (3-D) Smoothed Particle Hydrodynamics (SPH) simulations of the binary wind-wind collision in Eta Car, together with radiative transfer codes, we compute synthetic spectral images of [Fe III] emission line structures and compare them to existing Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) observations. We are thus able, for the first time, to constrain the absolute orientation of the binary orbit on the sky. An orbit with an inclination of i approx. 40deg, an argument of periapsis omega approx. 255deg, and a projected orbital axis with a position angle of approx. 312deg east of north provides the best fit to the observations, implying that the orbital axis is closely aligned in 3-1) space with the Homunculus symmetry axis, and that the companion star orbits clockwise on the sky relative to the primary.

Constraining the Properties of the Eta Carinae System via 3-D SPH Models of Space-Based Observations: The Absolute Orientation of the Binary Orbit

NASA Technical Reports Server (NTRS)

Madura, Thomas I.; Gull, Theodore R.; Owocki, Stanley P.; Okazaki, Atsuo T.; Russell, Christopher M. P.

2011-01-01

The extremely massive (> 90 Stellar Mass) and luminous (= 5 x 10(exp 6) Stellar Luminosity) star Eta Carinae, with its spectacular bipolar "Homunculus" nebula, comprises one of the most remarkable and intensely observed stellar systems in the Galaxy. However, many of its underlying physical parameters remain unknown. Multiwavelength variations observed to occur every 5.54 years are interpreted as being due to the collision of a massive wind from the primary star with the fast, less dense wind of a hot companion star in a highly elliptical (e approx. 0.9) orbit. Using three-dimensional (3-D) Smoothed Particle Hydrodynamics (SPH) simulations of the binary wind-wind collision, together with radiative transfer codes, we compute synthetic spectral images of [Fe III] emission line structures and compare them to existing Hubble Space Telescope/Space Telescope Imaging Spectrograph (HST/STIS) observations. We are thus able, for the first time, to tightly constrain the absolute orientation of the binary orbit on the sky. An orbit with an inclination of approx. 40deg, an argument of periapsis omega approx. 255deg, and a projected orbital axis with a position angle of approx. 312deg east of north provides the best fit to the observations, implying that the orbital axis is closely aligned in 3-D space with the Homunculus symmetry axis, and that the companion star orbits clockwise on the sky relative to the primary.

The Three-dimensional Structure of the Eta Carinae Homunculus

NASA Technical Reports Server (NTRS)

Steffen, W.; Teodoro, M.; Madura, T.I.; Groh, J.H.; Gull, T.R.; Mehner, A.; Corcoran, M.F.; Damineli, A.; Hamaguchi, K.

2014-01-01

We investigate, using the modeling code SHAPE, the three-dimensional structure of the bipolar Homunculus nebula surrounding Eta Carinae as mapped by new ESO VLT/X-Shooter observations of the H2 (lambda) = 2.12125 micrometers emission line. Our results reveal for the first time important deviations from the axisymmetric bipolar morphology: 1) circumpolar trenches in each lobe positioned point-symmetrically from the center and 2) offplanar protrusions in the equatorial region from each lobe at longitudinal (approximately 55 degrees) and latitudinal (10 degrees to 20 degrees) distances from the projected apastron direction of the binary orbit. The angular distance between the protrusions (approximately 110 degrees) is similar to the angular extent of each polar trench (approximately 130 degrees) and nearly equal to the opening angle of the wind-wind collision cavity (approximately 110 degrees). As in previous studies, we confirm a hole near the centre of each polar lobe and no detectable near-IR H2 emission from the thin optical skirt seen prominently in visible imagery. We conclude that the interaction between the outflows and/or radiation from the central binary stars and their orientation in space has had, and possibly still has, a strong influence on the Homunculus. This implies that prevailing theoretical models of the Homunculus are incomplete as most assume a single star origin that produces an axisymmetric nebula.We discuss how the newly found features might be related to the Homunculus ejection, the central binary and the interacting stellar winds.

Multiwavelength Imaging Of YSOs With Disk In South Pillars Of Eta Carina

NASA Astrophysics Data System (ADS)

Reyes, J. A.; Porras, B. A.

2013-04-01

We present multiwavelength imaginery and spectral energy distributions (SEDs) of 15 Young Stellar Objects (YSOs) with disk components lying on the South Pillars region close to Eta Carina (η Car). The SEDs include IR fluxes from 2MASS, IRAC, MSX, AKARI, and MIPS-24 μm, and 1.1 mm flux from AzTEC camera at the ASTE antenna. Millimeter fluxes help to constrain the number of fitted models, which provide the list of physical parameters for the star, the disk and the envelope. We then compare the parameters of the YSOs and their spatial location within the star forming region.

Eta Carinae and Its Ejecta, the Homunculus

NASA Technical Reports Server (NTRS)

Gull, Theodore R.

2014-01-01

Eta Carinae (Eta Car), its interacting winds and historical ejecta provide an unique astrophysical laboratory that permits addressing a multitude of questions ranging from stellar evolution, colliding winds, chemical enrichment, nebular excitation to the formation of molecules and dust. Every 5.54 years, Eta Car changes from high excitation to several-months-long low excitation caused by modulation of the massive interacting winds due to a very eccentric binary orbit. The surrounding Homunculus (Figure 1) and Little Homunculus, thrown out in the 1840s Great Eruption and the 1890s Lesser Eruption, respond to the changing flux, providing clues to many physical phenomena of great interest to astrophysicists.

Spectroscopic and photometric observations of M supergiants in Carina.

NASA Technical Reports Server (NTRS)

Humphreys, R. M.; Strecker, D. W.; Ney, E. P.

1972-01-01

Spectroscopic study of 30 Southern-Hemisphere M supergiants mostly in Carina in the blue and near-infrared, and photometrical study of these stars from 0.4 to 18 microns. The uncertainties in the determinations of interstellar extinction are discussed, and the spatial distribution of the M supergiants in the Carina arm is shown. The presence of the 11-micron excess attributed to silicate dust is a common feature. Stars of the same spectral type and luminosity class are remarkably homogeneous in their long-wave behavior. The silicate feature becomes more prominent in the more luminous stars and in stars of later spectral type. Four composite systems show little long-wave excess. The two VV Cephei objects have excesses probably produced by gas emission, and the other two have little or no excess - supporting the suggestion that the presence of the early star prohibits the formation of a dust envelope. Three stars - VY CMa, VX Sgr, and HD 9767 - appear to be extreme examples of stars with large excesses over the entire long-wave region. It is suggested that these objects are surrounded by large amounts of particulate material over a great range of distances from the stars.

SIMP J013656.5+093347 Is Likely a Planetary-mass Object in the Carina-Near Moving Group

NASA Astrophysics Data System (ADS)

Gagné, Jonathan; Faherty, Jacqueline K.; Burgasser, Adam J.; Artigau, Étienne; Bouchard, Sandie; Albert, Loïc; Lafrenière, David; Doyon, René; Bardalez Gagliuffi, Daniella C.

2017-05-01

We report on the discovery that the nearby (˜6 pc) photometrically variable T2.5 dwarf SIMP J013656.5+093347 is a likely member of the ˜200 Myr old Carina-Near moving group with a probability of >99.9% based on its full kinematics. Our v\\sin I measurement of 50.9 ± 0.8 km s-1 combined with the known rotation period inferred from variability measurements provide a lower limit of 1.01 ± 0.02 {R}{Jup} on the radius of SIMP 0136+0933, an independent verification that it must be younger than ˜950 Myr, according to evolution models. We estimate a field interloper probability of 0.2% based on the density of field T0-T5 dwarfs. At the age of Carina-Near, SIMP 0136+0933 has an estimated mass of 12.7 ± 1.0 {M}{Jup} and is predicted to have burned roughly half of its original deuterium. SIMP 0136+0933 is the closest known young moving group member to the Sun and is one of only a few known young T dwarfs, making it an important benchmark for understanding the atmospheres of young planetary-mass objects.

Detection of a Hot Binary Companion of eta Carinae

NASA Technical Reports Server (NTRS)

Sonnebom, G.; Iping, R. C.; Gull, T. R.; Massa, D. L.; Hillier, D. J.

2006-01-01

A hot companion of eta Carinae has been detected using high resolution spectra (905 - 1180 A) obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. Observations were obtained at two epochs of the 2024-day orbit: 2003 June during ingress to the 2003.5 X-ray eclipse and 2004 April several months after egress. These data show that essentially all the far-UV flux from eta Car shortward of Lyman alpha disappeared at least two days before the start of the X-ray eclipse (2003 June 29), implying that the hot companion, eta Car B, was also eclipsed by the dense wind or extended atmosphere of eta Car A. Analysis of the far-UV spectrum shows that eta Car B is a luminous hot star. N II 1084-1086 emission disappears at the same time as the far-UV continuum, indicating that this feature originates from eta Car B itself or in close proximity to it. The strong N II emission also raises the possibility that the companion star is nitrogen rich. The observed FUV flux levels and spectral features, combined with the timing of their disappearance, is consistent with eta Carinae being a massive binary system

Detection of a Hot Binary Companion of eta Carinae

NASA Technical Reports Server (NTRS)

Sonneborn, G.; Iping, R. C.; Gull, T. R.; Massa, D.; Hillier, D. J.

2006-01-01

A hot companion of eta Carinae has been detected using high resolution spectra (905 - 1 180 Angsroms) obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. Observations were obtained at two epochs of the 2024-day orbit: 2003 June during ingress to the 2003.5 X-ray eclipse and 2004 April several months after egress. These data show that essentially all the far-UV flux from eta Car shortward of Lyman alpha disappeared at least two days before the start of the X-ray eclipse (2003 June 29), implying that the hot companion, eta Car By was also eclipsed by the dense wind or extended atmosphere of eta Car A. Analysis of the far-UV spectrum shows that eta Car B is a luminous hot star. N II 1084-1086 emission disappears at the same time as the far-UV continuum, indicating that this feature originates from eta Car B itself or in close proximity to it. The strong N II emission also raises the possibility that the companion star is nitrogen rich. The observed FUV flux levels and spectral features, combined with the timing of their disappearance, are consistent with eta Carinae being a massive binary system.

Hubble Space Telescope imaging of Eta Carinae

NASA Technical Reports Server (NTRS)

Hester, J. J.; Westphal, James A.; Light, Robert M.; Currie, Douglas G.; Groth, Edward J.

1991-01-01

New high spatial resolution observations of the material around Eta Carinae, obtained with the Hubble Space Telescope Wide Field/Planetary Camera, are presented. The star Eta Carinae is one of the most massive and luminous stars in the Galaxy, and has been episodically expelling significant quantities of gas over the last few centuries. The morphology of the bright central nebulosity (the homunculus) indicates that it is a thin shell with very well defined edges, and is clumpy on 0.2 arcsec (about 10 to the 16th cm) scales. An extension to the northeast of the star (NN/NS using Walborn's 1976 nomenclature) appears to be a stellar jet and its associated bow shock. The bow shock is notable for an intriguing series of parallel linear features across its face. The S ridge and the W arc appear to be part of a 'cap' of emission located to the SW and behind the star. Together, the NE jet and the SW cap suggest that the symmetry axis for the system runs NE-SW rather than SE-NW, as previously supposed. Overall, the data indicate that the material around the star may represent an oblate shell with polar blowouts, rather than a bipolar flow.

Differential Motion Between Mediastinal Lymph Nodes and Primary Tumor in Radically Irradiated Lung Cancer Patients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schaake, Eva E.; Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam; Rossi, Maddalena M.G.

2014-11-15

Purpose/Objective: In patients with locally advanced lung cancer, planning target volume margins for mediastinal lymph nodes and tumor after a correction protocol based on bony anatomy registration typically range from 1 to 1.5 cm. Detailed information about lymph node motion variability and differential motion with the primary tumor, however, is lacking from large series. In this study, lymph node and tumor position variability were analyzed in detail and correlated to the main carina to evaluate possible margin reduction. Methods and Materials: Small gold fiducial markers (0.35 × 5 mm) were placed in the mediastinal lymph nodes of 51 patients with non-small cell lung cancermore » during routine diagnostic esophageal or bronchial endoscopic ultrasonography. Four-dimensional (4D) planning computed tomographic (CT) and daily 4D cone beam (CB) CT scans were acquired before and during radical radiation therapy (66 Gy in 24 fractions). Each CBCT was registered in 3-dimensions (bony anatomy) and 4D (tumor, marker, and carina) to the planning CT scan. Subsequently, systematic and random residual misalignments of the time-averaged lymph node and tumor position relative to the bony anatomy and carina were determined. Additionally, tumor and lymph node respiratory amplitude variability was quantified. Finally, required margins were quantified by use of a recipe for dual targets. Results: Relative to the bony anatomy, systematic and random errors ranged from 0.16 to 0.32 cm for the markers and from 0.15 to 0.33 cm for the tumor, but despite similar ranges there was limited correlation (0.17-0.71) owing to differential motion. A large variability in lymph node amplitude between patients was observed, with an average motion of 0.56 cm in the cranial-caudal direction. Margins could be reduced by 10% (left-right), 27% (cranial-caudal), and 10% (anteroposterior) for the lymph nodes and −2%, 15%, and 7% for the tumor if an online carina registration protocol replaced a protocol based on bony anatomy registration. Conclusions: Detailed analysis revealed considerable lymph node position variability, differential motion, and respiratory motion. Planning target volume margins can be reduced up to 27% in lung cancer patients when the carina registration replaces bony anatomy registration.« less

Diagnostic Value of Multidetector CT and Its Multiplanar Reformation, Volume Rendering and Virtual Bronchoscopy Postprocessing Techniques for Primary Trachea and Main Bronchus Tumors.

PubMed

Luo, Mingyue; Duan, Chaijie; Qiu, Jianping; Li, Wenru; Zhu, Dongyun; Cai, Wenli

2015-01-01

To evaluate the diagnostic value of multidetector CT (MDCT) and its multiplanar reformation (MPR), volume rendering (VR) and virtual bronchoscopy (VB) postprocessing techniques for primary trachea and main bronchus tumors. Detection results of 31 primary trachea and main bronchus tumors with MDCT and its MPR, VR and VB postprocessing techniques, were analyzed retrospectively with regard to tumor locations, tumor morphologies, extramural invasions of tumors, longitudinal involvements of tumors, morphologies and extents of luminal stenoses, distances between main bronchus tumors and trachea carinae, and internal features of tumors. The detection results were compared with that of surgery and pathology. Detection results with MDCT and its MPR, VR and VB were consistent with that of surgery and pathology, included tumor locations (tracheae, n = 19; right main bronchi, n = 6; left main bronchi, n = 6), tumor morphologies (endoluminal nodes with narrow bases, n = 2; endoluminal nodes with wide bases, n = 13; both intraluminal and extraluminal masses, n = 16), extramural invasions of tumors (brokethrough only serous membrane, n = 1; 4.0 mm-56.0 mm, n = 14; no clear border with right atelectasis, n = 1), longitudinal involvements of tumors (3.0 mm, n = 1; 5.0 mm-68.0 mm, n = 29; whole right main bronchus wall and trachea carina, n = 1), morphologies of luminal stenoses (irregular, n = 26; circular, n = 3; eccentric, n = 1; conical, n = 1) and extents (mild, n = 5; moderate, n = 7; severe, n = 19), distances between main bronchus tumors and trachea carinae (16.0 mm, n = 1; invaded trachea carina, n = 1; >20.0 mm, n = 10), and internal features of tumors (fairly homogeneous densities with rather obvious enhancements, n = 26; homogeneous density with obvious enhancement, n = 1; homogeneous density without obvious enhancement, n = 1; not enough homogeneous density with obvious enhancement, n = 1; punctate calcification with obvious enhancement, n = 1; low density without obvious enhancement, n = 1). MDCT and its MPR, VR and VB images have respective advantages and disadvantages. Their combination could complement to each other to accurately detect locations, natures (benignancy, malignancy or low malignancy), and quantities (extramural invasions, longitudinal involvements, extents of luminal stenoses, distances between main bronchus tumors and trachea carinae) of primary trachea and main bronchus tumors with crucial information for surgical treatment, are highly useful diagnostic methods for primary trachea and main bronchus tumors.

The 3D Structure of Eta Carinae's Nebula: A Definitive Picture from High-Dispersion Near-IR Spectra

NASA Technical Reports Server (NTRS)

Smith, N.

2006-01-01

High resolution long-slit spectra obtained with the Phoenix spectrograph on Gemini South provide our most accurate probe of the 3D structure of the Homunculus Nebula around Eta Carinae. Emission from molecular hydrogen at 2.122 microns traces a very thin outer skin, which contains the vast majority of the more than 10 solar masses of material in the nebula. This emission, in turn, yields our first definitive picture of the exact shape of the nebula, plus the latitude dependence of the mass-loss rate, speed, kinetic energy, shell thickness, and other properties associated with Eta Car's 19th century explosion. This will be critical for testing any models for the outburst mechanism. A preliminary analysis suggests that explosion from a critically rotating star was the dominant mechanism that gave rise to both the bipolar shape of the nebula and the production of its equatorial disk. [Fe II] emission in the near IR traces a geometrically thicker but less massive shell found on the inner surface of the H2 skin --- this is either a reverse shock that decelerates Eta Car's wind or a warm PDR. [Fe Ill emission also clarifies the structure of an inner "Little Homunculus" seen previously in HST/STlS spectra. Comparing these two tracers of cool molecular gas and warm partially-ionized gas resolves some significant confusion about the complex structure noted in previous studies.

3D Radiative Transfer in Eta Carinae: Application of the SimpleX Algorithm to 3D SPH Simulations of Binary Colliding Winds

NASA Technical Reports Server (NTRS)

Clementel, N.; Madura, T. I.; Kruip, C. J. H.; Icke, V.; Gull, T. R.

2014-01-01

Eta Carinae is an ideal astrophysical laboratory for studying massive binary interactions and evolution, and stellar wind-wind collisions. Recent three-dimensional (3D) simulations set the stage for understanding the highly complex 3D flows in Eta Car. Observations of different broad high- and low-ionization forbidden emission lines provide an excellent tool to constrain the orientation of the system, the primary's mass-loss rate, and the ionizing flux of the hot secondary. In this work we present the first steps towards generating synthetic observations to compare with available and future HST/STIS data. We present initial results from full 3D radiative transfer simulations of the interacting winds in Eta Car. We use the SimpleX algorithm to post-process the output from 3D SPH simulations and obtain the ionization fractions of hydrogen and helium assuming three different mass-loss rates for the primary star. The resultant ionization maps of both species constrain the regions where the observed forbidden emission lines can form. Including collisional ionization is necessary to achieve a better description of the ionization states, especially in the areas shielded from the secondary's radiation. We find that reducing the primary's mass-loss rate increases the volume of ionized gas, creating larger areas where the forbidden emission lines can form. We conclude that post processing 3D SPH data with SimpleX is a viable tool to create ionization maps for Eta Car.

3D Radiative Transfer in Eta Carinae: Application of the SimpleX Algorithm to 3D SPH Simulations of Binary Colliding Winds

NASA Technical Reports Server (NTRS)

Clementel, N.; Madura, T. I.; Kruip, C.J.H.; Icke, V.; Gull, T. R.

2014-01-01

Eta Carinae is an ideal astrophysical laboratory for studying massive binary interactions and evolution, and stellar wind-wind collisions. Recent three-dimensional (3D) simulations set the stage for understanding the highly complex 3D flows in eta Car. Observations of different broad high- and low-ionization forbidden emission lines provide an excellent tool to constrain the orientation of the system, the primary's mass-loss rate, and the ionizing flux of the hot secondary. In this work we present the first steps towards generating synthetic observations to compare with available and future HST/STIS data. We present initial results from full 3D radiative transfer simulations of the interacting winds in eta Car.We use the SimpleX algorithm to post-process the output from 3D SPH simulations and obtain the ionization fractions of hydrogen and helium assuming three different mass-loss rates for the primary star. The resultant ionization maps of both species constrain the regions where the observed forbidden emission lines can form. Including collisional ionization is necessary to achieve a better description of the ionization states, especially in the areas shielded from the secondary's radiation. We find that reducing the primary's mass-loss rate increases the volume of ionized gas, creating larger areas where the forbidden emission lines can form.We conclude that post processing 3D SPH data with SimpleX is a viable tool to create ionization maps for eta Car.

Astrophysical laser operating in the OI 8446-Åline in the Weigelt blobs of η Carinae

NASA Astrophysics Data System (ADS)

Johansson, S.; Letokhov, V. S.

2005-12-01

Within the framework of a simple model of photophysical processes in the Weigelt blobs in the vicinity of the luminous blue variable (LBV) star η Carinae, we explain the presence of the fluorescent 8446-Åand forbidden [OI] 6300-Ålines as well as the absence of the allowed OI 7774-Åline in spectra recorded with the Hubble Space Telescope (HST)/STIS instrument (Gull et al.). From atomic data and estimated stellar parameters we demonstrate that there is a population inversion and stimulated emission in the 3p3P-3s3S transition λ8446 due to photoexcitation by accidental resonance (PAR) by H Lyβ radiation.

Eta Carinae: X-ray Line Variations during the 2003 X-ray Minimum, and the Orbit Orientation

NASA Technical Reports Server (NTRS)

Corcoran, M. F.; Henley, D.; Hamaguchi, K.; Khibashi, K.; Pittard, J. M.; Stevens, I. R.; Gull, T. R.

2007-01-01

The future evolution of Eta Carinae will be as a supernova (or hypernova) and black hole. The evolution is highly contingent on mass and angular momentum changes and instabilities. The presence of a companion can serve to trigger instabilities and provide pathways for mass and angular momentum exchange loss. X-rays can be used a a key diagnostic tool: x-ray temperatures trace pre-shock wind velocities, periodic x-ray variability traces the orbit, and x-ray line variations traces the flow and orientation of shocked gas. This brief presentation highlights x-ray line variations from the HETG and presents a model of the colliding wind flow.

Bodotria jejuensis sp. nov. (Crustacea, Cumacea, Bodotriidae), a new Korean cumacean.

PubMed

Lee, Chang-Mok; Kim, Sung-Hyun; Kim, Young-Hyo

2016-09-06

A new species of Cumacea belonging to the genus Bodotria Goodsir, 1843 was collected from the Jeju-do Island, Korea. The new speices, Bodotria jejuensis sp. nov. is similar to B. similis Calman, 1907, B. rugosa Gamô, 1963, B. carinata Gamô, 1964, and B. biplicata Gamô, 1964 in having a pitted carapace, prominent dorso-lateral carina, and unarticulated endopod of uropod. However, longish elliptical shape of carapace, well-developed dorso-lateral carina and distinct lateral ridge are the major characteristics which serve to distinguish the new species from its congeners. The new species is fully illustrated and extensively compared with related species. A key to the Korean Bodotria species is also provided.

Spectrophotometry of the shell around AG Carinae

NASA Technical Reports Server (NTRS)

Mitra, P. Mila; Dufour, Reginald J.

1990-01-01

Spatially-resolved long-slit spectrophotometry are presented for two regions of the shell nebula around the P-Cygni variable star AG Carinae. The spectra cover the 3700-6800 A wavelength range. Emission-line diagnostics are used to derive extinction, electron temperatures, and densities for various positions in the nebula. The chemical abundances and ionization structure are calculated and compared with other types of planetary nebulae and shells around other luminous stars. It is found that the N/O and N/S ratios of Ag Car are high compared to solar neighborhood ISM values. The O/H depletion found for the AG Car shell approaches that found in the condensations of the Eta Car system.

SECULAR CHANGES IN ETA CARINAE'S WIND 1998-2011

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mehner, Andrea; Davidson, Kris; Humphreys, Roberta M.

2012-05-20

Stellar wind-emission features in the spectrum of eta Carinae have decreased by factors of 1.5-3 relative to the continuum within the last 10 years. We investigate a large data set from several instruments (STIS, GMOS, UVES) obtained between 1998 and 2011 and analyze the progression of spectral changes in direct view of the star, in the reflected polar-on spectra at FOS4, and at the Weigelt knots. We find that the spectral changes occurred gradually on a timescale of about 10 years and that they are dependent on the viewing angle. The line strengths declined most in our direct view ofmore » the star. About a decade ago, broad stellar wind-emission features were much stronger in our line-of-sight view of the star than at FOS4. After the 2009 event, the wind-emission line strengths are now very similar at both locations. High-excitation He I and N II absorption lines in direct view of the star strengthened gradually. The terminal velocity of Balmer P Cyg absorption lines now appears to be less latitude dependent, and the absorption strength may have weakened at FOS4. Latitude-dependent alterations in the mass-loss rate and the ionization structure of eta Carinae's wind are likely explanations for the observed spectral changes.« less

Resolving the Hα-emitting Region in the Wind of η Carinae

NASA Astrophysics Data System (ADS)

Wu, Ya-Lin; Smith, Nathan; Close, Laird M.; Males, Jared R.; Morzinski, Katie M.

2017-05-01

The massive evolved star η Carinae is the most luminous star in the Milky Way and has the highest steady wind mass-loss rate of any known star. Radiative transfer models of the spectrum by Hillier et al. predict that Hα is mostly emitted in regions of the wind at radii of 6-60 au from the star (2.5-25 mas at 2.35 kpc). We present diffraction-limited images (FWHM ˜ 25 mas) with Magellan adaptive optics in two epochs, showing that η Carinae consistently appears ˜2.5-3 mas wider in Hα emission compared to the adjacent 643 nm continuum. This implies that the Hα line-forming region may have a characteristic emitting radius of 12 mas or ˜30 au, in very good agreement with the Hillier stellar-wind model. This provides direct confirmation that the physical wind parameters of that model are roughly correct, including the mass-loss rate of \\dot{M}={10}-3 {M}⊙ {{yr}}-1, plus the clumping factor, and the terminal velocity. Comparison of the Hα images (ellipticity and PA) to the continuum images reveals no significant asymmetries at Hα. Hence, any asymmetry induced by a companion or by the primary’s rotation do not strongly influence the global Hα emission in the outer wind.

X-ray Monitoring of eta Carinae: Variations on a Theme

NASA Technical Reports Server (NTRS)

Corcoran, M. F.

2004-01-01

We present monitoring observations by the Rossi X-ray Timing Explorer of the 2-10 keV X-ray emission from the supermassive star eta Carinae from 1996 through late 2003. These data cover more than one of the stellar variability cycles in temporal detail and include especially detailed monitoring through two X-ray minima. We compare the current X-ray minimum which began on June 29, 2003 to the previous X-ray minimum which began on December 15, 1997, and refine the X-ray period to 2024 days. We examine the variations in the X-ray spectrum with phase and with time, and also refine our understanding of the X-ray peaks which have a quasi-period of 84 days, with significant variation. Cycle-to-cycle differences are seen in the level of X-ray intensity and in the detailed variations of the X-ray flux on the rise to maximum just prior to the X-ray minimum. Despite these differences the similarities between the decline to minimum, the duration of the minimum, and correlated variations of the X-ray flux and other measures throughout the electromagnetic spectrum leave little doubt that that the X-ray variation is strictly periodic and produced by orbital motion as the wind from eta Carinae collides with the wind of an otherwise unseen companion.

[Microcuff pediatric tracheal tube. A new tracheal tube with a high volume-low pressure cuff for children].

PubMed

Weiss, M; Dullenkopf, A; Gerber, A C

2004-01-01

Principles and characteristics of the recently introduced Microcuff paediatric tracheal tube (Microcuff, GmbH, Weinheim, Germany) with anatomically based depth markings, cuff-free subglottic tube shaft and short high volume-low pressure cuff with ultrathin cuff membrane are presented. First available tubes (ID 4.0 mm) were evaluated regarding cuff pressures required to seal the trachea and regarding the distance from the tube tip to the carina. After obtaining approval of the local ethical committee, 20 children aged 2-4 years, receiving tracheal intubation under general anaesthesia with muscle paralysis, were included. The tubes were placed during direct laryngoscopy and the glottic depth marking placed between the vocal cords. Cuff pressure to prevent audible air leakage at standardised ventilator settings (PIP 20 cm H(2)O/PEEP 5 cm H(2)O/RR20 x min(-1)) was assessed by means of a cuff pressure manometer within 5 min after intubation. Subsequently, the distance from the tube tip to the tracheal carina was measured by means of fibre bronchoscopy. Data are presented as the median (range). Patient age was 3.0 years (2.0-3.9 years), weight 13.5 kg (9.1-19.2 kg) and body length 95 cm (79-105 cm). The lowest cuff pressure required to seal the trachea ranged from 4-14 cmH(2)O (median 10 cm H(2)O), the distance from tube tip to tracheal carina was to 2.9 cm (2.0-4.5 cm). The new Microcuff paediatric tracheal tube with ultrathin high volume-low pressure cuff required tracheal sealing pressures below tracheal wall pressures usually required with uncuffed tracheal tubes for efficient sealing and ventilation at 20 cm H(2)O peak inspiratory pressure. The distance from the tube tip to carina was in the safe range in all patients.

Origin of the Central Constant Emission Component of Eta Carinae

NASA Technical Reports Server (NTRS)

Hamaguchi, Kenji; Corocoran, M. F.; Gull, T.; Ishibashi, K.; Pittard, J. M.; Hillier, D. J.; Damineli, A.; Davidson, K.; Nielsen, K. E.; Owocki, S.;

Phrenic nerve injury: An underrecognized and potentially preventable complication of pulmonary vein isolation using a wide-area circumferential ablation approach.

PubMed

Yong Ji, Sang; Dewire, Jane; Barcelon, Bernadette; Philips, Binu; Catanzaro, John; Nazarian, Saman; Cheng, Alan; Spragg, David; Tandri, Harikrishna; Bansal, Sandeep; Ashikaga, Hiroshi; Rickard, Jack; Kolandaivelu, Aravindan; Sinha, Sunil; Marine, Joseph E; Calkins, Hugh; Berger, Ronald

2013-10-01

Phrenic nerve injury (PNI) is a well-known, although uncommon, complication of pulmonary vein isolation (PVI) using radiofrequency energy. Currently, there is no consensus about how to avoid or minimize this injury. The purpose of this study was to determine how often the phrenic nerve, as identified using a high-output pacing, lies along the ablation trajectory of a wide-area circumferential lesion set. We also sought to determine if PVI can be achieved without phrenic nerve injury by modifying the ablation lesion set so as to avoid those areas where phrenic nerve capture (PNC) is observed. We prospectively enrolled 100 consecutive patients (age 61.7 ± 9.2 years old, 75 men) who underwent RF PVI using a wide-area circumferential ablation approach. A high-output (20 mA at 2 milliseconds) endocardial pacing protocol was performed around the right pulmonary veins and the carina where a usual ablation lesion set would be made. A total of 30% of patients had PNC and required modification of ablation lines. In the group of patients with PNC, the carina was the most common site of capture (85%) followed by anterior right superior pulmonary vein (RSPV) (70%) and anterior right inferior pulmonary vein (RIPV) (30%). A total of 25% of PNC group had capture in all 3 (RSPV, RIPV, and carina) regions. There was no difference in the clinical characteristics between the groups with and without PNC. RF PVI caused no PNI in either group. High output pacing around the right pulmonary veins and the carina reveals that the phrenic nerve lies along a wide-area circumferential ablation trajectory in 30% of patients. Modification of ablation lines to avoid these sites may prevent phrenic nerve injury during RF PVI. © 2013 Wiley Periodicals, Inc.

SU-E-T-538: Does Abdominal Compression Through Prone Patient Position Reduce Respiratory Motion in Lung Cancer Radiotherapy?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Catron, T; Rosu, M; Weiss, E

2014-06-01

Purpose: This study assesses the effect of physiological abdominal compression from prone positioning by comparing respiratory-induced tumor movements in supine and prone positions. Methods: 19 lung cancer patients underwent repeated supine and prone free-breathing 4DCT scans. The effect of patient position on motion magnitude was investigated for tumors, lymph nodes (9 cases), and subgroups of central (11 cases), peripheral (8 cases) and small peripheral tumors (5 cases), by evaluating the population average excursions, absolute and relative to a carina-point. Results: Absolute motion analysis: In prone, motion increased by ~20% for tumors and ~25% for lymph nodes. Central tumors moved moremore » compared to peripheral tumors in both supine and prone (~22%, and ~4% respectively). Central tumors movement increased by ~12% in prone. For peripheral tumors the increase in prone position was ~25% (~40% and 29% changes on along RL and AP directions). Motion relative to carina-point analysis: Overall, tumor excursions relative to carina-point increased by ~17% in prone. Lymph node relative magnitudes were lower by ~4%. Likewise, the central tumors moved ~7% less in prone. The subgroup of peripheral tumors exhibited increased amplitudes by ~44%; the small peripheral tumors had even larger relative displacements in prone (~46%). Conclusion: Tumor and lymph node movement in the patient population from this study averaged to be higher in prone than in supine position. Results from carina analysis also suggest that peripheral tissues have more physiologic freedom of motility when placed in the prone position, regardless of size. From these observations we should continue to avoid prone positioning for all types of primary lung tumor, suggesting that patients should receive radiotherapy for primary lung cancer in supine position to minimize target tissue mobility during normal respiratory effort. Further investigation will include more patients with peripheral tumors to validate our observations.« less

Effect of atelectasis changes on tissue mass and dose during lung radiotherapy.

PubMed

Guy, Christopher L; Weiss, Elisabeth; Jan, Nuzhat; Reshko, Leonid B; Christensen, Gary E; Hugo, Geoffrey D

2016-11-01

To characterize mass and density changes of lung parenchyma in non-small cell lung cancer (NSCLC) patients following midtreatment resolution of atelectasis and to quantify the impact this large geometric change has on normal tissue dose. Baseline and midtreatment CT images and contours were obtained for 18 NSCLC patients with atelectasis. Patients were classified based on atelectasis volume reduction between the two scans as having either full, partial, or no resolution. Relative mass and density changes from baseline to midtreatment were calculated based on voxel intensity and volume for each lung lobe. Patients also had clinical treatment plans available which were used to assess changes in normal tissue dose constraints from baseline to midtreatment. The midtreatment image was rigidly aligned with the baseline scan in two ways: (1) bony anatomy and (2) carina. Treatment parameters (beam apertures, weights, angles, monitor units, etc.) were transferred to each image. Then, dose was recalculated. Typical IMRT dose constraints were evaluated on all images, and the changes from baseline to each midtreatment image were investigated. Atelectatic lobes experienced mean (stdev) mass changes of -2.8% (36.6%), -24.4% (33.0%), and -9.2% (17.5%) and density changes of -66.0% (6.4%), -25.6% (13.6%), and -17.0% (21.1%) for full, partial, and no resolution, respectively. Means (stdev) of dose changes to spinal cord D max , esophagus D mean , and lungs D mean were 0.67 (2.99), 0.99 (2.69), and 0.50 Gy (2.05 Gy), respectively, for bone alignment and 0.14 (1.80), 0.77 (2.95), and 0.06 Gy (1.71 Gy) for carina alignment. Dose increases with bone alignment up to 10.93, 7.92, and 5.69 Gy were found for maximum spinal cord, mean esophagus, and mean lung doses, respectively, with carina alignment yielding similar values. 44% and 22% of patients had at least one metric change by at least 5 Gy (dose metrics) or 5% (volume metrics) for bone and carina alignments, respectively. Investigation of GTV coverage showed mean (stdev) changes in V Rx , D max , and D min of -5.5% (13.5%), 2.5% (4.2%), and 0.8% (8.9%), respectively, for bone alignment with similar results for carina alignment. Resolution of atelectasis caused mass and density decreases, on average, and introduced substantial changes in normal tissue dose metrics in a subset of the patient cohort.

Effect of atelectasis changes on tissue mass and dose during lung radiotherapy

PubMed Central

Guy, Christopher L.; Weiss, Elisabeth; Jan, Nuzhat; Reshko, Leonid B.; Christensen, Gary E.; Hugo, Geoffrey D.

2016-01-01

Purpose: To characterize mass and density changes of lung parenchyma in non-small cell lung cancer (NSCLC) patients following midtreatment resolution of atelectasis and to quantify the impact this large geometric change has on normal tissue dose. Methods: Baseline and midtreatment CT images and contours were obtained for 18 NSCLC patients with atelectasis. Patients were classified based on atelectasis volume reduction between the two scans as having either full, partial, or no resolution. Relative mass and density changes from baseline to midtreatment were calculated based on voxel intensity and volume for each lung lobe. Patients also had clinical treatment plans available which were used to assess changes in normal tissue dose constraints from baseline to midtreatment. The midtreatment image was rigidly aligned with the baseline scan in two ways: (1) bony anatomy and (2) carina. Treatment parameters (beam apertures, weights, angles, monitor units, etc.) were transferred to each image. Then, dose was recalculated. Typical IMRT dose constraints were evaluated on all images, and the changes from baseline to each midtreatment image were investigated. Results: Atelectatic lobes experienced mean (stdev) mass changes of −2.8% (36.6%), −24.4% (33.0%), and −9.2% (17.5%) and density changes of −66.0% (6.4%), −25.6% (13.6%), and −17.0% (21.1%) for full, partial, and no resolution, respectively. Means (stdev) of dose changes to spinal cord Dmax, esophagus Dmean, and lungs Dmean were 0.67 (2.99), 0.99 (2.69), and 0.50 Gy (2.05 Gy), respectively, for bone alignment and 0.14 (1.80), 0.77 (2.95), and 0.06 Gy (1.71 Gy) for carina alignment. Dose increases with bone alignment up to 10.93, 7.92, and 5.69 Gy were found for maximum spinal cord, mean esophagus, and mean lung doses, respectively, with carina alignment yielding similar values. 44% and 22% of patients had at least one metric change by at least 5 Gy (dose metrics) or 5% (volume metrics) for bone and carina alignments, respectively. Investigation of GTV coverage showed mean (stdev) changes in VRx, Dmax, and Dmin of −5.5% (13.5%), 2.5% (4.2%), and 0.8% (8.9%), respectively, for bone alignment with similar results for carina alignment. Conclusions: Resolution of atelectasis caused mass and density decreases, on average, and introduced substantial changes in normal tissue dose metrics in a subset of the patient cohort. PMID:27806593

Diagnostic Value of Multidetector CT and Its Multiplanar Reformation, Volume Rendering and Virtual Bronchoscopy Postprocessing Techniques for Primary Trachea and Main Bronchus Tumors

PubMed Central

Luo, Mingyue; Duan, Chaijie; Qiu, Jianping; Li, Wenru; Zhu, Dongyun; Cai, Wenli

2015-01-01

Purpose To evaluate the diagnostic value of multidetector CT (MDCT) and its multiplanar reformation (MPR), volume rendering (VR) and virtual bronchoscopy (VB) postprocessing techniques for primary trachea and main bronchus tumors. Methods Detection results of 31 primary trachea and main bronchus tumors with MDCT and its MPR, VR and VB postprocessing techniques, were analyzed retrospectively with regard to tumor locations, tumor morphologies, extramural invasions of tumors, longitudinal involvements of tumors, morphologies and extents of luminal stenoses, distances between main bronchus tumors and trachea carinae, and internal features of tumors. The detection results were compared with that of surgery and pathology. Results Detection results with MDCT and its MPR, VR and VB were consistent with that of surgery and pathology, included tumor locations (tracheae, n = 19; right main bronchi, n = 6; left main bronchi, n = 6), tumor morphologies (endoluminal nodes with narrow bases, n = 2; endoluminal nodes with wide bases, n = 13; both intraluminal and extraluminal masses, n = 16), extramural invasions of tumors (brokethrough only serous membrane, n = 1; 4.0 mm—56.0 mm, n = 14; no clear border with right atelectasis, n = 1), longitudinal involvements of tumors (3.0 mm, n = 1; 5.0 mm—68.0 mm, n = 29; whole right main bronchus wall and trachea carina, n = 1), morphologies of luminal stenoses (irregular, n = 26; circular, n = 3; eccentric, n = 1; conical, n = 1) and extents (mild, n = 5; moderate, n = 7; severe, n = 19), distances between main bronchus tumors and trachea carinae (16.0 mm, n = 1; invaded trachea carina, n = 1; >20.0 mm, n = 10), and internal features of tumors (fairly homogeneous densities with rather obvious enhancements, n = 26; homogeneous density with obvious enhancement, n = 1; homogeneous density without obvious enhancement, n = 1; not enough homogeneous density with obvious enhancement, n = 1; punctate calcification with obvious enhancement, n = 1; low density without obvious enhancement, n = 1). Conclusion MDCT and its MPR, VR and VB images have respective advantages and disadvantages. Their combination could complement to each other to accurately detect locations, natures (benignancy, malignancy or low malignancy), and quantities (extramural invasions, longitudinal involvements, extents of luminal stenoses, distances between main bronchus tumors and trachea carinae) of primary trachea and main bronchus tumors with crucial information for surgical treatment, are highly useful diagnostic methods for primary trachea and main bronchus tumors. PMID:26332466

Crew Earth Observations (CEO) taken during Expedition Six

NASA Image and Video Library

2003-02-01

ISS006-E-28028 (February 2003) --- The Southern Cross (left center), the Coal Sack Nebula (bottom left), and the Carina Nebula (upper right) are visible in this view photographed by astronaut Donald R. Pettit, Expedition Six NASA ISS science officer, on board the International Space Station (ISS). The Carina Nebula is a molecular cloud about 9000 light years from Earth where young stars are forming. The Coal Sack Nebula is an inky-black dust cloud about 2000 light years from Earth. Stars are probably condensing deep inside the Coal Sack, but their light has not yet broken through the cloud’s dense exterior. The Southern Cross, also known as The Crux, is a constellation familiar to southern hemisphere stargazers.

Computed-tomographic and conventional linear-tomographic evaluation of tracheobronchial lesions for laser photoresection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pearlberg, J.L.; Sandler, M.A.; Kvale, P.

1985-03-01

Laser therapy is a new modality for treatment of airway lesions. The authors examined 18 patients prior to laser photoresection of tracheobronchial lesions. Thirteen had cancers involving the distal trachea, carina, and/or proximal bronchi; five had benign lesions of the middle or proximal trachea. Each patient was examined by conventional linear tomography (CLT) and computed tomography (CT). CT was valuable in patients who had lesions of the distal trachea, carina, and/or proximal bronchi. Its particular usefulness, and its advantage relative to CLT, consisted in its ability to delineate vascular structures adjacent to the planned area of photoresection. Neither CLT normore » CT was helpful in evaluation of benign lesions of the proximal trachea.« less

Elemental and Molecular Relative Abundances in the Ejecta of Eta Carinae

NASA Technical Reports Server (NTRS)

Kober, G. V.; Gull, T. R.; Nielsen, K.; Bruhweiler, F.; Verner, K.; Stahl, O.; Weis, K.; Bomans, D.

2006-01-01

We are measuring relative elemental abundances for the ejecta in the line of sight from Eta Carinae using high dispersion spectroscopy with the HST/STIS and the VLT/UVES. While multiple velocity components have been identified, we focus on the -513 and -146 km/s components originating from the Homunculus and the Little Homunculus. Complicating factors are the complex nebular structures in the immediate vicinity of the bright, massive star: the very bright emission structures, Weigelt blobs B, C and D, the broad, clumpy structures of the extended wind apparently not photoionized by Eta Car B, and general scattered starlight from the extended wind and the dusty core of the circumstellar material. We have used the 3050 to 3160A region of overlap between STIS and UVES to intercompare equivalent widths of absorption lines to estimate the 'contributing factor', namely the amount of light originating from the star compared to nebular structures. While the extracted STIS spectra are from 0.1" wide aperture, the UVES spectra are limited by the 1" seeing conditions. Curiously we find that the scattering contribution in the UVES spectra changes with time, apparently with orbital phase of the 5.54-year period. This indicates that the dust may be modified by changes in the central source with phase. The noticeable drop in scattered light appears to occur about 1.7 years (phase 0.35) after the spectroscopic minimum. Relative abundances of iron peak elements and some molecules will be estimated. Observations in this study were accomplished with HST through STSci and with VLT through ESO and funded under STIS GTO resources.

Changes in the Far UV Spectrum of Eta Carinae Near the 2003 Minimum

NASA Technical Reports Server (NTRS)

Iping, R. C.; Gull, T. R.; Sonneborn, G.; Massa, D.; Vieira, G. L.; Nielsen, K. E.

2004-01-01

High resolution 905-1180 spectra of \\eta Carinae have been obtained with the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite at nine epochs between February 2000 and June 2003 . This period of time extends from the broad maximum up to the very beginning of the minimum of the 5.52-year period initially discovered by A. Damineli. The flux levels were unchanged between February 2000 through February 2003 with minor spectral differences. The X-Ray minimum started on June 29, 2003 . Three observations were accomplished on June 10, June 17 and June 27 leading up to the minimum. Substantial changes were present in the June 10 and June 17 spectra, but a very significant change occurred by June 27, 2003. Longward of 1100A, the overall flux dropped 10 to 30 %. Shortward of 1100A, there are spectral intervals with NO decrease in flux even down to the shortest wavelengths (920--950 ). This indicates that dust absorption has a negligible role in the observed spectral changes and that line absorptions play a major role. Throughout the spectrum there are intervals ranging in width of 3-10A with strong increased absorption. Significant absorptions may be associated with the red portion of the following stellar wind lines: C III 977, O VI 1031,1037, P V 1117, while other absorption features are much broader, more extended and not clearly associated with well-known spectral transitions. Given the complexity of the STIS echelle spectra taken in this period of time, many of these absorption features are likely due to multiple absorption lines

The Fe K Line Region Of η Carinae Around The X-ray Minima

NASA Astrophysics Data System (ADS)

Leyder, Jean-Christophe; Corcoran, M. F.; Henley, D. B.; Hamaguchi, K.; Ishibashi, K.; Pittard, J.

2011-09-01

We studied the Fe K line region of η Carinae with high-resolution X-ray Chandra grating spectra, using observations covering key phases around the last two X-ray minima (i.e. in 2003.5 and 2009). The line centroids are slightly redshifted, as opposed to the blueshifted lines observed at lower X-ray energies. This is the first observational evidence that the plasma producing the iron line emission is dynamically distinct from the plasma responsible for K-shell emission at lower energies, and is in agreement with the general colliding wind shock model. Gaussian modeling of the Fe XXV K-shell triplet blend shows apparent variations in centroid velocity, which are difficult to interpret as orbital motion of the companion star. Significant variability in the doppler broadening of the Fe K fluorescence emission line at 6.4 keV suggests that the formation of this line occurs in the wind of η Carinae at some particular phases. Of particular interest is the presence of a red wing in the profile of the Fe XXV triplet. This emission probably arises from iron in ionization states below Fe XXIV. Different mechanisms that might explain this emission will be discussed, e.g. an extremely bright, relatively cool, and heavily absorbed equilibrium plasma; emission from unshocked photoionized wind material; or assuming a fraction of the thermal plasma is not in ionization equilibrium.

Silicone Y-Stent Placement on the Secondary Left Carina.

PubMed

Oki, Masahide; Saka, Hideo

2015-01-01

The silicone Y-stent has mainly been used for the treatment of lesions around the main carina, and only a few case reports have been published on the technique for the lesions around the secondary left carina (LC2). We investigated the feasibility, efficacy and safety of a stenting technique using a silicone Y-stent for patients with airway stenosis around LC2. Patients who underwent airway stent placement between December 2010 and September 2014 in a single center were retrospectively reviewed. Under general anesthesia, using rigid and flexible bronchoscopes, the airway lumen was re-established followed by Y-stent placement on LC2. We performed 274 airway stenting procedures for 253 patients during the study period. Twelve of them (7 with lung cancer, 3 with esophageal cancer/carcinosarcoma, 1 with thyroid cancer and 1 with renal cancer) underwent a Y-stent placement on LC2. Respiratory symptoms were relieved in all patients. Six of 7 patients with supplemental oxygen, including the mechanically ventilated patient before stent placement, could be discharged without supplemental oxygen. The chest radiograph after the procedure showed increased lung volume in all 7 patients with partial or complete atelectasis. Median survival after stenting was 197 days at the time of data collection. Retention of secretions occurred in 1 and hemoptysis in another patient. Silicone Y-stent placement on LC2 is technically feasible, effective and acceptably safe. © 2015 S. Karger AG, Basel.

The Eta Carinae Homunculus in Full 3D with X-Shooter and Shape

NASA Technical Reports Server (NTRS)

Steffen, Wolfgang; Teodoro, Mairan; Madura, Thomas I.; Groh, Jose H.; Gull, Theodore R.; Mehner, Andrea; Corcoran, Michael F.; Damineli, Augusto; Hamaguchi, Kenji

2014-01-01

Massive stars like Eta Carinae are extremely rare in comparison to stars such as the Sun, and currently we know of only a handful of stars with masses of more than 100 solar mass in the Milky Way. Such massive stars were much more frequent in the early history of the Universe and had a huge impact on its evolution. Even among this elite club, Eta Car is outstanding, in particular because of its giant eruption around 1840 that produced the beautiful bipolar nebula now known as the Homunculus. In this study, we used detailed spatio-kinematic information obtained from X-shooter spectra to reconstruct the 3D structure of the Homunculus. The small-scale features suggest that the central massive binary played a significant role in shaping the Homunculus.

UV extinction properties of carina nebular dust

NASA Technical Reports Server (NTRS)

Massa, Derck

1993-01-01

I have performed an analysis of the UV extinction by dust along the line of sight to the young open cluster Tr 16. The observed curves are parameterized in order to extract quantitative information about the structure of the curves. Furthermore, by constructing differential extinction curves, obtained by differencing curves for stars which lie within a few arc seconds of each other on the sky, I was able to obtain a curve which is free of the effects of foreground extinction, and represents the extinction by the dust in the Tr 16 molecular cloud. I then show that this curve is nearly identical to one due to dust in the Orion molecular cloud. This result shows that dust in the Carina arm exhibits the same behavior as that in the local arm.

The -145 km/S Absorption System of Eta Carinae

NASA Technical Reports Server (NTRS)

Vieira, G.; Gull, T. R.; Danks, A.; Johansson, S.

2002-01-01

With the STIS E230H mode (R-118,000) , we have identified about twenty absorption components in line of sight from Eta Carinae. Two components, one at -513 km/s and another at -145 W s , are quite different in character from the others, mostly at intermediate velocities. The -145 km/s component is significantly wider in fwhm, is seen in many more species, and the lower level can be above 20,000/cm, well above the 2000/cm noted in the -513 km/s component. In the spectral region from 2400 to 3160A, approximately 500 absorption lines have been identified. In this poster, we will present line identifications and atomic parameters of the measured lines, hopefully providing insight as to what levels are being excited and by what processes.

Acyclic High-Energy Variability in Eta Carinae and WR 140

NASA Technical Reports Server (NTRS)

Corcoran, Michael F.

2012-01-01

Eta Carinae and WR 140 are similar long-period colliding wind binaries in which X-ray emission is produced by a strong shock due to the collision of the powerful stellar winds. The change in the orientation and density of this shock as the stars revolve in their orbits influences the X-ray flux and spectrum in a phase dependent way. Monitoring observations with RXTE and other X-ray satellite observatories since the 1990s have detailed this variability but have also shown significant deviations from strict phase dependence (short-term brightness changes or "flares", and cyc1e-to-cyc1e average flux differences). We examine these acylic variations in Eta Car and WR 140 and discuss what they tell us about the stability of the wind-wind collision shock.

Recent Efforts in Data Compilations for Nuclear Astrophysics

NASA Astrophysics Data System (ADS)

Dillmann, Iris

2008-05-01

Some recent efforts in compiling data for astrophysical purposes are introduced, which were discussed during a JINA-CARINA Collaboration meeting on ``Nuclear Physics Data Compilation for Nucleosynthesis Modeling'' held at the ECT* in Trento/Italy from May 29th-June 3rd, 2007. The main goal of this collaboration is to develop an updated and unified nuclear reaction database for modeling a wide variety of stellar nucleosynthesis scenarios. Presently a large number of different reaction libraries (REACLIB) are used by the astrophysics community. The ``JINA Reaclib Database'' on http://www.nscl.msu.edu/~nero/db/ aims to merge and fit the latest experimental stellar cross sections and reaction rate data of various compilations, e.g. NACRE and its extension for Big Bang nucleosynthesis, Caughlan and Fowler, Iliadis et al., and KADoNiS. The KADoNiS (Karlsruhe Astrophysical Database of Nucleosynthesis in Stars, http://nuclear-astrophysics.fzk.de/kadonis) project is an online database for neutron capture cross sections relevant to the s process. The present version v0.2 is already included in a REACLIB file from Basel university (http://download.nucastro.org/astro/reaclib). The present status of experimental stellar (n,γ) cross sections in KADoNiS is shown. It contains recommended cross sections for 355 isotopes between 1H and 210Bi, over 80% of them deduced from experimental data. A ``high priority list'' for measurements and evaluations for light charged-particle reactions set up by the JINA-CARINA collaboration is presented. The central web access point to submit and evaluate new data is provided by the Oak Ridge group via the http://www.nucastrodata.org homepage. ``Workflow tools'' aim to make the evaluation process transparent and allow users to follow the progress.

Comparative Computed Flow Dynamic Analysis of Different Optimization Techniques in Left Main Either Provisional or Culotte Stenting.

PubMed

Rigatelli, Gianluca; Dell'Avvocata, Fabio; Zuin, Marco; Giatti, Sara; Duong, Khanh; Pham, Trung; Tuan, Nguyen Si; Vassiliev, Dobrin; Daggubati, Ramesh; Nguyen, Thach

2017-12-01

Provisional and culotte are the most commonly used techniques in left main (LM) stenting. The impact of different post-dilation techniques on fluid dynamic of LM bifurcation has not been yet investigated. The aim of this study is to evaluate, by means of computational fluid dynamic analysis (CFD), the impact of different post-dilation techniques including proximal optimization technique (POT), kissing balloon (KB), POT-Side-POT and POT-KB-POT, 2-steps Kissing (2SK) and Snuggle Kissing balloon (SKB) on flow dynamic profile after LM provisional or culotte stenting. We considered an LM-LCA-LCX bifurcation reconstructed after reviewing 100 consecutive patients (mean age 71.4 ± 9.3 years, 49 males) with LM distal disease. The diameters of LAD and LCX were modelled according to the Finnet's law as following: LM 4.5 mm, LAD 3.5 mm, LCX 2.75 mm, with bifurcation angle set up at 55°. Xience third-generation stent (Abbot Inc., USA) was reconstructed and virtually implanted in provisional/cross-over and culotte fashion. POT, KB, POT-side-POT, POT-KB-POT, 2SK and SKB were virtually applied and analyzed in terms of the wall shear stress (WSS). Analyzing the provisional stenting, the 2SK and KB techniques had a statistically significant lower impact on the WSS at the carina, while POT seemed to obtain a neutral effect. In the wall opposite to the carina, the more physiological profile has been obtained by KB and POT with higher WSS value and smaller surface area of the lower WSS. In culotte stenting, at the carina, POT-KB-POT and 2SK had a very physiological profile; while at the wall opposite to the carina, 2SK and POT-KB-POT decreased significantly the surface area of the lower WSS compared to the other techniques. From the fluid dynamic point of view in LM provisional stenting, POT, 2SK and KB showed a similar beneficial impact on the bifurcation rheology, while in LM culotte stenting, POT-KB-POT and 2SK performed slightly better than the other techniques, probably reflecting a better strut apposition.

Extremely Hard X-ray Emission from Eta Carinae observed with XMM-Newton and NuSTAR around Periastron in 2014.5

NASA Astrophysics Data System (ADS)

Hamaguchi, Kenji; Corcoran, Michael F.; Takahashi, Hiromitsu; Yuasa, Tadayuki; Groh, Jose H.; Russell, Christopher Michael Post; Pittard, Julian M.; Madura, Thomas; Owocki, Stanley P.; Grefenstette, Brian

2015-01-01

The super massive colliding wind binary system, Eta Carinae, experienced another periastron passage in the summer of 2014. We monitored this event using the multiple X-ray observatories, Chandra, XMM-Newton, NuSTAR, Suzaku and Swift. With a high eccentricity of its 5.5 year orbit, X-ray emission from the wind-wind collision (WWC) increases strongly toward periastron but then drops sharply by more than two orders of magnitude in two weeks around periastron due probably to an eclipse and an intrinsic activity decline of the WWC plasma. In this observing campaign, XMM-Newton and NuSTAR coordinated two simultaneous observations around the X-ray flux maximum on June 6 and just before the flux minimum on July 28. These two observations captured Eta Carinae with X-ray focusing telescopes in the extreme hard X-ray band above 10 keV for the first time.During the first observation, XMM and NuSTAR detected stable X-ray emission from the central binary system between 1 - 40 keV. A fit of a 1-temperature bremsstrahlung model to the high energy slope in the NuSTAR spectrum derives an electron temperature of ~6 keV, which is significantly higher than an ionization temperature at ~4.5 keV, measured from the Fe K emission lines resolved in the XMM spectrum.This result suggests the presence of very hot plasma and/or X-ray reflection at surrounding cold material. During the second observation, the X-ray flux between 5 - 10 keV declined steadily by a factor of ~2 in a day, while the other energy bands were rather stable. This variation may be explained by an increase of the line of sight absorption to emission from the plasma component that dominates above 5 keV. NuSTAR did not detect, in either observation, the very hard non-thermal component that dominated emission above 25 keV seen in earlier INTEGRAL and Suzaku observations. We discuss the plasma condition and the wind structure of Eta Carinae around periastron, and the nature of the non-thermal component.

Origin of diffuse C II 158 micron and Si II 35 micron emission in the Carina nebula

NASA Astrophysics Data System (ADS)

Mizutani, M.; Onaka, T.; Shibai, H.

2004-08-01

We present the results of mapping observations with ISO of [O I] 63 μm, 145 μm, [N II] 122 μm, [C II] 158 μm, [Si II] 35 μm, and H_2 9.66 μm line emissions for the Carina nebula, an active star-forming region in the Galactic plane. The observations were made for the central 40 arcmin × 20 arcmin area of the nebula, including the optically bright H II region and molecular cloud lying in front of the ionized gas. Around the center of the observed area is the interface between the H II region and the molecular cloud which creates a typical photodissociation region (PDR). The [C II] 158 μm emission shows a good correlation with the [O I] 63 μm emission and peaks around the H II-molecular region interface. The correlated component has the ratio of [C II] 158 μm to [O I] 63 μm of about 2.8. We estimate from the correlation that about 80% of [C II] emission comes from the PDR in the Carina nebula. The photoelectric heating efficiency estimated from the ratio of the ([C II] 158 μm + [O I] 63 μm) intensity to the total far-infrared intensity ranges from 0.06 to 1.2%. [O I] 145 μm is detected marginally at 10 positions. The average ratio of [O I] 145 μm to [O I] 63 μm of these positions is about 0.09 ± 0.01 and is larger than model predictions. The observed [C II] 158 μm to [O I] 63 μm ratio indicates a relatively low temperature ( <500 K) of the gas, while the large [O I] 145 μm to 63 μm ratio suggests a high temperature (˜ 1000 K). This discrepancy cannot be accounted for consistently by the latest PDR model with the efficient photoelectric heating via polycyclic aromatic hydrocarbons (PAHs) even if absorption of [O I] 63 μm by foreground cold gas is taken into account. We suggest that absorption of [C II] 158 μm together with [O I] 63 μm by overlapping PDRs, in which the heating via PAHs is suppressed due to the charge-up effect, may resolve the discrepancy. Quite strong [Si II] 35 μm emission has been detected over the observed area. It shows a good correlation with [N II] 122 μm, but the correlation with [O I] 63 μm is very weak, indicating that [Si II] 35 μm comes mainly from the diffuse ionized gas rather than the PDR. The ratio of [Si II] 35 μm to [N II] 122 μm is about 8 and Si of about 50% of the solar abundance relative to N should be present in the gas phase. The present results suggest that efficient dust destruction takes place and a large fraction of Si returns to the gas in the Carina star-forming region. 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. Table 2 is only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/cgi-bin/qcat?J/A+A/423/579

3D Printing Meets Astrophysics: A New Way to Visualize and Communicate Science

NASA Astrophysics Data System (ADS)

Madura, Thomas Ignatius; Steffen, Wolfgang; Clementel, Nicola; Gull, Theodore R.

2015-08-01

3D printing has the potential to improve the astronomy community’s ability to visualize, understand, interpret, and communicate important scientific results. I summarize recent efforts to use 3D printing to understand in detail the 3D structure of a complex astrophysical system, the supermassive binary star Eta Carinae and its surrounding bipolar ‘Homunculus’ nebula. Using mapping observations of molecular hydrogen line emission obtained with the ESO Very Large Telescope, we obtained a full 3D model of the Homunculus, allowing us to 3D print, for the first time, a detailed replica of a nebula (Steffen et al. 2014, MNRAS, 442, 3316). I also present 3D prints of output from supercomputer simulations of the colliding stellar winds in the highly eccentric binary located near the center of the Homunculus (Madura et al. 2015, arXiv:1503.00716). These 3D prints, the first of their kind, reveal previously unknown ‘finger-like’ structures at orbital phases shortly after periastron (when the two stars are closest to each other) that protrude outward from the spiral wind-wind collision region. The results of both efforts have received significant media attention in recent months, including two NASA press releases (http://www.nasa.gov/content/goddard/astronomers-bring-the-third-dimension-to-a-doomed-stars-outburst/ and http://www.nasa.gov/content/goddard/nasa-observatories-take-an-unprecedented-look-into-superstar-eta-carinae/), demonstrating the potential of using 3D printing for astronomy outreach and education. Perhaps more importantly, 3D printing makes it possible to bring the wonders of astronomy to new, often neglected, audiences, i.e. the blind and visually impaired.

Connecting the dots: a correlation between ionizing radiation and cloud mass-loss rate traced by optical integral field spectroscopy

NASA Astrophysics Data System (ADS)

McLeod, A. F.; Gritschneder, M.; Dale, J. E.; Ginsburg, A.; Klaassen, P. D.; Mottram, J. C.; Preibisch, T.; Ramsay, S.; Reiter, M.; Testi, L.

2016-11-01

We present an analysis of the effect of feedback from O- and B-type stars with data from the integral field spectrograph Multi Unit Spectroscopic Explorer (MUSE) mounted on the Very Large Telescope of pillar-like structures in the Carina Nebular Complex, one of the most massive star-forming regions in the Galaxy. For the observed pillars, we compute gas electron densities and temperatures maps, produce integrated line and velocity maps of the ionized gas, study the ionization fronts at the pillar tips, analyse the properties of the single regions, and detect two ionized jets originating from two distinct pillar tips. For each pillar tip, we determine the incident ionizing photon flux Q0, pil originating from the nearby massive O- and B-type stars and compute the mass-loss rate dot{M} of the pillar tips due to photoevaporation caused by the incident ionizing radiation. We combine the results of the Carina data set with archival MUSE data of a pillar in NGC 3603 and with previously published MUSE data of the Pillars of Creation in M16, and with a total of 10 analysed pillars, find tight correlations between the ionizing photon flux and the electron density, the electron density and the distance from the ionizing sources, and the ionizing photon flux and the mass-loss rate. The combined MUSE data sets of pillars in regions with different physical conditions and stellar content therefore yield an empirical quantification of the feedback effects of ionizing radiation. In agreement with models, we find that dot{M}∝ Q_0,pil^{1/2}.

The VISTA Carina Nebula Survey. II. Spatial distribution of the infrared-excess-selected young stellar population

NASA Astrophysics Data System (ADS)

Zeidler, P.; Preibisch, T.; Ratzka, T.; Roccatagliata, V.; Petr-Gotzens, M. G.

2016-01-01

We performed a deep wide-field (6.76 sq. deg) near-infrared survey with the VISTA telescope that covers the entire extent of the Carina nebula complex (CNC). The point-source catalog created from these data contains around four million individual objects down to masses of 0.1 M⊙. We present a statistical study of the large-scale spatial distribution and an investigation of the clustering properties of infrared-excesses objects, which are used to trace disk-bearing young stellar objects (YSOs). A selection based on a near-infrared (J-H) versus (H-Ks) color-color diagram shows an almost uniform distribution over the entire observed area. We interpret this as a result of the very high degree of background contamination that arises from the Carina Nebula's location close to the Galactic plane. Complementing the VISTA near-infrared catalog with Spitzer IRAC mid-infrared photometry improves the situation of the background contamination considerably. We find that a (J-H) versus (Ks- [4.5]) color-color diagram is well suited to tracing the population of YSO-candidates (cYSOs) by their infrared excess. We identify 8781 sources with strong infrared excess, which we consider as cYSOs. This sample is used to investigate the spatial distribution of the cYSOs with a nearest-neighbor analysis. The surface density distribution of cYSOs agrees well with the shape of the clouds as seen in our Herschel far-infrared survey. The strong decline in the surface density of excess sources outside the area of the clouds supports the hypothesis that our excess-selected sample consists predominantly of cYSOs with a low level of background contamination. This analysis allows us to identify 14 groups of cYSOs outside the central area.Our results suggest that the total population of cYSOs in the CNC comprises about 164 000 objects, with a substantial fraction (~35%) located in the northern, still not well studied parts. Our cluster analysis suggests that roughly half of the cYSOs constitute a non-clustered, dispersed population. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under program ID 088.C-0117.Final VISTA+HAWKI+Spitzer catalog is 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/585/A49

Photophore counts in the deep-sea commercial shrimp Aristeus alcocki Ramadan, 1938 (Crustacea: Decapoda: Aristeidae), with a revised key to the Indo-West Pacific species of the genus.

PubMed

Chan, Tin-Yam; Kumar, Appukuttannair Biju; Yang, Chien-Hui

2017-10-06

The availability of abundant fresh material of Aristeus alcocki Ramadan, 1938 from India allowed the evaluation of the variation in the numbers of photophores on the pereiopods in this species, as well as other diagnostic characters for species discrimination. Although the pereiopodal photophore counts in A. alcocki largely overlap with those of A. semidentatus Bate, 1888, it is found that A. alcocki is unique in the Indo-West Pacific species of the genus by the lower end of the cervical carina considerably farther away from the branchiostegal carina. Molecular genetic analysis confirmed the distinct taxonomic status of the six currently known species in this genus from the Indo-West Pacific and a revised key is provided for distinguishing them.

The luminosity of the double-mode Cepheid Y Carinae

NASA Technical Reports Server (NTRS)

Evans, Nancy R.

1992-01-01

IUE spectra of the double-mode Cepheid Y Carinae have been used to determine the spectral type of the binary companion. From the companion spectral type (B9.O V), the absolute magnitude of the Cepheid is found to be -2.94 mag, with an estimated uncertainty of +/-0.3. This luminosity is in good agreement with that from the period-luminosity-color relation of Feast and Walker for the fundamental mode. This agreement, together with the large magnitude difference between the B9.0 V star and the Cepheid, confirm that the Cepheid is a normal classical Cepheid with a mass much larger than that inferred from the ratio of the two periods (beat mass). The two double-mode Cepheids with independently determined luminosities (Y Car and V 367 Sct) both fall on the blue edge of the instability strip.

Eta Carinae: A Demanding Mistress

NASA Technical Reports Server (NTRS)

Gull, Theodore

2012-01-01

In the 1840's a southern star, Eta Argus, brightened to rival Sirius for nearly a decade, then faded. Today, we see the Homunculus, an hourglass figure with tutu, a dusty shell exceeding 12 solar masses expanding outward at 500 km/s. Many observers have systematically studied the massive binary total shrouded by interacting winds and its ejecta. More recently 3-D wind-wind collision models have begun to explain the extended structures resolved by Hubble Space Telescope. Now Herschel Space Observatory infrared scans are revealing wind interaction emissions and complex molecules left over from the dust that formed out of gas originally overabundant in nitrogen and greatly-depleted in oxygen and carbon. Many questions remain to be answered: What is the dust that formed in the 1840s event? What are the end states of the two massive companions ... SN, GRB, Hypernova? and When

The -145 km/s Absorption System of Eta Carinae

NASA Technical Reports Server (NTRS)

Vieira, G.; Gull, Theodore R.; Danks, A.; Johansson, S.

2002-01-01

With the STIS E230H mode (R approx. 118,000), we have identified about twenty absorption components in line of sight from Eta Carinae. Two components, one at -513 km/s and another at -145 km/s, are quite different in character from the others, mostly at intermediate velocities. The -145 km/s component is significantly wider in fwhm, is seen in many more species, and the lower level can be above 20,000/cm, well above the 2000/cm noted in the -513 km/s component. In the spectral region from 2400 to 3160A, approximately 500 absorption lines have been identified. In this poster, we will present line identifications and atomic parameters of the measured lines, hopefully providing insight as to what levels are being excited and by what processes. Observations were accomplished through STScI under proposal 9242. Funding is through the STIS GTO resources.

Understanding the X-ray Flaring from Eta Carinae

NASA Technical Reports Server (NTRS)

Moffat, A.F.J.; Corcoran, Michael F.

2009-01-01

We quantify the rapid variations in X-ray brightness ("flares") from the extremely massive colliding wind binary Eta Carinae seen during the past three orbital cycles by RXTE. The observed flares tend to be shorter in duration and more frequent as periastron is approached, although the largest ones tend to be roughly constant in strength at all phases. Plausible scenarios include (1) the largest of multi-scale stochastic wind clumps from the LBV component entering and compressing the hard X-ray emitting wind-wind collision (WWC) zone, (2) large-scale corotating interacting regions in the LBV wind sweeping across the WWC zone, or (3) instabilities intrinsic to the WWC zone. The first one appears to be most consistent with the observations, requiring homologously expanding clumps as they propagate outward in the LBV wind and a turbulence-like powerlaw distribution of clumps, decreasing in number towards larger sizes, as seen in Wolf-Rayet winds.

Sanduleak's Star (LMC Anonymous) - Its similarity in the far-ultraviolet with the luminous object Eta Carinae and SN 1987A

NASA Technical Reports Server (NTRS)

Michalitsianos, A. G.; Kafatos, M.; Shore, S. N.

1989-01-01

Low-resolution IUE SWP spectra of the peculiar object LMC Anonymous (Sanduleak's Star) indicates strong evidence for CNO-processed nebula in the vicinity of the star. The far-UV spectrum of LMC Anonymous closely resembles that of the S Condensation of Eta Carinae. The similarity between LMC Anonymous and the S Condensation is apparent from the absolute intensity of the N V, semiforbidden N IV, and semiforbidden N III emission lines compared with the reduced strength of C IV or semiforbidden C III emission. IUE spectra of the S Condensation and SN 1987A may provide important clues concerning the nature of LMC Anonymous, which indicates departures from normal cosmic abundances of nitrogen relative to carbon that are extreme. This may suggest that carbon envelope burning and dredge-up occurred simultaneously during the helium-burning stage.

Hidden dental diversity in the oldest terrestrial apex predator Dimetrodon.

PubMed

Brink, Kirstin S; Reisz, Robert R

2014-01-01

Paleozoic sphenacodontid synapsids are the oldest known fully terrestrial apex predators. Dimetrodon and other sphenacodontids are the first terrestrial vertebrates to have strong heterodonty, massive skulls and well-developed labio-lingually compressed and recurved teeth with mesial and distal cutting edges (carinae). Here we reveal that the dentition of Dimetrodon and other sphenacodontids is diverse. Tooth morphology includes simple carinae with smooth cutting edges and elaborate enamel features, including the first occurrence of cusps and true denticles (ziphodonty) in the fossil record. A time-calibrated phylogenetic analysis indicates that changes in dental morphology occur in the absence of any significant changes in skull morphology, suggesting that the morphological change is associated with changes in feeding style and trophic interactions in these ecosystems. In addition, the available evidence indicates that ziphodonty evolved for the first time in the largest known species of the genus Dimetrodon and independently from the ziphodont teeth observed in some therapsids.

Sanduleak's Star (LMC Anonymous) - Its similarity in the far-ultraviolet with the luminous object Eta Carinae and SN 1987A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michalitsianos, A.G.; Kafatos, M.; Shore, S.N.

1989-06-01

Low-resolution IUE SWP spectra of the peculiar object LMC Anonymous (Sanduleak's Star) indicates strong evidence for CNO-processed nebula in the vicinity of the star. The far-UV spectrum of LMC Anonymous closely resembles that of the S Condensation of Eta Carinae. The similarity between LMC Anonymous and the S Condensation is apparent from the absolute intensity of the N V, semiforbidden N IV, and semiforbidden N III emission lines compared with the reduced strength of C IV or semiforbidden C III emission. IUE spectra of the S Condensation and SN 1987A may provide important clues concerning the nature of LMC Anonymous,more » which indicates departures from normal cosmic abundances of nitrogen relative to carbon that are extreme. This may suggest that carbon envelope burning and dredge-up occurred simultaneously during the helium-burning stage. 25 refs.« less

A radial velocity survey of the Carina Nebula's O-type stars

NASA Astrophysics Data System (ADS)

Kiminki, Megan M.; Smith, Nathan

2018-06-01

We have obtained multi-epoch observations of 31 O-type stars in the Carina Nebula using the CHIRON spectrograph on the CTIO/SMARTS 1.5-m telescope. We measure their radial velocities to 1-2 km s-1 precision and present new or updated orbital solutions for the binary systems HD 92607, HD 93576, HDE 303312, and HDE 305536. We also compile radial velocities from the literature for 32 additional O-type and evolved massive stars in the region. The combined data set shows a mean heliocentric radial velocity of 0.6 km s-1. We calculate a velocity dispersion of ≤9.1 km s-1, consistent with an unbound, substructured OB association. The Tr 14 cluster shows a marginally significant 5 km s-1 radial velocity offset from its neighbour Tr 16, but there are otherwise no correlations between stellar position and velocity. The O-type stars in Cr 228 and the South Pillars region have a lower velocity dispersion than the region as a whole, supporting a model of distributed massive star formation rather than migration from the central clusters. We compare our stellar velocities to the Carina Nebula's molecular gas and find that Tr 14 shows a close kinematic association with the Northern Cloud. In contrast, Tr 16 has accelerated the Southern Cloud by 10-15 km s-1, possibly triggering further massive star formation. The expansion of the surrounding H II region is not symmetric about the O-type stars in radial velocity space, indicating that the ionized gas is constrained by denser material on the far side.

He II lambda-4686 in Eta Carinae: Collapse of the Wind-Wind Collision Region During Periastron Passage

NASA Technical Reports Server (NTRS)

Teodoro, M.; Damineli, A.; Arias, J. I.; DeAraujo, F. X.; Barba, R. H.; Corcoran, M. F.; Fernandes, M. Borges; Fernandez-Lajus, E.; Fraga, L.; Gamen, R. C.;

The Orientation of Eta Carinae and the Powering Mechanism of Intermediate-luminosity Optical Transients (ILOTS)

NASA Astrophysics Data System (ADS)

Kashi, Amit; Soker, Noam

2018-05-01

Contrary to recent claims, we argue that the orientation of the massive binary system Eta Carinae is such that the secondary star is closer to us at periastron passage, and it is on the far side during most of the time of the eccentric orbit. The binary orientation we dispute is based on problematic interpretations of recent observations. Among these are the radial velocity of the absorption component of He I P-Cyg lines, of the He II λ4686 emission line, and of the Br γ line emitted by clumps close to the binary system. We also base our orientation on observations of asymmetric molecular clumps that were recently observed by ALMA around the binary system, and were claimed to compose a torus with a missing segment. The orientation has implications for the modeling of the binary interaction during the nineteenth century Great Eruption (GE) of Eta Carinae that occurred close to periastron passage. The orientation where the secondary is closer to us at periastron leads us to suggest that the mass-missing side of the molecular clumps is a result of accretion onto the secondary star during periastron passage when the clumps were ejected, probably during the GE. The secondary star accreted a few solar masses during the GE and the energy from the accretion process consists of the majority of the GE energy. This in turn strengthens the more general model according to which many intermediate-luminosity optical transients (ILOTS) are powered by accretion onto a secondary star.

NUV Spectroscopic Studies of Eta Car's Weigelt D across the 2003.5 Minimum

NASA Technical Reports Server (NTRS)

Ivarsson, S.; Nielsen, K. E.; Gull, T. R.; Hillier, J. D.

2006-01-01

HST/STIS high dispersion, high spatial resolution spectra in the near UV (2424-2705A) were recorded of Weigelt D, located 0.25" from Eta Carinae, before, during and after the star's 2003.5 minimum. Most nebular emission, including Lyman-alpha pumped Fe II and [Fe III] lines show phase dependent variations with disappearance at the minimum and reappearance a few months later. Circumstellar absorptions increase at minimum, especially in the Fe II resonance lines originating not only from ground levels but also meta stable levels well above the ground levels. These ionization/excitation effects can be explained by a sudden change in UV flux reaching the blobs, likely due to a line-of-sight obscuration of the hotter companion star, Eta Car B, recently discovered by Iping et al. (poster, this meeting). The scattered starlight seen towards Weigelt D display noticeable different line profiles than the direct starlight from Eta Carinae. P-Cygni absorption profiles in Fe II stellar lines observed directly towards Eta Carinae, show terminal velocities up to -550 km/s. However, scattered starlight of Weigelt D display significant lower velocities ranging from -40 to -150 km/s.We interpret this result to be indicative that no absorbing Fe II wind structure exists between the Central source and Weigelt D. The lower velocity absorption appears to be connected to the outer Fe II wind structure of Eta Car A extending beyond Weigelt D intersecting the observer's line of sight. This result is consistent with the highly extended wind of Eta Car A.

Specializations of the mandibular anatomy and dentition of Segnosaurus galbinensis (Theropoda: Therizinosauria).

PubMed

Zanno, Lindsay E; Tsogtbaatar, Khishigjav; Chinzorig, Tsogtbaatar; Gates, Terry A

2016-01-01

Definitive therizinosaurid cranial materials are exceptionally rare, represented solely by an isolated braincase and tooth in the North American taxon Nothronychus mckinleyi, the remarkably complete skull of the Asian taxon Erlikosaurus andrewsi, and the lower hemimandibles of Segnosaurus galbinensis. To date, comprehensive descriptions of the former taxa are published; however, the mandibular materials of S. galbinensis have remained largely understudied since their initial description in 1979. Here we provide a comprehensive description of the well-preserved hemimandibles and dentition of S. galbinensis (MPC-D 100/80), from the Upper Cretaceous Bayanshiree Formation, Gobi Desert, Mongolia. The subrectangular and ventrally displaced caudal hemimandible, extreme ventral deflection of the rostral dentary, and edentulism of the caudal dentary of S. galbinensis are currently apomorphic among therizinosaurians. Unique, unreported dental traits including lingually folded mesial carinae, development of a denticulated triangular facet on the distal carinae near the cervix, and extracarinal accessory denticles, suggest a highly specialized feeding strategy in S. galbinensis. The presence of triple carinae on the distalmost lateral tooth crowns is also unique, although may represent an abnormality. Contrasted with the simplistic dentition of the contemporaneous therizinosaurid E. andrewsi, the dentition of S. galbinensis is indicative of niche partitioning in food acquisition, processing, or resources among known therizinosaurids inhabiting Asian ecosystems in the Late Cretaceous. Although not quantitatively correlated with diet, this suite of specializations is otherwise unique among theropod dinosaurs and supports derived inferences of facultative or obligate herbivory in therizinosaurids, ultimately adding novel information to our understanding of ecomorphology in theropods.

Specializations of the mandibular anatomy and dentition of Segnosaurus galbinensis (Theropoda: Therizinosauria)

PubMed Central

Tsogtbaatar, Khishigjav; Chinzorig, Tsogtbaatar; Gates, Terry A.

2016-01-01

Definitive therizinosaurid cranial materials are exceptionally rare, represented solely by an isolated braincase and tooth in the North American taxon Nothronychus mckinleyi, the remarkably complete skull of the Asian taxon Erlikosaurus andrewsi, and the lower hemimandibles of Segnosaurus galbinensis. To date, comprehensive descriptions of the former taxa are published; however, the mandibular materials of S. galbinensis have remained largely understudied since their initial description in 1979. Here we provide a comprehensive description of the well-preserved hemimandibles and dentition of S. galbinensis (MPC-D 100/80), from the Upper Cretaceous Bayanshiree Formation, Gobi Desert, Mongolia. The subrectangular and ventrally displaced caudal hemimandible, extreme ventral deflection of the rostral dentary, and edentulism of the caudal dentary of S. galbinensis are currently apomorphic among therizinosaurians. Unique, unreported dental traits including lingually folded mesial carinae, development of a denticulated triangular facet on the distal carinae near the cervix, and extracarinal accessory denticles, suggest a highly specialized feeding strategy in S. galbinensis. The presence of triple carinae on the distalmost lateral tooth crowns is also unique, although may represent an abnormality. Contrasted with the simplistic dentition of the contemporaneous therizinosaurid E. andrewsi, the dentition of S. galbinensis is indicative of niche partitioning in food acquisition, processing, or resources among known therizinosaurids inhabiting Asian ecosystems in the Late Cretaceous. Although not quantitatively correlated with diet, this suite of specializations is otherwise unique among theropod dinosaurs and supports derived inferences of facultative or obligate herbivory in therizinosaurids, ultimately adding novel information to our understanding of ecomorphology in theropods. PMID:27069815

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abraham, Zulema; Beaklini, Pedro P. B.; Falceta-Gonçalves, Diego, E-mail: zulema.abraham@iag.usp.br

We report observations of η Carinae obtained with ALMA in the continuum of 100, 230, 280, and 660 GHz in 2012 November, with a resolution that varied from 2.''88 to 0.''45 for the lower and higher frequencies, respectively. The source is not resolved, even at the highest frequency; its spectrum is characteristic of thermal bremsstrahlung of a compact source, but different from the spectrum of optically thin wind. The recombination lines H42α, He42α, H40α, He40α, H50β, H28α, He28α, H21α, and He21α were also detected, and their intensities reveal non-local thermodynamic equilibrium effects. We found that the line profiles could onlymore » be fit by an expanding shell of dense and ionized gas, which produces a slow shock in the surroundings of η Carinae. Combined with fittings to the continuum, we were able to constrain the shell size, radius, density, temperature, and velocity. The detection of the He recombination lines is compatible with the high-temperature gas and requires a high-energy ionizing photon flux, which must be provided by the companion star. The mass-loss rate and wind velocity, necessary to explain the formation of the shell, are compatible with an luminous blue variable eruption. The position, velocity, and physical parameters of the shell coincide with those of the Weigelt blobs. The dynamics found for the expanding shell correspond to matter ejected by η Carinae in 1941 in an event similar to that which formed the Little Homunculus; for that reason, we called the new ejecta the 'Baby Homunculus'.« less

WISE First-Light Image

NASA Image and Video Library

2010-01-06

This infrared snapshot of a region in the constellation Carina near the Milky Way was taken shortly after NASA Wide-field Infrared Survey Explorer ejected its cover. The first-light picture shows thousands of stars and covers an area three times the s

Hubble Captures View of Mystic Mountain

NASA Image and Video Library

2010-04-22

NASA Hubble Space Telescope captures the chaotic activity atop a three-light-year-tall pillar of gas and dust that is being eaten away by the brilliant light from nearby bright stars in a tempestuous stellar nursery called the Carina Nebula.

Physical Conditions of Eta Car Complex Environment Revealed From Photoionization Modeling

NASA Technical Reports Server (NTRS)

Verner, E. M.; Bruhweiler, F.; Nielsen, K. E.; Gull, T.; Kober, G. Vieira; Corcoran, M.

2006-01-01

The very massive star, Eta Carinae, is enshrouded in an unusual complex environment of nebulosities and structures. The circumstellar gas gives rise to distinct absorption and emission components at different velocities and distances from the central source(s). Through photoionization modeling, we find that the radiation field from the more massive B-star companion supports the low ionization structure throughout the 5.54 year period. The radiation field of an evolved O-star is required to produce the higher ionization . emission seen across the broad maximum. Our studies utilize the HST/STIS data and model calculations of various regimes from doubly ionized species (T= 10,000K) to the low temperature (T = 760 K) conditions conductive to molecule formation (CH and OH). Overall analysis suggests the high depletion in C and O and the enrichment in He and N. The sharp molecular and ionic absorptions in this extensively CNO - processed material offers a unique environment for studying the chemistry, dust formation processes, and nucleosynthesis in the ejected layers of a highly evolved massive star.

Comparative Computed Flow Dynamic Analysis of Different Optimization Techniques in Left Main Either Provisional or Culotte Stenting

PubMed Central

Dell’Avvocata, Fabio; Zuin, Marco; Giatti, Sara; Duong, Khanh; Pham, Trung; Tuan, Nguyen Si; Vassiliev, Dobrin; Daggubati, Ramesh; Nguyen, Thach

2017-01-01

Abstract Background and Objectives Provisional and culotte are the most commonly used techniques in left main (LM) stenting. The impact of different post-dilation techniques on fluid dynamic of LM bifurcation has not been yet investigated. The aim of this study is to evaluate, by means of computational fluid dynamic analysis (CFD), the impact of different post-dilation techniques including proximal optimization technique (POT), kissing balloon (KB), POT-Side-POT and POT–KB-POT, 2-steps Kissing (2SK) and Snuggle Kissing balloon (SKB) on flow dynamic profile after LM provisional or culotte stenting. Methods We considered an LM-LCA-LCX bifurcation reconstructed after reviewing 100 consecutive patients (mean age 71.4 ± 9.3 years, 49 males) with LM distal disease. The diameters of LAD and LCX were modelled according to the Finnet’s law as following: LM 4.5 mm, LAD 3.5 mm, LCX 2.75 mm, with bifurcation angle set up at 55°. Xience third-generation stent (Abbot Inc., USA) was reconstructed and virtually implanted in provisional/cross-over and culotte fashion. POT, KB, POT-side-POT, POT-KB-POT, 2SK and SKB were virtually applied and analyzed in terms of the wall shear stress (WSS). Results Analyzing the provisional stenting, the 2SK and KB techniques had a statistically significant lower impact on the WSS at the carina, while POT seemed to obtain a neutral effect. In the wall opposite to the carina, the more physiological profile has been obtained by KB and POT with higher WSS value and smaller surface area of the lower WSS. In culotte stenting, at the carina, POT-KB-POT and 2SK had a very physiological profile; while at the wall opposite to the carina, 2SK and POT–KB-POT decreased significantly the surface area of the lower WSS compared to the other techniques. Conclusion From the fluid dynamic point of view in LM provisional stenting, POT, 2SK and KB showed a similar beneficial impact on the bifurcation rheology, while in LM culotte stenting, POT-KB-POT and 2SK performed slightly better than the other techniques, probably reflecting a better strut apposition. PMID:29340277

Omomyid primates (Tarsiiformes) from the Early Middle Eocene at South Pass, Greater Green River Basin, Wyoming.

PubMed

Muldoon, Kathleen M; Gunnell, Gregg F

2002-10-01

Recent fieldwork in the Gardnerbuttean (earliest Bridgerian) sediments along the northeastern edge of the Green River Basin at South Pass, Wyoming, has yielded a large and diverse sample of omomyid (tarsiiform) primates. This assemblage includes two species each of Artimonius gen. nov., Washakius, and Omomys, one species of Anaptomorphus, Trogolemur and Uintanius, and a new, primitive species of the rare omomyine genus,Utahia. Utahia is known elsewhere only from its type locality in the Uinta Basin and its phylogenetic position is poorly understood. Utahia carina sp. nov. allows for re-evaluation of the affinities of this genus relative to other omomyines. In most characters, such as a lesser degree of molar trigonid compression, more widely open talonid notches, and a lack of molar talonid crenulation, the new species is more primitive than U. kayi. The dental anatomy of U. carina also indicates that Utahia is morphologically intermediate between washakiins and omomyins, although the balance of anatomical features places Utahia as the sister taxon to a broadly defined "Ourayini" clade. Morphological similarity between U. carina, Loveina zephyri, and primitive Washakius suggests that while the omomyin and washakiin clades may have diverged by the middle Wasatchian, substantial morphological distinctions are first evidenced only in the early Bridgerian. This may be due either to a lack of appropriate faunal samples from older sediments, or, more likely, because ecological circumstances in the early Bridgerian favored omomyine diversification and subsequent replacement of previously occurring taxa. This hypothesis is further supported by the stratigraphic co-occurrence of U. carina, W. izetti, and a primitive variant of W. insignis at South Pass, a marginal area. Basin margins have been hypothesized to provide heterogeneous habitats conducive to the production of evolutionary innovation. Basin margin samples have also been cited as evidence that anaptomorphines were relegated to upland refugia as omomyine taxa began to appear in the later part of the early Eocene. Another possible explanation for the unusual co-occurrence of species at South Pass relates to fluctuating lake levels in the Green River Basin, which intermittently would have made lowland environments inhospitable for arboreal fauna. This would have created a situation whereby species which would normally be allopatric become sympatric at South Pass.

Anatomy and Neurophysiology of Cough

PubMed Central

Canning, Brendan J.; Chang, Anne B.; Bolser, Donald C.; Smith, Jaclyn A.; Mazzone, Stuart B.; Adams, Todd M.; Altman, Kenneth W.; Barker, Alan F.; Birring, Surinder S.; Blackhall, Fiona; Bolser, Donald, C.; Boulet, Louis-Philippe; Braman, Sidney S.; Brightling, Christopher; Callahan-Lyon, Priscilla; Canning, Brendan; Chang, Anne Bernadette; Coeytaux, Remy; Cowley, Terrie; Davenport, Paul; Diekemper, Rebecca L.; Ebihara, Satoru; El Solh, Ali A.; Escalante, Patricio; Feinstein, Anthony; Field, Stephen K.; Fisher, Dina; French, Cynthia T.; Gibson, Peter; Gold, Philip; Grant, Cameron; Harding, Susan M.; Harnden, Anthony; Hill, Adam T.; Irwin, Richard S.; Kahrilas, Peter J.; Keogh, Karina A.; Lane, Andrew P.; Lewis, Sandra Zelman; Lim, Kaiser; Malesker, Mark A.; Mazzone, Peter; Mazzone, Stuart; Molasiotis, Alex; Murad, M. Hassan; Newcombe, Peter; Nguyen, Huong Q.; Oppenheimer, John; Prezant, David; Pringsheim, Tamara; Restrepo, Marcos I.; Rosen, Mark; Rubin, Bruce; Ryu, Jay H.; Smith, Jaclyn; Tarlo, Susan M.; Turner, Ronald B.; Vertigan, Anne; Wang, Gang; Weir, Kelly

2014-01-01

Bronchopulmonary C-fibers and a subset of mechanically sensitive, acid-sensitive myelinated sensory nerves play essential roles in regulating cough. These vagal sensory nerves terminate primarily in the larynx, trachea, carina, and large intrapulmonary bronchi. Other bronchopulmonary sensory nerves, sensory nerves innervating other viscera, as well as somatosensory nerves innervating the chest wall, diaphragm, and abdominal musculature regulate cough patterning and cough sensitivity. The responsiveness and morphology of the airway vagal sensory nerve subtypes and the extrapulmonary sensory nerves that regulate coughing are described. The brainstem and higher brain control systems that process this sensory information are complex, but our current understanding of them is considerable and increasing. The relevance of these neural systems to clinical phenomena, such as urge to cough and psychologic methods for treatment of dystussia, is high, and modern imaging methods have revealed potential neural substrates for some features of cough in the human. PMID:25188530

Espectrofotometría en NGC 3255 y Hogg 17

NASA Astrophysics Data System (ADS)

Giorgi, E. E.; Solivella, G. R.; Vázquez, R. A.; Rizzo, L.

We present a spectrophotometric study of the open clusters NGC 3255 and Hogg 17, located in Carina and Centaurus respectively, based on new CCD UBVI photometry and spectral classification carried out in brightest stars in their fields. FULL TEXT IN SPANISH

The Carina Project. VI. The Helium-burning Variable Stars

NASA Astrophysics Data System (ADS)

Coppola, G.; Stetson, P. B.; Marconi, M.; Bono, G.; Ripepi, V.; Fabrizio, M.; Dall'Ora, M.; Musella, I.; Buonanno, R.; Ferraro, I.; Fiorentino, G.; Iannicola, G.; Monelli, M.; Nonino, M.; Pulone, L.; Thévenin, F.; Walker, A. R.

2013-09-01

We present new optical (BVI) time-series data for the evolved variable stars in the Carina dwarf spheroidal galaxy. The quality of the data and the observing strategy allowed us to identify 14 new variable stars. Eight out of the 14 are RR Lyrae (RRL) stars, 4 are Anomalous Cepheids (ACs), and 2 are geometrical variables. Comparison of the period distribution for the entire sample of RRLs with similar distributions in nearby dwarf spheroidal galaxies and in the Large Magellanic Cloud indicates that the old stellar populations in these systems share similar properties. This finding is also supported by the RRL distribution in the Bailey diagram. On the other hand, the period distribution and the Bailey diagram of ACs display significant differences among the above stellar systems. This evidence suggests that the properties of intermediate-age stellar populations might be affected both by environmental effects and structural parameters. We use the BV Period-Wesenheit (PW) relation of RRLs together with evolutionary prescriptions and find a true distance modulus of 20.09 ± 0.07 (intrinsic) ± 0.1 (statistical) mag that agrees quite well with similar estimates available in the literature. We identified four peculiar variables. Taking into account their position in the Bailey diagram and in the BV PW relation, two of them (V14 and V149) appear to be candidate ACs, while two (V158 and V182) might be peculiar RRLs. In particular, the variable V158 has a period and a V-band amplitude very similar to the low-mass RRL—RRLR-02792—recently identified by Pietrzyński et al. in the Galactic bulge. Based on images collected with the MOSAICII camera available at the CTIO 4 m Blanco telescope, La Serena (2003B-0051, 2004B-0227, and 2005B-0092; PI: A. R. Walker) and in part with the WFI available at the 2.2 m MPG/ESO telescope (A064.L-0327) and with images obtained from the ESO/ST-ECF Science Archive Facility.

[Ti II] and [Ni II] Emission from the Strontium Filament of eta Carinae

NASA Technical Reports Server (NTRS)

Bautista, M. A.; Hartman, H.; GUll, T. R.; Smith, N.; Lodders, K.

2007-01-01

We study the nature of the [Ti II] and [Ni II] emission from the so-called strontium filament found in the ejecta of eta Carinae. To this purpose we employ multilevel models of the Ti II and Ni II systems which are used to investigate the physical condition of the filament and the excitation mechanisms of the observed lines. For the Ti II ion, for which no atomic data was previously available, we carry out ab initio calculations of radiative transition rates and electron impact excitation rate coefficients. It is found that the observed spectrum is consistent with the lines being excited in a mostly neutral region with an electron density of the order of 10(exp 7) per cubic centimeter and a temperature around 6000 K. In analyzing three observations with different slit orientations recorded between March 2000 and November 2001 we find line ratios that change among various observations, in a way consistent with changes of up to an order of magnitude in the strength of the continuum radiation field. These changes result from different samplings of the extended filament, due to the different slit orientations used for each observation, and yield clues on the spatial extent and optical depth of the filament. The observed emission indicates a large Ti/Ni abundance ratio relative to solar abundances. It is suggested that the observed high Ti/Ni ratio in gas is caused by dust-gas fractionation processes and does not reflect the absolute Ti/Ni ratio in the ejecta of eta Carinae. We study the condensation chemistry of Ti, Ni and Fe within the filament and suggest that the observed gas phase overabundance of Ti is likely the result of selective photo-evaporation of Ti-bearing grains. Some mechanisms for such a scenario are proposed.

A Retrospective Multicentre Cohort Review of Patient Characteristics and Surgical Aspects versus the Long-Term Outcomes for Recipients of a Fully Implantable Active Middle Ear Implant

PubMed Central

Lefebvre, Philippe P.; Gisbert, Javier; Cuda, Domenico; Tringali, Stéphane; Deveze, Arnaud

2017-01-01

Objective To summarise treatment outcomes compared to surgical and patient variables for a multicentre recipient cohort using a fully implantable active middle ear implant for hearing impairment. To describe the authors' preferred surgical technique to determine microphone placement. Study Design Multicentre retrospective, observational survey. Setting Five tertiary referral centres. Patients Carina recipients (66 ears, 62 subjects) using the current Cochlear® Carina® System or the legacy device, the Otologics® Fully Implantable Middle Ear, with a T2 transducer. Methods Patient file review and routine clinical review. Patient outcomes assessed were satisfaction, daily use and feedback reports at the first fitting and ≥12 months after implantation. Descriptive and statistical analysis of correlations of variables and their influence on outcomes was performed. Independently reported preferred methods for microphone placement are collectively summarised. Results The average implant experience was 3.5 years. Satisfaction increased significantly over time (p < 0.05). No correlation with covariates examined was observed. Feedback significantly decreased over time, showing a significant correlation with microphone location, primary motivation, gender, age at implantation, and contralateral hearing aid use (p < 0.05). Patient satisfaction was inversely correlated with reports of system feedback (p < 0.05). The implantable microphone was most commonly on the posterior inferior mastoid line, in 42/66 (65%) cases, correlating with less likelihood for feedback and consistent with author surgical preference. Conclusion Carina recipients in this study present as satisfied consistent daily users with very few reports of persistent feedback. As microphone location is an influencing factor, a careful surgical consideration of microphone placement is required. The authors prefer a posterior inferior mastoid line position whenever possible. PMID:28052264

The Spatially-resolved Interacting Winds of Eta Carinae: Implications on the Orbit Orientation

NASA Technical Reports Server (NTRS)

Gull, Theodore R.; Nielsen, K.E.; Corcoran, M.; Hamaguchi, K.; Madura, T.; Russell, C.; Hillier, D.J.; Owocki. S.; Okazaki, A.T.

2010-01-01

Medium-dispersion long slit spectra, recorded by HST/STIS (R=8000, Theta=0.l"), resolve the extended wind-wind interaction region of the massive binary, Eta Carinae. During the high state, extending for about five years of the 5.54-year binary period, lines of [N II], [Fe III], [S III], [Ar III] and [Ne III] extend outwards to 0.4" with a velocity range of -500 to +200 km/s. By comparison, lines of [Fe II] and [Ni II] extend to 0.7" with a velocity range of -500 to +500 km/s. During the high state, driven by the lesser wind of Eta Car B and photo-ionized by the FUV of Eta Car B, the high excitation lines originate in or near the outer ballistic portions of the wind-wind interaction region. The lower excitation lines ([Fe II] and [Ni II D originate from the boundary regions of the dominating wind of Eta Car A. As the binary system has an eccentricity exceeding 0.9, the two stars approach quite close across the periastron, estimated to be within 1 to 2 AU. As a result, Eta Car B moves into the primary wind structure, cutting off the FUV supporting the ionization of the high state lines. Forbidden emission lines of the doubly-ionized species disappear, He II 4686 drops along with the collapse of the X-ray flux. This behavior is understood through the 3-D models of A. Okazaki and of E. R. Parkin and Pittard. Discussion will address the orbit orientation relative to the geometry of the Homunculus, ejected by Eta Carinae in the 1840s.

The Spatially-resolved Interacting Winds of Eta Carinae: Implications on the Orbit Orientation

NASA Astrophysics Data System (ADS)

Gull, Theodore R.; Nielsen, K. E.; Corcoran, M.; Hamaguchi, K.; Madura, T.; Russell, C.; Hillier, D. J.; Owocki, S.; Okazaki, A. T.

2010-01-01

Medium-dispersion long slit spectra, recorded by HST/STIS (R=8000, Theta=0.1"), resolve the extended wind-wind interaction region of the massive binary, Eta Carinae. During the high state, extending for about five years of the 5.54-year binary period, lines of [N II], [Fe III], [S III], [Ar III] and [Ne III] extend outwards to 0.4" with a velocity range of -500 to +200 km/s. By comparison, lines of [Fe II] and [Ni II] extend to 0.7" with a velocity range of -500 to +500 km/s. During the high state, driven by the lesser wind of Eta Car B and photo-ionized by the FUV of Eta Car B, the high excitation lines originate in or near the outer ballistic portions of the wind-wind interaction region. The lower excitation lines ([Fe II] and [Ni II]) originate from the boundary regions of the dominating wind of Eta Car A. As the binary system has an eccentricity exceeding 0.9, the two stars approach quite close across the periastron, estimated to be within 1 to 2 AU. As a result, Eta Car B moves into the primary wind structure, cutting off the FUV supporting the ionization of the high state lines. Forbidden emission lines of the doubly-ionized species disappear, He II 4686 drops along with the collapse of the X-ray flux. This behavior is understood through the 3-D models of A. Okazaki and of E. R. Parkin and Pittard. Discussion will address the orbit orientation relative to the geometry of the Homunculus, ejected by Eta Carinae in the 1840s.

Extinction in the Star Cluster SAI 113 and Galactic Structure in Carina

NASA Astrophysics Data System (ADS)

Carraro, Giovanni; Turner, David G.; Majaess, Daniel J.; Baume, Gustavo L.; Gamen, Roberto; Molina Lera, José A.

2017-04-01

Photometric CCD UB VI C photometry obtained for 4860 stars surrounding the embedded southern cluster SAI 113 (Skiff 8) is used to examine the reddening in the field and derive the distance to the cluster and nearby van Genderen 1. Spectroscopic color excesses for bright cluster stars, photometric reddenings for A3 dwarfs, and dereddening of cluster stars imply that the reddening and extinction laws match results derived for other young clusters in Carina: {E}U-B/{E}B-V≃ 0.64 and {R}V≃ 4. SAI 113 displays features that may be linked to a history of dynamical interactions among member stars: possible circumstellar reddening and rapid rotation of late B-type members, ringlike features in star density, and a compact core, with most stars distributed randomly across the field. The group van Genderen 1 resembles a stellar asterism, with potential members distributed randomly across the field. Distances of 3.90 ± 0.19 kpc and 2.49 ± 0.09 kpc are derived for SAI 113 and van Genderen 1, respectively, with variable reddenings {E}B-V ranging from 0.84 to 1.29 and 0.23 to 1.28. The SRC variables CK Car and EV Car may be outlying members of van Genderen 1, thereby of use for calibrating the period-luminosity relation for pulsating M supergiants. More importantly, the anomalous reddening and extinction evident in Carina and nearby regions of the Galactic plane in the fourth quadrant impact the mapping of spiral structure from young open clusters. The distribution of spiral arms in the fourth quadrant may be significantly different from how it is often portrayed.

The Populations of Carina. I. Decoding the Color-Magnitude Diagram

NASA Astrophysics Data System (ADS)

Norris, John E.; Yong, David; Venn, Kim A.; Dotter, Aaron; Casagrande, Luca; Gilmore, Gerard

2017-06-01

We investigate the color-magnitude diagram (CMD) of the Carina dwarf spheroidal galaxy using data of Stetson et al. and synthetic CMDs based on isochrones of Dotter et al., in terms of the parameters [Fe/H], age, and [α/Fe], for the cases when (I) [α/Fe] is held constant and (II) [α/Fe] is varied. The data are well described by four basic epochs of star formation, having [Fe/H] = -1.85, -1.5, -1.2, and ˜-1.15 and ages ˜13, 7, ˜3.5, and ˜1.5 Gyr, respectively (for [α/Fe] = 0.1, constant [α/Fe], and [α/Fe] = 0.2, 0.1, -0.2, -0.2, variable [α/Fe]), with small spreads in [Fe/H] and age of order 0.1 dex and 1-3 Gyr. Within an elliptical radius 13.‧1, the mass fractions of the populations, at their times of formation, were (in decreasing age order) 0.34, 0.39, 0.23, and 0.04. This formalism reproduces five observed CMD features (two distinct subgiant branches of old and intermediate-age populations, two younger, main-sequence components, and the small color dispersion on the red giant branch (RGB). The parameters of the youngest population are less certain than those of the others, and given it is less centrally concentrated, it may not be directly related to them. High-resolution spectroscopically analyzed RGB samples appear statistically incomplete compared with those selected using radial velocity, which contain bluer stars comprising ˜5%-10% of the samples. We conjecture these objects may, at least in part, be members of the youngest population. We use the CMD simulations to obtain insight into the population structure of Carina's upper RGB.

Esophageal motion during radiotherapy: quantification and margin implications.

PubMed

Cohen, R J; Paskalev, K; Litwin, S; Price, R A; Feigenberg, S J; Konski, A A

2010-08-01

The purpose was to evaluate interfraction and intrafraction esophageal motion in the right-left (RL) and anterior-posterior (AP) directions using computed tomography (CT) in esophageal cancer patients. Eight patients underwent CT simulation and CT-on-rails imaging before and after radiotherapy. Interfraction displacement was defined as differences between pretreatment and simulation images. Intrafraction displacement was defined as differences between pretreatment and posttreatment images. Images were fused using bone registries, adjusted to the carina. The mean, average of the absolute, and range of esophageal motion were calculated in the RL and AP directions, above and below the carina. Thirty-one CT image sets were obtained. The incidence of esophageal interfraction motion > or =5 mm was 24% and > or =10 mm was 3%; intrafraction motion > or =5 mm was 13% and > or =10 mm was 4%. The average RL motion was 1.8 +/- 5.1 mm, favoring leftward movement, and the average AP motion was 0.6 +/- 4.8 mm, favoring posterior movement. Average absolute motion was 4.2 mm or less in the RL and AP directions. Motion was greatest in the RL direction above the carina. Coverage of 95% of esophageal mobility requires 12 mm left, 8 mm right, 10 mm posterior, and 9 mm anterior margins. In all directions, the average of the absolute interfraction and intrafraction displacement was 4.2 mm or less. These results support a 12 mm left, 8 mm right, 10 mm posterior, and 9 mm anterior margin for internal target volume (ITV) and can guide margins for future intensity modulated radiation therapy (IMRT) trials to account for organ motion and set up error in three-dimensional planning.

EFFECTS OF TUMORS ON INHALED PHARMACOLOGIC DRUGS: I. FLOW PATTTERNS

EPA Science Inventory

ABSTRACT

Lung carcinomas are now the most common form of cancer. Clinical data suggest that tumors are found preferentially in upper airways, perhaps specifically at carina within bifurcations. The disease can be treated by aerosolized pharmacologic drugs. To enhance their...

Opening Doors for Marina and Carina

ERIC Educational Resources Information Center

Ritchey, Margaret

2011-01-01

This article describes the process of becoming a more reflective practitioner in the delivery of pediatric physical therapy through attention to 3 challenges: the therapist's resistance to addressing infant-parent mental health issues, the parents' resistance to acknowledging their infants' delays or disabilities, and the therapist's realization…

Multi-Wavelength Implications of the Companion Star in eta Carinae

NASA Technical Reports Server (NTRS)

Madura, Thomas I.; Gull, Theodore R.; Groh, Jose H.; Owocki, Stanley P.; Okazaki, Atsuo; Hillier, D. John; Russell, Christopher

2012-01-01

Eta-Carinae is considered to be a massive colliding wind binary system with a highly eccentric (e approximately 0.9), 5.54-yr orbit. However, the companion star continues to evade direct detection as the primary dwarfs its emission at most wavelengths. Using three-dimensional (3-D) SPH simulations of eta-Car's colliding winds and radiative transfer codes, we are able to compute synthetic observables across multiple wavebands for comparison to the observations. The models show that the presence of a companion star has a profound influence on the observed HST/STIS UV spectrum and H-alpha line profiles, as well as the ground-based photometric monitoring. Here, we focus on the Bore Hole effect, wherein the fast wind from the hot secondary star carves a cavity in the dense primary wind, allowing increased escape of radiation from the hotter/deeper layers of the primary's extended wind photosphere. The results have important implications for interpretations of eta-Car's observables at multiple wavelengths.

A 6 second periodic X-ray source in Carina

NASA Technical Reports Server (NTRS)

Seward, F. D.; Charles, P. A.; Smale, A. P.

1986-01-01

A serendipitous source, 1E 1048.1-5937, was discovered during Einstein imaging observations of the Carina nebula. On July 13, 1979, this source had an intensity of 0.14 IPC counts/s, and the signal was 65 percent pulsed with a period of 6.44 s. An earlier observation failed to detect any source with strength greater than 1/10 the above signal. The source is therefore highly variable, perhaps transient. An Exosat observation of this source on June 20, 1985 confirmed the pulse period and refined the source position to an accuracy of 10 arcsec. On the basis of the position, the source is tentatively identified with a V = 19 optical counterpart. The X-ray spectrum is best fitted by a power law with photon index = 2.26 and a column density of 1.6 x 10 to the 22nd atoms/sq cm. The X-ray characteristics are consistent with an accretion-powered Be star binary.

BANYAN. XII. New Members of Nearby Young Associations from GAIA–Tycho Data

NASA Astrophysics Data System (ADS)

Gagné, Jonathan; Roy-Loubier, Olivier; Faherty, Jacqueline K.; Doyon, René; Malo, Lison

2018-06-01

We present a search for stellar members of young associations within 150 pc of the Sun, based on TGAS and an updated version of the BANYAN Σ software to determine Bayesian membership probabilities that includes Gaia–2MASS color-magnitude diagrams. We identify 32 new F0–M3-type bona fide members of the 10–200 Myr old Sco-Cen, Carina, Tucana-Horologium, Columba, and Octans associations and the AB Doradus, β Pictoris, and Carina-Near moving groups. These new bona fide members have measurements of their full kinematics and literature data consistent with a young age. We also confirm the membership of 66 previously known candidate members using their Gaia–Tycho trigonometric distances or new literature radial velocities, and identify 219 additional new candidate members, most of which do not yet have a radial velocity measurement. This work is the first step toward a completeness-corrected survey of young association members based on Gaia DR2 in the near future.

Resolving the Wind Structure of Eta Carinae

NASA Technical Reports Server (NTRS)

Gull, T.; Hillier, J.; Ishibashi, K.; Davidson, K.

2000-01-01

Space Telescope Imaging Spectrograph (STIS) spectral observations of Eta Carinae have resolved the wind structure of the star(s) from the central point source. These observations were done with a 52 x 0.1" aperture, resolving power of about 5000 and complete spectral coverage from 1640A to 10400A. Various broad stellar Lines are seen to change within the central 0.511 of the nebular region. The Balmer lines, relative to the continuum, drop in strength while some Fe II lines scale with the continuum. Other Fe II lines increase in intensity while still others decrease. The structure to the southeast of the central source shows considerable variation in the stellar line strengths. To the Northwest, the emission is dominated by the very bright nebular knots, Weigelt blobs B and D. Three sets of observations have been done: March 1998, February 1999 and March 2000 to monitor the spectral variations. The stellar, wind and nebular emission changes considerably during this two year period. This work was done under the STIS GTO and HST GO funding.

Scandium and Chromium in the Strontium Filament in the Homunculus of eta Carinae

NASA Technical Reports Server (NTRS)

Gull, T.R.; Melendez, M.; Baustista, M.A.; Ballance, C.; Hartman, H.; Lodders, K.; Martinez, M.

2008-01-01

We continue a systematic study of chemical abundances of the Strontium Filament found in the ejecta of eta Carinae. To this end we interpret the emission spectrum of Sc II and Cr II using multilevel non-LTE models of these systems. Since the atomic data for these ions was previously unavailable, we carry out ab initio calculations of radiative transition rates and electron impact excitation rate coefficients. The observed spectrum is emitted from a mostly neutral region with electron density of the order of 10(exp 7) cm (exp -3) and a temperature between 6000 and 7000 K. These conditions are consistent with our previous diagnostics from [Ni II], [Ti II], amd [Sr II]. The observed spectrum indicates an abundance of Sc relative Ni that more than 40 times the solar values, while the Cr/Ni abundance ratio is roughly solar. Various scenarios of depletion and dust destruction are suggested to explain such abnormal abundances.

Molecules and Dust in the Humunculus: Ejecta of Eta Carinae

NASA Technical Reports Server (NTRS)

Gull, T.

2007-01-01

In the 18401s, Eta Carinae ejected massive amounts of nitrogen-rich, carbon- and oxygen-poor material which we see as the hourglass-shaped Homunculus. With the Hubble Space Telescope Imaging Spectrograph, we detected multiple shells in line of sight, the most massive and intriguing being at -513 km/s. Numerous lines of Fe I, Fe II, Ni II, Cr II, Sc II, Sr II, Ti II, V II, etc are identified as well as nearly a thousand H2 lines. The metals have energy level populations consistent with 760K and excited by photons < 8.5eV. We have now identified CH, CH+, OH, and NH at the same velocity, but at 60K, suggesting stratification in the outer ejecta. Analysis of the interior, photoionized emission hourglass structure, known as the Little Homunculus, indicates He, N overabundances and C, 0 underabundances (approximately 1/80 solar). A skirt of neutral and partially ionized gas lies between the lobes of the hourglasses. A portion is seen as the Strontium Filament, a metal- ionized, neutral hydrogen structure. Relative abundances of TiNi are 1/80 solar, CrNi are 1/20 solar. This complex of ejecta appears to have been ejected by a massive star(s) at the end of the hydrogen-burning phase when convection led to overproduction of nitrogen at the expense of carbon and oxygen. Given the underabundances of carbon and oxygen, the chemistry of this system is quite different to the normal ISM, leading to a nitrogen- dominated chemistry. What little C and 0 that is formed is immediately taken up by SiO and Al0 molecules leading to a very different gas/dust ratio than the normal ISM. Dust in this ejecta is abundance, but known to be very grey in character. Observations with HST/STIS and VLT/UVES will be presented along with simple physical models and CLOUD modeling. Insight by the participants will be solicited.

Through thick and thin: Structure of the Galactic thick disc from extragalactic surveys

NASA Astrophysics Data System (ADS)

Kordopatis, G.; Hill, V.; Irwin, M.; Gilmore, G.; Wyse, R. F. G.; Tolstoy, E.; de Laverny, P.; Recio-Blanco, A.; Battaglia, G.; Starkenburg, E.

2013-07-01

Context. We aim to understand the accretion history of the Milky Way by exploring the vertical and radial properties of the Galactic thick disc. Aims: We study the chemical and kinematic properties of roughly a thousand spectra of faint magnitude foreground Galactic stars observed serendipitously during extra-galactic surveys in four lines-of-sight: three in the southern Galactic hemisphere (surveys of the Carina, Fornax and Sculptor dwarf spheroidal galaxies) and one in the northern Galactic hemisphere (a survey of the Sextans dwarf spheroidal galaxy). The foreground stars span distances up to ~3 kpc from the Galactic plane and Galactocentric radii up to 11 kpc. Methods: The stellar atmospheric parameters (effective temperature, surface gravity, metallicity) are obtained by an automated parameterisation pipeline and the distances of the stars are then derived by a projection of the atmospheric parameters on a set of theoretical isochrones using a Bayesian approach. The metallicity gradients are estimated for each line-of-sight and compared with predictions from the Besançon model of the Galaxy, in order to test the chemical structure of the thick disc. Finally, we use the radial velocities in each line-of-sight to derive a proxy for either the azimuthal or the vertical component of the orbital velocity of the stars. Results: Only three lines-of-sight have a sufficient number of foreground stars for a robust analysis. Towards Sextans in the Northern Galactic hemisphere and Sculptor in the South, we measure a consistent decrease in mean metallicity with height from the Galactic plane, suggesting a chemically symmetric thick disc. This decrease can either be due to an intrinsic thick disc metallicity gradient, or simply due to a change in the thin disc/thick disc population ratio and no intrinsic metallicity gradients for the thick disc. We favour the latter explanation. In contrast, we find evidence of an unpredicted metal-poor population in the direction of Carina. This population was earlier detected, but our more detailed analysis provides robust estimates of its location (|Z| < 1 kpc), metallicity (-2 < [M/H] < -1 dex) and azimuthal orbital velocity (Vφ ~ 120 km s-1). Conclusions: Given the chemo-dynamical properties of the over-density towards the Carina line-of-sight, we suggest that it represents the metal-poor tail of the canonical thick disc. In spite of the small number of stars available, we suggest that this metal-weak thick disc follows the often suggested canonical thick disc velocity-metallicity correlation of ∂Vφ/∂ [M/H] ~ 40-50 km s-1 dex-1. Based on observations collected at the European Southern Observatory at Paranal, Chile, ESO Large Programme 171.B-0588 (DART) and 171.B-0520(A).Full Tables 2 and 4 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/555/A12

Resolving the Massive Binary Wind Interaction Of Eta Carinae with HST/STIS

NASA Technical Reports Server (NTRS)

Gull, Theodore; Nielsen, K.; Corcoran, M.; Hillier, J.; Madura, T.; Hamaguchi, K.; Kober, G.; Owocki, S.; Russell, C.; Okazaki, A.;

Eta Carinae - A Demanding Mistress

NASA Technical Reports Server (NTRS)

Gull, Theodore R.

2011-01-01

Over the past 15 years, a number of observers and modelers have increasingly focused on this massive system that is approaching its end stage, a supernova? a hypernova? When? The discovery by Augusto Damineli that Eta Carinae had a 5.5-year period proved timely as the newly-installed STIS was primed to observe its properties in the visible and ultraviolet. Initial observations occurred on January 1998, and through multiple programs, including the multi-cycle Hubble Treasury program, have sampled changes across two cycles. Now a multi-cycle program, focused on mapping variations in the extended wind-wind collision zones through early 2015, will test 3-D models of the interacting winds. In parallel, studies have been accomplished in X-rays with RXTE and CHANDRA, now in the far infrared with Herschel and from the ground with VLT. Each new observation is helping to peel back the veil of mystery on this massive binary system, but also opening up more questions to be answered. Timely inclusion of laboratory studies and models have greatly enhanced the observational results. We will summarize the latest results including submitted papers and very recent results with Herschel.

Suzaku Observation of Diffuse X-ray Emission from the Carina Nebula

NASA Technical Reports Server (NTRS)

Hamaguchi, Kenji; Petre, Robert; Matsumoti, Hironori; Tsujimoto, Masahiro; Holt, Stephan S.; Ezoe, Yuichiro; Ozawa, Hideki; Tsuboi, Yohko; Soong, Yang; Kitamoto, Shunji;

Interferometric Studies of Red Giants with MAPPIT

NASA Astrophysics Data System (ADS)

Ireland, Michael J.

2002-06-01

Powerful new tools for the analysis of wavelength-dispersed aperture masking data are presented, as applied to the MAPPIT instrument of the 3.9 m Anglo-Australia Telescope. By using both baseline and wavelength bootstrapping simultaneously, solutions were found for the phase of wavefronts degraded by atmospheric and instrumental effects. This allowed coherent processing of many data sets, greatly improving signal-to-noise both at the longest baselines for well resolved objects, and at all baselines in for data in TiO absorption bands. Using this new techniques, as well as power spectrum-based techniques, wavelength-dependent diameters are found in the range 650-950 nm for the following stars: R Carinae, R Leonis, omicron Ceti, R Hydrae, W Hydrae, R Doradus, L2 Puppis, alpha Orionis, gamma Crucis, eta Carinae and VY Canis Majoris. All the Mira-like stars showed greater than 50% variation in diameter over the available wavelength range. L2 Puppis, a semi-regular variable resolved for the first time, showed a variation in diameter consistent with scattering by a recently ejected shell of dust.

Ultraviolet studies of Cepheids

NASA Technical Reports Server (NTRS)

Boehm-Vitense, Erika

1992-01-01

We discuss whether with new evolutionary tracks we still have a problem fitting the Cepheids and their evolved companions on the appropriate evolutionary tracks. We find that with the Bertelli et al. tracks with convective overshoot by one pressure scale height the problem is essentially removed, though somewhat more mixing would give a better fit. By using the results of recent nonlinear hydrodynamic calculations, we find that we also have no problem matching the observed pulsation periods of the Cepheids with those expected from their new evolutionary masses, provided that Cepheids with periods less than 9 days are overtone pulsators. We investigate possible mass loss of Cepheids from UV studies of the companion spectrum of S Mus and from the ultraviolet spectra of the long period Cepheid l Carinae. For S Mus with a period of 9.6 days we derive an upper limit for the mass loss of M less than 10(exp -9) solar mass, if a standard velocity law is assumed for the wind. For l Carinae with a period of 35.5 days we find a probable mass loss of M is approximately 10(exp -5+/-2) solar mass.

The oldest South American occurrence of Spinosauridae (Dinosauria, Theropoda)

NASA Astrophysics Data System (ADS)

Sales, Marcos A. F.; Liparini, Alexandre; de Andrade, Marco B.; Aragão, Paulo R. L.; Schultz, Cesar L.

2017-03-01

A new fossil site, called 'Canafístula 01', has yielded the first archosaur remains from the Berriasian-Valanginian Feliz Deserto Formation, Sergipe-Alagoas Basin, northeastern Brazil. Most of them comprise crocodylomorph teeth and osteoderms. However, the most remarkable specimen is a partial tooth assigned to Spinosauridae, based on the unique combination of the following features: (1) unfluted root almost as wide as the crown base, with a large pulp cavity; (2) straight and more regularly spaced flutes of the crown, formed by both the enamel and the dentine; and (3) unserrated carina on a mesiodistal plane coinciding with the main plane of curvature of the crown. This is the oldest occurrence of a spinosaurid from South America. In addition, given the unserrated distal carina, this tooth might have closer affinities with the subfamily Spinosaurinae, which would also represent the oldest spinosaurine record worldwide. Thus, the occurrence of a spinosaurid in the Feliz Deserto Formation points to a latent potential for new relevant findings in northeastern Brazil and the necessity for greater collection efforts in this region.

Eclipsing Binaries in Open Clusters

NASA Astrophysics Data System (ADS)

Southworth, John; Clausen, Jens Viggo

2006-08-01

The study of detached eclipsing binaries in open clusters can provide stringent tests of theoretical stellar evolutionary models, which must simultaneously fit the masses, radii, and luminosities of the eclipsing stars and the radiative properties of every other star in the cluster. We review recent progress in such studies and discuss two unusually interesting objects currently under analysis. GV Carinae is an A0 m + A8 m binary in the Southern open cluster NGC 3532; its eclipse depths have changed by 0.1 mag between 1990 and 2001, suggesting that its orbit is being perturbed by a relatively close third body. DW Carinae is a high-mass unevolved B1 V + B1 V binary in the very young open cluster Collinder 228, and displays double-peaked emission in the centre of the Hα line which is characteristic of Be stars. We conclude by pointing out that the great promise of eclipsing binaries in open clusters can only be satisfied when both the binaries and their parent clusters are well-observed, a situation which is less common than we would like.

[Ti II] and [Ni II] Emission from the Strontium Filament of eta Carinae

NASA Technical Reports Server (NTRS)

Bautista, M. A.; Hartman, H.; Gull, T. R.; Smith, N.; Lodders, K.

2005-01-01

We study the nature of the [Ti II] and [Ni II] emission from the so-called strontium filament found in the ejecta of eta Carinae. To this purpose we employ multilevel models of the Ti II and Ni II systems which are used to investigate the physical condition of the filament and the excitation mechanisms of the observed lines. For the Ti II ion, for which no atomic data was previously available, we carry out ab initio calculations of radiative transition rates and electron impact excitation rate coefficients. It is found that the observed spectrum is consistent with the lines being excited in a mostly neutral region with electron density of the order of 10(exp 7) cm(exp -3) and a temperature around 6000 K. In analyzing three observations with different slit orientations recorded between March 2000 and November 2001 we find line ratios that change among various observations, in a way consistent with changes of up to an order of magnitude in the strength of the continuum radiation field. These changes result from different samplings of the extended filament, due to the different slit orientations used for each observation, and yield clues on the spatial extent and optical depth of the filament. The observed emission indicates a large Ti/Ni abundance ratio relative to solar abundances. It is suggested that the observed high Ti/Ni ratio in gas is caused dust-gas fractionation processes and does not reflect the absolute Ti/Ni ratio in the ejecta of eta Carinae. The condensation chemistry shows that if dust condensed in a sequence of layers according to decreasing temperature and increasing distance from the central star, the most refractory dust could be selectively affected by photoevaporation. Thus, Ti would be released back to the gas and the Ti/Ni ratio in the gas would increase to the observed super-solar ratio.

[Successful One-lung Ventilation with a Right-sided Double-lumen Tube in a Patient with a Right Upper Tracheal Bronchus, who Underwent Left Pneumonectomy for Left Hilar Lung Cancer].

PubMed

Kawagoe, Izumi; Kohchiyama, Tsukasa; Hayashida, Masakazu; Satoh, Daizoh; Suzuki, Kenji; Inada, Eiichi

2016-06-01

A 60-year-old male patient with left hilar lung cancer was scheduled to undergo left pneumonectomy or left sleeve lower lobectomy. Preoperative computer tomographic and bronchoscopic examinations revealed that the bronchus (B1) to the right apical segment (S1) was a tracheal bronchus (TB) originating from the trachea approximately 10 mm above the carina. Because the left main bronchus was to be dissected, a right-sided double-lumen tube (DLT) was selected to completely protect the right lung from spillage of secretions or cancer cells from the left lung. The right-sided DLT was placed so as to fit its lateral opening of the bronchial lumen to normal upper branches (B2, B3), while sacrificing ventilation of S1 with an abnormal branch (B1). However, one-lung ventilation (OLV) of the right lung could not be achieved, since a gas leakage from the opened tracheal lumen occurred, most probably due to intra-lobar micro-airway communications between S1 and S2/S3. The DLT was withdrawn until the blue bronchial cuff occluded the orifice of the TB (B1). Although the upper half of the blue bronchial cuff appeared above the tracheal carina, OLV through the two bronchial lumen openings could be achieved due to a specific, slanted doughnut shape of the blue bronchial cuff and the location of the abnormal branch (B1) approximate to the carina. Left pneumonectomy using successful OLV was completed safely without hypoxemia or hypercapnea. Our experience indicates that management of OLV for patients with a thoracheal bronchus needs special considerations of the exact location of the TB and intra-lobar micro-airway communications, in addition to types of scheduled surgical procedures.

Preoperative risk factors in total thyroidectomy of substernal goiter

PubMed Central

Bove, Aldo; Di Renzo, Raffaella Maria; D’Urbano, Gauro; Bellobono, Manuela; Addetta, Vincenzo D’; Lapergola, Alfonso; Bongarzoni, Giuseppe

2016-01-01

The definition of substernal goiter (SG) is based on variable criteria leading to a considerable variation in the reported incidence (from 0.2% to 45%). The peri- and postoperative complications are higher in total thyroidectomy (TT) for SG than that for cervical goiter. The aim of this study was to evaluate the preoperative risk factors associated with postoperative complications. From 2002 to 2014, 142 (8.5%; 98 women and 44 men) of the 1690 patients who underwent TT had a SG. We retrospectively evaluated the following parameters: sex, age, histology, pre- and retrovascular position, recurrence, and extension beyond the carina. These parameters were then related to the postoperative complications: seroma/hematoma, transient and permanent hypocalcemia, transient and permanent laryngeal nerve palsy, and the length of surgery. The results were further compared with a control group of 120 patients operated on in the same period with TT for cervical goiter. All but two procedures were terminated via cervicotomy, where partial sternotomies were required. No perioperative mortality was observed. Results of the statistical analysis (Student’s t-test and Fisher’s exact test) indicated an association between recurrence and extension beyond the carina with all postoperative complications. The group that underwent TT of SG showed a statistically significant higher risk for transient hypocalcemia (relative risk =1.767 with 95% confidence interval: 1.131–2.7605, P=0.0124, and need to treat =7.1) and a trend toward significance for transient recurrent laryngeal nerve palsy (relative risk =6.7806 with 95% confidence interval: 0.8577–53.2898, P=0.0696, and need to treat =20.8) compared to the group that underwent TT of cervical goiter. TT is the procedure to perform in SG even if the incidence of complications is higher than for cervical goiters. The major risk factors associated with postoperative complications are recurrence and extension beyond the carina. In the presence of these factors, greater care should be taken. PMID:27932888

The Populations of Carina. II. Chemical Enrichment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Norris, John E.; Yong, David; Casagrande, Luca

Chemical abundances are presented for 19 elements in a sample of 63 red giants in the Carina dwarf spheroidal galaxy (dSph), based on homogeneous 1D/LTE model atmosphere analyses of our own observations (32 stars) and data available in the literature (a further 31 independent stars). The (Fe) metallicity and [ α /Fe] distribution functions have mean values and dispersions of −1.59 and 0.33 dex ([Fe/H] range: −2.68 to −0.64) and 0.07 and 0.13 dex ([ α /Fe] range: −0.27 to 0.25), respectively. We confirm the finding of Venn et al. that a small percentage (some 10% in the present investigation) of themore » sample shows clear evidence for significant enrichment by Type Ia supernova (SN Ia) ejecta. Calcium, with the most accurately determined abundance of the α -elements, shows an asymmetric distribution toward smaller values of [Ca/Fe] at all [Fe/H], most significantly over −2.0 < [Fe/H] < −1.0, suggestive of incomplete mixing of the ejecta of SNe Ia with the ambient medium of each of Carina’s generations. Approximate color–magnitude diagram age estimates are presented for the sample, and together with our chemical abundances, compared with the results of our previous synthetic color–magnitude diagram analysis, which reported the details of Carina’s four well-defined populations. We searched for the Na–O anticorrelation universally reported in the Galaxy’s globular clusters and confirm that this phenomenon does not exist in Carina. We also found that one of the 32 stars in our sample has an extremely enhanced lithium abundance— A (Li){sub NLTE} = +3.36, consistent with membership of the ∼1% group of Li-rich stars in dSph described by Kirby et al.« less

The oldest known snakes from the Middle Jurassic-Lower Cretaceous provide insights on snake evolution.

PubMed

Caldwell, Michael W; Nydam, Randall L; Palci, Alessandro; Apesteguía, Sebastián

2015-01-27

The previous oldest known fossil snakes date from ~100 million year old sediments (Upper Cretaceous) and are both morphologically and phylogenetically diverse, indicating that snakes underwent a much earlier origin and adaptive radiation. We report here on snake fossils that extend the record backwards in time by an additional ~70 million years (Middle Jurassic-Lower Cretaceous). These ancient snakes share features with fossil and modern snakes (for example, recurved teeth with labial and lingual carinae, long toothed suborbital ramus of maxillae) and with lizards (for example, pronounced subdental shelf/gutter). The paleobiogeography of these early snakes is diverse and complex, suggesting that snakes had undergone habitat differentiation and geographic radiation by the mid-Jurassic. Phylogenetic analysis of squamates recovers these early snakes in a basal polytomy with other fossil and modern snakes, where Najash rionegrina is sister to this clade. Ingroup analysis finds them in a basal position to all other snakes including Najash.

Mapping of the extinction in giant molecular clouds using optical star counts

NASA Astrophysics Data System (ADS)

Cambrésy, L.

1999-05-01

This paper presents large scale extinction maps of most nearby Giant Molecular Clouds of the Galaxy (Lupus, rho Ophiuchus, Scorpius, Coalsack, Taurus, Chamaeleon, Musca, Corona Australis, Serpens, IC 5146, Vela, Orion, Monoceros R1 and R2, Rosette, Carina) derived from a star count method using an adaptive grid and a wavelet decomposition applied to the optical data provided by the USNO-Precision Measuring Machine. The distribution of the extinction in the clouds leads to estimate their total individual masses M and their maximum of extinction. I show that the relation between the mass contained within an iso-extinction contour and the extinction is similar from cloud to cloud and allows the extrapolation of the maximum of extinction in the range 5.7 to 25.5 magnitudes. I found that about half of the mass is contained in regions where the visual extinction is smaller than 1 magnitude. The star count method used on large scale ( ~ 250 square degrees) is a powerful and relatively straightforward method to estimate the mass of molecular complexes. A systematic study of the all sky would lead to discover new clouds as I did in the Lupus complex for which I found a sixth cloud of about 10(4) M_⊙.

Endotracheal tube placement by EMT-Basics in a rural EMS system.

PubMed

Pratt, Jeffrey C; Hirshberg, Alan J

2005-01-01

To evaluate the effectiveness of an intubation-training module and special-waiver project in which Emergency Medical Technician (EMT)-Basics were trained to perform endotracheal intubations in a rural community. This was a prospective observational study over a four-year period (July 1998 through May 2002) of all intubation attempts by EMT-Basics in the field. The authors observed intubation data, training methods, and quality-assurance methods of a special-waiver project agreed to by the State Department of Public Health to train and allow EMT-Basics to intubate patients. Data were from documentation unique to the project. Project documentation evaluated the placement and complication(s) of endotracheal tube (ETT) placement after arrival to the emergency department. An intubation attempt was defined as direct laryngoscopy. A successful attempt was defined as an appropriately sized ETT placed and secured in the trachea below the vocal cords and above the carina. Confirmation of placement in the field included accepted clinical methods and the use of qualitative colorimetric end-tidal carbon dioxide detectors. The EMT-Basics were trained using a paramedic curriculum, including operating room intubations on live adult patients. All patients were in either cardiopulmonary or respiratory arrest. Thirty-two intubations were performed by EMT-Basics. Thirty attempts were successful and two were unsuccessful (94%; 95% confidence interval [CI] 80-98%). Unsuccessful ETT placements were managed with accepted basic life support airway standards. There were no unrecognized esophageal ETT placements (0%; 95% CI 0-11%). This study demonstrated that with an intensive training program using selected highly motivated providers and close monitoring, a program of EMT-Basic ETT placement in a rural setting can achieve acceptable success rates in patients in cardiac or respiratory arrest.

Argo Navis

NASA Astrophysics Data System (ADS)

Murdin, P.

2000-11-01

(the Ship) a large southern constellation representing the ship Argo of Jason and the Argonauts in Greek mythology whose brightest stars were cataloged by Ptolemy (c. AD 100-175) in the Almagest. It was divided up by the French astronomer Nicolas L de Lacaille (1713-62), who charted the southern sky in 1751-2, into the constellations Carina (the Keel), Vela (the Sails), Puppis (the Poop or Stern)...

VizieR Online Data Catalog: Radio spectra of globulettes in Carina nebula (Haikala+, 2017)

NASA Astrophysics Data System (ADS)

Haikala, L. K.; Gahm, G. F.; Grenman, T.; Makela, M. M.; Persson, C. M.

2017-04-01

Radio spectral lines of globulettes in the Carina nebula are presented. The spectra were obtained with the Atacama Pathfinder Experiment (APEX), Llano Chajnantor, Chile (O-091.F-9316A and O-094.F-9312A) The observed molecular lines were 12CO(3-2), 12CO(2-1), 13CO(3-2), and 13CO (2-1). The APEX 350 and 230GHz single sideband heterodyne APEX-1 and APEX-2 SIS receivers and the 32768 channel RPG eXtended bandwidth Fast Fourier Transform Spectrometer (XFFTS) with a bandwidth of 2.5 GHz were used. The channel spacing 76.3kHz corresponds to velocity spacing of 0.1 and 0.07km/s at 230 and 345GHz, respectively. All observations were performed in position-switching mode. The telescope FWHM is 27" at 230GHz, and 18" at 345GHz, and the corresponding main beam efficiencies are 0.75 and 0.73. Second order baseline was subtracted from the spectra. The temperature scale is in Ta* units, i.e. corrected to outside of the atmosphere but not for beam coupling. The spectra are presented in one binary table FITS file. (2 data files).

Blue bubble in Carina

NASA Image and Video Library

2016-02-22

Sparkling at the centre of this beautiful NASA/ESA Hubble Space Telescope image is a Wolf–Rayet star known as WR 31a, located about 30 000 light-years away in the constellation of Carina (The Keel). The distinctive blue bubble appearing to encircle WR 31a, and its uncatalogued stellar sidekick, is a Wolf–Rayet nebula — an interstellar cloud of dust, hydrogen, helium and other gases. Created when speedy stellar winds interact with the outer layers of hydrogen ejected by Wolf–Rayet stars, these nebulae are frequently ring-shaped or spherical. The bubble — estimated to have formed around 20 000 years ago — is expanding at a rate of around 220 000 kilometres per hour! Unfortunately, the lifecycle of a Wolf–Rayet star is only a few hundred thousand years — the blink of an eye in cosmic terms. Despite beginning life with a mass at least 20 times that of the Sun, Wolf–Rayet stars typically lose half their mass in less than 100 000 years. And WR 31a is no exception to this case. It will, therefore, eventually end its life as a spectacular supernova, and the stellar material expelled from its explosion will later nourish a new generation of stars and planets.

Eta Carinae: At the Crossroads of becoming a Supernova

NASA Technical Reports Server (NTRS)

Gull, Theodore

2007-01-01

Since the 1840's, when Eta Carinae's visual magnitude rivaled Sirius, the brightest star in the night sky, astronomers have wondered what major event took place. Today with the Hubble Space Telescope Imaging Spectrograph, with CHANDRA X-ray spectroscopy and the Very Large Telescope spectrographs and interferometers, we have learned that over 12 solar masses of material was ejected at 500 to 700 km/s into interstellar space. This ejecta is quite different from the normal interstellar medium. It is rich in nitrogen, poor in oxygen and carbon. The dust properties are quite peculiar and many metals such as vanadium, strontium, cadmium are seen in both absorption against the central source, plus a number of molecules. The chemical and dust formation is likely dominated by nitrogen as we see H_2, CH, CH+, OH, NH, HCl and NH-3, but no CO. Other metals and molecules are being searched out in the FUSE, HST/STIS, VLT/UVES and VLT/CRIRES spectra. I will describe what we know about the massive binary stellar system, how it changes every 5.54 year in UV and X-ray output and how the massive ejecta responds in this astrophysical laboratory.

Eta Carinae: An Astrophysical Laboratory

NASA Technical Reports Server (NTRS)

Gull, T.

2008-01-01

In the 1840s, Eta Carinae, a massive binary near the end of its hydrogen burning cycle, ejected at least ten solar masses of material rich in nitrogen at the expense of carbon and oxygen. The resultant chemistry has led to a most peculiar mix of metals, molecules and dust. We identify thousands of nebular absorption lines of ions including Fe, Ni, V, Sr, Sc and molecules including H2, CH, OH, but no CO. Today we see a wind-enshrouded massive binary in the center of an expanding neutral hourglass and skirt. A similar ionized internal structure is associated with a lesser ejection of the 1890s. Both systems respond to the 5.54-year modulation of X-ray and ultraviolet radiation as the less massive, hotter companion plunges through the extended wind of the more massive, cooler primary. Observations and models are being brought together to understand the properties of the wind-enshrouded central binary. In turn we are learning much atomic spectroscopy, what molecules form in oxygen-and carbon-deprived environments and potentially about a dust that is quite different from the interstellar dust. As the next periastron occurs in January 2009, a number of observing teams are preparing to test these models with new observations.

3D Modeling of Forbidden Line Emission in the Binary Wind Interaction Region of Eta Carinae

NASA Technical Reports Server (NTRS)

Madura, Thomas; Gull, T. R.; Owocki, S.; Okazaki, A. T.; Russell, C. M. P.

2010-01-01

We present recent work using three-dimensional (3D) Smoothed Particle Hydrodynamics (SPH) simulations to model the high ([Fe III], [Ar III], [Ne III] and [S III]) and low ([Fe II], [Ni II]) ionization forbidden emission lines observed in Eta Carinae using the HST/STIS. These structures are interpreted as the time-averaged, outer extensions of the primary wind and the wind-wind interaction region directly excited by the FUV of the hot companion star of this massive binary system. We discuss how analyzing the results of the 3D SPH simulations and synthetic slit spectra and comparing them to the spectra obtained with the HST/STIS helps us determine the absolute orientation of the binary orbit and helps remove the degeneracy inherent to models based solely on the observed RXTE X-ray light curve. A key point of this work is that spatially resolved observations like those with HST/STIS and comparison to 3D models are necessary to determine the alignment or misalignment of the orbital angular momentum axis with the Homunculus, or correspondingly, the alignment of the orbital plane with the Homunculus skirt.

CEMP Stars in Dwarf Galaxies

NASA Astrophysics Data System (ADS)

Thidemann Hansen, Terese

2018-06-01

Exploration of the metal-poor stellar halo population of the Milky Way over the past decades has revealed a large number of stars strongly enhanced in carbon (CEMP stars). However, these stars are not as commonly detected in the dwarf galaxy satellites of the Milky Way (MW). The present-day satellites are thought to be similar to systems from which the MW and in particular its halo was formed via hierarchical mergers. I will present the results of abundance analysis for new samples of extremely metal-poor stars in Sculptor and Carina exploring the fraction of CEMP stars at low metallicity in these systems. I will also present the detailed abundance analyses of six CEMP stars detected in the Carina dwarf spheroidal galaxy. Five of these stars also show enhancement in slow neutron-capture elements and can thus be classified as CEMP-s stars, while the most metal-poor star with [Fe/H]=-2.5 shows no such enhancement and belongs to the CEMP-no class. The detection of CEMP stars in dwarf galaxies supports the hierarchical assembly of the MW halo and by providing a birth environment, can help to further constrain the formation of these stars.

A Broad 22 Micron Emission Feature in the Carina Nebula H ii Region.

PubMed

Chan; Onaka

2000-04-10

We report the detection of a broad 22 µm emission feature in the Carina Nebula H ii region by the Infrared Space Observatory (ISO) short-wavelength spectrometer. The feature shape is similar to that of the 22 µm emission feature of newly synthesized dust observed in the Cassiopeia A supernova remnant. This finding suggests that both of the features are arising from the same carrier and that supernovae are probably the dominant production sources of this new interstellar grain. A similar broad emission dust feature is also found in the spectra of two starburst galaxies from the ISO archival data. This new dust grain could be an abundant component of interstellar grains and can be used to trace the supernova rate or star formation rate in external galaxies. The existence of the broad 22 µm emission feature complicates the dust model for starburst galaxies and must be taken into account correctly in the derivation of dust color temperature. Mg protosilicate has been suggested as the carrier of the 22 µm emission dust feature observed in Cassiopeia A. The present results provide useful information in studies on the chemical composition and emission mechanism of the carrier.

Emission lines in the long period Cepheid l Carinae

NASA Technical Reports Server (NTRS)

Boehm-Vitense, Erika; Love, Stanley G.

1991-01-01

For the Cepheid (l) Carinae with a pulsation period of 35.5 days we have studied the emission line fluxes as a function of pulsational phase in order to find out whether we see chromosphere and transition layer emission or whether we see emission due to an outward moving shock. All emission lines show a steep increase in flux shortly before maximum light suggestive of a shock moving through the surface layers. The large ratio of the C IV to C II line fluxes shows that these are not transition layer lines. During maximum light the large ratio of the C IV to C II line fluxes also suggests that we see emission from a shock with velocities greater than 100 km/sec such that C IV emission can be excited. With such velocities mass outflow appears possible. The variations seen in the Mg II line profiles show that there is an internal absorption over a broad velocity band independent of the pulsational phase. We attribute this absorption to a circumstellar 'shell'. This 'shell' appears to be seen also as spatially extended emission in the O I line at 1300 angstrom, which is probably excited by resonance with Ly beta.

IR Variability of Eta Carinae

NASA Astrophysics Data System (ADS)

Smith, Nathan

2007-02-01

Every 5.5 years, η Carinae experiences a dramatic ``spectroscopic event'' when high-excitation lines in its UV, optical, and IR spectrum disappear, and its hard X-ray and radio continuum flux crash. This periodicity has been attributed to an eccentric binary system with a shell ejection occurring at periastron. In addition, η Car shows long term changes as it is still recovering from its giant 19th century outburst. Both types of variability are directly linked to the current mass-loss rate and dust formation in its wind. Mid-IR images and spectra with T-ReCS provide a direct measure of changes in the current bolometric luminosity and trace dust formation episodes. This will provide a direct measurement of the mass ejected. Near-IR emission lines trace related changes in the post-event wind and ionization changes in the circumstellar environment needed to test specific models for the cause of η Car's variability as it recovers from its recent ``event''. High resolution near-IR spectra with GNIRS will continue the important work of HST/STIS, investigating changes in the direct and reflected spectrum of the stellar wind, and ionization changes in the nebula.

The Mysterious Sickle Object in the Carina Nebula: A Stellar Wind Induced Bow Shock Grazing a Clump?

NASA Astrophysics Data System (ADS)

Ngoumou, Judith; Preibisch, Thomas; Ratzka, Thorsten; Burkert, Andreas

2013-06-01

Optical and near-infrared images of the Carina Nebula show a peculiar arc-shaped feature, which we call the "Sickle," next to the B-type star Trumpler 14 MJ 218. We use multi-wavelength observations to explore and constrain the nature and origin of the nebulosity. Using submillimeter data from APEX/LABOCA as well as Herschel far-infrared maps, we discovered a dense, compact clump with a mass of ~40 M ⊙ located close to the apex of the Sickle. We investigate how the B star MJ 218, the Sickle, and the clump are related. Our numerical simulations show that, in principle, a B-type star located near the edge of a clump can produce a crescent-shaped wind shock front, similar to the observed morphology. However, the observed proper motion of MJ 218 suggests that the star moves with high velocity (~100 km s-1) through the ambient interstellar gas. We argue that the star is just about to graze along the surface of the clump, and the Sickle is a bow shock induced by the stellar wind, as the object moves supersonically through the density gradient in the envelope of the clump.

Congenital cardiac disease in dogs.

PubMed

McCaw, D; Aronson, E

1984-07-01

Pulmonic stenosis is caused by a malformed pulmonic valve, stricture of the right ventricular outflow tract or stricture of the pulmonary artery. English Bulldogs, Beagles, Samoyeds, Fox Terriers and Chihuahuas are predisposed. Clinical signs in severely affected dogs include exercise intolerance, stunting, dyspnea, syncope and ascites. Auscultation reveals a high-frequency, crescendo-decrescendo murmur during systole, loudest over the left side of the thorax, near the sternal cardiac border. An ECG may reveal a right-axis deviation of greater than 120 degrees, S waves in leads I, II and III, deep S waves in CV6LL, CV6LU and V10, Q waves deeper than 0.5 mv in leads II, III and AVF, and positive T waves in lead V10. Plain film LAT thoracic radiographs reveal an elevated carina, increased sternal contact of the heart, loss of the cranial cardiac waist and a widened cardiac silhouette, with normal pulmonary vasculature. A DV projection reveals an inverted "D" shape of the right ventricle and a pulmonary artery bulge. A nonselective angiocardiogram reveals poststenotic dilation of the main pulmonary artery. Treatment involves surgical correction of the stenosis.

The Chrysalis Opens? Photometry from the η Carinae Hubble Space Telescope Treasury Project, 2002-2006

NASA Astrophysics Data System (ADS)

Martin, J. C.; Davidson, Kris; Koppelman, M. D.

2006-12-01

During the past decade η Car has brightened markedly, possibly indicating a change of state. Here we summarize photometry gathered by the Hubble Space Telescope (HST) as part of the HST Treasury Project on this object. Our data include Space Telescope Imaging Spectrograph (STIS) CCD acquisition images, Advanced Camera for Surveys HRC images in four filters, and synthetic photometry in flux-calibrated STIS spectra. The HST's spatial resolution allows us to examine the central star separate from the bright circumstellar ejecta. Its apparent brightness continued to increase briskly during 2002-2006, especially after the mid-2003 spectroscopic event. If this trend continues, the central star will soon become brighter than its ejecta, quite different from the state that existed only a few years ago. One precedent may be the rapid change observed in 1938-1953. We conjecture that the star's mass-loss rate has been decreasing throughout the past century. This research was conducted as part of the η Car Hubble Space Telescope Treasury project via grant GO-9973 from the Space Telescope Science Institute. HST is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Some of the data presented in this paper were obtained from the Multimission Archive at the Space Telescope Science Institute (MAST). STScI is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. Support for MAST for non-HST data is provided by the NASA Office of Space Science via grant NAG5-7584 and by other grants and contracts.

The Global Ocean Data Analysis Project version 2 (GLODAPv2) – an internally consistent data product for the world ocean

DOE PAGES

Olsen, Are; Key, Robert M.; van Heuven, Steven; ...

2016-08-15

Version 2 of the Global Ocean Data Analysis Project (GLODAPv2) data product is composed of data from 724 scientific cruises covering the global ocean. It includes data assembled during the previous efforts GLODAPv1.1 (Global Ocean Data Analysis Project version 1.1) in 2004, CARINA (CARbon IN the Atlantic) in 2009/2010, and PACIFICA (PACIFic ocean Interior CArbon) in 2013, as well as data from an additional 168 cruises. Data for 12 core variables (salinity, oxygen, nitrate, silicate, phosphate, dissolved inorganic carbon, total alkalinity, pH, CFC-11, CFC-12, CFC-113, and CCl 4) have been subjected to extensive quality control, including systematic evaluation of bias.more » The data are available in two formats: (i) as submitted but updated to WOCE exchange format and (ii) as a merged and internally consistent data product. In the latter, adjustments have been applied to remove significant biases, respecting occurrences of any known or likely time trends or variations. Adjustments applied by previous efforts were re-evaluated. Hence, GLODAPv2 is not a simple merging of previous products with some new data added but a unique, internally consistent data product. In conclusion, this compiled and adjusted data product is believed to be consistent to better than 0.005 in salinity, 1 % in oxygen, 2 % in nitrate, 2 % in silicate, 2 % in phosphate, 4 µmol kg -1 in dissolved inorganic carbon, 6 µmol kg -1 in total alkalinity, 0.005 in pH, and 5 % for the halogenated transient tracers.« less

The Global Ocean Data Analysis Project version 2 (GLODAPv2) – an internally consistent data product for the world ocean

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olsen, Are; Key, Robert M.; van Heuven, Steven

Version 2 of the Global Ocean Data Analysis Project (GLODAPv2) data product is composed of data from 724 scientific cruises covering the global ocean. It includes data assembled during the previous efforts GLODAPv1.1 (Global Ocean Data Analysis Project version 1.1) in 2004, CARINA (CARbon IN the Atlantic) in 2009/2010, and PACIFICA (PACIFic ocean Interior CArbon) in 2013, as well as data from an additional 168 cruises. Data for 12 core variables (salinity, oxygen, nitrate, silicate, phosphate, dissolved inorganic carbon, total alkalinity, pH, CFC-11, CFC-12, CFC-113, and CCl 4) have been subjected to extensive quality control, including systematic evaluation of bias.more » The data are available in two formats: (i) as submitted but updated to WOCE exchange format and (ii) as a merged and internally consistent data product. In the latter, adjustments have been applied to remove significant biases, respecting occurrences of any known or likely time trends or variations. Adjustments applied by previous efforts were re-evaluated. Hence, GLODAPv2 is not a simple merging of previous products with some new data added but a unique, internally consistent data product. In conclusion, this compiled and adjusted data product is believed to be consistent to better than 0.005 in salinity, 1 % in oxygen, 2 % in nitrate, 2 % in silicate, 2 % in phosphate, 4 µmol kg -1 in dissolved inorganic carbon, 6 µmol kg -1 in total alkalinity, 0.005 in pH, and 5 % for the halogenated transient tracers.« less

A new species of Esagonatopus Olmi (Hymenoptera, Dryinidae) from Central Brazil.

PubMed

Martins, AndrÉ Luis

2018-02-15

Esagonatopus antonioi Martins sp. nov. from Central Brazil is described and illustrated. The new species is characterized by having the head slightly excavated, almost flat, with granulate sculpture; the frontal line complete; the occipital carina absent; the mesosoma reticulate rugose and the scutum without lateral pointed apophyses. An updated key to the Neotropical species of the genus Esagonatopus Olmi is provided.

INTEGRAL detection of continued hard X-ray emission from MAXI J0911-655

NASA Astrophysics Data System (ADS)

Victor, J.-G.; Kuulkers, E.; Sidoli, L.; Sanchez-Fernandez, C.; Watanabe, K.; Pavan, L.; Bozzo, E.

2017-05-01

During the observations performed in the direction of the Carina Region and IGR J11014-6103 between 2017 May 8 at 04:50 and May 24 at 17:39, INTEGRAL detected activity from the accreting millisecond X-ray pulsar (AMXP) MAXI J0911-655 (Sanna et al., 2017, A & A, 598, 34; Atel #8872, #8884, #8914, #8971, #8986, #9738, #9740).

Ejecta of Eta Carinae: What We Learn about N-Rich Chemistry

NASA Technical Reports Server (NTRS)

Gull, Theodore

2006-01-01

At least one member of the binary system, Eta Carinae, is in the late stages of CNO-cycle. At least ten solar masses of ejecta make up the Homunculus, a neutral bi-polar shell ejected in the 1840s and the Little Homunculus, an internal, ionized bi-polar shell ejected in the 1890s. HST/STIS and VLTAJVES high dispersion spectroscopy revealed absorptions of multiple elements and diatomic molecules in these shells, some, such as V II and Sr II have not been seen previously in the ISM. The skirt region between the bi-lobes includes the very bright Weigelt blobs, within 0.1 to 0.3" of the central source, and the more distant, unusual Strontium Filament, a neutral emission nebula photoexcited by Balmer continuum, but shielded by Fe II from Lyman radiation. The 600+ emission lines are due to metals usually tied up in dust, but underabundances of C and O prevent precipitation as oxides onto the dust grains. Indications are that Ti/Ni is 100X solar, likely due not to nuclear processing, but the very different photo-excitation environments coupled with N-rich, C-, O-poor chemistry. In the Homunculus, level populations of the molecules indicate 60K gas; the metal absorption lines, 760K; that of the Little Homunculus 6400K during the broad spectroscopic maximum, relaxing to 5000K for the few month long minimum. Lyman radiation, including both continuum and Lyman lines, is trapped across periastron. leading to temporary relaxation of the ejecta. These ejecta are a treasure trove of information on material thrown out of massive stars in the CNO-cycle, well before the helium burning phase. Curiously, spectra of three very recent SWIFT GRBs indicate the presence of warm, photoexcited ejecta in the vicinity of the protoGRBs, but obviously of very different abundances. However, the ejecta of Eta Carinae promise to be a nearby example of massive ejecta, the study of which should lead to increased insight of earlier, very distant massive stars.

Ships Passing in the Night: Spectroscopic Analysis of Two Ultra-faint Satellites in the Constellation Carina

NASA Astrophysics Data System (ADS)

Li, T. S.; Simon, J. D.; Pace, A. B.; Torrealba, G.; Kuehn, K.; Drlica-Wagner, A.; Bechtol, K.; Vivas, A. K.; van der Marel, R. P.; Wood, M.; Yanny, B.; Belokurov, V.; Jethwa, P.; Zucker, D. B.; Lewis, G.; Kron, R.; Nidever, D. L.; Sánchez-Conde, M. A.; Ji, A. P.; Conn, B. C.; James, D. J.; Martin, N. F.; Martinez-Delgado, D.; Noël, N. E. D.; MagLiteS Collaboration

2018-04-01

We present Magellan/IMACS, Anglo-Australian Telescope/AAOmega+2dF, and Very Large Telescope/GIRAFFE+FLAMES spectroscopy of the Carina II (Car II) and Carina III (Car III) dwarf galaxy candidates, recently discovered in the Magellanic Satellites Survey (MagLiteS). We identify 18 member stars in Car II, including two binaries with variable radial velocities and two RR Lyrae stars. The other 14 members have a mean heliocentric velocity {v}hel}=477.2+/- 1.2 {km} {{{s}}}-1 and a velocity dispersion of {σ }v={3.4}-0.8+1.2 {km} {{{s}}}-1. Assuming Car II is in dynamical equilibrium, we derive a total mass within the half-light radius of {1.0}-0.4+0.8× {10}6 {M}ȯ , indicating a mass-to-light ratio of {369}-161+309 {M}ȯ /{L}ȯ . From equivalent width measurements of the calcium triplet lines of nine red giant branch (RGB) stars, we derive a mean metallicity of {{[Fe/H]}}=-2.44+/- 0.09 with dispersion {σ }{{[Fe/H]}}={0.22}-0.07+0.10. Considering both the kinematic and chemical properties, we conclude that Car II is a dark-matter-dominated dwarf galaxy. For Car III, we identify four member stars, from which we calculate a systemic velocity of {v}hel}={284.6}-3.1+3.4 {km} {{{s}}}-1. The brightest RGB member of Car III has a metallicity of {{[Fe/H]}} =-1.97+/- 0.12. Due to the small size of the Car III spectroscopic sample, we cannot conclusively determine its nature. Although these two systems have the smallest known physical separation ({{Δ }}d∼ 10 {kpc}) among Local Group satellites, the large difference in their systemic velocities, ∼ 200 {km} {{{s}}}-1, indicates that they are unlikely to be a bound pair. One or both systems are likely associated with the Large Magellanic Cloud (LMC), and may remain LMC satellites today. No statistically significant excess of γ-ray emission is found at the locations of Car II and Car III in eight years of Fermi-LAT data.

SN 2006gy: Discovery of the Most Luminous Supernova Ever Recorded, Powered by the Death of an Extremely Massive Star like η Carinae

NASA Astrophysics Data System (ADS)

Smith, Nathan; Li, Weidong; Foley, Ryan J.; Wheeler, J. Craig; Pooley, David; Chornock, Ryan; Filippenko, Alexei V.; Silverman, Jeffrey M.; Quimby, Robert; Bloom, Joshua S.; Hansen, Charles

2007-09-01

We report the discovery and early observations of the peculiar Type IIn supernova (SN) 2006gy in NGC 1260. With a peak visual magnitude of about -22, it is the most luminous supernova ever recorded. Its very slow rise to maximum took ~70 days, and it stayed brighter than -21 mag for about 100 days. It is not yet clear what powers the enormous luminosity and the total radiated energy of ~1051 erg, but we argue that any known mechanism-thermal emission, circumstellar interaction, or 56Ni decay-requires a very massive progenitor star. The circumstellar interaction hypothesis would require truly exceptional conditions around the star, which, in the decades before its death, must have experienced a luminous blue variable (LBV) eruption like the 19th century eruption of η Carinae. However, this scenario fails to explain the weak and unabsorbed soft X-rays detected by Chandra. Radioactive decay of 56Ni may be a less objectionable hypothesis, but it would imply a large Ni mass of ~22 Msolar, requiring SN 2006gy to have been a pair-instability supernova where the star's core was obliterated. While this is still uncertain, SN 2006gy is the first supernova for which we have good reason to suspect a pair-instability explosion. Based on a number of lines of evidence, we eliminate the hypothesis that SN 2006gy was a ``Type IIa'' event, that is, a white dwarf exploding inside a hydrogen envelope. Instead, we propose that the progenitor was a very massive evolved object like η Carinae that, contrary to expectations, failed to shed its hydrogen envelope. SN 2006gy implies that some of the most massive stars can explode prematurely during the LBV phase, never becoming Wolf-Rayet stars. SN 2006gy also suggests that they can create brilliant supernovae instead of experiencing ignominious deaths through direct collapse to a black hole. If such a fate is common among the most massive stars, then observable supernovae from Population III stars in the early universe will be more numerous than previously believed.

'Peony Nebula' Star Settles for Silver Medal

NASA Technical Reports Server (NTRS)

2008-01-01

[figure removed for brevity, see original site] [figure removed for brevity, see original site] Poster Version Movie

If our galaxy, the Milky Way, were to host its own version of the Olympics, the title for the brightest known star would go to a massive star called Eta Carina. However, a new runner-up now the second-brightest star in our galaxy has been discovered in the galaxy's dusty and frenzied interior. This image from NASA's Spitzer Space Telescope shows the new silver medalist, circled in the inset above, in the central region of our Milky Way.

Dubbed the 'Peony nebula' star, this blazing ball of gas shines with the equivalent light of 3.2 million suns. The reigning champ, Eta Carina, produces the equivalent of 4.7 million suns worth of light though astronomers say these estimates are uncertain, and it's possible that the Peony nebula star could be even brighter than Eta Carina.

If the Peony star is so bright, why doesn't it stand out more in this view? The answer is dust. This star is located in a very dusty region jam packed with stars. In fact, there could be other super bright stars still hidden deep in the stellar crowd. Spitzer's infrared eyes allowed it to pierce the dust and assess the Peony nebula star's true brightness. Likewise, infrared data from the European Southern Observatory's New Technology Telescope in Chile were integral in calculating the Peony nebula star's luminosity.

The Peony nebula, which surrounds the Peony nebular star, is the reddish cloud of dust in and around the white circle.

The movie begins by showing a stretch of the dusty and frenzied central region of our Milky Way galaxy. It then zooms in to reveal the 'Peony nebula' star the new second-brightest star in the Milky Way, discovered in part by NASA's Spitzer Space Telescope.

This is a three-color composite showing infrared observations from two Spitzer instruments. Blue represents 3.6-micron light and green shows light of 8 microns, both captured by Spitzer's infrared array camera. Red is 24-micron light detected by Spitzer's multiband imaging photometer.

An Astrometric Analysis of eta Carinae’s Eruptive History Using HST WF/PC2 and ACS Observations

DTIC Science & Technology

2007-07-11

Std Z39-18 to address the question of binarity. Based on an astrometric analysis of the data, binary reflex motion is detected in the primary and, by...Measurement Results 96 5.1 Primary Luminosity and Mass . . . . . . . . . . . . . . . . . . . . . . 96 5.2 Secondary Mass and Luminosity...Binary Models . . . . . . . . . . . 100 5.5 Primary –Secondary Distance . . . . . . . . . . . . . . . . . . . . . . . 102 5.6 Periastron passage

Lower tracheal and carinal resection associated with subtotal oesophagectomy for carcinoma of oesophagus involving trachea

PubMed Central

Thompson, D. T.

1973-01-01

The problem of the patient with a carcinoma of the oesophagus involving the lower trachea and one or other main stem bronchus is discussed. An operation in which the carina was excised and both main bronchi were re-anastomosed to the trachea in association with a subtotal oesophagectomy is described. The criteria for deciding to undertake such an operation are discussed. Images PMID:4731124

THE MYSTERIOUS SICKLE OBJECT IN THE CARINA NEBULA: A STELLAR WIND INDUCED BOW SHOCK GRAZING A CLUMP?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ngoumou, Judith; Preibisch, Thomas; Ratzka, Thorsten

2013-06-01

Optical and near-infrared images of the Carina Nebula show a peculiar arc-shaped feature, which we call the ''Sickle'', next to the B-type star Trumpler 14 MJ 218. We use multi-wavelength observations to explore and constrain the nature and origin of the nebulosity. Using submillimeter data from APEX/LABOCA as well as Herschel far-infrared maps, we discovered a dense, compact clump with a mass of {approx}40 M{sub Sun} located close to the apex of the Sickle. We investigate how the B star MJ 218, the Sickle, and the clump are related. Our numerical simulations show that, in principle, a B-type star locatedmore » near the edge of a clump can produce a crescent-shaped wind shock front, similar to the observed morphology. However, the observed proper motion of MJ 218 suggests that the star moves with high velocity ({approx}100 km s{sup -1}) through the ambient interstellar gas. We argue that the star is just about to graze along the surface of the clump, and the Sickle is a bow shock induced by the stellar wind, as the object moves supersonically through the density gradient in the envelope of the clump.« less

IR Variability of Eta Carinae

NASA Astrophysics Data System (ADS)

Smith, Nathan

2008-02-01

Every 5.5 years, η Carinae experiences a dramatic ``spectroscopic event'' when high-excitation lines in its UV, optical, and IR spectrum disappear, and its hard X-ray and radio continuum flux crash. This periodicity has been attributed to an eccentric binary system with a shell ejection occurring at periastron, and the next periastron event will occur at the very end of 2008. In addition, η Car shows long term changes as it is still recovering from its giant 19th century outburst. Both types of variability are directly linked to the current mass-loss rate and dust formation in its wind. Mid-IR images and spectra with T-ReCS provide a direct measure of changes in the current bolometric luminosity and a direct measure of the massw in dust formation episodes that may occur at periastron in the colliding wind shock. Near-IR emission lines trace related changes in the post-event wind and ionization changes in the circumstellar environment needed to test specific models for the cause of η Car's variability as it recovers from its recent ``event''. High resolution near-IR spectra with Phoenix will continue the important work of HST/STIS, investigating changes in the direct and reflected spectrum of the stellar wind, and ionization changes in the nebula.

IR Variability of Eta Carinae: The 2009 Event

NASA Astrophysics Data System (ADS)

Smith, Nathan

2008-08-01

Every 5.5 years, η Carinae experiences a dramatic ``spectroscopic event'' when high-excitation lines in its UV, optical, and IR spectrum disappear, and its hard X-ray and radio continuum flux crash. This periodicity has been attributed to an eccentric binary system with a shell ejection occurring at periastron, and the next periastron event will occur in January 2009. The last event in June/July 2003 was poorly observed because the star was very low in the sky, but this next event is perfectly suited for an intense ground-based monitoring campaign. Mid-IR images and spectra with T-ReCS provide a direct measure of changes in the current bolometric luminosity and a direct measure of the mass in dust formation episodes that may occur at periastron in the colliding wind shock. Near-IR emission lines trace related changes in the post-event wind and ionization changes in the circumstellar environment needed to test specific models for the cause of η Car's variability as it recovers from its recent ``event''. Because the nebular geometry is known very well from previous observations in this program, monitoring the changes in nebular ionization will yield a 3-D map of the changing asymmetric UV radiation field geometry in the binary system, and the first estimate of the orientation of its orbit.

Extended envelopes around Galactic Cepheids. I. ℓ Carinae from near and mid-infrared interferometry with the VLTI

NASA Astrophysics Data System (ADS)

Kervella, P.; Mérand, A.; Perrin, G.; Coudé du Foresto, V.

2006-03-01

We present the results of long-baseline interferometric observations of the bright southern Cepheid ℓ Carinae in the infrared N (8-13 μm) and K (2.0-2.4 μm) bands, using the MIDI and VINCI instruments of the VLT Interferometer. We resolve in the N band a large circumstellar envelope (CSE) that we model with a Gaussian of 3 Rstar (≈500 R⊙ ≈ 2-3 AU) half width at half maximum. The signature of this envelope is also detected in our K band data as a deviation from a single limb darkened disk visibility function. The superimposition of a Gaussian CSE on the limb darkened disk model of the Cepheid star results in a significantly better fit of our VINCI data. The extracted CSE parameters in the K band are a half width at half maximum of 2 Rstar, comparable to the N band model, and a total brightness of 4% of the stellar photosphere. A possibility is that this CSE is linked to the relatively large mass loss rate of ℓ Car. Though its physical nature cannot be determined from our data, we discuss an analogy with the molecular envelopes of RV Tauri, red supergiants and Miras.

The Great Cometary Show

NASA Astrophysics Data System (ADS)

2007-01-01

The ESO Very Large Telescope Interferometer, which allows astronomers to scrutinise objects with a precision equivalent to that of a 130-m telescope, is proving itself an unequalled success every day. One of the latest instruments installed, AMBER, has led to a flurry of scientific results, an anthology of which is being published this week as special features in the research journal Astronomy & Astrophysics. ESO PR Photo 06a/07 ESO PR Photo 06a/07 The AMBER Instrument "With its unique capabilities, the VLT Interferometer (VLTI) has created itself a niche in which it provide answers to many astronomical questions, from the shape of stars, to discs around stars, to the surroundings of the supermassive black holes in active galaxies," says Jorge Melnick (ESO), the VLT Project Scientist. The VLTI has led to 55 scientific papers already and is in fact producing more than half of the interferometric results worldwide. "With the capability of AMBER to combine up to three of the 8.2-m VLT Unit Telescopes, we can really achieve what nobody else can do," added Fabien Malbet, from the LAOG (France) and the AMBER Project Scientist. Eleven articles will appear this week in Astronomy & Astrophysics' special AMBER section. Three of them describe the unique instrument, while the other eight reveal completely new results about the early and late stages in the life of stars. ESO PR Photo 06b/07 ESO PR Photo 06b/07 The Inner Winds of Eta Carinae The first results presented in this issue cover various fields of stellar and circumstellar physics. Two papers deal with very young solar-like stars, offering new information about the geometry of the surrounding discs and associated outflowing winds. Other articles are devoted to the study of hot active stars of particular interest: Alpha Arae, Kappa Canis Majoris, and CPD -57o2874. They provide new, precise information about their rotating gas envelopes. An important new result concerns the enigmatic object Eta Carinae. Using AMBER with its high spatial and spectral resolution, it was possible to zoom into the very heart of this very massive star. In this innermost region, the observations are dominated by the extremely dense stellar wind that totally obscures the underlying central star. The AMBER observations show that this dense stellar wind is not spherically symmetric, but exhibits a clearly elongated structure. Overall, the AMBER observations confirm that the extremely high mass loss of Eta Carinae's massive central star is non-spherical and much stronger along the poles than in the equatorial plane. This is in agreement with theoretical models that predict such an enhanced polar mass-loss in the case of rapidly rotating stars. ESO PR Photo 06c/07 ESO PR Photo 06c/07 RS Ophiuchi in Outburst Several papers from this special feature focus on the later stages in a star's life. One looks at the binary system Gamma 2 Velorum, which contains the closest example of a star known as a Wolf-Rayet. A single AMBER observation allowed the astronomers to separate the spectra of the two components, offering new insights in the modeling of Wolf-Rayet stars, but made it also possible to measure the separation between the two stars. This led to a new determination of the distance of the system, showing that previous estimates were incorrect. The observations also revealed information on the region where the winds from the two stars collide. The famous binary system RS Ophiuchi, an example of a recurrent nova, was observed just 5 days after it was discovered to be in outburst on 12 February 2006, an event that has been expected for 21 years. AMBER was able to detect the extension of the expanding nova emission. These observations show a complex geometry and kinematics, far from the simple interpretation of a spherical fireball in extension. AMBER has detected a high velocity jet probably perpendicular to the orbital plane of the binary system, and allowed a precise and careful study of the wind and the shockwave coming from the nova. The stream of results from the VLTI and AMBER is no doubt going to increase in the coming years with the availability of new functionalities. "In addition to the 8.2-m Unit Telescopes, the VLTI can also combine the light from up to 4 movable 1.8-m Auxiliary Telescopes. AMBER fed by three of these AT's will be offered to the user community as of April this year, and from October we will also make FINITO available," said Melnick. "This 'fringe-tracking' device allows us to stabilise changes in the atmospheric conditions and thus to substantially improve the efficiency of the observations. By effectively 'freezing' the interferometric fringes, FINITO allows astronomers to significantly increase the exposure times." The Astronomy & Astrophysics special feature (volume 464 - March II 2007) on AMBER first results includes 11 articles. They are freely available on the A&A web site.

Use of Effects Based Operations in Asymmetric Conflicts

DTIC Science & Technology

2004-06-01

Institute, November. Fall, Bernard, B. 1972. Street Without Joy. New York, NY: Schocken Books. Fishbein , M ., I . Ajzen . 1975. Belief, Attitude, Intention...affect each other, and thus, the outcome a conflict. iv ACKNOWLEDGMENTS I would like to thank Carina for her unending support and encouragement...during the past year. Despite my assurances of only taking a few short months to write this thesis, she still supported me when I was working on it

Canopus

NASA Astrophysics Data System (ADS)

Murdin, P.

2000-11-01

The star α Carinae, named for the chief pilot of the fleet of Menelaos, who died in Egypt c. 1193 BC on the return from the Trojan War, the star being prominent at the time. It is the second brightest star, having an apparent magnitude of -0.62. It is a cream giant, spectral type F0Ib, at a distance of 326 light-years; its parallax is 0.010'', and it has an absolute magnitude of -5.6....

Probabilistic HR Diagrams: A New Infrared and X-ray Chronometer for Very Young, Massive Stellar Clusters and Associations

NASA Astrophysics Data System (ADS)

Maldonado, Jessica; Povich, Matthew S.

2016-01-01

We present a novel method for constraining the duration of star formation in very young, massive star-forming regions. Constraints on stellar population ages are derived from probabilistic HR diagrams (pHRDs) generated by fitting stellar model spectra to the infrared (IR) spectral energy distributions (SEDs) of Herbig Ae/Be stars and their less-evolved, pre-main sequence progenitors. Stellar samples for the pHRDs are selected based on the detection of X-ray emission associated with the IR source, and the lack of detectible IR excess emission at wavelengths ≤4.5 µm. The SED model fits were used to create two-dimensional probability distributions of the stellar parameters, specifically bolometric luminosity versus temperature and mass versus evolutionary age. We present first results from the pHRD analysis of the relatively evolved Carina Nebula and the unevolved M17 SWex infrared dark cloud, which reveal the expected, strikingly different star formation durations between these two regions. In the future, we will apply this method to analyze available X-ray and IR data from the MYStIX project on other Galactic massive star forming regions within 3 kpc of the Sun.

OPTICAL SPECTROSCOPY OF X-RAY-SELECTED YOUNG STARS IN THE CARINA NEBULA

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vaidya, Kaushar; Chen, Wen-Ping; Lee, Hsu-Tai

We present low-resolution optical spectra for 29 X-ray sources identified as either massive star candidates or low-mass pre-main-sequence (PMS) star candidates in the clusters Trumpler 16 and Trumpler 14 of the Carina Nebula. Spectra of two more objects (one with an X-ray counterpart, and one with no X-ray counterpart), not originally our targets, but found close (∼3″) to two of our targets, are presented as well. Twenty early-type stars, including an O8 star, seven B1–B2 stars, two B3 stars, a B5 star, and nine emission-line stars, are identified. Eleven T Tauri stars, including eight classical T Tauri stars (CTTSs) and threemore » weak-lined T Tauri stars, are identified. The early-type stars in our sample are more reddened compared to the previously known OB stars of the region. The Chandra hardness ratios of our T Tauri stars are found to be consistent with the Chandra hardness ratios of T Tauri stars of the Orion Nebula Cluster. Most early-type stars are found to be nonvariable in X-ray emission, except the B2 star J104518.81–594217.9, the B3 star J104507.84–594134.0, and the Ae star J104424.76–594555.0, which are possible X-ray variables. J104452.20–594155.1, a CTTS, is among the brightest and the hardest X-ray sources in our sample, appears to be a variable, and shows a strong X-ray flare. The mean optical and near-infrared photometric variability in the V and K{sub s} bands, of all sources, is found to be ∼0.04 and 0.05 mag, respectively. The T Tauri stars show significantly larger mean variation, ∼0.1 mag, in the K{sub s} band. The addition of one O star and seven B1–B2 stars reported here contributes to an 11% increase of the known OB population in the observed field. The 11 T Tauri stars are the first ever confirmed low-mass PMS stars in the Carina Nebula region.« less

Ships Passing in the Night: Spectroscopic Analysis of Two Ultra-faint Satellites in the Constellation Carina

DOE PAGES

Li, T. S.; Simon, J. D.; Pace, A. B.; ...

2018-04-25

Here, we present Magellan/IMACS, Anglo-Australian Telescope/AAOmega+2dF, and Very Large Telescope/GIRAFFE+FLAMES spectroscopy of the Carina II (Car II) and Carina III (Car III) dwarf galaxy candidates, recently discovered in the Magellanic Satellites Survey (MagLiteS). We identify 18 member stars in Car II, including two binaries with variable radial velocities and two RR Lyrae stars. The other 14 members have a mean heliocentric velocitymore » $${v}_{\\mathrm{hel}}=477.2\\pm 1.2$$ $$\\mathrm{km}\\,{{\\rm{s}}}^{-1}$$ and a velocity dispersion of $${\\sigma }_{v}={3.4}_{-0.8}^{+1.2}$$ $$\\mathrm{km}\\,{{\\rm{s}}}^{-1}$$. Assuming Car II is in dynamical equilibrium, we derive a total mass within the half-light radius of $${1.0}_{-0.4}^{+0.8}\\times {10}^{6}$$ $${M}_{\\odot }$$, indicating a mass-to-light ratio of $${369}_{-161}^{+309}$$ $${M}_{\\odot }$$/$${L}_{\\odot }$$. From equivalent width measurements of the calcium triplet lines of nine red giant branch (RGB) stars, we derive a mean metallicity of $${\\rm{[Fe/H]}}=-2.44\\pm 0.09$$ with dispersion $${\\sigma }_{{\\rm{[Fe/H]}}}={0.22}_{-0.07}^{+0.10}$$. Considering both the kinematic and chemical properties, we conclude that Car II is a dark-matter-dominated dwarf galaxy. For Car III, we identify four member stars, from which we calculate a systemic velocity of $${v}_{\\mathrm{hel}}={284.6}_{-3.1}^{+3.4}$$ $$\\mathrm{km}\\,{{\\rm{s}}}^{-1}$$. The brightest RGB member of Car III has a metallicity of $${\\rm{[Fe/H]}}\\,=-1.97\\pm 0.12$$. Due to the small size of the Car III spectroscopic sample, we cannot conclusively determine its nature. Although these two systems have the smallest known physical separation ($${\\rm{\\Delta }}d\\sim 10\\,\\mathrm{kpc}$$) among Local Group satellites, the large difference in their systemic velocities, $$\\sim 200\\,\\mathrm{km}\\,{{\\rm{s}}}^{-1}$$, indicates that they are unlikely to be a bound pair. One or both systems are likely associated with the Large Magellanic Cloud (LMC), and may remain LMC satellites today. No statistically significant excess of γ-ray emission is found at the locations of Car II and Car III in eight years of Fermi-LAT data.« less

Hubble Captures Spectacular "Landscape" in the Carina Nebula

NASA Image and Video Library

2017-12-08

NASA image release April 22, 2010 NASA's Hubble Space Telescope captured this billowing cloud of cold interstellar gas and dust rising from a tempestuous stellar nursery located in the Carina Nebula, 7,500 light-years away in the southern constellation Carina. This pillar of dust and gas serves as an incubator for new stars and is teeming with new star-forming activity. Hot, young stars erode and sculpt the clouds into this fantasy landscape by sending out thick stellar winds and scorching ultraviolet radiation. The low-density regions of the nebula are shredded while the denser parts resist erosion and remain as thick pillars. In the dark, cold interiors of these columns new stars continue to form. In the process of star formation, a disk around the proto-star slowly accretes onto the star's surface. Part of the material is ejected along jets perpendicular to the accretion disk. The jets have speeds of several hundreds of miles per second. As these jets plow into the surround nebula, they create small, glowing patches of nebulosity, called Herbig-Haro (HH) objects. Long streamers of gas can be seen shooting in opposite directions off the pedestal on the upper right-hand side of the image. Another pair of jets is visible in a peak near the top-center of the image. These jets (known as HH 901 and HH 902, respectively) are common signatures of the births of new stars. This image celebrates the 20th anniversary of Hubble's launch and deployment into an orbit around Earth. Hubble's Wide Field Camera 3 observed the pillar on Feb. 1-2, 2010. The colors in this composite image correspond to the glow of oxygen (blue), hydrogen and nitrogen (green), and sulfur (red). Object Names: HH 901, HH 902 Image Type: Astronomical Credit: NASA, ESA, and M. Livio and the Hubble 20th Anniversary Team (STScI) To read learn more about this image go to: www.nasa.gov/mission_pages/hubble/science/hubble20th-img.... NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Ships Passing in the Night: Spectroscopic Analysis of Two Ultra-faint Satellites in the Constellation Carina

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, T. S.; Simon, J. D.; Pace, A. B.

Here, we present Magellan/IMACS, Anglo-Australian Telescope/AAOmega+2dF, and Very Large Telescope/GIRAFFE+FLAMES spectroscopy of the Carina II (Car II) and Carina III (Car III) dwarf galaxy candidates, recently discovered in the Magellanic Satellites Survey (MagLiteS). We identify 18 member stars in Car II, including two binaries with variable radial velocities and two RR Lyrae stars. The other 14 members have a mean heliocentric velocitymore » $${v}_{\\mathrm{hel}}=477.2\\pm 1.2$$ $$\\mathrm{km}\\,{{\\rm{s}}}^{-1}$$ and a velocity dispersion of $${\\sigma }_{v}={3.4}_{-0.8}^{+1.2}$$ $$\\mathrm{km}\\,{{\\rm{s}}}^{-1}$$. Assuming Car II is in dynamical equilibrium, we derive a total mass within the half-light radius of $${1.0}_{-0.4}^{+0.8}\\times {10}^{6}$$ $${M}_{\\odot }$$, indicating a mass-to-light ratio of $${369}_{-161}^{+309}$$ $${M}_{\\odot }$$/$${L}_{\\odot }$$. From equivalent width measurements of the calcium triplet lines of nine red giant branch (RGB) stars, we derive a mean metallicity of $${\\rm{[Fe/H]}}=-2.44\\pm 0.09$$ with dispersion $${\\sigma }_{{\\rm{[Fe/H]}}}={0.22}_{-0.07}^{+0.10}$$. Considering both the kinematic and chemical properties, we conclude that Car II is a dark-matter-dominated dwarf galaxy. For Car III, we identify four member stars, from which we calculate a systemic velocity of $${v}_{\\mathrm{hel}}={284.6}_{-3.1}^{+3.4}$$ $$\\mathrm{km}\\,{{\\rm{s}}}^{-1}$$. The brightest RGB member of Car III has a metallicity of $${\\rm{[Fe/H]}}\\,=-1.97\\pm 0.12$$. Due to the small size of the Car III spectroscopic sample, we cannot conclusively determine its nature. Although these two systems have the smallest known physical separation ($${\\rm{\\Delta }}d\\sim 10\\,\\mathrm{kpc}$$) among Local Group satellites, the large difference in their systemic velocities, $$\\sim 200\\,\\mathrm{km}\\,{{\\rm{s}}}^{-1}$$, indicates that they are unlikely to be a bound pair. One or both systems are likely associated with the Large Magellanic Cloud (LMC), and may remain LMC satellites today. No statistically significant excess of γ-ray emission is found at the locations of Car II and Car III in eight years of Fermi-LAT data.« less

Dynamics of the Shocked Gas in the Eta Carinae System as Seen by Chandra

NASA Technical Reports Server (NTRS)

Corcoran, M. F.; Hamaguchi, K.; Henley, D. B.; Ishibashi, K.; Gull, T.; Nielsen, K.; Pittard, J. M.

2006-01-01

We report on a series of X-ray spectra of the supermassive star Eta Carinae obtained by the High Energy Transmission Grating Spectrometer on the CHANDRA X-ray observatory before, during and after the star's X-ray minimum in the summer of 2003. The X-ray spectra show significant variations in emission measure and absorption, in the strength of the iron K edge and fluorescent iron emission, but show little change in the distribution of emission measure with temperature. The CHANDRA spectra also resolve emission from Si, S, Fe and other elements in H-like and He-like configurations. The HETGS spectra show that these lines change in centroid energy along with evidence of changes in the forbidden-to-intercombination ratios of the He-like triplets. These spectra offer strong support that the X-ray emission originates within a shock cone around an unseen, massive companion. The variations of the X-ray line spectrum provide a direct measure of the dynamics of the shocked gas in this cone and also evidence that the hottest region of the shock is not always in collisional ionization equilibrium. We discuss these results in light of the recent discovery of He II 4686 emission and the reported discovery of FUV emission from the companion star. This work was supported by SAO/Chandra grant GO3-4008A.

The 2014 X-Ray Minimum of Eta Carinae as Seen by Swift

NASA Technical Reports Server (NTRS)

Corcoran, M. F.; Liburd, J.; Morris, D.; Russell, C. M. P.; Hamaguchi, K.; Gull, T. R.; Madura, T. I.; Teodoro, M.; Moffat, A. F. J.; Richardson, N. D.

2017-01-01

We report on Swift X-ray Telescope observations of Eta Carinae ( Car), an extremely massive, long-period, highly eccentric binary obtained during the 2014.6 X-ray minimumperiastron passage. These observations show that Car may have been particularly bright in X-rays going into the X-ray minimum state, while the duration of the 2014 X-ray minimum was intermediate between the extended minima seen in 1998.0 and 2003.5 by Rossi X-Ray Timing Explorer (RXTE), and the shorter minimum in 2009.0. The hardness ratios derived from the Swift observations showed a relatively smooth increase to a peak value occurring 40.5 days after the start of the X-ray minimum, though these observations cannot reliably measure the X-ray hardness during the deepest part of the X-ray minimum when contamination by the central constant emission component is significant. By comparing the timings of the RXTE and Swift observations near the X-ray minima, we derive an updated X-ray period of P X equals 2023.7 +/- 0.7 days, in good agreement with periods derived from observations at other wavelengths, and we compare the X-ray changes with variations in the He ii lambda 4686 emission. The middle of the Deep Minimum interval, as defined by the Swift column density variations, is in good agreement with the time of periastron passage derived from the He ii 4686 line variations.

X-Ray modeling of η Carinae & WR 140 from SPH simulations

NASA Astrophysics Data System (ADS)

Russell, Christopher M. P.; Corcoran, Michael F.; Okazaki, Atsuo T.; Madura, Thomas I.; Owocki, Stanley P.

2011-07-01

The colliding wind binary (CWB) systems η Carinae and WR140 provide unique laboratories for X-ray astrophysics. Their wind-wind collisions produce hard X-rays that have been monitored extensively by several X-ray telescopes, including RXTE. To interpret these RXTE X-ray light curves, we apply 3D hydrodynamic simulations of the wind-wind collision using smoothed particle hydrodynamics (SPH). We find adiabatic simulations that account for the absorption of X-rays from an assumed point source of X-ray emission at the apex of the wind-collision shock cone can closely match the RXTE light curves of both η Car and WR140. This point-source model can also explain the early recovery of η Car's X-ray light curve from the 2009.0 minimum by a factor of 2-4 reduction in the mass loss rate of η Car. Our more recent models account for the extended emission and absorption along the full wind-wind interaction shock front. For WR140, the computed X-ray light curves again match the RXTE observations quite well. But for η Car, a hot, post-periastron bubble leads to an emission level that does not match the extended X-ray minimum observed by RXTE. Initial results from incorporating radiative cooling and radiative forces via an anti-gravity approach into the SPH code are also discussed.

X-ray Modeling of η Carinae & WR140 from SPH Simulations

NASA Astrophysics Data System (ADS)

Russell, Christopher M. P.; Corcoran, Michael F.; Okazaki, Atsuo T.; Madura, Thomas I.; Owocki, Stanley P.

2011-01-01

The colliding wind binary (CWB) systems η Carinae and WR140 provide unique laboratories for X-ray astrophysics. Their wind-wind collisions produce hard X-rays that have been monitored extensively by several X-ray telescopes, including RXTE. To interpret these RXTE X-ray light curves, we model the wind-wind collision using 3D smoothed particle hydrodynamics (SPH) simulations. Adiabatic simulations that account for the emission and absorption of X-rays from an assumed point source at the apex of the wind-collision shock cone by the distorted winds can closely match the observed 2-10keV RXTE light curves of both η Car and WR140. This point-source model can also explain the early recovery of η Car's X-ray light curve from the 2009.0 minimum by a factor of 2-4 reduction in the mass loss rate of η Car. Our more recent models relax the point-source approximation and account for the spatially extended emission along the wind-wind interaction shock front. For WR140, the computed X-ray light curve again matches the RXTE observations quite well. But for η Car, a hot, post-periastron bubble leads to an emission level that does not match the extended X-ray minimum observed by RXTE. Initial results from incorporating radiative cooling and radiatively-driven wind acceleration via a new anti-gravity approach into the SPH code are also discussed.

Hubble's Wide View of 'Mystic Mountain' in Infrared

NASA Image and Video Library

2010-04-23

NASA image release April 22, 2010 This is a NASA Hubble Space Telescope near-infrared-light image of a three-light-year-tall pillar of gas and dust that is being eaten away by the brilliant light from nearby stars in the tempestuous stellar nursery called the Carina Nebula, located 7,500 light-years away in the southern constellation Carina. The image marks the 20th anniversary of Hubble's launch and deployment into an orbit around Earth. The image reveals a plethora of stars behind the gaseous veil of the nebula's wall of hydrogen, laced with dust. The foreground pillar becomes semi-transparent because infrared light from background stars penetrates through much of the dust. A few stars inside the pillar also become visible. The false colors are assigned to three different infrared wavelength ranges. Hubble's Wide Field Camera 3 observed the pillar in February and March 2010. Object Names: HH 901, HH 902 Image Type: Astronomical Credit: NASA, ESA, and M. Livio and the Hubble 20th Anniversary Team (STScI) To read learn more about this image go to: www.nasa.gov/mission_pages/hubble/science/hubble20th-img.... NASA Goddard Space Flight Center is home to the nation's largest organization of combined scientists, engineers and technologists that build spacecraft, instruments and new technology to study the Earth, the sun, our solar system, and the universe.

Evaluation of a central venous catheter tip placement for superior vena cava–subclavian central venous catheterization using a premeasured length

PubMed Central

Kwon, Hyun-Jung; Jeong, Young-Il; Jun, In-Gu; Moon, Young-Jin; Lee, Yu-Mi

2018-01-01

Abstract Subclavian central venous catheterization is a common procedure for which misplacement of the central venous catheter (CVC) is a frequent complication that can potentially be fatal. The carina is located in the mid-zone of the superior vena cava (SVC) and is considered a reliable landmark for CVC placement in chest radiographs. The C-length, defined as the distance from the edge of the right transverse process of the first thoracic spine to the carina, can be measured in posteroanterior chest radiographs using a picture archiving and communication system. To evaluate the placement of the tip of the CVC in subclavian central venous catheterizations using the C-length, we reviewed the medical records and chest radiographs of 122 adult patients in whom CVC catheterization was performed (from January 2012 to December 2014) via the right subclavian vein using the C-length. The tips of all subclavian CVCs were placed in the SVC using the C-length. No subclavian CVC entered the right atrium. Tip placement was not affected by demographic characteristics such as age, sex, height, weight, and body mass index. The evidence indicates that the C-length on chest radiographs can be used to determine the available insertion length and place the right subclavian CVC tip into the SVC. PMID:29480861

Much NICER Monitoring of the X-ray Spectrum of Eta Carinae

NASA Astrophysics Data System (ADS)

Corcoran, Michael Francis; Hamaguchi, Kenji; Drake, Stephen; Pasham, Dheeraj; Gendreau, Keith C.; Arzoumanian, Zaven

2018-01-01

Eta Carinae is the most massive and luminous stellar system within 3 kpc. It is a known binary system with an orbital period of 5.52 years in which bright, thermal, X-ray emission is produced by a strong shock driven by the collisions of the wind of the visible primary star with the thin, fast wind of an otherwise unseen companion. Variations of the X-ray spectrum are produced by intrinsic changes in the density of the hot shocked gas and by intervening changes in wind absorption as the two stars revolve in a long-period, highly eccentric orbit. Previous X-ray monitoring studies since 1996 have detailed these variations, but have been either restricted to the E>3 keV band or have been affected by optical loading which limited measurement of X-ray absorption changes which can be used to determine the overlying density profile of the primary's wind around the orbit. The Neutron Star Interior Composition Explorer (NICER) is an excellent general-purpose observatory for X-ray astronomy, and in particular, its soft response and large effective area facilitate monitoring of X-ray spectral variations for bright sources like Eta Car without any bias due to photon pileup. We present the first observations of the X-ray spectrum of Eta Car obtained by NICER, and discuss limits on changes in column density, emission measure and temperature we derive from the NICER spectra.

The X-ray Lightcurve of Eta Carinae, 1996-2014

NASA Astrophysics Data System (ADS)

Corcoran, Michael F.; Hamaguchi, Kenji; Liburd, Jamar; Gull, Theodore R.; Madura, Thomas; Teodoro, Mairan; Moffat, Anthony F. J.; Richardson, Noel; Russell, Christopher Michael Post; Pollock, A.; Owocki, Stanley P.

2015-01-01

Eta Carinae is the nearest example of a supermassive, superluminous, unstable star. Mass loss from the system is important in shaping its circumstellar medium and in determining the ultimate fate of the star. Eta Car loses mass via a dense, slow stellar wind and possesses one of the largest mass loss rates known. It is prone to episodes of extreme mass ejection via eruptions from some as-yet unspecified cause; the best examples of this are the large-scale eruptions which occurred in the mid-19th century, and then again about 50 years later. Eta Car is a colliding wind binary in which strong variations in X-ray emission and in other wavebands are driven by the violent collision of the wind of Eta Car and the fast, less dense wind of an otherwise hidden companion star. X-ray variations are the simplest diagnostic we have to study the wind-wind collision and allow us to measure the state of the stellar mass loss from both stars. We present the X-ray lightcurve over the last 20 years from monitoring observations with the Rossi X-ray Timing Explorer and the X-ray Telescope on the Swift satellite, and compare and contrast the behavior of the X-ray emission from the system over that timespan, including surprising variations during the 2014 X-ray minimum.

Evolutionary Relationship of the Scale-Bearing Kraken (incertae sedis, Monadofilosa, Cercozoa, Rhizaria): Combining Ultrastructure Data and a Two-Gene Phylogeny.

PubMed

Dumack, Kenneth; Mylnikov, Alexander P; Bonkowski, Michael

2017-07-01

The genus Kraken represents a distinct lineage of filose amoebae within the Cercozoa. Currently a single species, Kraken carinae, has been described. SSU rDNA phylogeny showed an affiliation to the Cercomonadida, branching with weak support at its base, close to Paracercomonas, Metabolomonas, and Brevimastigomonas. Light microscopical analyses showed several unique features of the genus Kraken, but ultrastructure data were lacking. In this study, K. carinae has been studied by electron microscopy, these data conjoined with a two-gene phylogeny were used to give more insight into the evolutionary relationship of the genus Kraken within Cercozoa. The data confirmed the absence of flagella, but also showed novel characteristics, such as the presence of extrusomes, osmiophilic bodies, and mitochondria with flat cristae. Surprising was the presence of single-tier scales which are carried by cell outgrowths, much of what is expected of the last common ancestor of the class Imbricatea. The phylogenetic analyses however confirmed previous results, indicating Kraken as a sister group to Paracercomonas in Sarcomonadea with an increased but still low support of 0.98 PP/63 BP. Based on the unique features of Kraken we establish the Krakenidae fam. nov. that we, due to contradictory results in morphology and phylogeny, assign incertae sedis, Monadofilosa. Copyright © 2017 Elsevier GmbH. All rights reserved.

High Definition Seismic and Microseismic Data Acquisition Using Distributed and Engineered Fiber Optic Acoustic Sensors

NASA Astrophysics Data System (ADS)

Parker, T.; Farhadiroushan, M.; Clarke, A.; Miller, D.; Gillies, A.; Shatalin, S.; Naldrett, G.; Milne, C.

2016-12-01

The benefits of Distributed Acoustic Sensors (DAS) have been demonstrated in number of seismic applications. Over the past few years Silixa have successfully used DAS to record microseismic events during hydraulic fracturing and re-fracking operations. Detection has been successful in a number of configurations, where the fibre has been in a horizontal treatment well, horizontal well adjacent to the treatment, or vertical observation well. We will discuss the sensitivity of the measurement, range of measurement, ability to localise the events and characteristics of the microseismic event. In addition to discussing the theory we will present case studies showing the detection and localisation and how these compare to conventional microseismic detection techniques.We also discuss the benefit of the low frequency response of DAS for measuring the strain field induced along the sensing fibre cable during the treatment and while monitoring the adjacent wells. In addition a step change in performance can be offered by the new engineered Carina fibre optic sensing system developed by Silixa. The Carina sensing system is being tested and it has been demonstrated that an improvement in signal-to-noise performance by a factor of hundred (100x) can be achieved. The initial results demonstrate the potential for acquiring high definition seismic data in the most challenging environments beyond the capabilities of current geophones.

High Definition Seismic and Microseismic Data Acquisition Using Distributed and Engineered Fiber Optic Acoustic Sensors

NASA Astrophysics Data System (ADS)

Parker, T.; Farhadiroushan, M.; Clarke, A.; Miller, D.; Gillies, A.; Shatalin, S.; Naldrett, G.; Milne, C.

2017-12-01

The benefits of Distributed Acoustic Sensors (DAS) have been demonstrated in number of seismic applications. Over the past few years Silixa have successfully used DAS to record microseismic events during hydraulic fracturing and re-fracking operations. Detection has been successful in a number of configurations, where the fibre has been in a horizontal treatment well, horizontal well adjacent to the treatment, or vertical observation well. We will discuss the sensitivity of the measurement, range of measurement, ability to localise the events and characteristics of the microseismic event. In addition to discussing the theory we will present case studies showing the detection and localisation and how these compare to conventional microseismic detection techniques.We also discuss the benefit of the low frequency response of DAS for measuring the strain field induced along the sensing fibre cable during the treatment and while monitoring the adjacent wells. In addition a step change in performance can be offered by the new engineered Carina fibre optic sensing system developed by Silixa. The Carina sensing system is being tested and it has been demonstrated that an improvement in signal-to-noise performance by a factor of hundred (100x) can be achieved. The initial results demonstrate the potential for acquiring high definition seismic data in the most challenging environments beyond the capabilities of current geophones.

Explaining the features of the Bipolar Nebulae of η-Carinae through gas dynamical simulations

NASA Astrophysics Data System (ADS)

de Gouveia dal Pino, E. M.; Gonzalez, R. F.; Raga, A. C.; Velezquez, P. F.

2005-09-01

Employing an alternative scenario to previous interacting stellar wind models that is supported both by theoretical and observational evidence, we let a nonspherical outburst wind (with a latitudinal velocity dependence that matches the observations of the large Homunculus) interact with a preeruptive slow wind also with a toroidal density distribution but with a much smaller equator-to-polar density contrast than that assumed in previous models. A second eruptive wind with spherical shape is ejected about 50 years after the first outburst and causes the development of the little internal nebula. We find that as a result of an appropriate combination of the parameters that control the degree of asymmetry of the interacting winds, the model is able to produce not only the structure and kinematics of both Homunculi but also the high-velocity components of the equatorial ejecta. These latter arise from the impact between the nonspherical outburst and the preoutburst winds in the equatorial plane (see Figs. 1 and 2 in Gonzalez, de Gouveia Dal Pino, Raga & Velazquez 2004a). Our model predicts that most of the features of the bipolar winds of eta-Carinae and the source ejection mechanism are directly linked to the central star only, therefore without requiring to invoke the secondary wind of the companion star to explain, e.g., the equatorial ejecta (Gonzalez, de Gouveia Dal Pino, Raga & Velazquez 2004b).

Massive Stars in the W33 Giant Molecular Complex

NASA Astrophysics Data System (ADS)

Messineo, Maria; Clark, J. Simon; Figer, Donald F.; Kudritzki, Rolf-Peter; Najarro, Francisco; Rich, R. Michael; Menten, Karl M.; Ivanov, Valentin D.; Valenti, Elena; Trombley, Christine; Chen, C.-H. Rosie; Davies, Ben

2015-06-01

Rich in H ii regions, giant molecular clouds are natural laboratories to study massive stars and sequential star formation. The Galactic star-forming complex W33 is located at l=˜ 12\\buildrel{\\circ}\\over{.} 8 and at a distance of 2.4 kpc and has a size of ≈ 10 pc and a total mass of ≈ (0.8-8.0) × {{10}5} M ⊙ . The integrated radio and IR luminosity of W33—when combined with the direct detection of methanol masers, the protostellar object W33A, and the protocluster embedded within the radio source W33 main—mark the region as a site of vigorous ongoing star formation. In order to assess the long-term star formation history, we performed an infrared spectroscopic search for massive stars, detecting for the first time 14 early-type stars, including one WN6 star and four O4-7 stars. The distribution of spectral types suggests that this population formed during the past ˜2-4 Myr, while the absence of red supergiants precludes extensive star formation at ages 6-30 Myr. This activity appears distributed throughout the region and does not appear to have yielded the dense stellar clusters that characterize other star-forming complexes such as Carina and G305. Instead, we anticipate that W33 will eventually evolve into a loose stellar aggregate, with Cyg OB2 serving as a useful, albeit richer and more massive, comparator. Given recent distance estimates, and despite a remarkably similar stellar population, the rich cluster Cl 1813-178 located on the northwest edge of W33 does not appear to be physically associated with W33.

Variable interstellar absorption lines in young stellar aggregates

NASA Astrophysics Data System (ADS)

Krełowski, J.; Strobel, A.; Vješnica, S.; Melekh, D.; Bondar, A.

2018-06-01

The variability of interstellar atomic lines, sporadically reported in the astronomical literature, has been confirmed both in the case of the nearby hot star δ Ori and the very young and violent star-forming region η Carinae, using high-resolution echelle spectra. The presented variability concerns the intensities and profiles of Na I, K I and Ca II. The time-scale of the above-mentioned variations clearly suggests very local phenomena as their cause. It is important to say that not all interstellar lines vary in unison.

Infrared Speckle Interferometry with 2-D Arrays

NASA Technical Reports Server (NTRS)

Harvey, P. M.; Balkum, S. L.; Monin, J. L.

1994-01-01

We describe results from a program of speckle interferometry with two-dimensional infrared array detectors. Analysis of observations of eta Carinae made with 58 x 62 InSb detector are discussed. The data have been analyzed with both the Labeyrie autocorrelation, a deconvolution of shift-and-add data, and a phase restoration process. Development of a new camera based on a much lower noise HgCdTe detector will lead to a significant improvement i limiting magnitude for IR speckle interferometry.

Dither and drizzle strategies for Wide Field Camera 3

NASA Astrophysics Data System (ADS)

Mutchler, Max

2010-07-01

Hubble's 20th anniversary observation of Herbig-Haro object HH 901 in the Carina Nebula is used to illustrate observing strategies and corresponding data reduction methods for the new Wide Field Camera 3 (WFC3), which was installed during Servicing Mission 4 in May 2009. The key issues for obtaining optimal results with offline Multidrizzle processing of WFC3 data sets are presented. These pragmatic instructions in "cookbook" format are designed to help new WFC3 users quickly obtain good results with similar data sets.

Pectus carinatum.

PubMed

Robicsek, Francis; Watts, Larry T

2010-11-01

Pectus carinatum or keel chest is a spectrum of progressive inborn anomalies of the anterior chest wall, named after the keel (carina) of ancient Roman ships. It defines a wide spectrum of inborn protrusion anomalies of the sternum and/or the adjacent costal cartilages. Pectus carinatum is often associated with various conditions, notably Marfan disease, homocystinuria, prune belly, Morquio syndrome, osteogenesis imperfecta, Noonan syndrome, and mitral valve prolapse. Treatment of pectus carinatum by nonsurgical methods such as exercise and casting has not been worthwhile, whereas surgical management is simple and successful.

Actividad actual y resultados de las observaciones en Base Belgrano Antártida

NASA Astrophysics Data System (ADS)

Recabarren, P.; Mosconi, M.; Ferreiro, D.; Lazarte, G.; Hutka, J.; García Lambas, D.; Ozu, R.

Several aspects of the experience acquired in ``J. L. Sérsic'' Antarctic Astronomical Station, at 78 degrees South, during the period 1995-1997 are analysed. We show results of 'seeing' measurements, extinction coeficients, monitoring of Eta Carinae, meteorogical conditions and logistic support. Seeing measurements show average values of 4.02" ('95), 5.25" ('96) y 4.43" (till July '97). We have found photometrical variations of Eta Car with a particular behaviour near June 5.

Two new species and a new record of Metacirolana Kussakin, 1979 (Crustacea: Isopoda: Cirolanidae) from Indonesia.

PubMed

Sidabalok, Conni M; Bruce, Niel L

2018-01-15

Two new species of Metacirolana from coral reefs in Indonesia are described and Metacirolana spinosa (Bruce, 1980) is recorded for the first time in Indonesia. Metacirolana lombok sp. nov. and Metacirolana mioskon sp. nov. show similarities with several other species of Metacirolana forming a species group within the genus, characterized by small body size (2.0-3.5 mm), smooth body surfaces, weakly produced rostrum, lack of dorsal carinae and abundant chromatophores.

Aortobronchial fistula caused by an endobronchial lobar Y stent: a word of caution.

PubMed

Härting, Margarete; Welter, Stefan; Aigner, Clemens

2018-04-25

A 17-year-old female patient with a history of pulmonary tuberculosis was admitted with progressive dyspnoea and haemoptysis. Five months prior to admission, a left bronchial carina Y stent was implanted. Because of the already destroyed parenchyma, a pneumonectomy was planned. Intraoperatively, an aortobronchial fistula was discovered as the source of bleeding, which could be stopped by pledget-armed sutures. The formation of an aortobronchial fistula has to be considered as a potential source of endobronchial bleeding after stent implantation.

Successful silicon stent for life-threatening tracheal wall laceration.

PubMed

Yamamoto, Shinichi; Endo, Shunsuke; Endo, Tetsuya; Mitsuda, Sayaka

2013-01-01

We report an 86-year-old woman with a large tracheal laceration caused by tracheal intubation at cardiopulmonary arrest who underwent a successful stent procedure. Tracheal laceration developed in the membranous portion longitudinally 6 cm in length to 2 cm above the carina. Following 9 days' tracheal intubation, a Y-shaped silicon stent was inserted over the lacerated trachea. Four months after the stenting procedure, we removed the Y-shaped silicon stent from the healed membranous wall. The patient returned to daily life without requiring thoracotomy.

The dusty silhouette jet HH 1019 in the Carina Nebula

NASA Astrophysics Data System (ADS)

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

2017-06-01

We report the discovery in Hubble Space Telescope (HST) images of the new Herbig-Haro jet, HH 1019, located near the Tr 14 cluster in the Carina Nebula. Like other HH jets in the region, this bipolar collimated flow emerges from the head of a dark dust pillar. However, HH 1019 is unique because - unlike all other HH jets known to date - it is identified by a linear chain of dark, dusty knots that are seen primarily in silhouette against the background screen of the H II region. Proper motions confirm that these dark condensations move along the jet axis at high speed. [S II] emission traces a highly collimated jet that is spatially coincident with these dust knots. The high extinction in the body of the jet suggests that this outflow has lifted a large amount of dust directly from the disc, although it is possible that it has entrained dust from its surrounding protostellar envelope before exiting the dust pillar. If dust in HH 1019 originates from the circumstellar disc, this provides further evidence for a jet launched from a range of radii in the disc, including those outside the dust sublimation radius. HH 1019 may be the prototype for a new subclass of dusty HH objects seen primarily in extinction against the background screen of a bright H II region. Such jets may be common, but difficult to observe because they require the special condition of a very bright background in order to be seen in silhouette.

Disentangling the outflow and protostars in HH 900 in the Carina Nebula

NASA Astrophysics Data System (ADS)

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

2015-04-01

HH 900 is a peculiar protostellar outflow emerging from a small, tadpole-shaped globule in the Carina Nebula. Previous Hα imaging with Hubble Space Telescope (HST)/Advanced Camera for Surveys showed an ionized outflow with a wide opening angle that is distinct from the highly collimated structures typically seen in protostellar jets. We present new narrowband near-IR [Fe II] images taken with the Wide Field Camera 3 on the HST that reveal a remarkably different structure than Hα. In contrast to the unusual broad Hα outflow, the [Fe II] emission traces a symmetric, collimated bipolar jet with the morphology and kinematics that are more typical of protostellar jets. In addition, new Gemini adaptive optics images reveal near-IR H2 emission coincident with the Hα emission, but not the [Fe II]. Spectra of these three components trace three separate and distinct velocity components: (1) H2 from the slow, entrained molecular gas, (2) Hα from the ionized skin of the accelerating outflow sheath, and (3) [Fe II] from the fast, dense, and collimated protostellar jet itself. Together, these data require a driving source inside the dark globule that remains undetected behind a large column density of material. In contrast, Hα and H2 emission trace the broad outflow of material entrained by the jet, which is irradiated outside the globule. As it get dissociated and ionized, it remains visible for only a short time after it is dragged into the H II region.

Eta Carinae and the Homunculus: An Astrophysical Laboratory

NASA Technical Reports Server (NTRS)

Gull, Theodore R.

2006-01-01

High spatial resolution spectroscopy with HST/STIS between 1998.0 and 2004.2 has provided much exciting information about the central binary system and the physics of its N-rich, C,O-poor ejecta. Stellar He I profiles, noticeably blue-shifted relative to P Cygni H and Fe II line profiles, originate from the ionized wind region between two massive companions. Changes in profiles of He I singlet and triplet lines provide clues to the excitation mechanisms involved as the hot, UV companion moves in its highly eccentric orbit. For 90% of the 5.54-year period, the spectra of nearby Weigelt blobs and the Little Homunculus include highly excited emission lines of Ar, Ne, and Fe. During the few month-long spectroscopic minimum, these systems are deprived of Lyman continuum. Recombination, plus cooling, occurs. In the skirt region between the bipolar Homunculus, a neutral emission region, devoid of hydrogen emission, glows in Ti II, Fe I, Sr II, Sc II, etc. We find the ejecta to have Ti/Ni abundances nearly 100 times solar, not due to nuclear processing, but due to lack of oxygen. Many metals normally tied up in interstellar dust remain in gaseous phase. Much information is being obtained on the physical processes in these warm N-rich gases, whose excitation varies with time in a predictable pattern. Indeed recent GRB high dispersion spectra include signatures of circumGRB warm gases. This indicates that the early, primordial massive stars have warm massive ejecta reminiscent to that around Eta Carinae.

The Time Evolution of Eta Carinae's Colliding Winds

NASA Technical Reports Server (NTRS)

Gull, Theodore R.; Madura, T. I.; Grobe, J. H.; Corcoran, M. F.

2011-01-01

We report new HST/STIS observations that map the high-ionization forbidden line emission in the inner arc second of Eta Car, the first that fully image the extended wind-wind interaction region of the massive colliding wind binary. These observations were obtained after the 2009.0 periastron at orbital phases 0.084, 0.163, and 0.323 of the 5.54-year spectroscopic cycle. We analyze the variations in brightness and morphology of the emission, and find that blue-shifted emission (-400 to -200 km/s is symmetric and elongated along the northeast-southwest axis, while the red-shifted emission (+ 100 to +200 km/s) is asymmetric and extends to the north-northwest. Comparison to synthetic images generated from a 3-D dynamical model strengthens the 3-D orbital orientation found by Madura et al. (2011), with an inclination i = 138 deg, argument of periapsis w = 270 deg, and an orbital axis that is aligned at the same P A on the sky as the symmetry axis of the Homunculus, 312 deg. We discuss the potential that these and future mappings have for constraining the stellar parameters of the companion star and the long-term variability of the system. Plain-Language Abstract: With HST, we resolved the interacting winds of the binary, Eta Carinae. With a 3-D model, we find the binary orbit axis is aligned to the Homunculus axis. This suggests a connection between the binary and Homunculus ejection mechanism.

The 2014 X-Ray Minimum of η Carinae as Seen by Swift

DOE Office of Scientific and Technical Information (OSTI.GOV)

Corcoran, M. F.; Hamaguchi, K.; Liburd, J.

We report on Swift X-ray Telescope observations of Eta Carinae ( η Car), an extremely massive, long-period, highly eccentric binary obtained during the 2014.6 X-ray minimum/periastron passage. These observations show that η Car may have been particularly bright in X-rays going into the X-ray minimum state, while the duration of the 2014 X-ray minimum was intermediate between the extended minima seen in 1998.0 and 2003.5 by Rossi X-Ray Timing Explorer ( RXTE ), and the shorter minimum in 2009.0. The hardness ratios derived from the Swift observations showed a relatively smooth increase to a peak value occurring 40.5 days aftermore » the start of the X-ray minimum, though these observations cannot reliably measure the X-ray hardness during the deepest part of the X-ray minimum when contamination by the “central constant emission” component is significant. By comparing the timings of the RXTE and Swift observations near the X-ray minima, we derive an updated X-ray period of P {sub X} = 2023.7 ± 0.7 days, in good agreement with periods derived from observations at other wavelengths, and we compare the X-ray changes with variations in the He ii 4686 emission. The middle of the “Deep Minimum” interval, as defined by the Swift column density variations, is in good agreement with the time of periastron passage derived from the He ii λ 4686 line variations.« less

Bronchial intubation could be detected by the visual stethoscope techniques in pediatric patients.

PubMed

Kimura, Tetsuro; Suzuki, Akira; Mimuro, Soichiro; Makino, Hiroshi; Sato, Shigehito

2012-12-01

We created a system that allows the visualization of breath sounds (visual stethoscope). We compared the visual stethoscope technique with auscultation for the detection of bronchial intubation in pediatric patients. In the auscultation group, an anesthesiologist advanced the tracheal tube, while another anesthesiologist auscultated bilateral breath sounds to detect the change and/or disappearance of unilateral breath sounds. In the visualization group, the stethoscope was used to detect changes in breath sounds and/or disappearance of unilateral breath sounds. The distance from the edge of the mouth to the carina was measured using a fiberoptic bronchoscope. Forty pediatric patients were enrolled in the study. At the point at which irregular breath sounds were auscultated, the tracheal tube was located at 0.5 ± 0.8 cm on the bronchial side from the carina. When a detectable change of shape of the visualized breath sound was observed, the tracheal tube was located 0.1 ± 1.2 cm on the bronchial side (not significant). At the point at which unilateral breath sounds were auscultated or a unilateral shape of the visualized breath sound was observed, the tracheal tube was 1.5 ± 0.8 or 1.2 ± 1.0 cm on the bronchial side, respectively (not significant). The visual stethoscope allowed to display the left and the right lung sound simultaneously and detected changes of breath sounds and unilateral breath sound as a tracheal tube was advanced. © 2012 Blackwell Publishing Ltd.

X-ray Emission From Eta Carinae near Periastron in 2009 I: A Two State Solution

NASA Technical Reports Server (NTRS)

Hamaguchi, Kenji; Corcoran, Michael F.; Russell, Christopher; Pollock, Andrew M. T.; Gull, Theodore R.; Teodoro, Mairan; Madura, Thomas I.; Damineli, Augusto; Pittard, Julian M.

2014-01-01

X-ray emission from the supermassive binary system Eta Carinae declines sharply around periastron. This X-ray minimum has two distinct phases the lowest flux phase in the first 3 weeks and a brighter phase thereafter. In 2009, the Chandra X-ray Observatory monitored the first phase five times and found the lowest observed flux at 1.91012 ergs/sq cm/s (38 keV). The spectral shape changed such that the hard band above 4 keV dropped quickly at the beginning and the soft band flux gradually decreased to its lowest observed value in 2 weeks. The hard band spectrum had begun to recover by that time. This spectral variation suggests that the shocked gas producing the hottest X-ray gas near the apex of the wind-wind collision (WWC) is blocked behind the dense inner wind of the primary star, which later occults slightly cooler gas down-stream. Shocked gas previously produced by the system at earlier orbital phases is suggested to produce the faint residual X-ray emission seen when the emission near the apex is completely blocked by the primary wind. The brighter phase is probably caused by the re-appearance of the WWC plasma, whose emissivity significantly declined during the occultation. We interpret this to mean that the X-ray minimum is produced by a hybrid mechanism of an occultation and a decline in emissivity of the WWC shock. We constrain timings of superior conjunction and periastron based on these results.

To v∞ and beyond! The He I absorption variability across the 2014.6 periastron passage of η Carinae

NASA Astrophysics Data System (ADS)

Richardson, Noel D.; Madura, Thomas I.; St-Jean, Lucas; Moffat, Anthony F. J.; Gull, Theodore R.; Russell, Christopher M. P.; Damineli, Augusto; Teodoro, Mairan; Corcoran, Michael F.; Walter, Frederick M.; Clementel, Nicola; Groh, José H.; Hamaguchi, Kenji; Hillier, D. John

2016-09-01

We have monitored the massive binary star η Carinae with the CTIO/Small and Moderate Aperture Research Telescope System 1.5 m telescope and CHIRON spectrograph from the previous apastron passage of the system through the recent 2014.6 periastron passage. Our monitoring has resulted in a large, homogeneous data set with an unprecedented time-sampling, spectral resolving power, and signal to noise. This allowed us to investigate temporal variability previously unexplored in the system and discover a kinematic structure in the P Cygni absorption troughs of neutral helium wind lines. The features observed occurred prior to the periastron passage and are seen as we look through the trailing arm of the wind-wind collision shock cone. We show that the bulk of the variability is repeatable across the last five periastron passages, and that the absorption occurs in the inner 230 au of the system. In addition, we found an additional, high-velocity absorption component superimposed on the P Cygni absorption troughs that has been previously unobserved in these lines, but which bears resemblance to the observations of the He I λ10830 Å feature across previous cycles. Through a comparison of the current smoothed particle hydrodynamical simulations, we show that the observed variations are likely caused by instabilities in the wind-wind collision region in our line of sight, coupled with stochastic variability related to clumping in the winds.

VizieR Online Data Catalog: Southern H II Region Discovery Survey: pilot survey (Brown+, 2017)

NASA Astrophysics Data System (ADS)

Brown, C.; Jordan, C.; Dickey, J. M.; Anderson, L. D.; Armentrout, W. P.; Balser, D. S.; Bania, T. M.; Dawson, J. R.; Mc Clure-Griffiths, N. M.; Wenger, T. V.

2018-05-01

The Southern H II Region Discovery Survey (SHRDS) is a multi-year project using the Australia Telescope Compact Array (ATCA) to complement the GBT and Arecibo HRDS by extending the survey area into the southern sky (δ<-45°). This area includes the Southern end of the Galactic Bar, the Near and Far 3 kpc Arms, the Norma/Cygnus Arm, the Scutum/Crux Arm, the Sagitttarius/Carina Arm, and outside the solar circle, the Perseus Arm, and the Outer Arm. All pilot SHRDS observations used the ATCA in the five antenna H75 array configuration, giving a nominal maximum baseline of 75 m and a beam size of FWHM ~65" at 7.8 GHz depending on the declination and hour angles of the observations. The SHRDS pilot observations were done in two sessions. Epoch I, observed 2013 June 30, focused on candidates that were expected to show bright radio recombination line (RRL) detections, which they did. Epoch II, observed 2014 June 26 and 27, used a list of candidates with expected flux densities typical of the SHRDS catalog as a whole. The two epochs also used different longitude ranges in order to generate samples of H II regions with different Galactic radii. (3 data files).

Formation of the young compact cluster GM 24 triggered by a cloud-cloud collision

NASA Astrophysics Data System (ADS)

Fukui, Yasuo; Kohno, Mikito; Yokoyama, Keiko; Nishimura, Atsushi; Torii, Kazufumi; Hattori, Yusuke; Sano, Hidetoshi; Ohama, Akio; Yamamoto, Hiroaki; Tachihara, Kengo

2018-05-01

High-mass star formation is an important step which controls galactic evolution. GM 24 is a heavily obscured star cluster including a single O9 star with more than ˜100 lower-mass stars within a 0.3 pc radius toward (l, b) ˜ (350.5°, 0.96°), close to the Galactic mini-starburst NGC 6334. We found two velocity components associated with the cluster by new observations of 12CO J =2-1 emission, whereas the cloud was previously considered to be single. We found that the distribution of the two components of 5 {km}s-1 separation shows complementary distribution; the two fit well with each other if a relative displacement of 3 pc is applied along the Galactic plane. A position-velocity diagram of the GM 24 cloud is explained by a model based on numerical simulations of two colliding clouds, where an intermediate velocity component created by the collision is taken into account. We estimate the collision time scale to be ˜Myr in projection of a relative motion tilted to the line of sight by 45°. The results lend further support for cloud-cloud collision as an important mechanism of high-mass star formation in the Carina-Sagittarius Arm.

NASA's Chandra Sees Brightest Supernova Ever

NASA Astrophysics Data System (ADS)

2007-05-01

WASHINGTON - The brightest stellar explosion ever recorded may be a long-sought new type of supernova, according to observations by NASA's Chandra X-ray Observatory and ground-based optical telescopes. This discovery indicates that violent explosions of extremely massive stars were relatively common in the early universe, and that a similar explosion may be ready to go off in our own galaxy. "This was a truly monstrous explosion, a hundred times more energetic than a typical supernova," said Nathan Smith of the University of California at Berkeley, who led a team of astronomers from California and the University of Texas in Austin. "That means the star that exploded might have been as massive as a star can get, about 150 times that of our sun. We've never seen that before." Chandra X-ray Image of SN 2006gy Chandra X-ray Image of SN 2006gy Astronomers think many of the first generation of stars were this massive, and this new supernova may thus provide a rare glimpse of how the first stars died. It is unprecedented, however, to find such a massive star and witness its death. The discovery of the supernova, known as SN 2006gy, provides evidence that the death of such massive stars is fundamentally different from theoretical predictions. "Of all exploding stars ever observed, this was the king," said Alex Filippenko, leader of the ground-based observations at the Lick Observatory at Mt. Hamilton, Calif., and the Keck Observatory in Mauna Kea, Hawaii. "We were astonished to see how bright it got, and how long it lasted." The Chandra observation allowed the team to rule out the most likely alternative explanation for the supernova: that a white dwarf star with a mass only slightly higher than the sun exploded into a dense, hydrogen-rich environment. In that event, SN 2006gy should have been 1,000 times brighter in X-rays than what Chandra detected. Animation of SN 2006gy Animation of SN 2006gy "This provides strong evidence that SN 2006gy was, in fact, the death of an extremely massive star," said Dave Pooley of the University of California at Berkeley, who led the Chandra observations. The star that produced SN 2006gy apparently expelled a large amount of mass prior to exploding. This large mass loss is similar to that seen from Eta Carinae, a massive star in our galaxy, raising suspicion that Eta Carinae may be poised to explode as a supernova. Although SN 2006gy is intrinsically the brightest supernova ever, it is in the galaxy NGC 1260, some 240 million light years away. However, Eta Carinae is only about 7,500 light years away in our own Milky Way galaxy. "We don't know for sure if Eta Carinae will explode soon, but we had better keep a close eye on it just in case," said Mario Livio of the Space Telescope Science Institute in Baltimore, who was not involved in the research. "Eta Carinae's explosion could be the best star-show in the history of modern civilization." A New Line of Stellar Evolution A New Line of Stellar Evolution Supernovas usually occur when massive stars exhaust their fuel and collapse under their own gravity. In the case of SN 2006gy, astronomers think that a very different effect may have triggered the explosion. Under some conditions, the core of a massive star produces so much gamma ray radiation that some of the energy from the radiation converts into particle and anti-particle pairs. The resulting drop in energy causes the star to collapse under its own huge gravity. After this violent collapse, runaway thermonuclear reactions ensue and the star explodes, spewing the remains into space. The SN 2006gy data suggest that spectacular supernovas from the first stars - rather than completely collapsing to a black hole as theorized - may be more common than previously believed. "In terms of the effect on the early universe, there's a huge difference between these two possibilities," said Smith. "One pollutes the galaxy with large quantities of newly made elements and the other locks them up forever in a black hole." The results from Smith and his colleagues will appear in The Astrophysical Journal. NASA's Marshall Space Flight Center, Huntsville, Ala., manages the Chandra program for the agency's Science Mission Directorate. The Smithsonian Astrophysical Observatory controls science and flight operations from the Chandra X-ray Center in Cambridge, Mass. Additional information and images are available at: http://chandra.harvard.edu and http://chandra.nasa.gov

Exposing the Binary Heart of ETA Carinae

NASA Technical Reports Server (NTRS)

Forman, WIlliam; Mushotzky, Richard (Technical Monitor)

2005-01-01

Continued progress was made last year on A1367. As noted before, A1367 is a puzzling cluster with a large elongation, suggesting a major merger but with an anti-correlation between the luminosity and temperature of the two components of the cluster (NE and SW). The less luminous subconcentration appears hotter and the more luminous portion of the cluster appears cooler in contradiction to the well-established positive correlation of temperature and luminosity for clusters and groups. With the XMM-Newton observation we have developed a merger model to explain this apparent contradiction.

VizieR Online Data Catalog: New OB star candidates in Carina Arm (Mohr-Smith+, 2015)

NASA Astrophysics Data System (ADS)

Mohr-Smith, M.; Drew, J. E.; Barentsen, G.; Wright, N. J.; Napiwotzki, R.; Corradi, R. L. M.; Eisloffel, J.; Groot, P.; Kalari, V.; Parker, Q. A.; Raddi, R.; Sale, S. E.; Unruh, Y. C.; Vink, J. S.; Wesson, R.

2017-08-01

We make use of the photometry from two VPHAS+ fields, numbered 1678 and 1679, that are, respectively, centred on RA=10:18:10.91, DE=-58:03:52.3 (J2000) and on RA=10:25:27.27, DE=-58:03:52.3 (J2000). These were observed in succession in the u, g and r filters on the night of 2012 January 22. The red filter data in Hα, r and i were obtained on 2012 April 29. (2 data files).

A new, well-preserved genus and species of fossil Glaphyridae (Coleoptera, Scarabaeoidea) from the Mesozoic Yixian Formation of Inner Mongolia, China

PubMed Central

Yan, Zhuo; Nikolajev, Georgiy V.; Ren, Dong

2012-01-01

Abstract A new genus and species of fossil Glaphyridae, Cretohypna cristata gen. et sp. n., is described and illustrated from the Mesozoic Yixian Formation. This new genus is characterized by the large body; large and strong mandibles; short labrum; elytra without longitudinal carina; and male meso- and possible metatibia apically modified. A list of described fossil glaphyrids of the world is provided. This significant finding broadens the known diversity of Glaphyridae in the Mesozoic China. PMID:23372414

A new species of seagrass-boring Limnoria (Limnoriidae, Isopoda, Crustacea) from Japan.

PubMed

Yoshino, Hiroki; Watabe, Hikari; Ohsawa, Takeshi A

2017-02-15

The marine seagrass-boring isopod, Limnoria rhombipunctata sp. nov. (Limnoriidae) is described from the rhizome of Phyllospadix iwatensis seagrass, in shallow coastal waters off Chiba Prefecture, Japan. L. rhombipunctata sp. nov. is distinguished from other Limnoria species by the unique carinae of pleonite 5 and pleotelson, two branched lacinia mobilis of the right mandible, 3 flagellar articles of antenna 1, and triangular epipod of the maxilliped. Specimens of L. magadanensis, a species similar to L. rhombipunctata sp. nov., are re-examined and compared with L. rhombipunctata sp. nov.

Sky distribution of artificial sources in the galactic belt of advanced cosmic life.

PubMed

Heidmann, J

1994-12-01

In line with the concept of the galactic belt of advanced life, we evaluate the sky distribution of detectable artificial sources, using a simple astrophysical model. The best region to search is the median band of the Milky Way in the Vulpecula-Cygnus region, together with a narrower one in Carina. Although this work was done in view of a proposal to send a SETI probe at a gravitational focus of the Sun, we recommend these sky regions particularly for the searches of the sky survey type.

NGC 6334 and NGC 6357. Insights from spectroscopy of their OB star populations

NASA Astrophysics Data System (ADS)

Russeil, D.; Adami, C.; Bouret, J. C.; Hervé, A.; Parker, Q. A.; Zavagno, A.; Motte, F.

2017-11-01

Aims: The formation of high-mass stars is still debated. For this reason, several projects such as Herschel-HOBYS are focussed on the study of the earliest phases of massive star formation. As a result, massive star-forming complexes such as NGC 6334 and NGC 6357 have been observed in the far-infrared to study their massive dense cores where massive stars are expected to form. However, to better characterise the environments of these cores we need to understand the previous massive star formation history. To better characterise the environment of these massive dense cores we study the previous high-mass star formation and how these stars act on their environments. Methods: This study is based on the spectral classification of the OB stars identified towards NGC 6334 and NGC 6357 with spectra taken with the AAOmega spectrograph on the Anglo-Australian Telescope (AAT). From the subsequent spectral classification of 109 stars across these regions we were able to evaluate the following: distance, age, mass, global star-forming efficiency (SFE), and star formation rate (SFR) of the regions. The physical conditions of the ionised gas for both complexes was also derived. Results: We confirm that NGC 6334 and NGC 6357 belong to the Saggitarius-Carina arm which, in this direction, extends from 1 kpc to 2.2 kpc. From the location of the stars in Hertzprung-Russell diagram we show that stars older than 10 Myr are broadly spread across these complexes, while younger stars are mainly located in the H II regions and stellar clusters. Our data also suggests that some of the young stars can be considered runaway stars. We evaluate a SFE of 0.019-0.007+0.008 and 0.021-0.003+0.004 and a SFR of 1.1 × 103 ± 300 M⊙ Myr-1 and 1.7 × 103 ± 400 M⊙ Myr-1 for NGC 6334 and NGC 6357, respectively. We note that 29 OB stars have X-ray counterparts, most of them belonging to NGC 6357. This suggests that molecular clouds in NGC 6357 are more impacted by X-ray flux and stellar winds than in NGC 6334. Finally, from the analysis of nebular lines (Hα, [NII], and [SII]) from spectra from several regions of ionised gas, we confirm that the filaments in NGC 6357 are shock heated. Full Tables 2 and A.1 and the normalised observed spectra displayed in Figs. B.1 are 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/607/A86

A Case Study in Astronomical 3D Printing: The Mysterious η Carinae

NASA Astrophysics Data System (ADS)

Madura, Thomas I.

2017-05-01

Three-dimensional (3D) printing moves beyond interactive 3D graphics and provides an excellent tool for both visual and tactile learners, since 3D printing can now easily communicate complex geometries and full color information. Some limitations of interactive 3D graphics are also alleviated by 3D printable models, including issues of limited software support, portability, accessibility, and sustainability. We describe the motivations, methods, and results of our work on using 3D printing (1) to visualize and understand the η Car Homunculus nebula and central binary system and (2) for astronomy outreach and education, specifically, with visually impaired students. One new result we present is the ability to 3D print full-color models of η Car’s colliding stellar winds. We also demonstrate how 3D printing has helped us communicate our improved understanding of the detailed structure of η Car’s Homunculus nebula and central binary colliding stellar winds, and their links to each other. Attached to this article are full-color 3D printable files of both a red-blue Homunculus model and the η Car colliding stellar winds at orbital phase 1.045. 3D printing could prove to be vital to how astronomer’s reach out and share their work with each other, the public, and new audiences.

THE OPTICAL WIND LINE VARIABILITY OF η CARINAE DURING THE 2009.0 EVENT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richardson, N. D.; Moffat, A. F. J.; St-Jean, L.

2015-10-15

We report on high-resolution spectroscopy of the 2009.0 spectroscopic event of η Carinae collected via SMARTS observations using the CTIO 1.5 m telescope and echelle spectrograph. Our observations were made almost every night over a two-month interval around the photometric minimum of η Car associated with the periastron passage of a hot companion. The photoionizing flux of the companion and heating related to colliding winds causes large changes in the wind properties of the massive primary star. Here we present an analysis of temporal variations in a sample of spectral lines that are clearly formed in the wind of themore » primary star. These lines are affected by a changing illumination of the flux of the secondary star during the periastron passage. We document the sudden onset of blueshifted absorption that occurred in most of the lines near or slightly after periastron, and we argue that these absorption components are seen when we view the relatively undisturbed wind of the foreground primary star. We present time series measurements of the net equivalent width of the wind lines and of the radial velocities of the absorption trough minima and the emission peak midpoints. Most lines decrease in emission strength around periastron, and those high excitation lines formed close to the primary exhibit a red-ward velocity excursion. We show how these trends can be explained using an illuminated hemisphere model that is based on the idea that the emission originates primarily from the side of the primary facing the hot companion.« less

A disrupted molecular torus around Eta Carinae as seen in 12CO with ALMA

NASA Astrophysics Data System (ADS)

Smith, Nathan; Ginsburg, Adam; Bally, John

2018-03-01

We present Atacama Large Millimeter Array (ALMA) observations of 12CO 2-1 emission from circumstellar material around the massive star Eta Carinae (η Car). These observations reveal new structural details about the cool equatorial torus located ˜4000 au from the star. The CO torus is not a complete azimuthal loop, but rather, is missing its near side, which appears to have been cleared away. The missing material matches the direction of apastron in the eccentric binary system, making it likely that η Car's companion played an important role in disrupting portions of the torus soon after ejection. Molecular gas seen in ALMA data aligns well with the cool dust around η Car previously observed in mid-infrared (IR) maps, whereas hot dust resides at the inner surface of the molecular torus. The CO also coincides with the spatial and velocity structure of near-IR H2 emission. Together, these suggest that the CO torus seen by ALMA is actually the pinched waist of the Homunculus polar lobes, which glows brightly because it is close to the star and warmer than the poles. The near side of the torus appears to be a blowout, associated with fragmented equatorial ejecta. We discuss implications for the origin of various features north-west of the star. CO emission from the main torus implies a total gas mass in the range of 0.2-1 M⊙ (possibly up to 5 M⊙ or more, although with questionable assumptions). Deeper observations are needed to constrain CO emission from the cool polar lobes.

Spitzer Space Telescope IRS Spectral Mapping of Photoionized Columns in M16 and the Carina HII Regions

NASA Astrophysics Data System (ADS)

Cotera, Angela; Simpson, J. P.; Sellgren, K.; Stolovy, S. R.

2013-01-01

Photoevaporated columns of dust and gas - also called elephant trunks, pillars or fingers - are found in the periphery of many H II regions. They have been observed within the Galaxy, the SMC and the LMC. These features are thought to be sites of current star formation, but the question remains whether the columns persist because stars formed in the denser regions prior to interactions with the UV radiation and stellar winds of nearby massive stars, or because of core collapse resulting from these interactions. We have obtained Spitzer IRS spectral maps of three columns within M 16 and three columns within the Carina nebula, to test our understanding of the impact on these transitory features of differing stellar populations and initial conditions. We use the wealth of molecular, atomic and PAH emission lines located within the spectral range of the high resolution IRS modes (9.9-37.2 micron) to determine the excitation state, dust and gas temperatures, and probe the shock characteristics within the columns as a function of location. Using the IRS spectral mapping mode, in conjunction with the CUBISM tool and the CLOUDY H II region model code, we have constructed detailed maps of the accessible emission lines and derived parameters for each column. Mapping the distribution of the physical states of the dust and gas in these columns is enhancing our understanding of the competing processes within these dynamic objects. The data presented here represent the only IRS spectral maps of photoionized pillars.

A moderately precise dynamical age for the Homunculus of Eta Carinae based on 13 years of HST imaging

NASA Astrophysics Data System (ADS)

Smith, Nathan

2017-11-01

The Hubble Space Telescope archive contains a large collection of images of η Carinae, and this paper analyses those most suitable for measuring its expanding Homunculus Nebula. Multiple intensity tracings through the Homunculus reveal the fractional increase in the overall size of the nebula; this avoids registration uncertainty, mitigates brightness fluctuations, and is independent of previous methods. Combining a 13 yr baseline of Wide Field Planetary Camera 2 images in the F631N filter, with a 4 yr baseline of Advanced Camera for Surveys/High Resolution Channel images in the F550M filter, yields an ejection date (assuming linear motion) of 1847.1 (±0.8 yr). This result improves the precision, but is in excellent agreement with the previous study by Morse et al., that used a shorter time baseline and a different analysis method. This more precise date is inconsistent with ejection during a periastron passage of the eccentric binary. Ejection occurred well into the main plateau of the Great Eruption, and not during the brief peaks in 1843 and 1838. The age uncertainty is dominated by a real spread in ages of various knots, and by some irregular brightness fluctuations. Several knots appear to have been ejected decades before or after the mean date, implying a complicated history of mass-loss episodes outside the main bright phase of the eruption. The extended history of mass ejection may have been largely erased by the passage of a shock through clumpy ejecta, as most material was swept into a thin shell with nearly uniform apparent age.

Gamma-ray follow-up studies on η Carinae

DOE PAGES

Reitberger, K.; Reimer, O.; Reimer, A.; ...

2012-08-01

Observations of high-energy γ-rays recently revealed a persistent source in spatial coincidence with the binary system η Carinae. Since modulation of the observed γ-ray flux on orbital time scales has not been reported so far, an unambiguous identification was hitherto not possible. In particular, the observations made by the Fermi Large Area Telescope (LAT) posed additional questions regarding the actual emission scenario. Analyses show two energetically distinct components in the γ-ray spectrum, which are best described by an exponentially cutoff power-law function (CPL) at energies below 10 GeV and a power-law (PL) component dominant at higher energies. The increased exposuremore » in conjunction with the improved instrumental response functions of the LAT now allow us to perform a more detailed investigation of location, spectral shape, and flux time history of the observed γ-ray emission. Furthermore, we detect a weak but regular flux decrease over time. This can be understood and interpreted in a colliding-wind binary scenario for orbital modulation of the γ-ray emission. We find that the spectral shape of the γ-ray signal agrees with a single emitting particle population in combination with significant absorption by γ-γ pair production. We are able to report on the first unambiguous detection of GeV γ-ray emission from a colliding-wind massive star binary. By studying the correlation of the flux decrease with the orbital separation of the binary components allows us to predict the behaviour up to the next periastron passage in 2014.« less

A new concept of the anatomy of the thoracic oesophagus: the meso-oesophagus. Observational study during thoracoscopic esophagectomy.

PubMed

Cuesta, Miguel A; Weijs, Teus J; Bleys, Ronald L A W; van Hillegersberg, Richard; van Berge Henegouwen, Mark I; Gisbertz, Suzanne S; Ruurda, Jelle P; Straatman, Jennifer; Osugi, Harushi; van der Peet, Donald L

2015-09-01

During thoracoscopic oesophageal surgery, we observed not previously described fascia-like structures. Description of similar structures in rectal cancer surgery was of paramount importance in improving the quality of resection. Therefore, we aimed to describe a new comprehensive concept of the surgical anatomy of the thoracic oesophagus with definition of the meso-oesophagus. We retrospectively evaluated 35 consecutive unedited videos of thoracoscopic oesophageal resections for cancer, to determine the surgical anatomy of the oesophageal fascia's vessels and lymphatic drainage. The resulting concept was validated in a prospective study, including 20 patients at three different centres. Additional confirmation was sought by a histologic study of a cadaver's thorax. A thin layer of connective tissue around the infracarinal oesophagus, involving the lymph nodes at the level of the carina, was observed during thoracoscopic esophagectomy in 32 of the 35 patients included in the retrospective study and in 19 of the 20 patients included in the prospective study. A thick fascia-like structure from the upper thoracic aperture to the lower thoracic aperture was visualized in all patients. This fascia is encountered between the descending aorta and left aspect of the infracarinal oesophagus. Above the carina it expands on both sides of the oesophagus to lateral mediastinal structures. This fascia contains oesophageal vessels, lymph vessels and nodes and nerves. The histologic study confirmed these findings. Here we described the concept of the "meso-oesophagus". Applying the description of the meso-oesophagus will create a better understanding of the oesophageal anatomy, leading to more adequate and reproducible surgery.

Micronutrient mineral and folate content of Australian and imported dried fruit products.

PubMed

Bennett, Louise E; Singh, Davinder P; Clingeleffer, Peter R

2011-01-01

A selection of Australian and imported fresh and dried fruit products, including sultanas, Sunmuscats, Carina currants, Zante currants, apricots, and prunes, were analyzed for selected minerals (Ca, Mg, Na, S, B, Al, Fe, Mn, Cu, Zn, Mo, and Se), folate and vitamin C, and the capacity of dried fruits for dietary provision of these micronutrients evaluated. Micro-nutrients were concentrated by a factor of 3-5 in dried fruits compared with their fresh fruit counterparts and were consequently present in nutritionally significant levels, in contrast to fresh fruit. Australian dried sultanas, Carina currant, Zante currant, apricots, and prunes contained Cu, Fe, K, and Mn at levels of >20% of daily Required Dietary Intake (RDI, taken as the average for adult men and women as nominated by the Australian National Health and Medical Research Council) and Sunmuscats contained Cu, Fe, and K at >20% of RDI. All dried fruits studied contained boron in the range of 1.5 to 5.4 mg per 100 g; however, the RDI for boron has not been defined by the NHMRC at the present time. All sultanas and currants studied contained folate at levels of 10-20% of RDI per 100 g. Experimental drying methods significantly affected folate levels with higher folate content in non-ground versus ground-based drying methods. Of the micro-nutrients supplying >20% of RDI, folate represents a particular nutrient for which the mean daily intake of adult Australians is typically inadequate. This study shows that dried fruit consumption, in contrast with fresh fruit, can provide significant proportions of daily requirements of several micronutrients, particularly folate.

Temporary use of silicone stents for severe airway stenosis in untreated malignant lymphoma.

PubMed

Oki, Masahide; Saka, Hideo

2013-01-01

Airway stenting has become a popular method for palliation of airway stenosis; however, little has been reported about their use for patients with malignant lymphoma that occasionally causes a life-threatening condition. The aim of the study was to evaluate the efficacy and safety of airway stenting in chemoradiotherapy naive patients with severe airway stenosis due to malignant lymphoma. Patients who underwent airway stent placement from April 2007 to July 2011 in a single center were retrospectively reviewed. All stenting procedures were performed using rigid and flexible bronchoscopes under general anesthesia. We performed 174 airway stenting procedures (silicone stents in 154 procedures and metallic in 20 procedures) for 150 patients during the study period. Of the patients, 7 had untreated malignant lymphomas (4 diffuse large B-cell lymphomas, 2 lymphoblastic lymphomas, 1 mucosa-associated lymphoid tissue lymphoma). All patients underwent stenting using the silicone Y-stent (6 on the main carina and 1 on the primary right carina). Dyspnea was relieved immediately in 6 of 7 patients including the mechanically ventilated patient. Stents could be removed in all patients (median 90 d after stenting; range, 32 to 245 d) because of the tumor response to tumor-specific therapy. One granuloma formation and 1 mucus retention triggered the decision to remove the stents. Airway stenting using silicone stents is safe and effective in palliation of airway stenosis in patients with untreated malignant lymphoma, and permits postprocedural tumor-specific therapy. The response to tumor-specific therapy can be expected, and so removable stents should be selected.

The Optical Gravitational Lensing Experiment. Planetary and Low-Luminosity Object Transits in the Carina Fields of the Galactic Disk

NASA Astrophysics Data System (ADS)

Udalski, A.; Szewczyk, O.; Zebrun, K.; Pietrzynski, G.; Szymanski, M.; Kubiak, M.; Soszynski, I.; Wyrzykowski, L.

2002-12-01

We present results of the second "planetary and low-luminosity object transit" campaign conducted by the OGLE-III survey. Three fields (35' X 35' each) located in the Carina regions of the Galactic disk (l ≈ 290°) were monitored continuously in February-May 2002. About 1150 epochs were collected for each field. The search for low depth transits was conducted on about 103 000 stars with photometry better than 15 mmag. In total, we discovered 62 objects with shallow depth (≤ 0.08 mag) flat-bottomed transits. For each of these objects several individual transits were detected and photometric elements were determined. Also lower limits on radii of the primary and companion were calculated. The 2002 OGLE sample of stars with transiting companions contains considerably more objects that may be Jupiter-sized (R < 1.6 R_Jup) compared to our 2001 sample. There is a group of planetary candidates with the orbital periods close to or shorter than one day. If confirmed as planets, they would be the shortest period extrasolar planetary systems. In general, the transiting objects may be extrasolar planets, brown dwarfs, or M-type dwarfs. One should be, however, aware that in some cases unresolved blends of regular eclipsing stars can mimic transits. Future spectral analysis and eventual determination of the amplitude of radial velocity should allow final classification. High resolution spectroscopic follow-up observations are, therefore, strongly encouraged. All photometric data are available to the astronomical community from the OGLE INTERNET archive.

A Correlational Study Assessing the Relationships among Information Technology Project Complexity, Project Complication, and Project Success

ERIC Educational Resources Information Center

Williamson, David J.

2011-01-01

The specific problem addressed in this study was the low success rate of information technology (IT) projects in the U.S. Due to the abstract nature and inherent complexity of software development, IT projects are among the most complex projects encountered. Most existing schools of project management theory are based on the rational systems…

Risk Management in Complex Construction Projects that Apply Renewable Energy Sources: A Case Study of the Realization Phase of the Energis Educational and Research Intelligent Building

NASA Astrophysics Data System (ADS)

Krechowicz, Maria

2017-10-01

Nowadays, one of the characteristic features of construction industry is an increased complexity of a growing number of projects. Almost each construction project is unique, has its project-specific purpose, its own project structural complexity, owner’s expectations, ground conditions unique to a certain location, and its own dynamics. Failure costs and costs resulting from unforeseen problems in complex construction projects are very high. Project complexity drivers pose many vulnerabilities to a successful completion of a number of projects. This paper discusses the process of effective risk management in complex construction projects in which renewable energy sources were used, on the example of the realization phase of the ENERGIS teaching-laboratory building, from the point of view of DORBUD S.A., its general contractor. This paper suggests a new approach to risk management for complex construction projects in which renewable energy sources were applied. The risk management process was divided into six stages: gathering information, identification of the top, critical project risks resulting from the project complexity, construction of the fault tree for each top, critical risks, logical analysis of the fault tree, quantitative risk assessment applying fuzzy logic and development of risk response strategy. A new methodology for the qualitative and quantitative risk assessment for top, critical risks in complex construction projects was developed. Risk assessment was carried out applying Fuzzy Fault Tree analysis on the example of one top critical risk. Application of the Fuzzy sets theory to the proposed model allowed to decrease uncertainty and eliminate problems with gaining the crisp values of the basic events probability, common during expert risk assessment with the objective to give the exact risk score of each unwanted event probability.

Double Engine for a Nebula

NASA Astrophysics Data System (ADS)

2009-08-01

ESO has just released a stunning new image of a field of stars towards the constellation of Carina (the Keel). This striking view is ablaze with a flurry of stars of all colours and brightnesses, some of which are seen against a backdrop of clouds of dust and gas. One unusual star in the middle, HD 87643, has been extensively studied with several ESO telescopes, including the Very Large Telescope Interferometer (VLTI). Surrounded by a complex, extended nebula that is the result of previous violent ejections, the star has been shown to have a companion. Interactions in this double system, surrounded by a dusty disc, may be the engine fuelling the star's remarkable nebula. The new image, showing a very rich field of stars towards the Carina arm of the Milky Way, is centred on the star HD 87643, a member of the exotic class of B[e] stars [1]. It is part of a set of observations that provide astronomers with the best ever picture of a B[e] star. The image was obtained with the Wide Field Imager (WFI) attached to the MPG/ESO 2.2-metre telescope at the 2400-metre-high La Silla Observatory in Chile. The image shows beautifully the extended nebula of gas and dust that reflects the light from the star. The central star's wind appears to have shaped the nebula, leaving bright, ragged tendrils of gas and dust. A careful investigation of these features seems to indicate that there are regular ejections of matter from the star every 15 to 50 years. A team of astronomers, led by Florentin Millour, has studied the star HD 87643 in great detail, using several of ESO's telescopes. Apart from the WFI, the team also used ESO's Very Large Telescope (VLT) at Paranal. At the VLT, the astronomers used the NACO adaptive optics instrument, allowing them to obtain an image of the star free from the blurring effect of the atmosphere. To probe the object further, the team then obtained an image with the Very Large Telescope Interferometer (VLTI). The sheer range of this set of observations, from the panoramic WFI image to the fine detail of the VLTI observations, corresponds to a zoom-in factor of 60 000 between the two extremes. The astronomers found that HD 87643 has a companion located at about 50 times the Earth-Sun distance and is embedded in a compact dust shell. The two stars probably orbit each other in a period between 20 and 50 years. A dusty disc may also be surrounding the two stars. The presence of the companion could be an explanation for the regular ejection of matter from the star and the formation of the nebula: as the companion moves on a highly elliptical orbit, it would regularly come very close to HD 87643, triggering an ejection. Notes [1]: B[e] stars are stars of spectral type B, with emission lines in their spectra, hence the "e". They are surrounded by a large amount of dust. More information The work on HD 87643 has been published in a paper to appear in Astronomy and Astrophysics: A binary engine fueling HD 87643's complex circumstellar environment using AMBER/VLTI imaging, by F. Millour et al. ESO, the European Southern Observatory, is the foremost intergovernmental astronomy organisation in Europe and the world's most productive astronomical observatory. It is supported by 14 countries: Austria, Belgium, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world's most advanced visible-light astronomical observatory. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning a 42-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become "the world's biggest eye on the sky".

Four New Ladybug Species Belonging to Decadiomus Chapin (Coleoptera: Coccinellidae) from Puerto Rico.

PubMed

Segarra-Carmona, A E; Otero, M

2014-12-01

While searching for native natural enemies attacking invasive insect pests in Puerto Rico, we found four undescribed ladybug species belonging to the Caribbean ladybug genus Decadiomus Chapin. In this article, we describe the following species from Puerto Rico: Decadiomus seini n. sp., Decadiomus ramosi n. sp., Decadiomus hayuyai n. sp., and Decadiomus martorelli n. sp. Illustrations of the dorsal habitus, shape of prosternal carinae, and drawings of male and female genitalia are presented. We also present a key for Diomini of Puerto Rico and discuss their importance as potential biocontrol agents.

Un nuevo estudio del cúmulo abierto Tr 14 en la región de Carina

NASA Astrophysics Data System (ADS)

García, B.; Malaroda, S.; Levato, H.; Morrell, N.

Presentamos nuevos datos espectroscópicos de 9 objetos entre los miembros más brillantes de Tr 14. Hemos medido un total de 80 nuevos espectrogramas para contribuir a la determinación de la real naturaleza de estos objetos desde el punto de vista de la duplicidad. Del nuevo material debemos concluir que la mayoría de las estrellas en la muestra son simples. Sin embargo existen algunos objetos cuyo seguimiento debe continuar ya que no nos es posible efectuar conclusiones definitivas con el presente material.

Eta Carinae: What We have learned recently with HST/STIS, VLT/UVES and VLTI: What We Might Learn with VLT/VLTI across the 2008/9 Minimum

NASA Technical Reports Server (NTRS)

Gull, Theodore R.

2005-01-01

Eta Carinae, the LBV that we have learned to love and hate, has revealed many clues of its character over the past seven years by studies with HST and VLT. Based upon X-Ray, optical and IR observations, Eta Carinae is convincingly a massive binary system that uniquely has major nebular ejecta that are connected with historical outbursts. We have successhlly followed the stellar and nebular changes over the 5.5 year cycle, especially with STIS and RXTE, and across the spectroscopic minimum in 2003.5 with STIS, CHANDRA, RXTE, FUSE, and VLT/UVES. The HST/STIS high spatial resolution, combined with appropriate spectral resolving powers from 1150 to 10300 A, has revealed much about the Central Source and especially the spatially resolved extended stellar atmosphere and the ejecta, known as the Homunculus. Indeed the neutral, dusty outer Homunculus, ejected in the 1840s, envelops the newly discovered ionized Little Homunculus, ejected in the 1890s. In line of sight, multiple hot clumps, both ionized and neutral, are seen in absorption and provide much information on the physical conditions of these massive ejecta. Against the nebular-scattered starlight, wind and nebular absorptions provide views at different angles from line of sight. The VLT/UVES studies from 2002 through 2004 provided very important time-sampled spectra of both the star as seen directly and as seen by the SE lobe viewing the polar region of the star. The VLTI 2.2 micron measures of the central source are consistent with a prolate spheroid with its axis extending along the axis of the Homunculus. This is consistent with the noticeably larger wind mass and higher terminal velocity along the axis of the Homunculus compared to that measured in line of sight at about 45 degrees from the polar axes. We understand the system to be a massive primary with an O or WR companion in a very highly elliptical orbit. The spectroscopic minimum occurs during periastron, when the greatly extended primary atmosphere and wind bottles up the ionizing uv radiation of the companion star. This transient drop in uv photons leads to recombination of much of the wind structure and of the nearby ejecta. Doubly-ionized elements (iron, neon, argon, vanadium) recombine to singly ionized forms and extended structures on the scales of below 0.03 arcseconds to an arcsecond change, appear, or disappear. With the loss of the STIS on HST, ground-based observations, especially with high spatial-resolution facilities, including the VLT and VLTI will be key to further studies across the minimum centered on 2009.0. Now is the time to plan for these studies.

Discovery of VHE emission towards the Carina arm region with the H.E.S.S. telescope array: HESS J1018-589

NASA Astrophysics Data System (ADS)

H. E. S. S. Collaboration; Abramowski, A.; Acero, F.; Aharonian, F.; Akhperjanian, A. G.; Anton, G.; Balzer, A.; Barnacka, A.; Becherini, Y.; Becker, J.; Bernlöh, K.; Birsin, E.; Biteau, J.; Bochow, A.; Boisson, C.; Bolmont, J.; Bordas, P.; Brucker, J.; Brun, F.; Brun, P.; Bulik, T.; Büsching, I.; Carrigan, S.; Casanova, S.; Cerruti, M.; Chadwick, P. M.; Charbonnier, A.; Chaves, R. C. G.; Cheesebrough, A.; Cologna, G.; Conrad, J.; Dalton, M.; Daniel, M. K.; Davids, I. D.; Degrange, B.; Deil, C.; Dickinson, H. J.; Djannati-Ataï, A.; Domainko, W.; Drury, L. O'C.; Dubus, G.; Dutson, K.; Dyks, J.; Dyrda, M.; Egberts, K.; Eger, P.; Espigat, P.; Fallon, L.; Fegan, S.; Feinstein, F.; Fernandes, M. V.; Fiasson, A.; Fontaine, G.; Förster, A.; Füßling, M.; Gallant, Y. A.; Gast, H.; Gérard, L.; Gerbig, D.; Giebels, B.; Glicenstein, J. F.; Glück, B.; Göring, D.; Häffner, S.; Hague, J. D.; Hahn, J.; Hampf, D.; Harris, J.; Hauser, M.; Heinz, S.; Heinzelmann, G.; Henri, G.; Hermann, G.; Hillert, A.; Hinton, J. A.; Hofmann, W.; Hofverberg, P.; Holler, M.; Horns, D.; Jacholkowska, A.; de Jager, O. C.; Jahn, C.; Jamrozy, M.; Jung, I.; Kastendieck, M. A.; Katarzyński, K.; Katz, U.; Kaufmann, S.; Keogh, D.; Khélifi, B.; Klochkov, D.; Klużniak, D.; Kneiske, T.; Komin, Nu.; Kosack, K.; Kossakowski, R.; Krayzel, F.; Laffon, H.; Lamanna, G.; Lenain, J.-P.; Lennarz, D.; Lohse, T.; Lopatin, A.; Lu, C.-C.; Marandon, V.; Marcowith, A.; Masbou, J.; Maxted, N.; Mayer, M.; McComb, T. J. L.; Medina, M. C.; Méhault, J.; Moderski, R.; Mohamed, M.; Moulin, E.; Naumann, C. L.; Naumann-Godo, M.; de Naurois, M.; Nedbal, D.; Nekrassov, D.; Nguyen, N.; Nicholas, B.; Niemiec, J.; Nolan, S. J.; Ohm, S.; de Oña Wilhelmi, E.; Opitz, B.; Ostrowski, M.; Oya, I.; Panter, M.; Paz Arribas, M.; Pekeur, N. W.; Pelletier, G.; Perez, J.; Petrucci, P.-O.; Peyaud, B.; Pita, S.; Pühlhofer, G.; Punch, M.; Quirrenbach, A.; Raue, M.; Rayner, S. M.; Reimer, A.; Reimer, O.; Renaud, M.; de los Reyes, R.; Rieger, F.; Ripken, J.; Rob, L.; Rosier-Lees, S.; Rowell, G.; Rudak, B.; Rulten, C. B.; Sahakian, V.; Sanchez, D. A.; Santangelo, A.; Schlickeiser, R.; Schulz, A.; Schwanke, U.; Schwarzburg, S.; Schwemmer, S.; Sheidaei, F.; Skilton, J. L.; Sol, H.; Spengler, G.; Stawarz, Ł.; Steenkamp, R.; Stegmann, C.; Stinzing, F.; Stycz, K.; Sushch, I.; Szostek, A.; Tavernet, J.-P.; Terrier, R.; Tluczykont, M.; Valerius, K.; van Eldik, C.; Vasileiadis, G.; Venter, C.; Viana, A.; Vincent, P.; Völk, H. J.; Volpe, F.; Vorobiov, S.; Vorster, M.; Wagner, S. J.; Ward, M.; White, R.; Wierzcholska, A.; Zacharias, M.; Zajczyk, A.; Zdziarski, A. A.; Zech, A.; Zechlin, H.-S.

2012-05-01

The Carina arm region, containing the supernova remnant SNR G284.3-1.8, the high-energy (HE; E > 100 MeV) binary 1FGL J1018.6-5856 and the energetic pulsar PSR J1016-5857 and its nebula, has been observed with the H.E.S.S. telescope array. The observational coverage of the region in very-high-energy (VHE; E > 0.1 TeV) γ-rays benefits from deep exposure (40 h) of the neighboring open cluster Westerlund 2. The observations have revealed a new extended region of VHE γ-ray emission. The new VHE source HESS J1018-589 shows a bright, point-like emission region positionally coincident with SNR G284.3-1.8 and 1FGL J1018.6-5856 and a diffuse extension towards the direction of PSR J1016-5857. A soft (Γ = 2.7 ± 0.5stat)photon index, with a differential flux at 1 TeV of N0 = (4.2 ± 1.1) × 10-13 TeV-1 cm-2 s-1 is found for the point-like source, whereas the total emission region including the diffuse emission region is well fit by a power-law function with spectral index Γ = 2.9 ± 0.4stat and differential flux at 1 TeV of N0 = (6.8 ± 1.6) × 10-13 TeV-1 cm-2 s-1. This H.E.S.S. detection motivated follow-up X-ray observations with the XMM-Newton satellite to investigate the origin of the VHE emission. The analysis of the XMM-Newton data resulted in the discovery of a bright, non-thermal point-like source (XMMU J101855.4-58564) with a photon index of Γ = 1.65 ± 0.08 in the center of SNR G284.3-1.8, and a thermal, extended emission region coincident with its bright northern filament. The characteristics of this thermal emission are used to estimate the plasma density in the region as n ≈ 0.5 cm-3 (2.9 kpc/d)2. The position of XMMU J101855.4-58564 is compatible with the position reported by the Fermi-LAT collaboration for the binary system 1FGL J1018.6-5856 and the variable Swift XRT source identified with it. The new X-ray data are used alongside archival multi-wavelength data to investigate the relationship between the VHE γ-ray emission from HESS J1018-589 and the various potential counterparts in the Carina arm region.

Probing the Dragonfish star-forming complex: the ionizing population of the young massive cluster Mercer 30

NASA Astrophysics Data System (ADS)

de la Fuente, D.; Najarro, F.; Borissova, J.; Ramírez Alegría, S.; Hanson, M. M.; Trombley, C.; Figer, D. F.; Davies, B.; Garcia, M.; Kurtev, R.; Urbaneja, M. A.; Smith, L. C.; Lucas, P. W.; Herrero, A.

2016-05-01

It has recently been claimed that the nebula, Dragonfish, is powered by a superluminous but elusive OB association. However, systematic searches in near-infrared photometric surveys have found many other cluster candidates in this region of the sky. Among these, the first confirmed young massive cluster was Mercer 30, where Wolf-Rayet stars were found.We perform a new characterization of Mercer 30 with unprecedented accuracy, combining NICMOS/HST and VVV photometric data with multi-epoch ISAAC/VLT H- and K-band spectra. Stellar parameters for most of spectroscopically observed cluster members are found through precise non-LTE atmosphere modeling with the CMFGEN code. Our spectrophotometric study for this cluster yields a new, revised distance of d = (12.4 ± 1.7) kpc and a total of QHMc30 ≈ 6.70 × 1050 s-1 Lyman ionizing photons. A cluster age of (4.0 ± 0.8) Myr is found through isochrone fitting, and a total mass of (1.6 ± 0.6) × 104M⊙ is estimated, thanks to our extensive knowledge of the post-main-sequence population. As a consequence, membership of Mercer 30 to the Dragonfish star-forming complex is confirmed, allowing us to use this cluster as a probe for the whole complex, which turns out to be extremely large (~400 pc across) and located at the outer edge of the Sagittarius-Carina spiral arm (~11 kpc from the Galactic center). The Dragonfish complex hosts 19 young clusters or cluster candidates (including Mercer 30 and a new candidate presented in this work) and an estimated minimum of nine field Wolf-Rayet stars. All these contributions account for, at least 73% of the ionization of the Dragonfish nebula and leaves little or no room for the alleged superluminous OB association; alternative explanations are discussed. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile, under programs IDs 179.B-2002, 081.D-0471, 083.D-0765, 087.D-0957, and 089.D-0989.

Ultraviolet Changes of the Central Source and the Very Nearby Ejecta

NASA Technical Reports Server (NTRS)

Gull, Theodore R.; Nielsen, Krister; Vierira, Gladys; Hillier, John; Walborn, Nolan; Davidson, Kris

2004-01-01

We utilized the high spatial and high spectral resolution of the HST/STIS MAMA echelle modes in the ultraviolet (0.025 inch spatial resolution and 30,000 to 120,000 spectral resolving power) to view changes in and around Eta Carinae before and after the X-Ray drop which occurred on June 29, 2003 (M. Corcoran, IAUC 8160). Major changes in the spectra of the Central Source and nearby nebulosities occurred between June 22 and July 5. Visibility of the Central Source dropped, especially between 1175 and 1350 Angstroms, but not uniformly throughout the ultraviolet. This fading is likely due to multiple line absorptions both in the source and in the intervening ejecta. Nebular emission of Si III] and Fe III, located 0.09 sec. to the west, disappeared. By July 29, a bright feature extending up to 0.071 sec. east of the Central Source became prominent in broad emission lines near 2500 Angstroms, but was not noticeable longward of 2900 Angstroms. ACS/HRC imagery and STIS CCD spectra taken concurrently are being examined for larger scale changes. Numerous narrow velocity components between -146 and -585 kilometers per second were identified in spectra before the minimum. New components appeared primarily in Fe II absorption lines with velocities between -170 and -380 kilometers per second. While the lines of the -513 kilometers per second component did not change, most lines of the -146 kilometers per second component changed considerably. Lines originating from high energy levels diminished or disappeared, while lines originating from lower energy levels strengthened. Strong absorption lines of Ti II, not present before the X-Ray drop, appeared within seven days, but disappeared by July 29. Further analysis of these unprecedented data will provide significant new information about the structure of Eta Carinae and its periodic variations.

The Strontium Filament within the Homunculus of Eta Carinae

NASA Technical Reports Server (NTRS)

Gull, Theodore R.; Hartman, H.; Zethson, T.; Johansson, S.; Ishibashi, K.; Davidson, K.; Fisher, Richard R. (Technical Monitor)

2001-01-01

During a series of HST/STIS observations of Eta Carinae and associated ejecta, we noticed a peculiar emission filament located a few arcseconds north of the central source. While bright in nebular standards, it is submerged in a sea of scattered starlight until moderately high dispersion, long-slit spectroscopy with the STIS (R- 8000) brings the emission lines out. The initial spectrum, centered on 6768A with the STIS G750M grating, led to identification of twenty lines from singly-Ionized species including [Sr II], [Fe II], [Ti II], [Ni II], [Mn II], and [Co II] (Zethson, etal., 2001, AJ 122,322). No Balmer emission is detected from this filament and the Fe II 2507,9 lines, known to be pumped by Lyman alpha radiation in other regions near the central source, are not detected. Followup observations have led to detection of hundreds more emission lines from iron group elements in neutral and singly-ionized states. Thus far all are excited by less than 10 eV. This peculiar nebular emission is thought to be due to very intense stellar radiation, stripped of uv flux shortward of Lyman alpha, bathing a neutral structure. We are systematically identifying the many lines (over 90% identified) and measuring line intensities that will then be modeled to determine excitation mechanisms, temperature and density. Two [Sr II] and two Sr II lines have now been measured. Bautista, etal. (in preparation) have modeled the strontium flux ratios and find that large radiation fluxes and/or high strontium abundances may account for the detected emission. These observations were supported by STIS GTO funding and GO funding through the STScI

Reconstructing the outburst history of Eta Carinae from WFPC2 proper motions

NASA Astrophysics Data System (ADS)

Smith, Nathan

2011-10-01

The HST archive contains several epochs of WFPC2 images of the nebula around Eta Carinae taken over a 15-year timespan, although only the earliest few years of data have been analyzed and published. The fact that all these images were taken with the same instrument, with the same pixel sampling and field distortion, makes them an invaluable resource for accurately measuring the expanding ejecta. So far, analysis of a subset of the data {with only a few year baseline} has shown that Eta Car's nebula was ejected around the time of the Great Eruption in the 1840s, but the full 15-yr dataset has much greater untapped potential. Historical data show multiple peaks in the light curve during the 1840s eruption, possibly the result of violent stellar collisions in the eccentric binary system. Proper motions with the full 15-yr dataset will definitively show if one of these is associated with the main mass ejection. Older material outside the main bipolar nebula traces previous major outbursts of the star with no recorded historical observations. We propose an ambitious reduction and analysis of the complete WFPC2 imaging dataset of Eta Car. These data can reconstruct its violent mass-loss history over the past several thousand years. This will constrain the behavior and timescale of eruptive mass loss in pre-SN evolution. The existence of several epochs over a long timespan will date older parts of the nebula that have not yet been measured, and can even measure the deceleration of the ejecta for the first time, essential for understanding their shaping and shock excitation during the nebula's continuing hydrodynamic evolution.

Latitude-Dependent Effects in the Stellar Wind of Eta Carinae

NASA Technical Reports Server (NTRS)

Smith, Nathan; Davidson, Kris; Gull, Theodore R.; Ishibashi, Kazunori; Hillier, D. John

2002-01-01

The Homunculus reflection nebula around eta Carinae provides the rare opportunity to observe the spectrum of a star from more than one direction. In the case of eta Car, the nebula's geometry is known well enough to infer how wind profiles vary with latitude. We present STIS spectra of several positions in the Homunculus, showing directly that eta Car has an aspherical and axisymmetric stellar wind. P Cygni absorption in Balmer lines depends on latitude, with relatively high velocities and strong absorption near the polar axis. Stronger absorption at high latitudes is surprising, and it suggests higher mass flux toward the poles, perhaps resulting from equatorial gravity darkening on a rotating star. Reflected profiles of He I lines are more puzzling, and offer clues to eta Car's wind geometry and ionization structure. During eta Car's high-excitation state in March 2000, the wind had a fast, dense polar wind, with higher ionization at low latitudes. Older STIS data obtained since 1998 reveal that this global stellar-wind geometry changes during eta Car's 5.5 year cycle, and may suggest that this star s spectroscopic events are shell ejections. Whether or not a companion star triggers these outbursts remains ambiguous. The most dramatic changes in the wind occur at low latitudes, while the dense polar wind remains relatively undisturbed during an event. The apparent stability of the polar wind also supports the inferred bipolar geometry. The wind geometry and its variability have critical implications for understanding the 5.5 year cycle and long-term variability, but do not provide a clear alternative to the binary hypothesis for generating eta Car s X-rays.

A census of the expected properties of classical Milky Way dwarfs in Milgromian dynamics

NASA Astrophysics Data System (ADS)

Lüghausen, F.; Famaey, B.; Kroupa, P.

2014-07-01

Prompted by the recent successful predictions of the internal dynamics of Andromeda's satellite galaxies, we revisit the classical Milky Way dwarf spheroidal satellites Draco, Sculptor, Sextans, Carina and Fornax in the framework of Milgromian dynamics (MOND). We use for the first time a Poisson solver with adaptive mesh refinement (AMR) in order to account simultaneously for the gravitational influence of the Milky Way and its satellites. This allows us to rigorously model the important external field effect (EFE) of Milgromian dynamics, which can reduce the effective acceleration significantly. We make predictions on the dynamical mass-to-light ratio (Mdyn/L) expected to be measured by an observer who assumes Newtonian dynamics to be valid. We show that Milgromian dynamics predicts typical Mdyn/L ≈ 10-50 M⊙/L⊙. The results for the most luminous ones, Fornax and Sculptor, agree well with available velocity dispersion data. Moreover, the central power-law slopes of the dynamical masses agree exceedingly well with values inferred observationally from velocity dispersion measurements. The results for Sextans, Carina and Draco are low compared to usually quoted observational estimates, as already pointed out by Angus. For Milgromian dynamics to survive further observational tests in these objects, one would thus need that either (a) previous observational findings based on velocity dispersion measurements have overestimated the dynamical mass due to, e.g. binaries and contaminant outliers, (b) the satellites are not in virial equilibrium due to the Milky Way tidal field, or (c) the specific theory used here does not describe the EFE correctly (e.g. the EFE could be practically negligible in some other theories), or a combination of (a)-(c).

DISCOVERY OF FIVE CANDIDATE ANALOGS FOR η CARINAE IN NEARBY GALAXIES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Khan, Rubab; Adams, Scott M.; Stanek, K. Z.

The late-stage evolution of very massive stars such as η Carinae may be dominated by episodic mass ejections that may later lead to Type II superluminous supernova (SLSN-II; e.g., SN 2006gy). However, as long as η Car is one of a kind, it is nearly impossible to quantitatively evaluate these possibilities. Here, we announce the discovery of five objects in the nearby (∼4–8 Mpc) massive star-forming galaxies M51, M83, M101, and NGC 6946 that have optical through mid-infrared (mid-IR) photometric properties consistent with the hitherto unique η Car. The Spitzer mid-IR spectral energy distributions of these L{sub bol} ≃ 3–8 × 10{sup 6} L{submore » ⊙} objects rise steeply in the 3.6–8 μm bands and then turn over between 8 and 24 μm, indicating the presence of warm (∼400–600 K) circumstellar dust. Their optical counterparts in HST images are ∼1.5–2 dex fainter than their mid-IR peaks and require the presence of ∼5–10 M{sub ⊙} of obscuring material. Our finding implies that the rate of η Car–like events is a fraction f = 0.094 (0.040 < f < 0.21 at 90% confidence) of the core-collapse supernova (ccSN) rate. If there is only one eruption mechanism and Type II superluminous supernovae are due to ccSNe occurring inside these dense shells, then the ejection mechanism is likely associated with the onset of carbon burning (∼10{sup 3}–10{sup 4} years), which is also consistent with the apparent ages of massive Galactic shells.« less

Rotation and Mass Loss

NASA Astrophysics Data System (ADS)

Owocki, S.

2008-06-01

Stellar rotation can play an important role in structuring and enhancing the mass loss from massive stars. Initial 1D models focussed on the expected centrifugal enhancement of the line-driven mass flux from the equator of a rotating star, but the review here emphasizes that the loss of centrifugal support away from the stellar surface actually limits the steady mass flux to just the point-star CAK value, with models near critical rotation characterized by a slow, subcritical acceleration. Recent suggestions that such slow outflows might have high enough density to explain disks in Be or B[e] stars are examined in the context of 2D simulations of the ``Wind Compressed Disk'' (WCD) paradigm, together with a review of the tendency for poleward components of the line-driving force to inhibit WCD formation. When one accounts for equatorial gravity darkening, the net tendency is in fact for the relatively bright regions at higher latitude to drive a faster, denser ``bipolar'' outflow. I discuss the potential relevance for the bipolar form of nebulae from LBV stars like η Carinae, but emphasize that, since the large mass loss associated with the eruption of eta Carinae's Homunculus would heavily saturate line-driving, explaining its bipolar form requires development of analogous models for continuum-driven mass loss. I conclude with a discussion of how radiation seems inherently ill-suited to supporting or driving a geometrically thin, but optically thick disk or disk outflow. The disks inferred in Be and B[e] stars may instead be centrifugally ejected, with radiation inducing an ablation flow from the disk surface, and thus perhaps playing a greater role in destroying (rather than creating) an orbiting, circumstellar disk.

Geometry and physical conditions in the stellar wind of AG Carinae

NASA Technical Reports Server (NTRS)

Leitherer, Claus; Allen, Richard; Altner, Bruce; Damineli, Augusto; Drissen, Laurent; Idiart, Thais; Lupie, Olivia; Nota, Antonella; Robert, Carmelle; Schmutz, Werner

1994-01-01

AG Carinae is one of the prototypes of the class of Luminous Blue Variables (LBVs). Since 1990 the star has continuously brightened in its visual continuum. We report on a multi-instrument and -wavelength observing campaign to monitor the current activity phase of AG Car. Ground-based photometry, polarimetry, spectroscopy, and space-ultraviolet spectroscopy and spectropolarimetry have been obtained. From the variability of the polarization at ultraviolet and optical wavelengths we detect significant intrinsic polarization. P(sub int) greater than or equal to 0.5% is a large value for a hot, luminous star, suggesting departure from spherical symmetry in the wind of AG Car. The intrinsic polarization is variable on a timescale of 2 months or less. The measured ultraviolet polarization (intrinsic + interstellar) dropped to 0.5% in 1992 May and returned to 1% in 1992 July. The results are interpreted in terms of a variable outflow with a density enhancement in the equatorial plane. A similar model was suggested for the related object R127 in the Large Magellanic Cloud (LMC). This geometry is reminiscent of the large-scale morphology of the gas nebula and dust 'jet' surrounding AG Car. It is therefore likely that physical conditions close to the stellar surface are responsible for the geometry of the spatially resolved circumstellar material around AG Car. Despite the drastic change of the photospheric conditions, the mass-loss rate did not increase. We find no evidence for a positive correlation between wind density and stellar radius. This makes models that explain the radius increase by opacity effects in the outflow unlikely. The mechanism responsible for the temperature and radius variations is still unknown but most likely has its origin in subphotospheric regions.

An enigmatic crocodyliform tooth from the bauxites of western Hungary suggests hidden mesoeucrocodylian diversity in the Early Cretaceous European archipelago

PubMed Central

Rabi, Márton; Makádi, László

2015-01-01

Background. The Cretaceous of southern Europe was characterized by an archipelago setting with faunas of mixed composition of endemic, Laurasian and Gondwanan elements. However, little is known about the relative timing of these faunal influences. The Lower Cretaceous of East-Central Europe holds a great promise for understanding the biogeographic history of Cretaceous European biotas because of the former proximity of the area to Gondwana (as part of the Apulian microcontinent). However, East-Central European vertebrates are typically poorly known from this time period. Here, we report on a ziphodont crocodyliform tooth discovered in the Lower Cretaceous (Albian) Alsópere Bauxite Formation of Olaszfalu, western Hungary. Methods. The morphology of the tooth is described and compared with that of other similar Cretaceous crocodyliforms. Results. Based on the triangular, slightly distally curved, constricted and labiolingually flattened crown, the small, subequal-sized true serrations on the carinae mesially and distally, the longitudinal fluting labially, and the extended shelves along the carinae lingually the tooth is most similar to some peirosaurid, non-baurusuchian sebecosuchian, and uruguaysuchid notosuchians. In addition, the paralligatorid Wannchampsus also possesses similar anterior teeth, thus the Hungarian tooth is referred here to Mesoeucrocodylia indet. Discussion. Supposing a notosuchian affinity, this tooth is the earliest occurrence of the group in Europe and one of the earliest in Laurasia. In case of a paralligatorid relationship the Hungarian tooth would represent their first European record, further expanding their cosmopolitan distribution. In any case, the ziphodont tooth from the Albian bauxite deposit of western Hungary belongs to a group still unknown from the Early Cretaceous European archipelago and therefore implies a hidden diversity of crocodyliforms in the area. PMID:26339542

Airway humidification during high-frequency percussive ventilation.

PubMed

Allan, Patrick F; Hollingsworth, Michael J; Maniere, Gordon C; Rakofsky, Anthony K; Chung, Kevin K; Naworol, Gregory A; Ward, John A; Perello, Michelle; Morris, Michael J

2009-03-01

We were concerned about the risk of inadequate humidification during high-frequency percussive ventilation (HFPV). We studied 5 humidifiers during HFPV with a lung model, at bias gas flows of 10 L/min, 30 L/min, and 50 L/min, and compared the results to those from a comparator ventilator/humidifier setup and to the minimum temperature (30 degrees C) and humidity (30 mg/L) [corrected] recommended by the American Association for Respiratory Care, at both regular room temperature and a high ambient temperature. Temperature was measured at the humidifier outflow point and at the artificial carina. Humidity was measured at the artificial carina. Of the 7 HFPV/humidifier combinations, 2 (the MR850 at a bias flow of 50 L/min, and the ConchaTherm Hi-Flow with VDR nebulizer) provided a carinal temperature equivalent to the comparator setup at room temperature, whereas one HFPV/humidifier combination (the ConchaTherm Hi-Flow with modified programming, at bias flows of 30 L/min and 50 L/min) provided a higher carinal temperature. At high ambient temperature, all of the setups delivered lower carinal temperature than the comparator setup. Only 2 setups (the ConchaTherm with modified programming at a bias flow of 50 L/min, and the ConchaTherm Hi-Flow with VDR nebulizer) provided carinal humidification equivalent to the comparator setup, without regard to ambient temperature; the other humidifiers were less effective. The ConchaTherm with modified programming, and the ConchaTherm with the VDR nebulizer provided the most consistent humidification. HFPV's distinctive gas-flow mechanism may impair gas heating and humidification, so all humidification systems should be tested with HFPV prior to clinical use.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Norris, John E.; Yong, David; Dotter, Aaron

We investigate the color–magnitude diagram (CMD) of the Carina dwarf spheroidal galaxy using data of Stetson et al. and synthetic CMDs based on isochrones of Dotter et al., in terms of the parameters [Fe/H], age, and [ α /Fe], for the cases when (i) [ α /Fe] is held constant and (ii) [ α /Fe] is varied. The data are well described by four basic epochs of star formation, having [Fe/H] = −1.85, −1.5, −1.2, and ∼−1.15 and ages ∼13, 7, ∼3.5, and ∼1.5 Gyr, respectively (for [ α /Fe] = 0.1, constant [ α /Fe], and [ α /Fe]more » = 0.2, 0.1, −0.2, −0.2, variable [ α /Fe]), with small spreads in [Fe/H] and age of order 0.1 dex and 1–3 Gyr. Within an elliptical radius 13.′1, the mass fractions of the populations, at their times of formation, were (in decreasing age order) 0.34, 0.39, 0.23, and 0.04. This formalism reproduces five observed CMD features (two distinct subgiant branches of old and intermediate-age populations, two younger, main-sequence components, and the small color dispersion on the red giant branch (RGB). The parameters of the youngest population are less certain than those of the others, and given it is less centrally concentrated, it may not be directly related to them. High-resolution spectroscopically analyzed RGB samples appear statistically incomplete compared with those selected using radial velocity, which contain bluer stars comprising ∼5%–10% of the samples. We conjecture these objects may, at least in part, be members of the youngest population. We use the CMD simulations to obtain insight into the population structure of Carina's upper RGB.« less

IRS Spectral Maps of Photoevaporative Columns in M16, Carina, and the Galactic Center

NASA Astrophysics Data System (ADS)

Cotera, Angela; Healy, Kevin; Hester, Jeff; Sellgren, Kris; Simpson, Janet; Stolovy, Susan

2008-03-01

Photoevaporated columns of dust and gas - also called elephant trunks, pillars or fingers - are found in the periphery of H II regions, and have been observed within the Galaxy, the SMC and the LMC. These features are sites of current star formation, but the question remains whether the columns persist because stars formed in the denser regions prior to interactions with the UV radiation and stellar winds of nearby massive stars, or because of core collapse resulting from these interactions. Mapping the distribution of the physical states of the dust and gas in these columns is a necessary step towards understanding the possible star formation mechanisms within these dynamic objects. We propose to obtain IRS spectral maps of columns within M 16, the Carina nebula, and the Galactic center (GC) to understand the effects on these pillars from different stellar populations and initial conditions, and to better understand star formation in the GC. Within the spectral range of the high resolution IRS modes (9.9-37.2 micron) there are a wealth of molecular, atomic and PAH emission lines that will enable us to determine the excitation state, dust and gas temperatures, and probe the shock characteristics within the columns. Using the IRS spectral mapping mode, in conjunction with the CUBISM tool and the CLOUDY H II region model code, we will be able to construct detailed maps of the accessible emission lines and derived parameters for each column. IRS mapping of elephant trunks has not been done to date, yet provides a wealth of information unobtainable for the foreseeable future once Cycle 5 is completed.

The accuracy of peres’ formula and topography anatomy in predicting the depth of CVC for installation in the right subclavia

NASA Astrophysics Data System (ADS)

Kambey, B. I.; Perdana, A.; Pryambodho

2017-08-01

Central venous catheter (CVC) insertion is a routine procedure in either intensive care or in perioperative circumstances. A simple and accurate method or rule is needed to predict the optimum depth of the CVC. The aim of this study is to evaluate the position and depth of CVCs using Peres’ formula ([height/10]-2) and landmark measurements, as well as assessing the incidence of malpositions of CVC installation. This research was an analytic observational study. Fifty patients undergoing central venous catheter (CVC) installation with the right subclavian vein approach were divided into two groups: a Peres’ formula ([height/10]-2) and an anatomy topography measurement group. The results of the calculations were used to determine the boundary prediction of skin fixation. CVC depth was evaluated by measuring the distance between the distal end of the CVC and the carina, from chest radiographs. The measurement results were analyzed by a Bland and Altman plot. The patient’s characteristics were equal for both groups. In the Peres’ formula group we found that the mean of the distal CVC was 1.5 (0.82) cm under the carina (CI 95%: 1.2 to 1.9 cm), with the limit of agreement as 0.0 cm to 3.0 cm. The mean of the landmark group was 0.85 (0.73) cm (CI 95%: 0.5 to 1.1 cm) with the limit of agreement as -0.5 cm to 2.2 cm. The incidence of malposition was found to be similar in both groups. The results showed that both prediction methods are not accurate enough to predict the depth of CVC insertion in Indonesian people.

Proper motions of collimated jets from intermediate-mass protostars in the Carina Nebula

NASA Astrophysics Data System (ADS)

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

2017-10-01

We present proper motion measurements of 37 jets and HH objects in the Carina Nebula measured in two epochs of H α images obtained ˜10 yr apart with Hubble Space Telescope/Advanced Camera for Surveys (ACS). Transverse velocities in all but one jet are faster than ≳ 25 km s-1, confirming that the jet-like H α features identified in the first epoch images trace outflowing gas. Proper motions constrain the location of the jet-driving source and provide kinematic confirmation of the intermediate-mass protostars that we identify for 20/37 jets. Jet velocities do not correlate with the estimated protostar mass and embedded driving sources do not have slower jets. Instead, transverse velocities (median ˜75 km s-1) are similar to those in jets from low-mass stars. Assuming a constant velocity since launch, we compute jet dynamical ages (median ˜104 yr). If continuous emission from inner jets traces the duration of the most recent accretion bursts, then these episodes are sustained longer (median ˜700 yr) than the typical decay time of an FU Orionis outburst. These jets can carry appreciable momentum that may be injected into the surrounding environment. The resulting outflow force, dP/dt, lies between that measured in low- and high-mass sources, despite the very different observational tracers used. Smooth scaling of the outflow force argues for a common physical process underlying outflows from protostars of all masses. This latest kinematic result adds to a growing body of evidence that intermediate-mass star formation proceeds like a scaled-up version of the formation of low-mass stars.

The Persistent Eruption of UGC 2773-OT: finally, a decade-long extragalactic Eta Carinae analogue

NASA Astrophysics Data System (ADS)

Smith, Nathan; Andrews, Jennifer E.; Mauerhan, Jon C.; Zheng, WeiKang; Filippenko, Alexei V.; Graham, Melissa L.; Milne, Peter

2016-02-01

While supernova (SN) impostors resemble the Great Eruption of η Carinae in the sense that their spectra show narrow H lines and they have typical peak absolute magnitudes of -13 to -14 mag, most extragalactic events observed so far are quite different from η Car in duration. Their bright phases typically last for ˜100 d or less, rather than persisting for several years. The transient object UGC 2773-OT (discovered in 2009) had a similar peak absolute magnitude to other SN impostors, but with a gradual 5-yr pre-discovery rise. In the ˜6 yr since discovery, it has faded very slowly (0.26 mag yr-1). Overall, we suggest that its decade-long eruption is so far the best-known analogue of η Car's 19th century eruption. We discuss extensive spectroscopy of the ongoing eruption. The spectra show interesting changes in velocity and line shape that we discuss in detail, including an asymmetric Hα emission line that we show is consistent with the ejection of a bipolar nebula that could be very much like the Homunculus of η Car. Moreover, changes in the line width, line profile, blue excess emission resembling that of Type IIn SNe, and the intensity of Hα suggest the presence of strong circumstellar interaction in the eruption at late times. This supports the hypothesis that the extended plateau of η Car's eruption may have been powered by shock interaction as well. One interesting difference compared to η Car, however, is that UGC 2773-OT so far does not exhibit the repeated brief spikes in luminosity that have been associated with binary periastron events.

3D Shape and Structure of the Homunculus of eta Carinae

NASA Astrophysics Data System (ADS)

Currie, D. G.; Christou, J.; Tyler, D.; Jefferies, S.; Le Mignant, D.; Bonaccini, D.

2000-12-01

The three-dimensional shape of the Homunculus of eta Carinae, as well as the detailed features of the SouthEast Lobe have been observed using the ADONIS system on the ESO 3.6 meter telescope at La Silla. To measure the normally invisible back wall of the Homunculus, we have observed in the infrared (to reduce the opacity of the front wall) and used the Fabry-Perot Interferometer (to distinguish between the Doppler shifts of the light reflected from the back wall and the brighter light reflected from the front wall). This analysis confirms the Double-Flask model and the orientation of the symmetry axis obtained from the previous analysis of the front wall emission and the assumption of rotational symmetry (Currie et. al. 1995, Currie et. al. 1996, Dowling 1996). To evaluate the fine detail of the turbulent motions in the front wall of the SouthEast Lobe, we use broad band observations in the H and K bands. This will be compared to the similar features seen in the shorter wavelengths (at the same resolution) by the WFPC. In the infrared, we see more detail of the shear behavior already seen at the visible wavelengths (Dowling, 1996). To further explore these features, the results of several types of deconvolution will be considered in order to obtain the optimal resolution for the AO data, and to compare the different data processing methodologies. We wish to thank ESO for the observation time, and the 3.6 meter team for observational support. We also wish to thank the STScI and WFPC IDT team. Support for individual authors has come from ESO, the University of Maryland, AFOSR, and CfAO.

How Project Managers Really Manage: An Indepth Look at Some Managers of Large, Complex NASA Projects

NASA Technical Reports Server (NTRS)

Mulenburg, Gerald M.; Impaeilla, Cliff (Technical Monitor)

2000-01-01

This paper reports on a research study by the author that examined ten contemporary National Aeronautics and Space Administration (NASA) complex projects. In-depth interviews with the project managers of these projects provided qualitative data about the inner workings of the project and the methodologies used in establishing and managing the projects. The inclusion of a variety of space, aeronautics, and ground based projects from several different NASA research centers helped to reduce potential bias in the findings toward any one type of project, or technical discipline. The findings address the participants and their individual approaches. The discussion includes possible implications for project managers of other large, complex, projects.

Eta Carinae: An Observational Testbed for 3-D Interacting Wind Modeling

NASA Technical Reports Server (NTRS)

Gull, Theodore; Madura, Tom; Groh, Jose; Corcoran, Mike; Owocki, Stan

2011-01-01

Eta Car, with its very massive interacting winds, provides shocked arc-like structures dense enough to trace in forbidden emission lines out to 0.7" (1700 AU). As the massive binary is in a very elliptical orbit (e approx. 0.9), the spatial and velocity structures of these winds change over the 5.54 year period. We can tract ionization structures by several forbidden emission lines. With the addition of radiative transfer on a time-step frame-by-frame basis, we are learning much new information on the ballistic structures, and may gain insight on how molecules and dust might form in these very massive systems.

GEMINI-TITAN (GT)-10 - MISC. - INFLIGHT (MILKY WAY) - OUTER SPACE

NASA Image and Video Library

1966-08-01

S66-45328 (19 July 1966) --- Ultraviolet spectra of stars in the Carina-Vela region of the southern Milky Way. These objective-grating spectra were obtained by astronauts John W. Young and Michael Collins during Gemini-10 stand-up EVA on July 19, 1966, with a 70mm Maurer camera and its f/3.3 focal length lens. The spectra extends from 2,200 angstroms to about 4,000 angstroms. The spacecraft was docked to the horizon-stabilized Agena-10; thus giving an apparent field of rotation resulting from the four-degree-per-minute orbital motion during the 20-second exposure time. Photo credit: NASA

Tracing the Arms of our Milky Way Galaxy

NASA Image and Video Library

2015-06-03

Astronomers using data from NASA's Wide-field Infrared Survey Explorer, or WISE, are helping to trace the shape of our Milky Way galaxy's spiral arms. This illustration shows where WISE data revealed clusters of young stars shrouded in dust, called embedded clusters, which are known to reside in spiral arms. The bars represent uncertainties in the data. The nearly 100 clusters shown here were found in the arms called Perseus, Sagittarius-Carina, and Outer -- three of the galaxy's four proposed primary arms. Our sun resides in a spur to an arm, or a minor arm, called Orion Cygnus. http://photojournal.jpl.nasa.gov/catalog/PIA19341

Monitoring the Galactic - Search for Hard X-Ray Transients

NASA Astrophysics Data System (ADS)

Marshall, Francis

Hard X-ray transients with fluxs from ~1 to ~30 mCrab are a common feature of the galactic plane with apparent concentrations in specific regions of the plane. Concentrations in the Scutum and Carina fields probably indicate an enhancement of Be X-ray binaries along the tangent direction of two spiral arms. The frequency of outbursts suggest that at any one time 1 or 2 transients are active in the Scutum field alone. We propose weekly scans of the galactic plane to understand this population of sources. The scans will also monitor about 50 already known sources with better spectral information than available with the ASM.

Photometric catalogue for stars in Selected Areas and other fields inthe RGU-system (X). Photometry of fields in and near to the Milky Way: Anticenter 5, Carina (IC 2581), Centaurus III, Aquila II, Cassiopeia(NGC 7654).

NASA Astrophysics Data System (ADS)

Becker, W.; Fenkart, R. P.; Spaenhauer, A.; Alfaro, E. A.; Kandemir, G.; Karaali, S.; Fang, C.; Garcia-Pelayo, J. M.; Steppe, H.; Topaktas, L.

The tenth volume of the Basle Photometric Catalogues contains the G-magnitudes, as well as the long- (G-R) and short-wave (U-G) colour indices of the stars in five galactic fields. Additionally, data as obtained from the interpretationof the two-colour diagrams are given, i.e.: if the star in question has been identified as a main-sequence star of either population, or asa late-type giant, or if it is blended on the photographic plates of one or more colours.

Studies on combined model based on functional objectives of large scale complex engineering

NASA Astrophysics Data System (ADS)

Yuting, Wang; Jingchun, Feng; Jiabao, Sun

2018-03-01

As various functions were included in large scale complex engineering, and each function would be conducted with completion of one or more projects, combined projects affecting their functions should be located. Based on the types of project portfolio, the relationship of projects and their functional objectives were analyzed. On that premise, portfolio projects-technics based on their functional objectives were introduced, then we studied and raised the principles of portfolio projects-technics based on the functional objectives of projects. In addition, The processes of combined projects were also constructed. With the help of portfolio projects-technics based on the functional objectives of projects, our research findings laid a good foundation for management of large scale complex engineering portfolio management.

Hybrid function projective synchronization in complex dynamical networks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wei, Qiang; Wang, Xing-yuan, E-mail: wangxy@dlut.edu.cn; Hu, Xiao-peng

2014-02-15

This paper investigates hybrid function projective synchronization in complex dynamical networks. When the complex dynamical networks could be synchronized up to an equilibrium or periodic orbit, a hybrid feedback controller is designed to realize the different component of vector of node could be synchronized up to different desired scaling function in complex dynamical networks with time delay. Hybrid function projective synchronization (HFPS) in complex dynamical networks with constant delay and HFPS in complex dynamical networks with time-varying coupling delay are researched, respectively. Finally, the numerical simulations show the effectiveness of theoretical analysis.

Complexity analysis of the cost effectiveness of PI-led NASA science missions

NASA Astrophysics Data System (ADS)

Yoshida, J.; Cowdin, M.; Mize, T.; Kellogg, R.; Bearden, D.

For the last 20 years, NASA has allowed Principal Investigators (PIs) to manage the development of many unmanned space projects. Advocates of PI-led projects believe that a PI-led implementation can result in a project being developed at lower cost and shorter schedule than other implementation modes. This paper seeks to test this hypothesis by comparing the actual costs of NASA and other comparable projects developed under different implementation modes. The Aerospace Corporation's Complexity-Based Risk Assessment (CoBRA) analysis tool is used to normalize the projects such that the cost can be compared for equivalent project complexities. The data is examined both by complexity and by launch year. Cost growth will also be examined for any correlation with implementation mode. Defined in many NASA Announcements of Opportunity (AOs), a PI-led project is characterized by a central, single person with full responsibility for assembling a team and for the project's scientific integrity and the implementation and integrity of all other aspects of the mission, while operating under a cost cap. PIs have larger degrees of freedom to achieve the stated goals within NASA guidelines and oversight. This study leverages the definitions and results of previous National Research Council studies of PI-led projects. Aerospace has defined a complexity index, derived from mission performance, mass, power, and technology choices, to arrive at a broad representation of missions for purposes of comparison. Over a decade of research has established a correlation between mission complexity and spacecraft development cost and schedule. This complexity analysis, CoBRA, is applied to compare a PI-led set of New Frontiers, Discovery, Explorers, and Earth System Science Pathfinder missions to the overall NASA mission dataset. This reveals the complexity trends against development costs, cost growth, and development era.

Interdependence and Integration Learning in Student Project Teams: Do Team Project Assignments Achieve What We Want Them to?

ERIC Educational Resources Information Center

Skilton, Paul F.; Forsyth, David; White, Otis J.

2008-01-01

Building from research on learning in workplace project teams, the authors work forward from the idea that the principal condition enabling integration learning in student team projects is project complexity. Recognizing the challenges of developing and running complex student projects, the authors extend theory to propose that the experience of…

Appreciating the Complexity of Project Management Execution: Using Simulation in the Classroom

ERIC Educational Resources Information Center

Hartman, Nathan S.; Watts, Charles A.; Treleven, Mark D.

2013-01-01

As the popularity and importance of project management increase, so does the need for well-prepared project managers. This article discusses our experiences using a project management simulation in undergraduate and MBA classes to help students better grasp the complexity of project management. This approach gives students hands-on experience with…

Dynamical Models for High-Energy Emission from Massive Stars

NASA Astrophysics Data System (ADS)

Owocki, Stanley %FAA(University of Delaware)

Massive stars are prominent sources of X-rays and gamma-rays detected by both targeted and survey observations from orbiting telescopes like Chandra, XMM/Newton, RXTE, and Fermi. Such high-energy emissions represent key probes of the dynamics of massive-star mass loss, and their penetration through many magnitudes of visible interstellar extinction makes them effective beacons of massive stars in distant reaches of the Galaxy, and in young, active star-forming regions. The project proposed here will develop a comprehensive theoretical framework for interpreting both surveys and targeted observations of high-energy emission from massive stars. It will build on our team's extensive experience in both theoretical models and observational analyses for three key types of emission mechanisms in the stellar wind outflows of these stars, namely: 1) Embedded Wind Shocks (EWS) arising from internal instabilities in the wind driving; 2) shocks in Colliding Wind Binary (CWB) systems; and 3) High-Mass X-ray Binaries (HMXB) systems with interaction between massive-star wind with a compact companion (neutron star or black hole). Taking advantage of commonalities in the treatment of radiative driving, hydrodynamics, shock heating and cooling, and radiation transport, we will develop radiation hydrodynamical models for the key observational signatures like energy distribution, emission line spectrum, and variability, with an emphasis on how these can be used in affiliated analyses of both surveys like the recent Chandra mapping of the Carina association, and targeted observations of galactic X-ray and gamma-ray sources associated with each of the above specific model types. The promises of new clumping-insensitive diagnostics of mass loss rates, and the connection to mass transfer and binarity, all have broad relevance for understanding the origin, evolution, and fate of massive stars, in concert with elements of NASA's Strategic Subgoal 3D. Building on our team's expertise, the project emphasizes training of a new generation of students and post-doctoral researchers to model and analyze observations by current and future NASA X-ray and gamma-ray observatories.

BANYAN. III. Radial velocity, rotation, and X-ray emission of low-mass star candidates in nearby young kinematic groups

DOE Office of Scientific and Technical Information (OSTI.GOV)

Malo, Lison; Artigau, Étienne; Doyon, René

2014-06-10

Based on high-resolution spectra obtained with PHOENIX at Gemini-South, CRIRES at VLT-UT1, and ESPaDOnS at the Canada-France-Hawaii Telescope, we present new measurements of the radial and projected rotational velocities of 219 low-mass stars. The target likely membership was initially established using the Bayesian analysis tool recently presented in Malo et al., taking into account only the position, proper motion, and photometry of the stars to assess their membership probability. In the present study, we include radial velocity as an additional input to our analysis, and in doing so we confirm the high membership probability for 130 candidates: 27 in βmore » Pictoris, 22 in Tucana-Horologium, 25 in Columba, 7 in Carina, 18 in Argus and 18 in AB Doradus, and 13 with an ambiguous membership. Our analysis also confirms the membership of 57 stars proposed in the literature. A subsample of 16 candidates was observed at 3 or more epochs, allowing us to discover 6 new spectroscopic binaries. The fraction of binaries in our sample is 25%, consistent with values in the literature. Of the stars in our sample, 20% show projected rotational velocities (vsin i) higher than 30 km s{sup –1} and therefore are considered as fast rotators. A parallax and other youth indicators are still needed to fully confirm the 130 highly probable candidates identified here as new bona fide members. Finally, based on the X-ray emission of bona fide and highly probable group members, we show that for low-mass stars in the 12-120 Myr age range, the X-ray luminosity is an excellent indicator of youth and better than the more traditionally used R {sub X} parameter, the ratio of X-ray to bolometric luminosity.« less

Study of supernovae and massive stars and prospects with the 4m International Liquid Mirror Telescope

NASA Astrophysics Data System (ADS)

Kumar, Brajesh

2014-11-01

Massive stars are the progenitors of the most energetic explosions in the Universe such as core-collapse supernovae (CCSNe) and gamma ray bursts. During their life time they follow various evolutionary phases (e.g. supergiant, luminous blue variable and Wolf-Rayet). They strongly influence their environments through their energetic ionization radiation and powerful stellar winds. Furthermore, the formation of low and intermediate-mass stars are also being regulated by them. The Carina nebula region, which hosts a large population of massive stars and several young star clusters, provides an ideal target for studying the feedback of massive stars. In this thesis, we investigated a wide field (32' × 31') region located in the west of the Carina nebula and centered on the massive binary WR 22. For our study, we used new optical photometry (UBVRI H-alpha), along with some low resolution spectroscopy, archival near infra-red (2MASS), and X-ray (Chandra, XMM-Newton) data. We estimated several parameters such as reddening, reddening law, etc. and also identified young stellar objects located in the region under study (Kumar et al., 2014b). Among the various types of CCSNe, Type IIb are recognized with their typical observational properties. Some of them show clear indication of double peaks in their light curves. The spectral features of these SNe show a transition between Type II and Type Ib/c events at early and later epochs, respectively. It has been noticed that the occurrence of these events is not common in volume limited surveys. In this thesis we have studied the properties of the light curve and spectral evolution of the Type IIb supernova 2011fu. The observational properties of this object show resemblance to those of SN 1993J with a possible signature of the adiabatic cooling phase (Kumar et al., 2013). When light passes through the expanding ejecta of the SNe, it retains information about the orientation of the ejected layers. In general, CCSNe exhibit a significant level of polarization during various phases of their evolution at different wavelengths. We have investigated the broad band polarimetric properties of a Type II plateau SN 2012aw and compared it with other well studied CCSNe of similar kinds (Kumar et al., 2014a). In the framework of the present thesis, we have also contributed to the development of the 4m International Liquid Mirror Telescope (ILMT) project which is a joint collaborative effort among different universities and research institutes in Belgium, India, Canada and Poland. We performed various experiments including the spin casting of the primary mirror, optical quality tests of the mercury surface, mylar film experiments, etc. The possible scientific capabilities and future contributions of this telescope are also discussed. We propose our plans to identify the transients (specially supernovae) with the ILMT and their further follow-up scheme. The installation of the ILMT will start very soon at the Devasthal observatory, ARIES Nainital, India.

Quasi-projective synchronization of fractional-order complex-valued recurrent neural networks.

PubMed

Yang, Shuai; Yu, Juan; Hu, Cheng; Jiang, Haijun

2018-08-01

In this paper, without separating the complex-valued neural networks into two real-valued systems, the quasi-projective synchronization of fractional-order complex-valued neural networks is investigated. First, two new fractional-order inequalities are established by using the theory of complex functions, Laplace transform and Mittag-Leffler functions, which generalize traditional inequalities with the first-order derivative in the real domain. Additionally, different from hybrid control schemes given in the previous work concerning the projective synchronization, a simple and linear control strategy is designed in this paper and several criteria are derived to ensure quasi-projective synchronization of the complex-valued neural networks with fractional-order based on the established fractional-order inequalities and the theory of complex functions. Moreover, the error bounds of quasi-projective synchronization are estimated. Especially, some conditions are also presented for the Mittag-Leffler synchronization of the addressed neural networks. Finally, some numerical examples with simulations are provided to show the effectiveness of the derived theoretical results. Copyright © 2018 Elsevier Ltd. All rights reserved.

VizieR Online Data Catalog: l Car radial velocity curves (Anderson, 2016)

NASA Astrophysics Data System (ADS)

Anderson, R. I.

2018-02-01

Line-of-sight (radial) velocities of the long-period classical Cepheid l Carinae were measured from 925 high-quality optical spectra recorded using the fiber-fed high-resolution (R~60,000) Coralie spectrograph located at the Euler telescope at La Silla Observatory, Chile. The data were taken between 2014 and 2016. This is the full version of Tab. 2 presented partially in the paper. Line shape parameters (depth, width, asymmetry) are listed for the computed cross-correlation profiles (CCFs). Radial velocities were determined using different techniques (Gaussian, bi-Gaussian) and measured on CCFs computed using three different numerical masks (G2, weak lines, strong lines). (1 data file).

Galactic gamma-ray sources, SNOBs, and giant H2 regions

NASA Technical Reports Server (NTRS)

Montmerle, T.

1985-01-01

Progress towards understanding the nature of the COS-B galactic gamma-ray sources was made by two recent developments. The developments are: (1) the existence of extensive wide-latitude CO surveys, from the Northern Hemisphere, and from the Southern Hemisphere which give more precise information on molecular cloud population of the Perseus, Sagittarius, and Carina spiral arms; (2) the study of the time variability of gamma-ray sources in gamma-rays but also at other wavelengths, leading to the discovery of four new variable sources in addition to the already known Crab and Vela pulsars. Three classes of gamma-ray sources are found; invariable sources, active sources, and passive sources.

A deep survey for Galactic Wolf-Rayet stars. I - Motivation, search technique, and first results

NASA Technical Reports Server (NTRS)

Shara, Michael M.; Smith, Lindsey F.; Potter, Michael; Moffat, Anthony F. J.

1991-01-01

Results are presented from a survey of large areas of the southern Milky Way for Wolf-Rayet (WR) stars to 17-18th magnitude, carried out using direct narrowband and broadband Schmidt plates. Thirteen new WR stars were detected in an about 40-deg-sq region in Carina, where 24 WR stars were already known; the new stars were found to be significantly redder, fainter, and farther away than the known stars. Of the new WR stars, 11 are of subtype WN, and two are WC, compared to the 17 WN and seven WC stars among the previously known WR stars in the same area.

Electronic construction collaboration system -- final phase : [tech transfer summary].

DOT National Transportation Integrated Search

2014-07-01

Construction projects have been growing more complex in terms of : project team composition, design aspects, and construction processes. : To help manage the shop/working drawings and requests for information : (RFIs) for its large, complex projects,...

A low complexity reweighted proportionate affine projection algorithm with memory and row action projection

NASA Astrophysics Data System (ADS)

Liu, Jianming; Grant, Steven L.; Benesty, Jacob

2015-12-01

A new reweighted proportionate affine projection algorithm (RPAPA) with memory and row action projection (MRAP) is proposed in this paper. The reweighted PAPA is derived from a family of sparseness measures, which demonstrate performance similar to mu-law and the l 0 norm PAPA but with lower computational complexity. The sparseness of the channel is taken into account to improve the performance for dispersive system identification. Meanwhile, the memory of the filter's coefficients is combined with row action projections (RAP) to significantly reduce computational complexity. Simulation results demonstrate that the proposed RPAPA MRAP algorithm outperforms both the affine projection algorithm (APA) and PAPA, and has performance similar to l 0 PAPA and mu-law PAPA, in terms of convergence speed and tracking ability. Meanwhile, the proposed RPAPA MRAP has much lower computational complexity than PAPA, mu-law PAPA, and l 0 PAPA, etc., which makes it very appealing for real-time implementation.

Radiative Rates for Forbidden Transitions in Doubly-Ionized Fe-Peak Elements

NASA Astrophysics Data System (ADS)

Fivet, Vanessa; Quinet, P.; Bautista, M.

2012-05-01

Accurate and reliable atomic data for lowly-ionized Fe-peak species (Sc, Ti, V, Cr, Mn, Fe, Co, Ni and Cu) are of paramount importance for the analysis of the high resolution astrophysical spectra currently available. The third spectra of several iron group elements have been observed in different galactic sources like Herbig-Haro objects in the Orion Nebula [1] and stars like Eta Carinae [2]. However, forbidden transitions between low-lying metastable levels of doubly-ionized iron-peak ions have been very little investigated so far and radiative rates for those lines remain sparse or inexistent. We are carrying out a systematic study of the electronic structure of doubly-ionized iron-peak elements. The magnetic dipole (M1) and electric quadrupole (E2) transition probabilities are computed using the pseudo-relativistic Hartree-Fock (HFR) code of Cowan [3] and the central Thomas-Fermi-Dirac potential approximation implemented in AUTOSTRUCTURE [4]. This multi-platform approach allows for consistency checks and intercomparison and has proven very successful in the study of the complex Fe-peak species where many different effects contribute [5]. References [1] A. Mesa-Delgado et al., MNRAS 395 (2009) 855 [2] S. Johansson et al., A&A 361 (2000) 977 [3] R.D. Cowan, The Theory of Atomic Structure and Spectra, Berkeley: Univ. California Press (1981) [4] N.R. Badnell, J. Phys. B: At. Mol. Opt. Phys. 30 (1997) 1 [5] M. Bautista et al., ApJ 718 (2010) L189

Novel high-resolution computed tomography-based radiomic classifier for screen-identified pulmonary nodules in the National Lung Screening Trial.

PubMed

Peikert, Tobias; Duan, Fenghai; Rajagopalan, Srinivasan; Karwoski, Ronald A; Clay, Ryan; Robb, Richard A; Qin, Ziling; Sicks, JoRean; Bartholmai, Brian J; Maldonado, Fabien

2018-01-01

Optimization of the clinical management of screen-detected lung nodules is needed to avoid unnecessary diagnostic interventions. Herein we demonstrate the potential value of a novel radiomics-based approach for the classification of screen-detected indeterminate nodules. Independent quantitative variables assessing various radiologic nodule features such as sphericity, flatness, elongation, spiculation, lobulation and curvature were developed from the NLST dataset using 726 indeterminate nodules (all ≥ 7 mm, benign, n = 318 and malignant, n = 408). Multivariate analysis was performed using least absolute shrinkage and selection operator (LASSO) method for variable selection and regularization in order to enhance the prediction accuracy and interpretability of the multivariate model. The bootstrapping method was then applied for the internal validation and the optimism-corrected AUC was reported for the final model. Eight of the originally considered 57 quantitative radiologic features were selected by LASSO multivariate modeling. These 8 features include variables capturing Location: vertical location (Offset carina centroid z), Size: volume estimate (Minimum enclosing brick), Shape: flatness, Density: texture analysis (Score Indicative of Lesion/Lung Aggression/Abnormality (SILA) texture), and surface characteristics: surface complexity (Maximum shape index and Average shape index), and estimates of surface curvature (Average positive mean curvature and Minimum mean curvature), all with P<0.01. The optimism-corrected AUC for these 8 features is 0.939. Our novel radiomic LDCT-based approach for indeterminate screen-detected nodule characterization appears extremely promising however independent external validation is needed.

Projective-anticipating, projective, and projective-lag synchronization of time-delayed chaotic systems on random networks.

PubMed

Feng, Cun-Fang; Xu, Xin-Jian; Wang, Sheng-Jun; Wang, Ying-Hai

2008-06-01

We study projective-anticipating, projective, and projective-lag synchronization of time-delayed chaotic systems on random networks. We relax some limitations of previous work, where projective-anticipating and projective-lag synchronization can be achieved only on two coupled chaotic systems. In this paper, we realize projective-anticipating and projective-lag synchronization on complex dynamical networks composed of a large number of interconnected components. At the same time, although previous work studied projective synchronization on complex dynamical networks, the dynamics of the nodes are coupled partially linear chaotic systems. In this paper, the dynamics of the nodes of the complex networks are time-delayed chaotic systems without the limitation of the partial linearity. Based on the Lyapunov stability theory, we suggest a generic method to achieve the projective-anticipating, projective, and projective-lag synchronization of time-delayed chaotic systems on random dynamical networks, and we find both its existence and sufficient stability conditions. The validity of the proposed method is demonstrated and verified by examining specific examples using Ikeda and Mackey-Glass systems on Erdos-Renyi networks.

BONA FIDE, STRONG-VARIABLE GALACTIC LUMINOUS BLUE VARIABLE STARS ARE FAST ROTATORS: DETECTION OF A HIGH ROTATIONAL VELOCITY IN HR CARINAE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Groh, J. H.; Damineli, A.; Moises, A. P.

2009-11-01

We report optical observations of the luminous blue variable (LBV) HR Carinae which show that the star has reached a visual minimum phase in 2009. More importantly, we detected absorptions due to Si IV lambdalambda4088-4116. To match their observed line profiles from 2009 May, a high rotational velocity of v{sub rot} approx = 150 +- 20 km s{sup -1} is needed (assuming an inclination angle of 30 deg.), implying that HR Car rotates at approx =0.88 +- 0.2 of its critical velocity for breakup (v{sub crit}). Our results suggest that fast rotation is typical in all strong-variable, bona fide galacticmore » LBVs, which present S-Dor-type variability. Strong-variable LBVs are located in a well-defined region of the HR diagram during visual minimum (the 'LBV minimum instability strip'). We suggest this region corresponds to where v{sub crit} is reached. To the left of this strip, a forbidden zone with v{sub rot}/v{sub crit}>1 is present, explaining why no LBVs are detected in this zone. Since dormant/ex LBVs like P Cygni and HD 168625 have low v{sub rot}, we propose that LBVs can be separated into two groups: fast-rotating, strong-variable stars showing S-Dor cycles (such as AG Car and HR Car) and slow-rotating stars with much less variability (such as P Cygni and HD 168625). We speculate that supernova (SN) progenitors which had S-Dor cycles before exploding (such as in SN 2001ig, SN 2003bg, and SN 2005gj) could have been fast rotators. We suggest that the potential difficulty of fast-rotating Galactic LBVs to lose angular momentum is additional evidence that such stars could explode during the LBV phase.« less

Multiple Absorption Components in the Post-Periastron He I P Cygni Absorption Troughs of Eta Carinae

NASA Technical Reports Server (NTRS)

Richardson, Noel D.; Damineli, Augusto; Gull, Ted; Moffat, Anthony; Groh, Jose; St.-Jean, Lucas; Walter, Frederick M.; Teodoro, Mairan; Madura, Tom; Corcoran, Michael;

Mapping and Modeling the Extended Winds of the Massive Interacting Binary, Eta Carinae

NASA Technical Reports Server (NTRS)

Gull, Ted

2010-01-01

The combination HST/STIS high spatial and moderate spectral resolutions have revealed the massive interacting wind structure of Eta Carinae by forbidden lines of singly and doubly ionized elements. Throughout the 5.54-year period, lines of Fe++, Ne++, Ar++, S++ and N+ reveal the interacting wind structures, near critical electron densities of 10(exp 5) to 3 x 10(exp 7)cu cm, photoionized by the hot secondary, Eta Car B, Lines of Fe+ and Ni+ trace the denser (>10(exp 7)cu cm. less-ionized (< 8 eV) primary wind of Eta Car A as it wraps around the interacting binary stars. For 5 years of the 5.54 year period, the FUV radiation from Eta Car B escapes the orbital region, ionizing the boundaries of the expanding wind structures. But for three to six months, Eta Car B plunges into the primary wind approaching to within 1 to 2 AU, leading to cutoff of FUV and X-ray fluxes. The interacting wind structure, resolved out to 0.8", drops io ionization and then rebuilds as Eta Car B emerges from the primary wind envelope. Solid Particle Hydrodynamical(SPH) models have been developed extending out to 2000 AU and adapted to include FUV radiation effects of the winds. In turn, synthetic spectroimages of selected forbidden lines have been constructed and compared to the spectroimages recorded by the HST/STIS throughout 1998.0 to 2004.3, extending across the 1998 and 2003.5 minima. By this method, we show that the orbital axis of the binary system must bc within 15 degrees of the Homunculus axis of symmetry and that periastron occurs with Eta Car B passing on the far side of Eta Car B. This result ties the current binary orbit with the bipolar ejection with intervening skirt and leads to implications that the binary system influenced the mass ejection of the l840s and the lesser ejection of the 1890s.

Intravascular Ultrasound Classification of Plaque in Angiographic True Bifurcation Lesions of the Left Main Coronary Artery.

PubMed

Li, Li; Dash, Debabrata; Gai, Lu-Yue; Cao, Yun-Shan; Zhao, Qiang; Wang, Ya-Rong; Zhang, Yao-Jun; Zhang, Jun-Xia

2016-07-05

Accurately, characterizing plaques is critical for selecting the optimal intervention strategy for the left main coronary artery (LMCA) bifurcation. Coronary angiography cannot precisely assess the location or nature of plaques in bifurcation lesions. Few intravascular ultrasound (IVUS) classification scheme has been reported for angiographic imaging of true bifurcation lesions of the unprotected LMCA thus far. In addition, the plaque composition at the bifurcation has not been elucidated. This study aimed to detect plaque composition at LMCA bifurcation lesions by IVUS. Fifty-eight patients were recruited. The location, concentricity or eccentricity, site of maximum thickness, and composition of plaques of the distal LMCA, ostial left anterior descending (LAD) coronary artery and, left circumflex (LCX) coronary artery were assessed using IVUS and described using illustrative diagrams. True bifurcation lesions of the unprotected LMCA were classified into four types: Type A, with continuous involvement from the distal LMCA to the ostial LAD and the ostial LCX with eccentric plaques; Type B, with concentric plaques at the distal LMCA, eccentric plaques at the ostial LAD, and no plaques at the LCX; Type C, with continuous involvement from the distal LMCA to the ostial LCX, with eccentric plaques, and to the ostial LAD, with eccentric plaques; and Type D, with continuous involvement from the distal LMCA to the ostial LAD, with eccentric plaques, and to the ostial LCX, with concentric plaques. The carina was involved in only 3.5% of the plaques. A total of 51.7% of the plaques at the ostium of the LAD were soft, while 44.8% and 44.6% were fibrous in the distal LMCA and in the ostial LCX, respectively. We classified LMCA true bifurcation lesions into four types. The carina was always free from disease. Plaques at the ostial LAD tended to be soft, whereas those at the ostial LCX and the distal LMCA tended to be fibrous.

Tracheal palpation to assess endotracheal tube depth: an exploratory study.

PubMed

McKay, William P; Klonarakis, Jim; Pelivanov, Vladko; O'Brien, Jennifer M; Plewes, Chris

2014-03-01

Correct placement of the endotracheal tube (ETT) occurs when the distal tip is in mid-trachea. This study compares two techniques used to place the ETT at the correct depth during intubation: tracheal palpation vs placement at a fixed depth at the patient's teeth. With approval of the Research Ethics Board, we recruited American Society of Anesthesiologists physical status I-II patients scheduled for elective surgery with tracheal intubation. Clinicians performing the tracheal intubations were asked to "advance the tube slowly once the tip is through the cords". An investigator palpated the patient's trachea with three fingers spread over the trachea from the larynx to the sternal notch. When the ETT tip was felt in the sternal notch, the ETT was immobilized and its position was determined by fibreoptic bronchoscopy. The position of the ETT tip was compared with our hospital standard, which is a depth at the incisors or gums of 23 cm for men and 21 cm for women. The primary outcome was the incidence of correct placement. Correct placement of the ETT was defined as a tip > 2.5 cm from the carina and > 3.5 cm below the vocal cords. Movement of the ETT tip was readily palpable in 77 of 92 patients studied, and bronchoscopy was performed in 85 patients. Placement by tracheal palpation resulted in more correct placements (71 [77%]; 95% confidence interval [CI] 74 to 81) than hospital standard depth at the incisors or gums (57 [61%]; 95% CI 58 to 66) (P = 0.037). The mean (SD) placement of the ETT tip in palpable subjects was 4.1 (1.7) cm above the carina, 1.9 cm (1.5-2.3 cm) below the ideal mid-tracheal position. Tracheal palpation requires no special equipment, takes only a few seconds to perform, and may improve ETT placement at the correct depth. Further studies are warranted.

WISE J080822.18-644357.3 - a 45 Myr-old accreting M dwarf hosting a primordial disc

NASA Astrophysics Data System (ADS)

Murphy, Simon J.; Mamajek, Eric E.; Bell, Cameron P. M.

2018-05-01

WISE J080822.18-644357.3 (WISE J0808-6443) was recently identified as a new M dwarf debris disc system and a candidate member of the 45 Myr-old Carina association. Given that the strength of its infrared excess (LIR/L⋆ ≃ 0.1) appears to be more consistent with a young protoplanetary disc, we present the first optical spectra of the star and reassess its evolutionary and membership status. We find WISE J0808-6443 to be a Li-rich M5 star with strong H α emission (-125 < EW < -65 Å over 4 epochs) whose strength and broad width are consistent with accretion at a low level (˜10-10 M⊙ yr-1) from its disc. The spectral energy distribution of the star is consistent with a primordial disc and is well-fitted using a two-temperature blackbody model with Tinner ≃ 1100 K and Touter ≃ 240 K. AllWISE multi-epoch photometry shows the system exhibits significant variability in the 3.4 and 4.6 μm bands. We calculate an improved proper motion based on archival astrometry, and combined with a new radial velocity, the kinematics of the star are consistent with membership in Carina at a kinematic distance of 90 ± 9 pc. The spectroscopic and photometric data are consistent with WISE J0808-6443 being a ˜0.1 M⊙ Classical T-Tauri star and one of the oldest known accreting M-type stars. These results provide further evidence that the upper limit on the lifetimes of gas-rich discs - and hence the time-scales to form and evolve protoplanetary systems - around the lowest mass stars may be longer than previously recognized, or some mechanism may be responsible for regenerating short-lived discs at later stages of pre-main sequence evolution.

Irradiated interfaces in the Ara OB1, Carina, Eagle Nebula, and Cyg OB2 massive star formation regions

DOE PAGES

Hartigan, P.; Palmer, J.; Cleeves, L. I.

2012-09-05

Regions of massive star formation offer some of the best and most easily-observed examples of radiation hydrodynamics. Boundaries where fully-ionized H II regions transition to neutral/molecular photodissociation regions (PDRs) are of particular interest because marked temperature and density contrasts across the boundaries lead to evaporative flows and fluid dynamical instabilities that can evolve into spectacular pillar-like structures. Furthermore, when detached from their parent clouds, pillars become ionized globules that often harbor one or more young stars. H2 molecules at the interface between a PDR and an H II region absorb ultraviolet light from massive stars, and the resulting fluoresced infraredmore » emission lines are an ideal way to trace this boundary independent of obscuring dust. This paper presents H2 images of four regions of massive star formation that illustrate different types of PDR boundaries. The Ara OB1 star formation region contains a striking long wall that has several wavy structures which are present in H2, but the emission is not particularly bright because the ambient UV fluxes are relatively low. In contrast, the Carina star formation region shows strong H2 fluorescence both along curved walls and at the edges of spectacular pillars that in some cases have become detached from their parent clouds. The less-spectacular but more well-known Eagle Nebula has two regions that have strong fluorescence in addition to its pillars. And while somewhat older than the other regions, Cyg OB2 has the highest number of massive stars of the regions surveyed and contains many isolated, fluoresced globules that have head–tail morphologies which point towards the sources of ionizing radiation. Our images provide a collection of potential astrophysical analogs that may relate to ablated interfaces observed in laser experiments of radiation hydrodynamics.« less

Is there a correlation between right bronchus length and diameter with age?

PubMed

Otoch, José Pinhata; Minamoto, Hélio; Perini, Marcos; Carneiro, Fred Olavo; de Almeida Artifon, Everson Luiz

2013-06-01

Right main bronchial anatomy knowledge is essential to guide endoscopic stent placement in modern era. The aim is to describe right bronchial anatomy, cross-area and its relation with the right pulmonary artery and patient's age. One hundred thirty four cadaveric specimens were studied after approval by the Research and Ethics Committee at the University of São Paulo Medical School and Medical Forensic Institute of São Paulo. All necropsies were performed in natura after 24 hours of death and patients with previous pulmonary disease were excluded. Landmarks to start measurement were the first tracheal ring, vertex of carina, first right bronchial ring, and right pulmonary artery area over the right main bronchus. After mobilization, the specimens were measured using a caliper and measurement of distances was recorded in centimeters at landmarks points. All the measures (distances, cross sectional area and planes) were performed by three independent observers and recorded as mean, standard error and ranges. Student t test was used to compare means and linear regression was applied to correlate the measurements. From 134 specimens studied, 34 were excluded (10 with previous history of pulmonary diseases, surgery or deformities and 24 of female gender). Linear regression showed proportionality between tracheal length and right bronchus length; with the area at first tracheal ring and carina and also between the cross sectional area at these points. Linear regression analysis between tracheal length and age (R=0.593 P<0.005), right bronchus length and age (R=0.523, P<0.005), area of contact between right bronchus and right pulmonary artery and age (R=0.35, P<0.005). We can conclude that large airways grow progressively with increasing age in male gender. There was a direct correlation between age and tracheal length; as has age and right bronchus length. There was a direct correlation between age and the area of the right bronchus covered by the right pulmonary artery.

Measuring Changes in the Distribution, Mass, and Composition of Dust in the Eruptive LBV Eta Carinae

NASA Astrophysics Data System (ADS)

Morris, Patrick

The luminous, massive binary system eta Carinae is both one of the nearest and most unstable objects in a class of evolved massive stars, near the end of its lifetime before expected destruction in a supernova. It experienced a major outburst in 1843, producing the well-known Homunculus nebula, containing some 15 to 40 Msun in warm ( 170 K) and cool (90-110 K) dust and gas, according to mid-infrared ISO spectroscopy. The location of these thermal components has been uncertain due to large apertures. In Cycle 3 we were approved for 10 hours to use the FORCAST imager with long wavelength filters to better locate and estimate the mass in thermal components of this material that may be resolved, constraining it to the interior regions or bipolar lobes of the Homunculus nebula, or in outer ejecta that would support the hypothesis of a major event prior to the 1843 eruption. About 40% of the program is planned for completion in Cycle 4. We are proposing in Cycle 5 to carry out spectroscopy of the dusty Homunculus nebula at two positions and one reference sky position, using the FORCAST grism with all four filters, in order to characterize changes in mass, composition, and grain properties of especially the cool dust containing >80% of the dust mass, and comparing the results to our spatially integrated ISO spectra taken in 1996/1997, and to 8-13.5 micron data of the warm dust obtained with VLTI/MIDI in 2002/2003 by Chesneau et al. (2005) . These changes may result from the ongoing production of dust in the colliding winds of the 5.5 year period eccentric binary system, particularly during periastron which has occurred three times since 1997. The proposed spectroscopy of especially the cool dust cannot be accomplished from the ground.

In Hot Pursuit of the Hidden Companion of Carinae: An X-Ray Determination of the Wind Parameters

NASA Technical Reports Server (NTRS)

Pittard, J. M.; Corcoran, M. F.; White, Nicholas E. (Technical Monitor)

2002-01-01

We present X-ray spectral fits to a recently obtained Chandra grating spectrum of eta Carinae, one of the most massive and powerful stars in the Galaxy and which is strongly suspected to be a colliding wind binary system. Hydrodynamic models of colliding winds are used to generate synthetic X-ray spectra for a range of mass-loss rates and wind velocities. They are then fitted against newly acquired Chandra grating data. We find that due to the low velocity of the primary wind (approximately 500 km per sec), most of the observed X-ray emission appears to arise from the shocked wind of the companion star. We use the duration of the lightcurve minimum to fix the wind momentum ratio at eta = 0.2. We are then able to obtain a good fit to the data by varying the mass-loss rate of the companion and the terminal velocity of its wind. We find that M(sub 2) is approximately 10(exp -5) solar mass per yr and upsilon(sub infinity(sub 2)) is approximately 3000 km per sec. With observationally determined values of approximately 500- 700 km per sec for the velocity of the primary wind, our fit implies a primary mass-loss rate of M(sub 1) approximately 2.5 x 10(exp -4) solar mass per yr. This value is smaller than commonly inferred, although we note that a lower mass-loss rate can reduce some of the problems noted when a value as high as 10(exp -3) solar mass per yr is used. The wind parameters of the companion are indicative of a massive star which may or may not be evolved. The line strengths appear to show slightly sub-solar abundances, although this needs further confirmation. It also appears that the primary star is responsible for the nebula.

The peculiar isolated neutron star in the Carina Nebula. Deep XMM-Newton and ESO-VLT observations of 2XMM J104608.7-594306

NASA Astrophysics Data System (ADS)

Pires, A. M.; Motch, C.; Turolla, R.; Schwope, A.; Pilia, M.; Treves, A.; Popov, S. B.; Janot-Pacheco, E.

2012-08-01

While fewer in number than the dominant rotation-powered radio pulsar population, peculiar classes of isolated neutron stars (INSs) - which include magnetars, the ROSAT-discovered "Magnificent Seven" (M7), rotating radio transients (RRATs), and central compact objects in supernova remnants (CCOs) - represent a key element in understanding the neutron star phenomenology. We report the results of an observational campaign to study the properties of the source 2XMM J104608.7-594306, a newly discovered thermally emitting INS. The evolutionary state of the neutron star is investigated by means of deep dedicated observations obtained with the XMM-Newton Observatory, the ESO Very Large Telescope, as well as publicly available γ-ray data from the Fermi Space Telescope and the AGILE Mission. The observations confirm previous expectations and reveal a unique type of object. The source, which is likely within the Carina Nebula (NH = 2.6 × 1021 cm-2), has a spectrum that is both thermal and soft, with kT∞ = 135 eV. Non-thermal (magnetospheric) emission is not detected down to 1% (3σ, 0.1-12 keV) of the source luminosity. Significant deviations (absorption features) from a simple blackbody model are identified in the spectrum of the source around energies 0.6 keV and 1.35 keV. While the former deviation is likely related to a local oxygen overabundance in the Carina Nebula, the latter can only be accounted for by an additional spectral component, which is modelled as a Gaussian line in absorption with EW = 91 eV and σ = 0.14 keV (1σ). Furthermore, the optical counterpart is fainter than mV = 27 (2σ) and no γ-ray emission is significantly detected by either the Fermi or AGILE missions. Very interestingly, while these characteristics are remarkably similar to those of the M7 or the only RRAT so far detected in X-rays, which all have spin periods of a few seconds, we found intriguing evidence of very rapid rotation, P = 18.6 ms, at the 4σ confidence level. We interpret these new results in the light of the observed properties of the currently known neutron star population, in particular those of standard rotation-powered pulsars, recycled objects, and CCOs. We find that none of these scenarios can satisfactorily explain the collective properties of 2XMM J104608.7-594306, although it may be related to the still poorly known class of Galactic anti-magnetars. Future XMM-Newton data, granted for the next cycle of observations (AO11), will help us to improve our currentobservational interpretation of the source, enabling us to significantly constrain the rate of pulsar spin down. Based on observations obtained with XMM-Newton, an ESA science mission with instruments and contributions directly funded by ESA Member States and NASA (Target 2XMM J104608.7-594306, obsid 0650840101). Optical observations were performed at the European Southern Observatory, Paranal, Chile, under programme IDs 382.D-0687(A) and 385.D-0209(A).

Managing Programmatic Risk for Complex Space System Developments

NASA Technical Reports Server (NTRS)

Panetta, Peter V.; Hastings, Daniel; Brumfield, Mark (Technical Monitor)

2001-01-01

Risk management strategies have become a recent important research topic to many aerospace organizations as they prepare to develop the revolutionary complex space systems of the future. Future multi-disciplinary complex space systems will make it absolutely essential for organizations to practice a rigorous, comprehensive risk management process, emphasizing thorough systems engineering principles to succeed. Project managers must possess strong leadership skills to direct high quality, cross-disciplinary teams for successfully developing revolutionary space systems that are ever increasing in complexity. Proactive efforts to reduce or eliminate risk throughout a project's lifecycle ideally must be practiced by all technical members in the organization. This paper discusses some of the risk management perspectives that were collected from senior managers and project managers of aerospace and aeronautical organizations by the use of interviews and surveys. Some of the programmatic risks which drive the success or failure of projects are revealed. Key findings lead to a number of insights for organizations to consider for proactively approaching the risks which face current and future complex space systems projects.

12om Methodology: Process v1.1

DTIC Science & Technology

2014-03-31

in support of the Applied Research Project (ARP) 12om entitled “Collaborative Understanding of Complex Situations”. The overall purpose of this...Definition ARP Applied Research Project CF Canadian Forces CFOPP Canadian Forces Operational Planning Process CIDA Canadian International... Research Project (ARP) 12om entitled “Collaborative Understanding of Complex Situations”. The overall purpose of this project is to develop a

X-rays from Eta Carinae

NASA Technical Reports Server (NTRS)

Chlebowski, T.; Seward, F. D.; Swank, J.; Szymkowiak, A.

1984-01-01

X-ray observations of Eta Car obtained with the high-resolution imager and solid-state spectrometer of the Einstein observatory are reported and interpreted in terms of a two-shell model. A soft component with temperature 5 million K is located in the expanding outer shell, and the hard core component with temperature 80 million K is attributed to the interaction of a high-velocity stellar wind from the massive central object with the inner edge of a dust shell. Model calculations based on comparison with optical and IR data permit estimation of the mass of the outer shell (0.004 solar mass), the mass of the dust shell (3 solar mass), and the total shell expansion energy (less than 2 x 10 to the 49th ergs).

Shell nebulae around luminous evolved stars

NASA Technical Reports Server (NTRS)

Dufour, Reginald J.

1989-01-01

Shell nebulae around luminous Population I Wolf-Rayet, Of, and P-Cygni stars are astrophysically interesting since they are indicators of pre-supernova mass loss and how such massive stars prepare their surrounding interstellar medium prior to explosion. Some twenty-odd such nebulae are known, for which detailed study of their morphological and spectroscopic characteristics have only begun in this decade. In this paper, some of these characteristics are reviewed in general, and new observations are reported. Emphasis has been placed on several 'prototype 'objects (NGC 7635, NGC 2359, NGC 6888, and the Eta Carinae condensations) to illustrate the varied massive-star mass-loss, the physics of their winds and shell ejecta, and related nucleosynthesis effects in the compositions of the winds and shells.

Monsters in the sky. I mostri del cielo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maffei, P.

1980-01-01

The book treats astronomical objects and phenomena which remain unexplained or unproven by current investigators. Specific objects discussed include comets, satellite clouds surrounding the earth, tektites, the planet Vulcan (within the orbit of Mercury), Planet X (beyond Pluto), the Gum Nebula, planetary nebulae, supernovae, supernova remnants, transient X-ray sources, the possible extinction of the dinosaurs by an X-ray explosion and super-supernovae. Attention is also given to the star Eta Carinae, black holes, BL Lacertae objects, active galaxies, Markarian galaxies, N and compact galaxies, Seyfert galaxies, quasars, redshift anomalies, Stephan's quintet of galaxies, and intergalactic black holes or black dwarfs whichmore » may account for the mass necessary to bind together clusters of galaxies.« less

Sarcoidosis with Pancreatic Mass, Endobronchial Nodules, and Miliary Opacities in the Lung.

PubMed

Matsuura, Shun; Mochizuka, Yasutaka; Oishi, Kyohei; Miyashita, Koichi; Naoi, Hyogo; Mochizuki, Eisuke; Mikura, Shinichiro; Tsukui, Masaru; Koshimizu, Naoki; Ohata, Akihiko; Suda, Takahumi

2017-11-15

Sarcoidosis affects multiple organs and rarely has unusual manifestations. A 78-year-old woman was referred to our hospital for coughing symptoms. A chest computed tomography (CT) scan revealed bilateral diffuse miliary patterns and right pleural effusion. Bronchoscopy showed multiple nodules in the carina and the bronchus intermedius. A CT scan of her abdomen revealed hypovascular lesions involving the pancreatic head and body. A transbronchial lung biopsy, bronchial mucosal biopsy, and endoscopic ultrasound-guided fine-needle aspiration of the pancreatic mass demonstrated non-caseating granulomas. We diagnosed the patient with sarcoidosis. She received no treatment for sarcoidosis and has been followed up for one year, during which no pulmonary disease progression had been observed and the pancreatic masses partially regressed.

Homogeneous photometry and star counts in the field of 9 Galactic star clusters

NASA Astrophysics Data System (ADS)

Seleznev, A. F.; Carraro, G.; Costa, E.; Loktin, A. V.

2010-01-01

We present homogeneous V, I CCD photometry of nine stellar fields in the two inner quadrants of the Galactic plane. The lines-of-view to most of these fields aim in the direction of the very inner Galaxy, where the Galactic field is very dense, and extinction is high and patchy. Our nine fields are, according to several catalogs, centred on Galactic star clusters, namely Trumpler 13, Trumpler 20, Lynga 4, Hogg 19, Lynga 12, Trumpler 25, Trumpler 26, Ruprecht 128, and Trumpler 34. Apart from their coordinates, and in some cases additional basic data (mainly from the 2MASS archive), their properties are poorly known. By means of star count techniques and field star decontaminated Color Magnitude diagrams, the nature and size of these visual over-densities has been established; and, when possible, new cluster fundamental parameters have been derived. To strengthen our findings, we complement our data-set with JHKs photometry from the 2MASS archive, that we analyze using a suitably defined Q-parameter. Most clusters are projected towards the Carina-Sagittarium spiral arm. Because of that, we detect in the Color Magnitude diagrams of most of the other fields several distinctive sequences produced by young population within the arm. All the clusters are of intermediate or old age. The most interesting cases detected by our study are, perhaps, that of Trumpler 20, which seems to be much older than previously believed, as indicated by its prominent - and double - red clump; and that of Hogg 19, a previously overlooked old open cluster, whose existence in such regions of the Milky Way is puzzling.

Visualizing the Complex Process for Deep Learning with an Authentic Programming Project

ERIC Educational Resources Information Center

Peng, Jun; Wang, Minhong; Sampson, Demetrios

2017-01-01

Project-based learning (PjBL) has been increasingly used to connect abstract knowledge and authentic tasks in educational practice, including computer programming education. Despite its promising effects on improving learning in multiple aspects, PjBL remains a struggle due to its complexity. Completing an authentic programming project involves a…

EpiCollect+: linking smartphones to web applications for complex data collection projects

PubMed Central

Aanensen, David M.; Huntley, Derek M.; Menegazzo, Mirko; Powell, Chris I.; Spratt, Brian G.

2014-01-01

Previously, we have described the development of the generic mobile phone data gathering tool, EpiCollect, and an associated web application, providing two-way communication between multiple data gatherers and a project database. This software only allows data collection on the phone using a single questionnaire form that is tailored to the needs of the user (including a single GPS point and photo per entry), whereas many applications require a more complex structure, allowing users to link a series of forms in a linear or branching hierarchy, along with the addition of any number of media types accessible from smartphones and/or tablet devices (e.g., GPS, photos, videos, sound clips and barcode scanning). A much enhanced version of EpiCollect has been developed (EpiCollect+). The individual data collection forms in EpiCollect+ provide more design complexity than the single form used in EpiCollect, and the software allows the generation of complex data collection projects through the ability to link many forms together in a linear (or branching) hierarchy. Furthermore, EpiCollect+ allows the collection of multiple media types as well as standard text fields, increased data validation and form logic. The entire process of setting up a complex mobile phone data collection project to the specification of a user (project and form definitions) can be undertaken at the EpiCollect+ website using a simple ‘drag and drop’ procedure, with visualisation of the data gathered using Google Maps and charts at the project website. EpiCollect+ is suitable for situations where multiple users transmit complex data by mobile phone (or other Android devices) to a single project web database and is already being used for a range of field projects, particularly public health projects in sub-Saharan Africa. However, many uses can be envisaged from education, ecology and epidemiology to citizen science. PMID:25485096

EpiCollect+: linking smartphones to web applications for complex data collection projects.

PubMed

Aanensen, David M; Huntley, Derek M; Menegazzo, Mirko; Powell, Chris I; Spratt, Brian G

2014-01-01

Previously, we have described the development of the generic mobile phone data gathering tool, EpiCollect, and an associated web application, providing two-way communication between multiple data gatherers and a project database. This software only allows data collection on the phone using a single questionnaire form that is tailored to the needs of the user (including a single GPS point and photo per entry), whereas many applications require a more complex structure, allowing users to link a series of forms in a linear or branching hierarchy, along with the addition of any number of media types accessible from smartphones and/or tablet devices (e.g., GPS, photos, videos, sound clips and barcode scanning). A much enhanced version of EpiCollect has been developed (EpiCollect+). The individual data collection forms in EpiCollect+ provide more design complexity than the single form used in EpiCollect, and the software allows the generation of complex data collection projects through the ability to link many forms together in a linear (or branching) hierarchy. Furthermore, EpiCollect+ allows the collection of multiple media types as well as standard text fields, increased data validation and form logic. The entire process of setting up a complex mobile phone data collection project to the specification of a user (project and form definitions) can be undertaken at the EpiCollect+ website using a simple 'drag and drop' procedure, with visualisation of the data gathered using Google Maps and charts at the project website. EpiCollect+ is suitable for situations where multiple users transmit complex data by mobile phone (or other Android devices) to a single project web database and is already being used for a range of field projects, particularly public health projects in sub-Saharan Africa. However, many uses can be envisaged from education, ecology and epidemiology to citizen science.

Preview of a Forthcoming Supernova

NASA Image and Video Library

2017-12-08

Supernova Supernovae can occur one of two ways. The first occurs when a white dwarf—the vestigial ember of a dead star—passes so close to a living star that its matter leaks into the white dwarf. This causes a catastrophic explosion. However most people understand supernovae as the death of a massive star. When the star runs out of fuel toward the end of its life, the gravity at its heart sucks the surrounding mass into its center. At temperatures rocketing above 100 billion degrees Fahrenheit, all the layers of the star abruptly explode outward. The explosions produced by supernovae are so brilliant that astronomers use their luminosity to measure the distance between galaxies, the scale of the universe and the effects of dark energy. For a short period of time, one dying star can appear to shine as brightly as an entire galaxy. Supernovae are relatively common events, one occurring in our own galaxy once every 100 years. In 2014, a person could see the supernova M82 with a pair of binoculars. The cosmologist Tycho Brahe’s observation of a supernova in 1572 allowed him to disprove Aristotle’s theory that the heavens never changed. After a supernova, material expelled in the explosion can form a nebula—an interstellar pile of gas and dust. Over millions of years, gravity pulls the nebula’s materials into a dense orb called a protostar, which will become a new star. Within a few million years, this new star could go supernova as well. ------------------------------ Original Caption: NASA image release Feb. 24, 2012 At the turn of the 19th century, the binary star system Eta Carinae was faint and undistinguished. In the first decades of the century, it became brighter and brighter, until, by April 1843, it was the second brightest star in the sky, outshone only by Sirius (which is almost a thousand times closer to Earth). In the years that followed, it gradually dimmed again and by the 20th century was totally invisible to the naked eye. The star has continued to vary in brightness ever since, and while it is once again visible to the naked eye on a dark night, it has never again come close to its peak of 1843. NASA's Hubble Telescope captured an image of Eta Carinae. This image consists of ultraviolet and visible light images from the High Resolution Channel of Hubble's Advanced Camera for Surveys. The field of view is approximately 30 arcseconds across. The larger of the two stars in the Eta Carinae system is a huge and unstable star that is nearing the end of its life, and the event that the 19th century astronomers observed was a stellar near-death experience. Scientists call these outbursts supernova impostor events, because they appear similar to supernovae but stop just short of destroying their star. Although 19th century astronomers did not have telescopes powerful enough to see the 1843 outburst in detail, its effects can be studied today. The huge clouds of matter thrown out a century and a half ago, known as the Homunculus Nebula, have been a regular target for Hubble since its launch in 1990. This image, taken with the Advanced Camera for Surveys High Resolution Channel, is the most detailed yet, and shows how the material from the star was not thrown out in a uniform manner, but forms a huge dumbbell shape. Eta Carinae is not only interesting because of its past, but also because of its future. It is one of the closest stars to Earth that is likely to explode in a supernova in the relatively near future (though in astronomical timescales the "near future" could still be a million years away). When it does, expect an impressive view from Earth, far brighter still than its last outburst: SN 2006gy, the brightest supernova ever observed, came from a star of the same type, though from a galaxy over 200 million light-years away. Credit: ESA/NASA More information: www.spacetelescope.org/images/potw1208a/ NASA image use policy. NASA Goddard Space Flight Center enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on Twitter Like us on Facebook Find us on Instagram

The Characteristics of Project Managers: An Exploration of Complex Projects in the National Aeronautics and Space Administration

NASA Technical Reports Server (NTRS)

Mulenburg, Gerald M.

2000-01-01

Study of characteristics and relationships of project managers of complex projects in the National Aeronautics and Space Administration. Study is based on Research Design, Data Collection, Interviews, Case Studies, and Data Analysis across varying disciplines such as biological research, space research, advanced aeronautical test facilities, aeronautic flight demonstrations, and projects at different NASA centers to ensure that findings were not endemic to one type of project management, or to one Center's management philosophies. Each project is treated as a separate case with the primary data collected during semi-structured interviews with the project manager responsible for the overall project. Results of the various efforts show some definite similarities of characteristics and relationships among the project managers in the study. A model for how the project managers formulated and managed their projects is included.

Absolute parameters of young stars: QZ Carinae

NASA Astrophysics Data System (ADS)

Walker, W. S. G.; Blackford, M.; Butland, R.; Budding, E.

2017-09-01

New high-resolution spectroscopy and BVR photometry together with literature data on the complex massive quaternary star QZ Car are collected and analysed. Absolute parameters are found as follows. System A: M1 = 43 (±3), M2 = 19 (+3 -7), R1 = 28 (±2), R2 = 6 (±2), (⊙); T1 ˜ 28 000, T2 ˜ 33 000 K; System B: M1 = 30 (±3), M2 = 20 (±3), R1 = 10 (±0.5), R2 = 20 (±1), (⊙); T1 ˜ 36 000, T2 ˜ 30 000 K (model dependent temperatures). The wide system AB: Period = 49.5 (±1) yr, Epochs, conjunction = 1984.8 (±1), periastron = 2005.3 (±3) yr, mean separation = 65 (±3), (au); orbital inclination = 85 (+5 -15) deg, photometric distance ˜2700 (±300) pc, age = 4 (±1) Myr. Other new contributions concern: (a) analysis of the timing of minima differences (O - C)s for the eclipsing binary (System B); (b) the width of the eclipses, pointing to relatively large effects of radiation pressure; (c) inferences from the rotational widths of lines for both Systems A and B; and (d) implications for theoretical models of early-type stars. While feeling greater confidence on the quaternary's general parametrization, observational complications arising from strong wind interactions or other, unclear, causes still inhibit precision and call for continued multiwavelength observations. Our high-inclination value for the AB system helps to explain failures to resolve the wide binary in the previous years. The derived young age independently confirms membership of QZ Car to the open cluster Collinder 228.

Injuries of the trachea and bronchi

PubMed Central

Bertelsen, S.; Howitz, P.

1972-01-01

Traumatic rupture of the trachea or the bronchi is reported with increasing frequency. Such rupture may follow penetrating wounds, but the common cause is blunt trauma of the throat or thorax. When the proximal trachea is damaged other cervical structures are usually involved. By contrast the distal trachea or bronchi are not infrequently the only thoracic structures damaged. In particular there may be no rib fractures, or obvious fractures may be uncomplicated and insignificant. Thoracic rupture usually occurs in the vicinity of the carina. Central rupture generally presents with emphysema of the mediastinum and neck. Diagnosis can usually be confirmed by tracheobronchoscopy. Rupture of the peripheral bronchi generally presents with pneumothorax and atelectasis. Central rupture should be treated by primary suture. Lobectomy is often necessary when small bronchi are ruptured. PMID:5034596

Hyalella cenotensis, a new species of Hyalellidae (Crustacea: Amphipoda) from the Yucatán Peninsula, Mexico.

PubMed

Marrón-Becerra, Aurora; Hermoso-Salazar, Margarita; Solís-Weiss, Vivianne

2014-06-03

In this study the first blind species of Hyalella for Mexico is described; it is the second in the genus to be recorded there. The new species is closer to the eyeless species: H. anophthalma Ruffo, 1957, H. muerta Baldinger, Shepard & Threloff, 2000, H. caeca Pereira, 1989, H. spelaea Bueno & Cardoso, 2011 in Cardoso et al. 2011, H. imbya Rodrigues & Bueno, 2012 in Rodrigues et al. 2012, but with no curved seta at the inner ramus of uropod 1, antennae 1 shorter than antennae 2, no apical setae on the telson and a characteristic dorsoposterior carina and three pappose setae on the inner plate of maxilla 1. The morphological intraspecific variations that can be found in this genus are discussed.

Airborne spectrophotometry of Eta Carinae from 4.5 to 7.5 microns and a model for source morphology

NASA Technical Reports Server (NTRS)

Russell, Ray W.; Lynch, David K.; Hackwell, John A.; Rudy, Richard J.; Rossano, George S.; Castelaz, M. W.

1987-01-01

Spectrophotometric observations of Eta Car between 4.5 and 7.5 microns show a featureless thermal-like spectrum with no fine-structure lines or broad emission or absorption features. The color temperature of the spectrum is approximately 375 K. High spatial resolution maps at 3.5, 4.8, and 10 microns obtained from the ground are used to discuss the dust distribution and temperature structure, and to present a model for general source morphology. The upper limit to the brightness of the forbidden Ar II fine-structure emission line at 6.98 microns is less than 7 x 10 to the -16th W/sq cm, which still allows for a significant overabundance of argon and is consistent with the evolved nature of the source.

Mining the Obscured OB Star Population in Carina

NASA Astrophysics Data System (ADS)

Smith, Michael

2016-04-01

Massive OB stars are very influential objects in the ecology of galaxies like our own. Current catalogues of Galactic OB stars are heavily biased towards bright (g < 13) objects, only typically including fainter objects when found in prominent star clusters (Garmany et al., 1982; Reed, 2003; Maíz-Apellaniz et al., 2004). Exploitation of the VST Photometric Hα Survey (VPHAS+) allows us to build a robust catalogue of photometrically-selected OB stars across the entire Southern Galactic plane, both within clusters and in the field, down to ∼20th magnitude in g. For the first time, a complete accounting of the OB star runaway phenomenon becomes possible. Along with making the primary selection using VPHAS+ colours, I have performed Markov-Chain Monte Carlo fitting of the spectral energy distributions of the selected stars by combining VPHAS+ u, g, r, i with published J, H, K photometry. This gives rough constraints on effective temperature and distance, whilst delivering much more precise reddening parameters A0 and RV - allowing us to build a much richer picture of how extinction and extinction laws vary across the Galactic Plane. My thesis begins with a description of the method of photometric selection of OB star candidates and its validation across a 2 square degree field including the well-known young massive star cluster Westerlund 2 (Mohr-Smith et al., 2015). Following on from this I present spectroscopy with AAOmega of 283 candidates identified by our method, which confirms that ∼94% of the sample are the expected O and early B stars. I then develop this method further and apply it to a Galactic Plane strip of 42 square-degrees that runs from the Carina Arm tangent region to the much studied massive cluster in NGC 3603. A new aspect I attend to in this expansion of method is tightening up the uniform photometric calibration of the data, paying particular attention to the always-challenging u band. This leads to a new and reliable catalogue of 5915 OB stars. As well as increasing the numbers of identified massive stars in this large region of the sky by nearly an order of magnitude, a more complete picture of massive star formation in the Carina Arm has emerged. I have found a broad over-density of O stars around the highly luminous cluster NGC 3603 and have uncovered two new candidate OB clusters/associations. I have also paired up the ionization sources of a number of HII regions catalogued by the RMS survey. It is also shown that the OB star scale-height can serve as a roughly standard ruler, leading to the result that the OB star layer shows the onset of warping at RG ∼10kpc. My results confirm that this entire region requires a non-standard (3.5 < RV < 4.0) reddening law for distances greater than ∼2 kpc. The methods developed in this study are ready to roll out across the rest of the VPHAS+ footprint that has been observed to date. This extension will take in a strip ∼ ±2 degrees across the entire Southern Galactic mid-plane (a sky area of over 700 square degrees), within which we expect to find the majority of massive OB stars. This will result in the largest catalogue of Galactic OB stars to date.

Risk management integration into complex project organizations

NASA Technical Reports Server (NTRS)

Fisher, K.; Greanias, G.; Rose, J.; Dumas, R.

2002-01-01

This paper describes the approach used in designing and adapting the SIRTF prototype, discusses some of the lessons learned in developing the SIRTF prototype, and explains the adaptability of the risk management database to varying levels project complexity.

Risk Reduction for Use of Complex Devices in Space Projects

NASA Technical Reports Server (NTRS)

Berg, Melanie; Poivey, Christian; Friendlich, Mark; Petrick, Dave; LaBel, Kenneth; Stansberry, Scott

2007-01-01

We present guidel!nes to reduce risk to an acceptable level when using complex devices in space applications. Application to Virtex 4 Field Programmable Gate Array (FPGA) on Express Logistic Carrier (ELC) project is presented.

Integrating Assessment and Research Strategies on a Large Development and Research Project: Kids as Airborne Mission Scientists (KaAMS).

ERIC Educational Resources Information Center

Grabowski, Barbara L.; Koszalka, Tiffany A.

Combining assessment and research components on a large development and research project is a complex task. There are many descriptions of how either assessment or research should be conducted, but detailed examples illustrating integration of such strategies in complex projects are scarce. This paper provides definitions of assessment,…

Community Learning Campus: It Takes a Simple Message to Build a Complex Project

ERIC Educational Resources Information Center

Pearson, George

2012-01-01

Education Canada asked Tom Thompson, president of Olds College and a prime mover behind the Community Learning Campus (CLC): What were the lessons learned from this unusually ambitious education project? Thompson mentions six lessons he learned from this complex project which include: (1) Dream big, build small, act now; (2) Keep a low profile at…

A Project Management Approach to Using Simulation for Cost Estimation on Large, Complex Software Development Projects

NASA Technical Reports Server (NTRS)

Mizell, Carolyn; Malone, Linda

2007-01-01

It is very difficult for project managers to develop accurate cost and schedule estimates for large, complex software development projects. None of the approaches or tools available today can estimate the true cost of software with any high degree of accuracy early in a project. This paper provides an approach that utilizes a software development process simulation model that considers and conveys the level of uncertainty that exists when developing an initial estimate. A NASA project will be analyzed using simulation and data from the Software Engineering Laboratory to show the benefits of such an approach.

Economic evaluation of environmental epidemiological projects in national industrial complexes.

PubMed

Shin, Youngchul

2017-01-01

In this economic evaluation of environmental epidemiological monitoring projects, we analyzed the economic feasibility of these projects by determining the social cost and benefit of these projects and conducting a cost/benefit analysis. Here, the social cost was evaluated by converting annual budgets for these research and survey projects into present values. Meanwhile, the societal benefit of these projects was evaluated by using the contingent valuation method to estimate the willingness-to-pay of residents living in or near industrial complexes. In addition, the extent to which these projects reduced negative health effects (i.e., excess disease and premature death) was evaluated through expert surveys, and the analysis was conducted to reflect the unit of economic value, based on the cost of illness and benefit transfer method. The results were then used to calculate the benefit of these projects in terms of the decrease in negative health effects. For residents living near industrial complexes, the benefit/cost ratio was 1.44 in the analysis based on resident surveys and 5.17 in the analysis based on expert surveys. Thus, whichever method was used for the economic analysis, the economic feasibility of these projects was confirmed.

NASA/DOD Aerospace Knowledge Diffusion Research Project. Report 15: Technical uncertainty and project complexity as correlates of information use by US industry-affiliated aerospace engineers and scientists: Results of an exploratory investigation

NASA Technical Reports Server (NTRS)

Pinelli, Thomas E.; Glassman, Nanci A.; Affelder, Linda O.; Hecht, Laura M.; Kennedy, John M.; Barclay, Rebecca O.

1993-01-01

An exploratory study was conducted that investigated the influence of technical uncertainty and project complexity on information use by U.S. industry-affiliated aerospace engineers and scientists. The study utilized survey research in the form of a self-administered mail questionnaire. U.S. aerospace engineers and scientists on the Society of Automotive Engineers (SAE) mailing list served as the study population. The adjusted response rate was 67 percent. The survey instrument is appendix C to this report. Statistically significant relationships were found to exist between technical uncertainty, project complexity, and information use. Statistically significant relationships were found to exist between technical uncertainty, project complexity, and the use of federally funded aerospace R&D. The results of this investigation are relevant to researchers investigating information-seeking behavior of aerospace engineers. They are also relevant to R&D managers and policy planners concerned with transferring the results of federally funded aerospace R&D to the U.S. aerospace industry.

The Strings of Eta Carina: The HST/STIS Spectra and [Ca II

NASA Technical Reports Server (NTRS)

Melendez, M. B.; Gull, T. R.; Bautista, M. A.; Badnell, N. R.

2006-01-01

Long linear, filamentary ejecta, are found to move at very high velocity external to the Homunculus, the circumstellar hourglass-shaped ejecta surrounding Eta Carinae. The origin of the strings is a puzzle. As an example, the Weigelt Blobs have N at 10X solar and C, O at 0.01X solar abundance, along with He/H significantly enhanced. This abundance pattern is evidence for extreme CNO-processing. Similarly, the Strontium Filament has Ti/Ni at 100X solar, presumably due to the lack of oxygen to form Ti-oxide precipitates onto dust grains. We have obtained 2-D spectra with the HST/STIS of the Strontium Filament and a portion of a string. These deep spectral exposures, at moderate dispersion, span much of the near red spectral region from 5000 to 9000A. We have identified twelve emission lines in these spectra with proper velocities and spatial structure of this string and obtained line ratios for [Ca II] (7293/7325A) and [Fe Ill (7157/8619A) which are useful for determining physical conditions in this nebulosity. In an attempt to use the [Ca II] ratio to determine the physical parameters, and ultimately the abundances in the strings, we have constructed a statistical equilibrium model for Ca II , including radiative and collisional rates. These results incorporate our newly calculated atomic data for levels n = 3,4,5 and 6 configurations of Ca II. The aim is to compute the [Ca II] line ratios and use them as a diagnostic of the physical parameters. Using the [Fe II] ratio we find that for Te=10,000 K, the electron density is Ne approx.10(exp 6)/cu cm. We plan to use the [Ca II] ratio to confirm this result. Then, we will extend the use of this multilevel model Ca II atom to study the physical conditions of the Strontium filament where eight lines of Ca II, both allowed and forbidden, had been identified. With the physical conditions determined, we will be able to derive reliable estimates for the gas phase abundances in the strings.

DISCOVERY OF PRECURSOR LUMINOUS BLUE VARIABLE OUTBURSTS IN TWO RECENT OPTICAL TRANSIENTS: THE FITFULLY VARIABLE MISSING LINKS UGC 2773-OT AND SN 2009ip

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Nathan; Miller, Adam; Li Weidong

2010-04-15

We present progenitor-star detections, light curves, and optical spectra of supernova (SN) 2009ip and the 2009 optical transient in UGC 2773 (U2773-OT), which were not genuine SNe. Precursor variability in the decade before outburst indicates that both of the progenitor stars were luminous blue variables (LBVs). Their pre-outburst light curves resemble the S Doradus phases that preceded giant eruptions of the prototypical LBVs {eta} Carinae and SN 1954J (V12 in NGC 2403), with intermediate progenitor luminosities. Hubble Space Telescope detections a decade before discovery indicate that the SN 2009ip and U2773-OT progenitors were supergiants with likely initial masses of 50-80more » M {sub sun} and {approx}>20 M {sub sun}, respectively. Both outbursts had spectra befitting known LBVs, although in different physical states. SN 2009ip exhibited a hot LBV spectrum with characteristic speeds of 550 km s{sup -1}, plus evidence for faster material up to 5000 km s{sup -1}, resembling the slow Homunculus and fast blast wave of {eta} Carinae. In contrast, U2773-OT shows a forest of narrow absorption and emission lines comparable to that of S Dor in its cool state, plus [Ca II] emission and an infrared excess indicative of dust, similar to SN 2008S and the 2008 optical transient in NGC 300 (N300-OT). The [Ca II] emission is probably tied to a dusty pre-outburst environment, and is not a distinguishing property of the outburst mechanism. The LBV nature of SN 2009ip and U2773-OT may provide a critical link between historical LBV eruptions, while U2773-OT may provide a link between LBVs and the unusual dust-obscured transients SN 2008S and N300-OT. Future searches will uncover more examples of precursor LBV variability of this kind, providing key clues that may help unravel the instability driving LBV eruptions in massive stars.« less

VLTI-AMBER Velocity-Resolved Aperture-Synthesis Imaging of Eta Carinae with a Spectral Resolution of 12 000: Studies of the Primary Star Wind and Innermost Wind-Wind Collision Zone

NASA Technical Reports Server (NTRS)

Weigelt, G.; Hofmann, K.-H.; Schertl, D.; Clementel, N.; Corcoran, M. F.; Damineli, A.; de Wit, W.-J.; Grellmann, R.; Groh, J.; Guieu, S.;

Assessment of Cardiac Device Position on Supine Chest Radiograph in the ICU: Introduction and Applicability of the Aortic Valve Location Ratio.

PubMed

Ouweneel, Dagmar M; Sjauw, Krischan D; Wiegerinck, Esther M A; Hirsch, Alexander; Baan, Jan; de Mol, Bas A J M; Lagrand, Wim K; Planken, R Nils; Henriques, José P S

2016-10-01

The use of intracardiac assist devices is expanding, and correct position of these devices is required for optimal functioning. The aortic valve is an important landmark for positioning of those devices. It would be of great value if the device position could be easily monitored on plain supine chest radiograph in the ICU. We introduce a ratio-based tool for determination of the aortic valve location on plain supine chest radiograph images, which can be used to evaluate intracardiac device position. Retrospective observational study. Large academic medical center. Patients admitted to the ICU and supported by an intracardiac assist device. We developed a ratio to determine the aortic valve location on supine chest radiograph images. This ratio is used to assess the position of a cardiac assist device and is compared with echocardiographic findings. Supine anterior-posterior chest radiographs of patients with an aortic valve prosthesis (n = 473) were analyzed to determine the location of the aortic valve. We calculated several ratios with the potential to determine the position of the aortic valve. The aortic valve location ratio, defined as the distance between the carina and the aortic valve, divided by the thoracic width, was found to be the best performing ratio. The aortic valve location ratio determines the location of the aortic valve caudal to the carina, at a distance of 0.25 ± 0.05 times the thoracic width for male patients and 0.28 ± 0.05 times the thoracic width for female patients. The aortic valve location ratio was validated using CT images of patients with angina pectoris without known valvular disease (n = 95). There was a good correlation between cardiac device position (Impella) assessed with the aortic valve location ratio and with echocardiography (n = 53). The aortic valve location ratio enables accurate and reproducible localization of the aortic valve on supine chest radiograph. This tool is easily applicable and can be used for assessment of cardiac device position in patients on the ICU.

The wind-wind collision hole in eta Car

NASA Astrophysics Data System (ADS)

Damineli, A.; Teodoro, M.; Richardson, N. D.; Gull, T. R.; Corcoran, M. F.; Hamaguchi, K.; Groh, J. H.; Weigelt, G.; Hillier, D. J.; Russell, C.; Moffat, A.; Pollard, K. R.; Madura, T. I.

2017-11-01

Eta Carinae is one of the most massive observable binaries. Yet determination of its orbital and physical parameters is hampered by obscuring winds. However the effects of the strong, colliding winds changes with phase due to the high orbital eccentricity. We wanted to improve measures of the orbital parameters and to determine the mechanisms that produce the relatively brief, phase-locked minimum as detected throughout the electromagnetic spectrum. We conducted intense monitoring of the He ii λ4686 line in η Carinae for 10 months in the year 2014, gathering ~300 high S/N spectra with ground- and space-based telescopes. We also used published spectra at the FOS4 SE polar region of the Homunculus, which views the minimum from a different direction. We used a model in which the He ii λ4686 emission is produced by two mechanisms: a) one linked to the intensity of the wind-wind collision which occurs along the whole orbit and is proportional to the inverse square of the separation between the companion stars; and b) the other produced by the `bore hole' effect which occurs at phases across the periastron passage. The opacity (computed from 3D SPH simulations) as convolved with the emission reproduces the behavior of equivalent widths both for direct and reflected light. Our main results are: a) a demonstration that the He ii λ4686 light curve is exquisitely repeatable from cycle to cycle, contrary to previous claims for large changes; b) an accurate determination of the longitude of periastron, indicating that the secondary star is `behind' the primary at periastron, a dispute extended over the past decade; c) a determination of the time of periastron passage, at ~4 days after the onset of the deep light curve minimum; and d) show that the minimum is simultaneous for observers at different lines of sight, indicating that it is not caused by an eclipse of the secondary star, but rather by the immersion of the wind-wind collision interior to the inner wind of the primary.

Characterization of the Unusual Product from the Reaction between Cobalt(II) Chloride, Ethane-1,2-diamine, and Hydrochloric Acid: An Undergraduate Project Involving an Unknown Metal Complex.

ERIC Educational Resources Information Center

Curtis, Neil F.; And Others

1986-01-01

Discusses the need for student research-type chemistry projects based upon "unknown" metal complexes. Describes an experiment involving the product from the reaction between cobalt(II) chloride, ethane-1,2-diamine (en) and concentrated hydrochloric acid. Outlines the preparation of the cobalt complex, along with procedure, results and…

Finite-time hybrid projective synchronization of the drive-response complex networks with distributed-delay via adaptive intermittent control

NASA Astrophysics Data System (ADS)

Cheng, Lin; Yang, Yongqing; Li, Li; Sui, Xin

2018-06-01

This paper studies the finite-time hybrid projective synchronization of the drive-response complex networks. In the model, general transmission delays and distributed delays are also considered. By designing the adaptive intermittent controllers, the response network can achieve hybrid projective synchronization with the drive system in finite time. Based on finite-time stability theory and several differential inequalities, some simple finite-time hybrid projective synchronization criteria are derived. Two numerical examples are given to illustrate the effectiveness of the proposed method.

A segmentation algorithm based on image projection for complex text layout

NASA Astrophysics Data System (ADS)

Zhu, Wangsheng; Chen, Qin; Wei, Chuanyi; Li, Ziyang

2017-10-01

Segmentation algorithm is an important part of layout analysis, considering the efficiency advantage of the top-down approach and the particularity of the object, a breakdown of projection layout segmentation algorithm. Firstly, the algorithm will algorithm first partitions the text image, and divided into several columns, then for each column scanning projection, the text image is divided into several sub regions through multiple projection. The experimental results show that, this method inherits the projection itself and rapid calculation speed, but also can avoid the effect of arc image information page segmentation, and also can accurate segmentation of the text image layout is complex.

Oslerus osleri (Cobbold, 1876) infection in maned wolf (Chrysocyon brachyurus, illiger, 1815).

PubMed

Dias, Rafael Grobério Souto; Legatti, Emerson; Rahal, Sheila Canevese; Teixeira, Carlos Roberto; Ruiz Júnior, Raul Lopes; Rocha, Noeme Sousa; dos Santos, Ivan Felismino Charas; Schmidt, Elizabeth Moreira dos Santos

2012-09-01

Oslerus osleri is a small nematode that infects the respiratory tract of domestic and wild canids and is responsible for causing chronic nodular tracheobronchitis. This paper aims to report a case of parasitism by O. osleri in a free-living maned wolf (Chrysocyon brachyurus) that was struck by a motor vehicle. Fecal samples were collected, and the presence of spiral larvae, with "S"-shaped tails, was observed on flotation. This characteristic was compatible with the Filaroididae Family larvae of O. osleri. Although the animal did not show clinical signs of respiratory system impairment, a tracheobronchoscopy was performed. Semitransparent nodules, 5 mm in diameter, containing adult parasites were observed in the third distal portion of the trachea, cranial to the carina. Larval morphological characteristics and the nodular locations were compatible with an O. osleri respiratory tract infection.

Description of five species of Xanthopimpla Saussure 1892 (Hymenoptera: Ichneumonidae: Pimplinae) from Malaysia

NASA Astrophysics Data System (ADS)

Dass, Angeline David; Ghani, Idris Abd.

2013-11-01

Description of five species of Xanthopimpla Saussure, 1829 (Hymenoptera: Ichneumonidae: Pimplinae) from Malaysia was done using specimens deposited in Centre for Insects Systematics, Universiti Kebangsaan Malaysia (CIS, UKM). Type and non-type specimens were loaned from several repositories namely Zoological Museum of Amsterdam Netherlands (ZMAN), Swedish Museum of Natural History (NRM), British Natural History Museum London (BMNH) and Department of Agricultural Malaysia (DOA) for identification and comparison. The specimens were identified to the species level which gives rise to five species namely Xanthopimpla conica Cushman, 1925, Xanthopimpla despinosa leipephelis Townes & Chiu, 1970, Xanthopimpla flavolineata Cameron, 1907, Xanthopimpla punctata (Fabricius, 1781) and Xanthopimpla tricapus impressa Townes & Chiu, 1970. A dichotomous key and descriptions for five Xanthopimpla spesies were provided. Photos and illustrations of carina on propodeum were also included in this paper.

Accurate VUV Laboratory Measurements of Fe III Transitions for Astrophysical Applications

NASA Technical Reports Server (NTRS)

Blackwell-Whitehead, R. J.; Pickering, J. C.; Smillie, D.; Nave, G.; Szabo, C. I.; Smith, Peter L.; Nielsen, K. E.; Peters, G.

2006-01-01

We report preliminary measurements of Fe III spectra in the 1150 to 2500 A wavelength interval. Spectra have been recorded with an iron-neon Penning discharge lamp (PDL) between 1600 and 2500 A at Imperial College (IC) using high resolution Fourier (FT) transform spectroscopy. These FT spectrometer measurements were extended beyond 1600 A to 1150 A using high-resolution grating spectroscopy at the National Institute of Standards and Technology (NIST). These recorded spectra represent the first radiometrically calibrated measurements of a doubly-ionized iron-group element spectrum combining the techniques of vacuum ultraviolet FT and grating spectroscopy. The spectral range of the new laboratory measurements corresponds to recent HST/STIS observations of sharp-lined B stars and of Eta Carinae. The new improved atomic data can be applied to abundance studies and diagnostics of astrophysical plasmas.

Waiting in the Wings: Reflected X-ray Emission from the Homunculus Nebula

NASA Technical Reports Server (NTRS)

Corcoran, M. F.; Hamaguchi, K.; Gull, T.; Davidson, K.; Petre, R.; Hillier, D. J.; Smith, N.; Damineli, A.; Morse, J. A.; Walborn, N. R.

2004-01-01

We report the first detection of X-ray emission associated with the Homunculus Nebula which surrounds the supermassive star eta Carinae. The emission is characterized by a temperature in excess of 100 MK, and is consistent with scattering of the time-delayed X-ray flux associated with the star. The nebular emission is bright in the northwestern lobe and near the central regions of the Homunculus, and fainter in the southeastern lobe. We also report the detection of an unusually broad Fe K fluorescent line, which may indicate fluorescent scattering off the wind of a companion star or some other high velocity outflow. The X-ray Homunculus is the nearest member of the small class of Galactic X-ray reflection nebulae, and the only one in which both the emitting and reflecting sources are distinguishable.

An Astronomical Time Machine: Light Echoes from Historic Supernovae and Stellar Eruptions

NASA Astrophysics Data System (ADS)

Rest, Armin

2014-01-01

Tycho Brahe's observations of a supernova in 1572 challenged the dogma that the celestial realm was unchanging. Now, 440 years later we have once again seen the light that Tycho saw as simple reflections from walls of Galactic dust. These light echoes, as well as ones detected from other historical events such as Cas A and Eta Carinae's Great Eruption, give us a rare opportunity in astronomy: the direct observation of the cause (the explosion/eruption) and the effect (the remnant) of the same astronomical event. But we can do more: the light echoes let us look at the explosion from different angles, and permit us to map the asymmetries in the explosion. I will discuss how the unprecedented three-dimensional view of these exciting events allows us to unravel some of their secrets.

Report of CEC Study Committee on Construction Management.

ERIC Educational Resources Information Center

Consulting Engineers Council of the U.S., Washington, DC.

Changing times place new demands on those involved in the implementation of construction projects. Within a relatively few years, the size and complexity of projects has grown substantially. Environmental and other public and social considerations are increasingly significant. With growing complexity, the requirements for effective project…

24 CFR 954.4 - Other Federal requirements.

Code of Federal Regulations, 2011 CFR

2011-04-01

... regional or village corporation as defined or established pursuant to the Alaska Native Claims Settlement..., and affordable dwelling unit in the building/complex upon completion of the project. (2) Temporary... building/complex upon completion of the project; and (D) The provisions of paragraph (e)(2)(i) of this...

General risks for tunnelling projects: An overview

NASA Astrophysics Data System (ADS)

Siang, Lee Yong; Ghazali, Farid E. Mohamed; Zainun, Noor Yasmin; Ali, Roslinda

2017-10-01

Tunnels are indispensable when installing new infrastructure as well as when enhancing the quality of existing urban living due to their unique characteristics and potential applications. Over the past few decades, there has been a significant increase in the building of tunnels, world-wide. Tunnelling projects are complex endeavors, and risk assessment for tunnelling projects is likewise a complex process. Risk events are often interrelated. Occurrence of a technical risk usually carries cost and schedule consequences. Schedule risks typically impact cost escalation and project overhead. One must carefully consider the likelihood of a risk's occurrence and its impact in the context of a specific set of project conditions and circumstances. A project's goals, organization, and environment impacts in the context of a specific set of project conditions and circumstances. Some projects are primarily schedule driven; other projects are primarily cost or quality driven. Whether a specific risk event is perceived fundamentally as a cost risk or a schedule risk is governed by the project-specific context. Many researchers have pointed out the significance of recognition and control of the complexity, and risks of tunnelling projects. Although all general information on a project such as estimated duration, estimated cost, and stakeholders can be obtained, it is still quite difficult to accurately understand, predict and control the overall situation and development trends of the project, leading to the risks of tunnelling projects. This paper reviews all the key risks for tunnelling projects from several case studies that have been carried out by other researchers. These risks have been identified and reviewed in this paper. As a result, the current risk management plan in tunnelling projects can be enhanced by including all these reviewed risks as key information.

Minor Distortions with Major Consequences: Correcting Distortions in Imaging Spectrographs

PubMed Central

Esmonde-White, Francis W. L.; Esmonde-White, Karen A.; Morris, Michael D.

2010-01-01

Projective transformation is a mathematical correction (implemented in software) used in the remote imaging field to produce distortion-free images. We present the application of projective transformation to correct minor alignment and astigmatism distortions that are inherent in dispersive spectrographs. Patterned white-light images and neon emission spectra were used to produce registration points for the transformation. Raman transects collected on microscopy and fiber-optic systems were corrected using established methods and compared with the same transects corrected using the projective transformation. Even minor distortions have a significant effect on reproducibility and apparent fluorescence background complexity. Simulated Raman spectra were used to optimize the projective transformation algorithm. We demonstrate that the projective transformation reduced the apparent fluorescent background complexity and improved reproducibility of measured parameters of Raman spectra. Distortion correction using a projective transformation provides a major advantage in reducing the background fluorescence complexity even in instrumentation where slit-image distortions and camera rotation were minimized using manual or mechanical means. We expect these advantages should be readily applicable to other spectroscopic modalities using dispersive imaging spectrographs. PMID:21211158

The Global Ocean Data Analysis Project version 2 (GLODAPv2) - an internally consistent data product for the world ocean

NASA Astrophysics Data System (ADS)

Olsen, Are; Key, Robert M.; van Heuven, Steven; Lauvset, Siv K.; Velo, Anton; Lin, Xiaohua; Schirnick, Carsten; Kozyr, Alex; Tanhua, Toste; Hoppema, Mario; Jutterström, Sara; Steinfeldt, Reiner; Jeansson, Emil; Ishii, Masao; Pérez, Fiz F.; Suzuki, Toru

2016-08-01

Version 2 of the Global Ocean Data Analysis Project (GLODAPv2) data product is composed of data from 724 scientific cruises covering the global ocean. It includes data assembled during the previous efforts GLODAPv1.1 (Global Ocean Data Analysis Project version 1.1) in 2004, CARINA (CARbon IN the Atlantic) in 2009/2010, and PACIFICA (PACIFic ocean Interior CArbon) in 2013, as well as data from an additional 168 cruises. Data for 12 core variables (salinity, oxygen, nitrate, silicate, phosphate, dissolved inorganic carbon, total alkalinity, pH, CFC-11, CFC-12, CFC-113, and CCl4) have been subjected to extensive quality control, including systematic evaluation of bias. The data are available in two formats: (i) as submitted but updated to WOCE exchange format and (ii) as a merged and internally consistent data product. In the latter, adjustments have been applied to remove significant biases, respecting occurrences of any known or likely time trends or variations. Adjustments applied by previous efforts were re-evaluated. Hence, GLODAPv2 is not a simple merging of previous products with some new data added but a unique, internally consistent data product. This compiled and adjusted data product is believed to be consistent to better than 0.005 in salinity, 1 % in oxygen, 2 % in nitrate, 2 % in silicate, 2 % in phosphate, 4 µmol kg-1 in dissolved inorganic carbon, 6 µmol kg-1 in total alkalinity, 0.005 in pH, and 5 % for the halogenated transient tracers.The original data and their documentation and doi codes are available at the Carbon Dioxide Information Analysis Center (http://cdiac.ornl.gov/oceans/GLODAPv2/). This site also provides access to the calibrated data product, which is provided as a single global file or four regional ones - the Arctic, Atlantic, Indian, and Pacific oceans - under the doi:10.3334/CDIAC/OTG.NDP093_GLODAPv2. The product files also include significant ancillary and approximated data. These were obtained by interpolation of, or calculation from, measured data. This paper documents the GLODAPv2 methods and products and includes a broad overview of the secondary quality control results. The magnitude of and reasoning behind each adjustment is available on a per-cruise and per-variable basis in the online Adjustment Table.

Imaging Shock Fronts in the Outer Ejecta of Eta Carinae

NASA Astrophysics Data System (ADS)

Smith, Nathan

2017-08-01

Although Eta Car has been imaged many times with HST to monitor the central star and the bright Homunculus Nebula, we propose the first WFC3 imaging of Eta Car to study the more extended Outer Ejecta from previous eruptions. WFC3 has two key filters that have not been used before to image Eta Car, which will provide critical physical information about its eruptive history: (1) F280N with WFC3/UVIS will produce the first Mg II 2800 image of Eta Car, the sharpest image of its complex Outer Ejecta, and will unambiguously trace shock fronts, and (2) F126N with WFC3/IR will sample [Fe II] 12567 arising in the densest post-shock gas. Eta Car is surrounded by a bright, soft X-ray shell seen in Chandra images, which arises from the fastest 1840s ejecta overtaking slower older material. Our recent proper motion measurements show that the outer knots were ejected in two outbursts several hundred years before the 1840s eruption, and spectroscopy of light echoes has recently revealed extremely fast ejecta during the 1840s that indicate an explosive event. Were those previous eruptions explosive as well? If so, were they as energetic, did they also have such fast ejecta, and did they have the same geometry? The structure and excitation of the Outer Ejecta hold unique clues for reconstructing Eta Car's violent mass loss history. The locations of shock fronts in circumstellar material provide critical information, because they identify past discontinuities in the mass loss. This is one of the only ways to investigate the long term (i.e. centuries) evolution and duty cycle of eruptive mass loss in the most massive stars.

Eta Carinae's Thermal X-Ray Tail Measured with XMM-Newton and NuStar

NASA Technical Reports Server (NTRS)

Hamaguchi, Kenji; Corcoran, Michael F.; Gull, Theodore R.; Takahashi, Hiromitsu; Grefenstette, Brian; Yuasa, Takayuki; Stuhlinger, Martin; Russell, Christopher; Moffat, Anthony F. J.; Madura, Thomas

2016-01-01

The evolved, massive highly eccentric binary system, Car, underwent a periastron passage in the summer of 2014. We obtained two coordinated X-ray observations with XMM-Newton and NuSTAR during the elevated X-ray flux state and just before the X-ray minimum flux state around this passage. These NuSTAR observations clearly detected X-ray emission associated with eta Car extending up to approx. 50 keV for the first time. The NuSTAR spectrum above 10 keV can be fit with the bremsstrahlung tail from a kT approx. 6 keV plasma. This temperature is delta kT 2 keV higher than those measured from the iron K emission line complex, if the shocked gas is in collisional ionization equilibrium. This result may suggest that the companion star's pre-shock wind velocity is underestimated. The NuSTAR observation near the X-ray minimum state showed a gradual decline in the X-ray emission by 40% at energies above 5 keV in a day, the largest rate of change of the X-ray flux yet observed in individual eta Car observations. The column density to the hardest emission component, N(sub H) approx. 10(exp24) H cm(exp-2), marked one of the highest values ever observed for eta Car, strongly suggesting the increased obscuration of the wind-wind colliding X-ray emission by the thick primary stellar wind prior to superior conjunction. Neither observation detected the power-law component in the extremely hard band that INTEGRAL and Suzaku observed prior to 2011. The power-law source might have faded before these observations.

FME Senior Project Managers: A Juggling Act of Multiple Projects | Poster

Cancer.gov

By Peggy Pearl, Contributing Writer It was not until the 1950s that organizations in the United States began to apply project management tools and techniques to complex construction and engineering projects (http://en.m.wikipedia.org/wiki/Project_life_cycle).

Investing In The Army Organic Industrial Base To Operate And Win In A Complex And Austere Environment

DTIC Science & Technology

2016-05-26

Complex and Austere Environment Sb. GRANT NUMBER Sc. PROGRAM ELEMENT NUMBER 6. AUTHOR(S) Sd. PROJECT NUMBER MAJ Sun Ryu Se. TASK NUMBER Sf...supports the United States Armed Forces to project combat power during hostilities. In 2014, TRADOC published the new Army Operating Concept (AOC...Sustaining the Army Organic Industrial Base in the Post- Afghanistan Conflict Era” (Civilian Research Project , US Army War College, 2014), 1. 8

A rapid parallelization of cone-beam projection and back-projection operator based on texture fetching interpolation

NASA Astrophysics Data System (ADS)

Xie, Lizhe; Hu, Yining; Chen, Yang; Shi, Luyao

2015-03-01

Projection and back-projection are the most computational consuming parts in Computed Tomography (CT) reconstruction. Parallelization strategies using GPU computing techniques have been introduced. We in this paper present a new parallelization scheme for both projection and back-projection. The proposed method is based on CUDA technology carried out by NVIDIA Corporation. Instead of build complex model, we aimed on optimizing the existing algorithm and make it suitable for CUDA implementation so as to gain fast computation speed. Besides making use of texture fetching operation which helps gain faster interpolation speed, we fixed sampling numbers in the computation of projection, to ensure the synchronization of blocks and threads, thus prevents the latency caused by inconsistent computation complexity. Experiment results have proven the computational efficiency and imaging quality of the proposed method.

Elliptic complexes over C∗-algebras of compact operators

NASA Astrophysics Data System (ADS)

Krýsl, Svatopluk

2016-03-01

For a C∗-algebra A of compact operators and a compact manifold M, we prove that the Hodge theory holds for A-elliptic complexes of pseudodifferential operators acting on smooth sections of finitely generated projective A-Hilbert bundles over M. For these C∗-algebras and manifolds, we get a topological isomorphism between the cohomology groups of an A-elliptic complex and the space of harmonic elements of the complex. Consequently, the cohomology groups appear to be finitely generated projective C∗-Hilbert modules and especially, Banach spaces. We also prove that in the category of Hilbert A-modules and continuous adjointable Hilbert A-module homomorphisms, the property of a complex of being self-adjoint parametrix possessing characterizes the complexes of Hodge type.

Impact of choice of future climate change projection on growth chamber experimental outcomes: a preliminary study in potato.

PubMed

Leisner, Courtney P; Wood, Joshua C; Vaillancourt, Brieanne; Tang, Ying; Douches, Dave S; Robin Buell, C; Winkler, Julie A

2018-04-01

Understanding the impacts of climate change on agriculture is essential to ensure adequate future food production. Controlled growth experiments provide an effective tool for assessing the complex effects of climate change. However, a review of the use of climate projections in 57 previously published controlled growth studies found that none considered within-season variations in projected future temperature change, and few considered regional differences in future warming. A fixed, often arbitrary, temperature perturbation typically was applied for the entire growing season. This study investigates the utility of employing more complex climate change scenarios in growth chamber experiments. A case study in potato was performed using three dynamically downscaled climate change projections for the mid-twenty-first century that differ in terms of the timing during the growing season of the largest projected temperature changes. The climate projections were used in growth chamber experiments for four elite potato cultivars commonly planted in Michigan's major potato growing region. The choice of climate projection had a significant influence on the sign and magnitude of the projected changes in aboveground biomass and total tuber count, whereas all projections suggested an increase in total tuber weight and a decrease in specific gravity, a key market quality trait for potato, by mid-century. These results demonstrate that the use of more complex climate projections that extend beyond a simple incremental change can provide additional insights into the future impacts of climate change on crop production and the accompanying uncertainty.

Transportation Infrastructure: Central Artery/Tunnel Project Faces Continued Financial Uncertainties

DOT National Transportation Integrated Search

1996-05-01

At a cost of over $1 billion a mile, the Central Artery/Tunnel project - an Interstate Highway System project in Boston, Massachusetts - is one of the largest, most complex, and most expensive highway construction projects ever undertaken. In respons...

How Does a Project Manager's Level of Development Influence Conceptualizations of Project Management and the Project Development Environment?

ERIC Educational Resources Information Center

Lynch, Margaret M.

2013-01-01

This study explores the meaning project managers (PMs) make of their project environment, how they lead their teams and have incorporate complexity into their project management approach. The exploration of the PM's developmental level and meaning making offers a different angle on the project management and leadership literature. The study…

Planning Complex Projects Automatically

NASA Technical Reports Server (NTRS)

Henke, Andrea L.; Stottler, Richard H.; Maher, Timothy P.

1995-01-01

Automated Manifest Planner (AMP) computer program applies combination of artificial-intelligence techniques to assist both expert and novice planners, reducing planning time by orders of magnitude. Gives planners flexibility to modify plans and constraints easily, without need for programming expertise. Developed specifically for planning space shuttle missions 5 to 10 years ahead, with modifications, applicable in general to planning other complex projects requiring scheduling of activities depending on other activities and/or timely allocation of resources. Adaptable to variety of complex scheduling problems in manufacturing, transportation, business, architecture, and construction.

Planning and management of the Nido Reef Complex Oil Field development, Philippines

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harry, R.Y.

1981-01-01

As Operator for the Northeast Palawan consortium, Philippines-Cities Service, Inc., commenced the Philippines first commercial offshore oil production from the Nido Reef Complex Oil Field on February 1, 1979, some 11 months after a decision by management to start development. The relative speed at which design, fabrication, and construction were accomplished is attributed to the use of the concepts of project planning, task force approach, and project management. This paper presents the above concepts as applied to the Nido Complex.

Schedule Matters: Understanding the Relationship between Schedule Delays and Costs on Overruns

NASA Technical Reports Server (NTRS)

Majerowicz, Walt; Shinn, Stephen A.

2016-01-01

This paper examines the relationship between schedule delays and cost overruns on complex projects. It is generally accepted by many project practitioners that cost overruns are directly related to schedule delays. But what does "directly related to" actually mean? Some reasons or root causes for schedule delays and associated cost overruns are obvious, if only in hindsight. For example, unrealistic estimates, supply chain difficulties, insufficient schedule margin, technical problems, scope changes, or the occurrence of risk events can negatively impact schedule performance. Other factors driving schedule delays and cost overruns may be less obvious and more difficult to quantify. Examples of these less obvious factors include project complexity, flawed estimating assumptions, over-optimism, political factors, "black swan" events, or even poor leadership and communication. Indeed, is it even possible the schedule itself could be a source of delay and subsequent cost overrun? Through literature review, surveys of project practitioners, and the authors' own experience on NASA programs and projects, the authors will categorize and examine the various factors affecting the relationship between project schedule delays and cost growth. The authors will also propose some ideas for organizations to consider to help create an awareness of the factors which could cause or influence schedule delays and associated cost growth on complex projects.

Effect of Climate Change on Soil Temperature in Swedish Boreal Forests

PubMed Central

Jungqvist, Gunnar; Oni, Stephen K.; Teutschbein, Claudia; Futter, Martyn N.

2014-01-01

Complex non-linear relationships exist between air and soil temperature responses to climate change. Despite its influence on hydrological and biogeochemical processes, soil temperature has received less attention in climate impact studies. Here we present and apply an empirical soil temperature model to four forest sites along a climatic gradient of Sweden. Future air and soil temperature were projected using an ensemble of regional climate models. Annual average air and soil temperatures were projected to increase, but complex dynamics were projected on a seasonal scale. Future changes in winter soil temperature were strongly dependent on projected snow cover. At the northernmost site, winter soil temperatures changed very little due to insulating effects of snow cover but southern sites with little or no snow cover showed the largest projected winter soil warming. Projected soil warming was greatest in the spring (up to 4°C) in the north, suggesting earlier snowmelt, extension of growing season length and possible northward shifts in the boreal biome. This showed that the projected effects of climate change on soil temperature in snow dominated regions are complex and general assumptions of future soil temperature responses to climate change based on air temperature alone are inadequate and should be avoided in boreal regions. PMID:24747938

Effect of climate change on soil temperature in Swedish boreal forests.

PubMed

Jungqvist, Gunnar; Oni, Stephen K; Teutschbein, Claudia; Futter, Martyn N

2014-01-01

Complex non-linear relationships exist between air and soil temperature responses to climate change. Despite its influence on hydrological and biogeochemical processes, soil temperature has received less attention in climate impact studies. Here we present and apply an empirical soil temperature model to four forest sites along a climatic gradient of Sweden. Future air and soil temperature were projected using an ensemble of regional climate models. Annual average air and soil temperatures were projected to increase, but complex dynamics were projected on a seasonal scale. Future changes in winter soil temperature were strongly dependent on projected snow cover. At the northernmost site, winter soil temperatures changed very little due to insulating effects of snow cover but southern sites with little or no snow cover showed the largest projected winter soil warming. Projected soil warming was greatest in the spring (up to 4°C) in the north, suggesting earlier snowmelt, extension of growing season length and possible northward shifts in the boreal biome. This showed that the projected effects of climate change on soil temperature in snow dominated regions are complex and general assumptions of future soil temperature responses to climate change based on air temperature alone are inadequate and should be avoided in boreal regions.

General catalogue of variable stars: Version GCVS 5.1

NASA Astrophysics Data System (ADS)

Samus', N. N.; Kazarovets, E. V.; Durlevich, O. V.; Kireeva, N. N.; Pastukhova, E. N.

2017-01-01

Work aimed at compiling detailed catalogs of variable stars in the Galaxy, which has been carried out continuously by Moscow variable-star researchers since 1946 on behalf of the International Astronomical Union, has entered the stage of the publication of the 5th, completely electronic edition of the General Catalogue of Variable Stars (GCVS). This paper describes the requirements for the contents of the 5th edition and the current state of the catalog in its new version, GCVS 5.1. The complete revision of information for variable stars in the constellation Carina and the compilation of the 81st Name-list of Variable Stars are considered as examples of work on the 5th edition. The GCVS 5.1 is freely accessible on the Internet. We recommend the present paper as a unified reference to the 5th edition of the GCVS.

Review of Dotocryptus Brèthes (Hymenoptera, Ichneumonidae, Cryptinae), with a New Species from Colombia.

PubMed

Santos, B F; Aguiar, A P

2018-04-23

The taxonomic limits of the Neotropical genus Dotocryptus Brèthes are reviewed. The genus is characterized mainly by the very long ovipositor, at least 2.2× as long as hind tibia; apex of ovipositor distinctly depressed, ventral valve expanded, and overlapping dorsal valve as a sheath; and mandible long with ventral tooth longer than dorsal one. A new species, Dotocryptus arcadius sp. nov., from Colombia is described and illustrated. The new species can be diagnosed mainly by the head and mesosoma with multiple whitish marks; epicnemial carina reaching 0.2-0.3 of distance to subalar ridge; legs marked with dark brown, orange, and whitish; and metasoma polished and glabrate. This is the northernmost record of the genus, previously known from Ecuador to southern Chile. An updated identification key to the species of the genus is provided, as well as diagnoses and new records for the previously known species.

VizieR Online Data Catalog: Local Group dSph radio survey with ATCA (Regis+, 2015)

NASA Astrophysics Data System (ADS)

Regis, M.; Richter, L.; Colafrancesco, S.; Massardi, M.; De Blok, W. J. G.; Profumo, S.; Orford, N.

2015-09-01

We present a catalogue of radio sources detected in the fields of six dwarf spheroidal galaxies of the Local Group, which are Carina, Fornax, Sculptor, BootesII, Segue2, and Hercules. Observations were performed during July/August 2011 with the six 22-m diameter Australia Telescope Compact Array antennae operating at 16cm wavelength. We mosaicked a region of radius of about one degree around the first three dwarfs, and of about half of degree around the last three dwarfs. The rms noise level is below 0.05mJy. The restoring beams FWHM ranged from 4.2x2.5-arcseconds to 30.0x2.1-arcseconds in the most elongated case. The catalogue includes different parameters describing 1835 entries which, in our classification, correspond to 1392 sources. See the publication for more details. (1 data file).

Multi-stage learning for robust lung segmentation in challenging CT volumes.

PubMed

Sofka, Michal; Wetzl, Jens; Birkbeck, Neil; Zhang, Jingdan; Kohlberger, Timo; Kaftan, Jens; Declerck, Jérôme; Zhou, S Kevin

2011-01-01

Simple algorithms for segmenting healthy lung parenchyma in CT are unable to deal with high density tissue common in pulmonary diseases. To overcome this problem, we propose a multi-stage learning-based approach that combines anatomical information to predict an initialization of a statistical shape model of the lungs. The initialization first detects the carina of the trachea, and uses this to detect a set of automatically selected stable landmarks on regions near the lung (e.g., ribs, spine). These landmarks are used to align the shape model, which is then refined through boundary detection to obtain fine-grained segmentation. Robustness is obtained through hierarchical use of discriminative classifiers that are trained on a range of manually annotated data of diseased and healthy lungs. We demonstrate fast detection (35s per volume on average) and segmentation of 2 mm accuracy on challenging data.

High-speed photometry of the eclipsing dwarf nova OY Carinae

NASA Technical Reports Server (NTRS)

Cook, M. C.

1985-01-01

High-speed photometry of the eclipsing dwarf nova OY Car in the quiescent state is presented. OY Car becomes highly reddened during eclipse, with minimum flux colours inconsistent with optically thick emission in the U and B bandpasses. Mass ratios in the range 6.5 to 12 are required to reconcile the eclipse structure with theoretical gas stream trajectories. Primary eclipse timings reveal a significant decrease in the orbital period and the duration of primary eclipse indicates the presence of a luminous ring about the white dwarf. The hotspot eclipse reveals a hotspot which is elongated along the rim of the accretion disc, with optical emission being non-uniformly distributed along the rim. The location of the hotspot in the accretion disc implies a disc radius larger than that of an inviscid disc, with variation in the position of the hotspot being consistent with a fixed stream trajectory.

Millimeter Wavelength Observations of Galactic Sources with the Mobile Anisotropy Telescope (MAT)

NASA Astrophysics Data System (ADS)

Cruz, K. L.; Caldwell, R.; Devlin, M. J.; Dorwart, W. B.; Herbig, T.; Miller, A. D.; Nolta, M. R.; Page, L. A.; Puchalla, J. L.; Torbet, E.; Tran, H. T.

1999-12-01

The Mobile Anisotropy Telescope (MAT) has completed two observing seasons (1997 and 1998) in Chile from the Cerro Toco site. Although the primary goal of MAT was to measure anisotropy in the Cosmic Microwave Background (CMB) radiation, the chosen observation scheme also allowed daily viewing of the Galactic Plane. We present filtered maps at 30, 40 and 144 GHz of a region of the Galactic Plane which contains several millimeter-bright regions including the Carinae nebula and IRAS 11097-6102. We report the best fit brightness temperatures as well as the total flux densities in the MAT beams (0.9, 0.6 and 0.2 degrees FWHM) . The data are calibrated with respect to Jupiter whose flux is known to better than 8% in all frequency bands. This work was funded by the National Science Foundation and the Packard Foundation.

Health impact assessment of industrial development projects: a spatio-temporal visualization.

PubMed

Winkler, Mirko S; Krieger, Gary R; Divall, Mark J; Singer, Burton H; Utzinger, Jürg

2012-05-01

Development and implementation of large-scale industrial projects in complex eco-epidemiological settings typically require combined environmental, social and health impact assessments. We present a generic, spatio-temporal health impact assessment (HIA) visualization, which can be readily adapted to specific projects and key stakeholders, including poorly literate communities that might be affected by consequences of a project. We illustrate how the occurrence of a variety of complex events can be utilized for stakeholder communication, awareness creation, interactive learning as well as formulating HIA research and implementation questions. Methodological features are highlighted in the context of an iron ore development in a rural part of Africa.

Identifying challenges in project consultants engagement practices

NASA Astrophysics Data System (ADS)

Shariffuddin, Nadia Alina Amir; Abidin, Nazirah Zainul

2017-10-01

Construction projects, green or conventional, involve multi-faceted disciplines engaged with the goal of delivering products i.e. building, infrastructure etc. at the best quality within stipulated budgets. For green projects, additional attention is added for environmental quality. Due to the various responsibilities and liabilities involved as well as the complexity of the construction process itself, formal engagement of multi-disciplinary professionals i.e. project consultants is required in any construction project. Poor selection of project consultants will lead to a multitude of complications resulting in delay, cost escalation, conflicts and poor quality. This paper explores the challenges that occur during the engagement of project consultants in a green project. As the engagement decision involves developers and architects, these two groups of respondents with green project backgrounds were approached qualitatively using interview technique. The challenges identified are limited experience and knowledge, consultants' fee vs. quality, green complexity, conflicts of interest, clients' extended expectation and less demand in green projects. The construction shifts to green project demands engagement of project consultants with added skills. It is expected that through the identification of challenges, better management and administration can be created which would give impact to the overall process of engagement in green projects.

How Do Structure and Charge Affect Metal-Complex Binding to DNA? An Upper-Division Integrated Laboratory Project Using Cyclic Voltammetry

ERIC Educational Resources Information Center

Kulczynska, Agnieszka; Johnson, Reed; Frost, Tony; Margerum, Lawrence D.

2011-01-01

An advanced undergraduate laboratory project is described that integrates inorganic, analytical, physical, and biochemical techniques to reveal differences in binding between cationic metal complexes and anionic DNA (herring testes). Students were guided to formulate testable hypotheses based on the title question and a list of different metal…

Development of Prostate Specific Membrane Antigen (PSMA) Inhibitors Coupled to 99mTc(CO)3+ with Enhanced Specific Activity for SPECT Imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paul; D.; Benny,

2011-12-20

The overall objectives of the project were two fold: 1) the development of new facile reactions for coupling radioactive complexes with biomolecules and 2) the development of a novel molecular imaging targeting vector for Prostate Specific Membrane Antigen (PSMA) for prostate cancer. The didactic approach allowed the synergistic exploration of new technologies for coupling reactions of radioactive complexes that can be applied to a novel targeting moiety. As part of the project, a number of students (undergraduate, graduate and post-doctoral) were trained in radiochemical techniques for preparing and characterizing radiometal complexes. Results from the experiments within the project have generatedmore » several presentations and publications.« less

Sensemaking in Enterprise Resource Planning Project Deescalation: An Empirical Study

ERIC Educational Resources Information Center

Battleson, Douglas Aloys

2013-01-01

Enterprise resource planning (ERP) projects, a type of complex information technology project, are very challenging and expensive to implement. Past research recognizes that escalation, defined as the commitment to a failing course of action, is common in such projects. While the factors that contribute to escalation (e.g., project conditions,…

Managing Complex Distance Education Projects in a Telework Environment

ERIC Educational Resources Information Center

Ally, Mohamed; Cleveland-Innes, Marti; Wiseman, Colin

2010-01-01

The advances of communication technologies have allowed professionals to work on distance education projects in a telework environment. Managers of these projects must have the skills to manage the projects from a distance. They must be able to select the appropriate team members to work on the project, orient team members, and monitor team…

Managing Risk and Uncertainty in Large-Scale University Research Projects

ERIC Educational Resources Information Center

Moore, Sharlissa; Shangraw, R. F., Jr.

2011-01-01

Both publicly and privately funded research projects managed by universities are growing in size and scope. Complex, large-scale projects (over $50 million) pose new management challenges and risks for universities. This paper explores the relationship between project success and a variety of factors in large-scale university projects. First, we…

Statistically Validated Networks in Bipartite Complex Systems

PubMed Central

Tumminello, Michele; Miccichè, Salvatore; Lillo, Fabrizio; Piilo, Jyrki; Mantegna, Rosario N.

2011-01-01

Many complex systems present an intrinsic bipartite structure where elements of one set link to elements of the second set. In these complex systems, such as the system of actors and movies, elements of one set are qualitatively different than elements of the other set. The properties of these complex systems are typically investigated by constructing and analyzing a projected network on one of the two sets (for example the actor network or the movie network). Complex systems are often very heterogeneous in the number of relationships that the elements of one set establish with the elements of the other set, and this heterogeneity makes it very difficult to discriminate links of the projected network that are just reflecting system's heterogeneity from links relevant to unveil the properties of the system. Here we introduce an unsupervised method to statistically validate each link of a projected network against a null hypothesis that takes into account system heterogeneity. We apply the method to a biological, an economic and a social complex system. The method we propose is able to detect network structures which are very informative about the organization and specialization of the investigated systems, and identifies those relationships between elements of the projected network that cannot be explained simply by system heterogeneity. We also show that our method applies to bipartite systems in which different relationships might have different qualitative nature, generating statistically validated networks in which such difference is preserved. PMID:21483858

Analysis of polarization in hydrogen bonded complexes: An asymptotic projection approach

NASA Astrophysics Data System (ADS)

Drici, Nedjoua

2018-03-01

The asymptotic projection technique is used to investigate the polarization effect that arises from the interaction between the relaxed, and frozen monomeric charge densities of a set of neutral and charged hydrogen bonded complexes. The AP technique based on the resolution of the original Kohn-Sham equations can give an acceptable qualitative description of the polarization effect in neutral complexes. The significant overlap of the electron densities, in charged and π-conjugated complexes, impose further development of a new functional, describing the coupling between constrained and non-constrained electron densities within the AP technique to provide an accurate representation of the polarization effect.

Heuristics in Managing Complex Clinical Decision Tasks in Experts’ Decision Making

PubMed Central

Islam, Roosan; Weir, Charlene; Del Fiol, Guilherme

2016-01-01

Background Clinical decision support is a tool to help experts make optimal and efficient decisions. However, little is known about the high level of abstractions in the thinking process for the experts. Objective The objective of the study is to understand how clinicians manage complexity while dealing with complex clinical decision tasks. Method After approval from the Institutional Review Board (IRB), three clinical experts were interviewed the transcripts from these interviews were analyzed. Results We found five broad categories of strategies by experts for managing complex clinical decision tasks: decision conflict, mental projection, decision trade-offs, managing uncertainty and generating rule of thumb. Conclusion Complexity is created by decision conflicts, mental projection, limited options and treatment uncertainty. Experts cope with complexity in a variety of ways, including using efficient and fast decision strategies to simplify complex decision tasks, mentally simulating outcomes and focusing on only the most relevant information. Application Understanding complex decision making processes can help design allocation based on the complexity of task for clinical decision support design. PMID:27275019

Heuristics in Managing Complex Clinical Decision Tasks in Experts' Decision Making.

PubMed

Islam, Roosan; Weir, Charlene; Del Fiol, Guilherme

2014-09-01

Clinical decision support is a tool to help experts make optimal and efficient decisions. However, little is known about the high level of abstractions in the thinking process for the experts. The objective of the study is to understand how clinicians manage complexity while dealing with complex clinical decision tasks. After approval from the Institutional Review Board (IRB), three clinical experts were interviewed the transcripts from these interviews were analyzed. We found five broad categories of strategies by experts for managing complex clinical decision tasks: decision conflict, mental projection, decision trade-offs, managing uncertainty and generating rule of thumb. Complexity is created by decision conflicts, mental projection, limited options and treatment uncertainty. Experts cope with complexity in a variety of ways, including using efficient and fast decision strategies to simplify complex decision tasks, mentally simulating outcomes and focusing on only the most relevant information. Understanding complex decision making processes can help design allocation based on the complexity of task for clinical decision support design.

77 FR 9692 - Keālia Pond National Wildlife Refuge and Kakahai`a National Wildlife Refuge, Maui County, HI...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-02-17

...: Glynnis Nakai, Project Leader, Maui National Wildlife Refuge Complex, P.O. Box 1042, K[imacr]hei, Hawai`i 96753. In-Person Viewing or Pickup: Call (808) 875-1582 to make an appointment during regular business... FURTHER INFORMATION CONTACT: Glynnis Nakai, Project Leader, Maui NWR Complex, phone number (808) 875-1582...

Becoming a Bricoleur: Constructing Sculptures to Explore Complex and Troublesome Dimensions in Educational Research

ERIC Educational Resources Information Center

Selkrig, Mark Andrew

2014-01-01

During a recent research project, it became apparent that the conventional taxonomic, textual and linguistic devices used to develop the narrative of a manuscript would not allow me to make sense, or tell the complex story, of my inquiry. I needed to employ multimodal approaches to grapple with the project related to artists who work in…

77 FR 38821 - Final Environmental Impact Statement for the Menominee Indian Tribe of Wisconsin's Proposed Fee...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-29

... Menominee Indian Tribe of Wisconsin's Proposed Fee-to-Trust Transfer and Casino-Hotel Project in the City of... casino-hotel complex. This notice also announces the FEIS is now available for public review. Hard copies... develop a casino-hotel complex. The proposed project is located at the site of the existing Dairyland...

Eta Carinae in the Context of the Most Massive Stars

NASA Technical Reports Server (NTRS)

Gull, Theodore R.; Damineli, Augusto

2009-01-01

Eta Car, with its historical outbursts, visible ejecta and massive, variable winds, continues to challenge both observers and modelers. In just the past five years over 100 papers have been published on this fascinating object. We now know it to be a massive binary system with a 5.54-year period. In January 2009, Car underwent one of its periodic low-states, associated with periastron passage of the two massive stars. This event was monitored by an intensive multi-wavelength campaign ranging from -rays to radio. A large amount of data was collected to test a number of evolving models including 3-D models of the massive interacting winds. August 2009 was an excellent time for observers and theorists to come together and review the accumulated studies, as have occurred in four meetings since 1998 devoted to Eta Car. Indeed, Car behaved both predictably and unpredictably during this most recent periastron, spurring timely discussions. Coincidently, WR140 also passed through periastron in early 2009. It, too, is a intensively studied massive interacting binary. Comparison of its properties, as well as the properties of other massive stars, with those of Eta Car is very instructive. These well-known examples of evolved massive binary systems provide many clues as to the fate of the most massive stars. What are the effects of the interacting winds, of individual stellar rotation, and of the circumstellar material on what we see as hypernovae/supernovae? We hope to learn. Topics discussed in this 1.5 day Joint Discussion were: Car: the 2009.0 event: Monitoring campaigns in X-rays, optical, radio, interferometry WR140 and HD5980: similarities and differences to Car LBVs and Eta Carinae: What is the relationship? Massive binary systems, wind interactions and 3-D modeling Shapes of the Homunculus & Little Homunculus: what do we learn about mass ejection? Massive stars: the connection to supernovae, hypernovae and gamma ray bursters Where do we go from here? (future directions) The Science Organizing Committee: Co-chairs: Augusto Damineli (Brazil) & Theodore R. Gull (USA). Members: D. John Hillier (USA), Gloria Koenigsberger (Mexico), Georges Meynet (Switzerland), Nidia Morrell (Chile), Atsuo T. Okazaki (Japan), Stanley P. Owocki (USA), Andy M.T. Pol- lock (Spain), Nathan Smith (USA), Christiaan L. Sterken (Belgium), Nicole St Louis (Canada), Karel A. van der Hucht (Netherlands), Roberto Viotti (Italy) and GerdWeigelt (Germany)

Detection of High Velocity Absorption Components in the He I Lines of Eta Carinae near the Time of Periastron

NASA Technical Reports Server (NTRS)

Richardson, Noel D.; St-Jean, Lucas; Gull, Theodore R.; Madura, Thomas; Hillier, D. John; Teodoro, Mairan; Moffat, Anthony; Corcoran, Michael; Damineli, Augusto

2014-01-01

We have obtained a total of 58 high spectral resolution (R90,000) spectra of the massive binary star eta Carinae since 2012 in an effort to continue our orbital and long-term echelle monitoring of this extreme binary (Richardson et al. 2010, AJ, 139, 1534) with the CHIRON spectrograph on the CTIO 1.5 m telescope (Tokovinin et al. 2013, PASP, 125, 1336) in the 45507500A region. We have increased our monitoring efforts and observation frequency as the periastron event of 2014 has approached. We note that there were multiple epochs this year where we observe unusual absorption components in the P Cygni troughs of the He I triplet lines. In particular, we note high velocity absorption components related to the following epochs for the following lines: He I 4713: HJD 2456754- 2456795 (velocity -450 to -560 kms) He I 5876: HJD 2456791- 2456819 (velocity -690 to -800 kms) He I 7065: HJD 2456791- 2456810 (velocity -665 to -730 kms) Figures: Note that red indicates a high-velocity component noted above. He I 4713: http:www.astro.umontreal.carichardson4713.png He I 5876: http:www.astro.umontreal.carichardson5876.png He I 7065: http:www.astro.umontreal.carichardson7065.png These absorptions are likely related to the wind-wind collision region and bow shock, as suggested by the high-velocity absorption observed by Groh et al. (2010, AA, 519, 9) in the He I 10830 Atransition. In these cases, we suspect that we look along an arm of the shock cone and that we will see a fast absorption change from the other collision region shortly after periastron. We suspect that this is related to the multiple-components of the He II 4686 line that was noted by Walter (ATel6334), and is confirmed in our data. Further, high spectral resolution data are highly encouraged,especially for resolving powers greater than 50,000.These observations were obtained with the CTIO 1.5 m telescope, operated by the SMARTS Consortium, and were obtained through both SMARTS and NOAO programs 2012A-0216,2012B-0194, and 2013b-0328). We thank Emily MacPherson (Yale) for her efforts in scheduling the observations that we have and will obtain in the coming weeks.

The interacting winds of Eta Carinae: Observed forbidden line changes and the Forbidden Blue(-Shifted) Crab

NASA Astrophysics Data System (ADS)

Gull, Theodore R.; Madura, Thomas; Corcoran, Michael F.; Teodoro, Mairan; Richardson, Noel; Hamaguchi, Kenji; Groh, Jose H.; Hillier, Desmond John; Damineli, Augusto; Weigelt, Gerd

2015-01-01

The massive binary, Eta Carinae (EC), produces such massive winds that strong forbidden line emission of singly- and doubly-ionized iron traces wind-wind interactions from the current cycle plus fossil interactions from one, two and three 5.54-year cycles ago.With an eccentricity of >0.9, the >90 solar mass primary (EC-A) and >30 solar mass secondary (EC-B) approach to within 1.5 AU during periastron and recede to nearly 30 AU across apastron. The wind-wind structures move outward driven by the 420 km/s primary wind interacting with the ~3000 km/s secondary wind yielding partially-accelerated compressed primary wind shells that are excited by mid-UV from EC-A and in limited lines of sight, FUV from EC-B.These structures are spectroscopically and spatially resolved by HST's Space Telescope Imaging Spectrograph. At critical binary phases, we have mapped the central 2'x2' region in the light of [Fe III] and [Fe II] with spatial resolution of 0.12' and velocity resolution of 40 km/s.1) The bulk of forbidden emission originates from the large cavity northwest of EC and is due to ionization of massive ejecta from the 1840s and 1890s eruptions. The brightest clumps are the Weigelt Blobs C and D, but there are additionally multiple, fainter emission clumps. Weigelt B appears to have faded.2) Three concentric, red-shifted [FeII] arcs expand at ~470 km/s excited by mid-UV of EC-A.3) The structure of primarily blue-shifted [Fe III] emission resembles a Maryland Blue Crab. The claws appear at the early stages of the high-excitation recovery from the periastron passage, expand at radial velocities exceeding the primary wind terminal velocity, 420 km/s and fade as the binary system approaches periastron with the primary wind enveloping the FUV radiation from EC-B.4) All [Fe III] emission faded by late June 2014 and disappeared by August 2, 2014, the beginning of periastron passage.Comparisons to HST/STIS observations between 1998 to 2004.3 indicate long-term fading of [Fe II]. Likewise, Na D emission has faded. 3D hydro/radiative models suggest a small decrease (< factor of 2) in primary mass loss rate to be the cause.

Using 3D dynamic models to reproduce X-ray properties of colliding wind binaries

NASA Astrophysics Data System (ADS)

Russell, Christopher Michael Post

Colliding wind binaries (CWBs) are unique laboratories for X-ray astrophysics. The two massive stars contained in these systems have powerful radiatively driven stellar winds, and the conversion of their kinetic energy to heat (up to 108 K) at the wind-wind collision region generates hard thermal X-rays (up to 10 keV). Rich data sets exist of several multi-year-period systems, as well as key observations of shorter period systems, and detailed models are required to disentangle the phase-locked emission and absorption processes in these systems. To interpret these X-ray light curves and spectra, this dissertation models the wind-wind interaction of CWBs using 3D smoothed particle hydrodynamics (SPH), and solves the 3D formal solution of radiative transfer to synthesize the model X-ray properties, allowing direct comparison with the colliding-wind X-ray spectra observed by, e.g., RXTE and XMM. The multi-year-period, highly eccentric CWBs we examine are eta Carinae and WR140. For the commonly inferred primary mass loss rate of ˜10 -3 Msun/yr, eta Carinae's 3D model reproduces quite well the 2-10 keV RXTE light curve, hardness ratio, and dynamic spectra in absolute units. This agreement includes the ˜3 month X-ray minimum associated with the 1998.0 and 2003.5 periastron passages, which we find to occur as the primary wind encroaches into the secondary wind's acceleration region. This modeling provides further evidence that the observer is mainly viewing the system through the secondary's shock cone, and suggests that periastron occurs ~1 month after the onset of the X-ray minimum. The model RXTE observables of WR140 match the data well in absolute units, although the decrease in model X-rays around periastron is less than observed. There is very good agreement between the observed XMM spectrum taken on the rise before periastron and the model. We also model two short-period CWBs, HD150136, which has a wind-star collision, and delta Orionis A, the closest eclipsing CWB. The asymmetry predicted in the unobserved portion of HD150136's orbit, and the line profile variations due to the cavity carved into the primary wind by the secondary in delta Orionis A, helped provide a basis for newly approved Chandra observations of both systems.

Comparison of a tube-holder (Rescuefix) versus tape-tying for minimizing double-lumen tube displacement during lateral positioning in thoracic surgery

PubMed Central

Byun, Sung Hye; Kang, Su Hwang; Kim, Jong Hae; Ryu, Taeha; Kim, Baek Jin; Jung, Jin Yong

2016-01-01

Abstract Background: Double-lumen endotracheal tubes (DLTs) are often displaced during change from the supine to the lateral decubitus position. The aim of this study was to determine whether Rescuefix, a recently developed tube-holder device, is more effective than the traditional tape-tying method for tube security during lateral positioning. Methods: Patients were randomly assigned to a Rescuefix (R) group (n = 22) or a tape (T) group (n = 22). After intubation with a left-sided DLT and adjustment of the appropriate DLT position using a fiberoptic bronchoscope, the DLT was fixed firmly at the side of the mouth by either Rescuefix or Durapore tape. “Tracheal depth” (from the tracheal carina to the elbow connector of the DLT) and “bronchial depth” (from the left bronchial carina to the elbow connector of the DLT) were measured in the supine position using the fiberoptic bronchoscope. After positional change, tracheal and bronchial depths were measured as described above. As the primary endpoint, displacement of the DLT during positional change was evaluated by obtaining the difference in depths measured when the patient was in the supine and lateral decubitus positions. In addition, after lateral positioning of the patient, any requirement for repositioning the DLT was recorded. Results: After lateral positioning, there were no significant differences in changes in tracheal and bronchial depths between the groups (tracheal depth 6.1 ± 4.4 mm [R group] and 9.1 ± 5.6 mm [T group], P = 0.058; bronchial depth 6.5 ± 4.4 mm [R group], and 8.5 ± 4.6 mm [T group], P = 0.132). Although the amount of change in tracheal and bronchial depths was not different between the groups, the need to reposition the DLT was significantly lower in the R group than in the T group (32% vs 68%, P = 0.016). Conclusion: This study demonstrated that use of Rescuefix did not reduce the amount of DLT displacement, but it did significantly lower the incidence of DLT repositioning compared with the tape-tying method. Therefore, Rescuefix appears to be an effective alternative to minimizing DLT displacement during lateral positioning in thoracic surgery. Trial registration: http://cris.nih.go.kr identifier: KCT0001949. PMID:27495093

TA 55 Reinvestment Project II Phase C Update Project Status May 23, 2017

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giordano, Anthony P.

The TA-55 Reinvestment Project (TRP) II Phase C is a critical infrastructure project focused on improving safety and reliability of the Los Alamos National Laboratory (LANL) TA-55 Complex. The Project recapitalizes and revitalizes aging and obsolete facility and safety systems providing a sustainable nuclear facility for National Security Missions.

Analysis of Factors Influencing Building Refurbishment Project Performance

NASA Astrophysics Data System (ADS)

Ishak, Nurfadzillah; Aswad Ibrahim, Fazdliel; Azizi Azizan, Muhammad

2018-03-01

Presently, the refurbishment approach becomes favourable as it creates opportunities to incorporate sustainable value with other building improvement. In this regard, this approach needs to be implemented due to the issues on overwhelming ratio of existing building to new construction, which also can contribute to the environmental problem. Refurbishment principles imply to minimize the environmental impact and upgrading the performance of an existing building to meet new requirements. In theoretically, building project's performance has a direct bearing on related to its potential for project success. However, in refurbishment building projects, the criteria for measure are become wider because the projects are a complex and multi-dimensional which encompassing many factors which reflect to the nature of works. Therefore, this impetus could be achieve by examine the direct empirical relationship between critical success factors (CSFs) and complexity factors (CFs) during managing the project in relation to delivering success on project performance. The research findings will be expected as the basis of future research in establish appropriate framework that provides information on managing refurbishment building projects and enhancing the project management competency for a better-built environment.

40 CFR 35.1650-6 - Reports.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Reports. (a) States with Phase 1 projects shall submit semi-annual progress reports (original and one copy... in the next six months. (b) Phase 2. States with Phase 2 projects shall submit progress reports... Phase 2 project progress reports shall be determined by the size and complexity of the project, and...

40 CFR 35.1650-6 - Reports.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Reports. (a) States with Phase 1 projects shall submit semi-annual progress reports (original and one copy... in the next six months. (b) Phase 2. States with Phase 2 projects shall submit progress reports... Phase 2 project progress reports shall be determined by the size and complexity of the project, and...

Perry Pinyon Pines Protection Project

Treesearch

Daniel McCarthy

2012-01-01

Fuel reduction treatments around pinyon pine trees began as a simple project but ended in something more complex, enjoyable, and rewarding. The project eventually led to pinyon species (Pinus monophylla and P. quadrifolia) reforestation efforts, something that has been tried in the past with disappointing results. The Perry Pinyon Pines Protection Project and current...

Some thoughts on the management of large, complex international space ventures

NASA Technical Reports Server (NTRS)

Lee, T. J.; Kutzer, Ants; Schneider, W. C.

1992-01-01

Management issues relevant to the development and deployment of large international space ventures are discussed with particular attention given to previous experience. Management approaches utilized in the past are labeled as either simple or complex, and signs of efficient management are examined. Simple approaches include those in which experiments and subsystems are developed for integration into spacecraft, and the Apollo-Soyuz Test Project is given as an example of a simple multinational approach. Complex approaches include those for ESA's Spacelab Project and the Space Station Freedom in which functional interfaces cross agency and political boundaries. It is concluded that individual elements of space programs should be managed by individual participating agencies, and overall configuration control is coordinated by level with a program director acting to manage overall objectives and project interfaces.

How Robust Is Your Project? From Local Failures to Global Catastrophes: A Complex Networks Approach to Project Systemic Risk.

PubMed

Ellinas, Christos; Allan, Neil; Durugbo, Christopher; Johansson, Anders

2015-01-01

Current societal requirements necessitate the effective delivery of complex projects that can do more while using less. Yet, recent large-scale project failures suggest that our ability to successfully deliver them is still at its infancy. Such failures can be seen to arise through various failure mechanisms; this work focuses on one such mechanism. Specifically, it examines the likelihood of a project sustaining a large-scale catastrophe, as triggered by single task failure and delivered via a cascading process. To do so, an analytical model was developed and tested on an empirical dataset by the means of numerical simulation. This paper makes three main contributions. First, it provides a methodology to identify the tasks most capable of impacting a project. In doing so, it is noted that a significant number of tasks induce no cascades, while a handful are capable of triggering surprisingly large ones. Secondly, it illustrates that crude task characteristics cannot aid in identifying them, highlighting the complexity of the underlying process and the utility of this approach. Thirdly, it draws parallels with systems encountered within the natural sciences by noting the emergence of self-organised criticality, commonly found within natural systems. These findings strengthen the need to account for structural intricacies of a project's underlying task precedence structure as they can provide the conditions upon which large-scale catastrophes materialise.

Software Transition Project Retrospectives and the Application of SEL Effort Estimation Model and Boehm's COCOMO to Complex Software Transition Projects

NASA Technical Reports Server (NTRS)

McNeill, Justin

1995-01-01

The Multimission Image Processing Subsystem (MIPS) at the Jet Propulsion Laboratory (JPL) has managed transitions of application software sets from one operating system and hardware platform to multiple operating systems and hardware platforms. As a part of these transitions, cost estimates were generated from the personal experience of in-house developers and managers to calculate the total effort required for such projects. Productivity measures have been collected for two such transitions, one very large and the other relatively small in terms of source lines of code. These estimates used a cost estimation model similar to the Software Engineering Laboratory (SEL) Effort Estimation Model. Experience in transitioning software within JPL MIPS have uncovered a high incidence of interface complexity. Interfaces, both internal and external to individual software applications, have contributed to software transition project complexity, and thus to scheduling difficulties and larger than anticipated design work on software to be ported.

2D and 3D X-ray phase retrieval of multi-material objects using a single defocus distance.

PubMed

Beltran, M A; Paganin, D M; Uesugi, K; Kitchen, M J

2010-03-29

A method of tomographic phase retrieval is developed for multi-material objects whose components each has a distinct complex refractive index. The phase-retrieval algorithm, based on the Transport-of-Intensity equation, utilizes propagation-based X-ray phase contrast images acquired at a single defocus distance for each tomographic projection. The method requires a priori knowledge of the complex refractive index for each material present in the sample, together with the total projected thickness of the object at each orientation. The requirement of only a single defocus distance per projection simplifies the experimental setup and imposes no additional dose compared to conventional tomography. The algorithm was implemented using phase contrast data acquired at the SPring-8 Synchrotron facility in Japan. The three-dimensional (3D) complex refractive index distribution of a multi-material test object was quantitatively reconstructed using a single X-ray phase-contrast image per projection. The technique is robust in the presence of noise, compared to conventional absorption based tomography.

Strategies for the structural analysis of multi-protein complexes: lessons from the 3D-Repertoire project.

PubMed

Collinet, B; Friberg, A; Brooks, M A; van den Elzen, T; Henriot, V; Dziembowski, A; Graille, M; Durand, D; Leulliot, N; Saint André, C; Lazar, N; Sattler, M; Séraphin, B; van Tilbeurgh, H

2011-08-01

Structural studies of multi-protein complexes, whether by X-ray diffraction, scattering, NMR spectroscopy or electron microscopy, require stringent quality control of the component samples. The inability to produce 'keystone' subunits in a soluble and correctly folded form is a serious impediment to the reconstitution of the complexes. Co-expression of the components offers a valuable alternative to the expression of single proteins as a route to obtain sufficient amounts of the sample of interest. Even in cases where milligram-scale quantities of purified complex of interest become available, there is still no guarantee that good quality crystals can be obtained. At this step, protein engineering of one or more components of the complex is frequently required to improve solubility, yield or the ability to crystallize the sample. Subsequent characterization of these constructs may be performed by solution techniques such as Small Angle X-ray Scattering and Nuclear Magnetic Resonance to identify 'well behaved' complexes. Herein, we recount our experiences gained at protein production and complex assembly during the European 3D Repertoire project (3DR). The goal of this consortium was to obtain structural information on multi-protein complexes from yeast by combining crystallography, electron microscopy, NMR and in silico modeling methods. We present here representative set case studies of complexes that were produced and analyzed within the 3DR project. Our experience provides useful insight into strategies that are more generally applicable for structural analysis of protein complexes. Copyright © 2011 Elsevier Inc. All rights reserved.

Molecular gas associated with IRAS 10361-5830

NASA Astrophysics Data System (ADS)

Vazzano, M. M.; Cappa, C. E.; Vasquez, J.; Rubio, M.; Romero, G. A.

2014-10-01

Aims: We analyze the distribution of the molecular gas and dust in the molecular clump linked to IRAS 10361-5830, located in the environs of the bubble-shaped Hii region Gum 31 in the Carina region, with the aim of determining the main parameters of the associated material and of investigating the evolutionary state of the young stellar objects identified there. Methods: Using the APEX telescope, we mapped the molecular emission in the J = 3-2 transition of three CO isotopologues, 12CO, 13CO and C18O, over a 1.´5 × 1.´5 region around the IRAS position. We also observed the high-density tracers CS and HCO+ toward the source. The cold- dust distribution was analyzed using submillimeter continuum data at 870 μm obtained with the APEX telescope. Complementary IR and radio data at different wavelengths were used to complete the study of the interstellar medium. Results: The molecular gas distribution reveals a cavity and a shell-like structure of ~0.32 pc in radius centered at the position of the IRAS source, with some young stellar objects projected onto the cavity. The total molecular mass in the shell and the mean H2volume density are ~40 M⊙ and ~(1-2) × 103 cm-3. The cold-dust counterpart of the molecular shell has been detected in the far-IR at 870 μm and in Herschel data at 350 μm. Weak extended emission at 24 μm from warm dust is projected onto the cavity, as well as weak radio continuum emission. Conclusions: A comparison of the distribution of cold and warm dust, and molecular and ionized gas allows us to conclude that a compact Hii region has developed in the molecular clump, indicating that this is an area of recent massive star formation. Probable exciting sources capable of creating the compact Hii region are investigated. The 2MASS source 10380461-5846233 (MSX G286.3773-00.2563) seems to be responsible for the formation of the Hii region. FITS files with datacubes corresponding to 12CO, 13CO, C180 maps 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/570/A109

Complete Characterization of trans- Co(en)2Cl2[3 Fe(ox)3[.4-1/2H2O: An Extended Undergraduate Project Involving an Unknown Metal Complex.

ERIC Educational Resources Information Center

Bull, Graham S.; Searle, Graeme H.

1986-01-01

Discusses the need for student experiments involving the complete characterization of "unknown" inorganic compounds. Describes a project employing a complex metal compound. The compound contains six different components in both inert and labile complexions. Outlines the complete procedure and the preparation of the unknown compound. (TW)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Celia, Michael A.

This report documents the accomplishments achieved during the project titled “Model complexity and choice of model approaches for practical simulations of CO 2 injection,migration, leakage and long-term fate” funded by the US Department of Energy, Office of Fossil Energy. The objective of the project was to investigate modeling approaches of various levels of complexity relevant to geologic carbon storage (GCS) modeling with the goal to establish guidelines on choice of modeling approach.

The Daily Readiness Huddle: a process to rapidly identify issues and foster improvement through problem-solving accountability.

PubMed

Donnelly, Lane F; Cherian, Shirley S; Chua, Kimberly B; Thankachan, Sam; Millecker, Laura A; Koroll, Alex G; Bisset, George S

2017-01-01

Because of the increasing complexities of providing imaging for pediatric health care services, a more reliable process to manage the daily delivery of care is necessary. Objective We describe our Daily Readiness Huddle and the effects of the process on problem identification and improvement. Our Daily Readiness Huddle has four elements: metrics review, clinical volume review, daily readiness assessment, and problem accountability. It is attended by radiologists, directors, managers, front-line staff with concerns, representatives from support services (information technology [IT] and biomedical engineering [biomed]), and representatives who join the meeting in a virtual format from off-site locations. Data are visually displayed on erasable whiteboards. The daily readiness assessment uses queues to determine whether anyone has concerns or outlier data in regard to S-MESA (Safety, Methods, Equipment, Supplies or Associates). Through this assessment, problems are identified and categorized as quick hits (will be resolved in 24-48 h, not requiring project management) and complex issues. Complex issues are assigned an owner, quality coach and report-back date. Additionally, projects are defined as improvements that are often strategic, are anticipated to take more than 60 days, and do not necessarily arise out of identified issues during the Daily Readiness Huddle. We tracked and calculated the mean, median and range of days to resolution and completion for complex issues and for projects during the first full year of implementing this process. During the first 12 months, 91 complex issues were identified and resolved, 11 projects were in progress and 33 completed, with 23 other projects active or in planning. Time to resolution of complex issues (in days) was mean 37.5, median 34.0, and range 1-105. For projects, time to completion (in days) was mean 86.0, median 84.0, and range 5-280. The Daily Readiness Huddle process has given us a framework to rapidly identify issues, bring accountability to problem-solving, and foster improvement. It has also had a positive effect on team-building and coordination.

Prioritization of forest restoration projects: Tradeoffs between wildfire protection, ecological restoration and economic objectives

Treesearch

Kevin C. Vogler; Alan A. Ager; Michelle A. Day; Michael Jennings; John D. Bailey

2015-01-01

The implementation of US federal forest restoration programs on national forests is a complex process that requires balancing diverse socioecological goals with project economics. Despite both the large geographic scope and substantial investments in restoration projects, a quantitative decision support framework to locate optimal project areas and examine...

Getting Girls EX.I.T.E.D about Project Management

ERIC Educational Resources Information Center

Norstrom, Bjorn; Smith, Carol; Haglund, Annika

2008-01-01

Students are asked to complete projects every day--from a simple PowerPoint presentation to college applications and financial aid forms. Students are expected to complete these projects to certain standards. However, students are often not provided with the tools and skills needed to successfully manage projects, especially complex ones. As…

Developing integrated parametric planning models for budgeting and managing complex projects

NASA Technical Reports Server (NTRS)

Etnyre, Vance A.; Black, Ken U.

1988-01-01

The applicability of integrated parametric models for the budgeting and management of complex projects is investigated. Methods for building a very flexible, interactive prototype for a project planning system, and software resources available for this purpose, are discussed and evaluated. The prototype is required to be sensitive to changing objectives, changing target dates, changing costs relationships, and changing budget constraints. To achieve the integration of costs and project and task durations, parametric cost functions are defined by a process of trapezoidal segmentation, where the total cost for the project is the sum of the various project cost segments, and each project cost segment is the integral of a linearly segmented cost loading function over a specific interval. The cost can thus be expressed algebraically. The prototype was designed using Lotus-123 as the primary software tool. This prototype implements a methodology for interactive project scheduling that provides a model of a system that meets most of the goals for the first phase of the study and some of the goals for the second phase.

Have we been successful? Monitoring horizontal forest complexity for forest restoration projects

Treesearch

Yvette L. Dickinson; Kristen A. Pelz; Emma Giles; Josh Howie

2016-01-01

Forest management today often seeks to restore ecological integrity and enhance human well-being by increasing forest complexity, resilience, and functionality. However, effective and financially expedient monitoring of forest complexity is challenging. In this study, we developed a practical and inexpensive technique to measure horizontal forest complexity....

A Complex Systems Perspective of Risk Mitigation and Modeling in Development and Acquisition Programs

DTIC Science & Technology

2016-04-30

also that we have started building in a domain where structural patterns matter, especially for large projects. Complex Systems Complexity has been...through minimalistic thinking and parsimony” and perceived elegance, which “hides systemic or organizational complexity from the user.” If the system

Transportation Infrastructure: Progress on and Challenges to Central Artery/Tunnel Project's Cost and Financing

DOT National Transportation Integrated Search

1997-07-01

The Central Artery/Tunnel project in Boston, Massachusetts--one of the largest, most complex, and most expensive highway construction projects ever undertaken--is well under way, with contracts worth nearly $8 billion either completed or awarded. Con...

Understanding the Effects of Team Cognition Associated with Complex Engineering Tasks: Dynamics of Shared Mental Models, Task-SMM, and Team-SMM

ERIC Educational Resources Information Center

Lee, Miyoung; Johnson, Tristan E.

2008-01-01

This study investigates how shared mental models (SMMs) change over time in teams of students in a manufacturing engineering course. A complex ill-structured project was given to each team. The objective of the team project was to analyze, test, and propose ways to improve their given manufactured product. Shared mental models were measured in…

Micronized coal-fired retrofit system for SO{sub x} reduction Krakow clean fossil fuels and energy efficiency program. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

This report describes results of a technical, financial and environmental assessment study for a project, which would have included a new TCS micronized coal-fired heating plant for the Produkcja I Hodowla Roslin Ogrodniczych (PHRO) Greenhouse Complex; Krzeszowice, Poland. Project site is about 20 miles west of Krakow, Poland. During the project study period, PHRO utilized 14 heavy oil-fired boilers to produce heat for its greenhouse facilities and also home heating to several adjacent apartment housing complexes. The boilers burn a high-sulfur content heavy crude oil, called mazute, The project study was conducted during a period extended from March 1996 throughmore » February 1997. For size orientation, the PHRO Greenhouse complex grows a variety of vegetables and flowers for the Southern Poland marketplace. The greenhouse area under glass is very large and equivalent to approximately 50 football fields, The new micronized coal fired boiler would have: (1) provided a significant portion of the heat for PHRO and a portion of the adjacent apartment housing complexes, (2) dramatically reduced sulfur dioxide air pollution emissions, while satisfying new Polish air regulations, and (3) provided attractive savings to PHRO, based on the quantity of displaced oil.« less

Project management for complex ground-based instruments: MEGARA plan

NASA Astrophysics Data System (ADS)

García-Vargas, María. Luisa; Pérez-Calpena, Ana; Gil de Paz, Armando; Gallego, Jesús; Carrasco, Esperanza; Cedazo, Raquel; Iglesias, Jorge

2014-08-01

The project management of complex instruments for ground-based large telescopes is a challenge itself. A good management is a clue for project success in terms of performance, schedule and budget. Being on time has become a strict requirement for two reasons: to assure the arrival at the telescope due to the pressure on demanding new instrumentation for this first world-class telescopes and to not fall in over-costs. The budget and cash-flow is not always the expected one and has to be properly handled from different administrative departments at the funding centers worldwide distributed. The complexity of the organizations, the technological and scientific return to the Consortium partners and the participation in the project of all kind of professional centers working in astronomical instrumentation: universities, research centers, small and large private companies, workshops and providers, etc. make the project management strategy, and the tools and procedures tuned to the project needs, crucial for success. MEGARA (Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía) is a facility instrument of the 10.4m GTC (La Palma, Spain) working at optical wavelengths that provides both Integral-Field Unit (IFU) and Multi-Object Spectrograph (MOS) capabilities at resolutions in the range R=6,000-20,000. The project is an initiative led by Universidad Complutense de Madrid (Spain) in collaboration with INAOE (Mexico), IAA-CSIC (Spain) and Universidad Politécnica de Madrid (Spain). MEGARA is being developed under contract with GRANTECAN.

Groundwater cleanup demonstrations at Complex 34, CCAS

NASA Technical Reports Server (NTRS)

2000-01-01

At Launch Complex 34, the Six-Phase Soil Heating site that is involved in a groundwater cleanup project can be seen. The project involves the Department of Defense, Environmental Protection Agency, Department of Energy and NASA. Concentrations of trichloroethylene solvent have been identified in the soil at the complex as a result of cleaning methods for rocket parts during the Apollo Program, which used the complex, in the 60s. The group formed the Interagency NDAPL Consortium (IDC) to study three contamination cleanup technologies: Six-Phase Soil Heating, Steam Injection and In Situ Oxidation with Potassium Permanganate. All three methods may offer a way to remove the contaminants in months instead of decades. In the background is the block house for the complex. KSC hosted a two-day conference that presented information and demonstrations of the three technologies being tested at the site.

Use of an Authentic, Industrially Situated Virtual Laboratory Project to Address Engineering Design and Scientific Inquiry in High Schools

ERIC Educational Resources Information Center

Gilbuena, Debra M.; Kirsch, F. Adam; Koretsky, Milo D.

2012-01-01

This paper is intended for engineering educators, high school curriculum designers, and high school teachers interested in integrating authentic, project-based learning experiences into their classes. These types of projects may appear complex, but have many advantages. We characterize the successful implementation of one such project, the…

Chapter 13 - Perspectives on LANDFIRE Prototype Project Accuracy Assessment

Treesearch

James Vogelmann; Zhiliang Zhu; Jay Kost; Brian Tolk; Donald Ohlen

2006-01-01

The purpose of this chapter is to provide a general overview of the many aspects of accuracy assessment pertinent to the Landscape Fire and Resource Management Planning Tools Prototype Project (LANDFIRE Prototype Project). The LANDFIRE Prototype formed a large and complex research and development project with many broad-scale data sets and products developed throughout...

36 CFR 800.14 - Federal agency program alternatives.

Code of Federal Regulations, 2010 CFR

2010-07-01

... program or the resolution of adverse effects from certain complex project situations or multiple... by the agreement. (3) Developing programmatic agreements for complex or multiple undertakings. Consultation to develop a programmatic agreement for dealing with the potential adverse effects of complex...

The Feed Materials Program of the Manhattan Project: A Foundational Component of the Nuclear Weapons Complex

NASA Astrophysics Data System (ADS)

Reed, B. Cameron

2014-12-01

The feed materials program of the Manhattan Project was responsible for procuring uranium-bearing ores and materials and processing them into forms suitable for use as source materials for the Project's uranium-enrichment factories and plutonium-producing reactors. This aspect of the Manhattan Project has tended to be overlooked in comparison with the Project's more dramatic accomplishments, but was absolutely vital to the success of those endeavors: without appropriate raw materials and the means to process them, nuclear weapons and much of the subsequent cold war would never have come to pass. Drawing from information available in Manhattan Engineer District Documents, this paper examines the sources and processing of uranium-bearing materials used in making the first nuclear weapons and how the feed materials program became a central foundational component of the postwar nuclear weapons complex.

A recent Cleanroom success story: The Redwing project

NASA Technical Reports Server (NTRS)

Hausler, Philip A.

1992-01-01

Redwing is the largest completed Cleanroom software engineering project in IBM, both in terms of lines of code and project staffing. The product provides a decision-support facility that utilizes artificial intelligence (AI) technology for predicting and preventing complex operating problems in an MVS environment. The project used the Cleanroom process for development and realized a defect rate of 2.6 errors/KLOC, measured from first execution. This represents the total amount of errors that were found in testing and installation at three field test sites. Development productivity was 486 LOC/PM, which included all development labor expended in design specification through completion of incremental testing. In short, the Redwing team produced a complex systems software product with an extraordinarily low error rate, while maintaining high productivity. All of this was accomplished by a project team using Cleanroom for the first time. An 'introductory implementation' of Cleanroom was defined and used on Redwing. This paper describes the quality and productivity results, the Redwing project, and how Cleanroom was implemented.

Understanding Complex Adaptive Systems by Playing Games

ERIC Educational Resources Information Center

van Bilsen, Arthur; Bekebrede, Geertje; Mayer, Igor

2010-01-01

While educators teach their students about decision making in complex environments, managers have to deal with the complexity of large projects on a daily basis. To make better decisions it is assumed, that the latter would benefit from better understanding of complex phenomena, as do students as the professionals of the future. The goal of this…

Molecular Cloning Designer Simulator (MCDS): All-in-one molecular cloning and genetic engineering design, simulation and management software for complex synthetic biology and metabolic engineering projects.

PubMed

Shi, Zhenyu; Vickers, Claudia E

2016-12-01

Molecular Cloning Designer Simulator (MCDS) is a powerful new all-in-one cloning and genetic engineering design, simulation and management software platform developed for complex synthetic biology and metabolic engineering projects. In addition to standard functions, it has a number of features that are either unique, or are not found in combination in any one software package: (1) it has a novel interactive flow-chart user interface for complex multi-step processes, allowing an integrated overview of the whole project; (2) it can perform a user-defined workflow of cloning steps in a single execution of the software; (3) it can handle multiple types of genetic recombineering, a technique that is rapidly replacing classical cloning for many applications; (4) it includes experimental information to conveniently guide wet lab work; and (5) it can store results and comments to allow the tracking and management of the whole project in one platform. MCDS is freely available from https://mcds.codeplex.com.

Experiences in managing the Prometheus Project

NASA Technical Reports Server (NTRS)

Lehman, David H.; Clark, Karla B.; Cook, Beverly A.; Gavit, Sarah A.; Kayali, Sammy A.; McKinney, John C.; Milkovich, David C.; Reh, Kim R.; Taylor, Randall L.; Casani, John R.

2006-01-01

Congress authorized NASA?s Prometheus Project in February 2003, with the first Prometheus mission slated to explore the icy moons of Jupiter. The Project had two major objectives: (1) to develop a nuclear reactor that would provide unprecedented levels of power and show that it could be processed safely and operated reliably in space for long-duration, deep-space exploration and (2) to explore the three icy moons of Jupiter - Callisto, Ganymede, and Europa - and return science data that would meet the scientific goals as set forth in the Decadal Survey Report of the National Academy of Sciences. Early in Project planning, it was determined that the development of the Prometheus nuclear powered Spaceship would be complex and require the intellectual knowledge residing at numerous organizations across the country. In addition, because of the complex nature of the Project and the multiple partners, approaches beyond those successfully used to manage a typical JPL project would be needed. This paper1 will describe the key experiences in managing Prometheus that should prove useful for future projects of similar scope and magnitude

Cosmic Explosions (Optical)

NASA Astrophysics Data System (ADS)

Kulkarni, S. R.

2012-04-01

One of the principal motivations of wide-field and synoptic surveys is the search for, and study of, transients. By transients I mean those sources that arise from the background, are detectable for some time, and then fade away to oblivion. Transients in distant galaxies need to be sufficiently bright as to be detectable, and in almost all cases those transients are catastrophic events, marking the deaths of stars. Exemplars include supernovæ and gamma-ray bursts. In our own Galaxy, the transients are strongly variable stars, and in almost all cases are at best cataclysmic rather than catastrophic. Exemplars include flares from M dwarfs, novæ of all sorts (dwarf novæ, recurrent novæ, classical novæ, X-ray novæ) and instabilities in the surface layers of stars such as S Dor or η Carina. In the nearby Universe (say out to the Virgo cluster) we have sufficient sensitivity to see novæ. In 1 I review the history of transients (which is intimately related to the advent of wide-field telescopic imaging). In 2 I summarize wide-field imaging projects, and I then review the motivations that led to the design of the Palomar Transient Factory (PTF). Next comes a summary of the astronomical returns from PTF (3), and that is followed by lessons that I have learnt from PTF (4). I conclude that, during this decade, the study of optical transients will continue to flourish (and may even accelerate as surveys at other wavelengths-notably radio, UV and X-ray-come on-line). Furthermore, it is highly likely that there will be a proliferation of highly-specialized searches for transients. Those searches may well remain active even in the era of LSST (5). I end the article by discussing the importance of follow-up telescopes for transient object studies-a topical issue, given the Portfolio Review that is being undertaken in the US.