42 research outputs found

    Chemical Abundances Of Open Clusters From High-Resolution Infrared Spectra. I. NGC 6940

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    We present near-infrared spectroscopic analysis of 12 red giant members of the Galactic open cluster NGC 6940. High-resolution (R\simeq45000) and high signal-to-noise ratio (S/N > 100) near-infrared H and K band spectra were gathered with the Immersion Grating Infrared Spectrograph (IGRINS) on the 2.7m Smith Telescope at McDonald Observatory. We obtained abundances of H-burning (C, N, O), α{\alpha} (Mg, Si, S, Ca), light odd-Z (Na, Al, P, K), Fe-group (Sc, Ti, Cr, Fe, Co, Ni) and neutron-capture (Ce, Nd, Yb) elements. We report the abundances of S, P, K, Ce, and Yb in NGC 6940 for the first time. Many OH and CN features in the H band were used to obtain O and N abundances. C abundances were measured from four different features: CO molecular lines in the K band, high excitation C I lines present in both near-infrared and optical, CH and C2C_2 bands in the optical region. We have also determined 12C/13C^{12}C/^{13}C ratios from the R-branch band heads of first overtone (2-0) and (3-1) 12CO^{12}CO (2-0) 13CO^{13}CO lines near 23440 \overset{\lower.5em\circ}{\mathrm{A}} and (3-1) 13CO^{13}CO lines at about 23730 \overset{\lower.5em\circ}{\mathrm{A}}. We have also investigated the HF feature at 23358.3 \overset{\lower.5em\circ}{\mathrm{A}}, finding solar fluorine abundances without ruling out a slight enhancement. For some elements (such as the α{\alpha} group), IGRINS data yield more internally self-consistent abundances. We also revisited the CMD of NGC 6940 by determining the most probable cluster members using Gaia DR2. Finally, we applied Victoria isochrones and MESA models in order to refine our estimates of the evolutionary stages of our targets.Comment: 16 pages, 10 figure

    Gaia-IGRINS synergy: Orbits of Newly Identified Milky Way Star Clusters

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    The recent exquisite Gaia astrometric, photometric, and radial velocity (RV) measurements resulted in a substantial advancement for the determination of the orbits for old star clusters, including the oldest Milky Way globular clusters (MW GCs). The main goal of this paper is to use the Gaia DR3 and the VVVX measurements to obtain the orbits for nearly a dozen new Galactic GC candidates that have been poorly studied or previously unexplored. We use the Gaia DR3 and VVVX databases to identify bonafide members of the Galactic GC candidates: VVV-CL160, Patchick122, Patchick125, Patchick126, Kronberger99, Kronberger119, Kronberger143, ESO92-18, ESO93-08, Gaia2, and Ferrero54. The relevant mean cluster physical parameters are derived (distances, Galactic coordinates, proper motions, RVs). We measure accurate mean RVs for the GCs VVV-CL160 and Patchick126, using observations acquired at the Gemini-South telescope with the IGRINS high-resolution spectrograph. Orbits for each cluster are then computed using the GravPot16 model, assuming typical Galactic bar pattern speeds. We reconstruct the orbits for these clusters for the first time. These include star clusters with retrograde and prograde orbital motions, both in the Galactic bulge and disk. Orbital properties, such as the mean time-variations of perigalactic and apogalactic distances, eccentricities, vertical excursions from the Galactic plane, and Z-components of the angular momentum are obtained for our sample. Our main conclusion is that, based on the orbital parameters, Patchick125 and Patchick126 are genuine MW bulge/halo GCs; Ferrero54, Gaia2 and Patchick122 are MW disk GCs. The orbits of Kronberger99, Kronberger119, Kronberger143, ESO92-18, and ESO93-08 are more consistent with old MW disk open clusters. VVV-CL160 falls very close to the Galactic centre, but reaches larger distances beyond the Sun, thus its origin is still unclear.Comment: 21 pages, 8 figures. Accepted for publication in A&

    Akut bronşiolit tedavisinde iki farkli bronkodilatörün etkinli?inin karşilaştirilmasi

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    Bronchiolitis is an acute inflammatory respiratory illness of children less than two years of age. Therapies used in the treatment of bronchiolitis include adequate hydration, supplementary oxygen, bronchodilators, ribavirin, corticosteroids, immune globulin, interferon alfa and vitamin A. We enrolled 34 infants who were hospitalized for bronchiolitis to evaluate the efficacy of two different bronchodilators. Thirty-four infants under two years of age were randomized to receive either nebulized salbutamol (Group I) or nebulized ipratropium bromide (Group II). Clinical severity was scored on admission and 12-hour intervals after the start of nebulization. The symptom score evaluated five items: respiratory rate, presence of wheezing, presence of retraction, presence of nasal flaring, and general appearance. No difference was observed between the two groups in the clinical improvement on hospital admission and at the 12th, 24th, 36th and 48th hours during treatment. The mean duration of hospital stay was not significantly different between the two groups. When the groups were evaluated independently, there was a significant difference in scores before treatment and at the 48th hour of nebulization. We conclude that, ipratropium bromide and salbutamol are equally effective in the clinical recovery of bronchiolitis. Because of the side effects of salbutamol, ipratropium bromide may be primarily preferred as a bronchodilator

    Neurofibromatosis type 1, gastrointestinal stromal tumor, leiomyosarcoma and osteosarcoma: Four cases of rare tumors and a review of the literature

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    PubMedID: 23218951Background: Neurofibromatosis type 1 (NF1) is a genetic syndrome that predisposes patients to benign and malignant tumor development. Patients with NF1 develop multiple neurofibromas that can transform into aggressive sarcomas known as malignant peripheral nerve sheath tumors. In contrast, malignant tumors unrelated to the nervous system rarely coexist with neurofibromatosis. The aim of this article was to present four cases of adult NF1 patients with malignant tumors unrelated to the nervous system as well as a bibliographic search for papers describing these tumors in NF1, focusing on osteosarcomas, gastrointestinal stromal tumors (GISTs), leiomyosarcomas and somatostatinomas and their genetic alterations in NF1. Methods: Search engines such as PubMed and MEDLINE were browsed for English-language articles since 1989 using a list of keywords, as well as references from review articles. Search terms were NF1, osteosarcoma, leiomyosarcoma, somatostatinoma and GIST. Data were summarized in a table at the end of the Results section. Results: In our four NF1 cases, there were one osteosarcoma, one leiomyosarcoma, one somatostatinoma and GIST and one GIST. NF1 was diagnosed at an adult age when these patients were admitted to our oncology department. The results generated by the literature search yielded 75 articles about NF and GIST. We summarized the clinical characteristics of 43 patients with NF1 and somatostatinoma. Forty-five articles involving NF and osteosarcoma were found, and of these, 26 involved NF1; from these articles, we identified the clinical features of 8 patients. Twenty-five articles were found concerning NF1 and leiomyosarcoma, and of those, we summarized the clinical features of 15 patients. Conclusions: Here we reviewed somatostatinomas, GISTs, osteosarcomas and leiomyosarcomas occurring in NF1 patients. Patients with NF1 who present with gastrointestinal symptoms, should be carefully evaluated carefully with a high index of suspicion of potential GISTs, periampullary and duodenal tumors. Patients with pathological fractures or bone pain along with NF1 should be carefully screened for malignant bone tumors. Patients with NF1 can develop leiomyosarcoma less frequently than other malignancies, but the association of uterine leiomyoma and NF1 may not be fortuitous. Somatic mutations were defined for frequent tumors, including neurogenic tumors and GISTs but not for sarcomas due to the complexity of underlying mechanisms of the disease and tumorigenesis. Based on the findings; all NF patients can develop malignant tumors, including the less frequently observed ones. Therefore, we recommend that new genetic studies should be performed for rare malignancies in cases of NF1. © 2012 Elsevier Ireland Ltd
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