618 research outputs found

    Molecular line and continuum study of the W40 cloud

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    The dense cloud associated with W40, one of the nearby H II regions, has been studied in millimeter-wave molecular lines and in 1.2 mm continuum. Besides, 1280 MHz and 610 MHz interferometric observations have been done. The cloud has complex morphological and kinematical structure, including a clumpy dust ring and an extended dense core. The ring is probably formed by the "collect and collapse" process due to the expansion of neighboring H II region. Nine dust clumps in the ring have been deconvolved. Their sizes, masses and peak hydrogen column densities are: 0.020.11\sim 0.02-0.11 pc, 0.48.1M\sim 0.4-8.1 M_{\odot} and (2.511)×1022\sim (2.5-11)\times 10^{22} cm2^{-2}, respectively. Molecular lines are observed at two different velocities and have different spatial distributions implying strong chemical differentiation over the region. The CS abundance is enhanced towards the eastern dust clump 2, while the NH3_3, N2_2H+^+, and H13^{13}CO+^+ abundances are enhanced towards the western clumps. HCN and HCO+^+ do not correlate with the dust probably tracing the surrounding gas. Number densities derived towards selected positions are: (0.33.2)×106\sim (0.3-3.2)\times 10^6 cm3^{-3}. Two western clumps have kinetic temperatures 21 K and 16 K and are close to virial equilibrium. The eastern clumps 2 and 3 are more massive, have higher extent of turbulence and are probably more evolved than the western ones. They show asymmetric CS(2--1) line profiles due to infalling motions which is confirmed by model calculations. An interaction between ionized and neutral material is taking place in the vicinity of the eastern branch of the ring and probably trigger star formation.Comment: 16 pages, 6 figure

    Multi-frequency Studies of Massive Cores with Complex Spatial and Kinematic Structures

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    Five regions of massive star formation have been observed in various molecular lines in the frequency range 8589\sim 85-89 GHz. The studied regions possess dense cores, which host young stellar objects. The physical parameters of the cores are estimated, including kinetic temperatures (2040\sim 20-40 K), sizes of the emitting regions (0.10.6\sim 0.1-0.6 pc), and virial masses (40500M\sim 40-500 M_{\odot}). Column densities and abundances of various molecules are calculated in the local thermodynamical equilibrium approximation. The core in 99.982+4.17, associated with the weakest IRAS source, is characterized by reduced molecular abundances. Molecular line widths decrease with increasing distance from the core centers (bb). For b\ga 0.1~pc, the dependences ΔV(b)\Delta V(b) are close to power laws (bp\propto b^{-p}), where pp varies from 0.2\sim 0.2 to 0.5\sim 0.5, depending on the object. In four cores, the asymmetries of the optically thick HCN(1--0) and HCO+^+(1--0) lines indicate systematic motions along the line of sight: collapse in two cores and expansion in two others. Approximate estimates of the accretion rates in the collapsing cores indicate that the forming stars have masses exceeding the solar mass.Comment: 18 pages, 7 figures, 6 table

    Cortical interstitial cell interactions induce sensitivity of hydronephrotic kidney to bradykinin

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    Cortical interstitial cell interactions induce sensitivity of hydronephrotic kidney to bradykinin. The mechanism of the increased prostaglandin production and induction of sensitivity to bradykinin by the cortex of the hydronephrotic rabbit kidney was investigated using tissue culture techniques. Cortical interstitial cells from normal, unilaterally hydronephrotic and contralateral kidneys were grown in tissue culture. Cells derived from hydronephrotic kidneys, but not normal or contralateral, increased PGE2 production when incubated with bradykinin. Of the two cell types, fibroblasts and macrophages, grown from hydronephrotic expiants, neither increased prostaglandin production when grown alone in tissue culture. Recombining the two cell types restored bradykinin responsiveness. Bradykinin responsiveness could be induced in either normal or contralateral cell cultures when macrophages from the hydronephrotic kidney were added to cultures of cells from normal or contralateral cortex. The data indicate unique characteristics of hydronephrotic macrophages are involved in the induction of bradykinin responsiveness in the cortex of the ureter-ligated kidney

    Extended Star Formation and Molecular Gas in the Tidal Arms near NGC3077

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    We report the detection of ongoing star formation in the prominent tidal arms near NGC 3077 (member of the M 81 triplet). In total, 36 faint compact HII regions were identified, covering an area of ~4x6 kpc^2. Most of the HII regions are found at HI column densities above 1x10^21 cm^-2 (on scales of 200 pc), well within the range of threshold columns measured in normal galaxies. The HII luminosity function resembles the ones derived for other low-mass dwarf galaxies in the same group; we derive a total star formation rate of 2.6x10^-3 M_sun/yr in the tidal feature. We also present new high-resolution imaging of the molecular gas distribution in the tidal arm using CO observations obtained with the OVRO interferometer. We recover about one sixth of the CO flux (or M_H2~2x10^6 M_sun, assuming a Galactic conversion factor) originally detected in the IRAM 30m single dish observations, indicating the presence of a diffuse molecular gas component in the tidal arm. The brightest CO peak in the interferometer map (comprising half of the detected CO flux) is coincident with one of the brightest HII regions in the feature. Assuming a constant star formation rate since the creation of the tidal feature (presumably ~3x10^8 years ago), a total mass of ~7x10^5 M_sun has been transformed from gas into stars. Over this period, the star formation in the tidal arm has resulted in an additional enrichment of Delta(Z)>0.002. The reservoir of atomic and molecular gas in the tidal arm is ~3x10^8 M_sun, allowing star formation to continue at its present rate for a Hubble time. Such wide-spread, low-level star formation would be difficult to image around more distant galaxies but may be detectable through intervening absorption in quasar spectra.Comment: Accepted for publication in the Astronomical Journa

    The benefits of reducing anxiety in a Podiatric Surgical Unit in the UK with Midazolam

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    La sedación se ha utilizado con frecuencia junto a muchas de las intervenciones quirúrgicas realizadas bajo anestésicos locales (AL) . En la cirugía podológica, hay una escasez de literatura sobre los efectos de la sedación ante las señales fisiológicas de los pacientes. La anestesia general se practica con mayor frecuencia que la sedación con anestésico local en podología . El objetivo de esta estudioa fue analizar la presión arterial ( PA) y frecuencia cardiaca (FC ) en contra de la administración de midazolam. Se realizó una evaluación retrospectiva de las registros de sedación antes de los procedimientos de podología llevadas a cabo durante los años 2008/2009 . La PA ( sistólica / diastólica mm de Hg ) y la FC ( latidos / min ) se registraron antes de la administración de midazolam y durante los primeros 30 minutos después de la administración . Noventa y cuatro pacientes ( 74 mujeres, 20 hombres) fueron ingresados para cirugía podológica . Se realizaron Noventa y nueve intervenciones , con cinco de los sujetos sometidos a dos procedimientos. La edad media fue de 59 ± 13,5 años ( 21-87 ) y la dosis media de midazolam administrado fue 2,8 ± 1,3 mg ( 0,5-8 ) . La media de la PA antes de administrar midazolam fue de 148 /85 mmHg y la FC 80. A los 30 minutos la PA era de 136 /80 y la FC 71 . La PA y la FC fueron significativamente diferentes con una p < 0,001 para la lectura antes de la administración. Los resultados presentados indican el uso de este fármaco junto con el anestesico local en un contexto de sedación tiene resultados favorables.Sedation has been frequently used alongside many surgical interventions under local anaesthetics (LA). In podiatric surgery, there is a paucity of literature on the effects of sedation drugs on surrogate measures of patients’ physiological signs. General anaesthetic is practised more frequently than sedation assisted local anaesthetic in podiatry. The aim of this audit was to analyse blood pressure (BP) and heart rate (HR) against the administration of midazolam. A retrospective assessment of sedation notes prior to podiatric procedures undertaken during the years 2008/2009 was performed. BP (systolic/diastolic mm Hg) and heart rate (beats/min) were recorded prior to the administration of midazolam and for the first 30 minutes following administration. Ninety-four consecutive patients (74 women, 20 men) were admitted for podiatric surgery. Ninety-nine interventions were performed, with five of the subjects undergoing two procedures. The mean age was 59±13.5 years (21-87) and average midazolam administered 2.8±1.3 mg (0.5-8). Average BP prior to midazolam was 148/85 mm Hg and HR 80. At 30 minutes assessment BP was 136/80 and HR 71. BP and HR differences were significantly different at p<0.001 to the reading prior to administration. The results presented indicate the use of such a drug as an adjunct to LA in a sedation context has favourable results

    VLA Observations of H I in the Helix Nebula (NGC 7293)

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    We report the detection of 21-cm line emission from H I in the planetary nebula NGC 7293 (the Helix). The observations, made with the Very Large Array, show the presence of a ring of atomic hydrogen that is associated with the outer portion of the ionized nebula. This ring is most probably gas ejected in the AGB phase that has been subsequently photodissociated by radiation from the central star. The H I emission spreads over about 50 km/s in radial velocity. The mass in H I is approximately 0.07 solar masses, about three times larger than the mass in molecular hydrogen and comparable with the mass in ionized hydrogen.Comment: 19 pages, 9 figure

    Extended Recurrence Plot Analysis and its Application to ERP Data

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    We present new measures of complexity and their application to event related potential data. The new measures base on structures of recurrence plots and makes the identification of chaos-chaos transitions possible. The application of these measures to data from single-trials of the Oddball experiment can identify laminar states therein. This offers a new way of analyzing event-related activity on a single-trial basis.Comment: 21 pages, 8 figures; article for the workshop ''Analyzing and Modelling Event-Related Brain Potentials: Cognitive and Neural Approaches`` at November 29 - December 01, 2001 in Potsdam, German

    Star formation around the H II region Sh2-235

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    We present a picture of star formation around the H ii region Sh2-235 (S235) based upon data on the spatial distribution of young stellar clusters and the distribution and kinematics of molecular gas around S235. We observed 13CO (1-0) and CS (2-1) emission toward S235 with the Onsala Space Observatory 20-m telescope and analysed the star density distribution with archival data from the Two Micron All-Sky Survey (2MASS). Dense molecular gas forms a shell-like structure at the southeastern part of S235. The young clusters found with 2MASS data are embedded in this shell. The positional relationship of the clusters, the molecular shell and the H ii region indicates that expansion of S235 is responsible for the formation of the clusters. The gas distribution in the S235 molecular complex is clumpy, which hampers interpretation exclusively on the basis of the morphology of the star-forming region. We use data on kinematics of molecular gas to support the hypothesis of induced star formation, and distinguish three basic types of molecular gas components. The first type is primordial undisturbed gas of the giant molecular cloud, the second type is gas entrained in motion by expansion of the H ii region (this is where the embedded clusters were formed) and the third type is a fast-moving gas, which might have been accelerated by winds from the newly formed clusters. The clumpy distribution of molecular gas and its kinematics around the H ii region implies that the picture of triggered star formation around S235 can be a mixture of at least two possibilities: the 'collect-and-collapse' scenario and the compression of pre-existing dense clumps by the shock wave. Journal compilation © 2008 RAS

    Anomalous radio emission from dust in the Helix

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    A byproduct of experiments designed to map the CMB is the recent detection of a new component of foreground Galactic emission. The anomalous foreground at ~ 10--30 GHz, unexplained by traditional emission mechanisms, correlates with 100um dust emission. We report that in the Helix the emission at 31 GHz and 100um are well correlated, and exhibit similar features on sky images, which are absent in H\beta. Upper limits on the 250 GHz continuum emission in the Helix rule out cold grains as candidates for the 31 GHz emission, and provide spectroscopic evidence for an excess at 31 GHz over bremsstrahlung. We estimate that the 100um-correlated radio emission, presumably due to dust, accounts for at least 20% of the 31 GHz emission in the Helix. This result strengthens previous tentative interpretations of diffuse ISM spectra involving a new dust emission mechanism at radio frequencies. Very small grains have not been detected in the Helix, which hampers interpreting the new component in terms of spinning dust. The observed iron depletion in the Helix favors considering the identity of this new component to be magnetic dipole emission from hot ferromagnetic grains. The reduced level of free-free continuum we report also implies an electronic temperature of Te=4600\pm1200K for the free-free emitting material, which is significantly lower than the temperature of 9500\pm500K inferred from collisionally-excited lines (abridged).Comment: Accepted for publication in Ap
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