160 research outputs found

    Modeling and Analysis Generic Interface for eXternal numerical codes (MAGIX)

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    The modeling and analysis generic interface for external numerical codes (MAGIX) is a model optimizer developed under the framework of the coherent set of astrophysical tools for spectroscopy (CATS) project. The MAGIX package provides a framework of an easy interface between existing codes and an iterating engine that attempts to minimize deviations of the model results from available observational data, constraining the values of the model parameters and providing corresponding error estimates. Many models (and, in principle, not only astrophysical models) can be plugged into MAGIX to explore their parameter space and find the set of parameter values that best fits observational/experimental data. MAGIX complies with the data structures and reduction tools of ALMA (Atacama Large Millimeter Array), but can be used with other astronomical and with non-astronomical data.Comment: 12 pages, 15 figures, 2 tables, paper is also available at http://www.aanda.org/articles/aa/pdf/forth/aa20063-12.pd

    APECS - The Atacama Pathfinder Experiment Control System

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    APECS is the distributed control system of the new Atacama Pathfinder EXperiment (APEX) telescope located on the Llano de Chajnantor at an altitude of 5107 m in the Atacama desert in northern Chile. APECS is based on Atacama Large Millimeter Array (ALMA) software and employs a modern, object-oriented design using the Common Object Request Broker Architecture (CORBA) as the middleware. New generic device interfaces simplify adding instruments to the control system. The Python based observer command scripting language allows using many existing software libraries and facilitates creating more complex observing modes. A new self-descriptive raw data format (Multi-Beam FITS or MBFITS) has been defined to store the multi-beam, multi-frequency data. APECS provides an online pipeline for initial calibration, observer feedback and a quick-look display. APECS is being used for regular science observations in local and remote mode since August 2005.Comment: 4 pages, A&A, accepte

    The inhomogeneous ISM toward PKS1830-211 SW - A detailed view on molecular gas at a look-back time of 7.5 Gyr

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    Based on measurements with the Effelsberg 100-m telescope, a multi-line study of molecular species is presented toward the south-western source of the gravitational lens system PKS 1830-211, which is by far the best known target to study molecular gas in absorption at intermediate redshift. Determining line parameters and optical depths and performing Large Velocity Gradient radiative transfer calculations, the aims of this study are (1) to evaluate physical parameters of the absorbing foreground gas at z~0.89, in particular its homogeneity, and (2) to monitor the spectroscopic time variability caused by fluctuations of the z~2.5 background continuum source. We find, that the gas is quite inhomogeneous with n(H2)~2 x 10^3 cm^-3 for most molecular species but with higher values for H2CO and lower ones for SO. Measuring the CS J=1-0 transition during a time interval of more than a decade, from 2001 to 2012, the peak absorption depth of the line remains approximately constant, while the line shape undergoes notable variations. Covering the time between 1996 and 2013, CS, HCO+, and CH3OH data indicate maximal integrated optical depths in ~2001 and 2011/2012. This is compatible with a ~10 yr periodicity, which, however, needs confirmation by substantially longer time monitoring. Comparing molecular abundances with those of different types of Galactic and nearby extragalactic clouds we find that the observed cloud complex does not correspond to one particular type but to a variety of cloud types with more diffuse and denser components as can be expected for an observed region with a transverse linear scale of several parsec and a likely larger depth along the line-of-sight. A tentative detection of Galactic absorption in the c-C3H2 1(10)-1(01) line at 18.343 GHz is also reported.Comment: Accepted for publication in A&A, 11 pages, 10 figures, 4 table

    The inhomogeneous ISM toward PKS 1830–211 SW: A detailed view of molecular gas at a look-back time of 7.5 Gyr

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    Based on measurements with the Effelsberg 100-m telescope, a multiline study of molecular species is presented toward the southwestern source of the gravitational lens system PKS 1830–211, which is by far the best known target for studying molecular gas in absorption at intermediate redshift. Determining line parameters and optical depths and performing large velocity gradient radiative transfer calculations, the aims of this study are (1) to evaluate physical parameters of the absorbing foreground gas at z ~ 0.89, in particular its homogeneity; and (2) to monitor the spectroscopic time variability caused by fluctuations in the z ~ 2.5 background continuum source. We find, that the gas is quite inhomogeneous with n(H2) ~ 2 × 103 cm-3 for most molecular species but with higher values for H2CO and lower ones for SO. Measuring the CS J = 1 ← 0 transition during a time interval of more than a decade, from 2001 to 2012, the peak absorption depth of the line remains approximately constant, while the line shape undergoes notable variations. Covering the time between 1996 and 2013, CS, HCO+, and CH3OH data indicate maximum integrated optical depths in ~2001 and 2011/2012. This is compatible with a ~10 yr periodicity, which, however, needs confirmation by substantially longer time monitoring. Comparing molecular abundances with those of different types of Galactic and nearby extragalactic clouds we find that the observed cloud complex does not correspond to one particular type but to a variety of cloud types with more diffuse and denser components as can be expected for an observed region with a transverse linear scale of several parsec and a likely greater depth along the line of sight. A tentative detection of Galactic absorption in the c-C3H2 110−101 line at 18.343 GHz is also reported

    Validation of core competencies during residency training in anaesthesiology

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    Background and goal: Curriculum development for residency training is increasingly challenging in times of financial restrictions and time limitations. Several countries have adopted the CanMEDS framework for medical education as a model into their curricula of specialty training. The purpose of the present study was to validate the competency goals, as derived from CanMEDS, of the Department of Anaesthesiology and Intensive Care Medicine of the Berlin Charité University Medical Centre, by conducting a staff survey. These goals for the qualification of specialists stipulate demonstrable competencies in seven areas: expert medical action, efficient collaboration in a team, communications with patients and family, management and organisation, lifelong learning, professional behaviour, and advocacy of good health. We had previously developed a catalogue of curriculum items based on these seven core competencies. In order to evaluate the validity of this catalogue, we surveyed anaesthetists at our department in regard to their perception of the importance of each of these items. In addition to the descriptive acquisition of data, it was intended to assess the results of the survey to ascertain whether there were differences in the evaluation of these objectives by specialists and registrars

    First 230 GHz VLBI Fringes on 3C 279 using the APEX Telescope

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    We report about a 230 GHz very long baseline interferometry (VLBI) fringe finder observation of blazar 3C 279 with the APEX telescope in Chile, the phased submillimeter array (SMA), and the SMT of the Arizona Radio Observatory (ARO). We installed VLBI equipment and measured the APEX station position to 1 cm accuracy (1 sigma). We then observed 3C 279 on 2012 May 7 in a 5 hour 230 GHz VLBI track with baseline lengths of 2800 Mλ\lambda to 7200 Mλ\lambda and a finest fringe spacing of 28.6 micro-arcseconds. Fringes were detected on all baselines with SNRs of 12 to 55 in 420 s. The correlated flux density on the longest baseline was ~0.3 Jy/beam, out of a total flux density of 19.8 Jy. Visibility data suggest an emission region <38 uas in size, and at least two components, possibly polarized. We find a lower limit of the brightness temperature of the inner jet region of about 10^10 K. Lastly, we find an upper limit of 20% on the linear polarization fraction at a fringe spacing of ~38 uas. With APEX the angular resolution of 230 GHz VLBI improves to 28.6 uas. This allows one to resolve the last-photon ring around the Galactic Center black hole event horizon, expected to be 40 uas in diameter, and probe radio jet launching at unprecedented resolution, down to a few gravitational radii in galaxies like M 87. To probe the structure in the inner parsecs of 3C 279 in detail, follow-up observations with APEX and five other mm-VLBI stations have been conducted (March 2013) and are being analyzed.Comment: accepted for publication in A&

    A rotating molecular jet in Orion

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    We present CO(2-1), 13^{13}CO(2-1), CO(6-5), CO(7-6), and SO(65−54_5-5_4) line observations made with the {\it IRAM 30 m} and {\it APEX} radiotelescopes and the {\it Submillimeter Array} toward the highly collimated and extended southwest lobe of the bipolar outflow {\it Ori-S6} located in the Orion South region. We report, for all these lines, the detection of velocity asymmetries about the flow axis, with velocity differences roughly on the order of 1 km s−1^{-1} over distances of about 5000 AU, 4 km s−1^{-1} over distances of about 2000 AU, and close to the source of between 7 and 11 km s−1^{-1} over smaller scales of about 1000 AU. We interpret these velocity differences as a signature of rotation but also discuss some alternatives which we recognize as unlikely in view of the asymmetries' large downstream continuation. This rotation across the {\it Ori-S6} outflow is observed out to (projected) distances beyond 2.5 ×\times 104^4 AU from the flow's presumed origin. Comparison of our large-scale and small-scale observations suggests the rotational velocity to decline not faster than 1/R with distance R from the axis; in the innermost few arcsecs an increase of rotational velocity with R is even indicated. The magnetic field lines threading the inner rotating CO shell may well be anchored in a disk of radius ∌\sim 50 AU; the field lines further out need a more extended rotating base.Comment: Accepted by Astronomy and Astrophysic

    Dense gas in nearby galaxies XVI. The nuclear starburst environment in NGC4945

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    A multi-line millimeter-wave study of the nearby starburst galaxy NGC 4945 has been carried out using the Swedish-ESO Submillimeter Telescope (SEST). The study covers the frequency range from 82 GHz to 354 GHz and includes 80 transitions of 19 molecules. 1.3 mm continuum data of the nuclear source are also presented. A large number of molecular species indicate the presence of a prominent high density interstellar gas component characterized by nH2∌105n_{\rm H_2}\sim10^5 cm−3^{-3}. Abundances of molecular species are calculated and compared with abundances observed toward the starburst galaxies NGC 253 and M 82 and galactic sources. Apparent is an `overabundance' of HNC in the nuclear environment of NGC 4945. While the HNC/HCN JJ=1--0 line intensity ratio is ∌\sim0.5, the HNC/HCN abundance ratio is ∌\sim1. While HCN is subthermally excited (Tex∌T_{\rm ex}\sim8 K), CN is even less excited (Tex∌T_{\rm ex}\sim3--4 K), indicating that it arises from a less dense gas component and that its NN=2--1 line can be optically thin even though its NN=1--0 emission is moderately optically thick. Overall, fractional abundances of NGC 4945 suggest that the starburst has reached a stage of evolution that is intermediate between those observed in NGC 253 and M 82. Carbon, nitrogen, oxygen and sulfur isotope ratios are also determined. Within the limits of uncertainty, carbon and oxygen isotope ratios appear to be the same in the nuclear regions of NGC 4945 and NGC 253. High 18^{18}O/17^{17}O, low 16^{16}O/18^{18}O and 14^{14}N/15^{15}N and perhaps also low 32^{32}S/34^{34}S ratios appear to be characteristic properties of a starburst environment in which massive stars have had sufficient time to affect the isotopic composition of the surrounding interstellar medium.Comment: 26 pages, 16 figures, accepted bt A&

    Clinical and Functional Characterization of a Patient Carrying a Compound Heterozygous Pericentrin Mutation and a Heterozygous IGF1 Receptor Mutation

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    Intrauterine and postnatal longitudinal growth is controlled by a strong genetic component that regulates a complex network of endocrine factors integrating them with cellular proliferation, differentiation and apoptotic processes in target tissues, particularly the growth centers of the long bones. Here we report on a patient born small for gestational age (SGA) with severe, proportionate postnatal growth retardation, discreet signs of skeletal dysplasia, microcephaly and moyamoya disease. Initial genetic evaluation revealed a novel heterozygous IGF1R p.Leu1361Arg mutation affecting a highly conserved residue with the insulin-like growth factor type 1 receptor suggestive for a disturbance within the somatotropic axis. However, because the mutation did not co-segregate with the phenotype and functional characterization did not reveal an obvious impairment of the ligand depending major IGF1R signaling capabilities a second-site mutation was assumed. Mutational screening of components of the somatotropic axis, constituents of the IGF signaling system and factors involved in cellular proliferation, which are described or suggested to provoke syndromic dwarfism phenotypes, was performed. Two compound heterozygous PCNT mutations (p.[Arg585X];[Glu1774X]) were identified leading to the specification of the diagnosis to MOPD II. These investigations underline the need for careful assessment of all available information to derive a firm diagnosis from a sequence aberration
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