Synthetic CO, H2 and H I surveys of the second galactic quadrant, and the properties of molecular gas

articleWe present CO, H2, H I and HISA (H I self-absorption) distributions from a set of simulations of grand design spirals including stellar feedback, self-gravity, heating and cooling. We replicate the emission of the second galactic quadrant by placing the observer inside the modelled galaxies and post-process the simulations using a radiative transfer code, so as to create synthetic observations. We compare the synthetic data cubes to observations of the second quadrant of the Milky Way to test the ability of the current models to reproduce the basic chemistry of the Galactic interstellar medium (ISM), as well as to test how sensitive such galaxy models are to different recipes of chemistry and/or feedback. We find that models which include feedback and self-gravity can reproduce the production of CO with respect to H2 as observed in our Galaxy, as well as the distribution of the material perpendicular to the Galactic plane. While changes in the chemistry/feedback recipes do not have a huge impact on the statistical properties of the chemistry in the simulated galaxies, we find that the inclusion of both feedback and self-gravity are crucial ingredients, as our test without feedback failed to reproduce all of the observables. Finally, even though the transition from H2 to CO seems to be robust, we find that all models seem to underproduce molecular gas, and have a lower molecular to atomic gas fraction than is observed. Nevertheless, our fiducial model with feedback and self-gravity has shown to be robust in reproducing the statistical properties of the basic molecular gas components of the ISM in our Galaxy.We thank the referee, Ralf Klessen, for his comments that helped strengthen the paper. ADC and CLD acknowledge funding from the European Research Council for the FP7 ERC starting grant project LOCALSTAR. The calculations for this paper were performed on the DiRAC Complexity machine, jointly funded by STFC and the Large Facilities Capital Fund of BIS, and the University of Exeter Supercomputer, a DiRAC Facility jointly funded by STFC, the Large Facilities Capital Fund of BIS and the University of Exeter. Fig. 1 was produced using SPLASH (Price 2007). We acknowledge the use of NASA’s SkyView facility (http://skyview.gsfc.nasa.gov) located at NASA Goddard Space Flight Center. We also thank A. Rodrigues for providing high-resolution dust column density maps for benchmarking

Liverpool Telescope 2: beginning the design phase

The Liverpool Telescope is a fully robotic 2-metre telescope located at the Observatorio del Roque de los Muchachos on the Canary Island of La Palma. The telescope began routine science operations in 2004, and currently seven simultaneously mounted instruments support a broad science programme, with a focus on transient followup and other time domain topics well suited to the characteristics of robotic observing. Work has begun on a successor facility with the working title ‘Liverpool Telescope 2’. We are entering a new era of time domain astronomy with new discovery facilities across the electromagnetic spectrum, and the next generation of optical survey facilities such as LSST are set to revolutionise the field of transient science in particular. The fully robotic Liverpool Telescope 2 will have a 4-metre aperture and an improved response time, and will be designed to meet the challenges of this new era. Following a conceptual design phase, we are about to begin the detailed design which will lead towards the start of construction in 2018, for first light ∼2022. In this paper we provide an overview of the facility and an update on progress. © (2016) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only

ATLASGAL - towards a complete sample of massive star forming clumps

By matching infrared-selected, massive young stellar objects (MYSOs) and compact HII regions in the Red MSX Source survey to massive clumps found in the submillimetre ATLASGAL (APEX Telescope Large Area Survey of the Galaxy) survey, we have identified ~1000 embedded young massive stars between 280 {ring operator} < l < 350 {ring operator} and 10 {ring operator} < l < 60 {ring operator} with | b | < 1 {ring operator} . 5. Combined with an existing sample of radio-selected methanol masers and compact HII regions, the result is a catalogue of ~1700 massive stars embedded within ~1300 clumps located across the inner Galaxy, containing three observationally distinct subsamples, methanol-maser, MYSO and HII-region associations, covering the most important tracers of massive star formation, thought to represent key stages of evolution. We find that massive star formation is strongly correlated with the regions of highest column density in spherical, centrally condensed clumps. We find no significant differences between the three samples in clump structure or the relative location of the embedded stars, which suggests that the structure of a clump is set before the onset of star formation, and changes little as the embedded object evolves towards the main sequence. There is a strong linear correlation between clump mass and bolometric luminosity, with the most massive stars forming in the most massive clumps. We find that the MYSO and HII-region subsamples are likely to cover a similar range of evolutionary stages and that the majority are near the end of their main accretion phase. We find few infrared-bright MYSOs associated with the most massive clumps, probably due to very short pre-main-sequence lifetimes in the most luminous sources. © 2014 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society

CHIMPS: the 13^{13}CO/C18^{18}O (J=3-2) Heterodyne Inner Milky Way Plane Survey

We present the $^{13}$CO/C$^{18}$O (J=3-2) Heterodyne Inner Milky Way Plane Survey (CHIMPS) which has been carried out using the Heterodyne Array Receiver Program on the 15 m James Clerk Maxwell Telescope (JCMT) in Hawaii. The high-resolution spectral survey currently covers |b| < 0.5 deg and 28 < l < 46 deg, with an angular resolution of 15 arcsec in 0.5 km/s velocity channels. The spectra have a median rms of $\sim$ 0.6 K at this resolution, and for optically thin gas at an excitation temperature of 10 K, this sensitivity corresponds to column densities of $N_{\mathrm{H}_{2}} \sim 3 \times 10^{20}\,$cm$^{-2}$ and $N_{\mathrm{H}_{2}} \sim 4 \times 10^{21}\,$cm$^{-2}$ for $^{13}$CO and C$^{18}$O, respectively. The molecular gas that CHIMPS traces is at higher column densities and is also more optically thin than in other publicly available CO surveys due to its rarer isotopologues, and thus more representative of the three-dimensional structure of the clouds. The critical density of the J=3-2 transition of CO is $\gtrsim 10^{4}$ cm$^{-3}$ at temperatures of $\leq 20$ K, and so the higher density gas associated with star formation is well traced. These data complement other existing Galactic plane surveys, especially the JCMT Galactic Plane Survey which has similar spatial resolution and column density sensitivity, and the Herschel infrared Galactic Plane Survey. In this paper, we discuss the observations, data reduction and characteristics of the survey, presenting integrated emission maps for the region covered. Position-velocity diagrams allow comparison with Galactic structure models of the Milky Way, and while we find good agreement with a particular four arm model, there are some significant deviations

In Vitro and In Vivo Activity of a Palladacycle Complex on Leishmania (Leishmania) amazonensis

Leishmaniasis is an important public health problem with an estimated annual incidence of 1.5 million of new human cases of cutaneous leishmaniasis and 500,000 of visceral leishmaniasis. Treatment of the diseases is limited by toxicity and parasite resistance to the drugs currently in use, validating the need to develop new leishmanicidal compounds. We evaluated the killing by the palladacycle complex DPPE 1.2 of Leishmania (Leishmania) amazonensis, an agent of human cutaneous leishmaniasis in the Amazon region, Brazil. DPPE 1.2 destroyed promastigotes of L. (L.) amazonensis in vitro at nanomolar concentrations, whereas intracellular amastigotes were killed at drug concentrations 10-fold less toxic than those displayed to macrophages. L. (L.) amazonensis-infected BALB/c mice treated by intralesional injection of DPPE 1.2 exhibited a significant decrease of foot lesion sizes and a 97% reduction of parasite burdens when compared to untreated controls. Additional experiments indicated the inhibition of the cathepsin B activity of L. (L.) amazonensis amastigotes by DPPE 1.2. Further studies are needed to explore the potential of DPPE 1.2 as an additional option for the chemotherapy of leishmaniasis

Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set

We report a measurement of the bottom-strange meson mixing phase \beta_s using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays in which the quark-flavor content of the bottom-strange meson is identified at production. This measurement uses the full data set of proton-antiproton collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity. We report confidence regions in the two-dimensional space of \beta_s and the B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2, -1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in agreement with the standard model expectation. Assuming the standard model value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +- 0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +- 0.009 (syst) ps, which are consistent and competitive with determinations by other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012

HIV Aspartyl Peptidase Inhibitors Interfere with Cellular Proliferation, Ultrastructure and Macrophage Infection of Leishmania amazonensis

Submitted by Sandra Infurna ([email protected]) on 2019-01-08T13:43:09Z No. of bitstreams: 1 Ellenf_Altoe_etal_IOC_2009.pdf: 1452755 bytes, checksum: 77127a59920cef6bca71296107f6ec63 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2019-01-08T13:51:34Z (GMT) No. of bitstreams: 1 Ellenf_Altoe_etal_IOC_2009.pdf: 1452755 bytes, checksum: 77127a59920cef6bca71296107f6ec63 (MD5)Made available in DSpace on 2019-01-08T13:51:34Z (GMT). No. of bitstreams: 1 Ellenf_Altoe_etal_IOC_2009.pdf: 1452755 bytes, checksum: 77127a59920cef6bca71296107f6ec63 (MD5) Previous issue date: 2009Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ. Brasil.Universidade Federal do Rio de Janeiro. Centro de Ciências da Saúde. Instituto de Microbiologia Prof. Paulo de Góes. Departamento de Microbiologia Geral,. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ. Brasil.Universidade Federal do Rio de Janeiro. Centro de Ciências da Saúde. Instituto de Biofísica Carlos Chagas Filho. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Centro de Ciências da Saúde. Instituto de Microbiologia Prof. Paulo de Góes. Departamento de Microbiologia Geral,. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Centro de Ciências da Saúde. Instituto de Microbiologia Prof. Paulo de Góes. Departamento de Microbiologia Geral,. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ. Brasil.Leishmania is the etiologic agent of leishmanisais, a protozoan disease whose pathogenic events are not well understood. Current therapy is suboptimal due to toxicity of the available therapeutic agents and the emergence of drug resistance. Compounding these problems is the increase in the number of cases of Leishmania-HIV coinfection, due to the overlap between the AIDS epidemic and leishmaniasis

Accelerating infall and rotational spin-up in the hot molecular core G31.41+0.31

As part of our effort to search for circumstellar disks around high-mass stellar objects, we observed the well-known core G31.41 +0.31 with ALMA at 1.4 mm with an angular resolution of ~0.′′22 (~1700 au). The dust continuum emission has been resolved into two cores namely Main and NE. The Main core, which has the stronger emission and is the more chemically rich, has a diameter of ~5300 au, and is associated with two free-free continuum sources. The Main core looks featureless and homogeneous in dust continuum emission and does not present any hint of fragmentation. Each transition of CH₃CN and CH₃OCHO, both ground and vibrationally excited, as well as those of CH₃CN isotopologues, shows a clear velocity gradient along the NE–SW direction, with velocity linearly increasing with distance from the center, consistent with solid-body rotation. However, when comparing the velocity field of transitions with different upper level energies, the rotation velocity increases with increasing energy of the transition, which suggests that the rotation speeds up toward the center. Spectral lines towardtoward the dust continuum peak show an inverse P-Cygni profile that supports the existence of infall in the core. The infall velocity increases with the energy of the transition suggesting that the infall is accelerating toward the center of the core, consistent with gravitational collapse. Despite the monolithic appearance of the Main core, the presence of red-shifted absorption, the existence of two embedded free-free sources at the center, and the rotational spin-up are consistent with an unstable core undergoing fragmentation with infall and differential rotation due to conservation of angular momentum. Therefore, the most likely explanation for the monolithic morphology is that the large opacity of the dust emission prevents the detection of any inhomogeneity in the core

The JCMT Plane Survey: early results from the l = 30 degree field

We present early results from the JCMT Plane Survey (JPS), which has surveyed the northern inner Galactic plane between longitudes l=7 and l=63 degrees in the 850-{\mu}m continuum with SCUBA-2, as part of the James Clerk Maxwell Telescope Legacy Survey programme. Data from the l=30 degree survey region, which contains the massive star-forming regions W43 and G29.96, are analysed after approximately 40% of the observations had been completed. The pixel-to-pixel noise is found to be 19 mJy/beam, after a smooth over the beam area, and the projected equivalent noise levels in the final survey are expected to be around 10 mJy/beam. An initial extraction of compact sources was performed using the FellWalker method resulting in the detection of 1029 sources above a 5-{\sigma} surface-brightness threshold. The completeness limits in these data are estimated to be around 0.2 Jy/beam (peak flux density) and 0.8 Jy (integrated flux density) and are therefore probably already dominated by source confusion in this relatively crowded section of the survey. The flux densities of extracted compact sources are consistent with those of matching detections in the shallower ATLASGAL survey. We analyse the virial and evolutionary state of the detected clumps in the W43 star-forming complex and find that they appear younger than the Galactic-plane average