695 research outputs found

    High Redshift HCN Emission: Dense Star-Forming Molecular Gas in IRAS F10214+4724

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    Hydrogen cyanide emission in the J=1-0 transition has been detected at redshift z=2.2858 in IRAS F10214+4724 using the Green Bank Telescope . This is the second detection of HCN emission at high redshift. The large HCN line luminosity in F10214 is similar to that in the Cloverleaf (z=2.6) and the ultra-luminous infrared galaxies Mrk231 and Arp220. This is also true of the ratio of HCN to CO luminosities. The ratio of far-infrared luminosity to HCN luminosity, an indicator of the star formation rate per solar mass of dense gas, follows the correlation found for normal spirals and infrared luminous starburst galaxies. F10214 clearly contains a starburst that contributes, together with its embedded quasar, to its overall infrared luminosity. A new technique for removing spectral baselines in the search for weak, broad emission lines is presented.Comment: 9 pages, 2 figures; accepted ApJ(Letters

    VLA Limits for Intermediate Mass Black Holes in Three Globular Clusters

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    The observational evidence for central black holes in globular clusters has been argued extensively, and their existence has important consequences for both the formation and evolution of the cluster. Most of the evidence comes from dynamical arguments, but the interpretation is difficult, given the short relaxation times and old ages of the clusters. One of the most robust signatures for the existence of a black hole is radio and/or X-ray emission. We observed three globular clusters, NGC6093 (M80), NGC6266 (M62), and NGC7078 (M15), with the VLA in the A and C configuration with a 3-sigma noise of 36, 36 and 25 microJy, respectively. We find no statistically-significant evidence for radio emission from the central region for any of the three clusters. NGC6266 shows a 2-sigma detection. It is difficult to infer a mass from these upper limits due to uncertainty about the central gas density, accretion rate, and accretion model.Comment: 5 pages, accepted for publication in the Astronomical Journa

    HCN Observations of Dense Star-Forming Gas in High Redshift Galaxies

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    We present here the sensitive HCN(1-0) observations made with the VLA of two submillimeter galaxies and two QSOs at high-redshift. HCN emission is the signature of dense molecular gas found in GMC cores, the actual sites of massive star formation. We have made the first detection of HCN in a submillimeter galaxy, SMM J16359+6612. The HCN emission is seen with a signal to noise ratio of 4σ\sigma and appears to be resolved as a double-source of \approxlt 2'' separation. Our new HCN observations, combined with previous HCN detections and upper limits, show that the FIR/HCN ratios in these high redshift sources lie systematically above the FIR/HCN correlation established for nearby galaxies by about a factor of 2. Even considering the scatter in the data and the presence of upper limits, this is an indication that the FIR/HCN ratios for the early Universe molecular emission line galaxies (EMGs) deviate from the correlation that fits Galactic giant molecular cloud cores, normal spirals, LIRGs, and ULIRGs. This indicates that the star formation rate per solar mass of dense molecular gas is higher in the high-zz objects than in local galaxies including normal spirals LIRGs and ULIRGs. The limited HCN detections at high-redshift show that the HCN/CO ratios for the high-zz objects are high and are comparable to those of the local ULIRGs rather than those of normal spirals. This indicates that EMGs have a high fraction of dense molecular gas compared to total molecular gas traced by CO emission.Comment: 14 pages including 4 figures; ApJL accepte

    First detection of the adventive egg parasitoid of Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) Trissolcus mitsukurii (Ashmead) (Hymenoptera: Scelionidae) in France

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    SIMPLE SUMMARY: The invasive brown marmorated stink bug (BMSB), Halyomorpha halys, is a polyphagous species and a serious pest worldwide. Classical biological control (CBC), i.e., the introduction of a natural enemy from the native area of the pest, is considered as the preferential solution for BMSB regulation. Adventive populations of exotic egg parasitoids of BSMB, Trissolcus japonicus and T. mitsukurii, have been reported worldwide. With the aim to characterize the French diversity of egg parasitoids associated to various stink bugs including BMSB, field surveys were conducted between 2018 and 2020. Surprisingly, morphological and molecular analyses unambiguously revealed 12 specimens of T. mitsukurii, an Asian egg parasitoid of BSMB. Although its permanent establishment has to be confirmed, this first record in France could actually facilitate CBC initiatives, T. mitsukurii being considered with T. japonicus as the two most promising biological control agents against BMSB. ABSTRACT: We report the first detection of Trissolcus mitsukurii in France. More than 1860 sentinel egg masses of Halyomorpha halys (BMSB) were exposed in the field during the 2018–2020 period, and 12 specimens of T. mitsukurii emerged from one egg mass. Their taxonomic identification was confirmed both by morphological and molecular analysis. Trissolcus mitsukurii, similar to T. japonicus, is an egg parasitoid of BMSB in its area of origin in Asia, and both species are considered to be candidates for a classical biological control strategy against BMSB. Trissolcus mitsukurii was previously recorded in Italy where it is well established and widespread, and this may be the source of the French population. Possible permanent establishment and dispersion of T. mitsukurii in France should be monitored with emphasis on its potential effect on BMSB populations

    A Search for Dense Molecular Gas in High Redshift Infrared-Luminous Galaxies

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    We present a search for HCN emission from four high redshift far infrared (IR) luminous galaxies. Current data and models suggest that these high zz IR luminous galaxies represent a major starburst phase in the formation of spheroidal galaxies, although many of the sources also host luminous active galactic nuclei (AGN), such that a contribution to the dust heating by the AGN cannot be precluded. HCN emission is a star formation indicator, tracing dense molecular hydrogen gas within star-forming molecular clouds (n(H2_2) 105\sim 10^5 cm3^{-3}). HCN luminosity is linearly correlated with IR luminosity for low redshift galaxies, unlike CO emission which can also trace gas at much lower density. We report a marginal detection of HCN (1-0) emission from the z=2.5832z=2.5832 QSO J1409+5628, with a velocity integrated line luminosity of LHCN=6.7±2.2×109L_{\rm HCN}'=6.7\pm2.2 \times10^{9} K km s1^{-1} pc2^2, while we obtain 3σ\sigma upper limits to the HCN luminosity of the z=3.200z=3.200 QSO J0751+2716 of LHCN=1.0×109L_{\rm HCN}'=1.0\times10^{9} K km s1^{-1} pc2^2, LHCN=1.6×109L_{\rm HCN}'=1.6\times10^{9} K km s1^{-1} pc2^2 for the z=2.565z= 2.565 starburst galaxy J1401+0252, and LHCN=1.0×1010L_{\rm HCN}'=1.0\times10^{10} K km s1^{-1} pc2^2 for the z=6.42z = 6.42 QSO J1148+5251. We compare the HCN data on these sources, plus three other high-zz IR luminous galaxies, to observations of lower redshift star-forming galaxies. The values of the HCN/far-IR luminosity ratios (or limits) for all the high zz sources are within the scatter of the relationship between HCN and far-IR emission for low zz star-forming galaxies (truncated).Comment: aastex format, 4 figures. to appear in the Astrophysical Journal; Revised lens magnification estimate for 1401+025

    Delayed Lithium Reintoxication in a Case of Severe Multidrug Intoxication:A Case Study

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    The authors present a case of severe multidrug intoxication following massive ingestion of lithium, nortriptyline, aripiprazole, lorazepam, and temazepam. After initial treatment, serum lithium levels decreased significantly. However, 28 hours post ingestion, recurrent elevated lithium levels were observed, and serum lithium level increased 0.71 mmol/L in 12 hours. The intensivist consulted a hospital pharmacist about this. After administering clearance-inducing therapy using continuous venovenous hemodialysis, the lithium level was reduced to a long-lasting nontoxic level. The occurrence of secondary elevation in lithium levels exceeding the toxic limit in cases of massive ingestion of lithium tablets, whether in combination with anticholinergic drugs, should be anticipated. Close monitoring and prompt initiation of clearance-inducing therapy can improve clinical outcomes.</p

    In vitro and in vivo gene transfer to pulmonary cells mediated by cationic liposomes

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    Cationic liposomes have been proposed as alternative to adenovirus in the treatment of cystic fibrosis lung disease. Therefore, we have investigated the efficiency of two lipid mixtures in mediating gene transfer in in vitro and in vivo models. The cationic lipid DOTMA (N-(1-(2,3(dioleyloxy)propyl)-n,n,n-trimethylammoniumchloride) and DOGS (dioctadecylamidoglycylspermine) were used in combination with the neutral lipid DOPE (dioleoylphosphatidylethanolamine). The relative transfection efficiencies of the two cationic liposomes were tested using the bacterial β-galactosidase (lacZ) and the firefly luciferase genes. Gene expression was detected in both cell lines and primary culture of rhesus monkey airway epithelium after transfection with plasmid DNA complexed with DOGS/DOPE or DOTMA/DOPE. Transfection efficiency of both types of lipids was higher in the mouse fibroblast 3T3 cell line as compared to human carcinoma A549 cells and primary epithelial cultures. Administration of DNA-liposome complexes via intratracheal instillation resulted in expression of the lacZ and luciferase marker gene in the mouse airways. In vivo transfection mediated by both types of liposomes were proven to be far less efficient than adenovirus treatment
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