Carbon monoxide in an extremely metal-poor galaxy

Extremely metal-poor galaxies with metallicity below 10% of the solar value in the local universe are the best analogues to investigating the interstellar medium at a quasi-primitive environment in the early universe. In spite of the ongoing formation of stars in these galaxies, the presence of molecular gas (which is known to provide the material reservoir for star formation in galaxies, such as our Milky Way) remains unclear. Here, we report the detection of carbon monoxide (CO), the primary tracer of molecular gas, in a galaxy with 7% solar metallicity, with additional detections in two galaxies at higher metallicities. Such detections offer direct evidence for the existence of molecular gas in these galaxies that contain few metals. Using archived infrared data, it is shown that the molecular gas mass per CO luminosity at extremely low metallicity is approximately one-thousand times the Milky Way value.Comment: 12 pages, 3 figures, 1 table. Supplementary data at http://www.nature.com/article-assets/npg/ncomms/2016/161209/ncomms13789/extref/ncomms13789-s1.pd

Tentative evidence of spatially extended GeV emission from SS433/W50

We analyze 10 years of Fermi-LAT data towards the SS433/W50 region. With the latest source catalog and diffuse background models, the gamma-ray excess from SS433/W50 is detected with a significance of 6{\sigma} in the photon energy range of 500 MeV - 10 GeV. Our analysis indicates that an extended flat disk morphology is preferred over a point-source description, suggesting that the GeV emission region is much larger than that of the TeV emission detected by HAWC. The size of the GeV emission is instead consistent with the extent of the radio nebula W50, a supernova remnant being distorted by the jets, so we suggest that the GeV emission may originate from this supernova remnant. The spectral result of the GeV emission is also consistent with an supernova remnant origin. We also derive the GeV flux upper limits on the TeV emission region, which put moderate constrains on the leptonic models to explain the multiwavelength data.Comment: 7 pages, 4 figures, accepted for publication in A&

Isolation an Antimicrobial Action of Endophytic Fungi from Sophora Flavescens and Effects on Microorganism Circumstances in Soil

AbstractThe aim of this study was to isolate the endophytic fungi from Sophora flavescens and define its antimicrobial action and structure. The effects of this active substance on soil microorganism circumstances were also conducted. Column chromatography and freeze drying were used to isolate and purify the antimicrobial substance. TLC biological autoradiography was applied to trace. HPLC method was employed to measure the purity. Analysis of the structure used 1H-NMR, 13C-NMR and LC-MS methods. Plate method was applied to measure the effect on microorganism circumstances. The results showed that after isolating and purifying the fermentation liquor of BS001, the structure of bacteriostatic active composition was 6,7-(2′E)dibutenyl-5,8-dihydroxy-(Z)-cyclooct-2-ene-1,4-dione, which was identified by spectroscopy. The substance could increase the number of bacteria and fungi while decreased the number of antinomies in soil. A new antimicrobial substance 6,7-(2′E)dibutenyl-5,8 -dihydroxy- (Z)- cyclooct - 2- ene-1,4-dione was extracted from fermenting liquor of BS001 which was an endophytic fungi of Sophora flavescens. It could promote the beneficial flora but detrimental flora. This conclusion provides exploiture foreground for biopharmaceuticals and biopesticide