An equatorial wind from the massive young stellar object S140 IRS 1

The discovery of the second equatorial ionized stellar wind from a massive young stellar object is reported. High resolution radio continuum maps of S140 IRS 1 reveal a highly elongated source that is perpendicular to the larger scale bipolar molecular outflow. This picture is confirmed by location of a small scale monopolar near-IR reflection nebula at the base of the blueshifted lobe. A second epoch of observations over a five year baseline show little ordered outward proper motion of clumps as would have been expected for a jet. A third epoch, taken only 50 days after the second, did show significant changes in the radio morphology. These radio properties can all be understood in the context of an equatorial wind driven by radiation pressure from the central star and inner disc acting on the gas in the surface layers of the disc as proposed by Drew et al. (1998). This equatorial wind system is briefly compared with the one in S106IR, and contrasted with other massive young stellar objects that drive ionized jets.Comment: 19 pages, 5 figures, accepted by ApJ, minor changes in light of referees repor

Mapping Hydrogen in the Galaxy, Galactic Halo, and Local Group with ALFA: The GALFA-HI Survey Starting with TOGS

Radio observations of gas in the Milky Way and Local Group are vital for understanding how galaxies function as systems. The unique sensitivity of Arecibo's 305m dish, coupled with the 7-beam Arecibo L-Band Feed Array (ALFA), provides an unparalleled tool for investigating the full range of interstellar phenomena traced by the HI 21cm line. The GALFA (Galactic ALFA) HI Survey is mapping the entire Arecibo sky over a velocity range of -700 to +700 km/s with 0.2 km/s velocity channels and an angular resolution of 3.4 arcminutes. We present highlights from the TOGS (Turn on GALFA Survey) portion of GALFA-HI, which is covering thousands of square degrees in commensal drift scan observations with the ALFALFA and AGES extragalactic ALFA surveys. This work is supported in part by the National Astronomy and Ionosphere Center, operated by Cornell University under cooperative agreement with the National Science Foundation.Comment: 3 pages, including 2 figure pages; figure image quality significantly reduced; for full resolution version, please see http://www.naic.edu/~gibson/cv/ao08_writeup.pdf ; to be published in AIP conference proceedings for ``The Evolution of Galaxies through the Neutral Hydrogen Window'', eds. R. Minchin & E. Momjia

Equation of State for Neutralino Star as a Form of Cold Dark Matter

In order to study the structure of neutralino star and dark galaxy, we consider dynamical interactions due to boson-exchange in the neutralino matter. Taking into account interactions of neutralinos with bosons, we derive the equation of state (EOS) of neutralino stars in terms of the relativistic mean field approach. Then we apply the resulting EOS to investigate properties of the neutralino star such as its density profile and mass limit. For example, if the neutralino mass is around 1 TeV, the Oppenheimer mass limit of the neutralino star is obtained as $6.06\times 10^{-7}M_\odot$, and the corresponding radius is about 7.8 mm. Actually, due to an increasing annihilation rate as indicated by our calculation, this dense state can never be realized in practice. Our results also show that the low density neutralino star may be a possible aggregation of the cold dark matter.Comment: 5 pages, 5 figures; v2: matches published versio

Magnetic field evolution in Bok globules

Using the Submillimeter Common-User Bolometer Array (SCUBA) at the James Clerk Maxwell Telescope (JCMT), we obtained submillimeter polarization maps of the Bok globules B335, CB230, and CB244 at 850micron. We find strongly aligned polarization vectors in the case of B335 and CB230, indicating a strong coupling of the magnetic field to the dust grains. Based on the distribution of the orientation and strength of the linear polarization we derive the magnetic field strengths in the envelopes of the globules. In agreement with previous submillimeter polarization measurements of Bok globules we find polarization degrees of several percent decreasing towards the centers of the cores. Furthermore, we compare the magnetic field topology with the spatial structure of the globules, in particular with the orientation of the outflows and the orientation of the nonspherical globule cores. In case of the globules B335 and CB230, the outflows are oriented almost perpendicular to the symmetry axis of the globule cores. The magnetic field, however, is aligned with the symmetry axis of the prolate cores in the case of the Bok globules B335 and CB230, while it is slightly aligned with the outflow axis in the case of the Bok globules CB26 and CB54. We discuss the possibility that the different orientations of the magnetic field relative to the outflow directions reflect different evolutionary stages of the single globules. The complete version of this article (containing all figures) can be downloaded from http://spider.ipac.caltech.edu/staff/swolf/homepage/public/preprints/mfe.ps.gzComment: ApJ, in pres

A blind HI survey of the M81 group

Results are presented of the first blind HI survey of the M81 group of galaxies. The data were taken as part of the HI Jodrell All Sky Survey (HIJASS). The survey reveals several new aspects to the complex morphology of the HI distribution in the group. All four of the known dwarf irregular (dIrr) galaxies close to M81 can be unambiguously seen in the HIJASS data. Each forms part of the complex tidal structure in the area. We suggest that at least three of these galaxies may have formed recently from the tidal debris in which they are embedded. The structure connecting M81 to NGC2976 is revealed as a single tidal bridge of mass approx. 2.1 x 10^8 Msol and projected spatial extent approx. 80 kpc. Two `spurs' of HI projecting from the M81 complex to lower declinations are traced over a considerably larger spatial and velocity extent than by previous surveys. The dwarf elliptical (dE) galaxies BK5N and Kar 64 lie at the spatial extremity of one of these features and appear to be associated with it. We suggest that these may be the remnants of dIrrs which has been stripped of gas and transmuted into dEs by close gravitational encounters with NGC3077. The nucleated dE galaxy Kar 61 is unambiguously detected in HI for the first time and has an HI mass of approx.10^8 Msol, further confirming it as a dE/dIrr transitional object. HIJASS has revealed one new possible group member, HIJASS J1021+6842. This object contains approx. 2 x 10^7 Msol of HI and lies approx.105arcmin from IC2574. It has no optical counterpart on the Digital Sky Survey.Comment: To be published in Astrophysical Journal Letters 9 pages, including 3 figure

Changes in mixed microbial inoculums to prevent the toxic side-effects in cattle grazing new varieties of Leucaena.

Leucaena leucocephala is a legume fodder crop that grows in tropical and subtropical environments. Leucaena provides a high quality feed for cattle boosting liveweight gain both per animal and per hectare, improving profitability for steer turnover by 121% compared with the base scenario of grazing buffel grass (Bowen and Chudleigh, 2018). A number of commercial leucaena cultivars, Cunningham, Peru, Taramba, El Salvadore, and Wondergraze, are used in Queensland. Leucaena contains a toxic amino acid, mimosine, which many rumen bacteria can degrade to a toxic metabolite 3-hydroxy-4-(1H)-pyridone (DHP). Productivity from leucaena-pasture can be reduced by DHP-induced depressions in intake. A DHP degrading bacterium, Synergistes jonesii was isolated from a mixed bacterial population isolated from a goat from Hawaii (Allison et al., 1992). For over twenty years DAF has provided a mixed bacterial rumen inoculum, containing S. jonesii, for cattle grazing Leucaenapastures, produced in an in vitro fermentation system with Cunningham cultivar as the feed source. All of the commercial cultivars are susceptible to attack by psyllid insects, limiting their use in higher rainfall areas - to address this limitation, a commercial psyllid-resistant cultivar, Redlands, was released in 2019. To assess if the leucaena inoculum is impacted by Redland’s anti-psyllid, chemical characteristics a series of 30 day in vitro anaerobic fermentations were undertaken feeding either Redlands, Cunningham or Wondergraze cultivars. The fermentations were conducted following the method of Klieve et al. (2002). Fermentations were started with either cryopreserved leuceana inoculum from a single day of a production fermentation; or day 30 of a Wondergraze or Redlands fermentation. Daily samples were taken and assays set up on days 10, 15, 20, 25 and 30 to monitor the fermentation’s ability to break down mimosine, 3,4 DHP and 2,3 DHP. Genomic DNA extracted from daily samples was used in a S. jonesii quantitative PCR and for barcoded amplicon sequencing of the 16S rRNA gene V3 –V4 region using the Illumina MiSeq platform

The Arecibo L-band Feed Array Zone of Avoidance Survey I: Precursor Observations through the Inner and Outer Galaxy

The Arecibo L-band Feed Array (ALFA) is being used to conduct a low-Galactic latitude survey, to map the distribution of galaxies and large-scale structures behind the Milky Way through detection of galaxies' neutral hydrogen (HI) 21-cm emission. This Zone of Avoidance (ZOA) survey finds new HI galaxies which lie hidden behind the Milky Way, and also provides redshifts for partially-obscured galaxies known at other wavelengths. Before the commencement of the full survey, two low-latitude precursor regions were observed, totalling 138 square degrees, with 72 HI galaxies detected. Detections through the inner Galaxy generally have no cataloged counterparts in any other waveband, due to the heavy extinction and stellar confusion. Detections through the outer Galaxy are more likely to have 2MASS counterparts. We present the results of these precursor observations, including a catalog of the detected galaxies, with their HI parameters. The survey sensitivity is well described by a flux- and linewidth-dependent signal-to-noise ratio of 6.5. ALFA ZOA galaxies which also have HI measurements in the literature show good agreement between our measurements and previous work. The inner Galaxy precursor region was chosen to overlap the HI Parkes Zone of Avoidance Survey so ALFA performance could be quickly assessed. The outer Galaxy precursor region lies north of the Parkes sky. Low-latitude large-scale structure in this region is revealed, including an overdensity of galaxies near l = 183 deg and between 5000 - 6000 km/s in the ZOA. The full ALFA ZOA survey will be conducted in two phases: a shallow survey using the observing techniques of the precursor observations, and also a deep phase with much longer integration time, with thousands of galaxies predicted for the final catalog.Comment: 26 pages, 7 figures, 2 tables, Astronomical Journal accepte