283 research outputs found

    NGC 6309, a Planetary Nebula that Shifted from Round to Multipolar

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    We present new narrow-band Ha, [N II], and [O III] high-resolution images of the quadrupolar planetary nebula (PN) NGC 6309 that show in great detail its bipolar lobes and reveal new morphological features. New high- and low-dispersion long-slit spectra have been obtained to help in the investigation of the new nebular components. The images and spectra unveil two diffuse blobs, one of them located at 55 arcsec from the central star along the NE direction (PA= +71) and the other at 78 arcsec in the SW direction (PA= -151). Therefore, these structures do not share the symmetry axes of the inner bipolar outflows. Their radial velocities relative to the system are quite low: +3 and -4 km/s, respectively. Spectroscopic data confirm a high [O III] to Ha ratio, indicating that the blobs are being excited by the UV flux from the central star. Our images convincingly show a spherical halo 60 arcsec in diameter encircling the quadrupolar nebula. The expansion velocity of this shell is low, 66 km/s. The software SHAPE has been used to construct a morpho-kinematic model for the ring and the bipolar flows that implies an age of 4,000 yrs, the expansion of the halo sets a lower limit for its age 46,000 yrs, and the very low expansion of the blobs suggests they are part of a large structure corresponding to a mass ejection that took place 150,000 yrs ago. In NGC 6309 we have direct evidence of a change in the geometry of mass-loss, from spherical in the halo to axially-symmetric in the two pairs of bipolar lobes.Comment: 8 pages, 7 figures, Accepted for publication in MNRA

    Observations of the planetary nebula RWT 152 with OSIRIS/GTC

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    10 pages, 6 figuresRWT 152 is one of the few known planetary nebulae with an sdO central star. We present subarcsecond red tunable filterHa imaging and intermediate-resolution, long-slit spectroscopy of RWT 152 obtained with OSIRIS/GTC (Optical System for Imaging and low-Intermediate-Resolution Integrated Spectroscopy/Gran Telescopio Canarias) with the goal of analysing its properties. The Ha image reveals a bipolar nebula with a bright equatorial region and multiple bubbles in the main lobes. A faint circular halo surrounds the main nebula. The nebular spectra reveal a very low excitation nebula with weak emission lines from H+, He+ and double-ionized metals, and absence of emission lines from neutral and single-ionized metals, except for an extremely faint [NII] lambda 6584 emission line. These spectra may be explained if RWT 152 is a density-bounded planetary nebula. Low nebular chemical abundances of S, O, Ar, N and Ne are obtained in RWT 152, which, together with the derived high peculiar velocity (similar to 92-131 km s(-1)), indicate that this object is a halo planetary nebula. The available data are consistent with RWT 152 evolving from a low-mass progenitor (similar to 1 M-circle dot) formed in a metal-poor environment.This paper has been partially supported by grant AYA 2011-24052 (AA, ES), AYA 2011-30228-C3-01 (LFM), ESP2014-55996-C2-2-R (AU) and AYA2014-57369-C3-3-P (LFM) of the Spanish MINECO (all them co-funded by FEDER funds). We also acknowledge support from grant IN-CITE09 312191PR (AU, LFM, AA) of Xunta de Galicia, partially funded by FEDER funds, from grant PRX15/00511 (AU) of the Spanish MECD, and from grant 12VI20 (AU, LFM, AA) of the University of Vigo. AA also acknowledges support from FONDECYT through postdoctoral grant 3160364. This research has made use of the SIMBAD data base, operated at the CDS, Strasbourg (France), Aladin, NASA's Astrophysics Data System Bibliographic Services and the Spanish Virtual Observatory supported from the Spanish MINECO through grant AYA2011-24052.Peer reviewe

    ETHNOBOTANICAL STUDY IN TOLEDO-PR DISTRICT: AN APPROACH ABOUT USED SPECIES VARIABILITY WITH THE SAME POPULAR NAME

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    The ethnopharmacological knowledge acquired throughout human evolution culminated in the development of high therapeutic relevance drugs. In ethnobotanical survey conducted in the city of Toledo in 2007, it was found that 79% of the population often use plants for medicinal purposes, mostly in the tea form, originated from own crops. They claimed that the consumption of these plants improved their health conditions. The plants mainly cited were: balm, chamomile and marcela. This study aimed to verify if the population habits related to medicinal plants have changed, also  proceed a literature review to find out if the most used plants have their biological activity scientifically proven and looking for  reports of homonymous to the most cited medicinal plants. There was small change in the species used by the population. In the literature, it was found out that different species are used with the same popular name, in practice, it was detected the use of two different species, Piper amalago L. (UNOP 7972) and Piper mikanianum (Kunth) (UNOP 7971), for  the medicinal plant commonly known as pariparoba, although none of them is recognized for the Brazilian Pharmacopoeia

    ALMA-IMF IX: Catalog and Physical Properties of 315 SiO Outflow Candidates in 15 Massive Protoclusters

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    We present a catalog of 315 protostellar outflow candidates detected in SiO J=5-4 in the ALMA-IMF Large Program, observed with ~2000 au spatial resolution, 0.339 km/s velocity resolution, and 2-12 mJy/beam (0.18-0.8 K) sensitivity. We find median outflow masses, momenta, and kinetic energies of ~0.3 M_{\odot}, 4 M_{\odot} km/s, and 1045^{45} erg, respectively. Median outflow lifetimes are 6,000 years, yielding median mass, momentum, and energy rates of M˙\dot{M} = 104.4^{-4.4} M_{\odot} yr1^{-1}, P˙\dot{P} = 103.2^{-3.2} M_{\odot} km/s yr1^{-1}, and E˙\dot{E} = 1 L_{\odot}. We analyze these outflow properties in the aggregate in each field. We find correlations between field-aggregated SiO outflow properties and total mass in cores (~3-5σ\sigma), and no correlations above 3σ\sigma with clump mass, clump luminosity, or clump luminosity-to-mass ratio. We perform a linear regression analysis and find that the correlation between field-aggregated outflow mass and total clump mass - which has been previously described in the literature - may actually be mediated by the relationship between outflow mass and total mass in cores. We also find that the most massive SiO outflow in each field is typically responsible for only 15-30% of the total outflow mass (60% upper limit). Our data agree well with the established mechanical force-bolometric luminosity relationship in the literature, and our data extend this relationship up to L \geq 106^6 L_{\odot} and P˙\dot{P} \geq 1 M_{\odot} km/s yr1^{-1}. Our lack of correlation with clump L/M is inconsistent with models of protocluster formation in which all protostars start forming at the same time.Comment: 46 pages, 14 figures, 10 tables. This publication has an associated Zenodo entry, which can be found here: https://zenodo.org/records/835059

    ALMA-IMF. VII. First release of the full spectral line cubes: Core kinematics traced by DCN J=(3-2)

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    ALMA-IMF is an Atacama Large Millimeter/submillimeter Array (ALMA) Large Program designed to measure the core mass function (CMF) of 15 protoclusters chosen to span their early evolutionary stages. It further aims to understand their kinematics, chemistry, and the impact of gas inflow, accretion, and dynamics on the CMF. We present here the first release of the ALMA-IMF line data cubes (DR1), produced from the combination of two ALMA 12m-array configurations. The data include 12 spectral windows, with eight at 1.3mm and four at 3mm. The broad spectral coverage of ALMA-IMF (~6.7 GHz bandwidth coverage per field) hosts a wealth of simple atomic, molecular, ionised, and complex organic molecular lines. We describe the line cube calibration done by ALMA and the subsequent calibration and imaging we performed. We discuss our choice of calibration parameters and optimisation of the cleaning parameters, and we demonstrate the utility and necessity of additional processing compared to the ALMA archive pipeline. As a demonstration of the scientific potential of these data, we present a first analysis of the DCN (3-2) line. We find that DCN traces a diversity of morphologies and complex velocity structures, which tend to be more filamentary and widespread in evolved regions and are more compact in the young and intermediate-stage protoclusters. Furthermore, we used the DCN (3-2) emission as a tracer of the gas associated with 595 continuum cores across the 15 protoclusters, providing the first estimates of the core systemic velocities and linewidths within the sample. We find that DCN (3-2) is detected towards a higher percentage of cores in evolved regions than the young and intermediate-stage protoclusters and is likely a more complete tracer of the core population in more evolved protoclusters. The full ALMA 12m-array cubes for the ALMA-IMF Large Program are provided with this DR1 release.Comment: 75 pages (21 main body; 54 appendix), 37 figures. The ALMA-IMF DR1 line release is hosted at https://dataverse.harvard.edu/dataverse/alma-im

    Integrated Functions of Pax3 and Pax7 in the Regulation of Proliferation, Cell Size and Myogenic Differentiation

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    Pax3 and Pax7 are paired-box transcription factors with roles in developmental and adult regenerative myogenesis. Pax3 and Pax7 are expressed by postnatal satellite cells or their progeny but are down regulated during myogenic differentiation. We now show that constitutive expression of Pax3 or Pax7 in either satellite cells or C2C12 myoblasts results in an increased proliferative rate and decreased cell size. Conversely, expression of dominant-negative constructs leads to slowing of cell division, a dramatic increase in cell size and altered morphology. Similarly to the effects of Pax7, retroviral expression of Pax3 increases levels of Myf5 mRNA and MyoD protein, but does not result in sustained inhibition of myogenic differentiation. However, expression of Pax3 or Pax7 dominant-negative constructs inhibits expression of Myf5, MyoD and myogenin, and prevents differentiation from proceeding. In fibroblasts, expression of Pax3 or Pax7, or dominant-negative inhibition of these factors, reproduce the effects on cell size, morphology and proliferation seen in myoblasts. Our results show that in muscle progenitor cells, Pax3 and Pax7 function to maintain expression of myogenic regulatory factors, and promote population expansion, but are also required for myogenic differentiation to proceed

    Synthetic Biology Open Language (SBOL) Version 1.1.0

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    In this BioBricks Foundation Request for Comments (BBF RFC), we specify the Synthetic Biology Open Language (SBOL) Version 1.1.0 to enable the electronic exchange of information describing DNA components used in synthetic biology. We define: 1. the vocabulary, a set of preferred terms and 2. the core data model, a common computational representation
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