The symbiotic star H1-36. A composite model of line and continuum spectra from radio to ultraviolet

In this paper we analyse the spectra of D-type SS H1-36 within a colliding-wind scenario. We aim to analyse the properties of this object taking into account the observational data along the whole electromagnetic spectrum, in order to derive a self-consistent picture able to interpret the nature of the system as a whole. After constraining the relative physical conditions by modelling more than 40 emission lines from radio to UV, we are able to explain the continuum spectral energy distribution by taking into account all the emitting contributions arising from both the stars, the dust shells and the gaseous nebulae. A comprehensive model of the radio spectra allows to reproduce the different slopes of the radio profile and the turnover frequency, as well as the different size of the observed shocked envelope at different frequencies in the light of the different contributions from the expanding and reverse nebulae. The IR continuum unveils the presence of two dust shells with different radii and temperatures, which might be a distinctive feature of D-type symbiotic systems as a class of objects. The broad profiles of IR lines direct us to investigate whether an X-ray jet may be present. This insight leads us to indicate H1-36 as a promising X-ray target and to encourage observations and studies which consistently take into account the complex nature of symbiotic stars throughout the whole electromagnetic spectrum.Comment: 8 pages, 3 figures, 5 tables, accepted for publication in A&A on 2th May 200

Effect of forage/concentrate ratio and soybean oil supplementation on milk yield and quality from dairy goats

Dietary energy level is a limiting factor of milk production mainly in early lactation goats. Energy intake may be increased by incorporation of fat in ration. Currently, rumen protected fat is mainly adopted in goats nutrition, since the several studies have clearly confirmed that supplies of protected fat markedly improved the fat percentage of goat milk (Schmidely and Sauvant, 2001; Chilliard et al., 2003)

Additional diagnostic value of implantable loop recorder for differentiating syncope from non-syncopal forms of transient loss of consciousness

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MASYS. The AKARI spectroscopic survey of Symbiotic Stars in the Magellanic Clouds

MASYS is the AKARI spectroscopic survey of Symbiotic Stars in the Magellanic Clouds, and one of the European Open Time Observing Programmes approved for the AKARI (Post-Helium) Phase-3. It is providing the first ever near-IR spectra of extragalactic symbiotic stars. The observations are scheduled to be completed in July 2009.Comment: 4 pages, 1 table. To appear in the Proceedings of the Conference "AKARI, a light to illuminate the misty Universe", Fukutake Hall, The University of Tokyo, Japan, 16-19 February 200

The Circum-Galactic Environment of Bright IRAS Galaxies

This paper studies systematically, for the first time, the circumgalactic environment of bright IRAS galaxies as defined by Soifer et al. (1989). While the role of gravitational interaction for luminous and ultraluminous IRAS galaxies has been well established by various studies, the situation is by far more obscure in the IR luminosity range of the bright IRAS sample, 10^{10}Lsol < Lfir < 10^{11} Lsol. To easily identify nearby companion galaxies, the bright IRAS sample was restricted to 87 objects with redshift range 0.008 < z < 0.018 and galactic latitude > 30^{o}. A control sample, selected from the Center for Astrophysics redshift survey catalogue, includes 90 objects matching the Bright IRAS sample for distribution of isophotal diameter, redshift, and morphological type. From a search of nearby companion galaxies within 250 Kpc on the second-generation Digitized Sky Survey (DSS-II), we found that the circumgalactic environment of the Bright IRAS galaxies contains more large companions than the galaxies in the optically selected control sample, and is similar to that of Seyfert 2 galaxies. We found a weak correlation over a wide range of far IR luminosity (10^9 Lsol < Lfir < 10^{12.5}Lsol) between projected separation and Lfir, which confirms a very close relationship between star formation rate of a galaxy and the strength of gravitational perturbations. We also find that the far IR colors depend on whether a source is isolated or interacting. Finally, we discuss the intrinsic difference and evolution expectations for the bright IRAS galaxies and the control sample, as well as the relationship between starbursting and active galaxies.Comment: 10 pages, 5 figs, 2 tables. Accepted for publication in Ap

The symbiotic star CH Cygni. II. The broad Ly alpha emission line explained by shocks

Context. In 1985, at the end of the active phase 1977-1986, a broad (4000 km/s) Ly alpha line appeared in the symbiotic system CH Cygni that had never been observed previously. Aims. In this work we investigate the origin of this anomalous broad Ly alpha line. Methods. We suggest a new interpretation of the broad Ly alpha based on the theory of charge transfer reactions between ambient hydrogen atoms and post-shock protons at a strong shock front. Results. We have found that the broad Ly alpha line originated from the blast wave created by the outburst, while the contemporary optical and UV lines arose from the nebula downstream of the expanding shock in the colliding wind scenario.Comment: 5 pages, 2 figures, accepted for publication in A&A on 7th April 200

Analysis of the Interaction Effects in the Southern Galaxy Pair Tol1238-364 and ESO381-G009

In the context of the connection among galaxy-galaxy interaction, starbursts and nuclear activity, we present and discuss a quantitative morphological analysis based on BVR images and a detailed spectroscopic investigation of two interacting galaxies, the Seyfert 2 Tol1238-364 (IC 3639) and its companion ESO381-G009, forming a triple system with ESO381-G006. Broad-band optical photometry is complemented by Halpha imaging, which provides information about the distribution of star forming regions across the galaxies. Long-slit spectroscopic data obtained at different position angles of the slit are employed to determine the physical conditions of circumnuclear and extranuclear regions. A mixture of thermal and non-thermal ionizing radiation is found in the surroundings of the nucleus of Tol1238-364 and the energy budget supports the presence of a circumnuclear starburst.Several regions in both the galaxies show anomalous line ratios: additional ionization by shock-heating and low ionization of some extranuclear HII regions are suggested as possible explanations. An analysis of the emission-line profiles reveals the presence of a broad Halpha component in the nuclear region of Tol1238-364. Independent estimates of the star formation rates (SFR) were obtained through flux-calibrated Halpha-images and FIR emission in the four IRAS bands. Overall SFR densities have been compared with the SFR densities derived from Halpha emission in the individual regions of the galaxies sampled by long-slit spectra. In both galaxies an enhancement of the star formation activity with respect to isolated galaxies is revealed. The prevalence of starburst or nuclear activity has been examined through FIR color indices. The interaction scenario is discussed on the basis of the observed galaxy properties.Comment: Tentatively scheduled for publication in ApJS, v184 n2 October 2003 issue. A version with full resolution figures is available as unedited preprint at http://www.journals.uchicago.edu/ApJ/future.htm

Examining the Seyfert - Starburst Connection with Arcsecond Resolution Radio Continuum Observations

We compare the arcsecond-scale circumnuclear radio continuum properties between five Seyfert and five starburst galaxies, concentrating on the search for any structures that could imply a spatial or causal connection between the nuclear activity and a circumnuclear starburst ring. No evidence is found in the radio emission for a link between the triggering or feeding of nuclear activity and the properties of circumnuclear star formation. Conversely, there is no clear evidence of nuclear outflows or jets triggering activity in the circumnuclear rings of star formation. Interestingly, the difference in the angle between the apparent orientation of the most elongated radio emission and the orientation of the major axis of the galaxy is on average larger in Seyferts than in starburst galaxies, and Seyferts appear to have a larger physical size scale of the circumnuclear radio continuum emission. The concentration, asymmetry, and clumpiness parameters of radio continuum emission in Seyferts and starbursts are comparable, as are the radial profiles of radio continuum and near-infrared line emission. The circumnuclear star formation and supernova rates do not depend on the level of nuclear activity. The radio emission usually traces the near-infrared Br-gamma and H2 1-0 S(1) line emission on large spatial scales, but locally their distributions are different, most likely because of the effects of varying local magnetic fields and dust absorption and scattering.Comment: 21 pages, 10 figures. Accepted for publication in the Astronomical Journa

The double AGN in NGC 6240 revealed through 3-5 micron spectroscopy

We present 3-5 micron spectroscopy of the interacting system NGC 6240, showing the presence of two active galactic nuclei. The brightest (southern) nucleus shows up with a starburst-like emission, with a prominent 3.3 micron emission feature. However, the presence of an AGN is revealed by the detection of a broad Br alpha emission line, with a width of ~1,800 km/s. The spectrum of the faintest (northern) nucleus shows typical AGN features, such as a steep continuum and broad absorption features in the M-band. We discuss the physical properties of the dusty absorbers/emitters, and show that in both nuclei the AGN is dominant in the 3-5 micron band, but its contribution to the total luminosity is small (a few percent of the starburst emission).Comment: 10 pages, 2 figures, accepted for publication in ApJ Letter

A Multi-Wavelength Study of the Nature of Type 1.8/1.9 Seyfert Galaxies

We focus on determining the underlying physical cause of a Seyfert galaxy's appearance as type a 1.8 or 1.9. Are these "intermediate" Seyfert types typical Seyfert 1 nuclei with reddened broad-line regions? Or are they objects with intrinsically weak continua and broad emission lines? We compare measurements of the optical reddening of the narrow and broad-line regions with each other and with the X-ray column derived from XMM-Newton 0.5-10 keV spectra to determine the presence and location of dust in the line of sight. We also searched the literature to see if the objects showed evidence for broad-line variability, and determined if the changes were consistent with a change in reddening or a change in the intrinsic ionizing continuum flux. We find that 10 of 19 objects previously classified as Seyfert 1.8/1.9s received this designation due to their low continuum flux. In four objects the classification was due to BLR reddening, either by the torus or dust structures in the vicinity of the NLR; in the remaining five objects there is not sufficient evidence to favor one scenario over the other. These findings imply that, in general, samples of 1.8/1.9s are not suitable for use in studies of the gas and dust in the central torus.Comment: 85 pages, accepted by Ap