VLT and GTC observations of SDSS J0123+00: a type 2 quasar triggered in a galaxy encounter?

We present long-slit spectroscopy, continuum and [OIII]5007 imaging data obtained with the Very Large Telescope and the Gran Telescopio Canarias of the type 2 quasar SDSS J0123+00 at z=0.399. The quasar lies in a complex, gas-rich environment. It appears to be physically connected by a tidal bridge to another galaxy at a projected distance of ~100 kpc, which suggests this is an interacting system. Ionized gas is detected to a distance of at least ~133 kpc from the nucleus. The nebula has a total extension of ~180 kpc. This is one of the largest ionized nebulae ever detected associated with an active galaxy. Based on the environmental properties, we propose that the origin of the nebula is tidal debris from a galactic encounter, which could as well be the triggering mechanism of the nuclear activity. SDSS J0123+00 demonstrates that giant, luminous ionized nebulae can exist associated with type 2 quasars of low radio luminosities, contrary to expectations based on type 1 quasar studies.Comment: 6 pages, 5 figures. Accepted for publication in MNRAS Letter

Nuevos registros de abejas megachilidas (Hymenoptera: Megachilidae) para Colombia

The bee family Megachilidae consists of solitary species, some of which are important pollinators of cultivated plants. Although literature records indicate the existence of about 50 species of 10 genera of megachilid bees in Colombia, taxonomic studies are lacking and thus limited information is available on their identity as well as their distribution in the country. Herein, we provide new geographical records for the following ten species: Anthidium sanguinicaudum Schwarz, Chelostomoides otomita (Cresson), Hoplostelis bilineolata (Spinola), Megachile amparo Gonzalez, M. kalina Gonzalez et al., M. lorenziensis Mitchell, M. moderata Smith, M. simillima Smith, Pseudomegachile lanata (Fabricius), and Stelis costaricensis Friese. We report M. kalina for the first time for the country.Las abejas de la familia Megachilidae son especies solitarias, algunas de ellas importantes polinizadores de cultivos. Aunque en la literatura se registran cerca de 50 especies de 10 géneros de abejas megachilidas en Colombia, faltan estudios taxonómicos y, por lo tanto, se dispone de información limitada sobre la identidad y la distribución de este grupo en el país. En este trabajo proporcionamos nuevos registros geográficos para 10 especies poco conocidas [Anthidium sanguinicaudum Schwarz, Chelostomoides otomita (Cresson), Hoplostelis bilineolata (Spinola), Megachile amparo Gonzalez, M. kalina Gonzalez et al., M. lorenziensis Mitchell, M. moderata Smith, M. simillima Smith, Pseudomegachile lanata (Fabricius), y Stelis costaricensis Friese]. Megachile kalina se registra por primera vez para Colombia

VLBA determination of the distance to nearby star-forming regions I. The distance to T Tauri with 0.4% accuracy

In this article, we present the results of a series of twelve 3.6-cm radio continuum observations of T Tau Sb, one of the companions of the famous young stellar object T Tauri. The data were collected roughly every two months between September 2003 and July 2005 with the Very Long Baseline Array (VLBA). Thanks to the remarkably accurate astrometry delivered by the VLBA, the absolute position of T Tau Sb could be measured with a precision typically better than about 100 micro-arcseconds at each of the twelve observed epochs. The trajectory of T Tau Sb on the plane of the sky could, therefore, be traced very precisely, and modeled as the superposition of the trigonometric parallax of the source and an accelerated proper motion. The best fit yields a distance to T Tau Sb of 147.6 +/- 0.6 pc. The observed positions of T Tau Sb are in good agreement with recent infrared measurements, but seem to favor a somewhat longer orbital period than that recently reported by Duchene et al. (2006) for the T Tau Sa/T Tau Sb system.Comment: 24 pages, 3 pages, AASTEX format, accepted for publication in Ap

Baryon Resonances

In this talk I show recent results on how many excited baryon resonances appear as systems of one meson and one baryon, or two mesons and one baryon, with the mesons being either pseudoscalar or vectors. Connection with experiment is made including a discussion on old predictions and recent results for the photoproduction of the $\Lambda(1405)$ resonance, as well as the prediction of one $1/2^+$ baryon state around 1920 MeV which might have been seen in the $\gamma p \to K^+ \Lambda$ reaction.Comment: Talk given at the 10th International Conference on Hypernuclear and Strange Particle Physics, Tokai, Japan, Sptember 200

Coerced Hospital Admission and Symptom Change-A Prospective Observational Multi-Centre Study

PMCID: PMC3227658 Freely available online via CCplosone.org