Interstellar matter related to Gould's belt

In this short review we outline some of the characteristics of the interstellar matter related to Gould's belt. We first describe the associated HI and mention some of the kinematical models which have been fitted to it. After mentioning the most important associated molecular complexes, the total mass of the neutral gas is estimated as being on the order of 2 x10⁸ M⊙. It looks like the neutral gas is a super-shell, whereas its interior has the characteristics of a super-bubble.Asociación Argentina de Astronomí

The interstellar medium surrounding the Scorpius-Centaurus association revisited

Aims: We want to make a large-scale study of the morphology, kinematics, and origin of the H I, which surrounds the Sco-Cen association. Methods. We combine our high-sensitivity southern H I survey with the Leiden/Dwingeloo Survey, considering l = 240◦−400◦, b = −60◦ to +60◦, and radial velocities of V = −41.8 to +40.8 km s−1. We point out the main H I branches surrounding the association and derive their kinematics. Kinematical H I-maps were compared with spatial maps of interstellar (IS) Na I from the literature. Upper limits for distances d were derived from optical IS absorption components from the literature. Models of expanding spherical H I shells were fitted around each stellar subgroup. Results: The expanding ring of H I associated with the Gould Belt (GB) is very prominent. At each l, its radial velocity shifts ∼−7 km s−1 within an interval Δb ∼ 10◦−25◦. On the sky, the shifts occur within a narrow stripe extending between l, b ∼ 250◦, −18◦ and 400◦, +50◦. The ranges of distances and radial thicknesses of most H I branches are nearly 70−160 pc and 40−90 pc, respectively. The shell-models fit the main branches. Interactions between the shells built a large expanding bubble with a transverse diameter of nearly 250 pc around the association. The near face is approaching with a mean velocity V¯ ∼ −6.6 km s−1 at d ≤ 76 pc from the Sun, covering about 102◦ × 65◦ (l, b), forming an “H I-wall”. There are streamers at V¯ ∼ −15 to −35 km s−1, as well as gas presumably overshot into Galactic Quadrant II. The receding gas is more tenuous. Conclusions: The association is traversing the ring since a time comparable to its age producing a significant disturbance on the expanding GB-ring of gas. The latter was almost totally shocked by the association, northerly of the stripe of velocity shifts. Southerly there are large amounts of preshocked gas, as well as smaller more localized shocked regions. Hot gas within the bubble produces most of the 1/4 keV radiation detected toward it by ROSAT. The total mass of the GB gas embedding the Sco-Cen association is estimated at Mt ∼ 368 000 M ± 60%, including ∼34 000 M of associated H2 and 30% of He. About 39% of the embedding gas was shocked by the association. At |b|≥ 35◦, a comparison of the observations with test points moving on ballistic orbits is consistent with the formation of the Sco-Cen association within the gas ring of the GB and the presumable explosive origin of the latter. The rotation of the ring is assumed.Fil: Pöppel, W, G. L.. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Bajaja, E.. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Arnal, Edmundo Marcelo. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Morras, Ricardo. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; Argentin

Cinemática del hidrógeno interestelar en las regiones de Scorpius y Lupus

The distribution of neutral hydrogen is studied in the region defined by (1). After subtracting a broad Gaussian component, which could be interpreted as the emission of a diffuse intercloud medium, a Gaussian analysis of the resulting profiles was carried out. The principal components are listed in Table 1. Component II, the most intense one, is interpreted as being identical with feature A of Lindblad 1967. However, its, Nₕ and velocity distributions show up a strong perturbation in a large area around the Lupus Loop. It is proposed that all the other narrow width components in Table 1 were blown off from Gould's belt main HI - shell due to supernova explosion which originated in the Lupus Loop SNR. As the paper will be published elsewhere, we give here only a synthesis.Asociación Argentina de Astronomí

Quantum effects in linguistic endeavors

Classifying the information content of neural spike trains in a linguistic endeavor, an uncertainty relation emerges between the bit size of a word and its duration. This uncertainty is associated with the task of synchronizing the spike trains of different duration representing different words. The uncertainty involves peculiar quantum features, so that word comparison amounts to measurement-based-quantum computation. Such a quantum behavior explains the onset and decay of the memory window connecting successive pieces of a linguistic text. The behavior here discussed is applicable to other reported evidences of quantum effects in human linguistic processes, so far lacking a plausible framework, since either no efforts to assign an appropriate quantum constant had been associated or speculating on microscopic processes dependent on Planck's constant resulted in unrealistic decoherence times

Distribución cinemática del material interestelar local

e hace una comparación critica de diversos resultados observacionales tomados de la literatura con los resultados predichos por un modelo basado en un evento explosivo producido hace irnos 30 a 37 millones de años dentro del estrato de gas neutro frío y a unos 120 - 200 pc de la posición actual del Sol.Asociación Argentina de Astronomí

HI y HII en Scorpius-Ophiuchus

The distribution of neutral hydrogen is studied in the region defined by eq. (1). After subtracting a broad Gaussian component, which could be interpreted as the emission of a hot inter-cloud medium, a Gaussian analysis of the residual 21-cm profiles was performed. The resultant components, of small velocity dispersion, have counterparts in interstellar absorption lines of Na I and Ca II. They could have originated by an expanding phenomenon (like a supernova explosion) produced within the gas related to feature A of Lindblad by stars of the association Sco OB2. As the paper will be published elsewhere, we give here only a synthesis.Asociación Argentina de Astronomí

Distribución de las nubes de alta velocidad (NAV) en todo el cielo

Sobre la base de toda la información existente sobre NAV se realizaron estudios sobre sus distribuciones espacial y en velocidad, a los efectos de distinguir las distintas poblaciones de NAV y permitir sugerir explicaciones sobre su origen.Asociación Argentina de Astronomí

High velocity clouds: a model to explain their spatial distribution

We analyzed the asymmetries in the distribution of High Velocity Clouds. Some of the asymmetries may be explained with the supposition that they are distributed on a sphere and that they are falling to its center with a velocity Vᵢ which can be measured by an observer at the center of the sphere and moving with a velocity Vₚ in the direction lₚ,bₚ. Adjusting the observational parameters we derive: Vᵢ= -75 km/sec; Vₚ= 385 ± 5 km/sec, lₚ=110°±5° and bₚ=10°±5°. The conclusion is that a sample of High Velocity Clouds can be interpreted as gas clouds falling to the center of the local group of galaxies.Asociación Argentina de Astronomí

Distribución del hidrógeno neutro a |b| ≥ 10°

Los datos obtenidos en el IAR con el radiotelescopio de 30 m fueron combinados con los obtenidos mediante el radiotelescopio de la Universidad de California en Hat Creek. De esta forma se obtuvieron mapas de la distribución de hidrógeno neutro que cubren todo el cielo, en el rango de velocidades de -40 a +40 km s⁻¹, cada 4 km s⁻¹. Se discuten las principales características de los mismos.Asociación Argentina de Astronomí

Distribución del hidrógeno neutro en el hemisferio sur

Se discuten dos estructuras de HI y sus asociaciones con el continuo, emisión de rayos X y polarización óptica.Asociación Argentina de Astronomí