Flip of the jet head position of 3C 84 in 2015

By performing the multi-epoch monitoring observation with KaVA at 43 GHz, we investigate the kinematics of the notable newborn bright component C3 located at the tip of the recurrent jet of 3C 84. During 2015 August-September,we discover the positional flip of the C3 component about 0.4 milli-arcsecond in angular scale. The flux density of the C3 component coherently showed the monotonic increase after the flip during our monitoring period. These phenomena are in good agreement with characteristic behaviors of a jet propagation in clumpy ambient medium predicted in hydrodynamical simulations.

β Lyrae - A Binary System with Anomalous Abundances and Magnetic Field

Study of dependence of chemical abundance on conditions of excitation within the limits which could exist in the atmosphere of bright component have led to conclusion that by no modification of physical parameters a “normal” abundance of chemical elements in the atmosphere can be obtained. The variable effective magnetic field with mean value (−1350±50) Gauss is discovered.

The interaction of the supermassive object R136a with the interstellar environment

R136a is the luminous object in the core of the 30 Dor nebula in the LMC, embedded in the extremely young star cluster NGC 2070 with the most recent star forming event less 106 yr ago. R136a-1 (V = 11.08) lies in the center of this cluster. The companion or foreground star R136a-2 (ca. 1.2m fainter than R 136a-1) 0′.5 apart does not impair the dominating role of R136a-1. The light distribution is strongly peaked to the center of R136a and disagrees completely with Moffat and Seggewiss's (1983) description and their interpretation as a dense core of a cluster (Chu and Wolfire, 1983). This is strenghtened by the UV observations (Cassinelli et al. 1981, Feitzinger et al. 1983, Savage et al. 1983): the spatial spread function of the IUE satellite is dominated by an object of extremely small ultraviolet extent, less than that of a gaussian with 1′.5. Speckle observations (Meaburn, 1982; Weigelt, 1981), are discordant in the interpretation of the faint background, but concordant in revealing the existence of a small bright component, with an upper limit of the diameter < 0.02 pc. This is also found, with somewhat lower resolution, by Chu (1934).

Are QSOs Gravitationally Lensed?

There are now four known cases of multiply imaged QSOs, one with a detected foreground object at roughly half the affine distance to the QSO: 0957+561 (17 mag, z=1.4, separation =6″), 1115+080 (17 mag, z=1.7, sl=1.8″, s2=2.3″), 2345+007 (19 mag, z=2.1, s=7″) and 1635+267 (19 mag z=2, s=5″). In addition, 1548+115 (19 mag, z=1.9) is a probable lens event with a foreground QSO, but no secondary image has been found. Perhaps 500 candidate QSOs have been surveyed optically for multiple images by all observers. 0957+561 is the only catalogued QSO shown to be multiple. Of the remaining 1548 QSOs currently catalogued, any secondary image is masked by atmospheric scattering of the QSO light. Typically, this sets detection limits of ≳ 3 mag fainter and < 2 arcsec separation from the bright component, for any secondary image. Objective prism and grism surveys look directly for multiple QSOs with identical emission lines and have surveyed 1500 QSOs. The remaining three lensed QSOs come from these more efficient surveys. Although the exciting search for multiply imaged QSOs has only begun, sufficient data already exist to test two hypotheses: (A) QSOs are intrinsically luminous and occasionally are multiply imaged through a chance alignment with a foreground galaxy of sufficient mass gradient and (B) all QSOs are the result of gravitational lens magnification of a distant Seyfert nucleus by foreground galaxy(s). I will first address hypothesis B, then A. I assume that mass (seen and unseen) clusters with galaxies and/or clusters of galaxies.

Observations sur les "stipites" de Balmarelesse (Aveyron)

The Jurassic coal of the Balmarelesse field, Aveyron, France, is composed of a bright component which cannot be classed either as vitrain or clarain, but which is probably a form of vitrain whose development was arrested, and a dull component containing typical fusain. The coal is difficult to classify because various of its properties are similar to those of several coal types. It is definitely not a lignite. The name stipite, previously proposed for the Balmarelesse coal, should therefore be retained to designate its classification.