Toward Resolving the Outflow Engine: An Observational Perspective

Jets from young stars represent one of the most striking signposts of star formation. The phenomenon has been researched for over two decades and there is now general agreement that such jets are generated as a by-product of accretion; most likely by the accretion disk itself. Thus they mimic what occurs in more exotic objects such as active galactic nuclei and micro-quasars. The precise mechanism for their production however remains a mystery. To a large degree, progress is hampered observationally by the embedded nature of many jet sources as well as a lack of spatial resolution: Crude estimates, as well as more sophisticated models, nevertheless suggest that jets are accelerated and focused on scales of a few AU at most. It is only in the past few years however that we have begun to probe such scales in detail using classical T Tauri stars as touchstones. Application of adaptive optics, data provided by the HST, use of specialised techniques such as spectro-astrometry, and the development of spectral diagnostic tools, are beginning to reveal conditions in the jet launch zone. This has helped enormously to constrain models. Further improvements in the quality of the observational data are expected when the new generation of interferometers come on-line. Here we review some of the most dramatic findings in this area since Protostars and Planets~IV including indications for jet rotation, i.e. that they transport angular momentum. We will also show how measurements, such as those of width and the velocity field close to the source, suggest jets are initially launched as warm magneto-centrifugal disk winds. (abridged)Comment: 14 pages, 8 figures, contributed chapter for Planets and Protostars V meeting (October 2005

Infrared Observation of Hot Cores

We report on mid-infrared imaging of hot cores performed with SpectroCam-10 and TIMMI2. The observations aimed at the detection of thermal emission presumably associated with the hot cores. Mid-infrared flux measurements are required to improve the luminosity and optical depth estimates for these sources. Results are presented for W3(H$_2$O), G9.62+0.19, G10.47+0.03, and the possible hot core candidate G232.620+0.996. They illustrate that the morphology of these sources cannot be described by simple geometries. Therefore, line-of-sight effects and considerable extinction even at mid-infrared wavelengths must not be neglected.Comment: 6 pages, 4 figures, Conference proceeding "Origins of stars and planets: The VLT view", ESO, Garching, April 24-27 200

Optische Counterparts von Gammaausbruechen Schlussbericht

SIGLEAvailable from TIB Hannover: DtF QN1(36,23) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Battery and Dynamo theory in the Kerr metric

. The generation and evolution of magnetic fields in the plasma accreting into a rotating black hole is studied in the 3+1 split of the Kerr metric. Attention is focused on effects of the gravitomagnetic potential. The gravitomagnetic force appears as battery term in the generalized Ohm's law. The gravitomagnetic battery is likely to saturate at higher field strength than the classical Biermann battery. The coupling of the gravitomagnetic potential with electric fields appears as gravitomagnetic current in Maxwell's equations. In the magnetohydrodynamic induction equation, this current re-appears as source term for the poloidal magnetic field, which can produce closed magnetic structures around an accreting black hole. In principle, even self-excited axisymmetric dynamo action is possible, which means that Cowling's anti-dynamo theorem does not hold in the Kerr metric. Finally, simulations of the ff\Omega dynamo in accretion flows into the hole are presented. I assume a simple expres..

Labor- und Inflight Kalibrierung von Space Experimenten zur Messung des Sonnenspektrums von 180 bis 3500 nm in internationaler Zusammenarbeit Abschlussbericht

Available from TIB Hannover: DtF QN1(61,27) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman

Entwurf, Bau und Installation von zwei Focal-Reduktor-Spectrographen fuer das Very Large Telescope (VLT) des European Southern Observatory (ESO) Schlussbericht

SIGLEAvailable from TIB Hannover: DtF QN1(50,36) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung, Wissenschaft, Forschung und Technologie, Bonn (Germany)DEGerman