The branching ratios of the different reaction pathways and the overall rate of the dissociative recombination of CD$_{3}$OD$_{2}^{+}$ were measured at the CRYRING storage ring located at the Manne Siegbahn Laboratory in Stockholm, Sweden. A preliminary analysis of the data yielded that formation of methanol accounts for only 6 $\pm$ 2% of the total reaction rate. Largely, dissociative recombination of CD$_{3}$OD$_{2}^{+}$ involves fragmentation of the C–O bond, the major process being the three-body break-up forming CD$_{3}$, OD and D (branching ratio 0.59). A non-negligible formation of interstellar methanol by the previously proposed mechanism is therefore very unlikely.

We present estimates of the integrated contribution of extragalactic sources to the diffuse X-ray background in the 2–10 keV energy interval. It appears that classes of objects already detected as X-ray sources easily account for at least 10% of the background. Quasistellar objects, and possibly Seyfert and radio galaxies might contribute a larger fraction of the background intensity.

We also suggest that several of the unidentified X-ray sources in the UHURU catalogue at high galactic latitudes may be bright QSO's as yet unknown. The detection of a larger number of QSO's in the X-ray band may allow a decisive test for the cosmological interpretation of the redshifts of QSO's.

Observations of the longitudinal component of the photospheric magnetic fields near sunspots imply that surges and Ellerman bombs occur at neutral points in the magnetic fields (i.e. |B|=0) in the chromosphere. The neutral points appear above satellite sunspots, which are defined as polarity reversals (in B||) near the edges of large-spot penumbrae. A series of magnetograph observations shows a point of satellite polarity vanishing during a period of almost continuous surge activity. The lost magnetic energy is comparable to the energy release evidenced by the surge.

The main properties of this class of rare objects are described, and the criteria selected for discovering new members are indicated. The abundance anomalies, resulting from the scanty analyses made up to now, are discussed together with the theoretical interpretation proposed in the framework of the modified diffusion theory and of the recent selective accretion proposal.

Finally, we discuss the evolutionary stage of the λ Boo stars which, in the HR diagram, lie near, but not on the main sequence.

The Following design of a Pulsar Survey System with a Huge Interferometric Array is discussed. (1) A Huge Array of 320m × 320m with 256(= 16 × 16) spherical dishes of 20m in diameter, (2) RF is 1.4 GHz, (3) Receivers are frequency modified GPS(1.57542, 1.2276GHz) ones, (4) Phase and Delay Tracking, (5) Phase Calibration using Differential GPS(GPS signal × 2 → CW), (6) (2+1+2)D FFT /256 pixel Imaging + 256 ch Filtering + Dispersion Removal and Period finding(17M point floating 2DFFT by DSP), (8) Observing time required for the same sensitivity to Arecibo τ/τA: 0.88(Timing), 0.003(Survey).

We present a novel approach for simultaneous extraction of stellar population parameters and internal kinematics from the spectra integrated along a line of sight. We fit a template spectrum into an observed one in a pixel space using a non-linear χ2 minimization in the multidimensional parameter space, including characteristics of the line-of-sight velocity distribution (LOSVD) and parametrized star formation history (SFH). Our technique has been applied to IFU and multi-object spectroscopy of low-luminosity early type galaxies.

We have reanalyzed in a consistent way existing reverberation data for 35 AGNs for the purpose of refining the black hole masses derived from these data. We find that the precision (or random component of the error) of reverberation-based black hole mass measurements is typically around 30%, comparable to the precision attained in measurement of black hole masses in quiescent galaxies by gas or stellar dynamical methods. As discussed in this volume by Onken et al., we have established an absolute calibration for AGN reverberation-based masses by assuming that AGNs and quiescent galaxies follow an identical relationship between black hole mass and host-galaxy bulge velocity dispersion. The scatter around this relationship implies that the typical systematic uncertainties in reverberation-based black hole masses are smaller than a factor of three. We present a preliminary version of a mass–luminosity relationship that is much better defined than any previous attempt. Scatter about the mass–luminosity relationship for these AGNs appears to be real and could be correlated with either Eddington ratio or source inclination.To search for other articles by the author(s) go to: http://adsabs.harvard.edu/abstract_service.html

We present a multi-wavelength (NIR to radio) and multi-scale (1 AU to 10 pc) study of the S255–S257 complex of young high-mass (proto)stars. The complex consists of two evolved HII regions and a molecular gas filament in which new generations of high mass stars form. Four distinct regions are identified within this dusty filament: a young NIR/optical source cluster, a massive protostar binary, a (sub)millimetre continuum and molecular clump in global collapse and a reservoir of cold gas. Interestingly, the massive binary protostellar system is detected through methanol maser and mid-IR emission at the interface between the NIR cluster and the cold gas filament. The collapsing clump is located to the north of the NIR cluster and hosts a young high-mass star associated with an outflow that is observed in mid-IR, methanol maser and radio emission. We interpret this anatomy as the possible result of triggered star formation, starting with the formation of two HII regions, followed by the compression of a molecular gas filament in which a first generation of high-mass stars forms (the NIR cluster), which then triggers the formation of high mass protostars in its near environment (the massive protostellar binary). The global collapse of the northern clump might be due to both the expansion of the HII regions that squashes the filament. In conclusion, we witness the formation of four generations of clusters of high-mass stars in S255–S257.

Symplectic integrators are numerical integration methods for Hamiltonian systems, which conserves the symplectic 2-form exactly. With use of symplectic integrators there is no secular increase in the error of the energy because of the existence of a conserved quantity closed to the original Hamiltonian. Higher order symplectic integrators are obtained by a composition of 2nd order ones.

Plasma wave electric field measurements with the solar orbiting Helios spacecraft have shown that intense electron plasma oscillations occur in association with type III solar radio bursts, thereby confirming a well known mechanism for generating solar radio emissions first proposed by Ginzburg and Zheleznyakov in 1958. In this paper we review the principal characteristics of these plasma oscillations and compare the observed plasma oscillation intensities with recent measurements of the emissivity of type III radio bursts. The observed emissivities are shown to be in good agreement with two current models for the conversion of electrostatic plasma oscillations to electromagnetic radiation.

Channels share with their filaments in a hemispheric dependance for the orientation of their axial magnetic fields. This property has significant implications for models of filaments. In support of new model-building exercises, this review examines known signatures of channels, presents evidence that emerging flux plays a key role in creating a new filament channel, and compares channels which form in the belts of active latitudes with those formed closer to the poles.

The workshop on Historical Time-Domain Astronomy (TDA) was attended by a near-capacity gathering of ~30 people. From information provided in turn by those present, an up-to-date overview was created of available plate archives, progress in their digitization, the extent of actual processing of those data, and plans for data distribution. Several recommendations were made for prioritising the processing and distribution of historical TDA data.

Helioseismic measurements with the MDI instrument aboard SOHO, and complementary measurements from the GONG network, are revealing changes deep within the Sun as the solar cycle progresses. We present results based on recent data from both experiments, including variations in the rotation rate deep inside the convection zone.

The actual characteristic average surface angular velocity ratio of the Be phenomenon may be higher than Ω/Ωc = 0.8 ± 0.1 derived from v sin i values not corrected from gravity darkening effects. Late Be Stars need not only higher values of Ω/Ωc, but also larger main sequence age ratios τ/τMS than early Be Stars to display the Be phenomenon. Galactic field Be Stars appear at any MS phase, but their frequency is higher for τ/τMS ≳ 0.5. Be Stars are probably neat differential rotators, i.e. they rotate with energy ratios kinetic/|gravitational| larger than withstood by critical rigid rotators. Initial formation conditions must favor the existence of fast rotators, while only a small fraction of them could be accounted for by mass transfer in close binary systems. Bn stars could perhaps represent a pre-Be phase.

The sublimation or artificial icy cometary nuclei with different inclusions is investigated. Formation of meteoroids is discussed in connection with new polarizational observations of comet West. The possibility of chemical reactions on the sublimating surface is noted.

Terrestrial biochemistry is based upon chiral (handed) molecules, of which only one of the two possible hands is predominantly employed. This biomolecular “homochirality”, may be a universal “signature” of life. Along with all living organisms, plant leaves are constructed from arrays of chiral molecules of a single hand. Through the development of a new spectroscopic approach, Diffuse Reflectance Circular Dichroism in the UV-visible wavelength regions, we have detected this chirality non-invasively from non-specular light scattered by leaves. The characteristic spectra are sensitive to plant species and leaf age/health. The technique may provide a means of remote sensing the state of flora and, at closer range, an indicator of living organisms for interplanetary landers.

IR imaging, K–band spectroscopy and X-ray data of the stellar cluster in M 17 suggests three categories of massive young objects: I) “Naked” early-type O-stars in the cluster center that exhibit X-ray emission and normal optical/IR-spectra; they do not show signs for any circumstellar material. II) Late O-type stars, that show X-ray emission and H/He absorption lines in their optical/IR-spectra. There is evidence for extended circumstellar material in the form of elongated L–band nebulae, circumstellar MIR emission from regions of about 10.000 AU in diameter and filaments of He I $1.083\,\mu$m. III) Massive stars without X-ray emission, K–band spectra with emission lines of H and He and in some cases with CO band head emission. They are heavily enshrouded and also show elongated L–band nebulae, circumstellar MIR emission from regions of about 4.000 AU and ionized He envelopes.

Obviously, M 17 harbors several generations of massive stars: Only the oldest “Category I”, located in the cluster center, is free of circumstellar material. “Category II” and “III” comprise younger dust-enshrouded objects of a second generation embedded in the interface of the HII region and the adjacent molecular cloud. Due to the presence of flattened dusty disks and perpendicular gaseous outflows, accretion seems to be important for the formation of stars up to type O8.

A population of X-ray emitting sources with($L_{\rm bol} \sim 10^4\,$L$_\odot$) shows CO band head absorption; one source was found to have variable CO absorption as known from FU Orionis stars.

New data on the 20.000 AU accretion disk in M 17 reveals a collimated H$_2$$2.122\,\mu$m jet with three distinct emission knots that emerges from the disk center. The broad H$\alpha$ and Ca II emission lines from the bipolar nebula display blue-shifted absorption originating from accretion disk-driven outflows with velocities of $\pm 500$ km/s.

Discovered in 1995 at the Caltech Submillimeter Observatory (CSO), the vibrationally-excited water maser line at 658 GHz (455 micron) is seen in oxygen-rich giant and supergiant stars. Because this maser can be so strong (up to thousands of Janskys), it was very helpful during the commissioning phase of the highest frequency band (620-700 GHz) of the Submillimeter Array (SMA) interferometer. From late 2002 to early 2006, brief attempts were made to search for emission from additional sources beyond the original CSO survey. These efforts have expanded the source count from 10 to 16. The maser emission appears to be quite compact spatially, as expected from theoretical considerations; thus these objects can potentially be used as atmospheric phase calibrators. Many of these objects also exhibit maser emission in the vibrationally-excited SiO maser at 215 GHz. Because both maser lines likely originate from a similar physical region, these objects can be used to test techniques of phase transfer calibration between millimeter and submillimeter bands. The 658 GHz masers will be important beacons to assess the performance of the Atacama Large Millimeter Array (ALMA) in this challenging high-frequency band.

Hybrid maps of the nuclei of radio galaxies and quasars show a variety of morphologies. Among compact sources, two structures are common: an asymmetric, “core-jet” morphology (eg, 3C 273), and an “equal double” morphology with two separated, similar components (eg, CTD 93). The nuclei of extended, double radio galaxies generally have a core-jet morphology with the jet directed toward one of the outer components.

We give results of models of massive stars which have a detailed physical treatment of rotation, including structural equations for shellular rotation, new treatments of shears in differentially rotating stars and of meridional circulation, together with mass loss rates depending on rotation. For a 20 M⊙ star, He- and N-enrichments at the stellar surface already occur during the MS phase for moderately low rotational velocities, thus most supergiants are enriched in helium and nitrogen. A long B- and A-supergiant phase results from rotational mixing, with some primary nitrogen formed at this stage. For the most massive stars, rotation makes the star to enter the WR stage during the MS phase thus avoiding the LBV and red supergiant stage.

The WR life-times are considerably increased by rotation and the minimum mass for forming WR stars is lowered. Interestingly enough, the increase of the WN life-time is larger than for WC stars, so that rotation leads to a decrease of the WC/WN number ratio. Also, the fraction of transition WN/WC stars is much larger at higher rotation.

Finally, on the basis of clusters in the SMC, in the LMC and towards the galactic interior and exterior, we show that for clusters with ages between about 1 and 3 x 107 yr the fraction of Be stars with respect to normal B stars is larger at lower metallicities. This may suggest a higher rotation at lower metallicities for massive stars, due to a different history of star formation.