Modes of Infernal Rave Dancing: for Orchestra

Modes of Infernal Rave Dancing is a lively and compact orchestral work combining many elements that would not otherwise belong together. It applies 20th-century harmonic techniques to a simple dance melody as one would hear in the electronic dance genre. The piece begins by emphasizing one pitch, and gradually adds more pitches before presenting the main melody. Each section builds to segments with harsh dissonances. The entire piece relies on the rhythmic pulse, which creates a sense of urgency in the beginning, nearly disappears in the middle, and returns energetically at the finale. My hope is that this work is suitable as a witty beginning or conclusion to any orchestral concert

Magnetic latitude effects in the solar wind

The Weber-Davis model of the solar wind is generalized to include the effects of latitude. The principal assumptions of high electrical conductivity, rotational symmetry, the polytropic relation between pressure and density, and a flow-alined field in a system rotating with the sun, are retained. An approximate solution to the resulting equations for spherical boundary conditions at the base of the corona indicates a small component of latitudinal flow toward the solar poles at large distances from the sun as result of latitudinal magnetic forces

Extended Gas in Seyfert Galaxies: Near Infrared Observations of NGC 2110 and Circinus

We present results of near--IR long-slit spectroscopy in the J and K bands of the Seyfert 2 galaxies NGC 2110 and Circinus, investigating the gaseous distribution, excitation, reddening and kinematics. In NGC 2110, the emission line ratio [FeII]/Pa beta increases towards the nucleus (to ~ 7). The nuclear [Fe II]1.257 (microns) and Pa beta lines are broader (FWHM ~ 500 km/s) than the H2 (2.121) line (FWHM ~ 300 km/s). Both these results suggest that shocks, driven by the radio jet, are an important source of excitation of [Fe II]. The H2 excitation appears to be dominated by X-rays from the nucleus. In Circinus, both [FeII]/Pa beta and H2/Br gamma decrease from ~ 2 at 4 arcsec from the nucleus to nuclear values of ~ 0.6 and ~ 1, respectively, suggesting that the starburst dominates the nuclear excitation, while the AGN dominates the excitation further out (r > 2 arcsec). For both galaxies, the gaseous kinematics are consistent with circular rotation in the plane of the disk. Our rotation curves suggest that the nucleus (identified with the peak of the IR continuum) is displaced from the kinematic centre of the galaxies. This effect has been observed previously in NGC 2110 based on the kinematics of optical emission lines, but the displacement is smaller in the infrared, suggesting the effect is related to obscuration. The continuum J-K colours of the nuclear region indicate a red stellar population in NGC 2110 and a reddened young stellar population in Circinus. Right at the nucleus of both galaxies, the colours are redder, apparently a result of hot dust emission from the inner edge of a circumnuclear torus.Comment: 11 pages, 14 figures, accepted for publication in MNRA

Extended Gas in Seyfert Galaxies: Near-Infrared Observations of 15 Active Nuclei

Results from an analysis of low resolution (R~250) near-IR long-slit spectra covering simultaneously the I, J, H, and K bands, for a sample of 15 Seyfert galaxies and the N5253 starburst nucleus, are presented. The Seyfert galaxies were selected as presenting `linear' or cone-like high excitation emission line in the optical, most probably due to the collimation of the central source's radiation by a dusty molecular torus. Our goal was to look for signatures of this torus, and to investigate the gaseous distribution, excitation and reddening. The IR emission lines are spatially extended in most cases, and we have used the [FeII]/Pa(beta) ratio as a measure of the gaseous excitation in Mrk573, N1386, and N7582. Values for this ratio between 1.5 and 6 are found, suggesting excitation of [FeII] by X-rays or shock waves in some regions. Nuclear Pa(beta) in N1365, and possibly nuclear Br(gama) in Mrk573, are broad. From analysis of the spatial distribution of the continuum (J-H) and (H-K) colours derived from our spectra, we find redder colours for the nucleus than the nearby bulge in most of the Seyfert 2s observed. Comparison with models including emission from dust and stars shows that hot (T~1000 K) dust emission dominates the nuclear continuum in N1365, N2110, N3281, N7582, and ESO362-G18. In N1386, N5643, and N5728 the main contributor is the underlying stellar population, combined with some foreground reddening and/or cool dust emission. In a few cases, the (J-H) colours on opposite sides of the nucleus differ by 0.3-0.8 mag, an effect that we interpret as partly due to differences in the local stellar population, and possibly extinction gradients.Comment: 19 pages (LaTeX, mn.sty), 27 Postscript figures embedded. Accepted for publication in the Monthly Notices of the R.A.

Feeding Versus Feedback in AGNs from Near-Infrared IFU Observations: The Case of Mrk 766

We have mapped the emission-line flux distributions and ratios as well as the gaseous kinematics of the inner 450 pc radius of the Seyfert 1 galaxy Mrk 766 using integral field near-IR J- and Kl-band spectra obtained with the Gemini nifs at a spatial resolution of 60 pc and velocity resolution of 40 km/s. Emission-line flux distributions in ionized and molecular gas extend up to ~ 300 pc from the nucleus. Coronal [S IX]{\lambda}1.2523{\mu}m line emission is resolved, being extended up to 150 pc from the nucleus. At the highest flux levels, the [Fe II]{\lambda}1.257{\mu}m line emission is most extended to the south-east, where a radio jet has been observed.The emission-line ratios [Fe II]{\lambda}1.2570{\mu}m/Pa{\beta} and $H_2${\lambda}2.1218{\mu}m/Br{\gamma} show a mixture of Starburst and Seyfert excitation; the Seyfert excitation dominates at the nucleus, to the north-west and in an arc-shaped region between 0.2" and 0.6" to the south-east at the location of the radio jet. A contribution from shocks at this location is supported by enhanced [Fe II]/[P II] line ratios and increased [Fe II] velocity dispersion. The gas velocity field is dominated by rotation that is more compact for $H_2$ than for Pa{\beta}, indicating that the molecular gas has a colder kinematics and is located in the galaxy plane. There is about $10^3$ solar masses of hot $H_2$, implying ~ $10^9$ solar masses of cold molecular gas. At the location of the radio jet, we observe an increase in the [Fe II] velocity dispersion (150 km/s), as well as both blueshift and redshifts in the channel maps, supporting the presence of an outflow there. The ionized gas mass outflow rate is estimated to be ~ 10 solar masses/yr, and the power of the outflow ~ 0.08 $L_{bol}$

Photometry and dynamics of the minor mergers AM\,1228-260 and AM\,2058-381

We investigate interaction effects on the dynamics and morphology of the galaxy pairs AM\,2058-381 and AM\,1228-260. This work is based on $r'$ images and long-slit spectra obtained with the Gemini Multi-Object Spectrograph at the Gemini South Telescope. The luminosity ratio between the main (AM\,2058A) and secondary (AM\,2058B) components of the first pair is a factor of $\sim$ 5, while for the other pair, the main (AM\,1228A) component is 20 times more luminous than the secondary (AM\,1228B). The four galaxies have pseudo-bulges, with a S\'ersic index $n<2$. Their observed radial velocities profiles (RVPs) present several irregularities. The receding side of the RVP of AM\,2058A is displaced with respect to the velocity field model, while there is a strong evidence that AM\,2058B is a tumbling body, rotating along its major axis. The RVPs for AM\,1228A indicate a misalignment between the kinematic and photometric major axes. The RVP for AM\,1228B is quite perturbed, very likely due to the interaction with AM\,1228A. NFW halo parameters for AM\,2058A are similar to those of the Milky Way and M\,31. The halo mass of AM\,1228A is roughly 10\% that of AM\,2058A. The mass-to-light (M/L) of AM\,2058 agrees with the mean value derived for late-type spirals, while the low M/L for AM\,1228A may be due to the intense star formation ongoing in this galaxy.Comment: 20 pages, 10 figures, accepted for publication in MNRA

Haffner 16: A Young Moving Group in the Making

The photometric properties of main sequence (MS) and pre-main sequence (PMS) stars in the young cluster Haffner 16 are examined using images recorded with the Gemini South Adaptive Optics Imager (GSAOI) and corrected for atmospheric blurring by the Gemini Multi-Conjugate Adapative Optics System (GeMS). A rich population of PMS stars is identified, and comparisons with isochrones suggest an age < 10 Myr assuming a distance modulus of 13.5 (D = 5 kpc). When compared with the solar neighborhood, Haffner 16 is roughly a factor of two deficient in objects with sub-solar masses. PMS objects in the cluster are also more uniformly distributed on the sky than bright MS stars. It is suggested that Haffner 16 is dynamically evolved, and that it is shedding protostars with sub-solar masses. Young low mass clusters like Haffner 16 are one possible source of PMS stars in the field. The cluster will probably evolve on time scales of ~ 100 - 1000 Myr into a diffuse moving group with a mass function that is very different from that which prevailed early in its life.Comment: To appear in the Publications of the Astronomical Society of the Pacifi

A photometric and kinematic study of the stars and interstellar medium in the central two kpc of NGC 3379

HST images of NGC 3379 show that the V and I luminosity profiles in the inner 13 arcsec of this E1 galaxy are represented by two different components: a stellar bulge following a Sersic Law with exponent n = 2.36, and a central core (r < 0.7 arcsec) with a characteristic "cuspy" profile. Subtraction of the underlying stellar component represented by the fitted Sersic profile revealed the presence of a small (r ~ 105 pc) dust disk of about 150 solar masses, oriented at PA = 125 degrees and inclined ~ 77 degrees with respect to the line of sight. The same absorption structure is detected in the color-index (V-I) image. The stellar rotation in the inner 20 arcsec is well represented by a parametric planar disk model, inclined ~ 26 degrees relative to the plane of the sky, and apparent major axis along PA ~ 67 degrees. The gas velocity curves in the inner 5 arcsec show a steep gradient, indicating that the gas rotates much faster than the stars, although in the same direction. The velocity field of the gaseous system, however, is not consistent with the simple model of Keplerian rotation sustained by the large (7 x 10E9 solar masses within a radius of ~ 90 pc) central mass implied by the maximum velocity observed, but the available data precludes a more detailed analysis.Comment: 23 pages, LaTeX(aaspp4.sty), 9 figures included. Figs. 1 and 5 are colour plates. Accepted for publication in The Astrophysical Journal (part 1

Structure, function, and assembly of heme centers in mitochondrial respiratory complexes

The sequential flow of electrons in the respiratory chain, from a low reduction potential substrate to O2, is mediated by protein-bound redox cofactors. In mitochondria, hemes—together with flavin, iron–sulfur, and copper cofactors—mediate this multi-electron transfer. Hemes, in three different forms, are used as a protein-bound prosthetic group in succinate dehydrogenase (complex II), in bc1 complex (complex III) and in cytochrome c oxidase (complex IV). The exact function of heme b in complex II is still unclear, and lags behind in operational detail that is available for the hemes of complex III and IV. The two b hemes of complex III participate in the unique bifurcation of electron flow from the oxidation of ubiquinol, while heme c of the cytochrome c subunit, Cyt1, transfers these electrons to the peripheral cytochrome c. The unique heme a3, with CuB, form a catalytic site in complex IV that binds and reduces molecular oxygen. In addition to providing catalytic and electron transfer operations, hemes also serve a critical role in the assembly of these respiratory complexes, which is just beginning to be understood. In the absence of heme, the assembly of complex II is impaired, especially in mammalian cells. In complex III, a covalent attachment of the heme to apo-Cyt1 is a prerequisite for the complete assembly of bc1, whereas in complex IV, heme a is required for the proper folding of the Cox 1 subunit and subsequent assembly. In this review, we provide further details of the aforementioned processes with respect to the hemes of the mitochondrial respiratory complexes