A VLA Study of 15 3CR Radio Galaxies

We present VLA radio maps in total intensity and polarization at 1.4, 4.9 and 8.4 GHz of fifteen 3CR radio galaxies for which good maps showing the large-scale radio structure have not previously been available. Previously unknown cores are detected in several sources and a bright one-sided jet in 3C 287.1 is mapped for the first time; several other jet-like features are also imaged. Total and core fluxes are tabulated and radio core positions are listed and compared to optical positions. The galaxy at the optical position listed for 3C 169.1 is found to lie farther from the radio core position than another dimmer, bluer galaxy. We discuss individual sources in some detail.Comment: 35 pages, 22 figures but 35 separate Postscript figure files, AASTeX, Accepted for publication in the Astrophysical Journal Supplemen

Sexual Deprivation, Emotion, and Longevity: Neuropeptidergic Regulation of Aging in Drosophila

While researchers often focus on the brain as a victim of aging via neurodegenerative diseases, recent work has demonstrated that the aging process is regulated by neural mechanisms. Thus, we asked which mechanisms and inputs might be important for the brain to regulate aging. We found that in male Drosophila melanogaster, the costs of reproduction on survival are mediated entirely through perception of the opposite sex, and that mating itself is actually beneficial. These effects are mediated through distinct neural circuits, with neuropeptide F (npf, an NPY homolog) required for the negative effects of pheromones and corazonin (crz, a GnRH homolog) driving the beneficial effects of mating. dFoxo, a common mediator of aging, regulates these effects on aging through an insulin-independent mechanism. Investigation of the dynamics of the effects of pheromones on mortality revealed two hypotheses: either population mortality rates reverse as a result of heterogeneity in individual probabilities of death, or the effects of pheromones on mortality rates are reversible in individuals. By combining in vivo and in silico approaches, we revealed that both explanations are correct, with individual reversibility dominating dynamics early in life, and heterogeneity becoming important in middle-age. Using a more global approach, we examined the effects of manipulating 78 distinct subsets of neurons on lifespan, and identified specific brain structures that are of prime importance for modulating aging. One of these structures is home to neurons expressing diuretic hormone 44 (Dh44, a CRH homolog). Dh44 and one of its receptors, Dh44R1, modulate lifespan, likely through insulin-like signaling pathways. Furthermore, this effect of Dh44 on lifespan is independent of diet, a fact obtained in part using the Fly Liquid-food Interaction Counter (FLIC), a novel assay developed to continuously measure feeding behavior in individual flies. The evolutionarily conserved neural circuits identified herein link aging to neural states consistent with primitive emotions in Drosophila, and these mechanisms deserve further exploration for their potential to explain connections between stress, emotions, and health in humans.PHDMol & Integrtv Physiology PhDUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/144128/1/harvanek_1.pd

The quasar Q0957+561: Lensed CO emission from a disk at z~1.4?

In recent years large efforts have been made to detect molecular gas towards high redshifted objects. Up to now the literature reports on only two cases of CO-detection in quasars at a redshift between 1 and 2 - Q0957+561, a gravitationally lensed system at z=1.41 (Planesas et al. 1999), and HR10 at z=1.44 (Andreani et al. 2000). According to Planesas et al. (1999), 12CO(2-1) emission was detected towards both the lensed images of Q0957+561 with the IRAM Plateau de Bure Interferometer (PdBI). In contrast to the optical spectra of the two images which support the idea that they are images of one and the same object, the CO-spectra were surprisingly different: the southern image (named CO-B) shows a single blueshifted line whereas a double-peaked line profile with a blue- and a redshifted part appears towards the northern image (CO-A). Based on the observations and on simulations with a gravitational lens program, we are tempted to argue that the line profile traces the presence of molecular gas of a disk in the host galaxy around the quasar. We have now new observations with the PdBI providing the necessary sensitivity to corroborate our disk model.Comment: 4 pages, 1 figure, to appear in "Proceedings of the 4th Cologne-Bonn-Zermatt-Symposium", ed. S. Pfalzner, C. Kramer, C. Straubmeier, and A. Heithausen (Springer Verlag

On the origin of X-shaped radio-sources: new insights from the properties of their host galaxies

A significant fraction of extended radio sources presents a peculiar X-shaped radio morphology: in addition to the classical double lobed structure, radio emission is also observed along a second axis of symmetry in the form of diffuse wings or tails. We re-examine the origin of these extensions relating the radio morphology to the properties of their host galaxies. The orientation of the wings shows a striking connection with the structure of the host galaxy as they are preferentially aligned with its minor axis. Furthermore, wings are only observed in galaxies of high projected ellipticity. Hydrodynamical simulations of the radio-source evolution show that X-shaped radio-sources naturally form in this geometrical situation: as a jet propagates in a non-spherical gas distribution, the cocoon surrounding the radio-jets expands laterally at a high rate producing wings of radio emission, in a way that is reminiscent of the twin-exhaust model for radio-sources.Comment: 7 pages, 6 figures, 1 table, accepted for publication in A&

The effect of three common tints upon the spherical component of the cross-cylinder finding at far

The purpose of this thesis is to determine whether or not any of three common absorptive lenses effect the spherical value of the far cross-cylinder findings when compared to white lenses

A Catalogue of Morphologically Classified Galaxies from the Sloan Digital Sky Survey: North Equatorial Region

We present a catalogue of morphologically classified bright galaxies in the north equatorial stripe (230 deg$^2$) derived from the Third Data Release of the Sloan Digital Sky Survey (SDSS). Morphological classification is performed by visual inspection of images in the $g$ band. The catalogue contains 2253 galaxies complete to a magnitude limit of $r=16$ after Galactic extinction correction, selected from 2658 objects that are judged as extended in the photometric catalogue in the same magnitude limit. 1866 galaxies in our catalogue have spectroscopic information. A brief statistical analysis is presented for the frequency of morphological types and mean colours in the catalogue. A visual inspection of the images reveals that the rate of interacting galaxies in the local Universe is approximately 1.5% in the $r\le16$ sample. A verification is made for the photometric catalogue generated by the SDSS, especially as to its bright end completeness.Comment: Accepted for publication in Astronomical Journal. Table 2 available at http://www.icrr.u-tokyo.ac.jp/~fukugita/MCGpaper/table2.tx