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277 results on '"Maciejewski, W"'

52. The Impact of Nuclear Star Formation on Gas Inflow to AGN

Author

Davies, R. I., primary, Hicks, E., additional, Schartmann, M., additional, Genzel, R., additional, Tacconi, L. J., additional, Engel, H., additional, Burkert, A., additional, Krause, M., additional, Sternberg, A., additional, Mueller Sánchez, F., additional, and Maciejewski, W., additional

Published
2009
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53. Supermassive black holes in the Sbc spiral galaxies NGC 3310, NGC 4303 and NGC 4258

Author

Pastorini, G., primary, Marconi, A., additional, Capetti, A., additional, Axon, D. J., additional, Alonso-Herrero, A., additional, Atkinson, J., additional, Batcheldor, D., additional, Carollo, C. M., additional, Collett, J., additional, Dressel, L., additional, Hughes, M. A., additional, Macchetto, D., additional, Maciejewski, W., additional, Sparks, W., additional, and van der Marel, R., additional

Published
2007
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55. Nuclear Properties of Nearby Spiral Galaxies fromHubble Space TelescopeNICMOS Imaging and STIS Spectroscopy

Author

Hughes, M. A., primary, Axon, D., additional, Atkinson, J., additional, Alonso-Herrero, A., additional, Scarlata, C., additional, Marconi, A., additional, Batcheldor, D., additional, Binney, J., additional, Capetti, A., additional, Carollo, C. M., additional, Dressel, L., additional, Gerssen, J., additional, Macchetto, D., additional, Maciejewski, W., additional, Merrifield, M., additional, Ruiz, M., additional, Sparks, W., additional, Stiavelli, M., additional, and Tsvetanov, Z., additional

Published
2005
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56. Supermassive black hole mass measurements for NGC 1300 and 2748 based on Hubble Space Telescope emission-line gas kinematics

Author

Atkinson, J. W., primary, Collett, J. L., additional, Marconi, A., additional, Axon, D. J., additional, Alonso-Herrero, A., additional, Batcheldor, D., additional, Binney, J. J., additional, Capetti, A., additional, Carollo, C. M., additional, Dressel, L., additional, Ford, H., additional, Gerssen, J., additional, Hughes, M. A., additional, Macchetto, D., additional, Maciejewski, W., additional, Merrifield, M. R., additional, Scarlata, C., additional, Sparks, W., additional, Stiavelli, M., additional, Tsvetanov, Z., additional, and van Der Marel, R. P., additional

Published
2005
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57. Nuclear Properties of a Sample of Nearby Spiral Galaxies fromHubble Space TelescopeSTIS Imaging

Author

Scarlata, C., primary, Stiavelli, M., additional, Hughes, M. A., additional, Axon, D., additional, Alonso-Herrero, A., additional, Atkinson, J., additional, Batcheldor, D., additional, Binney, J., additional, Capetti, A., additional, Carollo, C. M., additional, Dressel, L., additional, Gerssen, J., additional, Macchetto, D., additional, Maciejewski, W., additional, Marconi, A., additional, Merrifield, M., additional, Ruiz, M., additional, Sparks, W., additional, Tsvetanov, Z., additional, and van der Marel, R. P., additional

Published
2004
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58. An Atlas ofHubble Space TelescopeSpectra and Images of Nearby Spiral Galaxies

Author

Hughes, M. A., primary, Alonso-Herrero, A., additional, Axon, D., additional, Scarlata, C., additional, Atkinson, J., additional, Batcheldor, D., additional, Binney, J., additional, Capetti, A., additional, Carollo, C. M., additional, Dressel, L., additional, Gerssen, J., additional, Macchetto, D., additional, Maciejewski, W., additional, Marconi, A., additional, Merrifield, M., additional, Ruiz, M., additional, Sparks, W., additional, Stiavelli, M., additional, Tsvetanov, Z., additional, and van der Marel, R., additional

Published
2003
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59. Is There Really a Black Hole at the Center of NGC 4041? Constraints from Gas Kinematics

Author

Marconi, A., primary, Axon, D. J., additional, Capetti, A., additional, Maciejewski, W., additional, Atkinson, J., additional, Batcheldor, D., additional, Binney, J., additional, Carollo, M., additional, Dressel, L., additional, Ford, H., additional, Gerssen, J., additional, Hughes, M. A., additional, Macchetto, D., additional, Merrifield, M. R., additional, Scarlata, C., additional, Sparks, W., additional, Stiavelli, M., additional, Tsvetanov, Z., additional, and van der Marel, R. P., additional

Published
2003
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63. Codisposal of fine tails and overburden utilising pipelining techniques.

Author

Lord E.R.F., 4th International symposium on mine planning and equipment selection Calgary, Canada 31-Oct-9503-Nov-95, Maciejewski W., Lord E.R.F., 4th International symposium on mine planning and equipment selection Calgary, Canada 31-Oct-9503-Nov-95, and Maciejewski W.

Abstract

At the Syncrude Oil Sands mine, Alberta, the overburden consists predominantly of a naturally dry clay-shale. This material can be mixed with the fluid fine tails to produce a soft clay that is incorporated into geotechnically stable land masses. In this way, two materials which are normally disposed of separately, can be combined in a synergistic manner to reduce the volume of fluid fine tails and to create a solid deposit on which vegetation can grow. Pipeline techniques for this codisposal technique have been investigated. Small scale lump degradation tests were conducted at the Syncrude Research Centre. Slurry headloss and lump degradation tests were conducted at the Saskatchewan Research Council's pipeline facility using a 260 mm diameter pipeline. The geotechnical properties of the deposit and runoff have been evaluated. While codisposal remains a technical option, economic studies indicate that conventional overburden disposal using trucks and shovels currently has a lower cost., At the Syncrude Oil Sands mine, Alberta, the overburden consists predominantly of a naturally dry clay-shale. This material can be mixed with the fluid fine tails to produce a soft clay that is incorporated into geotechnically stable land masses. In this way, two materials which are normally disposed of separately, can be combined in a synergistic manner to reduce the volume of fluid fine tails and to create a solid deposit on which vegetation can grow. Pipeline techniques for this codisposal technique have been investigated. Small scale lump degradation tests were conducted at the Syncrude Research Centre. Slurry headloss and lump degradation tests were conducted at the Saskatchewan Research Council's pipeline facility using a 260 mm diameter pipeline. The geotechnical properties of the deposit and runoff have been evaluated. While codisposal remains a technical option, economic studies indicate that conventional overburden disposal using trucks and shovels currently has a lower cost.

Published
1995

78. Supermassive black hole mass measurements for NGC 1300 and 2748 based onHubble Space Telescopeemission-line gas kinematics.

Author

Atkinson, J. W., Collett, J. L., Marconi, A., Axon, D. J., Alonso-Herrero, A., Batcheldor, D., Binney, J. J., Capetti, A., Carollo, C. M., Dressel, L., Ford, H., Gerssen, J., Hughes, M. A., Macchetto, D., Maciejewski, W., Merrifield, M. R., Scarlata, C., Sparks, W., Stiavelli, M., and Tsvetanov, Z.

Subjects
SPIRAL galaxies, ASTRONOMICAL spectroscopy, GALAXY spectra, SUPERMASSIVE black holes, SPECTROGRAPHS
Abstract

We present Space Telescope Imaging Spectrograph emission-line spectra of the central regions of the spiral galaxies NGC 1300 and 2748. From the derived kinematics of the nuclear gas we have found evidence for central supermassive black holes in both galaxies. The estimated masses of the black holes in NGC 1300 and 2748 areand, respectively (both at the 95 per cent confidence level). These two black hole mass estimates contribute to the poorly sampled low-mass end of the nuclear black hole mass spectrum. [ABSTRACT FROM AUTHOR]

Published
2005
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81. Gas inflow in barred galaxies – effects of secondary bars.

Author

Maciejewski, W., Teuben, P.J., Sparke, L.S., and Stone, J.M.

Subjects
*GAS flow, *GALACTIC nuclei
Abstract

We report results of high-resolution hydrodynamical simulations of gas flows in barred galaxies, with a focus on gas dynamics in the central kiloparsec. In a single bar with an inner Lindblad resonance, we find either near-circular motion of gas in the nuclear ring, or a spiral shock extending towards the galaxy centre, depending on the sound speed in the gas. From a simple model of a dynamically possible doubly barred galaxy with resonant coupling, we infer that the secondary bar is likely to end well inside its corotation. Such a bar cannot create shocks in the gas flow, and therefore will not reveal itself in colour maps through straight dust lanes: the gas flows induced by it are different from those caused by the rapidly rotating main bars. In particular, we find that secondary stellar bars are unlikely to increase the mass inflow rate into the galactic nucleus. [ABSTRACT FROM AUTHOR]

Published
2002
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82. Orbits supporting bars within bars.

Author

Maciejewski, W. and Sparke, L.S.

Subjects
*BARRED galaxies, *IMAGING systems
Abstract

High-resolution observations of the inner regions of barred disc galaxies have revealed many asymmetrical, small-scale central features, some of which are best described as secondary bars. Because orbital time-scales in the galaxy centre are short, secondary bars are likely to be dynamically decoupled from the main kiloparsec-scale bars. Here we show that regular orbits exist in such doubly barred potentials, and that they can support the bars in their motion. We find orbits in which particles remain on loops: closed curves which return to their original positions after two bars have come back to the same relative orientation. Stars trapped around stable loops could form the building blocks for a long-lived, doubly barred galaxy. Using the loop representation, we can find which orbits support the bars in their motion, and the constraints on the sizes and shapes of self-consistent double bars. In particular, it appears that a long-lived secondary bar may exist only when an inner Lindblad resonance is present in the primary bar, and that it would not extend beyond this resonance. [ABSTRACT FROM AUTHOR]

Published
2000
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86. Immunoelectronmicroscopic examination of early lesions in histamine induced immune complex vasculitis in man.

Author

Wolff, Helmut H., Maciejewski, W., Scherer, R., and Braun-Falco, O.

Subjects
VASCULITIS, VASCULAR diseases, IMMUNE complexes, ANTIGENS, IMMUNOFLUORESCENCE, FLUORESCENCE
Abstract

In 4 cases of allergic vasculitis circulating immune complexes (IC) were demonstrated. Spontaneous and histamine induced vascular changes were studied by immunofluorescence microscopy. The early events in IC vasculitis were investigated at the ultrastructural level by immunoelectronmicroscopy using the peroxidase-antiperoxidase multistep technique. Our findings support the concept that human IC vasculitis is triggered by the deposition of circulating IC in the walls of postcapillary venules between endothelial cells, pericytes and the layers of the basal lamina. Tissue destruction is only secondary due to local complement activation and the release of lysosomal enzymes from chemotactically attracted leukocytes. [ABSTRACT FROM AUTHOR]

Published
1978
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95. Elektronenmikroskopische Untersuchungen bei bullösem Pemphigoid und Dermatitis herpetiformis Duhring

Author

Dabrowski J, Maciejewski W, and K Jakubowicz

Subjects
Chemistry, Dermatitis herpetiformis, medicine, Dermatology, General Medicine, medicine.disease, Molecular biology
Abstract

Die elektronenmikroskopischen Untersuchungen uber den Mechanismus der Blasenbildung bei Pemphigoid und Dermatitis herpetiformis ergaben wesentliche Unterschiede in der Ultrastruktur beider Krankheiten. 1. Beim Pemphigoid entsteht die Blase durch eine Kontinuitatstrennung zwischen der Zellmembran der epidermalen Basalzellen und der Basalmembran im Abschnitt der kontrastarmen Zwischenzone. 2. Beim Pemphigoid weist die Basalmembran auser einer deutlichen Verdickung keine pathologischen Veranderungen auf. Ihre Kontinuitat ist vollig erhalten und die Verbindung mit den Kollagenfasern ist normal. Im Corium sind die pathologischen Veranderungen schwach ausgepragt und hangen hauptsachlich von einem leichten Odem ab, das eine Auseinanderschiebung der Kollagenfasern verursacht. 3. Die Zerstorung der Basalmembran an betrachtlichen Abschnitten gehort zu den hochst charakteristischen Kennzeichen der Ultrastruktur der Blasen bei der Duhringschen Krankheit. 4. Bei Dermatitis herpetiformis entsteht die Blase im oberen Teil des Coriums unterhalb der dermo-epidermalen Grenze. Im Blasenlumen befinden sich zahlreiche Zellenfragmente des Infiltrates sowie Ablagerungen eines an Fibrin erinnernden Materials. 5. Bei beiden Krankheiten wiesen die Zellen der Basalschicht fortgeschrittene degenerative Veranderungen auf. Auffallend ist die streckenweise Schadigung der Zellmembran dieser Zellen. Diese Veranderungen sind weder fur Pemphigoid, noch fur Dermatitis herpetiformis spezifisch. 6. Der grundsatzliche Unterschied in der Ultrastruktur der bullosen Veranderungen beim Pemphigoid und bei Dermatitis herpetiformis beruht im Verhalten der Basalmembran. Die Lokalisation der Blase ist bei beiden Krankheiten unterschiedlich.

Published
1970
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96. LLAMA: The M-BH-sigma(x22c6;) relation of the most luminous local AGNs

Author

Caglar, T, Burtscher, L, Brandl, B, Brinchmann, J, Davies, R, Hicks, EKS, Koss, M, Lin, M-Y, Maciejewski, W, Mueller-Sanchez, F, Riffel, RA, Riffel, R, Rosario, DJ, Schartmann, M, Schnorr-Mueller, A, Shimizu, TT, Storchi-Bergmann, T, Veilleux, S, de Xivry, GO, and Bennert, VN

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics::Galaxy Astrophysics, QC, QB
Abstract

Context. The MBH–σ⋆ relation is considered a result of coevolution between the host galaxies and their supermassive black holes. For elliptical bulge hosting inactive galaxies, this relation is well established, but there is still discussion concerning whether active galaxies follow the same relation.\ud Aims. In this paper, we estimate black hole masses for a sample of 19 local luminous active galactic nuclei (AGNs; LLAMA) to test their location on the MBH–σ⋆ relation. In addition, we test how robustly we can determine the stellar velocity dispersion in the presence of an AGN continuum and AGN emission lines, and as a function of signal-to-noise ratio.\ud Methods. Supermassive black hole masses (MBH) were derived from the broad-line-based relations for Hα, Hβ, and Paβ emission line profiles for Type 1 AGNs. We compared the bulge stellar velocity dispersion (σ⋆) as determined from the Ca II triplet (CaT) with the dispersion measured from the near-infrared CO (2-0) absorption features for each AGN and find them to be consistent with each other. We applied an extinction correction to the observed broad-line fluxes and we corrected the stellar velocity dispersion by an average rotation contribution as determined from spatially resolved stellar kinematic maps.\ud Results. The Hα-based black hole masses of our sample of AGNs were estimated in the range 6.34 ≤ log MBH ≤ 7.75 M⊙ and the σ⋆CaT estimates range between 73 ≤ σ⋆CaT ≤ 227 km s−1. From the so-constructed MBH − σ⋆ relation for our Type 1 AGNs, we estimate the black hole masses for the Type 2 AGNs and the inactive galaxies in our sample.\ud Conclusions. We find that our sample of local luminous AGNs is consistent with the MBH–σ⋆ relation of lower luminosity AGNs and inactive galaxies, after correcting for dust extinction and the rotational contribution to the stellar velocity dispersion.

97. Supermassive black hole mass measurements for NGC 1300 and 2748 based on Hubble Space Telescope emission-line gas kinematics

Author

Atkinson, J. W., Collett, J. L., Marconi, A., Axon, D. J., Alonso-Herrero, A., Batcheldor, D., Binney, J. J., Capetti, A., Carollo, C. M., Dressel, L., Ford, H., Gerssen, J., Hughes, M. A., Macchetto, D., Maciejewski, W., Merrifield, M. R., Scarlata, C., Sparks, W., Stiavelli, M., Tsvetanov, Z., van Der Marel, R. P., Atkinson, J. W., Collett, J. L., Marconi, A., Axon, D. J., Alonso-Herrero, A., Batcheldor, D., Binney, J. J., Capetti, A., Carollo, C. M., Dressel, L., Ford, H., Gerssen, J., Hughes, M. A., Macchetto, D., Maciejewski, W., Merrifield, M. R., Scarlata, C., Sparks, W., Stiavelli, M., Tsvetanov, Z., and van Der Marel, R. P.

Abstract

We present Space Telescope Imaging Spectrograph emission-line spectra of the central regions of the spiral galaxies NGC 1300 and 2748. From the derived kinematics of the nuclear gas we have found evidence for central supermassive black holes in both galaxies. The estimated masses of the black holes in NGC 1300 and 2748 are (6.6+6.3−3.2) × 107 and (4.4+3.5−3.6) × 107 M⊙, respectively (both at the 95 per cent confidence level). These two black hole mass estimates contribute to the poorly sampled low-mass end of the nuclear black hole mass spectrum

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