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Related papers: Polar bulges and polar nuclear discs: the case of …

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We report the case of the geometrical and kinematical decoupling between the bulge and the disk of the Sa galaxy NGC 4698. The R-band isophotal map of this spiral shows that the bulge structure is elongated perpendicularly to the major axis…

We report the case of the early-type disk galaxy NGC 4672 as a new example of a galaxy characterized by the orthogonal geometrical decoupling between bulge and disk. The morphological features of this galaxy are discussed as well as the…

The R-band isophotal map of the Sa galaxy NGC 4698 shows that the inner region of the bulge structure is elongated perpendicularly to the major axis of the disk, this is also true for the outer parts of the bulge if a parametric photometric…

We report evidence for nuclear stellar disks in 3 early-type spirals, namely NGC 1425, NGC 3898 and NGC 4698, revealed by WFPC2/F606W images out of a sample of 38 spiral galaxies, selected from the Hubble Space Telescope Data Archive.…

Astrophysics · Physics 2009-11-07 A. Pizzella , E. M. Corsini , L. Morelli , M. Sarzi , C. Scarlata , M. Stiavelli , F. Bertola

We present detailed morphological, photometric, and stellar-kinematic analyses of the central regions of two massive, early-type barred galaxies with nearly identical large-scale morphologies. Both have large, strong bars with prominent…

We analyse IRAS and COBE DIRBE data at wavelengths between 2.2 and 240 mu of the central 500pc of the Galaxy and derive the large-scale distribution of stars and interstellar matter in the Nuclear Bulge. Models of the Galactic Disk and…

Astrophysics · Physics 2009-11-07 R. Launhardt , R. Zylka , P. G. Mezger

Hubble Space Telescope images of two early-type galaxies harboring both nuclear and outer stellar discs are studied in detail. By means of a photometric decomposition, the images of NGC 4342 and NGC 4570 are analyzed and the photometric…

Astrophysics · Physics 2009-10-30 Cecilia Scorza , Frank C. van den Bosch

We present the detection of nuclear stellar discs in the low-luminosity elliptical galaxies NGC 4458 and NGC 4478, which are known to host a kinematically-decoupled core. Using archival HST imaging, and available absorption line-strength…

We present Ks-band surface photometry of NGC 7690 (Hubble type Sab) and NGC 4593 (SBb). We find that, in both galaxies, a major part of the "bulge" is as flat as the disk and has approximately the same color as the inner disk. In other…

Astrophysics · Physics 2009-11-11 John Kormendy , Mark E. Cornell , David L. Block , Johan H. Knapen , Emma L. Allard

The Galactic bulge, that is the prominent out-of-plane over-density present in the inner few kiloparsecs of the Galaxy, is a complex structure, as the morphology, kinematics, chemistry and ages of its stars indicate. To understand the…

Astrophysics of Galaxies · Physics 2016-07-06 P. Di Matteo

Small and bright stellar disks with scale lengths of few tens of parsec are known to reside in the center of galaxies. They are believed to have formed in a dissipational process as the end result of star formation in gas either accreted in…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 L. Morelli , M. Cesetti , E. M. Corsini , A. Pizzella , E. Dalla Bontà , M. Sarzi , F. Bertola

Based on SDSS data, we have selected a sample of nine edge-on spiral galaxies with bulges whose major axes show a high inclination to the disk plane. Such objects are called polar-bulge galaxies. They are similar in their morphology to…

Astrophysics of Galaxies · Physics 2016-01-20 V. P. Reshetnikov , S. S. Savchenko , A. V. Mosenkov , N. Ya. Sotnikova , D. V. Bizyaev

Small kinematically-decoupled stellar discs with scalelengths of a few tens of parsec are known to reside in the centre of galaxies. Different mechanisms have been proposed to explain how they form, including gas dissipation and merging of…

Astrophysics of Galaxies · Physics 2016-02-17 E. M. Corsini , L. Morelli , N. Pastorello , E. Dalla Bontà , A. Pizzella , E. Portaluri

Observations of line emission from water masers near the center of the galaxy NGC 4258 have recently provided compelling evidence for rotating disk of gas, viewed nearly edge-on, surrounding a massive black hole (Miyoshi etal. 1995). We…

Astrophysics · Physics 2009-10-28 Eyal Maoz

Tilted and warped discs inside tilted dark matter haloes are predicted from numerical and semi-analytical studies. In this paper, we use deep imaging to demonstrate the likely existence of tilted outer structures in real galaxies. We…

The Galactic bulge is now considered to be the inner three-dimensional part of the Milky Way's bar. It has a peanut shape and is characterized by cylindrical rotation. In N-body simulations, box/peanut bulges arise from disks through bar…

Astrophysics of Galaxies · Physics 2014-08-04 Ortwin Gerhard

We have found that the bulge of the large, nearby Sb galaxy NGC 7331 rotates retrograde to its disk. Analysis of spectra in the region of the near-IR Ca II triplet along the major axis shows that, in the radial range between 5'' and ~20'',…

Astrophysics · Physics 2017-01-04 F. Prada , C. Gutierrez , R. F. Peletier , C. D. McKeith

The intrinsic shape and orientation of the elliptical galaxy NGC 3379 are estimated by dynamical modeling. The maximal ignorance shape estimate, an average over the parameter space, is axisymmetric and oblate in the inner parts, with an…

Astrophysics · Physics 2009-10-31 T. S. Statler

Approximately 20% of early-type galaxies host small nuclear stellar discs that are tens to a few hundred parsecs in size. Such discs are expected to be easily disrupted during major galactic encounters, hence their age serve to constrain…

We present the first measurement of the stellar kinematics in the polar ring of NGC 4650A. There is well defined rotation, with the stars and gas rotating in the same direction, and with similar amplitude. The gaseous and stellar kinematics…

Astrophysics · Physics 2009-11-07 R. A. Swaters , V. C. Rubin
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