Related papers: The central bar in M94
We have studied the face-on, barred spiral M83 (NGC 5236) with Chandra. Eighty-one point sources are detected (above 3.5-sigma) in the ACIS S3 image: 15 of them are within the inner 16 arcsec region (starburst nucleus, resolved for the…
We present a kinematic study of a sample of 298 planetary nebulas (PNs) in the outer halo of the central Virgo galaxy M87 (NGC~4486). The line-of-sight velocities of these PNs are used to identify sub-components, to measure the angular…
Recent hydrostatic X-ray studies of the hot interstellar medium (ISM) in early-type galaxies underestimate the gravitating mass as compared to stellar dynamics, implying modest, but significant deviations from exact hydrostatic equilibrium.…
We use 3.6 $\mu$m imaging from the S$^{4}$G survey to characterize the typical stellar density profiles ($\Sigma_{\ast}$) and bars as a function of fundamental galaxy parameters (e.g. the total stellar mass $M_{\ast}$), providing…
HD 100546 is one of the few known pre-main-sequence stars that may host a planetary system in its disk. We analyze new VLT/SPHERE/ZIMPOL polarimetric images of HD 100546 with filters in H$\alpha$ and the adjacent continuum. We have probed…
We report the detection of massive star formation along a bar in the peculiar starburst galaxy Mkn 439. We present optical B, R and H_alpha + [NII] emission line images as well as H band images to show that the signature of the bar becomes…
Context: The morphology of massive star formation in the central regions of galaxies is an important tracer of the dynamical processes that govern the evolution of disk, bulge, and nuclear activity. Aims: We present optical imaging of the…
We present a detailed morphological, photometric, and kinematic analysis of two barred S0 galaxies with large, luminous inner disks inside their bars. We show that these structures, in addition to being geometrically disk-like, have…
The rotation curve of the Large Magellanic Cloud, which we have derived from high-resolution HI position-velocity diagrams observed by Kim et al (1998), shows a steep central rise and flat rotation with a gradual rise toward the edge. Using…
We explore the kinematics (both the radial velocity and the proper motion) of the vertical X-shaped feature in the Milky Way with an N-body bar/bulge model. From the solar perspective, the distance distribution of particles is double-peaked…
We present a new analysis of very deep Chandra observations of the galaxy cluster Abell 1795. Utilizing nearly 750 ks of net ACIS imaging, we are able to resolve the thermodynamic structure of the Intracluster Medium (ICM) on length scales…
We present emission line mapping of the strongly barred galaxy NGC 1530 obtained from Fabry-Perot interferometry in Halpha, at significantly enhanced angular resolution compared with published studies. The main point of the work is to…
We analyse the stellar kinematics of the z=0.169 brightest cluster galaxy (BCG) in Abell 1201, using integral field observations with VLT/MUSE. This galaxy has a gravitationally-lensed arc located at unusually small radius ($\sim$5 kpc),…
Simulations have shown that bars are subject to a vertical buckling instability that transforms thin bars into boxy or peanut-shaped structures, but the physical conditions necessary for buckling to occur are not fully understood. We use…
We present a proper motion mini-survey of 35 fields in the vicinity of Baade window, (l, b) = (1 deg, -4 deg), sampling roughly a 5 x 2.5 deg region of the Galactic bar. Our second epoch observations collected with the ACS/HRC instrument on…
We study the Galactic bulge planetary nebula M 2-29 (for which a 3-year eclipse event of the central star has been attributed to a dust disk) using HST imaging and VLT spectroscopy, both long-slit and integral field. The central cavity of M…
I review recent studies about the gravitational potential and stellar dynamics of M87 in particular, and the dynamics of the stars in the presence of a super-massive central black hole, in general. At large radii, investigations of both the…
The S0 galaxy NGC 3245 contains a circumnuclear disk of ionized gas and dust with a radius of 1.1" (110 pc), making it an ideal target for dynamical studies with the Hubble Space Telescope. We have obtained spectra of the nuclear disk with…
We have obtained long-slit observations of the circumnuclear region of M87 at three different locations, with a spatial sampling of 0.028" using the Faint Object Camera f/48 spectrograph on board HST. These data allow us to determine the…
Based on 19 high-resolution N-body/gas-dynamical galaxy formation simulations in the LCDM cosmology it is shown, that for a galaxy like the Milky Way, in addition to the baryonic mass of the galaxy itself, about 70% extra baryonic mass…