Peanut shaped structures in edge-on galaxies
Proceedings of Science 2004-October (2004)
Abstract:
A photometric analysis of a sample of edge-on galaxies harboring a peanut shaped structure is presented. This structure is ideally suited to study the bar driven evolution of galaxies since it is slightly connected to the presence of vertical bar resonances. For our study we use K-band imaging which is dominated by Population II stars and minimally affected by dust. Applying the unsharp masking filtering technique we are able to isolate the periodic orbit families at the origin of the particular morphology of a peanut shaped structure. The rearrangement of disk material in the vertical direction through the presence of a bar is evidenced by our study of vertical scale heights along the major axis of the galaxies. Fitting of generalized Gaussians (equivalent to a Sersic law) to the vertical surface brightness profiles shows a radial variation of scale heights reaching a maximum at positions where the peanut structure is most prominent.A SAURON look at galaxy bulges
ASTRON NACHR 325:2 (2004) 92-95
Abstract:
Kinematic and population studies show that bulges are generally rotationally flattened systems similar to low-luminosity ellipticals. However, observations with state-of-the-art integral field spectrographs, such as SAURON, indicate that the situation is much more complex, and allow us to investigate phenomena such as triaxiality, kinematic decoupling and population substructure, and to study their connection to current formation and evolution scenarios for bulges of early-type galaxies. We present the examples of two SO bulges from galaxies in our sample of nearby galaxies: one that shows all the properties expected from classical bulges (NGC 5866), and another case that presents kinematic features appropriate for barred disk galaxies (NGC 7332).OASIS high-resolution integral field spectroscopy of the SAURON ellipticals and lenticulars
ASTRON NACHR 325:2 (2004) 100-103
Abstract:
We present a summary of high-spatial resolution follow-up observations of the elliptical (E) and lenticular (SO) galaxies in the SAURON survey using the OASIS integral field spectrograph. The OASIS observations explore the central 8" x 10" regions of these galaxies using a spatial sampling four times higher than SAURON, often revealing previously undiscovered features. Around 75% (31/48) of the SAURON E/SOs with central velocity dispersion greater than or similar to 120 kin s(-1) were observed with OASIS, covering well the original SAURON representative sample. We present here an overview of this follow-up survey, and some preliminary results on individual objects, including a previously unreported counter-rotating core in NGC4382; the decoupled stellar and gas velocity fields of NGC 2768; and the strong age gradient towards the centre of NGC 3489.SAURON: Observations of E/S0/SA galaxies
Revista Mexicana de Astronomia y Astrofisica: Serie de Conferencias 17 (2003) 199
Abstract:
We present results from a new and unique integral-field spectrograph, SAURON. It has a large field of view and high throughput and is primarily built for the study of stellar & gaseous kinematics and stellar populations in galaxies. Its aim is to carry out a systematic survey of the velocity fields, velocity dispersions, and line-strength distributions of nearby ellipticals, lenticular galaxies and spiral bulges.Comparing peanut-shaped `bulges' to N-body simulations and orbital calculations
Astrophysics and Space Science Springer Nature 284:2 (2003) 753-756