Hydrodynamic simulations of the triaxial bulge of M 31
Reads0
Chats0
TLDR
In this article, the potential of the stellar bulge is derived from its surface brightness prole, which is assumed to be triaxial and rotating in the same plane as the disk in order to explain the twisted nature of M 31's central isophotes and the non circular gas velocities in the inner disk.Abstract:
The interstellar gas flow in the inner disk of M 31 is modelled using a new, two dimensional, grid based, hydrodynamics code. The potential of the stellar bulge is derived from its surface brightness prole. The bulge is assumed to be triaxial and rotating in the same plane as the disk in order to explain the twisted nature of M 31's central isophotes and the non circular gas velocities in the inner disk. Results are compared with CO observations and the bulge is found to be a fast rotator with a B-band mass-to-light ratio, B =6 .5 0.8, and a ratio of co-rotation radius to bulge semi-major axis,R =1 .2 0.1, implying that any dark halo must have a low density core in contradiction to the predictions of CDM. These conclusions would be strengthened by further observations conrming the model's o axis CO velocity predictions.read more
Citations
More filters
Journal ArticleDOI
ΛCDM-based Models for the Milky Way and M31. I. Dynamical Models
TL;DR: In this article, the authors apply standard disk formation theory with adiabatic contraction within cuspy halo models predicted by the standard cold dark matter (?CDM) cosmology.
Journal ArticleDOI
Spitzer/mips infrared imaging of m31: further evidence for a spiral/ring composite structure
Karl D. Gordon,Jeremy Bailin,Charles W. Engelbracht,George H. Rieke,Karl Misselt,William B. Latter,Eric T. Young,Matthew L. N. Ashby,Pauline Barmby,Brad K. Gibson,Brad K. Gibson,Dean C. Hines,Joannah L. Hinz,Oliver Krause,D. Levine,Francine R. Marleau,Alberto Noriega-Crespo,Susan R. Stolovy,David A. Thilker,Michael W. Werner +19 more
TL;DR: In this article, the two spiral arms appear to start at the ends of a bar in the nuclear region and extend beyond the star-forming ring, and the star forming ring is very circular except for a region near M32 where it splits.
Journal ArticleDOI
Molecular gas in the Andromeda galaxy
Ch. Nieten,N. Neininger,N. Neininger,M. Guelin,H. Ungerechts,R. Lucas,Elly M. Berkhuijsen,Rainer Beck,Richard Wielebinski +8 more
TL;DR: M 31, the closest large spiral galaxy to our own, is the best object for studying molecular clouds and their relation to the spiral structure as discussed by the authors, and it is also one of the best places where to estimate molecular clouds masses through the Virial Theorem.
Journal ArticleDOI
A wide-field H I mosaic of Messier 31 - II. The disk warp, rotation, and the dark matter halo
TL;DR: In this article, a tilted ring model was used to fit the rotation curve of the nearest spiral galaxy, M 31, using a deep, full-disk 21-cm imaging survey smoothed to 466-pc resolution.
References
More filters
Journal ArticleDOI
Detection of CO in the inner part of M31's bulge
TL;DR: The first detection of CO in M31's bulge was reported in this article, where the 12CO (1-0) and (2-1) lines were both detected in the dust complex D395A/393/384, at 1.3" (~ 0.35 kpc) from the centre.
Journal ArticleDOI
Cold Massive Molecular Clouds in the Inner Disk of M31
TL;DR: In this article, the authors presented new interferometric 12CO (1-0) and single-dish 12CO(3-2) observations of the central parts of D478, a large (>200 pc) dark dust cloud located in a quiescent region of the inner disk of M31.
Journal ArticleDOI
The triaxial bulge of the Sa galaxy NGC 4845
TL;DR: In this article, the authors used kinematic and photometric data to determine the axial ratios of a triaxial bulge, which was applied to the spiral NGC 4845, where recent observations suggest that the emission-line velocity field in the bulge region is very regular but not axisymmetric.
Posted Content
Cold Massive Molecular Clouds in the Inner Disk of M31
TL;DR: In this paper, the authors present new interferometric CO(1-0) and single-dish CO(3-2) observations of the central parts of D478, a large (> 200 pc) dark dust cloud located in a quiescent region of the inner disk of M31 where single-and multi-scale CO(2-1) observations were previously obtained.