Astronomy and Astrophysics – Astrophysics
Scientific paper
1999-04-16
Astronomy and Astrophysics
Astrophysics
25 pages (AASTeX, aaspp4.sty), 11 jpg figures. Accepted for publication in The Astrophysical Journal. Online manuscript with P
Scientific paper
10.1086/307677
We develop diagnostics based on gas kinematics to identify the presence of a bar in an edge-on spiral galaxy and determine its orientation. We use position-velocity diagrams (PVDs) obtained by projecting edge-on two-dimensional hydrodynamical simulations of the gas flow in a barred galaxy potential. We show that when a nuclear spiral is formed, the presence of a gap in the PVDs, between the signature of the nuclear spiral and that of the outer parts of the disk, reliably indicates the presence of a bar. This gap is due to the presence of shocks and inflows in the simulations, leading to a depletion of the gas in the outer bar region. If no nuclear spiral signature is present in a PVD, only indirect arguments can be used to argue for the presence of a bar. The shape of the signature of the nuclear spiral, and to a lesser extent that of the outer bar region, allows to determine the orientation of the bar with respect to the line-of-sight. The presence of dust can also help to discriminate between viewing angles on either side of the bar. Simulations covering a large fraction of parameter space constrain the bar properties and mass distribution of observed galaxies. The strongest constraint comes from the presence or absence of the signature of a nuclear spiral in the PVD.
Athanassoula Evangelia
Bureau Martin
No associations
LandOfFree
Bar Diagnostics in Edge-On Spiral Galaxies. II. Hydrodynamical Simulations does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Bar Diagnostics in Edge-On Spiral Galaxies. II. Hydrodynamical Simulations, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bar Diagnostics in Edge-On Spiral Galaxies. II. Hydrodynamical Simulations will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-309385