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Related papers: The pattern speeds of NGC 6946

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We present observations of the HCN and HCO+ J=1-0 transitions in the center of the nearby spiral galaxy NGC 6946 made with the BIMA and CARMA interferometers. Using the BIMA SONG CO map, we investigate the change in the I_HCN/I_CO and I_…

Astrophysics · Physics 2009-11-13 E. S. Levine , Tamara T. Helfer , R. Meijerink , Leo Blitz

NGC 4945 is a Seyfert 2 galaxy at a distance of 3.82 Mpc. Its relative proximity has permitted a detailed SMA study of the circumnuclear molecular gas in a galaxy exhibiting an AGN. Based on an analysis of the high-resolution velocity field…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Lien-Hsuan Lin , Ronald E. Taam , David C. C. Yen , S. Muller , J. Lim

We use Schwarzschild's orbit-superposition technique to construct self-consistent models of the Galactic bar. Using $\chi^2$ minimisation, we find that the best-fit Galactic bar model has a pattern speed $\Omega_{\rm p}=60 \rm{km s^{-1}…

Astrophysics of Galaxies · Physics 2015-06-11 Yougang Wang , Hongsheng Zhao , Shude Mao , R. M. Rich

We present the results of the CO mapping observations of the barred spiral galaxy NGC3504 with the Nobeyama 45-m telescope. The distribution of the molecular gas shows offset ridges which correspond to the distribution of HII regions along…

Astrophysics · Physics 2015-06-24 N. Kuno , K. Nishiyama , N. Nakai , K. Sorai , B. Vila-Vilaro , T. Handa

We present a review on bar pattern speeds from preliminary results in the context of the Nuclei of Galaxies (NUGA) project. The large variety of molecular circumnuclear morphologies found in NUGA is a challenging result that implies the…

Previous work has related the Galactic bar to structure in the local stellar velocity distribution. Here we show that the bar also influences the spatial gradients of the velocity vector via the Oort constants. By numerical integration of…

Astrophysics of Galaxies · Physics 2010-02-10 Ivan Minchev , Jason Nordhaus , Alice Quillen

We present a study of the kinematics of the isolated spiral galaxy NGC 864, using H{\alpha} Fabry-Perot data obtained with the GH{\alpha}FaS instrument at the William Herschel Telescope in La Palma, complemented with images at 3.6 {\mu}m,…

Bars in spiral galaxies can weaken through gas inflow towards the center, and angular momentum transfer. Several bar episodes can follow one another in the life of the galaxy, if sufficient gas is accreted from the intergalactic medium to…

Astrophysics · Physics 2008-11-05 F. Combes

In this paper we analyse the methodology to derive the bar pattern speed from dynamical simulations. The results are robust to the changes in the vertical-scale height and in the mass-to-light (M/L) ratios. There is a small range of…

Astrophysics of Galaxies · Physics 2010-02-08 I. Perez , K. C. Freeman , R. Fux , A. Zurita

Dwarf barred galaxies are the perfect candidates for hosting slowly-rotating bars. They are common in dense environments and they have a relatively shallow potential well, making them prone to heating by interactions. When an interaction…

We report an intrinsic absorber with decreasing outflow velocity in the Seyfert 1 galaxy NGC 3783. This is the first detection of a change in radial velocity in an outflow associated with a Seyfert galaxy. These results are based on…

The bar pattern speed of the LMC has been measured using Gaia data, suggesting the presence of a slow pattern, perhaps not rotating at all. Numerical simulations of interacting LMC-SMC systems were able to reproduce a bar stoppage. Here, we…

Astrophysics of Galaxies · Physics 2025-11-05 V. Araya , L. Chemin , O. Jimenez-Arranz , M. Romero-Gomez

Rotation curves and velocity dispersion profiles are presented for both the stellar and gaseous components along five different position angles (P.A.=5, 50, 95, 125 and 155 degrees) of the nearby barred spiral NGC 6221. The observed…

[abridged] We used J and Ks band images acquired with the VISTA telescope as part of the science verification to quantify the structures in the stellar disk of the barred Sc galaxy NGC253. Moving outward from the galaxy center, we find a…

Astrophysics of Galaxies · Physics 2015-06-19 E. Iodice , M. Arnaboldi , M. Rejkuba , M. J. Neeser , L. Greggio , O. A. Gonzalez , M. Irwin , J. P. Emerson

We present near-infrared images of NGC 4314 in the $J$,$H$, and $K$ bands. Colors in these bands are constant across the bar of NGC 4314 indicating that the mass-to-light ratio is constant over much of the galaxy. We have developed an…

Astrophysics · Physics 2009-10-22 A. C. Quillen , Jay. A. Frogel , Rosa A. Gonz'alez

We report on our attempts to achieve a nearly steady-state gas flow in hydrodynamical simulations of doubly barred galaxies. After exploring the parameter space, we construct two models, for which we evaluate the photometric and the…

Astrophysics · Physics 2008-01-10 Witold Maciejewski , Hannah Singh

We are studying the properties of the holes and the high velocity gas in NGC 6946. Here we present some puzzling results.

Simulations predict that bars in galaxies should slow down over time. This is often attributed to the exchange of angular momentum between the bar and other regions of the galaxy, such as the outer disc and dark matter halo, which implies…

Astrophysics of Galaxies · Physics 2026-04-07 Tobias Géron , Kai Zhu , Steph Campbell , Chris Lintott , R. J. Smethurst , Behzad Tahmasebzadeh

The distribution of moving groups in the solar neighborhood has been used to constrain dynamical properties of the Milky Way for decades. The kinematic bimodality between the main mode (Hyades, Pleiades, Coma Berenices, and Sirius) and…

Astrophysics of Galaxies · Physics 2024-04-09 Scott Lucchini , Elena D'Onghia , J. Alfonso L. Aguerri

In the last few decades many efforts have been made to understand the effect of spiral arms on the gas and stellar dynamics in the Milky Way disc. One of the fundamental parameters of the spiral structure is its angular velocity, or pattern…

Astrophysics of Galaxies · Physics 2015-03-04 T. C. Junqueira , C. Chiappini , J. R. D. Lépine , I. Minchev , B. X. Santiago
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