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相关论文: Detection of a slow HI bar in the dwarf irregular …

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A sample of 69 galaxies with radial velocities less than 2500 km/s was selected from the HI Parkes All Sky Survey (HIPASS) and imaged in broad band B and R and narrow band H-alpha to deduce details about star formation in nearby disk…

天体物理学 · 物理学 2009-11-10 J. F. Helmboldt , R. A. M. Walterbos , G. D. Bothun , K. O'Neil , W. J. G. de Blok

Dwarf irregular galaxies are unique laboratories for studying the interaction between stars and the interstellar medium in low mass environments. We present the highest spatial resolution observations to date of the neutral hydrogen content…

天体物理学 · 物理学 2009-11-13 Amanda Kepley , Eric Wilcots , Deidre Hunter , Tyler Nordgren

We used 87 high resolution hydrodynamical cosmological simulations from the NIHAO suite to investigate the relation between the maximum circular velocity (Vmax) of a dark matter halo in a collisionless simulation and the velocity width of…

星系天体物理 · 物理学 2016-09-21 Andrea V. Macciò , Silviu M. Udrescu , Aaron A. Dutton , Aura Obreja , Liang Wang , Greg R. Stinson , Xi Kang

We investigate the stability of trajectories in barred galaxies with mildly triaxial halos by means of Liapunov exponents. This method is perfectly suitable for time-dependent 3D potentials where surfaces of sections and other simple…

天体物理学 · 物理学 2009-11-07 Amr El-Zant , Isaac Shlosman

Hypervelocity stars (HVSs) ejected by the massive black hole at the Galactic center have unique kinematic properties compared to other halo stars. Their trajectories will deviate from being exactly radial because of the asymmetry of the…

天体物理学 · 物理学 2009-06-23 Qingjuan Yu , Piero Madau

We present VLA observations of the distribution and kinematics of the HI gas in the classical ring galaxy VIIZw466 and its immediate surroundings. The HI gas corresponding to the bright optical star forming ring exhibits the typical profile…

天体物理学 · 物理学 2009-10-28 P. N. Appleton , V. Charmandaris , C. Struck

We show by numerical simulations that a purely stellar dynamical model composed of an exponential disc, a cuspy bulge, and an NFW halo with parameters relevant to the Milky Way Galaxy is subject to bar formation. Taking into account the…

星系天体物理 · 物理学 2016-08-17 Evgeny Polyachenko , Peter Berczik , Andreas Just

We investigate the dynamics of starbursting dwarf galaxies, using both new and archival HI observations. We consider 18 nearby galaxies that have been resolved into single stars by HST observations, providing their star formation history…

星系天体物理 · 物理学 2014-06-23 Federico Lelli , Marc Verheijen , Filippo Fraternali

We report a dynamical determination of the separate contributions of disk and dark halo masses to the rotation curve of a spiral galaxy. We use fluid-dynamical models of gas flow in the barred galaxy NGC 4123 to constrain the dynamical…

天体物理学 · 物理学 2008-11-26 Benjamin J. Weiner , J. A. Sellwood , T. B. Williams

In this paper, we use $\textit{B}$-band, $\textit{I}$-band, and 3.6 $\mu$m azimuthal light profiles of four low surface brightness (LSB) galaxies (UGC 628, F568-1, F568-3, F563-V2) to characterise three bar parameters: length, strength, and…

星系天体物理 · 物理学 2018-03-14 Wesley Peters , Rachel Kuzio de Naray

Two dwarf irregular galaxies DDO 187 and NGC 3738 exhibit a striking pattern of star formation: intense star formation is taking place in a large region occupying roughly half of the inner part of the optical galaxy. We use data on the HI…

A new deep HI survey of the galaxy Messier 33 is presented, based on observations obtained at the Dominion Radio Astrophysical Observatory. We observe a perturbed outer gas distribution and kinematics in M33, and confirm the disk warping as…

星系天体物理 · 物理学 2017-06-15 S. Zacharie Kam , Claude Carignan , Laurent Chemin , Tyler Foster , Ed Elson , Tom H. Jarrett

Estimating the bar pattern speed (\Om{}) is one of the main challenges faced in understanding the role of stellar bars in galaxy dynamical evolution. This work aims to characterise different uncertainty sources affecting the Tremaine…

An important dynamic parameter of barred galaxies is the bar pattern speed. Among several methods that are used for the determination of the pattern speed the Tremaine-Weinberg method has the advantage of model independency and accuracy. In…

星系天体物理 · 物理学 2010-08-30 R. F. Gabbasov , P. Repetto , M. Rosado

Barred galaxies constitute about two thirds of observed disc galaxies. Bars affect not only the mass distribution of gas and stars, but also that of the dark matter. An elongation of the inner dark matter halo is known as the halo bar. We…

星系天体物理 · 物理学 2024-05-28 Daniel A. Marostica , Rubens E. G. Machado , E. Athanassoula , T. Manos

Mapping of the HI disk of the isolated irregular galaxy DDO 154 with the C array of the Very Large Array and with the 3.2' upgraded Arecibo beam is presented. Our results show a truncation (or temporary drop) of the HI disk at a column…

天体物理学 · 物理学 2009-11-06 G. Lyle Hoffman , E. E. Salpeter , Nathan J. Carle

We have examined gas engaged in noncircular motions in 22 of the nearby LITTLE THINGS dwarf irregular galaxies. The HI data cubes have been deconvolved into kinematic components - bulk rotation and noncircular motions, to produce maps of…

星系天体物理 · 物理学 2019-06-26 Deidre A. Hunter , Lauren Laufman , Se-Heon Oh , Stephen E. Levine , Caroline E. Simpson

We present a disc-halo N-body model of the low surface brightness galaxy UGC 628, one of the few systems that harbours a "slow" bar with a ratio of corotation radius to bar length of $\mathcal{R} \equiv R_c/a_b \sim 2$. We select our…

星系天体物理 · 物理学 2016-09-07 Matthew H. Chequers , Kristine Spekkens , Lawrence M. Widrow , Colleen Gilhuly

The pattern speed in one of the fundamental parameters that determines the structure of barred galaxies. This quantity is usually derived from indirect methods or by employing model assumptions. The number of bar pattern speeds derived…

天体物理学 · 物理学 2009-11-10 Joris Gerssen , Konrad Kuijken , Michael R. Merrifield

We present the results of our recent HI observations conducted on the edge-on galaxy NGC2683 using the Five-hundred-meter Aperture Spherical radio Telescope (FAST). In comparison to previous observations made by the VLA, FAST has detected a…

星系天体物理 · 物理学 2025-05-07 Qian Jiao , Ming Zhu , Bernd Vollmer , Mei Ai , Haiyang Yu , Qinghua Tan , Cheng Cheng , Yang Gao