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The time-varying gravitational field produced by a Weber bar is used to explore mathematical features of the linearized Einstein equation. We present a self-contained formal framework for the treatment of the linear field, which is…

General Relativity and Quantum Cosmology · Physics 2013-07-17 R. A. Lewis , G. Modanese

We present SAURON integral-field stellar velocity and velocity dispersion maps for four double-barred early-type galaxies: NGC2859, NGC3941, NGC4725 and NGC5850. The presence of the inner bar does not produce major changes in the…

We present the results of the wide-field $^{12}$CO (1--0) observations of the nearby barred galaxy M83 carried out with the Nobeyama Millimeter Array (NMA). The interferometric data are combined with the data obtained with the Nobeyama 45-m…

We review general observational properties of bars in galaxies, and relations between bars, their dynamics, and (circum)nuclear activity. We consider new measurements of bar fractions and of the distribution of bars with host type, bar…

Astrophysics · Physics 2009-09-25 Johan H. Knapen

Large samples of Field Horizontal Branch (FHB) stars make excellent tracers of the Galactic halo; by studying their kinematics, one can infer important physical properties of our Galaxy. Here we present the results of a medium-resolution…

A survey of the inner Galaxy region of Galactic longitude l in [+15, +50] degree and latitude b in [-4,+4] degree is performed using one-third of the High Altitude Water Cherenkov (HAWC) Observatory operated during its construction phase.…

High Energy Astrophysical Phenomena · Physics 2016-01-27 A. U. Abeysekara , R. Alfaro , C. Alvarez , J. D. Álvarez , R. Arceo , J. C. Arteaga-Velázquez , H. A. Ayala Solares , A. S. Barber , B. M. Baughman , N. Bautista-Elivar , A. D. Becerril Reyes , E. Belmont , S. Y. BenZvi , A. Bernal , J. Braun , K. S. Caballero-Mora , T. Capistrán , A. Carramiñana , S. Casanova , M. Castillo , U. Cotti , J. Cotzomi , S. Coutiño de León , E. de la Fuente , C. De León , T. DeYoung , B. L. Dingus , M. A. DuVernois , R. W. Ellsworth , O. Enriquez-Rivera , D. W. Fiorino , N. Fraija , F. Garfias , M. M. González , J. A. Goodman , M. Gussert , Z. Hampel-Arias , J. P. Harding , S. Hernandez , P. Hüntemeyer , C. M. Hui , A. Imran , A. Iriarte , P. Karn , D. Kieda , A. Lara , R. J. Lauer , W. H. Lee , D. Lennarz , H. León Vargas , J. T. Linnemann , M. Longo , G. Luis Raya , K. Malone , A. Marinelli , S. S. Marinelli , H. Martinez , O. Martinez , J. Martínez-Castro , J. A. J. Matthews , P. Miranda-Romagnoli , E. Moreno , M. Mostafá , L. Nellen , M. Newbold , R. Noriega-Papaqui , B. Patricelli , R. Pelayo , E. G. Pérez-Pérez , J. Pretz , Z. Ren , C. Rivière , D. Rosa-González , H. Salazar , F. Salesa Greus , A. Sandoval , M. Schneider , G. Sinnis , A. J. Smith , K. Sparks Woodle , R. W. Springer , I. Taboada , O. Tibolla , K. Tollefson , I. Torres , T. N. Ukwatta , L. Villaseñor , K. Vrabel , T. Weisgarber , S. Westerhoff , I. G. Wisher , J. Wood , T. Yapici , G. B. Yodh , P. W. Younk , D. Zaborov , A. Zepeda , H. Zhou

Barred structures are important in understanding galaxy evolution, but they were not included explicitly in most dynamical models for nearby galaxies due to their complicated morphological and kinematic properties. We modify the triaxial…

Astrophysics of Galaxies · Physics 2022-12-21 Behzad Tahmasebzadeh , Ling Zhu , Juntai Shen , Ortwin Gerhard , Glenn van de Ven

Here we report the detection, in Halpha emission, of a radial corrugation in the velocity field of the spiral galaxy NGC 5427. The central velocity of the Halpha line displays coherent, wavy-like variations in the vicinity of the spiral…

The large-scale gaseous shocks in the bulge of M31 can be naturally explained by a rotating stellar bar. We use gas dynamical models to provide an independent measurement of the bar pattern speed in M31. The gravitational potentials of our…

Astrophysics of Galaxies · Physics 2023-11-14 Zi-Xuan Feng , Zhi Li , Juntai Shen , Ortwin Gerhard , Roberto Saglia , Matias Blana , Hui Li , Yingjie Jing

The Milky Way (MW) hosts a central bar whose pattern speed, orientation, and length remain uncertain, largely due to observational biases and selection effects, despite the transformative data provided by the Gaia mission. We aim to…

Most galaxies have a warped shape when they are seen from an edge-on point of view. The reason for this curious form is not completely known so far and in this work we apply dynamical system tools to contribute to its explanation. Starting…

Astrophysics of Galaxies · Physics 2016-03-23 Patricia Sanchez-Martin , Merce Romero-Gomez , Josep J. Masdemont

We study the peculiar velocity field inferred from the Mark III spirals using a new method of analysis. We estimate optimal values of Tully-Fisher scatter and zero-point offset, and we derive the 3-dimensional rms peculiar velocity…

Astrophysics · Physics 2009-10-31 Nelson Padilla , Diego G. Lambas

The arguments in favor of the unified formation mechanism for both slow (Lynden-Bell's) bars and common fast bars are given. This mechanism consists in a certain instability that is akin to the well-known radial orbit instability; it is…

Astrophysics · Physics 2007-05-23 E. V. Polyachenko , V. L. Polyachenko

Upcoming imaging surveys such as the Large Synoptic Survey Telescope will repeatedly scan large areas of sky and have the potential to yield million-supernova catalogs. Type Ia supernovae are excellent standard candles and will provide…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-25 Suman Bhattacharya , Arthur Kosowsky , Jeffrey A. Newman , Andrew R. Zentner

We have modelled 38 barred galaxies by using near-IR and optical data from the Ohio State University Bright Spiral Galaxy Survey. We constructed the gravitational potentials of the galaxies from $H$-band photometry, assuming constant…

Astrophysics · Physics 2009-11-13 P. Rautiainen , H. Salo , E. Laurikainen

We study the presence of low intensity high velocity components, which we have termed wing features in the integrated Halpha emission line profiles of the HII region populations of the spiral barred galaxies NGC 1530, NGC 3359 and NGC 6951.…

Astrophysics · Physics 2009-11-10 M. Relano , J. E. Beckman

We present a two-step method to simulate and study non-circular motions in strongly barred galaxies. The first step is to constrain the initial parameters using a Bayesian analysis of each galaxy's azimuthally averaged rotation curve, the…

Astrophysics of Galaxies · Physics 2018-10-24 T. H. Randriamampandry , N. Deg , C. Carignan , L. M. Widrow

Various sign-posts of recent star-formation activity, such as water and methanol maser emission or magnetically active low-mass young stars, can be detected with Very Long Baseline Interferometry (VLBI) radio arrays. The extremely accurate…

Astrophysics of Galaxies · Physics 2018-10-17 Laurent Loinard , Mark J. Reid

Multi-object and multi-fiber spectrographs on 4 and 8 meter telescopes make it possible to use extragalactic planetary nebulae (PNe) in the outer halos of early-type galaxies as kinematical tracers, where classical techniques based on…

We present a new technique to constrain the gravitational potential of a galaxy from the observed stellar mass surface density alone under a number of assumptions. It uses the classical Eddington Inversion Method to compute the phase-space…

Astrophysics of Galaxies · Physics 2025-02-19 Jorge Sanchez Almeida , Ignacio Trujillo , Mireia Montes , Angel R. Plastino