English
Related papers

Related papers: New Constraints on the Galactic Bar

200 papers

Galaxy cluster peculiar velocities can be inferred from high-sensitivity, high-resolution multiple-frequency observations in the 30 to 400 GHz range. While galaxy cluster counts and power spectra are sensitive to the growth factor, peculiar…

Astrophysics · Physics 2009-11-07 A. Peel , L. Knox

We show that bars in galaxy models having halos of moderate density and a variety of velocity distributions all experience a strong drag from dynamical friction unless the halo has large angular momentum in the same sense as the disk. The…

Astrophysics · Physics 2008-11-26 Victor P. Debattista , J. A. Sellwood

Galactic bars induce characteristic motions deviating from pure circular rotation, known as non-circular motions. As bars are non-axisymmetric structures, stronger bars are expected to show stronger non-circular motions. However, this has…

Astrophysics of Galaxies · Physics 2024-10-29 Taehyun Kim , Dimitri A. Gadotti , Yun Hee Lee , Carlos López-Cobá , Woong-Tae Kim , Minjin Kim , Myeong-gu Park

We investigate the effect of dust on the observed rotation rate of a stellar bar. The only direct way to measure this quantity relies on the Tremaine & Weinberg method which requires that the tracer satisfies the continuity equation. Thus…

Astrophysics · Physics 2008-11-26 Joris Gerssen , Victor Debattista

Based on published data, we have collected information about Galactic maser sources with measured distances. In particular, 44 Galactic maser sources located in star-forming regions have trigonometric parallaxes, proper motions, and radial…

Astrophysics of Galaxies · Physics 2013-02-07 A. S. Stepanishchev , V. V. Bobylev

We present a study of the connection between the galactic spin parameter $\lambda_{d}$ and the bar fraction in a volume-limited sample of 10,674 disk galaxies drawn from the Sloan Digital Sky Survey Data Release 7. The galaxies in our…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Bernardo Cervantes-Sodi , Cheng Li , Changbom Park , Lixin Wang

Many of the Milky Way's accreted substructures have been discovered and studied in the space of energy $E$, and angular momentum components $L_z$ and $L_{\bot}$. In a static axisymmetric system, these quantities are (reasonable…

Astrophysics of Galaxies · Physics 2025-08-27 Hanneke C. Woudenberg , Amina Helmi

Recently, Buta etal. (2009) examined the question "Do Bars Drive Spiral Density Waves?", an idea supported by theoretical studies and also from a preliminary observational analysis Block etal (2004). They estimated maximum bar strengths…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 H. Salo , E. Laurikainen , R. Buta , J. H. Knapen

I use distance- and mass-limited subsamples of the Spitzer Survey of Stellar Structure in Galaxies (S4G) to investigate how the presence of bars in spiral galaxies depends on mass, colour, and gas content and whether large, SDSS-based…

Astrophysics of Galaxies · Physics 2018-01-10 Peter Erwin

The Galactic disk exhibits complex chemical and dynamical substructure thought to be induced by the bar, spiral arms, and satellites. Here, we explore the chemical signatures of bar resonances in action and velocity space and characterize…

Astrophysics of Galaxies · Physics 2022-08-11 Adam Wheeler , Irene Abril-Cabezas , Wilma H. Trick , Francesca Fragkoudi , Melissa Ness

Among over 200,000 Galactic Bulge variable stars in the public domain OGLE catalogue, we found over 15,000 red giant variables following two well defined period -- amplitude relations. The periods are in the range 10 < P < 100 days, and…

Astrophysics · Physics 2009-11-10 J. J. Wray , L. Eyer , B. Paczynski

We revisit the stellar velocity distribution in the Galactic bulge/bar region with APOGEE DR16 and {\it Gaia} DR2, focusing in particular on the possible high-velocity (HV) peaks and their physical origin. We fit the velocity distributions…

Astrophysics of Galaxies · Physics 2021-02-17 Yingying Zhou , Zhao-Yu Li , Iulia Simion , Juntai Shen , Shude Mao , Chao Liu , Mingjie Jian , José. G. Fernández-Trincado

We present a novel method for constraining the length of the Galactic bar using 6D phase space information to directly integrate orbits. We define a pseudo-length for the Galactic bar, named $R_{Freq}$, based on the maximal extent of…

The now substantial evidence for a rotating bar in the inner Galaxy and its dynamical implications are reviewed.

Astrophysics · Physics 2007-05-23 Ortwin Gerhard

We use a gravitational bar torque method to compare bar strengths (the maximum tangential force normalized by radial force) in B and H-band images of 152 galaxies from the Ohio State University Bright Spiral Galaxy Survey. Our main…

Astrophysics · Physics 2009-11-13 T. Speltincx , E. Laurikainen , H. Salo

Based on published sources, we have created a kinematic database on 220 massive (>10 solar masses) young Galactic star systems located within <3 kpc of the Sun. Out of them, approximately 100 objects are spectroscopic binary and multiple…

Astrophysics of Galaxies · Physics 2013-07-08 V. V. Bobylev , A. T. Bajkova

We show that the effects of radial galactic tides alone can change the dynamics of an Oort cloud of comets around a star in a highly sensitive manner. The Oort cloud dynamics depends primarily from the star's position in the Galaxy and its…

Astrophysics · Physics 2007-05-23 Marco Masi

The analysis of the first three years of the OGLE data revealed 12 microlensing events of the Galactic bulge stars, with the characteristic time scales in the range $ 8.6 < t_0 < 80 $ days, where $ t_0 = R_E / V $. A complete sample of nine…

We study the dynamical stability against bar-mode deformation of rapidly and differentially rotating stars in the first post-Newtonian approximation of general relativity. We vary the compaction of the star $M/R$ (where $M$ is the…

Astrophysics · Physics 2008-11-26 Motoyuki Saijo , Masaru Shibata , Thomas W. Baumgarte , Stuart L. Shapiro

We propose a method to determine the galactic constants R_0 (distance to the Galactic Center) and V_0 (rotation velocity of the Sun) from measurements of distances, radial velocities and proper motions of objects near the solar circle. This…

Astrophysics of Galaxies · Physics 2015-05-28 Y. Sofue , T. Nagayama , M. Matsui , A. Nakagawa
‹ Prev 1 8 9 10 Next ›