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Related papers: An Outer Arm in the Second Galactic Quadrant: Stru…

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We examine the outer Galactic HI disk for deviations from the b=0 plane by constructing maps of disk surface density, mean height, and thickness. We find that the Galactic warp is well described by a vertical offset plus two Fourier modes…

Astrophysics · Physics 2007-05-23 E. S. Levine , Leo Blitz , Carl Heiles , Martin Weinberg

We present an investigation into the morphological features of the Milky Way. We use smoothed particle hydrodynamics (SPH) to simulate the interstellar medium (ISM) in the Milky Way under the effect of a number of different gravitational…

Astrophysics of Galaxies · Physics 2015-06-22 Alex R. Pettitt , Clare L. Dobbs , David M. Acreman , Daniel J. Price

We present high-resolution smoothed particle hydrodynamics simulations of a region of gas flowing in a spiral arm and identify dense gas clouds to investigate their kinematics with respect to a Milky Way model. We find that, on average, the…

Astrophysics of Galaxies · Physics 2017-12-27 F. G. Ramón-Fox , Ian A. Bonnell

The Milky Way is a spiral galaxy with the Schechter characteristic luminosity $L_*$, thus an important anchor point of the Hubble sequence of all spiral galaxies. Yet the true appearance of the Milky Way has remained elusive for centuries.…

Astrophysics of Galaxies · Physics 2020-12-21 Juntai Shen , Xing-Wu Zheng

We present distances to 56 molecular clouds within $10\degr \leq l \leq 20\degr$ and $|b| \leq 5.25\degr$ from the Milky Way Imaging Scroll Painting (MWISP) $^{12}$CO survey, 47 of which are first-time determinations. The molecular clouds…

Astrophysics of Galaxies · Physics 2026-04-20 Juan Mei , Zhiwei Chen , Min Fang , Miaomiao Zhang , Shiyu Zhang , Zhibo Jiang

The density wave theory predicted some physical offsets among different tracers of star formation. To test this prediction, here we compiled data on 40 galaxies searched observationally for a physical offset between spiral arm tracers, and…

Astrophysics of Galaxies · Physics 2019-11-21 Jacques P Vallee

Knowledge about the distribution of CO emission in the Milky Way is essential to understand the impact of Galactic environment on the formation and evolution of structures in the interstellar medium. However, currently our insight about the…

Astrophysics of Galaxies · Physics 2020-08-19 M. Riener , J. Kainulainen , J. D. Henshaw , H. Beuther

The nature of the spiral structure of the Milky Way has long been debated. Only in the last decade have astronomers been able to accurately measure distances to a substantial number of high-mass star-forming regions, the classic tracers of…

Astrophysics of Galaxies · Physics 2016-10-05 Ye Xu , Mark Reid , Thomas Dame , Karl Menten , Nobuyuki Sakai , Jingjing Li , Andreas Brunthaler , Luca Moscadelli , Bo Zhang , Xingwu Zheng

The Outer Scutum-Centaurus (OSC) spiral arm is the most distant molecular spiral arm in the Milky Way, but until recently little was known about this structure. Discovered by Dame and Thaddeus (2011), the OSC lies $\sim$15 kpc from the…

Astrophysics of Galaxies · Physics 2017-06-21 W. P. Armentrout , L. D. Anderson , Dana S. Balser , T. M. Bania , T. M. Dame , Trey V. Wenger

We investigate the structure of the Milky Way by determining how features in a spatial map correspond to CO features in a velocity map. We examine structures including logarithmic spiral arms, a ring and a bar. We explore the available…

Astrophysics of Galaxies · Physics 2015-06-03 C. L. Dobbs , A. Burkert

Spiral arm spurs are prominent features that have been observed in extinction and 8$\mu$m emission in nearby galaxies. In order to understand their molecular gas properties, we used the Owens Valley Radio Observatory to map the CO(J=1--0)…

Astrophysics · Physics 2009-11-13 S. A. Corder , K. Sheth , N. Z. Scoville , J. Koda , S. N. Vogel , E. Ostriker

Filamentary structures are common morphological features of the cold, molecular interstellar medium (ISM). Recent studies have discovered massive, hundred-parsec-scale filaments that may be connected to the large-scale, Galactic spiral arm…

Astrophysics of Galaxies · Physics 2016-06-01 J. Abreu-Vicente , S. Ragan , J. Kainulainen , Th. Henning , H. Beuther , K. Johnston

We apply the vertical Jeans equation to the Milky Way disk, in order to study non-axisymmetric variations in the thin disk surface density. We divide the disk plane into area cells with a 100 pc grid spacing, and use four separate subsets…

Astrophysics of Galaxies · Physics 2024-06-05 Axel Widmark , Aneesh P. Naik

We carry out analyses of some parameters of the galactic spiral arms, in the currently available samples. We present a catalog of the observed pitch angle for each spiral arm in the Milky Way disk. For each long spiral arm in the Milky Way,…

Astrophysics of Galaxies · Physics 2017-11-15 Jacques P Vallee

The spiral arm tangencies are ideal lines of sight in which to determine the distribution of interstellar gas components in the spiral arms and study the influence of spiral density waves on the interarm gas in the Milky Way. We present a…

Astrophysics of Galaxies · Physics 2015-04-15 T. Velusamy , W. D. Langer , P. F. Goldsmith , J. L. Pineda

From the sun's location in the Galactic disk, one can use different arm tracers (CO, HII, thermal or ionized or relativistic electrons, masers, cold or hot dust, etc) to locate a tangent to each spiral arm in the disk of the Milky Way…

Astrophysics of Galaxies · Physics 2015-04-28 Jacques P Vallee

We present a new satellite in the outer halo of the Galaxy, the first Milky Way satellite found in the stacked photometric catalog of the Panoramic Survey Telescope and Rapid Response System 1 (Pan-STARRS1) Survey. From follow-up photometry…

From the inception of radio astronomy, the study of the Interstellar Medium has been both aided and frustrated by one fact: we are right within it! Our embedded perspective is favourable to observing kinematic and structural details that…

Astrophysics of Galaxies · Physics 2010-10-05 Tyler Foster , Brendan Cooper

The spiral structure of our Milky Way Galaxy is not yet known. HII regions and giant molecular clouds are the most prominent spiral tracers. We collected the spiral tracer data of our Milky Way from the literature, namely, HII regions and…

Astrophysics of Galaxies · Physics 2015-05-13 L. G. Hou , J. L. Han , W. B. Shi

The position of the Sun inside the Milky Way's disc hampers the study of the spiral arm structure. We aim to analyse the spiral arms along the line-of-sight towards the Galactic centre (GC) to determine their distance, extinction, and…

Astrophysics of Galaxies · Physics 2021-09-08 Francisco Nogueras-Lara , Rainer Schödel , Nadine Neumayer