The Discovery of the Largest Gas Filament in Our Galaxy, or a New Spiral Arm?

ABSTRACT With backwards orbit integration, we estimate birth locations of young stellar associations and moving groups identified in the solar neighbourhood that are younger than 70 Myr. The birth locations of most of these stellar associations are at a smaller galactocentric radius than the Sun, implying that their stars moved radially outwards after birth. Exceptions to this rule are the Argus and Octans associations, which formed outside the Sun’s galactocentric radius. Variations in birth heights of the stellar associations suggest that they were born in a filamentary and corrugated disc of molecular clouds, similar to that inferred from the current filamentary molecular cloud distribution and dust extinction maps. Multiple spiral arm features with different but near corotation pattern speeds and at different heights could account for the stellar association birth sites. We find that the young stellar associations are located in between peaks in the radial/tangential (UV) stellar velocity distribution for stars in the solar neighbourhood. This would be expected if they were born in a spiral arm, which perturbs stellar orbits that cross it. In contrast, stellar associations seem to be located near peaks in the vertical phase-space distribution, suggesting that the gas in which stellar associations are born moves vertically together with the low-velocity dispersion disc stars.

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Theoretical investigation for the relation (supermassive black hole mass)–(spiral arm pitch angle): a correlation for galaxies with classical bulges

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/571/1/012118 ◽

2019 ◽

Vol 571 ◽

pp. 012118

Author(s):

Ismaeel A Al-Baidhany ◽

Sami S Chiad ◽

Wasmaa A Jabbar ◽

Rasha A Hussein ◽

Firas F K Hussain ◽

...

Keyword(s):

Black Hole ◽

Theoretical Investigation ◽

Pitch Angle ◽

Black Hole Mass ◽

Supermassive Black Hole ◽

Spiral Arm

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TESTING THE LINK BETWEEN TERRESTRIAL CLIMATE CHANGE AND GALACTIC SPIRAL ARM TRANSIT

The Astrophysical Journal ◽

10.1088/0004-637x/705/2/l101 ◽

2009 ◽

Vol 705 (2) ◽

pp. L101-L103 ◽

Cited By ~ 29

Author(s):

Andrew C. Overholt ◽

Adrian L. Melott ◽

Martin Pohl

Keyword(s):

Climate Change ◽

Galactic Spiral ◽

Spiral Arm

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The Dark Matter Halo Density Profile, Spiral Arm Morphology, and Supermassive Black Hole Mass of M33

ISRN Astronomy and Astrophysics ◽

10.5402/2011/725697 ◽

2011 ◽

Vol 2011 ◽

pp. 1-8 ◽

Cited By ~ 6

Author(s):

Marc S. Seigar

Keyword(s):

Black Hole ◽

Dark Matter ◽

Density Profile ◽

Pitch Angle ◽

Rotation Curve ◽

Dark Matter Halo ◽

Black Hole Mass ◽

Supermassive Black Hole ◽

Virial Mass ◽

Spiral Arm

We investigate the dark matter halo density profile of M33. We find that the HI rotation curve of M33 is best described by an NFW dark matter halo density profile model, with a halo concentration of and a virial mass of . We go on to use the NFW concentration of M33, along with the values derived for other galaxies (as found in the literature), to show that correlates with both spiral arm pitch angle and supermassive black hole mass.

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Is High-Velocity Cloud Complex C Associated with the Galactic Warp?

Publications of the Astronomical Society of Australia ◽

10.1071/as03028 ◽

2003 ◽

Vol 20 (3) ◽

pp. 263-269 ◽

Cited By ~ 4

Author(s):

Daisuke Kawata ◽

Christopher Thom ◽

Brad K. Gibson

Keyword(s):

High Latitude ◽

High Velocity ◽

Large Magellanic Cloud ◽

Alternative Interpretation ◽

North Polar ◽

Gas Cloud ◽

Cloud Complex ◽

Galactic Warp ◽

Velocity Cloud ◽

Spiral Arm

AbstractWe test the hypothesis that high-velocity gas cloud Complex C is actually a high-latitude spiral arm extension in the direction of the Galactic warp, as opposed to the standard interpretation — that of a once extragalactic, but now infalling, gas cloud. A parallel Tree N-body code was employed to simulate the tidal interaction of a satellite perturber with the Milky Way. We find that a model incorporating a perturber of the mass of the Large Magellanic Cloud on a south to north polar orbit, crossing the disk at ˜15 kpc, does yield a high-velocity, high-latitude extension consistent with the spatial, kinematical, and column density properties of Complex C. Unless this massive satellite remains undiscovered because of either a fortuitous alignment with the Galactic bulge (feasible within the framework of the model), or the lack of any associated baryonic component, we conclude that this alternative interpretation appears unlikely.

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