Kinematic Structure of the Milky Way Galaxy, Near the Spiral Arm Tangents

Vallée, J. P.

doi:10.4236/ijaa.2022.124022

Cited by 3 publications

(3 citation statements)

References 27 publications

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“…Comparing the mean direction of impact peaks with arm analyses (Table 2 ) reveals 165 Myr to be closest and is within error of an estimate based on astrophysical processes 34 . An important astrophysical implication of the impact model is the spiral arm pattern speed.…”

Section: Discussionsupporting

confidence: 67%

“…A key variable for unlocking the effects of spiral arms on events on Earth is the net time for the Solar System to pass through the four spiral arms of the Milky Way and return to the same point with respect to the spiral arms (defined as the galactic period 15 , 32 ), noting that both the Solar System and arms are rotating in the same direction at different speeds. More recently, the time for the Solar System to pass from one spiral arm to the next has been estimated as 157.5 ± 10 Myr based on astrophysical measurements 34 . The model is based on four equally separated arms and so the galactic period is estimated as 157.5 × 4 = 630 ± 40 Myr.…”

Section: Introductionmentioning

confidence: 99%

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Generation of a galactic chronology with impact ages and spiral arm tangents

Gillman,

Zhang

2024

Sci Rep

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Resolving the role of galactic processes in Solar System/Earth events necessitates a robust temporal model. However, astrophysical theory diverges with models varying from long-lasting spiral density waves with uniform pattern speeds and arm structures to others with fleeting and unpredictable features. Here, we address those issues with (1) an analysis of patterns of impact periodicity over periods of 10 to 250 million years (Myr) using circular statistics and (2), an independent logarithmic spiral arm model fitted to arm tangents of 870 micron dust. Comparison of the impact periodicity results with the best-fit spiral arm model suggests a galactic period of 660 Myr, i.e. 165 Myr to pass from one arm to the next in a four spiral arm model, with the most recent arm passage around 52 million years ago (Ma). The oldest impact ages imply that the emerging galactic chronology model is robust for at least the last 2 Gyr. The arm-passing time is consistent with spectral analyses of zircons across 3 Gyrs. Overall, the model provides a temporal framework against which to test hypotheses of galactic mechanisms for global events such as mass extinctions and superchrons.

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Section: Discussionsupporting

confidence: 67%

Section: Introductionmentioning

confidence: 99%

Generation of a galactic chronology with impact ages and spiral arm tangents

Gillman,

Zhang

2024

Sci Rep

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“…Their longitudes range from 47°to 53°, close to the tangent direction of the Sagittarius spiral arm at l = 50° (Vallee 2014a(Vallee , 2014b. The distance from the Sun to the center of the Sagittarius spiral arm measured along the plane by various tracers considered in the literature (e.g., Vallee 2008;Steiman-Cameron et al 2010;Hou & Han 2014;Reid et al 2014;Hu et al 2016;Griv et al 2017;Hou 2021;Vallee 2022) is 964 ± 157 pc. Using the same references, we can estimate the distance to the tangent point at the center of the arm, 1180 ± 230 pc.…”

Section: Where In the Galaxy Is Complex K?mentioning

confidence: 90%

Complex K: Supernova Origin of Anomalous-velocity H i Structure

Verschuur,

Schmelz,

Escorza

et al. 2024

ApJ

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We address one of the lingering mysteries of high-velocity clouds: If the anomalous negative velocities are the result of the approaching gas from old supernovae, then where are the receding counterparts of the expanding shells? Data from the λ-21 cm Galactic neutral hydrogen EBHIS survey (Winkel et al.) show multiple signatures of the expanding shells. The near-side (approaching) H i shells form part of Complex K. The high blueshifted velocities result from the H i moving into the low-density environment of inter-arm space. The H i data also show a distinctive, bow-shaped feature, the signature of the far-side (receding) emission of an expanding shell. The low redshifted velocity results from the gas expanding into volumes of space with a higher density. If we make the simplifying assumptions that the expansion of the shells is uniform and spherically symmetric, then the explosions took place about ⪅3 × 105 yr ago. The momentum, p ∼ 7 × 104 M ⊙ km s−1, agrees with recent model estimates for supernova evolution. Supernova explosions attributed to the unseen companion in several binary systems identified by the Third Gaia Data Release may be responsible for anomalous-velocity H i gas in Complex K. Four binary star systems with neutron-star candidates are located at the edge of the Sagittarius spiral arm and used to determine the distance to the H i features discussed here.

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Long-term periodicity of sedimentary basins in response to astronomical forcing: Review and perspective

Zhang,

Jin,

et al. 2023

Earth-Science Reviews

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Kinematic Structure of the Milky Way Galaxy, Near the Spiral Arm Tangents

Cited by 3 publications

References 27 publications

Generation of a galactic chronology with impact ages and spiral arm tangents

Generation of a galactic chronology with impact ages and spiral arm tangents

Complex K: Supernova Origin of Anomalous-velocity H i Structure

Long-term periodicity of sedimentary basins in response to astronomical forcing: Review and perspective

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