Dark impact and galactic star formation: Origin of the Gould belt

Abstract

The Milky Way has a giant stellar structure in the solar neighborhood, which has a size of $\sim 1$ kpc, a mass of $\sim 10^6{\mathrm{M}}_{\odot }$, and a ring-like distribution of young stars. Fundamental physical properties of this local enigmatic structure, known as the Gould belt (GB), have not been reproduced by previously proposed models. We first show that the local enigmatic structure can be formed about 30 Myr ago as a result of a high-speed, oblique collision between a gas cloud with a mass of $\sim 10^6{\mathrm{M}}_{\odot }$ and a dark matter clump with a mass of $\sim 10^7{\mathrm{M}}_{\odot }$ based on numerical simulations of the collision. We find that strong dynamical impact of the clump transforms the flattened cloud into a ring-like stellar structure after induced star formation within the cloud. Our simulations furthermore demonstrate that the stellar structure is moderately elongated and significantly inclined with respect to the disk of the Milky Way owing to the strong tidal torque by the colliding clump. We thus suggest that the GB is one of stellar substructures formed from collisions between gas clouds and dark matter clumps predicted in the hierarchical clustering scenario of galaxy formation. We also suggest that collisions of dark matter clumps with their host galaxies can significantly change star formation histories for some of their gas clouds thus influence galactic global star formation histories to some extent.

5 pages, 4 figures, accepted by MNRAS Letters

References in corpus (4)

• The Aquarius Project: the subhalos of galactic halos
• Clumps and streams in the local dark matter distribution
• The Resolved Properties of Extragalactic Giant Molecular Clouds
• Massive stars and globular cluster formation

Cited by in corpus (19)

• 3D mapping of young stars in the solar neighbourhood with Gaia DR2
• Untangling the Galaxy. II. Structure within 3 kpc
• Distances and Kinematics of Gould Belt Star-Forming Regions with Gaia DR2 results
• The Role of Gas In Maintaining Quasi-Steady Spiral Structure In Stellar Disks
• Untangling the Galaxy III: Photometric Search for Pre-main Sequence Stars with Deep Learning
• Gaia Data Release 3: Microlensing Events from All Over the Sky
• Discovery of a 21 Myr old stellar population in the Orion complex
• Resequencing the Hubble sequence and the quadratic (black hole mass)-(spheroid stellar mass) relation for elliptical galaxies
• The Gould Belt
• Parameters of the Radcliffe wave from masers, radio stars and T Tauri stars
• The Alma catalogue of OB stars. III. A cross-match with Gaia DR3 and an extension based on new spectral classifications
• Search for the evolutionary relationship between Galactic globular and open clusters using data from the Gaia DR2 Catalog
• The System of Molecular Clouds in the Gould Belt
• Topography of the Young Galactic Disk: Spatial and Kinematic Patterns of the Clustered Star Formation in the Solar Neighborhood
• On the nature of the Be star HR 7409 (7 Vul)
• A revised view of the Canis Major stellar overdensity with DECam and Gaia: new evidence of a stellar warp of blue stars
• A Search for a Globular Cluster whose Passage through the Galactic Disk Could Induce the Formation of the Gould Belt
• The density profile of Milky Way dark matter halo constrained from the OGLE microlensing sky map
• Gould Belt Members in X-ray RAVE: Cross-Matching RAVE Stars with 3XMM Point Sources