Search Publications
Cloud-cloud collisions and triggered star formation
Inoue, Tsuyoshi; Tachihara, Kengo; Fukui, Yasuo +2 more
Star formation is a fundamental process for galactic evolution. One issue over the last several decades has been determining whether star formation is induced by external triggers or self-regulated in a closed system. The role of an external trigger, which can effectively collect mass in a small volume, has attracted particular attention in connec…
ALMA CO observations of a giant molecular cloud in M 33: Evidence for high-mass star formation triggered by cloud-cloud collisions
Tokuda, Kazuki; Tachihara, Kengo; Sasaki, Manami +14 more
We report the first evidence for high-mass star formation triggered by collisions of molecular clouds in M 33. Using the Atacama Large Millimeter/submillimeter Array, we spatially resolved filamentary structures of giant molecular cloud 37 in M 33 using 12CO(J = 2-1), 13CO(J = 2-1), and C18O(J = 2-1) line emission …
The formation of young massive clusters triggered by cloud-cloud collisions in the Antennae galaxies NGC 4038/NGC 4039
Tokuda, Kazuki; Tachihara, Kengo; Ueda, Junko +5 more
The formation mechanism of super star clusters (SSCs), present-day analogs of the ancient globulars, still remains elusive. The major merger that is the Antennae galaxies is forming SSCs and is one of the primary targets to test the cluster formation mechanism. We reanalyzed the archival ALMA CO data of the Antennae and found three typical observa…
The formation of the young massive cluster B1 in the Antennae Galaxies (NGC 4038/NGC 4039) triggered by cloud-cloud collision
Tokuda, Kazuki; Tachihara, Kengo; Ueda, Junko +4 more
The Antennae Galaxies, one of major mergers, are a starburst. Tsuge et al. (2020, PASJ, 73, S35) showed that the five giant molecular complexes in the Antennae Galaxies have signatures of cloud-cloud collisions based on the Atacama Large Millimeter Array (ALMA) archival data with 60 pc resolution. In the present work we analyzed the new CO data to…
Subaru Hyper Suprime-Cam revisits the large-scale environmental dependence on galaxy morphology over 360 deg2 at z = 0.3-0.6
Shimakawa, Rhythm; Tanaka, Masayuki; Tanaka, Takumi S. +1 more
This study investigates the role of large-scale environments on the fraction of spiral galaxies at z = 0.3-0.6 sliced to three redshift bins of Δz = 0.1. Here, we sample 276220 massive galaxies in a limited stellar mass of 5 × 1010 solar mass (~M*) over 360 deg2, as obtained from the Second Public Data Release of the Hyper Su…
Atomic carbon [C I](3P1-3P0) mapping of the nearby galaxy M 83
Seta, Masumichi; Salak, Dragan; Nakai, Naomasa +6 more
Atomic carbon (C I) has been proposed to be a global tracer of the molecular gas as a substitute for CO, however, its utility remains unproven. To evaluate the suitability of C I as the tracer, we performed [C I](3P1-3P0) [hereinafter [C I](1-0)] mapping observations of the northern part of the nearby sp…