Warm CO gas generated by possible turbulent shocks in a low-mass star-forming dense core in Taurus

Abstract

We report ALMA Cycle 3 observations in CO isotopes toward a dense core, MC27/L1521F in Taurus, which is considered to be at an early stage of multiple star formation in a turbulent environment. Although most of the high-density parts of this core are considered to be as cold as $\sim$10 K, high-angular resolution ($\sim$20 au) observations in ${}^{12}$CO ($J$ = 3--2) revealed complex warm ($>$15--60 K) filamentary/clumpy structures with the sizes from a few tens of au to $\sim$1,000 au. The interferometric observations of ${}^{13}$CO and C${}^{18}$O show that the densest part with arc-like morphologies associated with the previously identified protostar and condensations are slightly redshifted from the systemic velocity of the core. We suggest that the warm CO clouds may be consequences of shock heating induced by interactions among the different density/velocity components that originated from the turbulent motions in the core. However, such a small-scale and fast turbulent motion does not correspond to a simple extension of the line-width-size relation (i.e., Larson'{}s law), and thus the actual origin remains to be studied. The high-angular resolution CO observations are expected to be essential in detecting small-scale turbulent motions in dense cores and to investigate protostar formation therein.

17 pages, 6 figures, accepted for publication in ApJ

References in corpus (17)

• Structural Analysis of Molecular Clouds: Dendrograms
• Signs of Early-Stage Disk Growth Revealed with ALMA
• Formation Scenario for Wide and Close Binary Systems
• The Five College Radio Astronomy Observatory CO Mapping Survey of the Taurus Molecular Cloud
• The Spitzer c2d Survey of Nearby Dense Cores: I: First Direct Detection of the Embedded Source in IRAM 04191+1522
• Triggered O star formation in M20 via cloud-cloud collision: Comparisons between high-resolution CO observations and simulations
• ALMA observations of dust polarization and molecular line emission from the Class 0 protostellar source Serpens SMM1
• Unveiling the Role of the Magnetic Field at the Smallest Scales of Star Formation
• ALMA Results of the Pseudodisk, Rotating disk, and Jet in Continuum and HCO+ in the Protostellar System HH 212
• ALMA observations of a high-density core in Taurus: dynamical gas interaction at the possible site of a multiple star formation
• Star formation in turbulent molecular clouds with colliding flow
• The initial conditions of isolated star formation - VII. Spitzer mapping of pre-stellar cores
• An origin of arc structures deeply embedded in dense molecular cloud cores
• Gravitationally unstable condensations revealed by ALMA in the TUKH122 prestellar core in the Orion A cloud
• A Detached Protostellar Disk around a $\sim$0.2$M_{\odot }$ protostar in a Possible Site of a Multiple Star Formation in a Dynamical Environment in Taurus
• Intensity-Corrected Herschel Observations of Nearby Isolated Low-Mass Clouds
• A turbulent origin for the complex envelope kinematics in the young low-mass core Per-Bolo 58

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