Probing the initial conditions of high-mass star formation: III. Fragmentation and triggered star formation

被引：0

作者：

Zhang, Chuan-Peng ^{[1
,2
,3
]}

Csengeri, Timea ^{[3
]}

Wyrowski, Friedrich ^{[3
]}

Li, Guang-Xing ^{[4
,5
]}

Pillai, Thushara ^{[3
,9
]}

Menten, Karl M. ^{[3
]}

Hatchell, Jennifer ^{[6
]}

Thompson, Mark A. ^{[7
]}

Pestalozzi, Michele R. ^{[8
]}

机构：

[1] National Astronomical Observatories, Chinese Academy of Sciences, Beijing,100101, China

[2] Max-Planck-Institut für Astronomie, Königstuhl 17, Heidelberg,69117, Germany

[3] Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, Bonn,53121, Germany

[4] University Observatory Munich, Scheinerstrasse 1, München,81679, Germany

[5] South-Western Institute for Astronomy Research, Yunnan University, Kunming, Yunnan,650500, China

[6] School of Physics, University of Exeter, Stocker Rd, Exeter,EX4 4QL, United Kingdom

[7] Centre for Astrophysics Research, University of Hertfordshire, College Lane, Hatfield, Herts,AL10 9AB, United Kingdom

[8] Istituto di Fisica dello Spazio Interplanetario - INAF, via Fosso del Cavaliere 100, Roma,00133, Italy

[9] Institute for Astrophysical Research, Boston University, 725 Commonwealth Ave, Boston,MA,02215, United States

来源：

Astronomy and Astrophysics | 2019年 / 627卷

基金：

中国国家自然科学基金;

关键词：

Interferometry;

D O I：

暂无

中图分类号：

学科分类号：

摘要：

Context. Fragmentation and feedback are two important processes during the early phases of star formation. Aims. Massive clumps tend to fragment into clusters of cores and condensations, some of which form high-mass stars. In this work, we study the structure of massive clumps at different scales, analyze the fragmentation process, and investigate the possibility that star formation is triggered by nearby H ii regions. Methods. We present a high angular resolution study of a sample of massive proto-cluster clumps G18.17, G18.21, G23.97N, G23.98, G23.44, G23.97S, G25.38, and G25.71. Combining infrared data at 4.5, 8.0, 24, and 70 μm, we use a few arcsecond resolution, radiometer and millimeter inteferometric data taken at 1.3 cm, 3.5 mm, 1.3 mm, and 870 μm to study their fragmentation and evolution. Our sample is unique in the sense that all the clumps have neighboring H ii regions. Taking advantage of that, we tested triggered star formation using a novel method where we study the alignment of the center of mass traced by dust emission at multiple scales. Results. The eight massive clumps, identified based on single-dish observations, have masses ranging from 228 to 2279 Mo within an effective radius of Reff 0.5 pc. We detect compact structures towards six out of the eight clumps. The brightest compact structures within infrared bright clumps are typically associated with embedded compact radio continuum sources. The smaller scale structures of Reff 0.02 pc observed within each clump are mostly gravitationally bound and massive enough to form at least a B3-B0 type star. Many condensations have masses larger than 8 Mo at a small scale of Reff 0.02 pc. We find that the two infrared quiet clumps with the lowest mass and lowest surface density with © ESO 2019.

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