科研成果 by Type: 期刊论文

2024
Zhang S, Liu T, Wang K, Zavagno A, Garay G, Liu H, Xu F, Liu X, Sanhueza P, Soam A, et al. ATOMS: ALMA three-millimeter observations of massive star-forming regions – XVIII. On the origin and evolution of dense gas fragments in molecular shells of compact H ii regions. Monthly Notices of the Royal Astronomical Society [Internet]. 2024:stae2415. 访问链接Abstract
Fragmentation and evolution for the molecular shells of the compact H ii regions are less explored compared to their evolved counterparts. We map nine compact H ii regions with a typical diameter of 0.4 pc that are surrounded by molecular shells traced by CCH. Several to a dozen dense gas fragments probed by H13CO+ are embedded in these molecular shells. These gas fragments, strongly affected by the H ii region, have a higher surface density, mass, and turbulence than those outside the shells but within the same pc-scale natal clump. These features suggest that the shells swept up by the early H ii regions can enhance the formation of massive dense structures that may host the birth of higher-mass stars. We examine the formation of fragments and find that fragmentation of the swept-up shell is unlikely to occur in these early H ii regions, by comparing the expected time scale of shell fragmentation with the age of H ii region. We propose that the appearance of gas fragments in these shells is probably the result of sweeping up pre-existing fragments into the molecular shell that has not yet fragmented. Taken together, this work provides a basis for understanding the interplay of star-forming sites with an intricate environment containing ionization feedback such as those observed in starburst regions.
Xu X, Wang K, Gou Q, Baug T, Di Li, Zhongshi Wang, Duan C, Lei J. The Milky Way atlas for linear filaments II. clump rotation versus filament orientation. MNRAS [Internet]. 2024;535:940. 访问链接
Wang K, Ge Y, Baug T. The Milky Way Atlas for Linear Filaments. A&A [Internet]. 2024;686:L11. 访问链接
Sun S, Wang K, Liu X, Xu F. The Formation of Milky Way “Bones”: Ubiquitous HI Narrow Self-absorption Associated with CO Emission. The Astrophysical Journal Letters [Internet]. 2024;973:L27. 访问链接Abstract
Long and skinny molecular filaments running along Galactic spiral arms are known as “bones,” since they make up the skeleton of the Milky Way. However, their origin is still an open question. Here, we compare spectral images of HI taken by the Five-hundred-meter Aperture Spherical radio Telescope (FAST) with archival CO and Herschel dust emission to investigate the conversion from HI to H2 in two typical Galactic bones, CFG028.68-0.28 and CFG047.06+0.26. Sensitive FAST HI images and an improved methodology enabled us to extract HI narrow self-absorption (HINSA) features associated with CO line emission on and off the filaments, revealing the ubiquity of HINSA toward distant clouds for the first time. The derived cold HI abundances, [HI]/[H2], of the two bones range from ∼(0.5 to 44.7) × 10−3, which reveal different degrees of HI–H2 conversion, and are similar to those of nearby, low-mass star-forming clouds, Planck Galactic cold clumps, and a nearby active high-mass star-forming region G176.51+00.20. The HI–H2 conversion has been ongoing for 2.2–13.2 Myr in the bones, a timescale comparable to that of massive star formation therein. Therefore, we are witnessing young giant molecular clouds (GMCs) with rapid massive star formation. Our study paves the way of using HINSA to study cloud formation in Galactic bones and, more generally, in distant GMCs in the FAST era.
Zhang C, Liu T, Ren Z-Y, Zhu F-Y, Liu H-L, Wang K, Wu J-W, Li D, Jiao S, Tatematsu K, et al. ATOMS: ALMA three-millimetre observations of massive star-forming regions - XVI. Neutral versus ion line widths. MNRAS. 2024;533:4234-4247.
Shen X, Liu H-L, Ren Z, Tej A, Di Li, Zhongshi Wang, Liu HB, Fuller GA, Xie J, Jiao S, Yang A, et al. JCMT 850 micron continuum observations of density structures in the G35 molecular complex. ApJ [Internet]. 2024;974:239. 访问链接
Wang K, Wang Y, Xu F. Massive Star Formation Starts in Sub-virial Dense Clumps Unless Resisted by Strong Magnetic Fields. ApJL [Internet]. 2024;974:L6. 访问链接
Jiao W, Wang K, Xu F. Absence of High-mass Prestellar Cores in the Orion Giant Molecular Cloud. The Astronomical Journal [Internet]. 2024;168:151. 访问链接Abstract
A fundamental difference between “core-fed” and “clump-fed” star-formation theories lies in the existence or absence of high-mass cores at the prestellar stage. However, only a handful of such cores have been observed. Here, different than previous search in distributed star-formation regions in the Galactic plane, we search for high-mass prestellar cores in the Orion GMC, by observing the seven most massive starless cores selected from previous deep continuum surveys. We present ALMA Atacama Compact Array Band 6 and Band 7 continuum and line observations toward the seven cores, in which we identify nine dense cores at both bands. The derived maximum core mass is less than 11 M ⊙, based on different dust temperatures. We find no high-mass prestellar cores in this sample, aligning with the results of previous surveys, thereby challenging the existence of such cores in Orion. Outside Orion, further detailed studies are needed for remaining high-mass prestellar core candidates to confirm their status as massive, starless cores.
Xu F, Wang K. Deep high-resolution observations reveal the dynamical picture of massive protostellar cluster evolution. Chinese Science Bulletin [Internet]. 2024;69(21):3061. 访问链接
Liu J, Zhang Q, Lin Y, Qiu K, Koch PM, Liu HB, Li Z-Y, Girart JM, Pillai TG  S, Li S, et al. Dark Dragon Breaks Magnetic Chain: Dynamical Substructures of IRDC G28.34 Form in Supported Environments. \apj. 2024;966:120.
Xu F, Wang K, Liu T, Zhu L, Garay G, Liu X, Goldsmith P, Zhang Q, Sanhueza P, Qin S, et al. The ALMA-QUARKS Survey. II. The ACA 1.3 mm Continuum Source Catalog and the Assembly of Dense Gas in Massive Star-Forming Clumps. Research in Astronomy and Astrophysics. 2024;24:065011.
Jiao W, Wang K, Xu F, Wang C, Beuther H. Relative alignment between gas structures and magnetic field in Orion A at different scales using different molecular gas tracers. \aap. 2024;686:A202.
Cheng Y, Lu X, Sanhueza P, Liu HB, Zhang Q, Galván-Madrid R, Wang K, Nakamura F, Liu T, Feng S, et al. Investigations of Massive Filaments and Star Formation (INFANT). I. Core Identification and Core Mass Function. \apj. 2024;967:56.
Liu X, Liu T, Zhu L, Garay G, Liu H-L, Goldsmith P, Evans N, Kim K-T, Liu S-Y, Xu F, et al. The ALMA-QUARKS Survey. I. Survey Description and Data Reduction. Research in Astronomy and Astrophysics. 2024;24:025009.
Wang C, Wang K, Xu F-W, Sanhueza P, Liu HB, Zhang Q, Lu X, Fontani F, Caselli P, Busquet G, et al. The role of turbulence in high-mass star formation: Subsonic and transonic turbulence are ubiquitously found at early stages. \aap. 2024;681:A51.
Xu F, Wang K, Liu T, Tang M, Evans, Neal J. II, Palau A, Morii K, He J, Sanhueza P, Liu H-L, et al. The ALMA Survey of Star Formation and Evolution in Massive Protoclusters with Blue Profiles (ASSEMBLE): Core Growth, Cluster Contraction, and Primordial Mass Segregation. \apjs. 2024;270:9.
Xu F, Wang K, Liu T, Eden D, Liu X, Juvela M, He J, Johnstone D, Goldsmith P, Garay G, et al. On the Scarcity of Dense Cores (n > 10⁵ cm^-3) in High-latitude Planck Galactic Cold Clumps. \apjl. 2024;963:L9.
Zhao X, Tang X  D, Henkel C, Gong Y, Lin Y, Li D  L, He Y  X, Ao Y  P, Lu X, Liu T, et al. Kinetic temperature of massive star-forming molecular clumps measured with formaldehyde V. The massive filament DR21. A&A [Internet]. 2024;687A:207Z. 访问链接
2023
Ren Z, Chen X, Liu T, Mannfors E, Bronfman L, Xu F, Feng S, Liu H, Meng FY, Stutz AM, et al. A High-mass, Young Star-forming Core Escaping from Its Parental Filament. \apj. 2023;955:104.
Feng Y, Li X, Millar TJ, Szczerba R, Wang K, Quan D, Qin S, Fang X, Tuo J, Miao Z, et al. Photochemical origin of SiC2 in the circumstellar envelope of carbon-rich AGB stars revealed by ALMA. Frontiers in Astronomy and Space Sciences. 2023;10:1215642.

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