Core fragmentation and Toomre stability analysis of W3(H2O)$a case study of the IRAM NOEMA large program CORE

• Verfasst von: Ahmadi, Aida [VerfasserIn]
• Verfasst von: Beuther, Henrik [VerfasserIn]
• Verfasst von: Henning, Thomas [VerfasserIn]
• Verfasst von: Bosco, Felix [VerfasserIn]
• Titel: Core fragmentation and Toomre stability analysis of W3(H2O)$a case study of the IRAM NOEMA large program CORE
• Verf.angabe: A. Ahmadi, H. Beuther, J.C. Mottram, F. Bosco, H. Linz, Th. Henning, J.M. Winters, R. Kuiper, R. Pudritz, Á Sánchez-Monge, E. Keto, M. Beltran, S. Bontemps, R. Cesaroni, T. Csengeri, S. Feng, R. Galvan-Madrid, K.G. Johnston, P. Klaassen, S. Leurini, S.N. Longmore, S. Lumsden, L.T. Maud, K.M. Menten, L. Moscadelli, F. Motte, A. Palau, T. Peters, S.E. Ragan, P. Schilke, J.S. Urquhart, F. Wyrowski, and H. Zinnecker
• E-Jahr: 2018
• Jahr: 11 October 2018
• Umfang: 22 S.
• Fussnoten: Im Titel ist die Zahl "2" tiefgestellt ; Gesehen am 17.04.2019
• Titel Quelle: Enthalten in: Astronomy and astrophysics
• Ort Quelle: Les Ulis : EDP Sciences, 1969
• Jahr Quelle: 2018
• Band/Heft Quelle: 618(2018) Artikel-Nummer A46, 22 Seiten
• ISSN Quelle: 1432-0746
• DOI: doi:10.1051/0004-6361/201732548
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1663228817

Abstract

<i>Context.<i/> The fragmentation mode of high-mass molecular clumps and the properties of the central rotating structures surrounding the most luminous objects have yet to be comprehensively characterised.<i>Aims.<i/> We study the fragmentation and kinematics of the high-mass star-forming region W3(H<sub>2<sub/>O), as part of the IRAM NOrthern Extended Millimeter Array (NOEMA) large programme CORE.<i>Methods.<i/> Using the IRAM NOEMA and the IRAM 30 m telescope, the CORE survey has obtained high-resolution observations of 20 well-known highly luminous star-forming regions in the 1.37 mm wavelength regime in both line and dust continuum emission.<i>Results.<i/> We present the spectral line setup of the CORE survey and a case study for W3(H<sub>2<sub/>O). At ~0.′′35 (700 AU at 2.0 kpc) resolution, the W3(H<sub>2<sub/>O) clump fragments into two cores (west and east), separated by ~2300 AU. Velocity shifts of a few km s<sup>−1<sup/> are observed in the dense-gas tracer, CH<sub>3<sub/>CN, across both cores, consistent with rotation and perpendicular to the directions of two bipolar outflows, one emanating from each core. The kinematics of the rotating structure about W3(H<sub>2<sub/>O) W shows signs of differential rotation of material, possibly in a disk-like object. The observed rotational signature around W3(H<sub>2<sub/>O) E may be due to a disk-like object, an unresolved binary (or multiple) system, or a combination of both. We fit the emission of CH<sub>3<sub/>CN (12<sub><i>K<i/><sub/>−11<sub><i>K<i/><sub/>), <i>K<i/> = 4−6 and derive a gas temperature map with a median temperature of ~165 K across W3(H<sub>2<sub/>O). We create a Toomre <i>Q<i/> map to study thestability of the rotating structures against gravitational instability. The rotating structures appear to be Toomre unstable close to their outer boundaries, with a possibility of further fragmentation in the differentially rotating core, W3(H<sub>2<sub/>O) W. Rapid cooling in the Toomre unstable regions supports the fragmentation scenario.<i>Conclusions.<i/> Combining millimetre dust continuum and spectral line data toward the famous high-mass star-forming region W3(H<sub>2<sub/>O), we identify core fragmentation on large scales, and indications for possible disk fragmentation on smaller spatial scales.