We present the first polarized dust emission measurements of the Horsehead Nebula, obtained using the POL-2 polarimeter on the Submillimetre Common-User Bolometer Array 2 (SCUBA-2) camera on the James Clerk Maxwell Telescope (JCMT). The Horsehead Nebula contains two sub-millimeter sources, a photodissociation region (PDR; SMM1) and a starless core (SMM2). We see well-ordered magnetic fields in both sources. We estimated plane-of-sky magnetic field strengths of 56$\pm$9 and 129$\pm$21 $μ$G in SMM1 and SMM2, respectively, and obtained mass-to-flux ratios and Alfvén Mach numbers of less than 0.6, suggesting that the magnetic field can resist gravitational collapse and that magnetic pressure exceeds internal turbulent pressure in these sources. In SMM2, the kinetic and gravitational energies are comparable to one another, but less than the magnetic energy. We suggest a schematic view of the overall magnetic field structure in the Horsehead Nebula. Magnetic field lines in SMM1 appear have been compressed and reordered during the formation of the PDR, while the likely more-embedded SMM2 may have inherited its field from that of the pre-shock molecular cloud. The magnetic fields appear to currently play an important role in supporting both sources.
The Horsehead nebula, a template source for interstellar physics and chemistry
我们提出了一个总结,我们以前的调查的马头星云的物理和化学结构,并讨论这些研究如何导致进步的理解FUV辐射对致密的星际云的结构。特定的分子示踪剂可用于隔离不同的环境,这些环境对FUV辐射或密度的变化比分子气体的经典示踪剂更敏感:CO同位素或尘埃(亚)毫米连续辐射。它们包括FUV照射界面的HCO或CCH自由基,或冷致密核的分子离子H $^{13}$ CO $^+$、DCO $^+$和其他氘代物质(DNC、DCN)。我们讨论的背景下,赫歇尔和ALMA的未来前景。
Weak, extended water vapor emission in the Horsehead nebula
Jet Propulsion Laboratory, California Institute of Technology(加州理工学院喷气推进实验室);LUX, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université(巴黎天文台卢克瑟姆宇宙学与天体物理实验室,巴黎文理研究大学,法国国家科学研究中心,索邦大学);Instituto de Física Fundamental (CSIC)(基础物理研究所(西班牙国家科学研究委员会));European Space Agency (ESA), European Space Astronomy Centre (ESAC)(欧洲空间局欧洲空间天文中心)
JWST observations of photodissociation regions: II. Warm molecular Hydrogen spectroscopy in the Horsehead nebula
Université Paris-Saclay, CNRS, Institut d’Astrophysique Spatiale(巴黎萨克雷大学);Sorbonne Université, CNRS, Institut d’Astrophysique de Paris(索邦大学);Space Telescope Science Institute(太空望远镜科学研究所);LUX, Observatoire de Paris, Université PSL, Sorbonne Université, CNRS(巴黎天文台);Université Paris-Cité(巴黎西岱大学);Steward Observatory, University of Arizona(亚利桑那大学斯图尔德天文台);Department of Physics & Astronomy, The University of Western Ontario(韦仕敦大学物理与天文学系);Ritter Astrophysical Research Center, University of Toledo(托莱多大学里特天体物理研究中心)
Spatial distribution of organics in the Horsehead nebula: Signposts of chemistry driven by atomic carbon
Pontificia Universidad Católica de Chile(智利天主教 Pontificia 大学);Millennium Nucleus on Young Exoplanets and their Moons (YEMS)(年轻系外行星及其卫星千年核);European Southern Observatory(欧洲南方天文台);IRAM(红外毫米波研究所);Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités(巴黎天文台,PSL研究大学,CNRS,索邦大学);Uppsala University(乌普萨拉大学);Instituto de Física Fundamental (CSIC)(基础物理研究所(CSIC))
H2 emission in the Orion Bar, NGC7023 and the Horsehead Nebula observed with the James Webb Space Telescope
Instituto de Física Fundamental (CSIC)(基础物理研究所(西班牙科学理事会));Institut d’Astrophysique Spatiale, Université Paris-Saclay, CNRS(空间天体物理学研究所,巴黎萨克雷大学,法国国家科学研究中心);Department of Physics and Astronomy, University of Western Ontario(韦仕敦大学物理与天文系);Institute for Earth and Space Exploration, The University of Western Ontario(韦仕敦大学地球与太空探索研究所);Department of Astronomy, University of Michigan(密歇根大学天文系);Astronomy Department, University of Maryland(马里兰大学天文系);Leiden Observatory, Leiden University(莱顿大学莱顿天文台)
Formation of dense structures induced by filament collisions. Correlation of density, kinematics and magnetic field in the Pipe nebula
上下文烟斗星云是一个分子云,缺乏恒星形成反馈,具有相对简单的形态和速度结构。这使得它成为测试云通过碰撞演化的理想目标。目的。我们的目标是绘制这个相对简单的云的全面图片,以更好地了解大尺度上分子云的形成和演化。方法.我们使用档案数据比较光学偏振特性,视觉消光,和13 CO速度和线宽的整个云,以确定可观测的趋势。结果烟斗星云可以大致分为两个方向和气体速度范围不同的细丝:E-W为2-4 km s-1,N-S为6-7 km s-1。这两个细丝在碗状结构处重叠,在碗状结构处,气体的速度梯度从2 km s-1到7 km s-1。与烟斗星云的其他部分相比,碗状气体看起来密度更大,线宽也更大。此外,在碗的偏振数据显示出较低的角色散和较高的偏振度。在碗的核心往往集群在空间和倾向于遵循13 CO速度梯度。在茎中,核心倾向于聚集在具有与碗相似性质的区域。结论.速度模式指向碗区域中的细丝之间的碰撞。磁场在冲击区似乎被压缩和加强。密度和磁场强度按与Alfvénic马赫数相似的因子成比例地增加,表明在磁通冻结的情况下,在低Alfvénic马赫数下存在连续激波。冲击区似乎促进了致密核的形成和聚集。