Protostellar jets are known to emit in a wide range of bands, from radio to IR to optical bands, and to date also about ten X-ray emitting jets have been detected, with a rate of discovery of about one per year. We aim at investigating the mechanism leading to the X-ray emission detected in protostellar jets and at constraining the physical parameters that describe the jet/ambient interaction by comparing our model predictions with observations. We perform 2D axisymmetric hydrodynamic simulations of the interaction between a supersonic jet and the ambient. The jet is described as a train of plasma blobs randomly ejected by the stellar source along the jet axis. We explore the parameter space by varying the ejection rate, the initial jet Mach number, and the initial density contrast between the ambient and the jet. We synthesized from the model the X-ray emission as it would be observed with the current X-ray telescopes. The mutual interactions among the ejected blobs and of the blobs with the ambient medium lead to complex X-ray emitting structures within the jet: irregular chains of knots; isolated knots with measurable proper motion; apparently stationary knots; reverse shocks. The predicted X-ray luminosity strongly depends on the ejection rate and on the initial density contrast between the ambient and the jet, with a weaker dependence on the jet Mach number. Our model represents the first attempt to describe the X-ray properties of all the X-ray emitting protostellar jets. The comparison between our model predictions and the observations can provide a useful diagnostic tool necessary for a proper interpretation of the observations. In particular, we suggest that the observable quantities derived from the spectral analysis of X-ray observations can be used to constrain the ejection rate, a parameter explored in our model that is not measurable by current observations.
Particle Acceleration and Depolarization in the Protostellar jet knots HH 80 and HH 81
Indian Institute of Space Science and Technology（印度空间科学与技术学院）；Indian Institute of Science（印度科学学院）；New Mexico Institute of Mining and Technology（新墨西哥矿业与技术学院）；Instituto de Radiastronomía y Astrofísica (IRyA) Universidad Nacional Autónoma de México (UNAM)（墨西哥国立自治大学射电天文学与天体物理研究所）；Instituto de Astronomía Teórica y Experimental (IATE) Universidad Nacional de Córdoba (UNC)（科尔多瓦国立大学理论与实验天体物理研究所）
The Structure and Kinematics of Three Class 0 Protostellar Jets from JWST
Ritter Astrophysical Research Center, Dept. of Physics and Astronomy, University of Toledo（托莱多大学物理与天文学系里特天文研究中心）；INAF-Osservatorio Astronomico di Capodimonte（意大利国家天体物理研究所卡波迪蒙特天文台）；Jet Propulsion Laboratory, California Institute of Technology（加州理工学院喷气推进实验室）；Tata Institute of Fundamental Research（塔塔基础研究所）；Department of Astronomy, The University of Texas at Austin（德克萨斯大学奥斯汀分校天文学系）；Dipartimento di Fisica, Università degli Studi di Milano（米兰大学物理系）；Leiden Observatory, Leiden University（莱顿大学莱顿天文台）；Max Planck Institute for Astronomy（马克斯·普朗克天文学研究所）；Departamento de Astronomía, Universidad de Concepción（康塞普西翁大学天文学系）
A Study of HH 270 with the James Webb Space Telescope
Universidad de Puerto Rico - Río Piedras（波多黎各大学里奥皮德拉斯分校）；Space Telescope Science Institute（太空望远镜科学研究所）；Universidad Nacional Autónoma de México（墨西哥国立自治大学）；Yale University（耶鲁大学）
Particle acceleration at recollimation shocks in sub-relativistic jets. A model for jets in Seyfert Galaxies, Microquasars and Protostellar Systems
INAF, Istituto Nazionale di Astrofisica（意大利国家天体物理研究所）；Universite Paris Cité（巴黎西岱大学）；Université Côte d’Azur, Observatoire de la Côte d’Azur, CNRS, Laboratoire Lagrange（法国蔚蓝海岸大学，蔚蓝海岸天文台，法国国家科学研究中心，拉格朗日实验室）；University of Pisa（比萨大学）；Institute of Nuclear Physics Polish Academy of Sciences（波兰科学院核物理研究所）
JOYS: Launch and destruction of dust in protostellar jets. The case of BHR71-IRS1 with JWST MIRI
Leiden University（莱顿大学）；INAF - Osservatorio Astronomico di Roma（罗马天文台国家天体物理研究所）；University of Helsinki（赫尔辛基大学）；Max-Planck-Institut für Extraterrestrische Physik（马克斯·普朗克地外物理学研究所）；INAF-Osservatorio Astronomico di Capodimonte（卡波迪蒙特天文台国家天体物理研究所）；University of Virginia（弗吉尼亚大学）；Virginia Institute of Theoretical Astronomy（弗吉尼亚理论天文研究所）；Institut de Cienciès de l’Espai (ICE-CSIC)（空间科学研究所（西班牙高等科学研究委员会））；Institut d’Estudis Espacials de Catalunya (IEEC)（加泰罗尼亚空间研究所）；Université Paris-Saclay（巴黎萨克雷大学）
JOYS$+$: A JWST/MIRI survey of the evolution of H$_2$ winds and jets from low-mass protostars
Leiden University（莱顿大学）；Max-Planck-Institut für Extraterrestrische Physik（马克斯·普朗克地外物理学研究所）；INAF-Osservatorio Astronomico di Capodimonte（意大利国家天体物理研究所卡波迪蒙特天文台）；Institut de Ciències de l’Espai (ICE-CSIC)（空间科学研究所（加泰罗尼亚高等研究委员会））；Institut d’Estudis Espacials de Catalunya (IEEC)（加泰罗尼亚空间研究所）；Max Planck Institute for Astronomy（马克斯·普朗克天文学研究所）；University of Helsinki（赫尔辛基大学）；Jet Propulsion Laboratory, California Institute of Technology（加州理工学院喷气推进实验室）；European Southern Observatory（欧洲南方天文台）
