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相关论文: Self-modulation of cosmic rays in molecular clouds…

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The theory of cosmic-ray (CR) penetration into dense molecular clouds developed recently for relativistic particles by Chernyshov et al. (2024) is extended to non-relativistic CRs. Interstellar CRs streaming into the clouds are able to…

高能天体物理现象 · 物理学 2025-10-06 D. O. Chernyshov , A. V. Ivlev , V. A. Dogiel

We analyze the processes governing cosmic-ray (CR) penetration into molecular clouds and the resulting generation of gamma-ray emission. The density of CRs inside a cloud is depleted at lower energies due to the self-excited MHD turbulence.…

高能天体物理现象 · 物理学 2018-12-05 V. A. Dogiel , D. O. Chernyshov , A. V. Ivlev , D. Malyshev , A. W. Strong , K. S. Cheng

We study penetration of interstellar cosmic rays (CRs) into molecular clouds surrounded by nonuniform diffuse envelopes. The present work generalizes our earlier model of CR self-modulation (Ivlev et al. 2018, Dogiel et al. 2018), in which…

高能天体物理现象 · 物理学 2024-07-08 D. O. Chernyshov , A. V. Ivlev , A. M. Kiselev

It was recently discovered that in some regions of the Galaxy, the cosmic ray (CR) abundance is several orders of magnitude higher than previously thought. Additionally, there is evidence that in molecular cloud envelopes, the CR ionization…

高能天体物理现象 · 物理学 2020-10-21 Kedron Silsbee , Alexei V. Ivlev

Observations of the properties of dense molecular clouds are critical in understanding the process of star-formation. One of the most important, but least understood, is the role of the magnetic fields. We discuss the possibility of using…

高能天体物理现象 · 物理学 2014-12-16 A. W. Strong , C. Dickinson , E. J. Murphy

The local cosmic-ray (CR) spectra are calculated for typical characteristic regions of a cold dense molecular cloud, to investigate two so far neglected mechanisms of dust charging: collection of suprathermal CR electrons and protons by…

星系天体物理 · 物理学 2015-11-05 Alexei Ivlev , Marco Padovani , Daniele Galli , Paola Caselli

We show radio continuum images of several molecular complexes in the inner Galaxy and report the presence of dark features that coincide with dense molecular clouds. Unlike infrared dark clouds, these features which we call "radio dark…

星系天体物理 · 物理学 2015-06-11 F. Yusef-Zadeh

The Galactic Central Molecular Zone (CMZ) is a region containing massive and dense molecular clouds, with dynamics driven by a variety of energy sources including a massive black hole. It is thus the nearest template for understanding…

星系天体物理 · 物理学 2017-01-16 W. D. Langer , T. Velusamy , M. R. Morris , P. F. Goldsmith , J. L. Pineda

From the rate of hydrogen ionization and the gamma ray flux, we derived the spectrum of relativistic and subrelativistic cosmic rays (CRs) nearby and inside the molecular cloud Sgr B2 near the Galactic Center (GC). We studied two cases of…

高能天体物理现象 · 物理学 2015-08-19 V. A. Dogiel , D. O. Chernyshov , A. M. Kiselev , M. Nobukawa , K. S. Cheng , C. Y. Hui , C. M. Ko , K. K. Nobukawa , T. G. Tsuru

Recent work has both illuminated and mystified our attempts to understand cosmic rays (CRs) in starburst galaxies. I discuss my new research exploring how CRs interact with the ISM in starbursts. Molecular clouds provide targets for CR…

高能天体物理现象 · 物理学 2015-06-17 Brian C. Lacki

Magnetic fields of molecular clouds in the Central Molecular Zone (CMZ) have been relatively underobserved at sub-parsec resolution. Here we report JCMT/POL2 observations of polarized dust emission in the CMZ, which reveal magnetic field…

We present highly sensitive measurements taken with MeerKAT at 1280 MHz as well as archival GBT, MWA and VLA images at 333, 88 and 74 MHz. We report the detection of synchrotron radio emission from the infrared dark cloud (IRDC) associated…

高能天体物理现象 · 物理学 2023-11-01 F. Yusef-Zadeh , M. Wardle , R. Arendt , J. W. Hewitt , Y. Hu , A. Lazarian , N. Kassim , S. Hyman , I. Heywood

We have mapped 20 molecular lines in the Central Molecular Zone (CMZ) around the Galactic Centre, emitting from 85.3 to 93.3 GHz. This work used the 22-m Mopra radio telescope in Australia, equipped with the 8-GHz bandwidth UNSW-MOPS…

Recent ammonia (1,1) inversion line data on the Galactic star forming region Sgr B2 show that the column density is consistent with a radial Gaussian density profile with a standard deviation of 2.75 pc. Deriving a formula for the virial…

天体物理学 · 物理学 2009-11-13 R. J. Protheroe , J. Ott , R. D. Ekers , D. I. Jones , R. M. Crocker

(Abridged) The inner couple hundred pcs of our Galaxy is characterized by significant amount of synchrotron-emitting gas, which appears to co-exist with a large reservoir of molecular gas. The spatial correlation between fluorescent Fe…

天体物理学 · 物理学 2008-11-26 F. Yusef-Zadeh , M. Muno , M. Wardle , D. C. Lis

The energy densities in magnetic fields and cosmic rays (CRs) in galaxies are often assumed to be in equipartition, allowing for an indirect estimate of the magnetic field strength from the observed radio synchrotron spectrum. However, both…

星系天体物理 · 物理学 2016-01-27 Tova M. Yoast-Hull , John S. Gallagher , Ellen G. Zweibel

We have imaged 24 spectral lines in the Central Molecular Zone (CMZ) around the Galactic Centre, in the range 42 to 50 GHz. The lines include emission from the CS, CH3OH, HC3N, SiO, HNCO, HOCO+, NH2CHO, OCS, HCS+, CCS, C34S, 13CS, 29SiO,…

星系天体物理 · 物理学 2015-06-15 P. A. Jones , M. G. Burton , M. R. Cunningham , N. F. H. Tothill , A. J. Walsh

We present 74 MHz radio continuum observations of the Galactic center region. These measurements show nonthermal radio emission arising from molecular clouds that is unaffected by free-free absorption along the line of sight. We focus on…

星系天体物理 · 物理学 2019-08-19 F. Yusef-Zadeh , M. Wardle , D. Lis , S. Viti , C. Brogan , E. Chambers , M. Pound , M. Rickert

The observed spectral bump in cosmic-ray (CR) proton and helium spectra, along with the phase and amplitude evolution of CR dipole anisotropy, provide plausible yet indirect evidence for the presence of a nearby CR source. This study…

高能天体物理现象 · 物理学 2025-06-25 Xing-Jian Lv , Xiao-Jun Bi , Kun Fang , Peng-Fei Yin , Meng-Jie Zhao

Understanding how cosmic rays (CRs) propagate within the giant molecular clouds (GMCs) is critical for studying the dynamics and chemical processes inside the clouds. The flux of low-energy CRs inside the dense cores of GMCs strongly…

高能天体物理现象 · 物理学 2024-12-03 Zhaodong Shi , Bing Liu , Rui-zhi Yang
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