Results 21 to 30 of about 173 (158)

Luminosity Outburst Energized by the Collision between the Infalling Streamer and Disk in W51 North

The Astronomical Journal, 2023
We report the detection of the disk/torus, outflow, and inflow structures traced by H _2 O masers toward a high-mass young stellar object W51 North during its H _2 O maser outburst stage using the Karl G. Jansky Very Large Array (VLA).
Yan-Kun Zhang, Xi Chen, Shi-Ming Song, You-Xin Wang   +3 more
doaj   +1 more source

Inverse MultiView. II. Microarcsecond Trigonometric Parallaxes for Southern Hemisphere 6.7 GHz Methanol Masers G232.62+00.99 and G323.74–00.26

The Astrophysical Journal, 2023
We present the first results from the Southern Hemisphere Parallax Interferometric Radio Astrometry Legacy Survey: 10 μ as accurate parallaxes and proper motions for two Southern Hemisphere 6.7 GHz methanol masers obtained using the inverse MultiView ...
L. J. Hyland, M. J. Reid, G. Orosz, S. P. Ellingsen, S. D. Weston, J. Kumar, R. Dodson, M. J. Rioja, W. J. Hankey, P. M. Yates-Jones, T. Natusch, S. Gulyaev, K. M. Menten, A. Brunthaler   +13 more
doaj   +1 more source

High-sensitivity Observations of the H2O Megamasers of NGC 1068: Precise Astrometry and Detailed Kinematics

The Astrophysical Journal, 2023
We present High Sensitivity Array observations of the H _2 O megamasers of NGC 1068. We obtain absolute astrometry with 0.3 mas precision that confirms the association of the disk masers with the nuclear radio continuum source S1.
Jack F. Gallimore, C. M. Violette Impellizzeri   +1 more
doaj   +1 more source

Saturation and beaming in astrophysical masers

The Astrophysical Journal, 1985
A 'four-stream' model system of equations that are closely analogous to the equations of radiative transfer in a maser spectral line and are amenable to numerical solution are constructed. This model is used to investigate radiative transfer in asymmetric maser clouds.
C. Alcock, R. R. Ross
openaire   +1 more source

Maser radiation from collisionless shocks: application to astrophysical jets [PDF]

High Power Laser Science and Engineering, 2019
This paper describes a model of electron energization and cyclotron-maser emission applicable to astrophysical magnetized collisionless shocks. It is motivated by the work of Begelman, Ergun and Rees [Astrophys. J. 625, 51 (2005)] who argued that the cyclotron-maser instability occurs in localized magnetized collisionless shocks such as those expected ...
Speirs, D. C., Ronald, K., Phelps, A. D. R., Koepke, M. E., Cairns, R. A., Rigby, A., Cruz, F., Trines, R., Bamford, R., Kellett, B. J., Albertazzi, B., Cross, J. E., Fraschetti, F., Graham, P., Kozlowski, P. M., Kuramitsu, Y., Miniati, F., Morita, T., Oliver, M., Reville, B., Sakawa, Y., Sarkar, S., Spindloe, C., Koenig, M., Silva, L. O., Lamb, D. Q., Tzeferacos, P., Lebedev, S., Gregori, G., Bingham, R.   +29 more
openaire   +5 more sources

Evolution of the Outflow in the Water Fountain Source IRAS 18043–2116

The Astrophysical Journal, 2023
We present the spectral and spatial evolution of H _2 O masers associated with the water fountain source IRAS 18043−2116, found in observations with the Nobeyama 45 m Telescope and the Australia Telescope Compact Array. We have found new highest-velocity
L. Uscanga, H. Imai, J. F. Gómez, D. Tafoya, G. Orosz, T. P. McCarthy, Y. Hamae, K. Amada   +7 more
doaj   +1 more source

Detection of a High-velocity Jet from MWC 349A Traced by Hydrogen Recombination Line Maser Emission

The Astrophysical Journal Letters, 2023
MWC 349A is one of the rare stars known to have hydrogen radio recombination line (RRL) masers. The bright maser emission makes it possible to study the dynamics of the system at milliarcsecond (mas) precision.
Sirina Prasad, Qizhou Zhang, James Moran, Yue Cao, Izaskun Jimenéz-Serra, Jesus Martín-Pintado, Antonio Martínez-Henares, Alejandro Báez-Rubio   +7 more
doaj   +1 more source

Cyclotron Maser Radiation from Astrophysical Shocks

The Astrophysical Journal, 2003
One of the most popular coherent radio emission mechanisms is electron cyclotron maser instability. In this article we demonstrate that electron cyclotron maser emission is directly associated with particular types of charged particle acceleration such as turbulence and shocks commonly inferred in astrophysical plasmas.
Bingham, R., Kellett, B.J., Cairns, R.A., Tonge, J., Mendonça, J.T.   +4 more
openaire   +3 more sources

Masers and Other Instabilities in a Weakly Magnetized Relativistic Plasma: Theory and the Astrophysical Relevance of the Maser [PDF]

The Astrophysical Journal, 2019
Abstract A sufficient condition for maser instability in a weakly magnetized relativistic plasma with an isotropic particle distribution function is given. Maser growth rates and polarizations are computed starting from the exact dielectric permittivity tensor of a magnetized plasma.
Andrei Gruzinov, Eli Waxman
openaire   +2 more sources

Effects of Fully Relativistic Condition on Electron Cyclotron Maser Emission

The Astrophysical Journal, 2023
The electron cyclotron maser (ECM) instability is a very important nonthermal radiation mechanism. It has been developed by proposing various electron distribution functions as well as the relativistic resonance condition, called the semirelativistic ...
Lijie Zhang, Jianfei Tang, Jinhua Shen, Dejin Wu, Ling Chen   +4 more
doaj   +1 more source