Results 121 to 130 of about 1,203,998 (246)

Angular Broadening of Intraday Variable AGNs. II. Interstellar and Intergalactic Scattering [PDF]

, 2008
We analyze a sample of 58 multiwavelength, Very Long Baseline Array observations of active galactic nuclei (AGNs) to determine their scattering properties.
Lazio, T. Joseph W., Jauncey, David L., Lovell, James E. J., Kedziora-Chudczer, Lucyna, Cordes, James M., Ojha, Roopesh, Fey, Alan L.   +6 more
core   +1 more source

Collisional excitation of interstellar chloronium: accurate rate coefficients with astrophysical applications [PDF]

International audienceRecent astronomical observations [1,2] have shown that chloronium (H2Cl+) is an important intermediate in Cl-chemistry of the interstellar medium (ISM) due to its specific thermodynamic properties. For a proper interpretation of the
Lique, François, Demes, S., Kȩdziera, Dariusz, Faure, Alexandre   +3 more
core  

Transient Blurring of the Scintillation Arc of Pulsar B1737+13

The Astrophysical Journal
For many pulsars, the scattering structures responsible for scintillation are typically dominated by a single, thin screen along the line of sight, which persists for years or decades.
Yen-Hua Chen, Sammy Siegel, Daniel Baker, Ue-Li Pen, Dan Stinebring   +4 more
doaj   +1 more source

Interstellar and intergalactic scattering as astrophysical probes [PDF]

, 2012
The scattering of radio waves and multipath propagation in the interstellar medium (ISM) of our Galaxy produces various observable phenomena such as the interstellar scintillation (ISS) and angular broadening of compact radio sources, as well as the ...
Koay, Jun Yi
core  

Precise Measurements of TeV Halos around Geminga and Monogem Pulsars with HAWC

The Astrophysical Journal
We present the most precise measurements to date for the spatial extension and energy spectrum of the γ -ray region between a pulsar’s wind nebula and the interstellar medium, better known as the halo, present around Geminga and PSR B0656+14 (Monogem ...
A. Albert, R. Alfaro, C. Alvarez, J. C. Arteaga-Velázquez, D. Avila Rojas, H. A. Ayala Solares, R. Babu, E. Belmont-Moreno, A. Bernal, K. S. Caballero-Mora, T. Capistrán, A. Carramiñana, S. Casanova, U. Cotti, J. Cotzomi, S. Coutiño de León, E. de la Fuente, D. Depaoli, N. Di Lalla, R. Diaz Hernandez, B. L. Dingus, M. A. DuVernois, M. Durocher, J. C. Díaz-Vélez, K. Engel, C. Espinoza, K. L. Fan, K. Fang, N. Fraija, J. A. García-González, F. Garfias, H. Goksu, M. M. González, J. A. Goodman, S. Groetsch, J. P. Harding, S. Hernández-Cadena, I. Herzog, P. Hüntemeyer, D. Huang, F. Hueyotl-Zahuantitla, A. Iriarte, V. Joshi, S. Kaufmann, D. Kieda, A. Lara, W. H. Lee, J. Lee, H. León Vargas, J. T. Linnemann, A. L. Longinotti, G. Luis-Raya, K. Malone, O. Martinez, J. Martínez-Castro, J. A. Matthews, P. Miranda-Romagnoli, J. A. Montes, J. A. Morales-Soto, E. Moreno, M. Mostafá, A. Nayerhoda, L. Nellen, R. Noriega-Papaqui, L. Olivera-Nieto, N. Omodei, Y. Pérez Araujo, E. G. Pérez-Pérez, C. D. Rho, D. Rosa-González, H. Salazar, D. Salazar-Gallegos, A. Sandoval, M. Schneider, G. Schwefer, J. Serna-Franco, Y. Son, R. W. Springer, O. Tibolla, K. Tollefson, I. Torres, R. Torres-Escobedo, R. Turner, F. Urea-Mena, E. Varela, L. Villaseñor, X. Wang, I. J. Watson, E. Willox, H. Wu, S. Yun-Cárcamo, H. Zhou, C. de León, HAWC Collaboration, M. Di Mauro   +94 more
doaj   +1 more source

Pulsar scintillation studies with LOFAR

Astronomy & Astrophysics
Context. The interstellar scintillation observed in radio pulsars arises from interference between electromagnetic waves scattered by electron density fluctuations in the turbulent interstellar plasma, providing a critical tool for probing the small ...
Cai Yanqing, Wu Ziwei, Zhu Weiwei, Verbiest Joris P. W., Liu Yulan, Moochickal Ambalappat Krishnakumar, Brüggen Marcus, Ciardi Benedetta, Dettmar Ralf-Jürgen, Fang Ziyao, Fu Qiuyang, Hoeft Matthias, Jin Jiawei, Künkel Lars, Künsemöller Jörn, Liu Caisong, Meng Lingqi, Miao Xueli, Niu Jiarui, Rejep Rukiya, Schwarz Dominik J., Shaifullah Golam M., Tiburzi Caterina, Vocks Christian, Wucknitz Olaf, Xue Mengyao, Yuan Mao, Yue Youling, Zhang Chunfeng, Zhang Zhen   +29 more
doaj   +1 more source

Probing the Interstellar Medium from Scintillation of the Swooshing Pulsar B0919+06

The Astrophysical Journal
Radio observations of pulsars offer a potential method to probe the intricate microstructure in the turbulent interstellar medium. Here we report on a high-resolution dynamic spectral analysis of the “swooshing pulsar” B0919+06 observed with the Five ...
Z. Wang, Z. G. Wen, J. P. Yuan, N. Wang, Z. Wang, J. L. Chen, H. G. Wang, W. Han, H. Wang, X. F. Duan, C. B. Lyu, J. P. Wang, Z. W. Wu   +12 more
doaj   +1 more source

Sensitivity of Polarization to Grain Shape. II. Aggregates

The Astrophysical Journal
A previous study (Paper I) investigated the polarization properties of a variety of simple convex grain shapes, some of which were found to be consistent with the observed polarization properties of interstellar dust from far-ultraviolet to far-infrared.
B. T. Draine
doaj   +1 more source

Photodissociation of OH in interstellar clouds [PDF]

, 1984
Calculations are presented of the lifetime of OH against photodissociation by the interstellar radiation field as a function of depth into interstellar clouds containing grains of various scattering properties.
Dalgarno, A., Dishoeck, E.F. van
core  

Tidal Disruption of “Snow Clouds” by Unassociated Stars

The Astrophysical Journal
It has been suggested that star-forming galaxies may host a substantial, dark reservoir of gas in the form of planetary-mass molecular clouds that are so cold that H _2 can condense.
Arthur G. Suvorov, Mark A. Walker
doaj   +1 more source