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相关论文: Microwave response to sunspot oscillations

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Polarization measurements at low radio frequencies allow detection of small Faraday rotation measures caused by regular magnetic fields in galaxies and in the foreground of the Milky Way. The galaxy M31 was observed in two overlapping…

宇宙学与河外天体物理 · 物理学 2015-06-17 René Gießübel , George Heald , Rainer Beck , Tigran Arshakian

We processed magnetograms that were obtained with the Michaelson Doppler Imager onboard the Solar and Heliospheric Observatory (SOHO/MDI). The results confirm the basic properties of long-period oscillations of sunspots that have previously…

太阳与恒星天体物理 · 物理学 2014-12-15 V. I. Efremov , L. D. Parfinenko , A. A. Solovev , E. A. Kirichek

With the Westerbork Synthesis Radio Telescope (WSRT), multi-frequency polarimetric images were taken of the diffuse radio synchrotron background in a region centered on (l,b) = (161,16). The observations were done simultaneously in 5…

天体物理学 · 物理学 2011-05-23 Marijke Haverkorn , Peter Katgert , Ger de Bruyn

We used the Pixelised Wavelet Filtering (PWF) method to compute narrow-band power maps of SDO/AIA imaging datasets in the 1700 \AA{}, 1600 \AA{} and 304 \AA{} bandpasses that correspond to different heights. The cut-off frequency was…

太阳与恒星天体物理 · 物理学 2014-04-15 Ding Yuan , R. Sych , V. E. Reznikova , V. M. Nakariakov

We present low-frequency (80-240 MHz) radio imaging of type III solar radio bursts observed by the Murchison Widefield Array (MWA) on 2015/09/21. The source region for each burst splits from one dominant component at higher frequencies into…

太阳与恒星天体物理 · 物理学 2018-01-10 Patrick I. McCauley , Iver H. Cairns , John Morgan , Sarah E. Gibson , James C. Harding , Colin Lonsdale , Divya Oberoi

We present new deep multi-frequency radio-polarimetric images of a sample of high redshift radio galaxies (HzRGs), having redshift between 1.7 and 4.1. The radio data at 4.7 and 8.2 GHz were taken with the Very Large Array in the A…

天体物理学 · 物理学 2019-08-17 L. Pentericci , W. Van Reeven , C. L. Carilli , H. J. A. Rottgering , G. K. Miley

The discovery of Persistent Radio Sources (PRSs) associated with three repeating fast radio bursts (FRBs) has provided insight into the local environments of these FRBs. Here, we present deep radio observations of the fields surrounding…

高能天体物理现象 · 物理学 2025-09-10 Yash Bhusare , Yogesh Maan , Ajay Kumar

We analyzed 11 epochs of archival Atacama Large Millimeter/submillimeter Array (ALMA) data to investigate flux density variability of Sgr A* at 340 GHz. In one epoch, the light curve exhibits two short-timescale components with…

高能天体物理现象 · 物理学 2026-05-13 Kazuki Yanagisawa , Tomoharu Oka , Tatsuya Kotani , Ryo Ariyama , Kazuki Yanagihara , Yuhei Iwata

We follow the eruption of two related intermediate filaments observed in H$\alpha$ (from GONG) and in EUV (from SDO/AIA) and the resulting large-amplitude longitudinal oscillations of the plasma in the filament channels. The events occurred…

太阳与恒星天体物理 · 物理学 2017-12-13 M. Luna , Y. Su , B. Schmieder , R. Chandra , T. A. Kucera

LS I +61 303 is a gamma-ray binary that exhibits an outburst at GHz frequencies each orbital cycle of $\approx$ 26.5 d and a superorbital modulation with a period of $\approx$ 4.6 yr. We have performed a detailed study of the low-frequency…

Recently, spiral wave patterns (SWPs) have been detected in 3 minute oscillations of sunspot umbrae, but the nature of this phenomenon has remained elusive. We present a theoretical model that interprets the observed SWPs as the…

太阳与恒星天体物理 · 物理学 2019-05-23 Juhyung Kang , Jongchul Chae , Valery M. Nakariakov , Kyuhyoun Cho , Hannah Kwak , Kyeore Lee

The umbral regions of sunspots and pores in the solar photosphere are generally dominated by $3$~mHz oscillations, which are due to $p$-modes penetrating the magnetic region. In these locations, wave power is also significantly reduced with…

In this study we combine the multiwavelength ultraviolet -- optical (Solar Dynamics Observatory, SDO) and radio (Nobeyama Radioheliograph, NoRH) observations to get further insight into space-frequency distribution of oscillations at…

太阳与恒星天体物理 · 物理学 2015-05-13 D. Y. Kolobov , N. I. Kobanov , A. A. Chelpanov , A. A. Kochanov , S. A. Anfinogentov , S. A. Chupin , I. I. Myshyakov , V. E. Tomin

We identified a highly-polarized, steep-spectrum radio source in a deep image with the Australian Square Kilometre Array Pathfinder (ASKAP) telescope at 888 MHz. After considering and rejecting a stellar origin for this source, we…

We use high-quality VLA images of the Fanaroff & Riley Class I radio galaxy 3C 31 at six frequencies in the range 1365 to 8440MHz to explore the spatial scale and origin of the rotation measure (RM) fluctuations on the line of sight to the…

天体物理学 · 物理学 2009-11-13 R. A. Laing , A. H. Bridle , P. Parma , M. Murgia

For about 500 intermediate-redshift sources ($0.04<z<0.4$), whose radio flux densities at $1.4\,{\rm GHz}$ are larger than 10 mJy, we performed additional observations at 4.85 GHz and 10.45 GHz using 100-m Effelsberg telescope. Our…

星系天体物理 · 物理学 2020-06-23 Michal Zajaček , Andreas Eckart , Silke Britzen , Bozena Czerny

Ground Level Enhancements (GLEs) of cosmic-ray intensity occur, on average, once a year. Due to their rareness, studying the solar sources of GLEs is especially important to approach understanding their origin. The SOL2001-12-26…

太阳与恒星天体物理 · 物理学 2016-12-14 V. V. Grechnev , A. A. Kochanov

We present 44 and 226 GHz observations of the Galactic center within 20$"$ of Sgr A*. Millimeter continuum emission at 226 GHz is detected from eight stars that have previously been identified at near-IR and radio wavelengths. We also…

高能天体物理现象 · 物理学 2017-08-02 F. Yusef-Zadeh , R. Schödel , M. Wardle , H. Bushouse , W. Cotton , M. J. Royster , D. Kunneriath , D. A. Roberts , E. Gallego-Cano