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High spatial and temporal resolution images of a sunspot, obtained simultaneously in multiple optical and UV wavelengths, are employed to study the propagation and damping characteristics of slow magnetoacoustic waves up to transition…

Solar and Stellar Astrophysics · Physics 2017-09-20 S. Krishna Prasad , D. B. Jess , T. Van Doorsselaere , G. Verth , R. J. Morton , V. Fedun , R. Erdelyi , D. J. Christian

We study the acoustic properties of the solar chromosphere in the high-frequency regime using a time sequence of velocity measurements in the chromospheric Ca II 854.2 nm line taken with the Interferometric Bidimensional Spectrometer…

Astrophysics · Physics 2010-11-11 K. P. Reardon , F. Lepreti , V. Carbone , A. Vecchio

We compute the emergent stellar spectra from the UV to far infrared for different viewing angles using realistic 3D model atmospheres for a large range in stellar parameters to predict the stellar limb darkening. We have computed full 3D…

Solar and Stellar Astrophysics · Physics 2014-12-24 Zazralt Magic , Andrea Chiavassa , Remo Collet , Martin Asplund

Hydrodynamic simulations of granular convection predict the existence of supersonic flows covering ~3-4% of the solar surface at any time, but these flows have not been detected unambigously as yet. Using data from the spectropolarimeter…

Solar and Stellar Astrophysics · Physics 2009-07-22 L. R. Bellot Rubio

Precise low-frequency light scattering experiments on silica glass are presented, covering a broad temperature and frequency range (9 GHz < \nu < 2 THz). For the first time the spectral shape of relaxations is observed over more than one…

Soft Condensed Matter · Physics 2009-10-31 Johannes Wiedersich , Sergei V. Adichtchev , Ernst R"ossler

The Helioseismic Magnetic Imager (HMI) onboard the Solar Dynamics Observatory (SDO) records line-of-sight Dopplergram images of convective flows on the surface. These images are used to obtain the multi-scale convective spectrum. We design…

Solar and Stellar Astrophysics · Physics 2021-08-09 Samarth G Kashyap , Shravan M Hanasoge

Alfven waves and ion-cyclotron absorption of high-frequency waves are frequently brought into models devoted to coronal heating and fast solar-wind acceleration. Signatures of ion-cyclotron resonance have already been observed in situ in…

Astrophysics · Physics 2009-11-13 L. Dolla , J. Solomon

The Hinode mission has revealed copious amounts of horizontal flux covering the quiet Sun. Local dynamo action has been proposed to explain the presence of this flux. We sought to test whether the quiet Sun flux detected by Hinode is due to…

Solar and Stellar Astrophysics · Physics 2013-07-03 D. Buehler , A. Lagg , S. K. Solanki

We study properties of waves of frequencies above the photospheric acoustic cut-off of $\approx$5.3 mHz, around four active regions, through spatial maps of their power estimated using data from Helioseismic and Magnetic Imager (HMI) and…

Solar and Stellar Astrophysics · Physics 2015-06-05 S. P. Rajaguru , S. Couvidat , Xudong Sun , K. Hayashi , H. Schunker

We have measured the 2 dimensional (2D) power spectrum of the Las Campanas Redshift Survey on scales between 30 and 200 Mpc (q_0=0.5, H_o=100h km sec^{-1} Mpc^{-1}). Such an analysis is more sensitive to structure on scales > 50 Mpc than a…

Astrophysics · Physics 2009-06-16 S. D. Landy , S. A. Shectman , H. Lin , R. P. Kirshner , A. A. Oemler , D. Tucker

We have developed an algorithm to identify solar spicules in the first ever systematic survey of on-disk spicules exclusively using Mg II spectral observations. Using this algorithm we identify 2021 events in three Interface Region Imaging…

Solar and Stellar Astrophysics · Physics 2023-04-11 Vicki L. Herde , Phillip C. Chamberlin , Don Schmit , Souvik Bose , Adrian Daw , Ryan O. Milligan , Vanessa Polito

We present the results of our power spectral density analysis for the BL Lac object OJ\,287, utilizing the {\it Fermi}-LAT survey at high-energy $\gamma$-rays, {\it Swift}-XRT in X-rays, several ground-based telescopes and the {\it Kepler}…

High Energy Astrophysical Phenomena · Physics 2018-08-29 A. Goyal , L. Stawarz , S. Zola , V. Marchenko , M. Soida , K. Nilsson , S. Ciprini , A. Baran , M. Ostrowski , P. J. Wiita , Gopal-Krishna , A. Siemiginowska , M. Sobolewska , S. Jorstad , A. Marscher , M. F. Aller H. D. Aller T. Hovatta , D. B. Caton , D. Reichart , K. Matsumoto , K. Sadakane , K. Gazeas , M. Kidger , V. Piirola , H. Jermak , F. Alicavus , K. S. Baliyan , A. Baransky , A. Berdyugin , P. Blay , P. Boumis , D. Boyd , Y. Bufan , M. Campas Torrent , F. Campos , J. Carrillo Gomez , J. Dalessio , B. Debski , D. Dimitrov , M. Drozdz , H. Er , A. Erdem , A. Escartin Perez , V. Fallah Ramazani , A. V. Filippenko , E. Gafton , F. Garcia , V. Godunova , F. Gomez Pinilla , M. Gopinathan , J. B. Haislip , S. Haque , J. Harmanen , R. Hudec , G. Hurst , K. M. Ivarsen , A. Joshi , M. Kagitani , N. Karaman , R. Karjalainen , N. Kaur , D. Kozie l-Wierzbowska , E. Kuligowska , T. Kundera , S. Kurowski , A. Kvammen , A. P. LaCluyze , B. C. Lee , A. Liakos , J. Lozano de Haro , I. Mohammed , J. P. Moore , M. Mugrauer , R. Naves Nogues , A. W. Neely , W. Ogloza , S. Okano , U. Pajdosz , J. C. Pandey , M. Perri , G. Poyner , J. Provencal , T. Pursimo , A. Raj , B. Rajkumar , R. Reinthal , T. Reynolds , J. Saario , S. Sadegi , T. Sakanoi , J. L. Salto Gonzalez , Sameer , A. Heung , O. Simon , M. Siwak , T. Schweyer , F. C. Soldan Alfaro , E. Sonbas , J. Strobl , L. O. Takalo , L. Tremosa Espasa , J. R. Valdes , V. V. Vasylenko , F. Verrecchia , J. R. Webb , M. Yoneda , M. Zejmo , W. Zheng , P. Zielinski , J. Janik , V. Chavushyan , C. C. Cheung , M. Giroletti

(Abridged) Wavelet analysis can be used to measure the power spectrum of solar wind fluctuations along a line in any direction with respect to the local mean magnetic field. This technique is applied to study solar wind turbulence in…

Earth and Planetary Astrophysics · Physics 2011-02-11 J. J. Podesta

We analyze the 1D spatial power spectra of dust surface density and mid to far-infrared emission at $24-500\,\mu$m in the LMC, SMC, M31, and M33. By forward-modelling the point-spread-function (PSF) on the power spectrum, we find that…

Astrophysics of Galaxies · Physics 2020-01-14 Eric W. Koch , I-Da Chiang , Dyas Utomo , Jérémy Chastenet , Adam K. Leroy , Erik W. Rosolowsky , Karin M. Sandstrom

The CLASP2 (Chromospheric LAyer SpectroPolarimeter 2) sounding rocket mission was launched on 2019 April 11. CLASP2 measured the four Stokes parameters of the Mg II h & k spectral region around 2800 Angstroms along a 200 arcsecond slit at…

By direct measurements of the gas temperature, the Atacama Large Millimeter/sub-millimeter Array (ALMA) has yielded a new diagnostic tool to study the solar chromosphere. Here we present an overview of the brightness-temperature…

We use Hinode/SOT Ca II H-line and blue continuum broadband observations to study the presence and power of high frequency acoustic waves at high spatial resolution. We find that there is no dominant power at small spatial scales; the…

In the present paper, we use Si IV 1393.755 \AA\ spectral line observed by the Interface Region Imaging Spectrograph (IRIS) in the quiet-Sun to determine physical nature of the solar transition region (TR) oscillations. We analyze the…

Solar and Stellar Astrophysics · Physics 2022-10-12 Kartika Sangal , A. K. Srivastava , P. Kayshap , T. J Wang , J. J. González-Avilés , Abhinav Prasad

We report on spectro-imaging observations employing Spitzer IRS and Herschel PACS, aiming to constrain the physical conditions around SMM3 and SMM4 in Serpens. The combined power of both instruments provides an almost complete wavelength…

The presence of intense magnetic fields in and around sunspots is expected to modify the solar structure and oscillation frequencies. Applying the ring diagram technique to data from the Michelson Doppler Imager (MDI) on board the Solar and…

Astrophysics · Physics 2009-11-07 S. P. Rajaguru , Sarbani Basu , H. M. Antia
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