Surface waves in solar granulation observed with {\sc Sunrise}

Abstract

Solar oscillations are expected to be excited by turbulent flows in the intergranular lanes near the solar surface. Time series recorded by the IMaX instrument aboard the {\sc Sunrise} observatory reveal solar oscillations at high resolution, which allow studying the properties of oscillations with short wavelengths. We analyze two times series with synchronous recordings of Doppler velocity and continuum intensity images with durations of 32\thinspace min and 23\thinspace min, resp., recorded close to the disk center of the Sun to study the propagation and excitation of solar acoustic oscillations. In the Doppler velocity data, both the standing acoustic waves and the short-lived, high-degree running waves are visible. The standing waves are visible as temporary enhancements of the amplitudes of the large-scale velocity field due to the stochastic superposition of the acoustic waves. We focus on the high-degree small-scale waves by suitable filtering in the Fourier domain. Investigating the propagation and excitation of $f$- and $p_1$-modes with wave numbers $k>1.4$\thinspace 1/Mm we find that also exploding granules contribute to the excitation of solar $p$-modes in addition to the contribution of intergranular lanes.

12 pages, 4 figures, to appear in a special volume on Sunrise in Astrophysical Journal Letters

References in corpus (4)

• Sunrise: instrument, mission, data and first results
• The Sunrise Mission
• The Filter Imager SuFI and the Image Stabilization and Light Distribution System ISLiD of the Sunrise Balloon-Borne Observatory: Instrument Description
• Detection of large acoustic energy flux in the solar atmosphere

Cited by in corpus (15)

• Sunrise: instrument, mission, data and first results
• Critical Science Plan for the Daniel K. Inouye Solar Telescope (DKIST)
• Waves in the lower solar atmosphere: the dawn of next-generation solar telescopes
• Detection of large acoustic energy flux in the solar atmosphere
• 3-D non-LTE radiative transfer effects in Fe I lines: II. Line formation in 3-D radiation hydrodynamic simulations
• The frontier between Small-scale bipoles and Ephemeral Regions in the solar photosphere: Emergence and Decay of an Intermediate-scale bipole observed with IMaX/SUNRISE
• First evidence of interaction between longitudinal and transverse waves in solar magnetic elements
• On the Magnetic Nature of an Exploding Granule as Revealed by Sunrise/IMaX
• Identifying acoustic wave sources on the Sun I. Two-dimensional waves in a simulated photosphere
• Newly formed downflow lanes in exploding granules in the solar photosphere
• Identifying Acoustic Wave Sources on the Sun. II. Improved Filter Techniques for Source Wavefield Seismology
• Observations of Locally Excited Waves in the Low Solar Atmosphere Using the Daniel K. Inouye Solar Telescope (DKIST)
• Understanding the surface wave characteristics using 2D particle-in-cell simulation and deep neural network
• Automated detection of exploding granules with SDO/HMI data
• Assessment of DKIST/VTF Capabilities for the Detection of Local Acoustic Source Wavefronts