Search Publications
The extent of dust in NGC 891 from Herschel/SPIRE images
Bianchi, S.; Xilouris, E. M.
We analyse Herschel/SPIRE images of the edge-on spiral galaxy NGC 891 at 250, 350, and 500 µm. Using a 3D radiative transfer model we confirm that the dust has radial fall-off similar to the stellar disk. The dust disk shows a break at about 12 kpc from the centre, where the profile becomes steeper. Beyond this break, emission can be traced …
Signatures of Emerging Subsurface Structures in Acoustic Power Maps of the Sun
Kosovichev, A. G.; Zhao, J.; Hartlep, T. +1 more
We show that under certain conditions, subsurface structures in the solar interior can alter the average acoustic power observed at the photosphere above them. By using numerical simulations of wave propagation, we show that this effect is large enough for it to be potentially used for detecting emerging active regions before they appear on the su…
Gas Kinematics in Lyα Nebulae
Kelson, Daniel D.; Davé, Romeel; Yang, Yujin +4 more
Exploring the origin of Lyα nebulae ("blobs") at high redshift requires measurements of their gas kinematics that are impossible with only the resonant, optically thick Lyα line. To define gas motions relative to the systemic velocity of the blob, the Lyα line must be compared with an optically thin line like Hα λ6563, which is not much altered by…
Concerning the Classical Cepheid VI C Wesenheit Function's Strong Metallicity Dependence
Gieren, W.; Turner, D.; Majaess, D.
Evidence is presented which supports findings that the classical Cepheid VI C period Wesenheit function is relatively insensitive to metallicity. The viability of a recently advocated strong metallicity dependence was evaluated by applying the proposed correction (γ = -0.8 mag dex-1) to distances established for the Magella…
Electron heating at Saturn's bow shock
Coates, A. J.; Dougherty, M. K.; Thomsen, M. F. +7 more
Collisionless shock waves are a widespread phenomenon in both solar system and astrophysical contexts. The nature of energy dissipation at such shocks is of particular interest, especially at high Mach numbers. We use data taken by the Cassini spacecraft to investigate electron heating at Saturn's bow shock, one of the strongest collisionless shoc…
A First Measurement of the Proper Motion of the Leo II Dwarf Spheroidal Galaxy
Lépine, Sébastien; Rich, R. Michael; Kuijken, Konrad +1 more
We use 14 year baseline images obtained with the Wide Field and Planetary Camera 2 on board the Hubble Space Telescope (HST) to derive a proper motion for one of the Milky Way's most distant dwarf spheroidal companions, Leo II, relative to an extragalactic background reference frame. Astrometric measurements are performed in the effective point-sp…
Chromospheric anemone jets and magnetic reconnection in partially ionized solar atmosphere
Shibata, K.; Isobe, H.; Singh, K. A. P. +1 more
The solar optical telescope onboard Hinode with temporal resolution of less than 5 s and spatial resolution of 150 km has observed the lower solar atmosphere with an unprecedented detail. This has led to many important findings, one of them is the discovery of chromospheric anemone jets in the solar chromosphere. The chromospheric anemone jets are…
Discovery of multiple dust shells beyond 1 arcmin in the circumstellar envelope of IRC +10216 using Herschel/PACS
Blommaert, J. A. D. L.; Barlow, M. J.; Ottensamer, R. +9 more
We present new Herschel/PACS images at 70, 100, and 160 µm of the well-known, nearby, carbon-rich asymptotic giant branch star IRC+10216 revealing multiple dust shells in its circumstellar envelope. For the first time, dust shells (or arcs) are detected until 320''. The almost spherical shells are non-concentric and have an angular extent be…
Star-formation efficiency and metal enrichment of the intracluster medium in local massive clusters of galaxies
Zhang, Y. -Y.; Schneider, P.; Reiprich, T. H. +3 more
We have investigated the baryon-mass content in a subsample of 19 clusters of galaxies extracted from the X-ray flux-limited sample HIFLUGCS according to their positions in the sky. For these clusters, we measured total masses and characteristic radii on the basis of a rich optical spectroscopic data set, the physical properties of the intracluste…
Power spectral analysis of Jupiter’s clouds and kinetic energy from Cassini
Showman, Adam P.; Choi, David S.
We present suggestive evidence for an inverse energy cascade within Jupiter’s atmosphere through a calculation of the power spectrum of its kinetic energy and its cloud patterns. Using Cassini observations, we composed full-longitudinal mosaics of Jupiter’s atmosphere at several wavelengths. We also utilized image pairs derived from these observat…