Search Publications
Dusty globules in the Crab Nebula
Gahm, G. F.; Grenman, T.; Elfgren, E.
Context. Dust grains are widespread in the Crab Nebula. A number of small, dusty globules, are visible as dark spots against the background of continuous synchrotron emission in optical images.
Aims: Our aim is to catalogue such dusty globules and investigate their properties.
Methods: From existing broad-band images obtained with the Hu…
Dawn Auroral Breakup at Saturn Initiated by Auroral Arcs: UVIS/Cassini Beginning of Grand Finale Phase
Badman, S. V.; Bonfond, B.; Gérard, J. -C. +4 more
We present Cassini auroral observations obtained on 11 November 2016 with the Ultraviolet Imaging Spectrograph at the beginning of the F-ring orbits and the Grand Finale phase of the mission. The spacecraft made a close approach to Saturn's southern pole and offered a remarkable view of the dayside and nightside aurora. With this sequence we ident…
Sparse Bayesian Inference and the Temperature Structure of the Solar Corona
Warren, Harry P.; Byers, Jeff M.; Crump, Nicholas A.
Measuring the temperature structure of the solar atmosphere is critical to understanding how it is heated to high temperatures. Unfortunately, the temperature of the upper atmosphere cannot be observed directly, but must be inferred from spectrally resolved observations of individual emission lines that span a wide range of temperatures. Such obse…
Characterization of Jupiter's secondary auroral oval and its response to hot plasma injections
Woodfield, E. E.; Gray, R. L.; Badman, S. V. +1 more
We present Jovian auroral observations from the 2014 January Hubble Space Telescope (HST) campaign and characterize the auroral second oval feature with particular attention to the response to hot plasma injections. The location of the second oval feature lies between the Ganymede and Europa moon footprint contours between 150 and 240° system III …
Further evidence for a quasar-driven jet impacting its neighbour galaxy: The saga of HE0450-2958 continues
Elbaz, D.; Sargent, M. T.; Papadopoulos, P. P. +2 more
HE0450-2958, an interacting quasar-starburst galaxy pair at z = 0.285, is one of the best-known examples of strong star formation activity in the presence of a quasar-driven jet. We present new multiband Karl G. Jansky Very Large Array-imaging covering 1-6 GHz and reaching an angular resolution of up to 0.6 arcsec (a sixfold improvement over exist…
Evidence for two-loop interaction from IRIS and SDO observations of penumbral brightenings
Patsourakos, S.; Nindos, A.; Alissandrakis, C. E. +1 more
Aims: We investigate small scale energy release events which can provide clues on the heating mechanism of the solar corona.
Methods: We analyzed spectral and imaging data from the Interface Region Imaging Spectrograph (IRIS), images from the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatoty (SDO), and magnetograms…
Double Stars and Astrometric Uncertainties in Gaia DR1
Makarov, Valeri V.; Frouard, Julien; Fabricius, Claus
A significant number of double stars with separations up to 2.5 arcsec are present in the Gaia Data Release 1 astrometric catalogs. Limiting our analysis to a well-studied sample of 1124 doubles resolved by Hipparcos, provided with individual Tycho component photometry and cross-matched with the TGAS catalog, we estimate a rate of at least 3% for …
Constraining the break of spatial diffeomorphism invariance with Planck data
Alcaniz, J. S.; Graef, L. L.; Benetti, M.
The current most accepted paradigm for the early universe cosmology, the inflationary scenario, shows a good agreement with the recent Cosmic Microwave Background (CMB) and polarization data. However, when the inflation consistency relation is relaxed, these observational data exclude a larger range of red tensor tilt values, prevailing the blue o…
Mutated hybrid inflation on brane and reheating temperature
Ferricha-Alami, M.; Sakhi, Z.; Chakir, H. +1 more
In the mutated hybrid-inflation standard case, the spectral index
SPIN: An Inversion Code for the Photospheric Spectral Line
Mathew, Shibu K.; Yadav, Rahul; Tiwary, Alok Ranjan
Inversion codes are the most useful tools to infer the physical properties of the solar atmosphere from the interpretation of Stokes profiles. In this paper, we present the details of a new Stokes Profile INversion code (SPIN) developed specifically to invert the spectro-polarimetric data of the Multi-Application Solar Telescope (MAST) at Udaipur …