Search Publications
Hot Horizontal Branch Stars in ω Centauri: Clues about their Origin from the Cluster Color Magnitude Diagram
Anderson, Jay; Salaris, Maurizio; Bedin, Luigi R. +5 more
We investigate a peculiar feature at the hottest, blue end of the horizontal branch of Galactic globular cluster ω Centauri, using the high-precision and nearly complete catalog that has been constructed from a survey taken with the Advanced Camera for Survey on board the Hubble Space Telescope, that covers the inner 10 × 10 arcmin. It is a densel…
Investigation of water signatures at gully-exposed sites on Mars by hyperspectral image analysis
Schulze-Makuch, Dirk; Fan, Chaojun; Xie, Hongjie +1 more
High-resolution images from the Mars Obiter Camera (MOC) onboard the Mars Global Surveyor (MGS) show a variety of gully features on sloped surfaces of Mars. The mechanism of gully formation is still under debate, although a majority of studies tend to favor a mechanism related to liquid water flow based on geomorphology and fluid mechanics conside…
Dynamical Mass of the M8+M8 Binary 2MASS J22062280 - 2047058AB
Dupuy, Trent J.; Bowler, Brendan P.; Liu, Michael C.
We present Keck laser guide star adaptive optics imaging of the M8+M8 binary 2MASS J2206 - 2047AB. Together with archival Hubble Space Telescope, Gemini-North, and Very Large Telescope data, our observations span 8.3 yr of the binary's 35+6 -5 yr orbital period, and we determine a total dynamical mass of 0.15+0.05 …
The properties of the stellar populations in ULIRGs - I. Sample, data and spectral synthesis modelling
Tadhunter, C. N.; González Delgado, R. M.; Rodríguez Zaurín, J.
We present deep long-slit optical spectra for a sample of 36 ultraluminous infrared galaxies (ULIRGs), taken with the William Herschel Telescope on La Palma with the aim of investigating the star formation histories and testing evolutionary scenarios for such objects. Here we present the sample, the analysis techniques and a general overview of th…
Conversion from Explosive to Gentle Chromospheric Evaporation During a Solar Flare
Brosius, Jeffrey W.
A GOES M1.5 solar flare was observed in NOAA AR 10652 on 2004 July 27 around 20:00 UT with the Coronal Diagnostic Spectrometer (CDS) aboard the Solar and Heliospheric Observatory (SOHO) spacecraft. Images obtained with SOHO's Extreme-ultraviolet Imaging Telescope and with the Transition Region And Coronal Explorer satellite show that the CDS slit …
The Discovery of Remote Globular Clusters in M33
Chapman, S. C.; Tanvir, N. R.; Ferguson, A. M. N. +5 more
We present the discovery of four remote star clusters in M33, one of which is of an extended nature. Three of the clusters were discovered using survey data from the Isaac Newton Telescope Wide-Field Camera while one was discovered serendipitously in a deep image taken with the Hubble Space Telescope's Advanced Camera for Surveys. With projected r…
Coronal Mass Ejections and Global Coronal Magnetic Field Reconfiguration
Vourlidas, Angelos; Bale, Stuart D.; Liu, Ying +3 more
We investigate the role of coronal mass ejections (CMEs) in the global coronal magnetic field reconfiguration, a debate that has lasted for about two decades. Key evidence of the coronal field restructuring during the 2007 December 31 CME is provided by combining imaging observations from widely separated spacecraft with the potential-field source…
Tailward and earthward flow onsets observed by Cluster in a thin current sheet
Petrukovich, A. A.; RèMe, H.; Nakamura, R. +1 more
From a Cluster survey of the magnetotail during 2001-2007 we select 49 episodes of thin current sheet observations ending with plasma sheet activity onsets. The onsets were defined as flow bursts and/or electric current decrease and/or Bz increase after a period of local quietness (in many cases with signatures of growth phase). Such on…
Mid-infrared imaging of 25 local AGN with VLT-VISIR
Gandhi, P.; Duschl, W. J.; Smette, A. +1 more
Context: High angular resolution N-band imaging is used to discern the torus of active galactic nuclei (AGN) from its environment in order to allow a comparison of its mid-infrared properties to the expectations of the unified scenario for AGN.
Aims: We present VLT-VISIR images of 25 low-redshift AGN of different Seyfert types, as well as N-ba…
Forward modelling to determine the observational signatures of propagating slow waves for TRACE, SoHO/CDS, and Hinode/EIS
Hood, A. W.; De Moortel, I.; Owen, N. R.
Context: The propagation and damping of slow MHD waves in the solar atmosphere are investigated by numerical simulations and forward modelling, with particular emphasis placed on waves with periodicities of the order of five minutes.
Aims: We extend a coronal model by adding an equilibrium temperature gradient allowing study of wave propagatio…