Search Publications
The zCOSMOS redshift survey: the three-dimensional classification cube and bimodality in galaxy physical properties
Kneib, J. -P.; Maccagni, D.; Cimatti, A. +56 more
Aims: We investigate the relationships between three main optical galaxy observables (spectral properties, colors, and morphology), exploiting the data set provided by the COSMOS/zCOSMOS survey. The purpose of this paper is to define a simple galaxy classification cube, with a carefully selected sample of ≈1000 galaxies.
Methods: Using medium …
Recent rheologic processes on dark polar dunes of Mars: Driven by interfacial water?
Möhlmann, D.; Kereszturi, A.; Berczi, Sz. +4 more
In springtime on HiRISE images of the Southern polar terrain of Mars flow-like or rheologic features were observed. Their dark color is interpreted as partly defrosted surface where the temperature is too high for CO 2 but low enough for H 2O ice to be present there. These branching streaks grow in size and can move by an ave…
Stray light correction and contrast analysis of Hinode broad-band images
Solanki, S. K.; Zakharov, V.; Mathew, S. K.
The contrasts of features in the quiet Sun are studied using filtergrams recorded by the broad-band filter imager mounted on the Hinode/Solar Optical Telescope. In a first step, the scattered light originating in the instrument is modeled using Mercury transit data. Combinations of four two-dimensional Gaussians with different widths and weights w…
A systematic study of variability among OB-stars based on HIPPARCOS photometry
Lefèvre, L.; Moffat, A. F. J.; Marchenko, S. V. +1 more
Context: Variability is a key factor for understanding the nature of the most massive stars, the OB stars. Such stars lie closest to the unstable upper limit of star formation.
Aims: In terms of statistics, the data from the HIPPARCOS satellite are unique because of time coverage and uniformity. They are ideal to study variability in this larg…
Titan's prolific propane: The Cassini CIRS perspective
Irwin, P. G. J.; Teanby, N. A.; Flasar, F. M. +7 more
Although propane gas ( C3H8) was first detected in the stratosphere of Titan by the Voyager IRIS infrared spectrometer in 1980, obtaining an accurate measurement of its abundance has proved difficult. All existing measurements have been made by modeling the ν26 band at 748cm-1: however, different analyze…
Forbush decreases and turbulence levels at coronal mass ejection fronts
Antia, H. M.; Subramanian, P.; Kojima, H. +14 more
Aims: We seek to estimate the average level of MHD turbulence near coronal mass ejection (CME) fronts as they propagate from the Sun to the Earth.
Methods: We examined the cosmic ray data from the GRAPES-3 tracking muon telescope at Ooty, together with the data from other sources for three closely observed Forbush decrease events. Each of thes…
Multiwavelength spectral and high time resolution observations of SWIFTJ1753.5-0127: new activity?
Dhillon, V. S.; Gandhi, P.; Shahbaz, T. +2 more
We have conducted an extensive observational campaign of SWIFTJ1753.5-0127 during 2007 June after its bright outburst episode in 2005. We have performed multiband optical photometry, optical spectroscopy, X-ray spectroscopy and timing and ULTRACAM optical photometry simultaneously in three bands. Both the optical spectrum and the X-ray spectrum al…
Propagating waves in polar coronal holes as seen by SUMER & EIS
Solanki, S. K.; Teriaca, L.; Gupta, G. R. +3 more
Context: To study the dynamics of coronal holes and the role of waves in the acceleration of the solar wind, spectral observations were performed over polar coronal hole regions with the SUMER spectrometer on SoHO and the EIS spectrometer on Hinode.
Aims: Using these observations, we aim to detect the presence of propagating waves in the coron…
RR Lyrae Variables in Two Fields in the Spheroid of M31
Lauer, Tod R.; Dressler, Alan; Grillmair, Carl +5 more
We present Hubble Space Telescope observations taken with the Advanced Camera for Surveys Wide Field Channel of two fields near M32—between 4 and 6 kpc from the center of M31. The data cover a time baseline sufficient for the identification and characterization of 681 RR Lyrae variables of which 555 are ab-type and 126 are c-type. The mean magnitu…
Distribution and properties of fragments and debris from the split Comet 73P/Schwassmann-Wachmann 3 as revealed by Spitzer Space Telescope
Reach, William T.; Lisse, Carey M.; Sykes, Mark V. +2 more
During 2006 March-2007 January, we used the IRAC and MIPS instruments on the Spitzer Space Telescope to study the infrared emission from the ensemble of fragments, meteoroids, and dust tails in the more than 3° wide 73P/Schwassmann-Wachmann 3 debris field. We also investigated contemporaneous ground-based and HST observations. In 2006 May, 55 frag…