Search Publications
The imaging performance of the SRC on Mars Express
Williams, D.; Jaumann, R.; Oberst, J. +14 more
The Mars Express spacecraft carries the pushbroom scanner high-resolution stereo camera (HRSC) and its added imaging subsystem super resolution channel (SRC). The SRC is equipped with its own optical system and a 1024×1024 framing sensor. SRC produces snapshots with 2.3 m ground pixel size from the nominal spacecraft pericenter height of 250 km, w…
Toward a Robust Estimate of the Merger Rate Evolution Using Near-IR Photometry
Hammer, Francois; Kembhavi, Ajit K.; Rawat, A. +1 more
We use a combination of deep, high angular resolution imaging data from the CDFS (HST/ACS GOODS survey) and ground-based near-IR Ks images to derive the evolution of the galaxy major merger rate in the redshift range 0.2 <= z<= 1.2. We select galaxies solely on the basis of their J-band rest-frame absolute magnitude, which is a go…
Reappraising Transition Region Line Widths in Light of Recent Alfvén Wave Discoveries
De Pontieu, Bart; McIntosh, Scott W.; Tarbell, Theodore D.
We provide a new interpretation of ultraviolet transition region emission line widths observed by the SUMER instrument on the Solar and Heliospheric Observatory (SOHO). This investigation is prompted by observations of the chromosphere at unprecedented spatial and temporal resolution from the Solar Optical Telescope (SOT) on Hinode revealing that …
The Quiet-Sun Differential Emission Measure from Radio and UV Measurements
Landi, E.; Chiuderi Drago, F.
In the present work we combine UV and radio observations of the quiet Sun to determine the differential emission measure (DEM) of the average quiet solar atmosphere from the photosphere (5600 K) to the corona. UV line intensities have been used to constrain the DEM above 30,000 K, and the radio spectrum from 1.5 to 345 GHz has been used to extend …
XMM-Newton and Chandra Observations of Abell 2626: Interacting Radio Jets and Cooling Core with Jet Precession?
Sarazin, Craig L.; Reiprich, Thomas H.; Wong, Ka-Wah +1 more
We present a detailed analysis of the XMM-Newton and Chandra observations of Abell 2626 focused on the X-ray and radio interactions. Within the region of the radio minihalo (~70 kpc), there are substructures that are probably produced by the central radio source and the cooling core. We find that there is no obvious correlation between the radio b…
Statistical properties of tail plasma sheet electrons above 40 keV
Lavraud, B.; Daly, P.; Taylor, M. G. G. T. +3 more
We use data from four tail seasons (2001-2004) of the Cluster spacecraft to study statistical features of energetic electrons (40-400 keV) in the magnetotail plasma sheet in combination with plasma parameters and indices of geomagnetic activity. We find that the horizontal magnetic field magnitude best orders the energetic electron observations. U…
Jupiter's polar clouds and waves from Cassini and HST images: 1993 2006
Hueso, R.; Sánchez-Lavega, A.; Pérez-Hoyos, S. +1 more
For a variety of reasons, Jupiter's polar areas are probably the less observed regions of the planet. To study the dynamics and cloud vertical structure in the polar regions of the planet (latitudes 50° to 80° in both hemispheres) we have used images of Jupiter obtained from the ultraviolet to near infrared (258 to 939 nm) by the Cassini Imagining…
Confirmation and utilization of the ``production function'' size-frequency distributions of Martian impact craters
Neukum, Gerhard; Werner, Stephanie; Hartmann, William K.
On any planetary surface, impacts of interplanetary bodies create an initial (or ``production function'') size-frequency distribution (SFD) of impact craters. Recent questions have been raised about whether this size distribution can be reliably detected, especially at small sizes. In a test area, we confirm an excellent fit to the distribution we…
Monitoring Venus’ mesospheric winds in support of Venus Express: IRAM 30-m and APEX observations
Lellouch, E.; Moreno, R.; Moullet, A. +1 more
We report on direct wind measurements in Venus' mesosphere (90-115 km), performed in support of Venus Express, and based on CO millimeter observations. Most observations, sampling the CO(2-1) and CO(1-0) lines, were acquired with the IRAM 30-m telescope, over four distinct periods: (i) Summer 2006; (ii) May-June 2007, in association with the coord…
Origin of chromatic features in multiple quasars. Variability, dust, or microlensing
Yonehara, A.; Richter, P.; Hirashita, H.
Aims:In some of lensed quasars, color differences between multiple images are observed at optical/near-infrared wavelengths. There are three possible origins for the color differences: intrinsic variabilities of quasars, differential dust extinction, and quasar microlensing. We examine how these possible scenarios can reproduce the observed chroma…