Search Publications
New constraints on Mars rotation determined from radiometric tracking of the Opportunity Mars Exploration Rover
Park, Ryan S.; Dehant, Veronique; Kuchynka, Petr +4 more
The Opportunity Mars Exploration Rover remained stationary between January and May 2012 in order to conserve solar energy for running its survival heaters during martian winter. While stationary, extra Doppler tracking was performed in order to allow an improved estimate of the martian precession rate. In this study, we determine Mars rotation by …
Morphological and Kinematic Evolution of Three Interacting Coronal Mass Ejections of 2011 February 13-15
Srivastava, Nandita; Mishra, Wageesh
During 2011 February 13-15, three Earth-directed coronal mass ejections (CMEs) launched in succession were recorded as limb CMEs by STEREO/SECCHI coronagraphs (COR). These CMEs provided an opportunity to study their geometrical and kinematic evolution from multiple vantage points. In this paper, we examine the differences in geometrical evolution …
Irradiated, colour-temperature-corrected accretion discs in ultraluminous X-ray sources
Done, Chris; Sutton, Andrew D.; Roberts, Timothy P.
Although attempts have been made to constrain the stellar types of optical counterparts to ultraluminous X-ray sources (ULXs), the detection of optical variability instead suggests that they may be dominated by reprocessed emission from X-rays which irradiate the outer accretion disc. Here, we report results from a combined X-ray and optical spect…
Diffusion of Magnetic Elements in a Supergranular Cell
Bellot Rubio, L.; Giannattasio, F.; Berrilli, F. +2 more
Small scale magnetic fields (magnetic elements) are ubiquitous in the solar photosphere. Their interaction can provide energy to the upper atmospheric layers, and contribute to heat the solar corona. In this work, the dynamic properties of magnetic elements in the quiet Sun are investigated. The high number of magnetic elements detected in a super…
The Herschel exploitation of local galaxy Andromeda (HELGA) - V. Strengthening the case for substantial interstellar grain growth
Fritz, J.; De Looze, I.; Baes, M. +7 more
In this paper, we consider the implications of the distributions of dust and metals in the disc of M31. We derive mean radial dust distributions using a dust map created from Herschel images of M31 sampling the entire far-infrared peak. Modified blackbodies are fit to approximately 4000 pixels with a varying, as well as a fixed, dust emissivity in…
Search for Surviving Companions in Type Ia Supernova Remnants
Pan, Kuo-Chuan; Ricker, Paul M.; Taam, Ronald E.
The nature of the progenitor systems of type Ia supernovae (SNe Ia) is still unclear. One way to distinguish between the single-degenerate scenario and double-degenerate scenario for their progenitors is to search for the surviving companions (SCs). Using a technique that couples the results from multi-dimensional hydrodynamics simulations with ca…
Physical properties of the jet from DG Tauri on sub-arcsecond scales with HST/STIS
Ray, T. P.; Eislöffel, J.; Podio, L. +5 more
Context. Stellar jets are believed to play a key role in star formation, but the question of how they originate is still being debated.
Aims: We derive the physical properties at the base of the jet from DG Tau both along and across the flow and as a function of velocity.
Methods: We analysed seven optical spectra of the DG Tau jet, take…
Time Evolution of Flares in GRB 130925A: Jet Precession in a Black Hole Accretion System
Hou, Shu-Jin; Liu, Tong; Gu, Wei-Min +4 more
GRB 130925A, composed of three gamma-ray emission episodes and a series of orderly flares, has been detected by Swift, Fermi, Konus-Wind, and INTEGRAL. If the third weakest gamma-ray episode can be considered a giant flare, we find that after the second gamma-ray episode observed by INTEGRAL located at about 2000 s, a positive relation exists betw…
Integral field unit spectroscopy of 10 early-type galactic nuclei - I. Principal component analysis Tomography and nuclear activity
Ricci, T. V.; Steiner, J. E.; Menezes, R. B.
Most massive galaxies show emission lines that can be characterized as LINERs. To what extent this emission is related to AGNs or to stellar processes is still an open question. In this paper, we analysed a sample of such galaxies to study the central region in terms of nuclear and circumnuclear emission lines, as well as the stellar component pro…
Glory on Venus cloud tops and the unknown UV absorber
Roatsch, T.; Markiewicz, W. J.; Titov, D. V. +6 more
We report on the implications of the observations of the glory phenomenon made recently by Venus Express orbiter. Glory is an optical phenomenon that poses stringent constraints on the cloud properties. These observations thus enable us to constrain two properties of the particles at the cloud tops (about 70 km altitude) which are responsible for …