Search Publications
A survey of T Tauri stars with AKARI towards the Taurus-Auriga region
Oyabu, S.; Ita, Y.; Ishihara, D. +4 more
Context. The first Japanese infrared astronomical satellite, AKARI, has completed an All-Sky Survey at mid- to far-infrared wavelengths with higher spatial resolutions and sensitivities than the previous survey with Infrared Astronomical Satellite (IRAS).
Aims: We search for new T Tauri star (TTS) candidates with the mid-infrared (MIR) part o…
A Photometric Catalog of 77 Newly Recognized Star Clusters in M31
Massey, Philip; Olsen, Knut; Bianchi, Luciana +2 more
This paper describes the results of a Hubble Space Telescope (HST) WFPC2 search for star clusters in active star-formation regions of M31. Nine of the clusters were previously cataloged and 77 are new. Our 23 fields cover key areas of the galaxy’s recent star-formation activity. We provide a catalog of positions and integrated magnitudes in four c…
Hipparcos, the New Reduction
van Leeuwen, Floor
An overview is presented on why and how the new reduction of the Hipparcos data was carried out, and in particular on how improved understanding of the dynamics of the Hipparcos satellite was obtained and made the new reduction possible. A brief description is given of the main torques acting on the spacecraft and some peculiar features in the sat…
Forward and reverse CIR shocks at 4-5 AU: Ulysses
Tsurutani, B. T.; Echer, E.; Guarnieri, F. L.
In this article, we study fast shocks at CIR boundaries during an extended interval of 15 consecutive major high speed solar wind streams in 1992-1993. Ulysses was 4-5 AU from the sun. The Abraham-Schrauner shock normal method and the Rankine-Hugoniot relations were used to determine fast shock directions and speeds. Out of 33 potential CIR shocks…
Permittivity estimation of layers beneath the northern polar layered deposits, Mars
Orosei, Roberto; Cartacci, Marco; Cicchetti, Andrea +6 more
Martian Polar Layered Deposits, most likely dusty ice are transparent to radar waves. In the North Pole bedrock has been detected by MARSIS up to a depth about 2 Km, whereas in the South Pole such interface has been located at about 3.7 Km. The reflected signal is generally above the noise and can be used to estimate the dielectric properties of t…
Herschel-SPIRE spectroscopy of the DR21 molecular cloud core
Miville-Deschênes, M. -A.; Boulanger, F.; Abergel, A. +47 more
We present far-infrared spectra and maps of the DR21 molecular cloud core between 196 and 671 µm, using the Herschel-SPIRE spectrometer. Nineteen molecular lines originating from CO, 13CO, HCO+ and H2O, plus lines of [N ii] and [CI] were recorded, including several transitions not previously detected. The CO …
Model uncertainties in predictions of arrival of coronal mass ejections at Earth orbit
Odstrcil, D.; Taktakishvili, A.; MacNeice, P.
It is very important, both for research and forecasting application, to be aware of uncertainty estimation of a scientific model, i.e., to know how model performance depends on the uncertainty in the input parameters. Scientific models are becoming more important as tools for space weather operators' applications and for space weather forecasting.…
Constraints on Titan’s topography through fractal analysis of shorelines
Byrne, Shane; Sharma, Priyanka
Titan's north polar hydrocarbon lakes offer a unique opportunity to indirectly characterize the statistical properties of Titan's landscape. The complexity of a shoreline can be related to the complexity of the landscape it is embedded in through fractal theory. We mapped the shorelines of 290 of the north polar titanian lakes in the Cassini synth…
A search for supernova remnants in the nearby spiral galaxy M 74 (NGC 628)
Balman, Ş.; Özel, M. E.; Sonbaş, E. +1 more
An optical search was carried out for supernova remnants (SNRs) in the Sc type nearby spiral galaxy M 74, using ground-based observations at the TUBITAK National Observatory (TUG, Antalya/Turkey) and the Special Astrophysics Observatory (SAO, Russia). Observations were supplemented by the spectral analysis of archived X-ray data from XMM-Newton an…
Probing the Transition Between the Synchrotron and Inverse-compton Spectral Components of 1ES 1959+650
Greiner, J.; Ajello, M.; Schady, P. +5 more
1ES 1959+650 is one of the most remarkable high-peaked BL Lacertae objects (HBL). In 2002, it exhibited a TeV γ-ray flare without a similar brightening of the synchrotron component at lower energies. This orphan TeV flare remained a mystery. We present the results of a multifrequency campaign, triggered by the INTEGRAL IBIS detection of 1ES 1959+6…