Search Publications
Subaru/HiCIAO HK s Imaging of LKHa 330: Multi-band Detection of the Gap and Spiral-like Structures
Henning, Thomas; Terada, Hiroshi; Usuda, Tomonori +56 more
We present H- and K s-bands observations of the LkHα 330 disk with a multi-band detection of the large gap and spiral-like structures. The morphology of the outer disk (r ∼ 0.″3) at PA = 0°-45° and PA° = 180-290° is likely density wave-induced spirals, and comparison between our observational results and simulations suggests a planet fo…
Statistical Properties of Ribbon Evolution and Reconnection Electric Fields in Eruptive and Confined Flares
Veronig, A. M.; Thalmann, J. K.; Pötzi, W. +2 more
A statistical study of the chromospheric ribbon evolution in Hα two-ribbon flares was performed. The data set consists of 50 confined (62%) and eruptive (38%) flares that occurred from June 2000 to June 2015. The flares were selected homogeneously over the Hα and Geostationary Operational Environmental Satellite (GOES) classes, with an emphasis on…
Variable Nature of Magnetically Driven Ultra-fast Outflows
Behar, Ehud; Tombesi, Francesco; Shrader, Chris +3 more
Among a number of active galactic nuclei that drive ionized outflows in X-rays, a low-redshift (z = 0.184) quasar, PDS 456, is long known to exhibit one of the exemplary ultra-fast outflows (UFOs). However, the physical process of acceleration mechanisms is yet to be definitively constrained. In this work, we model the variations of the Fe K UFO p…
Probing the nature and origin of dust in the reddened quasar IC 4329A with global modelling from X-ray to infrared
Mehdipour, Missagh; Costantini, Elisa
Cosmic dust is a key tracer of structure formation and evolution in the universe. In active galactic nuclei (AGN) the origin and role of dust are uncertain. Here, we have studied dust in the X-ray bright and reddened type-1 quasar IC 4329A, which exhibits an ionised AGN wind. We incorporated high-resolution X-ray and mid-IR spectroscopy, combined …
The 3CR Chandra Snapshot Survey: Extragalactic Radio Sources with Redshifts between 1 and 1.5
Forman, W. R.; Wilkes, B. J.; Liuzzo, E. +11 more
The aim of this paper is to present an analysis of newly acquired X-ray observations of 16 extragalactic radio sources listed in the Third Cambridge Revised (3CR) catalog and not previously observed by Chandra. Observations were performed during Chandra Cycle 17, extending X-ray coverage for the 3CR extragalactic catalog up to z = 1.5. Among the 1…
The HR 4796A Debris System: Discovery of Extensive Exo-ring Dust Material
Henning, Thomas; Debes, John H.; Schneider, Glenn +6 more
The optically and IR-bright and starlight-scattering HR 4796A ringlike debris disk is one of the most- (and best-) studied exoplanetary debris systems. The presence of a yet-undetected planet has been inferred (or suggested) from the narrow width and inner/outer truncation radii of its r = 1.″05 (77 au) debris ring. We present new, highly sensitiv…
Image Simulation and Assessment of the Colour and Spatial Capabilities of the Colour and Stereo Surface Imaging System (CaSSIS) on the ExoMars Trace Gas Orbiter
Seelos, Frank P.; El-Maarry, M. R.; Tornabene, Livio L. +21 more
This study aims to assess the spatial and visible/near-infrared (VNIR) colour/spectral capabilities of the 4-band Colour and Stereo Surface Imaging System (CaSSIS) aboard the ExoMars 2016 Trace Grace Orbiter (TGO). The instrument response functions for the CaSSIS imager was used to resample spectral libraries, modelled spectra and to construct spe…
The WISSH quasars project. V. ALMA reveals the assembly of a giant galaxy around a z = 4.4 hyper-luminous QSO
Fiore, F.; Marconi, A.; Piconcelli, E. +11 more
We present an ALMA high-resolution (0.18″ × 0.21″) observation of the 840 µm continuum and [CII] λ157.74 µm line emission in the WISE-SDSS selected hyper-luminous (WISSH) quasi-stellar object (QSO) J1015+0020, at z ∼ 4.4. Our analysis reveals an exceptional overdensity of [CII]-emitting companions with a very small (<150 km s-1…
Charged particles radiation measurements with Liulin-MO dosimeter of FREND instrument aboard ExoMars Trace Gas Orbiter during the transit and in high elliptic Mars orbit
Zelenyi, Lev; Semkova, Jordanka; Koleva, Rositza +21 more
ExoMars is a joint ESA-Rosscosmos program for investigating Mars. Two missions are foreseen within this program: one consisting of the Trace Gas Orbiter (TGO), that carries scientific instruments for the detection of trace gases in the Martian atmosphere and for the location of their source regions, plus an Entry, Descent and landing demonstrator …
Suppressed Far-UV Stellar Activity and Low Planetary Mass Loss in the WASP-18 System
France, K.; Fossati, L.; Lanza, A. F. +4 more
WASP-18 hosts a massive, very close-in Jupiter-like planet. Despite its young age (<1 Gyr), the star presents an anomalously low stellar activity level: the measured {log}{R}HK}{\prime } activity parameter lies slightly below the basal level; there is no significant time-variability in the {log}{R}HK}{\prim…