Search Publications
Theoretical studies of comets in the 55 Cancri system
Cuntz, Manfred; Dvorak, Rudolf; Loibnegger, Birgit
We present orbital integrations for various Jupiter family comets (JFCs) in the 55 Cancri system. This star is known to possess (at least) five planets with masses ranging from super-Earth to Jupiter-type. Furthermore, according to observational constraints, there is a space without planets between ∼0.8 and ∼5.7 au, offering the principal possibil…
Variability and transient search in the SUDARE-VOICE field: a new method to extract the light curves
Pignata, Giuliano; Vaccari, Mattia; Paolillo, Maurizio +12 more
The VLT Survey Telescope (VST) Optical Imaging of the CDFS and ES1 Fields Survey, in synergy with the SUDARE survey, is a deep optical ugri imaging of the CDFS and ES1 fields using the VST. The observations for the CDFS field comprise about 4.38 deg2 down to r ∼ 26 mag. The total on-sky time spans over 4 yr in this field, distributed ov…
Ionized gas in the NGC 5253 supernebula: high spatial and spectral resolution observations with the JVLA and TEXES
Beck, Sara C.; Liu, Hauyu Baobab; Ho, Paul T. P. +4 more
The youngest, closest, and most compact embedded massive star cluster known excites the supernebula in the nearby dwarf galaxy NGC 5253. It is a crucial target and test case for studying the birth and evolution of the most massive star clusters. We present observations of the ionized gas in this source with high spatial and spectral resolution. Th…
Swift/XRT, Chandra, and XMM-Newton observations of IGR J17091-3624 as it returns into quiescence
Court, J. M. C.; Altamirano, D.; Degenaar, N. +4 more
IGR J17091-3624 is a low-mass X-ray binary (LMXB), which received wide attention from the community thanks to its similarities with the bright black hole system GRS 1915+105. Both systems exhibit a wide range of highly structured X-ray variability during outburst, with time-scales from few seconds to tens of minutes, which make them unique in the …
A spectroscopic, photometric, polarimetric, and radio study of the eclipsing polar UZ Fornacis: the first simultaneous SALT and MeerKAT observations
Hewitt, D. M.; Pretorius, M. L.; Woudt, P. A. +17 more
We present phase-resolved spectroscopy, photometry, and circular spectropolarimetry of the eclipsing polar UZ Fornacis. Doppler tomography of the strongest emission lines using the inside-out projection revealed the presence of three emission regions: from the irradiated face of the secondary star, the ballistic stream and the threading region, an…
The inner gas mass-temperature profile in the core of nearby galaxy clusters
Fabian, Andrew C.; Pinto, Ciro; Liu, Haonan
We present a mass-temperature profile of gas within the central 10 kpc of a small sample of cool core clusters. The mass of the hottest gas phases, at 1.5 and 0.7 keV, is determined from X-ray spectra from the XMM Reflection Grating Spectrometers. The masses of the partially ionized atomic and the molecular phases are obtained from published H α a…
The hydrogen Balmer lines and jump in absorption in accretion disc modelling - an ultraviolet-optical spectral analysis of the dwarf novae UZ Serpentis and CY Lyrae
Blair, William P.; Szkody, Paula; Sion, Edward M. +1 more
The spectra of disc-dominated cataclysmic variables (CVs) often deviate from the spectra of accretion disc models; in particular, the Balmer jump and absorption lines are found to be shallower in the observations than in the models. We carried out a combined ultraviolet-optical spectral analysis of two dwarf novae (DNe): UZ Ser in outburst, declin…
White-light solar corona structure observed by naked eye and processed images
Rušin, Vojtech; Prikryl, Paul; Prikryl, Emil A.
Light and dark adaptation and luminance contrast enhancement are well-known characteristics of human vision that allow us to observe a wide range of light intensity not fully captured in standard camera images. The naked-eye observations of total eclipses, some recorded with spectacular detail in artists' paintings, reveal structure that is consis…
The ionic composition of the local absorber towards 3C 273
Behar, Ehud; Peretz, Uria; Gissis, Itay
Hot ionized gas is observed in the local vicinity of our galaxy through spectral absorption features. The most common hypothesis is that this gas forms a halo surrounding our Milky Way, in collisional ionization equilibrium. In this paper, we investigate the elemental abundance of this hot and ionized local gas. We use a 2.4 Ms stacked X-ray spect…
Some thoughts on emission-line spectroscopy
Judge, Philip G.
The interpretation of emission lines formed in large astrophysical plasmas such as the solar atmosphere faces many challenges. Relatively simple line-ratio estimates of physical parameters, while appealing, are heavily laden with assumptions. In practical cases, some critical assumptions are neither defensible from first principles, nor testable b…