Search Publications
On the saturation of acoustic mode frequencies at high solar activity
Rabello Soares, M. Cristina
Acoustic mode frequencies obtained by applying spherical harmonic decomposition to HMI, MDI, and GONG observations were analysed throughout the solar cycle. Evidence of a deviation from a linear relation with solar radio flux was found indicating a saturation effect at high solar activity. The Gompertz model, which is one of the most frequently us…
Search for exoplanetary transits in the Galactic bulge
Minniti, D.; Villanova, S.; Cortés, C. C.
A search for extrasolar planetary transits using extended Kepler mission (K2) campaigns 9 and 11 revealed five new candidates towards the Galactic bulge. The stars EPIC 224439122, 224560837, 227560005, 230778501 and 231635524 are found to have low-amplitude transits consistent with extrasolar planets, with periods P = 35.1695, 3.6390, 12.4224, 17.…
Molecular clumps towards compact H II regions
Gómez, M.; Rubio, M.; Cappa, C. E. +1 more
To better understand how the H II regions can affect their surrounding molecular clouds we have studied the molecular distribution towards three compact H II regions associated with IRAS sources (08140-3559, 09014-4736, and 09026-4842) by means of the observations of 12CO, 13CO, and C18O molecules in the J = 3-2 tr…
XMM-Newton and INTEGRALanalysis of the Supergiant Fast X-ray Transient IGR J17354-3255
Hill, A. B.; Bird, A. J.; Sguera, V. +2 more
We present the results of combined INTEGRALand XMM-Newton observations of the supergiant fast X-ray transient (SFXT) IGR J17354-3255. Three XMM-Newton observations of lengths 33.4, 32.5, and 21.9 ks were undertaken, the first an initial pointing to identify the correct source in the field of view and the latter two performed around periastron. Sim…
Deep lensing with a twist: E and B modes in a field with multiple lenses
Tyson, J. Anthony; Jee, M. James; Bradshaw, Andrew K.
We explore the weak lensing E- and B-mode shear signals of a field of galaxy clusters using both large-scale structure N-body simulations and multicolour Suprime-cam & Hubble Space Telescope observations. Using the ray-traced and observed shears along with photometric redshift catalogues, we generate mass maps of the foreground overdensities b…
A pre-merger stage galaxy cluster: Abell 3733
Caglar, Turgay; Kaya, H. Ilker; Sert, Hakan
The galaxy cluster Abell 3733 (A3733) is a very suitable candidate in addressing dynamical processes throughout galaxy cluster mergers. This study shows structural analysis results of A3733 (z = 0.038) based on X-ray and optical data. According to X-ray luminosity map, A3733 hosts two sub-structures separated in the sky by 0.25 Mpc, and the two di…
Absolute parameters of young stars: V454 Carinae
Demircan, O.; Özkardeş, B.; Erdem, A. +4 more
We present combined photometric and spectroscopic analyses of the multiple star V454 Carinae. High-resolution spectra of the system were taken at the University of Canterbury Mt. John Observatory during the years 2008-18. These have been processed using generic and purpose-built software. New digital single lens reflex photometry of the system has…
Hierarchical Bayesian approach for estimating physical properties in nearby galaxies: Age Maps (Paper II)
Bland-Hawthorn, Joss; Pérez, Enrique; Cerviño, Miguel +3 more
One of the fundamental goals of modern astrophysics is to estimate the physical parameters of galaxies. We present a hierarchical Bayesian model to compute age maps from images in the H α line (taken with Taurus tunable filter, TTF), ultraviolet band (GALEX far UV, FUV), and infrared bands (Spitzer 24, 70, and 160 µm). We present the burst a…
Local activity of comets: an indicator of non-uniform composition
Kossacki, Konrad J.; Czechowski, L.
In this paper, we investigate the conditions for the local ejection of a metamorphosed surface layer of material from a comet. We have calculated the strengthening of the material of the nucleus of comet 67P/Churyumov-Gerasimenko and the increase of gas pressure in pores. We are interested in the boundary between the regions Anhur and Bes, where a…
Interplay between physics and geometry in Balmer filaments: the case of SN 1006
Raymond, J. C.; Bandiera, R.; Morlino, G. +1 more
The analysis of Balmer-dominated emission in supernova remnants is potentially a very powerful way to derive information on the shock structure, on the physical conditions of the ambient medium and on the cosmic ray acceleration efficiency. However, the outcome of models developed in plane-parallel geometry is usually not easily comparable with th…