Search Publications
Spectroscopic identification of INTEGRAL high-energy sources with VLT/ISAAC
Chaty, S.; Tomsick, J. A.; Coleiro, A. +2 more
Context. The INTEGRAL satellite has been observing the γ-ray sky for 15 years and has detected over 900 X-ray sources of various nature. However, more than 200 of these sources still lack precise identification.
Aims: Our goal is to reveal the nature of the high-energy sources detected by INTEGRAL. In particular, we want to improve the census…
Objective Lagrangian Vortex Detection in the Solar Photosphere
Silva, Suzana S. A.; Requerey, Iker S.; Rempel, Erico Luiz +2 more
Vortices in the solar photosphere can be linked to a wide range of events, such as small-scale solar eruptions, wave excitation, and heating of the upper part of the solar atmosphere. Despite their importance in solar physics, most of the current studies on photospheric vortices are based on methods that are not invariant under time-dependent tran…
Kinematics of the SN Refsdal host revealed by MUSE: a regularly rotating spiral galaxy at z ≃ 1.5
Treu, T.; Grillo, C.; Balestra, I. +11 more
We use Multi Unit Spectroscopic Explorer (MUSE) observations of the galaxy cluster MACS J1149.5+2223 to explore the kinematics of the grand-design spiral galaxy (Sp1149) hosting the supernova `Refsdal'. Sp1149 lies at z ≃ 1.49, has a stellar mass M* ≃ 5 × 109 M⊙, has a star formation rate (SFR) ∼eq 1-6 M_{⊙} yr^{-1…
A Two-dimensional Spectroscopic Study of Emission-line Galaxies in the Faint Infrared Grism Survey (FIGS). I. Detection Method and Catalog
Finkelstein, Steven L.; Hathi, Nimish P.; Koekemoer, Anton M. +31 more
We present the results from the application of a two-dimensional emission line detection method, EMission-line two-Dimensional (EM2D), to the near-infrared G102 grism observations obtained with the Wide-Field Camera 3 (WFC3) as part of the Cycle 22 Hubble Space Telescope Treasury Program: the Faint Infrared Grism Survey (FIGS). Using the EM2D meth…
Gaia Data Release 2. Validating the classification of RR Lyrae and Cepheid variables with the Kepler and K2 missions
Molnár, László; Rimoldini, Lorenzo; Plachy, Emese +1 more
Context. The second data release of the Gaia mission (DR2) includes an advance catalogue of variable stars. The classifications of these stars are based on sparse photometry from the first 22 months of the mission.
Aims: We set out to investigate the purity and completeness of the all-sky Gaia classification results with the help of the conti…
Design, implementation, and performance of the Astro-H SXS calorimeter array and anticoincidence detector
Eckart, Megan E.; Kilbourne, Caroline A.; Leutenegger, Maurice A. +14 more
The calorimeter array of the JAXA Astro-H (renamed Hitomi) soft x-ray spectrometer (SXS) was designed to provide unprecedented spectral resolution of spatially extended cosmic x-ray sources and of all cosmic x-ray sources in the Fe-K band around 6 keV, enabling essential plasma diagnostics. The SXS had a square array of 36 x-ray calorimeters at th…
Whipping IC 63/IC 59
Tielens, A. G. G. M.; Okada, Y.; Peeters, E. +1 more
Context. IC 63 and IC 59 are a pair of cometary-shaped nebulae in the vicinity of the star γCas (also known as Tsih, "the Whip"). Both nebulae have very different optical appearances, despite the fact that both objects lie at similar projected distances from the star: IC 63 shows bright rims and filaments, while IC 59 looks more homogeneous and fa…
Confronting Kähler moduli inflation with CMB data
Bhattacharya, Sukannya; Dutta, Koushik; Gangopadhyay, Mayukh Raj +1 more
In models of inflation obtained from string compactification, moduli vacuum misalignment leads to an epoch in the postinflationary history of the Universe when the energy density is dominated by cold moduli particles. This effect leads to a modification in the number of e -foldings (Npivot) between the horizon exit of the CMB modes and …
A Gaia DR2 view of white dwarfs in the Hyades
Salaris, M.; Bedin, L. R.
We have exploited the very precise parallaxes, proper motions, and photometry of Gaia Data Release 2 to study white dwarf members of the Hyades star cluster. Gaia photometry and parallaxes for the eight DA white dwarfs confirmed members have been then used to compute absolute magnitudes and colours. These were compared to three independent sets of…
A remarkable oxygen-rich asymptotic giant branch variable in the Sagittarius Dwarf Irregular Galaxy
Marigo, Paola; Whitelock, Patricia A.; Feast, Michael W. +1 more
We report and discuss JHKS photometry for Sgr dIG, a very metal-deficient galaxy in the Local Group, obtained over 3.5 years with the Infrared Survey Facility in South Africa. Three large amplitude asymptotic giant branch variables are identified. One is an oxygen-rich star that has a pulsation period of 950 d, which was until recently …