Search Publications
MHD simulation of the solar wind flow around the coma of comet Churyumov-Gerasimenko during Rosetta's flyby
Baranov, V. B.; Alexashov, D. B.; Lebedev, M. G.
The magnetohydrodynamic (MHD) model of the interaction between the solar wind and a cometary ionosphere is applied to investigate certain peculiar features of the solar wind flow around comet Churyumov-Gerasimenko during Rosetta's flyby at this comet. The model accounts for photoionization of the neutral component of the cometary outflow and the r…
A method to analyse velocity structure
Arnold, Becky; Goodwin, Simon P.
We present a new method of analysing and quantifying velocity structure in star-forming regions suitable for the rapidly increasing quantity and quality of stellar position-velocity data. The method can be applied to data in any number of dimensions, does not require the centre or characteristic size (e.g. radius) of the region to be determined, a…
Early science with the Large Millimetre Telescope: new mm-wave detections of circumstellar discs in IC 348 from LMT/AzTEC
Gutermuth, Robert A.; Lane, James; Wilson, Grant W. +2 more
We present the most complete sample of mm measurements of protoplanetary discs in the star-forming region IC 348 to date. New observations from the Large Millimetre Telescope and the 1.1 mm camera AzTEC are combined with literature results in order to characterize the disc population as relating to both stellar properties within the IC 348 region …
Results from the SuperModel analysis of the X-COP galaxy clusters sample
Fusco-Femiano, Roberto
In this work, the analysis of the stacked projected temperature profile of 12 galaxy clusters of the X-COP sample is performed via the SuperModel, a tool for investigating the intracluster medium thermodynamic properties already tested on many clusters since 2009. Two separate fits have been carried out: to the joint X-ray and SZ-projected tempera…
A catalogue of nuclear stellar velocity dispersions of nearby galaxies from Hα STIS spectra to constrain supermassive black hole masses
Sarzi, Marc; Dalla Bontà, Elena; Corsini, Enrico Maria +4 more
We present new measurements for the nuclear stellar velocity dispersion σ* within sub-arcsecond apertures for 28 nearby galaxies. Our data consist of Space Telescope Imaging Spectrograph (STIS) long-slit spectra obtained with the G750M grating centred on the Hα spectral range. We fit the spectra using a library of single stellar populat…
High-resolution spectroscopy of Boyajian's star during optical dimming events
Simón-Díaz, S.; Collier Cameron, A.; González Hernández, J. I. +13 more
Boyajian's star is an apparently normal main-sequence F-type star with a very unusual light curve. The dipping activity of the star, discovered during the Kepler mission, presents deep, asymmetric, and aperiodic events. Here we present high-resolution spectroscopic follow-up during some dimming events recorded post-Kepler observations, from ground…
Parameter estimation for scarce stellar populations
Bitsakis, T.; Bruzual, G.; Cervantes Sodi, B. +1 more
We present a Bayesian method to determine simultaneously the age, metallicity, distance modulus, and interstellar reddening by dust of any resolved stellar population, by comparing the observed and synthetic colour magnitude diagrams on a star by star basis, with no need to bin the data into a carefully selected magnitude grid. We test the method …
Absolute parameters of young stars: HX Velorum
Demircan, O.; Özkardeş, B.; Erdem, A. +4 more
We present combined photometric and spectroscopic analyses of the southern multiple star HX Vel. High-resolution spectra of this system were taken at the University of Canterbury Mt. John Observatory in the years 2009-2015. Absolute parameters for HX Vel tend to confirm its young and near-main-sequence nature. We specify the main adopted parameter…
A high signal-to-noise HST spectrum towards J1009+0713: precise absorption measurements in the CGM of two galaxies
Nicastro, Fabrizio; Mathur, Smita; Weinberg, David H. +6 more
High signal-to-noise spectra towards background quasars are crucial for uncovering weak absorption in the circumgalactic medium (CGM) of intervening galaxies, such as the diagnostic lines of N V that provide insight to the ionization process of warm gas but typically have low equivalent widths. We present a new spectrum from the Hubble Space Teles…
Differential astrometric framework for the Jupiter relativistic experiment with Gaia
Abbas, Ummi; Bucciarelli, Beatrice; Lattanzi, Mario G.
We employ differential astrometric methods to establish a small field reference frame stable at the microarcsecond (µas) level on short time-scales using high-cadence simulated observations taken by Gaia in 2017 February of a bright star close to the limb of Jupiter, as part of the relativistic experiment on Jupiter's quadrupole. We achieve …