Search Publications
Analysis of integral field spectroscopy observations of the planetary nebula Hen 2-108 and its central star
Corradi, Romano L. M.; Akras, Stavros; Todt, Helge +3 more
The study of planetary nebulae provides important constraints for many aspects of stellar and Galactic evolution. Hen 2-108 is a poorly known planetary nebula with a slight elliptical morphology and a peculiar central star (CS), which has defied classification. In this work, we present the first detailed integral field spectroscopic study of the p…
Astrometric detection of binary asteroids
Ofek, Eran O.; Polishook, David; Segev, Noam
Binary asteroids probe thermal-radiation effects on the main-belt asteroids' evolution. We discuss the possibility of detecting binary minor planet systems by the astrometric wobble of the centre of light around the centre of mass. This method enables the exploration of the phase-space of binary asteroids, which is difficult to explore using commo…
The multizone chemical evolution of the Galactic bulge: predicting abundances for different radial zones
Mollá, M.; Cavichia, O.; Bazán, J. J.
Due to its proximity, the stellar populations of the Galactic bulge (GB) can be resolved and can be studied in detail. This allows tracing the bulge metallicity distribution function (MDF) for different spatial regions within the bulge, which may give us clues about the bulge formation and evolution scenarios. In this work, we developed a chemical…
Signatures of feedback in the spectacular extended emission region of NGC 5972
Koss, Michael; Sartori, Lia F.; Maksym, W. Peter +10 more
We present Chandra X-ray Observatory observations and Space Telescope Imaging Spectrograph spectra of NGC 5972, one of the 19 'Voorwerpjes' galaxies. This galaxy contains an extended emission-line region (EELR) and an arcsecond scale nuclear bubble. NGC 5972 is a faded active galactic nucleus (AGN), with EELR luminosity suggesting a 2.1 dex decrea…
Photometric variable stars in the young open cluster NGC 6823
Chen, W. P.; Bhatt, B. C.; Pandey, J. C. +8 more
We present stellar variability towards the young open cluster NGC 6823. Time series V- and I-band CCD photometry led to identification and characterization of 88 variable stars, of which only 14 have been previously recognized. We ascertain the membership of each variable with optical UBVI and infrared photometry, and with Gaia EDR3 parallax and p…
The source of electrons at comet 67P
Nilsson, H.; Goetz, C.; Henri, P. +8 more
We examine the origin of electrons in a weakly outgassing comet, using Rosetta mission data and a 3D collisional model of electrons at a comet. We have calculated a new data set of electron-impact ionization (EII) frequency throughout the Rosetta escort phase, with measurements of the Rosetta Plasma Consortium's Ion and Electron Sensor (RPC/IES). …
Chemodynamical ages of small-scale kinematic structures of the galactic disc in the solar neighbourhood from 250 000 K and M dwarfs
Lépine, Sébastien; Medan, Ilija
We combine photometric metallicities with astrometry from Gaia DR3 to examine the chemodynamic structure of ~250 000 K dwarfs in the solar neighbourhood (SN). In kinematics, we observe ridges/clumps of 'kinematic groups', like studies of more massive main-sequence stars. Here, we note clear differences in both metallicity and vertical velocity as …
Ultraluminous quasars at high redshift show evolution in their radio-loudness fraction in both redshift and ultraviolet luminosity
D'Eugenio, Francesco; Norris, Ray P.; Onken, Christopher A. +1 more
We take a sample of 94 ultraluminous, optical quasars from the search of over 14 486 deg2 by Onken et al. in the range 4.4 < redshift < 5.2 and match them against the Rapid ASKAP Continuum Survey (RACS) observed on the Australian Square Kilometre Array Pathfinder (ASKAP). From this most complete sample of the bright end of the red…
Dissecting a 30 kpc galactic outflow at z 1.7
Chisholm, John; Tejos, Nicolas; Rigby, Jane R. +10 more
We present the spatially resolved measurements of a cool galactic outflow in the gravitationally lensed galaxy RCS0327 at z ≈ 1.703 using VLT/MUSE IFU observations. We probe the cool outflowing gas, traced by blueshifted Mg II and Fe II absorption lines, in 15 distinct regions of the same galaxy in its image-plane. Different physical regions, 5 - …
Measuring mass transfer of AM CVn binaries with a space-based gravitational wave detector
Wang, Zijian; Cao, Zhoujian; Zhang, Xian-Fei
The formation mechanism of AM CVn binary has not been well understood yet. Accurate measurements of the mass transfer rate can help us to determine the formation mechanism. But unfortunately such observation by electromagnetic means is quite challenging. One possible formation channel of AM CVn binary is a semidetached white dwarf binary. Such sys…