Search Publications
Isochrone fitting of Galactic globular clusters - II. NGC 6205 (M13)
Gontcharov, George A.; Mosenkov, Aleksandr V.; Khovritchev, Maxim Yu
We present new isochrone fits to colour-magnitude diagrams of the Galactic globular cluster NGC 6205 (M13). We utilize 34 photometric bands from the ultraviolet to mid-infrared by use of data from the HST, Gaia DR2, SDSS, unWISE, Pan-STARRS DR1, and other photometric sources. In our isochrone fitting we use the PARSEC, MIST, DSEP, BaSTI, and IAC-B…
Spectroscopy of hot γ Doradus and A-F hybrid Kepler candidates close to the hot border of the δ Scuti instability strip
Handler, G.; Poretti, E.; Rainer, M. +4 more
If γ Dor-type pulsations are driven by the convective blocking mechanism, a convective envelope at a sufficient depth is essential. There are several hot γ Dor and hybrid star candidates in which there should not be an adequate convective envelope to excite the γ Dor-type oscillations. The existence of these hot objects needs an explanation. There…
Identifying new X-ray binary candidates in M31 using random forest classification
Barmby, P.; Vulic, N.; Arnason, R. M.
Identifying X-ray binary (XRB) candidates in nearby galaxies requires distinguishing them from possible contaminants including foreground stars and background active galactic nuclei. This work investigates the use of supervised machine learning algorithms to identify high-probability XRB candidates. Using a catalogue of 943 Chandra X-ray sources i…
A deep Chandra survey for faint X-ray sources in the Galactic globular cluster M30, and searches for optical and radio counterparts
Strader, Jay; Bahramian, Arash; Maccarone, Thomas J. +11 more
We present a deep (~330 ks) Chandra survey of the Galactic globular cluster M30 (NGC 7099). Combining the new Cycle 18 with the previous Cycle 3 observations we report a total of 10 new X-ray point sources within the 1${_{.}^{\prime}}$03 half-light radius, compiling an extended X-ray catalogue of a total of 23 sources. We incorporate imaging obser…
The assembly history of the nearest S0 galaxy NGC 3115 from its kinematics out to six half-light radii
Forbes, Duncan A.; Romanowsky, Aaron J.; Brodie, Jean P. +6 more
Using new and archival data, we study the kinematic properties of the nearest field S0 galaxy, NGC 3115, out to ∼6.5 half-light radii (Re) from its stars (integrated starlight), globular clusters (GCs), and planetary nebulae (PNe). We find evidence of three kinematic regions with an inner transition at ∼0.2 Re from a dispersi…
VVV WIN 1733-3349: a low extinction window to probe the far side of the Milky Way bulge
Minniti, D.; Benjamin, R. A.; Saito, R. K. +5 more
Windows of low extinction in the Milky Way (MW) have been used along the past decades for the study of the Galactic structure and the stellar population across the inner bulge and disc. Here, we report the analysis of another low extinction near-IR window discovered by the VISTA Variables in the Vía Láctea Survey (VVV). VVV WIN 1733-3349 is about …
Astrometric orbits of spectral binary brown dwarfs - I. Massive T dwarf companions to 2M1059-21 and 2M0805+48
Zapatero Osorio, M. R.; Martín, E. L.; Bouy, H. +7 more
Near-infrared spectroscopic surveys have uncovered a population of short-period, blended-light spectral binaries composed of low-mass stars and brown dwarfs. These systems are amenable to orbit determination and individual mass measurements via astrometric monitoring. Here, we present first results of a multiyear campaign to obtain high-precision …
First stars that could significantly perturb comet motion are finally found
Dybczyński, Piotr A.; Królikowska, Małgorzata; Wysoczańska, Rita
Since 1950 when Oort published his paper on the structure of the cloud of comets it is believed that stars passing near this hypothetical cometary reservoir play an important role in the dynamical evolution of long-period comets and injecting them into the observability region of the Solar system. The aim of this paper is to discuss two cases in w…
Photometric study of the young open clusters IC 1442, King 21, and Trumpler 7
Joshi, Y. C.; Maurya, Jayanand; Gour, A. S.
We carried out the UBVRcIc photometric study of three poorly studied young open clusters IC 1442, King 21, and Trumpler 7 (Tr 7). We obtained 263, 244, and 128 member stars using Gaia Data Release 2 proper motions and parallaxes in IC 1442, King 21, and Tr 7, respectively. The reddening, E(B - V), was derived to be 0.54 ± 0.0…
A precise benchmark for cluster scaling relations: Fundamental Plane, Mass Plane, and IMF in the Coma cluster from dynamical models
Krajnović, Davor; Kobayashi, Chiaki; Cappellari, Michele +4 more
We study a sample of 148 early-type galaxies in the Coma cluster using SDSS photometry and spectra, and calibrate our results using detailed dynamical models for a subset of these galaxies, to create a precise benchmark for dynamical scaling relations in high-density environments. For these galaxies, we successfully measured global galaxy properti…