Search Publications
A large amount of diffuse molecular gases in the bar of the strongly barred galaxy NGC 1300: cause of the low star formation efficiency
Ohta, Kouji; Maeda, Fumiya; Fujimoto, Yusuke +2 more
In many barred galaxies, star formation efficiency (SFE) in the bar is lower than those in the arm and bar-end, and its cause has still not been clear. Focusing on the strongly barred galaxy NGC 1300, we investigate the possibility that the presence of a large amount of diffuse molecular gas, which would not contribute to the SF, makes the SFE low…
The disintegrating old open cluster Czernik 3
Pandey, S. B.; Ojha, D. K.; Ghosh, S. K. +6 more
We have performed a detailed analysis of the Czernik 3 (Cz3) open cluster by using deep near-infrared photometry taken with TIRCAM2 on the 3.6 m Devasthal optical telescope along with the recently available high-quality proper motion data from the Gaia DR2 and deep photometric data from Pan-STARRS1. The cluster has a highly elongated morphology wi…
Know thy star, know thy planet: chemo-kinematically characterizing TESS targets
Vanderburg, Andrew; Hawkins, Keith; Bowler, Brendan P. +2 more
The Transiting Exoplanet Survey Satellite (TESS) has already begun to discover what will ultimately be thousands of exoplanets around nearby cool bright stars. These potential host stars must be well understood to accurately characterize exoplanets at the individual and population levels. We present a catalogue of the chemo-kinematic properties of…
Multi-timescale reverberation mapping of Mrk 335
Ingram, Adam; Mastroserio, Guglielmo; van der Klis, Michiel
Time lags due to X-ray reverberation have been detected in several Seyfert galaxies. The different traveltime between reflected and directly observed rays naturally causes this type of lag, which depends directly on the light-crossing time-scale of the system and hence scales with the mass of the central black hole. Featureless 'hard lags' not ass…
Magnetic activity based on LAMOST medium-resolution spectra and the Kepler survey
Shi, Jianrong; Gao, Qi; Han, Xianming L. +6 more
Stellar magnetic activity is an interesting phenomenon in late-type stars. We use the medium-resolution spectroscopic observations of 406 069 late-type stars from LAMOST to explore their properties. We perform a statistical analysis on the magnetic activity of the stars and their associated physical parameters. Our samples are cross-matched with o…
The dependence of Type Ia Supernovae SALT2 light-curve parameters on host galaxy morphology
Pruzhinskaya, M. V.; Pauna, N.; Novinskaya, A. K. +1 more
Type Ia Supernovae (SNe Ia) are widely used to measure distances in the Universe. Despite the recent progress achieved in SN Ia standardization, the Hubble diagram still shows some remaining intrinsic dispersion. The remaining scatter in supernova luminosity could be due to the environmental effects that are accounted for as mass step correction i…
Unlocking Galactic Wolf-Rayet stars with Gaia DR2 - II. Cluster and association membership
Parker, Richard J.; Crowther, Paul A.; Rate, Gemma
Galactic Wolf-Rayet (WR) star membership of star-forming regions can be used to constrain the formation environments of massive stars. Here, we utilize Gaia DR2 parallaxes and proper motions to reconsider WR star membership of clusters and associations in the Galactic disc, supplemented by recent near-infrared studies of young massive clusters. We…
The Cluster AgeS Experiment (CASE) - VIII. Age and distance of the Globular Cluster 47 Tuc from the analysis of two detached eclipsing binaries
Soszyński, I.; Udalski, A.; Szymański, M. K. +20 more
We use photometric and spectroscopic observations of the eclipsing binary E32 in the globular cluster 47 Tuc to derive the masses, radii, and luminosities of the component stars. The system has an orbital period of 40.9 d, a markedly eccentric orbit with e = 0.24, and is shown to be a member of or a recent escaper from the cluster. We obtain M_p =…
The first broad-band X-ray view of the narrow-line Seyfert 1 Ton S180
Ebrero, J.; Schartel, N.; Santos-Lleó, M. +15 more
We present joint XMM-Newton and NuSTAR observations of the 'bare' narrow-line Seyfert 1 Ton S180 (z = 0.062), carried out in 2016 and providing the first hard X-ray view of this luminous galaxy. We find that the 0.4-30 keV band cannot be self-consistently reproduced by relativistic reflection models, which fail to account simultaneously for the so…
A DECam view of the diffuse dwarf galaxy Crater II - Variable stars
Nidever, David L.; Olsen, Knut; Walker, Alistair R. +11 more
Time series observations of a single dithered field centred on the diffuse dwarf satellite galaxy Crater II were obtained with the Dark Energy Camera (DECam) at the 4m Blanco Telescope at Cerro Tololo Inter-American Observatory, Chile, uniformly covering up to two half-light radii. Analysis of the g and I time series results in the identification …