Search Publications
Possible evidence of a universal radio/X-ray correlation in a near-complete sample of hard X-ray selected seyfert galaxies
Ho, L. C.; Chang, N.; Xie, F. G. +4 more
Because the disc-jet coupling likely depends on various properties of sources probed, the sample control is always an important but challenging task. In this work, we re-analysed the INTEGRAL hard X-ray-selected sample of Seyfert galaxies. We only consider sources that have measurements in black hole (BH) mass, and luminosities in radio and X-rays…
Surface roughness of asteroid (162173) Ryugu and comet 67P/Churyumov-Gerasimenko inferred from in situ observations
Jaumann, R.; Stephan, K.; Mottola, S. +28 more
Alteration processes on asteroid and comet surfaces, such as thermal fracturing, (micrometeorite) impacts or volatile outgassing, are complex mechanisms that form diverse surface morphologies and roughness on various scales. These mechanisms and their interaction may differ on the surfaces of different bodies. Asteroid Ryugu and comet 67P/Churyumo…
Understanding X-ray and optical selection of galaxy clusters: a comparison of the XXL and CAMIRA cluster catalogues obtained in the common XXL-HSC SSP area
Okabe, N.; Chiappetti, L.; Altieri, B. +31 more
Large samples of galaxy clusters provide knowledge of both astrophysics in the most massive virialized environments and the properties of the cosmological model that defines our Universe. However, an important issue that affects the interpretation of galaxy cluster samples is the role played by the selection waveband and the potential for this to …
A fully-spectroscopic triple-source-plane lens: the Jackpot completed
Collett, Thomas E.; Smith, Russell J.
We present a spectroscopic determination of the redshift of the second source in the Jackpot gravitational lens system J0946 + 1006, for which only a photometric estimate of zphot = 2.41$^{+0.04}_{-0.21}$ has previously been available. By visually inspecting an archival Very Large Telescope (VLT) X-Shooter observation, we located a sing…
A new transient ultraluminous X-ray source in NGC 7090
Salvaterra, R.; Harrison, F. A.; Stern, D. +17 more
We report on the discovery of a new, transient ultraluminous X-ray source (ULX) in the galaxy NGC 7090. This new ULX, which we refer to as NGC 7090 ULX3, was discovered via monitoring with Swift during 2019-2020, and to date has exhibited a peak luminosity of LX ~ 6 × 1039 erg s-1. Archival searches show that, prio…
ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions-VI. On the formation of the 'L' type filament in G286.21+0.17
Kim, Kee-Tae; Lee, Chang Won; Liu, Hong-Li +16 more
Filaments play an important role in star formation, but the formation process of filaments themselves is still unclear. The high-mass star-forming clump G286.21+0.17 (G286 for short) that contains an 'L' type filament was thought to undergo global collapse. Our high-resolution ALMA band 3 observations resolve the gas kinematics of G286 and reveal …
Colliding stellar wind modelling of the X-ray emission from WR 140
Zhekov, Svetozar A.
We modelled the Chandra and Rossi X-ray Timing Explorer X-ray spectra of the massive binary WR 140 in the framework of the standard colliding stellar wind (CSW) picture. Models with partial electron heating at the shock fronts are a better representation of the X-ray data than those with complete temperature equalization. Emission measure of the X…
A synergy of the velocity gradients technique and the probability density functions for identifying gravitational collapse in self-absorbing media
Lazarian, A.; Hu, Yue
The velocity gradients technique (VGT) and the probability density functions (PDFs) of mass density are tools to study turbulence, magnetic fields, and self-gravity in molecular clouds. However, self-absorption can significantly make the observed intensity different from the column density structures. In this work, we study the effects of self-abs…
The evolution of merger fraction of galaxies at z < 0.6 depending on the star formation mode in the AKARI NEP-Wide Field
Hashimoto, Tetsuya; Goto, Tomotsugu; Kim, Seong Jin +19 more
We study the galaxy merger fraction and its dependence on star formation mode in the 5.4 deg2 of the North Ecliptic Pole-Wide Field. We select 6352 galaxies with AKARI 9 $\mu$m detections, and identify mergers among them using the Gini coefficient and M20 derived from the Subaru/Hyper Suprime-Cam (HSC) optical images. We obta…
Solo dwarfs IV: comparing and contrasting satellite and isolated dwarf galaxies in the Local Group
McConnachie, A. W.; Higgs, C. R.
We compare and contrast the stellar structures of isolated Local Group dwarf galaxies, as traced by their oldest stellar populations, with the satellite dwarf galaxies of the Milky Way and M 31. All Local Group dwarfs with Mv ≤ -6 and µo < 26.5 mag arcsec-2 are considered, taking advantage of measurements …