Search Publications
Investigation of Coronal Properties of X-Ray Bright G-dwarf Stars Based on the Solar Surface Magnetic Field-Corona Relationship
Takasao, Shinsuke; Mitsuishi, Ikuyuki; Ishihara, Daisuke +4 more
We investigated the coronal properties of G-dwarf stars including the Sun over a wide range of X-ray luminosity LX (3 × 1026 to 2 × 1030 erg s-1). We analyzed the archival data of 10 X-ray bright (LX > 1028 erg s-1) G-dwarf stars to derive their emission measure (EM) a…
Rotation and spots in normal A and Am/Fm stars
Joshi, Santosh; De Cat, Peter; Trust, Otto +1 more
Frequency analysis of long-term ultraprecise photometry can lead to precise values of rotation frequencies of rotating stars with `hump and spike' features in their periodograms. Using these features, we computed the rotation frequencies and amplitudes. The corresponding equatorial rotational velocity (V_{{rot}}) and spot size were estimated. On f…
Molecular gas and star formation activity in luminous infrared galaxies in clusters at intermediate redshifts
Arnaud, M.; Jablonka, P.; Krips, M. +10 more
We investigate the role of dense megaparsec-scale environments in processing molecular gas of cluster galaxies as they fall into the cluster cores. We selected a sample of ∼20 luminous infrared galaxies (LIRGs) belonging to intermediate-redshift clusters, mainly from the Herschel Lensing Survey and the Local Cluster Substructure Survey. These gala…
Cosmology with the submillimetre galaxies magnification bias: Proof of concept
Bonavera, L.; González-Nuevo, J.; Migliaccio, M. +6 more
Context. As recently demonstrated, high-z submillimetre galaxies (SMGs) are the perfect background sample for tracing the mass density profiles of galaxies and clusters (baryonic and dark matter) and their time-evolution through gravitational lensing. Their magnification bias, a weak gravitational lensing effect, is a powerful tool for constrainin…
The ancient main-sequence solar proxy HIP 102152 unveils the activity and rotational fate of our Sun
Meléndez, Jorge; Lorenzo-Oliveira, Diego; Ponte, Geisa +1 more
We present a detailed analysis of the possible future Sun's rotational evolution scenario based on the 8-Gyr-old solar twin HIP 102152. Using HARPS high-cadence observations (and TESS light curves), we analysed the modulation of a variety of activity proxies (Ca II, H I Balmer, and Na I lines), finding a strong rotational signal of 35.7 ± 1.4 d (l…
The Pre-He White Dwarfs in Eclipsing Binaries. I. WASP 0131+28
Koo, Jae-Rim; Hong, Kyeongsoo; Lee, Jae Woo +1 more
We report the first BV light curves and high-resolution spectra of the post-mass transfer binary star WASP 0131+28 to study the absolute properties of extremely low-mass white dwarfs. From the observed spectra, the double-lined radial velocities were derived, and the effective temperature and rotational velocity of the brighter, more massive prima…
Gravitational Lensing and Dynamics (GLaD): combined analysis to unveil properties of high-redshift galaxies
Halkola, A.; Suyu, S. H.; Yıldırım, A. +1 more
The dynamical modelling of integral field unit (IFU) stellar kinematics is a powerful tool to unveil the dynamical structure and mass build-up of galaxies in the local Universe, while gravitational lensing is nature's cosmic telescope to explore the properties of galaxies beyond the local Universe. We present a new approach, which unifies dynamica…
The contribution of quasar absorption outflows to AGN feedback
Xu, Xinfeng; Kriss, Gerard A.; Arav, Nahum +1 more
Determining the distance of quasar absorption outflows from the central source (R) and their kinetic luminosity ($\dot{E}_\mathrm{\scriptstyle k}$) is crucial for understanding their contribution to active galactic nucleus (AGN) feedback. Here, we summarize the results for a sample of nine luminous quasars that were observed with the Hubble Space …
Extended main sequence turnoffs in open clusters as seen by Gaia - II. The enigma of NGC 2509
Cabrera-Ziri, I.; Usher, C.; Bastian, N. +6 more
We investigate the morphology of the colour-magnitude diagram (CMD) of the open cluster NGC 2509 in comparison with other Galactic open clusters of similar age using Gaia photometry. At ∼900 {Myr} Galactic open clusters in our sample all show an extended main sequence turnoff (eMSTO) with the exception of NGC 2509, which presents an exceptionally …
XMM-Newton observations of eleven intermediate polars and possible candidates
Mukai, K.; Schwope, A. D.; Traulsen, I. +2 more
Aims: We aim to identify new intermediate polars (IPs) in XMM-Newton observations from a list of promising candidates. By selecting targets not previously known to be X-ray bright, we aim to uncover evidence for an X-ray underluminous IP subpopulation.
Methods: We performed period searches on the XMM-Newton X-ray and optical data of our …