Search Publications
BALRoGO: Bayesian Astrometric Likelihood Recovery of Galactic Objects - Global properties of over one hundred globular clusters with Gaia EDR3
Vitral, Eduardo
We present BALRoGO: Bayesian Astrometric Likelihood Recovery of Galactic Objects, a public code to measure the centres, effective radii, and bulk proper motions of Milky Way (MW) globular clusters and Local Group dwarf spheroidals, whose data are mixed with MW field stars. Our approach presents innovative methods such as surface density fits allow…
Long-term and multiwavelength evolution of a changing-look AGN Mrk 1018
Wu, Qingwen; Lyu, Bing; Yan, Zhen +1 more
The physical mechanism for triggering the changing-look phenomenon in active galactic nuclei (AGNs) is still unclear. We explore this issue based on the multiwavelength spectral and flux variations for a changing-look AGN Mrk 1018 with long-term observations in the X-ray, optical/ultraviolet (UV), and radio bands. Both the optical and the X-ray em…
Magnetic field orientation in self-gravitating turbulent molecular clouds
de Gouveia Dal Pino, E. M.; Santos-Lima, R.; Barreto-Mota, L. +3 more
Stars form inside molecular cloud filaments from the competition of gravitational forces with turbulence and magnetic fields. The exact orientation of these filaments with the magnetic fields depends on the strength of these fields, the gravitational potential, and the line of sight (LOS) relative to the mean field. To disentangle these effects we…
Quasi-periodic dipping in the ultraluminous X-ray source, NGC 247 ULX-1
Fabian, A. C.; Pinto, C.; Walton, D. +15 more
Most ultraluminous X-ray sources (ULXs) are believed to be stellar mass black holes or neutron stars accreting beyond the Eddington limit. Determining the nature of the compact object and the accretion mode from broad-band spectroscopy is currently a challenge, but the observed timing properties provide insight into the compact object and details …
XMM-Newton observations of the extremely X-ray luminous quasar CFHQS J142952+544717=SRGE J142952.1 + 544716 at redshift z = 6.18
Sunyaev, R.; Sazonov, S.; Schartel, N. +2 more
We present results from a 20 ks XMM-Newton director's discretionary time observation of the radio-loud quasar CFHQS J142952 + 544717 at z = 6.18, whose extreme X-ray luminosity was recently revealed by the SRG/eROSITA telescope in the course of its first all-sky survey. The quasar has been confidently detected with a total of ~1400 net counts in t…
Evolutionary stages and triggering process of a complex eruptive flare with circular and parallel ribbons
Joshi, Bhuwan; Joshi, Navin Chandra; Mitra, Prabir K.
We report multiwavelength study of a complex M-class solar eruptive flare that consists of three different sets of flare ribbons, viz. circular, parallel, and remote ribbons. Magnetic field modelling of source active region NOAA 12242 exhibits the presence of 3D null-point magnetic topology that encompasses an inner bipolar region. The event initi…
Total mass density slopes of early-type galaxies using Jeans dynamical modelling at redshifts 0.29 < z < 0.55
Emsellem, Eric; Jørgensen, Inger; McDermid, Richard M. +3 more
The change of the total mass density slope, γ, of early-type galaxies through cosmic time is a probe of evolutionary pathways. Hydrodynamical cosmological simulations show that at high redshifts density profiles of early-type galaxies were on average steep (γ ~ -3). As redshift approaches zero, gas-poor mergers progressively cause the total mass d…
Revisiting the gas kinematics in SSA22 Lyman-α Blob 1 with radiative transfer modelling in a multiphase, clumpy medium
Steidel, Charles C.; Gronke, Max; Li, Zhihui +1 more
We present new observations of Lyman-α (Lyα) Blob 1 (LAB1) in the SSA22 protocluster region (z = 3.09) using the Keck Cosmic Web Imager and Keck Multi-object Spectrometer for Infrared Exploration. We have created a narrow-band Lyα image and identified several prominent features. By comparing the spatial distributions and intensities of Lyα and Hβ,…
O VI traces photoionized streams with collisionally ionized boundaries in cosmological simulations of z ∼ 1 massive galaxies
Stern, Jonathan; Dekel, Avishai; Primack, Joel +6 more
We analyse the distribution and origin of O VI in the Circumgalactic Medium (CGM) of dark-matter haloes of ~1012 M⊙ at z ~ 1 in the VELA cosmological zoom-in simulations. We find that the O VI in the inflowing cold streams is primarily photoionized, while in the bulk volume it is primarily collisionally ionized. The photoioni…
Dissecting the Gaia HR diagram within 200 pc
Girardi, Léo; Marigo, Paola; Chen, Yang +6 more
We analyse the high-quality Hertzsprung-Russell diagram (HRD) derived from Gaia data release 2 for the Solar Neighbourhood. We start building an almost complete sample within 200 pc and for |b| > 25○, so as to limit the impact of known errors and artefacts in the Gaia catalogue. Particular effort is then put into improving the modell…