Search Publications
Ultraviolet spectroscopy of the supernova Ia hypervelocity runaway white dwarf J0927‑6335
El-Badry, Kareem; Gänsicke, Boris T.; Shen, Ken J. +1 more
The hot white dwarf (WD) J0927‑6335 (Gaia DR3 5250394728194220800 with an effective temperature of Teff = 60 000 K and a surface gravity of logg = 7) was detected as the fastest known Galactic hypervelocity star with a space velocity of ≈2800 km s‑1 and an atmosphere dominated by carbon and oxygen. It is thought to be the sur…
Open superclusters. I. The most populated primordial groups of open clusters in the third quadrant of the Galactic disk
Casado, Juan; Hendy, Yasser
We define an open supercluster (OSC) as a cluster of at least six open clusters (OCs) born from the same giant molecular cloud (GMC). We surveyed the recent catalogs of OCs based on Gaia data and relevant literature to find 17 OSCs of the third Galactic quadrant, along with 190 likely members of them. OSCs are frequent enough to be considered an e…
Growing a nuclear star cluster from star formation and cluster mergers: The JWST NIRSpec view of NGC 4654
Arribas, Santiago; Bunker, Andrew J.; Lützgendorf, Nora +10 more
We present a detailed study of the centre of NGC 4654, a Milky Way-like spiral galaxy in the Virgo cluster that has been reported to host a double stellar nucleus, thus promising a rare view of ongoing star cluster infall into a galaxy nucleus. Analysing JWST NIRSpec integral-field spectroscopic data in combination with Hubble Space Telescope Wide…
A spectroscopic and kinematic survey of fast hot subdwarfs
Rauch, T.; Geier, S.; Gänsicke, B. T. +19 more
Hot subdwarfs (sdO/B) are the stripped helium cores of red giants formed via binary interactions. Close hot subdwarf binaries with massive white dwarf companions have been proposed as possible progenitors of thermonuclear supernovae type Ia (SN Ia). If the supernova is triggered by stable mass transfer from the helium star, the companion should su…
ExoplaNeT accRetion mOnitoring sPectroscopic surveY (ENTROPY): I. Evidence for magnetospheric accretion in the young isolated planetary-mass object 2MASS J11151597+1937266
Viswanath, Gayathri; Janson, Markus; Szulágyi, Judit +7 more
Context. Accretion among planetary mass companions is a poorly understood phenomenon, due to the lack of both observational and theoretical studies. The detection of emission lines from accreting gas giants facilitates detailed investigations into this process. Aims. This work presents a detailed analysis of Balmer lines from one of the few known …
Sublimation of volatiles from H2O:CO2 bulk ices in the context of comet 67P/Churyumov-Gerasimenko. I. N2 and CO
Wurz, P.; Altwegg, K.; Rubin, M. +6 more
Context. Comets are considered to be remnants from the formation of the Solar System. ESA's Rosetta mission targeted comet 67P/Churyumov-Gerasimenko and was able to record high-quality data on its chemical composition and outgassing behaviour, including low abundances of N2 that are observed to be correlated with H2O and CO
Unraveling the kinematics of IZw18: A detailed study of ionized gas with MEGARA/GTC
Kehrig, C.; Pérez-Montero, E.; Vílchez, J. M. +6 more
This study offers an in-depth analysis of the kinematic behavior of ionized gas in IZw18, a galaxy notable for its extremely low metallicity and close proximity, utilizing data from MEGARA/GTC. We explored the structure and dynamics of the galaxy through Hα line profiles, applying single and double Gaussian component fittings to create detailed ma…
Non-thermal electrons in an eruptive solar event: Magnetic structure, confinement, and escape into the heliosphere
Klein, Karl-Ludwig; Kollhoff, Alexander; Salas Matamoros, Carolina +1 more
Context. Filament eruptions and coronal mass ejections (CMEs) reveal large-scale instabilities of magnetic structures in the solar corona. Some of them are accompanied by radio emission, which at decimetric and longer wavelengths is a signature of electron acceleration that may be different from the acceleration in impulsive flares. The radio emis…
Comparison of magnetic data products from Solar Orbiter SO/PHI-FDT and SDO/HMI
Woch, J.; Solanki, S. K.; Schou, J. +34 more
Context. The Polarimetric and Helioseismic Imager (SO/PHI), on board the Solar Orbiter mission, is the first photospheric magnetograph and tachograph to observe the Sun from outside the Sun-Earth line. The Full Disc Telescope (FDT) of SO/PHI, images the whole solar disk with a spatial resolution that varies with the distance between the Sun and th…
Periodicity from X-ray sources within the inner Galactic disk
Hailey, Charles J.; Mori, Kaya; Morris, Mark R. +9 more
Aims: For many years it had been claimed that the Galactic ridge X-ray emission at the Galactic Center (GC) is truly diffuse in nature. However, with the advancement of modern X-ray satellites, it has been found that most of the diffuse emission actually comprises thousands of previously unresolved X-ray point sources. Furthermore, many studi…