Search Publications
Measuring distances to galaxies with globular cluster velocity dispersions
Beasley, Michael A.; Fahrion, Katja; Gvozdenko, Anastasia
Accurate distances are key to obtaining intrinsic properties of astronomical objects such as luminosity or size. Globular clusters (GCs) follow a well-defined relation between their absolute magnitudes and internal stellar velocity dispersions (σ), offering an independent way to measure distances to their host galaxies via high-resolution spectros…
Key Factors Determining Nightside Energetic Electron Losses Driven by Whistler-Mode Waves
Ma, Qianli; Zhang, Xiao-Jia; Agapitov, Oleksiy +4 more
Energetic electron losses by pitch-angle scattering and precipitation to the atmosphere from the radiation belts are controlled, to a great extent, by resonant wave particle interactions with whistler-mode waves. The efficacy of such precipitation is primarily modulated by wave intensity, although its relative importance, compared to other wave an…
Energy dependence of quasi-periodic oscillations in accreting X-ray pulsars
Paul, Biswajit; Pradhan, Pragati; Sharma, Rahul +2 more
We present the results from an investigation of the energy dependence of quasi-periodic oscillations (QPOs) exhibited by accreting X-ray pulsars using data from archival XMM-Newton, NuSTAR, RXTE, and NICER observations. In a search for the presence of QPOs in 99 XMM-Newton and NuSTAR observations, we detected QPOs in eleven observations of five so…
Estimates of (convective core) masses, radii, and relative ages for ∼14 000 Gaia-discovered gravity-mode pulsators monitored by TESS
Aerts, Conny; Van Reeth, Timothy; Hey, Daniel +1 more
Context. Gravito-inertial asteroseismology saw its birth from the 4-year-long light curves of rotating main-sequence stars assembled by the Kepler space telescope. High-precision measurements of internal rotation and mixing are available for about 600 stars of intermediate mass so far that are used to challenge the state-of-the-art stellar structu…
The onset of stellar multiplicity in massive star formation: A search for low-mass companions of massive young stellar objects with L′-band adaptive optics imaging
Pauwels, T.; de Wit, W. -J.; Sana, H. +3 more
Context. Given the high incidence of binaries among mature field massive stars, it is clear that multiplicity is an inevitable outcome of high-mass star formation. Understanding how massive multiples form requires the study of the birth environments of massive stars, covering the innermost to outermost regions.
Aims: We aim to detect and char…
Star Formation in the H II Region Sh2-87: Evidence of Global Hierarchical Collapse
Baug, Tapas; Biswas, Siddhartha; Mondal, Soumen +3 more
We present a detailed study of the Sh2-87 H II region using a multiwavelength data set in optical to radio bands. A Herschel column density map revealed that the host cloud is filamentary in nature, and together they formed a central dense hub. The extinction map generated using near-infrared photometric data also signifies the nonuniform distribu…
Evidence for Abiotic Dimethyl Sulfide in Cometary Matter
De Keyser, Johan; Altwegg, Kathrin; Hänni, Nora +5 more
Technological progress related to astronomical observatories such as the recently launched James Webb Space Telescope (JWST) allows searching for signs of life beyond our solar system, namely, in the form of unambiguous biosignature gases in exoplanetary atmospheres. The tentative assignment of a 1σ–2.4σ spectral feature observed with JWST in the …
A Self-consistent Model of Shock-heated Plasma in Nonequilibrium States for Direct Parameter Constraints from X-Ray Observations
Yamaguchi, Hiroya; Ohshiro, Yuken; Suzuki, Shunsuke +2 more
X-ray observations of shock-heated plasmas, such as those found in supernova remnants (SNRs), often exhibit features of temperature and ionization nonequilibrium. For accurate interpretation of these observations, proper calculations of the equilibration processes are essential. Here, we present a self-consistent model of thermal X-ray emission fr…
Stochastic prior for non-parametric star-formation histories
Maiolino, Roberto; Johnson, Benjamin D.; Tacchella, Sandro +3 more
The amount of power contained in the variations in galaxy star-formation histories (SFHs) across a range of time-scales encodes key information about the physical processes which modulate star formation. Modelling the SFHs of galaxies as stochastic processes allows the relative importance of different time-scales to be quantified via the power spe…
The rise and fall of dust in the Universe
Eales, Stephen; Ward, Bradley
We estimate how the mean density of dust in the Universe varies with redshift, using submillimetre continuum observations and a method designed to minimize the effect of dust temperature. We have used the Herschel Astrophysical Terahertz Large Area Survey (Herschel-ATLAS) to show that the median temperature of dust in galaxies is $\simeq 22\ \math…