Search Publications
Inverse Seesaw, dark matter and the Hubble tension
Pierre, M.; Fernandez-Martinez, E.; Pinsard, E. +1 more
We consider the inverse Seesaw scenario for neutrino masses with the approximate Lepton number symmetry broken dynamically by a scalar with Lepton number two. We show that the Majoron associated to the spontaneous symmetry breaking can alleviate the Hubble tension through its contribution to Δ Neff and late decays to neutrinos. Among th…
Probabilistic Drag-Based Ensemble Model (DBEM) Evaluation for Heliospheric Propagation of CMEs
Veronig, Astrid M.; Dumbović, Mateja; Temmer, Manuela +4 more
The Drag-based Model (DBM) is a 2D analytical model for heliospheric propagation of Coronal Mass Ejections (CMEs) in ecliptic plane predicting the CME arrival time and speed at Earth or any other given target in the solar system. It is based on the equation of motion and depends on initial CME parameters, background solar wind speed, w and the dra…
TESS cycle 1 observations of roAp stars with 2-min cadence data
Derekas, A.; Niemczura, E.; Handberg, R. +41 more
We present the results of a systematic search for new rapidly oscillating Ap (roAp) stars using the 2-min cadence data collected by the Transiting Exoplanet Survey Satellite (TESS) during its Cycle 1 observations. We identify 12 new roAp stars. Amongst these stars we discover the roAp star with the longest pulsation period, another with the shorte…
Relation between AGN type and host galaxy properties
Georgantopoulos, I.; Masoura, V. A.; Mountrichas, G. +1 more
We use 3213 active galactic nuclei (AGNs) from the XMM-XXL northern field to investigate the relation of AGN type with host galaxy properties. Applying a Bayesian method, we derive the hardness ratios, and through these the hydrogen column density (NH) for each source. We consider those with NH > 1021.5 cm-…
Dynamical Model of the Milky Way Using APOGEE and Gaia Data
Neumayer, Nadine; Rix, Hans-Walter; Cappellari, Michele +2 more
We construct a dynamical model of the Milky Way disk from a data set that combines Gaia EDR3 and APOGEE data throughout galactocentric radii in the range 5.0 kpc ≤ R ≤ 19.5 kpc. We make use of the spherically aligned Jeans anisotropic method to model the stellar velocities and their velocity dispersions. Building upon our previous work, our model …
Constraining the Orbit and Mass of epsilon Eridani b with Radial Velocities, Hipparcos IAD-Gaia DR2 Astrometry, and Multiepoch Vortex Coronagraphy Upper Limits
Rice, Malena; Rosenthal, Lee J.; Hirsch, Lea A. +30 more
ϵ Eridani is a young planetary system hosting a complex multibelt debris disk and a confirmed Jupiter-like planet orbiting at 3.48 au from its host star. Its age and architecture are thus reminiscent of the early Solar System. The most recent study of Mawet et al., which combined radial-velocity data and Ms-band direct imaging upper limits, starte…
H II regions and high-mass starless clump candidates. II. Fragmentation and induced star formation at 0.025 pc scale: an ALMA continuum study
Liu, H.; Zavagno, A.; Zhang, S. +7 more
Context. The ionization feedback from H II regions modifies the properties of high-mass starless clumps (HMSCs, of several hundred to a few thousand solar masses with a typical size of 0.1-1 pc), such as dust temperature and turbulence, on the clump scale. The question of whether the presence of H II regions modifies the core-scale (~0.025 pc) fra…
The nature of VX Sagitarii. Is it a TŻO, a RSG, or a high-mass AGB star?
Negueruela, I.; Tabernero, H. M.; Dorda, R. +1 more
Aims: We present a spectroscopic analysis of the extremely luminous red star VX Sgr based on high-resolution observations combined with AAVSO light curve data. Given the puzzling characteristics of VX Sgr, we explore three scenarios for its nature: a massive red supergiant (RSG) or red hypergiant (RHG), a Thorne Żytkow object, and an extreme …
A Disk and No Signatures of Tidal Distortion in the Galaxy "Lacking" Dark Matter NGC 1052-DF2
Trujillo, Ignacio; Borlaff, Alejandro S.; Monelli, Matteo +2 more
Using ultra-deep imaging (µg = 30.4 mag arcsec-2; 3σ, 10″ × 10″), we probed the surroundings of the first galaxy "lacking" dark matter (DM) KKS2000[04] (NGC 1052-DF2). Signs of tidal stripping in this galaxy would explain its claimed low content of DM. However, we find no evidence of tidal tails. In fact, the galaxy rem…
Two Bright M Dwarfs Hosting Ultra-Short-Period Super-Earths with Earth-like Compositions
Barclay, Thomas; Vanderburg, Andrew; Bieryla, Allyson +60 more
We present observations of two bright M dwarfs (TOI-1634 and TOI-1685: J = 9.5-9.6) hosting ultra-short-period (USP) planets identified by the TESS mission. The two stars are similar in temperature, mass, and radius (Teff ≈ 3500 K, M⋆ ≈ 0.45-0.46 M⊙, and R⋆ ≈ 0.45-0.46 R⊙), and the planets are…