Search Publications
Spectral characterization of young LT dwarfs
Scholz, A.; Mužić, K.; Almendros-Abad, V. +1 more
Context. JWST and next-generation facilities are expected to uncover populations of free-floating objects below the deuterium-burning limit in a number of young clusters and star-forming regions. These young planetary-mass brown dwarfs have spectral types L and T; they are shaped by molecular absorption and modified by their low gravity, which mak…
Multimode δ Sct stars from the Zwicky Transient Facility Survey
Wang, Shu; Deng, Licai; Luo, Yangping +3 more
We obtain the largest catalog of multimode δ Sct stars in the northern sky to date using the Zwicky Transient Facility (ZTF) Data Release 20. The catalog includes 2254 objects, of which 2181 are new to our study. Among these multimode δ Sct stars, 2142 objects are double-mode δ Sct, while 109 objects are triple-mode δ Sct and three are quadruple-m…
Spectroscopic and dynamic orbital analyses of metal‑poor and high proper‑motion stars: I. HD 8724 and HD 195633
Bilir, S.; Şahin, T.; Plevne, O. +2 more
In this study, spectral, age, kinematic, and orbital dynamical analyses were conducted on metal‑poor and high proper‑motion (HPM) stars, HD 8724 and HD 195633, selected from the Solar neighborhood. This analysis combines detailed abundance measurements, kinematics, and orbital dynamics to determine their origin. Standard 1D local thermodynamic equ…
The "SEP Clock": A Discussion of First Proton Arrival Times in Wide-Spread Solar Energetic Particle Events
Posner, A.; Richardson, I. G.; Strauss, R. D. -T.
This work analyzes the appearance of wide-spread deka-MeV solar energetic proton (SEP) events, in particular the arrival of the first protons within ≈ 4.5 – 45 MeV measured at Earth–Sun L1, and their relationship with their relative solar source longitude. The definition of "wide-spread SEP event" for this study refers to events that are observed …
The prototypical major cluster merger Abell 754: I. Calibration of MeerKAT data and radio/X-ray spectral mapping of the cluster
Brunetti, G.; Gastaldello, F.; Kale, R. +6 more
Context. Abell 754 is a rich galaxy cluster at z = 0.0543 and is considered the prototype of a major cluster merger. As many dynamically unrelaxed systems, it hosts diffuse radio emission on megaparsec-scales. Extended synchrotron sources in the intra-cluster medium (ICM) are commonly interpreted as evidence that a fraction of the gravitational en…
The debris disc of HD 131488: bringing together thermal emission and scattered light
Henning, Thomas; Hughes, A. Meredith; Kirchschlager, Florian +9 more
We show the first SPHERE/IRDIS and IFS data of the CO-rich debris disc around HD 131488. We use N-body simulations to model both the scattered light images and the spectral energy distribution of the disc in a self-consistent way. We apply the Henyey-Greenstein approximation, Mie theory, and the Discrete Dipole Approximation to model the emission …
The extremely young planetary nebula M 3-27: an analysis of its evolution, physical conditions, and abundances
Peña, Miriam; Ruiz-Escobedo, Francisco; Beltrán-Sánchez, Ana Valeria
Spectrophotometric data of the young planetary nebula M 3-27, from 2004 to 2021, are presented and discussed. We corroborate that the H I Balmer lines present features indicating they are emitted by the central star, therefore He I lines were used to correct line fluxes by effects of reddening. Important variability on the nebular emission lines b…
Infrared surface brightness technique applied to RR Lyrae stars from the solar neighborhood
Gieren, Wolfgang; Pietrzyński, Grzegorz; Haas, Martin +9 more
Context. The Baade-Wesselink (BW) method, also known as the pulsation parallax method, allows us to estimate distances to individual pulsating stars. Accurate geometric parallaxes obtained by the Gaia mission serve us in the calibration of the method and in the determination of its precision. This method also provides a way of determining mean rad…
First comparative exoplanetology within a transiting multi-planet system: Comparing the atmospheres of V1298 Tau b and c
Fortney, Jonathan J.; Désert, Jean-Michel; Line, Michael R. +13 more
The V1298 Tau system is a multi-planet system that provides the opportunity to perform comparative exoplanetology between planets orbiting the same star. Because of its young age (20–30 Myr), this system also provides the opportunity to compare the planet's early evolutionary properties, right after their formation. We present the first atmospheri…
On the Determining Physical Factor of Jet-related Coronal Mass Ejections' Morphology in the High Corona
Shen, Yuandeng; Duan, Yadan; Tang, Zehao +2 more
A solar jet can often cause coronal mass ejections (CMEs) with different morphologies in the high corona, for example, jet-like CMEs, bubble-like CMEs, and so-called twin CMEs that include a pair of simultaneous jet-like and bubble-like CMEs. However, what determines the morphology of a jet-related CME is still an open question. Using high spatiot…