Search Publications
Is the RSGC4 (Alicante 8) Cluster a Real Star Cluster? Peculiar Radial Velocities of Red Supergiant Stars
Lee, Jae-Joon; Myeong, GyuChul; Oh, Heeyoung +1 more
Young massive star clusters, like the six red supergiant clusters in the Scutum complex, provide valuable insights into star formation and galaxy structures. We investigated the high-resolution near-infrared spectra of 60 RSG candidates in these clusters using the Immersion Grating Infrared Spectrograph. Among the candidates in RSGC4, we found sig…
JWST Observations Constrain the Time Evolution of Fine Structure Constants and Dark Energy-electromagnetic Coupling
Feng, Lei; Lei, Lei; Fan, Yi-Zhong +1 more
It was hypothesized in the literature that some physical parameters may be time-evolving and the astrophysical data can serve as a probe. Recently, the James Webb Space Telescope (JWST) released its early observations. In this work, we select the JWST spectroscopic observations of the high redshift (z > 7.1) galaxies with strong [O III] (λ = 49…
J-PLUS: Bayesian object classification with a strum of BANNJOS
Hernández-Monteagudo, C.; Hernán-Caballero, A.; Vázquez Ramió, H. +22 more
Context. With its 12 optical filters, the Javalambre-Photometric Local Universe Survey (J-PLUS) provides an unprecedented multicolor view of the local Universe. The third data release (DR3) covers 3192 deg2 and contains 47.4 million objects. However, the classification algorithms currently implemented in the J-PLUS pipeline are determin…
Nested active regions anchor the heliospheric current sheet and stall the reversal of the coronal magnetic field
Finley, A. J.
Context. During the solar cycle, the Sun's magnetic field polarity reverses due to the emergence, cancellation, and advection of magnetic flux towards the rotational poles. Flux emergence events occasionally cluster together, although it is unclear if this is due to the underlying solar dynamo or simply by chance. Aims. Regardless of the cause, we…
Probing the inner Galactic halo with blue horizontal-branch stars. Gaia DR3-based catalogue with atmospheric and stellar parameters
Geier, S.; Heber, U.; Pelisoli, I. +4 more
Context. Stars that are found on the blue horizontal-branch (BHB) evolved from low-mass stars that have completed their core hydrogen-burning main sequence (MS) stage and undergone the helium flash at the end of their red giant phase. Hence, they are very old objects that can be used as markers in studying galactic structure and formation history.…
TOI-757 b: an eccentric transiting mini-Neptune on a 17.5-d orbit
Alonso, R.; Bouchy, F.; Deleuil, M. +129 more
We report the spectroscopic confirmation and fundamental properties of TOI$-$757 b, a mini$-$Neptune on a 17.5$-$d orbit transiting a bright star ($V\, =\, 9.7$ mag) discovered by the TESS mission. We acquired high$-$precision radial velocity measurements with the HARPS, ESPRESSO, and PFS spectrographs to confirm the planet detection and determine…
A network of cooler white dwarfs as infrared standards for flux calibration
Sahu, Snehalata; Bohlin, Ralph C.; Gentile Fusillo, Nicola Pietro +6 more
The accurate flux calibration of observational data is vital for astrophysics and cosmology because absolute flux uncertainties of stellar standards propagate into scientific results. With the ever higher precision achieved by telescopic missions (e.g. JWST) in the infrared (IR), suitable calibrators are required for this regime. The basis of the …
Modeling Transition Region Hot Loops on the Sun: The Necessity of Rapid, Complex Spatiotemporal Heating and Nonequilibrium Ionization
Bahauddin, Shah Mohammad; Bradshaw, Stephen J.
The study examines the heating profile of hot solar transition region loops, particularly focusing on transient brightenings observed in IRIS 1400 Å slit-jaw images. The findings challenge the adequacy of simplistic, singular heating mechanisms, revealing that the heating is temporally impulsive and requires a spatially complex profile with multip…
Oxygen Abundance Throughout the Dwarf Starburst Galaxy IC 10
Sandstrom, Karin; Armus, Lee; Runco, Jordan N. +5 more
Measurements of oxygen abundance throughout galaxies provide insight to the formation histories and ongoing processes. Here we present a study of the gas-phase oxygen abundance in the H II regions and diffuse gas of the nearby starburst dwarf galaxy, IC 10. Using the Keck Cosmic Web Imager at W. M. Keck Observatory, we map the central region of IC…
Diffuse interstellar bands as dust indicators: The contribution from 3D maps
Lallement, R.; Cox, N. L. J.; Vergely, J. L.
Context. Three-dimensional (3D) distributions of the 862 nm diffuse interstellar band (DIB) carrier have been computed based on Gaia parallaxes and DIB catalogues, in parallel with 3D maps of dust extinction density. Three-dimensional maps provide local diagnostics and information on the distribution of structures in addition to line-of-sight (LOS…