Search Publications
Quasar and galaxy classification using Gaia EDR3 and CatWise2020
Bailer-Jones, Coryn A. L.; Hughes, Arvind C. N.; Jamal, Sara
In this work, we assess the combined use of Gaia photometry and astrometry with infrared data from CatWISE in improving the identification of extragalactic sources compared to the classification obtained using Gaia data. Here we perform a comprehensive study in which we assess different input feature configurations and prior functions to identify …
The peculiar abundances of HE 1005-1439. A carbon-enhanced extremely metal-poor star contaminated with products of both s- and i-process nucleosynthesis
Goswami, Aruna; Goswami, Partha Pratim
Context. Understanding the surface chemical composition of carbon-enhanced metal-poor (CEMP) stars with enhanced abundances of heavy elements remains problematic.
Aims: One of the primary objectives is to investigate the origin of the peculiar abundance pattern observed in the carbon-enhanced extremely metal-poor object HE 1005-1439, which is…
Plausibility of ultraviolet burst generation in the low solar chromosphere
Cheng, Guanchong; Ni, Lei; Lin, Jun
Context. Ultraviolet (UV) bursts and Ellerman bombs (EBs) are small-scale magnetic reconnection events taking place in the highly stratified, low solar atmosphere. The plasma density, reconnection mechanisms, radiative cooling and transfer processes clearly differ from one layer of the atmosphere to the next. In particular, EBs are believed to for…
Are the host galaxies of long gamma-ray bursts more compact than star-forming galaxies of the field?
Le Floc'h, E.; Vergani, S. D.; Schneider, B. +2 more
Context. Long gamma-ray bursts (GRBs) offer a promising tool for tracing the cosmic history of star formation, especially at high redshift, where conventional methods are known to suffer from intrinsic biases. Previous studies of GRB host galaxies at low redshift showed that high surface density of stellar mass and high surface density of star for…
A method for identifying metal-poor stars with Gaia BP/RP spectra
Lind, K.; Xylakis-Dornbusch, T.; Christlieb, N. +1 more
Context. The study of the oldest and most metal-poor stars in our Galaxy promotes our understanding of the Galactic chemical evolution and the beginning of Galaxy and star formation. However, they are notoriously difficult to find, with only seven stars at [Fe/H] < −5.0 having been detected to date. Thus, the spectrophotometric data of 219 mill…
White-light QFP wave train and the associated failed breakout eruption
Yao, Surui; Shen, Yuandeng; Zhou, Chengrui +5 more
Quasi-periodic fast-propagating (QFP) magnetosonic wave trains are commonly observed in the low corona at extreme ultraviolet wavelength bands. Here, we report the first white-light imaging observation of a QFP wave train propagating outwardly in the outer corona ranging from 2 to 4 R⊙. The wave train was recorded by the Large Angle Spe…
Pushing sub-arcsecond resolution imaging down to 30 MHz with the trans-European International LOFAR Telescope
Bondi, M.; Brunetti, G.; Callingham, J. R. +12 more
Relatively little information is available about the Universe at ultra-low radio frequencies (ULF; i.e., below 50 MHz), although the ULF spectral window contains a wealth of unique diagnostics for studying galactic and extragalactic phenomena. Subarcsecond resolution imaging at these frequencies is extremely difficult, due to the long baselines (&…
Gaia-ESO Survey: Detailed elemental abundances in red giants of the peculiar globular cluster NGC 1851
Gilmore, G.; Guiglion, G.; Lardo, C. +24 more
Context. NGC 1851 is one of several globular clusters for which multiple stellar populations of the subgiant branch have been clearly identified and a difference in metallicity detected. A crucial piece of information on the formation history of this cluster can be provided by the sum of A(C+N+O) abundances. However, these values have lacked a gen…
Sublimation origin of active asteroid P/2018 P3
Mutchler, Max; Jewitt, David; Agarwal, Jessica +4 more
Context. Active asteroids show (typically transient) cometary activity, driven by a range of processes. A sub-set, sometimes called main-belt comets, may be driven by sublimation and so could be useful for tracing the present-day distribution of asteroid ice. Object P/2018 P3 has a Tisserand parameter 3.096 but a high eccentricity 0.415, placing i…
High-resolution near-infrared spectroscopy of globular cluster and field stars toward the Galactic bulge
Lee, Young-Wook; Koch-Hansen, Andreas J.; Hong, Seungsoo +2 more
Globular clusters (GCs) play an important role in the formation and evolution of the Milky Way. New candidates are continuously found, particularly in the high-extinction low-latitude regions of the bulge, although their existence and properties have yet to be verified. In order to investigate the new GC candidates, we performed high-resolution ne…