Search Publications
Disentangling the X-ray variability in the Lyman continuum emitter Haro 11
Östlin, G.; Herenz, E. C.; Silich, S. +1 more
Context. Lyman break analogs in the local Universe serve as counterparts to Lyman break galaxies (LBGs) at high redshifts, which are widely regarded as major contributors to cosmic reionization in the early stages of the Universe. Aims. We studied XMM-Newton and Chandra observations of the nearby LBG analog Haro 11, which contains two X-ray-bright…
The MUSE eXtremely Deep Field: Detections of circumgalactic Si II* emission at z ≳ 2
Ouchi, Masami; Blaizot, Jérémy; Garel, Thibault +17 more
Context. The circumgalactic medium (CGM) serves as a baryon reservoir that connects galaxies to the intergalactic medium and fuels star formation. The spatial distribution of the metal-enriched cool CGM has not yet been directly revealed at cosmic noon (z ≃ 2–4), as bright emission lines at these redshifts are not covered by optical integral field…
Efficiency of solar microflares in accelerating electrons when rooted in a sunspot
Krucker, Säm; Veronig, Astrid M.; Dickson, Ewan C. M. +3 more
Context. The spectral shape of the X-ray emission in solar flares varies with the event size, with small flares generally exhibiting softer spectra than large events, indicative of a relatively lower number of accelerated electrons at higher energies.
Aims: We investigate two microflares of GOES classes A9 and C1 (after background subtraction…
HR-GO: I. Comprehensive NLTE abundance analysis of the Cetus stream
Sestito, F.; Sitnova, T. M.; Mashonkina, L. I. +8 more
Context. Dwarf galaxy streams encode vast amounts of information essential to understanding early galaxy formation and nucleosynthesis channels. Due to the variation in the timescales of star formation history in their progenitors, stellar streams serve as 'snapshots' that record different stages of galactic chemical evolution. Aims. This study fo…
Exsolution process in white dwarf stars
Rebassa-Mansergas, Alberto; Torres, Santiago; Camisassa, Maria +1 more
Context. White dwarf stars are considered to be suitable cosmic laboratories for studying the physics of dense plasma. Furthermore, the use of white dwarf stars as cosmic clocks to date stellar populations and main sequence companions demands an appropriate understanding of the physics of white dwarfs in order to provide precise ages for these sta…
Periodic variable A-F spectral type stars in the southern TESS continuous viewing zone. I. Identification and classification
Skarka, M.; Henzl, Z.
Aims: Our primary objective is to accurately identify and classify the variability of A-F stars in the southern continuous viewing zone of the TESS satellite. The brightness limit was set to 10 mag to ensure the utmost reliability of our results and allow for spectroscopic follow-up observations using small telescopes. We aim to compare our f…
Transition region response to quiet-Sun Ellerman bombs
Joshi, Jayant; Rouppe van der Voort, Luc; Bhatnagar, Aditi
Context. Quiet-Sun Ellerman bombs (QSEBs) are key indicators of small-scale photospheric magnetic reconnection events. Recent high-resolution observations have shown that they are ubiquitous and that large numbers of QSEBs can be found in the quiet Sun. Aims. We aim to understand the impact of QSEBs on the upper solar atmosphere by analyzing their…
Inferring the distribution of the ionising photon escape fraction
Mason, Charlotte A.; Cullen, Fergus; McLure, Ross J. +2 more
Context. The escape fraction of ionising photons from galaxies (fesc) is a key parameter for understanding how intergalactic hydrogen became reionised, but it remains mostly unconstrained. Measurements have been limited to the average value in galaxy ensembles and to handfuls of individual detections. Aims. To help understand which mech…
JWST imaging of the closest globular clusters: IV. Chemistry, luminosity, and mass functions of the lowest-mass members in the NIRISS parallel fields
Salaris, M.; Apai, D.; Anderson, J. +9 more
We present observations of the two closest globular clusters, NGC 6121 and NGC 6397, taken with the NIRISS detector of JWST. The combination of our new JWST data with archival Hubble Space Telescope (HST) images allows us to compute proper motions, disentangle cluster members from field objects, and probe the main sequence (MS) of the clusters dow…
The Galactic bulge exploration. II. Line-of-sight velocity templates for single-mode RR Lyrae stars
Smolec, R.; Prudil, Z.; Kunder, A. +2 more
We present a new set of tools to derive systemic velocities for single-mode RR Lyrae stars from visual and near-infrared spectra. We derived scaling relations and line-of-sight velocity templates using both APOGEE and Gaia spectroscopic products combined with photometric G-band amplitudes. We provide a means to estimate systemic velocities for the…