Search Publications
A Modeling Investigation for Solar Flare X-Ray Stereoscopy with Solar Orbiter/STIX and Earth-orbiting Missions
Krucker, Säm; Veronig, Astrid; Su, Yang +9 more
The Spectrometer/Telescope for Imaging X-rays (STIX) on board Solar Orbiter (SolO) provides a unique opportunity to systematically perform stereoscopic X-ray observations of solar flares with current and upcoming X-ray missions at Earth. These observations will produce the first reliable measurements of hard X-ray (HXR) directivity in decades, pro…
Cosmography from accurate mass modeling of the lens group SDSS J0100+1818: Five sources at three different redshifts
Zanella, A.; Grillo, C.; Christensen, L. +6 more
Systems where multiple sources at different redshifts are strongly lensed by the same deflector allow one to directly investigate the evolution of the angular diameter distances as a function of redshift, and thus to learn about the geometry of the Universe. We present measurements of the values of the total matter density, Ωm, and of t…
A dragon's flame of many colours: multiwavelength observations of flares from the active M binary CR Draconis
Loyd, R. O. Parke; Jackman, James A. G.; Walker, Gary +9 more
We present the results of a multiwavelength Professional-Amateur campaign to study the behaviour of flares from the active M1.5V star binary CR Draconis. CR Dra was observed with Transiting Exoplanet Survey Satellite (TESS) 20-s photometry, Swift near-ultraviolet (NUV) grism spectroscopy and with ground-based optical photometry and spectroscopy fr…
Imaging of I Zw 18 by JWST: II. Spatially resolved star formation history
Henning, Thomas; Hirschauer, Alec S.; Boyer, Martha L. +14 more
Context. The blue compact dwarf (BCD) galaxy I Zw 18 is one of the most metal-poor (Z ∼ 3% Z⊙) star-forming galaxies known in the local Universe. Since its discovery, the evolutionary status of this system has been at the center of numerous debates within the astronomical community. Aims. We aim to probe and resolve the stellar populati…
Possibly seismically triggered avalanches after the S1222a Marsquake and S1000a impact event
Rodriguez, S.; Lognonné, P.; Perrin, C. +9 more
Ground motion from seismic events detected by the SEIS/InSight seismometer on Mars could potentially trigger dust avalanches. Our research strongly suggests that the seismic event S1000a may have triggered a significant number of dust avalanches. In contrast, following the seismic event S1222a, there was only a modest increase in avalanche occurre…
Discovery of the magnetic cataclysmic variable XMM J152737.4-205305.9 with a deep eclipse-like feature
Brink, Jaco; Buckley, David A. H.; Schwope, Axel +1 more
We report the identification and subsequent examination of a polar-type cataclysmic variable named XMM J152737.4−205305.9 newly discovered with the X-ray Multi-Mirror Mission (XMM-Newton). This discovery was made by matching the XMM-Newton data archive with the cataclysmic variable candidate catalog provided by Gaia Data Release 3 (DR3). The use o…
JWST's PEARLS: Improved Flux Calibration for NIRCam
Grogin, Norman A.; Hathi, Nimish P.; Koekemoer, Anton M. +23 more
The Prime Extragalactic Areas for Reionization and Lensing Science, a James Webb Space Telescope (JWST) GTO program, obtained a set of unique NIRCam observations that have enabled us to significantly improve the default photometric calibration across both NIRCam modules. The observations consisted of three epochs of 4-band (F150W, F200W, F356W, an…
A Classification Catalog of Periodic Variable Stars for LAMOST DR9 Based on Machine Learning
Mei, Ying; Wang, Feng; Deng, Hui +4 more
Identifying and classifying variable stars is essential to time-domain astronomy. The Large Area Multi-Object Fiber Optic Spectroscopic Telescope (LAMOST) acquired a large amount of spectral data. However, there is no corresponding variable source-related information in the data, constraining LAMOST data utilization for scientific research. In thi…
First spectroscopic investigation of anomalous Cepheid variables
Ripepi, V.; Molinaro, R.; Marconi, M. +12 more
Context. Anomalous Cepheids (ACEPs) are intermediate-mass metal-poor pulsators that are mostly discovered in dwarf galaxies of the Local Group. However, recent Galactic surveys, including the Gaia Data Release 3, found a few hundred ACEPs in the Milky Way. Their origin is only poorly understood.
Aims: We aim to investigate the origin and evol…
The Complex Star Formation History of the Halo of NGC 5128 (Cen A)
Javadi, Atefeh; Saremi, Elham; van Loon, Jacco Th. +6 more
NGC 5128 (Cen A) is the nearest giant elliptical galaxy and one of the brightest extragalactic radio sources in the sky, boasting a prominent dust lane and jets emanating from its nuclear supermassive black hole. In this paper, we construct the star formation history (SFH) of two small fields in the halo of NGC 5128: a northeastern field (Field 1)…