Search Publications
The Smallest Scale of Hierarchy Survey (SSH): III. Dwarf-dwarf satellite merging phenomena in the low-mass regime
de Jong, Roelof S.; Cannon, John M.; Cignoni, Michele +13 more
We present new deep, wide-field imaging data from the Large Binocular Telescope (LBT) in g and r bands from the Smallest Scale of Hierarchy Survey (SSH) that reveal previously undetected tidal features and stellar streams in the outskirts of six dwarf irregular galaxies (NGC 5238, UGC 6456, UGC 6541, UGC 7605, UGC 8638, and UGC 8760) with stellar …
Calibrating and Standardizing the Tip of the Red Giant Branch in the Small Magellanic Cloud Using Small-amplitude Red Giants
Anderson, Richard I.; Koblischke, Nolan W.
We investigate the absolute calibration of the tip of the red giant branch (TRGB) in the Small Magellanic Cloud (SMC) using small amplitude red giant stars (SARGs) classified by the Optical Gravitational Lensing Experiment (OGLE). We show that all stars near the SMC's TRGB are SARGs. Distinguishing older and younger RGs near the tip according to t…
4XMM J182531.5−144036: A new persistent Be/X-ray binary found within the XMM-Newton serendipitous survey
Farrell, S. A.; Gosling, A. J.; Clark, J. S. +2 more
We aim to investigate the nature of time-variable X-ray sources detected in the XMM-Newton serendipitous survey. The X-ray light curves of objects in the XMM-Newton serendipitous survey were searched for variability, and coincident serendipitous sources observed by Chandra were also investigated. Subsequent infrared spectroscopy of the counterpart…
Dust mass in protoplanetary disks with porous dust opacities
Fang, Min; Flock, Mario; Henning, Thomas +8 more
Atacama Large Millimeter/submillimeter Array surveys have suggested that protoplanetary disks are not massive enough to form the known exoplanet population, based on the assumption that the millimeter continuum emission is optically thin. In this work, we investigate how the mass determination is influenced when the porosity of dust grains is cons…
Black Hole Scaling Relations in the Dwarf-galaxy Regime with Gaia-Sausage/Enceladus and ωCentauri
Limberg, Guilherme
The discovery of fast moving stars in Milky Way's most massive globular cluster, ωCentauri (ωCen), has provided strong evidence for an intermediate-mass black hole (IMBH). However, ωCen is known to be the stripped nuclear star cluster (NSC) of an ancient, now-destroyed, dwarf galaxy. The best candidate to be the original host progenitor of ωCen is…
Multiwavelength Observations of Quasiperiodic Pulsations in the Impulsive Phase of an Eruptive Flare with the Hard X-Ray Imager On Board ASO-S and Other Instruments
Chen, Wei; Warmuth, Alexander; Su, Yang +7 more
We investigated the quasiperiodic pulsations (QPPs) of the X1.2 solar flare (SOL2023-01-06T00:57) based on multi-instrument observations, especially the Hard X-ray Imager (HXI) on board the Advanced Space-based Solar Observatory (ASO-S). The quasiperiod of ≈27 s was identified in hard X-rays (HXR) and microwaves using the Markov Chain Monte Carlo …
Resolved UV and Optical Color Gradients Reveal Environmental Influence on Galaxy Evolution at Redshift z ∼ 1.6
Cooper, M. C.; van Kampen, E.; Demarco, R. +13 more
The changes in colors across a galaxy are intimately connected to the galaxy's formation, growth, quenching history, and dust content. A particularly important epoch in the growth of galaxies is near z ∼ 2, often referred to as "cosmic noon," where galaxies on average reach the peak of their star formation. We study a population of 125 cluster gal…
Multi-wavelength observations of the luminous fast blue optical transient AT 2023fhn: Up to ∼200 days post-explosion
Groot, P. J.; Levan, A. J.; Chrimes, A. A. +4 more
Context. Luminous fast blue optical transients (LFBOTs) are a class of extragalactic transients notable for their rapid rise and fade times, blue colour, and accompanying luminous X-ray and radio emission. Only a handful have been studied in detail since the prototypical example AT 2018cow. Their origins are currently unknown, but ongoing observat…
Jet formation in post-AGB binaries: Confronting cold magnetohydrodynamic disc wind models with observations
Ferreira, J.; Verhamme, O.; Van Winckel, H. +4 more
Context. Jets are launched from many classes of astrophysical objects, including post-asymptotic giant branch (post-AGB) binaries with a circumbinary disc. Despite dozens of detections, the formation of these post-AGB binary jets and their connection to the inter-component interactions in their host systems remains poorly understood. Aims. Buildin…
Variability and stellar pulsation incidence in Am and Fm stars using TESS and Gaia data
Niemczura, E.; Smalley, B.; Antoci, V. +3 more
Aims. We aim to study chemically peculiar Am and Fm stars, distinguished by their unique abundance patterns, which are crucial for studying mixing processes in intermediate-mass stars. These stars provide a window into the atomic diffusion in their stellar envelopes, the evolution-dependent changes in mixing, and the resulting effects on pulsation…