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Dissecting the Extended X-Ray Emission in the Merging Pair NGC 6240: Photoionization and Winds
Elvis, M.; Fabbiano, G.; Nardini, E. +3 more
We present a detailed spectral and imaging analysis of the central 15″ radius (~7.5 kpc) region of the merger galaxy NGC 6240 that makes use of all the available Chandra-ACIS data (0.3-3 keV effective exposure of ~190 ks). This region shows extended X-ray structures with lower-energy counterparts imaged in CO, [O III], and Hα line emission. We fin…
Orbital parameters and activity of ZZ Tau - a low-mass young binary with circumbinary disc
Safonov, B.; Belinski, A.; Emelyanov, N. +5 more
We present the results of our new observations of the young binary ZZ Tau with a circumbinary disc. The system was found to consist of two coeval (age < 2 Myr) classical T Tauri stars with the total mass 0.86 ± 0.09 M⊙, orbital period 46.8 ± 0.8 yr, semimajor axis 88.2 ± 2.1 mas, eccentricity 0.58 ± 0.02, and the orbital inclination …
The recurrent nova U Scorpii from the 2010.1 to 2022.4 eruptions; the missed eruption of 2016.78 ± 0.10 and the critical complex period changes
Schaefer, Bradley E.
U Sco is a recurrent nova with 11 observed eruptions, most recently in 2010.1 and 2022.4. I report on my program (running since 1989) of measuring eclipse times and brightnesses of U Sco in quiescence, from 2010 to 2022. The orbital period suddenly increased by +22.4 ± 1.0 parts-per-million across the 2010.1 eruption. This period change is greater…
Distributions of gas and small and large grains in the LkHα 330 disk trace a young planetary system
Zhu, Z.; Ginski, C.; Rosotti, G. +13 more
Planets that are forming around young stars are expected to leave clear imprints in the distribution of the gas and dust of their parental protoplanetary disks. In this paper, we present new scattered light and millimeter observations of the protoplanetary disk around LkHα 330, using SPHERE/VLT and ALMA, respectively. The scattered-light SPHERE ob…
A CHEOPS-enhanced view of the HD 3167 system
Alonso, R.; Deleuil, M.; Erikson, A. +92 more
Much remains to be understood about the nature of exoplanets smaller than Neptune, most of which have been discovered in compact multi-planet systems. With its inner ultra-short period planet b aligned with the star and two larger outer planets d-c on polar orbits, the multi-planet system HD 3167 features a peculiar architecture and offers the pos…
1RXH J082623.6-505741: A New Long-period Cataclysmic Variable with an Evolved Donor and a Low Mass-transfer Rate
Strader, Jay; Bahramian, Arash; Chomiuk, Laura +13 more
We report the discovery of 1RXH J082623.6-505741, a 10.4 hr orbital period compact binary. Modeling extensive optical photometry and spectroscopy reveals a ~0.4 M ⊙ K-type secondary transferring mass through a low-state accretion disk to a nonmagnetic ~0.8 M ⊙ white dwarf. The secondary is overluminous for its mass and domina…
The Emptiness Inside: Finding Gaps, Valleys, and Lacunae with Geometric Data Analysis
Hogg, David W.; Peek, Joshua E. G.; Hunt, Jason A. S. +2 more
Discoveries of gaps in data have been important in astrophysics. For example, there are kinematic gaps opened by resonances in dynamical systems, or exoplanets of a certain radius that are empirically rare. A gap in a data set is a kind of anomaly, but in an unusual sense: instead of being a single outlier data point, situated far from other data …
Quantifying kinematic substructure in star-forming regions with statistical tests of spatial autocorrelation
Parker, Richard J.; Wright, Nicholas J.; Arnold, Becky
We investigate whether spatial-kinematic substructure in young star-forming regions can be quantified using Moran's I statistic. Its presence in young star clusters would provide an indication that the system formed from initially substructured conditions, as expected by the hierarchical model of star cluster formation, even if the cluster were sp…
Solar and interplanetary events that drove two CIR-related geomagnetic storms of 1 June 2013 and 7 October 2015, and their ionospheric responses at the American and African equatorial ionization Anomaly regions
Akala, A. O.; Amaechi, P. O.; Simi, K. G. +3 more
This study investigates the sequence of solar and interplanetary events that drove the 1 June 2013 and October 2015 geomagnetic storms and how the American (68°-78oE) and African (32°-42oE) Equatorial Ionization Anomaly (EIA) regions responded to them. We constructed the EIA structures by using Total Electron Content (TEC) an…
The Host Galaxy of the Recoiling Black Hole Candidate in 3C 186: An Old Major Merger Remnant at the Center of a z = 1 Cluster
Bianchi, S.; Macchetto, F. D.; Capetti, A. +10 more
3C 186, a radio-loud quasar at z = 1.0685, was previously reported to have both velocity and spatial offsets from its host galaxy, and has been considered as a promising candidate for a gravitational wave recoiling black hole triggered by a black hole merger. Another possible scenario is that 3C 186 is in an ongoing galaxy merger, exhibiting a tem…