Search Publications
The nearby extreme accretion and feedback system PDS 456: finding a complex radio-emitting nucleus
Nardini, Emanuele; Paragi, Zsolt; Varenius, Eskil +5 more
When a black hole accretes close to the Eddington limit, the astrophysical jet is often accompanied by radiatively driven, wide-aperture and mildly relativistic winds. Powerful winds can produce significant non-thermal radio emission via shocks. Among the nearby critical accretion quasars, PDS 456 has a very massive black hole (about 1 billion sol…
Atomic Transition Probabilities of Neutral Calcium
Sneden, C.; Sobeck, J.; Roederer, I. U. +3 more
The goals of this study are (1) to test the best theoretical transition probabilities for Ca I (a relatively light alkaline earth spectrum) from a modern ab initio calculation using configuration interaction plus many-body perturbation theory against the best modern experimental transition probabilities and (2) to produce as accurate and comprehen…
The Post-impact Evolution of the X-Ray-emitting Gas in SNR 1987A as Viewed by XMM-Newton
Vink, Jacco; Zhou, Ping; Pühlhofer, Gerd +4 more
Since 1996 the blast wave driven by SN 1987A has been interacting with the dense circumstellar material, which provides us with a unique opportunity to study the early evolution of a newborn supernova remnant (SNR). Based on the XMM-Newton RGS and EPIC-pn X-ray observations from 2007 to 2019, we investigated the post-impact evolution of the X-ray-…
Mars moon ephemerides after 14 years of Mars Express data
Jaumann, R.; Oberst, J.; Rosenblatt, P. +7 more
The Mars Express (MEX) mission has been successfully operated around Mars since 2004. Among many results, MEX has provided some of the most accurate astrometric data of the two Mars moons, Phobos and Deimos. We present new ephemerides of the Mars moons benefitting from all previously published astrometric data to the most recent MEX SRC data. Obse…
The size and pervasiveness of Ly α-UV spatial offsets in star-forming galaxies at z ∼ 6
Ryan, R. E.; Alvarez, C.; Hoag, A. +21 more
We study the projected spatial offset between the ultraviolet continuum and Ly α emission for 65 lensed and unlensed galaxies in the Epoch of Reionization (5 ≤ z ≤ 7), the first such study at these redshifts, in order to understand the potential for these offsets to confuse estimates of the Ly α properties of galaxies observed in slit spectroscopy…
Classifying the Magnetosheath Behind the Quasi-Parallel and Quasi-Perpendicular Bow Shock by Local Measurements
Nilsson, H.; Karlsson, T.; Raptis, S. +1 more
We investigate and evaluate the possibility of using local magnetosheath measurements to classify the plasma according to upstream conditions. In order to do this, we use simultaneous measurements from the Cluster spacecraft from time intervals when one of them is located in the solar wind, and the other in the magnetosheath. In particular, we stu…
Tidal Effects on the Radial Velocities of V723 Mon: Additional Evidence for a Dark 3 M⊙ Companion
Hirano, Teruyuki; Masuda, Kento
Jayasinghe et al. identified a dark ≈3 M⊙ companion on a nearly edge-on ≈60 day orbit around the red giant star V723 Monoceros as a black hole candidate in the mass gap. This scenario was shown to explain most of the data presented by Jayasinghe et al., except for periodic radial velocity (RV) residuals from the circular Keplerian model…
Relation of Microstreams in the Polar Solar Wind to Switchbacks and Coronal X-Ray Jets
Neugebauer, Marcia; Sterling, Alphonse C.
Ulysses data obtained at high solar latitudes during periods of minimum solar activity in 1994 and 2007 are examined to determine the relation between velocity structures called microstreams and folds in the magnetic field called switchbacks. A high correlation is found. The possibility of velocity peaks in microstreams originating from coronal X-…
Quantitative inference of the H2 column densities from 3 mm molecular emission: case study towards Orion B
Peretto, Nicolas; Hughes, Annie; Kainulainen, Jouni +21 more
Context. Based on the finding that molecular hydrogen is unobservable in cold molecular clouds, the column density measurements of molecular gas currently rely either on dust emission observation in the far-infrared, which requires space telescopes, or on star counting, which is limited in angular resolution by the stellar density. The (sub)millim…
Optical photometry of two transitional millisecond pulsars in the radio pulsar state
Dhillon, V. S.; Marsh, T. R.; Clark, C. J. +7 more
We present ULTRACAM multiband optical photometry of two transitional millisecond pulsars (tMSPs), PSR J1023+0038 and PSR J1227-4853, taken while both were in their radio pulsar states. The light curves show significant asymmetry about the flux maxima in all observed bands, suggesting an asymmetric source of heating in the system. We model the ligh…