Search Publications
Nuclear spallation in active galaxies
Reynolds, C. S.; Gallo, L. C.; García, J. A. +3 more
A number of works point to the presence of narrow emission features at unusual energies in the X-ray spectra of active galactic nuclei or to potentially low iron abundances as possible evidence for the spallation of iron. With the imminence of high-resolution calorimeter spectroscopy, the potential to test spallation models in astrophysical source…
Unveiling the 100 pc scale nuclear radio structure of NGC 6217 with e-MERLIN and the VLA
Muxlow, T. W. B.; Argo, M. K.; Knapen, J. H. +13 more
We present high-sensitivity 1.51 GHz e-MERLIN (e-Multi-Element Radio-Linked Interferometer Network) radio images of the nearby galaxy NGC 6217. We resolve the compact radio source at the centre of NGC 6217 for the first time, finding a twin-lobed structure with a total linear size of ∼4 arcsec (∼400 pc). The radio source does not have a compact ce…
The Laboratory Millimeter and Submillimeter Rotational Spectrum of Lactaldehyde and an Astronomical Search in Sgr B2(N), Orion-KL, and NGC 6334I
McGuire, Brett A.; Brogan, Crystal L.; Guillemin, Jean-Claude +6 more
We present a laboratory rotational study of, and astronomical search for, lactaldehyde (CH3CH(OH)CH(O)), one of the simplest chiral molecules that could reasonably be seen in the interstellar medium (ISM), in the millimeter and submillimeter wave regions from 80 to 460 GHz. More than 5000 transitions were assigned to the most stable con…
The optical and NIR spectrum of the Crab pulsar with X-shooter
Sollerman, J.; Lundqvist, P.; Vreeswijk, P. M. +2 more
Context. Pulsars are well studied all over the electromagnetic spectrum, and the Crab pulsar may be the most studied object in the sky. Nevertheless, a high-quality optical to near-infrared (NIR) spectrum of the Crab or any other pulsar has not been published to date.
Aims: Obtaining a properly flux-calibrated spectrum enables us to measure t…
X-ray studies of the gamma-ray pulsar J1826-1256 and its pulsar wind nebula with Chandra and XMM-Newton
Karpova, Anna V.; Zyuzin, Dmitry A.; Shibanov, Yuriy A.
We have analysed archival XMM-Newton and Chandra observations of the γ-ray radio-quiet pulsar J1826-1256 and its pulsar wind nebula. The pulsar spectrum can be described by a power-law model with photon index Γ ≈ 1. We find that the nebular spectrum softens with increasing distance from the pulsar, implying synchrotron cooling. The empirical inter…
Constraints on HD 113337 fundamental parameters and planetary system. Combining long-base visible interferometry, disc imaging, and high-contrast imaging
Henning, T.; Meunier, N.; Lagrange, A. -M. +14 more
Context. HD 113337 is a main-sequence F6V field star more massive than the Sun. This star hosts one confirmed giant planet and possibly a second candidate, detected by radial velocities (RVs). The star also hosts a cold debris disc detected through the presence of an infrared excess, making it an interesting system to explore.
Aims: We aim to…
Synthetic Emissions of the Fe XXI 1354 Å Line from Flare Loops Experiencing Fundamental Fast Sausage Oscillations
Li, Bo; Huang, Zhenghua; Shi, Mijie +1 more
Inspired by recent IRIS observations, we forward model the response of the Fe XXI 1354 Å line to fundamental, standing, linear fast sausage modes (FSMs) in flare loops. Starting with the fluid parameters for an FSM in a straight tube with equilibrium parameters largely compatible with the IRIS measurements, we synthesize the line profiles by incor…
The origin of very massive stars around NGC 3603
Vink, J. S.; de Wit, W. J.; Méndez, R. A. +2 more
The formation mechanism of the most massive stars in the Universe remains an unsolved problem. Are they able to form in relative isolation in a manner similar to the formation of solar-type stars, or do they necessarily require a clustered environment? In order to shed light on this important question, we study the origin of two very massive stars…
Flares of accretion activity of the 20 Myr old UXOR RZ Psc
Grinin, V. P.; Potravnov, I. S.; Serebriakova, N. A.
We discuss a revision of accretion activity and kinematics of the enigmatic isolated UX Ori type star RZ Psc. Previously, RZ Psc was known to possess only spectroscopic signatures of outflow in the low-excitation lines of alkali metals. The archival high-resolution spectra reveal a short-lived episode of magnetospheric accretion in the system obse…
Discovery of δ Scuti Pulsations in the Young Hybrid Debris Disk Star HD 156623
Ireland, Michael J.; Bailey, John I., III; Kenworthy, Matthew A. +11 more
The bRing robotic observatory network was built to search for circumplanetary material within the transiting Hill sphere of the exoplanet β Pic b across its bright host star β Pic. During the bRing survey of β Pic, it simultaneously monitored the brightnesses of thousands of bright stars in the southern sky (V ≃ 4-8, δ ≲ -30°). In this work, we an…