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Discovery of a multiphase O VI and O VII absorber in the circumgalactic/intergalactic transition region
Finoguenov, Alexis; Schaye, Joop; Muzahid, Sowgat +4 more
Aims: The observational constraints on the baryon content of the warm-hot intergalactic medium (WHIM) rely almost entirely on far ultraviolet (FUV) measurements. However, cosmological, hydrodynamical simulations predict strong correlations between the spatial distributions of FUV and X-ray absorbing WHIM. We investigate this prediction by ana…
Exploring the planetary-mass population in the Upper Scorpius association
Hambly, N. C.; Lodieu, N.; Cross, N. J. G.
We aim at identifying very low-mass isolated planetary-mass member candidates in the nearest OB association to the Sun, Upper Scorpius (USco) (145 pc; 5-10 Myr), to constrain the form and shape of the luminosity function and mass spectrum in this regime. We conducted a deep multiband (Y = 21.2, J = 20.5, Z = 22.0 mag) photometric survey of 6 deg
Searching for energy-resolved quasi-periodic oscillations in AGN
Middleton, Matthew J.; Ashton, Dominic I.
X-ray quasi-periodic oscillations (QPOs) in active galactic nucleus (AGN) allow us to probe and understand the nature of accretion in highly curved space-time, yet the most robust form of detection (i.e. repeat detections over multiple observations) has been limited to a single source to-date, with only tentative claims of single observation detec…
Parsec-scale alignments of radio-optical offsets with jets in AGNs from multifrequency geodetic VLBI, Gaia EDR3, and the MOJAVE program
Liu, N.; Zhu, Z.; Barache, C. +5 more
Aims: We aim to study the relative positions of quasar emission centers at different wavelengths in order to help link the various realizations of the International Celestial Reference System (ICRS), and to unveil systematic uncertainties and individual source behavior at different wavelengths.
Methods: We based our study on four catalog…
Herschel observations of extraordinary sources: full Herschel/HIFI molecular line survey of Sagittarius B2(M)
Comito, C.; Schilke, P.; Lis, D. C. +5 more
Context. We present a full analysis of a broadband spectral line survey of Sagittarius B2 (Main), one of the most chemically rich regions in the Galaxy located within the giant molecular cloud complex Sgr B2 in the central molecular zone.
Aims: Our goal is to derive the molecular abundances and temperatures of the high-mass star-forming regio…
A [C II] 158 µm emitter associated with an O I absorber at the end of the reionization epoch
Hennawi, Joseph F.; Fan, Xiaohui; Prochaska, J. Xavier +11 more
The physical and chemical properties of the circumgalactic medium at z ≳ 6 have been studied successfully through the absorption in the spectra of background quasi-stellar objects1-3. One of the most crucial questions is to investigate the nature and location of the source galaxies that give rise to these early metal absorbers4-6
Simultaneous ALMA-Hinode-IRIS Observations on Footpoint Signatures of a Soft X-Ray Loop-like Microflare
Shimojo, Masumi; Shimizu, Toshifumi; Abe, Masashi
Microflares have been considered to be among the major energy input sources to form active solar corona. To investigate the response of the low atmosphere to events, we conducted an Atacama Large Millimeter/submillimeter Array (ALMA) observation at 3 mm, coordinated with Interface Region Imaging Spectrograph (IRIS) and Hinode observations, on 2017…
Sagittarius B1: A Patchwork of H II Regions and Photodissociation Regions
Kaufman, Michael J.; Colgan, Sean W. J.; Simpson, Janet P. +2 more
Sgr B1 is a luminous H II region in the Galactic center immediately next to the massive star-forming giant molecular cloud Sgr B2 and apparently connected to it from their similar radial velocities. In 2018 we showed from SOFIA FIFI-LS observations of the [O III] 52 and 88 µm lines that there is no central exciting star cluster and that the …
Numerical MHD Simulations of the 3D Morphology and Kinematics of the 2017 September 10 CME-driven Shock from the Sun to Earth
Shen, Fang; Feng, Xueshang; Zhang, Man +8 more
A global, three-dimensional (3D) numerical simulation model has been employed to study the 3D morphology and kinematics of the large shock driven by the 2017 September 10 coronal mass ejection (CME). Based on actual solar observations, which include the photospheric magnetic field and the CME's speed and source location, the simulation result is d…
X-Ray AGB Stars in the 4XMM-DR9 Catalog: Further Evidence for Companions
Guerrero, M. A.; Ortiz, R.
Single AGB stars are not normally expected to be X-ray emitters due to the lack of a corona capable of powering a hot plasma. Therefore, the detection of X-ray emission in AGB stars by the ROSAT, Chandra, and XMM-Newton observatories has been interpreted as evidence for binarity. The number of X-ray-emitting AGB stars is, however, very small, and …