Search Publications
uGMRT detection of cluster radio emission in low-mass Planck Sunyaev-Zel'dovich clusters
Raychaudhury, Somak; Paul, Surajit; Dabhade, Pratik +5 more
Low-mass (M500 < 5 × 1014 M⊙) galaxy clusters have been largely unexplored in radio observations, because of the inadequate sensitivity of existing telescopes. However, the upgraded Giant Metrewave Radio Telescope (uGMRT) and the Low Frequency ARray (LoFAR), with unprecedented sensitivity at low frequencies, hav…
Resolving the outer ring of HD 38206 using ALMA and constraining limits on planets in the system
Launhardt, Ralf; Booth, Mark; Krivov, Alexander V. +3 more
HD 38206 is an A0V star in the Columba association, hosting a debris disc first discovered by IRAS. Further observations by Spitzer and Herschel showed that the disc has two components, likely analogous to the asteroid and Kuiper belts of the Solar system. The young age of this star makes it a prime target for direct imaging planet searches. Possi…
The magnetic system SMSS J1606-1000 as a period bouncer
Vennes, Stéphane; Buckley, D. A. H.; Zejda, M. +7 more
We report the discovery of a rare close binary system, SMSS J160639.78-100010.7, comprising a magnetic white dwarf with a field of about 30 MG and a brown dwarf. We measured an orbital period of 92 min which is consistent with the photometric period. Minimum and maximum light occur at the orbital quadratures Φ = 0.25 and 0.75, respectively, and ca…
Towards realistic modelling of the astrometric capabilities of MCAO systems: detecting an intermediate-mass black hole with MAVIS
Monty, Stephanie; Mendel, J. Trevor; Fiorentino, Giuliana +9 more
Accurate astrometry is a key deliverable for the next generation of multiconjugate adaptive optics (MCAO) systems. The MCAO-Assisted Visible Imager and Spectrograph (MAVIS) is being designed for the Very Large Telescope Adaptive Optics Facility and must achieve 150 $\mu$as astrometric precision (50 $\mu$as goal). To test this before going on-sky, …
The multiphase environment in the centre of Centaurus A
De Marco, B.; Migliori, G.; Różańska, A. +6 more
We study the multiphase medium in the vicinity of the active galactic nucleus Centaurus A (Cen A). Combined high-resolution observations with the Atacama Large Millimeter/submillimeter Array (ALMA) and Chandra X-ray Observatory indicate that the hot X-ray emitting plasma coexists with the warm and cold media in Cen A. This complex environment is a…
Catalogue of in situ observed solar energetic electrons from ACE/EPAM instrument
Miteva, Rositsa; Samwel, Susan W.
We present the first comprehensive catalogue of in situ observed solar energetic electron (SEE) events that covers solar cycles [SCs] 23 and 24 in the energy range 103-315 keV. The electron enhancements are detected by the Electron, Proton, and Alpha Monitor - Deflected Electrons instrument [EPAM-DE] aboard the ACE spacecraft. Onset time, peak tim…
From downtown to the outskirts: a radio survey of the Orion Nebula Cluster
Bally, J.; Forbrich, J.; Dzib, S. A. +1 more
We present a newly enlarged census of the compact radio population towards the Orion Nebula Cluster (ONC) using high-sensitivity continuum maps (3-10 $\mu$Jy beam-1) from a total of ~30-h centimetre-wavelength observations over an area of ~20 × 20 arcmin2 obtained in the C-band (4-8 GHz) with the Karl G. Jansky Very Large Arr…
Towards a larger sample of radio jets from quiescent black hole X-ray binaries
Maccarone, T. J.; Gandhi, P.; Miller-Jones, J. C. A. +5 more
Quiescent black hole X-ray binaries (X-ray luminosities ${\lesssim} 10^{34}\,{\rm erg}\, {\rm s}^{-1}$) are believed to be fed by hot accretion flows that launch compact, relativistic jets. However, due to their low luminosities, quiescent jets have been detected in the radio waveband from only five systems so far. Here, we present radio observati…
The surface magnetic activity of the weak-line T Tauri stars TWA 7 and TWA 25
Donati, J. -F.; Wright, D.; Folsom, C. P. +5 more
We present an analysis of spectropolarimetric observations of the low-mass weak-line T Tauri stars TWA 25 and TWA 7. The large-scale surface magnetic fields have been reconstructed for both stars using the technique of Zeeman Doppler imaging. Our surface maps reveal predominantly toroidal and non-axisymmetric fields for both stars. These maps rein…
Direct geometrical measurement of the Hubble constant from galaxy parallax: predictions for the Vera C. Rubin Observatory and Nancy Grace Roman Space Telescope
Croft, Rupert A. C.
We investigate the possibility that a statistical detection of the galaxy parallax shifts due to the Earth's motion with respect to the cosmic microwave background frame (cosmic secular parallax) could be made by the Vera C. Rubin Observatory Legacy Survey of Space and Time (LSST) or by the Nancy Grace Roman Space Telescope (NGRST), and used to me…