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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…
A new method for detecting solar atmospheric gravity waves
Fleck, Bernhard; Berrilli, Francesco; Calchetti, Daniele +2 more
Internal gravity waves have been observed in the Earth's atmosphere and oceans, on Mars and Jupiter, and in the Sun's atmosphere. Despite ample evidence for the existence of propagating gravity waves in the Sun's atmosphere, we still do not have a full understanding of their characteristics and overall role for the dynamics and energetics of the s…
Quest for the Upcoming Periastron Passage of an Episodic Dust Maker and Particle-accelerating Colliding-wind Binary: WR 125
Pandey, J. C.; Pandey, S. B.; Sharma, Saurabh +4 more
We have carried out a long-term infrared and X-ray investigation of the colliding-wind binary WR 125 (WC7 + O9III). The source was monitored using AstroSat Soft X-ray Telescope and the Tata Institute of Fundamental Research Near Infrared Imaging Camera-II mounted at the back of 3.6 m Devasthal Optical Telescope. WR 125 appeared brighter in the nea…
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…
Properties of a hypothetical cold pulsar wind in LS 5039
Bosch-Ramon, V.
Context. LS 5039 is a powerful high-mass gamma-ray binary that probably hosts a young non-accreting pulsar. However, despite the wealth of data available, the means by which the non-thermal emitter is powered are still unknown.
Aims: We use a dynamical-radiative numerical model, and multiwavelength data, to constrain the properties of a hypot…
NGC 1605a and NGC 1605b: An Old Binary Open Cluster in the Galaxy
Camargo, Denilso
This work communicates the discovery of a binary open cluster within the Galaxy. NGC 1605 presents an unusual morphology with a sparse stellar distribution and a double core in close angular proximity. The 2MASS and Gaia-EDR3 field-star decontaminated color-magnitude diagrams (CMDs) show two distinct stellar populations located at the same helioce…
Revised Surface Abundances of R Coronae Borealis Stars
Reddy, Arumalla B. S.; Pandey, Gajendra; Hema, B. P.
Surface abundances of 14 (11 majority class and three minority class) R Coronae Borealis stars (RCBs) along with the final-flash object, V4334 Sgr (Sakurai's object) are revised based on their carbon abundances measured from the observed C2 bands; note that the earlier reported abundances were derived using an assumed carbon abundance d…
Relativistic Reflection in NGC 4151
Zdziarski, Andrzej A.; Szanecki, Michał; Niedźwiecki, Andrzej
We investigate the X-ray spectrum of the Seyfert galaxy NGC 4151 using the simultaneous Suzaku/NuSTAR observation and flux-resolved INTEGRAL spectra supplemented by Suzaku and XMM observations. Our best spectral solution indicates that the narrow Fe Kα line is produced in Compton-thin matter at a distance of several hundred gravitational radii. In…