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View article: MeerKAT discovery of 164 compact radio rings towards the Galactic plane
MeerKAT discovery of 164 compact radio rings towards the Galactic plane Open
We report the discovery of 164 compact (radius < 1 arcmin) radio rings using MeerKAT 1.3 GHz data from the SARAO (South African Radio Astronomy Observatory) MeerKAT Galactic Plane Survey ($l=2^{\circ } \!-\! 60^{\circ }, 252^{\circ } \!…
View article: Twenty years of blazar monitoring with the INAF radio telescopes
Twenty years of blazar monitoring with the INAF radio telescopes Open
Context . The extreme variability of blazars, in both timescale and amplitude, is generally explained as the effect of a relativistic jet closely aligned with the observer’s line of sight. Via causality arguments, variability characteristi…
View article: Twenty years of blazar monitoring with the INAF radio telescopes
Twenty years of blazar monitoring with the INAF radio telescopes Open
The extreme variability of blazars, in both timescale and amplitude, is generally explained as the effect of a relativistic jet closely aligned to the observer's line-of-sight. Due to causality arguments, variability characteristics transl…
View article: Broadband radio study of the supernova remnant Kes 73
Broadband radio study of the supernova remnant Kes 73 Open
Context . Strong shocks occurring in supernova remnants (SNRs), and their interaction with an often anisotropic surrounding medium, make SNRs ideal laboratories for studying the production and acceleration of cosmic rays (CRs). Due to thei…
View article: Discovery of the binary nature of the magnetospheric B-type star <i>ρ</i> Oph A
Discovery of the binary nature of the magnetospheric B-type star <i>ρ</i> Oph A Open
Context . The nearby B-type star ρ Oph A was recently identified as a rapidly rotating magnetic B-type star with variable radio and X-ray emission consistent with a magnetospheric origin. Aims . We aim to refine constraints on ρ Oph A’s ma…
View article: X-ray and radio data obtained by <i>XMM-Newton</i> and VLA constrain the stellar wind of the magnetic quasi-Wolf-Rayet star in HD45166
X-ray and radio data obtained by <i>XMM-Newton</i> and VLA constrain the stellar wind of the magnetic quasi-Wolf-Rayet star in HD45166 Open
Context. Recently, a powerful magnetic field was discovered in the hot helium star classified as a quasi-Wolf-Rayet (qWR) star (∼2 M ⊙ ), in the HD 45166 system. Upon its explosion as a core-collapse supernova, it is expected to produce a …
View article: The SARAO MeerKAT Galactic Plane Survey extended source catalogue
The SARAO MeerKAT Galactic Plane Survey extended source catalogue Open
We present a catalogue of extended radio sources from the SARAO MeerKAT Galactic Plane Survey (SMGPS). Compiled from 56 survey tiles and covering approximately 500 deg 2 across the first, third, and fourth Galactic quadrants, the catalogue…
View article: Searching for star-planet interactions in GJ 486 at radio wavelengths with the uGMRT
Searching for star-planet interactions in GJ 486 at radio wavelengths with the uGMRT Open
Aims. We search for radio emission from star–planet interactions in the M dwarf system GJ 486, which hosts an Earth-like planet. Methods. We observed the GJ 486 system with the upgraded Giant Metrewave Radio Telescope (uGMRT) from 550 to 7…
View article: Searching for star-planet interactions in GJ 486 at radio wavelengths with the uGMRT
Searching for star-planet interactions in GJ 486 at radio wavelengths with the uGMRT Open
We search for radio emission from star-planet interactions in the M-dwarf system GJ~486, which hosts an Earth-like planet. We observed the GJ~486 system with the upgraded Giant Metrewave Radio Telescope (uGMRT) from 550 to 750 MHz in nine …
View article: The MeerKAT view on Galactic supernova remnants
The MeerKAT view on Galactic supernova remnants Open
Context. The integrated radio spectrum of supernova remnants (SNRs) and the spatial variation of the spectral indices across these extended sources are powerful tools for studying the shocks and particle acceleration processes occurring in…
View article: Sifting the debris: Patterns in the SNR population with unsupervised ML methods
Sifting the debris: Patterns in the SNR population with unsupervised ML methods Open
Supernova remnants (SNRs) carry vast amounts of mechanical and radiative energy that heavily influence the structural, dynamical, and chemical evolution of galaxies. To this day, more than 300 SNRs have been discovered in the Milky Way, ex…
View article: Non-thermal radio emission from massive protostars in the SARAO MeerKAT Galactic Plane Survey
Non-thermal radio emission from massive protostars in the SARAO MeerKAT Galactic Plane Survey Open
We present an investigation of the L-band emission from known massive young stellar objects in the South African Radio Astronomy Observatory MeerKAT Galactic Plane Survey to search for non-thermal radio emitters in the sample. A total of 3…
View article: MeerKAT reveals a ghostly thermal radio ring towards the Galactic Centre
MeerKAT reveals a ghostly thermal radio ring towards the Galactic Centre Open
We present the serendipitous discovery of a new radio-continuum ring-like object nicknamed Kýklos (J1802–3353), with MeerKAT UHF and L -band observations. The radio ring, which resembles the recently discovered odd radio circles (ORCs), ha…
View article: The SARAO MeerKAT 1.3 GHz Galactic Plane Survey
The SARAO MeerKAT 1.3 GHz Galactic Plane Survey Open
We present the SARAO MeerKAT Galactic Plane Survey (SMGPS), a 1.3 GHz continuum survey of almost half of the Galactic Plane (251° ≤l ≤ 358° and 2° ≤l ≤ 61° at |b| ≤ $1{_{.}^{\circ}}5$). SMGPS is the largest, most sensitive, and highest ang…
View article: Self-supervised contrastive learning of radio data for source detection, classification and peculiar object discovery
Self-supervised contrastive learning of radio data for source detection, classification and peculiar object discovery Open
New advancements in radio data post-processing are underway within the SKA precursor community, aiming to facilitate the extraction of scientific results from survey images through a semi-automated approach. Several of these developments l…
View article: The distance to CRL 618 through its radio expansion parallax
The distance to CRL 618 through its radio expansion parallax Open
CRL 618 is a post-AGB star that has started to ionize its ejecta. Its central HII region has been observed over the last 40 years and has steadily increased in flux density at radio wavelengths. In this paper, we present data that we obtai…
View article: The distance to CRL 618 through its radio expansion parallax
The distance to CRL 618 through its radio expansion parallax Open
CRL 618 is a post-Asymptotic Giant Branch star that has started to ionize its ejecta. Its central H ii region has been observed over the last 40 yr and has steadily increased in flux density at radio wavelengths. In this paper, we present …
View article: Classification of compact radio sources in the Galactic plane with supervised machine learning
Classification of compact radio sources in the Galactic plane with supervised machine learning Open
Generation of science-ready data from processed data products is one of the major challenges in next-generation radio continuum surveys with the Square Kilometre Array (SKA) and its precursors, due to the expected data volume and the need …
View article: The SARAO MeerKAT 1.3 GHz Galactic Plane Survey
The SARAO MeerKAT 1.3 GHz Galactic Plane Survey Open
We present the SARAO MeerKAT Galactic Plane Survey (SMGPS), a 1.3 GHz continuum survey of almost half of the Galactic Plane (251°$\le l \le$ 358°and 2°$\le l \le$ 61°at $|b| \le 1.5°$). SMGPS is the largest, most sensitive and highest angu…
View article: The rich molecular environment of the luminous blue variable star AFGL 2298
The rich molecular environment of the luminous blue variable star AFGL 2298 Open
Context. Luminous blue variable (LBV) stars represent a short-lived stage in the late evolution of the most massive stars. Highly unstable, LBVs exhibit dense stellar winds and episodic eruptions that produce complex circumstellar nebulae,…
View article: The rich molecular environment of the luminous blue variable star AFGL 2298
The rich molecular environment of the luminous blue variable star AFGL 2298 Open
We investigated the molecular environment of AFGL 2298, an obscured Galactic Luminous blue variable (LBV) star which hosts a highly structured circumstellar environment with hints of multiple mass-loss events in the last few $10^4$ a. We p…
View article: Star-Planet Interaction at radio wavelengths in YZ Ceti: Inferring planetary magnetic field
Star-Planet Interaction at radio wavelengths in YZ Ceti: Inferring planetary magnetic field Open
In exoplanetary systems, the interaction between the central star and the planet can trigger Auroral Radio Emission (ARE), due to the Electron Cyclotron Maser mechanism. The high brightness temperature of this emission makes it visible at …
View article: First Detection of Silicon-bearing Molecules in η Car
First Detection of Silicon-bearing Molecules in η Car Open
We present ALMA band 6 observations of the luminous blue variable η Car obtained within the ALMAGAL program. We report SiO J = 5 → 4, SiS J = 12 → 11, and SiN N = 5 → 4 emission in the equatorial region of the Homunculus nebula, constituti…
View article: Testing a scaling relation between coherent radio emission and physical parameters of hot magnetic stars
Testing a scaling relation between coherent radio emission and physical parameters of hot magnetic stars Open
Coherent radio emission via electron cyclotron maser emission (ECME) from hot magnetic stars was discovered more than two decades ago, but the physical conditions that make the generation of ECME favourable remain uncertain. Only recently …
View article: Radio detection of chemically peculiar stars with LOFAR
Radio detection of chemically peculiar stars with LOFAR Open
Context. Chemically peculiar stars are upper main sequence stars that show anomalies in their optical spectra. These anomalies suggest peculiar chemical abundances of certain elements. Some chemically peculiar stars possess strong magnetic…
View article: Discovery and origin of the radio emission from the multiple stellar system KQVel
Discovery and origin of the radio emission from the multiple stellar system KQVel Open
KQVel is a binary system composed of a slowly rotating magnetic Ap star with a companion of unknown nature. In this paper, we report the detection of its radio emission. We conducted a multi-frequency radio campaign using the ATCA interfer…
View article: Towards coordinated site monitoring and common strategies for mitigation of Radio Frequency Interference at the Italian radio telescopes
Towards coordinated site monitoring and common strategies for mitigation of Radio Frequency Interference at the Italian radio telescopes Open
We present a project to implement a national common strategy for the mitigation of the steadily deteriorating Radio Frequency Interference (RFI) situation at the Italian radio telescopes. The project involves the Medicina, Noto, and Sardin…
View article: Centrifugal breakout reconnection as the electron acceleration mechanism powering the radio magnetospheres of early-type stars
Centrifugal breakout reconnection as the electron acceleration mechanism powering the radio magnetospheres of early-type stars Open
Magnetic B-stars often exhibit circularly polarized radio emission thought to arise from gyrosynchrotron emission by energetic electrons trapped in the circumstellar magnetosphere. Recent empirical analyses show that the onset and strength…
View article: MOBSTER – VI. The crucial influence of rotation on the radio magnetospheres of hot stars
MOBSTER – VI. The crucial influence of rotation on the radio magnetospheres of hot stars Open
Numerous magnetic hot stars exhibit gyrosynchrotron radio emission. The source electrons were previously thought to be accelerated to relativistic velocities in the current sheet formed in the middle magnetosphere by the wind opening magne…
View article: MOBSTER -- VI. The crucial influence of rotation on the radio magnetospheres of hot stars
MOBSTER -- VI. The crucial influence of rotation on the radio magnetospheres of hot stars Open
Numerous magnetic hot stars exhibit gyrosynchrotron radio emission. The source electrons were previously thought to be accelerated to relativistic velocities in the current sheet formed in the middle magnetosphere by the wind opening magne…