Context: Bow shocks are produced by many astrophysical objects where shock waves present. Stellar bow shocks, generated runaway stars, have been previously detected in small numbers and well-studied. Along with progress model development improvements observing instruments, our knowledge of the emission these its origin can now be more clearly understood. Aims: We produce a stellar bow-shock catalogue applying uniform search criteria systematic process. This is starting point for statistical...

<i>Context. <i/>The environs of massive, early-type stars have been inspected in recent years the search for sites where particles can be accelerated up to relativistic energies. Wind regions massive binaries that collide already established as sources high-energy emission; however, there is a different scenario strong shocks also produced: bow-shaped region matter piled by action stellar wind runaway star interacting with interstellar medium.<i>Aims. <i/>We study bow-shock produced very...

Context. Stellar bow shocks have been studied not only observationally, but also theoretically since the late 1980s. Only a few catalogues of them exist. The show emission along all electromagnetic spectrum, they are detected more easily in infrared wavelengths. release new and high-quality data eases discovery subsequent study objects. Aims. We search stellar bow-shock candidates associated with nearby runaway stars, gather together those found elsewhere, to enlarge list E-BOSS first...

In the colliding wind region of early-type binaries, electrons can be accelerated up to relativistic energies displaying power-law spectra, as demonstrated by detection non-thermal radio emission from several WR+OB systems. The particle acceleration region, located between stars, is exposed strong photon fields in such a way that inverse Compton cooling could result substantial high-energy flux. particular cases, ratio energy densities magnetic will determine whether given source produce or...

Context . The colliding-wind region in binary systems made up of massive stars allows us to investigate various aspects shock physics, including particle acceleration. Particle accelerators this kind are mainly identified thanks their synchrotron radio emission and dubbed particle-accelerating binaries. Aims Our objective is first validate the notion that obtaining snapshot high-resolution images binaries constitutes a relevant approach unambiguously identifying accelerators. Second, we...

HD 93129A is an O+O stellar system whose colliding-wind region (CWR) has been mapped by high angular resolution observations at centimetre wavelengths. The synchrotron nature of the radio emission confirms its particle accelerator status. Astrometric measurements since 1996 indicate that orbital period ∼120 yr and recently went through periastron passage. We attempted to characterise during epoch passage, when density local magnetic energy in CWR increase. monitored surroundings bands...

We present a study of 40 low-latitude unidentified 3EG gamma-ray sources which were found to be not positionally coincident with any known class potential emitters in the Galaxy (Romero, Benaglia & Torres, 1999). have performed variability analysis reveals that many these are variable. These have, addition, steep mean value spectral index, $<\Gamma> = 2.41 \pm 0.2$, which, combined high level seems rule out pulsar origin. The positional coincidences uncatalogued candidates supernova remnants...

We have compiled optical and radio astrometric data of the microquasar LS 5039 derived its proper motion. This, together with distance radial velocity system, allows us to state that this source is escaping from own regional standard rest, a total systemic about 150 km s-1 component perpendicular galactic plane larger than 100 s-1. This probably result an acceleration obtained during supernova event created compact object in binary system. computed trajectory past, searched for OB...

Runaway stars with peculiar high velocities can generate stellar bow shocks. Only a few shocks show clear radio emission. Our goal is to identify and characterize new around O Be runaway in the infrared (IR), as well study their possible emission nature. input data catalog of runaways compiled using Gaia DR3. We used WISE IR images search for shock structures these DR3 determine actual motion corrected interstellar medium (ISM) caused by Galactic rotation, archival signatures. finally...

PSR J2030+4415 is a gamma-ray pulsar with an X-ray wind nebula elongated along the north-south direction. The system shows prominent filament oriented at angle of 130{\deg} to axis. To improve our understanding non-thermal processes occurring in nebula, we attempted determine possible existence radio counterpart, study its morphology, and obtain restrictive upper limits emission wavelengths. We performed observations surroundings upgraded Giant Metrewave Radio Telescope (uGMRT) two frequency...

Runaway stars with peculiar high velocities can generate stellar bow shocks. Only a few shocks show clear radio emission. Our goal is to identify and characterize new around O Be runaway in the infrared (IR), study their possible emission nature. input data catalog of runaways compiled using Gaia DR3. We used WISE IR images search for these runaways, DR3 determine actual motion corrected interstellar medium (ISM) caused by Galactic rotation, archival signatures. finally explored...

Star-forming galaxies (SFGs) emit non-thermal radiation from radio to gamma-rays. We aim investigate the main mechanisms of global CR transport and cooling in SFGs. The way they contribute shaping relations between luminosities SFR could shed light onto their nature. develop a model compute populations SFGs, taking into account production, transport, cooling. is parameterised only through galaxy properties, describes emission both focus on role diffusive advective by galactic winds, either...

The HEGRA Cherenkov telescope array group recently reported a steady and extended unidentified TeV gamma-ray source lying at the outskirts of Cygnus OB2. This is most massive stellar association known in Galaxy, estimated to contain ~2600 OB type members alone. It has been previously argued that large scale shocks turbulence induced by multiple interacting supersonic winds from many young stars such associations may play role accelerating Galactic cosmic rays. Indeed, Cyg OB2 also coincides...

The binary stellar system HD 93129A is one of the most massive known binaries in our Galaxy. This presents non-thermal emission radio band, which can be used to infer its physical conditions and predict high-energy band. We intend constrain some unknown parameters through modelling emitter, also analyse detectability this source hard X-rays $\gamma$-rays. develop a broadband radiative model for wind-collision region taking into account evolution accelerated particles streaming along shocked...

We discuss the possibility that stellar system Cyg OB2 No. 5 can be a gamma-ray source in light of recent EGRET and radio data. This is formed by an O7 Ia + Ofpe/WN9 contact binary. A third star, probably B0 V star also associated with system, located at ∼1700 AU from primary. estimate expected luminosity colliding winds region, terminal shock wind, unstable zone base conclude that, under very reasonable assumptions, generate about half flux detected positionally coincident 3EG J2033+4118....

From the radial velocities of N IV 4058 and He II 4686 emission lines, V 4604-20 absorption determined in digital spectra, we report discovery that X-ray bright line star Wack 2134 (= WR 21a) is a spectroscopic binary system with an orbital period $31.673\pm0.002$ days. With this period, which originate atmosphere primary component, define rather eccentric orbit (e=0.64$\pm$0.03). The velocity variations absorptions have lower amplitude than those emission. Such behaviour could be due to...

Massive runaway stars produce bow shocks through the interaction of their winds with interstellar medium, prospect for particle acceleration by shocks. These objects are consequently candidates non-thermal emission. Our aim is to investigate X-ray emission from these sources. We observed XMM–Newton a sample five shock runaways, which constitutes significant improvement runaways studied in X-rays so far. A careful analysis data did not reveal any related However, detected, agreement expected...

Galactic cosmic rays (GCRs) constitute a significant part of the energy budget our Galaxy, and study their accelerators is high importance in modern astrophysics. Their main sources are likely supernova remnants (SNRs). These objects capable to convert mechanical into accelerated charged particles. However, even though reservoir SNRs promising, conversion rate particle 10 20% necessary feed population GCRs. Such an efficiency however not guaranteed. Complementary deserve thus be...

Abstract The supersonic winds produced by massive stars carry a large amount of kinetic power. In numerous scenarios such have been proven to produce shocks in which relativistic particles are accelerated emitting nonthermal (NT) radiation. Here, we report the first detection NT emission from single stellar bubble, G2.4+1.4, associated with WO star. We observed this source upgraded Giant Meterwave Radio Telescope Band 4 (550–850 MHz) and 5 (1050–1450 MHz). present intensity spectral index...

Context. Massive colliding-wind binaries (CWBs) can be non-thermal sources. The emission produced in their wind-collision region (WCR) encodes information of both the shock properties and relativistic electrons accelerated them. recently discovered system Apep , a unique massive hosting two Wolf-Rayet stars, is most powerful synchrotron radio emitter among known CWBs. It an exciting candidate which to investigate processes associated with stellar wind shocks. Aims. We intend break degeneracy...

A 50 ksec Chandra observation of the unidentified TeV source in Cygnus reported by HEGRA collaboration reveals no obvious diffuse X-ray counterpart. However, 240 Pointlike sources are detected within or nearby extended J2032+4130 region, which at least 36 massive stars and 2 may be radio emitters. That is a composite, having as counterpart multiple point-like we observe, cannot ruled out. Indeed, distribution appears non-uniform concentrated broadly extent region. We offer hypothesis for...

Context.Massive stars play a dominant role in the Universe, but one of main drivers for their evolution, mass loss, remains poorly understood.

We present H i synthesis imaging of the giant elliptical galaxy IC 1459 and its surroundings with Australia Telescope Compact Array. Our search for extended emission revealed a large complex clouds near 1459, likely to be debris from tidal interactions neighbouring galaxies. The total mass (∼109 M⊙) in detected spans 250 kpc north-east gas-rich spiral NGC 7418A south-east 1459. extent debris, which shows rather irregular morphology kinematics, are similar those other nearby groups. Together...