Related papers: Diffuse Galactic Gamma-rays from star clusters
The Galactic diffuse gamma-ray emission is conventionally modeled as the product of cosmic-ray interactions with the interstellar medium. However, the cumulative contribution of stellar atmospheres acting as hadronic interaction targets…
The numerous and massive young star clusters in blue compact galaxies (BCGs) are used to investigate the properties of their hosts. We test whether BCGs follow claimed relations between cluster populations and their hosts, such as the the…
The vast majority of the celestial gamma-ray sources detected so far have not yet been identified with secure counterparts at other wavelenghts. Here we report the preliminary evidence of a probable association between galaxy clusters and…
In this work, we use two gas mass fraction samples of galaxy clusters obtained from their X-ray surface brightness observations jointly with recent $H(z)$ data in a flat $\Lambda$CDM framework to impose limits on cosmic opacity. It is…
We find that dust clouds which eclipse young stars obscure the stellar disc inhomogeneously. In the particular case of CQ Tau, we find isolated optically thick structures with sizes $\lesssim0.6R_*$ and derive the typical $A_{V}$ gradient…
Star formation in galaxies is observed to be associated with gamma-ray emission. The detection of gamma rays from star-forming galaxies by the Fermi Large Area Telescope (LAT) has allowed the determination of a functional relationship…
Massive Star Clusters (SCs) have been proposed as important CR sources, with the potential of explaining the high-energy end of the Galactic cosmic-ray (CR) spectrum, that Supernova Remnants (SNRs) seem unable to account for. Thanks to fast…
The vast majority of stars in galaxy groups are contained within their constituent galaxies. Some small fraction of stars is expected, however, to follow the global dark matter potential of the group. In compact groups, interactions between…
The Galactic diffuse emission is potentially able to reveal much about the sources and propagation of cosmic rays (CR), their spectra and intensities in distant locations. It can possibly unveil WIMP dark matter (DM) through its…
The Large High-Altitude Air Shower Observatory (LHAASO) recently published measurements of diffuse Galactic gamma-ray emission (DGE) in the 10-1000 TeV energy range. The measured DGE flux is significantly higher than the expectation from…
The number of diffuse radio halos in clusters of galaxies has grown in recent years, making it possible to derive statistical properties of these sources and of the hosting clusters. We show that diffuse sources are associated with X-ray…
We report the Fermi Large Area Telescope's detection of extended gamma-ray emission towards the direction of the young massive star cluster NGC 3603. The emission shows a hard spectrum with a photon index of 2.3 from 1 GeV to 250 GeV. The…
Compact groups are associations of a few galaxies in which the environment plays an important role in galaxy evolution. The low group velocity dispersion favors tidal interactions and mergers, which may bring stars from galaxies to the…
The majority of the globular clusters associated with the Sagittarius dwarf galaxy are faint. In this respect it differs significantly from the globular cluster systems surrounding typical giant galaxies. The observation that most of…
We describe Spitzer images of a sample of dwarf and low surface brightness galaxies, using the high sensitivity and spatial resolution to explore the morphologies of dust in these galaxies. For the starbursting dwarf UGC 10445, we present a…
Recent results from the HESS gamma ray telescope have shown the presence of both a diffuse, extended, flux of gamma rays above ~0.4 TeV and discrete sources in and near the Galactic Centre. Here, we put forward a possible explanation in…
We present a spectrum of the diffuse Galactic light (DGL) between 3700 and 10,000 A, obtained by correlating optical sky intensity with far-infrared dust emission. We use nearly 250,000 blank-sky spectra from BOSS/SDSS-III together with…
The search for gamma radiation in clusters of galaxies represents a precious tool to investigate the history of these large scale structures. Clusters or sources within them accelerate cosmic rays, as demonstrated by the detection of radio…
The Galaxy appears to be richer in young, massive stellar clusters than previously known, due to advances in infrared surveys which have uncovered deeply embedded regions of star formation. Young, massive clusters can significantly impact…
Ultra-diffuse galaxies (UDGs) are spatially extended, low surface brightness stellar systems with regular elliptical-like morphology found in a wide range of environments. Studies of the internal dynamics and dark matter content of UDGs…