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Register a new userMultiwavelength study of the region around the ANTARES neutrino excess
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Added by
Fabian Sch\\\"ussler
Publication date
2013
fields
Physics
and research's language is
English
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The ANTARES collaboration reported the results of a search for point-like neutrino sources using data taken in the period 2007-2010. An unbinned maximum likelihood based all-sky search yielded a cluster of 9 (5) events within a cone of 3 (1) degrees around (R.A., Dec) = (-46.5deg, -65.0deg). The trial factor corrected p-value of 2.6% (2.2 sigma) is not significant enough to claim the observation of an astrophysical point source. However, it currently constitutes the most significant localized neutrino excess observed by ANTARES. Here we present a multi-wavelength analysis including optical to X-ray archival data and a dedicated analysis of gamma-ray data from Fermi-LAT. In order to cover the TeV domain, dedicated observations with the H.E.S.S. telescope array were carried out. We present these data and discuss implications of the results in terms of signatures for a cosmic-ray acceleration site.
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Star-forming regions are usually studied in the context of Galactic surveys, but dedicated observations are sometimes needed when the study reaches beyond the survey area. Here, we studied the G345.5+1.5 region, which is located slightly above the Galactic plane, to understand its star formation properties. We combined the LABOCA and $^{12}$CO(4$-$3) transition line observations complemented with the Hi-GAL and $it{Spitzer}$-GLIMPSE surveys to study the star formation toward this region. We used the Clumpfind algorithm to extract the clumps from the 870$mu$m and $^{12}$CO(4$-$3) data. Radio emission at 36cm was used to estimate the number of HII regions and to remove the contamination from the free-free emission at 870$mu$m. We employed color-color diagrams and spectral energy distribution slopes to distinguish between prestellar and protostellar clumps. We studied the boundedness of the clumps through the virial parameter. Finally, we estimated the star formation efficiency and star formation rate of the region and used the Schmidt-Kennicutt diagram to compare its ability to form stars. Of the 13 radio sources that we found using the MGPS-2 catalog, 7 are found to be associated with HII regions corresponding to late-B or early-O stars. We found 45 870$mu$m clumps, and 107 $^{12}$CO clumps. More than 50% of the clumps are protostellar and bounded and are able to host star formation. High SFR and SFR density values are associated with the region, with an SFE of a few percent. With submillimeter, CO transition, and short-wavelength infrared observations, our study reveals a population of massive stars, protostellar and bound starless clumps, toward G345.5+1.5. This region is therefore actively forming stars, and its location in the starburst quadrant of the Schmidt-Kennicutt diagram is comparable to other star-forming regions found within the Galactic plane.
The ANTARES telescope is the largest underwater neutrino telescope existing at present. It is based on the detection of Cherenkov light produced in sea water by neutrino-induced muons. The detector, consisting of a tri-dimensional array of 885 photomultipliers arranged on twelve vertical lines, is located at a depth of 2475 m in the Mediterranean Sea, 40 km off the French coast. The main goal of the experiment is to probe the Universe by means of neutrino events in an attempt to investigate the nature of high energy astrophysical sources, to contribute to the identification of cosmic ray sources, and to explore the nature of dark matter. In this contribution we will review the status of the detector, illustrate its operation and performance, and present the first results from the analysis carried out on atmospheric muons and neutrinos, as well as from the search for astrophysical neutrino sources.
The ANTARES neutrino telescope is currently the largest operating water Cherenkov detector and the largest neutrino detector in the Northern Hemisphere. Its main scientific target is the detection of high-energy (TeV and beyond) neutrinos from cosmic accelerators, as predicted by hadronic interaction models, and the measurement of the diffuse neutrino flux. Its location allows for surveying a large part of the Galactic Plane, including the Galactic Centre. In addition to the standalone searches for point-like and diffuse high-energy neutrino signals, ANTARES has developed a range of multi-messenger strategies to exploit the close connection between neutrinos and other cosmic messengers such as gamma-rays, charged cosmic rays and gravitational waves. This contribution provides an overview of the recently conducted analyses, including a search for neutrinos from the Fermi bubbles region, searches for optical counterparts with the TAToO program, and searches for neutrinos in correlation with gamma-ray bursts, blazars, and microquasars. Further topics of investigation, covering e.g. the search for neutrinos from dark matter annihilation, searches for exotic particles and the measurement of neutrino oscillations, are also reviewed.
The ANTARES experiment is currently the largest underwater neutrino telescope. It is taking high quality data since 2007 and aims to detect high energy neutrinos that are expected from the acceleration of cosmic rays from astrophysical sources. We will review the status of the detector and present several analyses carried out on atmospheric muons and neutrinos. For example we will show the latest results from searches for neutrinos from steady cosmic point-like sources, for neutrinos from Fermi Bubbles, for neutrinos from Dark Matter in the Sun and the measurement of atmospheric neutrino oscillation parameters.
A novel method to analyse the spatial distribution of neutrino candidates recorded with the ANTARES neutrino telescope is introduced, searching for an excess of neutrinos in a region of arbitrary size and shape from any direction in the sky. Techniques originating from the domains of machine learning, pattern recognition and image processing are used to purify the sample of neutrino candidates and for the analysis of the obtained skymap. In contrast to a dedicated search for a specific neutrino emission model, this approach is sensitive to a wide range of possible morphologies of potential sources of high-energy neutrino emission. The application of these methods to ANTARES data yields a large-scale excess with a post-trial significance of 2.5$sigma$. Applied to public data from IceCube in its IC40 configuration, an excess consistent with the results from ANTARES is observed with a post-trial significance of 2.1$sigma$.
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