399 research outputs found
Analysis of Fermi-LAT data from Tucana-II: Possible constraints on the Dark Matter models with an intriguing hint of a signal
Tucana-II (Tuc-II), a recently discovered and confirmed Ultra Faint Dwarf
Spheroidal galaxy, has a high mass to light ratio as well as a large
line-of-sight stellar velocity dispersion, thus making it an ideal candidate
for an indirect dark matter (DM) search. In this paper, we have analyzed nine
years of -ray data obtained from the \textit{Fermi}-LAT instrument from
the direction of Tuc-II. The fact that a very weak significant -ray
excess () over the background of Tuc-II have been detected from the
location of this galaxy. We have observed that this excess of -ray
emission from the of location Tuc-II rises with longer periods of data. If WIMP
pair annihilation is assumed for this faint emission, for
annihilation channel the test statistics (TS) value peaks at DM mass 14
GeV and for annihilation channel it peaks at DM mass 4 GeV.
It is then called for an estimation of the confidence level upper limit
of the possible velocity weighted self-annihilation cross-section of the DM
particles (WIMPs) within Tuc-II by fitting the observed -ray flux with
spectra expected for DM annihilation. The estimated upper limits of the
cross-sections from Tuc-II are then compared with two other dwarf galaxies that
are considered to be good DM candidates in several studies. We have also
compared our results with the cross-sections obtained in various popular
theoretical models of the WIMPs to find that our results impose reasonable
tight constraints on the parameter spaces of those DM models. In the concluding
section, we compared our results with the similar results obtained from a
combined dSph analysis by the \textit{Fermi}-LAT collaboration as well as the
results obtained from the studies of DM in the dwarf galaxies by the major
ground-based Cherenkov experiments.Comment: 23 pages, 16 figures, 7 table
Probing the dark matter capture rate in Brown Dwarfs with IceCube
This study explores the potential for dark matter (DM) annihilation within
brown dwarfs (BDs), investigating an unconventional mechanism for neutrino
production. Motivated by the efficient accumulation of DM particles in BDs
through scattering interactions, we focus on a mass range of 1 GeV to 100 TeV,
considering DM annihilation channels through long-lived mediators. Using ten years of IceCube data, we
assess the detection capability of local BDs and exclude DM-nucleon scattering
with cross sections as low as a few times . In this case,
high-energy neutrinos provide more stringent constraints on DM scattering cross
section than gamma rays.Comment: 10 pages, 4 figure
Investigating the region of 3C 397 in High Energy Gamma rays
We investigate the supernova remnant (SNR) 3C 397 and its neighboring pulsar
PSR J1906+0722 in high energy gamma rays by using nearly six years of archival
data of {\it Large Area Telescope} on board {\it Fermi Gamma Ray Space
Telescope} (Fermi-LAT). The off-pulse analysis of gamma-ray flux from the
location of PSR J1906+0722 reveals an excess emission which is found to be very
close to the radio location of 3C 397. Here, we present the preliminary results
of this gamma-ray analysis of 3C 397 and PSR J1906+0722.Comment: 4 pages, 3 figures, Proceeding of IAU Symposium No. 331, 201
Human rights of people with mental illness: Provisions made in mental healthcare act 2017
Human rights of people with mental illness are very frequently undermined or even violated by individuals, groups and agencies. Human rights are understood as those rights which are applicable to all human beings, regardless of race, sex, nationality, ethnicity, language, religion, or any other parameters. Human rights entail the right to life and liberty, freedom from slavery, discrimination and torture, freedom of speech and expression, the right to work and education, and many more. The Mental Health Care Act, 2017 (MHCA 2017) has replaced the Mental Health Act, 1987 for strengthening the rights and wellbeing of mentally ill people and making mental healthcare services more humane and complying to human rights of those people. This article aims to discuss how the Mental Healthcare Act 2017 is beneficial in protecting the human rights of mentally ill people in India.
Keywords: Mental health, mental healthcare act 2017, human rights, mental illnes
Gammapy: A Python package for gamma-ray astronomy
In this article, we present Gammapy, an open-source Python package for the
analysis of astronomical -ray data, and illustrate the functionalities
of its first long-term-support release, version 1.0. Built on the modern Python
scientific ecosystem, Gammapy provides a uniform platform for reducing and
modeling data from different -ray instruments for many analysis
scenarios. Gammapy complies with several well-established data conventions in
high-energy astrophysics, providing serialized data products that are
interoperable with other software packages. Starting from event lists and
instrument response functions, Gammapy provides functionalities to reduce these
data by binning them in energy and sky coordinates. Several techniques for
background estimation are implemented in the package to handle the residual
hadronic background affecting -ray instruments. After the data are
binned, the flux and morphology of one or more -ray sources can be
estimated using Poisson maximum likelihood fitting and assuming a variety of
spectral, temporal, and spatial models. Estimation of flux points, likelihood
profiles, and light curves is also supported. After describing the structure of
the package, we show, using publicly available -ray data, the
capabilities of Gammapy in multiple traditional and novel -ray analysis
scenarios, such as spectral and spectro-morphological modeling and estimations
of a spectral energy distribution and a light curve. Its flexibility and power
are displayed in a final multi-instrument example, where datasets from
different instruments, at different stages of data reduction, are
simultaneously fitted with an astrophysical flux model.Comment: 26 pages, 16 figure
Azimuthal anisotropy of charged jet production in root s(NN)=2.76 TeV Pb-Pb collisions
We present measurements of the azimuthal dependence of charged jet production in central and semi-central root s(NN) = 2.76 TeV Pb-Pb collisions with respect to the second harmonic event plane, quantified as nu(ch)(2) (jet). Jet finding is performed employing the anti-k(T) algorithm with a resolution parameter R = 0.2 using charged tracks from the ALICE tracking system. The contribution of the azimuthal anisotropy of the underlying event is taken into account event-by-event. The remaining (statistical) region-to-region fluctuations are removed on an ensemble basis by unfolding the jet spectra for different event plane orientations independently. Significant non-zero nu(ch)(2) (jet) is observed in semi-central collisions (30-50% centrality) for 20 <p(T)(ch) (jet) <90 GeV/c. The azimuthal dependence of the charged jet production is similar to the dependence observed for jets comprising both charged and neutral fragments, and compatible with measurements of the nu(2) of single charged particles at high p(T). Good agreement between the data and predictions from JEWEL, an event generator simulating parton shower evolution in the presence of a dense QCD medium, is found in semi-central collisions. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).Peer reviewe
Production of He-4 and (4) in Pb-Pb collisions at root(NN)-N-S=2.76 TeV at the LHC
Results on the production of He-4 and (4) nuclei in Pb-Pb collisions at root(NN)-N-S = 2.76 TeV in the rapidity range vertical bar y vertical bar <1, using the ALICE detector, are presented in this paper. The rapidity densities corresponding to 0-10% central events are found to be dN/dy4(He) = (0.8 +/- 0.4 (stat) +/- 0.3 (syst)) x 10(-6) and dN/dy4 = (1.1 +/- 0.4 (stat) +/- 0.2 (syst)) x 10(-6), respectively. This is in agreement with the statistical thermal model expectation assuming the same chemical freeze-out temperature (T-chem = 156 MeV) as for light hadrons. The measured ratio of (4)/He-4 is 1.4 +/- 0.8 (stat) +/- 0.5 (syst). (C) 2018 Published by Elsevier B.V.Peer reviewe
Forward-central two-particle correlations in p-Pb collisions at root s(NN)=5.02 TeV
Two-particle angular correlations between trigger particles in the forward pseudorapidity range (2.5 2GeV/c. (C) 2015 CERN for the benefit of the ALICE Collaboration. Published by Elsevier B. V.Peer reviewe
Event-shape engineering for inclusive spectra and elliptic flow in Pb-Pb collisions at root(NN)-N-S=2.76 TeV
Peer reviewe
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