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Concept

Magnétar

Publications associées (19)

GHOST commissioning science results - II: a very metal-poor star witnessing the early galactic assembly

Pascale Jablonka

This study focuses on Pristine_180956.78-294759.8 (hereafter P180956, [Fe/H] = -1.95 +/- 0.02), a star selected from the Pristine Inner Galaxy Survey (PIGS), and followed-up with the recently commissioned Gemini High-resolution Optical SpecTrograph (GHOST) ...

Oxford Univ Press2024

The Origins of Gas Accreted by Supermassive Black Holes: The Importance of Recycled Gas

Michaela Hirschmann

We investigate the fueling mechanisms of supermassive black holes (SMBHs) by analyzing 10 zoom-in cosmological simulations of massive galaxies, with stellar masses 1011-12 M circle dot and SMBH masses 108.9-9.7 M circle dot at z = 0, featuring various majo ...

Iop Publishing Ltd2024

Iterative removal of sources to model the turbulent electromotive force

Salim Bennouna, Abhijit Bhausaheb Bendre

We describe a novel method to compute the components of dynamo tensors from direct magnetohydrodynamic (MHD) simulations. Our method relies upon an extension and generalization of the standard H & ouml;gbom CLEAN algorithm widely used in radio astronomy to ...

Oxford Univ Press2024

Limit on the intergalactic magnetic field from the ultrahigh-energy cosmic ray hotspot in the Perseus-Pisces region

Andrii Neronov, Oleg Kalashev

The Telescope Array Collaboration has reported an evidence for existence of a source of ultrahigh energy cosmic ray events in Perseus-Pisces supercluster. We show that the mere existence of such a source imposes an upper bound on the strength of intergalac ...

American Physical Society2023

COSMOS-Web: An Overview of the JWST Cosmic Origins Survey

Michaela Hirschmann

We present the survey design, implementation, and outlook for COSMOS-Web, a 255 hr treasury program conducted by the James Webb Space Telescope in its first cycle of observations. COSMOS-Web is a contiguous 0.54 deg² NIRCam imaging survey in four filters ( ...

IOP Publishing Ltd2023

HD 213258: A new rapidly oscillating, super slowly rotating, strongly magnetic Ap star in a spectroscopic binary

Pierre North

We report on HD 213258, an Ap star that we recently identified as presenting a unique combination of rare, remarkable properties. Our study of this star is based on ESPaDOnS Stokes I and V data obtained at seven epochs spanning a time interval slightly sho ...

EDP SCIENCES S A2023

How much metal did the first stars provide to the ultra-faint dwarfs?

Pascale Jablonka, Yves Revaz, Mahsa Sanati, Fabien Nicolas Jeanquartier

Numerical simulations of dwarf galaxies have so far failed to reproduce the observed metallicity-luminosity relation, down to the regime of ultra-faint dwarfs (UFDs). We address this issue by exploring how the first generations of metal-free stars (Pop III ...

EDP SCIENCES S A2023

Gamma-Blind Fast Neutron Detection for Spent Nuclear Fuel Characterization

Alexander Wolfertz

In this thesis, the development and testing of a system for measuring the axial distribution of fast neutron emission of spent nuclear fuel rods is presented. Emphasis is placed on the novel fast neutron detector used which can reliably work in extremely h ...

EPFL2023

Observational signatures of galactic turbulent dynamos

Salim Bennouna, Abhijit Bhausaheb Bendre

We analyse the observational signatures of galactic magnetic fields that are self-consistently generated in magnetohydrodynamic simulations of the interstellar medium through turbulence driven by supernova (SN) explosions and differential rotation. In part ...

OXFORD UNIV PRESS2022

Euclid: Searching for pair-instability supernovae with the Deep Survey

Yi Wang, Frédéric Courbin, Georges Meylan, Giovanni Longo

Pair-instability supernovae are theorized supernovae that have not yet been observationally confirmed. They are predicted to exist in low-metallicity environments. Because overall metallicity becomes lower at higher redshifts, deep near-infrared transient ...

EDP SCIENCES S A2022

Signatures of anisotropic diffusion around PeVatrons in 100 TeV gamma-ray data

Andrii Neronov

The Tibet AS gamma collaboration has reported a diffuse gamma-ray emission signal from the Galactic Plane. We consider the possibility that the diffuse emission from the outer Galactic Plane at the highest energies is produced by cosmic rays spreading from ...

American Physical Society2022

The Gaia-ESO Survey: dynamics of ionized and neutral gas in the Lagoon nebula (M 8)

Carmela Lardo

Aims. We present a spectroscopic study of the dynamics of the ionized and neutral gas throughout the Lagoon nebula (M 8), using VLT-FLAMES data from the Gaia-ESO Survey. The new data permit exploration of the physical connections between the nebular gas an ...

Edp Sciences S A2017

Very-high-energy gamma-ray observations of the Type Ia Supernova SN 2014J with the MAGIC telescopes

Thomas Günther Bretz

Context. In this work we present data from observations with the MAGIC telescopes of SN 2014J detected on January 21 2014, the closest Type Ia supernova since Imaging Air Cherenkov Telescopes started to operate. Aims. We aim to probe the possibility of ver ...

Edp Sciences S A2017

Magnetic phase diagram of La2-xSrxCoO4 revised using muon-spin relaxation

Paul Gregory Freeman

We report the results of a muon-spin relaxation (mu SR) investigation of La2-xSrxCoO4, an antiferromagnetic insulating series which has been shown to support charge ordered and magnetic stripe phases and an hourglass magnetic excitation spectrum. We presen ...

Amer Physical Soc2016

Instrument intercomparison in the pulsed neutron fieldsat the CERN HiRadMat facility

Nikolaos Charitonidis

An intercomparison of the performances of active neutron detectors was carried out in pulsed neutron fields in the new HiRadMat facility at CERN. Five detectors were employed: four of them (two ionization chambers and two rem counters) are routinely employ ...

Pergamon-Elsevier Science Ltd2014

Time-Dependent Searches For Point Sources Of Neutrinos With The 40-String And 22-String Configurations Of Icecube

Matthias Wolf, Xiaoxia Bai, Mathieu Ribordy, Shirit Cohen

This paper presents four searches for flaring sources of neutrinos using the IceCube neutrino telescope. For the first time, a search is performed over the entire parameter space of energy, direction, and time with sensitivity to neutrino flares lasting be ...

2012

Flares from a candidate Galactic magnetar suggest a missing link to dim isolated neutron stars

Andrea Kraus

Magnetars(1) are young neutron stars with very strong magnetic fields of the order of 10(14)-10(15) G. They are detected in our Galaxy either as soft gamma-ray repeaters or anomalous X-ray pulsars. Soft gamma-ray repeaters are a rare type of gamma-ray tran ...

2008

Single-particle versus pair condensation of hard-core bosons with correlated hopping

Frédéric Mila, Julien Dorier

We investigate the consequences of correlated hopping on the ground state properties of hard-core bosons on a square lattice as revealed by extensive exact diagonalizations and quantum Monte Carlo simulations. While for noninteracting hard-core bosons the ...

2006

Primordial magnetic fields

Mikhail Chapochnikov

We discuss here the following questions related to magnetic fields in the early universe: 1. Observational constraints on primordial magnetic fields. 2. Different ideas put forward for explanation of large scale fields which can seed the galactic magnetic ...

2005