TY - JOUR A1 - Henault-Brunet, V. A1 - Oskinova, Lida A1 - Guerrero, M. A. A1 - Sun, W. A1 - Chu, Y.-H. A1 - Evans, C. J. A1 - Gallagher, J. S. A1 - Gruendl, R. A. A1 - Reyes-Iturbide, J. T1 - Discovery of a Be/X-ray pulsar binary and associated supernova remnant in the wing of the small magellanic cloud JF - Monthly notices of the Royal Astronomical Society N2 - We report on a new Be/X-ray pulsar binary located in the Wing of the Small Magellanic Cloud (SMC). The strong pulsed X-ray source was discovered with the Chandra and XMM-Newton X-ray observatories. The X-ray pulse period of 1062 s is consistently determined from both Chandra and XMM-Newton observations, revealing one of the slowest rotating X-ray pulsars known in the SMC. The optical counterpart of the X-ray source is the emission-line star 2dFS 3831. Its B0-0.5(III)e+ spectral type is determined from VLT-FLAMES and 2dF optical spectroscopy, establishing the system as a Be/X-ray binary (Be-XRB). The hard X-ray spectrum is well fitted by a power law with additional thermal and blackbody components, the latter reminiscent of persistent Be-XRBs. This system is the first evidence of a recent supernova in the low-density surroundings of NGC602. We detect a shell nebula around 2dFS 3831 in H alpha and [OIII] images and conclude that it is most likely a supernova remnant. If it is linked to the supernova explosion that created this new X-ray pulsar, its kinematic age of (2-4) x 10(4) yr provides a constraint on the age of the pulsar. KW - stars: emission-line, Be KW - ISM: supernova remnants KW - Magellanic Clouds KW - X-rays: binaries Y1 - 2012 U6 - https://doi.org/10.1111/j.1745-3933.2011.01183.x SN - 0035-8711 VL - 420 IS - 1 SP - L13 EP - L17 PB - Wiley-Blackwell CY - Malden ER - TY - JOUR A1 - Telezhinsky, Igor O. A1 - Dwarkadas, Vikram V. A1 - Pohl, Martin T1 - Time-dependent escape of cosmic rays from supernova remnants, and their interaction with dense media JF - Astronomy and astrophysics : an international weekly journal N2 - Context. Supernova remnants (SNRs) are thought to be the main source of Galactic cosmic rays (CRs) up to the "knee" in CR spectrum. During the evolution of a SNR, the bulk of the CRs are confined inside the SNR shell. The highest-energy particles leave the system continuously, while the remaining adiabatically cooled particles are released when the SNR has expanded sufficiently and decelerated so that the magnetic field at the shock is no longer able to confine them. Particles escaping from the parent system may interact with nearby molecular clouds, producing.-rays in the process via pion decay. The soft gamma-ray spectra observed for a number of SNRs interacting with molecular clouds, however, challenge current theories of non-linear particle acceleration that predict harder spectra. Aims. We study how the spectrum of escaped particles depends on the time-dependent acceleration history in both Type Ia and core-collapse SNRs, as well as on different assumptions about the diffusion coefficient in the vicinity of the SNR. Methods. We solve the CR transport equation in a test-particle approach combined with numerical simulations of SNR evolution. Results. We extend our method for calculating the CR acceleration in SNRs to trace the escaped particles in a large volume around SNRs. We calculate the evolution of the spectra of CRs that have escaped from a SNR into a molecular cloud or dense shell for two diffusion models. We find a strong confinement of CRs in a close region around the SNR, and a strong dilution effect for CRs that were able to propagate out as far as a few SNR radii. KW - ISM: supernova remnants KW - ISM: clouds KW - cosmic rays Y1 - 2012 U6 - https://doi.org/10.1051/0004-6361/201118639 SN - 0004-6361 VL - 541 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Rettig, R. A1 - Pohl, M. T1 - The properties of non-thermal X-ray filaments in young supernova remnants JF - Astronomy and astrophysics : an international weekly journal N2 - Context. Young supernova remnants (SNRs) exhibit narrow filaments of non-thermal X-ray emission whose widths can be limited either by electron energy losses or damping of the magnetic field. Aims. We want to investigate whether or not different models of these filaments can be observationally tested. Methods. Using observational parameters of four historical remnants, we calculated the filament profiles and compared the spectra of the filaments with those of the total non-thermal emission. For that purpose, we solved a one-dimensional stationary transport equation for the isotropic differential number density of the electrons. Results. We find that the difference between the spectra of filament and total non-thermal emission above 1 keV is more pronounced in the damping model than in the energy-loss model. Conclusions. A considerable damping of the magnetic field can result in an observable difference between the spectra of filament and total non-thermal emission, thus potentially permitting an observational discrimination between the energy-loss model and the damping model of the X-ray filaments. KW - acceleration of particles KW - ISM: supernova remnants KW - ISM: magnetic fields KW - X-rays: ISM Y1 - 2012 U6 - https://doi.org/10.1051/0004-6361/201219409 SN - 0004-6361 VL - 545 IS - 5 PB - EDP Sciences CY - Les Ulis ER - TY - JOUR A1 - Niemiec, Jacek A1 - Pohl, Martin A1 - Bret, Antoine A1 - Wieland, Volkmar T1 - Nonrelativistic parallel shocks in unmagnetized and weakly magnetized plasmas JF - The astrophysical journal : an international review of spectroscopy and astronomical physics N2 - We present results of 2D3V particle-in-cell simulations of nonrelativistic plasma collisions with absent or parallel large-scale magnetic field for parameters applicable to the conditions at young supernova remnants. We study the collision of plasma slabs of different density, leading to two different shocks and a contact discontinuity. Electron dynamics play an important role in the development of the system. While nonrelativistic shocks in both unmagnetized and magnetized plasmas can be mediated by Weibel-type instabilities, the efficiency of shock-formation processes is higher when a large-scale magnetic field is present. The electron distributions downstream of the forward and reverse shocks are generally isotropic, whereas that is not always the case for the ions. We do not see any significant evidence of pre-acceleration, neither in the electron population nor in the ion distribution. KW - acceleration of particles KW - instabilities KW - ISM: supernova remnants KW - methods: numerical KW - plasmas KW - shock waves Y1 - 2012 U6 - https://doi.org/10.1088/0004-637X/759/1/73 SN - 0004-637X SN - 1538-4357 VL - 759 IS - 1 PB - IOP Publ. Ltd. CY - Bristol ER -