TY - JOUR
A1 - Aliu, E.
A1 - Archambault, S.
A1 - Arlen, T.
A1 - Aune, T.
A1 - Beilicke, M.
A1 - Benbow, W.
A1 - Bouvier, A.
A1 - Buckley, J. H.
A1 - Bugaev, V.
A1 - Cesarini, A.
A1 - Ciupik, L.
A1 - Collins-Hughes, E.
A1 - Connolly, M. P.
A1 - Cui, W.
A1 - Dickherber, R.
A1 - Duke, C.
A1 - Dumm, J.
A1 - Dwarkadas, V. V.
A1 - Errando, M.
A1 - Falcone, A.
A1 - Federici, S.
A1 - Feng, Q.
A1 - Finley, J. P.
A1 - Finnegan, G.
A1 - Fortson, L.
A1 - Furniss, A.
A1 - Galante, N.
A1 - Gall, D.
A1 - Gillanders, G. H.
A1 - Godambe, S.
A1 - Gotthelf, E. V.
A1 - Griffin, S.
A1 - Grube, J.
A1 - Gyuk, G.
A1 - Hanna, D.
A1 - Holder, J.
A1 - Hughes, G.
A1 - Humensky, T. B.
A1 - Kaaret, P.
A1 - Kargaltsev, O.
A1 - Karlsson, N.
A1 - Khassen, Y.
A1 - Kieda, D.
A1 - Krawczynski, H.
A1 - Krennrich, F.
A1 - Lang, M. J.
A1 - Lee, K.
A1 - Madhavan, A. S.
A1 - Maier, G.
A1 - Majumdar, P.
A1 - McArthur, S.
A1 - McCann, A.
A1 - Moriarty, P.
A1 - Mukherjee, R.
A1 - Nelson, T.
A1 - de Bhroithe, A. O&rsquo
A1 - Faolain,
A1 - Ong, R. A.
A1 - Orr, M.
A1 - Otte, A. N.
A1 - Park, N.
A1 - Perkins, J. S.
A1 - Pohl, M.
A1 - Prokoph, H.
A1 - Quinn, J.
A1 - Ragan, K.
A1 - Reyes, L. C.
A1 - Reynolds, P. T.
A1 - Roache, E.
A1 - Roberts, M.
A1 - Saxon, D. B.
A1 - Schroedter, M.
A1 - Sembroski, G. H.
A1 - Slane, P.
A1 - Smith, A. W.
A1 - Staszak, D.
A1 - Telezhinsky, I.
A1 - Tesic, G.
A1 - Theiling, M.
A1 - Thibadeau, S.
A1 - Tsurusaki, K.
A1 - Tyler, J.
A1 - Varlotta, A.
A1 - Vassiliev, V. V.
A1 - Vincent, S.
A1 - Vivier, M.
A1 - Wakely, S. P.
A1 - Weekes, T. C.
A1 - Weinstein, A.
A1 - Welsing, R.
A1 - Williams, D. A.
A1 - Zitzer, B.
T1 - DISCOVERY OF TeV GAMMA-RAY EMISSION FROM CTA 1 BY VERITAS
JF - ASTROPHYSICAL JOURNAL
N2 - We report the discovery of TeV gamma-ray emission coincident with the shell-type radio supernova remnant (SNR) CTA 1 using the VERITAS gamma-ray observatory. The source, VER J0006+729, was detected as a 6.5 standard deviation excess over background and shows an extended morphology, approximated by a two-dimensional Gaussian of semimajor (semiminor) axis 0.degrees 30 (0.degrees 24) and a centroid 5’ from the Fermi gamma-ray pulsar PSR J0007+7303 and its X-ray pulsar wind nebula (PWN). The photon spectrum is well described by a power-law dN/dE = N-0(E/3 TeV)(-Gamma), with a differential spectral index of Gamma = 2.2 +/- 0.2(stat) +/- 0.3(sys), and normalization N-0 = (9.1 +/- 1.3(stat) +/- 1.7(sys)) x 10(-14) cm(-2) s(-1) TeV-1. The integral flux, F-gamma = 4.0 x 10(-12) erg cm(-2) s(-1) above 1 TeV, corresponds to 0.2% of the pulsar spin-down power at 1.4 kpc. The energetics, colocation with the SNR, and the relatively small extent of the TeV emission strongly argue for the PWN origin of the TeV photons. We consider the origin of the TeV emission in CTA 1.
KW - gamma-rays: stars
KW - pulsars: individual (PSR J0007+7303)
KW - supernovae: individual (G119.5+10.2)
KW - X-rays: individual (RX J0007.0+7303)
Y1 - 2013
U6 - http://dx.doi.org/10.1088/0004-637X/764/1/38
SN - 0004-637X
(print)
VL - 764
IS - 1
PB - IOP PUBLISHING LTD
CY - BRISTOL
ER -
TY - JOUR
A1 - Aliu, E.
A1 - Archambault, S.
A1 - Arlen, T.
A1 - Aune, T.
A1 - Beilicke, M.
A1 - Benbow, W.
A1 - Bouvier, A.
A1 - Bradbury, S. M.
A1 - Buckley, J. H.
A1 - Bugaev, V.
A1 - Byrum, K.
A1 - Cannon, A.
A1 - Cesarini, A.
A1 - Ciupik, L.
A1 - Collins-Hughes, E.
A1 - Connolly, M. P.
A1 - Cui, W.
A1 - Decerprit, G.
A1 - Dickherber, R.
A1 - Duke, C.
A1 - Dumm, J.
A1 - Dwarkadas, V. V.
A1 - Errando, M.
A1 - Falcone, A.
A1 - Feng, Q.
A1 - Finley, J. P.
A1 - Finnegan, G.
A1 - Fortson, L.
A1 - Furniss, A.
A1 - Galante, N.
A1 - Gall, D.
A1 - Godambe, S.
A1 - Griffin, S.
A1 - Grube, J.
A1 - Gyuk, G.
A1 - Hanna, D.
A1 - Holder, J.
A1 - Huan, H.
A1 - Hughes, G.
A1 - Humensky, T. B.
A1 - Kaaret, P.
A1 - Karlsson, N.
A1 - Kertzman, M.
A1 - Khassen, Y.
A1 - Kieda, D.
A1 - Krawczynski, H.
A1 - Krennrich, F.
A1 - Lang, M. J.
A1 - Lee, K.
A1 - Maier, G.
A1 - Majumdar, P.
A1 - McArthur, S.
A1 - McCann, A.
A1 - Millis, J.
A1 - Moriarty, P.
A1 - Mukherjee, R.
A1 - Nunez, P. D.
A1 - Ong, R. A.
A1 - Orr, M.
A1 - Otte, A. N.
A1 - Pandel, D.
A1 - Park, N.
A1 - Perkins, J. S.
A1 - Pohl, M.
A1 - Prokoph, H.
A1 - Quinn, J.
A1 - Ragan, K.
A1 - Reyes, L. C.
A1 - Reynolds, P. T.
A1 - Roache, E.
A1 - Rose, H. J.
A1 - Ruppel, J.
A1 - Saxon, D. B.
A1 - Schroedter, M.
A1 - Sembroski, G. H.
A1 - Skole, C.
A1 - Smith, A. W.
A1 - Staszak, D.
A1 - Telezhinsky, I.
A1 - Tesic, G.
A1 - Theiling, M.
A1 - Thibadeau, S.
A1 - Tsurusaki, K.
A1 - Tyler, J.
A1 - Varlotta, A.
A1 - Vincent, S.
A1 - Vivier, M.
A1 - Wakely, S. P.
A1 - Ward, J. E.
A1 - Weekes, T. C.
A1 - Weinstein, A.
A1 - Weisgarber, T.
A1 - Welsing, R.
A1 - Williams, D. A.
A1 - Zitzer, B.
T1 - Veritas observations of the nova in V407 CYGNI
JF - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2 - We report on very high energy (E > 100 GeV) gamma-ray observations of V407 Cygni, a symbiotic binary that underwent a nova outburst producing 0.1-10 GeV gamma rays during 2010 March 10-26. Observations were made with the Very Energetic Radiation Imaging Telescope Array System during 2010 March 19-26 at relatively large zenith angles due to the position of V407 Cyg. An improved reconstruction technique for large zenith angle observations is presented and used to analyze the data. We do not detect V407 Cygni and place a differential upper limit on the flux at 1.6 TeV of 2.3 x 10(-12) erg cm(-2) s(-1) (at the 95% confidence level). When considered jointly with data from Fermi-LAT, this result places limits on the acceleration of very high energy particles in the nova.
KW - gamma rays: general
KW - novae, cataclysmic variables
KW - white dwarfs
Y1 - 2012
U6 - http://dx.doi.org/10.1088/0004-637X/754/1/77
SN - 0004-637X (print)
VL - 754
IS - 1
PB - IOP Publ. Ltd.
CY - Bristol
ER -
TY - JOUR
A1 - Aliu, E.
A1 - Archambault, S.
A1 - Aune, T.
A1 - Behera, B.
A1 - Beilicke, M.
A1 - Benbow, W.
A1 - Berger, K.
A1 - Bird, R.
A1 - Buckley, J. H.
A1 - Bugaev, V.
A1 - Cardenzana, J. V.
A1 - Cerruti, M.
A1 - Chen, Xuhui
A1 - Ciupik, L.
A1 - Collins-Hughes, E.
A1 - Connolly, M. P.
A1 - Cui, W.
A1 - Dumm, J.
A1 - Dwarkadas, V. V.
A1 - Errando, M.
A1 - Falcone, A.
A1 - Federici, Simone
A1 - Feng, Q.
A1 - Finley, J. P.
A1 - Fleischhack, H.
A1 - Fortin, P.
A1 - Fortson, L.
A1 - Furniss, A.
A1 - Galante, N.
A1 - Gall, D.
A1 - Gillanders, G. H.
A1 - Griffin, S.
A1 - Griffiths, S. T.
A1 - Grube, J.
A1 - Gyuk, G.
A1 - Hanna, D.
A1 - Holder, J.
A1 - Hughes, G.
A1 - Humensky, T. B.
A1 - Kaaret, P.
A1 - Kertzman, M.
A1 - Khassen, Y.
A1 - Kieda, D.
A1 - Krennrich, F.
A1 - Kumar, S.
A1 - Lang, M. J.
A1 - Madhavan, A. S.
A1 - Maier, G.
A1 - McCann, A. J.
A1 - Meagher, K.
A1 - Millis, J.
A1 - Moriarty, P.
A1 - Mukherjee, R.
A1 - Nieto, D.
A1 - Ong, R. A.
A1 - Otte, A. N.
A1 - Pandel, D.
A1 - Park, N.
A1 - Pohl, Martin
A1 - Popkow, A.
A1 - Prokoph, H.
A1 - Quinn, J.
A1 - Ragan, K.
A1 - Rajotte, J.
A1 - Ratliff, G.
A1 - Reyes, L. C.
A1 - Reynolds, P. T.
A1 - Richards, G. T.
A1 - Roache, E.
A1 - Rousselle, J.
A1 - Sembroski, G. H.
A1 - Shahinyan, K.
A1 - Sheidaei, F.
A1 - Smith, A. W.
A1 - Staszak, D.
A1 - Telezhinsky, Igor
A1 - Tsurusaki, K.
A1 - Tucci, J. V.
A1 - Tyler, J.
A1 - Varlotta, A.
A1 - Vassiliev, V. V.
A1 - Vincent, S.
A1 - Wakely, S. P.
A1 - Ward, J. E.
A1 - Weinstein, A.
A1 - Welsing, R.
A1 - Wilhelm, Alina
T1 - Investigating the TeV morpholoy of MGRO J1908+06 with veritas
JF - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2 - We report on deep observations of the extended TeV gamma-ray source MGRO J1908+06 made with the VERITAS very high energy gamma-ray observatory. Previously, the TeV emission has been attributed to the pulsar wind nebula (PWN) of the Fermi-LAT pulsar PSR J1907+0602. We detect MGRO J1908+06 at a significance level of 14 standard deviations (14 sigma) and measure a photon index of 2.20 +/- 0.10(stat) +/- 0.20(sys). The TeV emission is extended, covering the region near PSR J1907+0602 and also extending toward SNR G40.5-0.5. When fitted with a two-dimensional Gaussian, the intrinsic extension has a standard deviation of sigma(src) = 0 degrees.44 +/- 0 degrees.02. In contrast to other TeV PWNe of similar age in which the TeV spectrum softens with distance from the pulsar, the TeV spectrum measured near the pulsar location is consistent with that measured at a position near the rim of G40.5-0.5, 0 degrees.33 away.
KW - gamma rays: general
KW - gamma-ray burst: individual (MGRO J1908+06, VER J1907+062)
KW - pulsars: individual (PSR J1907+0602)
KW - ISM: supernova remnants
Y1 - 2014
U6 - http://dx.doi.org/10.1088/0004-637X/787/2/166
SN - 0004-637X (print)
SN - 1538-4357 (online)
VL - 787
IS - 2
PB - IOP Publ. Ltd.
CY - Bristol
ER -
TY - JOUR
A1 - tAliu, E.
A1 - Archambault, S.
A1 - Arlen, T.
A1 - Aune, T.
A1 - Beilicke, M.
A1 - Benbow, W.
A1 - Bird, R.
A1 - Bouvier, A.
A1 - Bradbury, S. M.
A1 - Buckley, J. H.
A1 - Bugaev, V.
A1 - Byrum, K.
A1 - Cannon, A.
A1 - Cesarini, A.
A1 - Ciupik, L.
A1 - Collins-Hughes, E.
A1 - Connolly, M. P.
A1 - Cui, W.
A1 - Dickherber, R.
A1 - Duke, C.
A1 - Dumm, J.
A1 - Dwarkadas, V. V.
A1 - Errando, M.
A1 - Falcone, A.
A1 - Federici, Simone
A1 - Feng, Q.
A1 - Finley, J. P.
A1 - Finnegan, G.
A1 - Fortson, L.
A1 - Furniss, A.
A1 - Galante, N.
A1 - Gall, D.
A1 - Gillanders, G. H.
A1 - Godambe, S.
A1 - Gotthelf, E. V.
A1 - Griffin, S.
A1 - Grube, J.
A1 - Gyuk, G.
A1 - Hanna, D.
A1 - Holder, J.
A1 - Huan, H.
A1 - Hughes, G.
A1 - Humensky, T. B.
A1 - Kaaret, P.
A1 - Karlsson, N.
A1 - Kertzman, M.
A1 - Khassen, Y.
A1 - Kieda, D.
A1 - Krawczynski, H.
A1 - Krennrich, F.
A1 - Lang, M. J.
A1 - Lee, K.
A1 - Madhavan, A. S.
A1 - Maier, G.
A1 - Majumdar, P.
A1 - McArthur, S.
A1 - McCann, A.
A1 - Millis, J.
A1 - Moriarty, P.
A1 - Mukherjee, R.
A1 - Nelson, T.
A1 - de Bhroithe, A. O'Faolain
A1 - Ong, R. A.
A1 - Orr, M.
A1 - Otte, A. N.
A1 - Pandel, D.
A1 - Park, N.
A1 - Perkins, J. S.
A1 - Pohl, Martin
A1 - Popkow, A.
A1 - Prokoph, H.
A1 - Quinn, J.
A1 - Ragan, K.
A1 - Reyes, L. C.
A1 - Reynolds, P. T.
A1 - Roache, E.
A1 - Rose, H. J.
A1 - Ruppel, Jens
A1 - Saxon, D. B.
A1 - Schroedter, M.
A1 - Sembroski, G. H.
A1 - Sentuerk, G. D.
A1 - Skole, C.
A1 - Telezhinsky, Igor
A1 - Tesic, G.
A1 - Theiling, M.
A1 - Thibadeau, S.
A1 - Tsurusaki, K.
A1 - Tyler, J.
A1 - Varlotta, A.
A1 - Vassiliev, V. V.
A1 - Vincent, S.
A1 - Wakely, S. P.
A1 - Ward, J. E.
A1 - Weekes, T. C.
A1 - Weinstein, A.
A1 - Weisgarber, T.
A1 - Welsing, R.
A1 - Williams, D. A.
A1 - Zitzer, B.
T1 - Discovery of TeV Gamma-Ray emission toward supernova remnant SNR G78.2+2.1
JF - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2 - We report the discovery of an unidentified, extended source of very-high-energy gamma-ray emission, VER J2019+407, within the radio shell of the supernova remnant SNR G78.2+2.1, using 21.4 hr of data taken by the VERITAS gamma-ray observatory in 2009. These data confirm the preliminary indications of gamma-ray emission previously seen in a two-year (2007-2009) blind survey of the Cygnus region by VERITAS. VER J2019+407, which is detected at a post-trials significance of 7.5 standard deviations in the 2009 data, is localized to the northwestern rim of the remnant in a region of enhanced radio and X-ray emission. It has an intrinsic extent of 0 degrees.23 +/- 0 degrees.03(stat-0 degrees.02sys)(+0 degrees.04) and its spectrum is well-characterized by a differential power law (dN/dE = N-0 x (E/TeV)-Gamma) with a photon index of Gamma = 2.37 +/- 0.14(stat) +/- 0.20(sys) and a flux normalization of N-0 = 1.5 +/- 0.2(stat) +/- 0.4(sys) x 10(-12) photon TeV-1 cm(-2) s(-1). This yields an integral flux of 5.2 +/- 0.8(stat) +/- 1.4(sys) x 10(-12) photon cm(-2) s(-1) above 320 GeV, corresponding to 3.7% of the Crab Nebula flux. We consider the relationship of the TeV gamma-ray emission with the GeV gamma-ray emission seen from SNR G78.2+2.1 as well as that seen from a nearby cocoon of freshly accelerated cosmic rays. Multiple scenarios are considered as possible origins for the TeV gamma-ray emission, including hadronic particle acceleration at the SNR shock.
KW - acceleration of particles
KW - cosmic rays
KW - gamma rays: general
KW - ISM: supernova remnants
Y1 - 2013
U6 - http://dx.doi.org/10.1088/0004-637X/770/2/93
SN - 0004-637X (print)
VL - 770
IS - 2
PB - IOP Publ. Ltd.
CY - Bristol
ER -
TY - JOUR
A1 - Telezhinsky, I.
A1 - Dwarkadas, V. 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 - http://dx.doi.org/10.1051/0004-6361/201118639
SN - 0004-6361 (print)
VL - 541
PB - EDP Sciences
CY - Les Ulis
ER -
TY - JOUR
A1 - Aliu, E.
A1 - Aune, T.
A1 - Behera, B.
A1 - Beilicke, M.
A1 - Benbow, W.
A1 - Berger, K.
A1 - Bird, R.
A1 - Bouvier, A.
A1 - Buckley, J. H.
A1 - Bugaev, V.
A1 - Cerruti, M.
A1 - Chen, Xuhui
A1 - Ciupik, L.
A1 - Connolly, M. P.
A1 - Cui, W.
A1 - Dumm, J.
A1 - Dwarkadas, V. V.
A1 - Errando, M.
A1 - Falcone, A.
A1 - Federici, Simone
A1 - Feng, Q.
A1 - Finley, J. P.
A1 - Fleischhack, H.
A1 - Fortin, P.
A1 - Fortson, L.
A1 - Furniss, A.
A1 - Galante, N.
A1 - Gillanders, G. H.
A1 - Gotthelf, E. V.
A1 - Griffin, S.
A1 - Griffiths, S. T.
A1 - Grube, J.
A1 - Gyuk, G.
A1 - Hanna, D.
A1 - Holder, J.
A1 - Hughes, G.
A1 - Humensky, T. B.
A1 - Johnson, C. A.
A1 - Kaaret, P.
A1 - Kargaltsev, O.
A1 - Kertzman, M.
A1 - Khassen, Y.
A1 - Kieda, D.
A1 - Krennrich, F.
A1 - Lang, M. J.
A1 - Madhavan, A. S.
A1 - Maier, G.
A1 - McArthur, S.
A1 - McCann, A.
A1 - Millis, J.
A1 - Moriarty, P.
A1 - Mukherjee, R.
A1 - Nieto, D.
A1 - Ong, R. A.
A1 - Otte, A. N.
A1 - Pandel, D.
A1 - Park, N.
A1 - Pohl, Martin
A1 - Popkow, A.
A1 - Prokoph, H.
A1 - Quinn, J.
A1 - Ragan, K.
A1 - Rajotte, J.
A1 - Reyes, L. C.
A1 - Reynolds, P. T.
A1 - Richards, G. T.
A1 - Roache, E.
A1 - Roberts, M.
A1 - Sembroski, G. H.
A1 - Shahinyan, K.
A1 - Smith, A. W.
A1 - Staszak, D.
A1 - Telezhinsky, Igor
A1 - Tucci, J. V.
A1 - Tyler, J.
A1 - Vincent, S.
A1 - Wakely, S. P.
A1 - Weinstein, A.
A1 - Welsing, R.
A1 - Wilhelm, Alina
A1 - Williams, D. A.
A1 - Zitzer, B.
T1 - Spatially resolving the very high energy emission from MRGO J2019+37 wih veritas
JF - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2 - We present very high energy (VHE) imaging of MGRO J2019+37 obtained with the VERITAS observatory. The bright extended (similar to 2 degrees) unidentified Milagro source is located toward the rich star formation region Cygnus-X. MGRO J2019+37 is resolved into two VERITAS sources. The faint, point-like source VER J2016+371 overlaps CTB 87, a filled-center remnant (SNR) with no evidence of a supernova remnant shell at the present time. Its spectrum is well fit in the 0.65-10 TeV energy range by a power-law model with photon index 2.3 +/- 0.4. VER J2019+378 is a bright extended (similar to 1 degrees) source that likely accounts for the bulk of the Milagro emission and is notably coincident with PSR J2021+3651 and the star formation region Sh 2-104. Its spectrum in the range 1-30 TeV is well fit with a power-law model of photon index 1.75 +/- 0.3, among the hardest values measured in the VHE band, comparable to that observed near Vela-X. We explore the unusual spectrum and morphology in the radio and X-ray bands to constrain possible emission mechanisms for this source.
KW - gamma rays : stars
KW - pulsars : individual (PSR J2021+3651)
KW - supernovae : individual (CTB 87)
Y1 - 2014
U6 - http://dx.doi.org/10.1088/0004-637X/788/1/78
SN - 0004-637X (print)
SN - 1538-4357 (online)
VL - 788
IS - 1
PB - IOP Publ. Ltd.
CY - Bristol
ER -
TY - JOUR
A1 - Telezhinsky, I.
A1 - Dwarkadas, V. V.
A1 - Pohl, Martin
T1 - Particle spectra from acceleration at forward and reverse shocks of young Type Ia Supernova Remnants
JF - Astroparticle physics
N2 - We study cosmic-ray acceleration in young Type Ia Supernova Remnants (SNRs) by means of test-particle diffusive shock acceleration theory and 1-D hydrodynamical simulations of their evolution. In addition to acceleration at the forward shock, we explore the particle acceleration at the reverse shock in the presence of a possible substantial magnetic field, and consequently the impact of this acceleration on the particle spectra in the remnant. We investigate the time evolution of the spectra for various time-dependent profiles of the magnetic field in the shocked region of the remnant. We test a possible influence on particle spectra of the Alfvenic drift of scattering centers in the precursor regions of the shocks. In addition, we study the radiation spectra and morphology in a broad band from radio to gamma-rays. It is demonstrated that the reverse shock contribution to the cosmic-ray particle population of young Type la SNRs may be significant, modifying the spatial distribution of particles and noticeably affecting the volume-integrated particle spectra in young SNRs. In particular spectral structures may arise in test-particle calculations that are often discussed as signatures of non-linear cosmic-ray modification of shocks. Therefore, the spectrum and morphology of emission, and their time evolution, differ from pure forward-shock solutions.
KW - Supernova Remnants
KW - Cosmic rays
KW - Cosmic-ray acceleration
KW - Hydrodynamics
KW - Forward and reverse shocks
Y1 - 2012
U6 - http://dx.doi.org/10.1016/j.astropartphys.2011.10.001
SN - 0927-6505 (print)
VL - 35
IS - 6
SP - 300
EP - 311
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Acharya, B. S.
A1 - Aramo, C.
A1 - Babic, A.
A1 - Barrio, J. A.
A1 - Baushev, Anton
A1 - Tjus, J. Becker
A1 - Berge, D.
A1 - Bohacova, M.
A1 - Bonardi, A.
A1 - Brown, A.
A1 - Bugaev, V.
A1 - Bulik, T.
A1 - Burton, M.
A1 - Busetto, G.
A1 - Caraveo, P.
A1 - Carosi, R.
A1 - Carr, J.
A1 - Chadwick, P.
A1 - Chudoba, J.
A1 - Conforti, V.
A1 - Connaughton, V.
A1 - Contreras, J. L.
A1 - Cotter, G.
A1 - Dazzi, F.
A1 - De Franco, A.
A1 - de la Calle, I.
A1 - Lopez, R. de los Reyes
A1 - De Lotto, B.
A1 - De Palma, F.
A1 - Di Girolamo, T.
A1 - Di Giulio, C.
A1 - Di Pierro, F.
A1 - Dournaux, J. -L.
A1 - Dwarkadas, V.
A1 - Ebr, J.
A1 - Egberts, K.
A1 - Fesquet, M.
A1 - Fleischhack, H.
A1 - Font, L.
A1 - Fontaine, G.
A1 - Foerster, A.
A1 - Füßling, Matthias
A1 - Garcia, B.
A1 - Lopez, R. Garcia
A1 - Garczarczyk, M.
A1 - Gargano, F.
A1 - Garrido, D.
A1 - Gaug, M.
A1 - Giglietto, N.
A1 - Giordano, F.
A1 - Giuliani, A.
A1 - Godinovic, N.
A1 - Gonzalez, M. M.
A1 - Grabarczyk, T.
A1 - Hassan, T.
A1 - Hoerandel, J.
A1 - Hrabovsky, M.
A1 - Hrupec, D.
A1 - Humensky, T. B.
A1 - Huovelin, J.
A1 - Jamrozy, M.
A1 - Janecek, P.
A1 - Kaaret, P. E.
A1 - Katz, U.
A1 - Kaufmann, S.
A1 - Khelifi, B.
A1 - Kluzniak, W.
A1 - Kocot, J.
A1 - Komin, N.
A1 - Kubo, H.
A1 - Kushida, J.
A1 - Lamanna, G.
A1 - Lee, W. H.
A1 - Lenain, J. -P.
A1 - Lohse, T.
A1 - Lombardi, S.
A1 - Lopez-Coto, R.
A1 - Lopez-Oramas, A.
A1 - Lucarelli, F.
A1 - Maccarone, M. C.
A1 - Maier, G.
A1 - Majumdar, P.
A1 - Malaguti, G.
A1 - Mandat, D.
A1 - Mazziotta, M. N.
A1 - Meagher, K.
A1 - Mirabal, N.
A1 - Morselli, A.
A1 - Moulin, E.
A1 - Niemiec, J.
A1 - Nievas, M.
A1 - Nishijima, K.
A1 - Nosek, D.
A1 - Nunio, F.
A1 - Ohishi, M.
A1 - Ohm, S.
A1 - Ong, R. A.
A1 - Orito, R.
A1 - Otte, N.
A1 - Palatka, M.
A1 - Pareschi, G.
A1 - Pech, M.
A1 - Persic, M.
A1 - Pohl, Manuela
A1 - Prouza, M.
A1 - Quirrenbach, A.
A1 - Raino, S.
A1 - Fernandez, G. Rodriguez
A1 - Romano, P.
A1 - Rovero, A. C.
A1 - Rudak, B.
A1 - Schovanek, P.
A1 - Shayduk, M.
A1 - Siejkowski, H.
A1 - Sillanpaa, A.
A1 - Stefanik, S.
A1 - Stolarczyk, T.
A1 - Szanecki, M.
A1 - Szepieniec, T.
A1 - Tejedor, L. A.
A1 - Telezhinsky, Igor
A1 - Teshima, M.
A1 - Tibaldo, L.
A1 - Tibolla, O.
A1 - Tovmassian, G.
A1 - Travnicek, P.
A1 - Trzeciak, M.
A1 - Vallania, P.
A1 - van Eldik, C.
A1 - Vercellone, S.
A1 - Vigorito, C.
A1 - Wagner, S. J.
A1 - Wakely, S. P.
A1 - Weinstein, A.
A1 - Wierzcholska, A.
A1 - Wilhelm, Alina
A1 - Wojcik, P.
A1 - Yoshikoshi, T.
T1 - The Cherenkov Telescope Array potential for the study of young supernova remnants
JF - Astroparticle physics
N2 - Supernova remnants (SNRs) are among the most important targets for gamma-ray observatories. Being prominent non-thermal sources, they are very likely responsible for the acceleration of the bulk of Galactic cosmic rays (CRS). To firmly establish the SNR paradigm for the origin of cosmic rays, it should be confirmed that protons are indeed accelerated in, and released from, SNRs with the appropriate flux and spectrum. This can be done by detailed theoretical models which account for microphysics of acceleration and various radiation processes of hadrons and leptons. The current generation of Cherenkov telescopes has insufficient sensitivity to constrain theoretical models. A new facility, the Cherenkov Telescope Array (CTA), will have superior capabilities and may finally resolve this long standing issue of high-energy astrophysics. We want to assess the capabilities of CTA to reveal the physics of various types of SNRs in the initial 2000 years of their evolution. During this time, the efficiency to accelerate cosmic rays is highest. We perform time-dependent simulations of the hydrodynamics, the magnetic fields, the cosmic-ray acceleration, and the non-thermal emission for type Ia, Ic and IIP SNRs. We calculate the CTA response to the y-ray emission from these SNRs for various ages and distances, and we perform a realistic analysis of the simulated data. We derive distance limits for the detectability and resolvability of these SNR types at several ages. We test the ability of CTA to reconstruct their morphological and spectral parameters as a function of their distance. Finally, we estimate how well CTA data will constrain the theoretical models. (C) 2014 Elsevier B.V. All rights reserved.
KW - Acceleration of particles
KW - Gamma rays: General
KW - ISM: Supernova remnants
KW - Radiation mechanisms: Non-termal
Y1 - 2015
U6 - http://dx.doi.org/10.1016/j.astropartphys.2014.08.005
SN - 0927-6505 (print)
SN - 1873-2852 (online)
VL - 62
SP - 152
EP - 164
PB - Elsevier
CY - Amsterdam
ER -
TY - JOUR
A1 - Dwarkadas, V. V.
A1 - Rosenberg, D.
T1 - X-ray Emission from Ionized Wind-Bubbles around Wolf-Rayet Stars
JF - Wolf-Rayet Stars : Proceedings of an International Workshop held in Potsdam, Germany, 1.–5. June 2015
N2 - Using a code that employs a self-consistent method for computing the effects of photoionization on circumstellar gas dynamics, we model the formation of wind-driven nebulae around massive Wolf-Rayet (W-R) stars. Our algorithm incorporates a simplified model of the photo-ionization source, computes the fractional ionization of hydrogen due to the photoionizing flux and recombination, and determines self-consistently the energy balance due to ionization, photo-heating and radiative cooling. We take into account changes in stellar properties and mass-loss over the star's evolution. Our multi-dimensional simulations clearly reveal the presence of strong ionization front instabilities. Using various X-ray emission models, and abundances consistent with those derived for W-R nebulae, we compute the X-ray flux and spectra from our wind bubble models. We show the evolution of the X-ray spectral features with time over the evolution of the star, taking the absorption of the X-rays by the ionized bubble into account. Our simulated X-ray spectra compare reasonably well with observed spectra of Wolf-Rayet bubbles. They suggest that X-ray nebulae around massive stars may not be easily detectable, consistent with observations.∗
Y1 - 2015
U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-88301
SP - 329
EP - 332
ER -