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LOFAR Transients and the Radio Sky Monitor

Sissa Medialab Srl (2008) 030
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Predicting Radio Activity in X-ray Binaries with Optical/Infrared Monitoring

Sissa Medialab Srl (2008) 012

Authors:

David M Russell, Rob Fender
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Simultaneous X-ray/Radio Observations of Cir X-1

Sissa Medialab Srl (2008) 037

Authors:

Paolo Soleri, Valeriu M Tudose, Rob Fender, M van der Klis
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Coupled radio and X-ray emission and evidence for discrete ejecta in the jets of SS 433

Astrophysical Journal 682:2 (2008) 1141-1151

Authors:

JCA Miller-Jones, S Migliari, RP Fender, TWJ Thompson, M Van Der Klis, M Méndez

Abstract:

We present five epochs of simultaneous radio (VLA) and X-ray (Chandra) observations of SS 433 to study the relation between the radio and X-ray emission in the arcsecond-scale jets of the source. We detected X-ray emission from the extended jets in only one of the five epochs of observation, indicating that the X-ray reheating mechanism is transient. The reheating does not correlate with the total flux in the core or in the extended radio jets. However, the radio emission in the X-ray reheating regions is enhanced when X-ray emission is present. Deep images of the jets in linear polarization show that outside of the core, the magnetic field in the jets is aligned parallel to the local velocity vector, strengthening the case for the jets to be composed of discrete bullets rather than being continuous flux tubes. We also observed anomalous regions of polarized emission well away from the kinematic trace, confirming the large-scale anisotropy of the magnetic field in the ambient medium surrounding the jets. © 2008. The American Astronomical Society. All rights reserved.
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The metamorphosis of supernova SN 2008D/XRF 080109: a link between supernovae and GRBs/hypernovae.

Science (New York, N.Y.) 321:5893 (2008) 1185-1188

Authors:

Paolo A Mazzali, Stefano Valenti, Massimo Della Valle, Guido Chincarini, Daniel N Sauer, Stefano Benetti, Elena Pian, Tsvi Piran, Valerio D'Elia, Nancy Elias-Rosa, Raffaella Margutti, Francesco Pasotti, L Angelo Antonelli, Filomena Bufano, Sergio Campana, Enrico Cappellaro, Stefano Covino, Paolo D'Avanzo, Fabrizio Fiore, Dino Fugazza, Roberto Gilmozzi, Deborah Hunter, Kate Maguire, Elisabetta Maiorano, Paola Marziani, Nicola Masetti, Felix Mirabel, Hripsime Navasardyan, Ken'ichi Nomoto, Eliana Palazzi, Andrea Pastorello, Nino Panagia, LJ Pellizza, Re'em Sari, Stephen Smartt, Gianpiero Tagliaferri, Masaomi Tanaka, Stefan Taubenberger, Nozomu Tominaga, Carrie Trundle, Massimo Turatto

Abstract:

The only supernovae (SNe) to show gamma-ray bursts (GRBs) or early x-ray emission thus far are overenergetic, broad-lined type Ic SNe (hypernovae, HNe). Recently, SN 2008D has shown several unusual features: (i) weak x-ray flash (XRF), (ii) an early, narrow optical peak, (iii) disappearance of the broad lines typical of SN Ic HNe, and (iv) development of helium lines as in SNe Ib. Detailed analysis shows that SN 2008D was not a normal supernova: Its explosion energy (E approximately 6x10(51) erg) and ejected mass [ approximately 7 times the mass of the Sun (M(middle dot in circle))] are intermediate between normal SNe Ibc and HNe. We conclude that SN 2008D was originally a approximately 30 M(middle dot in circle) star. When it collapsed, a black hole formed and a weak, mildly relativistic jet was produced, which caused the XRF. SN 2008D is probably among the weakest explosions that produce relativistic jets. Inner engine activity appears to be present whenever massive stars collapse to black holes.
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