TITLE: GCN GRB OBSERVATION REPORT NUMBER: 1252 SUBJECT: IPN Upper Limits to a GRB Associated With SN2002ap DATE: 02/02/19 16:45:51 GMT FROM: Kevin Hurley at UCBerkeley/SSL K. Hurley, on behalf of the Ulysses GRB team; E. Mazets, S. Golenetskii, on behalf of the Konus-Wind GRB team; C. Guidorzi, E. Montanari, F. Frontera, and M. Feroci, on behalf of the BeppoSAX GRBM team; G. Ricker, D. Lamb, S. Woosley, G. Crew, J. Doty, G. Monnelly, J. Villasenor, N. Butler, J.G. Jernigan, A. Levine, F. Martel, E. Morgan, G. Prigozhin, J. Braga, R. Manchanda, G. Pizzichini, N. Kawai, M. Matsuoka, Y. Shirasaki, T. Tamagawa, K. Torii, T. Sakamoto, A. Yoshida, E. Fenimore, M. Galassi, T. Donaghy, C. Graziani, T. Tavenner, J-L Atteia, M. Boer, J-F Olive, and J-P Dezalay, on behalf of the HETE Team; I.Mitrofanov, D.Anfimov and M.Litvak on behalf on HEND/Odyssey GRB team; W. Boynton, C. Fellows, K. Harshman, and C. Shinohara, on behalf of the GRS/Odyssey GRB team; and T. Cline, on behalf of the Ulysses, Konus, and HETE GRB teams, report: We have searched for a gamma ray burst that might be associated with SN2002ap (Nakano, IAUC 7810), to investigate its similarity to the hypernova SN1998bw (Meikle et al. IAUC 7811). We have limited our search to data obtained between January 21 and January 29, 2002. During that period, no burst which could be localized by the IPN was found to have a source position in any way consistent with that of the supernova. That is, there was no event observed with two or more spacecraft that produced a source annulus or error box consistent with the supernova, and, although several events were observed each by single spacecraft in the network during this time, none of these unconfirmed events could be localized with any precision. Thus, lacking any definite evidence for an association, we quote only upper limits to a GRB from the direction of SN2002ap. These upper limits depend on the duration, spectrum, and arrival time within the search window, all of which are unknown. Each instrument in the network has a different sensitivity and duty cycle (determined by, among other things, the periods for which data were recovered, Earth-occultation for those spacecraft in low Earth orbit, Mars-occultation for the Mars Odyssey spacecraft, and the angle which the direction of SN2002ap made with the detector axis). For simplicity, we have assumed a 1 s long burst with a typical hard GRB spectrum to obtain the following fluence upper limits. We note that since SN2002ap is about 4 times closer than SN1998bw, then assuming that GRB980425 indeed originated in SN1998bw, a burst from SN2002ap might have been at least an order of magnitude more intense (neglecting beaming), and therefore easily detectable. 1. Ulysses. Duty cycle 95%. The Ulysses GRB detector has a quasi-isotropic response, so the arrival angle makes little difference. Upper limit: ~10^-6 erg/cm^2, 25-150 keV. 2. Konus. Duty cycle ~98%. The Wind spacecraft is several light-seconds from Earth, so the source was not occulted. Konus consists of two uncollimated right circular cylindrical detectors facing the north and south ecliptic poles. The ecliptic latitude of SN2002ap is approximately 5 degrees, so it is seen edge-on by the detectors. Upper limit: 5 x 10^-7 erg/cm^2, 20-2000 keV. 3. BeppoSAX GRBM. Complex response pattern and time-dependent duty cycle. Start date End date Duty Cycle 40-700 keV fluence, erg/cm^2 ------------------------------------------------------------------------ 20 Jan 06:32:49 21 Jan 13:00:00 47% 4 x 10^(-7) 21 Jan 13:00:00 22 Jan 14:41:09 0% (NO DATA) -- 22 Jan 14:41:09 22 Jan 20:00:58 36% 1 x 10^(-7) 22 Jan 20:00:58 24 Jan 17:00:00 0% (NO DATA) -- 24 Jan 17:00:00 25 Jan 09:35:00 42% 4 x 10^(-7) 25 Jan 09:35:00 29 Jan 23:59:59 0% (NO DATA) -- ------------------------------------------------------------------------ 4. HETE-FREGATE. Duty cycle 22%. The FREGATE instrument consists of four collimated right circular cylindrical detectors facing the anti-solar direction. SN2002ap made an angle of ~96 degrees to the detector axis, so any burst from it would not only have been observed edge-on, but also through the collimator. It would not have been observed by the WXM or the SXC. Nevertheless, bursts have been detected by FREGATE under precisely these non-ideal conditions. Sensitivity: 3.2 x 10^-6 erg/cm^2, 250-400 keV. The high energy range is due to the fact that the burst would have had to traverse the collimator. 5. Mars Odyssey HEND experiment. Duty cycle 64%. Sensitivity 10^-6 erg/cm^2 >60 keV. Many of these numbers are preliminary, and depend strongly on the assumptions about the time history, duration, arrival time, and spectrum of the assumed burst. More detailed information may be obtained from the people directly responsible for each experiment in the network.