اشترك بالحزمة الذهبية واحصل على وصول غير محدود شمرا أكاديميا
تسجيل مستخدم جديدGRB 040403: a faint X-ray rich Gamma-ray Burst discovered by INTEGRAL
87
0
0.0
(
0
)
اسأل ChatGPT حول البحث
ﻻ يوجد ملخص باللغة العربية
GRB 040403 is one of the faintest gamma-ray bursts for which a rapid and accurate localization has been obtained. Here we report on the gamma-ray properties of this burst, based on observations with the IBIS instrument aboard INTEGRAL, and the results of searches for its optical afterglow. The steep spectrum (power law photon index = 1.9 in the 20-200 keV range) implies that GRB 040403 is most likely an X-ray rich burst. Our optical limit of R > 24.2 at 16.5 hours after the burst, indicates a rather faint afterglow, similar to those seen in other relatively soft and faint bursts.
قيم البحث
اقرأ أيضاً
We present the X- and $gamma$-ray detection of GRB 990704 and the discovery and study of its X-ray afterglow, 1SAX J1219.5-0350. Two pointed BeppoSAX observations with the narrow field instruments were performed on this source, separated in time by o
ne week. The decay of the X-ray flux within the first observation appears unusually slow, being best-fit by a power law with negative index 0.83$pm$0.16. Such a slow decay is consistent with the non-detection in our second observation, but its back-extrapolation to the time of the GRB largely underestimates the detected GRB X-ray prompt emission. In addition, the GRB prompt event shows, among the BeppoSAX-WFC detected sample, unprecedentedly high ratios of X- and gamma-ray peak fluxes (F$_{2-10 keV}$/F$_{40-700 keV}$$sim$0.6, and F$_{2-26 keV}$/F$_{40-700 keV}$$sim$1.6) and fluences (S$_{2-10 keV}$/S$_{40-700 keV}$$sim$1.5 and S$_{2-26 keV}$/S$_{40-700 keV}$$sim$2.8), making it, among the BeppoSAX arcminute-localized GRBs, the closest to the recently discovered class of Fast X-ray Transients.
INTEGRAL has observed 47 long-duration GRBs (T_90 > 2s) and 1 short-duration GRB (T_90 < 2s) in five years of observation since October 2002. This work presents the properties of the prompt emission of GRB 070707, which is the first short hard GRB ob
served by INTEGRAL. The spectral and temporal properties of GRB 070707 were determined using the two sensitive coded-mask gamma-ray instruments on board INTEGRAL, IBIS and SPI. The T_90 duration was 0.8s, and the spectrum of the prompt emission was obtained by joint deconvolution of IBIS and SPI data to yield a best fit power-law with photon index alpha = -1.19 +0.14 -0.13, which is consistent with the characteristics of short-hard gamma-ray bursts. The peak flux over 1 second was 1.79 photons/cm^2/s and the fluence over the same interval was 2.07 x 10^-7 erg/cm^2 in the energy range 20-200keV. The spectral lag measured between 25-50keV and 100-300keV is 20 +/- 5ms, consistent with the small or negligible lags measured for short bursts. The spectral and temporal properties of GRB 070707 are comparable to those of the short hard bursts detected by other gamma-ray satellites, including BATSE and Swift. We estimate a lower limit on the Lorentz factor Gamma >~ 25 for GRB 070707, assuming the typical redshift for short GRBs of z=0.35. This limit is consistent with previous estimates for short GRBs and is smaller than the lower limits of Gamma >~ 100 calculated for long GRBs. If GRB 070707 is a member of the recently postulated class of short GRBs at z ~ 1, the lower limit on Gamma increases to Gamma >~ 35.
GRB 020321 is a faint GRB that received wide follow-up attention in X-rays (BeppoSAX/NFI, Chandra/ACIS-S, XMM-Newton), radio (ATCA) and optical (ESO, HST). We identify a weak X-ray afterglow by a combined study of the Chandra and XMM-Newton observati
ons. Its decay index of 1.2 is typical for GRB afterglows. Inside the 4-accurate error box there is a weak optical counterpart candidate with a much shallower decay index.
The TESS exoplanet-hunting mission detected the rising and decaying optical afterglow of GRB 191016A, a long Gamma-Ray Burst (GRB) detected by Swift-BAT but without prompt XRT or UVOT follow-up due to proximity to the moon. The afterglow has a late p
eak at least 1000 seconds after the BAT trigger, with a brightest-detected TESS datapoint at 2589.7 s post-trigger. The burst was not detected by Fermi-LAT, but was detected by Fermi-GBM without triggering, possibly due to the gradual nature of rising light curve. Using ground-based photometry, we estimate a photometric redshift of $z_mathrm{phot} = 3.29pm{0.40}$. Combined with the high-energy emission and optical peak time derived from TESS, estimates of the bulk Lorentz factor $Gamma_mathrm{BL}$ range from $90-133$. The burst is relatively bright, with a peak optical magnitude in ground-based follow-up of $R=15.1$ mag. Using published distributions of GRB afterglows and considering the TESS sensitivity and sampling, we estimate that TESS is likely to detect $sim1$ GRB afterglow per year above its magnitude limit.
GRB 070724B is the first Gamma Ray Burst localized by SuperAGILE, the hard X-ray monitor aboard the AGILE satellite. The coordinates of the event were published $sim 19$ hours after the trigger. The Swift X-Ray Telescope pointed at the SuperAGILE loc
ation and detected the X-ray afterglow inside the SuperAGILE error circle. The AGILE gamma-ray Tracker and Minicalorimeter did not detect any significant gamma ray emission associated with GRB 070724B in the MeV and GeV range, neither prompt nor delayed. Searches of the optical afterglow were performed by the Swift UVOT and the Palomar automated 60-inch telescopes without any significant detection. Similarly the Very Large Array did not detect a radio afterglow. This is the first GRB event with a firm upper limit in the 100 MeV -- 30 GeV energy range, associated with an X-ray afterglow.
سجل دخول لتتمكن من نشر تعليقات
التعليقات
جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
