GRB 0305028: Chandra observations

Kristian Pedersen and Jens Hjorth

Chandra ACIS-I images

First epoch (GRB trigger +5.98 -> 6.28 days) Chandra ACIS-S3 26.1 ksec image with HETE/IPN localization (blue circle). Sources labeled with numbers refer to GCN #2275, while sources labeled with letters are our own detections (using wavdetect). Second epoch (GRB trigger +11.81 -> 12.04 days) Chandra ACIS-S3 20 ksec image with HETE/IPN localization (blue circle). Our own source detections are shown (using wavdetect). Cuts and colors similar to first epoch image.

Sources:
Comparing count rates for detected sources in epoch 1 and epoch 2 (using wavdetect):



Source Epoch 1 counts *Epoch 2 counts
1 39 +/-6 (18 sigma)10 +/-3.3 (4.5 sigma)
4 29 +/-5 (13 sigma) 20 +/-4.6 (8.8 sigma)
10 10 +/-3 (4.8 sigma) 9.3+/-3.2 (4.2 sigma)
9 11 +/-4 (5.4 sigma) 7.2+/-2.8 (3.2 sigma)
6 13 +/-4 (6.0 sigma)-
15 4.7+/-2.2 (2.3 sigma) -
A 8.4+/-3.0 (3.9 sigma) 18 +/-4.5 (7.0 sigma)
B 11 +/-3.6 (5.3 sigma) (probably less than 5 counts)
C 19 +/-4.5 (8.5 sigma) 12 +/-3.6 (5.2 sigma)
D 7.3+/-2.8 (3.3 sigma) -
E 7.5+/-2.8 (3.5 sigma) -
F 15 +/-3.9 (6.8 sigma) 10 +/-3.3 (4.5 sigma)

* For comparison to epoch 1, multiply with relative exposure: 26.1/20=1.3.

A: 17 03 59.0, -22 36 17.4 No obvious optical counterpart on DSS
B: 17 04 07.5, -22 36 08.3 Star at 17 04 07.5, -22 36 18.3, but too large off-set...
C: 17 03 51.3, -22 39 14.5 No obvious optical counterpart on DSS
D: 17 04 08.1, -22 40 01.0 Star/galaxy (?)
F: 17 03 54.0, -22 36 57.8 Star/galaxy(?)
E: Spurious detection?
6: 17 04 03.9, -22 35 43.0 No obvious optical counterpart on DSS


Version: June 25, 2003.