//////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8884 SUBJECT: GRB 090205: Swift detection of a burst DATE: 09/02/05 23:17:10 GMT FROM: Scott Barthelmy at NASA/GSFC M. Perri (ASDC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), D. N. Burrows (PSU), N. Gehrels (NASA/GSFC), O. Godet (U Leicester), C. Gronwall (PSU), S. T. Holland (CRESST/USRA/GSFC), E. A. Hoversten (PSU), W.B Landsman (GSFC), C. B. Markwardt (CRESST/GSFC/UMD), F. E. Marshall (NASA/GSFC), D. M. Palmer (LANL), M. Stamatikos (NASA/ORAU), G. Stratta (ASDC), M. C. Stroh (PSU) and L. Vetere (PSU) report on behalf of the Swift Team: At 23:03:14 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 090205 (trigger=342121). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 220.925, -27.864 which is RA(J2000) = 14h 43m 42s Dec(J2000) = -27d 51' 48" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve shows a single peak with a duration of about 10 sec. The peak count rate was ~900 counts/sec (15-350 keV), at ~1 sec after the trigger. The XRT began observing the field at 23:04:42.4 UT, 87.6 seconds after the BAT trigger. Using promptly downlinked data we find an uncatalogued X-ray source located at RA, Dec 220.91150, -27.85298 which is equivalent to: RA(J2000) = 14h 43m 38.76s Dec(J2000) = -27d 51' 10.7" with an uncertainty of 3.8 arcseconds (radius, 90% containment). This location is 58 arcseconds from the BAT onboard position, within the BAT error circle. This position may be improved as more data are received; the latest position is available at http://www.swift.ac.uk/sper. A power-law fit to a spectrum formed from promptly downlinked event data gives a column density consistent with the Galactic value of 7.72e+20 cm^-2 (Kalberla et al. 2005). UVOT took a finding chart exposure of 150 seconds with the White filter starting 92 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The 8'x8' region for the list of sources generated on-board covers 100% of the BAT error circle and 100% of the XRT error circle. The list of sources is typically complete to about 18 mag. No correction has been made for the expected extinction corresponding to E(B-V) of 0.12. Burst Advocate for this burst is M. Perri (perri AT asdc.asi.it). Please contact the BA by email if you require additional information regarding Swift followup of this burst. In extremely urgent cases, after trying the Burst Advocate, you can contact the Swift PI by phone (see Swift TOO web site for information: http://www.swift.psu.edu/too.html.) //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8885 SUBJECT: GRB 090205: Enhanced Swift-XRT position DATE: 09/02/06 02:40:31 GMT FROM: Phil Evans at U of Leicester P.A. Evans, M.R. Goad, J.P. Osborne and A.P. Beardmore (U. Leicester) report on behalf of the Swift-XRT team. Using 944 s of XRT Photon Counting mode data and 1 UVOT images for GRB 090205, we find an astrometrically corrected X-ray position (using the XRT-UVOT alignment and matching UVOT field sources to the USNO-B1 catalogue): RA, Dec = 220.91119, -27.85267 which is equivalent to: RA (J2000): 14h 43m 38.69s Dec (J2000): -27d 51' 09.6" with an uncertainty of 1.8 arcsec (radius, 90% confidence). This position may be improved as more data are received. The latest position can be viewed at http://www.swift.ac.uk/xrt_positions. Position enhancement is described by Goad et al. (2007, A&A, 476, 1401 http://www.swift.ac.uk/xrt_positions/Goad.pdf), the current algorithm is an extension of this method. This circular was automatically generated, and is an official product of the Swift-XRT team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8886 SUBJECT: GRB 090205: Swift-BAT refined analysis DATE: 09/02/06 03:30:35 GMT FROM: Scott Barthelmy at NASA/GSFC GRB 090205: Swift-BAT refined analysis J. R. Cummings (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. M. Palmer (LANL), M. Perri (ASDC), T. Sakamoto (GSFC/UMBC), G. Sato (ISAS), M. Stamatikos (GSFC/ORAU), J. Tueller (GSFC), T. N. Ukwatta (GWU) (i.e. the Swift-BAT team): Using the data set from T-239 to T+455 sec from recent telemetry downlinks, we report further analysis of BAT GRB 090205 (trigger #342121) (Perri, et al., GCN Circ. 8884). The BAT ground-calculated position is RA, Dec = 220.917, -27.848 deg which is RA(J2000) = 14h 43m 40.0s Dec(J2000) = -27d 50' 51.4" with an uncertainty of 2.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 100%. The mask-weighted light curve shows a single peak starting at ~T-5 sec, peaking at ~T+3 sec, and returning to background at ~T+100 sec. T90 (15-350 keV) is 8.8 +- 1.8 sec (estimated error including systematics). The time-averaged spectrum from T-2.9 to T+6.6 sec is best fit by a simple power-law model. The power law index of the time-averaged spectrum is 2.15 +- 0.23. The fluence in the 15-150 keV band is 1.9 +- 0.3 x 10^-7 erg/cm2. The 1-sec peak photon flux measured from T+4.09 sec in the 15-150 keV band is 0.5 +- 0.1 ph/cm2/sec. All the quoted errors are at the 90% confidence level. The results of the batgrbproduct analysis are available at http://gcn.gsfc.nasa.gov/notices_s/342121/BA/ //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8887 SUBJECT: GRB 090205: VLT candidate afterglow DATE: 09/02/06 07:20:57 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo, C. C. Thoene, D. Fugazza (INAF-OAB), V. D'Elia, S. Piranomonte (INAF-OAR), R. Salvaterra, S. Covino, S. Campana (INAF-OAB), G. Chincarini (Univ. Bicocca) report, on behalf of the MISTICI collaboration: We observed the field of GRB 090205 (Perri et al., GCN 8884) with the ESO-VLT in imaging mode starting about 7.1 hours after the burst. Observations were carried out in R and I-band with the FORS1 camera. Inside the enhanced XRT error circle (Evans et al. GCN 8885) we find a source at the following coordinates (J2000): R.A. = 14:43:38.65 Dec. = -27:51:10.7 +/- 0.4" Preliminary photometry of this candidate afterglow gives R ~ 22.0 . We acknowledge the VLT staff for their support, in particular G. James and J. Smoker. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8888 SUBJECT: GRB 090205: GROND observations and photometric redshift estimate DATE: 09/02/06 07:26:53 GMT FROM: Thomas Kruehler at MPE/MPI T. Kruehler and J.Greiner (both MPE Garching) report on behalf of the GROND team: We observed the field of GRB 090205 (Swift trigger 342121, M. Perri et al.,GCN #8884) simultaneously in g'r'i'z'JHK with GROND mounted at the 2.2m ESO/MPI telescope at La Silla Observatory (Chile). Observations started on 03 Feb. 2009 at 05:25 UT, 6.33 h after the burst. The object reported by D'Avanzo et al. (GCN #8887) is very well detected in the i' band and redder, marginally in r' and not in g'. A preliminary i' band magnitude is 20.7 +- 0.2 roughly 7 hours after the burst. Interpreting the large r'-i' color and the g' band non detection as Lyman-alpha absorption in the GRB host, we derive a photometric redshift of 4.7 +- 0.3. This redshift estimate has been obtained using hyperZ (Bolzonella et al. 2000). We caution that this is based on a preliminary calibration. No statement about variability can be made at this point. [GCN OPS NOTE(06feb09): Per author's request, date and time in the sentence in the second paragraph were changed from "03 Feb" to "06 Feb" and from "05:25" to "05:23".] //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8889 SUBJECT: GRB 090205: VLT spectroscopic redshift DATE: 09/02/06 08:57:35 GMT FROM: Paolo D'Avanzo at INAF-OAB C. C. Thoene, D. Fugazza, P. D'Avanzo (INAF-OAB), V. D'Elia, S. Piranomonte (INAF-OAR), R. Salvaterra, S. Covino, S. Campana (INAF-OAB), G. Chincarini (Univ. Bicocca) report, on behalf of the MISTICI collaboration: We observed the optical afterglow of GRB 090205 (D'Avanzo et al. GCN 8887; Kruehler & Greiner GCN 8888) with the ESO VLT about 9.0 hours after the burst with the FORS1 camera in spectroscopic mode. We took a 20 min spectrum covering the range 4000-9000 Angstrom (based on a preliminary wavelength calibration) with a resolution of R=440. We detect a broad absorption feature around lambda_obs = 6800 Angstrom. Interpreting this feature as Ly-alpha absorption the inferred redshift is z = 4.6 in agreement with the photometric redshift reported by Kruehler & Greiner (GCN 8888). We acknowledge excellent support from the ESO staff, in particular G. James and J. Smoker. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8890 SUBJECT: GRB 090205: Swift burst of interest DATE: 09/02/06 14:46:05 GMT FROM: Neil Gehrels at GSFC N. Gehrels (GSFC) & M. Perri (ASDC) report on behalf of the Swift team Based on its high redshift, relatively bright optical afterglow and variable X-ray afterglow, the Swift team declares GRB 090205 to be a burst of interest to be followed by Swift as long as detectable. We encourage ground-based follow-ups. Please post your results / plans or send us informal information to help with observation planning. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8891 SUBJECT: GRB 090205: Swift-XRT refined analysis DATE: 09/02/06 15:58:50 GMT FROM: Matteo Perri at ISAC/ASDC M. Perri and G. Stratta (ASDC) report on behalf of the Swift XRT team: We have analyzed the first 13.5 ks of Swift-XRT data of the BAT GRB 090205 (Perri et al., GCN Circ. 8884). The data, starting at 2009-02-05 23:04:55 UT and ending at 2009-02-06 09:10:33 UT, is all taken in Photon Counting (PC) mode. The best XRT position is the UVOT-enhanced position reported by Evans et al. (GCN Circ. 8885). In the time interval T+94s-T+580 s the X-ray light curve can be modeled by a simple power law with a decay index alpha_1= 1.4 ± 0.3 (90% confidence) followed by a re-brightening around T+1 ks. After the re-brightnening, from T+5 ks up to T+30 ks, the light curve decays with a power law index alpha_2= 0.9 ± 0.2. The X-ray spectrum is well fit by an absorbed power-law model with a photon index of 2.0 (+/-0.2) and a column density consistent with the Galactic one in the direction of the source (7.7e20 cm**-2, Kalberla et al. 2005). The estimated 3-sigma (2-sigma) upper limit on the intrinsic column density at z=4.6 (Thoene et al., GCN Circ. 8889) is 4.1e22cm**-2 (2.8e22cm**-2). Assuming the X-ray emission continues to decline at the same rate, we predict a 0.3-10 keV XRT count rate of 6e-3 count/s at T+24hr, which corresponds to an observed 0.3-10 keV flux of ~2e-13 erg/cm**2/s. This circular is an official product of the Swift-XRT Team. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8892 SUBJECT: GRB 090205: VLT refined redshift DATE: 09/02/06 16:23:14 GMT FROM: Paolo D'Avanzo at INAF-OAB D. Fugazza, C. C. Thoene (INAF-OAB), V. D'Elia (INAF-OAR), P. D'Avanzo (INAF-OAB), S. Piranomonte (INAF-OAR), R. Salvaterra, S. Covino, S. Campana (INAF-OAB), G. Chincarini (Univ. Bicocca) report, on behalf of the MISTICI collaboration: We performed further analysis of our VLT spectrum of the optical afterglow of GRB 090205 (D'Avanzo et al. GCN 8887; Kruehler & Greiner, GCN 8888; Thoene et al., GCN 8889). We clearly detect the following absorption features: Ly_alpha (1215.67), SiII (1260.66), SiII (1303.27), CII (1334.53), SiIV (1393.76, 1402.77) doublet, SiII (1526.71) and CIV (1548.20,1550.77) doublet at a redshift of z = 4.6497 ± 0.0025 consistent with previous claims (Kruehler & Greiner, GCN 8888; Thoene et al., GCN 8889). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8893 SUBJECT: GRB 090205: Swift/UVOT Upper Limits DATE: 09/02/06 16:54:59 GMT FROM: Wayne Landsman at GSFC/SSAI W. Landsman (NASA/GSFC) and M. Perri (ASDC) report on behalf of the Swift UVOT team The Swift/UVOT began settled observations of the field of GRB 090205 92s after the BAT trigger (Perri et al., GCN 8884). We do not detect any source at the enhanced Swift XRT position (Evans et al. GCN 8885) or at the VLT optical candidate position (D'Avanzo et al. GCN 8887). The UVOT non-detections are consistent with the spectroscopic redshift of 4.6 reported by Thoene et al. (GCN 8889). Our 3-sigma upper limits are reported below. Filter T_start T_stop Exp(s) Mag (3-sigma upper limit) ------------------------------------------------------------- white 92 242 148 > 21.1 white 92 7633 824 > 21.9 v 580 12829 1234 > 20.7 b 506 34930 2073 > 21.7 u 250 500 246 > 20.5 u 298 18581 1660 > 21.4 uvw1 629 17668 1415 > 21.4 uvm2 604 23148 1882 > 21.4 uvw2 555 11915 1322 > 21.5 The quoted upper limits have not been corrected for the expected Galactic extinction along the line of sight of E_(B-V) = 0.12 mag. All photometry is on the UVOT photometric system described in Poole et al. (2008, MNRAS, 383, 627). //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8895 SUBJECT: GRB 090205: VLT optical decay DATE: 09/02/07 09:35:05 GMT FROM: Paolo D'Avanzo at INAF-OAB P. D'Avanzo, D. Fugazza (INAF-OAB), V. D'Elia (INAF-OAR), R. Salvaterra, C. C. Thoene (INAF-OAB), S. Piranomonte (INAF-OAR), S. Covino, S. Campana (INAF-OAB), G. Chincarini (Univ. Bicocca) report, on behalf of the MISTICI collaboration: We continued monitoring GRB 090205 (Perri et al., GCN 8884) with the ESO-VLT in imaging mode. Observations were carried out in R-band with the FORS1 camera about 1.35 days after the burst. Preliminary analysis of a first set of images (total exposure: 12 min) reveals that the optical afterglow (D'Avanzo et al. GCN 8887; Kruehler & Greiner GCN 8888) is still detected and that it faded by about 3 mags with respect to our previous epoch of VLT observations (D'Avanzo et al. GCN 8887). Assuming a power-law decy, the inferred decay index between this two epochs is alpha ~ 1.8, steeper than what measured in the X-rays at earlier epochs (Perri & Stratta, GCN 8891). Further optical observations are ongoing. We acknowledge the VLT staff for their support, in particular G. James and L. Schmidtobreick. //////////////////////////////////////////////////////////////////////// TITLE: GCN CIRCULAR NUMBER: 8896 SUBJECT: VLA radio upper limit on GRB 090205 DATE: 09/02/07 14:57:15 GMT FROM: Poonam Chandra at U Virginia/NRAO Poonam Chandra (RMC) and Dale A. Frail (NRAO) report on behalf of the Caltech-NRAO-Carnegie GRB Collaboration: "We used the Very Large Array to observe the field of view toward GRB 090205 (GCN 8884) at a frequency of 8.46 GHz on 2009 Jan 07.50 UT. The GRB radio afterglow is undetected at 3-sigma level. The flux density at the VLT afterglow position (GCB 8887) is 21 ± 47 uJy. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc."