GRB090709A

This page lists all entries on GRB090709A in GRBweb

Summary IPN Swift GCN 9625 GCN 9626 GCN 9628 GCN 9630 GCN 9632 GCN 9634 GCN 9635 GCN 9636 GCN 9637 GCN 9638 GCN 9639 GCN 9640 GCN 9642 GCN 9643 GCN 9644 GCN 9645 GCN 9646 GCN 9647 GCN 9648 GCN 9649 GCN 9651 GCN 9652 GCN 9653 GCN 9654 GCN 9655 GCN 9657 GCN 9658 GCN 9685 GCN 9696 GCN 9737 GCN 10903

Summary table
Variable Value Source
T0 7:38:34 UTC GCN_circulars,Swift Det
ra 289.9270° Swift
decl 60.7275° Swift
pos_error 1.81e-04° Swift
T90 89.0 s Swift
T90_start 7:38:34 UTC Swift
fluence 2.57e-05 erg/cm² Swift
redshift 8.5000 GCN_circulars,Swift-BAT Det
T100 89.0 s
GBM_located False
mjd 55021.318449074075 GCN_circulars,Swift Det
IPN table
GRB_name GRB090709A
ra 289.9333°
decl 60.7333°
pos_error 5.00e-02°
Swift table
GRB_name GRB090709A
t_trigger 7:38:34 UTC
ra 289.9270°
decl 60.7275°
pos_error 1.81e-04°
T90 89.0 s
fluence 2.57e-05 erg/cm²
GCN 9625 table
GRB_name GRB090709A
GCN_number 9625
Detection_method Swift Det
t_trigger 7:38:34 UTC
ra 289.9330°
decl 60.7310°
Circular_text TITLE: GCN CIRCULAR NUMBER: 9625 SUBJECT: GRB 090709: Swift detection of a bright burst DATE: 09/07/09 08:07:08 GMT FROM: David Palmer at LANL D. C. Morris (PSU), A. P. Beardmore (U Leicester), P. A. Evans (U Leicester), H. A. Krimm (CRESST/GSFC/USRA), V. Mangano (INAF-IASFPA), J. Mao (INAF-OAB), C. B. Markwardt (CRESST/GSFC/UMD), K. L. Page (U Leicester), D. M. Palmer (LANL), A. Rowlinson (U Leicester), M. H. Siegel (PSU), M. A. Stark (PSU), G. Tagliaferri (INAF-OAB), T. N. Ukwatta (GSFC/GWU) and H. Ziaeepour (UCL-MSSL) report on behalf of the Swift Team: At 07:38:34 UT, the Swift Burst Alert Telescope (BAT) triggered and located GRB 090709 (trigger=356890). Swift slewed immediately to the burst. The BAT on-board calculated location is RA, Dec 289.933, +60.731 which is RA(J2000) = 19h 19m 44s Dec(J2000) = +60d 43' 52" with an uncertainty of 3 arcmin (radius, 90% containment, including systematic uncertainty). The BAT light curve showed about four major peaks starting at T-20 and continuing to T+100 seconds. The peak count rate was ~15000 counts/sec (15-350 keV), at ~25 sec after the trigger. The XRT began observing the field at 07:39:42 UT, 67.8 seconds after the BAT trigger. In the 2.5-s image-mode data we find a fading, uncatalogued X-ray source with a position: RA, Dec 289.9291, +60.7271 which is equivalent to: RA(J2000) = 19h 19m 42.99s Dec(J2000) = +60d 43' 37.5" with an uncertainty of 4 arcseconds (radius, 90% containment). This location is 16 arcseconds from the BAT onboard position, within the BAT error circle. UVOT took a finding chart exposure of 150 seconds with the White filter starting 76 seconds after the BAT trigger. No credible afterglow candidate has been found in the initial data products. The overlap of the sub-image and the XRT error circle is 100%. The overlap of the 8'x8' region for the list of sources generated on-board and the XRT error circle is 100%. No correction has been made for the expected extinction corresponding to E(B-V) of 0.09. Burst Advocate for this burst is D. C. Morris (morris AT astro.psu.edu). 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.)
GCN 9626 table
GRB_name GRB090709A
GCN_number 9626
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 9626 SUBJECT: GRB 090709: ROTSE-III Optical Limits DATE: 09/07/09 08:32:56 GMT FROM: Fang Yuan at ROTSE S. B. Pandey (U Mich), W. Rujopakarn (Steward), H. Flewelling (IfA/ Hawaii), F. Yuan (U Mich), B. E. Schaefer (Louisiana State), report on behalf of the ROTSE collaboration: ROTSE-IIIb, located at McDonald Observatory, Texas, responded to GRB 090709 (Swift trigger 356890; Morris D. C., GCN 9625), producing images beginning 5.6 s after the GCN notice time. An automated response took the first image at 07:39:00.6 UT, 26.0 s after the burst, and during the gamma-ray emission, under good conditions. We took 10 5-sec and 50 20-sec exposures. These unfiltered images are calibrated relative to USNO A2.0 (R). Imaging is on going. Comparison to the DSS (second epoch) reveals no new sources within the 3-sigma Swift/BAT error circle or the XRT error circle, for both single images and coadding into sets of 10. Individual images have limiting magnitudes ranging from 16.4-17.2; we set the following specific limits. start UT end UT t_exp(s) mlim t_start-tGRB(s) Coadd? -------------------------------------------------------------------- 07:39:00.6 07:39:05.6 5 16.5 26.0 N 07:39:00.6 07:40:07.7 67 17.8 26.0 Y 07:40:20.2 07:45:02.4 282 18.2 105.6 Y
GCN 9628 table
GRB_name GRB090709A
GCN_number 9628
Detection_method correction
Circular_text TITLE: GCN CIRCULAR NUMBER: 9628 SUBJECT: GRB 090709: PAIRITEL NIR Upper Limits DATE: 09/07/09 08:58:46 GMT FROM: Adam Morgan at U.C. Berkeley A. N. Morgan, C. R. Klein, D. A. Perley, J. S. Bloom, (UC Berkeley), report: We observed the field of GRB 090709 (Morris et al., GCN 9625) with the 1.3m PAIRITEL located at Mt. Hopkins, Arizona. Observations began at 2009-07-09 07:40:22 UT, ~108 seconds after the Swift trigger. In preliminary mosaics (effective exposure time of ~374 seconds) taken simultaneously in the J, H, and Ks filters, we detect no source at the XRT position. The preliminary photometry yields: post_burst t_mid(s) exp(s) filt U. Limit (3 sig) 438 374 J > 17.7 438 374 H > 16.9 438 374 Ks > 15.3 All magnitudes given in the Vega system, calibrated to 2MASS. No correction for Galactic extinction has been made to the above reported values. Observations are ongoing. [GCN OPS NOTE(09jul09): Per author's request, in the Subject line the "090609" was changed to "090709".]
GCN 9630 table
GRB_name GRB090709A
GCN_number 9630
Detection_method Swift Det
t_trigger 7:41:27 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 9630 SUBJECT: GRB 090709: Faulkes Telescope North Upper Limits DATE: 09/07/09 09:35:32 GMT FROM: Zach Cano at ARI/John Moores Liverpool GRB 090709: Faulkes Telescope North Upper Limits Z. Cano (Liverpool JMU), A. Melandri, C. Guidorzi (U. Ferrara), D. Bersier, I.A. Steele, R.J. Smith, C. Mundell (Liverpool JMU) report, on behalf of a large collaboration: Following Swift detection of burst (Morris et al. GCN Circ. 9625), Faulkes Telescope North (Hawaii) reacted robotically and began observing the field of GRB 090709 in BVRi bands starting at 07:41:27 UT. We detect no new source within the XRT error circle: t_exp t-T0(mid exposure) mag 30s 207 s R2 > 19.3 180s 457 s I > 18.3 The upper limits are determined against stars in the USNO B1 catalog.
GCN 9632 table
GRB_name GRB090709A
GCN_number 9632
Detection_method Other
ra 289.9291°
decl 60.7271°
Circular_text TITLE: GCN CIRCULAR NUMBER: 9632 SUBJECT: GRB 090709 : planned Suzaku-ToO observation DATE: 09/07/09 13:01:58 GMT FROM: Kazutaka Yamaoka at Aoyama Gakuin U Kazuhisa Mitsuda on behalf of the Suzaku GRB-ToO team: We will carry out a Suzaku-ToO observation of GRB 090709 (Morris et al., GCN 9625) at location (RA=289.9291, DEC=+60.7271, J2000) with the narrow field instruments (the XIS and HXD). It will start 13:00 UT on July 9, 2009, and will continue until 21:32 UT on July 10, 2009.
GCN 9634 table
GRB_name GRB090709A
GCN_number 9634
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 9634 SUBJECT: GRB 090709A: Subaru NIR observation DATE: 09/07/09 18:47:52 GMT FROM: Nobuyuki Kawai at Tokyo Tech K. Aoki, M. Ishii (Subaru Telescope), M. Kuzuhara (Univ. of Tokyo), Y. Takahashi (Univ. of Advanced Study) and N. Kawai (Tokyo Tech) report on behalf of the Subaru GRB team: We observed the field of GRB 090709A (Morris et al. GCN 9625) with MOIRCS on Subaru Telescope in J and K bands under a cirrus condition, starting at ~9:30 UT on July 9, approximately 2 hours after the burst. We detected following two objects near the XRT error circle. Their preliminary magnitudes based on a nearby 2MASS star are following. object A: J(Vega)=19.0, K(Vega)=18.2 object B: J undetected, K(Vega)=18.6 We placed the K band finding chart at http://www.hp.phys.titech.ac.jp/nkawai/grb/090709/GRB090709.jpg We further performed spectroscopy for them with the following results: Object A: zJH spectroscopy, a flat spectrum with no break detected. Object B: HK and zJH spectroscopy, a continuum detected in K-band, no continuum detected in J band, possibly no continuum in H-band but with high background. Lack of H band continuum could suggest that the object B is at high redshift (z~10), though its poor SNR does not allow us to confirm it. Fading is not confirmed for either of them. Further NIR/optical observations are strongly encouraged.
GCN 9635 table
GRB_name GRB090709A
GCN_number 9635
Detection_method correction
ra 289.9277°
decl 60.7276°
Circular_text TITLE: GCN CIRCULAR NUMBER: 9635 SUBJECT: GRB 090709A - PAIRITEL Discovery of a Red Afterglow DATE: 09/07/09 19:03:47 GMT FROM: Adam Morgan at U.C. Berkeley A. N. Morgan, J. S. Bloom, C. R. Klein (UC Berkeley), report: Using a re-reduction of the early PAIRITEL data for GRB 090709A (Morgan et al. GCN 9628) we report a probable detection of a red source in the H and Ks bands within the XRT circle (Morris et al. GCN 9625). The source is located at the following J2000 position (3.15 arcsec away from the center of the current XRT position): RA = 19:19:42.64 Dec = +60:43:39.3 The uncertainty in this position relative to the ICRS is 0.4" in each direction. The preliminary photometry yields: post_burst t_mid(s) exp(s) filt mag 438 374 J > 17.7 (3 sig) 438 374 H 16.7 +/- 0.2 438 374 Ks 15.3 +/- 0.2 Deeper mosaics obtained later in the night do not contain this source, indicating that it has faded. We thus conclude that this is the afterglow of GRB 090709A. Note that this is the same source 'B' as that was just reported in Aoki et al. (GCN 9634). Our detection in the H band places a less stringent redshift limit on the afterglow (although this limit is still high; z > 8.5), if indeed our non-detection in J is due to a Lyman break and not extinction. We also note that source 'A' of GCN 9634, which is of comparable brightness to 'B' 2 hours after the burst, is not detected in our shallower image, confirming our conclusion that source 'B' has faded and is the afterglow. All magnitudes given in the Vega system, calibrated to 2MASS. No correction for Galactic extinction has been made to the above reported values.
GCN 9636 table
GRB_name GRB090709A
GCN_number 9636
Detection_method Swift-XRT Det
ra 289.9266°
decl 60.7276°
Circular_text TITLE: GCN CIRCULAR NUMBER: 9636 SUBJECT: GRB 090709A: Enhanced Swift-XRT position DATE: 09/07/09 20:21:41 GMT FROM: Phil Evans at U of Leicester J.P. Osborne, A.P. Beardmore, P.A. Evans and M.R. Goad (U. Leicester) report on behalf of the Swift-XRT team. Using 2188 s of XRT Photon Counting mode data and 6 UVOT images for GRB 090709A, 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 = 289.92664, +60.72764 which is equivalent to: RA (J2000): 19h 19m 42.39s Dec (J2000): +60d 43' 39.5" with an uncertainty of 1.5 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) and Evans et al. (2009, arXiv:0812.3662). This circular was automatically generated, and is an official product of the Swift-XRT team.
GCN 9637 table
GRB_name GRB090709A
GCN_number 9637
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 9637 SUBJECT: GRB 090709A, RIMOTS optical upper limits DATE: 09/07/09 21:16:12 GMT FROM: Kenta Kono at Miyazaki U K.Kono, E.Sonoda, N.Ohmori, H.hayasi, A.Daikyuji, Y.Nisioka, K.Noda, M.Yamauchi (University of Miyazaki) We have observed the field covering the error circle of GRB090709A (Swift trigger 356890, GCN 9625, D.C.Morriset al.) with the unfiltered CCD camera on the 30-cm telescope at University of Miyazaki. The observation was started 11:42:32 UT (4.1 hr after the Swift trigger), under cloudy condition. First analyzable image was obtained at 16:18:26 UT (8.8 hr after the Swift trigger). We have compared our data of 30 sec exposures with the USNO-A2.0 catalog, There is no new source at the reported position. (GCN 9634, K.Aoki et al. GCN 9636, J.P.Osborne et al.) the upper limits are as follows: -------------------------------------------------------------- Start(UT) End(UT) Num. of frames Limit (mag.) -------------------------------------------------------------- 16:18:26 16:18:56 1 13.6 16:18:26 18:39:38 38 16.4 ---------------------------------------------------------------
GCN 9638 table
GRB_name GRB090709A
GCN_number 9638
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9638 SUBJECT: GRB 090709A: Wyoming Infrared Observatory NIR upper limits DATE: 09/07/09 21:57:07 GMT FROM: Jerry Bonnell at NASA-GSFC/LHEA GRB 090709A: Wyoming Infrared Observatory NIR upper limits Jay Norris (U. Denver), Jerry Bonnell (CRESST/UMCP/GSFC), Tzitlaly Barajas (Los Angeles City College), Amanda McAuley (Cal State U. Los Angeles) report on behalf of the Goddard/Univ. Wyoming NIR camera collaboration. We observed the Swift XRT position reported by Morris et al. (GCN Circ. 9625) for GRB 090709A with the 2.3-meter WIRO telescope and the Goddard IR camera starting 52 minutes after the Swift trigger. Using stacked J- and K- band exposures begining at 08:30 UT, we derive the following 2 sigma upper limits for the afterglow source reported by Morgan et al. (GCN Circ. 9635) from PAIRITEL observations. Tmid (UT) Mag 09:30 J-band > 21.5 09:55 K-band > 18.5 The source is designated source B in the Subaru K-band finder chart from Aoki et al. (GCN Circ. 9634). Our K-band observations were compromised by cirrus. Our upper limits are derived based on a comparison with two field stars with J-band magnitudes 14.5 and 15.7 in the 2MASS catalog. Further analysis of J- and K-band images is ongoing.
GCN 9639 table
GRB_name GRB090709A
GCN_number 9639
Detection_method Swift-BAT Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 9639 SUBJECT: GRB090709A: High Energy BAT/XRT Analysis Suggests Low to Moderate Redshift DATE: 09/07/09 22:39:12 GMT FROM: S. Bradley Cenko at Caltech Nat Butler (UC Berkeley) Reports: We reduce the Swift XRT and BAT data using our automated pipeline (see, http://astro.berkeley.edu/~nat/swift for more details of the fits and summary plots for this and other Swift GRBs). The intermediate time PC mode XRT data (t=4-10 ksec post trigger) are well-fit (chi^2/nu=80.48/59) by an absorbed powerlaw with photon index Gamma=1.9+/-0.1 and column density 1.7+/-0.5 x 10^21 cm^-2 in excess of the anticipated Galactic contribution (6.6 x 10^20 cm^-2) at the 6.7-sigma level. This detection of an excess column is suggestive of a low to moderate redshift (i.e., z<~2) for the GRB (e.g,. Grupe et al. 2007, ApJ, 133, 2216). The time-integrated BAT spectrum is well-modeled by a powerlaw times exponential function (chi^2/nu=29.67/55). We derive Epeak,obs = 200 (176,298) keV and a rest-frame isotropic equivalent energy release Eiso ~ 1.4 x 10^53 erg (z=1). If the GRB were at very high z~8, Eiso ~ 4.5 x 10^54 erg, comparable to the intrinsically brightest few GRBs ever detected, further suggestive of a low to moderate redshift for this event.
GCN 9640 table
GRB_name GRB090709A
GCN_number 9640
Detection_method Swift-BAT Det
ra 289.9440°
decl 60.7280°
Circular_text TITLE: GCN CIRCULAR NUMBER: 9640 SUBJECT: GRB 090709A: Swift-BAT refined analysis DATE: 09/07/09 22:52:32 GMT FROM: Scott Barthelmy at NASA/GSFC T. Sakamoto (GSFC/UMBC), S. D. Barthelmy (GSFC), W. H. Baumgartner (GSFC/UMBC), J. R. Cummings (GSFC/UMBC), E. E. Fenimore (LANL), N. Gehrels (GSFC), H. A. Krimm (GSFC/USRA), C. B. Markwardt (GSFC/UMD), D. C. Morris (PSU), D. M. Palmer (LANL), 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+505 sec from recent telemetry downlinks, we report further analysis of BAT GRB 090709A (trigger #356890) (Morris, et al., GCN Circ. 9625). The BAT ground-calculated position is RA, Dec = 289.944, 60.728 deg, which is RA(J2000) = 19h 19m 46.7s Dec(J2000) = +60d 43' 40.8" with an uncertainty of 1.0 arcmin, (radius, sys+stat, 90% containment). The partial coding was 75%. The mask-weighted light curve shows a complex structure. It starts at ~T-80 sec, peaks at T-70 sec, and returns to almost background at ~T-20 sec. Then a series of overlapping peaks starts with the brightest centered at ~T+22 sec. Then begins an exponential decay with a series of decreases eventually returning to background level at ~T+270 sec. There two more peaks at ~T+330 and ~T+400 sec. A third peak is chopped off while still rising when the source went out of the BAT FOV at ~T+490 sec due to the spacecraft slewing because of an observing constraint. T90 (15-350 keV) is 89 +- 3 sec (estimated error including systematics). The time-averaged spectrum from T-66.7 to T+101.5 sec is well fit by simple power law. The power law index of the time-averaged spectrum is 1.22 +- 0.03. The fluence in the 15-150 keV band is 2.57 +- 0.03 x 10^-5 erg/cm2. The 1-sec peak photon flux measured from T+21.80 sec in the 15-150 keV band is 7.8 +- 0.3 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/356890/BA/
GCN 9642 table
GRB_name GRB090709A
GCN_number 9642
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9642 SUBJECT: GRB 090709A: Swift XRT Refined Analysis DATE: 09/07/09 23:06:12 GMT FROM: Antonia Rowlinson at U.of Leicester A. Rowlinson (U Leicester) and D. C. Morris (PSU) report on behalf of the Swift-XRT team: We have analysed 9.4 ks of XRT data for GRB 090709A (Morris et al. GCN Circ. 9625), from 74 s to 27.3 ks after the BAT trigger. The data comprise 445 s in Windowed Timing (WT) mode with the remainder in Photon Counting (PC) mode. The enhanced XRT position for this burst was given by Osborne et al. (GCN. Circ 9636). The light curve can be modelled with a broken power-law decay. The initial decay index is alpha=0.77(+/-0.1), at T+7918 s the light curve breaks to a decay with alpha=1.51(+/-0.06). A spectrum formed from the WT mode data can be fitted with an absorbed power-law with a photon spectral index of 1.78 (+/-0.04). The best-fitting absorption column is 2.14 (+0.13, -0.12) x 10^21 cm^-2, in excess of the Galactic value of 6.6 x 10^20 cm^-2 (Kalberla et al. 2005). The PC mode spectrum has a photon index of 2.05 (+/-0.08) and a best-fitting absorption column of 2.68 (+0.26, -0.25) x 10^21 cm^-2. The counts to observed (unabsorbed) 0.3-10 keV flux conversion factor deduced from this spectrum is 4.2 x 10^-11 (6.7 x 10^-11) erg cm^-2 count^-1. If the light curve continues to decay with a power-law decay index of 1.51, the count rate at T+24 hours will be 0.043 count s^-1, corresponding to an observed (unabsorbed) 0.3-10 keV flux of 1.8 x 10^-12 (2.9 x 10^-12) erg cm^-2 s^-1. The results of the XRT-team automatic analysis are available at http://www.swift.ac.uk/xrt_products/00356890. This circular is an official product of the Swift-XRT team.
GCN 9643 table
GRB_name GRB090709A
GCN_number 9643
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9643 SUBJECT: GRB 090709A: RAPTOR Limits During Gamma-Ray Emission DATE: 09/07/09 23:41:47 GMT FROM: James Wren at LANL J. Wren, W.T. Vestrand, P.R. Wozniak, H. Davis, B. Norman of Los Alamos National Laboratory report: The RAPTOR telescope system responded to Swift trigger 356890 (Morris et al., GCN 9625) under good observing conditions. Our narrow-field instruments began observing the location at 07:39:03.4 UTC, 28.8 s after the Swift trigger (7.1 s after receipt of GCN message). We obtained simultaneous observations during the gamma-ray emitting interval in Cousins V, R, and I bands as well as unfiltered data. We do not detect the counterpart observed by the Subaru Telescope (Aoki et al., GCN 9634) and PARITEL (Morgan et al., GCN 9635). The data from our unfiltered and filtered systems was calibrated to the USNO-B1 catalog. We can put the following limits on the prompt emission: t-mid(s) exp(s) filter mag mag-err [since trigger] ---------------------------------------------------- 31.34 5 clear 17.1 5 sigma limit 52.35 5 V 14.8 5 sigma limit 52.35 5 R 15.1 5 sigma limit 52.35 5 I 15.5 5 sigma limit 89.95 40 V 16.9 5 sigma limit
GCN 9644 table
GRB_name GRB090709A
GCN_number 9644
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 9644 SUBJECT: GRB 090709A: NOT optical observations DATE: 09/07/10 00:10:54 GMT FROM: Daniele Malesani at Dark Cosmology Centre, Niels Bohr Inst D. Malesani (DARK/NBI), J. Telting (NOT), P. Wilson (NOT and Univ. Oslo), P. Jakobsson (Univ. Iceland), J.P.U. Fynbo, G. Leloudas (DARK/NBI), A.J. Levan (Univ. Warwick), and K. Wiersema (Univ. Leicester), report on behalf of a larger collaboration: We observed the field of GRB 090709A (Morris et al., GCN 9625) with the NOT equipped with ALFOSC. Observations were carried out in the R band, starting on 2009 Jul 9.943 (14.97 hr after the trigger), for a total exposure time of 30 min. At the position of the NIR transient (Aoki et al., GCN 9634; Morgan et al., GCN 9635) we do not detect any source, down to a limiting magnitude R >~ 24. The calibration is based on a number of closeby USNO-B1 stars (R2 magnitudes).
GCN 9645 table
GRB_name GRB090709A
GCN_number 9645
Detection_method Swift-BAT Det
redshift 8.5000
Circular_text TITLE: GCN CIRCULAR NUMBER: 9645 SUBJECT: GRB 090709A: Quasiperiodic variations in the BAT light curve DATE: 09/07/10 01:00:23 GMT FROM: Craig Markwardt at NASA/GSFC/UMD C. B. Markwardt (GSFC/UMD), F. P. Gavriil (GSFC/UMBC), D. M. Palmer (LANL), W. H. Baumgartner (GSFC/UMBC), S. D. Barthelmy (GSFC) We performed a timing analysis of GRB 090709A. Visually, there appears to be a quasiperiodic signal at period near 8 seconds. More formally, a power spectrum of the full burst shows an apparent strong excess at 8.06 seconds. This analysis is based on a de-trended 64 msec BAT light curve (15-350 keV), T-50 s to T+150 s, where the trend was based on a smoothed version of the light curve (smoothing scale 10 sec). After normalizing the power spectrum by the local noise level (0.2 to 0.6 Hz), we find a peak power of ~52, which has a probability of occurring by random chance of ~1e-6 after adjusting for the number of trials. The results are relatively insensitive to trend smoothing timescale, to within a factor of ~2. The number of trials is based on the number of independent Fourier frequencies examined (~2000) and an estimated 100 BAT bursts long enough in duration to perform such an analysis. We consider this to be a conservative estimate: we are likely to have overestimated the number bursts for which we could do this analysis; and the 0.2 to 0.6 Hz range used to compute the noise level has the most noise, which decreases the overall peak significance. The amplitude of the modulations is as high as ~70% of the smoothed light curve, and as small as 10%. The signal is not strictly coherent. The "Q factor", the ratio of peak centroid frequency to FWHM, is ~11 (whereas a coherent signal with a duration of ~200 seconds could be as sharp as Q=24). We believe such a detection is the first time strong near-periodic oscillations have been seen at this significance for classical gamma-ray bursts. Periodic variations at 8 seconds would be typical for galactic magnetars. If this source is at a redshift of 8.5-10 (Aoki et al. GCN 9634, Morgan et al. GCN 9635), then the intrinsic period would be ~800 milliseconds, which falls outside of the magnetar range. If on the other hand the source is at low redshift (Butler, GCN 9639), the observed period would be typical of magnetars. Figures GRB 090709A BAT light curve http://gcn.gsfc.nasa.gov/gcn/other/grb090709a_bat_lc.gif GRB 090709A BAT light curve after removing trend http://gcn.gsfc.nasa.gov/gcn/other/grb090709a_bat_detrended.gif GRB 090709A BAT light curve (black) and trend (red) http://gcn.gsfc.nasa.gov/gcn/other/grb090709a_bat_trend.png GRB 090709A power spectrum of detrended BAT light curve, normalized by local noise level http://gcn.gsfc.nasa.gov/gcn/other/grb090709a_powspec.png
GCN 9646 table
GRB_name GRB090709A
GCN_number 9646
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9646 SUBJECT: GRB 090709A: P60 Observations DATE: 09/07/10 06:31:02 GMT FROM: S. Bradley Cenko at Caltech S. B. Cenko, J. S. Bloom, A. N. Morgan, and D. A. Perley (UC Berkeley) report on behalf of a larger collaboration: We have imaged the field of GRB090709A (Morris et al., GCN 9625) with the automated Palomar 60-inch telescope. Observations began at 7:40:26 UT on 9 July 2009 (~ 2 minutes after the burst trigger) and were taken in the r', i', and z' filters. We marginally detect a faint source at the location of the NIR afterglow (Aoki et al., GCN 9634, Morgan et al., GCN 9635) in our first r' and z' images. However, nothing is detected at this location in subsequent images or deeper coadditions at later times. We therefore cannot entirely rule out that these represent chance statistical fluctuations. We report the following photometry and upper limits (referenced with respected to the USNO-B1 catalog): UT Midpoint Exposure (s) Filter AB Mag ---------------------------------------------------------------------- 7:40:56 60 r' 21.7 +- 0.4 7:45:12 60 r' > 21.4 8:08:57 600 r' > 22.9 7:46:38 60 i' > 21.0 8:11:59 480 i' > 22.8 7:45:55 120 z' 20.5 +- 0.5 8:13:59 480 z' > 21.5 The r' and z' detections, if real, would argue strongly in favor of a low or moderate redshift origin with a large extinction column in the GRB host galaxy (Butler, GCN 9639). A combined fit of approximately co-eval PAIRITEL (GCN 9635, Morgan et al.) and P60 photometry assuming moderate redshift (z < 4) is consistent with a highly dust-extinguished (A_V > 2 mag) power-law spectral energy distribution. A smoothed version of our first r' image can be found at: http://astro.berkeley.edu/~cenko/public/grb/grb090709/p60r.jpg The blue circle is the refined XRT localization (Osborne et al., GCN 9639), while the red circle is the location of the PAIRITEL NIR afterglow (Morgan et al., GCN 9635).
GCN 9647 table
GRB_name GRB090709A
GCN_number 9647
Detection_method Konus-Wind Det
t_trigger 7:38:34.965 UTC
Circular_text TITLE: GCN CIRCULAR NUMBER: 9647 SUBJECT: Konus-Wind and Konus-RF observations of GRB 090709A DATE: 09/07/10 10:43:10 GMT FROM: Dmitry Frederiks at Ioffe Institute S. Golenetskii, R.Aptekar, E. Mazets, V. Pal'shin, D. Frederiks, P. Oleynik, M. Ulanov, and D. Svinkin on behalf of the Konus-Wind and Konus-RF teams, and T. Cline on behalf of the Konus-Wind team, report: The long GRB 090709A (Morris et al., GCN 9625) triggered Konus-Wind at T0=27514.965 s UT (07:38:34.965), and Konus-RF instrument onboard CORONAS-PHOTON s/c at T0(KRF)=27513.934 s UT (07:38:33.934). The burst light curve shows a multi-peaked structure with a duration of ~100 s. We confirm presence of quasi-period in the light curve (Markwardt et al., GCN 9645). The corresponding peaks in the FFT power spectrum of 128 ms light curve are clearly seen around P=8.28s (0.1208 Hz) and P=16.56s (0.0604 Hz). The Konus-Wind light curves of this GRB are vailable at http://www.ioffe.ru/LEA/GRBs/GRB090709_T27514/ The normalized power spectrum of the detrended Konus-Wind light curve (128 ms, in 20-1150 keV range) is available at http://www.ioffe.ru/LEA/GRBs/GRB090709_T27514/GRB090709_T27514_KW_power.png As observed by Konus-Wind the burst had a fluence of (9.1 0.07)x10-5 erg/cm2, and a 256-ms peak flux measured from T0+23.308 s of (3.9 0.6)x10-6 erg/cm2/s (both in the 20 keV - 3 MeV energy range). The time-integrated spectrum of the burst (from T0 to T0+102.912 s) is well fitted (in the 20 keV - 3 MeV range) by GRB (Band) model for which: the low-energy photon index alpha = -0.85 0.08, the high-energy photon index beta = -2.7(-0.3, +0.2), the peak energy Ep = 298 27 keV (chi2 = 71/67 dof). The spectrum at the maximum count rate, measured from T0+16.640 to T0+24.320 s, is well fitted (in the 20 keV - 3 MeV range) by GRB (Band) model for which: the low-energy photon index alpha = -0.86 (-0.07, +0.10), the high-energy photon index beta = -2.6(-2.6, +0.53), the peak energy Ep = 416(-100, +95) keV (chi2 = 63/67 dof). All the quoted values are preliminary. The quoted errors are at the 90% confidence level.
GCN 9648 table
GRB_name GRB090709A
GCN_number 9648
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9648 SUBJECT: GRB 090709A: evidence for a very red afterglow at low z DATE: 09/07/10 12:02:42 GMT FROM: Cristiano Guidorzi at Ferrara U,Italy C. Guidorzi (U. Ferrara), A. Melandri, C.G. Mundell, D. Bersier, Z. Cano, S. Kobayashi, I.A. Steele, R.J. Smith (Liverpool JMU), and A. Gomboc (U. Ljubljana) report, on behalf of a large collaboration: We re-analysed the data promptly acquired with the 2-m Faulkes Telescope North in the R and i' filters (Cano et al. GCN 9630) of the Swift GRB 090709A (Morris et al. GCN 9625). From the stacked images, we marginally detect a source in the r' frame at the position of the NIR afterglow found by PAIRITEL (Morgan et al. GCN 9635), identified as source 'B' by Subaru (Aoki et al. GCN 9634) and possibly detected in the r' and z' bands (Cenko et al. GCN 9646). The same object is not detected in the i' band frame (although with a shorter total exposure). Start time End time Exposure Filter mag (min) (min) (s) ------------------------------------------------------------------- 2.88 55.02 720 R 22.7 +/- 0.5 7.55 47.05 520 i' > 20.6 ------------------------------------------------------------------- Calibration was performed against the I and R2 values of the USNOB1 nearby star at 19:19:44.575, +60:43:27.44 assuming I=14.68 and R2=15.70. We built a tentative SED at the PAIRITEL observation mid time of 438 s (Morgan et al. GCN 9635), combining the P60 values in the z' filter (Cenko et al. GCN 9646) and the assuming for the r' filter an intermediate value comprising both the P60 and our own value. This value as well as our i' band upper limits were backextrapolated to the chosen time assuming a range of power-law decay indices, from 0.3 to 1. The SED was finally corrected for the Galactic reddening of E(B-V)=0.09. We found that the SED can be fitted with a simple power-law with spectral index beta=3.4 +/- 0.8 (90%cl) and no evidence for a Lyman drop. We therefore support the nature of a very red afterglow at low z (Butler et al. GCN 9639) and possibly associated with a non-GRB progenitor as suggested by the quasi-periodic oscillations found in the gamma-ray profile (Markwardt et al. GCN 9645; Golenetskii et al. GCN 9647). Our stacked R band frame is available at the following link (red and green circles show the Swift-XRT and PAIRITEL circles, respectively): http://www.fe.infn.it/u/guidorzi/GRB090709A/090709A_R.jpg
GCN 9649 table
GRB_name GRB090709A
GCN_number 9649
Detection_method Konus-Wind Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 9649 SUBJECT: GRB 090709A: confirmation of the periodicity in the SPI-ACS data DATE: 09/07/10 12:15:28 GMT FROM: Diego Gotz at CEA D. Gotz (CEA-Saclay), S. Mereghetti (IASF-Milano), A. von Kienlin (MPE Garching), M. Beck (ISDC Versoix) report: The Swift GRB 090709A (Morris at al., GCN 9625) is clearly detected also in the data of Anticoincidence System (ACS) of the spectrometer SPI on board INTEGRAL. SPI-ACS consists on 91 BGO detectors that are sensitive to photons above 100 keV, and their light curves are continuously stored in 50 ms bins. No directional or spectral information is available. The light curve of GRB 090709A can be found here http://ibas.iasf-milano.inaf.it/090709Alc.jpg The ~8 s periodicity reported by Markwardt et al. (GCN 9645) in the Siwft/BAT data and by Golenetskii et al. (GCN 9647) in Konus-Wind data is clearly detected also in the SPI-ACS data. A periodogram over the entire burst duration can be found here http://ibas.iasf-milano.inaf.it/090709A.jpg By fitting the peak of the periodogram using a gaussian function one obtains a best period of 8.11 s. A light curve folded to the best period can be fond here http://ibas.iasf-milano.inaf.it/090709A_folded.jpg This message can be cited.
GCN 9651 table
GRB_name GRB090709A
GCN_number 9651
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9651 SUBJECT: GRB 090709A: WHT LIRIS observations DATE: 09/07/10 19:51:09 GMT FROM: Klaas Wiersema at U of Leicester K. Wiersema, D. Malesani and A. Levan report on behalf of a larger collaboration: We observed the field of GRB 090709A (Morris et al., GCN 9625) with the William Herschel Telescope, using the LIRIS instrument. We obtained a total of 1890 secs of exposure time in J band, under reasonable conditions, starting at 04:48 UT July 10th (20.8 hrs after burst). We do not detect the afterglow (Aoki et al. GCN 9634; Morgan et al. GCN 9635), with limiting magnitude J>~20. Source A of Aoki et al is clearly detected. We are grateful to Don Pollaco and Ian Skillen for performing these observations.
GCN 9652 table
GRB_name GRB090709A
GCN_number 9652
Detection_method Swift-UVOT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9652 SUBJECT: GRB 090709A: Swift UVOT upper limits DATE: 09/07/10 20:34:40 GMT FROM: Erik Hoversten at Swift/Penn State T. A. Pritchard (PSU), E. A. Hoversten (PSU) and D. C. Morris (PSU) report on behalf of the Swift/UVOT team: The Swift/UVOT began observing the field of GRB 090709A, 77 seconds after the BAT trigger (Morris et al., GCN 9625). We do not detect any source at the Swift enhanced XRT position (Osborne et al., GCN 9636). The 3-sigma upper limits in each filter are: Filter T_start(s) T_stop(s) Exp(s) Mag (3-sigma upper limit) ------------------------------------------------------------- white(FC) 77 227 150 > 21.03 v 4697 4897 200 > 19.59 b 4081 4281 200 > 20.01 u 290 471 181 > 20.09 uvw1 5107 5307 200 > 19.83 uvm2 4902 5102 200 > 19.63 uvw2 4492 4692 200 > 19.85 ------------------------------------------------------------- The quoted upper limits have not been corrected for the expected Galactic extinction along the line of sight of E_(B-V) = 0.09 mag. All photometry is on the UVOT photometric system described in Poole et al. (2008, MNRAS, 383, 627).
GCN 9653 table
GRB_name GRB090709A
GCN_number 9653
Detection_method Suzaku WAM Det
Circular_text TITLE: GCN CIRCULAR NUMBER: 9653 SUBJECT: GRB 090709A: Suzaku WAM observation of the prompt emission DATE: 09/07/11 11:34:36 GMT FROM: Masanori Ohno at ISAS/JAXA M. Ohno (ISAS/JAXA), W. Iwakiri (Saitama U.), M. Suzuki, M. Kokubun, T. Takahashi (ISAS/JAXA), M. Tashiro, Y. Terada, A. Endo, K. Onda, T. Sugasahara (Saitama U.), Y. E. Nakagawa, T. Tamagawa (RIKEN), N. Ohmori, A. Daikyuji, E. Sonoda, K. Kono, H. Hayashi, K. Noda, Y. Nishioka, M. Yamauchi (Univ. of Miyazaki), K. Yamaoka, S. Sugita (Aoyama Gakuin U.), S. Hong (Nihon U.), N. Vasquez (Tokyo Tech.), Y. Urata (NCU), Y. Hanabata, T. Uehara, T. Takahashi, Y. Fukazawa (Hiroshima U.), on behalf of the Suzaku WAM team, report: The bright, long GRB 090709A (Swift/BAT trigger #356890 ; Morris et al., GCN 9625) triggered the Suzaku Wide-band All-sky Monitor (WAM) which covers an energy range of 50 keV - 5 MeV at 07:38:33 UT (=T0). The observed light curve shows a multi-peaked structure with a duration (T90) of about 81 seconds. The corresponding peaks in the FFT power spectrum of 1 s light curve are clearly seen around P=8.06(-0.20,+0.20) s, which is consistent with the previous reports (Markwardt et al., GCN 9645; Golenetskii et al., GCN 9647; Gotz et al., GCN 9649). The fluence in 100 - 1000 keV was 6.06(-0.36, +0.48) x10^-5 erg/cm^2. The 1-s peak flux measured from T0+70s was 4.83(-0.69, +0.27) photons/cm^2/s in the same energy range. Preliminary result shows that the time-averaged spectrum from T0-10s to T0+110s is well fitted by a power-law with exponential cutoff model: dN/dE ~ E^{-alpha} * exp(-(2-alpha)*E/Epeak) with alpha 0.97(-0.43, +0.52), and Epeak 439(-58, -48) keV (chi^2/d.o.f. = 62.9/48). All the quoted errors are at statistical 90% confidence level, in which the systematic uncertainties are not included. The light curves for this burst are available at: http://www.astro.isas.jaxa.jp/suzaku/HXD-WAM/WAM-GRB/grb/trig/grb_table.html
GCN 9654 table
GRB_name GRB090709A
GCN_number 9654
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9654 SUBJECT: GRB090709A : WSRT Radio observation DATE: 09/07/11 12:15:37 GMT FROM: Atish Kamble at U. of Amsterdam "Atish Kamble (U of Amsterdam), A.J. van der Horst (NASA/MSFC/ORAU), C. Kouveliotou (NASA/MSFC), R.A.M.J. Wijers and E. Rol (U of Amsterdam) report on behalf of a large collaboration" The Westerbork Synthesis Radio Telescope observed the position of the GRB090709A afterglow (Morris et al. GCN 9625) at 4.9 GHz between July 10.71 and 11.26, 2009 (i.e. about 1.67 days after the burst). No radio counterpart to the afterglow was detected up to three sigma rms limit of 141 microJy. The formal flux measured at the position of the NIR counterpart (Morgan et al. GCN 9635) is 104 +/- 47 microJy. We would like to thank the WSRT staff for rapidly scheduling and obtaining these observations."
GCN 9655 table
GRB_name GRB090709A
GCN_number 9655
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 9655 SUBJECT: GRB 090709A: deep optical observation with the 10.4m GTC DATE: 09/07/11 12:18:38 GMT FROM: Alberto Castro-Tirado at Inst.de Astro. de Andalucia A. J. Castro-Tirado (IAA-CSIC Granada), A. de Ugarte Postigo (OAB-INAF), J. Gorosabel, S. Guziy, M. Jelnek (IAA-CSIC), P. Kubnek (IAA-CSIC and GACE Valencia), D. Prez-Ramrez (Univ. de Jan), N. Mirabal (UCM Madrid), A. Llorente, J. M. Castro Cern (ESAC Villafranca del Castillo), C. Alvarez (IAC/GTC La Palma) and J. Cepa (IAC Tenerife), report: Following the detection of GRB 090709A by Swift (Morris et al. GCNC 9625), we have conducted follow-up observations with the 10.4-m Gran Telescopio Canarias (GTC) at the Observatorio del Roque de los Muchachos of the Instituto de Astrofsica de Canarias, in the island of La Palma. Images in the i-band filter (7 x 300-s) under 1.0 seeing were gathered with the OSIRIS instrument (Cepa et al. 2009, in prep.) on 11 July 2009, 00:45 UT (i.e. 41 hr after the event). At the position of the reported nIR/optical afterglow (Aoki et al. GCNC 9634, Morgan et al. GCNC 9635, Cenko et al. GCNC 9646) we detect no single object down to i ~ 25.5 (preliminary 3-sigma limit), or i ~ 25.2 when taking into account the foreground Galactic extinction. We note two nearby faint objects, which lie 3.3 south-east and 4 north of the afterglow. The stacked GTC .jpg image is available at the following link: http://www.iaa.es/~gss/GRB090709A Although we cannot exclude that GRB 090709A occurred in a low redshift galaxy (Butler et al. GCNC 9639, Guidorzi et al. GCNC 9648), our non-detection of a host galaxy, together with the reported 8-s quasi-periodic oscillations (Markwardt et al. GCN 9645, Golenetskii et al. 9647, Gotz et al. GCNC 9649, Ohno et al. GCNC 9653) and the fact that the event is at galactic coordinates of about (l = 91, b = 20) cannot rule out that the initial observed gamma-ray emission arose from a nearby magnetar candidate in the Milky Way, much closer than GRB 070610 / SWIFT J195509+261406 (Castro-Tirado et al. 2008, Nature 455, 506). Multiwavelength observations are encouraged. We acknowledge the excellent support from the GRANTECAN staff. This Circular can be quoted.
GCN 9657 table
GRB_name GRB090709A
GCN_number 9657
Detection_method Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9657 SUBJECT: VLA radio observations of GRB 090709A DATE: 09/07/12 01:40:32 GMT FROM: Poonam Chandra at U Virginia/NRAO Poonam Chandra (RMC) and Dale A. Frail (NRAO) report on behalf of a larger collaboration: "We used the Very Large Array to observe the field of view towards the GRB 090709A (GCN 9625) at a frequency of 8.46 GHz on 2009 Jul. 10.46 UT and Jul. 11.42 UT, and at a frequency of 1.43 GHz on 2009 Jul. 11.39 UT. The GRB radio afterglow is undetected at the PAIRITEL NIR afterglow position (GCN 9635). The peak flux at the GRB afterglow position on 11th July observations is 62+/-35 uJy in 8.46 GHz band and 79+/-144 uJy at 1.43 GHz band. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc."
GCN 9658 table
GRB_name GRB090709A
GCN_number 9658
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 9658 SUBJECT: GRB 090709A: Xinglong TNT optical upper limit DATE: 09/07/12 03:16:43 GMT FROM: L.P. Xin at NAOC L.P. Xin, W.K. Zheng, Y.L. Qiu, J.Y. Wei, J. Wang, J.S. Deng and J.Y. Hu on behalf of EAFON report: We have observed GRB 090709A (Morris et al.GCN 9625) with Xinglong TNT telescope from July 9, 13:41:18 (UT), 6.04 hour after the burst. After combined 10*600s R band images, no new source or afterglow counterpart (Morgan et al.GCN 9635;Guidorzi et al. GCN 9648) was found in our combined image within the XRT errorbox (Morris et al. GCN 9625). The uplimit is estimated to be about 20.6 mag at the mean time of 6.816 hours since the trigger. This message may be cited. For more information about Xinglong GRBs Follow-up observations, please visit the website: http://www.xinglong-naoc.org/grb/
GCN 9685 table
GRB_name GRB090709A
GCN_number 9685
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 9685 SUBJECT: GRB 090709A - CARMA mm Observations DATE: 09/07/17 22:01:56 GMT FROM: Adam Morgan at U.C. Berkeley A. N. Morgan, G. C. Bower (UC Berkeley), report: We observed the field of GRB 090709A (Morris et al., GCN 9625) with the Combined Array for Research in Millimeter-Wave Astronomy (CARMA) at an average frequency of 88.5 GHz beginning at 2009-07-15 04:41:33 UT, ~5.88 days after the Swift trigger. No source was detected at the position of the NIR/optical afterglow (Aoki et al., GCN 9634; Morgan et al., GCN 9635; Cenko et al., GCN 9646; Guidorzi et al., GCN 9648) down to the following limits: post_burst t_mid(d) exp(h) freq_mid(GHz) bandwidth(MHz) flux (mJy) 5.98 3.79 88.5 3000 < 1.1 (3 sig) The quasar 1849+670 was used as a phase calibrator, and fluxes were calibrated to an observation of Neptune taken at the end of the track. We thank the staff and observers at CARMA and instructors of the CARMA Summer School for excellent support during the observations and analysis.
GCN 9696 table
GRB_name GRB090709A
GCN_number 9696
Detection_method Swift Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9696 SUBJECT: GRB 090709A: Swift XRT Timing Analysis DATE: 09/07/21 12:18:24 GMT FROM: Nestor Mirabal at U.Complutense de Madrid N. Mirabal (U. Complutense de Madrid) and E. V. Gotthelf (Columbia U.) report: In light of recent reports of quasi-periodic variations in the gamma-ray light curve of GRB 090709A (Markwardt et al., GCN 9645; Golenetskii et al., GCN 9647, Gotz et al., GCN 9649; Ohno et al., GCN 9653), we have analyzed Swift XRT observations of GRB 090709A obtained between 2009 July 9.319 UT and 2009 July 11.862 UT (79s - 61 hr after the trigger assuming T at 2009 July 9, 07:38:34 UT). This period overlaps the BAT light curve from T+79 s to T+150 s (Markward et al., GCN 9645). The first set of observations (390 s) was taken in WT mode (1.77 ms timing resolution), followed by three pointings in PC mode (2.5 s timing resolution). Fast Fourier Transform (FFT) analysis applied to the light curves in each interval shows no significant power down to the Nyquist limit of f < 283 Hz and f < 2 Hz, for the WT and PC mode data, respectively. Furthermore, the power spectrum of the first 120 s of WT mode data (79-469 s after the trigger) does not reveal any significant signal. The FFTs show typical characteristics of both white and red noise during the interval. The absence of oscillations in the X-ray band appears to rule out coherent quasi-periodic variations extending beyond T+150 s. We note that the 8-second cycle derived from the gamma-ray light curve seems at odds with the spin period P ~ 1 ms required to produce an energy release Egamma ~ 10^50 erg from a magnetar engine (Thompson et al. 2004, ApJ, 611, 380), unless the neutron star was born a millisecond pulsar and spun down to a 1-8 s period (depending on the actual GRB redshift) on a ~10 s timescale. The power spectrum of the GRB 090709A light curve (WT mode, 79-469 s after the trigger) can be found at: http://www.gae.ucm.es/~mirabal/grbs/grb090709a/grb090709a_fft.gif
GCN 9737 table
GRB_name GRB090709A
GCN_number 9737
Detection_method Swift-XRT Other
Circular_text TITLE: GCN CIRCULAR NUMBER: 9737 SUBJECT: GRB 090709A : Quick look analysis of the Suzaku observation DATE: 09/07/30 16:07:34 GMT FROM: Yujin E. Nakagawa at RIKEN Y. E. Nakagawa, T. Tamagawa (RIKEN), K. Yamaoka, S. Sugita, A. Yoshida (Aoyama Gakuin University), R. Sato, M. Ohno (ISAS/JAXA), K. Nakazawa (University of Tokyo), M. Tashiro, T. Sugasahara, W. Iwakiri, K. Onda (Saitama University), Y. Urata (National Central University), D. Yonetoku, T. Murakami (Kanazawa University), N. Kawai, R. Usui, H. Nakajima, A. Endo (Tokyo Institute of Technology), M. Yamauchi, E. Sonoda, N. Ohmori, K. Kohno, H. Hayashi, A. Daikyuji, K. Noda, Y. Nishioka (University of Miyazaki), M. Suzuki (TKSC/JAXA), F. Tazaki, S. Eguchi, K. Kubota, Y. Ishino, K. Hiroi, Y. Ueda (Kyoto University), on behalf of the Suzaku GRB ToO team, report: We report on a Suzaku ToO observation of the GRB 090709A X-ray afterglow (Morris et al. 2009, GCN 9625), started on 2009-07-09 13:16:17 UT, for a net exposure time of about 62 ksec (Mitsuda et al. 2009, GCN 9632). The observation covers time ranging from 23 ksec to 135 ksec after the Swift/BAT trigger time (2009-07-09 07:38:34 UT). The X-ray afterglow was clearly detected in the XIS CCDs at a position consistent with that of the Swift/XRT observations (Morris et al. 2009, 9625). The 0.2-12 keV light curve is well fit by a power law with a decay index of 1.53+/-0.02. A preliminary analysis of the XIS data shows that a time average spectrum in 0.2-12 keV band is well fit by a power law with a photon index of 2.02+/-0.03, absorbed by a hydrogen column density of (2.2+/-0.2)*10^21 cm^-2. The unabsorbed 0.2-12 keV flux is (5.2+/-0.2)*10^-12 ergs cm^-2 s^-1. The XIS data confirm the hydrogen column density in excess of the Galactic value of 6.6*10^20 cm^-2, consistent with the Swift/XRT result (Rowlinson et al. 2009, GCN 9642). We would like to thank the Suzaku managers and the operation team for approving and carrying out the ToO observation.
GCN 10903 table
GRB_name GRB090709A
GCN_number 10903
Detection_method Optical
Circular_text TITLE: GCN CIRCULAR NUMBER: 10903 SUBJECT: GRB 090709A: Host galaxy detection DATE: 10/06/29 04:44:26 GMT FROM: Daniel Perley at U.C. Berkeley D. A. Perley, S. B. Cenko, and J. S. Bloom (UC Berkeley) report: We observed the field of GRB 090709A (Morris et al., GCN 9625) using NIRI on Gemini-North on the night of 2010-06-23 between 11:54 and 14:46 UT, under good conditions. Our co-added stack contains a total of 146 images of 60 seconds each (2.43 hours of imaging) in the K' filter. The 3-sigma limiting magnitude of the stack is K' ~ 23.7. (Calibration of the field was established relative to several 2MASS stars in the image.) Matching our image directly to early-time PAIRITEL imaging (Morgan et al., GCN 9635), we detect a faint, extended source slightly offset (0.6 arcsec) from the position of the IR afterglow. The orientation of the offset is along the apparent direction of extension of the source (E-W). Aperture photometry within a 1.0 arcsec aperture centered on the object gives a magnitude of K' = 22.0 +/- 0.2 mag. The chance probability for this alignment is approximately one percent (Bloom et al. 2002, AJ 123:1111, Djorgovski et al. 1995, ApJL 438:L13). We therefore associate this object with the host galaxy of GRB 090709A. The detection of a host galaxy confirms the extragalactic, cosmological nature of this event (de Luca et al. 2010, MNRAS 402:1870; Cenko et al. 2010, AJ 140:224). We note that deep optical imaging of this field by the GTC (Castro-Tirado et al., GCN 9655) detected no object at this position to a limit of i' > 25.5, suggesting that the host galaxy may be internally dust-reddened. The infrared afterglow also showed evidence of strong reddening (Cenko et al. 2010), and foreground extinction in this direction is low; E(B-V) = 0.09 mag. Additional imaging is encouraged to test this hypothesis. An image of the field is posted to: http://lyra.berkeley.edu/~dperley/090709a/090709a_niri.png We are happy to thank Marie Lemoine-Busserolle, Matthew Dillman, and Andrew Stephens for their support during our classical NIRI run.