Early optical and millimeter observations of GRB 030226 afterglow

Abstract

The CCD magnitudes in Johnson $UBV$ and Cousins $RI$ photometric passbands for the afterglow of the long duration GRB 030226 are presented. Upper limits of a few mJy to millimeter wave emission at the location of optical are obtained over the first two weeks. The optical data presented here, in combination with other published data on this afterglow, show an early $R$ band flux decay slope of 0.77$\pm$0.04, steepening to 2.05$\pm$0.04 about 0.65$\pm$0.03 day after the burst. Interpreted as the ``jet break'', this indicates a half opening angle of $\sim 3.2$ degree for the initial ejection, for an assumed ambient density of $\sim 1{\mathrm{cm}}^{-3}$. Broadband spectra show no appreciable evolution during the observations, and indicate the presence of synchrotron cooling frequency ${\nu }_c$ near the upper edge of the optical band. From the broadband spectra we derive an electron energy distribution index $p=2.07\pm 0.06$ and an intrinsic extinction $E(B-V)\sim 0.17$. Millimeter upper limits are consistent with these derived parameters.

arXiv comment6 pages, 2 figures, Accepted to A&A

References in corpus (19)

• Maps of Dust IR Emission for Use in Estimation of Reddening and CMBR Foregrounds
• Beaming in Gamma-Ray Bursts: Evidence for a Standard Energy Reservoir
• Jets in GRBs
• The Dynamics and Light Curves of Beamed Gamma Ray Burst Afterglows
• Theories of Gamma-Ray Bursts
• Reddening and Star Formation in Starburst Galaxies
• A Common Origin for Cosmic Explosions Inferred from Fireball Calorimetry
• The prompt energy release of gamma-ray bursts using a cosmological k-correction
• Optical and Radio Observations of the Afterglow from GRB990510: Evidence for a Jet
• BVRI Observations of the Optical Afterglow of GRB 990510
• The bright optical afterglow of the nearby gamma-ray burst of 29 March 2003
• GRB 030226 in a Density-Jump Medium
• The Near Infrared and Multiwavelength Afterglow of GRB 000301c
• GRB010222: afterglow emission from a rapidly decelerating shock
• The jet and circumburst stellar wind of GRB 980519
• The afterglow and the host galaxy of GRB 011211
• Rapid UBVRI Follow-up of the Highly Collimated Optical Afterglow of GRB010222
• Early optical and millimeter observations of GRB 030226 afterglow
• GRB000301C with peculiar afterglow emission

Cited by in corpus (17)

• The collimation--corrected GRB energies correlate with the peak energy of their $\nu F_{\nu }$ spectrum
• Signatures of Extragalactic Dust in pre-Swift GRB Afterglows
• Swift Identification of Dark Gamma-Ray Bursts
• Probing a GRB progenitor at a redshift of z=2: a comprehensive observing campaign of the afterglow of GRB 030226
• The clustering of the luminosities of optical afterglows of long Gamma Ray Bursts
• Jets, Structured Outflows, and Energy Injection in GRB Afterglows: Numerical Modelling
• Phenomenology of Reverse-Shock Emission in the Optical Afterglows of Gamma Ray Bursts
• Pre-ALMA observations of GRBs in the mm/submm range
• Models for Achromatic Light-Curve Breaks in GRB Afterglows: Jets, Structured Outflows, and Energy Injection
• Statistical study of gamma-ray bursts with jet break feature in multi-wavelength afterglow emissions
• Jet break time -- flux density relationship and constraints on physical parameters of GRB afterglows
• A Large Catalogue of Multi-wavelength GRB Afterglows I: Color Evolution And Its Physical Implication
• Early optical and millimeter observations of GRB 030226 afterglow
• SCUBA sub-millimeter observations of gamma-ray bursters IV. GRB 021004, 021211, 030115, 030226, 041006
• Early Re-brightenings in GRB Afterglows as Signatures of Low-to-High Density Boundary
• Core-collapse Supernovae and Gamma-ray Bursts in TMT Era
• Recent observations of peculiar Gamma-ray bursts using 3.6 m Devasthal Optical Telescope (DOT)