Detailed optical and near-infrared polarimetry, spectroscopy and broad-band photometry of the afterglow of GRB 091018: polarization evolution

Follow-up observations of large numbers of gamma-ray burst (GRB) afterglows, facilitated by the Swift satellite, have produced a large sample of spectral energy distributions and light curves, from which their basic micro- and macro-physical parameters can in principle be derived. However, a number of phenomena have been observed that defy explanation by simple versions of the standard fireball model, leading to a variety of new models. Polarimetry can be a major independent diagnostic of afterglow physics, probing the magnetic field properties and internal structure of the GRB jets. In this paper we present the first high-quality multi-night polarimetric light curve of a Swift GRB afterglow, aimed at providing a well-calibrated data set of a typical afterglow to serve as a benchmark system for modelling afterglow polarization behaviour. In particular, our data set of the afterglow of GRB 091018 (at redshift z = 0.971) comprises optical linear polarimetry (R band, 0.13–2.3 d after burst); circular polarimetry (R band) and near-infrared linear polarimetry (Ks band). We add to that high-quality optical and near-infrared broad-band light curves and spectral energy distributions as well as afterglow spectroscopy. The linear polarization varies between 0 and 3 per cent, with both long and short

[1]  E. Rol,et al.  Variable polarization in the optical afterglow of GRB 021004 , 2003, astro-ph/0305227.

[2]  Kenji Toma,et al.  Probing the Efficiency of Electron-Proton Coupling in Relativistic Collisionless Shocks through the Radio Polarimetry of Gamma-Ray Burst Afterglows , 2008 .

[3]  R. Lupton,et al.  A Method for Optimal Image Subtraction , 1997, astro-ph/9712287.

[4]  T. Grav,et al.  The Strongly Polarized Afterglow of GRB 020405 , 2002, astro-ph/0206465.

[5]  A. Loeb,et al.  Probing the Magnetic Field Structure in Gamma-Ray Bursts through Dispersive Plasma Effects on the Afterglow Polarization , 2004, astro-ph/0401620.

[6]  S. Savaglio,et al.  THE GALAXY POPULATION HOSTING GAMMA-RAY BURSTS , 2008, 0803.2718.

[7]  Rony Keppens,et al.  Two-shell collisions in the gamma-ray burst afterglow phase , 2011 .

[8]  S. B. Pandey,et al.  Optical observations of the bright long duration peculiar GRB 021004 afterglow , 2002 .

[9]  P. Schady,et al.  The SEDs and host galaxies of the dustiest GRB afterglows , 2011, 1108.0674.

[10]  K. Wiersema.  The extinction properties of long GRB host galaxies from H and He I recombination lines , 2011, 1101.0814.

[11]  M. Feroci,et al.  Discovery of the X-Ray Afterglow of the Gamma-Ray Burst of February 28 1997 , 1997 .

[12]  E. H. Gudmundsson,et al.  Energy Injection Episodes in Gamma-Ray Bursts: The Light Curves and Polarization Properties of GRB 021004 , 2004, astro-ph/0409584.

[13]  M. Rees,et al.  Optical and Long-Wavelength Afterglow from Gamma-Ray Bursts , 1996, astro-ph/9606043.

[14]  C. Kouveliotou,et al.  Transient optical emission from the error box of the γ-ray burst of 28 February 1997 , 1997, Nature.

[15]  D. S. Mathewson,et al.  Wavelength dependence of interstellar polarization and ratio of total to selective extinction. , 1975 .

[16]  D. Bersier,et al.  The spectroscopic variability of GRB 021004 , 2003 .

[17]  Ryan Chornock,et al.  GRB 021004: A Possible Shell Nebula around a Wolf-Rayet Star Gamma-Ray Burst Progenitor , 2003, astro-ph/0303616.

[18]  John T. Rayner,et al.  Spextool: A Spectral Extraction Package for SpeX, a 0.8–5.5 Micron Cross‐Dispersed Spectrograph , 2004 .

[19]  Jonathan Granot,et al.  LINEAR POLARIZATION IN GAMMA-RAY BURSTS: THE CASE FOR AN ORDERED MAGNETIC FIELD , 2003 .

[20]  T. Sakamoto,et al.  JET BREAKS AND ENERGETICS OF Swift GAMMA-RAY BURST X-RAY AFTERGLOWS , 2008, 0812.4780.

[21]  J. Bloom,et al.  Optical-Infrared ANDICAM Observations of the Transient Associated with GRB 030329 , 2003, astro-ph/0308034.

[22]  Z. Dai,et al.  Gamma-ray bursts: polarization of afterglows from two-component jets , 2004, astro-ph/0412011.

[23]  Javier Gorosabel,et al.  Optical Photometry of GRB 021004: The First Month , 2003 .

[24]  E. Rol,et al.  TESTING THE STANDARD FIREBALL MODEL OF GAMMA-RAY BURSTS USING LATE X-RAY AFTERGLOWS MEASURED BY SWIFT , 2006 .

[25]  Christoph Ries,et al.  Evolution of the polarization of the optical afterglow of the γ-ray burst GRB030329 , 2003, Nature.

[26]  T. Dwelly,et al.  The dust extinction curves of gamma-ray burst host galaxies , 2011, 1110.3218.

[27]  Tsvi Piran,et al.  Jets in Gamma-Ray Bursts , 1999 .

[28]  Peter G. Martin,et al.  Interstellar Extinction and Polarization in the Infrared , 1990 .

[29]  S. R. Kulkarni,et al.  Optical Spectropolarimetry of the GRB 020813 Afterglow , 2002, astro-ph/0212554.

[30]  A. Gal-Yam,et al.  Early optical emission from the γ-ray burst of 4 October 2002 , 2003, Nature.

[31]  C. Guidorzi,et al.  Ten per cent polarized optical emission from GRB 090102 , 2009, Nature.

[32]  Paola Andreani,et al.  European ALMA operations: the interaction with and support to the users , 2008, Astronomical Telescopes + Instrumentation.

[33]  P. Schady,et al.  The nature of "dark" gamma-ray bursts , 2010, 1011.0618.

[34]  Davide Lazzati,et al.  Polarization light curves and position angle variation of beamed gamma-ray bursts , 1999, astro-ph/9906471.

[35]  William B. Sparks,et al.  Panoramic Polarimetry Data Analysis , 1999 .

[36]  E. Rol,et al.  GRB 060206 and the quandary of achromatic breaks in afterglow light curves , 2007, 0706.1188.

[37]  Davide Lazzati,et al.  Polarization in the prompt emission of gamma-ray bursts and their afterglows , 2006, astro-ph/0607663.

[38]  Re'em Sari,et al.  Linear Polarization and Proper Motion in the Afterglow of Beamed Gamma-Ray Bursts , 1999, astro-ph/9906503.

[39]  Nathaniel Butler,et al.  Gamma-Ray Burst Energetics in the Swift Era , 2007, 0707.4478.

[40]  Y. Yatsu,et al.  Earliest Detection of the Optical Afterglow of GRB 030329 and Its Variability , 2003 .

[41]  S. B. Pandey,et al.  Optical and near-infrared observations of the GRB020405 afterglow ? , 2003, astro-ph/0302350.

[42]  A. Yoldas,et al.  CORRELATED OPTICAL AND X-RAY FLARES IN THE AFTERGLOW OF XRF 071031 , 2009, 0903.1184.

[43]  E. O. Ofek,et al.  THE ASTROPHYSICAL JOURNAL,???:??1–??7, 2004 MONTH, ASTRO-PH/0312594 Preprint typeset using L ATEX style emulateapj v. 4/9/03 THE DETAILED OPTICAL LIGHT CURVE OF GRB 030329 , 2004 .

[44]  Wijers,et al.  UvA-DARE ( Digital Academic Repository ) Physical parametres of GRB 970508 and GRB 971214 from their afterglow synchroton emission , 1999 .

[45]  N. Gehrels,et al.  Evidence for a Canonical Gamma-Ray Burst Afterglow Light Curve in the Swift XRT Data , 2005, astro-ph/0508332.

[46]  Sandra Savaglio,et al.  Rapid-response mode VLT/UVES spectroscopy of GRB 060418. Conclusive evidence for UV pumping from the time evolution of Fe II and Ni II excited- and metastable-level populations , 2006 .

[47]  R. Scoccimarro.  Cosmological Perturbations: Entering the Nonlinear Regime , 1996, astro-ph/9612207.

[48]  J. Rhoads.  How to Tell a Jet from a Balloon: A Proposed Test for Beaming in Gamma-Ray Bursts , 1997, astro-ph/9705163.

[49]  Interstellar Dust and Related Topics , 2012 .

[50]  STAR FORMATION IN GALAXIES ALONG THE HUBBLE SEQUENCE , 1998, astro-ph/9807187.

[51]  J. Rhoads.  The Dynamics and Light Curves of Beamed Gamma-Ray Burst Afterglows , 1999, astro-ph/9903399.

[52]  A. J. Castro-Tirado,et al.  Simultaneous polarization monitoring of supernovae SN 2008D/XT 080109 and SN 2007uy: isolating geometry from dust , 2008, 0810.4333.

[53]  M. Rees,et al.  High-entropy fireballs and jets in gamma-ray burst sources , 1992 .

[54]  S. R. Kulkarni,et al.  BEAMING IN GAMMA-RAY BURSTS: EVIDENCE FOR A STANDARD ENERGY RESERVOIR , 2001 .

[55]  Martino Romaniello,et al.  Error Analysis for Dual‐Beam Optical Linear Polarimetry , 2005, astro-ph/0509153.

[56]  J. P. Osborne,et al.  Methods and results of an automatic analysis of a complete sample of Swift-XRT observations of GRBs , 2008, 0812.3662.

[57]  C. Kouveliotou,et al.  Identification of two classes of gamma-ray bursts , 1993 .

[58]  Taichi Kato,et al.  Structure in the early afterglow light curve of the γ-ray burst of 29 March 2003 , 2003, Nature.

[59]  Jay D. Salmonson,et al.  The polarization of afterglow emission reveals γ‐ray bursts jet structure , 2004 .

[60]  M. Honsberg,et al.  GROND—a 7-Channel Imager , 2008, 0801.4801.

[61]  D. Fugazza,et al.  Intrinsic and dust-induced polarization in gamma-ray burst afterglows: The case of GRB 021004 , 2003, astro-ph/0308540.

[62]  E. Rol,et al.  The prompt to late-time multiwavelength analysis of GRB 060210 , 2007 .

[63]  Eli Waxman,et al.  Gamma-ray burst afterglow: Polarization and analytic light curves , 1999 .

[64]  R. Lenzen,et al.  The instrumental polarization of the Nasmyth focus polarimetric differential imager NAOS/CONICA (NACO) at the VLT - Implications for time-resolved polarimetric measurements of Sgr A* , 2010, 1010.4708.

[65]  Ronnie Killough,et al.  The Swift Ultra-Violet/Optical Telescope , 2001 .

[66]  Alan A. Wells,et al.  The Swift Gamma-Ray Burst Mission , 2004, astro-ph/0405233.

[67]  E. Berger,et al.  A common origin for cosmic explosions inferred from calorimetry of GRB030329 , 2003, Nature.

[68]  F. M. Zerbi,et al.  Polarization Evolution of the GRB 020405 Afterglow , 2002, astro-ph/0211245.

[69]  Jeremy Bailey,et al.  Systematic variations in the wavelength dependence of interstellar linear polarization , 1976 .

[70]  E. Rol,et al.  On the jet structure and magnetic field configuration of GRB 020813 , 2004, astro-ph/0401315.

[71]  T. Grav,et al.  The Unusual Optical Afterglow of the Gamma-Ray Burst GRB 021004: Color Changes and Short-Timescale Variability , 2002, astro-ph/0211130.

[72]  T. Sakamoto,et al.  The lag–luminosity relation in the GRB source frame: an investigation with Swift BAT bursts , 2011, 1109.0666.

[73]  L. A. Antonelli,et al.  Discovery of an X-ray afterglow associated with the γ-ray burst of 28 February 1997 , 1997, Nature.

[74]  Alessandro Monfardini,et al.  Early Optical Polarization of a Gamma-Ray Burst Afterglow , 2007, Science.

[75]  J. Granot,et al.  Radio Flares and the Magnetic Field Structure in Gamma-Ray Burst Outflows , 2004, astro-ph/0412309.

[76]  S. R. Kulkarni,et al.  The Observed Offset Distribution of Gamma-Ray Bursts from Their Host Galaxies: A Robust Clue to the Nature of the Progenitors , 2000, astro-ph/0010176.

[77]  Gruzinov,et al.  Strongly Polarized Optical Afterglows of Gamma-Ray Bursts , 1999, The Astrophysical journal.

[78]  J. Mathis,et al.  The relationship between infrared, optical, and ultraviolet extinction , 1989 .

[79]  C. Kouveliotou,et al.  Detailed study of the GRB 030329 radio afterglow deep into the non-relativistic phase , 2007, 0706.1321.

[80]  T. Piran,et al.  Gamma-ray burst theory after Swift , 2007, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences.

[81]  N. Masetti,et al.  Prospects for multiwavelength polarization observations of GRB afterglows and the case GRB 030329 , 2004, astro-ph/0403504.

[82]  J. Wardle,et al.  The linear polarization of quasi-stellar radio sources at 3.71 and 11.1 centimeters. , 1974 .