Browsing by Author "Kann, D. A."

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    ALMA and GMRT Constraints on the Off-axis Gamma-Ray Burst 170817A from the Binary Neutron Star Merger GW170817.
    (2017) Kim, Sam; González López, Jorge; Bauer, Franz Erik; Schulze, Steve.; Resmi, L.; Higgins, A. B.; Ishwara-Chandra, C. H.; Gregorio-Monsalvo, I. de; Pasquale, M. de; Ugarte Postigo, A. de; Kann, D. A.; Kim, Sam; González López, Jorge; Bauer, Franz Erik; Schulze, Steve.; Resmi, L.; Higgins, A. B.; Ishwara-Chandra, C. H.; Gregorio-Monsalvo, I. de; Pasquale, M. de; Ugarte Postigo, A. de; Kann, D. A.
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    Four GRB supernovae at redshifts between 0.4 and 0.8
    (2019) Klose, S.; Schmidl, S.; Kann, D. A.; Guelbenzu, A. Nicuesa; Schulze, S.; Greiner, J.; Olivares E, F.; Kruehler, T.; Schady, P.; Afonso, P. M. J.; Filgas, R.; Fynbo, J. P. U.; Rau, A.; Rossi, A.; Takats, K.; Tanga, M.; Updike, A. C.; Varela, K.
    Twenty years ago, GRB 980425/SN 1998bw revealed that long gamma-ray bursts (GRBs) are physically associated with broad-lined type-Ic supernovae (SNe). Since then more than 1000 long GRBs have been localized to high angular precision, but only in similar to 50 cases has the underlying SN component been identified. Using the Gamma-Ray Burst Optical Near-Infrared Detector (GROND) multi-channel imager at ESO/La Silla, during the last ten years we have devoted a substantial amount of observing time to reveal and study SN components in long-GRB afterglows. Here we report on four more GRB SNe (associated with GRBs 071112C, 111228A, 120714B, and 130831A) which were discovered and/or followed-up with GROND and whose redshifts lie between z = 0.4 and 0.8. We study their afterglow light curves, follow the associated SN bumps over several weeks, and characterize their host galaxies. Using SN 1998bw as a template, the derived SN explosion parameters are fully consistent with the corresponding properties of the currently known GRB-SN ensemble, with no evidence for an evolution of their properties as a function of redshift. In two cases (GRB 120714B/SN 2012eb at z = 0.398 and GRB 130831A/SN 2013fu at z = 0.479) additional Very Large Telescope (VLT) spectroscopy of the associated SNe revealed a photospheric expansion velocity at maximum light of about 40 000 and 20 000 km s(-1), respectively. For GRB 120714B, which was an intermediate-luminosity burst, we find additional evidence for a black-body component in the light of the optical transient at early times, similar to what has been detected in some GRB SNe at lower redshifts.
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    Highly luminous supernovae associated with gamma-ray bursts I. GRB 111209A/SN 2011kl in the context of stripped-envelope and superluminous supernovae
    (2019) Kann, D. A.; Schady, P.; Olivares, F. E.; Klose, S.; Rossi, A.; Perley, D. A.; Kruehler, T.; Greiner, J.; Guelbenzu, A. Nicuesa; Elliott, J.; Knust, F.; Filgas, R.; Pian, E.; Mazzali, P.; Fynbo, J. P. U.; Leloudas, G.; Afonso, P. M. J.; Delvaux, C.; Graham, J. F.; Rau, A.; Schmidl, S.; Schulze, S.; Tanga, M.; Updike, A. C.; Varela, K.
    Context. GRB 111209A, one of the longest gamma-ray bursts (GRBs) ever observed, is linked to SN 2011kl, which is the most luminous GRB supernova (SN) detected so far. Several lines of evidence indicate that this GRB-SN is powered by a magnetar central engine.
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    Identifying the host galaxy of the short GRB 100628A
    (EDP SCIENCES S A, 2015) Guelbenzu, A. Nicuesa; Klose, S.; Palazzi, E.; Greiner, J.; Michalowski, M. J.; Kann, D. A.; Hunt, L. K.; Malesani, D.; Rossi, A.; Savaglio, S.; Schulze, S.; Xu, D.; Afonso, P. M. J.; Elliott, J.; Ferrero, P.; Filgas, R.; Hartmann, D. H.; Kruehler, T.; Knust, F.; Masetti, N.; Olivares E, F.; Rau, A.; Schady, P.; Schmidl, S.; Tanga, M.; Updike, A. C.; Varela, K.
    We report on the results of a comprehensive observing campaign to reveal the host galaxy of the short GRB 100628A. This burst was followed by a faint X-ray afterglow but no optical counterpart was discovered. However, inside the X-ray error circle a potential host galaxy at a redshift of z = 0.102 was soon reported in the literature. If this system is the host, then GRB 100628A was the cosmologically most nearby unambiguous short burst with a measured redshift so far. We used the multi-colour imager GROND at the ESO/La Silla MPG 2.2 in telescope. ESO/VLT spectroscopy, and deep Australia Telescope Compact Array (ATCA) radio-continuum observations together with publicly available Gemini imaging data to study the putative host and the galaxies in the field of GRB 100628A. We confirm that inside the X-ray error circle the most probable host-galaxy candidate is the morphologically disturbed, interacting galaxy system at z = 0.102. The interacting galaxies are connected by a several kpc long tidal stream, which our VLT/FORS2 spectroscopy reveals strong emission lines of [O II] [O III], H alpha and H beta, characteristic for the class of extreme emission-line galaxies and indicative of ongoing star formation. The latter leaves open the possibility that the ORB progenitor was a member of a young stellar population. However, we indentify a second host-galaxy candidate slightly outside the X-ray error circle. It is a radio-bright, luminous elliptical galaxy at a redshift z = 0.311. With a K-band luminosity of 2 x 10(11) L-circle dot this galaxy resembles the probable giant elliptical host of the first well-localized short burst. GRB 050509B. If this is the host, then the progenitor of GRB 100628A was a member of an old stellar population.
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    Investigating the off-axis GRB afterglow scenario for extragalactic fast X-ray transients
    (2024) Wichern, H. C. I.; Ravasio, M. E.; Jonker, P. G.; Quirola-Vasquez, J. A.; Levan, A. J.; Bauer, F. E.; Kann, D. A.
    Context. Extragalactic fast X-ray transients (FXTs) are short-duration (similar to ks) X-ray flashes of unknown origin, potentially arising from binary neutron star (BNS) mergers, tidal disruption events, or supernova shock breakouts. Aims. In the context of the BNS scenario, we investigate the possible link between FXTs and the afterglows of off-axis merger-induced gamma-ray bursts (GRBs). Methods. By modelling well-sampled broadband afterglows of 13 merger-induced GRBs, we make predictions for their X-ray light curve behaviour had they been observed off-axis, considering both a uniform jet with core angle theta(C) and a Gaussian-structured jet whose edge lies at an angle theta(W) = 2 theta(C). We compare their peak X-ray luminosity, duration, and temporal indices alpha (where F proportional to t(alpha)) with those of the currently known extragalactic FXTs. Results. Our analysis reveals that a slightly off-axis observing angle of theta(obs) approximate to (2.2 - 3)theta(C) and a structured jet are required to explain the shallow (|alpha|less than or similar to 0.3) temporal indices of the FXT light curves, which cannot be reproduced in the uniform-jet case at any viewing angle. In the case of a structured jet with truncation angle theta(W) = 2 theta(C), the distributions of the duration of the FXTs are consistent with those of the off-axis afterglows for the same range of observing angles, theta obs approximate to (2.2 - 3)theta(C). While the distributions of the off-axis peak X-ray luminosity are consistent only for theta(obs) = 2.2 theta(C), focussing on individual events with different intrinsic luminosities reveals that the match of all three properties (peak X-ray luminosity, duration and temporal indices) of the FXTs at the same viewing angle is possible in the range theta(obs) similar to (2.2 - 2.6)theta(C). Despite the small sample of GRBs analysed, these results show that there is a region of the parameter space - although quite limited - where the observational properties of off-axis GRB afterglow can be consistent with those of the newly discovered FXTs. Future observations of FXTs discovered by the recently launched Einstein Probe mission and GRB population studies combined with more complex afterglow models will shed light on this possible GRB-FXT connection, and eventually unveil the progenitors of some FXTs.
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    Molecular hydrogen in the damped Lyman α system towards GRB 120815A at z=2.36
    (2013) Kruhler, T.; Ledoux, C.; Fynbo, J. P. U.; Vreeswijk, P. M.; Schmidl, S.; Malesani, D.; Christensen, L.; De Cia, A.; Hjorth, J.; Jakobsson, P.; Kann, D. A.; Kaper, L.; Vergani, S. D.; Afonso, P. M. J.; Covino, S.; de Ugarte Postigo, A.; D'Elia, V.; Filgas, R.; Goldoni, P.; Greiner, J.; Hartoog, O. E.; Milvang-Jensen, B.; Nardini, M.; Piranomonte, S.; Rossi, A.; Sanchez-Ramirez, R.; Schady, P.; Schulze, S.; Sudilovsky, V.; Tanvir, N. R.; Tagliaferri, G.; Watson, D. J.; Wiersema, K.; Wijers, R. A. M. J.; Xu, D.
    We present the discovery of molecular hydrogen (H-2), including the presence of vibrationally-excited H-2* in the optical spectrum of the of GRB 120815A at z = 2.36 obtained with X-shooter at the VLT. Simultaneous photometric broad-band data from GROND X-ray observations by SwiftXRT place further constraints on the amount and nature of dust along the sightline. The galactic of GRB 120815A is characterized by a strong DLA with log(N(H I) = cm(-2)) = 21.95 +/- 0.10, prominent H-2 absorption the Lyman-Werner bands (log(N(H-2) = cm(-2)) = 20.54 +/- 0.13) and thus a molecular gas fraction log f(H-2) = 1.14 +/- 0.15. The d between the absorbing neutral gas and GRB 120815A is constrained via photo-excitation modeling of fine-structure and stable transitions of Fe II and Ni II to d = 0.5 +/- 0.1 kpc. The DLA metallicity ([Zn = H] = 1.15 +/- 0.12), visual extinction AV less than or similar to 0.15 mag) and dust depletion ([Zn = Fe] = 1.01 +/- 0.10) are intermediate between the values of well-studied, H-2-deficient DLAs observed at high spectral resolution, and the approximately solar metallicity, highly-obscured and H-2-rich GRB 080607 With respect to N(H I), metallicity, as well as dust-extinction and depletion, GRB 120815A is fairly representative of the properties of GRB-DLAs. This demonstrates that molecular hydrogen is present in at least a fraction of the more typical GRB- and H-2 and H-2* are probably more wide-spread among GRB-selected systems than the few examples of previous detections suggest. Because H-2* transitions are located redwards of the Lyman alpha absorption, H-2* opens a second route for positive searches molecular absorption also in GRB afterglows at lower redshifts and observed at lower spectral resolution. Further detections of gas in GRB-DLAs would allow statistical studies, and, coupled with host follow-up and sub-mm spectroscopy, provide insights into the process and conditions of star-formation at high redshift.
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    Observational constraints on the optical and near-infrared emission from the neutron star-black hole binary merger candidate S190814bv
    (2020) Ackley, K.; Amati, L.; Barbieri, C.; Bauer, F. E.; Benetti, S.; Bernardini, M. G.; Bhirombhakdi, K.; Botticella, M. T.; Branchesi, M.; Brocato, E.; Bruun, S. H.; Bulla, M.; Campana, S.; Cappellaro, E.; Castro-Tirado, A. J.; Chambers, K. C.; Chaty, S.; Chen, T-W; Ciolfi, R.; Coleiro, A.; Copperwheat, C. M.; Covino, S.; Cutter, R.; D'Ammando, F.; D'Avanzo, P.; De Cesare, G.; D'Elia, V; Della Valle, M.; Denneau, L.; De Pasquale, M.; Dhillon, V. S.; Dyer, M. J.; Elias-Rosa, N.; Evans, P. A.; Eyles-Ferris, R. A. J.; Fiore, A.; Fraser, M.; Fruchter, A. S.; Fynbo, J. P. U.; Galbany, L.; Gall, C.; Galloway, D. K.; Getman, F., I; Ghirlanda, G.; Gillanders, J. H.; Gomboc, A.; Gompertz, B. P.; Gonzalez-Fernandez, C.; Gonzalez-Gaitan, S.; Grado, A.; Greco, G.; Gromadzki, M.; Groot, P. J.; Gutierrez, C. P.; Heikkila, T.; Heintz, K. E.; Hjorth, J.; Hu, Y-D; Huber, M. E.; Inserra, C.; Izzo, L.; Japelj, J.; Jerkstrand, A.; Jin, Z. P.; Jonker, P. G.; Kankare, E.; Kann, D. A.; Kennedy, M.; Kim, S.; Klose, S.; Kool, E. C.; Kotak, R.; Kuncarayakti, H.; Lamb, G. P.; Leloudas, G.; Levan, A. J.; Longo, F.; Lowe, T. B.; Lyman, J. D.; Magnier, E.; Maguire, K.; Maiorano, E.; Mandel, I; Mapelli, M.; Mattila, S.; McBrien, O. R.; Melandri, A.; Michalowski, M. J.; Milvang-Jensen, B.; Moran, S.; Nicastro, L.; Nicholl, M.; Guelbenzu, A. Nicuesa; Nuttal, L.; Oates, S. R.; O'Brien, P. T.; Onori, F.; Palazzi, E.; Patricelli, B.; Perego, A.; Torres, M. A. P.; Perley, D. A.; Pian, E.; Pignata, G.; Piranomonte, S.; Poshyachinda, S.; Possenti, A.; Pumo, M. L.; Quirola-Vasquez, J.; Ragosta, F.; Ramsay, G.; Rau, A.; Rest, A.; Reynolds, T. M.; Rosetti, S. S.; Rossi, A.; Rosswog, S.; Sabha, N. B.; Carracedo, A. Sagues; Salafia, O. S.; Salmon, L.; Salvaterra, R.; Savaglio, S.; Sbordone, L.; Schady, P.; Schipani, P.; Schultz, A. S. B.; Schweyer, T.; Smartt, S. J.; Smith, K. W.; Smith, M.; Sollerman, J.; Srivastav, S.; Stanway, E. R.; Starling, R. L. C.; Steeghs, D.; Stratta, G.; Stubbs, C. W.; Tanvir, N. R.; Testa, V; Thrane, E.; Tonry, J. L.; Turatto, M.; Ulaczyk, K.; van der Horst, A. J.; Vergani, S. D.; Walton, N. A.; Watson, D.; Wiersema, K.; Wiik, K.; Wyrzykowski, L.; Yang, S.; Yi, S-X; Young, D. R.
    Context. Gravitational wave (GW) astronomy has rapidly reached maturity, becoming a fundamental observing window for modern astrophysics. The coalescences of a few tens of black hole (BH) binaries have been detected, while the number of events possibly including a neutron star (NS) is still limited to a few. On 2019 August 14, the LIGO and Virgo interferometers detected a high-significance event labelled S190814bv. A preliminary analysis of the GW data suggests that the event was likely due to the merger of a compact binary system formed by a BH and a NS.Aims. In this paper, we present our extensive search campaign aimed at uncovering the potential optical and near infrared electromagnetic counterpart of S190814bv. We found no convincing electromagnetic counterpart in our data. We therefore use our non-detection to place limits on the properties of the putative outflows that could have been produced by the binary during and after the merger.Methods. Thanks to the three-detector observation of S190814bv, and given the characteristics of the signal, the LIGO and Virgo Collaborations delivered a relatively narrow localisation in low latency - a 50% (90%) credible area of 5 deg(2) (23 deg(2)) - despite the relatively large distance of 26752 Mpc. ElectromagNetic counterparts of GRAvitational wave sources at the VEry Large Telescope collaboration members carried out an intensive multi-epoch, multi-instrument observational campaign to identify the possible optical and near infrared counterpart of the event. In addition, the ATLAS, GOTO, GRAWITA-VST, Pan-STARRS, and VINROUGE projects also carried out a search on this event. In this paper, we describe the combined observational campaign of these groups.Results. Our observations allow us to place limits on the presence of any counterpart and discuss the implications for the kilonova (KN), which was possibly generated by this NS-BH merger, and for the strategy of future searches. The typical depth of our wide-field observations, which cover most of the projected sky localisation probability (up to 99.8%, depending on the night and filter considered), is r similar to 22 (resp. K similar to 21) in the optical (resp. near infrared). We reach deeper limits in a subset of our galaxy-targeted observations, which cover a total similar to 50% of the galaxy-mass-weighted localisation probability. Altogether, our observations allow us to exclude a KN with large ejecta mass M greater than or similar to 0.1 M-circle dot to a high (> 90%) confidence, and we can exclude much smaller masses in a sub-sample of our observations. This disfavours the tidal disruption of the neutron star during the merger.Conclusions. Despite the sensitive instruments involved in the campaign, given the distance of S190814bv, we could not reach sufficiently deep limits to constrain a KN comparable in luminosity to AT 2017gfo on a large fraction of the localisation probability. This suggests that future (likely common) events at a few hundred megaparsecs will be detected only by large facilities with both a high sensitivity and large field of view. Galaxy-targeted observations can reach the needed depth over a relevant portion of the localisation probability with a smaller investment of resources, but the number of galaxies to be targeted in order to get a fairly complete coverage is large, even in the case of a localisation as good as that of this event.
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    Panning for gold, but finding helium: Discovery of the ultra-stripped supernova SN 2019wxt from gravitational-wave follow-up observations
    (2023) Agudo, I.; Amati, L.; An, T.; Bauer, F. E.; Benetti, S.; Bernardini, M. G.; Beswick, R.; Bhirombhakdi, K.; de Boer, T.; Branchesi, M.; Brennan, S. J.; Brocato, E.; Caballero-Garcia, M. D.; Cappellaro, E.; Castro Rodriguez, N.; Castro-Tirado, A. J.; Chambers, K. C.; Chassande-Mottin, E.; Chaty, S.; Chen, T. -W.; Coleiro, A.; Covino, S.; D'Ammando, F.; D'Avanzo, P.; D'Elia, V.; Fiore, A.; Floers, A.; Fraser, M.; Frey, S.; Frohmaier, C.; Fulton, M.; Galbany, L.; Gall, C.; Gao, H.; Garcia-Rojas, J.; Ghirlanda, G.; Giarratana, S.; Gillanders, J. H.; Giroletti, M.; Gompertz, B. P.; Gromadzki, M.; Heintz, K. E.; Hjorth, J.; Hu, Y. -D.; Huber, M. E.; Inkenhaag, A.; Izzo, L.; Jin, Z. P.; Jonker, P. G.; Kann, D. A.; Kool, E. C.; Kotak, R.; Leloudas, G.; Levan, A. J.; Lin, C. -C.; Lyman, J. D.; Magnier, E. A.; Maguire, K.; Mandel, I.; Marcote, B.; Sanchez, D. Mata; Mattila, S.; Melandri, A.; Michalowski, M. J.; Moldon, J.; Nicholl, M.; Guelbenzu, A. Nicuesa; Oates, S. R.; Onori, F.; Orienti, M.; Paladino, R.; Paragi, Z.; Perez-Torres, M.; Pian, E.; Pignata, G.; Piranomonte, S.; Quirola-Vasquez, J.; Ragosta, F.; Rau, A.; Ronchini, S.; Rossi, A.; Sanchez-Ramirez, R.; Salafia, O. S.; Schulze, S.; Smartt, S. J.; Smith, K. W.; Sollerman, J.; Srivastav, S.; Starling, R. L. C.; Steeghs, D.; Stevance, H. F.; Tanvir, N. R.; Testa, V.; Torres, M. A. P.; Valeev, A.; Vergani, S. D.; Vescovi, D.; Wainscost, R.; Watson, D.; Wiersema, K.; Wyrzykowski, L.; Yang, J.; Yang, S.; Young, D. R.
    We present the results from multi-wavelength observations of a transient discovered during an intensive follow-up campaign of S191213g, a gravitational wave (GW) event reported by the LIGO-Virgo Collaboration as a possible binary neutron star merger in a low latency search. This search yielded SN 2019wxt, a young transient in a galaxy whose sky position (in the 80% GW contour) and distance (similar to SIM;150 Mpc) were plausibly compatible with the localisation uncertainty of the GW event. Initially, the transient's tightly constrained age, its relatively faint peak magnitude (M-i similar to -16.7 mag), and the r-band decline rate of similar to 1 mag per 5 days appeared suggestive of a compact binary merger. However, SN 2019wxt spectroscopically resembled a type Ib supernova, and analysis of the optical-near-infrared evolution rapidly led to the conclusion that while it could not be associated with S191213g, it nevertheless represented an extreme outcome of stellar evolution. By modelling the light curve, we estimated an ejecta mass of only similar to 0.1 M circle dot, with Ni-56 comprising similar to 20% of this. We were broadly able to reproduce its spectral evolution with a composition dominated by helium and oxygen, with trace amounts of calcium. We considered various progenitor channels that could give rise to the observed properties of SN 2019wxt and concluded that an ultra-stripped origin in a binary system is the most likely explanation. Disentangling genuine electromagnetic counterparts to GW events from transients such as SN 2019wxt soon after discovery is challenging: in a bid to characterise this level of contamination, we estimated the rate of events with a volumetric rate density comparable to that of SN 2019wxt and found that around one such event per week can occur within the typical GW localisation area of O4 alerts out to a luminosity distance of 500 Mpc, beyond which it would become fainter than the typical depth of current electromagnetic follow-up campaigns.
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    The 80 Ms follow-up of the X-ray afterglow of GRB 130427A challenges the standard forward shock model
    (OXFORD UNIV PRESS, 2016) De Pasquale, M.; Page, M. J.; Kann, D. A.; Oates, S. R.; Schulze, S.; Zhang, B.; Cano, Z.; Gendre, B.; Malesani, D.; Rossi, A.; Troja, E.; Piro, L.; Boer, M.; Stratta, G.; Gehrels, N.
    GRB 130427A was the brightest gamma-ray burst detected in the last 30 yr. With an equivalent isotropic energy output of 8.5 x 10(53) erg and redshift z = 0.34, it uniquely combined very high energetics with a relative proximity to Earth. As a consequence, its X-ray afterglow has been detected by sensitive X-ray observatories such as XMM-Newton and Chandra for a record-breaking baseline longer than 80 million seconds. We present the X-ray light curve of this event over such an interval. The light curve shows a simple power-law decay with a slope alpha = 1.309 +/- 0.007 over more than three decades in time (47 ks-83 Ms). We discuss the consequences of this result for a few models proposed so far to interpret GRB 130427A, and more in general the significance of this outcome in the context of the standard forward shock model. We find that this model has difficulty in explaining our data, in both cases of constant density and stellar-wind circumburst media, and requires far-fetched values for the physical parameters involved.
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    The central engine of GRB 130831A and the energy breakdown of a relativistic explosion
    (OXFORD UNIV PRESS, 2016) De Pasquale, M.; Oates, S. R.; Racusin, J. L.; Kann, D. A.; Zhang, B.; Pozanenko, A.; Volnova, A. A.; Trotter, A.; Frank, N.; Cucchiara, A.; Troja, E.; Sbarufatti, B.; Butler, N. R.; Schulze, S.; Cano, Z.; Page, M. J.; Castro Tirado, A. J.; Gorosabel, J.; Lien, A.; Fox, O.; Littlejohns, O.; Bloom, J. S.; Prochaska, J. X.; de Diego, J. A.; Gonzalez, J.; Richer, M. G.; Roman Zuniga, C.; Watson, A. M.; Gehrels, N.; Moseley, H.; Kutyrev, A.; Zane, S.; Hoette, V.; Russell, R. R.; Rumyantsev, V.; Klunko, E.; Burkhonov, O.; Breeveld, A. A.; Reichart, D. E.; Haislip, J. B.
    Gamma-ray bursts (GRBs) are the most luminous explosions in the Universe, yet the nature and physical properties of their energy sources are far from understood. Very important clues, however, can be inferred by studying the afterglows of these events. We present optical and X-ray observations of GRB 130831A obtained by Swift, Chandra, Skynet, Reionization And Transients Infra-Red camera, Maidanak, International Scientific Optical-Observation Network, Nordic Optical Telescope, Liverpool Telescope and Gran Telescopio Canarias. This burst shows a steep drop in the X-ray light curve at similar to 10(5) s after the trigger, with a power-law decay index of a similar to 6. Such a rare behaviour cannot be explained by the standard forward shock (FS) model and indicates that the emission, up to the fast decay at 105 s, must be of 'internal origin', produced by a dissipation process within an ultrarelativistic outflow. We propose that the source of such an outflow, which must produce the X-ray flux for similar to 1 d in the cosmological rest frame, is a newly born magnetar or black hole. After the drop, the faint X-ray afterglow continues with a much shallower decay. The optical emission, on the other hand, shows no break across the X-ray steep decrease, and the late-time decays of both the X-ray and optical are consistent. Using both the X-ray and optical data, we show that the emission after similar to 10(5) s can be explained well by the FS model. We model our data to derive the kinetic energy of the ejecta and thus measure the efficiency of the central engine of a GRB with emission of internal origin visible for a long time. Furthermore, we break down the energy budget of this GRB into the prompt emission, the late internal dissipation, the kinetic energy of the relativistic ejecta, and compare it with the energy of the associated supernova, SN 2013 fu.
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    The MUSE view of the host galaxy of GRB 100316D
    (2017) Izzo, L.; Thöne, C. C.; Schulze, S.; Mehner, A.; Flores, H.; Cano, Z.; De Ugarte Postigo, A.; Kann, D. A.; Amorín, R.; Bauer, Franz Erik
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    The optical identification of events with poorly defined locations: the case of the Fermi GBM GRB 140801A
    (OXFORD UNIV PRESS, 2016) Lipunov, V. M.; Gorosabel, J.; Pruzhinskaya, M. V.; de Ugarte Postigo, A.; Pelassa, V.; Tsvetkova, A. E.; Sokolov, I. V.; Kann, D. A.; Xu, Dong; Gorbovskoy, E. S.; Krushinski, V. V.; Kornilov, V. G.; Balanutsa, P. V.; Boronina, S. V.; Budnev, N. M.; Cano, Z.; Castro Tirado, A. J.; Chazov, V. V.; Connaughton, V.; Delvaux, C.; Frederiks, D. D.; Fynbo, J. F. U.; Gabovich, A. V.; Goldstein, A.; Greiner, J.; Gress, O. A.; Ivanov, K. I.; Jakobsson, P.; Klose, S.; Knust, F.; Komarova, V. N.; Konstantinov, E.; Krylov, A. V.; Kuvshinov, D. A.; Kuznetsov, A. S.; Lipunova, G. V.; Moskvitin, A. S.; Pal'shin, V. D.; Pandey, S. B.; Poleshchuk, V. A.; Schmidl, S.; Sergienko, Yu. P.; Sinyakov, E. V.; Schulze, S.; Sokolov, V. V.; Sokolova, T. N.; Sparre, M.; Thoene, C. C.; Tlatov, A. G.; Tyurina, N. V.; Ulanov, M. V.; Yazev, S. A.; Yurkov, V. V.
    We report the early discovery of the optical afterglow of gamma-ray burst (GRB) 140801A in the 137 deg(2) 3-sigma error-box of the Fermi Gamma-ray Burst Monitor (GBM). MASTER is the only observatory that automatically reacts to all Fermi alerts. GRB 140801A is one of the few GRBs whose optical counterpart was discovered solely from its GBM localization. The optical afterglow of GRB 140801A was found by MASTER Global Robotic Net 53 s after receiving the alert, making it the fastest optical detection of a GRB from a GBM error-box. Spectroscopy obtained with the 10.4-m Gran Telescopio Canarias and the 6-m Big Telescope Alt-azimuth of the Special Astrophysical Observatory of the Russian Academy of Sciences reveals a redshift of z = 1.32. We performed optical and near-infrared photometry of GRB 140801A using different telescopes with apertures ranging from 0.4 to 10.4 m. GRB 140801A is a typical burst in many ways. The rest-frame bolometric isotropic energy release and peak energy of the burst are E-iso = 5.54(-0.24)(+0.26) x 10(52) erg and E-p,E- rest similar or equal to 280 keV, respectively, which is consistent with the Amati relation. The absence of a jet break in the optical light curve provides a lower limit on the half-opening angle of the jet theta = 6 degrees.1. The observed E-peak is consistent with the limit derived from the Ghirlanda relation. The joint Fermi GBM and Konus-Wind analysis show that GRB 140801A could belong to the class of intermediate duration. The rapid detection of the optical counterpart of GRB 140801A is especially important regarding the upcoming experiments with large coordinate error-box areas.
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    The optical/NIR afterglow of GRB 111209A: Complex yet not unprecedented
    (2018) Kann, D. A.; Schady, P.; Olivares, E. F.; Klose, S.; Rossi, A.; Perley, D. A.; Zhang, B.; Kruehler, T.; Greiner, J.; Guelbenzu, A. Nicuesa; Elliott, J.; Knust, F.; Cano, Z.; Filgas, R.; Pian, E.; Mazzali, P.; Fynbo, J. P. U.; Leloudas, G.; Afonso, P. M. J.; Delvaux, C.; Graham, J. F.; Rau, A.; Schmidl, S.; Schulze, S.; Tanga, M.; Updike, A. C.; Varela, K.
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    The supermassive black hole coincident with the luminous transient ASASSN-15lh.
    (2017) Krühler, Thomas; Kim, Sam; Fraser, M.; Leloudas, G.; Schulze, Steve; Stone, N. C.; Velzen, S. van; Amorin, R.; Hjorth, J.; Jonker, P. G.; Kann, D. A.
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    VLT/X-Shooter emission-line spectroscopy of 96 gamma-ray-burst-selected galaxies at 0.1 < z < 3.6
    (EDP SCIENCES S A, 2015) Kruehler, T.; Malesani, D.; Fynbo, J. P. U.; Hartoog, O. E.; Hjorth, J.; Jakobsson, P.; Perley, D. A.; Rossi, A.; Schady, P.; Schulze, S.; Tanvir, N. R.; Vergani, S. D.; Wiersema, K.; Afonso, P. M. J.; Bolmer, J.; Cano, Z.; Covino, S.; D'Elia, V.; de Ugarte Postigo, A.; Filgas, R.; Friis, M.; Graham, J. F.; Greiner, J.; Goldoni, P.; Gomboc, A.; Hammer, F.; Japelj, J.; Kann, D. A.; Kaper, L.; Klose, S.; Levan, A. J.; Leloudas, G.; Milvang Jensen, B.; Guelbenzu, A. Nicuesa; Palazzi, E.; Pian, E.; Piranomonte, S.; Sanchez Ramirez, R.; Savaglio, S.; Selsing, J.; Tagliaferri, G.; Vreeswijk, P. M.; Watson, D. J.; Xu, D.
    We present data and initial results from VLT/X-Shooter emission-line spectroscopy of 96 galaxies selected by long gamma-ray bursts (GRBs) at 0.1 < z < 3.6, the largest sample of GRB host spectra available to date. Most of our GRBs were detected by Swift and 76% are at 0.5 < z < 2.5 with a median z(med) similar to 1.6. Based on Balmer and/or forbidden lines of oxygen, nitrogen, and neon, we measure systemic redshifts, star formation rates (SFR), visual attenuations (A(V)), oxygen abundances (12 + log(O/H)), and emission-line widths (sigma). We study GRB hosts up to z similar to 3.5 and find a strong change in their typical physical properties with redshift. The median SFR of our GRB hosts increases from SFRmed similar to 0.6 M circle dot yr(-1) at z similar to 0.6 up to SFRmed similar to 15 M circle dot yr(-1) at z similar to 2. A higher ratio of [O III]/[O II] at higher redshifts leads to an increasing distance of GRB-selected galaxies to the locus of local galaxies in the Baldwin-Phillips-Terlevich diagram. There is weak evidence for a redshift evolution in A(V) and similar to, with the highest values seen at z similar to 1.5 (A(V)) or z similar to 2 (sigma). Oxygen abundances of the galaxies are distributed between 12 + log(O/H) = 7.9 and 12 + log(O/H) = 9.0 with a median 12 + log(O/H)(med) similar to 8.5. The fraction of GRB-selected galaxies with super-solar metallicities is similar to 20% at z < 1 in the adopted metallicity scale. This is significantly less than the fraction of total star formation in similar galaxies, illustrating that GRBs are scarce in high metallicity environments. At z similar to 3, sensitivity limits us to probing only the most luminous GRB hosts for which we derive metallicities of Z less than or similar to 0.5 Z circle dot. Together with a high incidence of Z similar to 0.5 Z circle dot galaxies at z similar to 1.5, this indicates that a metallicity dependence at low redshift will not be dominant at z similar to 3. Significant correlations exist between the hosts' physical properties. Oxygen abundance, for example, relates to A(V) (12 + log(O/H) proportional to 0.17 A(V)), line width (12 + log(O/H) proportional to sigma(0.6)), and SFR (12 + log(O/H) proportional to SFR0.2). In the last two cases, the normalization of the relations shift to lower metallicities at z > 2 by similar to 0.4 dex. These properties of GRB hosts and their evolution with redshift can be understood in a cosmological context of star-forming galaxies and a picture in which the hosts' properties at low redshift are influenced by the tendency of GRBs to avoid the most metal-rich environments.
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    X-shooter and ALMA spectroscopy of GRB 161023A.
    (2018) Ugarte Postigo, A. de; Kim, Sam; Thöne, Christina C.; Bolmer, J.; Schulze, Steve.; Martín, S.; Kann, D. A.; D’Elia, V.; Selsing, J.; Martin-Carrillo, A.; Perley, Daniel A.