ERRATUM: “LOW-RESOLUTION SPECTROSCOPY OF GAMMA-RAY BURST OPTICAL AFTERGLOWS: BIASES IN THE
                    <i>SWIFT</i>
                    SAMPLE AND CHARACTERIZATION OF THE ABSORBERS” (2009, ApJS, 185, 526)

Fynbo, J. P. U.; Jakobsson, P.; Prochaska, J. X.; Malesani, D.; Ledoux, C.; Postigo, A. de Ugarte; Nardini, M.; Vreeswijk, P. M.; Wiersema, K.; Hjorth, J.; Sollerman, J.; Chen, Hsiao‐Wen; Thöne, C. C.; Björnsson, G.; Bloom, J.; Castro-Tirado, A. J.; Christensen, L.; De, A.; Fruchter, A. S.; Gorosabel, J.; Graham, John F.; Jaunsen, A. O.; Jensen, B. L.; Канн, Д. А.; Kouveliotou, C.; Levan, A. J.; Maund, Justyn R.; Masetti, N.; Milvang-Jensen, B.; Palazzi, E.; Perley, D.; Pian, E.; Rol, E.; Schady, P.; Starling, R. L. C.; Tanvir, N. R.; Watson, Derrick G.; Xu, D.; Augusteijn, T.; Grundahl, F.; Telting, J. H.; Quirion, Pierre-Olivier

doi:10.1088/0067-0049/186/2/485

Cited by 154 publications

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“…Our calculated escape fraction, f esc = 1.0 per cent, is somewhat smaller than recent estimates have suggested. In particular, it falls short of the 2 ± 0.3 per cent derived by Chen et al (2007) from reasonable extrapolation of the observed GRB–DLA statistics (see also Fynbo et al 2009); this is a reflection of our previously described underestimate of the abundance of absorbers in the observational bin 10 17 < N H i /cm −2 < 10 19 . More worryingly, our derived fraction is very sensitive to assumptions we make about launching the GRB sightlines; for instance, adding a 200 pc Gaussian random offset to our stellar particle loci raises the fraction to f esc = 2 per cent.…”

Section: Resultsmentioning

confidence: 65%

“…For such systems, it is possible to determine observationally the column density of neutral hydrogen. We compiled a list of N H i ‐values for 38 GRB–DLAs in the redshift interval 2 < z < 4 by combining data from Jakobsson et al (2006), Chen et al (2007) and Fynbo et al (2009). We caution that, unlike for the QSO–DLAs for which homogeneous catalogues are available (e.g.…”

Section: Resultsmentioning

confidence: 99%

“…As well as providing insights into individual objects, GRB–DLAs offer an unusually direct way to probe the escape of ionizing photons from the star‐forming regions with which they are associated. On the assumption that the GRB rate traces the star formation accurately, one may construct a global escape fraction 〈 f esc 〉≃ 2 per cent by modest extrapolation from the GRB–DLA column density distribution (Chen et al 2007; Fynbo et al 2009). Conversely, recent simulations by Gnedin, Kravtsov & Chen (2008), aimed at constraining escape fraction statistics, have incidentally been able to account for the GRB–DLA distribution (albeit with some mismatch at high column densities).…”

Section: Introductionmentioning

confidence: 99%

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The nature of H i absorbers in gamma-ray burst afterglows: clues from hydrodynamic simulations

Pontzen

Deason

Governato

et al. 2010

Monthly Notices of the Royal Astronomical Society

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In recent work, we have shown that it is possible to link quantitatively many aspects of damped Lyman α (DLA) absorbers in the spectra of quasars to high‐resolution simulations of galaxy formation. Using runs from the same series of hydrodynamic numerical studies, we consider the expected properties of intrinsic Lyman α absorbers seen in the spectra of high‐redshift (z > 2) gamma‐ray burst afterglows (GRB–DLAs). If GRBs are associated with the death of massive stars, their afterglows provide insights into otherwise unprobed regions of protogalactic objects, but detailed physical interpretations are currently embryonic. We find that median impact parameters (measured from the potential minimum) are approximately 1 kpc for GRBs compared with 4 kpc for quasi‐stellar object–DLA (QSO–DLA). However, an equally important difference is that GRB–DLAs are predominantly associated with haloes of mass 1010 < Mvir/M⊙ < 1012, an order of magnitude larger than the hosts of QSO–DLAs. Accordingly, there are differences in the stellar properties of hosts. For instance, mean star formation rates are higher: for GRB–DLAs compared with for QSO–DLAs. Our simulations accurately predict the form of the GRB–DLA H i column density distribution, producing quantitative agreement for NH i > 1019 cm−2, but they somewhat underpredict the incidence of low column densities NH i < 1019 cm−2. This is reflected in our estimate of the ionizing photon escape fraction, fesc≃ 1 per cent, which is lower than the observational GRB‐derived escape fraction (2 per cent). Line‐of‐sight neutral gas metallicities predicted by our simulations (10−2 < Z/Z⊙ < 1) are consistent with the modest observational constraints. Because of large internal dispersions in gas metallicities, this agreement is not significantly compromised by imposing a cut‐off on the metallicity of stars able to launch GRBs (Z★ < Z⊙/3), confounding claims that the observed metallicity of GRB–DLAs poses a severe challenge to current GRB models.

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Section: Resultsmentioning

confidence: 65%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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The nature of H i absorbers in gamma-ray burst afterglows: clues from hydrodynamic simulations

Pontzen

Deason

Governato

et al. 2010

Monthly Notices of the Royal Astronomical Society

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“…Fynbo et al 2001; Lazzati, Covino & Ghisellini 2002; Jakobsson et al 2004; Levan et al 2006a; Rol et al 2007; Perley et al 2009) dust destruction by X‐rays could still be effective enough to allow UV/optical observations of the afterglow according to Fruchter, Krolik & Rhoads (2001). However, Fynbo et al (2009) suggests very convincingly that dark bursts may not be representative of the general GRB population, and trace different environmental properties than bursts with detected optical afterglows. Either way, even in the absence of any transient optical emission it is possible to identify a redshift for a GRB from its X‐ray identified host galaxy (e.g.…”

Section: Selection Effectsmentioning

confidence: 99%

The host galaxies of core-collapse supernovae and gamma-ray bursts

Svensson

Levan

Tanvir

et al. 2010

Monthly Notices of the Royal Astronomical Society

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306

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We present a comparative study of the galactic and small‐scale environments of gamma‐ray bursts (GRBs) and core‐collapse supernovae (CCSNe). We use a sample of 34 GRB hosts at z < 1.2, and a comparison sample of 58 supernova hosts located within the Great Observatories Origins Deep Survey footprint. We fit template spectra to the available photometric data, which span the range 0.45–24 μm, and extract absolute magnitudes, stellar masses and star formation rates from the resulting fits. Our results broadly corroborate previous findings, but offer significant enhancements in spectral coverage and a factor 2–3 increase in sample size. Specifically, we find that CCSNe occur frequently in massive spirals (spiral fraction ∼50 per cent). In contrast GRBs occur in small, relatively low mass galaxies with high specific and surface star formation rates, and have a spiral fraction of only ∼10 per cent. A comparison of the rest‐frame absolute magnitudes of the GRB and CCSN sample is less conclusive than found in previous work, suggesting that while GRB hosts are typically both smaller and bluer than those of CCSN their total blue light luminosities are only slightly lower. We suggest this is likely due to rapid periods of intensified star formation activity, as indicated by the high specific SFRs, which both create the GRB progenitors and briefly significantly enhance the host galaxy blue luminosity. Finally, our analysis of local environments of GRBs and CCSNe shows that GRBs are highly concentrated on their host light, and further occur in regions of higher absolute surface luminosity than CCSNe.

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“…GRB 071025, detected by the Swift mission (Gehrels et al 2004), provides among the best probes of the early‐time behaviour of a GRB to date. While no secure spectroscopic redshift was attained [ z ∼ 5.2 was estimated from a low‐quality High Resolution Echelle Spectrometer (HIRES) optical spectrum at Keck; Fynbo et al 2009], the photometric SED presented here shows clear evidence of a Lyman α break in the observer‐frame R band and indicates a photometric redshift of 4.4 < z < 5.2 (), making this among the highest redshift bursts to date and one of only a few observed in simultaneous colours during prompt emission. Our infrared (IR) and optical observations start at ∼30 s after the burst in the rest frame and follow the rise, peak and fall of an afterglow in simultaneous rest‐frame optical colours.…”

Section: Introductionmentioning

confidence: 99%

Evidence for supernova-synthesized dust from the rising afterglow of GRB 071025 at z∼ 5

Perley¹,

Bloom²,

Klein³

et al. 2010

Monthly Notices of the Royal Astronomical Society

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We present observations and analysis of the broad‐band afterglow of Swift GRB 071025. Using optical and infrared (RIYJHK) photometry, we derive a photometric redshift of 4.4 < z < 5.2; at this redshift our simultaneous multicolour observations begin at ∼30 s after the gamma‐ray burst trigger in the host frame, during the initial rising phase of the afterglow. We associate the light‐curve peak at ∼580 s in the observer frame with the formation of the forward shock, giving an estimate of the initial Lorentz factor Γ0∼ 200. The red spectral energy distribution (even in regions not affected by the Lyman α break) provides secure evidence of a large dust column. However, the inferred extinction curve shows a prominent flat component between 2000 and 3000 Å in the rest frame, inconsistent with any locally observed template but well fitted by models of dust formed by supernovae. Time‐dependent fits to the extinction profile reveal no evidence of dust destruction and limit the decrease in the extinction column to ΔA3000 < 0.54 mag after t= 50 s in the rest frame. Together with studies of high‐z quasars, our observations suggest a transition in dust properties in the early Universe, possibly associated with a transition between supernova‐dominated and asymptotic giant branch‐dominated modes of dust production.

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ERRATUM: “LOW-RESOLUTION SPECTROSCOPY OF GAMMA-RAY BURST OPTICAL AFTERGLOWS: BIASES IN THE SWIFT SAMPLE AND CHARACTERIZATION OF THE ABSORBERS” (2009, ApJS, 185, 526)

Abstract: Low-resolution spectroscopy of gamma-ray burst optical afterglows: Biases in the swift sample and characterization of the absorbers http:

Cited by 154 publications

References 0 publications

The nature of H i absorbers in gamma-ray burst afterglows: clues from hydrodynamic simulations

The nature of H i absorbers in gamma-ray burst afterglows: clues from hydrodynamic simulations

The host galaxies of core-collapse supernovae and gamma-ray bursts

Evidence for supernova-synthesized dust from the rising afterglow of GRB 071025 at z∼ 5

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