DSpace Angular :: Browsing by Author "Fynbo, J. P. U."

Browsing by Author "Fynbo, J. P. U."

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Broad Absorption Line Disappearance/Emergence in Multiple Ions in a Weak Emission-line Quasar
(2019) Yi, W.; Vivek, M.; Brandt, W. N.; Wang, T.; Timlin, J.; Ak, N. Filiz; Schneider, D. P.; Fynbo, J. P. U.; Ni, Q.; Vito, F.; Indahl, B. L.; Sameer
We report the discovery of the disappearance of Mg II, Al III, C IV, and Si IV broad absorption lines (BALs) at the same velocity (0.07c), accompanied by a new C IV BAL emerging at a higher velocity (up to 0.11c), in the quasar J0827+4252 at z = 2.038. This is the first report of BAL disappearance (i) over Mg II, Al III, C IV, and Si IV ions and (ii) in a weak emission-line quasar (WLQ). The discovery is based on four spectra from the Sloan Digital Sky Survey and one follow-up spectrum from Hobby-Eberly Telescope/Low-Resolution Spectrograph-2. The simultaneous C IV BAL disappearance and emergence at different velocities, together with no variations in the Catalina Real-Time Transient Survey light curve, indicate that ionization changes in the absorbing material are unlikely to cause the observed BAL variability. Our analyses reveal that transverse motion is the most likely dominant driver of the BAL disappearance/emergence. Given the presence of mildly relativistic BAL outflows and an apparently large C IV emission-line blueshift that is likely associated with strong bulk outflows in this WLQ, J0827+4252 provides a notable opportunity to study extreme quasar winds and their potential in expelling material from inner to large-scale regions.
DETECTION OF THREE GAMMA-RAY BURST HOST GALAXIES AT z similar to 6
(IOP PUBLISHING LTD, 2016) McGuire, J. T. W.; Tanvir, N. R.; Levan, A. J.; Trenti, M.; Stanway, E. R.; Shull, J. M.; Wiersema, K.; Perley, D. A.; Starling, R. L. C.; Bremer, M.; Stocke, J. T.; Hjorth, J.; Rhoads, J. E.; Curtis Lake, E.; Schulze, S.; Levesque, E. M.; Robertson, B.; Fynbo, J. P. U.; Ellis, R. S.; Fruchter, A. S.
Long-duration gamma-ray bursts (GRBs) allow us to pinpoint and study star-forming galaxies in the early universe, thanks to their orders of magnitude brighter peak luminosities compared to other astrophysical sources, and their association with the deaths of massive stars. We present Hubble Space Telescope Wide Field Camera 3 detections of three Swift GRB host galaxies lying at redshifts z = 5.913 (GRB 130606A), z = 6.295 (GRB 050904), and z = 6.327 (GRB 140515A) in the F140W (wide-JH band, lambda(obs) similar to 1.4 mu m) filter. The hosts have magnitudes (corrected for Galactic extinction) of m(lambda obs) = 26.34(-0.16)(+0.14), 27.56(-0.22)(+0.18), and 28.30(-0.33)(+0.25) respectively. In all three cases, the probability of chance coincidence of lower redshift galaxies is less than or similar to 2%, indicating that the detected galaxies are most likely the GRB hosts. These are the first detections of high-redshift (z > 5) GRB host galaxies in emission. The galaxies have luminosities in the range 0.1-0.6 L-z=6* (with M-1600* = -20.95 +/- 0.12) and half-light radii in the range 0.6-0.9 kpc. Both their half-light radii and luminosities are consistent with existing samples of Lyman-break galaxies at z similar to 6. Spectroscopic analysis of the GRB afterglows indicate low metallicities ([M/H] less than or similar to -1) and low dust extinction (AV less than or similar to 0.1) along the line of sight. Using stellar population synthesis models, we explore the implications of each galaxy's luminosity for its possible star-formation history and consider the potential for emission line metallicity determination with the upcoming James Webb Space Telescope.
DISCOVERY OF THE BROAD-LINED TYPE Ic SN 2013cq ASSOCIATED WITH THE VERY ENERGETIC GRB 130427A
(2013) Xu, D.; de Ugarte Postigo, A.; Leloudas, G.; Kruehler, T.; Cano, Z.; Hjorth, J.; Malesani, D.; Fynbo, J. P. U.; Thoene, C. C.; Sanchez-Ramirez, R.; Schulze, S.; Jakobsson, P.; Kaper, L.; Sollerman, J.; Watson, D. J.; Cabrera-Lavers, A.; Cao, C.; Covino, S.; Flores, H.; Geier, S.; Gorosabel, J.; Hu, S. M.; Milvang-Jensen, B.; Sparre, M.; Xin, L. P.; Zhang, T. M.; Zheng, W. K.; Zou, Y. C.
Long-duration gamma-ray bursts (GRBs) at z < 1 are found in most cases to be accompanied by bright, broadlined Type Ic supernovae (SNe Ic-BL). The highest-energy GRBs are mostly located at higher redshifts, where the associated SNe are hard to detect observationally. Here, we present early and late observations of the optical counterpart of the very energetic GRB 130427A. Despite its moderate redshift, z = 0.3399+/-0.0002, GRB 130427A is at the high end of the GRB energy distribution, with an isotropic-equivalent energy release of E-iso similar to 9.6 x 10(53) erg, more than an order of magnitude more energetic than other GRBs with spectroscopically confirmed SNe. In our dense photometric monitoring, we detect excess flux in the host-subtracted r-band light curve, consistent with that expected from an emerging SN, similar to 0.2 mag fainter than the prototypical SN 1998bw. A spectrum obtained around the time of the SN peak (16.7 days after the GRB) reveals broad undulations typical of SNe Ic-BL, confirming the presence of an SN, designated SN 2013cq. The spectral shape and early peak time are similar to those of the high expansion velocity SN 2010bh associated with GRB 100316D. Our findings demonstrate that high-energy, long-duration GRBs, commonly detected at high redshift, can also be associated with SNe Ic-BL, pointing to a common progenitor mechanism.
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.
GRB 140606B/iPTF14bfu: detection of shock-breakout emission from a cosmological gamma-ray burst?
(OXFORD UNIV PRESS, 2015) Cano, Zach; de Ugarte Postigo, A.; Perley, D.; Kruehler, T.; Margutti, R.; Friis, M.; Malesani, D.; Jakobsson, P.; Fynbo, J. P. U.; Gorosabel, J.; Hjorth, J.; Sanchez Ramirez, R.; Schulze, S.; Tanvir, N. R.; Thoene, C. C.; Xu, D.
We present optical and near-infrared photometry of GRB 140606B (z = 0.384), and optical photometry and spectroscopy of its associated supernova (SN). The results of our modelling indicate that the bolometric properties of the SN (M-Ni = 0.4 +/- 0.2 M-circle dot, M-ej = 5 +/- 2 M-circle dot, and E-K = 2 +/- 1 x 10(52) erg) are fully consistent with the statistical averages determined for other gamma-ray burst (GRB)-SNe. However, in terms of its gamma-ray emission, GRB 140606B is an outlier of the Amati relation, and occupies the same region as low luminosity (ll) and short GRBs. The gamma-ray emission in llGRBs is thought to arise in some or all events from a shock breakout (SBO), rather than from a jet. The measured peak photon energy (E-p approximate to 800 keV) is close to that expected for. -rays created by an SBO (greater than or similar to 1 MeV). Moreover, based on its position in the M-V,M- (p)- L-iso,L-gamma plane and the E-K-Gamma eta plane, GRB 140606B has properties similar to both SBO-GRBs and jetted-GRBs. Additionally, we searched for correlations between the isotropic gamma-ray emission and the bolometric properties of a sample of GRB-SNe, finding that no statistically significant correlation is present. The average kinetic energy of the sample is (E) over bar (K) = 2.1 x 10(52) erg. All of the GRB-SNe in our sample, with the exception of SN 2006aj, are within this range, which has implications for the total energy budget available to power both the relativistic and non-relativistic components in a GRB-SN event.
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.
Mass and metallicity scaling relations of high-redshift star-forming galaxies selected by GRBs
(2018) Arabsalmani, M.; Moller, P.; Perley, D. A.; Freudling, W.; Fynbo, J. P. U.; Le Floc'h, E.; Zwaan, M. A.; Schulze, S.; Tanvir, N. R.; Christensen, L.; Levan, A. J.; Jakobsson, P.; Malesani, D.; Cano, Z.; Covino, S.; D'Elia, V.; Goldoni, P.; Gomboc, A.; Heintz, K. E.; Sparre, M.; Postigo, A. de Ugarte; Vergani, S. D.
We present a comprehensive study of the relations between gas kinematics, metallicity and stellar mass in a sample of 82 gamma-ray burst (GRB)-selected galaxies using absorption and emission methods. We find the velocity widths of both emission and absorption profiles to be a proxy of stellar mass. We also investigate the velocity-metallicity correlation and its evolution with redshift. Using 33 GRB hosts with measured stellar mass and metallicity, we study the mass-metallicity relation for GRB host galaxies in a stellarmass range of 10(8.2)-10(11.1) M-circle dot and a redshift range of z similar to 0.3-3.4. TheGRB-selected galaxies appear to track themass-metallicity relation of star-forming galaxies but with an offset of 0.15 towards lower metallicities. This offset is comparable with the average error bar on the metallicity measurements of the GRB sample and also the scatter on the mass-metallicity relation of the general population. It is hard to decide whether this relatively small offset is due to systematic effects or the intrinsic nature of GRB hosts. We also investigate the possibility of using absorption-line metallicity measurements of GRB hosts to study the mass-metallicity relation at high redshifts. Our analysis shows that the metallicity measurements from absorption methods can significantly differ from emission metallicities and assuming identical measurements from the two methods may result in erroneous conclusions.
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.
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.
Spectroscopy of the short-hard GRB 130603B The host galaxy and environment of a compact object merger
(2014) Postigo, A. de Ugarte; Thone, C. C.; Rowlinson, A.; Garcia-Benito, R.; Levan, A. J.; Gorosabel, J.; Goldoni, P.; Schulze, S.; Zafar, T.; Wiersema, K.; Sanchez-Ramirez, R.; Melandri, A.; D'Avanzo, P.; Oates, S.; D'Elia, V.; De Pasquale, M.; Kruehler, T.; van der Horst, A. J.; Xu, D.; Watson, D.; Piranomonte, S.; Vergani, S. D.; Milvang-Jensen, B.; Kaper, L.; Malesani, D.; Fynbo, J. P. U.; Cano, Z.; Covino, S.; Flores, H.; Greiss, S.; Hammer, F.; Hartoog, O. E.; Hellmich, S.; Heuser, C.; Hjorth, J.; Jakobsson, P.; Mottola, S.; Sparre, M.; Sollerman, J.; Tagliaferri, G.; Tanvir, N. R.; Vestergaard, M.; Wijers, R. A. M. J.
Context. Short duration gamma-ray bursts (SGRBs) are thought to be related to the violent merger of compact objects, such as neutron stars or black holes, which makes them promising sources of gravitational waves. The detection of a "kilonova"-like signature associated to the Swift-detected GRB 130603B has suggested that this event is the result of a compact object merger.
The host galaxy of the short GRB 111117A at z=2.211 Impact on the short GRB redshift distribution and progenitor channels
(2018) Selsing, J.; Kruehler, T.; Malesani, D.; D'Avanzo, P.; Schulze, S.; Vergani, S. D.; Palmerio, J.; Japelj, J.; Milvang-Jensen, B.; Watson, D.; Jakobsson, P.; Bolmer, J.; Cano, Z.; Covino, S.; D'Elia, V.; de Ugarte Postigo, A.; Fynbo, J. P. U.; Gomboc, A.; Heintz, K. E.; Kaper, L.; Levan, A. J.; Piranomonte, S.; Pugliese, G.; Sanchez-Ramirez, R.; Sparre, M.; Tanvir, N. R.; Thone, C. C.; Wiersema, K.
It is notoriously difficult to localize short gamma-ray bursts (sGRBs) and their hosts to measure their redshifts. These measurements, however, are critical for constraining the nature of sGRB progenitors, their redshift distribution, and the r-process element enrichment history of the universe. Here we present spectroscopy of the host galaxy of GRB 111117A and measure its redshift to be z = 2.211. This makes GRB 111117A the most distant high-confidence short duration GRB detected to date. Our spectroscopic redshift supersedes a lower, previously estimated photometric redshift value for this burst. We use the spectroscopic redshift, as well as new imaging data to constrain the nature of the host galaxy and the physical parameters of the GRB. The rest-frame X-ray derived hydrogen column density, for example, is the highest compared to a complete sample of sGRBs and seems to follow the evolution with redshift as traced by the hosts of long GRBs. From the detection of Ly alpha emission in the spectrum, we are able to constrain the escape fraction of Ly alpha in the host. The host lies in the brighter end of the expected sGRB host brightness distribution at z = 2 : 211, and is actively forming stars. Using the observed sGRB host luminosity distribution, we find that between 43% and 71% of all Swift-detected sGRBs have hosts that are too faint at z similar to 2 to allow for a secure redshift determination. This implies that the measured sGRB redshift distribution could be incomplete at high redshift. The high z of GRB 111117A is evidence against a lognormal delay-time model for sGRBs through the predicted redshift distribution of sGRBs, which is very sensitive to high-z sGRBs. From the age of the universe at the time of GRB explosion, an initial neutron star (NS) separation of a(0) < 3.1 R-circle dot is required in the case where the progenitor system is a circular pair of inspiralling NSs. This constraint excludes some of the longest sGRB formation channels for this burst.
The Intergalactic medium transmission towards z>4 galaxies with VANDELS and the impact of dust attenuation
(2020) Thomas, R.; Pentericci, L.; Le Fevre, O.; Zamorani, G.; Schaerer, D.; Amorin, R.; Castellano, M.; Carnall, A. C.; Cristiani, S.; Guaita, Lucía; Cullen, F.; Finkelstein, S. L.; Fontanot, F.; Hibon, P.; Hathi, N.; Fynbo, J. P. U.; Khusanova, Y.; Koekemoer, A. M.; McLeod, D.; McLure, R. J.; Marchi, F.; Pozzetti, L.; Saxena, A.; Talia, M.; Bolzonella, M.
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.
THE SWIFT GRB HOST GALAXY LEGACY SURVEY. II. REST-FRAME NEAR-IR LUMINOSITY DISTRIBUTION AND EVIDENCE FOR A NEAR-SOLAR METALLICITY THRESHOLD
(IOP PUBLISHING LTD, 2016) Perley, D. A.; Tanvir, N. R.; Hjorth, J.; Laskar, T.; Berger, E.; Chary, R.; de Ugarte Postigo, A.; Fynbo, J. P. U.; Kruhler, T.; Levan, A. J.; Michalowski, M. J.; Schulze, S.
We present rest-frame near-IR (NIR) luminosities and stellar masses for a large and uniformly selected population of gamma-ray burst (GRB) host galaxies using deep Spitzer Space Telescope imaging of 119 targets from the Swift GRB Host Galaxy Legacy Survey spanning 0.03 < z < 6.3, and we determine the effects of galaxy evolution and chemical enrichment on the mass distribution of the GRB host population across cosmic history. We find a rapid increase in the characteristic NIR host luminosity between z similar to 0.5 and z similar to 1.5, but little variation between z similar to 1.5 and z similar to 5. Dust-obscured GRBs dominate the massive host population but are only rarely seen associated with low-mass hosts, indicating that massive star-forming galaxies are universally and (to some extent) homogeneously dusty at high. redshift while low-mass star-forming galaxies retain little dust in their interstellar medium. Comparing our luminosity distributions with field surveys and measurements of the high-z mass-metallicity relation, our results have good consistency with a model in which the GRB rate per unit star formation is constant in galaxies with gas-phase metallicity below approximately the solar value but heavily suppressed in more metal-rich environments. This model also naturally explains the previously reported "excess" in the GRB rate beyond z greater than or similar to 2; metals stifle GRB production in most galaxies at z < 1.5 but have only minor impact at higher redshifts. The metallicity threshold we infer is much higher than predicted by single-star models and favors a binary progenitor. Our observations also constrain the fraction of cosmic star formation in low-mass galaxies undetectable to Spitzer to be small at z < 4.
The VANDELS ESO public spectroscopic survey: Final data release of 2087 spectra and spectroscopic measurements
(2021) Garilli, B.; McLure, R.; Pentericci, L.; Franzetti, P.; Gargiulo, A.; Carnall, A.; Cucciati, O.; Iovino, A.; Amorin, R.; Bolzonella, M.; Bongiorno, A.; Castellano, M.; Cimatti, A.; Cirasuolo, M.; Cullen, F.; Dunlop, J.; Elbaz, D.; Finkelstein, S.; Fontana, A.; Fontanot, F.; Fumana, M.; Guaita, L.; Hartley, W.; Jarvis, M.; Juneau, S.; Maccagni, D.; McLeod, D.; Nandra, K.; Pompei, E.; Pozzetti, L.; Scodeggio, M.; Talia, M.; Calabro, A.; Cresci, G.; Fynbo, J. P. U.; Hathi, N. P.; Hibon, P.; Koekemoer, A. M.; Magliocchetti, M.; Salvato, M.; Vietri, G.; Zamorani, G.; Almaini, O.; Balestra, I.; Bardelli, S.; Begley, R.; Brammer, G.; Bell, E. F.; Bowler, R. A. A.; Brusa, M.; Buitrago, F.; Caputi, C.; Cassata, P.; Charlot, S.; Citro, A.; Cristiani, S.; Curtis-Lake, E.; Dickinson, M.; Fazio, G.; Ferguson, H. C.; Fiore, F.; Franco, M.; Georgakakis, A.; Giavalisco, M.; Grazian, A.; Hamadouche, M.; Jung, I.; Kim, S.; Khusanova, Y.; Le Fevre, O.; Longhetti, M.; Lotz, J.; Mannucci, F.; Maltby, D.; Matsuoka, K.; Mendez-Hernandez, H.; Mendez-Abreu, J.; Mignoli, M.; Moresco, M.; Nonino, M.; Pannella, M.; Papovich, C.; Popesso, P.; Roberts-Borsani, G.; Rosario, D. J.; Saldana-Lopez, A.; Santini, P.; Saxena, A.; Schaerer, D.; Schreiber, C.; Stark, D.; Tasca, L. A. M.; Thomas, R.; Vanzella, E.; Wild, V.; Williams, C.; Zucca, E.
VANDELS is an ESO Public Spectroscopic Survey designed to build a sample of high-signal-to-noise ratio, medium-resolution spectra of galaxies at redshifts between 1 and 6.5. Here we present the final Public Data Release of the VANDELS Survey, comprising 2087 redshift measurements. We provide a detailed description of sample selection, observations, and data reduction procedures. The final catalogue reaches a target selection completeness of 40% at i(AB)=25. The high signal-to-noise ratio of the spectra (above 7 in 80% of the spectra) and the dispersion of 2.5 angstrom allowed us to measure redshifts with high precision, the redshift measurement success rate reaching almost 100%. Together with the redshift catalogue and the reduced spectra, we also provide optical mid-infrared photometry and physical parameters derived through fitting the spectral energy distribution. The observed galaxy sample comprises both passive and star forming galaxies covering a stellar mass range of 8.3 < Log(M-*/M-circle dot) < 11.7.
The warm, the excited, and the molecular gas: GRB 121024A shining through its star-forming galaxy
(OXFORD UNIV PRESS, 2015) Friis, M.; De Cia, A.; Kruehler, T.; Fynbo, J. P. U.; Ledoux, C.; Vreeswijk, P. M.; Watson, D. J.; Malesani, D.; Gorosabel, J.; Starling, R. L. C.; Jakobsson, P.; Varela, K.; Wiersema, K.; Drachmann, A. P.; Trotter, A.; Thoene, C. C.; de Ugarte Postigo, A.; D'Elia, V.; Elliott, J.; Maturi, M.; Goldoni, P.; Greiner, J.; Haislip, J.; Kaper, L.; Knust, F.; LaCluyze, A.; Milvang Jensen, B.; Reichart, D.; Schulze, S.; Sudilovsky, V.; Tanvir, N.; Vergani, S. D.
We present the first reported case of the simultaneous metallicity determination of a gamma- ray burst (GRB) host galaxy, from both afterglow absorption lines as well as strong emission- line diagnostics. Using spectroscopic and imaging observations of the afterglow and host of the long- duration Swift GRB 121024A at z = 2.30, we give one of the most complete views of a GRB host/ environment to date. We observe a strong damped Lya absorber (DLA) with a hydrogen column density of log N(H i) = 21.88 +/- 0.10, H-2 absorption in the Lyman- Werner bands (molecular fraction of log(f) approximate to- 1.4; fourth solid detection of molecular hydrogen in a GRB- DLA), the nebular emission lines H alpha, H beta, [OII], [O III] and [N II], as well as metal absorption lines. We find aGRB host galaxy that is highly star forming (SFR similar to 40M circle dot yr(-1)), with a dust- corrected metallicity along the line of sight of [Zn/ H](corr) =- 0.6 +/- 0.2 ([O/H]similar to- 0.3 from emission lines), and a depletion factor [Zn/ Fe] = 0.85 +/- 0.04. The molecular gas is separated by 400 km s(-1) (and 1-3 kpc) from the gas that is photoexcited by the GRB. This implies a fairly massive host, in agreement with the derived stellar mass of log(M*/M-circle dot) = 9.9(-0.3)(+0.2). We dissect the host galaxy by characterizing its molecular component, the excited gas, and the line- emitting star- forming regions. The extinction curve for the line of sight is found to be unusually flat (R-V similar to 15). We discuss the possibility of an anomalous grain size distributions. We furthermore discuss the different metallicity determinations from both absorption and emission lines, which gives consistent results for the line of sight to GRB 121024A.
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.

Browsing by Author "Fynbo, J. P. U."

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