ALBERT

Description: Biochemistry DOI: 10.1021/acs.biochem.5b00419

Description: A new class of ultra-long-duration (more than 10,000 seconds) gamma-ray bursts has recently been suggested. They may originate in the explosion of stars with much larger radii than those producing normal long-duration gamma-ray bursts or in the tidal disruption of a star. No clear supernova has yet been associated with an ultra-long-duration gamma-ray burst. Here we report that a supernova (SN 2011kl) was associated with the ultra-long-duration gamma-ray burst GRB 111209A, at a redshift z of 0.677. This supernova is more than three times more luminous than type Ic supernovae associated with long-duration gamma-ray bursts, and its spectrum is distinctly different. The slope of the continuum resembles those of super-luminous supernovae, but extends further down into the rest-frame ultraviolet implying a low metal content. The light curve evolves much more rapidly than those of super-luminous supernovae. This combination of high luminosity and low metal-line opacity cannot be reconciled with typical type Ic supernovae, but can be reproduced by a model where extra energy is injected by a strongly magnetized neutron star (a magnetar), which has also been proposed as the explanation for super-luminous supernovae.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Greiner, Jochen -- Mazzali, Paolo A -- Kann, D Alexander -- Kruhler, Thomas -- Pian, Elena -- Prentice, Simon -- Olivares E, Felipe -- Rossi, Andrea -- Klose, Sylvio -- Taubenberger, Stefan -- Knust, Fabian -- Afonso, Paulo M J -- Ashall, Chris -- Bolmer, Jan -- Delvaux, Corentin -- Diehl, Roland -- Elliott, Jonathan -- Filgas, Robert -- Fynbo, Johan P U -- Graham, John F -- Guelbenzu, Ana Nicuesa -- Kobayashi, Shiho -- Leloudas, Giorgos -- Savaglio, Sandra -- Schady, Patricia -- Schmidl, Sebastian -- Schweyer, Tassilo -- Sudilovsky, Vladimir -- Tanga, Mohit -- Updike, Adria C -- van Eerten, Hendrik -- Varela, Karla -- England -- Nature. 2015 Jul 9;523(7559):189-92. doi: 10.1038/nature14579.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉1] Max-Planck-Institut fur Extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching, Germany [2] Excellence Cluster Universe, Technische Universitat Munchen, Boltzmannstrasse 2, 85748 Garching, Germany. ; 1] Astrophysics Research Institute, Liverpool John Moores University, IC2, Liverpool Science Park, 146 Browlow Hill, Liverpool L3 5RF, UK [2] Max-Planck-Institut fur Astrophysik, Karl-Schwarzschild-Strasse 1, 85748 Garching, Germany. ; 1] Max-Planck-Institut fur Extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching, Germany [2] Excellence Cluster Universe, Technische Universitat Munchen, Boltzmannstrasse 2, 85748 Garching, Germany [3] Thuringer Landessternwarte Tautenburg, Sternwarte 5, 07778 Tautenburg, Germany. ; European Southern Observatory, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago 19, Chile. ; 1] INAF, Institute of Space Astrophysics and Cosmic Physics, via P. Gobetti 101, 40129 Bologna, Italy [2] Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy. ; Astrophysics Research Institute, Liverpool John Moores University, IC2, Liverpool Science Park, 146 Browlow Hill, Liverpool L3 5RF, UK. ; Departamento de Ciencias Fisicas, Universidad Andres Bello, Avenida Republica 252, Santiago, Chile. ; 1] Thuringer Landessternwarte Tautenburg, Sternwarte 5, 07778 Tautenburg, Germany [2] INAF, Institute of Space Astrophysics and Cosmic Physics, via P. Gobetti 101, 40129 Bologna, Italy. ; Thuringer Landessternwarte Tautenburg, Sternwarte 5, 07778 Tautenburg, Germany. ; 1] Max-Planck-Institut fur Astrophysik, Karl-Schwarzschild-Strasse 1, 85748 Garching, Germany [2] European Southern Observatory, Karl-Schwarzschild-Strasse 2, 85748 Garching, Germany. ; Max-Planck-Institut fur Extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching, Germany. ; American River College, Physics and Astronomy Department, 4700 College Oak Drive, Sacramento, California 95841, USA. ; 1] Max-Planck-Institut fur Extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching, Germany [2] Technische Universitat Munchen, Physik Department, James-Franck-Strasse, 85748 Garching, Germany. ; 1] Max-Planck-Institut fur Extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching, Germany [2] Astrophysics Data System, Harvard-Smithonian Center for Astrophysics, Garden Street 60, Cambridge, Massachusetts 02138, USA. ; Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, 128 00 Prague 2, Czech Republic. ; DARK Cosmology Center, Niels-Bohr-Institut, University of Copenhagen, Juliane Maries Vej 30, 2100 Kobenhavn, Denmark. ; 1] DARK Cosmology Center, Niels-Bohr-Institut, University of Copenhagen, Juliane Maries Vej 30, 2100 Kobenhavn, Denmark [2] Department of Particle Physics and Astrophysics, Weizmann Institute of Science, Rehovot 76100, Israel. ; 1] Max-Planck-Institut fur Extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching, Germany [2] Universita della Calabria, 87036 Arcavacata di Rende, via P. Bucci, Italy. ; Roger Williams University, 1 Old Ferry Road, Bristol, Rhode Island 02809, USA.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26156372" target="_blank"〉PubMed〈/a〉

Description: 〈p〉An interacting quantum system that is subject to disorder may cease to thermalize owing to localization of its constituents, thereby marking the breakdown of thermodynamics. The key to understanding this phenomenon lies in the system’s entanglement, which is experimentally challenging to measure. We realize such a many-body–localized system in a disordered Bose-Hubbard chain and characterize its entanglement properties through particle fluctuations and correlations. We observe that the particles become localized, suppressing transport and preventing the thermalization of subsystems. Notably, we measure the development of nonlocal correlations, whose evolution is consistent with a logarithmic growth of entanglement entropy, the hallmark of many-body localization. Our work experimentally establishes many-body localization as a qualitatively distinct phenomenon from localization in noninteracting, disordered systems.〈/p〉

Description: Microquasars are stellar-mass black holes accreting matter from a companion star and ejecting plasma jets at almost the speed of light. They are analogues of quasars that contain supermassive black holes of 10(6) to 10(10) solar masses. Accretion in microquasars varies on much shorter timescales than in quasars and occasionally produces exceptionally bright X-ray flares. How the flares are produced is unclear, as is the mechanism for launching the relativistic jets and their composition. An emission line near 511 kiloelectronvolts has long been sought in the emission spectrum of microquasars as evidence for the expected electron-positron plasma. Transient high-energy spectral features have been reported in two objects, but their positron interpretation remains contentious. Here we report observations of gamma-ray emission from the microquasar V404 Cygni during a recent period of strong flaring activity. The emission spectrum around 511 kiloelectronvolts shows clear signatures of variable positron annihilation, which implies a high rate of positron production. This supports the earlier conjecture that microquasars may be the main sources of the electron-positron plasma responsible for the bright diffuse emission of annihilation gamma-rays in the bulge region of our Galaxy. Additionally, microquasars could be the origin of the observed megaelectronvolt continuum excess in the inner Galaxy.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Siegert, Thomas -- Diehl, Roland -- Greiner, Jochen -- Krause, Martin G H -- Beloborodov, Andrei M -- Bel, Marion Cadolle -- Guglielmetti, Fabrizia -- Rodriguez, Jerome -- Strong, Andrew W -- Zhang, Xiaoling -- England -- Nature. 2016 Mar 17;531(7594):341-3. doi: 10.1038/nature16978.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Max-Planck-Institut fur extraterrestrische Physik, Giessenbachstrasse 1, 85748 Garching, Germany. ; Universitats-Sternwarte Munchen, Ludwig-Maximilians-Universitat, Scheinerstrasse 1, 81679 Munchen, Germany. ; Physics Department and Columbia Astrophysics Laboratory, Columbia University, 550 West 120th Street, New York, New York 10027, USA. ; Max Planck Computing and Data Facility, Giessenbachstrasse 2, 85748 Garching, Germany. ; Laboratoire Astrophysique Instrumentation Modelisation, UMR 7158, CEA/CNRS/Universite Paris Diderot, CEA DSM/IRFU/SAp, 91191 Gif-sur-Yvette, France.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/26934231" target="_blank"〉PubMed〈/a〉

Description: Nature Physics 13, 276 (2017). doi:10.1038/nphys3942 Authors: A. Caratti o Garatti, B. Stecklum, R. Garcia Lopez, J. Eislöffel, T. P. Ray, A. Sanna, R. Cesaroni, C. M. Walmsley, R. D. Oudmaijer, W. J. de Wit, L. Moscadelli, J. Greiner, A. Krabbe, C. Fischer, R. Klein & J. M. Ibañez Solar-mass stars form via disk-mediated accretion. Recent findings indicate that this process is probably episodic in the form of accretion bursts, possibly caused by disk fragmentation. Although it cannot be ruled out that high-mass young stellar objects arise from the coalescence of their low-mass brethren, the latest results suggest that they more likely form via disks. It follows that disk-mediated accretion bursts should occur. Here we report on the discovery of the first disk-mediated accretion burst from a roughly twenty-solar-mass high-mass young stellar object. Our near-infrared images show the brightening of the central source and its outflow cavities. Near-infrared spectroscopy reveals emission lines typical for accretion bursts in low-mass protostars, but orders of magnitude more luminous. Moreover, the released energy and the inferred mass-accretion rate are also orders of magnitude larger. Our results identify disk-accretion as the common mechanism of star formation across the entire stellar mass spectrum.

Description: We report the results of spectrophotometric observations of the massive star MN18 revealed via discovery of a bipolar nebula around it with the Spitzer Space Telescope . Using the optical spectrum obtained with the Southern African Large Telescope, we classify this star as B1 Ia. The evolved status of MN18 is supported by the detection of nitrogen overabundance in the nebula, which implies that it is composed of processed material ejected by the star. We analysed the spectrum of MN18 by using the code cmfgen , obtaining a stellar effective temperature of 21 kK. The star is highly reddened, E ( B – V )  2 mag. Adopting an absolute visual magnitude of M V  = –6.8 ± 0.5 (typical of B1 supergiants), MN18 has a luminosity of log L /L   5.42 ± 0.30, a mass-loss rate of (2.8-4.5) x 10 – 7 M yr – 1 , and resides at a distance of 5.6 $^{+1.5} _{-1.2}$  kpc. We discuss the origin of the nebula around MN18 and compare it with similar nebulae produced by other blue supergiants in the Galaxy (Sher 25, HD 168625, [SBW2007] 1) and the Large Magellanic Cloud (Sk–69 $\deg$ 202). The nitrogen abundances in these nebulae imply that blue supergiants can produce them from the main-sequence stage up to the pre-supernova stage. We also present a K -band spectrum of the candidate luminous blue variable MN56 (encircled by a ring-like nebula) and report the discovery of an OB star at 17 arcsec from MN18. The possible membership of MN18 and the OB star of the star cluster Lynga 3 is discussed.

Description: 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 Lyα absorber (DLA) with a hydrogen column density of log  $N({\rm H\,{\small I}})\,=\,21.88\pm 0.10$ , H 2 absorption in the Lyman–Werner bands (molecular fraction of log( f ) –1.4; fourth solid detection of molecular hydrogen in a GRB-DLA), the nebular emission lines Hα, Hβ, [O ii ], [O iii ] and [N ii ], as well as metal absorption lines. We find a GRB host galaxy that is highly star forming (SFR ~ 40 M  yr –1 ), with a dust-corrected metallicity along the line of sight of [Zn/H] corr  = –0.6 ± 0.2 ([O/H] ~ –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 ) =  $9.9^{+0.2}_{-0.3}$ . 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  ~ 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.

Description: We present optical observations of the peculiar Type Ibn supernova (SN Ibn) OGLE-2012-SN-006, discovered and monitored by the Optical Gravitational Lensing Experiment-IV survey, and spectroscopically followed by Public ESO Spectroscopic Survey of Transient Objects (PESSTO) at late phases. Stringent pre-discovery limits constrain the explosion epoch with fair precision to JD = 245 6203.8 ± 4.0. The rise time to the I -band light-curve maximum is about two weeks. The object reaches the peak absolute magnitude M I  = –19.65 ± 0.19 on JD = 245 6218.1 ± 1.8. After maximum, the light curve declines for about 25 d with a rate of 4 mag (100 d) –1 . The symmetric I -band peak resembles that of canonical Type Ib/c supernovae (SNe), whereas SNe Ibn usually exhibit asymmetric and narrower early-time light curves. Since 25 d past maximum, the light curve flattens with a decline rate slower than that of the 56 Co– 56 Fe decay, although at very late phases it steepens to approach that rate. However, other observables suggest that the match with the 56 Co decay rate is a mere coincidence, and the radioactive decay is not the main mechanism powering the light curve of OGLE-2012-SN-006. An early-time spectrum is dominated by a blue continuum, with only a marginal evidence for the presence of He i lines marking this SN type. This spectrum shows broad absorptions bluewards than 5000 Å, likely O ii lines, which are similar to spectral features observed in superluminous SNe at early epochs. The object has been spectroscopically monitored by PESSTO from 90 to 180 d after peak, and these spectra show the typical features observed in a number of SN 2006jc-like events, including a blue spectral energy distribution and prominent and narrow ( v FWHM   1900 km s –1 ) He i emission lines. This suggests that the ejecta are interacting with He-rich circumstellar material. The detection of broad (10 4 km s –1 ) O i and Ca ii features likely produced in the SN ejecta (including the [O i ] 6300,6364 doublet in the latest spectra) lends support to the interpretation of OGLE-2012-SN-006 as a core-collapse event.

Description: 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 Lyα absorber (DLA) with a hydrogen column density of log  $N({\rm H\,{\small I}})\,=\,21.88\pm 0.10$ , H 2 absorption in the Lyman–Werner bands (molecular fraction of log( f ) –1.4; fourth solid detection of molecular hydrogen in a GRB-DLA), the nebular emission lines Hα, Hβ, [O ii ], [O iii ] and [N ii ], as well as metal absorption lines. We find a GRB host galaxy that is highly star forming (SFR ~ 40 M  yr –1 ), with a dust-corrected metallicity along the line of sight of [Zn/H] corr  = –0.6 ± 0.2 ([O/H] ~ –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 ) =  $9.9^{+0.2}_{-0.3}$ . 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  ~ 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.