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1. Emission lines due to ionizing radiation from a compact object in the remnant of Supernova 1987A

Author

Fransson, C., Barlow, M. J., Kavanagh, P. J., Larsson, J., Jones, O. C., Sargent, B., Meixner, M., Bouchet, P., Temim, T., Wright, G. S., Blommaert, J. A. D. L., Habel, N., Hirschauer, A. S., Hjorth, J., Lenkić, L., Tikkanen, T., Wesson, R., Coulais, A., Fox, O. D., Gastaud, R., Glasse, A., Jaspers, J., Krause, O., Lau, R. M., Nayak, O., Rest, A., Colina, L., van Dishoeck, E. F., Gudel, M., Henning, Th., Lagage, P. -O., Őstlin, G., Ray, T. P., and Vandenbussche, B.

Subjects
Astrophysics - High Energy Astrophysical Phenomena, Astrophysics - Solar and Stellar Astrophysics
Abstract

The nearby Supernova 1987A was accompanied by a burst of neutrino emission, which indicates that a compact object (a neutron star or black hole) was formed in the explosion. There has been no direct observation of this compact object. In this work, we observe the supernova remnant with JWST spectroscopy finding narrow infrared emission lines of argon and sulphur. The line emission is spatially unresolved and blueshifted in velocity relative to the supernova rest frame. We interpret the lines as gas illuminated by a source of ionizing photons located close to the center of the expanding ejecta. Photoionization models show that the line ratios are consistent with ionization by a cooling neutron star or pulsar wind nebula. The velocity shift could be evidence for a neutron star natal kick., Comment: Authors version of manuscript published in Science on 22 Feb 2024

Published
2024
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6. Detecting life outside our solar system with a large high-contrast-imaging mission

Author

Snellen, Ignas A. G., Snik, F., Kenworthy, M., Albrecht, S., Anglada-Escudé, G., Baraffe, I., Baudoz, P., Benz, W., Beuzit, J.-L., Biller, B., Birkby, J. L., Boccaletti, A., van Boekel, R., de Boer, J., Brogi, Matteo, Buchhave, L., Carone, L., Claire, M., Claudi, R., Demory, B.-O., Désert, J.-M., Desidera, S., Gaudi, B. S., Gratton, R., Gillon, M., Grenfell, J. L., Guyon, O., Henning, T., Hinkley, S., Huby, E., Janson, M., Helling, C., Heng, K., Kasper, M., Keller, C. U., Krause, O., Kreidberg, L., Madhusudhan, N., Lagrange, A.-M., Launhardt, R., Lenton, T. M., Lopez-Puertas, M., Maire, A.-L., Mayne, N., Meadows, V., Mennesson, B., Micela, G., Miguel, Y., Milli, J., Min, M., de Mooij, E., Mouillet, D., N’Diaye, M., D’Orazi, V., Palle, E., Pagano, I., Piotto, G., Queloz, D., Rauer, H., Ribas, I., Ruane, G., Selsis, F., Sozzetti, A., Stam, D., Stark, C.C., Vigan, A., and de Visser, Pieter

Published
2022
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10. Detection of a Noble Gas Molecular Ion, {36}ArH^+, in the Crab Nebula

Author

Barlow, M. J., Swinyard, B. M., Owen, P. J., Cernicharo, J., Gomez, H. L., Ivison, R. J., Krause, O., Lim, T. L., Matsuura, M., Miller, S., Olofsson, G., and Polehampton, E. T.

Subjects
Astrophysics - Galaxy Astrophysics
Abstract

Noble gas molecules have not hitherto been detected in space. From spectra obtained with the Herschel Space Observatory, we report the detection of emission in the 617.5 GHz and 1234.6 GHz J = 1-0 and 2-1 rotational lines of {36}ArH^+ at several positions in the Crab Nebula, a supernova remnant known to contain both H2 molecules and regions of enhanced ionized argon emission. {36}Ar is believed to have originated from explosive nucleosynthesis in massive stars during core-collapse supernova events. Its detection in the Crab Nebula, the product of such a supernova event, confirms this expectation. The likely excitation mechanism for the observed {36}ArH^+ emission lines is electron collisions in partially ionized regions with electron densities of a few hundred per centimeter cubed., Comment: Published in Science on 13th December 2013; 14 pages, 2 figures, 1 table

Published
2013
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11. Infrared Echoes near the Supernova Remnant Cassiopeia A

Author

Krause, O., Rieke, G. H., Birkmann, S. M., Floc'h, E. Le, Gordon, K. D., Egami, E., Bieging, J., Hughes, J. P., Young, E. T., Hinz, J. L., Quanz, S. P., and Hines, D. C.

Subjects
Astrophysics
Abstract

Two images of Cassiopeia A obtained at 24 micrometer with the Spitzer Space Telescope over a one year time interval show moving structures outside the shell of the supernova remnant to a distance of more than 20 arcmin. Individual features exhibit apparent motions of 10 to 20 arcsec per year, independently confirmed by near-infrared observations. The observed tangential velocities are at roughly the speed of light. It is likely that the moving structures are infrared echoes, in which interstellar dust is heated by the explosion and by flares from the compact object near the center of the remnant., Comment: To be published in Science on June 10, 2005. 11 pages, 4 figures. Additional information available at http://www.spitzer.caltech.edu/Media/releases/ssc2005-14/index.shtml

Published
2005
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16. KINGFISH—Key Insights on Nearby Galaxies: A Far-Infrared Survey with Herschel : Survey Description and Image Atlas 1

Author

Kennicutt, R. C., Calzetti, D., Aniano, G., Appleton, P., Armus, L., Beirão, P., Bolatto, A. D., Brandl, B., Crocker, A., Croxall, K., Dale, D. A., Meyer, J. Donovan, Draine, B. T., Engelbracht, C. W., Galametz, M., Gordon, K. D., Groves, B., Hao, C.-N., Helou, G., Hinz, J., Hunt, L. K., Johnson, B., Koda, J., Krause, O., Leroy, A. K., Li, Y., Meidt, S., Montiel, E., Murphy, E. J., Rahman, N., Rix, H.-W., Roussel, H., Sandstrom, K., Sauvage, M., Schinnerer, E., Skibba, R., Smith, J. D. T., Srinivasan, S., Vigroux, L., Walter, F., Wilson, C. D., Wolfire, M., and Zibetti, S.

Published
2011
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21. EChO: Exoplanet characterisation observatory

Author

Tinetti, G., Beaulieu, J. P., Henning, T., Meyer, M., Micela, G., Ribas, I., Stam, D., Swain, M., Krause, O., Ollivier, M., Pace, E., Swinyard, B., Aylward, A., van Boekel, R., Coradini, A., Encrenaz, T., Snellen, I., Zapatero-Osorio, M. R., Bouwman, J., Cho, J. Y-K., Coudé de Foresto, V., Guillot, T., Lopez-Morales, M., Mueller-Wodarg, I., Palle, E., Selsis, F., Sozzetti, A., Ade, P. A. R., Achilleos, N., Adriani, A., Agnor, C. B., Afonso, C., Prieto, C. Allende, Bakos, G., Barber, R. J., Barlow, M., Batista, V., Bernath, P., Bézard, B., Bordé, P., Brown, L. R., Cassan, A., Cavarroc, C., Ciaravella, A., Cockell, C., Coustenis, A., Danielski, C., Decin, L., Kok, R. De, Demangeon, O., Deroo, P., Doel, P., Drossart, P., Fletcher, L. N., Focardi, M., Forget, F., Fossey, S., Fouqué, P., Frith, J., Galand, M., Gaulme, P., Hernández, J. I. González, Grasset, O., Grassi, D., Grenfell, J. L., Griffin, M. J., Griffith, C. A., Grözinger, U., Guedel, M., Guio, P., Hainaut, O., Hargreaves, R., Hauschildt, P. H., Heng, K., Heyrovsky, D., Hueso, R., Irwin, P., Kaltenegger, L., Kervella, P., Kipping, D., Koskinen, T. T., Kovács, G., La Barbera, A., Lammer, H., Lellouch, E., Leto, G., Lopez Morales, M., Lopez Valverde, M. A., Lopez-Puertas, M., Lovis, C., Maggio, A., Maillard, J. P., Maldonado Prado, J., Marquette, J. B., Martin-Torres, F. J., Maxted, P., Miller, S., Molinari, S., Montes, D., Moro-Martin, A., Moses, J. I., Mousis, O., Nguyen Tuong, N., Nelson, R., Orton, G. S., Pantin, E., Pascale, E., Pezzuto, S., Pinfield, D., Poretti, E., Prinja, R., Prisinzano, L., Rees, J. M., Reiners, A., Samuel, B., Sánchez-Lavega, A., Forcada, J. Sanz, Sasselov, D., Savini, G., Sicardy, B., Smith, A., Stixrude, L., Strazzulla, G., Tennyson, J., Tessenyi, M., Vasisht, G., Vinatier, S., Viti, S., Waldmann, I., White, G. J., Widemann, T., Wordsworth, R., Yelle, R., Yung, Y., and Yurchenko, S. N.

Published
2012
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22. The molecular hydrogen explorer H2EX

Author

Boulanger, F., Maillard, J. P., Appleton, P., Falgarone, E., Lagache, G., Schulz, B., Wakker, B. P., Bressan, A., Cernicharo, J., Charmandaris, V., Drissen, L., Helou, G., Henning, T., Lim, T. L., Valentjin, E. A., Abergel, A., Bourlot, J. Le, Bouzit, M., Cabrit, S., Combes, F., Deharveng, J. M., Desmet, P., Dole, H., Dumesnil, C., Dutrey, A., Fourmond, J. J., Gavila, E., Grangé, R., Gry, C., Guillard, P., Guilloteau, S., Habart, E., Huet, B., Joblin, C., Langer, M., Longval, Y., Madden, S. C., Martin, C., Miville-Deschênes, M. A., Pineau des Forêts, G., Pointecouteau, E., Roussel, H., Tresse, L., Verstraete, L., Viallefond, F., Bertoldi, F., Jorgensen, J., Bouwman, J., Carmona, A., Krause, O., Baruffolo, A., Bonoli, C., Bortoletto, F., Danese, L., Granato, G. L., Pernechele, C., Rampazzo, R., Silva, L., Zotti, G. de, Pardo, J., Spaans, M., van der Tak, F. F. S., Wild, W., Ferlet, M. J., Ramsay Howat, S. K., Smith, M. D., Swinyard, B., Wright, G. S., Joncas, G., Martin, P. G., Davis, C. J., Draine, B. T., Goldsmith, P. F., Mainzer, A. K., Ogle, P., Rinehart, S. A., Stacey, G. J., and Tielens, A. G. G. M.

Published
2009
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23. Interprofessionelle Lehre in der Geriatrie: Übersicht der internationalen Entwicklung im Vergleich zum aktuellen Stand in Deutschland.

Author

Hofmann, W., Flägel, K., and Krause, O.

Abstract

Copyright of Zeitschrift für Gerontologie und Geriatrie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2022
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25. Determination of aluminum diffusion parameters in silicon.

Author

Krause, O., Ryssel, H., and Pichler, P.

Subjects
*SEMICONDUCTOR doping, *COMPUTER-aided design
Abstract

Aluminum as the fastest diffusing acceptor dopant in silicon is commonly used for the fabrication of power semiconductors with p–n junction depths ranging from some microns to more than a hundred microns. Although long used, its diffusion behavior was not sufficiently characterized to support computer–aided design of devices. In this work, the intrinsic diffusion of aluminum was investigated in the temperature range from 850 to 1290 °C. Combining nitridation and oxidation experiments, the fractional diffusivity via self-interstitials was determined. By diffusion in high-concentration boron- and phosphorus-doped silicon the behavior of aluminum under extrinsic conditions was investigated. © 2002 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
2002
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27. Are even geriatric patients becoming older and older?

Author

Krause, O., Junius-Walker, U., Wiese, B., and Hager, K.

Abstract

Copyright of Zeitschrift für Gerontologie und Geriatrie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2018
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42. Carbon in different phases ([CII], [CI], and CO) in infrared dark clouds: Cloud formation signatures and carbon gas fractions.

Author

Beuther, H., Ragan, S. E., Henning, Th., Linz, H., Nielbock, M., Krause, O., Ossenkopf, V., Stutzki, J., Schilke, P., Glover, S., and Güsten, R.

Subjects
CARBON monoxide, KINEMATICS, STAR formation, INTERSTELLAR medium, ULTRAVIOLET radiation
Abstract

Context. How molecular clouds form out of the atomic phase and what the relative fractions of carbon are in the ionized, atomic, and molecular phase are questions at the heart of cloud and star formation. Aims. We want to understand the kinematic processes of gas flows during the formation of molecular clouds. In addition to that, we aim at determining the abundance ratios of carbon in its various gas phases from the ionized to the molecular form. Methods. Using multiple observatories from Herschel and SOFIA to APEX and the IRAM 30m telescope, we mapped the ionized and atomic carbon as well as carbon monoxide ([CII] at 1900 GHz, [CI] at 492 GHz, and C18O(2-1) at 220 GHz) at high spatial resolution (12"-25") in four young massive infrared dark clouds (IRDCs). Results. The three carbon phases were successfully mapped in all four regions, only in one source does the [CII] line remain a nondetection. With these data, we dissect the spatial and kinematic structure of the four IRDCs and determine the abundances of gas phase carbon in its ionized, atomic, and most abundant molecular form (CO). Both the molecular and atomic phases trace the dense structures well, with [CI] also tracing material at lower column densities. [CII] exhibits diverse morphologies in our sample from compact to diffuse structures, probing the cloud environment. In at least two out of the four regions, we find kinematic signatures strongly indicating that the dense gas filaments have formed out of a dynamically active and turbulent atomic and molecular cloud, potentially from converging gas flows. The atomic carbon-to-CO gas mass ratios are low between 7% and 12% with the lowest values found toward the most quiescent region. In the three regions where [CII] is detected, its mass is always higher by a factor of a few than that of the atomic carbon. While the ionized carbon emission depends on the radiation field, we also find additional signatures that indicate that other processes, for example, energetic gas flows can contribute to the [CII] excitation as well. Conclusions. Combining high-resolution maps in the different carbon phases reveals the dynamic interplay of the various phases of the interstellar medium during cloud formation. Extending these studies to more evolved stages and combining the observations with molecular cloud formation simulations including the chemistry and radiative transfer will significantly improve our understanding of the general interstellar medium, cloud, and star formation processes. [ABSTRACT FROM AUTHOR]

Published
2014
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43. A zero carbon future: Based on current initiatives, how long before Australia meets its energy needs from renewable energies?

Author

Doshi, N., Lelekakis, N., Martin, D., and Krause, O.

Abstract

The Australian government has a target for 20% of electricity to be generated from renewable sources by 2020. In this paper we review the progress of installing renewable generation in Australia and ask, firstly, whether Australia is on track to meet its target and secondly, whether a goal should be set to generate all of Australia's electricity needs from renewables. If it is concluded that there is the potential for 100% generation by renewable how should this be accomplished? We found that progress on the state level was not consistent. It was also notable that while all states had a plan to reach the federal government's target, none appeared to have concrete plans to manage the reduction of fossil fuel usage by retiring old power stations. There seemed to be an expectation that the renewables target would be reached by installing new capacity. In order to reach the federal government 20% target, an annual growth of 10% in renewable energy production is required. Extrapolating this rate of increase in renewable energy share into the future suggests that Australia could achieve 100% renewable generation by the 2040s. With respect to the obvious technical hurdles in reaching full renewable coverage (e.g. intermittency and reliability), geothermal appears as a valuable option for exploitation, and as such its use is currently being explored in Australia. [ABSTRACT FROM PUBLISHER]

Published
2013
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45. Analytic solution of the classic probabilistic load flow problem on a full AC model.

Author

Krause, O., Schwippe, J., Lehnhoff, S., and Rehtanz, Ch.

Abstract

Since the 1970s the application of probabilistic methods to power system analysis was addressed in many papers. Main objective was and still is to find a probabilistic counterpart to the deterministic Load Flow Calculation techniques that can cope with uncertainty about the grid usage. The term “Classical Probabilistic Load Flow Problem” refers to the problem to determine probability information about a line's absolute current from the probability information about nodal powers. Until now approaches that use model simplifications leading to inherent imprecision were used to address this problem. In this paper the authors present a novel approach that allows for the exact solution of the before described ‘Classical Probabilistic Load Flow Problem’ based on a full-steady state AC-network model. [ABSTRACT FROM PUBLISHER]

Published
2011
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46. Support vector machines for an efficient representation of voltage band constraints.

Author

Blank, M., Gerwinn, S., Krause, O., and Lehnhoff, S.

Abstract

Future Smart Grids emphasize the (at least) partial coordination of a large number of stochastic consumers and producers to balance consumption and generation of electrical energy. However, this coordinated and often time-synchronous activation and deactivation of demand and supply may result in the violation of the grid's feasibility constraints, since it may increase statistical simultaneity above the level assumed in the initial design of such networks. The detection and avoidance of such operational infeasibilities is essential for secure grid operations. In order to handle the complexity of the optimization problem at hand, autonomous software agents will play a vital role in future power management systems. The system's complexity is reduced down to several less complex sub-problems, which may then be solved in parallel, based on locally available information. In this paper we present ongoing work on the development of autonomous grid management under stability constraints imposed by the power grid. [ABSTRACT FROM PUBLISHER]

Published
2011
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