Black holes, gravitational waves and fundamental physics: a roadmap

(2018)

Authors:

Leor Barack, Vitor Cardoso, Samaya Nissanke, Thomas P Sotiriou, Abbas Askar, Krzysztof Belczynski, Gianfranco Bertone, Edi Bon, Diego Blas, Richard Brito, Tomasz Bulik, Clare Burrage, Christian T Byrnes, Chiara Caprini, Masha Chernyakova, Piotr Chrusciel, Monica Colpi, Valeria Ferrari, Daniele Gaggero, Jonathan Gair, Juan Garcia-Bellido, SF Hassan, Lavinia Heisenberg, Martin Hendry, Ik Siong Heng, Carlos Herdeiro, Tanja Hinderer, Assaf Horesh, Bradley J Kavanagh, Bence Kocsis, Michael Kramer, Alexandre Le Tiec, Chiara Mingarelli, Germano Nardini, Gijs Nelemans, Carlos Palenzuela, Paolo Pani, Albino Perego, Edward K Porter, Elena M Rossi, Patricia Schmidt, Alberto Sesana, Ulrich Sperhake, Antonio Stamerra, Leo C Stein, Nicola Tamanini, Thomas M Tauris, L Arturo Urena-Lopez, Frederic Vincent, Marta Volonteri, Barry Wardell, Norbert Wex, Kent Yagi, Tiziano Abdelsalhin, Miguel Angel Aloy, Pau Amaro-Seoane, Lorenzo Annulli, Manuel Arca-Sedda, Ibrahima Bah, Enrico Barausse, Elvis Barakovic, Robert Benkel, Charles L Bennett, Laura Bernard, Sebastiano Bernuzzi, Christopher PL Berry, Emanuele Berti, Miguel Bezares, Jose Juan Blanco-Pillado, Jose Luis Blazquez-Salcedo, Matteo Bonetti, Mateja Boskovic, Zeljka Bosnjak, Katja Bricman, Bernd Bruegmann, Pedro R Capelo, Sante Carloni, Pablo Cerda-Duran, Christos Charmousis, Sylvain Chaty, Aurora Clerici, Andrew Coates, Marta Colleoni, Lucas G Collodel, Geoffrey Compere, William Cook, Isabel Cordero-Carrion, Miguel Correia, Alvaro de la Cruz-Dombriz, Viktor G Czinner, Kyriakos Destounis, Kostas Dialektopoulos, Daniela Doneva, Massimo Dotti, Amelia Drew, Christopher Eckner, James Edholm, Roberto Emparan, Recai Erdem, Miguel Ferreira, Pedro G Ferreira, Andrew Finch, Jose A Font, Nicola Franchini, Kwinten Fransen, Dmitry Gal'tsov, Apratim Ganguly, Davide Gerosa, Kostas Glampedakis, Andreja Gomboc, Ariel Goobar, Leonardo Gualtieri, Eduardo Guendelman, Francesco Haardt, Troels Harmark, Filip Hejda, Thomas Hertog, Seth Hopper, Sascha Husa, Nada Ihanec, Taishi Ikeda, Amruta Jaodand, Philippe Jetzer Xisco Jimenez-Forteza, Marc Kamionkowski, David E Kaplan, Stelios Kazantzidis, Masashi Kimura, Shiho Kobayashi, Kostas Kokkotas, Julian Krolik, Jutta Kunz, Claus Lammerzahl, Paul Lasky, Jose PS Lemos, Jackson Levi Said, Stefano Liberati, Jorge Lopes, Raimon Luna, Yin-Zhe Ma, Elisa Maggio, Marina Martinez Montero, Andrea Maselli, Lucio Mayer, Anupam Mazumdar, Christopher Messenger, Brice Menard, Masato Minamitsuji, Christopher J Moore, David Mota, Sourabh Nampalliwar, Andrea Nerozzi, David Nichols, Emil Nissimov, Martin Obergaulinger, Niels A Obers, Roberto Oliveri, George Pappas, Vedad Pasic, Hiranya Peiris, Tanja Petrushevska, Denis Pollney, Geraint Pratten, Nemanja Rakic, Istvan Racz, Miren Radia, Fethi M Ramazanouglu, Antoni Ramos-Buades, Guilherme Raposo, Roxana Rosca-Mead, Marek Rogatko, Dorota Rosinska, Stephan Rosswog, Ester Ruiz Morales, Mairi Sakellariadou, Nicolas Sanchis-Gual, Om Sharan Salafia, Anuradha Samajdar, Alicia Sintes, Majda Smole, Carlos Sopuerta, Rafael Souza-Lima, Marko Stalevski, Nikolaos Stergioulas, Chris Stevens, Tomas Tamfal, Alejandro Torres-Forne, Sergey Tsygankov, Kivanc Unluturk, Rosa Valiante, Maarten van de Meent, Jose Velhinho, Yosef Verbin, Bert Vercnocke, Daniele Vernieri, Rodrigo Vicente, Vincenzo Vitagliano, Amanda Weltman, Bernard Whiting, Andrew Williamson, Helvi Witek, Aneta Wojnar, Kadri Yakut, Haopeng Yan, Stoycho Yazadjiev, Gabrijela Zaharijas, Miguel Zilhao

$\texttt{stella}$: a mixed implicit-explicit, delta-f gyrokinetic code for general magnetic field configurations

(2018)

Authors:

Michael Barnes, Felix Parra-Diaz, Matt Landreman

Black hole mergers from an evolving population of globular clusters

(2018)

Authors:

Giacomo Fragione, Bence Kocsis

Collisions in primordial star clusters: formation pathway for intermediate mass black holes

Astronomy and Astrophysics EDP Sciences 614 (2018) A14

Authors:

B Reinoso, Drg Schleicher, M Fellhauer, Rs Klessen, TCN Boekholt

Abstract:

Collisions were suggested to potentially play a role in the formation of massive stars in present day clusters, and have likely been relevant during the formation of massive stars and intermediate mass black holes within the first star clusters. In the early Universe, the first stellar clusters were particularly dense, as fragmentation typically only occurred at densities above 109 cm−3, and the radii of the protostars were enhanced as a result of larger accretion rates, suggesting a potentially more relevant role of stellar collisions. We present here a detailed parameter study to assess how the number of collisions and the mass growth of the most massive object depend on the properties of the cluster. We also characterize the time evolution with three effective parameters: the time when most collisions occur, the duration of the collisions period, and the normalization required to obtain the total number of collisions. We apply our results to typical Population III (Pop. III) clusters of about 1000 M⊙, finding that a moderate enhancement of the mass of the most massive star by a factor of a few can be expected. For more massive Pop. III clusters as expected in the first atomic cooling halos, we expect a more significant enhancement by a factor of 15–32. We therefore conclude that collisions in massive Pop. III clusters were likely relevant to form the first intermediate mass black holes.

Eccentric Black Hole Gravitational-wave Capture Sources in Galactic Nuclei: Distribution of Binary Parameters

ASTROPHYSICAL JOURNAL American Astronomical Society 860:1 (2018) ARTN 5

Authors:

Laszlo Gondan, Bence Kocsis, Peter Raffai, Zsolt Frei

Abstract:

Mergers of binary black holes on eccentric orbits are among the targets for second-generation ground-based gravitational-wave detectors. These sources may commonly form in galactic nuclei due to gravitational-wave emission during close flyby events of single objects. We determine the distributions of initial orbital parameters for a population of these gravitational-wave sources. Our results show that the initial dimensionless pericenter distance systematically decreases with the binary component masses and the mass of the central supermassive black hole, and its distribution depends sensitively on the highest possible black hole mass in the nuclear star cluster. For a multi-mass black hole population with masses between 5 Msun and 80 Msun, we find that between 43-69% (68-94%) of 30 Msun - 30 Msun (10 Msun - 10 Msun) sources have an eccentricity greater than 0.1 when the gravitational-wave signal reaches 10 Hz, but less than 10% of the sources with binary component masses less than 30 Msun remain eccentric at this level near the last stable orbit (LSO). The eccentricity at LSO is typically between 0.005-0.05 for the lower-mass BHs, and 0.1 - 0.2 for the highest-mass BHs. Thus, due to the limited low-frequency sensitivity, the six currently known quasi-circular LIGO/Virgo sources could still be compatible with this originally highly eccentric source population. However, at the design sensitivity of these instruments, the measurement of the eccentricity and mass distribution of merger events may be a useful diagnostic to identify the fraction of GW sources formed in this channel.