Article
Astronomy & Astrophysics
Xiao-Jun Wu, Ye-Fei Yuan, Rajiv Kumar, Yan Luo
Summary: The study investigates the use of millisecond pulsars to detect hidden binary black holes, constructing a triple system to analyze the effects of the inner black holes on the outer pulsar's orbit. It is found that different parameters of the inner black holes can lead to distinct periodic signals.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Fabio Antonini, Mark Gieles, Fani Dosopoulou, Debatri Chattopadhyay
Summary: This study explores the mass distribution of merging black hole binaries formed dynamically in globular clusters using the cBHBd model and compares it to the inferred distributions from the third gravitational wave transient catalog. The study finds that the main peak in the inferred primary black hole mass distribution cannot be explained by the models. However, a globular cluster origin can account for the presence of a secondary peak. Furthermore, the lack of a high-mass cut-off in the inferred mass distribution can be explained by the repopulation of an initial mass gap through hierarchical mergers.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Jeremy J. Webb, Jason A. S. Hunt, Jo Bovy
Summary: We applied the made-to-measure method to modelling dynamical systems in globular clusters. By adjusting the masses of particles in a model cluster, the method can reproduce select properties of an observed cluster. We found that the method can reproduce a cluster's 3D density profile easily, but minor discrepancies may occur in the outer regions when fitting against the cluster's projected surface density or kinematic properties.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Zhen Wan, Anthony D. Arnold, William H. Oliver, Geraint F. Lewis, Holger Baumgardt, Mark Gieles, Vincent Henault-Brunet, Thomas de Boer, Eduardo Balbinot, Gary Da Costa, Dougal Mackey, Denis Erkal, Annette Ferguson, Pete Kuzma, Elena Pancino, Jorge Penarrubia, Nicoletta Sanna, Antonio Sollima, Roeland P. van der Marel, Laura L. Watkins
Summary: In this study, the outskirts of four globular clusters - 1261, NGC 4590, NGC 1904, and NGC 1851 - were surveyed using spectroscopic measurements from 2dF/AAOmega and FLAMES instruments. Chemo-dynamical information for individual stars were extracted to estimate the velocity dispersion profile and rotation of each cluster. The results show that NGC 1851 and NGC 1261 exhibit internal rotation, and the dispersion profiles of NGC 1261, NGC 1851, and NGC 1904 do not follow the predictions of limepy/spes models, while NGC 4590's results align with the predictions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Eduardo Vitral, Gary A. Mamon
Summary: Analyzing the motions and density profiles of the nearby globular cluster NGC 6397, it was found that there is strong evidence suggesting the presence of a central dark component rather than an intermediate-mass black hole. This dark component may be composed of unresolved objects, indicating a high concentration of compact stars due to dynamical friction. The results also suggest that stellar-mass black holes could dominate this dark component, potentially playing a role in the gravitational wave events detected by LIGO.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
P. B. Kuzma, A. M. N. Ferguson, A. L. Varri, M. J. Irwin, E. J. Bernard, E. Tolstoy, J. Penarrubia, D. B. Zucker
Summary: In this paper, the authors conducted a spectroscopic study of the tidal tails of Palomar 5 cluster, focusing on the leading tail. By combining their measurements with photometric data and astrometry, they identified 16 stars belonging to the Pal 5 stream and characterized the 3D kinematics of the system. They also provided a catalogue for future modeling work.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
F. Abbate, A. Ridolfi, E. D. Barr, S. Buchner, M. Burgay, D. J. Champion, W. Chen, P. C. C. Freire, T. Gautam, J. M. Griessmeier, L. Kuenkel, M. Kramer, P. Padmanabh, A. Possenti, S. Ransom, M. Serylak, B. W. Stappers, V. Venkatraman Krishnan, J. Behrend, R. P. Breton, L. Levin, Y. Men
Summary: This study reports the discovery of four new pulsars in the core-collapsed globular cluster NGC 6624 using the MeerKAT telescope. The pulsars exhibit expected properties and were accurately localized using the TRAPUM backend.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Physics, Multidisciplinary
Dandan Zhang, Zhenzhao Tao, Mao Yuan, Jumei Yao, Pei Wang, Qijun Zhi, Weiwei Zhu, Xun Shi, Michael Kramer, Di Li, Lei Zhang, Guangxing Li
Summary: We used the FAST to detect scintillation arcs for pulsars in globular clusters M5, M13, and M15 for the first time. We inferred the existence of screen-like scattering medium at distances of 4.1(-0.3)(+0.2) kpc, 6.7(-0.2)(+0.2) kpc, and 1.3(-1.0)(+0.7) kpc in the directions of M5, M13, and M15, respectively. The findings provide evidence for understanding the medium circulation in the Milky Way.
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
(2023)
Article
Astronomy & Astrophysics
Wenbo Wu, Gang Zhao
Summary: This study reveals that most Galactic globular clusters exhibit mass segregation, with larger core to half-mass-radius ratios leading to less mass segregation. By combining mass segregation and core binary fractions, a moderate anticorrelation is found when the core binary fraction is below 0.15.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
Enrico Vesperini, Jongsuk Hong, Mirek Giersz, Arkadiusz Hypki
Summary: This study utilized Monte Carlo simulations to investigate fundamental aspects of the dynamical evolution of multiple stellar populations in globular clusters, including the evolution of 2G star fractions, the link between different dynamical processes, the spatial mixing dynamics of 1G and 2G stars, the implications of initial spatial distribution differences, and the variation of energy equipartition in different evolutionary phases of clusters.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Ying Wang, Wei Sun, Fuyao Liu, Xin Wu
Summary: Symplectic integrators that preserve the geometric structure of Hamiltonian flows and do not exhibit secular growth in energy errors are suitable for long-term integration in N-body Hamiltonian systems, but constructing explicit symplectic algorithms in general relativity can be challenging. Implicit symplectic integrators, such as the midpoint rule, are more applicable in such cases.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
T. Gautam, A. Ridolfi, P. C. C. Freire, R. S. Wharton, Y. Gupta, S. M. Ransom, L. S. Oswald, M. Kramer, M. E. DeCesar
Summary: This study used the upgraded Giant Metrewave Radio Telescope to search for pulsars in globular clusters and observed these clusters to obtain radio images. A new pulsar was discovered and a timing solution was derived for the system. Several unidentified radio sources were also detected.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Jiaqi Zhao, Craig O. Heinke
Summary: We conducted a comprehensive census of X-ray millisecond pulsars (MSPs) in 29 Galactic globular clusters (GCs), finding a large number of MSPs with different luminosities. They can be divided into redback pulsars and black widows. By estimating the correlation between the number of MSPs and stellar encounter rate in 36 GCs, we suggest that between 600 and 1500 MSPs exist in these clusters. We also estimated the number of X-ray detectable MSPs in the Galactic bulge.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Jiaqi Zhao, Yue Zhao, Craig O. Heinke
Summary: The study analysed 55 ks of Chandra X-ray observations of the Galactic globular cluster M13, revealing X-ray and optical counterparts of millisecond pulsars with details on their luminosities and spectra. The research also provides insight into the properties of these celestial objects and enhances the understanding of MSPs in globular clusters.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
S. Dai, S. Johnston, M. Kerr, J. Berteaud, B. Bhattacharyya, F. Camilo, E. Keane
Summary: In this study, we report the timing of the first five millisecond pulsars discovered in the globular cluster Omega Centauri and the discovery of a pulsar with a spin period of 3.68 ms. With a timing baseline of approximately 3.5 years, we are able to measure the derivative of the spin frequency (nu) for these pulsars. Upper limits on the pulsar line-of-sight acceleration are estimated and compared with analytical models of the cluster. We find discrepancies between the observed accelerations and the minimum acceleration predicted by the models for PSRs J1326-4728B and D.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Yi-Han Wang, Nathan Leigh, Alberto Sesana, Rosalba Perna
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2019)
Article
Astronomy & Astrophysics
Yi-Han Wang, Nathan W. C. Leigh, Alberto Sesana, Rosalba Perna
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2019)
Article
Astronomy & Astrophysics
Sean McGee, Alberto Sesana, Alberto Vecchio
Article
Astronomy & Astrophysics
Manuel Arca Sedda, Christopher P. L. Berry, Karan Jani, Pau Amaro-Seoane, Pierre Auclair, Jonathon Baird, Tessa Baker, Emanuele Berti, Katelyn Breivik, Chiara Caprini, Xian Chen, Daniela Doneva, Jose M. Ezquiaga, K. E. Saavik Ford, Michael L. Katz, Shimon Kolkowitz, Barry McKernan, Guido Mueller, Germano Nardini, Igor Pikovski, Surjeet Rajendran, Alberto Sesana, Lijing Shao, Nicola Tamanini, Niels Warburton, Helvi Witek, Kaze Wong, Michael Zevin
Summary: In the coming years, both ground-based and space-based gravitational-wave observatories will continue to discover binary systems, with a focus on the uncharted decihertz frequency band. Decihertz observatories will play a key role in early detection of binary mergers, as well as providing new tests for general relativity and particle physics.
EXPERIMENTAL ASTRONOMY
(2021)
Article
Astronomy & Astrophysics
Elisa Bortolas, Alessia Franchini, Matteo Bonetti, Alberto Sesana
Summary: Massive black hole binaries are expected to be the loudest sources of low-frequency gravitational waves, with their evolution driven by interactions with surrounding stars and gas. While the presence of a gaseous disk may lead to binary outspiral, ultimately the binary's mass grows large enough for gravitational waves to drive it to coalescence, unaffected by gas-driven expansion.
ASTROPHYSICAL JOURNAL LETTERS
(2021)
Article
Astronomy & Astrophysics
Alberto Sesana, Natalia Korsakova, Manuel Arca Sedda, Vishal Baibhav, Enrico Barausse, Simon Barke, Emanuele Berti, Matteo Bonetti, Pedro R. Capelo, Chiara Caprini, Juan Garcia-Bellido, Zoltan Haiman, Karan Jani, Oliver Jennrich, Peter H. Johansson, Fazeel Mahmood Khan, Valeriya Korol, Astrid Lamberts, Alessandro Lupi, Alberto Mangiagli, Lucio Mayer, Germano Nardini, Fabio Pacucci, Antoine Petiteau, Alvise Raccanelli, Surjeet Rajendran, John Regan, Lijing Shao, Alessandro Spallicci, Nicola Tamanini, Marta Volonteri, Niels Warburton, Kaze Wong, Miguel Zumalacarregui
Summary: A proposal for a space-based interferometer to survey the gravitational wave sky in the milli-Hz to mu-Hz frequency range, filling the largest gap in the astrophysically relevant GW spectrum and addressing many outstanding questions related to astrophysics and cosmology. This new instrument is envisioned to be a comprehensive observatory, significantly expanding the potential of LISA and serving as a cornerstone for multimessenger astronomy.
EXPERIMENTAL ASTRONOMY
(2021)
Article
Astronomy & Astrophysics
Alessia Franchmi, Alessandro Lupi, Alberto Sesana
Summary: Studying the interaction between a massive black hole binary and its gaseous environment is crucial for predicting merger rates and electromagnetic counterparts of gravitational-wave signals. However, the understanding of the evolution of the binary semimajor axis resulting from this interaction is still debated due to numerical limitations. In this study, using a new computational approach, the researchers were able to properly resolve the dynamics inside the cavity and determine the influence of different disk temperatures on the binary orbit.
ASTROPHYSICAL JOURNAL LETTERS
(2022)
Article
Astronomy & Astrophysics
Laura Sberna, Stanislav Babak, Sylvain Marsat, Andrea Caputo, Giulia Cusin, Alexandre Toubiana, Enrico Barausse, Chiara Caprini, Tito Dal Canton, Alberto Sesana, Nicola Tamanini
Summary: This study shows that black hole binaries like GW190521 may form in the disks of active galactic nuclei (AGNs) and have connections with transient electromagnetic counterparts. The Laser Interferometer Space Antenna (LISA) is capable of detecting these binaries and measuring the parameters of the AGNs through Doppler modulation and Shapiro effects.
Article
Astronomy & Astrophysics
Alberto Mangiagli, Antoine Klein, Matteo Bonetti, Michael L. Katz, Alberto Sesana, Marta Volonteri, Monica Colpi, Sylvain Marsat, Stanislav Babak
Article
Astronomy & Astrophysics
Roberto Serafinelli, Paola Severgnini, Valentina Braito, Roberto Della Ceca, Cristian Vignali, Filippo Ambrosino, Claudia Cicone, Alessandra Zaino, Massimo Dotti, Alberto Sesana, Vittoria E. Gianolli, Lucia Ballo, Valentina La Parola, Gabriele A. Matzeu
ASTROPHYSICAL JOURNAL
(2020)
Article
Astronomy & Astrophysics
Khai Nguyen, Tamara Bogdanovic, Jessie C. Runnoe, Stephen R. Taylor, Alberto Sesana, Michael Eracleous, Steinn Sigurdsson
ASTROPHYSICAL JOURNAL LETTERS
(2020)
Proceedings Paper
Astronomy & Astrophysics
Hannah Middleton, Siyuan Chen, Walter Del Pozzo, Alberto Sesana, Alberto Vecchio
16TH INTERNATIONAL CONFERENCE ON TOPICS IN ASTROPARTICLE AND UNDERGROUND PHYSICS (TAUP 2019)
(2020)
Article
Astronomy & Astrophysics
Tito Dal Canton, Alberto Mangiagli, Scott C. Noble, Jeremy Schnittman, Andrew Ptak, Antoine Klein, Alberto Sesana, Jordan Camp
ASTROPHYSICAL JOURNAL
(2019)
Article
Astronomy & Astrophysics
Alexander Rasskazov, Giacomo Fragione, Nathan W. C. Leigh, Hiromichi Tagawa, Alberto Sesana, Adrian Price-Whelan, Elena Maria Rossi
ASTROPHYSICAL JOURNAL
(2019)
Article
Astronomy & Astrophysics
Alberto Mangiagli, Antoine Klein, Alberto Sesana, Enrico Barausse, Monica Colpi
