Article
Astronomy & Astrophysics
A. M. Chen, Y. D. Guo, Y. W. Yu, J. Takata
Summary: This study investigates the absorption process of pulsars in high-mass gamma-ray binaries and applies the model to well-studied systems such as PSR B1259-63/LS 2883 and LS 5039. The orientation of the equatorial disc in LS 2883 influences the absorption of radio pulsations from PSR B1259-63, while strong wind absorption in LS 5039 may be mitigated by wind interaction and orbital motion. The radio optical depth depends on observing frequencies, orbital inclination angle, and wind parameters, and deep monitoring at high radio frequencies could reveal the nature of compact objects in LS 5039 and other systems.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Maria Chernyakova, Denys Malyshev, Brian van Soelen, Shane O'Sullivan, Charlotte Sobey, Sergey Tsygankov, Samuel Mc Keague, Jacob Green, Matthew Kirwan, Andrea Santangelo, Gerd Puehlhofer, Itumeleng M. Monageng
Summary: PSR B1259-63 is a gamma-ray binary system where a radio pulsar orbits around an O9.5Ve star LS 2883 with a period of approximately 3.4 years. The interaction of the pulsar wind with the LS 2883 outflow results in unpulsed broadband emissions in various domains. One of the unique features of the system is the outburst of GeV energies near the periastron, exceeding the expected energy release under the assumption of isotropic emission. In this study, the authors present the initial findings of a recent multi-wavelength campaign and analyze publicly available GeV Fermi/LAT data, highlighting significant differences compared to previous observations during the 2021 periastron passage.
Article
Astronomy & Astrophysics
Zhi Chang, Shu Zhang, Yu-Peng Chen, Long Ji, Ling-Da Kong, Peng-Ju Wang
Summary: Researchers analyzed the peculiar gamma-ray flares of the gamma-ray binary system PSR B1259-63 and discovered a delay in the GeV flux peak time, with the delay being larger in the latest periastron passage compared to previous periastrons.
Article
Astronomy & Astrophysics
E. Gugercinoglu, M. Y. Ge, J. P. Yuan, S. Q. Zhou
Summary: This study presents timing solutions from observations of gamma-ray pulsars, identifying new glitches, analyzing their properties, and obtaining important information about the structure of neutron stars. The observed results are in qualitative agreement with the theoretical predictions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Jeremy Hare, George G. Pavlov, Gordon P. Garmire, Oleg Kargaltsev
Summary: Observations with the Chandra X-ray Observatory have found X-ray-emitting clumps ejected from the high-mass gamma-ray binary LS 2883/PSR B1259-63 during previous binary cycles, but no similar clumps were observed in the most recent cycle, potentially due to changes in the decretion disk of the Be star.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
J. G. Stringer, R. P. Breton, C. J. Clark, G. Voisin, M. R. Kennedy, D. Mata Sanchez, T. Shahbaz, V. S. Dhillon, M. van Kerkwijk, T. R. Marsh
Summary: ULTRACAM multiband optical photometry of two transitional millisecond pulsars (tMSPs), PSR J1023+0038 and PSR J1227-4853, reveals significant asymmetry in the light curves around the flux maxima, indicating an asymmetric source of heating in the system. Modelling shows that companion stars in both tMSPs have underfilled Roche lobes, contradicting the expected rapid filling of Roche lobes in these systems. Future research is suggested to further investigate the role of filling factor in the tMSP cycle.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Parul Janagal, Manoneeta Chakraborty, N. D. Ramesh Bhat, Bhaswati Bhattacharyya, Samuel J. McSweeney
Summary: In this study, we conducted a detailed investigation of subpulse drifting in PSR J1822-2256 using the upgraded Giant Meterwave Radio Telescope (uGMRT). Our observations revealed four distinct subpulse drifting modes and identified new features not previously reported. We also explored the frequency dependence of the pulsar emission and discussed its implications for the emission mechanism and spark configuration.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Rukiye Rejep, N. Wang, W. M. Yan, Z. G. Wen
Summary: This paper investigates the emission properties of PSR J1727-2739, which shows both nulling and subpulse drifting. The study reveals two distinct drift modes with vertical drift band separations consistent with earlier studies. PSR J1727-2739 exhibits changes in drift periodicity and drift rate variations between components, providing a unique opportunity to investigate the physical mechanism responsible for these phenomena.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
A. S. Tanashkin, A. Karpova, A. Y. Potekhin, Y. A. Shibanov, D. A. Zyuzin
Summary: XMM-Newton observations of the middle-aged radio-quiet gamma-ray pulsar J0554+3107 allowed us to identify it in X-rays for the first time. The pulse profile shows two peaks separated by about a half of the rotation phase, with a pulsed fraction of 25+/- 6% in the 0.2-2 keV band. The profile and spectrum can be described by thermal emission from the neutron star with a hydrogen atmosphere and a dipole magnetic field of around 10(13) G.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
D. A. Zyuzin, A. Karpova, Y. A. Shibanov, A. Y. Potekhin, V. F. Suleimanov
Summary: The study confirms the pulsar nature of J1957+5033 through the detection of X-ray pulsations, the pulsar's spectrum is dominated by a thermal emission component, and new hydrogen atmosphere models are constructed to analyze the pulsar's average effective temperature. Additionally, a faint trail-like feature potentially powered by J1957+5033 in the form of a pulsar wind nebula is observed in the X-ray observations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Parul Janagal, Samuel J. McSweeney, Manoneeta Chakraborty, N. D. Ramesh Bhat
Summary: PSR J0026-1955, discovered by the Murchison Widefield Array, exhibits subpulse drifting and nulling. Our observations with the upgraded Giant Metrewave Radio Telescope reveal two distinct subpulse drifting modes and short nulls. Our findings provide insight into the intricacies of pulsar emission physics.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Erbil Gugercinoglu, Elif Koksal, Tolga Guver
Summary: The long-term rotational evolution of the old, isolated pulsar, PSR B0950+08, displays sinusoidal-like oscillations in its spin-down rate due to alternating variations in the second time derivative of the pulse frequency. This can be explained by the linear creep interaction between vortex lines and pinning sites in the pulsar, which is influenced by the large internal temperature to pinning energy ratio. The oscillatory spin-down rate can help constrain the radial extension of the closed magnetic field region in the outer core of neutron stars.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
D. A. Zyuzin, S. Zharikov, A. Karpova, A. Yu Kirichenko, Yu A. Shibanov, S. Geier, A. Y. Potekhin, V. F. Suleimanov, A. Cabrera-Lavers
Summary: This article introduces an 840,000-year-old pulsar PSR J1957+5033. Optical observations were conducted using a 10.4-metre telescope, and a potential optical counterpart was discovered. Analysis suggests that thermal emission from the surface of the neutron star has a significant contribution to the optical flux. This reveals the potential of optical data in providing new constraints on the temperature and distance of pulsars.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
S. N. Sun, W. M. Yan, N. Wang
Summary: By observing the emission variations in PSR J1047-6709, we detected giant pulses for the first time in the bright state, with 75 GPs found and their energy following a power-law distribution. The brightest GP observed was 110 times stronger than the mean pulse profile. Furthermore, the polarization properties of the average profile of GPs in the bright state were similar to those of pulses with energy less than 10 times the average pulse energy, indicating a shared emission mechanism.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Z. Y. Tu, R. Yuen, Z. G. Wen, N. Wang, W. M. Yan, J. P. Yuan, J. L. Chen, H. G. Wang
Summary: This study investigates the properties of the low emission mode in PSR B0329+54, and finds that it is characterized by a drop in intensity in the central component. The low mode is related to the two emission modes, and the integrated profile of the low mode is unique. The occurrence rate of low modes is higher in the normal emission mode, and the intensity drop in the central component is separated from the emission of the other two components.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
O. Just, M. A. Aloy, M. Obergaulinger, S. Nagataki
Summary: This study presents global models of collapsars and finds that neutron-rich, neutrino-dominated accretion flows are only established for short times or relatively low viscosities, while stable NDAFs are unable to release neutron-rich ejecta. The research suggests that collapsar models based on the alpha-viscosity are inefficient r-process sites and that magnetohydrodynamic effects may be required to generate neutron-rich outflows to improve the prospects for obtaining neutron-rich ejecta.
ASTROPHYSICAL JOURNAL LETTERS
(2022)
Article
Astronomy & Astrophysics
M. G. Dainotti, V Nielson, G. Sarracino, E. Rinaldi, S. Nagataki, S. Capozziello, O. Y. Gnedin, G. Bargiacchi
Summary: Gamma-ray bursts can be used as standardized candles to expand the distance ladder, and when combined with Type Ia supernovae, can provide comparable precision. By using different samples and analysis methods, the same accuracy as Type Ia supernovae can be achieved.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
F. Rogers, T. Aramaki, M. Boezio, S. E. Boggs, V Bonvicini, G. Bridges, D. Campana, W. W. Craig, P. von Doetinchem, E. Everson, L. Fabris, S. Feldman, H. Fuke, F. Gahbauer, C. Gerrity, C. J. Hailey, T. Hayashi, A. Kawachi, M. Kozai, A. Lenni, A. Lowell, M. Manghisoni, N. Marcelli, B. Mochizuki, S. A. Mognet, K. Munakata, R. Munini, Y. Nakagami, J. Olson, R. A. Ong, G. Osteria, K. M. Perez, S. Quinn, V Re, E. Riceputi, B. Roach, J. Ryan, N. Saffold, V Scotti, Y. Shimizu, R. Sparvoli, A. Stoessl, A. Tiberio, E. Vannuccini, T. Wada, M. Xiao, M. Yamatani, K. Yee, A. Yoshida, T. Yoshida, G. Zampa, J. Zeng, J. Zweerink
Summary: The General Antiparticle Spectrometer (GAPS) is a balloon mission aimed at measuring low-energy cosmic-ray antinuclei. It will detect around 500 cosmic antiprotons per flight and produce a precise antiproton spectrum. This measurement will be sensitive to dark matter, primordial black holes, and cosmic ray propagation.
ASTROPARTICLE PHYSICS
(2023)
Article
Astronomy & Astrophysics
Keiichi Maeda, Poonam Chandra, Takashi J. Moriya, Andrea Reguitti, Stuart Ryder, Tomoki Matsuoka, Tomonari Michiyama, Giuliano Pignata, Daichi Hiramatsu, K. Azalee Bostroem, Esha Kundu, Hanindyo Kuncarayakti, Melina C. Bersten, David Pooley, Shiu-Hang Lee, Daniel Patnaude, Osmar Rodriguez, Gaston Folatelli
Summary: SN 2018ivc is an unusual Type II supernova with characteristics between SNe IIP and SNe IIb. Observations suggest that it is an SN IIb-like explosion of an He star, similar to SN IIb 1993J. The prompt follow-up observations indicate that the light curve of SN 2018ivc is primarily caused by the interaction between the supernova ejecta and the circumstellar material.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
O. Petruk, V Beshley, S. Orlando, F. Bocchino, M. Miceli, S. Nagataki, M. Ono, S. Loru, A. Pellizzoni, E. Egron
Summary: The polarized radio emission from SN1987A provides the opportunity to reveal the pre-supernova magnetic field structure in the circumstellar medium. By using a three-dimensional numerical model, a method for reconstructing the 3D magnetic field structure inside the remnant has been developed. Different initial configurations of the magnetic field and the synchrotron emission structure in SN987A have been tested and compared to observations, and it has been found that the radial component of the pre-SN magnetic field dominates in SN1987A.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Akira Dohi, Emanuele Greco, Shigehiro Nagataki, Masaomi Ono, Marco Miceli, Salvatore Orlando, Barbara Olmi
Summary: Observations from ALMA and X-ray spectra have suggested the presence of a central compact object (CCO) in SN 1987A, but no direct evidence has been found yet. This study analyzes Chandra X-ray observations of SN 1987A and synthesizes Lynx spectra to estimate the temporal evolution of upper limits on the intrinsic luminosity of the CCO. The results provide important constraints on the physical properties of the CCO and will be confirmed by future observations.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
M. G. Dainotti, G. Bargiacchi, A. L. Lenart, S. Nagataki, S. Capozziello
Summary: Currently, the cold dark matter model along with a cosmological constant is the best representation of the universe. However, we lack information in the high-redshift region and the study of quasars up to z = 7.54 has provided important insights into the matter density parameter omega( M ). This demonstrates the reliability of quasars as standard cosmological candles.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Aleksander Lukasz Lenart, Giada Bargiacchi, Maria Giovanna Dainotti, Shigehiro Nagataki, Salvatore Capozziello
Summary: By studying high-redshift objects such as quasars, the value of the Hubble constant can be corrected, which can help resolve the current discrepancy between the cosmic microwave background radiation and the value obtained from Type Ia supernovae observations.
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2023)
Article
Astronomy & Astrophysics
G. Bargiacchi, M. G. Dainotti, S. Nagataki, S. Capozziello
Summary: The recent tension observed in the value of H-0 between CMB and SNe Ia is a significant problem in astrophysics. To address this, we use GRBs and QSOs at intermediate redshifts along with BAO and SNe Ia. We investigate the Gaussianity assumption and find that only GRBs fulfill this assumption.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Yuki Moritani, Akiko Kawachi, Atsuo T. Okazaki, Sho Chimasu, Hiromi Yoshida
Summary: We conducted near-infrared photometric monitoring observations of two TeV gamma-ray binaries with O-stars (LS 5039 and 1FGL J1018.6-5856) using IRSF/SIRIUS at SAAO to study their stellar parameters and perturbations caused by binary interactions. No significant variabilities, including orbital modulations, were observed for either target. Assuming the two systems are colliding wind binaries, we estimated the amplitude of flux variation caused by the difference in optical depth of the O-star wind and obtained the upper limit of the dust formation rate resulting from wind-wind collision in O-star gamma-ray binaries for the first time using near-infrared variability data.
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN
(2023)
Article
Astronomy & Astrophysics
Taylor Jacovich, Daniel Patnaude, Patrick Slane, Carles Badenes, Shiu-Hang Lee, Shigehiro Nagataki, Dan Milisavljevic
Summary: The dynamics and spectral characteristics of supernova ejecta provide important information about the energetics of supernovae, explosive nucleosynthesis, and progenitor evolution. However, this information is currently obtained only from CCD-resolution X-ray spectra of shock-heated material. Higher resolution observations could reveal important clues to explosion energetics through measurements of Doppler motions and turbulence in the ejecta. Additionally, unshocked ejecta in supernovae and young remnants can obscure emission from ejecta on the opposite side. To address these effects, we present line-of-sight spectral maps and explore bulk Doppler broadening and time-dependent absorption from both shocked and unshocked ejecta. We also discuss how future X-ray missions can resolve these effects in nearby and extragalactic supernovae and their remnants.
ASTROPHYSICAL JOURNAL
(2023)
Article
Optics
Hiroyuki Tajima, Yuta Sekino, Daisuke Inotani, Akira Dohi, Shigehiro Nagataki, Tomoya Hayata
Summary: We discuss the non-Hermitian superfluid phase transition in one-dimensional two-component Fermi gases near the p-wave Feshbach resonance with dipolar relaxation-induced two-body loss. We found that this system provides a unique opportunity to investigate the interplay between various nontrivial properties, including universal thermodynamics at divergent p-wave scattering lengths, topological phase transitions at zero chemical potential, and the non-Hermitian BCS-to-BEC transition. In the BCS phase, the loss-induced superfluid-normal transition occurs at the exceptional point of the effective non-Hermitian Hamiltonian. In the BEC phase, the diffusive gapless mode serves as a precursor to the instability of the superfluid state. Additionally, we demonstrate that the superfluid state is fragile against two-body loss near the topological phase transition point.
Article
Astronomy & Astrophysics
M. G. Dainotti, A. L. Lenart, A. Chraya, G. Sarracino, S. Nagataki, N. Fraija, S. Capozziello, M. Bogdan
Summary: Currently, there is a debate about cosmological models and their corresponding parameters due to the discrepancy between H-0 obtained from SNe Ia and the Planck data. Considering high redshift probes like gamma-ray bursts (GRBs) is necessary but challenging due to the large range of GRB luminosities. In this study, we use the 3D Dainotti fundamental plane relation to infer cosmological parameters, and by considering selection and evolutionary effects, we obtain a lower intrinsic scatter compared to previous results. Our analysis, using GRB correlations and complemented with SNe Ia and BAO measurements, confirms the parameters of the Lambda cold dark matter model but with the advantage of using probes detected up to z = 5.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Mayu Tominaga, Masahiro Tsujimoto, Ken Ebisawa, Teruaki Enoto, Kimitake Hayasaki
Summary: Circinus X-1 is a young neutron star binary system with complex X-ray behavior. By conducting high-cadence observations, we were able to identify spectral changes and propose a simple model to explain the observations.
ASTROPHYSICAL JOURNAL
(2023)