Article
Astronomy & Astrophysics
P. Jimenez-Hernandez, S. J. Arthur, J. A. Toala, A. P. Marston
Summary: The characterization of dust in the Wolf-Rayet nebula RCW58 around the WN8h star WR 40 was conducted using archival infrared and radio observations. It was found that there are two populations of dust grains with different sizes, and the nebula has a very high dust-to-gas ratio. Based on the model, RCW58 may have formed through a common envelope channel.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
P. F. Rohde, S. Walch, S. D. Clarke, D. Seifried, A. P. Whitworth, A. Klepitko
Summary: The study utilizes smoothed particle hydrodynamic simulations to investigate the impact of episodic outflow feedback on stellar multiplicity and star formation efficiency. The simulations with outflow feedback better replicate the characteristics of young stellar populations, including binary statistics. The entrainment factors of outflows can vary depending on the total mass of stars formed and the frequency of outflow episodes.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
L. R. Baalmann, K. Scherer, J. Kleimann, H. Fichtner, D. J. Bomans, K. Weis
Summary: This study used two-dimensional and three-dimensional magnetohydrodynamics simulations to model the interaction between stellar winds and the surrounding interstellar medium. The results showed that when the inflow speed of the interstellar medium is higher than the fast magnetosonic speed, the results of the two-dimensional and three-dimensional models are consistent. However, the two-dimensional models cannot accurately simulate the stellar wind magnetic field and show asymmetry when the magnetic field is not dominant. Therefore, a three-dimensional approach is necessary. Additionally, simulations of astrospheres with slower interstellar medium inflows can exceed the lifetime of the corresponding star.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Brian L. Flores, D. John Hillier, Luc Dessart
Summary: The spectra of Wolf-Rayet (WR) stars, caused by their radiatively driven winds, exhibit strong, broad emission lines originating from clumps formed by hydrodynamic instabilities. The volume-filling factor (VFF) approach, commonly used to model these spectra, assumes that the entire wind mass resides in optically thin clumps, which may not be valid in dense winds. To test this assumption, the 'shell' approach is applied to study line and continuum formation in the dense wind of the WN4 star, HD 50896. The results suggest that the wind of HD 50896, and possibly other WR stars, consist of small radially compressed and laterally confined clumps, indicating the need for 'broken' shells in modeling.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Elias Aydi, Shazrene Mohamed
Summary: We present 3D hydrodynamic models of the interaction between the outflows of evolved, pulsating, Asymptotic Giant Branch (AGB) stars and nearby substellar companions. Our models show that resonances between the orbital period of the companion and the pulsation period of the AGB star can lead to the formation of multiple spiral structures. The gravitational potential of the companion also enhances the mass-loss from the AGB star. These findings have implications for observing these structures with high-resolution instruments and finding substellar companions around bright, evolved stars.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
James Wurster, Matthew R. Bate, Ian A. Bonnell
Summary: Through three-dimensional simulations, this study found that the Hall effect in non-ideal magnetohydrodynamic processes has the greatest impact on star formation. Different non-ideal processes affect the collapse of rotating clouds and the formation of early disk structures, promoting or hindering the occurrence of outflows.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
J. M. Winters, D. T. Hoai, K. T. Wong, W-J Kim, P. T. Nhung, P. Tuan-Anh, P. Lesaffre, P. Darriulat, T. Le Bertre
Summary: By studying the AGB star RS Cancri, researchers have analyzed the structure and dynamics of its wind-forming environment. The observations reveal features such as rotation, equatorial density enhancement, and bipolar outflows, but the underlying mechanisms require further investigation.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Shingo Nozaki, Masahiro N. Machida
Summary: We calculated the evolution of cloud cores embedded in different envelopes to study the effects of the environment on the mass accretion rate onto protostars. The simulations showed that the mass accretion rate decreases when the outer envelope density is low, but temporarily increases when the outer envelope density is high and the protostellar mass exceeds the initial mass of the core. These findings could explain recent observations that suggest the mass of pre-stellar cores is too small to reproduce the stellar mass distribution.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
A. Soulain, A. Lamberts, F. Millour, P. Tuthill, R. M. Lau
Summary: A few binary Wolf-Rayet stars with spiral structures and high dust production rates provide a unique laboratory for studying dust nucleation in hostile environments. By simulating and observing, we obtained important parameters and properties of dust nucleation, and found that dust can escape beyond the boundaries of the spiral.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
F. A. Driessen, J. O. Sundqvist, A. Dagore
Summary: In hot, massive (OB) stars, the amount of wind driving and mass loss is dependent on the stellar metallicity. In addition, the line-driven winds are inhomogeneous and clumpy, and the degree of wind clumping is found to decrease with metallicity. However, the decrease is rather weak, suggesting that the power-law dependencies of mass-loss rate on metallicity should be only modestly altered by clumping.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Asif ud-Doula, Stanley P. Owocki, Christopher Russell, Marc Gagne, Simon Daley-Yates
Summary: We present new self-consistent 3D magnetohydrodynamics simulations to study the magnetospheres of massive stars with an oblique dipole magnetic axis. Our results show that the accumulation surfaces in the magnetospheres resemble the forms predicted by the analytical rigidly rotating magnetosphere model, but the mass buildup distorts the magnetic field and warps the accumulation surface towards the rotational equator. This study provides a tool to synthesize rotational modulation of photometric absorption and Hα emission for comparison with observations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
H. Neilson, N. Steenken, J. Simpson, R. Ignace, M. Shrestha, C. Erba, G. Henson
Summary: The semi-regular variable star V CVn is known for its unusual linear polarization position angle (PA). Despite variations in optical brightness and polarization amplitude, the constant PA has persisted over decades of observations. Our study reveals that the polarization maximum does not always coincide precisely with the brightness minimum, but instead exhibits a small lead or lag. Furthermore, the polarization position angle sometimes undergoes noticeable rotation, particularly at lower polarization levels. We find a correlation between this unusual optical behavior and high tangential space velocities, suggesting a relationship between the long-term constant PA and the shaping of circumstellar gas by the star's high-speed motion through the interstellar medium.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
C. Adam, J. Olofsson, R. G. van Holstein, A. Bayo, J. Milli, A. Boccaletti, Q. Kral, C. Ginski, Th. Henning, M. Montesinos, N. Pawellek, A. Zurlo, M. Langlois, A. Delboulbe, A. Pavlov, J. Ramos, L. Weber, F. Wildi, F. Rigal, J. -F. Sauvage
Summary: This study presents new observations of the nearly edge-on disk around the pre-main-sequence M-type star GSC 07396-00759, aiming to better understand the morphology, dust properties, and star-disk interaction. The modeling of polarimetric observations reveals an extended and highly inclined disk with dust distribution centered at a radius of about 107 au. The average mass-loss rate of GSC 07396-00759 is estimated to be up to 500 times stronger than that of the Sun, indicating efficient evacuation of small dust grains by stellar winds from low-mass stars.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
J. A. Toala, D. M. Bowman, T. Van Reeth, H. Todt, K. Dsilva, T. Shenar, G. Koenigsberger, S. Estrada-Dorado, L. M. Oskinova, W-R Hamann
Summary: In this article, we present an analysis of the optical variability of the early, nitrogen-rich Wolf-Rayet (WR) star WR 7. The analysis of TESS light curves and high-resolution spectroscopic observations confirms multiperiodic variability on time-scales of years, with a dominant period detected in the TESS sectors 33 and 34 light curves.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
D. O. Fionnagain, A. A. Vidotto, P. Petit, C. Neiner, W. Manchester, C. P. Folsom, G. Hallinan
Summary: Researchers reconstructed the surface magnetic field of lambda And using spectropolarimetric observations, and simulated two stellar wind scenarios. By comparing model results with previous radio observations, conclusions were drawn regarding the mass-loss rate of lambda And.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
S. Anathpindika, J. Freundlich
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF AUSTRALIA
(2015)
Article
Astronomy & Astrophysics
S. Anathpindika
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF AUSTRALIA
(2015)
Article
Astronomy & Astrophysics
Debanjan Sarkar, Somnath Bharadwaj, S. Anathpindika
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2016)
Review
Astronomy & Astrophysics
S. Anathpindika
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF AUSTRALIA
(2016)
Article
Astronomy & Astrophysics
S. Anathpindika, A. Burkert, R. Kuiper
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2018)
Article
Astronomy & Astrophysics
S. Anathpindika, A. Burkert, R. Kuiper
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2017)
Article
Astronomy & Astrophysics
S. Anathpindika, H. C. Bhatt
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2011)
Article
Astronomy & Astrophysics
S. Anathpindika, H. C. Bhatt
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2012)
Article
Astronomy & Astrophysics
S. Anathpindika, James Di Francesco
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2013)
Article
Astronomy & Astrophysics
S. Anathpindika
Article
Astronomy & Astrophysics
S. Anathpindika
Article
Astronomy & Astrophysics
S. Anathpindika, J. Di Francesco
Summary: Filaments play a crucial role in the star formation process and their morphology and evolution are influenced by external pressure. Increasing external pressure leads to lower efficiency in star formation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
S. Anathpindika, J. Di Francesco
Summary: This study explores the formation of prestellar cores and reveals that cores formed under different pressures exhibit distinct shapes, as well as the relationship between velocity gradient variations and filament evolution.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Sumedh Anathpindika
ASTRONOMY & GEOPHYSICS
(2015)
Article
Astronomy & Astrophysics
Miaomiao Zhang, Min Fang, Hongchi Wang, Jia Sun, Min Wang, Zhibo Jiang, Sumedh Anathipindika
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES
(2015)