Article
Engineering, Aerospace
C. Muthumariappan, B. M. Amrutha, G. Selvakumar
Summary: We present dusty photo-ionization models for two Planetary Nebulae, NGC 2452 and IC 2003, with [WR] type central stars, using the 1D photo-ionization code Cloudy17.02. Our models are constrained by medium resolution optical spectra and archival IRAS photometry. The physical size of the ionized nebula, determined by accurate distance measurements and absolute Hb flux, serves as an additional constraint. We investigate the impact of photo-electric heating and find that it does not significantly affect the models for both PNe.
ADVANCES IN SPACE RESEARCH
(2023)
Article
Astronomy & Astrophysics
Howard E. Bond, Klaus Werner, Gregory R. Zeimann, Jonathan Talbot
Summary: This paper reports the discovery of a 14th-magnitude central star in the faint emission nebula G126.8-15.5. Spectrograms and model-atmosphere analysis were used to determine the spectral classification and physical parameters of the star. The location of the central star on the log g-T-eff plane suggests it is not in a post-asymptotic-giant-branch evolutionary status. The researchers propose that Fr 2-30 is a 'PN mimic', resulting from a chance encounter between a hot sdO star and an interstellar cloud.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Roldan A. Cala, Jose F. Gomez, Luis F. Miranda, Lucero Uscanga, Shari L. Breen, Joanne R. Dawson, Itziar De Gregorio-Monsalvo, Hiroshi Imai, Hai-Hua Qiao, Olga Suarez
Summary: This study investigates the evolution process of asymptotic giant branch stars into planetary nebulae with various shapes. By processing unpublished data from Southern Parkes Large-Area Survey in Hydroxyl (SPLASH), the authors identified and characterized eight candidate OH maser-emitting planetary nebulae (OHPNe). The evidence suggests that these candidates are evolved stars, but further optical/infrared spectroscopy is required for confirmation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
J. Garcia-Rojas, C. Morisset, D. Jones, R. Wesson, H. M. J. Boffin, H. Monteiro, R. L. M. Corradi, P. Rodriguez-Gil
Summary: In this study, we used MUSE deep integral-field unit spectroscopy to observe three planetary nebulae with high-abundance discrepancy factors (ADF > 20) and investigated the extinction, electron temperature, electron density, and ionic abundances of various ionic species. We found evidence of two distinct gas phases within each nebula, with similar oxygen content in the cold and warm regions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Chih-Hao Hsia, Yong Zhang, SeyedAbdolreza Sadjadi, Wayne Chau, Hui-Jie Han, Jian-Feng Chen
Summary: This study presents visible-infrared imaging of the young planetary nebula Hubble 12, revealing its complex structures and mixed chemistry. The observations suggest the presence of multiple mass-ejection events during the pre-PN phase, and a three-dimensional model shows similarities with other nested hourglass nebulae. The infrared spectra and spectral energy distribution analysis suggest the existence of a cool companion in the nucleus of this object.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
M. A. Guerrero, R. Ortiz, L. Sabin, G. Ramos-Larios, E. J. Alfaro
Summary: Sab 19 is a planetary nebula consisting of an inner double-shell nebula with a small radius and an outer shell with a larger radius. Analysis of its sub-solar N/O ratio abundances, low ionized mass, peculiar radial velocity, and low-mass central star classifies it as a Type III planetary nebula, indicating that the main nebula evolved from crossing the Perseus Arm.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Ivan Rapoport, Ealeal Bear, Noam Soker
Summary: In certain exoplanetary systems, planets will accelerate the rotation of their parent stars' envelopes, potentially leading to non-spherical mass-loss processes.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Barbara L. Miranda Marques, Hektor Monteiro, Isabel Aleman, Stavros Akras, Helge Todt, Romano L. M. Corradi
Summary: This study presents the first detailed integral field spectroscopic study of the planetary nebula Hen 2-108 and its central star (CS). Spatially resolved flux maps, diagnostic maps of extinction and electronic density and temperature, and physical conditions and chemical abundances were obtained. The analysis showed consistent results with some variations in physical and chemical properties using the satellite code. Abundance discrepancy factors for O/H and possibly for N/H were found, and a pseudo-3D photoionization model supported the low-ionization nature of the nebula with a CS temperature of T-eff = 40 kK and a shell structure.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
B. Montoro-Molina, M. A. Guerrero, E. Santamaria, J. A. Toala, Y-h Chu, G. Ramos-Larios, R. Infante-Sainz, M. Akhlaghi, S. Eskandarlou, C. Lopez-Sanjuan
Summary: We conducted a detailed study on NGC 2022, a planetary nebula, including its physical properties, mass loss history, and chemical abundances. Our observations confirmed the existence of a faint halo surrounding a double-layered elliptical structure. The expansion velocities along the major and minor axes of the inner shell were determined to be 43 +/- 3 and 34 +/- 3 km s(-1) respectively. The chemical abundances of each shell were found to be typical of Type II in the Peimbert classification of PNe.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
J. A. Toala, V Lora, B. Montoro-Molina, M. A. Guerrero, A. Esquivel
Summary: This study presents 3D radiation-hydrodynamic simulations on the formation and evolution of born-again planetary nebulae, focusing on the case of HuBi 1. The simulations suggest that the inner shell of HuBi 1 may have been formed by an explosive very late thermal pulse, affecting the velocity and pressure structure of the outer nebula and creating turbulent ionized structures. The results also show that the kinetic energy of the H-poor ejecta of HuBi 1 is significantly higher compared to other born-again PNe, indicating a truly unique VLTP event.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
I Gallardo Cava, V Bujarrabal, J. Alcolea, M. Gomez-Garrido, M. Santander-Garcia
Summary: We studied the molecular content of nebulae around binary post-AGB stars with Keplerian dynamics and found that the molecular content in these nebulae is relatively low with weaker molecular lines and abundances compared to AGB stars.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
A. Danehkar, M. Parthasarathy
Summary: This study investigates the physical conditions and chemical abundances of the planetary nebula IC 4997. By analyzing spectral data, the electron densities, electron temperatures, and elemental abundances of this object are determined, revealing large abundance discrepancy factors. Further research is needed to understand the formation mechanisms of these discrepancy factors and variable emissions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Giulia C. Cinquegrana, Amanda Karakas
Summary: As metallicity increases, the mixing efficiency on the TP-AGB decreases significantly, leading to much of the nucleosynthesis being locked inside white dwarf remnants for very metal-rich stars. Additionally, temperatures at the base of the convective envelope decrease with increasing metallicity, resulting in only partial hydrogen burning for intermediate-mass models. Minor production of heavy elements via the s-process peak at strontium is found in the study, which decreases sharply with increasing metallicity. The dominance of proton capture nucleosynthesis in the models is reflected in the yields, weighted towards the lower mass regime to match the mass distribution within a galaxy.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Christophe Morisset, Romano L. M. Corradi, Jorge Garcia-Rojas, Antonio Mampaso, David Jones, Karen B. B. Kwitter, Laura Magrini, Eva Villaver
Summary: This study investigates the discrepancies between the proper plasma analysis method (PPAP) and the use of standard values to calculate physical conditions. The results show that while the PPAP method accurately measures plasma properties, there is some error in measuring interstellar extinction. Therefore, the authors emphasize the need to critically assess the choice of reference lines when using the PPAP method and ensure that results are obtained for non-de-reddened line ratios.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
David Jones, James Munday, Romano L. M. Corradi, Pablo Rodriguez-Gil, Henri M. J. Boffin, Jiri Zak, Paulina Sowicka, Steven G. Parsons, Vik S. Dhillon, S. P. Littlefair, T. R. Marsh, Nicole Reindl, Jorge Garcia-Rojas
Summary: We conducted a detailed study on the post-common envelope binary central star of the planetary nebula Ou 5, obtaining information about the companion star's spectral type, parameters of both stars, and orbital characteristics. The modelling results suggest that the companion star is of low mass with a larger radius, and the characteristics of the nebular progenitor are consistent with a post-red giant branch evolution. However, accurately determining the component masses remains challenging.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)