Article
Astronomy & Astrophysics
Xinghan Zhang, Xiaofeng Wang, Hanna Sai, Jun Mo, A. P. Nagy, Jicheng Zhang, Yongzhi Cai, Han Lin, Jujia Zhang, Eddie Baron, James M. DerKacy, Tianmeng Zhang, Zhitong Li, Melissa Graham, Fang Huang
Summary: We present observations of the type II supernova, SN 2019va, which exhibits an unusually flat plateau-phase evolution in its V-band light curve and even shows a weak brightening towards the end of the plateau phase. These features are related to the influence of Ni-56 decay on the light curve, and the Ni-56 mass of SN 2019va is significantly larger than most SNe II. After removing the influence of Ni-56 decay, the progenitor/explosion parameters derived for SN 2019va are found to be more reasonable. SN 2019va also shows weaker metal lines in its spectra, suggesting a low-metallicity progenitor.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Xinghan Zhang, Xiaofeng Wang, Hanna Sai, Maria Niculescu-Duvaz, Alexei Filippenko, WeiKang Zheng, T. G. Brink, Han Lin, Jicheng Zhang, Yongzhi Cai, Jun Mo, Jujia Zhang, E. Baron, J. M. DerKacy, F. Huang, T-M Zhang
Summary: SN 2018hfm is an unusual Type II supernova that exploded in a nearby dwarf galaxy, exhibiting a relatively low amount of Ni-56 synthesis, low ejecta mass, and low explosion energy. Spectral features indicate significant interaction between the supernova ejecta and circumstellar matter, as well as continuous dust formation.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Anirban Dutta, Avinash Singh, G. C. Anupama, D. K. Sahu, Brajesh Kumar
Summary: The study examines the optical and ultraviolet properties of Type Ia supernova SN 2017hpa, finding that it falls within the normal range for this type of supernova. Spectroscopic analysis reveals unique features in the evolution of SIII and CII absorption lines, providing insights into the composition and velocity gradients in the supernova ejecta.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
S. Yang, J. Sollerman, N. L. Strotjohann, S. Schulze, R. Lunnan, E. Kool, C. Fremling, D. Perley, E. Ofek, T. Schweyer, E. C. Bellm, M. M. Kasliwal, F. J. Masci, M. Rigault, Y. Yang
Summary: SN 2020cxd is a low-luminosity Type IIP supernova that shows similarities with LL SNe IIP in terms of luminosity, timescale, and colors. By analyzing optical and ultraviolet data, as well as spectra, specific physical parameters and features of this supernova were determined. Comparison with observation and spectral synthesis models helped constrain the nebular spectrum and progenitor properties of SN 2020cxd.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Subhash Bose, Subo Dong, C. S. Kochanek, M. D. Stritzinger, Chris Ashall, Stefano Benetti, E. Falco, Alexei Filippenko, Andrea Pastorello, Jose L. Prieto, Auni Somero, Tuguldur Sukhbold, Junbo Zhang, Katie Auchettl, Thomas G. Brink, J. S. Brown, Ping Chen, A. Fiore, Dirk Grupe, T. W. S. Holoien, Peter Lundqvist, Seppo Mattila, Robert Mutel, David Pooley, R. S. Post, Naveen Reddy, Thomas M. Reynolds, Benjamin J. Shappee, K. Z. Stanek, Todd A. Thompson, S. jR Villanueva, Weikang Zheng
Summary: ASASSN-18am / SN 2018gk is a newly discovered member of rare, luminous, hydrogen-rich supernovae with significant differences in spectrum and luminosity compared to typical IIb supernovae, requiring a high mass of Ni-56 and high kinetic energy for powering.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
B. Ailawadhi, R. Dastidar, K. Misra, R. Roy, D. Hiramatsu, D. A. Howell, T. G. Brink, W. Zheng, L. Galbany, M. Shahbandeh, I Arcavi, C. Ashall, K. A. Bostroem, J. Burke, T. Chapman, Dimple, A. Filippenko, A. Gangopadhyay, A. Ghosh, A. M. Hoffman, G. Hosseinzadeh, C. Jennings, V. K. Jha, A. Kumar, E. Karamehmetoglu, C. McCully, E. McGinness, T. E. Mueller-Bravo, Y. S. Murakami, S. B. Pandey, C. Pellegrino, L. Piscarreta, J. Rho, M. Stritzinger, J. Sunseri, S. D. Van Dyk, L. Yadav
Summary: We observed SN 2020jfo in UV and optical/near-infrared bands and found it to be a hydrogen-rich Type II supernova with a short plateau duration. Compared to similar SNe II, SN 2020jfo has a fainter peak absolute magnitude and exhibits a prominent [Ni ii] emission line. We determined the Ni/Fe production ratio to be 0.08-0.10, which is 1.5 times the solar value. Spectral modeling and semi-analytical modeling suggest a progenitor mass of 12-15 M-circle dot and a massive H envelope in SN 2020jfo, which is unusual for SNe II with short plateaus.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Mridweeka Singh, Kuntal Misra, Devendra K. Sahu, Bhavya Ailawadhi, Anirban Dutta, D. Andrew Howell, G. C. Anupama, K. Azalee Bostroem, Jamison Burke, Raya Dastidar, Anjasha Gangopadhyay, Daichi Hiramatsu, Hyobin Im, Curtis McCully, Craig Pellegrino, Shubham Srivastav, Rishabh Singh Teja
Summary: This study presents optical photometric and spectroscopic analysis of a Type Iax supernova (SN) 2020rea, which is situated at the brighter luminosity end of Type Iax SNe. The authors model the pseudo-bolometric light curve and early spectra of SN 2020rea, and determine the mass of Ni-56 and ejecta mass. The results suggest that SN 2020rea matches the predictions of a pure deflagration model, and its host galaxy metallicity is similar to that of other SNe of the same type.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Mariana Orellana, Melina C. Bersten
Summary: This study investigates the applicability of a double-peaked distribution of radioactive material in modeling the double-peaked light curves of supernovae. They propose a model involving an inner zone corresponding to explosive nucleosynthesis and an outer Ni-56-rich shell possibly related to jet-like outflows. They present a parametric model for the Ni-56 distribution and explore its consequences on the light curves.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Eulalia Gallego-Cano, Luca Izzo, Carlos Dominguez-Tagle, Francisco Prada, Enrique Perez, Nandita Khetan, In Sung Jang
Summary: Having two sibling Type Ia supernovae in the same galaxy allows for a more precise estimation of the Hubble constant. By observing and measuring the luminosity of SN 2021J and SN 1974G in NGC 4414, researchers obtained a new estimate of the Hubble constant. Using a sample of 96 SNe Ia, they constructed a Hubble diagram and calibrated it with the two sibling supernovae. The reported value for the Hubble constant is 72.19 +/- 2.32 (stat.) +/- 3.42 (syst.) km s(-1) Mpc(-1).
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
E. Kankare, A. Efstathiou, R. Kotak, E. C. Kool, T. Kangas, D. O'Neill, S. Mattila, P. Vaisanen, R. Ramphul, M. Mogotsi, S. D. Ryder, S. Parker, T. Reynolds, M. Fraser, A. Pastorello, E. Cappellaro, P. A. Mazzali, P. Ochner, L. Tomasella, M. Turatto, J. Kotilainen, H. Kuncarayakti, M. A. Perez-Torres, Z. Randriamanakoto, C. Romero-Canizales, M. Berton, R. Cartier, T-W Chen, L. Galbany, M. Gromadzki, C. Inserra, K. Maguire, S. Moran, T. E. Muller-Bravo, M. Nicholl, A. Reguitti, D. R. Young
Summary: The paper discusses the discovery and follow-up observations of two core-collapse supernovae in the luminous infrared galaxy NGC 3256, as well as additional supernovae in related systems. It suggests that different types of CCSNe may have different underlying progenitor age distributions, with H-poor progenitors generally being younger.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
M. Polletta, M. Nonino, B. Frye, A. Gargiulo, S. Bisogni, N. Garuda, D. Thompson, M. Lehnert, M. Pascale, S. P. Willner, P. Kamieneski, R. Leimbach, C. Cheng, D. Coe, S. H. Cohen, C. J. Conselice, L. Dai, J. Diego, H. Dole, S. P. Driver, J. C. J. D'Silva, A. Fontana, N. Foo, L. J. Furtak, N. A. Grogin, K. Harrington, N. P. Hathi, R. A. Jansen, P. Kelly, A. M. Koekemoer, C. Mancini, M. A. Marshall, J. D. R. Pierel, N. Pirzkal, A. Robotham, M. J. Rutkowski, R. E. Ryan Jr, J. M. Snigula, J. Summers, S. Tompkins, C. N. A. Willmer, R. A. Windhorst, H. Yan, M. S. Yun, A. Zitrin
Summary: Supernova (SN) H0pe was discovered as a new transient in James Webb Space Telescope (JWST) NIRCam images of the galaxy cluster PLCK G165.7 +67.0. The transient is a compact source associated with a background galaxy that is stretched and triply imaged by the strong gravitational lensing of the cluster. Spectra obtained two weeks after the JWST observations show the [O ii] lambda lambda 3727,3730 doublet and the Balmer and 4000A breaks at redshift z = 1:783 +/- 0:002, indicating that SN H0pe might be a type Ia SN. Further observations with JWST will confirm its association with the analyzed galaxy and determine its classification.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
A. A. Hakobyan, A. G. Karapetyan, L. Barkhudaryan, M. H. Gevorgyan, V Adibekyan
Summary: By analyzing 185 supernovae Ia in nearby spiral galaxies, it was found that supernovae in star formation deserts tend to decline faster in brightness and are related to progenitor age, while galaxies without star formation deserts have supernovae with slower decline rates in the inner bar radius and outer disc. Further studies using the star formation desert phenomenon are encouraged to better understand the delay times of supernovae Ia.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
N. Elias-Rosa, P. Chen, S. Benetti, S. Dong, J. L. Prieto, E. Cappellaro, J. A. Kollmeier, N. Morrell, A. L. Piro, M. M. Phillips
Summary: The study presented the spectrum and light curve characteristics of a Type Ia supernova SN 2016jae, identifying a narrow Hα emission line in its nebular-phase spectra, possibly originating from an expanding hydrogen-rich shell. This new observation provides insights into the evolution of such supernovae.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
S. Moran, M. Fraser, R. Kotak, A. Pastorello, S. Benetti, S. J. Brennan, C. P. Gutierrez, E. Kankare, H. Kuncarayakti, S. Mattila, T. M. Reynolds, J. P. Anderson, P. J. Brown, S. Campana, K. C. Chambers, T-W Chen, M. Della Valle, M. Dennefeld, N. Elias-Rosa, L. Galbany, F. J. Galindo-Guil, M. Gromadzki, D. Hiramatsu, C. Inserra, G. Leloudas, T. E. Mueller-Bravo, M. Nicholl, A. Reguitti, M. Shahbandeh, S. J. Smartt, L. Tartaglia, D. R. Young
Summary: We present the five-year follow-up campaign of the long-lived type IIn supernova SN 2017hcc, which was found in a spiral dwarf host of near-solar metallicity. The supernova shows a slow evolution both spectroscopically and photometrically, similar to SN 2010jl. The infrared excess and blueshifts in the Balmer lines suggest the presence of an IR light echo and the condensation of new dust grains at later epochs.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
S. Yang, J. Sollerman, T-W Chen, E. C. Kool, R. Lunnan, S. Schulze, N. Strotjohann, A. Horesh, M. Kasliwal, T. Kupfer, A. A. Mahabal, F. J. Masci, P. Nugent, D. A. Perley, R. Riddle, B. Rusholme, Y. Sharma
Summary: The observations of SN 2020faa show great similarity to the behavior of iPTF14hls during the first 6 months, allowing for a forecasting of the former and reflection on the less well observed early evolution of the latter.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Green & Sustainable Science & Technology
Souvik Manik, Manoj Mandal, Sabyasachi Pal
Summary: India has been strongly affected by the Coronavirus, and research indicates that air pollutants may play a role in the spread of the virus.
ENVIRONMENT DEVELOPMENT AND SUSTAINABILITY
(2023)
Article
Astronomy & Astrophysics
Iain A. Steele, Klaas Wiersema, Callum McCall, Andrew Newsam, Manisha Shrestha
Summary: We conducted polarization observations during the totality of the lunar eclipse on May 16, 2022. The results showed polarization degrees of 2.1% ± 0.4% in B, 1.2% ± 0.3% in V, 0.5% ± 0.2% in R, and 0.2% ± 0.2% in I. These findings provide further evidence that the change in polarization is event-dependent and support the interpretation that the polarization originates from scattering in the Earth's atmosphere.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Debasish Saha, Manoj Mandal, Sabyasachi Pal
Summary: We studied the timing and spectral properties of the new Galactic X-ray transient Swift J1728.9-3613 using NICER and Swift. The source exhibited multiple transitions to different spectral states during the outburst, forming a 'q'-shaped track in the hardness-intensity diagram. A partial hysteresis was observed in the RMS-intensity diagram, indicating its classification as a black hole transient. Power-density spectra in soft intermediate states showed broad-band noise components and two type-B quasi-periodic oscillations. Based on the evolution of timing and spectral properties, Swift J1728.9-3613 is concluded to be a black hole X-ray binary.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Raffaella Morganti, Suma Murthy, Pierre Guillard, Tom Oosterloo, Santiago Garcia-Burillo
Summary: We summarized the study on the distribution of molecular gas around eight young radio galaxies with peaked-spectrum. Tracing the gas distribution and kinematics around these sources allowed us to understand the interaction between the jets and the surrounding medium. New CO(1-0) observations with arcsecond resolution were presented for three of the sources, while CN lines were detected in two of them. The results showed that there is an interaction between the radio plasma and the cold molecular gas, with the ability of newly born and young radio jets to drive massive outflows of cold gas before expanding and gently pushing aside the gas.
Article
Astronomy & Astrophysics
Arijit Manna, Sabyasachi Pal
Summary: The detection of complex organic molecule ethyl cyanide (C2H5CN) in the hot molecular core G10.47 + 0.03 using the Atacama Large Millimeter/Submillimeter Array (ALMA) provides valuable insight into the chemical complexity in the interstellar medium. The estimated column density of C2H5CN is (7.7 +/- 0.5) x 10(16) cm(-2) with a high rotational temperature of 352.9 +/- 66.8 K. The fractional abundance of C2H5CN with respect to H-2 is 5.70 x 10(-9). The similarity between the observed fractional abundance and the existing warm-up chemical modeling abundance suggests a possible formation mechanism involving a radical-radical reaction.
ASTROPHYSICS AND SPACE SCIENCE
(2023)
Article
Astronomy & Astrophysics
Arijit Manna, Sabyasachi Pal
Summary: We detected the rotational emission lines of the amide-like molecule cyanamide (NH2CN) in the hot molecular core G358.93-0.03 MM1 for the first time, using the Atacama Large Millimeter/Submillimeter Array (ALMA). The derived column density of NH2CN in G358.93-0.03 MM1 was (5.9 +/- 2.5)x10(14) cm(-2) with a rotational temperature of 100.6 +/- 30.4 K. The fractional abundance of NH2CN with respect to H-2 in G358.93-0.03 MM1 was (4.72 +/- 2.0)x10(-10), which is similar to the abundances in other sources like the sculptor galaxy NGC 253 and the low-mass protostars IRAS 16293-2422 B and NGC 1333 IRAS4A2. The NH2CN molecule in G358.93-0.03 MM1 was found to be created on grain surfaces through the neutral-neutral reaction between NH2 and CN.
ASTROPHYSICS AND SPACE SCIENCE
(2023)
Article
Astronomy & Astrophysics
Justyn R. Maund, Peter A. Hoflich, Iain A. Steele, Yi Yang, Klaas Wiersema, Shiho Kobayashi, Nuria Jordana-Mitjans, Carole Mundell, Andreja Gomboc, Cristiano Guidorzi, Robert J. Smith
Summary: The Liverpool telescope RINGO3 observed AT2018cow, the closest example of fast blue optical transients (FBOTs), and recorded the highest intrinsic polarization for a non-relativistic explosive transient. The polarization showed a chromatic spike at red wavelengths at 5.7 days post-explosion, before rapidly declining. Another polarization "bump" was observed at blue wavelengths at approximately 12 days, indicating an extremely aspherical geometry for a brief period.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Manoj Mandal, Sabyasachi Pal, Jaiverdhan Chauhan, Anne Lohfink, Priya Bharali
Summary: The millisecond pulsar MAXI J1816-195, discovered in 2022, exhibited thermonuclear bursts during its outburst. We used data from the NuSTAR and NICER observations to study the properties of the pulsar. The burst profiles showed a relatively long tail at lower energies and the broad-band time-resolved spectra were successfully modeled with an absorbed blackbody and a non-thermal component.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
A. A. Chrimes, A. J. Levan, J. J. Eldridge, M. Fraser, N. Gaspari, P. J. Groot, J. D. Lyman, G. Nelemans, E. R. Stanway, K. Wiersema
Summary: By using precise proper motion surveys, it is possible to trace the motion of stars near young remnants and search for ejected companions, providing insights into supernova progenitors. The study uses binary population synthesis to make predictions about kinematic and photometric properties of ejected secondary stars.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Kavita Kumari, G. C. Dewangan, I. E. Papadakis, Max W. J. Beard, I. M. McHardy, K. P. Singh, D. Bhattacharya, S. Bhattacharyya, S. Chandra
Summary: We studied the accretion disc-corona connection in Seyfert 1 galaxies through simultaneous UV/X-ray observations of NGC 4593 and NGC 7469 using AstroSat. X-ray and UV data were analyzed, and cross-correlation analysis was performed. The results showed different time lags between X-ray and UV variations in the two galaxies, favoring different models. Our findings provide direct observational evidence for variable intrinsic UV emission and can contribute to the understanding of the accretion process in active galactic nuclei.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
G. E. Anderson, T. D. Russell, H. M. Fausey, A. J. van der Horst, P. J. Hancock, A. Bahramian, M. E. Bell, J. C. A. Miller-Jones, G. Rowell, M. W. Sammons, R. A. M. J. Wijers, T. J. Galvin, A. J. Goodwin, R. Konno, A. Rowlinson, S. D. Ryder, F. Schuessler, S. J. Wagner, S. J. Zhu
Summary: We observed the rapid radio brightening of GRB 210702A shortly after the burst and tracked its early-time radio variability over a 5-hour period at different frequencies. The observed temporal and spectral evolution deviates from the standard internal-external shock model. The early-time radio flare is likely due to weak interstellar scintillation (ISS), and this provides valuable insights into the size and evolution of the blast wave.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Multidisciplinary Sciences
Brendan O'Connor, Eleonora Troja, Geoffrey Ryan, Paz Beniamini, Hendrik van Eerten, Jonathan Granot, Simone Dichiara, Roberto Ricci, Vladimir Lipunov, James H. Gillanders, Ramandeep Gill, Michael Moss, Shreya Anand, Igor Andreoni, Rosa L. Becerra, David A. H. Buckley, Nathaniel R. Butler, Stephen B. Cenko, Aristarkh Chasovnikov, Joseph Durbak, Carlos Francile, Erica Hammerstein, Alexander J. van der Horst, Mansi M. Ksilwal, Chryssa Kouveliotou, Alexander S. Kutyrev, William H. Lee, Gokul P. Srinivasaragavan, Vladislav Topolev, Alan M. Watson, Yuhan Yang, Kirill Zhirkov
Summary: GRB 221009A, the brightest long-duration gamma-ray burst ever observed, displays X-ray brightness that decays as a power law, indicating a shallow energy profile of the relativistic jet. This behavior challenges standard predictions and suggests a common central engine powering the most extreme explosions, as observed in other energetic GRBs.
Article
Astronomy & Astrophysics
B. O'Connor, J. Brink, D. A. H. Buckley, K. Mukai, C. Kouveliotou, E. Gogus, S. B. Potter, P. Woudt, A. Lien, A. Levan, O. Kargaltsev, M. G. Baring, E. Bellm, S. B. Cenko, P. A. Evans, J. Granot, C. Hailey, F. Harrison, D. Hartmann, A. J. van der Horst, D. Huppenkothen, L. Kaper, J. A. Kennea, P. O. Slane, D. Stern, E. Troja, R. A. M. J. Wijers, G. Younes
Summary: We present the results of our X-ray, ultraviolet, and optical follow-up campaigns of 1RXS J165424.6-433758, which is identified as a nearby polar magnetic cataclysmic variable (CV) based on its X-ray spectrum, emission features in the optical spectroscopy, and the orbital period.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
B. O'Connor, E. Gogus, J. Hare, K. Mukai, D. Huppenkothen, J. Brink, D. A. H. Buckley, A. Levan, M. G. Baring, R. Stewart, C. Kouveliotou, P. Woudt, E. Bellm, S. B. Cenko, P. A. Evans, J. Granot, C. Hailey, F. Harrison, D. Hartmann, A. J. van der Horst, L. Kaper, J. A. Kennea, S. B. Potter, P. O. Slane, D. Stern, R. A. M. J. Wijers, G. Younes
Summary: In this paper, we present the results of a multiwavelength campaign aimed at classifying Swift J170800-402551.8. By utilizing various observatories and archival data, we identified the periodicity and X-ray spectrum of the source, as well as studied its multiwavelength counterpart. Based on our findings, we classify Swift J170800-402551.8 as a candidate intermediate polar cataclysmic variable with a spin period of 784 seconds.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Payel Nandi, C. S. Stalin, D. J. Saikia, Rogemar A. Riffel, Arijit Manna, Sabyasachi Pal, O. L. Dors, Dominika Wylezalek, Vaidehi S. Paliya, Payaswini Saikia, Pratik Dabhade, Markus-Kissler Patig, Ram Sagar
Summary: Studies have shown that black-hole-driven outflows in galaxies hosting active galactic nuclei (AGN) can interact with their interstellar medium (ISM), affecting star formation (SF). In this study, the authors observed a radio jet-ISM interaction in NGC 4395 on a scale of about 10 pc, providing evidence that conditions for SF are less favorable in the central region.
ASTROPHYSICAL JOURNAL
(2023)
