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Astronomy & Astrophysics
I. M. McHardy, M. Beard, E. Breedt, J. H. Knapen, F. M. Vincentelli, M. Veresvarska, V. S. Dhillon, T. R. Marsh, S. P. Littlefair, K. Horne, R. Glew, M. R. Goad, E. Kammoun, D. Emmanoulopoulos
Summary: This study presents fast and precise multi-band photometry of the low-mass AGN NGC4395 using the Liverpool Telescope and HiPERCAM. The results show the fastest ever AGN multiband photometry and very accurate lag measurements. The study provides evidence for a truncated AGN disc and suggests caution in reverberation lag modeling.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Jing Chen, Zhongmu Li, Su Zhang, Yangyang Deng, Wenchang Zhao
Summary: This paper investigates the extended main-sequence turnoffs (eMSTOs) and stellar populations of three clusters with different ages using Gaia Data Release 2 (DR2) data in detail. The colour-magnitude diagrams (CMDs) of three Galactic clusters show broad main sequences, eMSTOs, blue stragglers, and red giant clumps. The effects of age spread, binaries, and rotating stars on the morphology of the entire CMD are explored, with particular emphasis on the effects of binary stars and rotating stars on eMSTOs.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
K. Fahrion, M. Lyubenova, G. van de Ven, M. Hilker, R. Leaman, J. Falcon-Barroso, A. Bittner, L. Coccato, E. M. Corsini, D. A. Gadotti, E. Iodice, R. M. McDermid, I. Martin-Navarro, F. Pinna, A. Poci, M. Sarzi, P. T. de Zeeuw, L. Zhu
Summary: Nuclear star clusters (NSCs) are the densest stellar systems in the Universe and are thought to form via mergers of star clusters or in situ star formation at galaxy centers. Research shows that NSCs in low-mass galaxies are more metal-poor than their hosts, while NSCs in massive galaxies exhibit diverse star formation histories. There is a clear transition in the dominant formation channel of NSCs with both galaxy and NSC mass.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Rose A. Finn, Benedetta Vulcani, Gregory Rudnick, Michael L. Balogh, Vandana Desai, Pascale Jablonka, Dennis Zaritsky
Summary: We investigate the role of dense environments in suppressing star formation by studying galaxies with log(10)(M- * / M-?) > 9.7 in nine clusters from the Local Cluster Survey. We find that SFR suppression increases with increasing bulge-to-total ratio in all environments. In addition, cluster and infall galaxies have more suppressed SFRs compared to field counterparts at all values of B/T, suggesting an additional mechanism in dense environments.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
F. Sakhibov, A. S. Gusev, C. Hemmerich
Summary: Star formation induced by a spiral shock wave, generated by a spiral density wave, results in an azimuthal age gradient across the spiral arm with opposite signs on either side of the corotational resonance. By analyzing the spatial separation between young star clusters and nearby H II regions, researchers were able to determine the position of the corotation radius in the galaxies studied. Fourier analysis of the gas velocity field independently confirmed the corotation radius estimates provided by the morphological method presented.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Jun Yang, Xiaolong Yang, Joan M. Wrobel, Zsolt Paragi, Leonid Gurvits, Luis C. Ho, Kristina Nyland, Lulu Fan, Daniel Tafoya
Summary: NGC 4395 is a dwarf galaxy hosting an intermediate-mass black hole. Observations suggest the presence of a diffuse feature, possibly formed by episodic ejection or outflow from the black hole. Additionally, a diffuse feature on a larger scale, potentially related to a thermal emission region, was detected near the black hole, while no jet base was found.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
M. Sanchez-Garcia, S. Garcia-Burillo, M. Pereira-Santaella, L. Colina, A. Usero, M. Querejeta, A. Alonso-Herrero, A. Fuente
Summary: This study analyzes the influence of the dynamical environment on the star formation relations of dense molecular gas in the starburst ring of the Seyfert 2 galaxy NGC 1068. The results suggest that galactic dynamics plays a major role in the efficiency of gas-to-star conversion. This research provides important insights into the regulation mechanisms of star formation.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Jordan A. Turner, Daniel A. Dale, Janice C. Lee, Mederic Boquien, Rupali Chandar, Sinan Deger, Kirsten L. Larson, Angus Mok, David A. Thilker, Leonardo Ubeda, Bradley C. Whitmore, Francesco Belfiore, Frank Bigiel, Guillermo A. Blanc, Eric Emsellem, Kathryn Grasha, Brent Groves, Ralf S. Klessen, Kathryn Kreckel, J. M. Diederik Kruijssen, Adam K. Leroy, Erik Rosolowsky, Patricia Sanchez-Blazquez, Eva Schinnerer, Andreas Schruba, Schuyler D. Van Dyk, Thomas G. Williams
Summary: The sensitivity and angular resolution of photometric surveys conducted by the Hubble Space Telescope allow for the study of individual star clusters in galaxies up to a few tens of megaparsecs away. By fitting the spectral energy distributions of star clusters using the cigale package, researchers can derive ages, stellar masses, and reddenings. Analysis of star clusters in NGC 3351 revealed that clusters in the inner star-forming ring are young and massive, while clusters in the stellar bulge are older.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
David A. Thilker, Bradley C. Whitmore, Janice C. Lee, Sinan Deger, Rupali Chandar, Kirsten L. Larson, Stephen Hannon, Leonardo Ubeda, Daniel A. Dale, Simon C. O. Glover, Kathryn Grasha, Ralf S. Klessen, J. M. Diederik Kruijssen, Erik Rosolowsky, Andreas Schruba, Richard L. White, Thomas G. Williams
Summary: The study introduces an innovative approach for detecting and classifying stellar clusters in the PHANGS-HST program, utilizing the Multiple Concentration Index (MCI) parameter to distinguish cluster candidates from stars and incorporating Machine Learning for improved selection accuracy. Performance comparisons with LEGUS show high agreement in cluster identification, with subtle differences attributed to specific project choices. The ML-classified catalogues in PHANGS-HST reach fainter magnitudes and lower stellar masses, suggesting improved efficiency compared to human classification.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
S. Avdan, A. Akyuz, S. Acar, I. Akkaya Oralhan, S. Allak, N. Aksaker
Summary: We investigated the connection between types of X-ray binaries (XRBs) and the properties of compact star clusters in NGC 628. Using Chandra data, we detected 75 X-ray sources, including 69 XRBs and one ultraluminous X-ray source. We identified optical counterparts for 15 XRBs and classified them as high-mass XRBs (HMXBs), while the others were classified as low-mass XRBs (LMXBs). We also identified and analyzed 864 compact star clusters in NGC 628, finding that HMXBs are associated with younger clusters and LMXBs with older clusters.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Alan H. Su, Heikki Salo, Joachim Janz, Aku Venhola, Reynier F. Peletier
Summary: This study investigates the relations between nuclear star clusters and their host galaxies and compares the structural properties of nucleated and non-nucleated galaxies. The results show that the properties of nuclear star clusters differ based on the host galaxy's stellar mass, and the environment plays a significant role in the nucleation of galaxies.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Natalia Lahen, Thorsten Naab, Guinevere Kauffmann
Summary: In this study, a photometric analysis of star and star cluster formation in a dwarf galaxy starburst is presented using a high-resolution simulation. The results show that different observational methods have varying levels of accuracy in tracing star formation during different phases, and aperture photometry analysis can lead to deviations in mass function and cluster formation efficiency.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Sunil Laudari, Pavel Jachym, Ming Sun, Will Waldron, Marios Chatzikos, Jeffrey Kenney, Rongxin Luo, Paul Nulsen, Craig Sarazin, Francoise Combes, Tim Edge, Mark Voit, Megan Donahue, Luca Cortese
Summary: This work presents observations of the RPS phenomenon in the galaxy ESO 137-002, revealing features indicative of RPS such as asymmetric dust distribution, dust filaments, and dust clouds. The observations also suggest star formation triggered by RPS and asymmetrical distribution of molecular gas. The findings contribute to our understanding of RPS galaxies and the evolution of stripped material.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
M. Mastropietro, S. De Rijcke, R. F. Peletier
Summary: This study investigates the formation and morphology of the arrow-shaped dwarf irregular galaxy NGC 1427A in the Fornax Cluster, using simulations to show similar tail structures. The analysis provides insights into the galaxy's position and velocity in the cluster without the need for interaction with nearby galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Enrichetta Iodice, Antonio La Marca, Michael Hilker, Michele Cantiello, Giuseppe D'Ago, Marco Gullieuszik, Marina Rejkuba, Magda Arnaboldi, Marilena Spavone, Chiara Spiniello, Duncan A. Forbes, Laura Greggio, Roberto Rampazzo, Steffen Mieske, Maurizio Paolillo, Pietro Schipani
Summary: The VEGAS imaging survey of the Hydra I cluster has identified a faint and diffuse ultra-diffuse galaxy (UDG 32) located within the extended network of stellar filaments near the spiral galaxy NGC 3314A. While the exact origin of UDG 32 is still uncertain, its spatial coincidence with the stellar filaments of NGC 3314A suggests a possible formation from material within the filaments. Further analysis is needed to determine the nature of the stellar filaments and the formation processes of UDG 32 in the Hydra I cluster.
ASTRONOMY & ASTROPHYSICS
(2021)