Article
Astronomy & Astrophysics
R. Rampazzo, P. Mazzei, A. Marino, L. Bianchi, J. Postma, R. Ragusa, M. Spavone, E. Iodice, S. Ciroi, E. Held
Summary: This study investigates star formation in the actively evolving Dorado group. Using far-UV (FUV) imaging, it is found that young stellar populations exist in early-type galaxies. The results indicate that star formation primarily occurs at the periphery of the galaxy group, with early-type galaxies having a significantly higher star formation rate compared to late-type galaxies.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Yu-Zhong Wu, Wei Zhang
Summary: This study analyzes 4615 star-forming early-type galaxies (ETGs) using data from the Galaxy Zoo and Max Planck Institute for Astrophysics-Johns Hopkins University (MPA-JHU) emission-line measurements. It reveals a significant trend of lower/higher stellar mass ETGs having lower/higher star formation rates (SFRs), and establishes a best-fit model for the SFR and stellar mass relationship. The study also highlights the correlation of stellar mass-metallicity (MZ) relation in star-forming ETGs, as well as potential sources for higher metallicity measurements.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
E. Perez-Hernandez, S. N. Kemp, V. H. Ramirez-Siordia, A. Nigoche-Netro
Summary: This study presents a comprehensive investigation of deep optical long-slit spectroscopy and deep broad-band photometry of NGC 6086. The results reveal the presence of two separate structures in NGC 6086 and the existence of an envelope. Additionally, the study finds radial discontinuity in the distribution of galaxies in the cluster A2162, indicating the need for further investigation of the cluster's kinematics.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Xue Ge, Qiu-Sheng Gu, Ruben Garcia-Benito, Shi-Ying Lu, Cheng-Long Lei, Nan Ding
Summary: This study presents observations of four dwarf lenticular galaxies with multiple star formation regions, showing that these galaxies exhibit significant rotation and follow the Kennicutt-Schmidt law in their star formation processes. The gas-phase metallicities in star-forming regions of these galaxies are lower, indicating that extended star formation may be related to abundant atomic hydrogen, a long dynamic time-scale, and a low-density environment.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Hyunjin Jeong, Kyuseok Oh, Seok-Joo Joo, Sukyoung K. Yi
Summary: Based on GALEX UV data and SUSS data, a study characterized the stellar population properties of luminous early-type galaxies, finding that 7.7% of the sample galaxies exhibit recent star formation and tend to be more metal-poor, possibly due to external processes such as mergers or interactions driving the observed star formation activity.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Evelyn J. Johnston, Boris Haussler, Keerthana Jegatheesan, Amelia Fraser-McKelvie, Lodovico Coccato, Arianna Cortesi, Yara Jaffe, Gaspar Galaz, Marcelo Mora, Yasna Ordenes-Briceno
Summary: This study used BUDDI to extract the spectra of the bulges and discs of 78 S0 galaxies and compared their stellar populations. The results show that bulges are generally older and more metal rich than discs. The stellar mass of a galaxy plays a more significant role in the formation of bulges. More massive S0 galaxies form through an inside-out scenario, while lower mass ones may form through an outside-in scenario or together with the discs.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Suraj Dhiwar, Kanak Saha, Avishai Dekel, Abhishek Paswan, Divya Pandey, Arianna Cortesi, Mahadev Pandge
Summary: We studied the evolution of L-* elliptical galaxies in terms of their star formation history and environment in the colour-magnitude diagram to understand their quenching process. We selected 1109 L-* galaxies from a sample of 36,500 galaxies based on visual extraction and spectroscopic selection. Among them, 51 elliptical galaxies were selected based on their surface-brightness profile. Most of the red-sequence and green-valley L-* elliptical galaxies have either recently been quenched or are still forming stars, while the blue-cloud L-* elliptical galaxies are showing vigorous star formation. The galaxy colour is correlated with the cosmic-web environment.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
C. De Sa-Freitas, T. S. Goncalves, R. R. de Carvalho, K. Menendez-Delmestre, P. H. Barchi, V. M. Sampaio, Antara Basu-Zych, Behnam Darvish, Christopher Martin
Summary: In this study, the effectiveness of changes in star formation rates and their relation to galaxy morphology were measured using a new parameter called Star Formation Acceleration (SFA). The results show that elliptical galaxies have shorter quenching time-scales compared to spiral galaxies, and the majority of bursting galaxies in the green valley are massive spirals.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Simon Deeley, Michael J. Drinkwater, Sarah M. Sweet, Kenji Bekki, Warrick J. Couch, Duncan A. Forbes
Summary: By combining observational and simulation data, it has been found that compact elliptical galaxies have two main formation pathways: stripping from a larger host galaxy and gradual buildup of stellar mass in isolated environments. The proportions are 32% and 68% respectively. The observed differences between isolated and host-associated compact elliptical galaxies can be fully explained by the dominance of different formation pathways in each environment.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Simon Deeley, Michael J. Drinkwater, Sarah M. Sweet, Kenji Bekki, Warrick J. Couch, Duncan A. Forbes, Arianna Dolfi
Summary: The formation of S0 galaxies is complex, with two main pathways identified: gas stripping via group infalls and significant merger events. S0 galaxies formed through mergers feature a transient star-forming ring that matches observations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Jindra Gensior, J. M. Diederik Kruijssen
Summary: In certain conditions, galactic dynamics can suppress star formation and play a significant role in galaxy evolution. The study suggests that dynamical suppression is more effective at low gas fractions and may have an impact in the low redshift and high galaxy mass range.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
P. Saracco, F. La Barbera, R. De Propris, D. Bevacqua, D. Marchesini, G. De Lucia, F. Fontanot, M. Hirschmann, M. Nonino, A. Pasquali, C. Spiniello, C. Tortora
Summary: We analyzed the stellar ages and metallicities of 70 passive early-type galaxies from the VANDELS survey at redshift 1.0 < z < 1.4 and stellar mass range 10 < log(M-*/M-?) < 11.6. We found systematic variations in the estimates depending on models and wavelength ranges used. Using the full-spectrum fitting technique, we observed that both metallicity and age increase with mass, consistent with local early-type galaxies. The star formation histories revealed that the fraction of stellar mass formed at early epochs increases with galaxy mass.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Francesco D'Eugenio, Matthew Colless, Nicholas Scott, Arjen van der Wel, Roger L. Davies, Jesse van de Sande, Sarah M. Sweet, Sree Oh, Brent Groves, Rob Sharp, Matt S. Owers, Joss Bland-Hawthorn, Scott M. Croom, Sarah Brough, Julia J. Bryant, Michael Goodwin, Jon S. Lawrence, Nuria P. F. Lorente, Samuel N. Richards
Summary: The study focuses on the Fundamental Plane (FP) of early-type galaxies using data from the SAMI survey. It finds that the FP residuals are most strongly correlated with luminosity-weighted simple stellar population (SSP) age, rather than with structural observables. The scatter in the FP is partly attributed to the broad age and Upsilon(*) distribution at any given surface mass density.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Ivan Yu Katkov, Alexei Yu Kniazev, Olga K. Sil'chenko, Damir Gasymov
Summary: The study reveals the presence of ring structures in interstellar matter in S0 galaxies, which differ from star formation in spiral galaxies. Observations of NGC 254 show that the interstellar gas counter-rotates with respect to the stars, indicating an external origin. The gas is believed to have originated from a gas-rich galaxy merger with a retrograde orbit. The counter-rotating gas fuels star formation in two rings within the galaxy. Approximately 1% of the stars in situ are formed from the counter-rotating gas.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
L. Posti, S. M. Fall
Summary: By analyzing the near-infrared luminosities and globular cluster systems of early-type galaxies, a declining trend in the stellar-to-halo mass relation with mass, peaking at a specific point, has been observed. This result aligns with the standard relation derived for the general population of galaxies, but differs significantly from the relation for late-type galaxies. The differences between early-type and late-type galaxies can be attributed to the distinct formation processes of galactic discs and spheroids.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Sophia Lilleengen, Michael S. Petersen, Denis Erkal, Jorge Penarrubia, Sergey E. Koposov, Ting S. Li, Lara R. Cullinane, Alexander P. Ji, Kyler Kuehn, Geraint F. Lewis, Dougal Mackey, Andrew B. Pace, Nora Shipp, Daniel B. Zucker, Joss Bland-Hawthorn, Tariq Hilmi
Summary: Recent research shows that the Large Magellanic Cloud (LMC) significantly impacts the Milky Way's stellar halo and stellar streams. This study examines how deformations of the Milky Way and LMC's dark matter haloes affect stellar streams and investigates if these effects can be observed. The Orphan-Chenab (OC) stream, which passes close to the LMC and spans a large portion of the Milky Way's halo, is the main focus. Using a basis function expansion, the Milky Way-LMC system is represented to capture their evolution in an N-body simulation. The study finds that the simulated OC stream is strongly influenced by the deformations of both the Milky Way and LMC, and these effects are larger than current observational errors. The Milky Way dipole has the greatest impact on the stream, followed by the evolution of the LMC's monopole and quadrupole. Detecting these effects would confirm a key prediction of collisionless, cold dark matter and serve as a powerful test for alternative dark matter and alternative gravity models.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
C. Ramos Almeida, D. Esparza-Arredondo, O. Gonzalez-Martin, I Garcia-Bernete, M. Pereira-Santaella, A. Alonso-Herrero, J. A. Acosta-Pulido, P. S. Bessiere, N. A. Levenson, C. N. Tadhunter, D. Rigopoulou, M. Martinez-Paredes, S. Cazzoli, B. Garcia-Lorenzo
Summary: Mrk 477 is a type-2 quasar located at a distance of 163 Mpc, making it an excellent study subject for investigating the relationship between nuclear activity and star formation. New mid-infrared data obtained from the Gran Telescopio Canarias reveal the absence of specific features that are commonly used as tracers of recent star formation in the central region of the galaxy. Despite the large X-ray column density and modest X-ray luminosity, it is suggested that even the most resilient molecules are likely being destroyed near the active nucleus, emphasizing the need for caution when using these features as star formation tracers.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
D. Fernandez-Arenas, E. Carrasco, R. Terlevich, E. Terlevich, R. Amorin, F. Bresolin, R. Chavez, A. L. Gonzalez-Moran, D. Rosa-Gonzalez, Y. D. Mayya, O. Vega, J. Zaragoza-Cardiel, J. Mendez-Abreu, R. Izazaga-Perez, A. Gil de Paz, J. Gallego, J. Iglesias-Paramo, M. L. Garcia-Vargas, P. Gomez-Alvarez, A. Castillo-Morales, N. Cardiel, S. Pascual, A. Perez-Calpena
Summary: We conducted a spatially resolved spectroscopic study on the metal poor H ii galaxy J084220+115000 using MEGARA Integral Field Unit observations at the Gran Telescopio Canarias. Gas metallicity was estimated using the direct method for oxygen, nitrogen, and helium, revealing a mean value of 12 + log (O/H) = 8.03 +/- 0.06, and integrated electron density and temperature of approximately 161 cm(-3) and 15400 K, respectively. The metallicity distribution showed a large range, with values ranging from 7.69 +/- 0.06 to 8.42 +/- 0.05, indicating unusual characteristics for a dwarf star-forming galaxy. The data supported a possible scenario of an ongoing interaction triggering multiple star-forming regions within two dominant clumps.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
B. Groves, K. Kreckel, F. Santoro, F. Belfiore, E. Zavodnik, E. Congiu, O. Egorov, E. Emsellem, K. Grasha, A. Leroy, F. Scheuermann, E. Schinnerer, E. J. Watkins, A. T. Barnes, F. Bigiel, D. A. Dale, S. C. O. Glover, I Pessa, P. Sanchez-Blazquez, T. G. Williams
Summary: Ionized nebulae provide critical insights into the conditions of the interstellar medium (ISM). The PHANGS-MUSE survey has produced optical spectroscopic coverage of the central star-forming discs of nearby galaxies, identifying thousands of nebulae per galaxy. Using diagnostic line ratios, the physical properties and environmental characteristics of each nebula are determined, providing a rich database for ISM studies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Bradley C. Whitmore, Rupali Chandar, Janice C. Lee, Matthew Floyd, Sinan Deger, James Lilly, Rebecca Minsley, David A. Thilker, Mederic Boquien, Daniel A. Dale, Kiana Henny, Fabian Scheuermann, Ashley T. Barnes, Frank Bigiel, Eric Emsellem, Simon Glover, Kathryn Grasha, Brent Groves, Stephen Hannon, Ralf S. Klessen, Kathryn Kreckel, J. M. Diederik Kruijssen, Kirsten L. Larson, Adam Leroy, Angus Mok, Hsi-An Pan, Francesca Pinna, Patricia Sanchez-Blazquez, Eva Schinnerer, Mattia C. Sormani, Elizabeth Watkins, Thomas Williams
Summary: This study addresses the degeneracy problem in deriving the physical properties of stellar populations, particularly in age estimation. The authors propose a method to correct age-dating for old globular clusters and identify young interlopers based on H alpha flux. They also discover a population of approximately 300 Myr clusters in the central region of NGC 1365.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
J. V. Smoker, A. Mueller, A. Monreal Ibero, M. Elyajouri, C. J. Evans, F. Najarro, A. Farhang, N. L. J. Cox, J. Minniti, K. T. Smith, J. Pritchard, R. Lallement, A. Smette, H. M. J. Boffin, M. Cordiner, J. Cami
Summary: The study found correlations between near-infrared DIBs and reddening, as well as between different wavelengths of DIBs and optical DIBs. However, further research is needed to investigate the time variability of DIBs using higher quality data and longer time intervals.
ASTRONOMY & ASTROPHYSICS
(2023)
Article
Astronomy & Astrophysics
Nora Shipp, Nondh Panithanpaisal, Lina Necib, Robyn Sanderson, Denis Erkal, Ting S. Li, Isaiah B. Santistevan, Andrew Wetzel, Lara R. Cullinane, Alexander P. Ji, Sergey E. Koposov, Kyler Kuehn, Geraint F. Lewis, Andrew B. Pace, Daniel B. Zucker, Joss Bland-Hawthorn, Emily C. Cunningham, Stacy Y. Kim, Sophia Lilleengen, Jorge Moreno, Sanjib Sharma
Summary: This study presents the first detailed comparison between dwarf galaxy stellar streams in cosmological simulations and in the Milky Way. Streams around 13 Milky Way analogs in the FIRE-2 simulations are compared to streams observed by the Southern Stellar Stream Spectroscopic Survey (S5). The number and stellar mass distributions of detectable stellar streams are consistent, but there are differences in the distributions of pericenters and apocenters.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Joss Bland-Hawthorn, Thor Tepper-Garcia, Oscar Agertz, Ken Freeman
Summary: Recent observations have found a negative correlation between baryon surface density and dark matter fraction in high-redshift galactic disks. This implies that early massive galaxies are dominated by baryons over dark matter, similar to the Milky Way. Stellar bars are shown to form quickly in these disks at early times, leading to a high bar fraction as observed by the James Webb Space Telescope. The formation time of these bars depends on the disk mass fraction, with a faster formation time for higher disk fractions.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Caroline Foster, Sam Vaughan, Amelia Fraser-McKelvie, Sarah Brough, Julia J. Bryant, Scott M. Croom, Francesco D'Eugenio, Brent Groves, Iraklis S. Konstantopoulos, Angel R. Lopez-Sanchez, Sree Oh, Matt S. Owers, Sarah M. Sweet, Jesse van de Sande, Emily Wisnioski, Sukyoung K. Yi, Henry R. M. Zovaro
Summary: We examine the differences in dynamics between ionized gas and stars in galaxies. Local velocities and dispersion of gas and stars agree better in younger systems, suggesting initial coupling. The scatter in velocity and dispersion relations increases with stellar age and mass, indicating the role of subsequent mechanisms. Older galaxies have hotter global dynamical support and ionized gas is generally colder than stars. The local difference in velocity dispersion is more pronounced than the local difference in velocity, possibly due to turbulence, inflow, and feedback.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Eirini Angeloudi, Jesus Falcon-Barroso, Marc Huertas-Company, Regina Sarmiento, Annalisa Pillepich, Daniel Walo-Martin, Lukas Eisert
Summary: Quantifying the contribution of mergers to the stellar mass of galaxies is crucial for understanding galaxy formation. This study uses machine learning to investigate the accuracy of inferring the fraction of accreted stars in nearby galaxies based on observable properties and different galaxy formation models. The results show high accuracy at fixed simulation, but a lack of generalization to different models. However, using only stellar mass and kinematics maps for training can remove the bias and recover the ex situ stellar mass fraction with low scatter in both simulations. This suggests the potential for robust inference of galaxy accretion histories from existing surveys.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Benne W. Holwerda, Frank Bigiel, Albert Bosma, Helene M. Courtois, Nathan Deg, Helga Denes, Ahmed Elagali, Bi-Qing For, Baerbel Koribalski, Denis A. Leahy, Karen Lee-Waddell, Angel R. Lopez-Sanchez, Se-Heon Oh, Tristan N. Reynolds, Jonghwan Rhee, Kristine Spekkens, Jing Wang, Tobias Westmeier, O. Ivy Wong
Summary: This study finds that galaxy morphology in atomic hydrogen and ultraviolet are closely linked, and thus can be combined to quantify morphology. The researchers analyze the WALLABY Survey data and GALEX data, and find that even shallow GALEX data is sufficient to identify extended ultraviolet discs. They also use machine learning techniques to isolate galaxies undergoing ram-pressure stripping in the atomic hydrogen morphological space.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Alice Desmons, Sarah Brough, Cristina Martinez-Lombilla, Roberto De Propris, Benne Holwerda, Angel R. Lopez-Sanchez
Summary: We compare merging galaxy populations detected by visual identification of tidal features and spectroscopically detected close pairs of galaxies to investigate potential biases in our understanding of galaxy interactions. Our study uses a sample of 852 galaxies from the GAMA survey and compares visual classifications of tidal features to the GAMA spectroscopic close-pair sample. We find evidence that close pair samples are more likely to detect early stage mergers, while the tidal feature sample detects later-stage mergers.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Alessandro Loni, Paolo Serra, Marc Sarzi, Gyula I. G. Jozsa, Pablo M. Galan-de Anta, Nikki Zabel, Dane Kleiner, Filippo M. Maccagni, Daniel Molnar, Mpati Ramatsoku, Francesca Loi, Enrico M. Corsini, D. J. Pisano, Peter Kamphuis, Timothy A. Davis, W. J. G. de Blok, Ralf J. Dettmar, Jesus Falcon-Barroso, Enrichetta Iodice, Maritza A. Lara-Lopez, S. Ilani Loubser, Kana Morokuma-Matsui, Reynier Peletier, Francesca Pinna, Adriano Poci, Matthew W. L. Smith, Scott C. Trager, Glenn van de Ven
Summary: We study the evolutionary path of NGC 1436 in the Fornax Cluster and find that it is transitioning from a spiral to a lenticular morphology. The star-forming disc is confined within the inner region, while the cold gas disc has settled and has not been affected by environmental interactions in the last 1 billion years. The star-formation history shows a burst of star formation 5 billion years ago followed by quenching in the outer disc and continued star formation in the inner disc.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Paola Marziani, Swayamtrupta Panda, Alice Deconto Machado, Ascension Del Olmo
Summary: The optical and UV properties of radio-quiet and radio-loud active galactic nuclei (AGN) are different, but it is unclear whether the differences are due to sample selection or intrinsic differences in their emitting regions. Recent studies have shown that strong Feii emitters require high metal content. However, the chemical composition of jetted radio-loud sources is not well understood. This study presents a pilot analysis of the chemical composition of low-z radio-loud and radio-quiet quasars.
Article
Astronomy & Astrophysics
A. Camps-Farina, P. Sanchez-Blazquez, S. Roca-Fabrega, S. F. Sanchez
Summary: This study provides insight into the processes that regulate the chemical composition of the interstellar medium in galaxies, using information from stellar populations. The results support the idea that a steady and substantial supply of pristine gas is necessary for persistent star formation in galaxies.
ASTRONOMY & ASTROPHYSICS
(2023)