Article
Astronomy & Astrophysics
Yasuhiro Hashimoto, Hans Boehringer, Keiichi Umetsu
Summary: In this study, we investigate the luminosity function of dwarf galaxies in 33 clusters at redshifts ranging from 0.15 to 0.3. We find that the faint end of the cluster luminosity function has a relatively flat slope, comparable to the field luminosity function. Additionally, the faint-end slope becomes steeper at larger cluster-centric distances and for blue dwarf galaxies. The X-ray luminosity of the clusters also affects the slope, although there are significant variations among individual clusters.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Nelvy Choque-Challapa, J. Alfonso L. Aguerri, Pavel E. Mancera Pina, Reynier Peletier, Aku Venhola, Marc Verheijen
Summary: In this study, 12 galaxy clusters were analyzed to identify dwarf galaxy candidates, revealing that the distribution of dwarfs is influenced by the cluster environment and tends to increase with distance from the cluster center. These results highlight the impact of the cluster environment on the observational properties of low-mass haloes.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Yingtian Chen, Oleg Y. Gnedin
Summary: The presence of globular clusters (GCs) in some satellite galaxies and their absence in most dwarf galaxies pose a challenge for understanding their origins. We investigated the stochasticity and number of GCs in dwarf galaxies and found that more than 50% of low-mass dwarf galaxies do not host GCs, while higher-mass dwarf galaxies almost always contain some GCs. Our findings are consistent with observations and confirm a linear relationship between GC system mass and halo mass. We also highlighted the potential bias in observational samples due to detection limits and large radii.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
M. Siudek, M. Mezcua, J. Krywult
Summary: Dwarf galaxies hosting active galactic nuclei (AGNs) are studied to understand their relationship with the environment. Previous studies have focused on low-redshift (z < 0.5) dwarf galaxies. In this study, the environments of dwarf galaxies at 0.5 < z < 0.9 are investigated using the VIPERS survey. It is found that AGN and non-AGN dwarf galaxies prefer low-density environments, and the presence of AGNs does not affect the properties of the host galaxies.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Aku Venhola, Reynier F. Peletier, Heikki Salo, Eija Laurikainen, Joachim Janz, Caroline Haigh, Michael H. F. Wilkinson, Enrichetta Iodice, Michael Hilker, Steffen Mieske, Michele Cantiello, Marilena Spavone
Summary: This study explores the significance of low surface brightness dwarf galaxies in galaxy clusters using a novel object detection algorithm. By detecting previously undetected LSB galaxies, the completeness of the galaxy catalog is increased, contributing to a better understanding of LSB dwarfs' evolution and their impact on the luminosity function.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
Seyda Sen, Ersin Gogus, Reynier F. Peletier, Nelvy Choque-Challapa, Amirnezam Amiri
Summary: In this study, a deep search and analysis of X-ray sources in dwarf galaxies within twelve galaxy clusters is conducted. The researchers found 20 X-ray emitting dwarf galaxies, indicating their likelihood of being black holes. The study also estimated the mass range of these black holes using a scaling relation and observed a trend between X-ray to optical flux ratio and X-ray flux, emphasizing the importance of X-ray observations in studying dwarf galaxy properties.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
A. E. Watkins, H. Salo, S. Kaviraj, C. A. Collins, J. H. Knapen, A. Venhola, J. Roman
Summary: Dwarf galaxies are important cosmological tools, but key parameters such as the relationship between size and mass are still debated. This study re-examines the dwarf population in the Fornax Cluster and finds a population of structural outliers with lower central mass surface density and larger half-light radii, likely formed through tidal disturbances. Comparing these outliers with ultra-diffuse galaxies (UDGs), it is found that the UDG classification lacks discriminatory power.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Joachim Janz, Heikki Salo, Alan H. Su, Aku Venhola
Summary: The study analyses the color versus surface brightness for galaxies in the Virgo cluster and compares it to the Fornax cluster to examine the impact of ram pressure on galaxy transformation. The results show similarities in the color-surface brightness correlation between the two clusters, indicating a scenario of transformation through the quenching of star formation. However, there are differences in the fraction of early-type galaxies between the Virgo and Fornax clusters, suggesting unique characteristics of the Virgo cluster despite its high mass.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
Robin Herlan, Alessandra Mastrobuono-Battisti, Nadine Neumayer
Summary: Observations show that M54, the nuclear star cluster of the Sgr dSph galaxy, matches a decayed globular cluster (GC) in a dark matter (DM) halo with a density profile proportional to r(-gamma) and gamma <= 1, based on its rotational signal and flattening. Steeper density profiles result in highly rotating and more flattened nuclear star clusters (NSCs) that do not match the properties of M54.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
A. Boselli, A. Lupi, B. Epinat, P. Amram, M. Fossati, J. P. Anderson, S. Boissier, M. Boquien, G. Consolandi, P. Cote, J. C. Cuillandre, L. Ferrarese, L. Galbany, G. Gavazzi, J. A. Gomez-Lopez, S. Gwyn, G. Hensler, J. Hutchings, H. Kuncarayakti, A. Longobardi, E. W. Peng, H. Plana, J. Postma, J. Roediger, Y. Roehlly, C. Schimd, G. Trinchieri, B. Vollmer
Summary: The study of galaxy IC 3476 reveals that it is undergoing an almost edge-on ram pressure stripping event, resulting in the complete quenching of star formation activity in the leading edge of the disc. Gas compression along the stellar disc increases electron density and boosts the star formation process.
ASTRONOMY & ASTROPHYSICS
(2021)
Article
Astronomy & Astrophysics
F. Davis, S. Kaviraj, M. J. Hardcastle, G. Martin, R. A. Jackson, K. Kraljic, K. Malek, S. Peirani, D. J. B. Smith, M. Volonteri, L. Wang
Summary: In this study, optical and radio data were combined to investigate AGN in nearby dwarf galaxies. The results showed that AGN and control samples have similar environments, star formation rates, and incidence of tidal features. The properties of the AGN were explored using simulations, and it was found that AGN feedback could be plausible and important for dwarf galaxy evolution.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Teymoor Saifollahi, Ignacio Trujillo, Michael A. Beasley, Reynier F. Peletier, Johan H. Knapen
Summary: Studies have found that previous estimates of the number of globular clusters around DF44 in the Coma cluster were higher, while new research indicates a lower actual number, consistent with other dwarf galaxies of similar stellar mass, and the dark matter halo mass also matches expectations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Gandhali D. Joshi, Annalisa Pillepich, Dylan Nelson, Elad Zinger, Federico Marinacci, Volker Springel, Mark Vogelsberger, Lars Hernquist
Summary: The study presents the cumulative star formation histories of over 15,000 dwarf galaxies, revealing that the central/satellite status and stellar mass are key factors influencing the star formation histories of galaxies. Satellites tend to assemble stellar mass at later times, while centrals and more massive dwarfs do so earlier.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
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
Michael J. Greener, Michael Merrifield, Alfonso Aragon-Salamanca, Thomas Peterken, Brett Andrews, Richard R. Lane
Summary: The heavy elements in stars are influenced by previous stellar generations, providing insight into galaxy formation. High-mass spirals typically exhibit a shortage of low-metallicity stars, suggesting a common history of gas accretion with the Milky Way. In contrast, low-mass spirals do not show a G-dwarf problem, indicating a metallicity distribution consistent with a closed box model.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2021)
Article
Astronomy & Astrophysics
Melina Poulain, Francine R. Marleau, Rebecca Habas, Pierre-Alain Duc, Ruben Sanchez-Janssen, Patrick R. Durrell, Sanjaya Paudel, Oliver Mueller, Sungsoon Lim, Michal Bilek, Jeremy Fensch
Summary: The study aims to understand the HI content of 2210 identified dwarf galaxies in the Mass Assembly of early-Type GaLAxies with their fine Structures (MATLAS) deep imaging survey. The majority of the dwarfs show irregular morphologies, and 8% have an HI line detection. The study also finds a relationship between the color of the dwarfs and their HI content.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Multidisciplinary Sciences
Nicolas F. Martin, Kim A. Venn, David S. Aguado, Else Starkenburg, Jonay I. Gonzalez Hernandez, Rodrigo A. Ibata, Piercarlo Bonifacio, Elisabetta Caffau, Federico Sestito, Anke Arentsen, Carlos Allende Prieto, Raymond G. Carlberg, Sebastien Fabbro, Morgan Fouesneau, Vanessa Hill, Pascale Jablonka, Georges Kordopatis, Carmela Lardo, Khyati Malhan, Lyudmila I. Mashonkina, Alan W. McConnachie, Julio F. Navarro, Ruben Sanchez-Janssen, Guillaume F. Thomas, Zhen Yuan, Alessio Mucciarelli
Summary: Stellar ejecta gradually enrich the gas, forming fossilized structures of the early Universe. However, the least chemically enriched stellar systems have not been found in globular clusters. Recent observations of a stellar stream with extremely low metallicity suggest the existence of stellar clusters with lower metallicity in the past, contributing to the Milky Way halo.
Article
Astronomy & Astrophysics
Youkyung Ko, Eric W. Peng, Patrick Cote, Laura Ferrarese, Chengze Liu, Alessia Longobardi, Ariane Lancon, Roberto P. Munoz, Thomas H. Puzia, Karla A. Alamo-Martinez, Laura Sales, Felipe Ramos-Almendares, Mario G. Abadi, Myung Gyoon Lee, Ho Seong Hwang, Nelson Caldwell, John P. Blakeslee, Alessandro Boselli, Jean-Charles Cuillandre, Pierre-Alain Duc, Susana Eyheramendy, Puragra Guhathakurta, Stephen Gwyn, Andres Jordan, Sungsoon Lim, Ruben Sanchez-Janssen, Elisa Toloba
Summary: This study investigates the stellar populations of globular clusters (GCs) in the core area near M87 in the Virgo Cluster. The mean age, total metallicity, and alpha-element abundance of blue and red GCs show radial and azimuthal variations. Blue GCs exhibit a steep metallicity gradient, while red GCs have a shallower gradient driven by iron abundance. Simulations suggest that more massive satellites sink further into the central galaxy, leading to gradient flattening. The dense environment around M87 and the mass range of GC progenitors influence their gradients. Red GCs in the northwest of M87 are found to be slightly more metal-rich.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Andrea Negri, Claudio Dalla Vecchia, J. Alfonso L. Aguerri, Yannick Bahe
Summary: In this study, we computed the luminosity of simulated galaxies in the c-eagle project and found a defined red sequence and well-populated blue cloud in the galaxy mass-color diagram. The inner regions of galaxy clusters are dominated by red-sequence galaxies, but blue galaxies are also present. Bayesian inference was used to compute the clusters' luminosity functions, which showed different trends at the faint end depending on color and mass. The simulated luminosity functions were in agreement with observational data from SDSS and XXL surveys up to z = 0.67.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Raphael Errani, Julio F. Navarro, Rodrigo Ibata, Nicolas Martin, Zhen Yuan, David S. Aguado, Piercarlo Bonifacio, Elisabetta Caffau, Jonay Gonzalez Hernandez, Khyati Malhan, Ruben Sanchez-Janssen, Federico Sestito, Else Starkenburg, Guillaume F. Thomas, Kim A. Venn
Summary: The C-19 stellar stream is a collection of metal-poor stars in the Milky Way's halo without an obvious progenitor. The stream's width and velocity dispersion are similar to those of disrupted dwarf galaxies, suggesting a different origin than globular clusters. A proposed unconventional model suggests that the C-19 progenitor is a dark matter-dominated system with globular cluster-like abundance patterns, supported by N-body simulations.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Nicolas Longeard, Pascale Jablonka, Anke Arentsen, Guillaume F. Thomas, David S. Aguado, Raymond G. Carlberg, Romain Lucchesi, Khyati Malhan, Nicolas Martin, Alan W. McConnachie, Julio F. Navarro, Ruben Sanchez-Janssen, Federico Sestito, Else Starkenburg, Zhen Yuan
Summary: This study presents a new spectroscopic analysis of the dwarf galaxy Boo I using data from the Anglo-Australian Telescope. Through the combination of Gaia and Pristine survey data, the researchers successfully discovered 27 new Boo I stars and determined their metallicities. The findings also revealed velocity and metallicity gradients, as well as a higher ellipticity for Boo I. These results suggest that Boo I may have been affected by tidal forces.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
V Cuomo, E. M. Corsini, L. Morelli, J. A. L. Aguerri, Y. H. Lee, L. Coccato, A. Pizzella, C. Buttitta, D. Gasparri
Summary: This study presents the surface photometry and stellar kinematics of IC 3167, a dwarf galaxy with a lopsided weak bar that is infalling into the Virgo cluster. The analysis shows that the probability of the bar rotating slowly is more than twice as likely as it rotating fast, suggesting that the bar formation was triggered by ongoing external interactions.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
F. Garzon, M. Balcells, J. Gallego, C. Gry, R. Guzman, P. Hammersley, A. Herrero, C. Munoz-Tunon, R. Pello, M. Prieto, E. Bourrec, C. Cabello, N. Cardiel, C. Gonzalez-Fernandez, N. Laporte, B. Milliard, S. Pascual, L. R. Patrick, J. Patron, S. Ramirez-Alegria, A. Streblyanska
Summary: We present EMIR, a powerful NIR camera and MOS installed at the 10.4 m GTC. It offers broad spectral coverage and field of view, and features a robotic configurable cold slit mask system for rapid reconfiguration. EMIR also has excellent dispersing units for recording multiple atmospheric window spectra in a single shot.
ASTRONOMY & ASTROPHYSICS
(2022)
Article
Astronomy & Astrophysics
O. C. Jones, M. Reiter, R. Sanchez-Janssen, C. J. Evans, C. S. Robertson, M. Meixner, B. Ochsendorf
Summary: This study presents medium-resolution spectroscopy of candidate young stellar objects in NGC 346, a metal-poor star formation region. The spectra reveal various features indicative of accretion, discs, and outflowing material in these objects.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Nicolas F. Martin, Rodrigo A. Ibata, Else Starkenburg, Zhen Yuan, Khyati Malhan, Michele Bellazzini, Akshara Viswanathan, David Aguado, Anke Arentsen, Piercarlo Bonifacio, Ray Carlberg, Jonay I. Gonzalez Hernandez, Vanessa Hill, Pascale Jablonka, Georges Kordopatis, Carmela Lardo, Alan W. McConnachie, Julio Navarro, Ruben Sanchez-Janssen, Federico Sestito, Guillaume F. Thomas, Kim A. Venn, Sara Vitali, Karina T. Voggel
Summary: This study uses photometric metallicities from the Pristine survey to investigate the existence and determine the metallicities of stellar streams found using the STREAMFINDER algorithm on Gaia Early Data Release 3. All 26 streams in Pristine show clear metallicity distributions, supporting the authenticity of these structures and the effectiveness of STREAMFINDER and Pristine in finding and measuring metallicities. The study identifies six candidate structures with coherent phase-space and metallicity signals that are likely to be stellar streams. Most of the studied streams are very metal-poor, potentially originating from low-luminosity dwarf galaxies or globular clusters with significantly lower metallicity than any known Milky Way globular cluster. The study highlights the importance of high-quality photometric metallicities in utilizing Gaia data for Galactic Archeology studies, enabling a closer examination of the early stages of our Galaxy's formation and its stellar halo constituents.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2022)
Article
Astronomy & Astrophysics
Debra Meloy Elmegreen, Bruce G. Elmegreen, John S. Gallagher, Ralf Kotulla, Jorge Sanchez Almeida, Casiana Munoz-Tunon, Nicola Caon, Marc Rafelski, Ben Sunnquist, Mitchell Revalski, Morten Andersen
Summary: Study of four tadpole galaxies with clear metallicity drops shows that each galaxy contains numerous young stellar complexes and clusters with typical ages of 3-10 million years. The mass function and distribution function of the clusters exhibit specific patterns.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
V Fernandez, R. Amorin, R. Sanchez-Janssen, M. G. del Valle-Espinosa, P. Papaderos
Summary: This work focuses on the gas chemical composition and spatial behavior of CGCG007-025, a compact dwarf undergoing a galaxy wide star-forming burst. A new line measurement library is presented to analyze the abundance and distribution of ions in this system. The study finds normal distributions for the ionic abundances, oxygen abundance, temperature, density, and ionization parameter, with discrepancies between the direct method and photoionization model fitting discussed.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Macarena G. del Valle-Espinosa, Ruben Sanchez-Janssen, Ricardo Amorin, Vital Fernandez, Jorge Sanchez Almeida, Begona Garcia Lorenzo, Polychronis Papaderos
Summary: Nearby metal-poor starburst dwarf galaxies provide a unique opportunity to study high-density star formation. The chemodynamical study of the gas-rich starburst dwarf CGCG 007-025 using VLT/MUSE integral field spectroscopy reveals clumpy distribution of star formation rate (SFR) surface density, dominated by disordered ionized gas kinematics. The gas-phase metallicity of the galaxy drops with increasing SFR surface density, indicating accretion of metal-poor gas as the origin of the recent starburst.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Article
Astronomy & Astrophysics
Nicolas Longeard, Pascale Jablonka, Giuseppina Battaglia, Khyati Malhan, Nicolas Martin, Ruben Sanchez-Janssen, Federico Sestito, Else Starkenburg, Kim A. Venn
Summary: This study presents a new spectroscopic analysis of stars near the dwarf galaxy Hercules, and finds no evidence of tidal disruption.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
(2023)
Proceedings Paper
Instruments & Instrumentation
S. Cristiani, J. M. Alcala, S. H. P. Alencar, S. A. Balashev, N. Bastian, B. Barbuy, U. Battino, A. Calcines, G. Calderone, P. Cambianica, R. Carini, B. Carter, S. Cassisi, B. V. Castilho, G. Cescutti, N. Christlieb, R. Cirami, I. Coretti, R. Cooke, S. Covino, G. Cremonese, K. Cunha, G. Cupani, A. R. da Silva, V. De Caprio, A. De Cia, H. Dekker, V. D'Elia, G. De Silva, M. Diaz, P. Di Marcantonio, D. D'Auria, V. D'Odorico, A. Fitzsimmons, H. Ernandes, C. Evans, M. Franchini, M. Genoni, B. Gansicke, R. E. Giribaldi, C. Gneiding, A. Grazian, C. J. Hansen, F. La Forgia, M. Landoni, M. Lazzarin, D. Lunney, W. Maciel, W. Marcolino, M. Marconi, A. Migliorini, C. Miller, P. Noterdaeme, C. Opitom, G. Pariani, B. Pilecki, S. Piranomonte, A. Quirrenbach, E. M. A. Redaelli, C. B. Pereira, S. Randich, S. Rossi, R. Sanchez-Janssen, W. Seifert, R. Smiljanic, C. Snodgrass, I. Stilz, J. Stuermer, E. Vanzella, P. Ventura, O. Verducci, C. Waring, S. Watson, M. Wells, D. Wright, T. Zafar, A. Zanutta
Summary: In the era of Extremely Large Telescopes, current 8-10m facilities are expected to remain competitive in ground-UV wavelengths. The Cassegrain U-Band Efficient Spectrograph (CUBES) is designed to provide high-efficiency observations in the near UV range and offer new possibilities in various fields of astrophysics. The project has entered the detailed design and construction phase, with first science operations planned for 2028.
GROUND-BASED AND AIRBORNE INSTRUMENTATION FOR ASTRONOMY IX
(2022)
